JPH087932Y2 - Tool position controller for bending machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a tool position control device for a bending machine, in which a bending angle of an arbitrary portion can be controlled during bending.

[Conventional technology]

Conventionally, when bending a long plate material, a bending machine such as a press brake is used.

This bending machine has a tool consisting of long punches and dies, and bends plate material between these punches and dies.However, the bending that occurs in the tool during bending is corrected and the bending angle is changed. Various devices and methods have been proposed that can be adjusted arbitrarily.

For example, the deflection of a tool is corrected by detecting the deflection of punches and dies with a strain gauge and supplying hydraulic pressure to multiple hydraulic cylinders provided on the lower side of the die during bending, depending on the amount of deflection. And Japanese Examined Sho 57-27773
Issue, Japanese Examined Sho 52-20431, Japanese Examined Sho 54-417, Examined Sho 55-418
No. 48 bulletin etc.

[Problems to be solved by the device]

However, in the case where the hydraulic pressure is supplied to the hydraulic cylinder according to the flexure of the tool, the flexure can be corrected, but the position of each hydraulic cylinder is not controlled, so that the bending angle cannot be adjusted.

Also, the bending tool described in Japanese Patent Publication No. 57-27773 is
Since it is not possible to finely adjust the bending angle such that the bending angle is continuously reduced while applying pressure, there is a problem that even if the bending angle locally varies, it cannot be corrected during pressing. Furthermore, Japanese Patent Publication No. 52-20431 and Japanese Patent Publication No. 54-417
The one described in the publication is a mechanical press brake that moves the ram up and down by a link mechanism, and adjusts the bending angle by pushing up the die with a hydraulic cylinder, but since it does not have a position control function, In addition to being unable to cope with variations in angle due to various factors, the system controls the pressure of the hydraulic cylinders, which causes a problem that the forces are dispersed and effective variation correction control cannot be performed. Moreover, since the conventional die uses a complicated structure that is divided into a fixed die and a movable die, the die becomes expensive, and the sliding part wears during use and rattling occurs. However, there was also a problem that the precision of bending was difficult because the precision of machining was affected by backlash.

The present invention has been made for the purpose of improving the above problems, and an object of the present invention is to provide a tool position control device for a bending mechanism capable of controlling the bending angle of an arbitrary portion during processing.

[Means and Actions for Solving the Problems]

In order to achieve the above-mentioned object, this invention bends a work by bending a punch attached to the tip of a ram movable up and down by a pressure holding cylinder and a die provided below the punch. In a machine, a die pushing-up means is provided at least at one position in the longitudinal direction below a die integrally formed, and the die pushing-up means is formed by a bending cylinder, and at least one of the bending cylinders is provided. A servo valve is provided between the hydraulic pressure sources, and this servo valve is switched and controlled by a screw-in amount command screw rotated by a servo motor controlled based on previously input data, to thereby raise the die position. Is controlled.

Further, in a bending machine that bends a work between a punch attached to the tip of a ram that can be moved up and down by a pressure holding cylinder and a die provided below the pinch, a die integrally formed. A die push-up means at least at one position in the longitudinal direction below the bowl, and the die push-up means is driven to rotate the bowl screw abutted on the die, the nut screwed to the bowl screw, and the nut. The servo motor is configured to control the servo motor by a control signal output from a control unit that calculates the amount of dicing of the dice based on previously input data, thereby controlling the rising position of the dice. It was done.

With the above configuration, the bending angle of an arbitrary portion of the work being bent can be adjusted by adjusting the amount of pushing by the pushing means based on the data input in advance.
It is possible to obtain a product with high bending accuracy, which is locally free from variations in bending angle and has no craze.

〔Example〕

 An embodiment of the present invention will be described in detail with reference to the drawings.

In the figure, reference numeral 1 is a main body of a bending machine, and a die base 4 is supported on a table 3 provided on an upper portion of a lower beam 2 so as to be vertically movable.

A slide liner 3a for smoothing the vertical movement of the die base 4 is provided between one side surface of the die base 4 and the table 3, and the other side surface is provided at a plurality of positions in the longitudinal direction on the table 3 side. A guide roller 9 provided over the entire area is in contact with the roller.

As shown in FIG. 3, the guide roller 9 is a compression spring.
It is urged toward the die base 4 side by 9a and is rotatably attached to the tip of a piston 9d whose rotation is locked by a key 9c so as to press the die base 4 against the sliding liner 3a.

A die 5 having an integral structure having a V groove on the upper surface is provided on the die base 4 via a die holder 4a, and above the die 5 is a lower end of a ram 7 which is vertically movable by a pressure holding cylinder 6. A punch 8 is attached and attached.

