JPH05177259A - Method for controlling speed of clamp part on metal sheet bending machine - Google Patents

Abstract

PURPOSE:To accelerate simultaneously the carriage and the movable clamping part without generating the slipping on the metal sheet at the metal sheet bend ing machine. CONSTITUTION:A metal sheet rotating device 5 of the main clamp, a sub- carriage 6 having a sub-clamp 7 and a metal sheet bending machine provided on a carriage 4, etc., are applied. The sub-carriage 6 is mounted on the carriage 4 freely advancing and retiring, and it is used for changing the clamping position of the metal sheet with the metal sheet rotating device 4. In the case the carriage 4 and the sub-carriage 6 are moved simultaneously in the same direction at the speed control is made as next. That is, the accelerating and decelerating time constant of one side, at least, of the sub-carriage 6 and the carriage 4 is made smaller as compared with the case moving individually. More, in the case moving the carriage 4 while rotating the metal sheet with the metal sheet rotating device 5, the constant of accelerating and decelerating time is made smaller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the speed of a clamp portion in a plate material folding machine in which a movable clamp portion provided on a carriage grips and feeds a plate material.

[0002]

2. Description of the Related Art Conventionally, as a device for feeding a plate material to a folding machine body, a carriage having a main clamp for holding the plate material and moving back and forth toward the folding machine body, and a carriage having a sub clamp are mounted on the carriage. Some carriages are provided with a sub-carriage that moves forward and backward independently of the carriage. In this case, the sub-carriage is used when adjusting the plate material position in order to change the gripping position of the plate material by the main clamp. The moving speed and the acceleration / deceleration time constant of each of the carriage and the sub-carriage are set to values within the maximum range in which the plate material is not displaced in the clamp portion.

[0003]

However, for example, when the sub-carriage is gripping the plate material, the operation of accelerating the carriage toward the folding machine body (acceleration time constant x
1) and an operation of accelerating the sub-carriage on the carriage (acceleration time constant is x2) are overlapped, the ground acceleration time constant of the plate material is x1 + x2,
A larger acceleration is applied to the plate material than when the carriage alone or the sub-carriage alone moves. As a result, the plate material that is about to stop due to inertia may be displaced with respect to the portion held by the sub-carriage. In order to avoid this, it is necessary to move the carriage and the sub-carriage independently and stagger each time. However, if they are sequentially moved individually in this way, a waiting time occurs and the cycle time becomes long.

An object of the present invention is to control the speed of a clamp part in a plate material folding machine capable of simultaneously accelerating a carriage and a movable clamp part without causing a deviation of the plate material and shortening a cycle time. It is to provide a method.

[0005]

The structure of the present invention will be described with reference to FIG. 1 corresponding to an embodiment. The speed control method of this clamp part is such that the movable clamp parts (5) and (6) for clamping the plate material (W) and the movable clamp parts (5) and (6).
It is applied to a plate material folding machine having a carriage (4) that supports and can move the carriage (4) and the movable clamp portions (5) and (6) simultaneously in the same direction. Simultaneous in this case means that at least a part of the acceleration / deceleration period of the carriage (4) and the acceleration / deceleration period of the movable clamp portions (5) and (6) overlap. At this time, the movable clamp parts (5) and (6) and the carriage (4)
At least one of the acceleration and deceleration time constants is set smaller than that in the case of moving independently. In this case, the movable clamp portions (5) and (6) may be sub-carriage (6) mounted on the carriage (4) so as to be movable back and forth along a straight path along the moving direction of the carriage (4). It may be a plate material rotating device (5) for rotating the plate material (W) installed on the carriage (4).

[0006]

According to the method of the present invention, when the carriage (4) and the movable clamp parts (5) and (6) are simultaneously moved in the same direction, the carriage (4) and the movable clamp parts (5) and (6) are used. At least one of the acceleration / deceleration time constants is made smaller than that in the case of moving independently. Therefore, the acceleration / deceleration with respect to the ground of the plate material (W) is suppressed to be smaller than that in the case where both are moved with the acceleration / deceleration time constant during independent movement, and the deviation of the plate material (W) is prevented. In addition, the cycle time can be shortened as compared with the case of sequentially moving independently.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. First, the structure of a plate bending machine to which the method of the present invention is applied will be described. As shown in FIG. 2, this plate material folding machine is composed of a folding machine body 3 and a plate material feeding device 1, and the folding machine body 3 has a holding die 3a that can be opened and closed vertically and a bending mechanism that is driven up and down. A mold 3b is provided.

