JP3196032B2 - Press brake clamping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device for fixing or releasing an upper die to a press brake ram by hydraulic pressure in a press brake used for bending a long steel plate or the like. .

[0002]

2. Description of the Related Art Conventionally, this type of clamping device has
There is one described in Japanese Utility Model Laid-Open Publication No. 64-49318. In this method, a clamp receiving member is provided on a rear side of a lower portion of a ram, a clamp holding member including a plurality of pressing plates is provided on a front side of a lower portion of the ram in a left-right direction, and a hydraulic cylinder for clamping is provided in each holding plate. . The upper die abutted from below on the lower part of the ram is clamped and fixed between the clamp receiving member and the holding plate by the hydraulic pressure of each hydraulic cylinder. A pressure oil supply / discharge port communicating with the hydraulic oil chamber of the hydraulic cylinder is opened on the upper surface of each holding plate. Then, adjacent pressure oil supply / discharge ports are sequentially connected by an inverted U-shaped hydraulic pipeline along the front space of the ram.

[0003]

In the above prior art,
Since the hydraulic pipeline projects into the front space of the ram, the bending range of the long steel plate is narrowed by the amount of the projection, and the hydraulic pipeline may be damaged by the bent steel plate. The present invention is to expand the forming range of the processed steel sheet,
It is another object of the present invention to prevent breakage of a hydraulic pipeline.

[0004]

According to the present invention, in order to achieve the above object, for example, as shown in FIG. 1 to FIG. 6 or FIG. 7 to FIG. Configured.

(Invention of Claim 1) The upper part (3a) of the upper die (3) is attached to the lower part (2) of the ram (1) extending in the horizontal direction by the first clamp member (5) and the second clamp member.
(6), the second clamp member (6) is composed of at least three holding plates (8), (8), (8) arranged side by side in the horizontal direction. On the holding plate (8)
Unclamp drive means (13) for moving the presser plate (8) away from the first clamp member (5) and clamp drive means (14) for bringing the presser plate (8) closer to the first clamp member (5) are provided. At least one of the two driving means (13) and (14) is constituted by a hydraulic cylinder (19), and the adjacent pressing plate (8)
(8) A press brake provided with a plurality of communicating pipes (23) for sequentially communicating hydraulic oil chambers (20), (20), (20) of hydraulic cylinders (19), (19), (19) of (8). A first lateral end surface which is both lateral end surfaces of the holding plate (8).
(8b) and the second lateral end face (8a) , the first lateral end face described above.
(8b) and the hydraulic oil chamber (2)
0) and the above-mentioned second lateral end face (8a).
And the pressure oil outlet (42) that opens in
In both cases, the pressure oil inlet (41) of each holding plate (8) and the pressure
The oil outlet (42) is formed substantially coaxially with substantially the same diameter, and the plurality of communicating pipes (23) are formed linearly so that the adjacent holding plates (8), (8), (8) The pressure oil outlet (42) and the pressure oil inlet (41) facing each other are sequentially connected by the communication pipe (23).

[0006] The hydraulic cylinder (19) may be used in either one of the unclamping drive means (13) and the clamp drive means (14), and may be constructed as a double-acting type to serve both unclamping and clamping purposes. Is considered. Also,
The first clamp member (5) can be considered as a case where a plurality of receiving plates (7) are arranged side by side or a case where the first clamp member (5) is integrally formed. The first clamp member (5) may be formed separately from the ram (1) or may be formed integrally therewith.

(Invention of Claim 2) The invention of Claim 2 is directed to a lower portion of the ram (1) extending in the horizontal direction.
At least three holding plates (8), (8) and (8)
A hydraulic oil chamber (20) is provided in each holding plate (8).
The first lateral end face (8b), which is both lateral end faces of the holding plate (8), and the second lateral end face
An opening is formed between the first lateral end surface (8b) and the end surface (8a).
Communicating with the hydraulic oil inlet (41) and the hydraulic oil chamber (20).
Pressure oil opening in the communication passage (22) and the second lateral end surface (8a)
The outlet (42) is formed linearly in order, and each holding plate
(8) The pressure oil inlet (41) and the pressure oil outlet (42)
Are formed approximately coaxially and approximately the same diameter, and
The pressure oil outlets (42) facing each other of the plates (8), (8) and (8)
The oil inlet (41) is connected by a plurality of linear communication pipes (23).
It is characterized by being connected in order .

