JPH06297058A - Table controller of metal plate machine - Google Patents

Abstract

PURPOSE:To surely keep the stopping precision of the Y axis independently of the X axis directional position of a cross slide applied to a punch press machine, a laser beam machine and a shearing machine, etc. CONSTITUTION:A cross slide 7 having a work holder 8 is mounted on an advancing and retreating carriage 4 movably fitted freely forwards and backwards to the orthogonally crossing direction against the advancing and retreating directions. In this table device, a Y axis servo controlling means 19 which controls with feeding back the advancing and retreating drive of the carriage 4 is provided. A parameter changing means 30 changing the velocity loop gain Gp and the position loop gain Gs corresponding to the X axis directional position of the cross slide 7 is provided in this Y axis servo controlling means 19. The Y axis servo controlling means 19 makes possible, for example, the variable gain as the software servo.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to a punch press machine,
The present invention relates to a table control device in a plate material processing machine such as a laser processing machine and a shearing machine.

[0002]

2. Description of the Related Art In a plate material processing machine such as a punch press, as a table device thereof, as shown in FIG. 4, a cross slide 52 is mounted on a carriage 51 moving forward and backward in the Y-axis direction so as to be movable in the X-axis direction. A work holder 53 that holds W is provided on the cross slide 52. As the carriage 51 and the cross slide 52 advance and retreat, the work W is driven back and forth and left and right on a table (not shown), and an arbitrary portion thereof is sent to a processing position P such as a punch center.

Carriage 51 and cross slide 52
The forward / backward drive of is performed by the Y-axis servo motor 54, the X-axis servo motor 55, and each axis feed screw. Feedback control is generally adopted for the control of the servomotors 54 and 55 in order to improve the accuracy. Parameters such as position loop gain and velocity loop gain in the feedback control are finely adjusted to appropriate values by trial machining at the time of machine installation, etc., and fixed to those values.

[0004]

However, when the work W is fed, the center of gravity of the load viewed from the Y-axis varies depending on the position of the cross slide 52 in the X-axis direction, and the natural frequency changes. Therefore, the stopping accuracy in the Y-axis direction deteriorates, and the processing accuracy decreases. Each parameter of the feedback control is adjusted so that the machining error due to the position of the cross slide 52 in the X-axis direction is minimized. However, with the fixed parameter, it is very difficult to ensure the stop accuracy over the entire range in the X-axis direction. It's difficult.

An object of the present invention is to provide a table control device for a plate material processing machine which can ensure the stopping accuracy of the Y axis regardless of the position of the cross slide in the X axis direction.

[0006]

The structure of the present invention will be described with reference to FIG. 1 corresponding to an embodiment. A table control device of this plate material processing machine is a table in which a cross slide (7) having a work holder (8) is mounted on a carriage (4) which moves forward and backward so as to be able to move forward and backward in a direction (Y) and a direction (X) orthogonal to the direction. Applies to equipment. In this table device,
The cross slide (7) is added to the Y-axis servo control means (19) that feedback-controls the forward / backward drive of the carriage (4).
Providing a speed loop gain in response to the X-axis position of (G _S) and the parameter changing means for changing at least one of the position loop gain (G _P) (30).

[0007]

According to the action this arrangement, the speed loop gain of the Y-axis control (G _S) and the position loop gain (G _P) is a variable gain, the X-axis direction position of the cross slide (7) is changed in its position depending loop gain was _{(G S), (G P} )
Is changed to. Therefore, it becomes possible to set the loop gain corresponding to the change of the natural frequency of the carriage (4) due to the change of the position of the cross slide 7 in the X axis direction, and the stop accuracy of the Y axis can be ensured regardless of the position of the cross slide (7). Can be improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a plan view of a punch press machine which is a plate material processing machine of this embodiment. A turret 2 is installed on the frame 1, and a punch drive mechanism (not shown) built in the frame 1 performs punching by a mold of the turret 2 at a processing position P.

The work table 3 comprises a fixed table 3a at the center and slide tables 3b on both sides. The slide tables 3b on both sides are integrally fixed to the carriage 4, and move back and forth in the front-rear direction (Y-axis direction) on the rail 6 of the bed 5 together with the carriage 4. A cross slide 7 is mounted on the carriage 4 so as to be movable back and forth in the left-right direction (X-axis direction), and a plurality of work holders 8 provided on the cross slide 7 hold a work W on the table 3.

