JP2730514B2 - Press working method and press working equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press working method and a press working apparatus, and more particularly to a simple press-fitting method for wrinkle press failure caused by vibration of a wrinkle press ring supported via a plurality of hydraulic cylinders. It relates to the technology to prevent.

[0002]

[Prior art]

(A) a plurality of cushion pads to which a predetermined movement resistance is applied, and (b) a plurality of cushion pads which are interposed in parallel between the cushion pads and the wrinkle retaining ring, and in which the pressure chambers are communicated with each other and through which fluid can flow. With a hydraulic cylinder, when wrinkling the peripheral portion of the press material between the wrinkle holding ring and the die, the pistons of the plurality of hydraulic cylinders are driven into neutral by being driven respectively. While the wrinkle holding load is evenly applied to the wrinkle holding ring through the plurality of fluid pressure cylinders, the wrinkle holding ring and the die mold together with the cushion pad in this state are opposed to the punch type against the movement resistance. Press machine which draws the press material along the forming surface of the punch by being relatively moved in the press direction. It is. JP-A-5-285
The device described in Japanese Patent No. 557 is an example of such a device, in which a wrinkle holding ring is placed via a cushion pin on a plurality of hydraulic cylinders provided on a substantially horizontal cushion pad, and a wrinkle holding ring added to the cushion pad is provided. When the hydraulic oil is elastically compressed by the load (movement resistance), the pistons of the plurality of hydraulic cylinders are respectively driven into a neutral state. Thus, the wrinkle holding load is transmitted uniformly to the wrinkle holding ring via the plurality of cushion pins regardless of the variation in the length of the cushion pin, the inclination of the cushion pad, and the dimensional error of the die.

On the other hand, it is proposed to provide a stroke holding pin for defining the approach position between the cushion pad and the die so that the pistons of the plurality of fluid pressure cylinders are driven into a neutral state at the time of wrinkle holding. According to such a press working device, the fluid pressure cylinder is reliably brought into the neutral state. In addition, since the cushion pad and the die are positioned via the stroke holding pins, the vibration of the wrinkle holding ring disposed between them and pressed by the fluid pressure cylinder toward the die, that is, wrinkles, Fluctuations in the wrinkle holding load during holding are suppressed. The press working apparatus described in Japanese Utility Model Laid-Open Publication No. Sho 62-20711 is an example of such a press working apparatus, in which a stroke holding pin is disposed outside a wrinkle holding ring so as to pass through a punch type or a bolster.

[0004]

However, when the stroke holding pin is arranged outside the wrinkle holding ring in this manner, a through hole is formed in the punch type or the bolster, or the stroke holding pin is formed in the die type or the cushion pad. A contact portion where the pin collides must be provided, and a large-scale remodeling is required not only for the die but also for the press working device itself. Also, since the wrinkle holding ring itself is supported only by the fluid pressure cylinder, the vibration of the wrinkle holding ring due to the collision with the die and the relative vibration between the wrinkle holding ring and the cushion pad, in other words, the change in the volume of the fluid However, pressure fluctuations caused by wrinkling cannot always be sufficiently prevented, and some fluctuations in the wrinkle holding load cannot be avoided.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a simple modification of a wrinkle holding defect caused by vibration of a wrinkle holding ring caused by collision with a die. It is to prevent it surely.

[0006]

A first invention for solving the problems is as follows.
(A) a plurality of cushion pads to which a predetermined movement resistance is applied, and (b) a plurality of cushion pads which are interposed in parallel between the cushion pads and the wrinkle retaining ring, and in which the pressure chambers are communicated with each other and through which fluid can flow. With a hydraulic cylinder, when wrinkling the peripheral portion of the press material between the wrinkle holding ring and the die, the pistons of the plurality of hydraulic cylinders are driven into neutral by being driven respectively. While the wrinkle holding load is evenly applied to the wrinkle holding ring through the plurality of fluid pressure cylinders, the wrinkle holding ring and the die mold together with the cushion pad in this state are opposed to the punch type against the movement resistance. Is relatively moved in the pressing direction by a pressing method in which the press material is drawn along the forming surface of the punch mold. (C) A part of the plurality of hydraulic cylinders is used as a torsion cylinder so as to butt at the time of holding down the wrinkle, thereby defining an approach position between the wrinkle holding ring and the cushion pad and equalizing other hydraulic pressure cylinders. The pressure cylinder is held in a neutral state, and the wrinkle press is performed by uniformly applying a predetermined wrinkle press load to the wrinkle press ring from the pressure equalizing cylinder.

[0007]

In such a press working method, a part of the fluid pressure cylinder may be caused to protrude at the time of wrinkle holding by, for example, a spacer. It requires only a small modification and can be easily and inexpensively applied to existing press working equipment. In addition, since the wrinkle holding ring and the cushion pad are positioned via the torso cylinder, the vibration of the wrinkle holding ring itself and the wrinkle holding ring can be reduced compared to the conventional case where the cushion pad and the die are positioned. Vibration relative to the cushion pad (pressure vibration of the fluid) is favorably suppressed, and fluctuations in the wrinkle holding load are further reduced.

In order to hold the wrinkle holding ring in a predetermined posture, it is desirable to set three or more of the above-mentioned thrust cylinders and to define the approach position between the cushion pad and the wrinkle holding ring at three or more points.

[0009]

According to a second aspect of the present invention, in the press working method according to the first aspect of the present invention, the fluid pressure increases due to a decrease in the volume of the fluid accompanying the pistons of the pressure equalizing cylinder and the thrust cylinder. By being
A predetermined wrinkle holding load is applied from the pressure equalizing cylinder to the wrinkle holding ring, and the wrinkle holding load is adjusted by changing the approach position.

[0010]

In other words, if the position of the cushion pad, which is defined by the torso cylinder, approaches the wrinkle holding ring, the follow-up stroke of the piston of the pressure equalizing cylinder changes. And the generated fluid pressure, that is, the wrinkle holding load changes, and the wrinkle holding load can be adjusted by the approach position. Thereby, it is possible to perform good drawing while wrinkle holding with a desired wrinkle holding load. By changing the approach position in the process of drawing, it is also possible to perform drawing while changing the wrinkle holding load.

[0011] The fluid pressure at the time of wrinkle holding down the piston of the fluid pressure cylinder is called generated fluid pressure, and is distinguished from the initial fluid pressure before the piston is driven.

[0012]

A third aspect of the present invention is directed to a first aspect of the present invention.
In the press working method of the invention or the second invention, a wrinkle holding load applied to the wrinkle holding ring from the pressure equalizing cylinder at the time of wrinkle holding is adjusted by a physical quantity of the fluid.

