JPS59193718A - Controlling method for maintaining parallel between top and bottom dies in press brake - Google Patents

Abstract

PURPOSE:To bend a plate material with high accuracy without avalanche while maintaining the parallel between top and bottom dies by detecting the displacement at the longitudinal center of upper and lower aprons during bending of said material and curving at least one of the top and bottom dies. CONSTITUTION:When a plate material is disposed on a bottom die 5 of a press brake 1 and the pressing between said die and a bottom die 5 is started, the die 13 and an upper apron 11 curve to project upward integrally. An upper apron 11 attached with an automatic length measuring device 25 on the dog 27 at the center of a stretching plate 23 ascends relatively at this time. The displacement is detected and is informed to a control device. A fluid pressure cylinder 29 forces upward the part around the center of a lower apron 5 according to the displacement, then the die 5 curves integrally as well so that the part around the center of said die moves upward. The dies 5 and 13 are thus automatically curved relatively with the curving displacement generated during the working, by which the parallel between the two dies is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the parallel maintenance of upper and lower aprons in a press brake. This invention relates to a parallel maintenance control method for upper and lower molds, which detects the amount by which the central portion of the upper and lower molds is curved and displaced, and curves at least one of the upper and lower molds to maintain the above-mentioned parallelism.

First, the background of the implementation of the present invention will be explained based on FIGS. 1 and 2.

The press brake 1 shown in FIG. 1 is mounted on the front surface of a machine base (a lower mold 5 is fixed to the upper surface of a lower apron 3), and is mounted, for example, above the left and right side plates 7, 7 that stand up from the machine base. An elevating drive device 9.9 such as a dynamic fluid pressure cylinder is provided to vertically move the upper apron 11, which is guided by the side plates 7, 7 and approaches and moves away from the lower mold 5'.

The press brake 1 described above has an upper die 13 attached to the lower surface of an upper apron 11, and when moving integrally with the upper apron 11 and approaching downward, a plate material 15 placed on the lower die 5 is moved between the upper and lower dies. The so-called upper movable press brake is shown as an example in which the product is taken out by pressing, bending, lifting and separating, but the upper apron 11 is fixed to the side plate 7.7,
The present invention can also be applied to a press brake in which the lower apron 3 is movable.

In FIG. 2A, the plate ttA15 is placed on the lower mold 5, and the upper mold 13 is relatively close to the lower mold 5, and the plate 15 is placed on the lower mold 5.
It shows the state where it is separated after being bent.

Figure 2B shows the state of the upper die 13 and the lower die 5 when the press brake 1 is at rest.The two dies form a straight line over their entire length in the longitudinal direction and maintain an equal distance from each other. They are parallel in the broad sense, and since they are straight lines, they are parallel in the narrow sense i).

Fig. 2C is an exaggerated view of the state of the upper and lower dies when the upper die 13 and the lower die 5 are relatively close to each other and press the plate material 15 for bending. In order to drive both ends of the mold and place the plate material 15 in the center for processing, the upper mold 13 is curved in an upwardly convex manner, and the lower mold 5 is curved in a downwardly convex manner.

In the second drawing, the upper mold 13 and the lower mold 5 are curved with the same curvature, and the corresponding positions of the upper and lower molds are in a parallel state in a broad sense where the distances are equal.

The expression "parallel" used in this specification does not indicate that the distance between the corresponding positions is the same, regardless of whether the upper and lower molds are linear or curved.

Conventionally, the press brake 1 has had the problem that the longitudinal centers of the upper and lower molds curve away from each other during pressurization of the plate material 15, as shown in FIG. 2C.

When the upper and lower molds curve away from each other in this way, the approach distance of the upper and lower molds near the center is smaller than that at both ends, and the amount of suppression is small, resulting in a so-called sagging phenomenon in which the bending angle becomes small and rough. [.

For example, even if the vicinity of both longitudinal ends of the plate material 15 are bent at a desired angle of 90 degrees, the vicinity of the center is bent at an angle of 80 degrees.

A method conventionally adopted as a countermeasure for the above-mentioned sag phenomenon is a method in which, for example, the upper mold 13 is curved downwardly in a convex manner in anticipation of the amount by which the central portions of the upper and lower molds will move away from each other.

However, the above-mentioned measures vary depending on the thickness of the plate material 15, the bending angle, the heat treatment state, etc., and are uneconomical and inefficient as trial bending is not repeated.