A plurality of pins 10 are provided below the die base 4 so as to be vertically movable, and the lower ends of the pins 10 are in contact with the upper surface of the upper wedge 11a of the pin height adjusting mechanism 11.

The pin height adjusting mechanism 11 is divided into two, and the compression spring is
The upper wedge 11a biased in the separating direction by 11b and the lower wedge 11c formed in a substantially mountain shape.
By adjusting the upper and lower wedges 11a to move toward and away from each other by adjusting screws 11e provided at a plurality of positions on side plates 11d fixed to both side surfaces of 1c, the height of the die 5 can be increased through the die base 4 and the die holder 4a. The position can be adjusted, and the adjustment position can be fixed by the lock nut 11f.

Further, the lower part of the lower wedge 11c is supported by the tip of the piston rod 12a of the bending cylinder 12 installed at one or a plurality of positions along the longitudinal direction of the beam 2 via a support portion 12b.

Each of the support portions 12b is provided with a driving amount command screw 14 which is rotated by a servo motor 13 provided for each bending cylinder 12 and which can be adjusted up and down freely. A mechanical servo valve 15 provided for each cylinder 12 is operated.

On the other hand, FIG. 4 is a hydraulic system diagram for supplying hydraulic pressure to the pressure holding cylinder 6 and each of the bending cylinders 12.
The discharged hydraulic pressure is supplied to the head side of the pressure holding cylinder 6 via the mechanical servo valve 18 and the descending speed switching solenoid valve 20, and to the rod side of the pressure holding cylinder via the servo valve 18. It is supposed to be done.

A part of the discharge pressure of the hydraulic pump 17 is part of the servo valves 15 described above.
It can be supplied to the bending cylinder 12 via the solenoid valve and to the forced pull-down cylinder 24 provided on the left and right ends of the die holder 3 via the solenoid valve 23, respectively.

In the figure, reference numeral 25 is a solenoid valve for selecting the pressurizing force setting relief valve 26 and the pulling pressure setting / rising pressure setting relief valve 27.

 Next, the operation will be described.

With input from the control unit A the information required for folding, the beam drive motor 61 to the solenoid valve 25 is attached to the ram 7 after Tsu switching to position 25 ₁ is high speed operation First, the move gear box 62, The mechanical servo valve 18 is operated via the rack 63 and the lever 64 (the cylinder 6 is
Has a double structure divided into the cylinder chamber ₆₁ for performing the cylinder chamber ₆₁ and the actual pressing action industry in order to speed down the upper beam. ) Hydraulic flow into the cylinder 6 _2, the upper beam is rapidly lowered. At the same time, the solenoid valve 66 is switched to the position 66 ₂ so that the pressure oil makes the pilot check valve 67 conductive so that the oil is smoothly sucked from the tank into the cylinder chamber 6 ₁ .

Limit switch 68 with ram 7 lowered and in place
When There actuated by the dog 69 had attached to the ram 7, the electromagnetic switching valve 20 is switched solenoid valve 66 simultaneously switched to the position 20 ₁ to position 66 _1, the ram drive motor 61 pilot check valve 67 is closed in the low-speed operation switched, pressure oil flows into the cylinder chamber _61, the ram 7 is a slow decreasing state.
After that, the tip of the punch 8 attached to the tip of the ram 7 comes into contact with the work 40 on the die 25 from above, and the bent portion of the work 40 is held under pressure.

After that, a control signal is output from the control unit A to the servo motor 13, which causes the servo motor 13 to rotate the drive amount command screw 14 to operate the mechanical servo valve 15 provided for each bending cylinder 12. , The discharge pressure of the hydraulic pump 17 flows into the bottom side of the bending cylinder 12 from each servo valve 15 and raises the die 5 by a predetermined pushing amount, so that the work 40 is pre-input by the angle between the die 5 and the punch 8. Can be folded into

After that, the solenoid valve 20 is switched to the position 20 ₂ and the pressure oil in the pressurizing and holding cylinder 6 is drained, then the solenoid switching valve 25 is switched to the position 25 ₂ and at the same time the ram drive motor 61 reverses to move above the servo valve 18. The hydraulic pressure set by the pressurization setting relief valve 27 is supplied to the rod side of the pressurizing and holding cylinder 6, and the ram 7 and the punch 8 rise. Solenoid switching valve at the same time
66 is switched to position 66 ₂ and the parrot check 67 is opened so that the oil in the cylinder chamber 6 ₁ can be smoothly discharged to the tank.