[0013]

[Operation and effect of the third invention] That is, if the initial fluid pressure or volume of the fluid before wrinkle holding is changed, or if a plurality of types of fluids having different bulk elastic coefficients are used properly,
Even if the follow-up stroke of the piston of the pressure equalizing cylinder is the same, in other words, even if the volume change amount of the fluid is the same, the generated fluid pressure changes and the wrinkle holding load changes. The load can be adjusted. Thereby, it is possible to perform good drawing while wrinkle holding with a desired wrinkle holding load. By changing the physical quantity of the fluid in the process of drawing, it is also possible to perform drawing while changing the wrinkle holding load.

In this case, the physical quantity of the fluid is such that the fluid pressure generated during compression can be changed even if the volume change of the fluid is the same as described above. For example, volume and bulk modulus.

[0015]

A fourth aspect of the present invention is directed to a first aspect of the invention.
In the press working method according to any one of the inventions to the third invention, a transmitted load of the body pushing cylinder at the time of wrinkle pressing is detected, and the approach position, the physical quantity of the fluid, and the transmitted load are equal to or less than a predetermined value. And adjusting at least one of the movement resistances of the cushion pad.

[0016]

In other words, if the approach position and the physical quantity of the fluid are changed, the load transmitted by the pressure equalizing cylinder at the time of holding down the wrinkles, that is, the load of holding down the wrinkles, changes. Since the sum of the load and the transmitted load of all the butting cylinders is the movement resistance of the cushion pad, the transmitted load of the butting cylinder changes according to the change in the transmitted load of the pressure equalizing cylinder, and the approach position and fluid By increasing the wrinkle holding load by adjusting the physical quantity, the transmission load of the trunk cylinder can be reduced to a predetermined value or less.
In addition, since the transfer load of the pressure equalizing cylinder is subtracted from the transfer resistance of the cushion pad, the transfer load of the thrust cylinder is determined by adjusting the shift resistance of the cushion pad. It is possible to Thus, it is possible to avoid a failure caused by an excessive transmission load such as buckling or plastic deformation of a cushion pin provided in a load transmission path of the body pushing cylinder.

In this case, the total transmitted load of all the butting cylinders can be obtained by an arithmetic expression or the like. Therefore, the approach position is determined so that the total transmitted load becomes equal to or less than a predetermined value without detecting the actual transmitted load. It is possible to adjust the physical quantity of the fluid and the fluid, and the movement resistance. However, in the case of a thrust cylinder, since the transmitted load greatly changes due to a slight dimensional error, even if the total transmitted load is less than a predetermined value, the transmitted load of any of the thrust cylinders may be excessive. Failures such as buckling and plastic deformation occur. For this reason, according to the present invention, the transmitted load of the torsion cylinder is actually detected and adjusted so that the transmitted load becomes equal to or less than a predetermined value, whereby a failure due to an excessive transmitted load is reliably avoided. You.

[0018]

A fifth aspect of the present invention is directed to a first aspect of the present invention.
In the press working method according to any one of the inventions to the fourth invention, a relative displacement between the cushion pad and the wrinkle holding ring at the time of wrinkle holding is detected, and the approaching position is set so that the relative displacement is equal to or less than a predetermined value. And adjusting at least one of a physical quantity of the fluid and a movement resistance of the cushion pad.

[0019]

[Function and effect of the fifth invention] That is, the relative displacement between the cushion pad and the wrinkle holding ring at the time of wrinkle holding is due to the fact that the thrust cylinder is not securely thrust.
Meaning that the generated fluid pressure and the wrinkle holding load fluctuate, but if the relative displacement is less than a predetermined value, it means that the thrust cylinder is securely hitting the cylinder and the fluctuation of the generated fluid pressure and the wrinkle holding load is small. means. Whether or not the butting cylinder collides is determined by the relationship between the transmitted load of the butting cylinder and the generated fluid pressure, and if the transmitted load of the butting cylinder is relatively larger than the transmitted load of the equalizing cylinder,
The butt cylinder protrudes. And since the transmitted load of the pressure equalizing cylinder, that is, the wrinkle holding load, can be adjusted by the approach position and the physical quantity of the fluid, the relative displacement between the cushion pad and the wrinkle holding ring is detected, and when the relative displacement is large, By adjusting the approach position and the physical quantity of the fluid so as to reduce the wrinkle holding load, it is possible to increase the transmission load of the thrust cylinder to cause thrust. In addition, since the transfer load of the pressure equalizing cylinder is subtracted from the transfer resistance of the cushion pad, the transfer load of the push cylinder is obtained. Therefore, the transfer load of the push cylinder is increased by adjusting the transfer resistance of the cushion pad. It is possible to do. As a result, the effect of preventing the wrinkle pressing load from fluctuating due to the butting of the butting cylinder can be reliably obtained.

[0020]

Sixth invention for solving the problems The sixth invention is a first invention.
In the press working method according to any one of the inventions to the fifth invention, a relative displacement between the wrinkle holding ring and the die mold at the time of wrinkle holding is detected, and abnormality is diagnosed based on whether or not the relative displacement is equal to or less than a predetermined value. It is characterized by performing.

[0021]

In other words, if the relative displacement between the cushion pad and the wrinkle holding ring is small, the change in the volume of the fluid is small and the fluctuation of the generated fluid pressure is small. Is relatively displaced substantially integrally with the die, even if the fluctuation of the generated fluid pressure is small, the actual wrinkle holding load on the press material may fluctuate, and a wrinkle holding defect may occur. For this reason, the relative displacement between the wrinkle holding ring and the die is detected, and if the relative displacement is larger than a predetermined value, the wrinkle presser is diagnosed as abnormal and an abnormal display lamp or the like is used. To let them know. This makes it possible to reliably and promptly prevent the occurrence of a defective product due to a wrinkle holding defect.

