JP6710406B2 - Press mold, press machine, and mold confirmation method - Google Patents

Description

The present invention relates to a press machine that realizes an analysis result in processing using a press mold in manufacturing pressed parts for automobiles, and a molding confirmation method for the mold using the machine.

The 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, etc., but in reality molding results that match the analysis results are obtained. Therefore, the skilled worker judges the molding result and corrects the mold as molding adjustment.

Mold analysis techniques are roughly classified into two types: molding analysis and structural analysis (also referred to as rigidity analysis). Molding analysis is mainly based on the plastic deformation analysis of the non-linear region based on the "stress-strain" characteristic of the material to be molded, and assuming that the pressing force that the mold receives from the press machine is uniform, The shape surface on which the required pressing force and the amount of deformation can be applied to the object is determined. In the structural analysis, a structure having rigidity that does not affect the forming is analyzed and determined based on the pressing force distribution of the forming analysis result.

Mold adjustment work is performed by checking and measuring the actual molding result, surface contact state using Komeitan or pressure measurement film, and the gap between upper and lower molding surfaces using fuse, clay, etc. A skilled worker estimates the state during molding and corrects the mold. Since these adjustment tools do not quantitatively indicate the adjustment range and the adjustment amount, the technician makes an original judgment based on his/her skill and experience. For this reason, the modification policy differs for each technician, but it is common to repeat modification and confirmation many times. Before the actual production starts, immediately after the completion of the assembly of the mold, the molding adjustment press of the mold called the try press is used to make the molding adjustments many times, and after that, the molding confirmation and adjustment are performed 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 measuring the shape of the molding product and the shape of the molding part of the 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 workers and the difference in ability between skilled workers, it has not led to a dramatic improvement in the initial quality of a mold, that is, molding.

In the molding adjustment by a technician, in addition to the adjustment of the shape of the molding surface, the positional relationship between the upper and lower dies is adjusted in consideration of the variation in the thickness of the object to be molded. To adjust the positional relationship between the upper and lower molds, a push-cut block is used that prevents excessive pressing down and determines the positional relationship between the upper and lower molding surfaces when the upper and lower molds are completely pressed. This press-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 measurement film, a method of mounting a strain gauge on the molding surface or inside and measuring the strain has been invented (Patent Document 1). However, since distortion is dimensionless and does not have a physical quantity, it is effective as a relative comparison such as the change of its own, but in order to make a relative comparison with others, conversion to a physical quantity is necessary. However, there are many problems in practical application.

The die height adjusting device and overload protector device of the press machine, which are the main devices related to molding, will be described. In the following description, the most common four-point press machine in the production site of automobile press parts, that is, a press machine in which the slide is connected to the drive unit 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 for adjusting the die height of the press machine, that is, the die cutting height from the top surface of the polster 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 machines assembled for each plunger rod, and synchronously operates 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 another die height adjuster and a drive motor, the worm wheel screw is attached 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 to adjust its position with respect to the plunger rod, whereby the slide position where the slide adjusting machine is fixed is moved up and down, and the die height is adjusted.

The relationship between the die height and the 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, the motors are mechanically synchronously operated. The slide parallelism is determined by the mounting condition of the die height adjuster and cannot be adjusted arbitrarily. Since slide parallelism affects molding, it is established as part of the accuracy class in JIS. The press machine for press parts for automobiles is usually of JIS class 1, for example, the tolerance of the slide parallelism of the die space length 4 [m] is 0.44 [mm]. As an example of the influence of the slide parallelism on the mold, if the parallelism deviates from the allowable value when driving the die height adjusting device at the bottom dead center, a regulation part such as a guide that regulates the horizontal positional relationship between the upper and lower dies. It causes interference trouble. 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) or a parallelism adjusting device using a hydraulic cylinder (Patent Document 2) Reference 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 the allowable value in the process of adjusting the die height. Further, the individual motor method (Patent Document 2) requires a large installation space. The hydraulic cylinder system (Patent Document 3) has a complicated structure and additionally has an active expansion and contraction function added to the overload protector device. Therefore, the compression at the time of pressurization of the press and the temperature change of the viscosity of the oil are changed. Etc., requires a higher degree of control.

Also, in recent years, a servo press using a servo motor as a drive source for a press machine has been put into practical use. In some servo presses, a servo motor provided for each pressurizing point is synchronized to cause a bottom dead center. It has been stopped. In this form of servo press as well, similar to the method of adjusting independently by individual motors (Patent Document 2), synchronicity is unstable, and maintaining parallelism during operation is a problem. In addition, both the bottom dead center position itself and the parallelism at the bottom dead center position have accuracy differences in each cycle and are not reproducible. Regarding the parallelism of the servo press, many mechanisms for maintaining the parallelism have been invented, but the large number of inventions is also a visa for the degree of the problem regarding the parallelism.

