JPS633690B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bending machine such as a press brake for forming thin sheet metal, and more particularly to a bending angle for detecting the bending angle during the bending process or at the end of bending in the bending machine. This invention relates to a detection device.

Generally, in order to process and form a plate material (workpiece) into the required dimensions and shape using a bending machine, a bending angle is used to detect the angle during the bending process or at the end of bending, relative to the plate thickness dimension of the workpiece. A detector is required.

However, conventionally used detectors of this type cannot be used when touching a workpiece depending on the bent shape. In addition, the distance from the lower die is long, and the bending angle changes depending on how the workpiece is held, making it impossible to accurately detect the bending angle.

Furthermore, in other detectors, the tip of the detection part requires a small outer diameter in the lower mold having a small V-shaped groove width, which is difficult in practice. Moreover, there is a risk of scratching the product, and there are problems such as hitting the side wall of the V-shaped groove of the lower die during bottoming, making it impossible to accurately detect the bending angle.

This invention was devised in order to improve the conventional problems as described above, and its purpose is to
The present invention provides a bending angle detection device for a bending machine that can always detect accurate bending angles.

For example, in a bending machine that bends plate materials, the present invention includes a contact body that presses the surface of the plate material during bending and is movable to follow the bending of the plate material, and detects the amount of movement of this contact body. The object of the present invention is to provide a detection section and detect the bending angle based on the amount of movement of the contact body, thereby achieving the above object.

A preferred embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a side view of a press brake embodying the present invention, and a plate-shaped fixed body 5 is attached to the upper front side (right side in FIG. 1) of a C-shaped frame 3 of the press brake 1. At the bottom of the fixed body 5,
An upper die 7 as a first die is detachably attached by appropriate means. Further, a plate-shaped ram 9 is mounted on the front lower part of the frame 3 at a position facing the fixed body 5 so as to be movable up and down, and a lower mold 11 as a second mold is mounted on the upper part of the ram 9. is attached removably. The upper mold 7 and the lower mold 11 work together to bend the plate-shaped workpiece W. On the upper surface of the lower mold 11, there is a V-shaped edge formed on the lower edge of the upper mold 7. V that can be freely engaged with part 7V
Bend grooves 11a and 11b are formed in parallel to the longitudinal direction. In FIG. 1, one bending groove 11a and the upper die 7 are shown corresponding to each other, but in order to make the other bending groove 11b correspond to the upper die 7, the lower die 11 must be mounted at an appropriate position. It is something to be repaired. Thus, when the ram 9 is raised to bring the lower mold 11 closer to the upper mold 7, the edge portion 7V of the upper mold 7 and the V-shaped bending groove 11a or 11b provided directly below the edge portion 7V are This is for bending a workpiece W shown by imaginary lines in Figure 2. Note that the ram 9 rises when the pedal 13 provided at the bottom of the frame 3 is pressed down, and
When the bullet 3 is rotated upward by the ammunition 15, it descends. Although this invention refers to a hydraulic press brake 1 for bending sheet metal, it is applicable to any type of press or the like. Further, the present invention provides a lower mold 1 to which a ram having an upper mold 7 is fixed.
It can also be applied to a type of press that descends relative to 1 and processes a workpiece W.

As shown in FIG. 2, the angle at which the workpiece W is bent by the upper die 7 and the lower die 11 depends on the vertical position of the V-shaped bending groove 11a or 11b and the V-shaped edge portion 7V. In other words, the bending angle of the workpiece W is determined by the upper mold 7.
Depending on the distance between the lower mold 11 and the lower mold 11,
This is determined by the upward stroke position of . If the upper position of the lower mold 11 is higher, the bending angle of the workpiece W becomes sharper, but the square root angle of the workpiece cannot be made sharper than the angle of the bending groove 11a or 11b.