[0022]

[Seventh Means for Solving the Problems] A seventh aspect of the present invention provides:
(A) A cushion pad to which predetermined movement resistance is applied by the movement resistance applying means, and (b) a fluid interposed between the cushion pad and the wrinkle holding ring in parallel and the pressure chambers communicate with each other, so that fluid is A plurality of fluid pressure cylinders that can be circulated, and when wrinkling the peripheral portion of the press material between the wrinkle holding ring and the die, the pistons of the plurality of hydraulic pressure cylinders are driven into a neutral state, respectively. With this configuration, the wrinkle holding load is uniformly applied to the wrinkle holding ring via the plurality of fluid pressure cylinders, and in this state, the wrinkle holding ring and the die die together with the cushion pad resist the movement resistance. The punch material is relatively moved in the pressing direction with respect to the punch die, so that the press material is drawn along the forming surface of the punch die. A press processing apparatus for Engineering,
(C) A body thrust member for making a part of the plurality of hydraulic cylinders thrust a predetermined stroke earlier than the other hydraulic cylinders is provided, and some of the hydraulic cylinders are thrust at the time of wrinkle pressing as a thrust cylinder. ,
The approach position between the wrinkle holding ring and the cushion pad is defined, and the other fluid pressure cylinder is held in a neutral state as a pressure equalizing cylinder, and is uniformly acted on the wrinkle holding ring from the pressure equalizing cylinder. It is characterized in that wrinkle holding is performed by a wrinkle holding load.

[0023]

In such a press working apparatus, a part of the plurality of fluid pressure cylinders can be made to protrude when the wrinkle is pressed down by providing the protruding member, so that the above-mentioned press working apparatus can be used. 1
In the same manner as in the invention, the approach position between the wrinkle holding ring and the cushion pad is defined, and another fluid pressure cylinder is held in a neutral state as a pressure equalizing cylinder, and the wrinkle presser applied to the wrinkle holding ring from the pressure equalizing cylinder. Wrinkle holding is performed by the load. Therefore, the same function and effect as those of the first invention can be obtained.

[0024]

According to an eighth aspect of the present invention, in the press working apparatus according to the seventh aspect of the present invention, an elastic member is interposed at a position where the cylinder comes into contact with the cylinder when the cylinder collides. .

[0025]

In such a press working apparatus, since an elastic member is interposed in a portion where the butt cylinder pierces, the impact at the time of piercing is alleviated by its elastic deformation, and the cushion pad and the cushion pad are formed. The relative speed with respect to the wrinkle holding ring changes smoothly and becomes substantially zero.
Thereby, the relative vibration (fluid pressure vibration) between the wrinkle holding ring and the cushion pad is suppressed, and the fluctuation of the wrinkle holding load is more effectively prevented.

Further, when the elastic member is interposed in this manner, the dimensional error of the thrust cylinder is absorbed by the elastic deformation of the elastic member, so that the variation in the transmission load of each thrust cylinder caused by the dimensional error is suppressed. Thus, a failure such as a case where the transmitted load is biased to a specific cylinder end cylinder and the cushion pin provided in the load transmission path of the cylinder end cylinder is plastically deformed is prevented.

[0027]

According to a ninth aspect of the present invention, there is provided the press working apparatus according to the seventh or eighth aspect of the present invention, wherein the fluid flows through a flow path that connects the thrust cylinder and the pressure equalizing cylinder. Characterized in that a distribution restricting means for restricting the above is provided.

[0028]

In such a press working apparatus, in the press working apparatus, when the piston of the ram cylinder is driven in and the fluid in the pressure chamber is pushed out and flows to the pressure equalizing cylinder side, the pressure between the pressure equalizing cylinder and the pressure equalizing cylinder is reduced. Since the flow is restricted by the flow restricting means provided in the flow path, the repulsion resistance of the piston is increased to reduce the impact at the time of body thrust, and the relative speed between the cushion pad and the wrinkle holding ring changes smoothly. Is almost zero. Thereby, the relative vibration (fluid pressure vibration) between the wrinkle holding ring and the cushion pad is suppressed, and the fluctuation of the wrinkle holding load is more effectively prevented.

[0029]

Tenth aspect of the present invention is to provide a tenth aspect of the present invention.
In the press working apparatus according to any one of the seventh to ninth aspects of the present invention, the thrust cylinder is a fluid pressure cylinder at a portion where a wrinkle pressing force is to be partially increased.

[0030]

Operation and effect of the tenth invention For example, when drawing is performed on a substantially rectangular press material, it is necessary to increase the wrinkle holding force at the corner in order to reduce the inflow of the corner. Although a large wrinkle holding surface pressure is obtained by forming or increasing the wrinkle holding surface, a fluid pressure cylinder in a portion where it is desired to partially increase the wrinkle holding force is used as a body pushing cylinder. . In other words, since the transmitted load of the torso cylinder is larger than the transmitted load of the pressure equalizing cylinder, if the fluid pressure cylinder at the position where the wrinkle pressing force is to be increased is used as the torsion cylinder, it is possible to increase the bead pressing force such as increasing the bead. Special measures are unnecessary or reduced,
It is also possible to avoid occurrence of a wrinkle holding defect due to a partial increase in the wrinkle holding load caused by the body thrust.

Although the above is the operation and effect peculiar to the tenth invention, it is also possible to use a fluid pressure cylinder in a portion where no press material is present as a thrust cylinder, in which case, at a position substantially corresponding to the thrust cylinder. It is desirable that the wrinkle holding ring and the die mold be brought into contact with each other by a distance block or the like.

[0032]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the press working apparatus 10 of FIG. 1, the bolster 14 to which the punch mold 12 is attached is positioned and fixed substantially horizontally at a predetermined position on the bed 16, while the slide plate 20 to which the die mold 18 is attached is moved by an elevation drive means (not shown). It can be moved up and down. The bolster 14 is provided with a large number of through holes 26 for disposing the cushion pins 24, and a cushion pad 28 for supporting the cushion pins 24 is disposed below the bolster 14. . The cushion pins 24 support the wrinkle holding ring 30 provided together with the punch mold 12, and are provided in an arbitrary number at predetermined positions predetermined according to the shape of the wrinkle holding ring 30. You. The punch type 12 and the die type 1
A press die is configured by the wrinkle holding ring 8 and the wrinkle holding ring 30, and is used by being detachably attached to the press working device 10.

