JP2006068901A - Machine tool controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically machine a product only by inputting shape data of the product to be machined and data regarding an unmachined workpiece. <P>SOLUTION: A machine tool controller 100 includes: an input unit 1 for inputting machining shape data 1a and workpiece data 1b; a database 3 for storing at least one of machine data and tool data of a machine tool 11; a prediction operation unit 7 for predicting at least a machining load or interference between the tool and the workpiece based on the data in the input unit 1 and the data in the database 3; a tool path determination unit 5 for creating a tool path and determining machining conditions based on the data in the input unit 1, the data in the database 3 and the prediction operation results of the operation unit 7; and an operator change operation determination unit 5f for reflecting a change operation on the tool path and machining conditions if theres is the change operation in the determined tool path and the machining conditions. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention inputs an unmachined workpiece and inputs data related to the final product machining shape (hereinafter referred to as machining shape data), whereby the workpiece is machined based on the machining shape data. The present invention relates to a machine tool control device capable of obtaining a processed product.

  Conventionally, when a product is processed by an NC machine tool, first, a drawing representing the shape of the target processed product is created. The programmer determines a machining process from the drawing and creates an NC program manually or with an automatic programming device. The operator inputs the NC program to the NC machine tool and attaches an unprocessed workpiece to be processed to the NC machine tool manually or by an automatic workpiece changer. Then, the preset of the tool to be used and the tool offset amount are set, and the tool to be used is mounted on the tool magazine of the NC machine tool. Thereafter, the NC program is executed to process the workpiece and produce a product. Various inventions have been made to automate these processes as much as possible and reflect the know-how accumulated by programmers and operators in machining.

  First, there is an automatic programming device disclosed in Patent Document 1 as a first conventional technique. This is because the shape recognition means for extracting the machining shape from the data representing the machining shape of the workpiece, the machining condition storage means for storing the optimum machining conditions for the machining shape of the workpiece to be machined, and the shape recognition means And automatic machining condition setting means for automatically setting optimum machining conditions stored in the machining condition storage means. As a result, the operator can automatically set the machining conditions without setting the machining conditions, the operator's human error can be eliminated, good machining can be performed, the operator's load can be reduced, and the working time can be shortened. Is.

  As a second conventional technique, there is a processing system disclosed in Patent Document 2. In this system, data relating to a workpiece such as material, surface roughness, dimensional accuracy and the like are stored in advance, and a machining condition is determined by a first neural network. The machining conditions can be corrected by the operator. Then, after the actual processing is performed, the processing condition is corrected based on the processing result to obtain the corrected processing condition, and learning means for correcting the weight of the first neural network is provided. Furthermore, it has a sensor that detects sparks, sound, force, etc. that occur during processing, and the input data from this sensor is input to the second neural network as time-series data, and the processing status at a certain point in time is input. An adaptive control means is provided that averages and grasps a predetermined time width and dynamically corrects machining conditions. In this way, it is possible to perform machining under optimum machining conditions even if not a skilled worker.

  As a third conventional technique, there is a processing method using numerical control disclosed in Patent Document 3. This is based on the registration of various information files, input of machining figure data, finishing figure processing, pattern recognition and machining process decision processing, and optimal selection of machining processes and machine tools through simplified data input. Set the machining area and machining procedure with high production efficiency, determine the optimal tool, machining conditions, and tool path for the input figure, and increase the production efficiency and machining accuracy by measuring and correcting after machining. It is what.

JP-A-4-315550 JP-A-4-138504 JP-A-9-26811

  A technique for automatically generating a tool path from shape data of a product to be machined is well known, and an NC program can be automatically created by adding various machining conditions thereto. In the invention according to the first prior art, the processing conditions are selected from a database according to a predetermined algorithm based on the shape data of the product to be processed. This is a so-called static processing condition. On the other hand, the invention according to the second prior art detects the machining state by the sensor and adaptively controls the machining condition set based on the detection result using the learning function of the neural network. The dynamic machining conditions according to the above are obtained. The first and second prior arts place emphasis on automatic determination of machining conditions.

  In the third prior art, when the operator inputs data, the processing conditions are automatically determined using the same technology as the first and second prior art, and further, the automatic determination of the tool and the tool path, and the post-processing It is an invention for unattended processing of a target product by combining measurement and correction techniques.

  However, these conventional technologies are technical ideas that ensure high accuracy and production efficiency by a method of feedback and correction of the machining state. However, by predicting the machining state, the tool path and It does not determine the processing conditions and realizes high-precision and high-efficiency processing.

  It is an object of the present invention to perform machining with high efficiency by simply inputting shape data of a product to be machined and data concerning an unmachined workpiece with high efficiency, and automatically machining a target product. A control device for a machine tool is provided.

  Another object of the present invention is to predict the machining state, automatically determine the tool path and machining conditions so as to match the predicted machining state, and perform high-precision machining at high speed. A control device for a machine tool is provided.

  It is still another object of the present invention to provide a machine tool control device that enables an operator to change a tool path, a machining condition, and a manual operation by the operator.

  The present invention is a machine tool control device for machining a workpiece by inputting machining shape data, and is an input for inputting machining shape data relating to a final workpiece shape, workpiece material before machining, and workpiece data relating to a shape. Means for storing at least one of machine data representing machine specifications of the machine tool for machining the workpiece, tool data representing tool specifications of the tool held by the machine tool, and the input means. Based on the input data and the data stored in the data storage means, at least a processing load or a prediction calculation means for predicting the interference between the tool and the workpiece, the data input by the input means, the data storage means When a tool path for machining the workpiece is generated based on the stored data and the prediction calculation result by the prediction calculation means Tool path determining means for determining machining conditions for machining the workpiece such as the spindle rotation speed and feed speed of the machine tool, and an operator for the tool path and machining conditions generated and determined by the tool path determining means. Recognizing and storing the change operation by the operator, determining whether or not the change operation is appropriate, and comprising an operator change operation determination means for reflecting the change operation in generation and determination of the tool path and the machining condition. The gist is a machine tool control device.

The tool path determining means preferably includes a machining process determining means for selecting a tool and a machining pattern and determining a machining process.
The operator change operation determination means recognizes the machining shape data and workpiece data input by the input means, and the tool selected by the machining step determination means, and at the time of manual feed operation or fast feed operation of the tool The region in which the tool does not interfere with the workpiece is defined as the movable region of the tool, and when the operation is attempted beyond the movable region, the operation of the tool may be stopped before the interference with the workpiece occurs. preferable.

  Furthermore, according to one embodiment of the present invention, there is provided a machine tool control apparatus for processing a workpiece by inputting machining shape data, the machining shape data relating to the final workpiece shape, the material and shape of the workpiece before machining. Data storage for storing at least one of input means for inputting work data relating to, machine data representing machine specifications of the machine tool for machining the workpiece, and tool data representing tool specifications of the tool held by the machine tool And a tool path for machining the workpiece based on the data input by the input means, the data input by the input means, and the data stored in the data storage means, and the workpiece such as the spindle rotational speed and feed speed of the machine tool. Tool path determining means for determining a machining condition when machining a tool, and a tool path and machining conditions generated and determined by the tool path determining means An operator change operation determination means for recognizing and storing a change operation by an operator, determining whether the change operation is appropriate, and reflecting the change operation in generation and determination of a tool path and a machining condition. A machine tool control apparatus is provided.