Next, FIG. 3 is a front sectional view of the main part of the present invention, and FIG. 4 is a structural diagram of the detector in FIG. The lower mold 11 is removably installed on the upper surface of a lower apron 17 extending in the longitudinal direction via a lower mold holder 19. Bending groove 11 of lower die 11 extending left and right
a and 11b are selected depending on the thickness of the workpiece W and the size of the bending inner radius of the workpiece W.

Further, the bottoms of the bending grooves 11a and 11b are provided with arcuate small radii (not shown), and similarly the bending groove shoulders 1
2a and 12b are also provided with arcuate small radii. The press brake 1 is attached to the edge portion 7V of the upper mold 7.
This bending groove shoulder 12a or 1
2b, the workpiece W is bent. The arcuate radii of the bending groove shoulders 12a, 12b are formed to have various dimensions depending on the groove width.

The detector 21 is detachably installed in the lower die 11 within the opening of the lower die holder 19 and is composed of a cylinder portion 23 and a detection portion 25 . The cylinder portion 23 includes a frame 27, a piston 29 provided slidably within the frame 27, and the piston 2.
9 and a piston rod 31 integrally provided. Above this piston rod 31 is the lower mold 1
1 and fixes a connecting plate 33 at the bottom. The piston 29 is moved by a bullet 35 like a spring.
The fluid pressure that is always urged upward and is supplied from the fluid pressure supply hole 37 to the upper chamber of the piston 29, for example,
The air pushes down the piston 29 and the piston rod 31 against the bullet 35. In this way,
The cylinder portion 23 allows the piston rod 31 to move freely in the vertical direction where the upper die 7 and the lower die 11 approach and separate.

The detection part 25 is connected to a guide rod 3 which can be raised and lowered in the vertical direction integrally with the piston rod 31 by means of a connecting plate 33.
9, a wiper pedestal 43 that is locked by the guide rod 39 and always urged upward by a bullet 41 such as a spring, and a base plate 45.
The wiper pedestal 43 is guided vertically by a guide rod 39 along the cylindrical outer periphery of the frame 27, and has a wiper 49 slidably in contact with a resistor 47 provided on a base plate 45. Further, the board 45 has a terminal 51 and is connected to a display device (not shown), etc., to display the bending angle of the workpiece W.

A contact body 53 is screwed onto the head of the piston rod 31, and an engagement portion 55 formed in a spherical shape is provided at the tip of the head of the contact body 53. Further, C is the bending groove shoulder 12a from the center of the contact body 53.
As shown in FIG. 5, the contact body 53 is normally provided at a central position between the bending groove shoulders 12a and 12b. HD is the height of the lower die 11.

The operation of the bending angle detection device configured as above will be explained. When the pedal 13 shown in FIG. 1 is not pressed down, air is supplied to the cylinder portion 23 through the fluid pressure supply hole 37, and the engaging portion 55 of the contact body 53 is moved against the elastic force 35. As shown in FIG. 8, it is positioned slightly below the upper surface of the lower die 11 so as not to hinder the loading and unloading of the workpiece W.

After the workpiece W has been carried in, at the same time as the pedal 13 is pressed down, the supply of air to the cylinder section 23 is stopped by a solenoid valve or the like that operates in response to a signal from a limit switch (not shown), and then the frame body 27
The air inside is released to the atmosphere, and the engaging portion 55 of the contact body 53 comes into contact with the lower surface of the workpiece W and stops.

When the edge portion 7V of the upper mold 7 comes into contact with the upper surface of the work W and the work W begins to curve, the engaging portion 55 continues to rise while maintaining contact with the work W. The wiper 49 of the wiper holder 43 provided on the guide rod 39 interlocked with the cylinder portion 23 via the connecting plate 33 moves while maintaining contact with the resistor 47 of the base plate 45. The potentiometer consisting of the resistor 47 and the wiper 49 serves as a linear gauge and can accurately detect the movement of the wiper 49, that is, the moving distance of the contact body 53 as a linear voltage change. After the bending of the workpiece W is completed, when the pedal 13 is rotated upward by the bullet 15, air is again supplied to the cylinder section 23, the piston 29 is pushed down against the bullet 35, and the contact body 53 The engaging portion 55 is returned to a position slightly below the upper surface of the lower die 11. After this return, the workpiece W is taken out from the press brake 1.