The cushion pad 28 has a through hole 26
, A plurality of hydraulic cylinders 32 are provided, and the lower ends of the cushion pins 24 are mounted on the pistons of the corresponding hydraulic cylinders 32a and 32b. The hydraulic cylinder 32 corresponds to a hydraulic cylinder using hydraulic oil as a fluid, and the pressure chambers to which the hydraulic oil is supplied are communicated with each other through a communication oil passage 34, and the hydraulic pressure is controlled by hydraulic pressure adjusting means 36. It is supposed to be. The hydraulic cylinders 32a and 32b are
The wrinkle holding ring 30 is actually provided via the cushion pin 24.
And the hydraulic cylinder 3
Reference numeral 2a functions as a pressure equalizing cylinder, and allows the press material 38 to flow while wrinkle-pressing with a predetermined wrinkle-pressing force. The hydraulic cylinder 32b functions as a thrust cylinder, and three or more are set. The boss 40 provided on the lower surface of the wrinkle holding ring 30 causes the piston to be driven forward by the boss 40 before the hydraulic cylinder 32a, thereby causing a thrust. The approach position to the cushion pad 28 is defined while holding the wrinkle holding ring 30 in a substantially horizontal posture. Hereinafter, when the two are distinguished from each other, they are referred to as a pressure equalizing cylinder 32a and a cylinder end cylinder 32b. And
For example, when the wrinkle holding ring 30 is rectangular as shown in FIG. 2, bosses 40 are provided at four corners that impede the inflow of the press material 38 with a large wrinkle holding force, and the boss 40 is provided at a position corresponding to the corner. The hydraulic cylinder 32 is a torsion cylinder 32b. FIG. 1 shows a state in which the wrinkle holding ring 30 is lowered until the lower surface of the wrinkle holding ring 30 comes into contact with the cushion pin 24 on the pressure equalizing cylinder 32a. Only being driven. The boss 40 corresponds to a trunk member. Strictly speaking, the boss 40 is also provided on a portion of the equalizing cylinder 32a where the cushion pin 24 is brought into contact.
Although a boss having a smaller height is provided, it is omitted in this embodiment.

The cushion pad 28 is vertically movable while being guided by a guide (not shown). The cushion pad 28 is always urged upward by an air cylinder 42 functioning as a movement resistance applying means, and is always at a rising end position. Is to be held. Therefore, when the die 18 is further lowered from the state shown in FIG. 1, the hydraulic cylinders 32a and 32b are pinched between the cushion pad 28 and the wrinkle holding ring 30, and the cylinder thrust cylinder 32b is pressed.
Of the wrist press ring 30 and the cushion pad 28 is defined, and the pressure equalizing cylinder 32a is set in a neutral state so that the wrinkle press load corresponding to the hydraulic pressure generated at that time is equalized. It is uniformly applied to the wrinkle holding ring 30 from the cylinder 32a via the cushion pin 24. When the die 18 is further lowered, the cushion pad 28 is lowered integrally with the wrinkle holding ring 30 against the urging force (movement resistance) of the air cylinder 42, and the peripheral edge of the press material 38 is wrinkled down. In this state, drawing is performed along the forming surface of the punch mold 12. An air pressure adjusting means 46 is connected to the air chamber 44 of the air cylinder 42, and the movement resistance of the cushion pad 28 is controlled by adjusting the air pressure. In the present embodiment, a pressure equalizing cushion device 48 includes the air cylinder 42, the cushion pad 28, the hydraulic cylinder 32, the cushion pin 24, and the like.

As described above, the press working apparatus 1 of this embodiment
0 indicates that a part of the large number of hydraulic cylinders 32 is made to butt at the time of wrinkle holding (during drawing) as the ramming cylinder 32b, whereby the approach position between the wrinkle holding ring 30 and the cushion pad 28 is defined, The pressure equalizing cylinder 32a is maintained in a neutral state, and the wrinkle pressing load is transmitted evenly. In that case, it is only necessary to provide the boss 40 on the wrinkle holding ring 30 in order to make the torso cylinder 32b to butt, so that a stroke holding pin is provided and the approach position between the cushion pad 28 and the die 18 is defined. It requires only a small modification and can be easily and inexpensively applied to existing press working equipment.

Further, since the wrinkle holding ring 30 and the cushion pad 28 are positioned through the cylinder thrust cylinder 32b, the wrinkle holding ring is compared with the conventional case where the cushion pad 28 and the die 18 are positioned. Vibration of the cushion 30 itself and relative vibration (hydraulic vibration) between the wrinkle holding ring 30 and the cushion pad 28 are favorably suppressed,
Fluctuations in the wrinkle holding load are further reduced.

Although the transmitted load of the body pushing cylinder 32b is larger than the transmitted load of the pressure equalizing cylinder 32a, in this embodiment, the wrinkle holding ring 30 which requires a large wrinkle holding force in order to inhibit the inflow of the press material 38. Since the boss 40 is provided at the corner portion, and the hydraulic cylinder 32 at the corner portion is made to butt as the butt cylinder 32b, a wrinkle holding defect occurs due to a partial increase in the wrinkle holding load due to the butt end. Is avoided, and special means such as enlarging the bead to increase the wrinkle holding force at the corner portion is unnecessary or reduced.

The press working method and the press working apparatus 10 of this embodiment correspond to one embodiment of the first, seventh and tenth aspects.

Here, assuming that the maximum stroke of the hydraulic cylinder 32 is X _max , the height h _{b of the} boss 40 is
Is set within the range of the following equation (1). The number of the hydraulic cylinders 32a and 32b used is n, the number of the thrust cylinders 32b is m, the transmitted load of the equalizing cylinder 32a, ie, the wrinkle holding load for each cylinder, is f, and the total of the plurality of thrust cylinders 32b is The transmission load is F _D , the movement resistance of the cushion pad 28 due to the air cylinder 42 is F, the initial volume of the entire hydraulic oil including the pressure chamber of the hydraulic cylinder 32 and the inside of the communication oil passage 34, that is, the die 18 is separated upward. V ₀ , the initial hydraulic pressure at that time is P ₀ , and the hydraulic oil at the time when the pistons of the hydraulic cylinders 32 are driven into the pistons of the hydraulic cylinders 32. The amount of change in volume is ΔV, the generated oil pressure at that time is P ₁ , and the amount of change in oil pressure is ΔP (= P ₀ −
P ₁ ), the bulk modulus of the hydraulic oil is K, the hydraulic cylinder 32
When the cross-sectional area of the (pressure receiving area) S, a mean thrust dimensions of the piston of the pressure equalization cylinder 32a and X _av, the following equation (2) -
(5) is established. _{h b <X max ··· (1} ) F = F D + (n-m) f ··· (2) K = -ΔP / (ΔV / V 0) ··· (3) ΔV = S (n −m) X _av + Sm (X _av + h _b ) = SnX _av + Smh _b (4) f = SP ₁ (5)

From the above equations (3) and (4), the following equation (6) is obtained. By rewriting this, the following equation (7) is obtained, and the following equation (7) is obtained.
By substituting into the equation, the equation (8) is obtained. And
When F _D is obtained from the above equations (2) and (8), the following equation (9) is obtained.