The overload protector device will be described. Immediately below each plunger rod, which is a pressurizing point of the press machine, there is a hydraulic chamber called an overload protector. 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 push-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 piping, and a common hydraulic pressure is supplied. When an overload occurs, this hydraulic pressure supply is stopped, 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 adjusting device and sets the die height of the press machine (sliding height at the bottom dead center) lower than the die height of the die (height during vertical die cutting). As a result, the overload protector is compressed at the bottom dead center to generate a reaction force, and this reaction force is the pressing force of the press machine. Generally, the press machine is positioned as a general-purpose machine, and is designed on the assumption that it applies uniform pressure to the mold, and all overload protectors are connected to each other by hydraulic piping as described above, and hydraulic pressure is applied. The sources are also the same, and the pressing force, which is the reaction force of all overload protectors, is equal regardless of the amount of compression.

For adjusting the hydraulic pressure of the overload protector device, as a similar invention, 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 of the inventions aim at adjusting the slide parallelism, but the technique for adjusting the hydraulic pressure at the pressurizing point is common. Since both of the inventions are active hydraulic pressure adjustment methods, they require an expensive hydraulic device, and have large variations in the viscosity of the hydraulic pressure due to temperature changes and compression amounts, and thus require highly accurate control.

The above is the technical background before shifting to actual production from the production of the mold to the adjustment. After the shift to production, the press machine is adjusted at the time of production setup with the adjustment result of the press machine such as the die height value obtained in the mold adjustment process as the production requirement. However, when the press machine is changed due to transfer of production, 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 processing, a molding result that matches the analysis result cannot be obtained. The main reason for this is that the simplification or simplification factor in the analysis technique, that is, the factor such as the difference in precision of the press machine or the die actually affects the molding. Quantitative factor analysis of the influence of these factors on molding is also insufficient, and analysis technology for this part has not been established. Moreover, the return of the molding result to the analysis technique is incomplete, and the improvement of the performance of the analysis technique is limited. As described above, the present invention provides a means for detecting the actual condition of molding that can be compared with the analysis technique including the preconditions and the calculation process, and by using the means, the factors affecting the molding of the press machine and the mold can be eliminated or minimized. It is an object to provide a means for realizing the above.

The fitting reference block of the present invention is fixed to the fitting surface of the upper and lower dies, that is, either the upper surface of the lower die or the lower surface of the upper die. By forming it as a contact reference that is associated with the reference of 1 to 1, the molding surfaces of the upper and lower dies can be restricted to a positional relationship that matches the molding analysis result, and vertical strain between the upper and lower dies can be converted into a pressing force. It consists of a structure with area accuracy, and strain gauges are attached to the side of the structure, and 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 pressing force 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 realize a fitting push-cut state that matches the molding analysis result by eliminating or minimizing the molding influencing factors of the press machine and the die. The measured value, which is the pressing force 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, and if the measured value is lower than the set value, Connect the clutch of only part of the die height adjuster, release the pair of brakes, drive the adjustment motor, lower the die height until the measured value is within the allowable range of the set value, and temporarily For parts where is higher than the set value, the function to drive only the necessary parts using the operation of the clutch, brake and motor, and raise the die height until the measured value falls within the allowable range of the set value. Is characterized by.

The multi-point overload protector hydraulic adjusting device of the present invention is intended to eliminate or minimize the molding influencing factors of the press machine and the mold, and to realize a fitting push-cut state that matches the molding analysis result, When changing the output balance of the press machine according to the unbalanced load, the measured value that is the pressing force information obtained from the fitting reference block and the set value that is the molding analysis result of the pressing force of the fitting reference block. And the overload protector that needs to be changed, the check function of the pilot operated check valve, which is paired with the overload protector, is effective to shut off the overload protector from other hydraulic chambers, and the die height of the overload protector part. If it is necessary to increase the pressure using the adjuster, lower the die height until the measured value matches the allowable range of the set value, and if depressurization is required, the measured value falls 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 the temperature reaches, and matching the pressure distribution in the mold with the molding analysis result.

A press machine according to 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 adjusting device. It is characterized by having an interface function capable of receiving a strain gauge signal from the strain gauge of the matching reference block.

A control device of the present invention is a control device used for the press machine, wherein the strain gauge signal from the strain gauge of the fitting reference block is converted into a pressing force, and the pressing force is applied to a molding analysis result. The multi-point die height adjusting device and the multi-point overload protector hydraulic adjusting device are adjusted so as to match the pressure.