(Invention of Claim 3) In the invention of Claim 3, the following configuration is added to the invention of Claim 1 or 2. For example, as shown in FIG. 5 (and FIG. 6) or FIG. 8, the first pipe end (4) of the linear communication pipe (23) is formed.
5) and the second pipe end (46) are movably fitted in the pressure oil outlet (42) and the pressure oil inlet (41) in the axial direction, and these fitting portions (53) (54), the communication pipe (2)
Pipe relief space (57a) that allows 3) to be withdrawn
(57b), and a fitting / holding stopper (62) for preventing the communication pipe (23) from moving to the pipe escape space (57a) (57b).

(Invention of Claim 4) The invention of Claim 4 has the following configuration added to the invention of Claim 3. For example, as shown in FIG.
The tube escape space (57b) is provided at the back of (41), and the receiving wall (73) for preventing the communication tube (23) from moving toward the first tube end (45). ) To the pressure oil outlet (4
It is provided at the back of 2).

[0010]

The present invention operates as follows. According to the first aspect of the present invention, since the communication pipe 23 can be mounted between the adjacent pressing plates 8, 8, 8, unlike the conventional example, the front side or the rear side of the ram is different from the conventional example. No need to protrude into the side space. For this reason, it becomes possible to expand the bending forming range of the processed steel plate. In addition, since the communication pipe 23 is mounted between the front and rear surfaces of the holding plate 8 to be protected by the holding plate 8, it can be prevented from being damaged by the bent steel plate.

In addition, in each of the holding plates 8 described above,
The pressure oil inlet 41 and the pressure oil outlet 42 are substantially coaxial.
Pressure oil is supplied to the holding plate 8
The hydraulic pressure at the time of
To balance. For this reason, the above pressure is
The moving plate 8 is displaced in the direction of the two lateral end surfaces 8b and 8a .
Can be prevented. As a result, the above-mentioned holding plate 8 is
Means for receiving in the direction of b · 8a can be omitted. Also,
Since the pressurized oil inlet 41 and the pressurized oil outlet 42 are opened substantially coaxially on both lateral end surfaces 8b and 8a of each presser plate 8, the opposing presser oil outlets 42 and the pressurized oil inlets 4 of the adjacent presser plates 8 and 8 are provided.
1 can concentrically face each other. For this reason, a plurality of presser plates 8 can be used as a common part, and the manufacturing cost of the entire clamp device can be reduced.

The first aspect of the present invention operates as follows in comparison with the above-described conventional example. Since the conventional hydraulic pipeline corresponding to the communication pipe 23 of the present invention rises in an inverted U-shape, air is easily accumulated and the pipeline length is large. In addition, since the above-mentioned inverted U-shaped hydraulic pipeline is difficult to bleed air, the amount of air mixed into the pressurized oil must be increased. The amount of pressurized oil discharged by the hydraulic pump needs to be increased by the amount of the air mixture, and the operation time of the clamp operation is long. This problem has been a serious problem when the hydraulic pipeline is formed of a hose, because the expansion volume due to the pressure oil is large. On the other hand, according to the invention of claim 1, the plurality of communication pipes 23
Is made straight and straight, so that the space for storing air in the pressurized oil is extremely small and the length of the piping is short.
Therefore, the operation of bleeding the pressurized oil is completed in a short time. In addition, since the air can be easily removed and the amount of air mixed into the pressure oil can be reduced, the operation time of the clamp or unclamping operation is short.

