JP2017196659A - Press metal dies and press machine, and method for checking metal die formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem in formation in an actual press machine using a metal die made on the basis of analysis technique, in which a formation result conforming to an analysis result has not been obtained, by providing detect means for detecting an actual state of formation which can be compared with a result of analysis techniques including preconditions and calculation process, as well as providing means for eliminating or minimizing factors impacting formation by the press machine and the metal die, using the detect means.SOLUTION: A method for checking formation of press metal dies comprises: adjusting a multiple points die-height adjustment device and a multiple-point overload protector hydraulic adjustment device, to adjust a slide parallelism and a distribution of pressure outputs, at press-cutting by fitting upper and lower dies, using a fitting reference block having a structure for restricting positional relationship between forming surfaces of the upper and lower dies, to conform to a result of vertical formation analysis, as well as functions for measuring pressure inside the metal dies, so as to achieve a state of press-cutting by fitting the upper and lower dies which conforms to the analysis result.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a press machine that realizes an analysis result in processing using a press die in manufacturing a press part of an automobile, and a mold forming confirmation method using the machine.

  Press dies that produce automotive stamping parts (hereinafter referred to as dies) are designed and manufactured using computer analysis technology and NC processing, but in practice, molding results that match the analysis results are obtained. However, the skilled technician determines the molding result and corrects the mold as a molding adjustment.

  There are two types of mold analysis techniques: molding analysis and structural analysis (also referred to as rigidity analysis). Molding analysis mainly consists of plastic deformation analysis in the non-linear region based on the “stress-strain” characteristics of the workpiece. A shape surface capable of applying a necessary pressure and deformation amount to the molding is determined. In the structural analysis, a structure having rigidity that does not affect the forming is analyzed and determined with respect to the pressure distribution of the forming analysis result.

  Mold adjustment work of the mold is performed by checking and measuring the actual molding result, the surface contact state using Komyotan, pressure measurement film, etc., and the gap between the upper and lower molding surfaces using fuse, clay, etc. A skilled technician guesses the state at the time of molding and corrects the mold. Since these adjustment tools do not quantitatively clarify the adjustment range and the adjustment amount, the technician makes an independent determination based on his skill and experience. For this reason, although a correction policy differs for every technician, it is common to repeat correction and confirmation many times. Immediately before the start of production, immediately after the assembly of the mold is completed, the mold is adjusted many times with a press for mold adjustment called a tri-press. After that, the mold is checked and adjusted on the production line. Therefore, it takes a long time to adjust the molding of the mold. Along with the development of measurement technology in recent years, a method of adjusting a mold by measuring a molding result and a molding part shape of a mold and re-executing molding analysis based on the result is performed. This method is effective in reducing the shortage of skilled technicians and the ability difference between technicians, but has not led to a dramatic improvement in the initial quality of the mold, that is, molding.

  In the molding adjustment by the technician, in addition to the adjustment of the shape of the molding surface, the positional relationship between the upper and lower molds is adjusted in consideration of the variation in the thickness of the molding. For adjusting the positional relationship between the upper and lower molds, a pressing block that prevents excessive pressing and determines the positional relationship between the upper and lower molding surfaces while the upper and lower molds are completely pressed is used. This pressing block determines the vertical positional relationship between the entire upper mold and the entire lower mold, and is adjusted as part of the molding adjustment in the process of molding adjustment. Finally completed.

  As an engineering method for knowing the molding state in a mold in place of Komyotan or a pressure measurement film, a method of measuring strain by attaching a strain gauge on the molding surface or inside thereof (Patent Document 1) has been invented. However, since distortion is dimensionless and has no physical quantity, it is effective as a relative comparison such as its own change, but in order to make a relative comparison with others, it needs to be converted into a physical quantity. There are many problems in practical application.

  A die height adjusting device and an overload protector device of a press machine, which are main devices related to molding, will be described. In addition, the description will exemplify a four-point press machine, which is the most common on the production site of press parts for automobiles, that is, a press machine in which a slide is connected to a drive device by four plunger rods.

  A die height adjusting device will be described. The die height adjusting device is a device for adjusting the die cut height of the die from the die height of the press machine, that is, the top surface of the Porstag plate (or bed) to the bottom surface of the slide at the slide bottom dead center. The die height adjusting device mechanically connects all the die height adjusting devices assembled for each plunger rod, and operates synchronously with one motor. The die height adjusting machine is constituted by a pair of a worm screw and a worm wheel screw. The worm screw is mechanically connected to another die height adjuster and a drive motor, the worm wheel screw is assembled to the plunger rod, and the die height adjuster main body is fixed to the slide. The worm wheel screw is rotated by the worm screw, and the position with respect to the plunger rod is adjusted, whereby the slide position to which the slide adjuster is fixed moves up and down, and the die height is adjusted.

  The relationship between die height and slide parallelism will be described. In general, the die height adjustment amount is several tens to several hundreds [mm], and is mechanically operated synchronously with one motor as described in the previous section. The slide parallelism is determined by the assembled state of the die height adjuster and cannot be arbitrarily adjusted. Since slide parallelism affects molding, it is established as a part of accuracy grade by JIS. A press machine for press parts for automobiles is normally a JIS grade 1 grade. For example, the tolerance of slide parallelism with a die space length of 4 [m] is 0.44 [mm]. As an example of the influence of the slide parallelism on the mold, when the die height adjustment device is driven at the bottom dead center, if the parallelism deviates from the allowable value, a regulating part such as a guide that regulates the horizontal positional relationship of the upper and lower molds This causes interference failure. As described above, the die height adjusting device and the slide parallelism are closely related, and it is necessary to keep the slide parallelism within an allowable value even during the adjustment operation of the die height.

  In some press machines, as a method of adjusting the parallelism of the slide, a method of adjusting each die height adjuster independently with an individual motor (Patent Document 2) and a parallelism adjusting device using a hydraulic cylinder (Patent) Document 3) has been invented. However, both inventions do not have a mechanical synchronization structure between the adjustment axes, and require an additional mechanism such as control for keeping the parallelism within an allowable value in the process of adjusting the die height. The individual motor system (Patent Document 2) requires a large installation space. The hydraulic cylinder method (Patent Document 3) has a complicated structure and an active expansion / contraction function added to the overload protector device. Correction during compression during press pressurization and temperature change of oil viscosity Etc., more sophisticated control is required.