  Furthermore, according to another embodiment of the present invention, there is provided a machine tool control apparatus for machining a workpiece by inputting machining shape data, the machining shape data relating to the final workpiece shape, and the workpiece material before machining. Storing at least one of input means for inputting workpiece data relating to the shape, machine data representing the machine specifications of the machine tool for machining the workpiece, and tool data representing the tool specifications of the tool held by the machine tool Based on data storage means, data input by the input means, and data stored in the data storage means, a tool path for machining the workpiece is generated, and the spindle rotational speed, feed speed, etc. of the machine tool are generated. Tool path determining means for determining a machining condition when machining the workpiece, and the tool path and the machining line generated and determined by the tool path determining means. An operator change operation determination means for recognizing and storing a change operation by an operator, determining whether the change operation is appropriate, and reflecting the change operation in generation and determination of a tool path and a machining condition, and the input means Cost calculation for calculating the machining cost of the workpiece based on the input data, the data stored in the data storage means, the tool path determination means or the tool path and machining condition data determined by the operator change operation determination means There is provided a machine tool control device comprising the above-described means.

Embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram of a machine tool control apparatus 100 according to an embodiment of the present invention. The control device 100 includes an input unit 1, a database 3, a tool path determination unit 5, and a prediction calculation unit 7 as main components. Although not shown in detail, the control device 100 can be constituted by a CPU, a RAM, a ROM, an input / output interface, a data storage device, and a bidirectional bus interconnecting them.

  The input unit 1 is a device configuration for inputting necessary data and commands to the control device 100. The input unit 1 is not only a keyboard, but also an information medium such as a floppy disk or a magneto-optical disk and its driving device, and will be described later. It can be constituted by a network computer that stores various data and issues commands, and its interface device.

  The operator can input data and commands such as machining shape data 1a, workpiece data 1b, tool path changing operation command 1c, manual operation command 1d, and machining condition changing operation command 1e from the input unit 1. The processed shape data 1a is data relating to the shape of the target processed product, and can be, for example, digitized graphic information such as CAD data. Further, the machining shape data 1a may include data related to machining accuracy, surface roughness, and the like. The workpiece data 1b is data relating to the shape and material of an unprocessed workpiece that is used to process the product. The workpiece data 1b includes dimensions and shapes of jigs such as fixtures and pallets for mounting and fixing an unmachined workpiece on the machine tool 11, an attachment position on the machine tool 11, and an unmachined workpiece on the jig. Data regarding the mounting position may also be included.

  The tool path changing operation command 1c is a command for the operator to change the tool path automatically generated by the control device 100 while the workpiece machining progresses. The manual operation command 1d is a command for the operator to perform manual processing while the workpiece processing progresses. The machining condition change operation command 1e is a command for the operator to change the machining conditions automatically generated by the control device 100 while the workpiece machining progresses. The tool path changing operation command 1c, the manual operation command 1d, and the machining condition changing operation command 1e will be described in detail later.

  Data input from the input unit 1 is stored in a database 3 as data storage means. The database 3 includes a machine database 3a, a tool / holder database 3b, a machining condition database 3c, a material database 3d, an NC / servo database 3e, an input database 3f, and a user database 3g. The database 3 can be configured by a data storage device such as a hard disk device or an optical disk device. Each of the machine database 3a, tool / holder database 3b, machining condition database 3c, material database 3d, NC / servo database 3e, input database 3f, and user database 3g in the database 3 is configured by an individual data storage device. Alternatively, one data storage device may be divided into a plurality of areas to form the databases 3a to 3g.

  Referring to FIG. 2, the data stored in the machine database 3a includes the stroke of each feed axis of the machine tool 11, the maximum rotation speed of the spindle, the maximum feed speed, data on the deformation characteristics of the machine with respect to temperature, and the machine based on the weight of the workpiece. Data on the deformation characteristics of the Data stored in the tool / holder database 3b includes tool management number, tool and tool holder dimensions, shape, tool material, tool life, tilt characteristics with respect to tool load, and deflection characteristics, spindle tip Dimensions, shapes, etc. The data stored in the machining condition database 3c includes a feed amount per blade, a cut amount, a pick feed amount, whether or not coolant is used, a machining pattern, and region classification data for dividing a machining surface into a plurality of machining regions. Basic data for selecting an optimum tool for machining a certain machining surface is included. The data stored in the material database 3d includes the type of material, hardness, tensile strength, elastic modulus, and the like. The data stored in the NC / servo database 3e includes specifications of the numerical control device, setting parameters, servo time constant, gain, and the like. The input database 3f stores data related to the machining shape data 1a, the workpiece data 1b, the tool path changing operation command 1c, the manual operation command 1d, and the machining condition changing operation command 1e input from the input unit 1. In the user database 3g, data related to machining conditions changed in the past by an operator or a user, which will be described later, is accumulated and stored.

  Here, the data stored in the database 3 may be at least one of data arbitrarily input by the operator, data already registered in the machine tool 11, and data stored in advance in a predetermined storage unit. .

The tool path determination unit 5 will be described with reference to FIGS.
The tool path determination unit 5 includes a machining step determination unit 5a, a tool path generation unit 5b, a machining condition determination unit 5c, and a correction unit 5d, which will be described in detail below, as main components.

  First, the machining shape data 1a and the workpiece data 1b stored in the input database 3f are sent to the machining process determination unit 5a (step S11). Based on this data, the machining process determination unit 5a recognizes the shape of the machined surface of the unmachined workpiece and the workpiece finally produced. Next, the machining process determining unit 5a uses the curvature, inclination angle, depth, etc. of the machining surface as surface parameters based on the recognized shape of the machining surface and the area classification data stored in the machining condition database 3c. Are divided into a plurality of processing regions (step S13). Next, the machining step determination unit 5a stores the optimum tool and machining pattern for machining the machining area in correspondence with the respective surface parameters of the machining area, stored in the machining condition database 3c. Is selected from basic data and a machining pattern for selecting an optimum tool for machining (step S15). For example, if a steeply inclined surface is machined with a scan path, the tool is overloaded or abnormal vibration occurs. In order to prevent this, a contour line machining path is selected on a steeply inclined surface. At this time, data on the necessity of coolant supply is also introduced from the processing condition database 3c. Next, the processing order for processing each processing region is determined (step S17).

  Examples of processing patterns are shown in FIGS. FIG. 5 shows a scanning (scanning) processing pass, and FIG. 6 shows a contour contour processing pass. FIG. 7 shows a scan processing path, ie, a so-called character line processing pass, in which only the portion where the workpiece is present is used as a processing region to improve cutting efficiency, and FIG. 8 shows a radial processing pass centered on the point O.

  Fig. 9 shows a workpiece that has a certain amount of machining allowance from the finished shape, such as a casting, and is driven by a certain amount in the normal direction of the shape. For example, the contour is narrowed by offsetting the workpiece. FIG. 10 shows a contour machining path, FIG. 10 shows a workpiece that has a certain amount of machining allowance from the finished shape, such as a casting, and a scanning machining path in which a certain amount is driven in the normal direction of the shape. FIG. For example, starting from the part where the workpiece is present, or reducing the pick feed amount when the workpiece is close to the machining shape to be machined. This is a contour line processing path for improvement.

