JPH08281355A - Clamp release method in roll feeding - Google Patents

Abstract

PURPOSE: To provide a clamp release method in roll feeding, a method that is capable of following up the high speed operation of a press. CONSTITUTION: A position control and a torque control are switched by an apparatus 12 for switching the two controls: the torque control which generates the signals of a specified clamp pressure set in a clamp setting apparatus 11; and the position control that inputs the absolute minimum release quantity R set in a release quantity setting apparatus 14, in the position command part 15, in which a reference position S is stored at the time of clamping a pair of rolls, of the encoder 16 connected to a servo motor 10 and that generates the processed signals. The operation is repeated such that the signals are supplied to the servo motor 10 through an amplifier 13, controlling the clamp pressure and the release quantity of a pair of rolls to a set value, releasing it between the command point for the release start and the completion point of the actual clamp, and feeding the material intermittently at a specific length in roll between the completion point of the actual clamp and the command point for the release start.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll feed clamp / release method for intermittently feeding a material to a press machine by a constant length.

[0002]

2. Description of the Related Art In a conventional roll feed clamp / release method, as shown in FIGS. And a release spring that rotatably supports one end of the lever 5 on the fulcrum 6 of the machine body 2 and rotatably supports the other end of the lever 5, and a piston 8 of a clamp cylinder 7 that urges the other end downward and an upward bias. 9, the piston 8 of the clamp cylinder 7 pushes down the upper roll 4 toward the lower roll 3, and clamps a material (not shown) between the upper roll 4 and the lower roll 3,
The upper roll 4 and the lower roll 3 are rotated to feed the material at a constant length.

Subsequently, the pressing force of the piston 8 is removed, and the upper roll 4 is pulled up by the urging force of the release spring 9 so that the material is released between the upper roll 4 and the lower roll 3 so that the material is not biased in the feeding direction. The method of correcting and repeating this and intermittently feeding the material to the press machine at a constant length has been widely used.

[0004]

According to the above-mentioned method of the prior art, the clamping force between the upper and lower rolls can be controlled by changing the pressure of the compressed air supplied to the clamp cylinder to cope with the change in the plate thickness of the material. Although there is an advantage, when pressure air is supplied to the clamp cylinder to clamp the upper and lower rolls and the pressure air is exhausted to release it, it is necessary to switch the solenoid valve to supply and exhaust the pressure air. Therefore, the operation of the upper and lower rolls has a drawback that the operation of the solenoid valve and the supply / exhaust of the pressure air causes a large operation delay of the piston of the clamp cylinder, and the roll feed cannot follow the press machine operating at high speed. .

Further, since the clamp release is for correcting the deviation in the feed direction of the material, it is necessary to adjust the stroke to the minimum in order to follow the high speed operation of the press machine. Therefore, it is necessary to readjust each time the plate thickness of the material changes, and it is necessary to equip such an adjusting mechanism.

An object of the present invention is to provide a method for clamping and releasing a roll feed which can follow the high speed operation of a press machine, except for this drawback.

[0007]

In order to achieve the above-mentioned object, the present invention provides a press machine with either one of a pair of rolls of a roll feed for intermittently feeding a constant length of material. A servo motor is attached via the clamp / release mechanism, and the torque control of this servo motor controls the clamping force that clamps the material of the pair of rolls, and the position control of the servo motor controls the distance between the pair of rolls. Is controlled between a material clamping position and a material releasing position.

[0008]

Since the servomotor operates without delay by the command signal, the delay of the clamp release operation of the pair of rolls is small, and the clamp force of the pair of rolls is always controlled to the set value by the torque control of the servomotor. The release amount of a pair of rolls of the servo motor is minimized to the minimum required,
And it can be controlled to be constant. Therefore, the roll feed can be operated at high speed, and the press machine that operates at high speed can be followed.

[0009]

FIG. 1 and FIG. 2 show an embodiment of the present invention,
2 shows the configuration and operation of a control system used to perform a clamp / release operation for a pair of rolls. In FIG. 1A, the servomotor 10 is connected to a pair of rolls (not shown). When the clamp pressure setter 11 sets the clamp pressure according to the material handled by the roll feed,
A signal corresponding to the set value is transmitted and input to the servo motor 10 via the position control / torque control switching device 12 and the amplifier 13 to perform torque control for rotating the servo motor 10 with a torque according to the set value. The required clamping pressure is generated on the roll. The servo motor 10 is controlled by feeding back a current from the output side of the amplifier 13 to the input side.

The release amount setting unit 14 sets a required minimum release amount R. This release amount R is input to the position command unit 15. A position signal of the current position of the servo motor 10 is input to the position command unit 15 from an encoder 16 connected to the servo motor 10, and the position where the material is clamped when the pair of rolls is clamped is set as a reference position S. Remember. In the position command unit 15, the reference position S
When the release start command B is received, the position signal of the release amount R is transmitted, and when the release end command C is received, the material release position of the release amount R is used as the reference and R- △ is reversed. Sends the R position signal.

The minute release amount ΔR is a position signal extremely close to the reference position S and is stored in the position command unit 15 in advance. The output of the position command unit 15 is fed back to the position and speed of the encoder 16 in the deviation signal P and the deviation signal Q, input to the servo motor 10 via the position control / torque control switching device 12 and the amplifier 13, and Make the roll perform accurate release action.