  In recent years, the so-called servo press, which uses a servo motor as a drive source for press machines, has been put into practical use. In some servo presses, the servo motor provided for each pressurizing point is synchronized with the bottom dead center. Stopped. Even in this form of servo press, as in the method of independent adjustment with individual motors (Patent Document 2), the problem is that the synchronization is unstable and the parallelism during operation is maintained. In addition, both the bottom dead center position itself and the parallelism at the bottom dead center position have accuracy differences from cycle to cycle and are not reproducible. Regarding the parallelism of the servo press, many mechanisms for maintaining the parallelism have been invented, but the number of inventions is also a visa for the magnitude of the problem related to parallelism.

  An overload protector device will be described. A hydraulic chamber called an overload protector exists directly under each plunger rod, which is a pressurizing point of the press machine. The overload protector (hydraulic chamber) is a mechanism equivalent to a hydraulic damper, and only generates a reaction force due to compression at the time of pressing at the bottom dead center, and does not have an active expansion / contraction function. In the overload protector device, all of the overload protector hydraulic chambers are connected by hydraulic piping, and a common hydraulic pressure is supplied. When overload occurs, this hydraulic pressure supply is stopped, and the hydraulic pressure in the overload protector is discharged, and the reaction force due to compression is reduced. The overload protector device is closely related to the die height adjustment device, and sets the die height (slide height at the bottom dead center) of the press machine lower than the die height of the die (height at the time of vertical die pressing). As a result, the overload protector is compressed at the bottom dead center and a reaction force is generated, and this reaction force is the pressing force of the press machine. In general, the press machine is positioned as a general-purpose machine, and is designed on the premise that uniform pressure is generated on the mold. All overload protectors are interconnected by hydraulic piping as described above, and hydraulic The source is also the same, and the applied pressure that is the reaction force of all overload protectors is equal regardless of the amount of compression.

  For the hydraulic adjustment of the overload protector device, as a similar invention, a parallelism adjusting device using a overload protector (Patent Document 4) and a parallelism adjusting device using a cylinder (Patent Document 5) have been invented. Both inventions aim at adjusting the slide parallelism, but share the same technique for adjusting the hydraulic pressure at the press pressure point. Since both inventions are active hydraulic pressure adjustment systems, an expensive hydraulic device is required, and the variation in the viscosity of the hydraulic pressure due to temperature changes and compression amounts is large, requiring high-precision control.

  The above is the technical background before shifting to actual production from mold production to adjustment. After shifting to production, the press machine is adjusted at the time of production setup using the adjustment result of the press machine such as the die height value obtained in the mold adjustment process as a production requirement. However, if the press machine is changed due to production transfer, etc., or depending on the maintenance content of the press machine or the mold, it is necessary to confirm and adjust the molding again.

JP 2010-115702 A JP 2001-121297 A JP 2010-131620 A JP 2001-71198 A JP 2009-178726 A

  In actual press molding using a die designed and manufactured using analysis technology and NC machining, a molding result that matches the analysis result cannot be obtained. The main cause is that factors that are simplified or simplified in the analysis technique, that is, factors such as accuracy differences between the press machine and the die actually affect the forming. Quantitative factor analysis of the influence of these factors on molding is insufficient, and the analysis technology for this part has not been established. Further, the return of the molding result to the analysis technology is incomplete, and the improvement of the performance of the analysis technology is limited. As described above, the present invention provides means for detecting the actual state of molding that can be compared with analysis techniques including preconditions and calculation processes, and eliminates or minimizes molding influencing factors of the press machine and the mold using the means. It is a problem to provide means for realizing the above.

  The fitting reference block of the present invention is fixed to the upper and lower mold fitting surfaces, that is, either the upper surface of the lower mold or the lower surface of the upper mold, and the contact surface with the mating mold when the upper and lower molds are fitted to each other. By forming it as a contact reference that has a one-to-one relationship with the standard of the upper and lower molds, it is possible to restrict the molding surface of the upper and lower molds to a positional relationship that matches the molding analysis result, and to convert the vertical strain between the upper and lower molds into a pressure A structure with area accuracy is formed, and a strain gauge is attached to the side of the structure. This fitting reference block is placed at a key point in the mold. The positional relationship of the molding surface is regulated so as to match the molding analysis result, and the pressure distribution is used as an index for matching the molding analysis result.

  The multi-point die height adjusting device of the present invention aims to eliminate a molding machine influence factor between a press machine and a mold or minimize the influence, and to realize a fitting press-cut state that matches a molding analysis result. Compare the measured value, which is the pressure information obtained from the block, with the set value, which is the molding analysis result of the pressure of the fitting reference block, and for the part where the measured value is lower than the set value, Connect the clutch of only the part die height adjuster and release the paired brake, drive the adjustment motor, lower the die height until the measured value is within the allowable range of the set value, tentatively measured value For parts where is higher than the set value, similarly, only the necessary parts are driven using the operation of the clutch, brake and motor, and the die height is raised until the measured value falls within the allowable range of the set value. And wherein the door.

  The multi-point overload protector hydraulic pressure adjusting device of the present invention aims to eliminate a molding influencing factor of the press machine and the mold or minimize the influence, and realize a fitting press-cut state that matches the molding analysis result, When changing the output balance of the press machine in response to the unbalanced load, the measured value that is the pressure information obtained from the fitting reference block and the setting value that is the molding analysis result of the pressure of the fitting reference block , The check function of the pilot operated check valve that is paired with the overload protector that needs to be changed is enabled to shut off the overload protector from the other hydraulic chambers, and the above-mentioned die height of the overload protector section If pressure increase is necessary using the adjuster, the die height is lowered until the measured value is within the allowable range of the set value, and pressure reduction is required. In this case, a pilot-operated check valve having an adjustment function for increasing the die height until the measured value falls within the allowable range of the set value and matching the pressure distribution in the mold with the molding analysis result is used. And

  The press machine of the present invention is a press machine having two or more pressurizing points including the fitting reference block, the multi-point die height adjusting device, and the multi-point overload protector hydraulic pressure adjusting device. It has an interface function for receiving a strain gauge signal from the strain gauge of the reference block.