(Operation of the Invention of Claim 2) The invention of claim 2 operates as follows, similarly to the above-mentioned invention of claim 1. That is, since the communication pipe 23 can be mounted between the adjacent holding plates 8, 8, 8, unlike the conventional example,
There is no need to project into the front or rear space of the ram. For this reason, it becomes possible to expand the bending forming range of the processed steel plate. In addition, since the communication pipe 23 is mounted between the front and rear surfaces of the holding plate 8 to be protected by the holding plate 8, it can be prevented from being damaged by the bent steel plate.

In addition, in each of the holding plates 8 described above,
The pressure oil inlet 41 and the pressure oil outlet 42 are substantially coaxial.
Pressure oil is supplied to the holding plate 8
The hydraulic pressure at the time of
To balance. For this reason, the above pressure is
The moving plate 8 is displaced in the direction of the two lateral end surfaces 8b and 8a.
Can be prevented. As a result, the above-mentioned holding plate 8 is
Means for receiving in the direction of b · 8a can be omitted. Also,
Since the pressurized oil inlet 41 and the pressurized oil outlet 42 are opened substantially coaxially on both lateral end surfaces 8b and 8a of each presser plate 8, the opposing presser oil outlets 42 and the pressurized oil inlets 4 of the adjacent presser plates 8 and 8 are provided.
1 can concentrically face each other. For this reason, a plurality of presser plates 8 can be used as a common part, and the manufacturing cost of the entire clamp device can be reduced. Further, since the plurality of communication pipes 23 of the present invention are formed straight and straight, the space for the air pool in the pressurized oil is extremely small and the length of the pipes can be short. Therefore, the operation of bleeding the pressurized oil is completed in a short time.
In addition, since the air can be easily removed and the amount of air mixed into the pressure oil can be reduced, the operation time of the clamp or unclamping operation is short.

In the first or second aspect of the present invention, the communication pipe 23 is connected to the pressure oil inlet 41 and the pressure oil outlet 42.
Is screwed from the connecting portion between the holding plate 8 and the communication pipe 23 when the press-fitting is carried out, the connection by the impact when the press brake is operated can be omitted. It is possible to prevent the pressure oil from leaking due to the loosening of the part.

In the first or second aspect of the present invention, the first pipe end 45 and the second pipe end 46 of the communication pipe 23 are swung with respect to the pressure oil outlet 42 and the pressure oil inlet 41. When the fitting is swingably performed, the one-side contact of the sealing means 47 is suppressed by the swinging swing of the first pipe end 45 or the second pipe end 46, so that the pressure oil leakage is further reduced. It can be reliably prevented.

According to the third aspect of the present invention, when any one of the plurality of pressing plates 8 arranged in the left-right direction is removed from the ram 1, the communication pipe is provided. 23 into one tube escape space 57a (5
7b), any of the holding plates 8 can be retracted.
Is allowed, maintenance of the hydraulic cylinder 19 and the like provided on the holding plate 8 is easy.

(Function of the Invention of Claim 4) According to the invention of claim 4, for example, as shown in FIG. 8, a pipe escape space 57b is provided in the deep portion of the pressure oil inlet 41 so that the communication pipe 23 is formed. When a receiving wall 73 for preventing movement to the first pipe end 45 side is provided at the back of the pressure oil outlet 42,
It works as follows.

When the pressure oil is discharged from the hydraulic oil chamber 20 of each holding plate 8, the pressure of the pressure oil inlet 41 far from the pressure oil discharge port is reduced by the action of air mixed in the pressure oil. It may be higher than the pressure at the outlet 42. In this case, the differential pressure tends to strongly press the communication pipe 23 toward the pressure oil outlet 42 side. However, the pressing force is reduced by the holding plate 8.
The receiving wall 73 is strongly received, so that the fitting / holding stopper 62 can be prevented from being damaged.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIGS. 1 to 6 show a first embodiment. As shown in FIGS. 1 to 3, an upper portion 3a of an upper die 3 is abutted against a lower portion 2 of a ram 1 of a press brake from below. The upper portion 3a of the upper die 3 is held and fixed to the ram lower portion 2 from both front and rear sides by a clamp receiving member 5 as a first clamp member and a clamp holding member 6 as a second clamp member.
The clamp receiving member 5 is disposed on the rear side (the left side in FIGS. 2 and 3; the same applies hereinafter).
Is arranged on the front side (the right side in the figure, the same applies hereinafter). The upper mold 3 can appropriately change the overall length in the left-right direction by selecting and combining a number of molds having different left-right dimensions.