(Equation 1)

As is apparent from the above equation (8), the transmitted load by the pressure equalizing cylinder 32a, that is, the wrinkle pressing load f
Because represented the initial oil pressure P ₀ as a parameter, it is possible to adjust the holding force f by the initial oil pressure P _0, the initial oil pressure P ₀ which holding force f ₀ is obtained desired, wrinkle holding By substituting f ₀ as the load f, the _value can be obtained according to the equation (8). Therefore, the hydraulic pressure adjusting means 36 is functionally set to P as shown in FIG.
₀ and calculating means 50 and the hydraulic control unit 52 controller 54 with a pump 58 to be output to the hydraulic cylinder 32 side pumping hydraulic oil from the tank 56, communicating oil passage 34
An electromagnetic on-off valve 60 for releasing hydraulic oil in the tank to the tank 56 and a hydraulic pressure sensor 62 are provided, and when a desired wrinkle holding load f ₀ or the like is input, the P ₀ calculating means 50 performs the above (8). together determine the initial pressure P ₀ from the equation, the pump 5 while reading the actual hydraulic pressure from the oil pressure sensor 62 by a hydraulic control unit 52 so that its initial pressure P ₀
8 and the operation of the electromagnetic on-off valve 60 can be controlled, and the hydraulic pressure can be automatically adjusted so that the wrinkle press is performed with a desired wrinkle press load f ₀ . Thereby, it is possible to perform good drawing while wrinkle holding with a desired wrinkle holding load f ₀ . Such a method of adjusting the wrinkle pressing load f corresponds to an embodiment of claim 3,
As is clear from the equation (8), the wrinkle holding load f can be adjusted by the initial volume V ₀ and the bulk elastic coefficient K. For example, a volume changing cylinder is provided to change the initial volume V _0. Is also good. Further, the hydraulic pressure and the volume can be changed according to the press stroke, and the wrinkle pressing load f can be changed in the process of drawing.

[0042] The blank-holding force f also because it is a parameter of the height h _b of the boss 40 as is clear from equation (8), also adjust the blank-holding force f by the height h _b Possible and desired wrinkle holding load f ₀
Into the equation (8) to obtain the wrinkle holding load f
₀ is required to have the height h _b obtained. Since the boss 40 in this embodiment is provided integrally with the pressure ring 30, it may be set the height h _b in accordance with the blank-holding force f ₀ to a desired during processing of the boss 40 but, boss Even after the processing of the boss 40 and the cushion pin 2
And the like sandwiching the shim between 4 can adjust the height h _b. Thereby, it is possible to perform good drawing while wrinkle holding with a desired wrinkle holding load f ₀ . Such a method of adjusting the wrinkle pressing load f corresponds to an embodiment of the present invention. Note that sandwich the wedge constitutes a boss 40 separately, such as changing the height h _b by advancing and retracting the wedge, provided Dozuki size changing means for changing the height h _b manually or automatically lever, it is possible to easily change the height h _b.

Further, in order to make the cylinder thrust cylinder 32b thrust, as shown in the following equation (10), each transmission load F _D / m of the thrust cylinder 32b is equalized with the pressure equalizing cylinder 32a.
Must be larger than the transmission load f. By substituting the above equation (2) into this relationship, the following equation (11) is obtained. Therefore, the desired wrinkle holding load f ₀ is
It is necessary to set the value within the range satisfying the expression (11). If the expression (11) is not satisfied within the allowable range of the wrinkle pressing load f ₀ , the movement resistance F satisfying the expression (11) is obtained. ,
The air pressure of the air cylinder 42 may be changed by the air pressure adjusting means 46 so that the movement resistance F is obtained. However, the equations (10) and (11) represent the total transmitted load F _D
Are equally distributed to the m thrust cylinders 32b. Actually, each of the thrust cylinders 32 b
b, the transmitted load greatly differs.
Cushion pin 24 is required to ensure that 2b
It is necessary to set the movement resistance F with a margin in consideration of the variation in the length dimension. F _D / m> f (10) F-nf> 0 (11)

On the other hand, if the transmission load of the cylinder 32b becomes excessive, the cushion pin 24 on the cylinder 32b may buckle or plastically deform. failure so as not to cause the (9) total transmitted load F _D required by the equation it is desirable to have a smallest possible value range that yields Dozuki. That is, the wrinkle holding load f, the initial oil pressure P ₀ , and the height dimension h _b are:
(9) Total transmitted load F _D is calculated according to equation, is to set in a range equal to or smaller than a predetermined value so as not to cause failure of buckling.

However, each cylinder 32
The transmission load of b is slightly smaller than the length of the cushion pin 24.
As described above,
To the total transmitted load F_DWrinkles so that
Pressing load f and initial oil pressure P₀, Height dimension h_bSet
Also, the transmission load of any of the cylinders 32b is excessive.
Otherwise, a failure such as buckling may occur. So, for example,
For example, as shown in FIG.
A load sensor 66 such as a strain gauge is attached to the cushion pin 24.
Mounting, actual transmitted load of individual cushion pins 24
And the maximum value of the transmitted load is
A value less than a predetermined value to prevent failure
It is possible to perform the proper wrinkle presser
Wafer holding load f₀Within the allowable range of the initial hydraulic pressure P₀Adjust
It is desirable to do. In this way, excessive transmission load
Failures such as buckling due to weight can be reliably avoided. this
Corresponds to one embodiment of claim 4, but the initial oil
Pressure P₀Instead of the initial volume V ₀And height dimension h_bAdjust
You may make it. Also, as is apparent from equation (9).
The total transmitted load F_DCan be adjusted,
If the above transmitted load exceeds the specified value, move resistance
Adjust the air pressure of the air cylinder 42 so that F becomes smaller.
It may be performed.

In FIG. 4 described above, an optional equalizing cylinder 3
A load sensor 68 such as a strain gauge is also attached to the cushion pin 24 on the upper side 2a to detect the actual transmitted load (corresponding to the wrinkle holding load f) of the pressure equalizing cylinder 32a, and the transmitted load is detected by the cylinder thrust cylinder 32b. It is possible to determine whether or not the torsion cylinder 32b is in a torsion state, depending on whether or not the transmission load is smaller. That is, as shown in FIG. 5, since the transmitted load of the torsion cylinder 32b vibrates due to the impact of the collision, it is difficult to determine whether or not the torsion state has occurred from this load waveform alone. If the value f _b is greater than load transmitted f _a pressure equalization cylinder 32a is mean that Dozuki state is maintained. Therefore, for example, the press working apparatus 10 is operated while gradually decreasing the initial oil pressure P ₀ from the maximum value within the allowable range of the wrinkle holding load f ₀ at which the appropriate wrinkle holding is performed, and the pressure equalizing cylinder 32 a
Of the minimum value f _b of the transmission load of the load transmitted f _a and Dozuki cylinder 32b are respectively measured, f _a <Dozuki cylinder 32b Once turned f _b is determined to what became Dozuki state, the initial hydraulic pressure P at that time Actual drawing may be performed at ₀ . As a result, it is possible to reliably obtain the effect of preventing the wrinkle pressing load from fluctuating due to the butting of the torsion cylinder 32b.
The transmission load of 2b is substantially minimized, and the buckling of the cushion pin 24 and the like are well avoided. Instead of the initial oil pressure P ₀ , the initial volume V ₀ and the height dimension h _b may be changed, or the movement resistance F may be changed by adjusting the air pressure of the air cylinder 42. When the adjustment is made by the movement resistance F, for example, the range that satisfies the above equation (11), that is, nf may be gradually increased with the minimum value.

