JPH0647635Y2 - High precision processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is capable of achieving high precision between a numerically controllable processing device, for example, a tool of a spindle and a workpiece, which is provided in a station of a transfer machine, for example. Therefore, the present invention relates to improvement of position detecting means in the X and Y directions for enabling relative positioning.

[Outline of the Invention] In the processing apparatus of the present invention, in order to detect the position in the X and Y directions with high accuracy by using one contact, the first and second magnetoelectric conversion elements and the contact are provided at the tip of the contact. Each section is provided. On the plane of the magnetic body provided on the support member of the workpiece, four plate-shaped magnet members facing the first and second magnetoelectric conversion elements and having magnetic pole boundaries in orthogonal directions, respectively, A reference member that comes into contact with the contact portion is provided, and the position is detected in the X and Y directions during the machining feed by the magnetoelectric conversion element. The contactor and the reference member are made of a non-magnetic material.

[Prior Art] In a transfer machine, a work piece is supported by a jig or a pallet in a positioning state, and is fixed in a positioning state for each station by them. Then, at each of these stations, the necessary cutting work is performed by the working unit.

Recently, as a machining unit of this kind, one equipped with a numerical control device has come to be used, and the position of the tool with respect to the workpiece is automatically determined, and the feed amount (machining depth) required at that position is also calculated. It is designed to be cut and processed.

By the way, during machining, the feed screw, spindle, column, base, etc. on the processing unit side are thermally deformed, and the jig itself on the transfer machine side has dimensional variations and positioning of the workpiece with respect to the jig, and further A relative positioning error occurs between the work piece and the processing unit due to the accumulated error of the processing accuracy of 1.

Therefore, even if the machining unit controls the positioning and the feed amount with high accuracy according to the preset numerical control program, there is a machining error on the workpiece due to the above-mentioned thermal deformation and dimensional variation of each part. Will appear.

[Problems to be solved by the device] Therefore, the applicant of the present utility model is invented in Japanese Utility Model Publication No. Sho 63-31877. We have already proposed a technology to control the working depth by numerical control after determining the relative position with the tool on the side.

Although high-precision machining was realized by the above idea,
When setting the position of the spindle in the feed direction, that is, when the sensor detects the reference position, a means for indexing the rotational position of the spindle is required, and the feed is temporarily stopped, resulting in loss of time, which increases machining efficiency. Remained the problem.

Therefore, the applicant of the present invention further devised the invention of Japanese Utility Model Publication No. 2-39720, which does not require a rotational position setting function in the spindle feeding process, determines the reference position from the feeding motion, and continues the subsequent cutting motion. We have proposed a processing device that can be efficiently executed.

However, this device has a problem that it can detect and correct only the position in one direction (Z direction), and the installation position of the position detecting magnet is limited.

In order to improve the above-mentioned problems of the prior art, the applicant of the present invention has previously proposed the invention of Japanese Utility Model Publication No. 3-54834 to perform three-dimensional position detection with a single contact with high accuracy and to perform Z during machining feed. The present invention provides a high-precision machining apparatus capable of detecting and correcting the original position in the direction, shortening the detection time, and further reducing the detection time to zero.

With this device, highly accurate position detection in the X and Y directions was possible in principle, but there are still the following problems in practical use.

That is, since the position-detecting magnetoelectric conversion element in the X and Y directions cannot be traced by sliding contact with the magnet because of various problems, it has to be traced so as to be opposed to and close to the magnet. The magnetoelectric conversion element detects the boundary of the magnetic pole, but the boundary of the magnetic pole is distorted in space and does not become a straight line in the X and Y directions.
The detection position (actual trace position) is originally several 10 to 200.
Since there is a deviation of about μ, correct correction cannot be performed even if position detection is carried out due to this deviation and the above distortion, and it was difficult to realize the desired high-precision machining due to a large detection error. .

Therefore, an object of the present invention is to provide a concrete structure of a position detecting means in the X and Y directions suitable for solving the problems of the prior art and realizing high precision machining.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention comprises a position detecting means in the X and Y directions, a magnetic body fixed to a support member, and four magnetic body fixed to the plane of the magnetic body. It is composed of a plate-shaped magnet member and a reference member fixed to the magnetic body or the magnet member, and a reference surface of the reference member is provided with a flat surface in the XY direction. A third Z-axis direction sensor when the reference member and the contactor are made of a non-magnetic material and the contact portion of the contactor is in contact with the reference surface.
It is characterized in that the magnetoelectric conversion element of is configured so as to face the second magnet.

[Operation] In the processing apparatus having the above-described configuration, when the contact portion of the contactor comes into contact with the reference surface of the reference member, the magnetoelectric conversion element closely faces the magnetic pole pattern of the magnet member, and is positioned in the X and Y directions. Detection is performed. As a result of this detection, if the positions in the X and Y directions are deviated, the numerical control device receives the output signal from the magnetoelectric conversion element and corrects the numerical control program by the amount of the deviation, and the X and Y axis servo motors are corrected. Are driven and controlled.

