JP6932882B2 - Multi-point overload protector hydraulic regulator for press machines - Google Patents

Description

The present invention relates to a press machine that realizes an analysis result in processing using a press die in the manufacture of stamped parts of an automobile, and a method for confirming molding of the die using the machine.

Press dies (hereinafter referred to as dies) that produce stamped parts for automobiles are designed and manufactured using analysis technology using electronic computers and NC processing, but in reality, molding results that match the analysis results are obtained. Instead, a skilled technician judges the molding result and corrects the mold as molding adjustment.

Mold analysis technology is roughly divided into two types: molding analysis and structural analysis (also called rigidity analysis). The molding analysis is mainly the plastic deformation analysis of the non-linear region based on the "stress-strain" characteristic of the object to be molded, and on the premise that the pressing force received by the die from the press machine is uniform, the intended plastic deformation is achieved. Determine the shape surface on which the required pressing force and deformation amount can be applied to the object to be molded. In the structural analysis, a structure having rigidity that does not affect the molding is analyzed and determined with respect to the pressure distribution of the molding analysis result.

Mold molding adjustment work is performed by checking and measuring the actual molding result, the surface contact state using Komeitan, pressure measurement film, etc., and the gap between the upper and lower molded surfaces using fuse, clay, etc. A skilled technician estimates the state at the time of molding and corrects the mold. Since these adjustment tools do not quantitatively indicate the adjustment range and the adjustment amount, the technician makes his / her own judgment based on his / her skill and experience. For this reason, the correction policy differs for each technician, but it is common to repeat correction and confirmation many times. Before the actual production starts, immediately after the mold assembly is completed, molding adjustment is performed many times with a mold molding adjustment press called a tri-press, and after that, molding confirmation and adjustment are performed on the production line. Therefore, it takes a long time to adjust the molding of the mold. With the development of measurement technology in recent years, a method of measuring the shape of a molded part of a molded product and a mold and re-executing the molding analysis based on the result to adjust the mold is also performed. Although this method is effective in alleviating the shortage of skilled technicians and the difference in ability between technicians, it has not dramatically improved the initial quality of molds, that is, molding.

In the molding adjustment by a technician, in addition to adjusting the shape of the molded surface, the positional relationship between the upper and lower molds is also adjusted in consideration of the variation in the thickness of the object to be molded. To adjust the positional relationship of the upper and lower molds, a push-cut block that prevents excessive pressing and determines the positional relationship of the upper and lower molded surfaces is used in a state where the upper and lower molds are completely pressed. This push-cut 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 instead of Komeitan or a pressure measuring film, a method of measuring strain by attaching a strain gauge to the molding surface or the inside thereof (Patent Document 1) has been invented. However, since the strain is dimensionless and has no physical quantity, it is effective as a relative comparison such as its own progress, but in order to make a relative comparison with others, it is necessary to convert it to a physical quantity. , There are many problems in practical use.

The die height adjusting device and the overload protector device of the press machine, which are the main devices involved in molding, will be described. In the following description, the most common 4-point press machine in the production site of automobile press parts, that is, a press machine in which slides are connected to a drive device by four plunger rods will be taken as an example.

The die height adjusting device will be described. The die height adjusting device is a device that adjusts the die height of the press machine, that is, the push-cut height of the die from the upper surface of the bolster plate (or bed) to the bottom surface of the slide at the bottom dead center of the slide. The die height adjusting device mechanically connects all the die height adjusting machines assembled for each plunger rod and operates synchronously with one motor. The die height adjuster is composed of a worm screw and a worm wheel screw as a pair. The worm screw is mechanically connected to the drive motor with another die height adjuster, the worm wheel screw is assembled to the plunger rod, and the die height adjuster body is fixed to the slide. The worm wheel screw is rotated by the worm screw to adjust its position with respect to the plunger rod, which raises and lowers the slide position to which the slide adjuster is fixed and adjusts the die height.

The relationship between die height and slide parallelism will be described. Generally, the die height adjustment amount is several tens to several hundreds [mm], and as described in the previous section, one motor is mechanically synchronously operated. The slide parallelism is determined by the assembled state of the die height adjuster and cannot be adjusted arbitrarily. Since slide parallelism affects molding, it is established by JIS as part of the accuracy grade. Press machines for automobile press parts are usually JIS grade 1 grade, and for example, a slide parallelism tolerance of a die space length of 4 [m] is 0.44 [mm]. As an example of the effect of slide parallelism on the mold, if the parallelism deviates from the permissible value when driving the die height adjustment device at bottom dead center, a regulating part such as a guide that regulates the horizontal positional relationship of the upper and lower molds. This causes interference problems. 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 the allowable value even during the die height adjusting operation.

In some press machines, as a method of adjusting the parallelism of slides, a method of independently adjusting each die height adjusting machine 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 to keep the parallelism within the permissible value in the process of adjusting the die height. Further, the individual motor system (Patent Document 2) requires a large installation space. The hydraulic cylinder method (Patent Document 3) has a complicated structure and has an overload protector device with an active expansion / contraction function. Etc., more advanced control is required.

Further, in recent years, a servo press, commonly known as a servo press, which uses a servo motor as a drive source of a press machine, has been put into practical use. It is stopped. Also in this form of servo press, as in the method of adjusting independently by individual motors (Patent Document 2), there is a problem that the synchronization is unstable and the parallelism is maintained during operation. In addition, both the bottom dead center position itself and the parallelism at the bottom dead center position have accuracy differences for each 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 regarding parallelism.