In detail, the control device of the present invention gives the fitting reference block a management number corresponding to each fitting reference block, and the management number and the management number from the strain gauge for each management number. At the actual load, which is used as a set value for the molding adjustment and the molding quality check, with the conversion factor for converting the strain gauge signal to the pressing force and the molding analysis result or the pressing force of all the fitting reference blocks measured by the press machine. The upper and lower limits of the molding allowance pressure and the center upper and lower limits of the pressurizing force in the center range of the upper and lower limits of the pressurizing force, and the set values used during molding adjustment and die setup The upper and lower limits of the no-load pressure, as well as the set values for molding adjustment and molding quality confirmation, are used for all pressure points when the pressure distribution at actual load matches the pressure distribution of the molding analysis result. The die height setting upper limit value and lower limit value obtained from the actual measurement value of the multipoint die height adjusting device, the setting state of the check function of the pilot operated check valve of all the multipoint overload protector hydraulic adjusting devices, and When the point die height adjuster has a die height value that matches the pressure distribution under actual load with the pressure distribution in the molding analysis result, the overload protector hydraulic pressure of all pressurization points at both actual load and no load It has a function of storing 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 actual measurement value for each mold as a production requirement, and the strain gauge of the fitting reference block. From the strain gauges of all the fitting reference blocks at the time of production, and having 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. The measured value, which is the pressurizing force obtained by converting the strain gauge signal, is compared with the molding margin pressurizing upper and lower limit values of the production requirement that is the stored information, for each control number corresponding to the fitting reference block, If the measured value exceeds the molding allowance pressure upper limit value, the control number of the fitting reference block and the overpressure warning are output, and if the measured value does not reach the molding allowance pressure lower limit value, Outputs the control number of the mating reference block and the pressurization insufficient alarm, and if the measured value is within the upper and lower limits of the molding allowance pressure, the central range of the upper and lower limits of the molding allowance pressure of the production requirement, which is the stored information. If the measured value is within the central upper and lower limits of the pressing force, the molding state is judged to be good, and if the measured value exceeds the central upper and lower limits of the pressing force, Criteria It has a function to output the control number of the block and the overpressure warning, and output the control number of the fitting reference block and the underpressure warning if the measured value does not reach the center lower limit value of the pressing force. And, when mounting the die, at the top dead center immediately before mounting, the actual measurement value which is the die height value of all the die height adjusting machines of the multi-point die height adjusting device, and the die height setting of the production requirement which is the memory information. Compared with the upper and lower limit values individually, if the measured value is lower than the die height setting lower limit value, the die height is raised, and if the actually measured value is higher than the die height set upper limit value, the die height is lowered and the production requirement die height setting upper and lower limits are set. Adjust the value within the range, and set the check function of the pilot operated check valve of the multi-point overload protector hydraulic pressure adjustment device to the valid or invalid state in accordance with the production requirement which is stored information, and At bottom dead center, the measured values, which are the hydraulic pressure values of all the overload protectors of the multi-point overload protector hydraulic adjustment device, are individually compared with the no-load output pressure upper and lower limit values of the production requirement, which is 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 does not reach 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 added. The pressure value obtained by converting the signal is used as the actual measurement value, and it is compared with the upper and lower limits of the no-load pressure force, which is a production requirement. If the control number of the block and the die height excessive lowering alarm are output, and the measured value does not reach the no-load pressure lower limit value, the control number of the relevant mating reference block and the die height lowering alarm are output, and the measured value is temporarily It is characterized in that it has a function of outputting a normal mounting signal when it is within the upper and lower limits of the no-load pressing force which is a production requirement.

A method for confirming molding of a press die of the present invention is a method for confirming molding of a press die using the control device, wherein the strain gauge signal of the strain gauge of the fitting reference block is obtained by converting the strain gauge signal. It is characterized in that the multipoint die height adjusting device and the multipoint overload protector hydraulic adjusting device are adjusted so that the pressurizing force matches 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, according to the present invention, it becomes possible to correct the influence of the precision difference between the press machine and the mold and the mold adjusting process by the tri-press immediately after the mold is manufactured, 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 only the analysis technology that eliminates the influence of the difference in precision between the press machine and the mold. , The performance of analysis technology is improved.

As a side effect, human resources can be effectively used. Conventionally, a skilled person having a certain level of skill and years of experience was required for adjusting the mold even after the start of mass production. According to the present invention, since the molding state can be numerically controlled, most of the work of a skilled person can be performed on behalf of him. Therefore, the skilled person can be devoted from the follow-up work in the past to the preparatory work such as the die manufacturing and the molding process innovation.

It is explanatory drawing of a fitting reference block. It is explanatory drawing which showed the upper and lower type fitting push-off state for demonstrating the function of a fitting reference block. It is explanatory drawing which showed the example of arrangement|positioning of a fitting reference block. It is explanatory drawing of the multipoint die height adjusting device in a 4-point press machine. It is an explanatory view of a multipoint overload protector oil pressure adjusting device in a 4-point press machine.

