JPH0351495B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a folding machine such as a press brake, and more particularly to a folding machine that supports a mold such as an upper die or a lower die with respect to a frame of the folding machine. It concerns improvements to equipment.

When bending a plate material using a bending machine such as a press brake, the center portions of the upper and lower dies tend to curve away from each other, making it difficult to achieve the accuracy of the bending process. It is well known that it gets worse. In order to solve the above problems, in the past, multiple wedge mechanisms of various configurations were interposed between the bending machine and the upper mold, lower mold, etc., or multiple hydraulic cylinders were used. As a structure in which they are installed side by side on a frame, the central part of the upper or lower mold is curved to an appropriate curvature in advance so that it is convex, so that the upper mold and the lower mold are parallel to each other during the bending process. It is configured.

On the other hand, in recent years, automatic die changing devices for bending machines such as press brakes have been developed, and automatic material supply devices that automatically feed materials such as plates to the bending machines have also been developed. Efforts are being made to make the bending process unmanned using a bending machine. However, the work of appropriately bending the upper mold or the lower mold into a convex shape as described above is performed by manually adjusting a plurality of wedge mechanisms and the like. Therefore, when the thickness, width, etc. of the materials differ, the wedge mechanism etc. must be adjusted each time, resulting in poor work efficiency when producing a wide variety of products in small quantities.

The present invention was invented in view of the above problems, and its purpose is to provide a device that can automatically adjust and set the curvature of a mold in a bending machine.

In order to achieve the above objects, in the present invention, a shape memory alloy which memorizes an extended state is interposed between a frame and a mold in a bending machine in a shortened state, and this shape memory alloy is It is equipped with a control device for temperature control.

Now, referring to FIG. 1, the general reference numeral 1 indicates a folding machine such as a press brake, and this folding machine 1 is equipped with a lower frame 5 supporting a lower die 3, and an upper die 3. It has an upper frame 9 that supports 7. The bending machine 1 moves up and down at least one of the lower frame 5 and the upper frame 9. In this embodiment, the case where the upper frame 9 is moved up and down by the operation of a hydraulic cylinder 11 provided at the upper part is exemplified. There is.

As shown in more detail in FIGS. 2 and 3, lower mold holding plates 13 and 15 are attached to the front and rear surfaces of the upper part of the lower frame 5 with a plurality of bolts 17, and the lower mold 3 is positioned in the front and back direction. is regulated.
Both ends of the lower mold 3 are connected to the lower frame 5 by a connecting member 19 and a plurality of bolts 21. Between the lower mold 3 and the lower frame 5,
A plurality of shape memory alloys 23 having an appropriate shape that memorizes the shape of the stretched state in the vertical direction are provided.
Each shape memory alloy 23 is attached to the lower mold 3 at appropriate intervals.
are arranged in the longitudinal direction of each shape memory alloy 2.
A heating element 25 is attached to each of the parts 3 in an electrically insulated manner. The energizing time and current of each heating element 25 are controlled by a suitable control device 27 such as a computer or a numerical control device. That is, each shape memory alloy 23 is controlled by the control device 2.
7, each temperature is controlled separately.

In the above configuration, the control device 27 appropriately controls the energization time and current to each heating element 25 to appropriately control the temperature of each shape memory alloy 23. Since the amount of deformation (displacement) of the shape memory alloy 23 corresponds almost directly to the temperature when the temperature is kept constant, each shape memory alloy 23 only corresponds to the temperature at which it is heated. This results in stretching and pushing up the lower mold 3.

Therefore, if the temperature is controlled so that the temperature of the shape memory alloy 23 near the center is higher than the temperature of the shape memory alloy 23 near both sides, the amount of elongation of the shape memory alloy 23 near the center is higher than that of the shape memory alloy 23 near both sides. The amount of stretching of the shape memory alloy 23 increases,
The vicinity of the center of the lower die 3 is pushed up significantly. That is, the lower die 3 is curved into a convex shape with the center portion protruding upward. Therefore, by appropriately controlling the temperature of each shape memory alloy 23,
The upward curvature of the lower mold 3 can be set extremely easily.
It can be changed.

As already understood from the description of the embodiments above, the gist of the present invention is to provide a plurality of shape memory devices that memorize shapes extending in the vertical direction between a frame and a mold in a bending machine. Since the alloy is interposed in a shortened and deformed state and a control device is installed to control the temperature of multiple shape memory alloys, it is possible to automatically set and change the curvature of the mold in the bending machine. It can be done to
This is useful when attempting to make the bending machine unmanned.

Note that the present invention is not limited to the above-described embodiments, but can be implemented in other embodiments by making appropriate changes. For example, it is possible to have a configuration in which a shape memory alloy is interposed between the upper frame and the upper mold, and it is also possible to heat each shape memory alloy by applying a linear current to it.

[Brief explanation of drawings]

1 is a front view of the folding machine, FIG. 2 is an enlarged sectional view taken along the line - in FIG. 1, and FIG. 3 is a detailed enlarged view of the portion in FIG. 1. 5, 9...Frame, 3,7...Mold, 23...
...shape memory alloy, 27...control device.

Claims (1)

[Claims] 1. Between the frame and the mold in the bending machine,
A plurality of shape memory alloys that memorize the shape of the vertically extending state are interposed in a shortened and deformed state,
A bending machine characterized by being equipped with a control device that controls the temperature of a plurality of shape memory alloys.