The present invention has been made to improve the disadvantages of the conventional methods described above, and preferred embodiments thereof will be described in detail below with reference to the drawings.

In the first embodiment shown in FIG. 1, shaft bins 17 and 19 are installed at a horizontal height position in front of the thickness center position of the side plate 7 near both ends of the upper apron 11, which is one of the upper and lower aprons,
Stretch plate 2 that is swingable around one shaft pin 19 and engages the other shaft pin 17 in a horizontal elongated hole 21
3 was established.

Central part of the upper apron 11] Automatic length measuring device 25 on the near front
is fixed, and a dog 27 is installed which goes from the above-mentioned switch brakes 1 to 23 to the automatic length measuring device 25.

The two-part apron 11 also mentioned above for the lower apron 3
The shaft pin 17', 19-1 elongated hole 21 is exactly the same as that for
, stretch plate 23-2 automatic length measuring device 25'.

Further, in this embodiment, a fluid pressure cylinder 29 is provided below the lower part 1 cylinder 3 to mold the vicinity of the center of the lower apron 3 and curve the lower apron 3 upwardly.

In the press brake 1 shown in FIG. 1, the left and right sides of the upper apron 11 are lowered at the same speed by a left and right balance device (not shown), and the upper mold 13 and lower apron 3 attached to the lower surface of the upper apron 11 are Toritsu (
) The lower die 5 maintains parallelism in a narrow sense as shown in box 2 when the press brake 1 is at rest.

The procedure for applying this embodiment to the press brake 1 described above is as follows.

The plate material 15 is placed in the lower mold 5 at approximately medium heat, and the gastric unloading device 9 is placed.
, 9, the upper mold 13 approaches the plate 15 together with the upper apron 11, and starts pressing the plate 15 between it and the lower mold 5. As shown in FIG. 2C, the upper mold 13 and the upper apron 11 begins to curve upwardly convexly.

As mentioned above, the trench plates 1 to 1 and 23 are supported at both left and right ends by the upper apron 11 and do not bend, so the automatic sub-lengthening device 25 is attached to the dog 27 installed near the middle of the trench plate 23. The attached upper apron 11 is relatively raised due to the curvature, and the amount of this upward displacement is detected and the amount of displacement is notified to a control device (not shown).

In response to the above-mentioned detected displacement (■), the fluid pressure cylinder 29 pushes up the central part (near J) of the lower apron 5, and the lower die 5 attached to the upper surface of the lower apron 5 is also curved integrally, so that the central part (near J) is pushed up. It will rise.

The amount of upward displacement near the center of the lower apron 5 is determined by stretch plays 1 to 23-. The dog 27' is detected by the automatic sub-length device 25-, so its illustration is omitted.
Fluid B-cylinder 2
9.

The curve shown by the broken line in FIG. 1 is an exaggerated view of the curve when the upper die 13 has finished bending the plate material 15, and is shown below near the center of the upper die 13 when the press brake 1 is at rest. When the end surface is 62 [)] When the plate U15 has been bent due to the distance δ1 between the upper end of the dog 27 and the lower end of the automatic vice lengthener 25 when the press brake 1 is in a resting state, the plate U15 has been bent. The distance δ3 between the upper end of the dog 27 and the lower end of the automatic sub-length device 25 is δ3-61+62.

The automatic length measuring device 25 detects the above-mentioned δ3, and the lower mold 5 that activates the fluid pressure cylinder 29 is bent so as to be convex upward.
And installed on the lower apron 3 [notas 1 ~ ledge plate 2]
For example, if the distance between the dog 27- of No. 3- and the automatic length measuring device 25- is set at 61 when the press brake 1 is at rest, the distance is controlled so that the above-mentioned distance is 63 when the bending process is completed. be.

In the above explanation, for easy understanding, the body of the press brake 1 ■ The temporary dog 27 - and the automatic length measuring device 25 '' The distance is the same as 61 of the upper apron 11, and the distance when the bending is completed is 63. However, in short, the amount of bending displacement of the upper die 13 is detected by the automatic length measuring device 25, and the lower die 5 is continuously tracked to have the same amount of bending displacement with a slight time lag when the upper and lower dies are at rest. This is to maintain a parallel state.

FIG. 3 shows a second embodiment of the invention.