Clamp receiving member 5 and clamp holding member 6
Means a plurality of receiving plates 7 and a plurality of holding plates 8, respectively.
Are arranged side by side in the left-right direction. As shown in FIG. 2, each receiving plate 7 is screwed into a through screw hole 10 in the lower part of the ram lower part 2 with a fixing bolt 11.

Each holding plate 8 includes an unclamping drive unit 13 and a clamp drive unit 14. As shown in FIG. 2, the clamp driving means 14 holds the pressing plate 8 against the spring receiving bolt 16 fixed to the through screw hole 10.
Is driven toward the receiving plate 7 by the clamp spring 17.

The unclamping drive means 13 comprises a hydraulic cylinder 19, as shown in FIG. That is, the unclamping piston 21 is inserted into each hydraulic oil chamber 20 formed on each holding plate 8 so as to be slidable in an oil-tight manner in the front-rear direction. The hydraulic oil inlets 41 and the hydraulic oil outlets 42 on both lateral end surfaces of the presser plate 8 are connected to the respective hydraulic oil chambers 20 through the communication passages 22. Then, as shown in FIG. 1, the respective hydraulic oil chambers 20 of the adjacent holding plates 8 are connected to each other through a communication pipe 23.

Further, as shown in FIG.
A supply / discharge switching valve (not shown) and a hydraulic pump 26 are connected to a pressure oil inlet 41 of the (leftmost) holding plate 8 via a terminal pipe 25 and a pressure oil supply / discharge fitting 24 in this order. You. The pressure oil outlet 42 of the holding plate 8 on the most downstream side (rightmost side) has a terminal pipe 30.
Is connected to the valve box 29 of the air release valve 28.

As shown in FIG. 4, the air release valve 28 is formed by bringing a ball valve body 33 into close contact with an air release valve seat 32 with a valve closing member 34. The ball valve body 33 has an air vent hole 35.
Are prevented from coming off by a spring pin 36 inserted through the hole.

When the upper die 3 is unclamped, hydraulic oil is supplied from the hydraulic pump 26 to the hydraulic oil chamber 20 in each holding plate 8. Then, the hydraulic pressure of the unclamping piston 21 overcomes the elastic force of the clamping spring 17 and drives the holding plate 8 in a direction to move it away from the clamp receiving member 5.

As shown in FIGS. 2 and 3, a urethane rubber 37 extending horizontally is fitted into the lower rear surface of each holding plate 8. The urethane rubber 37 is bulged rearward (to the left in the drawing) via a bolt 38 and a compression tool 39. When the upper portion 3a of the upper die 3 is inserted from below into the space between the clamp members 5 and 6 while the clamp device is unclamped, the upper portion 3a of the upper die 3 is positioned by the frictional force of the urethane rubber 37. Is done. As a result, the preparation work before clamping the upper die 3 on the ram 1 does not require much labor.

Next, the structure of the communication pipe 23 will be described in detail with reference to FIGS. FIG. 5 is an enlarged vertical sectional view of an arrow A portion in FIG. The second side, which is the downstream side end surface of the holding plate 8 located on the upstream side (left side) of the adjacent holding plates 8.
The above-mentioned pressure oil outlet 42 is opened in the lateral end face 8a, and the downstream side
The above-mentioned pressure oil inlet 41 is opened at the first horizontal end face 8b which is the upstream side end face of the holding plate 8 located on the (right side), and the pressure oil outlet 42 and the pressure oil inlet 41 are concentrically opposed to each other. is there.