  The control device of the present invention is a control device used in the press machine, which converts the strain gauge signal from the strain gauge of the fitting reference block into a pressurizing force, and applies the pressurizing force to the molding analysis result. The multi-point die height adjusting device and the multi-point overload protector hydraulic pressure adjusting device are adjusted so as to coincide with the pressure.

  Specifically, the control device of the present invention assigns a management number corresponding to each of the fitting reference blocks to the fitting reference block, and the management number and the management number from the strain gauge for each of the management numbers. At the time of actual load, used as a set value when checking the molding adjustment and molding quality in the conversion coefficient for converting the strain gauge signal into the pressing force and the pressing analysis force of all the fitting reference blocks measured by the molding analysis result or the press machine Upper limit value and lower limit value of molding margin pressure, and upper limit value and lower limit value of the central range of the upper and lower limits of molding margin pressure, and set values for molding adjustment and mold setup. When the load distribution at the actual load matches the pressure distribution in the molding analysis result, which is also used as the set value for molding adjustment and molding quality confirmation The die height setting upper limit value and lower limit value obtained from the measured values of the multipoint die height adjusting device at all the pressurizing points, and the check function of the pilot operated check valve of all the multipoint overload protector hydraulic adjusting devices All pressurization points at both actual load and no load when the set state and the above-mentioned multi-point die height adjustment device are die height values that match the pressure distribution at the actual load with the pressure distribution of the molding analysis result The actual load output upper limit value and lower limit value and no-load output upper limit value and lower limit value obtained from the actual measured values of the overload protector hydraulic pressure of each mold are stored as production requirements for each mold, and the above-mentioned fitting It has a calculation function for converting the strain gauge signal from the strain gauge of the reference block into a pressurizing force for each control number corresponding to the fitting reference block, and at the time of production, An actual measurement value obtained by converting the strain gauge signal from the strain gauge of the fitting reference block is stored for each management number corresponding to the fitting reference block according to the production requirements. Compared with the upper and lower limit values of the forming margin pressure, if the measured value exceeds the upper limit value of the molding margin pressure, the control number of the fitting reference block and the over-pressurization alarm are output, and the measured value is temporarily set to the molding margin. If the lower limit of the applied pressure is not reached, the control number of the fitting reference block and the insufficient pressurization alarm are output. If the measured value is within the upper and lower limits of the molding allowance applied pressure, the production requirement that is further stored information Compared with the median upper / lower limit of the pressurization center pressure range, if the measured value is within the median upper / lower limit value, the molding condition is judged to be good and the measured value is temporarily added. If the upper pressure median value is exceeded, the mating standard Outputs block control number and overpressurization warning, and if the measured value is less than the median lower limit of pressurization, it has a function to output the control number of the fitting reference block and underpressurization warning In addition, when mounting the mold, at the top dead center immediately before mounting, the measured height values of all the die height adjusters of the multi-point die height adjusting device are set to the die height of the production requirements as stored information. Compared with the upper and lower limit values, if the measured value is lower than the die height setting lower limit value, the die height is increased, and if the measured value is higher than the die height setting upper limit value, the die height is lowered and the die height setting upper and lower limits of the production requirements Adjust the value within the range, and match the production requirement as the stored information with the check function of the pilot operated check valve of the multi-point overload protector hydraulic adjustment device. At the bottom dead center at the time of installation, the measured values, which are the hydraulic values of all the overload protectors of the multipoint overload protector hydraulic adjustment device, are stored as no-load output of production information If the measured value exceeds the upper limit value of the no-load output pressure, the die height of the pair is raised until the overload protector hydraulic pressure is within the set range. If the lower limit of the no-load output pressure is not reached, the corresponding die height is lowered until the overload protector hydraulic pressure is within the set range. Using the applied pressure obtained by converting the strain gauge signal from the strain gauge of the block as an actual measurement value, it compares the upper and lower limits of the no-load applied pressure that is a production requirement, and the actual measured value is assumed to be no-load applied pressure. If the limit value is exceeded, the control number of the fitting reference block and the die height excessive descent warning are output, and if the measured value is less than the no-load pressure lower limit value, the control number of the fitting reference block is A die height descent insufficient alarm is output, and if the actually measured value is within the upper and lower limits of the no-load applied pressure that is a production requirement, it has a function of outputting a mounting normal signal.

  The press mold forming confirmation method of the present invention is a press mold forming confirmation method using the control device, and is obtained by converting the strain gauge signal of the strain gauge of the fitting reference block. The multi-point die height adjusting device and the multi-point overload protector hydraulic pressure adjusting device are adjusted so that the pressurizing force coincides with the pressurizing force of the molding analysis result.

  The molding state of the press die can be matched with the molding analysis result. For example, if the present invention is used, the correction of the influence of accuracy difference between the press machine and the die and the die adjustment process by the tri-press immediately after the die production are unnecessary, and the period can be shortened.

  It is possible to return to the analysis technology as high-quality data that narrows down the cause of the difference between the molding analysis result and the actual molding result to the factor of only the analysis technology that eliminates the influence of accuracy difference between the press machine and the mold. , Analysis technology performance will improve.

  Effective utilization of human resources becomes possible as a secondary ripple effect. Conventionally, skilled workers with a certain level of skill and years of experience are necessary for mold adjustment, including after the start of mass production. According to the present invention, the molding state can be numerically managed, so that most of the work of skilled workers can be performed. Therefore, it is possible to turn the skilled person from the conventional follow-up work to the advance work such as mold production and molding process innovation.

It is explanatory drawing of a fitting reference | standard block. It is explanatory drawing which showed the fitting push-cut state of the up-and-down type | mold for demonstrating the function of a fitting reference | standard block. It is explanatory drawing which showed the example of arrangement | positioning of a fitting reference | standard block. It is explanatory drawing of the multipoint die height adjustment apparatus in a 4-point press machine. It is explanatory drawing of the multipoint overload protector hydraulic pressure adjustment apparatus in a 4-point press machine.

