JP2521759B2 - Folding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a bending machine such as a press brake.

(Prior Art) Conventionally, when bending a work with a bending machine such as a press brake, in order to obtain a predetermined bending angle on the work, several bending operations are tried and punching is performed. I had to adjust the distance to the die. Such adjustment requires a lot of time and labor, and relies heavily on the experience and intuition of the operator, which has been a major obstacle to improving work efficiency.

Therefore, a device for automatically detecting this bending angle has been developed, and a device using reflected light or image processing has been known so far.

(Problems to be Solved by the Invention) By the way, in the above-described conventionally known bending angle detection device using reflected light, image processing, etc., there is a bending angle detection error and reliability is still insufficient and high accuracy is achieved. The bending angle was not obtained.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bending machine for improving the efficiency of bending by detecting a bending angle with high accuracy in order to improve the above problems.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned conventional problems, in the present invention, the punch 21 and the die 9 cooperate with each other in the vertical direction to bend the work. In a bending machine that performs processing, a supporting hole 25 extending in the bending direction of the work is provided at a position close to the bending apex 21P of the punch 21, and the distance to the work to be bent is detected in this supporting hole 25. Sensor body 2 equipped with multiple capacitive sensors 23A and 23B in parallel
3 is embedded, and each capacitance type sensor 23A, 23B is configured to extend in the bending direction, and each capacitance type sensor 23A, 23B
Is characterized in that an arithmetic processing unit 35 for arithmetically processing the bending angle of the work based on the distances A and B to the work respectively detected by is provided.

(Operation) With the above configuration, after the work is supported by the die 9, the punch 21 is moved down relative to the die 9 so that the work is bent by the cooperation of the punch 21 and the die 9. can do.

In the process of bending, the plurality of capacitance type sensors 23A, 23B detect the distances A, B to the work to be bent, and the arithmetic processing unit 35 causes the respective capacitance sensors 23A, 23B.
The bending angle θ of the workpiece is calculated based on the distances A and B to the workpiece detected by B respectively. In other words, the bending angle θ of the work is detected by the plurality of capacitance type sensors 23A and 23B and the arithmetic processing unit 35. Here, since the plurality of capacitance type sensors 23A, 23B are close to the bending apex 21P of the punch 21, it is possible to reduce the distance between the bent work and the capacitance type sensors 23A, 23B, and The detection accuracy of the capacitance type sensors 23A and 23B is high. Further, by configuring each of the capacitance type sensors 23A and 23B to extend in the bending direction, the capacitance type sensor sensor 23
The bending angle θ of the work is detected by the A, 23B and the arithmetic processing unit 35 in the bending direction.

In addition, while detecting the bending angle θ of the work as described above, the relative lowering of the punch 21 with respect to the die 9 is controlled so that the bending angle of the work becomes a predetermined bending angle.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

Referring to FIG. 1, a C-shaped side frame in a press brake 1 which is an example of a bending machine.
A lower frame 5 is provided below the 3R and 3L.
A die 9 as a lower die is mounted on the lower frame 5 via a lower die holder 7 so as to extend in the left-right direction in FIG.

An upper frame 11 is provided above the side frames 3R and 3L.
Are attached, and fluid pressure cylinders 13R and 13L are provided on the left and right of the upper frame 11. A ram 17 is connected to the piston rods 15R and 15L of the fluid pressure cylinders 13R and 13L. The ram 17 is moved up and down via the piston rods 15R and 15L by the operation of the fluid pressure cylinders 13R and 13L.

A punch 21 as an upper die is attached to the lower portion of the ram 17 via an upper die holder 19, and the punch 21 is moved up and down relative to the die 9 to form a U-shape on a work (not shown). And V-shaped bending is performed.

A bending angle sensor 23 is built in the punch 21. More specifically, as shown in FIG. 2, the support hole 25 has a support hole 25 in a direction orthogonal to one side 21A of the two sides 21A and 21B sandwiching the bending apex 21P of the punch 21. Is formed so as to extend in the bending direction, and the bending angle sensor main body 23 is guided and built in the support hole 25 thereof.

The bending angle sensor 23 is composed of a plurality of, for example, two capacitance type sensors 23A and 23B. The sensors 23A and 23B are parallel to each other as shown in FIG. In the bending direction). Moreover,
A plurality of screw holes 27 in a direction substantially orthogonal to the side 21B.
The set screw 29 is screwed and inserted into the screw hole 27, and the bending angle sensor body 23 is inserted into the punch 21.
Has been fixed.

With the above configuration, the work W is placed on the die 9 and the ram 17
The punch 21 comes close to the die 9 and is bent by the downward movement. It is assumed that the work W is bent and the work W becomes the work W _A. That is, the bending angle when the work W is bent into the work W _A is θ, the inter-sensor distance between each sensor 23A and the sensor 23B is 1, and the side 21A of the punch 21 and the work WA. The angle is θ ₁
And a vertical line from the bending apex 21P of the punch 21 and the side 21A.
The angle formed by and is θ ₂ .

In addition, a vertical line is drawn from the center of each sensor 23A, 23B to make the work W The following relational expression is established, where A and B are the distances between the center planes of the sensors 23A and 23B and the intersections.

θ = 90- (θ ₁ + θ ₂ ) From the above two equations, the bending angle θ is Is required. Since θ ₂ and l are preset values, the bending angle θ of the work W can be obtained by measuring the distance between A and B.

