JPH05245541A - Method and device for bending - Google Patents

Abstract

PURPOSE:To facilitate bending as accurately as possible. CONSTITUTION:The method includes a process in which a work W is held in contact with a punch P by pressing and, in this state, the punch P and a die 100 are transferred a small distance to part each other shift from a pressing state to an unloading state, a process in which a bending angle for the work W held in contact with the punch P by pressing is measured when the die 100 and the punch P are parted and a process in which a correcting data for working is calculated from the measured bending angle and the punch P and the die 100 are mutually pressuriged again based on the correcting data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending method and a bending method in which a punch and a die are pressed against each other to bend a work such as a plate material interposed between the punch and the die. Regarding the device.

[0002]

2. Description of the Related Art When a punch and a die are pressed against each other to bend a workpiece such as a plate material interposed between the punch and the die, the spring back must be taken into consideration. ..

For this reason, conventionally, test bending is performed in advance using a test material under the same conditions (plate thickness, plate width, etc.) as the above-mentioned work, and the bending angle of the work is measured by this test bending, that is, the springback amount. The processing data is calculated from the above, and the actual work is bent based on the processing data.

[0004]

By the way, in the above bending process, even if the conditions such as dimensions are the same, the bending angle of the work to be actually processed is not measured. The bending angle may vary greatly.

Moreover, when a large number of different types of workpieces are to be machined, it is necessary to carry out a test bending process for all of these types of workpieces, resulting in a significant complication of the machining work.

Therefore, for example, Japanese Patent Laid-Open No. 1-228612
In the publication, the punch and the die are temporarily separated from each other during processing, the actual bending angle of the workpiece is measured in this state, and the processing correction data is calculated based on the measured bending angle of the workpiece. The punch and the die are repressurized to each other based on the correction data.

However, if the punch and the die are simply separated from each other as described above, a positional deviation occurs between the punch and the die and the work, such as a bending line being displaced during re-pressurization, and the work will be misaligned. There is a possibility that an accurate bending angle cannot be given.

In view of the above situation, it is an object of the present invention to provide a bending method and a bending apparatus which can easily and accurately give a bending angle to a work.

[0009]

A bending method according to the present invention is a bending method in which a punch and a die are pressed against each other to bend a work interposed between the punch and the die. In the method, a step of moving the die and the punch relative to each other by a very small distance in order to bring the die and the punch into a unloading state in a state where the work is brought into contact with and held by the punch; When the punch is separated by the minute distance, a step of measuring the bending angle of the work held in contact with the punch, and calculating processing correction data from the measured bending angle of the work,
The method includes a step of pressing the punch and the die against each other again based on the processing correction data.

In the bending apparatus according to the present invention, the punch and the die are pressed against each other so that the workpiece interposed between the punch and the die is bent, and then the pressing apparatus is in the pressed state. The punch and the die are moved apart by a relatively small distance so as to be in an unloaded state,
A bending apparatus for measuring the bending angle of a work interposed between the punch and the die, and again pressing the punch and the die together based on the measured bending angle of the work. And a work holding means for holding the work in contact with the punch while at least moving the punch and the die by the minute distance.

[0011]

According to the above structure, since the work is held in contact with the punch while the punch and the die are moved by a minute distance, the punch and the work are prevented from being displaced from each other when the pressure is applied again.

[0012]

The present invention will be described in detail below with reference to the drawings illustrating the embodiments. FIG. 2 conceptually shows the main part of the bending apparatus according to the present invention. The punch P is held by a ram (not shown), and the die 100 is arranged so as to face the punch P. The plate-shaped work W is interposed therebetween, and the ram (not shown) is moved downward to pressurize the punch P and the die 100 against each other.
A press brake device that gives a desired bending angle is illustrated.

As shown in FIGS. 2 and 4, the die 100 of this press brake device has a V-shaped groove 111 formed on its upper surface 110a and a rectangular groove 11 formed on its bottom surface 110b.
2 and a rectangular protrusion 121 is formed on the upper surface 120a of the die main body 110, and the support 120 is disposed below the die main body 110 in such a manner that the protrusion 121 is fitted into the rectangular groove 112. And is held by the die holder 140 via the support 120 by a plurality of bolts 130.