The overload protector device will be described. There is a hydraulic chamber called an overload protector directly under each plunger rod, which is the pressurizing point of the press machine. The overload protector (hydraulic chamber) has a mechanism equivalent to that of a hydraulic damper, and only generates a reaction force due to compression when pushing off at bottom dead center, and does not have an active expansion / contraction function. In the overload protector device, all the overload protector hydraulic chambers are connected by hydraulic pipes, and common oil pressure is supplied. When overload occurs, this oil supply is stopped, the oil 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 adjusting device, and sets the die height (slide height at bottom dead center) of the press machine lower than the die height of the die (height at the time of pushing the upper and lower molds). As a result, the overload protector is compressed at bottom dead center and a reaction force is generated, and this reaction force is the pressing force of the press machine. Generally, a press machine is regarded as a general-purpose machine, and is designed on the assumption that a uniform pressing force is generated on a die. The source is also the same, and the pressing force, which is the reaction force of all overload protectors, is equal regardless of the amount of compression.

As a similar invention for adjusting the hydraulic pressure of the overload protector device, a parallelism adjusting device using an 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 oil pressure at the press pressure point. Since both inventions are active hydraulic adjustment methods, they require an expensive hydraulic device, and the viscosity of the hydraulic pressure varies greatly depending on the temperature change and the amount of compression, and high-precision control is required.

The above is the technical background before shifting to actual production, from mold manufacturing 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 molding 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 die, it is necessary to confirm and adjust the molding again.

Japanese Unexamined Patent Publication No. 2010-115702 Japanese Unexamined Patent Publication No. 2001-121297 Japanese Unexamined Patent Publication No. 2010-131620 Japanese Unexamined Patent Publication No. 2001-71198 Japanese Unexamined Patent Publication No. 2009-178726

In actual press molding using a mold designed and manufactured using analysis technology and NC processing, molding results that match the analysis results cannot be obtained. The main reason for this is that factors that are simplified or simplified in the analysis technique, that is, factors such as the difference in accuracy of the press machine and the die, actually affect the molding. Quantitative factor analysis on the influence of these factors on molding is also insufficient, and the analysis technique for this part has not been established. In addition, the return of the molding result to the analysis technique is incomplete, and the improvement in the performance of the analysis technique is limited. Based on the above, the present invention provides a means for detecting the actual state of molding that can be compared with the analysis technique including preconditions and calculation processes, and eliminates or minimizes the molding influencing factors of the press machine and the die by using the means. The challenge is to provide a means of conversion.

The fitting reference block of the present invention is fixed to the upper and lower fitting surfaces of the upper and lower molds, 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 at the time of fitting the upper and lower molds is formed positively. By forming as a contact standard associated with the standard of 1 to 1, the molding surface of the upper and lower dies can be regulated to a positional relationship that matches the molding analysis result, and the longitudinal strain between the upper and lower dies can be converted into pressing force. A structure with area accuracy is formed, a strain gauge is attached to the side surface of the structure, and this fitting reference block is placed at a key point in the mold. It is characterized in that the positional relationship of the molding surface is regulated so as to match the molding analysis result, and the pressing force distribution is used as an index to match the molding analysis result.

The multi-point die height adjusting device of the present invention aims to realize a fitting push-off state that matches the molding analysis result by eliminating or minimizing the molding influence factor of the press machine and the die, and is a fitting reference. The measured value, which is the pressing information obtained from the block, is compared with the set value, which is the molding analysis result of the pressing force of the fitting reference block portion. Connect the clutch of only the die height adjuster of the part, 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, and tentatively, the measured value For parts where is higher than the set value, similarly, it has the function of driving only the necessary parts using the operation of the clutch, brake and motor, and raising the die height until the measured value falls within the allowable range of the set value. It is characterized by.

The purpose of the multi-point overload protector hydraulic regulator of the present invention is to eliminate or minimize the influence of the molding influence factor of the press machine and the mold, and to realize the fitting push-off state that matches the molding analysis result. When changing the output balance of the press machine in response to an eccentric load, the measured value, which is the pressing force information obtained from the fitting reference block, and the set value, which is the molding analysis result of the pressing force of the fitting reference block portion. The overload protector is shut off from other hydraulic chambers by enabling the check function of the pilot-operated check valve that is paired with the overload protector that needs to be changed, and the die height of the overload protector section is described above. Using a regulator, if pressure increase is required, the die height is lowered until the measured value matches the allowable range of the set value, and if decompression is required, the measured value is within the allowable range of the set value. It is characterized by using a pilot-operated check valve having an adjusting function of raising the die height until it enters and matching the pressure distribution in the mold with the molding analysis result.

The press machine of the present invention is a press machine having two or more pressurizing points having the fitting reference block, the multipoint die height adjusting device, and the multipoint overload protector hydraulic adjusting device, and the fitting. It is characterized by having an interface function that can receive 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, converts the strain gauge signal from the strain gauge of the fitting reference block into a pressing force, and applies the pressing force to the pressing force as a result of molding analysis. It is characterized in that the multi-point die height adjusting device and the multi-point overload protector hydraulic adjusting device are adjusted so as to match the pressure.