If the variation of the transmitted load of the pressure equalizing cylinder 32a is substantially zero as shown in FIG.
Is in the torsion state, and if the transmitted load of the equalizing cylinder 32a fluctuates, it can be determined that the torsion cylinder 32b is not torsion, so the torsion cylinder 32b is torsion only from the waveform of the transmitted load of the equalizing cylinder 32a. It can also be determined whether or not. Therefore, for example, the press working device 10 is operated while gradually reducing the initial oil pressure P ₀ from the maximum value within the allowable range of the wrinkle holding load f ₀ at which the appropriate wrinkle holding is performed, thereby reducing the transmitted load of the equalizing cylinder 32a. measured, when it varies the width of the transmitted load is below a predetermined value of approximately zero, it is determined that Dozuki cylinder 32b becomes Dozuki state, by to perform the actual drawing an initial pressure P ₀ at the time Good. As a result, the effect of preventing the wrinkle holding load from fluctuating due to the butting of the torsion cylinder 32b can be reliably obtained. In this case,
The transmitted load of the torsion cylinder 32b is substantially minimized in a range where the torsion cylinder 32b is in the torsion state, so that the buckling of the cushion pin 24 and the like are favorably avoided. It should be noted that the initial volume V ₀ and the height h _b may be changed instead of the initial oil pressure P ₀ , and the movement resistance F may be changed by adjusting the air pressure of the air cylinder 42.

The pressing device 10 shown in FIG.
The acceleration is applied to the pad 28 and the wrinkle holding ring 30, respectively.
Attach sensors 70 and 72, and press
The acceleration in the vertical direction
In addition to calculating the displacement, the difference between the displacements,
The displacement is calculated and the initial displacement is set so that the relative displacement becomes substantially zero.
Period hydraulic pressure P₀This is the case when adjusting. That is, the acceleration
When the integration is performed twice, the displacement amount is obtained, and the displacement amount is calculated.
From the difference between the cushion pad 28 and the wrinkle holding ring 30
Relative displacement is determined. In addition, cushion at the time of wrinkle holding
The relative displacement between the pad 28 and the wrinkle holding ring 30
Indicates that the torsion cylinder 32b is not
The hydraulic pressure generated by the change in hydraulic oil volume₁Yashiwawa foot
While it means that the load f is fluctuating, its relative change
If the position is almost zero, the torsion cylinder 32b is
And there is no change in the volume of hydraulic oil.₁Yaw
This means that the fluctuation of the pressing load f is substantially zero. But
Thus, for example, the initial hydraulic pressure P ₀The proper wrinkle presser is done
Wrinkle holding load f₀Gradually from the maximum value within the allowable range
Activating the press working device 10 while lowering
Displacement is measured, and the relative displacement falls below a predetermined value of approximately zero.
If the ramming cylinder 32b is in the ramming state
And the initial hydraulic pressure P at that time₀Perform the actual drawing process with
Just do it. Thereby, the torsion cylinder 32
The effect of preventing the wrinkle holding load from fluctuating due to the torso b
And in this case,
In the range in which the solder 32b is in the torsion state.
The transmission load of the damper 32b becomes substantially minimum, and the cushion pin 2
The buckling of No. 4 is well avoided. This is one of claims 5
This corresponds to the embodiment, but the initial hydraulic pressure P₀instead of
Initial volume V₀And height dimension h_bTo adjust
good. Also moved by adjusting the air pressure of the air cylinder 42
The resistance F is changed so that the relative displacement becomes substantially zero.
You can also. The speed is measured by the speed sensor
To calculate the relative displacement,
It is also possible to directly detect the relative displacement.

In FIG. 6, an acceleration sensor 74 is further attached to the die 18 to measure the acceleration in the pressing direction, that is, the vertical direction when the wrinkle is pressed, to obtain the amount of displacement, and to determine the amount of displacement and the wrinkle holding ring. The difference from the displacement amount of No. 30, that is, the relative displacement is calculated, and abnormality diagnosis is performed based on whether the relative displacement is substantially zero or not.
That is, the cushion pad 28 and the wrinkle holding ring 30
If substantially zero relative displacement between, although variation of the hydraulic pressure generated P ₁ hydraulic oil volume change of as described above without meant to be substantially zero, the cushion pad 28 and pressure ring it, etc. When the die 30 is relatively displaced substantially integrally with the die 18, the actual wrinkle pressing load on the press material 38 fluctuates, and a wrinkle holding defect may occur. For this reason, the relative displacement between the wrinkle holding ring 30 and the die 18 is determined, and if the relative displacement is larger than a predetermined value of substantially zero, the wrinkle presser is diagnosed as abnormal and an abnormal display is performed. The abnormality is notified by a lamp or the like.
This makes it possible to reliably and promptly prevent the occurrence of a defective product due to a wrinkle holding defect. This corresponds to an embodiment of claim 6, but also in this case, the relative displacement can be obtained by measuring the speed by a speed sensor, or the relative displacement can be directly detected by a distance sensor. is there.

The press machine 10 and its adjustment method and abnormality diagnosis method have been described in detail above.
Another embodiment of the present invention will be described. In the following embodiments, portions common to the press working apparatus 10 are denoted by the same reference numerals, and description thereof is omitted.

In the press working apparatus 80 shown in FIG. 7, instead of providing the boss 40 on the wrinkle holding ring 30, a bobbin pin 82 longer than the length L of the cushion pin 24 by ΔL is provided on each of the bobbin cylinders 32b. This is the case when it is set. The dimension ΔL corresponds to the height dimension h _b of the boss 40. The same operation and effect as those of the press working device 10 are obtained, and the adjustment method and the abnormality diagnosis method can be applied by attaching a load sensor or an acceleration sensor. . In addition, in this embodiment, since it is only necessary to prepare the torsion pin 82 longer than the cushion pin 24 and to dispose it in place of the cushion pin 24, it is not necessary to modify the main body or the mold of the press working device 80, and the conventional art is not required. It can be applied very simply and inexpensively to a press working device. The body push pin 82 corresponds to a body push member.