A first pipe end 45, which is an upstream end of the communication pipe 23, is fitted to the pressurized oil outlet 42 in an oil-tight manner through sealing means 47 formed of an O-ring. Further, a second pipe end 4 which is a downstream end of the communication pipe 23 is connected to the pressurized oil inlet 41.
6 is fitted in an oil-tight manner via another sealing means 47. A swing allowance gap 49 and a swing allowance groove 50 are formed on the left and right sides of the sealing means 47 at the first tube end 45 and the second tube end 46, respectively. Thereby, the communication pipe 2
Each of the pipe ends 45 and 46 of No. 3 is swingable with respect to the pressure oil outlet 42 and the pressure oil inlet 41 so that the misalignment between the pressure oil outlet 42 and the pressure oil inlet 41 can be absorbed. Is easy.

The fitting portion 53 between the pressure oil outlet 42 and the first pipe end 45 and the fitting portion 54 between the pressure oil inlet 41 and the second pipe end 46 are configured as follows. A tube escape space 57a is formed in the deep portion of the pressure oil outlet 42, and a tube escape space 57b is also formed in the deep portion of the pressure oil inlet 41. In addition, fitting / holding stoppers 62 composed of retaining rings are detachably fitted to the first pipe end 45 and the second pipe end 46.

The communication pipe 23 functions as follows in the use state shown in FIG. That is, the first pipe end 45 on the left side
By connecting the stopper 62 to the stop position and switching the stopper 62 to the stop position, the communication pipe 23 is prevented from moving to the left, and the fitting part 54 on the right is held in the fitted state. Further, another stopper 6 is attached to the second pipe end 46 on the right side.
By mounting 2, the communication pipe 23 is prevented from moving to the right, and the fitting part 53 on the left is also held in the fitted state.

On the other hand, when removing the presser plate 8 from the ram 1 for maintenance of the hydraulic cylinder 19, as shown in FIG. 6, the stopper 62 is removed from the first pipe end 45 on the left side and the stopper 62 is removed. 62 is switched to the stop release position, and the first tube end 45 is slid leftward. Thereby, the second pipe end 46 is pulled out from the pressure oil inlet 41, and the right fitting portion 54 is fitted and removed.

FIGS. 7 to 11 and FIG. 12 show the second and third embodiments. In each embodiment, members having the same functions as those in the first embodiment are given the same reference numerals in principle.

(Second Embodiment) FIGS. 7 to 11 show a second embodiment. As shown in FIG. 7, the communication path 22 is formed in a rearward portion (leftward portion in the figure) in the upper portion of the holding plate 8. The communication path 22 is
It is connected to the hydraulic oil chamber 20 of the hydraulic cylinder 19 through the two through holes 71 and 72. The hydraulic cylinder 1
The 9 piston 21 is disposed above the upper end surface of the upper portion 3a of the upper die 3.

As shown in FIG. 8, the sealing means 47 of the communication pipe 23 is composed of an O-ring 47a and a cap-shaped sealing member 47b.
It is constituted by and. Further, the pipe relief space 57b of the communication pipe 23 is formed only in the right pressure oil inlet 41. A fitting holding stopper 62 made of a screw is screwed into the peripheral wall 59b of the pressurized oil inlet 41, and the stopper 6
The lower end of the second tube 2 projects into the swingable groove 50 of the second tube end 46. The stopper 62 is switched to the stop position by advancing downward as shown, and conversely, is switched to the stop release position by retreating upward. Further, the pressure oil outlet 42
A receiving wall 73 is provided at the back of the device. The receiving wall 73
Prevents the communication pipe 23 from moving to the first pipe end 45 side (upstream on the left side).

As shown in FIG. 9, the valve box 29 of the air vent valve 28 is fixed to the lateral end face of the ram 1 via a spacer 74. By appropriately selecting the thickness of the spacer 74, the communication pipe 23 having a standard length can be used between the lowermost holding plate 8 and the valve box 29. The first of the communication pipe 23
The pipe end 45 is also prevented from moving to the left upstream by the receiving wall 73. Further, the sealing means 47 of the communication pipe 23 is configured in the same manner as in FIG.