The carriage 4 is driven back and forth by a Y-axis servomotor 9 and a feed screw 11 installed on the bed 5,
The X slide servo motor 10 and the feed screw 12 installed on the carriage 4 drive the cross slide 7 back and forth.
The Y-axis servomotor 9 has a pulse coder 9 (FIG. 1) that generates a pulse at a constant small angle of the rotor and a zero-phase pulse as a position detector and a speed detector, and each pulse is a motor rotation angle. Feedback counter 14 indicating
Entered in. The X-axis servomotor 10 also includes a similar pulse coder (not shown).

FIG. 1 is a block diagram showing a conceptual configuration of this table control device. The table controller is mainly N
The C device 15 includes an arithmetic control unit, a memory device, and the like, which form an X-axis servo control unit 18 and a Y-axis servo control unit 19 which are software servos, and a program decoding / background unit processing unit 17. The program decoding / background portion processing means 17 decodes the machining program 16 and gives each axis servo control means 18, 19 a command for the axis feed amount of the machining program 16 and performs processing on a programmable controller section (not shown). It is a means for giving a sequence command of a program.

Each axis servo control means 18, 19 is
The Y-axis servo control means 19 is provided with respective speed and current feedback control functions, and the Y-axis servo control means 19 has a position loop gain G _P and a speed rule gain G as will be described later.
_S is a variable gain. X-axis servo control means 18
Indicates that each loop gain is a fixed gain, and other configurations are similar to those of the Y-axis servo control means 19.

The Y-axis servo control means 19 comprises a position control means 20, a speed control means 21, a Y-axis servo control means 19, a parameter changing means 30, and a feedback signal converting means 35. Feedback signal converting means 3
Reference numeral 5 is means for calculating a position feedback signal Yf, a speed feedback signal ωf, and a rotor angle signal Lω from the count value of the feedback counter 14.

The position control means 24 includes a position command generator 23.
And a position controller 24. The position command generator 23
It is a means for outputting a position command Yc at each time according to a preset speed distribution curve a in accordance with the feed amount command Y ₀ transferred from the program decoding / background portion processing means 17. The position control unit 24 compares the position feedback signal Yf with the position command Yc by the comparison unit 33, and multiplies the position error Ye by the position loop gain G _P times by the position error amplification means 25 and outputs the speed command ωc. It is a means. The position feedback signal Yf is obtained from the pulse coder 13 of the Y-axis servomotor 9 via the feedback signal conversion means 35.

The speed control means 21 is a speed feedback signal ωf obtained from the feedback signal conversion means 35.
Is compared with the speed command ωc by the comparison unit 34, and the speed error Ye is multiplied by the speed loop gain G _P times in the speed error amplification means 26 to output the torque command τc.

The current control means 22 is a torque control means 27 constituted by a program of the NC device 15, and the NC device 1.
D / A converter 2 each of which is composed of electric elements different from 5
8, current loop power amplifier 29, and current detector 36
Consists of. The torque control means 27 is means for outputting a current command ic according to the rotor angle of the Y-axis servomotor 9 in accordance with the torque command τc.
If it is a servo motor or a synchronous motor, vector control is performed. In case of DC servo motor, simply torque command τc
Is multiplied by a constant to output the current command ic.

The current command ic is converted into an analog signal by the D / A converter 28 and input to the current loop power amplifier 29. The amplifier 29 calculates a current error between the motor current feedback signal and the current command, and outputs electric power according to the error signal.

The parameter changing means 30 comprises a variable parameter table 31 and a parameter selecting means 32. The variable parameter table 31 is used for the cross slide 7
The X-axis stroke of is divided into a plurality of sections, and the optimum position loop gain G _P and velocity loop gain G _S are calculated for each section.
Is set. The parameter selection means 32 sets the position loop gain G _P and the speed loop gain G _S , which are respectively set as variables in the position error amplification means 25 and the speed error amplification means 26, to the variable parameter table 31 according to the current position of the cross slide 7. Is a means for substituting the values of the corresponding loop gains G _P and G _S. The current position of the cross slide 7 at this time is the X-axis servo control means 1
Alternatively, the carriage 4 may be provided with a detector for detecting in which section the cross slide 7 is located, and the carriage 4 may be directly provided with the detector.

