JP2753675B2 - Die cushion device for press machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die cushion device for a press machine, and more particularly to a die cushion device capable of changing a wrinkle pressing load during press working.

[0002]

[Prior art]

(A) a cushion pad urged upward by a predetermined urging force by a wrinkle pressing load applying means, and (b) a plurality of hydraulic cylinders provided on the cushion pad and having hydraulic chambers communicated with each other. (C) a plurality of cushion pins respectively disposed on the hydraulic cylinder and supporting a wrinkle presser die at an upper end portion, and the press upper die is lowered by lowering the press upper die and the wrinkle presser. When press working is performed between the upper press die and the lower press die while clamping the work between the dies, the wrinkle pressing load corresponding to the urging force of the wrinkle pressing load applying means is applied to the wrinkle pressing die. There is known a die cushion device of a press machine which acts and distributes a wrinkle pressing load substantially equally to the plurality of cushion pins by the hydraulic cylinder. The apparatus described in Japanese Utility Model Laid-Open Publication No. 1-60721 is an example of such an apparatus. The hydraulic pressure of the hydraulic cylinder is controlled by the hydraulic pressure of each hydraulic cylinder during the press working regardless of the variation in the length of the cushion pin or the inclination of the cushion pad. In order to prevent the piston from being pushed into the cylinder by being pushed by the cushion pin and reaching the stroke end, it is determined by an arithmetic expression, trial driving, or the like according to the magnitude of the wrinkle holding load. According to such a die cushion device, regardless of the inclination of the cushion pad, etc., the wrinkle pressing load can be applied to the wrinkle pressing die substantially uniformly, so that good press working can be always performed.

On the other hand, a pair of pistons of a pair of air cylinders and hydraulic cylinders arranged in series with each other are integrally connected, and the air pressure of compressed air supplied to the air cylinders and the relief valve of the relief valve connected to the hydraulic cylinders are connected. A wrinkle-holding load control device that generates a wrinkle-holding load based on the relief pressure and changes the relief-pressing load by changing the relief pressure of the relief valve during press working is disclosed in, for example, Japanese Utility Model Laid-Open No. 61-190316. It is disclosed in gazettes and the like. According to such a wrinkle holding load control device, since the wrinkle holding load can be extremely finely controlled according to the press stroke, that is, the progress of the press working, for example, it is possible to reduce the vibration at the time of collision with the upper press die and the wrinkle holding die. Prevents the inflow of material during press working to improve the surface quality, reduces the wrinkle holding load during pressing to prevent breakage of the work, and prevents the breakage of the work to downgrade the material. Various advantages can be obtained, for example, Therefore, if such a wrinkle holding load control device is employed as the wrinkle holding load applying means of the die cushion device, it is possible to perform more favorable press working in conjunction with the equalization of the wrinkle holding load.

[0004]

However, if the wrinkle holding load control device as described above is directly used as the wrinkle holding load applying means, two hydraulic circuits are required in addition to the hydraulic circuit for equalizing the pressure. There is a problem that the apparatus is large and expensive. In addition, it is possible to apply the wrinkle press load control device to a die cushion device of a newly manufactured press machine, but a large-scale remodeling is required to assemble the die cushion device of a press machine already in use, This was almost impossible in terms of cost and the like, and could not be practically applied to the die cushion device of an existing press machine.

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 die cushion device having a hydraulic cylinder for equalizing the pressure without any major design change. An object of the present invention is to make it possible to control the wrinkle holding load inside.

[0006]

In order to achieve the above object, the hydraulic oil for the pressure equalizing hydraulic cylinder is discharged during press working to temporarily reduce the hydraulic pressure. Preferably, the first invention is characterized in that (a) a cushion pad which is urged upward by a predetermined urging force by a wrinkle pressing load applying means, and (b) a hydraulic chamber which is disposed on the cushion pad and communicates with each other. A plurality of hydraulic cylinders provided, and (c) a plurality of cushion pins respectively disposed on the hydraulic cylinders and supporting a wrinkle presser die at an upper end, and the upper press die is lowered, The urging force of the wrinkle holding load applying means is
Cushion pad from the cushion pad
Is transmitted to the wrinkle holding mold through the
When press working is performed between the upper press die and the lower press die while clamping the work between the upper press die and the wrinkle pressing load corresponding to the urging force of the wrinkle pressing load applying means, In a die cushion device of a press machine, which acts on a wrinkle holding die and distributes a wrinkle holding load to the plurality of cushion pins substantially equally by the hydraulic cylinder, (d) communicating with each hydraulic chamber of the plurality of hydraulic cylinders An outflow oil passage through which the hydraulic oil flows out of the hydraulic chamber; (e) an outflow prevention state provided in the outflow oil passage for preventing the outflow of the hydraulic oil; and allowing the hydraulic oil to flow at a predetermined flow rate. a flow rate adjusting means is switching control to the outflow state, (f) the holding force imparted hand I hydraulic cylinder to the
The cushion pad and the cushion are
Down almost integrally with the pinching pin
In the course of the pressing, the wrinkle presser is controlled in accordance with the outflow flow rate by controlling the flow rate adjusting means so that the hydraulic oil flows out at a predetermined flow rate.
An outflow control means for changing a load is provided.