In FIG. 2, the bending angle sensor 23 is one side of the punch 21.
Punch 2 is installed in the direction orthogonal to 21A.
The bending angle θ of the work W may be measured by incorporating the work W in a direction orthogonal to the other side 21B.

Next, FIG. 4 is a block diagram showing a configuration for obtaining the bending angle θ of the work W based on the change in capacitance detected by the capacitance type sensors 23A and 23B.

In FIG. 4, the capacitance type sensors 23A and 23B are connected to the arithmetic processing unit 35 via the A / D conversion units 31A and 31B and the distance A and B conversion units 33A and 33B. An angle reference setting storage unit 37, a distance reference setting storage unit 39, and a display unit 41 are connected to the arithmetic processing unit 35, respectively.

Capacitance sensors 23A and 23B change the capacitance between the workpiece W _A and A / D converters 31A and 31B for distance A and B conversion unit 33
At A, 33B, the voltage change is converted into distances A, B. The converted distances A and B are input to the arithmetic processing unit 35. On the other hand, the angle set value θ stored in advance in the angle reference setting storage unit 37
₂ and the length set value stored in advance in the distance reference setting storage unit 39 Are previously input to the arithmetic processing unit 35.

In the arithmetic processing unit 35, Then, the bending angle θ of the work W is obtained. The obtained bending angle θ is transferred to the display unit 41,
Displayed on the display or printer.

In FIG. 2, the origin is fixed by positioning and fixing the bending angle sensor main body 23 in the punch 21, and thus the origin is fixed. Therefore, from the difference voltage based on the electrostatic capacity of the angle sensors 23A and 23B, the workpiece W is detected. The bending angle θ can also be obtained. That is, as shown in FIG. 5, each sensor 23A, 23B
The differential voltage and the bending angle θ ₁ are in a proportional relationship, and the data of this relational expression is stored in the data storage unit. Bending angle θ corresponding to the difference voltage obtained by each sensor 23A, 23B
₁ is taken out from the data stored in the data storage unit, the arithmetic processing unit 35 performs the arithmetic processing of θ = 90− (θ ₁ + θ ₂ ), and the result is displayed on the display unit 41 or displayed on the printer. By doing so, the bending angle θ can be obtained.

A flowchart of the operation based on the embodiment shown in FIG. 2 is shown in FIG. First step in FIG.
Set and input θ ₂ , l in advance with 43. Ram in Step 45
Set and enter the falling target value D of 17. Then step 47
Start the bending process with. At step 49, the ram 17 descends at high speed.

In step 51, the current position of the ram 17 is compared with the target value D, and if not equal, the process returns to the step before step 49, and if equal, the ram 17 is moved down at a slight speed in step 53. In step 55, starting the measurement of the bending angle, each sensor 23A,
A / D converter 31A, 31B converts the voltage value based on the capacitance change of 23B.
Convert with. In step 57, the distance A / B converter 33A, 3
Convert to distances A and B at 3B and measure.

In step 59, the arithmetic processing unit 35 causes θ = 90− (θ ₁ + θ ₂ ), Is calculated, and the bending angle θ is calculated in step 61 each time.
Is displayed on the display unit 41 by a display or a printer. In step 63, it is judged whether or not θ− [90− (θ ₁ + θ ₂ )] = 0. If they are not equal, the process returns to the step before step 53. If they are equal, the process proceeds to step 65 and the ram 17 is stopped. finish.

Since the capacitance type sensors 23A and 23B are built in the punch 21 and extend in the longitudinal direction of the side 21A as described above, the bending angle θ of the work W can be accurately and accurately measured. As a result, the efficiency of bending can be improved.

(Effects of the Invention) As will be understood from the description of the embodiments as described above,
According to the present invention, since the plurality of capacitance sensors are close to the bending apex of the punch, the distance between the bent work and the capacitance sensor is reduced, and the capacitance sensor As the detection accuracy increases, each capacitive sensor is configured to extend in the bending direction, so that the bending angle of the workpiece can be detected in the bending direction by the capacitive sensor and the arithmetic processing unit. It Therefore, the bending angle of the work can be detected with high accuracy in the bending direction by the plurality of capacitance type sensors and the arithmetic processing unit, which leads to highly accurate bending of the work.

[Brief description of drawings]

FIG. 1 is a schematic front view of a press brake according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a perspective view of a bending angle sensor. , 4th
Figure building block for detecting the bending angle by the bending angle sensor view, FIG. 5 is a flowchart of an example of the operation of the graph and FIG. 6 is the embodiment showing a relationship between the differential voltage and the angle theta ₁ of the sensors Is. [Explanation of symbols showing main parts of drawing] 1 ... press brake, 9 ... die 17 ... ram, 21 ... punch 23 ... bending angle sensor 23A, 23B ... capacitance type sensor 35 ... … Processing unit, 41 …… Display unit

Claims (1)

(57) [Claims] 1. A bending machine for vertically bending a work by the cooperation of a punch and a die, the support extending in the bending direction of the work at a position close to a bending apex of the punch. A hole is provided, and a sensor main body equipped with a plurality of capacitance type sensors that detect the distance to the work to be bent is embedded in parallel in the support hole, and each capacitance type sensor extends in the bending direction. And a processing unit for calculating the bending angle of the work based on the distance to the work detected by each capacitance type sensor.