There are molding analysis and structural analysis as analysis techniques in mold design. The forming analysis analyzes and determines a forming shape capable of applying the pressing force and the amount of deformation necessary for the intended plastic deformation to the object based on the "stress-strain" characteristic of the object. This molding shape is a molding surface that has a shape that serves as a “mold” that determines the amount of deformation that achieves the intended shape for the molded object, and the stress that is required to align the molded object with the “mold”. And a molding surface for applying a force form a pair with the object to be molded interposed therebetween. The structural analysis determines a structure having sufficient rigidity that does not affect the molding, with respect to both the pressing force from the press machine required for molding and the molding load in the mold. In the mold manufactured by using both the molding and structural analysis techniques and the NC processing, the actual molding result does not match the analysis result. This cause is caused not only by the performance of the analysis technique but also by 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 that affect the molding result are separated into factors related to the performance of the analysis technology and factors related to the press machine and the die, and It is necessary to eliminate the influence or minimize it to the extent that the influence can be ignored, and there is a means to detect the actual state of molding that is comparable to the analysis technology including preconditions and calculation processes, and the press machine and the metal using the means. There is a need for means to eliminate or minimize the factors that influence the molding of the mold. It should be noted that variations in the shape such as the thickness of the object to be molded and the stress characteristics should be included in the performance of the analysis technique as a problem of the molding margin.

The molding surface that is the "die" that determines the amount of deformation in the molding analysis result is the positive molding surface with the positive reference (plane), the object to be molded is along that "die", and the required stress is applied. The molding surface to be used is a secondary molding surface. In order to obtain a molding result that matches the molding analysis result, in the pressurizing state during press molding, that is, in the mating push-cut state of the upper and lower dies, the positional relationship between the positive and the secondary molding surfaces and the pressure between both molding surfaces are applied. Both pressure distributions must match the molding analysis results. As described above, the fitting reference block (the fitting reference block of the present invention as a means for regulating the positional relationship between the positive and the secondary molding surfaces and measuring the distribution of the pressing force between the molding surfaces under the fitting push-cut 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 an upper and lower fitting push-cut state using the fitting reference block (10) of FIG. It will be explained using and. The fitting reference block may be attached to either the upper or lower mold, but the explanation will be given on the premise that the fitting reference block is attached to the lower mold having a good setup property such as the processing of the pressure measurement wiring. The fitting reference block (10) shown in FIG. 1 is a sub-block that faces the positive molding surface (21a, 22a) and the object to be molded (23) in the upper and lower fitting push-cut state shown in FIG. 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 die that comes into contact with the upper surface (10a) are defined as the contact reference at the time of fitting that is associated with the positive reference for molding one-to-one, It is formed as a fitting reference surface by analysis. Specifically, if the positive molding surfaces (21a, 22a) are present on the upper and lower molds, the positive molding surface (21a, 22a) is only on one of the upper and lower molds so that the positional relationship between them matches the molding analysis result. Even if 21a or 22a does not exist, the secondary molding surface (22a for 21a, 21b for 22a) facing the positive molding surface (21a or 22a) is restricted to the positional relationship that matches the molding analysis result. It is analyzed as a possible fitting reference (face) with guaranteed accuracy that is associated with a positive reference (face) in a one-to-one relationship. As an example of means for assuring the accuracy of the fitting reference surface, after the fitting reference block is assembled, it is machined as a fitting reference surface that is associated with the positive reference of molding one-to-one.

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

Since the output signal ε of the strain gauge (11) is dimensionless, it is converted into a force [N] which is a physical quantity and compared with the molding analysis result. The elastic coefficient [Pa] of the measurement unit (10b) of the fitting reference block is multiplied by the horizontal cross-sectional area [m ² ] or the fitting reference block (10) is calibrated as a load cell, and the force [N] is a physical quantity. Treat as. There is no restriction on the material of the fitting reference block except for the load bearing capacity and the uniformity of the elastic coefficient, and if it is made of general steel, the elastic coefficient of the steel is about 206 GPa (201 to 206 GPa for mild steel). By controlling the manufacturing accuracy of the horizontal cross-sectional area of the fitting reference block, it is possible to measure the pressing force 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 a pressing force and comparing it with the pressing force distribution of the molding analysis result. More specifically, a conversion number for converting a strain gauge signal into a control number assigned to the fitting reference block (10) and a product of an elastic coefficient and a horizontal cross-sectional area or a calibration coefficient as a load cell for each control number. As a coefficient, it has a function of storing as a production requirement for each mold. Further, it also has a calculation function (12) of FIG. 1 for converting into a pressing force using the strain gauge signal (11) corresponding to the conversion coefficient for each management number. 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 for the fitting reference block (10), and the pressing force at the time of push-fitting is cut 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 state of molding, and a multi-point die height device and a multi-point overload protector hydraulic adjusting device, which will be described later, are used to eliminate the factors affecting the molding of the press machine and the die. Alternatively, it is used as a means for minimizing the influence, and the fitting push-off state is made to match the molding analysis result.