  Analysis techniques in mold design include molding analysis and structural analysis. The molding analysis is based on the “stress-strain” characteristic of the molding, and analyzes and determines a molding shape that can apply the pressure and deformation necessary for the intended plastic deformation to the molding. This molded shape has a molding surface that has a shape that is a “mold” that determines the amount of deformation that achieves the intended shape of the molded product, and that the molded product conforms to the “mold” and has the necessary stress. And a molding surface for applying a pair of materials with a molding object in between. In the structural analysis, a structure having sufficient rigidity that does not affect the molding is determined with respect to both the pressing force from the press machine necessary for molding and the molding load in the mold. In a mold manufactured using both the molding and structural analysis techniques and NC machining, the actual molding results do not match the analysis results. The cause of this is not only due to the performance of the analysis technique, but also due to the difference in accuracy of the press machine and the difference in manufacturing accuracy of the mold. Therefore, in order to obtain a molding result that matches the analysis result, the factors affecting the molding result are separated into factors relating to the performance of the analysis technology and factors relating to the press machine and the die, and the latter factors other than the analysis technology. It is necessary to eliminate the influence or minimize it to the extent that the influence can be ignored, a means for detecting the actual condition of the molding that can be compared with the analysis technology including the preconditions and the calculation process, and the press machine and the gold using the means. There is a need for means to eliminate or minimize the mold influencing factors. Note that variations in the shape and stress characteristics of the workpiece, such as the thickness, should be included as part of the performance of the analysis technique as a problem of molding margin.

  In the molding analysis result, the molding surface that is the “mold” that determines the amount of deformation is the positive molding surface with the positive reference (surface), the workpiece is placed along the “mold”, and the necessary stress is applied. The molding surface to be used is the secondary molding surface. In order to obtain a molding result that matches the molding analysis result, the positional relationship between the positive and secondary molding surfaces and the addition between the molding surfaces in the pressurized state during press molding, that is, the upper and lower molds are fitted and cut off. Both pressure distributions need to match the molding analysis results. From the above, as a means for regulating the positional relationship between both the primary and secondary molding surfaces and measuring the pressure distribution between the molding surfaces in the fitted push-off state, the fitting reference block according to the present invention ( 10) is used.

  About the structure of a fitting reference | standard block (10), explanatory drawing of the fitting reference | standard block (10) of FIG. 1, and explanatory drawing of the upper and lower type fitting push-off state using the fitting reference | standard block (10) of FIG. And will be described. The fitting reference block may be attached to any of the upper and lower molds, but the description will be made on the assumption that the fitting reference block is attached to the lower mold with good set-up characteristics such as processing of pressure measurement wiring. The mating reference block (10) shown in FIG. 1 is a slave that faces the positive molding surfaces (21a, 22a) and the molding (23) with the upper and lower molds shown in FIG. This is a structure that regulates the positional relationship of the molding surface (22b for 21a, 21b for 22a) to coincide with the molding analysis result. Therefore, both the upper surface (10a) of the fitting reference block and the contact surface of the upper die that contacts the upper surface (10a) are determined as the contact reference at the time of fitting in a one-to-one relationship with the positive reference of molding, and molding is performed. It is formed as a fitting reference plane by analysis. Specifically, if the positive molding surfaces (21a, 22a) are present in the upper and lower molds, the positive molding surface (only on one of the upper and lower molds) Even if 21a or 22a) does not exist, the secondary molding surface (22b for 21a, 21b for 22a) facing the positive molding surface (21a or 22a) is restricted to a positional relationship that matches the molding analysis result. Analyzes are made as possible fitting standards (surfaces) with guaranteed accuracy in a one-to-one relationship with the positive standard (surface). As an example of means for assuring the accuracy of the fitting reference surface, machining is performed as a fitting reference surface associated with the molding positive reference one-to-one after the fitting reference block is assembled.

  The fitting reference block (10) is also used as a means for measuring the pressure distribution between the positive and secondary molding surfaces. The fitting reference block (10) includes a mounting portion (10c) using a bolt and a measuring portion (10b), and a strain gauge (11) is attached to the side surface of the measuring portion (10b). The upper surface (10a) of the fitting reference block (10) is a flat surface, and the upper surface (10a) and the side surface of the measurement unit (10b) are perpendicular to each other. And the area accuracy of a cross section parallel to the fitting reference block upper surface (10a) in a measurement part (10b) is ensured. The strain gauge (11) is attached to the side surface of the measurement portion (10b) whose area is guaranteed so as to measure the vertical strain in the direction perpendicular to the upper surface of the fitting reference block (10a). When the fitting reference block (10) is mounted in the mold, the mounting portion (10c) is bolted so that the upper surface (10a) always receives the applied pressure vertically. For example, if the applied pressure is vertical, the fitting reference block upper surface (10a) is horizontal, and if the applied pressure is horizontal, for example, the fitting reference block upper surface (10a) is always vertical, etc. The mounting direction is perpendicular to the upper surface (10a) of the fitting reference block. Since the movable direction of the molding surface coincides with the direction of the applied pressure, and its movement is restricted by the guide structure against lateral displacement, the fitting reference block (10) is located on the fitting reference block upper surface (10a). It is only necessary to regulate the positional relationship in the vertical direction, which is the direction of the applied pressure.

Since the output signal ε of the strain gauge (11) is dimensionless, it is converted to a force [N], which is a physical quantity, and compared with the molding analysis result. Multiplying the elastic modulus [Pa] and horizontal cross-sectional area [m ² ] of the measurement part (10b) of the fitting reference block, or calibrating the fitting reference block (10) as a load cell, and the force [N] which is a physical quantity Treat as. There is no restriction on the material of the fitting reference block except for the load resistance and the uniformity of the elastic coefficient, and if manufactured with general steel, the elastic coefficient of the steel is about 206 GPa (201 to 206 GPa for mild steel). If the manufacturing accuracy of the horizontal sectional area of the fitting reference block is managed, the applied pressure can be measured with an accuracy of 5% or less without performing calibration for the load cell.