Specifically, the control device of the present invention assigns a control number corresponding to each fitting reference block to the fitting reference block, and the control number and the control number from the strain gauge are described for each control number. At the time of actual load, which is used as a set value at the time of molding adjustment and molding quality confirmation in the conversion coefficient that converts the strain gauge signal into the pressing force and the pressing force of the molding analysis result or all the fitting reference blocks measured by the pressing machine. Molding margin pressure upper and lower limit values, and those molding margin pressure upper and lower limit values in the central range of pressure center upper and lower limit values, and used as set values during molding adjustment and mold setup, when there is no load No-load pressurization upper limit and lower limit, and all pressurization points when the pressurization distribution under actual load, which is also used as a set value at the time of molding adjustment and molding quality confirmation, matches the pressurization distribution of the molding analysis result. The die height setting upper limit value and lower limit value obtained from the measured values of the multi-point die height adjusting device, the setting state of the check function of the pilot-operated check valve of all the multi-point overload protector hydraulic regulators, and the above-mentioned many. Overload protector hydraulic pressure of all pressurization points at both actual load and no load when the point die height adjuster has a die height value that matches the pressurization distribution under actual load with the pressurization distribution of the molding analysis result. It has a function to store the actual load output upper limit value and lower limit value and the no-load output upper limit value and lower limit value obtained from the measured values for each mold as production requirements, and also has the strain gauge of the fitting reference block. Has a calculation function of converting the strain gauge signal from the above into a pressing force for each control number corresponding to the fitting reference block, and at the time of production, from the strain gauge of all the fitting reference blocks. The measured value, which is the pressing force obtained by converting the strain gauge signal of the above, is compared with the upper and lower limit values of the forming margin pressurization of the production requirement, which is the stored information, for each control number corresponding to the fitting reference block. If the measured value exceeds the molding margin pressurization upper limit value, the control number of the fitting reference block and the overpressurization alarm are output, and if the measured value is less than the molding margin pressurization lower limit value, the relevant fitting reference block is output. The control number of the mating reference block and the insufficient pressurization alarm are output, and if the measured value is within the upper and lower limit values of the molding margin pressurization, the central range of the upper and lower limit values of the molding margin pressurization of the production requirement, which is stored information. If the measured value is within the central upper and lower limit of the pressing force, the molding state is judged to be good, and if the measured value exceeds the upper and lower limit of the central pressing force, the fitting is concerned. Criteria It has a function to output the control number of the block and the overpressurization warning, and if the measured value is less than the central lower limit of the pressing force, the control number of the mating reference block and the underpressurization warning are output. In addition, when mounting the mold, at the top dead point immediately before mounting, the measured values, which are the die height values of all the die height adjusters of the multipoint die height adjusting device, are set as the die height of the production requirement, which is stored information. Compared with the upper and lower limits individually, if the measured value is lower than the die height setting lower limit, the die height is increased, and if the measured value is higher than the die height setting upper limit, the die height is lowered to lower the die height setting upper and lower limits of the production requirement. Adjust within the value, and set the enable or disable of the check function of the pilot-operated check valve of the multi-point overload protector hydraulic regulator to match the production requirements that are stored information, and when installed. At the bottom dead point, the measured values, which are the hydraulic values of all the overload protectors of the multipoint overload protector hydraulic regulator, are individually compared with the no-load output pressure upper and lower limit values of the production requirements, which are stored information. If the measured value exceeds the no-load output pressure upper limit value, the paired die height is increased until the overload protector hydraulic pressure is within the set range, and the measured value is less than the no-load output pressure lower limit value. In this case, similarly, the paired die height is lowered until the overload protector hydraulic pressure is within the set range, and if the measured value is within the set range, the strain gauge from the strain gauge of the fitting reference block is further lowered. The pressing force obtained by converting the signal is used as the measured value, and it is compared with the upper and lower limit values of the no-load pressing force, which is a production requirement. The block control number and die height excessive descent alarm are output, and if the measured value is less than the no-load pressure lower limit value, the control number of the mating reference block and die height descent insufficient alarm are output, and the measured value is tentatively set. When it is within the upper and lower limit values of no-load pressing force, which is a production requirement, it is characterized by having a function of outputting a normal mounting signal.

The press die molding confirmation method of the present invention is a press die molding confirmation method using the control device, and is obtained by converting the strain gauge signal of the strain gauge of the fitting reference block. It is characterized in that the multipoint die height adjusting device and the multipoint overload protector hydraulic adjusting device are adjusted so that the pressing force matches the pressing force of the molding analysis result.

The molding state of the press die can be matched with the molding analysis result. For example, according to the present invention, it is possible to shorten the period by correcting the influence of the accuracy difference between the press machine and the die and eliminating the need for the die adjustment process by the tripress immediately after the die is manufactured.

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 factors only for the analysis technology that eliminates the influence of the accuracy difference between the press machine and the die. , The performance of analysis technology is improved.

Effective utilization of human resources becomes possible as a secondary spillover effect. Conventionally, a skilled person with a certain level of skill and years of experience has been required for mold adjustment even after the start of mass production. According to the present invention, the molding state can be numerically controlled, so that most of the work of a skilled worker can be performed on behalf of the worker. Therefore, it is possible to shift skilled workers from conventional follow-up work to pre-emptive work such as mold making and molding process innovation.

It is explanatory drawing of the fitting reference block. It is explanatory drawing which showed the fitting push-off state of the upper and lower type for demonstrating the function of the fitting reference block. It is explanatory drawing which showed the arrangement example of the fitting reference block. It is explanatory drawing of the multi-point die height adjustment apparatus in a 4-point press machine. It is explanatory drawing of the multi-point overload protector hydraulic control device in a 4-point press machine.