At the same time, the servo motor 13 is rotated in the reverse direction and the drive amount command screw 14 is raised, so that the servo valve 15 is switched and hydraulic pressure is supplied to the rod side of the bending cylinder 12.

This together with the die 5 is lowered, this time the solenoid valve 23 is because it is switched to position 23 _1, forced cuts the hydraulic pressure is supplied to the rod side of the cylinder 24, the die 5 is lowered by forced pull-down cylinder 24.

Although the work 40 as described above is bent to complete the product, the bending angle of an arbitrary portion can be controlled by changing the amount of pushing for each bending cylinder 12 during the bending process.

In the above embodiment, the servo valve 15 is operated by the servo motor 13 via the thrust amount command screw 13.
As shown in the figure, the electrohydraulic servo valve 50 may be directly controlled by a command from the control unit A, and the driving amount is read from the linear skate 51 attached to the lower beam 21 and fed back.

Further, FIG. 6 shows another embodiment in which the bending cylinder 12 is a ball screw 53 driven by a servomotor 52. The servomotor 52 and a nut 53a screwed to the ball screw 53 are linked by a bevel gear 54. When the nut 53a is rotated via the servo motor 52 in response to a command from the control unit A, the ball screw 53 screwed into the nut 53a ascends and pushes up the die 5.

[Effect of device]

As described in detail above, the present invention provides one or a plurality of positions in the longitudinal direction of the die by inputting the processing conditions such as the bending angle of the product, the plate thickness, and the material in advance, and the amount of pushing of the bending cylinder is automatically set. As a result, it is possible to obtain a product with a high bending accuracy that locally causes a variation in the bending angle and does not have a warp.

In addition, since the bending angle of any part can be controlled during bending, it is possible to correct the variation of bending angle during processing, and rotate the drive amount command screw by the servo motor controlled by the data input in advance, Since the servo valve is controlled during pressurization, even if the load changes or vibration or shock occurs during bending, it is not affected by these, so it is highly accurate. Bending is possible.

Furthermore, since the die that can be raised and lowered by the pushing-up means is an integral structure, the structure is simpler than that of a die that is divided into a fixed die and a movable die, and there is no sliding part, so backlash does not occur due to abrasion. Therefore, the control accuracy of the servo valve is not affected by the backlash of the die.

On the other hand, in the case where the die push-up means is composed of a ball screw that abuts against the die and a nut that is screwed onto this ball screw and rotation-controlled by a servomotor, the amount of drive-in of the dust is set mechanically. Since the compressibility does not change due to temperature, etc., the amount of drive can be set accurately, which improves pressurization accuracy and does not require hydraulic piping or expensive servo valves. Therefore, it can be provided at a low cost, and there is no concern about oil leakage, so that maintainability is improved.

[Brief description of drawings]

The drawing shows one embodiment of the present invention, and FIG. 1 is a longitudinal sectional view,
2 is an arrow view from the direction of FIG. 1 II, FIG. 3 is an enlarged cross-sectional view near the guide roller, FIG. 4 is a hydraulic system circuit diagram, and FIG.
FIG. 6 and FIG. 6 are explanatory views showing another embodiment. 5 is a die, 6 is a pressure holding cylinder, 8 is a punch, 40 is a work, and A is a control unit.

Claims (2)

[Scope of utility model registration request] 1. A bending process for bending a work 40 between a punch 8 attached to the tip of a ram 7 which can be moved up and down by a pressure holding cylinder 6 and a die 5 provided below the punch 8. In the machine, a die push-up means is provided at least at one position in the longitudinal direction below the die 5 formed as an integral structure, and the die push-up means is used for bending the cylinder 12.
And a servo valve 15 is provided between at least one of the bending cylinders 12 and a hydraulic pressure source, and the servo valve 15 is rotated by a servo motor 13 controlled based on previously input data. A tool position control device for a bending machine, characterized in that the rising position of the die 5 is controlled by switching control with a drive-in command screw 14 for controlling. 2. A bending process for bending a work 40 between a punch 8 attached to the tip of a ram 7 which can be moved up and down by a pressure holding cylinder 6 and a die 5 provided below the punch 8. In the machine, the die 5 formed as an integral structure
A die push-up means at least at one position in the longitudinal direction, and the bowl push-up 53 contacted with the die 5 and the bolus screw 53.
It is composed of a nut 53a screwed into the shaft and a servo motor 52 for rotationally driving the nut 53a, and the servo motor 52 is output from a control unit A which calculates a pushing amount of the die 5 from previously input data. A tool position control device for a bending machine, characterized in that the rising position of the die 5 is controlled by controlling with a control signal.