  FIG. 12 automatically overlaps the boundary portion of the machining area with the adjacent machining area, and smoothly retracts the overlap portion to prevent the step of the boundary portion. For example, a predetermined distance in the machining area is separated The tool starts moving from the retracted position to the machining area and is moved in the normal direction by a predetermined amount from the tool path at the tool diameter to be used, and matches the tool path at the tool diameter to be used in the machining area. This is a machining path for moving the tool so that the machining area is machined. These machining patterns are stored in the database 3 so that the machining patterns can be selected by reflecting the accumulated know-how and corresponding to surface parameters such as the curvature, inclination angle, and depth of the machining area. The illustrated processing pattern is an example and is not intended to limit the present invention.

  Next, with reference to FIG. 13 to FIG. 15, an automatic determination method of the cutting direction in the processing step determination unit 5a will be described. FIG. 13A shows one curved surface Rc of the workpiece to be machined. As an example, when the curved surface Rc of the workpiece as shown in FIG. 13 is machined by the scanning (scanning) machining path of FIG. 5, the longitudinal direction of the workpiece curved surface Rc is determined, and the direction parallel to this is determined as the tool feed direction. By doing so, the number of pick feeds can be reduced as much as possible. By reducing the number of pick feeds, the tool movement stop time associated with the pick feed is shortened, and the machining time can be shortened.

  First, a plane TP that gives the maximum projected area of the workpiece curved surface Rc as shown in FIG. 13B is determined (step S21). Next, the workpiece curved surface Rc is projected onto the plane TP (step S23). FIG. 14 shows a figure obtained by projecting the workpiece curved surface Rc onto the plane TP. Next, the center of gravity G of the projected figure Prc is obtained (step 25). This can be uniquely determined if the figure Prc is determined. A straight line Li (i = 1 to n) passing through the center of gravity G is generated (step 27). The method of generating the straight line Li may be arbitrarily generated for a sufficiently large i, or may be generated at equal angular intervals around the center of gravity G.

  Next, intersections Ai and Bi between the figure Prc and the straight line Li are obtained (step S29), and distances | Ai and Bi | between the intersections Ai and Bi are calculated (step S31). The direction of the straight line Li where this distance is the maximum value | Ai, Bi | max is determined as the longitudinal direction (step S33). When generating the tool path by the tool path generation unit 5b described later, the direction of the straight line Li thus determined is the longitudinal direction, and the number of pick feeds is minimized by feeding the tool to the workpiece in this direction. Thus, the machining time can be shortened.

  Next, a method of processing a character line with high accuracy in a scan processing path as shown in FIG. 7 will be described with reference to FIGS. FIG. 16 is a perspective view of one curved surface Rc of a workpiece to be machined having a character line Lc. In the following description, a case where a convex character line is processed as shown in FIGS. 16 to 19 will be described. However, a case where a concave character line is processed in a scan processing pass as shown in FIG. It goes without saying that the same applies.

  A character line is a curved or straight part provided to add a facial expression to a curved surface, and is a conspicuous part of the other curved surface area, so it must be processed with higher accuracy than other processing areas. Is done. Therefore, it is necessary to specify this character line and process only this part under processing conditions different from those of other regions.

  In order to extract the character line Lc from the workpiece curved surface Rc, in the present embodiment, first, as shown in FIG. 17, the workpiece curved surface Rc is divided into a plurality of curved surface elements S1 to Sn (n = 14 in this embodiment). (Step S35). The size of each of the curved surface elements S1 to S14 is appropriately determined in consideration of the curvature of the curved surface element portion. Next, a boundary line L between adjacent curved surface elements (in this embodiment, the surface element S1 and the surface element S13 as shown in FIG. 18) is determined (step S37).

  Further, a tangent line Lt in contact with the boundary line L is obtained (step S39). In this case, the contact point Pt between the boundary line L and the tangent line Lt can be arbitrarily selected on the boundary line L, but can be, for example, the midpoint of the boundary line L 1. Next, a plane Tp perpendicular to the tangent line Lt at the contact point Tt is obtained (step S41). Then, intersecting lines L1 and L12 between the plane Tp and the two surface elements S1 and S13 are obtained (step S43), and the continuity of the two intersecting lines L1 and L13 is confirmed (step S45). As the method, a method of confirming that the differential coefficients of the intersection lines L1 and L13 at the contact point Pt coincide can be adopted. If the intersection lines L1 and L13 are discontinuous (Yes in step S47), the boundary line L is determined to be a character line (step S49), and if the intersection lines L1 and L13 are continuous (in step S47). In the case of No), it is determined that the boundary line L is not a character line (step S51). After the character line Lc is extracted by the processing step determination unit 5a in this way, as shown in FIG. 21, a tool path that moves by a predetermined pick feed amount P with the direction perpendicular to the character line Lc as the processing direction is shown. By generating with the tool path generation unit 5b, cutting can be performed with high accuracy. At this time, it is also possible to determine whether the two character lines are one character line from the inclination of the tangent line at the intersection of two adjacent character lines, thereby determining the processing step.

  Further, as a processing region that must be finished with high accuracy like the character line, there is a convex R portion of a press mold. An example of the convex R portion is shown in FIG. The convex R portion indicated by A in FIG. 22 (a) is, for example, in a mold, the surface shape of the mold is very well transferred when pressed, and is also a conspicuous portion. This is an area that must be finished with high precision.

  For example, in order to determine such a machining region, the machining process determination unit 5a divides the machining surface from the machining shape data into small triangular surface elements approximating a certain tolerance or less (see FIG. 22B). A region where the surface elements whose size is smaller than the predetermined threshold is concentrated is extracted as a shape sudden change region, and it is determined whether the sudden change region is a convex shape or a concave shape. It can be a convex R part. By generating a tool path for processing only the convex R portion thus determined with high accuracy by the tool path generation unit 5b, it is possible to eliminate unnecessary waste of processing the entire workpiece with high accuracy.

  Next, referring to FIG. 23, a description will be given of groove processing by contouring as an example of a processing pattern. As shown in FIG. 23 (a), when the groove machining is performed using the tool T having the same diameter as the width of the groove 30 to be machined into the workpiece W, the tool T is bent at the entrance to the workpiece W or the deflection is released. As a result, the load fluctuation increases, and a ridge is formed at the bottom of the groove 30. On the other hand, as shown in FIG. 23 (b), the tool path generating unit 5b generates a tool path that causes an oval contouring operation using a tool T having a diameter smaller than the width of the groove 30 to perform grooving. If it does, since the cutting load applied to the tool T will become small and the bending of the tool T will also become small, a load fluctuation will become small by releasing the bending and bending of the tool T in the entrance and exit to a workpiece | work. In addition, stable cutting can be obtained by high-speed high-precision feed and light load high-speed feed.

  Data relating to the machining area, tool, machining pattern, and machining order determined by the machining process determination unit 5a as described above is temporarily stored in a machining process storage unit (not shown) of the machining process determination unit 5a. It is sent to the tool path generator 5b. The tool path generation unit 5b includes data on the machining area, tool, and machining pattern, workpiece data 1b stored in the input database 3f, particularly material data of an unmachined workpiece, and material data stored in the material database 3d. Optimum for machining the workpiece from the data group of feed amount, cutting amount, and pick feed amount per blade stored in the machining condition database 3c, corresponding to the data on type, tensile strength, and elastic modulus. A tool path and a pick feed path are generated. The generation of the tool path and the pick feed path is performed by an arithmetic expression stored in the machining condition database 3c.