The plate material feeding device 1 is provided with a table 2 on which a plate material W is placed, and a carriage 4 which holds the plate material W on the table 2 by a plate material rotating device 5 and moves back and forth (B direction). The carriage 4 is installed on the bed 13 via rails, and is fed back and forth by a ball screw 14 and a servomotor 15 that drives the ball screw 14. The plate material rotating device 5 serves as a main clamp and has a pair of pads 5a and 5b for sandwiching the plate material W from above and below. Lower pad 5
b is rotatably supported by a bracket 19 at the front end of the carriage 4, and an indexing device is connected to the rotary shaft 20 thereof,
The plate material W can be indexed and rotated at every predetermined angle (for example, 90 °). The upper pad 5a is attached to an elevating holder 18 which can be moved up and down along a vertical rail 17 provided at the tip of the carriage 4, and is lifted and lowered by an elevating device 16 such as a cylinder device.

FIG. 3 is a plan view of the plate material feeding device 1. The table 2 has a carriage passage 10 that allows the carriage 4 to pass therethrough in the center, and is composed of a large number of strip-shaped plates 2a. A centering pin 8 for determining the width of the plate material W projects in a gap 9 between the strip-shaped plates 2a of the table 2 so as to project and retract, and is projected and retracted at the front edge of the table 2 by a cylinder device (not shown). An end locator 11 for front-back positioning is provided.

A pair of sub-carriage 6 is provided with the carriage 4 sandwiched therebetween, and each is supported so as to be movable back and forth along a rail 21. Both sub-carriage 6 are provided with a ball screw 22 (FIG. 2) provided on the carriage 4 and a servo motor.
It is driven by a servo mechanism 24 composed of 23 and. That is, the bracket 26 is fixed to the nut 25 screwed to the ball screw 22, and the connecting bar 27 connecting the both sub-carriage 6 is engaged with the bracket 26. The sub clamp device 7 is
Each of the sub-carriage 6 is composed of a clamp cylinder 7a and a receiving piece 7b provided at the tips thereof.

FIG. 1 is a block diagram of a control system. The machining program executing means 28 is means for executing the machining program 29 to output operation commands for the plate material feeding device 1 and the bending machine body 3, and is configured by an arithmetic control unit of the NC device. The operation command of the plate material feeding device 1 in this case includes a carriage feeding command and a sub-carriage feeding command.

The carriage feed command is input to the carriage speed control means 30 and the simultaneous drive determination means 32, and the subcarriage feed command is input to the subcarriage speed control means 31 and the simultaneous drive determination means 32. The simultaneous drive determination means 32 is a means for determining whether or not the carriage 4 and the sub-carriage 6 are simultaneously driven based on the inputted carriage feed command and sub-carriage feed command, and the determination output is the carriage speed. It is input to the control means 30 and the sub-carriage speed control means 31.

The carriage speed control means 30 comprises a servo mechanism, and specifies each value of an acceleration time constant at the start of movement, a deceleration time constant at the time of stop, and a speed at constant speed movement in the feeding operation of the carriage 4. To do. These values are prepared separately for the case where the carriage 4 is fed independently and the case where the carriage 4 is fed simultaneously with the sub-carriage 6. Based on the judgment output sent from the simultaneous drive judgment means 32, the values of the single movement or the simultaneous movement are prepared. The value of movement is selected and specified. Each value of the acceleration time constant, the deceleration time constant, and the speed which are selected and specified is given to the control system of the servo motor 15 of the carriage 4,
Thereby, the feed speed of the carriage 4 is controlled.

The sub-carriage speed control means 31 also comprises a servo mechanism for designating each value of the acceleration time constant, deceleration time constant and speed in the feeding operation of the sub-carriage 6, and these values designate the sub-carriage 6. It is prepared separately for the case of single feeding and the case of simultaneous feeding with the carriage 4. Based on the judgment output sent from the simultaneous drive judging means 32, the value of single movement or the value of simultaneous movement is selectively designated. It The values of the acceleration time constant, the deceleration time constant, and the speed that are selected and designated are given to the control system of the servomotor 23 of the subcarriage 6, and the feed speed of the subcarriage 6 is controlled by this.