[0007]

In other words, the wrinkle holding load applied to the wrinkle holding die by the die cushion device is basically determined by the urging force of the wrinkle holding load applying means, but the cushion pad, the hydraulic cylinder, and the cushion pin are substantially integrated. When the hydraulic oil in the hydraulic cylinder flows out during the press working, the hydraulic pressure in the hydraulic cylinder temporarily decreases due to the inertia of the hydraulic oil, and the wrinkle holding load decreases accordingly. Further, the width of the change of the wrinkle pressing load varies depending on the flow rate of the hydraulic oil flowing out of the hydraulic cylinder, and is determined by the original wrinkle pressing load, that is, the urging force of the wrinkle pressing load applying means if the outflow of the hydraulic oil is stopped halfway. It rises to the wrinkle holding load. Therefore,
The flow control means provided in the outflow oil passage is controlled by the outflow control means at the time of press working, and when the hydraulic oil in the hydraulic cylinder flows out at a predetermined flow rate through the flow control means, the flow rate is controlled according to the outflow flow rate. The wrinkle holding load is reduced, and the wrinkle holding load is changed during the press working.

[0008]

As described above, the die cushion device according to the first aspect of the present invention allows the hydraulic oil to flow out of the equalizing hydraulic cylinder for uniformly applying the wrinkle holding load, thereby reducing wrinkles in the press working process. Since the presser load is changed, the device is simpler and less expensive than when a conventional wrinkle press load control device that controls the wrinkle press load with the relief pressure is used as the wrinkle press load applying means. You. Moreover, since it is only necessary to connect the outflow oil passage to the hydraulic chamber of the hydraulic cylinder for equalizing pressure, and to provide the flow control means in the outflow oil passage and control the outflow control means, the die cushion of the existing press machine can be used. It can be easily applied to the device without major modifications.

[0009]

According to a second aspect of the present invention, there is provided a cushion pad which is urged upward by a predetermined urging force by a wrinkle pressing load applying means. (B) a plurality of hydraulic cylinders disposed on the cushion pad, and (c) a plurality of cushion pins respectively disposed on the hydraulic cylinders and supporting a wrinkle presser at an upper end, By lowering the press upper mold, the wrinkle press load applying means
The urging force is applied from the cushion pad to the hydraulic cylinder,
Transmitted to the wrinkle retainer via the cushion pin.
When pressing is performed between the press upper die and the press lower die while pressing the work between the wrinkle press die and the press upper die , the urging force of the wrinkle press load applying means is increased.
In a die cushion device of a press machine for applying a corresponding wrinkle press load to the wrinkle press die, (d) the plurality of hydraulic cylinders are divided into a plurality of areas, and a plurality of independent hydraulic oil supply cylinders are provided for each of those areas. Supply oil channel
(E) a plurality of outflow oil passages for allowing the hydraulic oil to flow out for each of the plurality of areas; and (f) an outflow prevention state provided in each of the plurality of outflow oil passages for preventing the outflow of the hydraulic oil. a plurality of flow rate adjusting means to be switching control hydraulic fluid to the outflow state to flow out at a predetermined flow rate, (g) the hydraulic
The cylinder is moved forward by the urging force of the
Pressure between the cushion pad and the cushion pin
In the process of the press working which is lowered substantially integrally in the state of being pressed, the plurality of flow rate adjusting means are individually separated such that the hydraulic oil flows out at a predetermined flow rate respectively in the plurality of areas. By controlling the outflow
The wrinkle holding load is changed for each area according to the flow rate.
Characterized by providing a runoff control means for causing.