    The control device of the press machine corresponding to the fitting reference block (10) has a function of converting the strain gauge (11) signal into the applied pressure and comparing it with the applied pressure distribution of the forming analysis result. Specifically, the control number assigned to the fitting reference block (10), and the conversion of the product of the elastic coefficient and the horizontal cross-sectional area or the calibration coefficient as a load cell for each management number, to convert the strain gauge signal into the applied pressure As a coefficient, each die has a function of storing it as a production requirement. In addition, for each management number, the calculation function (12) shown in FIG. 1 for converting into a pressurizing force using the strain gauge signal (11) corresponding to the conversion coefficient is also provided. For each control number, the pressure actually obtained from the fitting reference block (10) is compared with the molding analysis result of the pressure applied to the fitting reference block (10), and the pressure applied at the time of fitting push-off Detect and judge the distribution. Therefore, the fitting reference block (10) of the present invention is used as a means for detecting the actual condition of molding, and a multi-point die height device and a multi-point overload protector hydraulic pressure adjusting device, which will be described later, are excluded from molding influencing factors of the press machine and the mold. Alternatively, it is used as a means for minimizing the influence, and the fitted and cut-off state is matched with the molding analysis result.

  If the intended molding results cannot be obtained even when the upper and lower molding surfaces are in the same state as the molding analysis results, it may be due to performance problems in the molding analysis and / or structural analysis techniques. Therefore, both the pressure distribution obtained from the fitting reference block (10) and the actual molding result are fed back to the analysis technique. The above-mentioned “method for measuring and comparing the molding result product and the shape of the molded part of the mold” includes the influence of accuracy difference between the press machine and the mold, and has not led to quantitative factor analysis of the difference. On the other hand, the data obtained by the present invention is high-quality data narrowed down to the factor of only the analysis technique that eliminates the influence of the accuracy difference of the press machine. If the press-fit state between the upper and lower molding surfaces does not match the molding analysis result, and the measured pressure value partially does not meet the allowable lower limit value of the design pressure, the mold is processed or assembled. If there is a manufacturing defect at the time of mounting, or insufficient rigidity in the vicinity of the under-pressurized part, and if the actual measured pressure value exceeds the allowable upper limit value of the design pressure, if the mold is processed or assembled, It is a manufacturing defect or a rigidity other than the vicinity of the insufficiently pressurized portion. If the rigidity is insufficient, the measured value of the pressure distribution obtained from the fitting reference block is fed back to the structural analysis. As described above, the feedback data of the present invention is high-quality data limited to the factors of the analysis technique, and is numerical data of “force” that can be compared with “stress-strain”, and thus contributes to improvement of the analysis technique. .

  The form using a fitting reference | standard block (10) is demonstrated using the example of arrangement | positioning of the fitting reference | standard block of FIG. In addition, the symbols LF, RF, LR, and RR in FIG. 3 are divided into four parts in the four-point press machine including the subsequent FIG. 4 and FIG. That is, the section corresponding to the pressurizing point is matched to the name of the press machine, and LF = front left, RF = front right, LR = back left, and RR = back right. The fitting reference block (10) uses a multi-point die height adjusting device and a multi-point overload protector hydraulic pressure adjusting device, which will be described later, to eliminate factors that affect the molding of the press machine and the mold or minimize the influence. Since it is also an index, it is arranged in all the sections so as to be an adjustment index of the sections at the pressurization points of LF, RF, LR, and RR. And it arrange | positions with sufficient balance so that the positional relationship between both the positive and sub molding surfaces may maintain stability at the time of fitting and cutting. Assuming that the mold structure having the molding surface has sufficient rigidity that does not affect the molding in the structural analysis, the fitting reference block (10) interferes with the workpiece. It is not necessary to arrange in the molding surface, and it is arranged in the vicinity of the molding surface that does not interfere with the workpiece. Rather, the vicinity of the molding surface that does not interfere with the molding object is desirable so as not to be affected by variations in the thickness of the molding object. However, this is not the case when the pressing structure is a spring function such as a cushion pad or a presser pad and does not affect the flow of the molding. In addition, if many fitting reference blocks (10) are arranged in the vicinity of a molding part that particularly requires priority management, and the fitting reference block (10) is calibrated and used in the same manner as the load cell, the accuracy of molding management can be improved. Is possible.

  In using the fitting reference block (10), a management number is assigned to all the fitting reference blocks (10), and the control device of the press machine performs molding analysis or The molding upper and lower limits of the molding allowance pressure at the time of molding the molded article obtained by actual measurement, the median upper and lower limits of the pressing margin in the middle range of the molding margin pressing force upper and lower limits, and In addition, it has a function of storing and storing the no-load pressurization upper limit value and lower limit value of the allowable range of the fitting push-off state at no load as a production requirement for each die in the control device of the press machine. If these values do not agree with the molding analysis results in the pressure distribution at the time of fitting the upper and lower molds or the actual molding results, the actual pressure distribution obtained from the mating reference block is determined from the molding analysis or structure. Return to analysis, improve the performance of analysis technology, and recalculate to keep it up to date.

  A method of measuring strain by attaching a strain gauge to a molding surface (Patent Document 1) has been invented. However, since distortion is dimensionless and has no physical quantity, it is effective as a relative comparison such as its own change, but it is difficult to convert it into a physical quantity unless the entire molded part is calibrated in the same way as a load cell. is there. If it cannot be handled as a physical quantity, the relative comparison with other parts cannot be correlated with the “stress-strain” characteristic of the molded product, that is, compared with the molding analysis result. Further, since the present invention does not have a structure that regulates the positional relationship between the molding surfaces of the upper and lower molds, it cannot be measured when there is no object to be molded. Even when a load is applied, especially when a strain gauge is attached to the surface of the molded part, the effects of variations in the plate thickness of the molded object, and the behavior of the molded object during molding, such as material inflow during drawing, are measured. It affects both the molding and the measurement value. In particular, since protrusions and foreign matters having a size of more than a dozen [μm] cause poor quality of the appearance of the molded object, they cannot be applied to a mold for an outer plate part. In addition, the strain gauge needs to be closely integrated with the mounting part, and it is difficult to treat the molding surface and repair the strain gauge. Issues such as impact remain.

  Compared to the invention of the previous paragraph (Patent Document 1), the fitting reference block (10) of the present invention is a restricting structure that matches the positional relationship between the molding surfaces with the molding analysis result, so that measurement at no load is also possible. It is. Moreover, it has a shape that can be converted into a force [N] that is a physical quantity. In addition, the fitting reference block (10) is premised on assembling bolts to the mold as a single structure, and it is easy to perform surface treatment and repair of the mold, repair of the strain gauge, and calibration as a load cell.