Next, a method of controlling the speed of the carriage 4 and the sub-carriage 6 having the above construction will be described with reference to FIGS. 4 and 5. In the state where the plate material W is gripped by the sub-clamping device 7 of the sub-carriage 6, for example, first, the carriage 4 independently starts to move toward the folding machine body 3,
When the sub-carriage 6 starts moving in the same direction after reaching the constant speed, the feed speeds of the carriage 4 and the sub-carriage 6 change as shown in FIG.

That is, at the time t0, only the carriage feed command sent from the machining program executing means 28 is inputted to the simultaneous drive judging means 32, so that the judgment output outputs the value of the independent movement in the carriage speed control means 30. Selected and set. Therefore, as shown by the solid line in FIG. 4A, the carriage 4 is accelerated and sent with the acceleration time constant ΔV1 / Δt during the independent movement. When the speed reaches the speed V1 which is set as the constant speed feed speed during the independent movement, the movement continues while maintaining the speed V1.

Next, when the sub-carriage feed command is output from the machining program executing means 28 at time t3,
The driving of the servo motor 23 is started based on the output from the sub-carriage speed control means 31, and the feeding of the sub-carriage 6 is started. In this case, since the acceleration periods of the carriage 4 and the sub-carriage 6 do not overlap, the simultaneous drive determination means 32
Then, it is determined to be a single movement. Based on the determination output, the value of the independent movement is selectively set in the sub-carriage speed control means 31 as in the carriage speed control means 30.
As shown by the broken line in (A), the acceleration time constant ΔV during independent movement
The subcarriage 6 is accelerated and sent at 2 / Δt. V2, which is set as the constant feed rate for independent movement
When the speed reaches, the movement continues while maintaining the speed V2. Therefore, the ground speed V0 of the plate material W in this case is as shown in FIG. 4 (B).

On the other hand, the feeding of the carriage 4 is started at time t0, and the feeding of the sub-carriage 6 in the same direction is started at time t1 during which the speed does not reach the constant speed V1 during the independent movement. When the carriage 4 and the sub-carriage 6 are moved, the feed speed changes as shown in FIG.

That is, at the time t1, the simultaneous drive determination means 32 determines that the acceleration periods of the carriage 4 and the sub-carriage 31 overlap, that is, the simultaneous movement is performed. Based on the judgment output, the carriage speed control means 30 and the sub-carriage speed control means 31 selectively set the value of the simultaneous movement. As a result, as shown by the solid line in FIG. 5A, the acceleration time constant of the carriage 4 is smaller than ΔV1 / Δt during the independent movement and smaller than this value by the ΔV during the simultaneous movement.
It is switched to 1 '/ Δt.

The sub-carriage 6 also has an acceleration time constant .DELTA.V2 / .DELTA.t during a single movement as shown by a broken line in FIG.
The feeding is started with an acceleration time constant ΔV2 ′ / Δt at the time of simultaneous movement smaller than that. When the feed start time t0 of the carriage 4 and the feed start time t1 of the sub-carriage 6 are the same, both the carriage 4 and the sub-carriage 6 have acceleration time constants ΔV1 ′ / Δt, ΔV during simultaneous movement from the beginning.
2 ′ / Δt is selected. When the feed speed of the carriage 4 reaches the constant feed speed V1 ′ during the simultaneous movement, the carriage is kept at that speed thereafter and the constant velocity movement is performed. The sub-carriage 6 also has a constant feed speed V2 'when the feed speeds thereof are simultaneously moved.
When the speed reaches, the speed is kept at that speed and a constant speed movement is performed thereafter. The ground speed V0 of the plate material W at this time is shown by the solid line in FIG.