An example of a method for determining the direction of the pick feed path will be described with reference to FIGS.
As shown in FIG. 24, when a workpiece machining surface having a shape with a constant inclination angle in the circumferential direction is cut with a contour machining pattern and the pick feed amount is set as a tangential amount, the pick feed is performed on a steep slope. If this is performed, the gap with the previous tool path becomes too wide at the looser part, and uncut parts are generated. Therefore, as shown by the arrows in FIG. 24, such uncut portions can be prevented by performing pick-feeding at a position with a gentle slope.

  First, the machining step determination unit 5a determines a plurality of tangent planes along the tool path of the contour machining pattern (step S53), and calculates a normal vector of the tangent planes (step S55). The tangent plane can be obtained, for example, by discretely defining a plurality of contacts at equal angular intervals in the circumferential direction along the tool path of the contour machining pattern and calculating the tangent plane with respect to the workpiece curved surface at the contacts. Next, the inclination of each normal vector is obtained (step S57), and the contact point of the tangent plane having the normal vector with the steepest angle is obtained (step S59). Since the tangential plane with the steepest inclination of the normal vector is the gradual surface, the tool path generation unit 5b performs pick-feed path so that pick feed is performed from the contact point that gives the normal vector with the steepest inclination. Is generated (step S61). That is, a pick feed path is generated in which the amount of movement in the tangential direction at the contact is the pick feed amount set. The direction of pick feed is a tangential direction perpendicular to the straight line in contact with the tool path at the contact point.

  Here, the operator may arbitrarily input or change the tool, the machining pattern, and the machining process as will be described later, without selecting and determining the tool, the machining pattern, and the machining process by the machining process determination unit 5a. . It is also possible to perform another processing step during a certain processing step.

  Next, the machining condition determination unit 5c determines the spindle rotational speed and feed speed of the machine tool 11 from the feed amount, cutting amount, and pick feed amount per blade based on the calculation result from the tool path generation unit 5b. A tool change command for each machining process and a command related to insertion of a measurement process by the sensor unit 13 described later are generated in the numerical control unit 9.

  With reference to FIGS. 26 and 27, an example of a method for determining the pick feed amount P and the feed speed F among the processing conditions determined by the processing condition determination unit 5c will be described. FIG. 26 is a perspective view showing a state in which the ball end mill T is cut in a scan (scanning) pass by sending the ball end mill T in the direction of the arrow Df with respect to the workpiece W.

First, the cusp height h is determined from the finishing accuracy included in the machining shape data in the input database 3f (step S63). Next, a tool to be used is determined by referring to the machine database 3a and the tool / tool holder database 3b from the machining shape data and work data (step S65). When the tool to be used is determined, the tool radius r and the number n of blades are automatically determined. The pick feed amount P is calculated from the cusp height h and the tool radius r thus determined by the following equation (step S67).
P = √ (8 rh)

Next, the cutting speed V is determined from the workpiece material included in the workpiece data with reference to the tool / tool holder database 3b and the machining condition database 3c (step S69), and the spindle rotational speed is determined from the pick feed amount P and the cutting speed V. N (rpm) is obtained (step S71). Here, it is confirmed whether or not the obtained spindle rotational speed N exceeds the maximum spindle rotational speed Nmax of the actual machine (step S73). If the spindle rotational speed N does not exceed the maximum spindle rotational speed Nmax of the actual machine tool (Yes in step S73), cutting is performed at the spindle rotational speed N obtained in step S71 (step S75). ) When the spindle speed N exceeds the maximum spindle speed Nmax of the actual machine tool (No in step S73), cutting is performed with the maximum spindle speed Nmax of the machine tool set as the spindle speed N. (Step S77). Next, the feed speed F is obtained by the following formula from the number n of blades obtained in this way, the feed amount f per blade of the tool set equal to the pick feed amount P, and the spindle rotational speed N (step S97). .
F = nfN

  As a result, as shown in FIG. 26, the wavy traces formed on the machining surface of the workpiece W have the same feed amount f and pick feed amount P per blade of the tool, and the machining surface is uniformly distributed. It becomes. Thereby, especially when processing a mold, there is no specific direction in the polishing process in the subsequent process, and it is possible to perform polishing finishing along the shape, and the time required for polishing finishing is shortened.

  Here, without determining the processing conditions by the processing condition determination unit 5c, the processing conditions arbitrarily input by the operator as described later are used, or the processing conditions stored in advance in a predetermined storage unit are used. May be.

  The correction unit 5d generates a correction command to the tool path generation unit 5b or the machining process determination unit 5a based on the prediction calculation result from the prediction calculation unit 7 described later.

  The numerical control unit 9 includes a generally known NC device 9a and a servo system 9b including a servo motor and an amplifier, and controls the axis feed of the machine tool 11 and the rotation of the spindle. That is, as is well known, the NC device 9a generates movement commands for the X, Y, and Z feed axes from the tool path data and machining condition data, and also starts and stops the spindle of the machine tool 11, and turns the coolant on / off. Issue operation commands such as automatic tool change and automatic pallet change. The servo system 9b receives a movement command from the NC device 9a and controls the servo motor of the feed axis. Thus, the machine tool 11 is controlled by the numerical controller 9.

  The machine tool 11 is a generally well-known machine tool such as a machining center equipped with an automatic tool changer, for example. The machine tool 11 includes a temperature sensor such as a thermistor for measuring the temperature of each part of the machine body such as a column and a bed of the machine tool 11, the temperature of the coolant, and the environment temperature where the machine tool 11 is installed, and a motor of the machine tool 11. Machine sensor including an ammeter for measuring a current value supplied to the tool, a tool sensor for measuring a tool length, a tool diameter, a tool tip shape, and the like of a tool mounted on the machine tool 11, and being processed A sensor unit 13 including a workpiece sensor that actually measures the shape of the workpiece is provided. The value measured by the sensor unit 13 is sent to the prediction calculation unit 7 described later. Further, the tool diameter, the tool length, the deflection of the rotating tool, the fluctuation of the center position, and the like measured by the tool sensor of the sensor unit 13 are sent to the tool / holder database 3b of the database 3 via the data correction unit 15, and the database 3 is corrected and updated, in particular, the wear characteristics of the tool, the tool life, and the runout characteristics of the tool.

  Further, the temperature of each part of the machine body, the temperature of the coolant, the environmental temperature, etc. measured by the temperature sensor of the mechanical sensor of the sensor unit 13 are sent to the machine database 3a of the database 3 via the data correction unit 15, and the corresponding of the machine database 3a. Parts are corrected and updated. Further, a positioning error during the operation of the machine tool 11 is calculated from the machining error measured by the work sensor of the sensor unit 13, and sent to the machine database 3a of the database 3 via the data correction unit 15, and the corresponding part of the machine database 3a. May be corrected and updated. The machining error measured by the work sensor of the sensor unit 13 is sent to the correction unit 5d of the tool path determination unit 5, where correction data is generated from the machining error data, and a correction tool path is generated by the tool path generation unit 5b. It can also be reworked.

Next, the prediction calculation unit 7 will be described with reference to FIG.
The prediction calculation unit 7 includes a machining state simulation unit 7a, a machine behavior simulation unit 7b, a workpiece simulation unit 7c, and a tool behavior simulation unit 7d as main components.