In FIG. 1B, the operation of the roll position will be described with reference to FIG. The pair of rolls are initially in the release state. When the clamp operation is performed at the start point 0, a movement command signal is transmitted from the position command section 15, the position control / torque control switching device 12 is switched to position control, and the servo motor 10 causes the rolls to move toward each other at a constant speed. To move. The torque (current value) of the servo motor 10 is monitored.

At the clamp completion point A, when the pair of rolls clamps the material, the torque value of the servomotor 10 rises, and when it exceeds a preset value, the position control / torque control switching device 12 switches to torque control. The torque value is controlled so as to match the set value of the clamp pressure setting device 11, and the clamp pressure is held constant. Between the clamp completion point A and the release start command point (B1), a pair of rolls is rotated to feed the material to the press machine in fixed lengths.

Rotary cam etc. of the press machine (not shown)
When the release start command B1 transmitted from the control unit is input to the position command unit 15 at the point B1, a position signal of the release amount R is transmitted, and at the same time, the position control / torque control switching device 12 switches to position control, and the servo motor 10 Thus, the rolls are separated by the release amount R.

When the release end command C1 transmitted from the rotary cam of the press machine is input to the position command section 15 at the point C1, the position signal of R-ΔR is transmitted in the reverse direction,
The roll reaches the switching point D from the position control to the torque control, which is separated by a minute release amount ΔR.

When the roll reaches the position D point which is separated by the minute release amount ΔR, the position control / torque control switching device 12 switches to the torque control, and at the actual clamp completion point E,
A pair of rolls clamp the material to reach a constant clamping pressure. From the actual clamp completion point E to the next release start command point (B2), the pair of rolls are rotated to feed the material to the press machine in fixed lengths.

From the input of the release start command B1 to the position command section 15 to the next release start command point (B2), the operation is repeated to continuously feed the material to the press machine at a constant length. To be done.

FIG. 2 shows an embodiment of the circuit configuration of the control system shown in FIG. RAM (20) and ROM (2
Clamp pressure setter 1 to CPU (22) connected to 1)
1 and the release amount setter 14, the servomotor 10 and the encoder 16 via the amplifier 13, the release start command Bn
And a rotary cam or the like of the press machine that transmits the release end command Cn are connected via the I / O (23), and the circuit is configured to control the servo motor 10 by a digital signal and execute the operation described in FIG. You can

FIG. 3 shows an embodiment of a roll-feed clamp / release mechanism when the upper roll is a release roll. The rack 39 connected to the upper roll 34 that meshes with the pinion 35 attached to the servo motor 10 is guided by the guide 36 provided on the machine body 32 of the roll feed 31 by the rotation of the servo motor 10, and moves up and down to move the upper roll 34. Clamp and release.

The material 40 clamped by the upper roll 34 and the lower roll 33 is fed to the press machine by a predetermined length by intermittent rotation of the lower roll 33 connected to a servomotor (not shown).

[0021]

As is apparent from the above description, according to the present invention, it is possible to control the set clamp pressure and release amount of the roll by one servo motor, and the operation delay is minimized. It can be limited. Also, regardless of the plate thickness of the material, the minimum required release amount can be set based on the position of the roll clamp, so the release operation time is short, high-speed roll feed operation is possible, and high-speed press Can follow the machine.

[Brief description of drawings]

FIG. 1A is a control system diagram in one embodiment of the present invention. FIG. 1B is a roll position operation diagram in one embodiment of the present invention.

FIG. 2 is a circuit configuration diagram in an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a clamp / release mechanism according to an embodiment of the present invention.

FIG. 4 is a front view of a roll feed in a conventional example.

FIG. 5 is a side view of a roll feed in a conventional example.

[Explanation of symbols]

10 is a servo motor, 11 is a clamp pressure setting device, 12 is a position control / torque control switching device, 13 is an amplifier, 14 is a release amount setting device, 15 is a position command section, 16 is an encoder, 20 is RAM, 21 is ROM. , 22 is a CPU, 23
Is I / O (input / output), 31 is roll feed, 32
Is a body of roll feed 31, 33 is a lower roll, 34 is an upper roll, 35 is a pinion, 36 is a guide, 39 is a rack, 40 is a material, 0 is a starting point, A is a clamp completion point, Bn, B1 and B2 are Release start command, Cn, C1
Is a release end command, D is a switching point from position control to torque control, E is an actual clamp completion point, P and Q are deviation signals, R is a release amount, ΔR is a minute relacing amount, and S is a pair of rolls. It is a reference position at the time of clamping.

Claims (1)

[Claims] 1. A clamp / release method of a roll feed for feeding a material to a press machine by a pair of rolls which clamp the material and rotate intermittently so as to feed the material at a constant length. A servomotor is attached to one side through a clamp / release mechanism, and the torque control of the servomotor controls the clamping force for clamping the material of the pair of rolls, and the position control of the servomotor controls the pair of rolls. A method of clamping / releasing a roll feed, characterized in that the distance between the rolls is controlled between a material clamping position and a material releasing position.