The structure of the sealing portion will be described with reference to FIG. 10, which is an enlarged view of a portion indicated by an arrow B in FIG. Sealing means 4
No. 7 is formed by externally fitting a cap-shaped sealing member 47b made of a fluorine resin on a rubber O-ring 47a. The sealing member 47
Swing allowance gaps 49 are formed on both left and right sides of b. Accordingly, the second pipe end 46 is allowed to swing around the center C on the pipe axis with the radius R, and the misalignment between the pressure oil outlet 42 (not shown here) and the pressure oil inlet 41 is performed. Can be absorbed. Then, even when the second pipe end 46 swings and swings, the oil pressure acting in the pressurized oil inlet 41 is reduced by the O-ring 47a.
The outer peripheral surface of the seal member 47b is strongly brought into contact with the inner peripheral surface of the pressure oil inlet 41 via the hole, so that pressure oil leakage can be reliably prevented. The first pipe end 45 (not shown here) is also configured in the same manner as the second pipe end 46 described above.

As shown in the modified example of FIG.
7 is an O-ring 47a and a rectangular sealing member 47
b.

The structure of the second embodiment operates as follows, as shown in FIG. During the unclamping operation of the clamp device, as described above, the hydraulic oil chamber of each holding plate 8 is operated.
(Not shown here) to supply pressurized oil. In this case,
As indicated by the solid arrow in the figure, the pressure oil flows from the upstream pressure oil outlet 42 to the downstream pressure oil inlet 41, and a small amount of pressing force acts on the communication pipe 23 due to the flow. An attempt is made to move the communication pipe 23 to the right. But,
The pressing force is received by the stopper 62 and the communication pipe 23 is received.
Of the first pipe end 45 from the pressure oil outlet 42 is prevented.

On the contrary, during the clamping operation,
When the pressurized oil is discharged from the hydraulic oil chamber of each holding plate 8, the pressurized oil flows to the left as indicated by a two-dot chain line arrow in the figure. In this case, the pressure in the upstream (left) hydraulic oil chamber near the pressure oil discharge port decreases instantaneously, whereas the pressure in the downstream (right) hydraulic oil chamber decreases due to the action of air mixed in the pressure oil. There is a time delay. For this reason, the pressure at the pressure oil inlet 41 becomes higher than that at the pressure oil outlet 42, and the pressure difference between the pressure
3 is strongly pressed to the left. However, the receiving wall 73 of the holding plate 8 receives the pressing force without any trouble.

(Third Embodiment) FIG. 12 shows a third embodiment. The communication pipe 23
The pressure oil outlet 42 and the peripheral walls 59a and 59b of the pressure oil inlet 41 are fitted externally. The fitting holding stopper 62 and the pipe escape space 57a are provided only on the upstream (left side) holding plate 8.

Incidentally, the clamp device of the present invention can be modified as follows. Clamp receiving member 5
Instead of being constituted by a plurality of receiving plates 7, it is formed by one sheet. In addition, the clamp receiving member 5 is formed integrally with the ram 1 of the press brake, instead of being fixed to the ram 1 of the press brake with a fixing bolt 11.

Instead of forming the unclamping drive means 13 by a hydraulic cylinder 19 and forming the clamp driving means 14 by a spring force type, the clamp driving means is constituted by a hydraulic cylinder and the unclamping drive means is formed by a spring force type. To be configured. Or, these two driving means 13.1
4 is composed of one double-acting hydraulic cylinder.

[0044]

The present invention has the following effects because it is constructed and operates as described above. (Invention of claim 1) Since the communication pipe can be mounted between the adjacent pressing plates, unlike the conventional example, it is not necessary to project into the front or rear space of the ram. For this reason, it becomes possible to expand the bending forming range of the processed steel plate. Moreover, since the communication pipe can be mounted between the front surface and the rear surface of the holding plate, the communication tube is prevented from being damaged by the bent steel plate. In addition, each of the above
In the holding plate, the pressure oil inlet and the pressure oil outlet are connected to each other.
Since they are formed almost coaxially and almost the same diameter, the pressure
When the oil pressure is supplied, the oil pressure
Lance. For this reason, the presser
The plate can be prevented from moving in the direction of the two lateral end faces.
As a result, the above-mentioned holding plate is received in the direction of both lateral end surfaces.
Means can be omitted. Also, since the pressurized oil inlet and the pressurized oil outlet are opened substantially coaxially on both lateral end faces of each presser plate, the opposing pressurized oil outlet and the pressurized oil inlet of the adjacent presser plates can be concentrically faced. it can. For this reason, the manufacturing cost of the whole clamp device can be reduced by using a plurality of pressing plates as common parts. Further, since the plurality of communication pipes of the present invention are made straight and straight, the space for storing air in the pressurized oil is extremely small and the length of the pipes can be short. Therefore, the operation of bleeding the pressurized oil is completed in a short time. In addition, since the air can be easily removed and the amount of air mixed into the pressure oil can be reduced, the operation time of the clamp or unclamping operation is short.