[0010]

In the die cushion device according to the second aspect of the present invention, the hydraulic cylinder is connected to each hydraulic cylinder via a supply oil passage provided independently for each of a plurality of areas divided in advance. Hydraulic oil is supplied, and the hydraulic oil in each area is determined in advance by a plurality of flow rate adjusting means individually switched and controlled by the outflow control means from a plurality of outflow oil passages provided for each of the plurality of areas. Is discharged at a predetermined flow rate. That is, it is possible to change the hydraulic pressure and outflow flow rate of the hydraulic oil for each area, thereby making it possible to make the wrinkle holding load different for each area, and to reduce the wrinkle holding bead (projection) provided on the mold. The wrinkle holding load can be controlled very finely according to uneven wear, work specifications, and the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. In FIG. 1, a bolster 12 to which a punch die 10 is mounted is disposed on a base 16 via a press carrier 14, while a press slide 20 to which a die die 18 is mounted includes a crank and a link which are rotationally driven by a motor. It is driven up and down by a drive mechanism (not shown) provided with the above. Bolster 1
2 is provided with a large number of through holes 24 for disposing the cushion pins 22, and below the bolster 12,
A cushion pad 26 for supporting the cushion pins 22 is provided. The cushion pins 22 support a wrinkle holding ring 28 that is provided together with the punch mold 10, and are provided in an arbitrary number at predetermined positions predetermined according to the shape of the wrinkle holding ring 28. .
The cushion pad 26 includes a number of hydraulic cylinders 30 corresponding to the through holes 24, and
The lower ends of the two are each made to contact the piston rod of the hydraulic cylinder 30. The punch die 10 corresponds to a press lower die, the die die 18 corresponds to an upper press die, and the wrinkle pressing ring 28 corresponds to a wrinkle pressing die.

The cushion pad 26 is disposed in the press carrier 14 so as to be vertically movable, and is normally urged upward by an air cylinder 32. The pressure chamber of the air cylinder 32 is communicated with an air tank 34, and the air tank 34 is supplied with pressure air of a predetermined air pressure Pa from an air pressure source 36 via an air regulator 38. I have. This air pressure Pa is set according to the wrinkle holding load. That is, when the die 18 is lowered together with the press slide 20, while pressing the peripheral portion of the work 40 between the die 18 and the wrinkle holding ring 28,
When the air cylinder 32 is pushed down via the wrinkle holding ring 28, the cushion pin 22, the hydraulic cylinder 30, and the cushion pad 26 when the drawing is performed between the die 18 and the punch 10, the air pressure is reduced. Pa
Is applied to the wrinkle holding ring 28.

In the present embodiment, a wrinkle holding load applying means 42 including the air cylinder 32, the air tank 34, the air pressure source 36, and the air regulator 38 is provided. A die cushion device 44 of the first invention for applying a predetermined wrinkle holding load to the wrinkle holding ring 28 including the cylinder 30, the cushion pin 22 and the like is configured.

The hydraulic chambers of the plurality of hydraulic cylinders 30
While being communicated with each other via a pipe 46,
The pipe 46 is connected to a hydraulic control circuit 54 via a flexible tube 48, a pipe 50, and an ON / OFF solenoid valve 52. The ON / OFF solenoid valve 52 is switched by the controller 56 between a communication state in which the pipe 50 communicates with the hydraulic control circuit 54 and a shut-off state in which the piping 50 and the hydraulic control circuit 54 are shut off. The hydraulic control circuit 54 is supplied with hydraulic oil pumped from a tank 60 by an air-driven hydraulic pump 58.
The hydraulic pressure is controlled by a pressure reducing valve or the like controlled by the controller 56. This hydraulic control is performed by controlling the hydraulic pressure in the hydraulic cylinder 30 before press working to a predetermined initial hydraulic pressure P.
The controller 56 receives a signal indicating the oil pressure in the pipe 46, that is, the hydraulic cylinder 30, from a hydraulic sensor 62 provided in the pipe 46. Controller 56
Is configured to include a microcomputer having a CPU, a RAM, a ROM, and the like, and performs ON / OFF by performing signal processing according to a predetermined program.
Switching of the solenoid valve 52, hydraulic control, and the like are performed. The initial hydraulic pressure Po is set such that the piston of each hydraulic cylinder 30 is pushed by the cushion pin 22 and pressed into the cylinder during the press working, regardless of the variation in the length of the cushion pin 22 and the inclination of the cushion pad 26, and the stroke end. , Or in other words, is determined by a predetermined arithmetic expression, trial driving, or the like so that wrinkle holding is performed while the piston of the hydraulic cylinder 30 is held at the neutral position. O
The N-OFF solenoid valve 52 is in a communicating state during hydraulic control before the press working, and is in a shut-off state during the press working.