Even if the mating push-off state between the upper and lower molding surfaces matches the molding analysis result, if the intended molding result is not obtained, there is a problem with the performance of the molding analysis or 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 for measuring and comparing the shape of the molded product and the shape of the molding part” includes the influence of the difference in precision between the press machine and the mold, and has not reached the quantitative factor analysis of the difference. On the other hand, the data obtained by the present invention is good quality data narrowed down to the factors of only the analysis technique that eliminates the influence of the difference in precision of the press machine. In addition, if the mating push-off state between the upper and lower molding surfaces does not match the molding analysis result and the measured actual pressure value does not reach the allowable lower limit value of the design pressure force, it is necessary to process or assemble the mold. If the actual measurement of pressure exceeds the allowable upper limit of the design pressure due to a manufacturing defect during mounting or insufficient rigidity in the vicinity of the under-pressurized portion, it may occur during machining or assembly of the mold. Poor manufacturing or insufficient rigidity other than near the under-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, the feedback data of the present invention is of high quality limited to the factors of the analysis technique and is numerical data of “force” which can be compared with “stress-strain”, and therefore contributes to 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 in FIG. In addition, the symbols LF, RF, LR, and RR in FIG. 3, including those in FIGS. 4 and 5 below, are divided into four parts in the machine center of the press machine in the front, rear, left, and right of each point. That is, the section corresponding to the pressurizing point is matched with the nominal name of the press machine, and LF=left front, RF=right front, LR=left rear, and RR=right rear are shown. The fitting reference block (10) uses a multi-point die height adjusting device or a multi-point overload protector hydraulic adjusting device, which will be described later, to eliminate or minimize factors that affect the molding of the press machine and the die. Since it is also an index, it is arranged in all the sections so as to be an adjustment index for the sections at each pressurizing 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 push-fitting. Regarding the mounting position, assuming that the structure of the mold 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 molding target. 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, the vicinity of the molding surface that does not interfere with the object to be molded is desirable so as not to be affected by variations in the thickness of the object to be molded. However, this is not the case if the pressing structure portion such as a cushion pad or a presser pad is provided by a spring function and the flow of the molding target is not affected. In addition, if many fitting reference blocks (10) are arranged in the vicinity of the molding site that requires particularly important management, and the fitting reference blocks (10) are calibrated and used similarly to the load cell, the accuracy of molding management can be improved. It is possible.

When using the fitting reference block (10), a management number is given to all the fitting reference blocks (10), and the control device of the press machine performs the molding analysis or the management number for each management number. The upper limit and the lower limit of the molding margin pressurizing force at the time of the load for molding the object to be molded, the central upper limit value and the lower limit value of the pressurizing force in the center range of the molding margin pressing force upper and lower limits, and further, It has a function of storing and storing the upper limit value and the lower limit value of the no-load pressing force within the permissible range of the mating push-off state under no load as a production requirement for each mold in the control device of the press machine. If these values do not match 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 the structure. Return to the analysis, improve the performance of the analysis technology, recalculate and always keep the latest version.

A method (Patent Document 1) has been invented in which a strain gauge is attached to a molding surface to measure strain. However, since strain is dimensionless and does not have a physical quantity, it is effective as a relative comparison such as the change over time of itself, but it is difficult to convert it to a physical quantity unless the entire molding part is calibrated equivalent to a load cell. is there. If it cannot be handled as a physical quantity, the relative comparison with other parts cannot be associated with the "stress-strain" characteristic of the molding target, that is, it cannot be compared with the molding analysis result. Further, since the invention does not have a structure for restricting the positional relationship between the upper and lower mold surfaces, it is impossible to measure when there is no load on the molded object. Even under load, especially when a strain gauge is attached to the surface of the forming part, it is possible to measure the influence of variations in the plate thickness of the forming object and the behavior of the forming object during forming, such as material inflow in drawing. They affect each other in molding and also affect the measured values. In particular, projections and foreign matter of more than ten [μm] or more cause poor quality of the appearance of the molding object, and therefore cannot be applied to a die for outer panel parts. In addition, the strain gauge must be closely integrated with the mounting part, which makes surface treatment of the molding surface and repair of the strain gauge difficult.In addition, when mounting the strain gauge inside, the rigidity of the molding surface depends on 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 restricting structure that matches the positional relationship between the molding surfaces with the molding analysis result, so measurement without load is also possible Is. It also 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 the bolt assembling to the mold as a single structure, and the surface treatment and repair of the mold, the strain gauge repair and the calibration as the load cell are easy.

Further, the fitting reference block (10) is particularly conceptually different from the conventional push-cut block. The push-cut block is a subordinate 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 index for For example, in the conventional adjustment of the mating state, Komeitan, the object to be molded, clay, etc. are used, the slide is raised and lowered many times, and the molding adjustment and molding confirmation are repeated. Also adjust. On the other hand, the fitting reference block (10) according to the present invention is a positive reference that forms a regulation structure that matches the fitting push-cut state with the molding analysis result, and at the same time is an index that adjusts other parts. By using the multi-point die height adjusting device and multi-point overload protector hydraulic adjusting device of the press machine based on the pressure information obtained from the combined reference block (10), the slide can be lowered to the bottom dead center once and 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 efficient. In particular, in a press machine that is actually produced, a molding state that matches the molding analysis result can be realized, so the conventional molding adjustment using the tri-press has no meaning and can be abolished.