Although the lower mold 5 and lower apron 3 are omitted in the example of FIG. 3, there is a mold holder 31 between the upper apron 11 and the upper mold 13 that holds the upper mold 13 on the lower surface, and which operates in the vertical direction. An appropriate number of fluid pressure cylinders 33 are provided.

In the embodiment shown in FIG. 3, the automatic length measuring device 25 explained in FIG. Detected near the fire part A 4 and activated an appropriate number of fluid pressure cylinders 3
3 to curve the vicinity of the center in the longitudinal direction of the mold boulder 31 and the upper mold 13 in a downwardly convex manner by a displacement amount corresponding to the above-mentioned curving displacement m.

As mentioned above, since the same mechanism is provided upward in the lower apron 3 (not shown), according to the control method shown in FIG. 3 of the second embodiment of the present invention, the upper apron 11 and the lower apron The apron 3 is curved upwardly and downwardly during the bending process of the plate material 15, but the upper and lower dies continue to maintain their parallel state with a slight time lag while the press brake 1 is at rest.

FIG. 4 shows the fluid pressure cylinder 29 shown in FIG.
The lower apron 3 and the lower mold 5 according to
This shows another mechanism as a means for curving the upper nib 1 in an upwardly convex manner until it matches the amount of upwardly convex bending displacement near the center of the upper nib 11 on the automatic length measuring device 25 installed in the It is.

That is, the lower apron 3 of the press brake 1 is formed into legs 35, 35 spaced apart in the longitudinal direction, and a downwardly directed hydraulic cylinder 37 is provided near the center, and the screws 1 to 35 and the legs 35, 35 are arranged in a downward direction. A toggle mechanism is constructed by connecting the parts 35 and 35 with links 39 and 41.

Therefore, it goes without saying that it can be used as is to control the amount of curvature of the lower apron 3 and lower mold 5 shown in FIG.

For example, as explained with reference to FIG. 3, the upper mold 13 is used as the lower mold 5 and the lower mold apron 3 of the press brake 1 which are designed to prevent the upper mold 13 from being bent during the bending process of the plate material 5. It can also be used when the fluid pressure cylinder 37 is operated to correct the occurrence of downward convex curvature as shown in the lower mold 5, and the length measurement value of the automatic length measuring device 25- is maintained unchanged.

In each of the control methods of the embodiments of the present invention described in detail above, the curvature that will occur during the bending process is predicted on the upper and lower aprons and the upper and lower molds before the bending process using a conventional press brake, and a corresponding curvature is set. Unlike the method of bending, this control method automatically curves the upper and lower molds in response to the amount of bending displacement that occurs during the bending process to maintain the parallelism of the lower L mold, making it difficult to perform unskilled work. This made it possible for even a technician to perform high-precision bending without the so-called sagging phenomenon, and also eliminated the uneconomical and inefficient process of repeatedly making test bends.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the first control method of the embodiment of the present invention, Fig. 2 is an explanatory diagram of upper and lower type curvature, Fig. 3 is an explanatory diagram of the second embodiment, and Fig. 4 is an explanatory diagram of the following curvature. An explanatory diagram of another embodiment to be carried out. (Explanation of the symbols representing the main parts of the drawing) 1...Press brake 3...Lower l-bron 5.
...Lower mold 11...Upper apron 13...
・Upper mold 23...S1 to Retch plate 25...Automatic length measuring device 27...Dog-12: Fig. 2 fA)

Claims (2)

[Claims] (1) Attach to the underside of the upper apron of the press brake The amount of displacement near the longitudinal center of the apron from the reference mentioned above during the bending process of the plate material is detected, and the corresponding center portion of the apron (near 1) is bent in the same direction and the amount of displacement is maintained the same. A method for controlling the parallel maintenance of upper and lower molds in a press brake, which is characterized in that the bending process is performed using a press brake. (2) Attach the upper die attached to the underside of the upper nib □ron of the press brake and the upper surface of the lower apron (with reference to the position where the lower die and the lower die are parallel to each other while the press brake is at rest). , a displacement (■) in which the vicinity of the longitudinal center of at least one apron is displaced from the above-mentioned reference during the bending process of the plate material is detected, and the central part (I) of the mold on the detected side is detected.
A method for parallel maintenance control of the upper and lower type for press brakes, characterized by displacing the near side in the opposite direction to the above-mentioned displacement and by the same amount of displacement.