When the press working is performed in such a state that the piston of the hydraulic cylinder 30 is held at the neutral position,
Irrespective of variations in the length dimension of the cushion pin 22 and the inclination of the cushion pad 26, the wrinkle holding load is applied to the wrinkle holding ring 28 substantially uniformly through the plurality of hydraulic cylinders 30, Good press working can always be performed.

On the other hand, an outflow oil passage 66 is connected to the pipe 50 so that hydraulic oil in the hydraulic cylinder 30 can be relieved to the tank 60. A flow control valve 68 that continuously changes the flow rate of the outflowing hydraulic oil, that is, the flow cross-sectional area (opening amount), is provided in the outflow oil passage 66. Is controlled to switch between an outflow preventing state in which the outflow is prevented and an outflow state in which the outflow is performed at a predetermined flow rate. The controller 56 is supplied with signals indicating a plurality of lowered positions of the press slide 20 from a position detection sensor 70 such as a limit switch provided in the press machine. In the process of pressing between the die 18 and the punch 10 while pressing the peripheral portion of the work 40 between the flow control valve 28 and the flow control valve 68, the flow control valve 68 is switched from the outflow preventing state to the outflow state. The opening amount of the flow control valve 68 is controlled so that the hydraulic oil flows out at a predetermined flow rate that is predetermined based on the descending position of the slide 20, that is, the press stroke.

Here, if the press work is performed with the flow control valve 68 in the outflow preventing state, a substantially constant wrinkle pressing load corresponding to the air pressure Pa of the air cylinder 32 (strictly speaking, a reduction in the volume of the air cylinder 32). And the wrinkle pressing load is increased by a plurality of hydraulic cylinders 3.
The wrinkle press is performed in a state where the wrinkles are distributed substantially evenly through the zero and the cushion pin 22. However, when the hydraulic oil in the hydraulic cylinder 30 flows out during press working in which the cushion pad 26, the hydraulic cylinder 30, and the cushion pin 22 are integrally lowered, the hydraulic pressure in the hydraulic cylinder 30 is temporarily reduced due to the inertia thereof. However, the wrinkle holding load decreases accordingly. The variation width of the wrinkle holding load varies depending on the flow rate of the hydraulic oil flowing out of the hydraulic cylinder 30, and if the outflow of the hydraulic oil is stopped halfway, the wrinkle holding load corresponding to the original wrinkle holding load, ie, the air pressure Pa. To rise.

Therefore, by opening the flow control valve 68 provided in the outflow oil passage 66 at the time of press working to allow the operating oil in the hydraulic cylinder 30 to flow out and controlling the opening amount, that is, the outflow flow rate, the press working of the press working is performed. In the process, the wrinkle pressing load can be changed arbitrarily. For example, as shown in FIG. 5, if the hydraulic pressure in the hydraulic cylinder 30 is gradually decreased in the process from the press start point Sa to the bottom dead center Sd. The wrinkle holding load is also reduced stepwise with the change in the oil pressure. It is also possible to control the hydraulic pressure as shown in FIGS. The amount of opening of the flow control valve 68 is adjusted so that the oil pressure of the hydraulic cylinder 30, that is, the wrinkle pressing load, changes as desired.
Is set in advance by an experiment or the like based on the press stroke detected by. However, it is also possible to correct the opening amount of the flow control valve 68 or to perform feedback control based on the actual oil pressure detected by the oil pressure sensor 62. Such adjustment of the wrinkle pressing load may be performed as needed based on the press working conditions and the like. If the hydraulic oil in the hydraulic cylinder 30 flows out during the press working, the next press working is performed. It is necessary to readjust the initial oil pressure Po beforehand. In the present embodiment, the flow control valve 6
Reference numeral 8 corresponds to a flow control unit, and the controller 56 corresponds to an outflow control unit.

According to the die cushion device 44 of the present embodiment to which the first invention is applied, since the wrinkle pressing load can be controlled in the process of press working, for example, the die die 1
By adjusting the outflow rate of the hydraulic oil so as to cancel the vibration of the wrinkle holding load at the time of collision with the wrinkle holding ring 28, the inflow of the material at the time of press working can be prevented and the surface quality can be improved. . In addition, various advantages can be obtained, such as reducing the wrinkle holding load during the press to prevent the work 40 from breaking, and preventing the work from breaking, so that the material can be downgraded.
Therefore, in combination with the equalization of the wrinkle holding load by the hydraulic cylinder 30, more favorable press working can be performed.