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

The configuration of the multipoint die height adjusting device will be described with reference to the explanatory view of the multipoint die height adjusting device in FIG. The multi-point die height adjusting device is characterized in that a pair of clutches (40a) and brakes (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 worm wheel screws (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. To adjust the die height, the die height adjuster (43) to be adjusted is connected to the paired clutch (40a), the paired brake (40b) is released, and the drive motor (41) is driven to adjust the die height. The companion worm wheel screw (43b) is rotated through the worm screw (43a) of the machine (43). By rotating the worm wheel screw (43b), the position of the worm wheel screw (43b) with respect to the plunger rod (45) incorporating the worm wheel screw (43b) is adjusted, and as a result, the worm wheel screw (43b). The positions of the die height adjuster (43) that is mechanically integrated with the slide height 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 opening the paired clutch (40a) of the die height adjuster (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), so that the die height is not adjusted. By the above mechanism, the parallelism of the slide and the distribution of the pressing force in the mold are adjusted, and the fitting push-cut state that matches the molding analysis result is realized. In addition, when changing the output balance of the press machine according to the unbalanced 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 adjusting device, It is necessary to use an overload protector oil pressure 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 the fitting reference block and the multipoint die height adjusting device, which is a feature of the present invention, will be described. Set the upper and lower molds to the mating push-off state at the bottom dead center of the slide, and set the upper and lower limits of the no-load pressing force, which is the stored information, for the pressing force of the fitting reference block (10) if there is no load. In the case of actual load, it is the pressurizing force obtained from the fitting reference block (10) in the mold by setting the pressurizing force central upper limit value and the lower limit value of the molding analysis result, which is stored information, as the setting upper and lower limit values. The measured value is compared with each of the LF, RF, LR, and RR sections to make a determination. As a result, if the measured value does not reach the set lower limit value, the clutch (40a) of the die height adjusting device of the section is connected, the pair of brakes (40b) is released, and the adjustment 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 pressing force falls within the set upper and lower limits. If the measured value exceeds the set upper limit, 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 pressing force is set. The compression amount of the overload protector (51) is reduced until it falls within the lower limit, and if the actually measured value is within the set upper and lower limit values, the clutch (40a) of the die height adjusting device of the partition is released and a pair is formed. The brake (40b) is not connected and the die height is not adjusted, and as a result, the slide parallelism and the pressing force distribution in the mold are matched with the molding analysis result. Then, the measured value of the die height detector (42) of the multi-point die height adjusting device in the state of the pressure distribution that matches the molding analysis result is 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 ranges, as the production requirement in the die height value in the state where the pressing force distribution matches the molding analysis result. You

As a method of adjusting the parallelism of the slide, an individual motor method (Patent Document 2) and a hydraulic cylinder method (Patent Document 3) have been invented. Generally, the amount of die height adjustment is several tens to several hundreds [mm], and the allowable value of parallelism is less than 1 [mm]. In both inventions, in long-distance driving in die height adjustment other than 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 required. On the other hand, in the present invention, during normal die height adjustment, all clutches (40a) are connected and all brakes (40b) are released for synchronous operation, and only when adjusting parallelism of the slide, the clutch (40a) is 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 is space-saving.

The configuration of the multi-point overload protector hydraulic pressure adjusting device of FIG. 5 will be described with reference to the drawing. Since the overload protector, which is a main component of the device, has a hydraulic damper structure, the overload protector and the overload protector hydraulic chamber have the same meaning. The multi-point overload protector oil pressure adjusting device adds an overload protector blocking device (50) as a pair to the overload protector (51), and adds an overload protector blocking device (51) as a pair to the overload protector blocking device (51). 50) and is connected to another overload protector by hydraulic piping. The overload protector shutoff device (50) has a pilot operated check valve (50a) and a pilot operated valve (50b) as basic components. The hydraulic pressure detector (52) will be described later, but is used as an index during adjustment during setup during production using a multi-point die height adjusting device.