  The machining state simulation unit 7a receives the machining shape data 1a and the workpiece data 1b from the input database 3f, and the tool, tool holder size, shape, and spindle tip determined by the machining process decision unit 5a from the tool / holder database 3b. Receives the shape and dimensions of the part. Further, the machining state simulation unit 7a receives the feed amount per blade, the cutting amount, the pick feed amount, the tool path, and the pick feed path determined and calculated by the tool path generation unit 5b, and the machining condition determination unit 5c. The spindle rotation speed and feed speed determined in (1) are received.

  Prior to machining, that is, when the tool path determination unit 5 first generates a tool path or the like, the machining state simulation unit 7a performs machining shape data 1a and workpiece data 1b, a tool, a tool holder, and a spindle tip. Whether the tool, the tool holder, the spindle tip, and the workpiece interfere with each other during machining is predicted from the shape and size of the part, the tool path, and the pick feed path. When it is predicted that interference will occur during machining in a certain machining area, the machining state simulation unit 7a instructs the machining process determination unit 5a to make the machining area a non-machining area. At this time, when the non-machining area can be machined by another tool or when the machining pattern of the non-machining area can be changed, the machining step determination unit 5a changes the machining area or tool by changing the tool or the machining pattern. Then, the machining pattern and the machining order are determined again and sent to the tool path determination unit 5. Then, the above procedure is repeated. When the tool or the machining pattern cannot be changed, the machining process determination unit 5a sends the machining sequence in which the non-machining region is excluded from the machining process to the tool path determination unit 5.

  With reference to FIG. 29, an example of a method for determining a machining area in consideration of a prediction calculation result will be described. When an area 21a where no interference occurs with a tool is predicted and calculated by the machining state simulation unit 7a, an area that can be machined by the tool, for example, an area having a surface inclination angle of 66 degrees or less is shown as an area 21b. In such a case (FIG. 29A), the overlapping portion of both is determined as the processing region 21c (FIG. 29B).

  In the same manner as the method shown in FIG. 29, the machining process determination unit 5 a is a tool that is arbitrarily determined with respect to the machining region determined by the interference check between the tool and the workpiece, or the machining shape data 1 a input from the input unit 1. Range to be overlapped with the machining area determined by the interference check with the workpiece and the machining area determined based on the surface inclination angle, surface curvature, and depth of the machining shape data 1a input from the input unit 1 It can also be.

  The machining state simulation unit 7a further performs a similar interference check in real time even after machining is started. As a result, when the interference between the tool and the workpiece is predicted, data to that effect is sent to the tool path generation unit 5b. The tool path generation unit 5b calculates and generates a tool path that avoids this interference, for example, an interference avoidance tool path that escapes in the Z-axis direction.

  In addition, the machining state simulation unit 7a is configured to provide a corner portion (in-corner unit) in a workpiece in which machining progresses based on data on the machining shape data 1a, the workpiece data 1b, the machining pattern, and the tool path while machining is actually performed. ). This prediction result is sent to the machining condition determining unit 5c, and the machining condition determining unit 5c determines a machining condition for decelerating the feed speed of the tool at the corner (in-corner portion).

  Further, the machining state simulation unit 7a includes a workpiece data 1b, a tool path generation unit 5b, and a tool feed amount, a cutting amount, a pick feed amount, a tool path, and a machining condition determination unit 5c determined and calculated per tool. The machining load is predicted and calculated from the spindle rotation speed and the feed speed determined in (1). Further, the machining state simulation unit 7a determines the machining shape data 1a, the workpiece data 1b, the shape and dimensions of the tool, tool holder and spindle tip determined by the machining process determination unit 5c, and the tool path generation unit 5b. The current shape of the workpiece being processed is predicted from the calculated pick feed amount and the tool path, and the contact point between the tool and the workpiece and the weight of the workpiece are predicted.

  Further, the machining state simulation unit 7a predicts the load inertia of the workpiece based on the expected change in the weight of the workpiece and the machining condition determined by the machining condition determination unit 5c. This predicted load inertia is sent to the numerical control unit 9, and the parameters of the servo system 9b of the numerical control unit 9 are corrected.

  Based on the prediction of the contact point between the tool and the workpiece, for example, when it is predicted that a so-called air cut that does not cut the workpiece while the tool is moving along a certain tool path will occur, the machining state simulation unit 7a Data to that effect is sent to the machining condition determination unit 5c. Thereby, the machining condition determination unit 5c can issue a command to the numerical control unit 9 to move at the maximum feed speed when the tool moves along the tool path passing through the region where the air cut is predicted. Become.

  The machine behavior simulation unit 7b predicts the thermal deformation of the machine tool 11 based on the data regarding the thermal deformation characteristics of the machine with respect to the temperature stored in the machine database 3a and the temperature data from the temperature sensor of the sensor unit 13. Further, the deformation due to the weight of the workpiece of the machine tool 11 is predicted based on the weight data of the workpiece calculated by the machining state simulation unit 7a and the data regarding the deformation characteristics of the machine due to the weight of the workpiece stored in the machine database 3a. .

  The workpiece simulation unit 7c receives the machining shape data 1a and the workpiece data 1b from the input database 3f, and the tool and tool holder dimensions and shapes determined by the machining process decision unit 5c from the tool / holder database 3b, and the spindle tip portion. Receive the shape and dimensions. Further, the workpiece simulation unit 7c receives the feed amount, cutting amount, pick feed amount, tool path, and pick feed path of the tool determined and calculated by the tool path generation unit 5b, and a machining condition determination unit. The spindle rotation speed and feed speed determined in 5c are received. Then, the workpiece simulation unit 7c predicts and calculates the intermediate shape of the workpiece for which machining progresses based on the received data, and sends the prediction calculation result to the machining state simulation unit 7a and the machine behavior simulation unit 7b.

  The tool behavior simulation unit 7d predicts the amount of tool tilt and the amount of deflection from the processing load predicted by the machining state simulation unit 7a, the data on the tilt and the deflection characteristics of the tool stored in the tool / holder database 3b. . The tool wear amount and wear distribution are predicted and calculated from the tool life data stored in the tool / holder database 3b and the machining load, machining contact point, cutting depth and machining time predicted by the machining state simulation unit 7a. To do. For example, in the case of a ball end mill, the wear distribution is a prediction of the wear site of the tool such as whether the tip is worn, where the tip is worn, or whether it is a straight portion. By this wear prediction calculation, it is determined whether or not the tool life has been reached. Furthermore, the predicted value is corrected from the change in the shape (tool diameter, tool length, center position, posture, etc.) of the rotating tool also by the tool sensor of the sensor unit 13.

  Further, the amount of tool fall predicted by the tool behavior simulation unit 7d is sent to the correction unit 5d of the tool path determination unit 5, and when the predicted amount of tool fall is larger than a predetermined value, the tool fall is considered. The generated tool path is sent to the tool path generation unit 5b. For example, if the machining load is large when the workpiece and the tool are moved relative to each other in the horizontal direction, the tool tip deforms so as to fall forward with respect to the moving direction, so that the tip position of the tool is delayed from the coordinate position of the spindle. Move. Therefore, in order to perform necessary machining, it is necessary to correct the feed amount so that the tip position of the tool moves to a predetermined machining position. Thereby, highly accurate processing becomes possible.

Next, the operator change operation determination unit 5f will be described.
While the machine tool 11 is performing the automatic machining, the operator looks at the intermediate shape of the workpiece that is being machined, and desires to change the tool path in light of the operator's experience, or controls the machining as described above. The operator may want to change the machining conditions automatically presented by the apparatus 100. The operator change operation determination unit 5f enables the operator to change the machining conditions and the tool path presented by the control device 100.