FIG. 8 shows a press working device 84 in which a spacer 86 is inserted into a pressure chamber of each of the cylinders 32b. The thickness of the spacer 86 corresponds to the height h _b of the boss 40, the the similar effects as the press working apparatus 10 is obtained, the adjusting method and the abnormality diagnosis method by attaching a load sensor or an acceleration sensor Can be applied. The spacer 86 corresponds to a trunk member.

The pressing device 88 shown in FIG. 9 is a case where a spacer 90 is provided below each of the cylinders 32b. The thickness of the spacer 90 is the height h _{b of the} boss 40.
In addition to the above, the same operation and effect as those of the press working apparatus 10 can be obtained, and the adjustment method and the abnormality diagnosis method can be applied by attaching a load sensor or an acceleration sensor. The spacer 90 corresponds to a trunk member.

FIG. 10 shows the press working device 84 of FIG.
In place of the spacer 86, an elastic member 92, such as rubber, urethane, or a spring, is pressed into the bottom of the pressure chamber of the push cylinder 32b, that is, when the piston 94 is pushed.
The elastic member 92 functions as a body pushing member, which corresponds to an embodiment of the present invention. In this case, since the impact when the piston 94 of the cylinder thrust cylinder 32b strikes the body is alleviated by the elastic deformation of the elastic member 92, the relative speed between the cushion pad 28 and the wrinkle holding ring 30 changes smoothly to substantially zero. Becomes Thus, the relative vibration of the pressure ring 30 and cushion pad 28 (the vibration of the hydraulic pressure generated P ₁₎ is suppressed, the variation of the blank-holding force is better prevented.

When the elastic member 92 is interposed in this way, the dimensional errors of the plurality of cylinders 32b and the cushion pins 24 are absorbed by the elastic deformation of the elastic member 92. Variations in the transmitted load of the torsion cylinder 32b are suppressed, and a failure such as the cushion pin 24 being plastically deformed due to the transfer load being biased toward a specific torsion cylinder 32b is prevented.

Here, the barrel piercing syringe at the time of wrinkle holding is used.
Total transmission load F of the damper 32b_DIs transmitted by the elastic member 92.
Total load F_EAnd generated oil pressure P₁Total transmitted load due to
F_FAnd the load F_EIs the bullet of the elastic member 92
Coefficient k, average deformation Y at wrinkle holding_avAnd the following equation
Expressed in (12), the load F_FIs the sectional area S of the elastic member 92
_EIs represented by the following equation (13). Also, the elastic member 9
If the height dimension of T is 2, the height dimension h_bAgainst
The relationship of the following equation (14) holds, and one of the elastic members 92 hits.
Volume of V_EThen, the initial volume V of the hydraulic oil₀Is
The following equation (15) is obtained. And these equations (14),
Substituting equation (15) into equations (8) and (9)
Thus, the following equations (16) and (17) are obtained. But
Therefore, also in this case, the initial hydraulic pressure P₀And height dimension T
Further, the wrinkle holding load f can be adjusted or the initial hydraulic pressure P can be adjusted.₀And high
The total transmitted load F is adjusted by adjusting the length T, the moving resistance F, etc._D
Is not more than a predetermined value.

(Equation 2)

In the above example, the elastic member 92 itself functions as a torsion member. However, the elastic member and the torsion member may be provided separately. For example, in the press working device 10 in FIG. 1, the press working device 80 in FIG. 7, and the press working device 88 in FIG. 9, elastic members such as rubber, urethane, and spring may be provided in the pressure chambers of the respective cylinders 32b. it can.

FIG. 11 shows an orifice 98 for reducing the flow cross section as a flow restricting means for restricting the flow of the hydraulic oil at a branch portion 96 of the communication oil passage 34 which communicates with the pressure chamber of the cylinder thrust cylinder 32b. The case corresponds to an embodiment of claim 9. In this case, the torso cylinder 3
When the hydraulic oil in the pressure chamber is pushed out by the piston of 2b and pushed out to the pressure equalizing cylinder 32a side, the flow is hindered by the orifice 98. As a result, the relative speed between the cushion pad 28 and the wrinkle holding ring 30 changes smoothly and becomes substantially zero. Thus, the relative vibration of the pressure ring 30 and cushion pad 28 (the vibration of the hydraulic pressure generated P ₁₎ is suppressed, the variation of the blank-holding force is better prevented.

In the press working apparatus 100 shown in FIG. 12, the boss 40 is provided on the lower surface of the portion where the press material 38 does not exist, that is, the portion where the wrinkle pressing is not performed, and the hydraulic cylinder 32 immediately below the boss 40 is used as a cylinder end cylinder 32b. Boss 4
In this case, a distance block 102 that comes into contact with the die 18 when the press material 38 is pressed with a predetermined wrinkle pressing load is attached to the upper surface of the portion where 0 is provided. In this case, since the transmitted load of the torsion cylinder 32b is directly transmitted to the die 18 via the distance block 102, an excessive load does not act on the press material 38, and the wrinkle holding defect does not occur. In addition, the cushion pad 28 and the wrinkle holding ring 30 are
b and wrinkle holding ring 3
Since the 0 and the die 18 are positioned by the distance block 102, the fluctuation of the wrinkle holding load is more effectively prevented. FIG. 12 shows the distance block 102 strictly because the wrinkle press is not sufficiently performed in a state before the butting cylinder 32b does the butting.
A gap remains between the die and the die 18. Further, the distance block 102 only needs to be interposed between the wrinkle holding ring 30 and the die 18 or a member that moves integrally with the die 18, and is attached to the die 18 or abuts on the slide plate 20. You may let it.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be embodied in other forms.

For example, in the above-described embodiment, all the hydraulic cylinders 32 are communicated via the communication oil passage 34.
A large number of hydraulic cylinders 32 may be divided into a plurality of areas, and the pressure chambers may be communicated for each area to control wrinkle holding load. In this case, it is desirable to provide three or more torso cylinders 32b as a whole.

In the above-described embodiment, the air cylinder 42 is used as the moving resistance applying means. However, various other means such as a spring or a means using a flow resistance of a fluid can be used.

Although the hydraulic cylinder is used as the hydraulic cylinder in the above embodiment, other hydraulic cylinders such as those using other liquids or gel-like fluids may be used.