Analysis techniques in mold design include molding analysis and structural analysis. The molding analysis analyzes and determines the molding shape in which the pressing force and the amount of deformation required for the intended plastic deformation can be applied to the object to be formed based on the "stress-strain" characteristic of the object to be formed. This molding shape has a molding surface having a shape that serves as a "mold" that determines the amount of deformation that realizes the intended shape with respect to the object to be molded, and the required stress that causes the object to be molded to follow the "mold". The molding surface for applying the above is paired with the object to be molded sandwiched between them. The structural analysis determines a structure having sufficient rigidity that does not affect molding against both the pressing force from the press machine required for molding and the molding load in the die. In the mold manufactured by using both the molding and structure analysis techniques and NC processing, the actual molding result does not match the analysis result. This cause is caused not only by the performance of the analysis technology but also by the difference in the accuracy of the press machine and the difference in the manufacturing accuracy of the die. Therefore, in order to obtain a molding result that matches the analysis result, the factors that affect the molding result are separated into a factor related to the performance of the analysis technology and a factor related to the press machine and the die, and the latter other than the analysis technology. It is necessary to eliminate the influence or minimize the influence to the extent that the influence can be ignored. There is a need for means to eliminate or minimize the molding influencing factors of the mold. Variations in shape and stress characteristics such as the thickness of the object to be molded should be included as part of the performance of the analysis technology 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 used as the positive molding surface as the positive reference (plane), the object to be molded is aligned with the "mold", and the necessary stress is applied. The molding surface to be formed is used as a 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 both molding surfaces are performed in the pressurized state during press molding, that is, in the upper and lower mold fitting and pressing state. Both pressure distributions need to match the molding analysis results. Based on the above, the fitting reference block of the present invention is used as a means for regulating the positional relationship between both the positive and secondary molding surfaces and measuring the pressure distribution between both molding surfaces under the fitting push-off state. 10) is used.

Regarding the structure of the fitting reference block (10), an explanatory view of the fitting reference block (10) of FIG. 1 and an explanatory view of a vertical fitting push-off state using the fitting reference block (10) of FIG. It will be described using and. The fitting reference block may be attached to either the upper or lower die, but the description will be made on the premise that the fitting reference block is attached to the lower die having good setup such as processing of wiring for pressure measurement. The fitting reference block (10) shown in FIG. 1 faces the positive molding surface (21a, 22a) and the object to be molded (23) in the upper and lower fitting push-off state shown in FIG. It is a structure that regulates the positional relationship of the molding surface (22b for 21a and 21b for 22a) so as to match the molding analysis result. Therefore, both the upper surface (10a) of the fitting reference block and the contact surface of the upper mold in contact with the upper surface (10a) are defined as the contact reference at the time of fitting associated with the positive reference of molding one-to-one, and molding is performed. It is formed as a fitting reference plane by analysis. Specifically, if positive molding surfaces (21a, 22a) are present in the upper and lower molds, the positional relationship between the two molds matches the molding analysis result, and only one of the upper and lower molds has a positive molding surface (21a, 22a). Even if 21a or 22a) does not exist, the secondary molding surface (22b for 21a and 21b for 22a) facing the positive molding surface (21a or 22a) is restricted to a positional relationship that matches the molding analysis result. It is analyzed as a possible, accuracy-guaranteed fitting reference (face) associated with a positive reference (face) on a one-to-one basis. As an example of means for guaranteeing the accuracy of the fitting reference surface, after assembling the fitting reference block, machining is performed as a fitting reference surface associated with a positive reference of molding on a one-to-one basis.

The fitting reference block (10) is also used as a means for measuring the pressure distribution between both the positive and secondary forming surfaces. The fitting reference block (10) is composed of a bolt mounting portion (10c) 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 flat, and the upper surface (10a) and the side surface of the measuring portion (10b) are perpendicular to each other. In addition, the area accuracy of the cross section parallel to the upper surface (10a) of the fitting reference block in the measuring unit (10b) is guaranteed. The strain gauge (11) is attached to the side surface of the area-guaranteed measuring unit (10b) so as to measure the longitudinal strain in the direction perpendicular to the upper surface (10a) of the fitting reference block. When mounting the fitting reference block (10) into the mold, the mounting portion (10c) is bolted so that the upper surface (10a) of the fitting reference block (10) always receives the pressing force vertically. For example, if the pressing force is vertical, the upper surface of the fitting reference block (10a) is horizontal, and if the pressing force is horizontal, the upper surface of the fitting reference block (10a) is vertical. Is installed so that the direction of is perpendicular to the upper surface (10a) of the fitting reference block. Since the movable direction of the molded surface coincides with the direction of the pressing force and the movement is regulated by the guide structure against lateral displacement, the fitting reference block (10) is relative to the upper surface (10a) of the fitting reference block. It is only necessary to regulate the positional relationship in the vertical direction, which is the direction of pressing force.