  That is, the operator change control unit 5f allocates to the numerical control unit 9 during machining in response to the tool path change operation command 1c, manual operation command 1d, and machining condition change operation command 1e input from the input unit 1. This makes it possible for the operator to change the machining process.

With reference to FIG. 30, an operation for changing the tool path during machining will be described.
First, in step S81, it is determined whether or not a tool path changing operation command 1c has been input. If the tool path changing operation command 1c has not been input (that is, in the case of No in step S81), the operator changing operation determination unit 5f does not perform any processing and continues the previous machining as it is. When the tool path changing operation command 1c is input to the input unit 1 (in the case of Yes in step S81), in step S83, the operator changing operation determination unit 5f determines that the change of the tool path is the current feed speed or the rotation speed of the spindle. It is determined whether or not the processing conditions are appropriate.

  If it is determined that the change of the tool path is appropriate (in the case of Yes in step S83), it is determined in step S85 whether or not there is an uncut portion, that is, an uncut portion on the work surface of the workpiece. This determination can be made based on the data from the prediction calculation unit 15 described above. If it is determined that no uncut portion remains on the machined surface of the workpiece (No in step S83), a tool path change command is issued from the operator change operation determination unit 5f to the tool path generation unit 5b in step S87. .

  If it is determined that the change of the tool path is not appropriate (No in step S83), it is determined in step S89 whether or not the tool path can be changed by changing the machining conditions. When it is determined that the appropriate tool path is changed by changing the machining conditions (Yes in step S89), in step S91, the operator change operation determination unit 5f makes a reasonable decision to the machining condition determination unit 5c. A command is issued to change the machining condition to change the tool path, and the process proceeds to step S85 described above to determine whether or not there is an uncut portion. If it is determined in step S89 that the appropriate tool path is not changed even if the machining conditions are changed (No in step S89), in step S97, from the operator change operation determination unit 5f to the display unit 17 described later. A command is issued to indicate that the change is not acceptable.

  In step S85, when it is predicted that an uncut portion exists (in the case of Yes in step S85), by waiting for the change of the tool path in step S93, that is, the machining process that is currently progressing is continued for a certain time. If it is predicted that an uncut portion will not remain by changing the tool path later (Yes in step S93), the tool path is waited for a predetermined time in step S95 and then the tool path is changed in step S87. Changes are performed. If it is determined that there is an uncut portion even after waiting for a change in the tool path for a certain time (No in step S93), the status indicating that the change cannot be accepted is displayed in step S97.

  Next, with reference to FIG. 31, an operation for changing the machining condition changed by the operator with respect to the machining condition automatically presented by the control device 100 at the start of machining will be described. As described above, when the operator inputs the machining shape data 1a and the workpiece data 1b to the input unit 1, the tool path determination unit 5, particularly the machining condition determination unit 5c presents the machining conditions to the operator based on the input data ( Step 99). This machining condition is determined by referring to past results, empirical rules, and data relating to machining conditions based on known techniques stored in the database 3. On the other hand, a user or an operator often has machining conditions stored by a unique experience different from this. Further, there may be a case where a machining condition is desired in which the machining time is shorter than the machining condition presented by the control device 100 due to the delivery date of the product.

  In step S101, it is determined whether or not a machining condition change operation command 1e has been input. If the operator does not input the machining condition change operation command 1e from the input unit 1 (No in step S101), machining is started under the machining conditions presented in step S99 (step S103).

  When the operator inputs a machining condition change operation command 1e from the input unit 1 (in the case of Yes in step S101), the contents of the change are analyzed in step S105, and the validity is judged (step S107). If it is determined that the content of the change is not appropriate (No in step S107), the operator change operation determination unit 5f displays a reason why the change of the processing condition is not appropriate, and prompts the change or correction of the processing condition. The display unit 17 is instructed (step S109), and the process returns to step S101. When the operator inputs a change in the machining conditions again, the validity is determined as described above. If it is determined that the change is not appropriate in step S107, the program can be programmed so that the processing conditions presented in step S99 can be reset.

  If it is determined in step S107 that the change of the machining condition is appropriate (Yes in step S107), the change contents of the machining condition by the operator are stored in the user database 3g in step S111. The change contents of the machining conditions by the operator are analyzed and classified according to the past change contents, and the frequency of changing the machining conditions having the same contents is calculated (step S113). When the change frequency is high, it can be determined that the operator or the user often desires a change belonging to this high-frequency type or a similar change. Therefore, in step S115, it is determined whether the change frequency is higher than a predetermined threshold value. If the change frequency is high (in the case of Yes in step S115), when presenting the machining conditions, it is possible to preferentially present the machining conditions belonging to the type with a high change frequency reflecting the intention or preference of the operator or the user. As described above, the contents of the user database 3g are corrected and the contents of the database 3 are updated (step S117). Next, processing is performed under the changed processing conditions (step S119).

Further, the operator change operation determination unit 5f further enables manual operation by the operator.
Referring to FIGS. 32 and 33, as described above, when the operator inputs the machining shape data 1a and the workpiece data 1b from the input unit 1, the control device 100 causes the machining shape and the shape before machining to be the final workpiece shape. Are recognized (step S121), and the tool T and tool holder TH selected based on the machining shape data 1a are recognized (step S123). Next, whether the workpiece is fixed to the work table, whether the tool T is mounted on the spindle SP, or whether the spindle SP is rotating is checked to determine whether or not preparation for machining is ready (step). S125). If preparation is not complete (No in step S125), the operator change operation determination unit 5f does not perform any processing.

  If processing preparation is complete (Yes in step S125), it is determined in step S127 whether or not a manual operation command 1d is input. When the manual operation command 1d is not input (No in step S127), the operator change operation determination unit 5f does not perform any processing. When the manual operation command 1d is input, it is determined whether or not the manual operation command 1d is fast-forward (step S129).

  In the case of fast-forwarding (in the case of Yes in step S129), in step S131, the tool T and the tool holder TH interfere with the workpiece, particularly the workpiece shape input to the input unit 1, based on the prediction calculation result by the prediction calculation unit 7. Whether or not (see FIG. 33). When it is determined that the tool T and the tool holder TH interfere with the workpiece (Yes in Step S131), the operator change operation determination unit 5f issues a command to the numerical control unit 9 to stop the feed axis (Step S131). S133). When it is determined that the tool T and the tool holder TH do not interfere with the workpiece (No in step S131), the operator change operation determination unit 5f does not perform any particular processing, and the operator manually operates the feed axis by rapid feed. It becomes possible.

  If the manual operation command 1d is not a rapid feed (No in step S129), it is further determined in step S135 whether the manual operation command 1d is a jog (JOG) feed or a handle operation feed. If the manual operation command 1d is none of them (No in step S135), it is determined that the axis feed is stopped (step S137), and the operator change operation determination unit 5f performs further processing. Absent.

  When the manual operation command 1d is a jog (JOG) feed or a feed by a handle operation (Yes in step 135), the operator change operation determination unit 5f determines the tool based on the prediction calculation result by the prediction calculation unit 7. It is determined whether or not the holder TH interferes with the workpiece, particularly the workpiece shape (step S139). If it is determined that the tool holder TH interferes with the workpiece (Yes in step S139), the operator change operation determination unit 5f issues a command to the numerical control unit 9 to stop the feed axis (step S133).