On the other hand, the die cushion device 44 of this embodiment
Is designed to adjust the wrinkle holding load in the process of press working by allowing hydraulic oil to flow out from the pressure equalizing hydraulic cylinder 30 for uniformly applying the wrinkle holding load. Compared to the case where a conventional wrinkle holding load control device for controlling the load is used as the wrinkle holding load applying means 42, the device is configured simply and at low cost. Further, an outflow oil passage 66 is connected to a hydraulic chamber of the equalizing hydraulic cylinder 30, and a flow control valve 68 is provided in the outflow oil passage 66. The controller 56 opens and closes the flow control valve 68 in accordance with the press stroke. Since it is only necessary to control the amount, there is an advantage that it can be easily applied to a die cushion device of an existing press machine without major modification.

Next, some other embodiments of the first invention will be described with reference to FIGS. 2 to 4 and FIG. In the following embodiments, portions substantially common to the embodiment of FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

The die cushion device 74 shown in FIG. 2 is provided with an ON / OFF solenoid valve 76 and a manual flow control valve 78 in series in the spill oil passage 66, and the flow control valve 78 has a predetermined opening. Manually adjusted to quantity. ON ・ O
The FF solenoid valve 76 is switched between a communicating state and a shut-off state by the controller 56. When the FF solenoid valve 76 is controlled to open during a press working process, for example, a predetermined press stroke Sb, the hydraulic cylinder 3
Hydraulic oil within 0 flows out of the flow control valve 78 at a predetermined flow rate, and the hydraulic pressure of the hydraulic cylinder 30, that is, the wrinkle holding load is changed as shown in FIG. In FIG. 6, the increase in hydraulic pressure from the press start point to the press stroke Sb is a change accompanying a decrease in the volume of the air cylinder 32. The outflow rate by the flow rate control valve 78 and the outflow start point by the ON / OFF solenoid valve 76 are appropriately set according to the press working conditions and the like. In this embodiment, ON / OFF
The solenoid valve 76 and the flow control valve 78 correspond to a flow control means.

The die cushion device 80 of FIG. 3 is ON / OFF compared to the die cushion device 74 of FIG.
Manual open / close valves 82a, 82 are provided downstream of the solenoid valve 76.
2b and 82c are connected in parallel, and manual flow control valves 84a, 84b and 84c are connected in series with the manual on-off valves 82a, 82b and 82c. While the flow rate adjustment valves 84a, 84b, 84c are manually adjusted to predetermined different opening amounts, respectively,
The manual opening / closing valves 82a, 82b, 82c are manually opened / closed according to press working conditions and the like. The manual on-off valves 82a, 82
The combination of opening and closing of 2b and 82c allows the hydraulic cylinder 30
The flow rate of hydraulic oil flowing out of the cylinder is changed in various ways, and the rate of decrease in the wrinkle holding load is accordingly changed. FIG. 7 shows two types of oil pressure changes in which the ON / OFF solenoid valve 76 is controlled to open at the press start point Sa and the combination of opening and closing of the manual opening / closing valves 82a, 82b, 82c is different. In this embodiment, the ON / OFF solenoid valve 76, the manual on-off valves 82a, 82b, 82c, and the flow control valves 84a, 84b, 84c correspond to the flow control means.

The die cushion device 86 shown in FIG. 4 is the same as that of the die cushion device 80 shown in FIG.
Instead of b and 82c, there are provided ON / OFF solenoid valves 88a, 88b and 88c that can be switched between a communication state and a cutoff state by the controller 56. In this case, the ON / OFF solenoid valve 88
Not only can the rate of reduction of the wrinkle holding load be controlled by the combination of opening and closing a, 88b, 88c, but also the ON / OFF solenoid valves 88a, 88b,
By changing the combination of opening and closing of 88c, it is possible to change the rate of reduction of the wrinkle holding load during pressing, for example, as shown in FIG. In this embodiment, the ON / OFF solenoid valves 76, 88a, 88b, 88c and the flow control valves 84a, 84b, 84c correspond to flow control means.