Since the output signal ε of the strain gauge (11) is dimensionless, it is converted into a physical quantity force [N] and compared with the molding analysis result. Multiply the elastic modulus [Pa] of the measuring part (10b) of the fitting reference block and the horizontal cross section [m ² ], or calibrate the fitting reference block (10) as a load cell and force it as a physical quantity [N]. Treat as. There are no restrictions on the material of the mating reference block except for the load resistance and the uniformity of the elastic modulus. If it is made of general steel, the elastic modulus of the steel material is about 206 GPa (201 to 206 GPa for mild steel). If the manufacturing accuracy of the horizontal cross-sectional area of the fitting reference block is controlled, the pressing force can be measured with an accuracy of 5% or less without 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 a pressing force and comparing it with the pressing force distribution of the molding analysis result. Specifically, the product of the control number assigned to the fitting reference block (10) and the product of the elastic modulus and the horizontal cross-sectional area for each control number, or the calibration coefficient as a load cell is converted into a strain gauge signal to be pressed. As a coefficient, it has a function to store each mold as a production requirement. In addition, each control number also has a calculation function (12) of FIG. 1 for converting into a pressing force using a strain gauge signal (11) corresponding to the conversion coefficient. For each control number, the pressing force actually obtained from the fitting reference block (10) is compared with the molding analysis result of the pressing force on the fitting reference block (10), and the pressing force at the time of fitting push-off is compared. Detect and judge the distribution. Therefore, the fitting reference block (10) of the present invention is used as a means for detecting the actual state of molding, and the multi-point die-height device and the multi-point overload protector hydraulic adjustment device, which will be described later, are used to eliminate the molding influencing factors of the press machine and the die. Alternatively, it is used as a means for minimizing the influence, and the fitting and pressing state is made to match the molding analysis result.

If the intended molding result cannot be obtained even if the fitting and pressing state between the upper and lower molding surfaces matches the molding analysis result, there is a problem with the performance of molding analysis, structural analysis, or both analysis techniques. Therefore, both the distribution of the pressing force obtained from the fitting reference block (10) and the actual molding result are returned to the analysis technique. The above-mentioned "method of measuring and comparing the shape of the molded portion of the molded product and the die" includes the influence of the accuracy difference between the press machine and the die, and has not reached the 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 factors of the analysis technique excluding the influence of the accuracy difference of the press machine. If the fitting and pressing state between the upper and lower molding surfaces does not match the molding analysis result and the measured pressure value partially does not reach the allowable lower limit of the design pressure, the die is machined or assembled. If there is a manufacturing defect at the time of attachment, or the rigidity in the vicinity of the insufficient pressurization part is insufficient, and the measured pressurization value exceeds the allowable upper limit of the design pressurization, when processing or assembling the mold. There is a manufacturing defect or insufficient rigidity other than in the vicinity of the insufficiently pressurized part. If the rigidity is insufficient, the measured value of the pressing force distribution obtained from the fitting reference block is returned to the structural analysis. As described above, since the feedback data of the present invention is of good quality limited to the factors of the analysis technique and is the numerical data of the "force" comparable to the "stress-strain", it also contributes to the improvement of the analysis technique. ..

A mode in which the fitting reference block (10) is used will be described with reference to an arrangement example of the fitting reference block of FIG. The symbols LF, RF, LR, and RR in FIG. 3 are divided into four parts in front, back, left, and right at the center of the press machine in a four-point press machine including the following FIGS. 4 and 5, and each point is divided into four points. That is, the section corresponding to the pressurizing point is matched with the name of the press machine, and LF = left front, RF = right front, LR = left rear, RR = right rear. The mating reference block (10) uses a multi-point die height adjusting device and a multi-point overload protector hydraulic adjusting device, which will be described later, to eliminate or minimize the influence of factors affecting the molding of the press machine and the die. Since it is also an index, it is arranged in all the compartments so as to be an adjustment index of the compartments at each pressurization point of LF, RF, LR, and RR. In addition, the positional relationship between the positive and secondary molding surfaces is arranged in a well-balanced manner so as to maintain stability at the time of fitting and pushing. Regarding the mounting position, the fitting reference block (10) interferes with the object to be molded, assuming that the structure of the mold having the molding surface has sufficient rigidity that does not affect the molding in the structural analysis. It is not necessary to arrange it in the molding surface, and it is arranged in the vicinity of the molding surface that does not interfere with the object to be molded. Rather, it is desirable that the vicinity of the molded surface does not interfere with the object to be molded so as not to be affected by the variation in the thickness of the object to be molded. However, this does not apply if the pressing structure is formed by a spring function such as a cushion pad or a presser pad and does not affect the flow of the object to be molded. If a large number of fitting reference blocks (10) are placed in the vicinity of the molding site where priority management is particularly required, and if the fitting reference blocks (10) are calibrated and used in the same manner as the load cell, the accuracy of molding management can be improved. It is possible.

When using the fitting reference block (10), a control number is assigned to all the fitting reference blocks (10), and the control device of the press machine performs molding analysis or molding analysis for each control number and the control number. The upper and lower limits of the forming margin pressurization at the time of loading to mold the object to be molded, the central upper limit and lower limit of the pressurization margin in the central range of the upper and lower limit values of the forming margin, and further. It has a function to store the upper limit value and the lower limit value of the no-load pressing force in the allowable range of the mating push-off state at the time of no load in the control device of the press machine as a production requirement for each die. If these values do not match the molding analysis result in the pressure distribution at the time of fitting the upper and lower molds or the actual molding result, the actual pressure distribution obtained from the fitting reference block is used for the molding analysis or structure. Return to the analysis, improve the performance of the analysis technology, recalculate and 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 strain is dimensionless and does not have a physical quantity, it is effective as a relative comparison such as its own progress change, but it is difficult to convert it to a physical quantity unless the entire molded part is calibrated in the same way as a load cell. be. If it is not treated as a physical quantity, the relative comparison with other parts cannot be associated with the "stress-strain" property of the object to be molded, that is, it cannot be compared with the molding analysis result. Further, since the present invention does not have a structure that regulates the positional relationship between the upper and lower molded surfaces, measurement is not possible when there is no object to be molded and no load is applied. Even under load, especially when the strain gauge is attached to the surface of the molded part, the influence of the variation in the plate thickness of the object to be molded and the behavior of the object to be molded such as the inflow of material in draw forming are measured. It interacts with both moldings and affects the measured values. In particular, protrusions and foreign substances having a size of more than a dozen [μm] deteriorate the appearance of the object to be molded, and therefore cannot be applied to molds for outer plate parts. In addition, the strain gauge must be tightly integrated with the mounting part, making it difficult to surface-treat the molded surface and repair the strain gauge, and when mounting inside, the rigidity of the molded surface due to the mounting space Issues such as impact remain.