  When it is determined that the tool holder TH does not interfere with the workpiece (No in step S139), the operator change operation determination unit 5f causes the tool T to interfere with the machining shape based on the prediction calculation result by the prediction calculation unit 7. Whether or not (step S141). When it is determined that the tool T interferes with the machining shape (Yes in step S141), the operator change operation determination unit 5f issues a command to the numerical control unit 9 to stop the feed axis (step S133). When it is determined that the tool T does not interfere with the machining shape (No in step S141), the operator change operation determination unit 5f does not perform any particular processing, and the operator manually performs jog (JOG) feed or handle feed. The feed axis can be operated with.

Next, the cost calculation unit 5e will be described.
It is expected that the change of the processing conditions by the operator described above is performed in relation to the delivery date of the product and the processing cost. That is, even if the machining conditions presented by the control device 100 are considered optimal from past results, empirical rules, and publicly known techniques, the spindle rotation speed is slightly higher than the optimum value because the delivery date of the product is imminent. The selection of the feed speed is conventionally performed. Therefore, the cost calculation unit 5e calculates the cost or profit of the presented machining condition or the changed machining condition, and assists the operator in selecting the machining condition in consideration of the cost and the delivery date.

  Referring to FIG. 35, a cost curve with respect to processing time is shown. In general, the longer the machining time, the higher the running cost curve I of the machine tool, such as the power consumption of the machine tool and the consumed cutting oil, and the tool cost curve based mainly on the tool change necessary for tool wear II Becomes lower. The total cost of processing can be shown by curve III, and there is a processing time A that gives the minimum cost. In the present embodiment, the cost calculation unit 5e uses such a cost curve to assist the operator in selecting processing conditions that take cost and delivery time into consideration as described above.

  First, a cost curve as shown by curve III in FIG. 35 is obtained (step S143). Basically, the cost curve is obtained from the running cost of the machine tool and the tool cost, but it is also possible to consider labor costs, utility costs and other costs. Next, the minimum cost as indicated by A in FIG. 35 and the machining conditions at that time are obtained and presented to the operator via the display unit 17 (step S145). At this time, not only numerical values but also cost curves as shown in FIG. 35 may be used.

  The operator may change the machining conditions in consideration of the presented machining conditions, cost, delivery date, and the like. In step S147, the cost calculation unit 5e monitors whether the machining conditions have been changed. If the machining conditions are not changed (No in step S147), the machining is started as it is (step S149). When the operator changes the machining condition (Yes in step S147), the operator calculates the cost under the changed machining condition (step S151), presents the cost (step S153), and returns to step S147 again. If the operator selects the cost and processing conditions, the processing is started (step S149), and if the change is desired again, the change is calculated and presented (steps S151 and S153). The machining condition changing operation command 1e described above can be input as a machining condition changing method. For example, the machining conditions are set so that the control device 100 matches the input machining time with the machining time as an input parameter. You may make it select. For example, the processing time A that gives the minimum cost in FIG. 35 may be changed to B.

  In FIGS. 34 and 35, it has been described that the operator selects the processing conditions by simply presenting the total cost to the operator. However, if the sales obtained by the product processing are known, the operator can benefit. Alternatively, the profit margin can be presented. Referring to FIG. 37A, a curve V is a total cost curve corresponding to the curve III in FIG. 35, a straight line IV represents sales, and a curve VI represents a profit obtained by subtracting the total cost from the sales. It goes without saying that profits will be negative if costs are greater than sales. Further, by dividing the profit curve VI by time, a profit curve VII per unit time shown in FIG. 37B is obtained. In FIG. 37 (b), the condition that maximizes the profit per unit time is indicated by C.

  First, a profit curve VI is obtained (step S155), and then the profit curve VI is divided by time to obtain a profit curve VII per unit time (step S157). Next, the maximum profit per unit time and processing conditions at that time are presented via the display unit 17. The operator may change the machining conditions in consideration of the machining conditions presented as described above, the profit per unit time, the delivery date, and the like. In step S161, the cost calculation unit 5e monitors whether the machining conditions have been changed. If the machining conditions are not changed (No in step S161), machining is started as it is (step S167). When the operator changes the machining conditions (Yes in step S161), the operator calculates the profit per unit time under the changed machining conditions (step S163) and presents the cost (step S165) again. Return to If the operator selects the profit per unit time and the processing conditions, the processing is started (step S167), and if the change is desired again, the change is calculated and presented (steps S163, S165). The machining condition changing operation command 1e described above can be input as a machining condition changing method. For example, the machining conditions are set so that the control device 100 matches the input machining time with the machining time as an input parameter. You may make it select. For example, the machining time C that gives the maximum profit per unit time in FIG. 37B may be changed from D to D.

  Next, the display unit 17 will be described. The display unit 17 includes an image processing unit 17a and a monitor 17b such as a CRT. The display unit 17 can display a machining area, a machining pattern, a tool shape, a management number, and the like determined by the machining process determination unit 5a of the tool path determination unit 5. The image processing unit 17a can receive data on the curvature, inclination angle, and depth of the processing region from the processing step determination unit 5a, and can generate data for three-dimensional display by color-coding each region.

  Although not shown in detail in FIG. 1, it is connected to the database 3, the prediction calculation unit 7, the numerical control unit 9, and the sensor unit 13, and information from each can be displayed graphically or in text. . For example, the display unit 17 can graphically display the result of the interference check between the tool and the workpiece based on the data from the prediction calculation unit 7. Furthermore, the machining accuracy data in the machining shape data 1a input to the input database 3f and the workpiece shape measurement data measured by the sensor unit 13 may be compared and displayed. Further, as described above, the uncut portion of the workpiece can be displayed graphically by the interference avoidance tool path for avoiding the interference between the workpiece and the tool. Further, as shown in FIG. 38, the progress of the processing such as “Tool path generation in progress”, “Tool path generation completed”, “Processing in progress”, “Processed” in the text display screen, and “Area 1: Contour processing”. Processing areas such as “Area 2: Scanning” may be displayed in different colors according to their progress, or the corresponding areas may be displayed on the graphic screen by highlight blinking display or color display.

The operation of the embodiment of the present invention will be described.
First, when the operator inputs the machining shape data 1a and the workpiece data 1b from the input unit 1 to the database 3, the tool path is based on the inputted machining shape data 1a and workpiece data 1b and each data stored in the database 3. The machining area, tool, machining pattern, and machining process are selected and determined by the machining process determination unit 5a of the determination unit 5. Next, the tool path generation unit 5b of the tool path determination unit 5 determines the tool path, and the processing condition determination unit 5c determines the processing conditions. The machine tool 11 is driven and controlled through the numerical control unit 9 based on the machine drive data such as the tool path and machining conditions generated and determined in this way, and the workpiece is machined to complete the machined product.

  At this time, in the predictive calculation unit 7, the operator performs various processes such as machining load, interference between the tool and the workpiece based on the machining shape data 1 a and the workpiece data 1 b from the input unit 1 and each data stored in the database 3. The prediction calculation result is sent to the machining step determination unit 5a of the tool path determination unit 5, and the tool, the machining pattern, and the machining step are determined based on the prediction calculation result in the prediction calculation unit 7. . Similarly, a tool path is determined by the tool path generation unit 5b of the tool path determination unit 5 and a machining condition is determined by the machining condition determination unit 5c based on the prediction calculation result of the prediction calculation unit 7, and the cost and profit corresponding to the tool path are determined as costs. It is calculated by the calculation unit 5e. When the operator changes the tool path and machining conditions or performs manual operation, the operator change operation determination unit 5f monitors such operation.

