JPH0716714B2 - Press brake lower mold changer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lower mold exchanging device for exchanging a lower mold in a press brake.

[Prior Art] Conventionally, as a lower mold exchanging device in a bending machine such as a press brake, several lower molds, for example, three lower molds are mounted in a front-rear direction on a lower mold holder provided on an upper surface of a lower table. Then, the lower die holder is moved back and forth with the air cylinder to replace the die. Further, several lower molds, for example, three lower molds are attached to the circumferential portion of the lower mold holder provided on the lower table, and the lower mold holder is moved by a series of operations of rising-rotating-lowering to move the molds. There are known exchanges.

[Problems to be Solved by the Invention] However, among the above-mentioned conventional techniques, the former has the advantage of being inexpensive and having a short replacement time, but has a problem in reverse bending of a work such as a plate material. . That is, when the work is inverted and the lower die having a deep bending groove is reversely bent, the height of the lower die must be adjusted to be high.
Further, there is a problem in that when the lower mold is used which can be reverse bent without inverting the work, the dimension between the lower molds must be increased.

The latter does not have a size restriction during reverse bending, but has a problem that it takes time to replace the mold. That is, since the lower holder carries out the mold replacement in a series of operations in which one cycle of ascending-rotating-lowering is carried out, it takes time to replace the mold. Further, because of the structure, the driving device can be attached only to both ends of the lower die, so that the rigidity of the lower die holder must be increased in the case of a long die.

[Means for Solving the Problems] In view of the problems of the related art as described above, the present invention provides a first brake provided on an upper portion of the lower table on at least one of the front side and the rear side of the lower table in the press brake. A mold exchanging device that supports a second lower mold that can be freely placed is mounted and provided on the upper side of the lower mold, and the mold exchanging device has no displacement in the front-rear direction with respect to the first lower mold. As described above, the second lower mold is moved up and down with respect to the first lower mold by the first parallel link mechanism and the second lower mold via the first parallel link mechanism. A second parallel link mechanism that moves between a position aligned above the first lower mold and a lateral lower position retracted from the upper position of the first lower mold; and the first parallel link mechanism. A first link operating device that operates a link mechanism and a second link operating device that operates the second parallel link mechanism. And a link actuating device.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings.

Referring to FIG. 1, a movable lower table 7 which is vertically moved by a hydraulic cylinder 5 is provided below a frame 3 in a press brake 1 which is an example of a folding machine.
A die 11 which is a lower die is fixed to the upper part of the movable lower table 7 through a die holder 9 which is a lower die holder.

On the other hand, a fixed upper table hanging from the upper part of the frame 3
A punch 17, which is an upper die, is fixed to the lower end of 13 through a punch holder 15, which is an upper die holder. This punch
The plate-like work W is bent between the die 17 and the die 11.

In the front of the movable lower table 7 in this press brake 1, in the upper part on the right side in FIG.
A mold exchanging device 19 for exchanging 11 is provided.

Referring to FIGS. 2 (A) and 2 (B), a mold exchanging device
19 is attached to the upper front part of the movable lower table 7 via a bracket 21 of a supporting member. Rotating shafts 23 and 25 are attached to a lower side portion of the bracket 21 with a certain interval. The rotary shafts 23 and 25 are provided with upper portions of a first air cylinder 27 and a second air cylinder 29 as first and second link actuating devices, respectively.

Each of the first air cylinder 27 and the second air cylinder 29 can be slightly rotated with respect to the bracket 21. Tip portion 31 of piston rod 31 of first cylinder 27
The T is fixed to one end of the first link 33 by a pin 35 so that it can be slightly rotated.

On the other hand, the tip portion of the piston rod 37 of the second air cylinder 29 is fixed to the substantially central portion of the second link 39 with a pin 41. One end of the second link 39 has a pin 43 on the bracket 21.
It's stopped at. The other end of the second link 39 is fixed to one end of the third link 45 with a pin 47. A pin 51 fixes the substantially central portion of the third link 45, the substantially central portion of the first link 33, and one end of the fourth link 49.

The other end of the fourth link 49 has a pin 53 on the upper portion of the bracket 21.
It's stopped at. The other end of the third link 45 is fixed to one end of the fifth link 55 with a pin 57. The other end of the first link 33 and the lower end of the sixth link 59 are fixed by a pin 61. Further, the other end of the fifth link 55 is pinned to the sixth link 59 so that the fifth link 55 is attached substantially parallel to the first link 33.
It's stopped at 63. A screw 65 is provided downward at one end of the fifth link 55.

A roller 67 is provided at a part of the upper part of the movable lower table 7.
Is installed. A die holder 69, which is a lower die holder for lower die die replacement, is provided at one end on the upper side of the sixth link 59. The die holder 69 has a second lower die die for lower die die replacement. The model 11K is installed.