A mode in which a fitting reference block, a multipoint die height adjusting device, and a multipoint overload protector hydraulic adjusting device, which are features of the present invention, are used will be described. The multi-point overload protector hydraulic adjustment device is used to adjust the above-mentioned multi-point die height when changing the press machine output balance in response to an eccentric load in the mold or when the parallelism of the slide exceeds the tolerance of the press machine. Used with equipment. 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 the other compartments. Is valid. Next, the upper and lower molds are set to the mating push-off state, and regarding the pressing force of the fitting reference block (10), if there is no load, the no-load pressing force upper limit value and lower limit value, which are stored information, are set upper and lower limit values. If the load is an actual load, the central upper and lower limits 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 LF, RF, LR, and RR sections are compared and judged. As a result, if the measured value does not reach the set lower limit value, operate the die height adjusting device for 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, operate the die height adjusting device of the section as described in the previous item to raise the die height and set the measured value of the pressing force. The compression amount 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 for each point, and the distribution of the pressing force in the die is analyzed by molding. To match. Then, in the multipoint overload protector hydraulic pressure adjusting device in a state where the pressurizing force 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 in the controller for use as a production requirement. Therefore, the control device of the press machine sets the check function of the pilot operated check valve (50a) in the state of the multipoint overload protector hydraulic pressure adjusting device in the state of the pressurizing force distribution that matches the molding analysis result. And the overload protector has a function of storing the actual load output upper limit value and the lower limit value, which are allowable ranges of hydraulic pressure, as the production requirement. In addition, under the condition of die height that realizes the pressure distribution that matches the molding analysis result, as a production condition for production setup, the overload protector hydraulic pressure adjusting device with no load and no molded object is used. The measured value of the oil pressure detector (52) is also stored in the control device. Therefore, the control device of the press machine sets the upper limit and lower limit of the no-load output, which is the allowable range of the overload protector hydraulic pressure under no load, under the die height setting condition that realizes the mating push-off condition that matches the molding analysis result. The value also has a function of storing it as a production requirement. In addition, there is no technical regulation on 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 form of the pilot operated valve (50b). In an environment where the check function is frequently used, when the pilot operated valve (50b) is demagnetized, the check function of the pilot operated check valve (50a) is enabled, and conversely, in an environment where the check function is not frequently used, It is rational to disable the check function of the pilot operated check valve when the pilot operated valve is demagnetized, but this is not a necessary condition.

Similar configurations (Patent Document 4 and Patent Document 5) have been invented for the hydraulic adjustment of the overload protector device. Both of the inventions are systems that actively adjust the hydraulic pressure at the pressurizing point, and thus require an expensive hydraulic pressure generating and adjusting device or a hydraulic device having a higher function than the conventional one. On the other hand, the present invention is a simple method of passively adjusting the hydraulic pressure by using the multi-point die height adjusting device, and does not require the addition of a high-priced hydraulic device or the enhancement of the function.

A form of confirmation of molding at the time of production using a fitting reference block, a multipoint die height adjusting device, and a multipoint overload protector hydraulic adjusting device, which are features of the present invention, will be described. There are two types of form confirmation during production: a form in which the mating push-off state during production coincides with the form analysis result, and a form in which quality is confirmed during production.

As a form in which the mating push-off state during production matches the molding analysis result, the mating push-off state matches the molding analysis result when the mold is mounted during production setup, achieving stable quality in production. .. In the conventional die mounting, only the die height of the entire slide is adjusted at the top dead center, and the conformity with the molding analysis result is not confirmed. The control device for a press machine according to the present invention has a die-height setting upper limit value and lower limit value for each of the LF, RF, LR, and RR sections in which a fitting and pressing state that matches a molding analysis result, that is, a molding result can be obtained. Point Setting of whether the check function of the pilot operated check valve (50a) of the overload protector hydraulic pressure regulator is enabled or disabled, and the upper limit of the no-load output pressure of the overload protector hydraulic pressure during mating push-off with no load It has a function of storing the value and the lower limit value and the no-load pressure upper limit value and the lower limit value of all the fitting reference blocks as the production requirement, and at the top dead center, it is a multi-point die height adjusting device. The multi-point overload protector oil pressure adjustment device is used to adjust the die height of each of the LF, RF, LR, and RR sections, and the sections that need to be blocked by the overload protector are blocked. By using the reference block, multi-point die height adjusting device, and multi-point overload protector hydraulic adjusting device, a pressure distribution that matches the molding analysis result is realized.

Specifically, first, at the top dead center immediately before mounting the die, the die heights of the LF, RF, LR, and RR sections are measured for each section, and the die height detector (42 in FIG. 4) and the die height setting upper limit value are set. If the measured value exceeds the set upper limit value, if the measured value is lower than the set lower limit value, the multi-point die height adjusting device is used to lower the die height. 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 set upper and lower limits. Further, whether the check function of the pilot operated check valve (50a in FIG. 5) of the multi-point overload protector hydraulic pressure adjusting device of each section is set valid or invalid is set to a state consistent with the production requirement.