  Further, the fitting reference block (10) is particularly different in concept from the conventional press-cut block. The press-cut block is a dependent result of the molding adjustment that is adjusted together with the molding adjustment, whereas the fitting reference block (10) is a structure that regulates the positional relationship between the molding surfaces and adjusts the others. It is also an indicator for. For example, in the conventional adjustment of the mating state, the slide block is moved up and down many times by using Komyotan, moldings, clay, etc., and the molding adjustment and the molding confirmation are repeated. Also adjust. On the other hand, the fitting reference block (10) according to the present invention is a positive reference for forming a restricting structure that matches the fitting push-cut state with the molding analysis result, and at the same time is an index for adjusting others. Based on the applied pressure information obtained from the combined reference block (10), the multi-point die height adjusting device and the multi-point overload protector hydraulic pressure adjusting device of the press machine can be used to lower the slide once to the bottom dead center. It is possible to make the mating cut state coincide with the molding analysis result. Thus, if this invention is used, the shaping | molding adjustment of a metal mold | die can be made efficient. In particular, in a press machine that is actually produced, a molding state that matches the molding analysis result can be realized. Therefore, molding adjustment using a conventional tri-press has no meaning and can be abolished.

  FIG. 4 is an explanatory view of a multipoint die height adjusting device, and FIG. 5 is an explanatory view of a multipoint overload protector hydraulic pressure adjusting device. In each of the LF, RF, LR, and RR sections, the fitting reference block, the die height adjuster, and the overload protector device in the same section are managed as the same group.

  The configuration of the multi-point die height adjusting device shown in FIG. The multipoint die height adjusting device is characterized in that a pair of clutches (40a) and a brake (40b) are added to the die height adjusting machine (43) as a pair to the die height adjusting machine (43). The die height adjuster (43) mainly includes a pair of worm screws (43a) and a worm wheel screw (43b), and the main body is fixed to the slide (46). The worm screw (43a) is mechanically connected to another die height adjuster (43) and a drive motor (41) by a drive shaft (44). In the present invention, the clutch (40a) is provided between the drive side of the worm screw (43a) and the drive shaft (44), and the clutch (40a) is paired on the non-drive side of the worm screw (43a). A brake (40b) is provided. For adjusting the die height, the die height adjuster (43) to be adjusted is connected to the clutch (40a) as a pair, the brake (40b) as a pair is released, and the drive motor (41) is driven to adjust the die height. A pair of worm wheel screws (43b) are rotated via a worm screw (43a) of the machine (43). The rotation of the worm wheel screw (43b) adjusts the position of the worm wheel screw (43b) with respect to the plunger rod (45) in which the worm wheel screw (43b) is incorporated. As a result, the worm wheel screw (43b) And the position of the slide (46) to which the die height adjusting machine (43) is fixed. When the adjustment of the die height is not required, the driving force of the driving motor (41) can be increased by opening the clutch (40a) as a pair of the die height adjusting machine (43) and connecting the brake (40b) as a pair. It is not transmitted to the worm screw (43a) of the die height adjuster (43), and the position of the die height adjuster (43) is held by the brake (40b), and the die height is not adjusted. With the above mechanism, the parallelism of the slide and the pressure distribution in the mold are adjusted, and a fitting push-off state that matches the molding analysis result is realized. When changing the output balance of the press machine corresponding to the uneven load in the mold, or when the parallelism of the slide exceeds the allowable value of the press machine, in addition to the multi-point die height adjustment device, the multi-point described later It is necessary to use an overload protector hydraulic adjustment device. First, the multipoint die height adjusting device will be described, and the multipoint overload protector hydraulic pressure adjusting device will be described later.

  An embodiment using a fitting reference block and a multipoint die height adjusting device, which is a feature of the present invention, will be described. Set the upper and lower molds at the bottom dead center of the slide, and set the upper and lower limits of the no-load force upper limit and lower limit values that are stored information if there is no load, with regard to the force applied to the fitting reference block (10). Value, and in the case of an actual load, it is the pressure obtained from the fitting reference block (10) in the mold, with the median upper limit value and lower limit value of the molding analysis result that is stored information as the set upper and lower limit values. Judgment is made by comparing the actual measurement value with each of LF, RF, LR, and RR sections. As a result, if the actually measured value is less than the set lower limit value, the clutch (40a) of the die height adjusting device in the section is connected, the paired brake (40b) is released, and the adjusting motor (41) is driven. Then, the die height of the section is lowered and the compression amount of the overload protector (51) is increased until the measured value of the applied pressure falls within the set upper and lower limits. If the measured value exceeds the set upper limit value, The clutch (40a) of the die height adjusting device is connected, the paired brake (40b) is released, the adjusting motor (41) is driven to raise the die height of the section, and the measured value of the applied pressure is set. The amount of compression of the overload protector (51) is reduced until it falls within the lower limit, and if the measured value is within the set upper and lower limit values, the clutch (40a) of the die height adjusting device in the section is released. And without adjusting the die height by connecting a brake (40b) forming a pair, the result causes the pressure distribution of the slide in the parallelism and the mold is consistent with forming analysis results. Then, the actual measurement value of the die height detector (42) of the multipoint die height adjusting device in a state where the applied pressure distribution matches the molding analysis result is stored and saved in the control device as a production requirement. Therefore, the control device of the press machine has a function of storing the die height setting upper limit value and lower limit value, which are allowable ranges, as the production requirements in the die height value in a state where the pressure distribution is consistent with the molding analysis result. The

  As a method for adjusting the parallelism of the slide, an individual motor system (Patent Document 2) and a hydraulic cylinder system (Patent Document 3) have been invented. In general, the die height adjustment amount is several tens to several hundreds [mm], and the allowable value of parallelism is less than 1 [mm]. However, in both inventions, long distance driving in die height adjustment other than during slide parallelism adjustment, There is no guarantee of synchronism between the adjustment axes, and the parallelism becomes unstable. In addition, expensive equipment such as motors and hydraulic devices and installation space are also required. On the other hand, in the present invention, during normal die height adjustment, all clutches (40a) are connected, all brakes (40b) are released and synchronized operation is performed, and only when adjusting the parallelism of the slide, the clutch (40a) is paired. It is possible to adjust the parallelism by operating the brake (40b). In addition, it does not require expensive equipment such as a plurality of motors and hydraulic devices, and is space-saving.