In this case, since the magnet member is plate-shaped and is fixed to the plane of the magnetic body, and the reference member and the contactor other than the magnet member and the magnetic body are formed of a non-magnetic material, the magnetic pole in the space is The boundary distortion is as smooth as possible, which is effective in reducing the measurement error. Particularly preferably, when the magnetoelectric conversion element is made to trace the intermediate portion of the boundary, the distortion is further reduced and the measurement error can be reduced.

[Embodiment of the Invention] Hereinafter, the present invention will be described with reference to the drawings. FIGS. 1 and 2 show a main part of a high-precision machining apparatus 1 to which the present invention is applied. This high-precision machining device 1 uses a numerical controller 2
A processing unit 3 controlled in the three-dimensional axial directions of X, Y, and Z is provided. The machining unit 3 is moved in and out by a special cylinder 4 in the Z-axis direction, and in the vicinity of the tip of the contact 5, the first and second magnetoelectric conversion elements 6, 7 as X, Y direction sensors are provided. (For example, a magnetic analog sensor) is provided, and a third magnetoelectric conversion element 8 as a Z-direction sensor is provided on the intermediate side portion of the contact 5.

The Z-direction spindle 9 is supported by a spindle holder 10 in parallel with the contacts 5, and a ring-shaped magnet holder 11 fixed to the spindle holder 10 has a bar-shaped magnet at one position.
12 (second magnet) is fixed, and this magnet has N and S magnetic poles arranged in the axial direction of the spindle.

On the other hand, the workpiece 13 is transferred to the front side of the processing unit 3 by the transfer device 14 together with the supporting member 15 such as a pallet.
That is, they are sequentially guided to the processing station. In this device, the work piece 13 is supported by the side surface of the support member 15, and the predetermined processing is performed by the cutting tool 16 attached to the tip of the spindle 9.

Further, on the upper side surface of the support member 15, there are provided a reference surface 17 with which the tips of the contacts 5 come into contact and an X, Y magnet 18 (first magnet) arranged to face the X, Y direction sensors 6,7. ing.

As shown in FIG. 3, for example, the X, Y magnet 18 has a magnet pattern in which the boundaries of the N and S poles are horizontal and vertical, and the reference plane 17 is arranged at the center of the magnet pattern. The member is X,
If it is set correctly at the reference position in the Y direction,
The X and Y direction sensors 6 and 7 face the boundary between the N and S poles in the X and Y directions, and the machining program of the numerical controller 2 incorporates the boundary between the N and S poles as the origin. Is.

In the high-precision machining apparatus 1 having the above configuration, the machining operation of the machining unit 3 is executed according to the NC machining program of the numerical controller 2. First, the special cylinder 4 is operated while the spindle 9 is returned to the return position, and the contact 5 is moved forward, so that the tip of the special contact 4 is brought into contact with the reference surface 17. As a result, X and Y direction sensors 6,7
Is closely opposed to the boundary of the N and S poles of the X and Y magnets 18, but if it is slightly deviated from the above boundary due to various displacements and accumulated errors, A corresponding analog output is generated and sent to the numerical controller 2. Specifically, the analog output corresponding to the deviation amount is digitally converted and sent to the numerical control device. Since the numerical control device stores the relationship between the deviation amount and the digital value in advance,
The program is automatically corrected by the amount of deviation.

In parallel with this, the processing unit 3 rotates the spindle 9 and moves forward by the feeding motion to move the sword tool 16 to the workpiece.
Get closer to 13.

In this forward movement process, that is, in the movement range during the machining operation, the Z-direction sensor 8 in which the contact 5 comes into contact with the reference surface 17 and stops.
Comes to face the second magnet 12, detects the magnetic pole boundary thereof, and sends the detection signal to the numerical controller 2.

The numerical controller 2 corrects the program by the amount of deviation in the X and Y directions, and drives the X and Y axis servo motors (not shown) to drive the program and responds to the detection signal from the Z direction sensor to execute the program. By starting (as the origin of predetermined processing) and advancing the processing unit 3 by a predetermined predetermined feed amount, the workpiece 13 is cut by the sword tool 16 to a predetermined depth.

As the Z direction detecting method, the method of Japanese Patent Application No. 60-61111 using an annular magnet may be adopted.

Also, the X, Y direction detection method is not limited to the method of detecting the amount of deviation from the detection values in the X, Y directions as in the above device,
Drive the X and Y axis servomotors so that the direction sensor completely faces the boundary of the second magnet, and
A method of correcting the X and Y positions can also be adopted.