(Invention of claim 2) The invention of claim 2 also has the following effect similar to the above-mentioned invention of claim 1. That is, since the communication pipe of the present invention can be mounted between the adjacent holding plates, unlike the conventional example, the communication pipe does not need to protrude into the front or rear space of the ram. For this reason, it becomes possible to expand the bending forming range of the processed steel plate. Moreover, since the communication pipe can be mounted between the front surface and the rear surface of the holding plate, the communication tube is prevented from being damaged by the bent steel plate. In addition, in each of the above holding plates,
The pressure oil inlet and the pressure oil outlet are almost coaxial and almost the same diameter.
The hydraulic pressure when supplying pressurized oil to the presser plate
The forces balance in the direction of the two lateral end faces. For this reason,
Due to the oil pressure, the holding plate is
It can be prevented from moving in the opposite direction. As a result, the above holding plate
Can be omitted in the direction of both lateral end surfaces. Also, since the pressurized oil inlet and the pressurized oil outlet are opened substantially coaxially on both lateral end faces of each presser plate, the opposing pressurized oil outlet and the pressurized oil inlet of the adjacent presser plates can be concentrically faced. it can. For this reason, the manufacturing cost of the whole clamp device can be reduced by using a plurality of pressing plates as common parts. Further, since the plurality of communication pipes of the present invention are made straight and straight, the space for storing air in the pressurized oil is extremely small and the length of the pipes can be short. Therefore, the operation of bleeding the pressurized oil is completed in a short time. In addition, since the air can be easily removed and the amount of air mixed into the pressure oil can be reduced, the operation time of the clamp or unclamping operation is short.

(Invention of Claim 3) According to the invention of Claim 3, since the communication pipe is retracted to one of the pipe escape spaces, an arbitrary holding plate can be removed, so that maintenance of the hydraulic cylinder and the like provided on the holding plate can be performed. Easy.

(Invention of Claim 4) The invention of claim 4 is to prevent the fitting / holding stopper from being damaged even when the communication pipe is strongly pressed in the axial direction by the pressure difference of the pressure oil. Can be prevented.

[Brief description of the drawings]

FIG. 1 shows a first embodiment and is a front view of a clamp device.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG.

5 is an enlarged longitudinal sectional view of an arrow A portion in FIG. 1,
It is a figure showing the fitting state of the communicating pipe.

FIG. 6 is a view showing a state in which the communication pipe is fitted and removed.

FIG. 7 is a view showing a second embodiment and corresponding to FIG. 3;

FIG. 8 is a view showing a second embodiment of the present invention and corresponding to FIG. 5;

FIG. 9 is a longitudinal sectional view of the air vent valve according to the second embodiment.

FIG. 10 shows the second embodiment of the above, and is indicated by an arrow B in FIG.
It is an enlarged view of a part.