Further, the height HD of the lower mold 11 has a tolerance depending on the lower mold 11, and also changes in size due to re-polishing for reproduction. Therefore, the mounting position of the detector 21 is such that a flat gauge is placed on the upper surface of the lower mold 11 and the position where the engaging portion 55 of the contact body 53 contacts the upper surface of the lower mold 11 is adjusted. In addition, in order to replace the bending grooves 11a and 11b of the lower mold 11, as shown in FIG. The lower mold holder 19 is movable in the front and rear directions on the upper surface thereof. After that, the edge part 7V of the upper mold 7 is matched with either of the bending grooves 11a, 11b to perform mold matching, and then fixed by screwing the fastener 63 again via the receiving plate 59 and the bullet 61. do.

Furthermore, the joint portion 55 of the contact body 53 that does not match the arcuate radius of the bending groove shoulders 12a, 12b of the lower mold 11
Alternatively, the contact body 53 may be replaced, or a plurality of detectors 21 may be arranged, and the contact body 53 of the unused detector 21 may be pressed down.
Furthermore, it is desirable that the detector 21 placed on the lower mold 11 be provided close to the center of the lower apron 17 in the longitudinal direction. Note that when the lower mold has only one bending groove, the detector 21 is attached to the lower surface or the front and rear surfaces of the lower mold 11.

As described above, according to the present invention, the contact body movable in the vertical direction toward and away from the lower die is detachably attached to the lower die, and the detection unit for detecting the amount of movement of the contact body is provided. is provided close to the shoulder of the bending groove, is advantageous for return bends, can be applied regardless of the width of the bending groove, does not have the risk of damaging the plate, and directly contacts the plate, so even overbends cannot be detected. This provides advantages such as being able to easily and always reliably detect the bending angle.

In addition to displaying this bending angle, it can also be used as a feedback amount to control the ram stroke of the bending machine to a preset bending angle.

Furthermore, in the NC control device of conventional bending machines,
A method is adopted in which the ram stroke is automatically determined based on bending specifications such as bending groove width, bending angle, plate thickness, tensile strength, and bending length. However, it is not possible to automatically correct differences in the ratio of bending pressure due to the width of the bending groove, or differences in plate thickness or tensile strength.
That is, the control of the ram stroke was a closed system, but the amount of bending was an open system. However, by feeding back the bending angle detected by the present invention, it is controlled as a closed system, and a more accurate bending angle can be obtained, which is very effective.

Furthermore, the present invention is not limited to the embodiments described above, and the present invention can be implemented in other embodiments than those described above.

[Brief explanation of the drawing]

Fig. 1 is a side view of a press brake embodying the present invention, Fig. 2 is an enlarged explanatory view of the main parts, Fig. 3 is a front sectional view of the main parts of the invention, and Fig. 4 is the main parts in Fig. 3. 5 is a side view of FIG. 4,
6 is a plan view of FIG. 4, FIG. 7 is an explanatory diagram of the attachment position of the contact body, and FIG. 8 is an explanatory diagram of the attachment state of the lower mold and the detector. Explanation of symbols representing main parts of the drawing, 7...
Upper mold, 17...Lower apron, 11...Lower mold, 5
3... Contact body, 25... Detection section.

Claims (1)

[Claims] 1 Upper mold 7 provided on the lower surface of the upper apron≡
and a lower mold 1 provided on the upper surface of the lower apron 17.
In a bending machine that bends a workpiece by moving toward and away from the upper apron ≡ or the lower apron 17, the surface of the workpiece is constantly pressed during processing, and the contact is movable following the bending direction. a detection unit 25 for detecting the amount of movement of the contact body 53;
5. A bending angle detection device for a bending machine, characterized in that the bending angle of a workpiece is detected based on the detection value detected by No. 5.