FIG. 9 is a plan view schematically showing the structure of the die cushion device 90.
0, an outflow oil passage 92 individually connected to each of the hydraulic chambers of the plurality of hydraulic cylinders 30 is provided separately from the pipe 46 on the supply side, and the outflow oil passage 92 Flow control valves 94 are provided near the connection portions with the respective hydraulic cylinders 30 so that hydraulic oil in the hydraulic chamber flows out. The outflow oil passage 92 is connected to the tank 60 via a flexible tube 96. Each of the flow rate control valves 94 is a relatively compact flow rate control means equivalent to the flow rate control valve 68, and the hydraulic oil is supplied in accordance with a common electric signal supplied from the controller 56 as in the embodiment of FIG. Is controlled to switch between an outflow preventing state in which the outflow is prevented and an outflow state in which the outflow is performed at a predetermined flow rate. In this embodiment, the outflow amount of the hydraulic oil flowing out of each hydraulic cylinder 30 is controlled by the flow control valve 94 provided in each of them, so that the outflow oil passage 66 is connected to the pipe 50 as in the embodiment of FIG. Is connected, and the variation of the hydraulic pressure in each hydraulic cylinder 30 is less likely to vary than in the case where the outflow flow rate is controlled by the flow rate adjustment valve 68. It can be performed. Further, since the hydraulic oil quickly flows out from each hydraulic cylinder 30, the control width of the outflow flow rate is increased, and the control range of the wrinkle holding load is accordingly widened.

It is also possible to individually control the opening amount and the opening / closing timing of each flow control valve 94.

Next, an embodiment of the second invention will be described. The parts substantially common to the embodiment of FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

FIG. 10 is a plan view schematically showing the configuration of the die cushion device 100. As shown in FIG. The die cushion device 100 is similar to the embodiment of FIG.
A plurality of hydraulic cylinders 30 are provided on the upper side, and cushion pins 22 (not shown) are respectively in contact with the piston rods. This die cushion device 1
In the case of the hydraulic cylinder 30, the wrinkle holding load is required to be partially changed due to uneven wear of the wrinkle holding bead provided on the mold, the specification of the work 40, and the like.
A is divided into front, rear, left and right (up, down, left and right in FIG. 10)
It is divided into four areas B, C and D.

Each of the above areas has a supply oil passage 10
2a to 102d are independently disposed and connected to hydraulic chambers of a plurality of hydraulic cylinders 30a to 30d in each area. Each of those supply oil passages 102a-10
In 2d, the hydraulic control circuits 104a to 104d are ON / O
They are connected via FF solenoid valves 106a to 106d and flexible tubes 108a to 108d, respectively. Hydraulic control circuits 104a to 104d and ON / OFF solenoid valves 106a to 106d
Are controlled independently in accordance with signals from the controller 56, and the initial hydraulic pressures Poa to Pod are pressure-controlled for each area.

Each of the supply oil passages 102a to 102d has a hydraulic pressure sensor 110a for detecting a hydraulic pressure in each supply oil passage.
To 110d are provided, respectively, and the outflow oil passages 112a to 112d allow the hydraulic oil in each supply oil passage to flow out.
d are respectively connected. Oil spillway 112
The flow control devices 114a to 114d are provided with the flow control valves 68 and the like, respectively, and the downstream sides of the flow control devices 114a to 114d are connected via a pipe 116 and a flexible tube 118 to the flow control devices a to 112d. It is connected to the tank 60. Signals are individually supplied from the controller 56 to the flow rate adjusting means 114a to 114d, and their outflow states (opening amounts)
And the outflow prevention state is independently switched and controlled. For this reason, in the process of press working, hydraulic oil is caused to flow out at a predetermined outflow rate for each area, and the hydraulic pressure in each of the hydraulic cylinders 30a to 30d is reduced according to the outflow rate. Controller 56
The initial hydraulic pressure Poa-Pod and the flow rate adjusting means 114a
The opening timing of .about.114d, and in some cases, the opening amount, are predetermined for each area.

As described above, the above-described die cushion device 1
At 00, the hydraulic cylinders 30a, 30a, and 40d are supplied with hydraulic oil through the supply oil passages 102a, 102b, 102c, and 102d for each of the four areas A, B, C, and D so as to have a predetermined initial oil pressure Poa to Pod. Hydraulic control is performed on the oil supply passages 30b, 30c, and 30d, and the operating oil in the supply oil passages is discharged at a predetermined flow rate from the outflow oil passages 112a, 112b, 112c, and 112d provided for each area. In addition, the wrinkle holding load can be made different for each area, and the fine wrinkle holding load can be controlled for each of four areas A, B, C, and D.

The die cushion device 130 shown in FIG.
Is a mode in which the hydraulic control means for each area is shared in the embodiment of FIG. In each of the areas A, B, C, and D, the supply oil passages 132a independently provided so as to supply the hydraulic oil to the hydraulic cylinders 30a to 30d, respectively.
132d is the ON / OFF solenoid valve 10
6a-106d, flexible tubes 108a-10
8d, and the hydraulic control circuit 5 via the common pipe 134.
4 and its hydraulic control circuit 54 and ON
The hydraulic pressure in each of the supply oil passages 132a to 132d and further in the hydraulic cylinders 30a to 30d can be controlled independently by the OFF solenoid valves 106a to 106d. In addition, each supply oil passage 132a-13
The outflow oil passages 112a to 112d and the flow rate adjusting means 114a to 114d are connected to 2d so that hydraulic oil can flow out at a predetermined flow rate.