With the above configuration, the operation of the mold exchanging device 19 will be described.
The mold exchanging device 19 operates as shown in FIGS. 2 (A) to 2 (B). That is, the first and fifth links 33 and 35 are parallel, the second and fourth links 39 and 49 are parallel, and the third and sixth links 45 and 59 are parallel. 1, second
The second lower mold 11K is supported by the mold matching mechanism that is a combination of the parallel link mechanisms of the above, and when the first air cylinder 27 moves up, the second lower mold 11K is used as a substitute for the spring. While being pushed by the air cylinder 29, the second link 39 and the fourth link 49 rotate counterclockwise as shown in FIG. 2B with the pins 43 and 53 as fulcrums, respectively. At this time, the first link 33 and the fifth link 55 do not rotate, and the screw 65 is inserted into the first link 33 via the third link 45.
Rises in contact with. The sixth link 59 is shown in FIG. 2 (B).
Roller attached to the movable lower table 7 as shown in FIG.
When it comes into contact with 67, it becomes a mode in which the second lower mold 11K is positioned with the core aligned with the upper position of the first lower mold 11 so that there is no displacement in the front-rear direction. 4 links
The rotation of 49 stops. Then, the first link 33 and the fifth link
55 starts to rotate counterclockwise, and the upper surface of the die 11 attached to the upper surface of the die holder 9 is held in contact with the lower surface of the die holder 69 to complete the die replacement. As shown in FIG. 2 (B), bending can be easily and easily performed on the surface opposite to the bending surface of the plate-shaped work W in the state shown in FIG. 2 (A).

When returning the mold exchanging device 19 from FIG. 2 (B) to FIG. 2 (A), that is, when the die holder 69 descends,
Since the link 39 and the fourth link 49 are still pushed by the second air cylinder 29, when the first air cylinder 27 descends, the first link 33 and the fifth link 55 rotate clockwise with the pins 61 and 63 as fulcrums. When the screw 65 contacts the first link 33, the second link 39 and the fourth link 49 move the pins 43 and 53, respectively, while resisting the force of the second air cylinder 29.
The die holder 69 descends by rotating clockwise about the fulcrum and returns to the original state as shown in FIG. 2 (A).

Although the mold exchanging device 19 is described as being attached to the front of the movable lower table 7, the mold exchanging device 19 may be provided only on the rear side of the movable lower table 7 or on either of the front side and the rear side described above. May be attached. The die 3 type can be exchanged by attaching it to both the front and the rear of the movable lower table 7.

[Effects of the Invention] As will be understood from the above description of the embodiments, in short, the present invention provides the above-mentioned lower table (7) on at least one of the front side and the rear side of the lower table (7) in the press brake. The mold exchanging device (19) supporting the second lower mold (11K) which can be placed on the upper side of the first lower mold (11) provided on the upper part is installed and provided. (1
9) moves the second lower mold (11K) up and down with respect to the first lower mold (11) so that the first lower mold (11) is not displaced in the front-rear direction. A first parallel link mechanism to perform,
A position where the second lower mold (11K) is aligned above the first lower mold (11) and a position above the first lower mold (11) via the first parallel link mechanism. A second parallel link mechanism that moves between a lower side position retracted from the first parallel link mechanism, a first link actuating device (27) that operates the first parallel link mechanism, and the second parallel link mechanism. And a second link actuation device (29) for actuating the.

As is apparent from the above configuration, the present invention provides the first lower mold provided on the upper portion of the lower table 7 in the press brake.
Second lower mold 11 so that there is no deviation in the front-back direction with respect to 11.
The first parallel link mechanism that moves K upward and downward, and the second lower mold 11K through the first parallel link mechanism are retracted from the position aligned above the first lower mold 11 and the upper position. And a second parallel link mechanism that moves between the first and second parallel link mechanisms that move between the first and second parallel link mechanisms.
This is a configuration including the first and second link actuating devices 27 and 29.

That is, in the present invention, the first parallel link mechanism for vertically engaging the second lower mold 11K with the first lower mold 11 and the upper position of the first lower mold 11 are engaged. Second lower mold 11
When the second parallel link mechanism for moving K is provided, for example, when the first lower mold 11 is replaced, the shape and size of the first lower mold 11 may be slightly different. However, the second lower mold 11K can be placed and aligned on the first lower mold 11 by aligning them so that there is no displacement in the front-rear direction.

[Brief description of drawings]

FIG. 1 is a side sectional view of a press brake which is an example of a folding machine equipped with the mold exchanging device of the present invention. 2 (A) and 2 (B) are enlarged views taken in the direction of the arrow II in FIG. 1, FIG. 2 (A) is a state diagram before the mold replacement, and FIG. 2 (B) is the mold replacement. FIG. [Description of Symbols Representing Main Parts of Drawing] 1 ... Press brake 7 ... Movable lower tail 9 ... Die holder, 11 ... Die 19 ... Mold changing device 27 ... First air cylinder 29 ... Second air cylinder 33 ... Second 1st link, 39 ... 2nd link 45 ... 3rd link, 49 ... 4th link 55 ... 5th link, 59 ... 6th link 67 ... Roller, 69 ... Die holder

Claims (1)

[Claims] 1. A press brake, which can be placed on at least one of the front side and the rear side of a lower table (7) and an upper side of a first lower mold (11) provided above the lower table (7). The mold exchanging device (19) supporting the second lower mold (11K) of the
9) moves the second lower mold (11K) up and down with respect to the first lower mold (11) so that the first lower mold (11) is not displaced in the front-rear direction. A first parallel link mechanism to perform,
A position where the second lower mold (11K) is aligned above the first lower mold (11) and a position above the first lower mold (11) via the first parallel link mechanism. A second parallel link mechanism that moves between a lower side position retracted from the first parallel link mechanism, a first link actuating device (27) that operates the first parallel link mechanism, and the second parallel link mechanism. And a second link actuating device (29) for actuating the press brake lower die changing device.