Although not explicitly shown in the drawing, the die body 110 has a uniform cross-sectional shape over the entire length thereof, and a plurality of long piece portions 113 fixed to the support 120 and the long piece portions 113. Each of the short piece portions 114 is composed of a plurality of short piece portions (workpiece holding means) 114 interposed between the portions 113 and movably in the vertical direction with respect to the long piece portions 113. Angle measuring means 150 is provided on each side surface.

As shown in FIG. 2, the angle measuring means 150 includes a sensor holding portion 152 having an inclined surface 151, and a pair of reflection type lasers arranged in parallel with each other on the inclined surface 151 of the sensor holding portion 152. A distance measuring sensor 153 is provided, and the inclined surface 151 of the sensor holding portion 152 is held on one side surface of the short piece portion 114 via the sensor holding portion 152 in such a manner that the inclined surface 151 is 45 ° with respect to the horizontal direction. ing.

On the other hand, as shown in FIGS. 2 and 4, the support body 120 has a receiving hole 122 and an insertion hole 123 at portions corresponding to the short piece portion 114 of the die body 110, respectively.
And have. The accommodation hole 122 has a substantially rectangular cross section, and is provided so as to extend in the horizontal direction. Insertion hole 1
Reference numeral 23 denotes the top surface 122 of the accommodation hole 122.
It is formed vertically upward from the central portion of a, and has an opening on the upper surface of the rectangular protrusion 121.

Each of the supports 120 has a hydraulic cylinder actuator (workpiece holding means) 160 inside the accommodation hole 122. As clearly shown in FIG. 2, the hydraulic cylinder actuator 160 is pressed in a direction in which the operating rod 164 thereof is always retracted by the elastic force of the return spring 163 interposed between the end surface of the piston 161 and the cylinder body 162. The actuating rod 164 is inserted into the insertion hole 123, and the tip of the actuating rod 164 is fixed to the bottom surface of the short piece portion 114 of the die body 110. The support body is supported by the plurality of bolts 165 via the cylinder body 162. It is held at 120. As is clear from the figure, the electromagnetic switching valve 16 is provided in the pressure chamber 160a of the hydraulic cylinder actuator 160.
6, the hydraulic pump 167 and the strainer 168 are connected to the oil storage tank 169. A reference numeral 170 in the drawing is a height adjusting shim that is interposed between the bottom surface of the cylinder body 162 of the hydraulic cylinder actuator 160 and the support body 120.

In the press brake device constructed as described above, the hydraulic cylinder actuator 160 is OF
In the F state, that is, when the solenoid 166a of the electromagnetic switching valve 166 is not excited, as shown in FIG.
Since no hydraulic pressure is applied to the pressure chamber 160a, the operating rod 164 is held in a retracted state by the elastic force of the return spring 163. At this time, the long piece 113 and the short piece of the die body 110 of the die 100 are held. 114 and 114 are arranged at positions that match each other.

On the other hand, when the solenoid 166a of the electromagnetic switching valve 166 is excited from the above state, the hydraulic pressure is applied to the pressure chamber 160a, whereby the hydraulic cylinder actuator 160 is turned on, and the elastic force of the return spring 163 is resisted. Then, the operating rod 164 is moved so as to project, and as shown in FIG. 3, the short piece portion 114 is held in a state of protruding with respect to the long piece portion 113.

Further, from the above state, the electromagnetic switching valve 1
When the solenoid 166a of 66 is demagnetized to return the hydraulic cylinder actuator 160 to the OFF state, the elastic force of the return spring 163 causes the operating rod 164 to retract and move, and as shown in FIG. The piece portion 113 and the short piece portion 114 are arranged at the positions that match each other.

FIG. 1 is a flow chart showing a procedure for performing a V-bending process on a plate-like work W using the above-mentioned press brake device. The processing method of the present invention will be described below according to this procedure.

In this procedure, first, the material data of the work W, that is, the data relating to the work W such as the plate thickness and the material, is input to a device control unit (not shown) (step 200), and then the device control is performed. The preliminary bending angle α is input to the section (not shown) (step 201). Here, the preliminary bending angle α is an angle slightly smaller than the target bending angle X of the work W, and is α = X− (0 to 4 °), for example.