Now, in the processing apparatus having the above-described configuration and operation, the boundary between the magnetic poles of the X and Y magnets 18 is distorted in space as described above, and there is a deviation in the detection position (actual trace position of the sensor). In view of the fact that this causes a large detection error, in the present invention, in order to improve this point, the X, Y magnets 18 and the like forming the position detecting means in the X, Y directions are constructed as follows.

That is, as shown in FIG. 4, a magnetic body (yoke) 20 is used to form a recessed flat surface 21, and four flat rectangular magnet members 22, for example, are formed on this flat surface as in FIG. Stick them together. Then, a circular thin plate-shaped reference member 23 (for example, a non-magnetic material such as ceramics) having a thickness of about 1 mm is attached to the central portion thereof. The magnet member plane and the reference member plane (reference plane) are aligned with the X and Y planes.

Next, the contact 5 is formed of a non-magnetic material such as zirconia, and is disposed so as to face the reference member 23.
It is convenient to make a hole 24 in the center of the hole 24 so that it can be cleaned by injecting air from the hole when it is not in operation. Further, the two sensors 6 and 7 in the X and Y directions, which are mounted integrally with the contact 5 while being displaced by 90 °, are located next to the middle part of the corresponding magnetic pole boundary when the contact 5 is advanced, for example, the boundaries in the X and Y directions. The position is shifted by 200 to 300 μm. Here, the above-mentioned middle part is respectively from both ends of the magnetic pole boundary.
The portion excluding the length of 30% is preferable.

The correction operation of the detection error (deviation amount) of the position detecting means in the X and Y directions having such a configuration is performed in the following steps, but basically it is the same as that described above.

(I) The contactor 5 is advanced to bring the contact portion into contact with the reference surface of the reference member 23. (Therefore, the size of the reference member 23 is a size that causes an error as a machine, for example, about 200 μ at most in a numerically controlled machine tool, and 1 mm from the tip diameter of the contact 5.
A large diameter is sufficient. (Ii) Return the processing unit 3 by about 0.1 to 0.2 mm and stop it. In this state, the machining unit 3 is fed in the X direction by about 300 to 500 μm, and the X direction sensor output position is set as the X direction origin of the machining program.

(Iii) Next, from this state, the machining unit 3 is fed in the Y direction by about 300 to 500 μm, and the Y direction origin of the machining program is determined in the same manner as above.

[Effects of the Invention] As is apparent from the above description, according to the present invention, X,
± 5 μm because the position detection accuracy in the Y direction is greatly improved
The above-described highly accurate processing can be realized, and the detection is made efficient and the time is shortened, which is a practical effect.

The magnet member may have the same shape as the reference member made of a non-magnetic material as shown in FIG. In addition, the contact
The amount of movement in the X and Y directions may be set to a value slightly larger than the predicted maximum amount of deviation (determined by the capability of the machine), and is not limited to the above example.

Further, this deviation amount is not limited to the above measuring method, and may be an amount up to the boundary, for example.

In addition, when using the rectangular magnet member, one side is
Use of 8 mm or more is advantageous because there is little distortion, and this distortion changes greatly with changes in the facing distance between the magnet and sensor, so it is advantageous in terms of detection accuracy that this distance does not change when tracing the contact. Becomes

[Brief description of drawings]

FIG. 1 is a side view showing the outline of a high-precision machining device to which the present invention is applied, FIG. 2 is an enlarged view of the essential parts thereof, and FIG. 3 is a diagram illustrating the magnet pattern of X and Y magnets in the device,
FIG. 4 is a schematic view showing an embodiment of the present invention. 1 …… High-precision machining device, 2 …… Numerical control device, 5 …… Contact, 6,7,8 …… Sensor, 13 …… Workpiece, 15 …… Supporting member, 17 …… Reference, 18… … X, Y magnet, 20 …… Magnetic material, 22 …… Magnetic member, 23 …… Reference member.

Claims (1)

[Scope of utility model registration request] 1. A contactor which is provided in a numerically controllable processing unit and has an abutting portion and first and second magnetoelectric conversion elements at its tip, an advancing / retreating means of the contactor, and a contactor of the contactor. A support member for a workpiece having a reference surface with which the abutting portion contacts when advancing, and a support member provided on the support member so as to face the first and second magnetoelectric conversion elements, respectively. In a device including at least a first magnet having a boundary of magnetic poles in a direction orthogonal to the above, and a second magnet for position detection in the Z-axis direction, a magnetic body holding the first magnet on the support member. Is fixed, a flat surface is formed on the side of the magnetic body facing the contactor, and four plate-shaped magnet members as the magnets are fixed on the flat surface by attaching different poles to each other to form a boundary in the orthogonal direction. Then, a reference member is formed on the first magnet or the magnetic body, and the base member is formed. The reference surface is formed on the quasi member, and the reference member and the contact are formed of a non-magnetic material,
A high-precision machining apparatus comprising a third magnetoelectric conversion element facing the second magnet when the contact portion of the contactor is in contact with the reference surface.