  The configuration of the multi-point overload protector hydraulic adjustment device shown in FIG. In addition, since the overload protector which is a main component of the apparatus has a hydraulic damper structure, the overload protector and the overload protector hydraulic chamber are synonymous. The multi-point overload protector hydraulic adjustment device includes an overload protector cutoff device (50) as a pair added to the overload protector (51), and the overload protector cutoff device (51) as a pair. 50), and connected to another overload protector by hydraulic piping. The overload protector shut-off device (50) basically includes a pilot operated check valve (50a) and a pilot operated valve (50b). As will be described later, the oil pressure detector (52) is used as an index at the time of setup during production using the multi-point die height adjusting device.

  An embodiment using a fitting reference block, a multipoint die height adjusting device, and a multipoint overload protector hydraulic pressure adjusting device, which are features of the present invention, will be described. The multi-point overload protector hydraulic adjuster adjusts the press machine output balance in response to the uneven load in the mold, or the multi-point die height adjustment described above when the slide parallelism exceeds the tolerance of the press machine. Used with the device. First, before the compressive force acts on the overload protector (51), for example, at the top dead center, the check function of the pilot operated check valve (50a) that is a pair of the overload protector (51) that shuts off from other sections. Is valid. Next, when the upper and lower molds are in the fitted push-off state, and the applied pressure of the fitting reference block (10) is assumed to be no load, the no-load applied pressure upper limit value and the lower limit value, which are stored information, are set as upper and lower limit values. In the case of an actual load, the pressurization median upper limit value and lower limit value, which are stored information, are set as upper and lower limit values, an actual measurement value obtained from the fitting reference block (10) in the mold, LF, Comparison is made for each section of RF, LR, and RR. As a result, if the measured value does not reach the set lower limit value, operate the die height adjustment device for the section as described in the previous section to lower the die height, and overload until the measured value of the applied pressure falls within the set range. If the amount of compression of the protector (51) is increased and the actual measured value exceeds the set upper limit value, the die height adjustment device for that section is operated as described in the previous section to raise the die height, and the measured value of the applied pressure is set. The amount of compression of the overload protector (51) is reduced until it falls within the range, and as a result, the output of the press machine, which is the reaction force of the overload protector, is adjusted point by point, and the pressure distribution in the mold is the result of molding analysis. To match. Then, in the multipoint overload protector hydraulic pressure adjusting device in a state where the applied pressure distribution matches the molding analysis result, the setting state of the check function of the pilot operated check valve (50a) and the actual measurement of the hydraulic pressure detector (52). The value is stored and stored in the control device for use as a production requirement. Accordingly, the control device of the press machine sets the check function setting state of the pilot operated check valve (50a) in the state of the multipoint overload protector hydraulic pressure adjusting device in a state where the pressure distribution is consistent with the molding analysis result. And the actual load output upper limit value and lower limit value that are the allowable range of overload protector hydraulic pressure are stored as production requirements. In addition, under the condition of a die height that realizes the pressure distribution that matches the molding analysis results, the overload protector hydraulic adjustment device at the time of no load without molding is used as a production requirement for production setup. The measured value of the hydraulic pressure detector (52) is also stored and saved in the control device. Therefore, the control device of the press machine has the no-load output upper limit value and the lower limit that are the allowable range of the overload protector hydraulic pressure when there is no load under the setting state of the die height that realizes the fitting push-off state that matches the molding analysis result. The value also has a function to memorize as production requirements. In addition, there is no technical regulation regarding the relationship between the excited state of the pilot operated valve (50b) and the check function of the pilot operated check valve (50a) as the operation mode of the pilot operated valve (50b). In an environment where the check function is frequently used, the check function of the pilot operated check valve (50a) is enabled when the pilot operated valve (50b) is demagnetized. Conversely, in an environment where the check function is not frequently used, Although it is reasonable to disable the check function of the pilot operated check valve when the pilot operated valve is demagnetized, it is not a necessary condition.

  Similar forms (Patent Document 4 and Patent Document 5) have been invented for adjusting the hydraulic pressure of the overload protector device. Both of the inventions require a hydraulic device that actively adjusts the hydraulic pressure at the pressurizing point, adding a high-priced hydraulic pressure generating and adjusting device, or having a higher function than conventional ones. On the other hand, the present invention is a simple method for passively adjusting the hydraulic pressure using a multi-point die height adjusting device, and does not require the addition of a high-priced hydraulic device or the enhancement of functionality.

  The form of forming confirmation at the time of production using the fitting reference block, the multi-point die height adjusting device and the multi-point overload protector hydraulic pressure adjusting device, which is a feature of the present invention, will be described. Forms for forming confirmation at the time of production include a form for matching the fitting / cut-off state at the time of production with the result of the forming analysis, and a form for quality confirmation during production.

  As a form to match the mating press-cut state during production with the molding analysis result, when fitting a mold during production setup, the mating press-cut state is matched with the molding analysis result to achieve stable production quality. . In the conventional mold mounting, only the die height of the entire slide is adjusted at the top dead center, and the consistency with the molding analysis result is not confirmed. The control device for the press machine of the present invention includes a die height setting upper limit value and lower limit value in each of the LF, RF, LR, and RR sections that can obtain a molding result, that is, a fitting and cutting state that matches the molding analysis result, Point overload protector hydraulic adjustment device pilot operation check valve (50a) check function enable / disable setting state and overload protector hydraulic no-load output pressure upper limit at the time of mating push-off without load Value and lower limit value, and the no-load pressure upper limit value and lower limit value of all mating reference blocks are stored and stored as production requirements, and at the top dead center, a multipoint die height adjusting device Use the multi-point overload protector hydraulic adjustment device to adjust the die height of each of the LF, RF, LR, and RR sections, and to block the overload protector. Blocked In the bottom dead center, with a fitting reference block and multi-point die height adjusting device and the multi-point overload protector hydraulic adjustment device, to realize the pressurizing force distribution consistent with forming analysis results.