FIG. 11 is a partial view showing a modification and corresponding to FIG. 10;

FIG. 12 shows a third embodiment and is a view corresponding to FIG. 5;

[Explanation of symbols]

1 ... ram, 2 ... lower, 3 ... upper die, 3a ... upper, 5 ... first
Clamp member (clamp receiving member), 6: second clamp member (clamp holding member), 8: holding plate, 8a: second lateral end face, 8b: first lateral end face, 13: unclamping drive means,
14 ... clamp drive means, 19 ... hydraulic cylinder, 20 ...
Hydraulic oil chamber, 22 communication path, 23 communication pipe, 41 pressure oil inlet, 42 pressure oil outlet, 45 first pipe end, 46 second pipe end, 47 sealing means, 53 54 ... fitting part, 57a
57b: pipe relief space, 59a: peripheral wall of pressure oil outlet 42,
59b: peripheral wall of the pressure oil inlet 41; 62: stopper for fitting and holding; 73: receiving wall.

Claims (4)

(57) [Claims] 1. Lower part (2) of a horizontally extending ram (1)
The upper part (3a) of the upper die (3) is clamped and fixed from both front and rear sides by a first clamp member (5) and a second clamp member (6), and the second clamp member (6) is horizontally moved. And at least three holding plates (8), (8), (8) arranged side by side in the direction, and each holding plate (8) is separated from the first clamping member (5) by the holding plate (8). Clamp driving means (13);
A clamp driving means (14) for bringing the presser plate (8) closer to the first clamp member (5) is provided.
3) At least one of (14) is constituted by a hydraulic cylinder (19), and each hydraulic cylinder (19) of the adjacent holding plate (8) (8) (8)
(19) In the clamp device for press brake provided with a plurality of communication pipes (23) for sequentially communicating the hydraulic oil chambers (20), (20), and (20) of (19), the press plate (8) A first lateral end face (8b) which is both lateral end faces;
Between the second lateral end face (8a) and the first lateral end face (8b),
Communicates with the open hydraulic oil inlet (41) and the hydraulic oil chamber (20)
Opening in the communication passage (22) and the second lateral end surface (8a).
The pressurized oil outlet (42) is formed linearly in order and
The pressure oil inlet (41) and the pressure oil outlet (4)
And 2) are formed substantially coaxially with substantially the same diameter, and the plurality of communication pipes (23) are formed linearly, and the pressure oils of the adjacent holding plates (8), (8), (8) facing each other are formed. Exit (4
2) A clamp device for press brakes, characterized in that the pressure oil inlet (41) is communicated with the communication pipe (23) in order. 2. At least three holding plates (8), (8), (8) are arranged along the lower part (2) of the ram (1) extending in the horizontal direction.
Then, a hydraulic oil chamber (20) is provided in each holding plate (8),
A first lateral end face (8b), which is both lateral end faces of the plate (8), and a second lateral end face
(8a) and the pressure opening at the first lateral end surface (8b).
Communication between the oil inlet (41) and the hydraulic oil chamber (20)
Pressure oil outlet opening in the passage (22) and the second lateral end surface (8a).
(42) are sequentially formed in a linear shape, and each holding plate (8)
Between the pressure oil inlet (41) and the pressure oil outlet (42).
Formed almost coaxially on the same axis, and
(8) (8) Pressure oil outlet (42) and pressure oil facing each other in (8)
The inlet (41) is sequentially connected by a plurality of linear communication pipes (23).
A clamp device for press brakes, wherein the clamp device is connected to a device. 3. The clamp device for press brake according to claim 1, wherein the first pipe end (45) of the linear communication pipe (23) is connected to the second pipe end (45).
The pipe end (46) is fitted to the above-mentioned pressure oil outlet (42) and the above-mentioned pressure oil inlet (41) so as to be movable in the axial direction, and among these fitting portions (53) and (54), A pipe escape space (57a) (57b) for allowing the communication pipe (23) to be withdrawn from the other fitting part is provided at the back of at least one of the fitting parts. ) Is the tube escape space (57a)
(57b) A stopper for holding the fitting for preventing the movement to (57b)
(62) A clamp device for press brakes, characterized by having (62). 4. The clamp device for a press brake according to claim 3, wherein said pipe relief space (5) is provided at a depth of said pressurized oil inlet (41).
7b), wherein the communication pipe (23) is connected to the first pipe end.
A clamp device for press brakes, characterized in that a receiving wall (73) for preventing movement to the (45) side is provided in a deep portion of the pressure oil outlet (42).