In contrast to the invention of the preceding paragraph (Patent Document 1), the fitting reference block (10) of the present invention is a regulated structure that matches the positional relationship between the molding surfaces with the molding analysis result, so that measurement under no load is possible. Is. It also has a shape that can be converted into a force [N], which is a physical quantity. In addition, the fitting reference block (10) is premised on bolt assembly to the mold as a single structure, and surface treatment and repair of the mold, repair of strain gauges, and calibration as a load cell are easy.

Further, the fitting reference block (10) is particularly ideologically different from the conventional push-cut block. Whereas the push-cut block is a dependent result of the forming adjustment that is adjusted with the forming adjustment, the fitting reference block (10) is a structure that regulates the positional relationship between the forming surfaces and adjusts others. It is also an index for. For example, in the conventional adjustment of the mating state, Komeitan, the object to be molded, clay, etc. are used to raise and lower the slide many times, and the molding adjustment and molding confirmation are repeated, and each time, the push-cut block is used as part of the molding adjustment. Also adjust. On the other hand, the fitting reference block (10) of the present invention is a positive reference forming a regulation structure that matches the fitting push-off state with the molding analysis result, and at the same time, it is also an index for adjusting others. Based on the pressurizing information obtained from the reference block (10), by using the multi-point die-height adjustment device and the multi-point overload protector hydraulic adjustment device of the press machine, the slide can be fitted by simply lowering it to the bottom dead point. It is possible to match the push-cut state with the molding analysis result. As described above, according to the present invention, the molding adjustment of the mold can be made more efficient. In particular, in a press machine that is actually produced, a molding state that matches the molding analysis result can be realized, so that molding adjustment using a conventional tri-press becomes meaningless and can be abolished.

FIG. 4 shows an explanatory diagram of a multi-point die height adjusting device, and FIG. 5 shows an explanatory diagram of a multi-point overload protector hydraulic adjusting device. In each section of LF, RF, LR, and RR, 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 multipoint die height adjusting device of FIG. 4 will be described with reference to the explanatory view of the device. The multi-point 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. The die height adjuster (43) mainly consists of a pair of worm screws (43a) and worm wheel screws (43b), and the main body is fixed to a 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, a 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 opposite drive side of the worm screw (43a). A brake (40b) is provided. To adjust the die height, connect the die height adjuster (43) to be adjusted and the paired clutch (40a), release the paired brake (40b), drive the drive motor (41), and adjust the die height. The pair of worm wheel screws (43b) are rotated via the 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, and as a result, the worm wheel screw (43b) The positions of the die height adjuster (43) and the slide (46) to which the die height adjuster (43) is fixed are adjusted. When the die height adjustment is not required, the driving force of the drive motor (41) can be increased by releasing the paired clutch (40a) of the die height adjusting machine (43) and connecting the paired brake (40b). 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. If the output balance of the press machine is changed in response to the eccentric load in the die, or if the parallelism of the slide exceeds the allowable value of the press machine, in addition to the multi-point die height adjusting device, the multi-point described later It is necessary to use an overload protector hydraulic regulator. First, the multi-point die height adjusting device will be described, and the multi-point overload protector hydraulic adjusting device will be described later.

A mode using a fitting reference block and a multi-point die height adjusting device, which is a feature of the present invention, will be described. At the bottom dead point of the slide, the upper and lower dies are set to the mating push-off state, and regarding the pressurization of the mating reference block (10), if there is no load, the upper and lower limits of the no-load pressurization upper and lower limits, which are stored information, are set. As a value, in the case of an actual load, the central upper limit value and the lower limit value of the pressing force of the molding analysis result, which are stored information, are set as the upper and lower limit values, and the pressing force obtained from the fitting reference block (10) in the mold. The measured value is compared and judged for each section of LF, RF, LR, and RR. As a result, if the measured value is less than the set lower limit value, the clutch (40a) of the die height adjusting device in the relevant section is engaged, the paired brake (40b) is released, and the adjusting motor (41) is driven. Then, the die height of the section is lowered, and the amount of compression of the overload protector (51) is increased until the measured value of the pressing force falls within the set upper and lower limits. If the measured value exceeds the set upper limit, the section is concerned. The clutch (40a) of the die height adjustment device of the above is connected, the paired brake (40b) is released, the adjustment motor (41) is driven to raise the die height of the relevant section, and the measured value of the pressing force 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 relevant section is released and paired. The brake (40b) is not connected and the die height is not adjusted, and as a result, the slide parallelism and the pressure distribution in the mold are made to match the molding analysis result. Then, the measured value of the die height detector (42) of the multipoint die height adjusting device in a state where the pressing force distribution matches the molding analysis result is stored and stored 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 the lower limit value, which are the allowable range, as the production requirements in the die height value in the state where the pressing force distribution matches the molding analysis result. vinegar.