  Specifically, first, at the top dead center just before the mold is mounted, the die heights of the LF, RF, LR, and RR sections are measured for each section, and the measured values of the die height detector (42 in FIG. 4) and the die height setting upper limit value. If the measured value exceeds the set upper limit value, the die height of the section is lowered using the multi-point die height adjustment device, and the measured value does not reach the set lower limit value. Uses a multi-point die height adjusting device to raise the die height of the section and adjust the die heights of all sections within the upper and lower limits. In addition, whether the check function of the pilot check valve (50a in FIG. 5) of the multi-point overload protector hydraulic regulator of each section is valid or invalid is set to a state that matches the production requirements.

  Next, the slide is lowered to the bottom dead center to be in the fitted push-off state, and the no-load output pressure upper limit value and lower limit value, which are stored information, are set in the overload protector in each of the LF, RF, LR, and RR sections. Compared with the actual value of the overload protector's oil pressure detector (52 in FIG. 5), if the actual value exceeds the set upper limit value, use the multi-point die height adjustment device to The die height is increased until it falls within the no-load output pressure upper / lower limit value. If the measured value is less than the set lower limit value, the measured value falls within the no-load upper / lower limit value using a multipoint die height adjustment device. Lower the die height until Further, in this state, the no-load applied pressure upper limit value and the lower limit value of each fitting reference block of the production requirements that are stored information are set as upper and lower limit values, and the pressure is obtained from the fitting reference block (10). Compare the actual measurement value with each management number of the mating reference block.If the actual measurement value exceeds the set upper limit value, the management number of the mating reference block and the die height excessive descent warning are output. When the set lower limit value is not reached, a management number of the fitting reference block and a die height descent deficiency warning are output. If the measured value is within the set upper and lower limits, a normal mounting signal at the time of setup is output.

  Of the form confirmation forms during production, the form of quality confirmation during production will be described. In the quality inspection at the time of production, the mating press-cut state is compared with the molding analysis result, and automatic quality inspection is realized. The control device for a press machine according to the present invention includes a molding margin pressure upper limit value and a lower limit value, and upper and lower limits of molding margin pressure when molding a molding, for all fitting reference blocks (10). Measured value that has the function of storing and storing the median upper limit value and lower limit value of the central range for each mold as production requirements, and is the pressure obtained from these production requirements and the fitting reference block (10) And automatically inspecting the molding quality during production.

  Specifically, during the production operation of the press machine, the actual value that is the applied pressure obtained from all the fitting reference blocks (10) and the upper and lower limits of the molding allowance pressing force of the production requirements that are stored information are the fitting criteria. Compared to each block control number, if the measured value exceeds the upper limit of the molding allowance pressure, the control number of the fitting reference block and an over-pressurization alarm are output, and the measured value is assumed to be the molding margin pressure If the lower limit value is not reached, the control number of the fitting reference block and the insufficient pressurization alarm are output. Also compare with the median upper / lower limit value of the pressure in the middle range of the upper / lower pressure value. As a result of comparison, if it is within the upper and lower limits of the pressurizing force, the molding state is judged to be good, and if the upper limit of the pressurizing force is exceeded, the control number of the fitting reference block and the overpressurization warning are displayed. If it is less than the pressurization median lower limit value, the management number of the fitting reference block and the insufficient pressurization warning are output.

  The fitting reference block can be applied to general press molding using a mold.

  The multipoint die height adjusting device and the multipoint overload protector hydraulic pressure adjusting device can be applied to a press machine having two or more points.

10 Fitting reference block 10a Upper surface of fitting reference block (upper mold contact surface)
10b Fitting reference block measuring section 10c Fitting reference block mounting section 11 Strain gauge 12 Converter (function) from strain gauge signal to applied pressure
21 Upper mold (block with molding surface)
21a Positive molding surface of upper mold (positive reference)
21b Secondary molding surface of upper mold 22 Lower mold (block having molding surface)
22a Positive molding surface of lower mold (positive reference)
22b Secondary mold secondary molding surface 23 Molded object 40a Clutch 40b Brake 41 Motor 42 Die height detector 43 Die height adjusting device 43a Worm screw 43b Worm wheel screw 44 Drive shaft 45 Plunger rod (screw part)
46 Slide 50 Overload protector shut-off device 50a Pilot operated check valve 50b Pilot operated valve 51 Overload protector (hydraulic chamber)
52 Oil pressure detector

Claims (6)

  A fitting reference block fixed to either the upper or lower mold fitting surface, that is, either the upper surface of the lower mold or the lower surface of the upper mold. Area accuracy that can be formed as a contact reference that is in one-to-one relationship with the standard for the upper and lower molds, restricts the molding surface of the upper and lower molds to a positional relationship that matches the molding analysis result, and converts the vertical strain into a pressure force between the upper and lower molds A fitting reference block characterized by comprising a structure body having a strain gauge attached to a side surface of the structure body.   In a press machine having two or more pressurization points, a pair of clutches and brakes are arranged as a pair on each die height adjuster at each pressurization point. A multi-point die height adjusting device characterized in that a die height adjusting machine can be individually adjusted.   In a press machine having two or more pressurization points, a pilot operated check valve is arranged as a pair of the overload protector hydraulic chambers in each of the overload protector hydraulic chambers at all pressurization points. The overload protector hydraulic chamber is shut off from other hydraulic chambers by enabling the check function of the valve, the compression amount of the overload protector hydraulic chamber is adjusted using the multipoint die height adjusting device according to claim 2, and a press machine A multi-point overload protector hydraulic pressure adjusting device characterized in that the pressurizing force at each pressurizing point can be adjusted.   A press machine having two or more pressurizing points having the fitting reference block according to claim 1, the multi-point die height adjusting device according to claim 2, and the multi-point overload protector hydraulic adjusting device according to claim 3. A press machine having an interface function capable of receiving a strain gauge signal from the strain gauge of the fitting reference block.   5. The control device used in the press machine according to claim 4, wherein the strain gauge signal of the strain gauge of the fitting reference block is converted into a pressurizing force, and the pressurizing force is made to coincide with the pressurizing force of the molding analysis result. And adjusting the multi-point die height adjusting device and the multi-point overload protector hydraulic pressure adjusting device.   A press mold forming confirmation method using the control device according to claim 5, wherein the applied pressure obtained by converting the strain gauge signal of the strain gauge of the fitting reference block is expressed as a molding analysis result. A method for confirming molding of a press die, wherein the multi-point die height adjusting device and the multi-point overload protector hydraulic pressure adjusting device are adjusted so as to coincide with a pressing force.

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