JPH06226352A - Press brake - Google Patents

Abstract

PURPOSE:To obtain a press brake by which a state in which a second upper metallic die provided on a metallic die exchanging device is always in close contact with the lower part of a first upper metallic die provided on the lower part of a first table is maintained without longitudinal off-center in the press brake provided with the metallic die exchanging device. CONSTITUTION:The press brake is provided with the metallic die exchanging device 19 by which the second upper metallic die 11K is held freely engaged with the lower side of the first upper metallic die 17 provided on the lower part of the upper table 13, at least, on one of the front or rear sides of the table 13. When a work is carried out using the second upper metallic die 11K by operating the metallic die exchanging device 19, the second upper metallic die 11K is always held in close contact with the lower part of the first upper metallic die 17 and the longitudinal center lines of the first and second upper metallic dies 17 and 11K are always coincident with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press brake mold exchanging device, and more particularly to a first upper mold provided on an upper table of a press brake and a second excavating device provided on the mold exchanging device. Related to a mold exchanging device capable of performing bending with higher accuracy because the cores in the front-rear direction of the upper mold coincide with each other and there is no relative displacement in the vertical direction between the upper molds during processing. Is.

[0002]

2. Description of the Related Art Conventionally, as a die exchanging device for an upper die in a press brake, for example, JP-A-53-10985 is known.
No. 8 (hereinafter simply referred to as "prior example 1") and U.S. Pat. No. 36.
No. 81994 (hereinafter simply referred to as "prior example 2").

[0003]

However, in the above-mentioned first example, the die exchanging device is provided with respect to the first upper die preliminarily attached to the lower portion of the upper table in the press brake. The second upper mold thus formed is crimped to the side surface, and when the work is bent, the upper surface of the second upper mold is slightly displaced upward so as to come into contact with the lower surface of the upper table due to the reaction force. Therefore, for example, there is a problem in performing air bending with high accuracy.

Further, in the structure of the prior art example 2, the first table preliminarily mounted on the upper table of the press brake is used.
The core of the upper mold and the core of the second upper mold provided in the mold exchanging device are in a state of being displaced in the front-rear direction. For example, when a back gauge is used, position correction is necessary and operation is required. There are problems such as being troublesome.

[0005]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention is directed to at least one of a front side and a rear side of an upper table in a press brake, and a first lower portion of the upper table. A press brake is formed by mounting a mold exchanging device supporting a second upper mold engageable on the lower side of the upper mold, and the second upper mold is operated by the operation of the mold exchanging device. When performing processing using the second upper mold, the second upper mold is always supported in close contact with the lower part of the first upper mold, and the cores of the first and second upper molds in the front-rear direction are always aligned. The configuration is in.

[0006]

In the above structure, when a work is bent by using the second upper mold supported by the mold exchanging device, the second upper mold is placed below the first upper mold. The position of the lower end portion of the second upper mold can be accurately grasped without being displaced upward due to the drag force of the work and the like, which is always in close contact. Therefore, accurate bending can be performed even during air bending.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

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

On the other hand, at the lower end of the upper table 13 fixed to the upper part of the frame 3, a punch 17 as a first upper die is fixed via a punch holder 15 as an upper die holder. The plate-shaped work W is bent between the punch 17 and the die 11.

On the front side (left side in FIG. 1) of the upper table 13 of the press brake 1, a die exchanging device 19 for exchanging the punch 17 which is an upper die is mounted.

In order to align the second upper mold 11K provided in the mold exchanging device 19 with the lower side of the punch 17 so that there is no displacement in the front-rear direction, the mold exchanging device 19 has a metal mold. Equipped with a type matching mechanism.

That is, referring to FIGS. 2A and 2B, the mold exchanging device 19 is attached to the upper front part of the upper table 13 via a bracket 21 which is a supporting member. Rotating shafts 23 and 25 are attached to the upper side of the bracket 21 with a certain distance. The rotating shafts 23, 2
5, the first air cylinders 27,
The lower parts of the second air cylinders 29 are provided respectively.
Therefore, each of the first air cylinder 27 and the second air cylinder 29 can slightly swing with respect to the bracket 21. The tip end portion 31T of the piston rod 31 of the first cylinder 27 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 end portion of the piston rod 37 of the second air cylinder 29 is fixed to the substantially central portion of the second link 39 by a pin 41. One end of the second link 39 is fixed to the bracket 21 with a pin 43. Second link 3
The other end of 9 has a pin 47 on one end of the vertical third link 45.
It's stopped at. A fourth center parallel to the substantially central portion of the third link 45, the substantially central portion of the first link 33, and the second link 39.
One end of the link 49 is fixed by a pin 51. The other end of the fourth link 49 is fixed to the bracket 21 by a pin 53 at a position vertically below the pin 43. 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, so that the fifth link 55 is attached substantially parallel to the first link 33,
The other end of the fifth link 55 is fixed to the sixth link 59 by a pin 63. A screw 65 is provided upward at one end of the fifth link 55.

As is clear from the above description and FIGS. 2 (A) and 2 (B), the first link 33 and the fifth link 55 are configured as a parallel link mechanism that always maintains parallelism, and the second link This is a configuration of a parallel link mechanism in which the link 39 and the fourth link 49 are always maintained in parallel. Also, the third link 45
The sixth link 59 is constructed so as to always maintain a vertical position. That is, the first link 33 to the sixth link 59 are formed in a structure in which a plurality of sets of parallel link mechanisms are combined.