  As described above, the present invention is based on the machining shape data 1a and the workpiece data 1b input from the input unit 1 and each data stored in the database 3, and the prediction calculation unit 7 uses the machining load and the interference between the tool and the workpiece. Various prediction calculations such as are performed in advance. In other words, in the past, machining was first performed, and the machining state at that time was detected and fed back to attempt optimal control. In the present invention, first, a prediction calculation is performed, and the prediction calculation result is fed forward. Control and process. Further, the accuracy of feedforward control is further improved by feeding back the detected machining state. Therefore, the speed to be optimized becomes faster than before, and high-precision machining can be performed faster.

A comparative example of the prior art and the present invention is shown in FIG.
In contrast to the drawing shape as shown in FIG. 39 (a), when there is actually an uncut portion as shown in FIG. 39 (b), in the prior art, the tool feed rate remains at a high speed, for example, 16 m. When machining at / min, an excessive load is applied to the tool at the uncut portion, and the machining accuracy may be significantly lowered, or the tool may be damaged in an extreme case. Even in the prior art, if the tool is fed at a low speed, for example, machining at 200 mm / min, such inconvenience does not occur, but the machining time is greatly prolonged. On the other hand, in the present invention, such a problem does not occur even if machining is performed while keeping the feed speed of the tool high. This is achieved for the first time by using the various databases stored in the database 3 in advance, in which the predicted calculation unit 9 calculates the predicted value of the machining load and checks for avoiding the interference between the tool and the workpiece. Is done.

  As described above, according to the present invention, the operator can input only the shape data of the product to be processed and the data regarding the shape and material of the unprocessed workpiece to be input, so that the processing that matches the required accuracy is appropriate. It is automatically executed according to the tool, tool path, and processing conditions, and the product can be processed in a short time.

It is a block diagram of a control device of a machine tool according to an embodiment of the present invention. It is a block diagram of a database. It is a block diagram of a tool path determination part. It is a flowchart of a process process determination part. It is a schematic diagram showing a scanning (scanning) processing path as an example of a processing pattern. It is a schematic diagram showing a contour contour processing path as an example of a processing pattern. It is a schematic diagram showing a character line processing pass as an example of a processing pattern. It is a schematic diagram showing a radiation processing path as an example of a processing pattern. It is a schematic diagram showing rough cutting by a contour contour processing pass as an example of a processing pattern. FIG. 6 is a schematic diagram showing another scan (scanning) processing path as an example of the processing pattern. It is a schematic diagram showing a contour line processing path as an example of a processing pattern. FIG. 5 is a schematic diagram showing a machining path that prevents a step in the boundary portion by automatically overlapping a boundary portion of a machining region with an adjacent machining region as an example of a machining pattern and smoothly retracting the overlap portion. It is a schematic diagram for demonstrating the longitudinal direction determination method of the process curved surface of a workpiece | work. It is explanatory drawing for demonstrating the longitudinal direction determination method of the process curved surface of a workpiece | work. It is a flowchart of the longitudinal direction determination method of the process curved surface of a workpiece | work. It is a schematic diagram for demonstrating the determination method of a character line. It is another schematic diagram for demonstrating the determination method of a character line. It is explanatory drawing for demonstrating the determination method of a character line. It is another explanatory drawing for demonstrating the determination method of a character line. It is a flowchart of the determination method of a character line. It is a schematic diagram showing a processing pass for processing a character line. It is a schematic diagram for demonstrating the convex R part determination method, (a) is a whole perspective view of a workpiece | work, (b) is the elements on larger scale of (a). It is explanatory drawing of a groove processing, (a) is a figure which shows the groove processing by a prior art, (b) is a figure which shows the groove processing by the contouring of this invention. It is a schematic diagram explaining the determination method of the position which performs the pick feed in a contour processing pass. It is a flowchart of the determination method of the position which performs the pick feed in a contour processing pass. It is a schematic diagram for demonstrating the determination method of the pick feed amount and feed speed in surface processing. It is a flowchart of the determination method of the pick feed amount and feed speed in surface processing. It is a block diagram of a prediction calculation part. It is a schematic diagram for demonstrating the determination method of a process area. It is a flowchart of the tool path change operation method by an operator. It is a flowchart of the processing condition change operation method by an operator. It is a flowchart of the manual operation method by an operator. It is a schematic diagram for demonstrating the manual operation method by an operator. It is a flowchart of the change operation method of the process conditions in consideration of cost. It is a figure for demonstrating the change operation method of the process conditions in consideration of cost. It is a flowchart of the change operation method of the process conditions which considered the profit per unit time. It is a figure for demonstrating the change operation method of the process conditions which considered the profit per unit time, (a) is a profit curve, (b) is the profit curve per unit time. It is a schematic diagram for demonstrating the display of a process progress condition. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic for demonstrating the effect of this invention, (a) is drawing shape based on process shape data, (b) is a figure which compares the case where it processed using the control apparatus of this invention, and a prior art. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input part 3 Database 3a Machine database 3b Tool / holder database 3c Processing condition database 3d Material database 3e NC / servo database 3f Input database 3g User database 5 Tool path determination part 5a Machining process determination part 5b Tool path generation part 5c Machining condition determination Unit 5d Correction unit 5e Cost calculation unit 5f Operator change operation determination unit 7 Prediction calculation unit 7a Machining state simulation unit 7b Machine behavior simulation unit 7c Work simulation unit 7d Tool behavior simulation unit 9 Numerical control unit 11 Machine tool 13 Sensor unit 15 Data correction Unit 17 Display unit 100 Control device

Claims (3)

A machine tool control device for machining a workpiece by inputting machining shape data,
An input means for inputting the machining shape data related to the final workpiece shape, the material of the workpiece before machining, and the workpiece data relating to the shape,
Data storage means for storing at least one of machine data representing machine specifications of the machine tool for machining the workpiece and tool data representing tool specifications of the tool held by the machine tool;
Prediction calculating means for predicting at least machining load or interference between a tool and a workpiece based on data input by the input means and data stored in the data storage means;
Based on the data input by the input means, the data stored in the data storage means, and the prediction calculation result by the prediction calculation means, a tool path for machining the workpiece is generated, and the spindle rotational speed of the machine tool Tool path determining means for determining processing conditions when processing the workpiece such as a feed rate;
Recognizing and storing a change operation by the operator with respect to the tool path and machining conditions generated and determined by the tool path determination means, determining whether or not the change operation is valid, and generating the change operation as a tool path and a machining condition Operator change operation determination means to be reflected in the decision;
A machine tool control device comprising:   The machine tool control device according to claim 1, wherein the tool path determination unit includes a machining step determination unit that selects a tool and a machining pattern and determines a machining step.   The operator change operation determination means recognizes the machining shape data and workpiece data input by the input means, the tool selected by the machining step determination means, and at the time of manual feed operation or fast feed operation of the tool, The region in which the tool does not interfere with the workpiece is defined as a movable region of the tool, and when the operation is attempted beyond the movable region, the operation of the tool is stopped before the interference with the workpiece occurs. The machine tool control device described.

Images