In the die cushion device 130, the same operation and effect as those of the die cushion device 100 can be obtained.

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 embodiment, the press slide 2
Although a case has been described where the present invention is applied to a mechanical press that is driven up and down by a motor, a crank, and the like, the present invention can be similarly applied to a hydraulic press that drives the press slide 20 up and down by hydraulic pressure.

In the above embodiment, the position detection sensor 70
Thus, the outflow control of the hydraulic oil in the hydraulic cylinder 30 is performed by detecting the press stroke. However, the start point of the outflow control can be determined based on the hydraulic pressure detected by the hydraulic pressure sensor 62. As the position detection sensor 70, a magnescale or a rotary encoder that continuously detects the position of the press slide 20, the crank angle of the press machine, and the like can be used.

In the above embodiment, the punch die 10 is arranged on the base 16 via the press carrier 14. However, the present invention is also applicable to a press machine fixedly mounted on the base 16. Such as may be applied as well
The arrangement of the punch 10 can be changed as appropriate.

Although the wrinkle holding load applying means 42 of the above embodiment applies the wrinkle holding load based on the air pressure, the wrinkle holding load is applied by a hydraulic cylinder or a spring having a variable relief valve. You can also.

In the above embodiment, the single controller 56 controls the hydraulic pressure of the initial hydraulic pressure Po and the outflow control of the hydraulic oil in the hydraulic cylinder 30 during the press working. It is also possible to do this with a separate controller. In the embodiment of FIG. 10, a controller may be provided for each area.

In the embodiment shown in FIG. 10, four areas A, B, C, and D are divided into front, rear, left, and right. obtain. The minimum unit of the area is each hydraulic cylinder 30, and it is also possible to connect an independent supply oil passage and an outflow oil passage to each hydraulic cylinder 30 to independently control the initial oil pressure and the outflow flow rate. .

In the embodiment of FIG. 10, all the hydraulic cylinders 30a to 30d are held in a neutral state by the respective hydraulic control circuits 104a to 104d in each area according to the air pressure of the single air cylinder 32. The hydraulic pressure can be controlled so that the initial hydraulic pressures Poa to Pod are different from each other within a possible range. However, if the air cylinder 32 and the cushion pad 26 are separately provided for each of the above-mentioned areas, the basic wrinkles can be obtained. The presser load can be controlled to a different value for each area, and the initial hydraulic pressures Poa to Pod can be set to different values with a correspondingly large adjustment width.

In the embodiment shown in FIG. 11, the hydraulic pressure sensors 110a to 110d are provided for each of the four areas so that the initial hydraulic pressure can be adjusted independently. OFF solenoid valve 106a-
Even if a single oil pressure sensor is arranged between the area 106d and the initial oil pressure of each area to be controlled to the same oil pressure, it is possible to individually control wrinkle holding load for each area by the flow rate adjusting means 114a to 114d. It is.

Although not specifically exemplified, the present invention can be embodied with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main configuration of a press machine provided with a die cushion device according to an embodiment of the first invention.

FIG. 2 is a diagram showing a main configuration of another embodiment of the first invention.

FIG. 3 is a diagram showing a main configuration of still another embodiment of the first invention.

FIG. 4 is a diagram showing a configuration of a main part of still another embodiment of the first invention.

FIG. 5 is a view showing an example of a change in hydraulic pressure obtained by causing hydraulic oil in a hydraulic cylinder to flow out in the embodiment of FIG. 1;

FIG. 6 is a diagram showing an example of a change in hydraulic pressure obtained by causing hydraulic oil in a hydraulic cylinder to flow out in the embodiment of FIG. 2;

FIG. 7 is a diagram illustrating an example of a change in hydraulic pressure obtained by causing hydraulic oil in a hydraulic cylinder to flow out in the embodiment of FIG. 3;

8 is a diagram showing an example of a change in hydraulic pressure obtained by causing hydraulic oil in a hydraulic cylinder to flow out in the embodiment of FIG.

FIG. 9 is a diagram schematically showing a configuration according to still another embodiment of the first invention.

FIG. 10 is a view showing a schematic configuration of a die cushion device according to an embodiment of the second invention.

FIG. 11 is a diagram showing a schematic configuration of another embodiment of the second invention.