As a method for adjusting the parallelism of slides, an individual motor system (Patent Document 2) and a hydraulic cylinder system (Patent Document 3) have been invented. Generally, the amount of die height adjustment is several tens to several hundreds [mm], and the permissible value of parallelism is less than 1 [mm]. There is no guarantee of synchronization between the adjustment axes, and the parallelism becomes unstable. In addition, expensive equipment such as motors and hydraulic devices and installation space are 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 synchronous operation is performed, and only when slide parallelism adjustment is performed, the clutch (40a) and the pair are paired. It is possible to adjust the parallelism by operating the brake (40b). Moreover, it does not require expensive equipment such as a plurality of motors and hydraulic devices, and saves space.

The configuration of the multi-point overload protector hydraulic control device of FIG. 5 will be described with reference to the explanatory view of the device. Since the overload protector, which is the main component of the device, has a hydraulic damper structure, the overload protector and the overload protector hydraulic chamber are synonymous. The multi-point overload protector hydraulic control device is an overload protector cutoff device (51) in which a pair of overload protector cutoff device (50) is added to the overload protector (51), and the overload protector (51) is used as a pair. It is configured by connecting to another overload protector via a hydraulic pipe via 50). The overload protector shutoff device (50) has a basic configuration of a pilot-operated check valve (50a) and a pilot-operated valve (50b). The oil pressure detector (52), which will be described later, is used as an index at the time of adjustment at the time of setup at the time of production using the multi-point die height adjusting device.

A mode in which the fitting reference block, the multipoint die height adjusting device, and the multipoint overload protector hydraulic adjusting device, which are the features of the present invention, are used will be described. The multi-point overload protector hydraulic regulator adjusts the multi-point die height as described above when the output balance of the press machine is changed in response to the eccentric load in the die, or when the parallelism of the slide 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 compartments. Is enabled. Next, the upper and lower molds are set to the fitting push-off state, and regarding the pressing force of the fitting reference block (10), if there is no load, the no-load pressing upper limit value and the lower limit value, which are stored information, are set as the upper and lower limit values. In the case of an actual load, the central upper limit value and the lower limit value of the pressing force, which are stored information, are set as the upper and lower limit values, and the measured value which is the pressing force obtained from the fitting reference block (10) in the mold, and the LF, The RF, LR, and RR sections are compared and judged. As a result, if the measured value is less than the set lower limit, operate the die height adjusting device in the section as described in the previous section to lower the die height and overload until the measured value of the pressing force falls within the set range. If the amount of compression of the protector (51) is increased and the measured value exceeds the set upper limit value, the die height adjusting device in the relevant section is operated as described in the previous section to raise the die height, and the measured value of the pressing force is set. The amount of compression of the overload protector (51) is reduced until it falls within the range. Match with. Then, the setting state of the check function of the pilot-operated check valve (50a) and the actual measurement of the oil pressure detector (52) in the multipoint overload protector oil pressure adjusting device in the state where the pressing force distribution matches the molding analysis result. The value is stored in the control device for use as a production requirement. Therefore, the control device of the press machine is in the state of the multi-point overload protector hydraulic control device in the state where the pressing force distribution matches the molding analysis result, and the setting state of the check function of the pilot-operated check valve (50a). And overload protector It has a function to store the actual load output upper limit value and lower limit value, which are the allowable range of flood control, as production requirements. In addition, under a die-height state that realizes a state of pressure distribution that matches the molding analysis result, as a production requirement for production setup, an overload protector hydraulic adjustment device when there is no object to be molded and no load is applied. The measured value of the oil pressure detector (52) is also stored and stored in the control device. Therefore, the control device of the press machine has the upper and lower limits of the no-load output, which is the permissible range of the overload protector oil pressure when there is no load, under the die-height setting state that realizes the fitting push-off state that matches the molding analysis result. The value also has a function of storing it as a production requirement. As the operating mode of the pilot-operated valve (50b), 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). In an environment where the same check valve is frequently used, the check function of the pilot-operated check valve (50a) is enabled when the pilot-operated valve (50b) is demagnetized, and conversely, in an environment where the same check function is not frequently used. It is rational, but not a requirement, to disable the check function of the pilot-operated check valve when the pilot-operated valve is demagnetized.

Similar forms (Patent Document 4 and Patent Document 5) have been invented for adjusting the hydraulic pressure of the overload protector device. Since both inventions are a method of actively adjusting the hydraulic pressure at the press pressure point, a high-priced hydraulic pressure generating and adjusting device is added or a hydraulic device having higher functionality than the conventional one is required. On the other hand, the present invention is a simple method of passively adjusting the oil pressure by using the multi-point die height adjusting device, and does not require the addition of an expensive hydraulic device or high functionality.

A form of molding 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 adjusting device, which are the features of the present invention, will be described. The molding confirmation form at the time of production includes a form in which the fitting push-off state at the time of production matches the molding analysis result and a form of quality confirmation during production.

As a form of matching the fitting push-cut state at the time of production with the molding analysis result, the fitting push-cut state at the time of mounting the mold at the time of production setup is matched with the molding analysis result, and the quality at the time of production is stabilized. .. 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 of the press machine of the present invention has a lot of die-height setting upper limit values and lower limit values in the fitting push-off state that matches the molding analysis result, that is, in each section of LF, RF, LR, and RR from which the molding result can be obtained. Point Overload protector The setting state of whether the check valve (50a) of the pilot operation check valve (50a) of the hydraulic regulator is enabled or disabled, and the upper limit of the no-load output pressure of the overload protector flood control at the time of fitting push-off with no load. It has a function to store the values and the lower limit value and the no-load pressurizing upper limit value and the lower limit value of all the fitting reference blocks as production requirements, and at the top dead point, it is a multi-point die height adjusting device. The multi-point overload protector hydraulic control device is used to adjust the die height of each section of LF, RF, LR, and RR, and the section that needs to be blocked by the overload protector is blocked. A reference block, a multi-point die-height adjustment device, and a multi-point overload protector hydraulic adjustment device are used to realize a pressure distribution that matches the molding analysis results.