By the way, even if the acceleration periods of the carriage 4 and the sub-carriage 6 are overlapped with each other, if the acceleration time constants ΔV1 / Δt and ΔV2 / Δt during the independent movement are set, the ground speed V0 of the plate W is as shown in FIG. 5 (B). It becomes as shown by the broken line. Therefore, in the case of this embodiment, the acceleration applied to the plate material W can be suppressed sufficiently smaller than in the case of the conventional example, and the plate material W gripped by the sub-clamp device 7 can be prevented from being displaced by the acceleration. Become.

In the above example, the speed control operation during acceleration has been described, but the speed control operation during deceleration is performed in the same manner. That is, when the deceleration periods of the carriage 4 and the sub-carriage 6 overlap, the carriage speed control means 30
Also, in the sub-carriage speed control means 31, a deceleration time constant for simultaneous movement smaller than the value for single movement is selectively set.

Further, in this embodiment, the sub-carriage 6 and the carriage 4 holding the plate material W by the sub-clamping device 7 are used.
The feed speed control in the case where and move in the same direction has been described, but the upper and lower pads 5a and 5b of the carriage 4 can be used for the plate material W.
The same can be applied to a case where the plate material rotating device 5 is driven and the plate material W is rotationally indexed while the carriage 4 is advanced and retracted in a state where the plate material W is sandwiched.

That is, in this case, the rotational moment of the plate material W and the acceleration / deceleration of the carriage 4 overlap each other, so that a larger acceleration is applied to the plate material W than in the case where the carriage 4 and the plate material rotation device 5 operate independently. As a result, the plate material W is displaced, but at least the acceleration / deceleration time constant of the plate material rotation device 5 and the acceleration / deceleration time constant of the carriage 4 are applied by applying the speed control method during the simultaneous driving. By making one smaller than the value in the case of the single drive, the deviation of the plate material W can be similarly prevented.
The deviation during rotation of the plate material W is likely to occur when the plate material W is held away from the center position, but in such a case, the effect of preventing deviation due to the reduction of the acceleration / deceleration time constant is great.

In each of the above embodiments, the constant velocity feed speed is changed between the simultaneous movement and the single movement, but the constant velocity speed may be the same.

[0026]

According to the speed control method of the present invention, when the movable clamp portion for clamping the plate member and the movable carriage supporting the movable clamp portion are simultaneously moved in the same direction, the movable clamp portion is moved. Since the acceleration / deceleration time constant of at least one of the carriage and the carriage is set to be smaller than that in the case where the carriage and the carriage are moved independently, it is possible to accelerate the carriage and the movable clamp portion at the same time without causing the plate material to shift. Therefore, the cycle time can be shortened without degrading the processing accuracy due to the displacement of the plate material.

[Brief description of drawings]

FIG. 1 is a block diagram of a control system of a plate bending machine to which an embodiment of the present invention is applied.

FIG. 2 is a cutaway side view of the plate bending machine.

FIG. 3 is a plan view of the plate material folding machine.

FIG. 4 is a graph showing speed control when the plate bending machine is independently moved.

FIG. 5 is a graph showing speed control when the plate material folding machines move simultaneously.

[Explanation of symbols]

1 ... Plate feeding device, 2 ... Table, 3 ... Bending machine body, 3
a ... pinching type, 3b ... bending type, 4 ... carriage, 5 ... plate material rotating device, 6 ... sub-carriage, 7 ... sub-clamping device, 14 ... ball screw, 15 ... servo motor, 20 ... rotating shaft,
22 ... Ball screw, 23 ... Servo motor, 28 ... Machining program execution means, 29 ... Machining program, 30 ... Carriage speed control means, 31 ... Sub-carriage speed control means, 32 ... Simultaneous drive determination means, W ... Plate material

Claims (3)

[Claims] 1. A movable clamp part for clamping a plate material,
When simultaneously moving a movable carriage that supports the movable clamp portion in the same direction, the acceleration / deceleration time constant of at least one of the movable clamp portion and the carriage is
A method for controlling the speed of a clamp part in a plate bending machine, which is smaller than the case of moving it alone. 2. The speed control method for a clamp part in a plate bending machine according to claim 1, wherein the movable clamp part is a sub-carriage mounted on the carriage so as to be movable back and forth along a straight line along the carriage moving direction. 3. The speed control method of the clamp part in a plate material folding machine according to claim 1, wherein the movable clamp part is a plate material rotating device which is installed on a carriage and rotates a plate material.