[Explanation of symbols]

10: Punch type (press lower type) 18: Die type (press upper type) 22: Cushion pin 26: Cushion pad 28: Wrinkle holding ring (Wrinkle holding type) 30: Hydraulic cylinder 40: Work 42: Wrinkle holding load applying means 44, 74, 80, 86, 90: die cushion device (first invention) 56: controller (outflow control means) 66: outflow oil passage 68: flow control valve (flow control means) 76: ON / OFF solenoid valve 78 : Flow control valves 82a, 82b, 82c: Manual open / close valves 84a, 84b, 84c: Flow control valves 88a, 88b, 88c: ON / OFF solenoid valves 92: Outflow oil passages 94: Flow control valves (flow control means) 100, 130: die cushion device (second invention) 102a, 102b, 102c, 102d: supply oil passage 112a, 12b, 112c, 112d: outflow oil path 114a, 114b, 114c, 114d: flow rate adjusting means 132a, 132b, 132c, 132d: supply oil passage A, B, C, D: Area

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shigehiro Kirii 1-149 Kugata, Tenpaku-ku, Nagoya-shi, Aichi 23, Aioyama housing complex 23 building 201

Claims (2)

(57) [Claims] A cushion pad which is urged upward by a predetermined urging force by a wrinkle pressing load applying means; a plurality of hydraulic cylinders provided on the cushion pad and having a hydraulic chamber communicated with each other; A plurality of cushion pins respectively disposed on the hydraulic cylinder and supporting a wrinkle presser die at an upper end portion, and the press upper die is lowered to urge the wrinkle presser load applying means.
The force is applied from the cushion pad to the hydraulic cylinder,
It is transmitted to the wrinkle presser via a cushion pin,
When pressing is performed between the upper press die and the lower press die while pressing the work between the wrinkle press die and the press upper die, the press work corresponds to the biasing force of the wrinkle press load applying means. While applying a wrinkle holding load to the wrinkle holding mold,
In a die cushion device of a press machine for distributing a wrinkling load approximately equally to the plurality of cushion pins by the hydraulic cylinder, the hydraulic cylinder is communicated with each hydraulic chamber of the plurality of hydraulic cylinders to discharge hydraulic oil in the hydraulic chamber. an outflow oil path, provided in the flow Deyu path and the overflow blocking state for blocking the outflow of the working oil, a flow rate adjusting means is switching control to the outflow state to flow out the hydraulic oil at a predetermined flow rate, the The hydraulic cylinder is biased by the wrinkle holding load applying means.
Between the cushion pad and the cushion pin
In clamping pressure state in the course of the press substantially brought into integrally lowered working between, said hydraulic fluid to control the flow rate adjusting means so as to flow out at a predetermined flow rate to a predetermined
Changes the wrinkle holding load according to the outflow flow rate.
A die cushion device for a press machine, comprising: an outflow control unit for causing the die to flow. 2. A cushion pad which is urged upward by a predetermined urging force by a wrinkle pressing load applying means, a plurality of hydraulic cylinders provided on the cushion pad, and a plurality of hydraulic cylinders provided on the hydraulic cylinder, respectively. And a plurality of cushion pins that support the wrinkle presser die at the upper end thereof, and the press upper die is lowered so that the wrinkle press load is reduced.
The urging force of the applying means is changed from the cushion pad to the hydraulic pressure.
Cylinder, the wrinkle pressing mold through said leading Yonpin
When pressing is performed between the upper press die and the lower press die while clamping the work between the wrinkle press die and the upper press die, the wrinkle presser is In a die cushion device of a press machine for applying a wrinkle pressing load corresponding to the urging force of a load applying means to the wrinkle pressing die, the plurality of hydraulic cylinders are divided into a plurality of areas, and hydraulic oil is supplied for each area. A plurality of independent supply oil passages, a plurality of outflow oil passages for allowing the hydraulic oil to flow out for each of the plurality of areas, and an outflow prevention state provided in each of the plurality of outflow oil passages for preventing the outflow of the hydraulic oil. When the biasing force of the plurality of flow rate adjusting means and the hydraulic cylinder is the wrinkle holding force applying means to be the working fluid control switch to the outflow state to flow out at a predetermined flow rate
Between the cushion pad and the cushion pin
In the process of the press working , which is lowered substantially integrally in a state of being pinched between, so that the hydraulic oil flows out at a predetermined flow rate respectively predetermined for each of the plurality of areas,
By individually controlling the plurality of flow rate adjusting means ,
The wrinkle holding load is changed for each area according to the outflow flow rate.
A die cushion device for a press machine, comprising a flow control means for changing the flow rate.