Specifically, first, at the top dead center immediately before mounting the mold, the die height of each section of LF, RF, LR, and RR is determined, and the measured value of the die height detector (42 in FIG. 4) and the upper limit value of the die height setting are set for each section. And the lower limit value is compared, and if the measured value exceeds the set upper limit value, the die height of the relevant section is lowered using the multi-point die height adjustment device, and if the measured value is less than 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 height of all sections within the set upper and lower limits. In addition, whether the check valve of the pilot-operated check valve (50a in FIG. 5) of the multi-point overload protector hydraulic control device in each section is enabled or disabled is set in a state that matches the production requirements.

Next, the slide is lowered to the bottom dead center, the fitting is pushed out, and the overload protector in each section of LF, RF, LR, and RR sets the upper limit value and the lower limit value of the no-load output pressure, which are stored information. The lower limit is set, and the measured value is compared with the measured value of the oil pressure detector of the overload protector (52 in FIG. 5). The die height is raised until it falls within the no-load output pressure upper and lower limit values, and if the measured value does not reach the set lower limit value, the measured value falls within the no-load upper and lower limit values using a multi-point die height adjustment device. The die height is lowered until. Further, in this state, the no-load pressing upper limit value and the lower limit value of each fitting reference block of the production requirement, which is the stored information, are set as the set upper and lower limit values, and the pressing force obtained from the fitting reference block (10). The measured value is compared with each control number of the mating reference block, and if the measured value exceeds the set upper limit value, the control number of the mating reference block and the die height excessive descent warning are output, and the measured value is assumed to be. If it is less than the set lower limit, the control number of the fitting reference block and the die height lowering insufficient alarm are output, and if the measured value is within the set upper and lower limits, the normal mounting signal at the time of setup is output.

Among the forms of molding confirmation during production, the form of quality confirmation during production will be described. In the quality inspection at the time of production, the fitting push-off state is compared with the molding analysis result, and the quality inspection is realized automatically. The control device of the press machine of the present invention has, for all the fitting reference blocks (10), the upper and lower limits of the forming margin pressing force when molding the object to be molded, and the upper and lower limit values of the forming margin pressing force. Pressurization in the central range The central upper limit and lower limit are stored as production requirements for each mold, and the actual measurement value is the pressurization obtained from those production requirements and the fitting reference block (10). And automatically inspect the molding quality at the time of production.

Specifically, during the production operation of the press machine, the actual measurement value which is the pressing force obtained from all the fitting reference blocks (10) and the molding margin upper and lower limit values of the production requirement which is the stored information are set as the fitting reference. Comparing each block control number, if the measured value exceeds the molding margin pressurization upper limit value, the control number of the fitting reference block and the overpressurization alarm are output, and the measured value is the molding margin pressurization. If it does not reach the lower limit, the control number of the fitting reference block and the pressurization insufficient alarm are output. It is also compared with the pressure center upper and lower limit values in the central range of the pressure upper and lower limit values. As a result of comparison, if it is within the upper and lower limits of the central pressure, it is judged that the molding state is good, and if it exceeds the upper limit of the central pressure, the control number of the fitting reference block and the overpressurization warning are issued. If the pressure is less than the central lower limit of the pressing force, the control number of the fitting reference block and the warning of insufficient pressurization are output.

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

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

10 Fitting reference block 10a Upper surface of fitting reference block (upper mold contact surface)
10b Mating reference block measuring unit 10c Mating reference block mounting unit 11 Strain gauge 12 Strain gauge signal to pressure converter (function)
21 Upper mold (block with molding surface)
21a Positive molding surface of upper mold (positive standard)
21b Subordinate molding surface of upper mold 22 Lower mold (block having molding surface)
22a Positive molding surface of lower mold (positive standard)
22b Subordinate molding surface of lower mold 23 Object 40a Clutch 40b Brake 41 Motor 42 Die height detector 43 Die height adjustment device 43a Worm screw 43b Warm wheel screw 44 Drive shaft 45 Plunger rod (screw part)
46 Slide 50 Overload protector shutoff device 50a Pilot-operated check valve 50b Pilot-operated valve 51 Overload protector (flood control chamber)
52 Flood control detector

Claims (1)

In each of the overload protector hydraulic chamber of the pressure point for all locations of the press machine and each of the die height adjustment device having two or more points of pressure points,
Each to each of the overload protector hydraulic chamber pilot operated check valve, arranged as the only pair of non-return of the overload protector hydraulic chamber, the overload protector hydraulic chamber a check function of the check valve as an effective reverse sealed shut off from other hydraulic chamber, and,
A pair of clutches and brakes are arranged for each die height adjuster as a pair of the die height adjuster so that the die height adjuster can be arbitrarily selected and controlled, and can be arbitrarily selected by one die height adjustment motor. Overload protector at the same pressurization point as the die-height adjuster by controlling the die-height adjuster The pressurization of the pressurization point can be adjusted by adjusting the amount of compression in the hydraulic chamber. Road protector hydraulic regulator.

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