In each of the press working apparatuses of the above-described embodiments, the punch die 12 is provided at a fixed position. However, a punch die and a wrinkle holding ring are disposed above a fixed die die, and these are placed below. The configuration of the press working device can be changed as appropriate, for example, the drawing process can be performed by moving the pressing device.

Although not specifically exemplified, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of a press working apparatus according to claim 7, which can suitably execute the press working method according to claim 1;

FIG. 2 is a view for explaining a positional relationship between a cylinder butting cylinder and a wrinkle holding ring in the press working apparatus of FIG.

FIG. 3 is a diagram illustrating a specific example of a hydraulic pressure adjusting unit in the press working device of FIG. 1;

FIG. 4 is a diagram showing an example of a case where a load sensor is attached to a cushion pin of the press working device of FIG. 1;

FIG. 5 is a diagram showing an example of a load waveform detected by the load sensor of FIG.

FIG. 6 is a diagram showing an example of a case where the acceleration sensor is attached to a cushion pad, a wrinkle holding ring, and a die of the press working apparatus of FIG. 1;

FIG. 7 is a schematic diagram for explaining another example of the press working apparatus of claim 7, which can suitably execute the press working method of claim 1;

FIG. 8 is a schematic diagram for explaining still another example of the press working apparatus of claim 7, which can suitably execute the press working method of claim 1;

FIG. 9 is a schematic diagram for explaining still another example of the press working apparatus of claim 7, which can suitably carry out the press working method of claim 1;

FIG. 10 is a cross-sectional view illustrating an example of a case where an elastic member is disposed in a pressure chamber of a cylinder butting cylinder.

FIG. 11 is a diagram illustrating an example of a case where a flow restricting unit is provided in a flow path communicating with a pressure chamber of a trunk cylinder.

FIG. 12 is a schematic view for explaining still another example of the press working apparatus of claim 7, which can suitably carry out the press working method of claim 1;

[Explanation of symbols]

 10, 80, 84, 88, 100: Pressing machine 12: Punch type 18: Die type 28: Cushion pad 30: Wrinkle holding ring 32a: Equalizing cylinder (fluid pressure cylinder) 32b: Cylinder cylinder (fluid pressure cylinder) 40 : Boss (body push member) 42: Air cylinder (movement resistance applying means) 82: Body push pin (body push member) 86, 90: Spacer (body push member) 92: Elastic member (body push member) 98: Orifice (flow restriction means)

Claims (10)

(57) [Claims] 1. A plurality of fluids which are interposed in parallel between a cushion pad to which a predetermined movement resistance is given and a cushion pad and a wrinkle retaining ring, and in which pressure chambers are communicated with each other to allow fluid to flow. A pressure cylinder, and when wrinkling the peripheral portion of the press material between the wrinkle holding ring and the die, the pistons of the plurality of fluid pressure cylinders are driven into a neutral state, respectively. While applying a wrinkle holding load to the wrinkle holding ring evenly through the plurality of fluid pressure cylinders, in this state, the wrinkle holding ring and the die mold work together with the cushion pad against the punching mold against the movement resistance. A press working method of drawing the press material along the forming surface of the punch by being relatively moved in a press direction, A part of the plurality of hydraulic cylinders is made to butt against the cylinder as a ramming cylinder, thereby defining an approach position between the wrinkle retaining ring and the cushion pad, and the other hydraulic cylinders are in a neutral state as equalizing cylinders. And pressurizing the wrinkle holding ring by uniformly applying a predetermined wrinkle holding load from the pressure equalizing cylinder to the wrinkle holding ring. 2. A predetermined wrinkle holding load is applied from the equalizing cylinder to the wrinkle holding ring by increasing the fluid pressure by reducing the volume of the fluid accompanying the piston of the pressure equalizing cylinder and the thrust cylinder. 2. The press working method according to claim 1, wherein the wrinkle pressing load is adjusted by changing the approach position. 3. The press working method according to claim 1, wherein a wrinkle holding load applied from the pressure equalizing cylinder to the wrinkle holding ring at the time of wrinkle holding is adjusted by a physical quantity of the fluid. 4. A method for detecting a transmission load of the cylinder butting cylinder at the time of wrinkle holding, and at least one of the approach position, the physical quantity of the fluid, and the movement resistance of the cushion pad so that the transmission load becomes a predetermined value or less. The press working method according to any one of claims 1 to 3, wherein 5. A relative displacement between the cushion pad and the wrinkle holding ring at the time of wrinkle holding is detected, and the approach position, the physical quantity of the fluid, and the displacement of the cushion pad are set so that the relative displacement becomes a predetermined value or less. The press working method according to any one of claims 1 to 4, wherein at least one of the movement resistances is adjusted. 6. The apparatus according to claim 1, wherein a relative displacement between the wrinkle holding ring and the die during the wrinkle holding is detected, and an abnormality is diagnosed based on whether the relative displacement is equal to or less than a predetermined value.
The press working method according to any one of the above. 7. A fluid is circulated by interposing a cushion pad to which a predetermined moving resistance is applied by a moving resistance applying means and a cushion pad and a wrinkle retaining ring in parallel, and a pressure chamber communicating with each other. A plurality of possible hydraulic cylinders, and when wrinkling the peripheral portion of the press material between the wrinkle holding ring and the die, the pistons of the plurality of hydraulic cylinders are respectively driven into a neutral state. By doing so, the wrinkle holding load is uniformly applied to the wrinkle holding ring through the plurality of fluid pressure cylinders, and in that state, the wrinkle holding ring and the die die work together with the cushion pad against the movement resistance. The press material is drawn along the forming surface of the punch die by being relatively moved in the press direction with respect to the punch die. A press working device, comprising: a piercing member that pierces a part of the plurality of hydraulic cylinders by a predetermined stroke earlier than the other hydraulic cylinders; By being abutted, the approach position between the wrinkle holding ring and the cushion pad is defined, the other fluid pressure cylinder is held in a neutral state as a pressure equalizing cylinder, and the wrinkle holding ring is moved from the pressure equalizing cylinder. A press working apparatus for performing wrinkle holding by a wrinkle holding load that acts uniformly on the wrinkle. 8. The press working apparatus according to claim 7, wherein an elastic member is interposed at a position where the cylinder strikes when the cylinder strikes. 9. The press working apparatus according to claim 7, wherein a flow restricting means for restricting a flow of the fluid is provided in a flow path that connects the cylinder butting cylinder and the pressure equalizing cylinder. 10. The cylinder in which the torso cylinder is a fluid pressure cylinder at a portion where it is desired to partially increase the wrinkle holding force.
10. The press working device according to any one of claims 9 to 9.