Next, the slide is lowered to the bottom dead center, and the mating push-off state is set. In the overload protector of each section of LF, RF, LR, and RR, the no-load output pressure upper limit value and lower limit value, which are stored information, are set. The lower limit value is set and compared with the actual measurement value of the oil pressure detector (52 in FIG. 5) of the overload protector. If the actual measurement value exceeds the set upper limit value, the multi-point die height adjusting device is used to determine the actual measurement value. Raise the die height until it falls within the upper and lower limits of the no-load output pressure, and if the measured value does not reach the set lower limit, use a multi-point die height adjuster to put the measured value within the upper and lower limits of no load. Down the die height. Furthermore, in this state, the no-load pressurizing force upper limit value and the lower limit value of each fitting reference block of the production requirement, which is the stored information, are 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.If the measured value exceeds the set upper limit value, the control number of the mating reference block and the die height excess descent alarm are output, and the measured value is temporarily If the set lower limit value is not reached, the control number of the fitting reference block and the die height drop shortage alarm are output, and if the measured value is within the set upper and lower limits, a mounting normal signal at the time of setup is output.

Among the forms of confirmation of molding at the time of production, the forms of quality confirmation during production will be described. In quality inspection at the time of production, the mating push-off state is compared with the molding analysis result to realize automatic quality inspection. The control device for a press machine according to the present invention, for all the fitting reference blocks (10), sets the upper limit and the lower limit of the molding margin pressurizing force when molding the object to be molded and the upper and lower limits of the molding margin pressing force. Pressurized value of the central range The central upper limit value and the lower limit value have the function of storing and storing for each mold as the production requirement, and the measured value that is the pressurization force obtained from the production requirement and the fitting reference block (10). And the molding quality at the time of production is automatically inspected.

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 allowance upper and lower limit values of the production requirement, which is stored information, are used as the fitting reference. If the measured value exceeds the molding allowance pressure upper limit, the control number of the fitting reference block and the overpressure warning are output, and the measured value is the molding allowance pressure. If the lower limit value is not reached, the control number of the fitting reference block and the insufficient pressure alarm are output. It is also compared with the central upper and lower limits of the applied pressure in the central range of the upper and lower limits. As a result of comparison, if the center of the pressing force is within the upper and lower limits, it is judged that the molding state is good, and if it exceeds the center upper limit of the pressing force, the control number of the fitting reference block and the overpressure warning are issued. If it does not reach the central lower limit value of the pressing force, the control number of the fitting reference block and the insufficient pressure warning are output.

The fitting reference block can be applied to general 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 press machines with two or more points.

10 Fitting reference block 10a Top of fitting reference block (upper die contact surface)
10b Fitting reference block measuring unit 10c Fitting 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 reference)
21b Upper mold sub-molding surface 22 Lower mold (block having molding surface)
22a Positive molding surface of lower mold (positive standard)
22b Lower mold secondary molding surface 23 Object to be molded 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 shutoff device 50a Pilot operated check valve 50b Pilot operated valve 51 Overload protector (hydraulic chamber)
52 Oil pressure detector

Claims (4)

In the fitting reference block fixed to either the upper or lower mold fitting surface, that is, either the lower mold upper surface or the upper mold lower surface, and the contact surface with the mating mold when the upper and lower molds are fitted, It is formed as a contact reference that is associated with the reference of 1 to 1, and regulates the molding surfaces of the upper and lower molds to a positional relationship that matches the molding analysis result, and the area accuracy that can convert the vertical strain to the pressing force between the upper and lower molds. The fitting reference block is characterized in that a strain gauge is attached to the side surface of the structure. A press machine having the fitting reference block according to claim 1 and two or more pressurizing points, wherein a pair of clutches and brakes are provided to each die height adjuster at each pressurizing point. In a multi- point die height adjusting device, which is arranged as a pair, and the die height adjusting device can be individually adjusted with one motor, and in a press machine having two or more pressing points, A pilot operated check valve is arranged in each overload protector hydraulic chamber at each pressure point as a pair of the overload protector hydraulic chamber, and the check function of the check valve is enabled to enable the overload protector hydraulic chamber to the other hydraulic pressure. Shut off from the chamber, adjust the compression amount of the overload protector hydraulic chamber using the multi-point die height adjusting device, and adjust the pressurizing force at each pressurizing point of the press machine. A press machine having two or more pressurizing points having a load protector hydraulic pressure adjusting device, the press machine having an interface function of receiving a strain gauge signal from the strain gauge of the fitting reference block. machine. It is a control device used for the press machine of Claim 2, Comprising: The strain gauge signal of the said strain gauge of the said fitting reference block is converted into pressurizing force, and the pressurizing force is made to correspond with the pressurizing force of a molding analysis result. , the control apparatus characterized by adjusting the said multipoint die height adjusting device multipoint overload protector hydraulic adjustment device. A method for confirming molding of a press die using the control device according to claim 3, wherein the pressing force obtained by converting the strain gauge signal of the strain gauge of the fitting reference block is a result of a molding analysis. so as to coincide with the pressure, the multi-point die height adjusting device and said forming confirmation method of the press die, characterized in that adjusting the multipoint overload protector hydraulic adjustment device.

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