A roller 67 is attached to a part of the lower portion of the upper table 13. An upper die holder 69 for exchanging an upper die is provided at a lower end of the sixth link 59, and a second upper die 11K for exchanging an upper die is attached to the upper die holder 69. There is.

The operation of the mold exchanging device 19 having the above structure will be described. The mold exchanging device 19 is shown in FIGS.
Operates as in (B). That is, when the first air cylinder 27 operates and the piston rod 31 descends,
While resisting the second air cylinder 29, which is used as a substitute for the balance spring, the first to sixth links are lowered by their own weight. 4th link 49 is pin 4 respectively
3, the pin 53 is rotated counterclockwise in FIG. At this time, since the weights of the sixth link 59, the second upper mold 11, and the like act on the first link 33 and the fifth link 55, the screw 65 remains in the state of being in contact with the first link 33. To descend. Next, when the sixth link 59 comes into contact with the roller 67 attached to the upper table 13,
The downward rotation of the second link 39 and the fourth link 49 is stopped.

In this way, the sixth link 59 is connected to the roller 67.
The second upper mold 11K attached to the lower portion of the sixth link 59 is positioned below the punch 17 when it comes into contact with the. When the piston rod 31 of the air cylinder 27 is further lowered in this state, the first link 33 and the fifth link 55 start to rotate in the counterclockwise direction and the sixth link 59 is vertically lifted. A second upper mold 11K is held at the lower end of the punch 17 attached to the lower surface of the holder 15 in a state where the second upper mold 11K is in close contact with the upper and lower parts with the core having no positional deviation in the front-rear direction and is stacked. The mold exchange is completed.

As will be understood, after the sixth link 59 comes into contact with the roller 67 as described above, the sixth link 59 holds the vertical position and is lifted vertically.
By the rise of the sixth link 59, the second upper mold 11K
However, as shown in FIG. 2B, the punch 17 comes into close contact with the lower side of the punch 17 in a state in which a core having no positional displacement in the front and rear is fitted (a state in which there is no lateral displacement in FIG. 2). Therefore, when the sixth link 59 comes into contact with the roller 67 as described above, the front-rear core of the second upper mold 11K is already aligned with the front-rear core of the punch 17.

When the mold exchanging device 19 is in the state shown in FIG. 2B, the piston rod 3 of the first air cylinder 27 is
When 1 is contracted and lifted up, the first link 33 and the fifth link 55 first rotate clockwise with the pins 51 and 57 as fulcrums due to the weight of the sixth link 59 and the second upper mold 11K. Pivot and the second upper die 11K punches 1
It descends so as to separate from 7. And the first link 3
When 3 abuts on the screw 65 provided on the fifth link 55, the rotation of the first and fifth links 33, 55 is restricted. Therefore, when the piston rod 31 is moved upward,
The fifth link 33, 55 is lifted, and the second link
The link 39 and the fourth link 49 are pins 43 and 53, respectively.
With the fulcrum as a fulcrum, it rotates upward in the clockwise direction and returns to the original state as shown in FIG.

The mold exchanging device 19 is the upper table 1
Although it has been described that it is attached to the front side of No. 3, the mold exchanging device 19 may be attached only to the rear side of the upper table 13 or to both the front side and the rear side described above.

[0021]

As will be understood from the above description of the embodiments, according to the present invention, the first upper mold 1 preliminarily attached to the lower portion of the upper table 13 in the press brake.
7, the second upper mold 1 provided in the mold changing device 19
1K is the second upper mold 11K below the first upper mold 17
The second upper mold 1K does not move upward due to the reaction force of the work when the work is bent, and the second upper mold 1 is
Since the position of the lower end of 1K can always be grasped accurately, it is possible to perform accurate machining during air bending.

Further, since the first and second upper molds are aligned with each other in the front-rear direction without shifting in the front-rear direction, the machining position does not change in the front-rear direction, and the second upper mold does not move during machining. It is possible to perform stable processing without applying a moment to the die in the front-rear direction.

The present invention is not limited to the above-mentioned embodiments, but can be implemented in other modes by making appropriate changes.

[Brief description of drawings]

FIG. 1 is a side cross-sectional view of a press brake that is an example of a folding machine equipped with the mold exchanging device of the present invention.

FIG. 2 is an enlarged view taken along the arrow II in FIG. 1, in which (A) is a state diagram before die exchange, and (B) is a state diagram after die exchange.

[Explanation of symbols]

 1 Press Brake 13 Upper Table 17 Punch 19 Mold Change Device 27 Air Cylinder 33 1st Link 39 2nd Link 45 3rd Link 49 4th Link 55 5th Link 59 6th Link 67 Roller

Claims (1)

[Claims] 1. An upper table 1 in a press brake.
A mold exchanging device that supports a second upper mold 11K that is freely engageable with the lower side of the first upper mold 17 provided in the lower portion of the upper table 13 on at least one side of the front side or the rear side of 3. 1
9 is used as a press brake, and when the second upper mold 11K is processed by the operation of the mold exchanging device 19, the second upper mold 11K is the first upper mold. A press brake characterized in that it is always in close contact with and supported by the lower part of 17, and the cores of the first and second upper molds 17, 11K in the front-rear direction are always aligned.