When the material data and the preliminary bending angle α are input, the processing data such as the stroke amount S1 and the pressing time T1 for giving the preliminary bending angle α to the work W are calculated from these data (step 202). ) Then, the ram (not shown) moves down from the top dead center based on the calculated processing data, so that the punch P is moved closer to the work W installed on the die 100 (step 203). At this time, as shown in FIG.
At about / 3, the processing time is shortened by increasing the descending speed, while the above ram (not shown)
The punch P held on the work W abuts on the work W, or immediately before that, the descending speed is slowed to reduce the work W.
The process is gradually performed. In addition, FIG.
As shown in FIG. 6, the foot (not shown) of the press brake device is actuated from the start of the downward movement of the ram (not shown).

When the ram (not shown) moves down by the calculated stroke amount S1, the ram (not shown) stops moving at that point, and at the same time, the pressurizing time T1 of the work W is reached. When the corresponding timer T1 is started,
A timer T0 'which is shorter than the pressurizing time T1 of the work W by a time T0 is started (step 204). During this time, the work W is held in a pressed state between the punch P held by the ram (not shown) and the die 100, and the bending process based on the above-described processing data sequentially proceeds.

When the timer T0 'times out (step 205), the solenoid 166a of the electromagnetic switching valve 166 is excited and the hydraulic pressure is applied to the pressure chamber 160a of the hydraulic cylinder actuator 160, as shown in FIG. 5 (c). As a result, the hydraulic cylinder actuator 160 is turned on (step 206). In addition,
In this state, since the ram (not shown) is held in the lowered state, the actuation rod 164 of the hydraulic cylinder actuator 160 does not actually project and move. Further, the hydraulic pressure applied to the pressure chamber 160a of the hydraulic cylinder actuator 160 is set to a level slightly larger than the elastic force of the return spring 163 in advance by appropriately adjusting the variable pressure control valve 171 in FIG. It is set to a value that does not deform the work W or prevent its springback.

When the timer T1 is further timed up from the above state (step 207), the ram (not shown) is raised by a minute distance S0, that is, the punch P and the die, as shown in FIG. 5A. 100 is moved away from each other (step 208), and the punch P and the die 10 are moved.
0 and 0 are stopped in the unloaded state with each other, and the pair of reflection type laser distance measuring sensors 153 of the angle measuring means 150 are respectively activated, and within the time shown in FIG. 5C, each sensor 153. Optical paths d1 and d2 from the workpiece to the workpiece W
The actual pre-bending angle α ′ of the work W is measured based on the difference (step 209).

At that time, due to the hydraulic pressure applied to the pressure chamber 160a of the hydraulic cylinder actuator 160,
As shown in FIG. 3, as the ram (not shown) moves upward, the short piece portion 114 of the die body 110 is moved upward with respect to the long piece portion 113, and the work W is in contact with the punch P. Therefore, the position of the work W does not shift with respect to the punch P.

Moreover, in the above state, the punch P
The workpiece W is the V-shaped groove 11 of the long piece portion 113 of the die body 110 regardless of the accuracy of the die such as the die 100 or the accuracy of the processing device such as the inclination of the ram (not shown).
Since the state is deviated from 1 and the state is completely unloaded, the angle bending means 150 measures the preliminary bending angle α ′ after the spring back is completely performed.

An apparatus control unit (not shown) that measures the preliminary bending angle α'of the actual workpiece W is different from the set preliminary bending angle α, that is, the actual spring back amount (α'-α) of the workpiece W. ), Processing correction data such as the correction stroke amount S2 and the correction pressurization time T2 for imparting the target bending angle X to the work W are calculated within the time shown in FIG. 5 (e) (step 210). Based on the calculated machining correction data, the ram (not shown) is moved down again (step 211).

When the downward movement of the ram (not shown) proceeds, the punch P held by the ram (not shown) eventually comes out.
Presses the die 100 through the work W,
The operating rod 164 is retracted against the hydraulic pressure applied to the pressure chamber 160a of the hydraulic cylinder actuator 160, and the long piece portion 113 and the short piece portion 114 of the die main body 110 are returned to the positions in which they are aligned with each other. The work W is arranged between the punch P and the die 100.

In the above operation, the work W is punched by the punch P.
The work W is not displaced with respect to the punch P or the die 100 because the bending line is displaced.

When the ram (not shown) moves downward by the calculated correction stroke amount S2, the downward movement of the ram (not shown) is stopped at that time, and at the same time, the correction pressurization time of the work W is stopped. The timer T2 corresponding to T2 is started and the timer T0 is started (step 212). During this time, the work W is held in a pressed state between the punch P and the die 100 in the same state as before the punch P was moved away from the die 100, and bending work is sequentially performed based on the working correction data. proceed.

When the timer T0 expires (step 213), the solenoid 166a of the electromagnetic switching valve 166 is demagnetized, as shown in FIG. 5C, and the hydraulic cylinder actuator 160 is turned off (step 214). When the timer T2 is further timed up (step 215), the ram (not shown) returns to the top dead center and the machining of the work W is completed (step 21).
6).

As described above, according to this processing method,
Since the work W is kept in contact with the punch P at all times while the punch P and the die 100 are moved by a small distance S0, the actual bending angle α'of the work W can be accurately measured. In addition, it is possible to prevent the work W and the punch P from being displaced during re-pressurization, and it is possible to give the work W an accurate bending angle X.

In the above embodiment, a ram (not shown)
Although the press brake device in which the punch P is moved up and down by holding the punch P in the above is illustrated, the present invention is, of course, applicable to a work in which the work is bent by moving the die side. Can be applied. Further, a pair of reflection type laser distance measuring sensors 153 are applied, and the optical paths d1 of these sensors 153 with respect to the work W,
Although the angle measuring means for measuring the bending angle from the difference of d2 is illustrated, the angle measuring means of this kind is not necessarily applied in the present invention, and the bending angle of the workpiece is measured by, for example, a CCD camera or the like. May be used.

Further, in the above embodiment, the work holding means 114 and 160 are arranged on the die 100, but of course the work holding means may be arranged on the punch side. Further, although the work W is held in contact with the punch P using hydraulic pressure, a work holding means using fluid pressure other than hydraulic pressure or using elastic force such as a spring is applied. It doesn't matter.

[0037]

As described above, according to the present invention,
With the work held in contact with the punch, the punch and die can be moved apart by a small distance to easily and reliably bring the work into the unloading state. Can be measured.

Moreover, since the work is held in contact with the punch while the punch and the die are moved by a very small distance, it is possible to prevent the punch and the work from being displaced from each other during re-pressurization. It is possible to give an accurate bending angle.

[Brief description of drawings]

FIG. 1 is a flowchart showing a bending method according to the present invention.

FIG. 2 is a sectional view conceptually showing a main part of a bending apparatus according to the present invention.

FIG. 3 is a sectional view showing the operation.

FIG. 4 is an arrow view IV in FIG.

FIG. 5A to FIG. 5E are charts showing operation timings.

[Explanation of symbols]

 P punch 100 Die W Work 114,160 Work holding means

Claims (2)

[Claims] 1. A bending method in which a punch and a die are pressed against each other to bend a work interposed between the punch and the die. In the bending method, the work is held in contact with the punch. In a state where the die and the punch are moved apart from each other by a relatively small distance in order to bring the die from the pressurized state to the unloading state, and when the die and the punch are separated by the minute distance, A step of measuring a bending angle of the work held in contact with the punch, calculating machining correction data from the measured bending angle of the work, and again based on the machining correction data, the punch and the die are And a step of pressurizing each other. 2. The punch and the die are pressed against each other to bend the work interposed between the punch and the die, and then the punch and the die under pressure are unloaded from each other. The punch and the die are bent by a relatively small distance to measure the bending angle of the work interposed between the punch and the die. Based on the measured bending angle of the work, the punch and the punch are again moved. A bending apparatus adapted to press a die against each other, comprising work holding means for holding the work in contact with the punch while at least moving the punch and the die by the minute distance. A bending device characterized in that