FIG. 3 shows an example of an interrupt program which constitutes the Y-axis servo control means 19 of FIG. This interrupt program interrupts the main program of the program decoding / background processing means 17 and periodically interrupts at a predetermined sampling time. The current control step (S4) in this interrupt program is a step constituting the torque control means 27 of FIG. 1, and is executed every time an interrupt occurs. The speed control step (S3) is a step constituting the speed control means 21 of FIG. 1, and is executed every time a preset number of interrupts occur. Position control step (S
2) is a step constituting the position control means 20,
It is executed every time the speed control step (S3) of the set number of times is executed. The feedback processing step (S1) is a step constituting the feedback signal converting means 35 of FIG. 1, and is executed for each interrupt.

The X-axis servo control means 18 of FIG. 1, for example, in each of steps S1 to S4 of FIG. 3, performs the process of the X-axis in the same manner as the Y-axis before or after the process of the Y-axis. It is composed of a program that allows it. The parameter selecting means 32 directly outputs the loop gains G _P and G of the variable parameter table 31 when the position error amplifying means 25 and the speed error calculating means 26 perform calculations.
Alternatively, _S may be selected, or a storage area for reading the predetermined gains of the loop gains G _P and G _S may be provided, and the value of the storage area is updated each time the X-axis current position changes to a different section. It may be configured to do so.

The operation of the above configuration will be described. The plate-shaped work W on the work table 3 is moved in the biaxial (X, Y) directions by advancing and retracting the carriage 4 and the cross slide 7, and an arbitrary position is sent to the processing position P. The feed in the two-axis directions is feedback-controlled by the servo control means 18 and 19 for each axis, and the positioning is performed with high accuracy.

In this case, the center of gravity of the carriage 4 viewed from the Y axis moves depending on the position of the cross slide 7 in the X axis direction, and the natural frequency of the carriage 4 changes with respect to the movement in the Y axis direction. However, since the position feedback and velocity feedback loop gains G _P and G _S are changed according to the position of the cross slide 7 in the X axis direction, the optimum loop gain G is always obtained regardless of the X axis position of the cross slide 7. Feedback control can be performed with _P and G _S , and the stopping accuracy in the Y-axis direction can be improved. Therefore, the processing accuracy is improved.

In the above embodiment, the position loop gain G
_Although both _P and the velocity loop gain G _S are configured to be changed, only one of the loop gains G _P and G _S may be changed. In addition, the current loop gain in the current loop power amplification unit 29 can be changed according to the cross slide position to further improve the accuracy. Further, although the variable gain is realized by the software servo in the above-mentioned embodiment, the gain may be changed by constructing the position and speed error amplifying means 25 and 26 by an electric circuit.

[0024]

According to the table control device for a plate material processing machine of the present invention, the Y-axis servo control means for feedback-controlling the forward / backward drive of the carriage controls the velocity loop gain and the position loop gain according to the position of the cross slide in the X-axis direction. Since the parameter changing means for changing at least one of them is provided, the Y-axis stopping accuracy can be improved regardless of the position of the cross slide.

[Brief description of drawings]

FIG. 1 is a block diagram showing a conceptual configuration of an embodiment of the present invention.

FIG. 2 is a plan view showing the plate material processing machine.

FIG. 3 is a flow chart of an interrupt program forming a software servo.

FIG. 4 is an operation explanatory diagram of a conventional example.

[Explanation of symbols]

3 ... Work table, 4 ... Carriage, 7 ... Cross slide, 8 ... Work holder, 9 ... Y-axis servo motor, 10
... X-axis servo motor, 11, 12 ... Feed screw, 13 ... Pulse coder, 15 ... NC device, 18 ... X-axis servo control means, 19 ... Y-axis servo control means, 20 ... Position control means,
21 ... Speed control means, 22 ... Current control means, 25 ... Position error amplification means, 27 ... Torque control means, 28 ... D / A converter, 29 ... Current loop power amplification section, 30 ... Parameter changing means, 31 ... Variable Parameter table, 32 ... Parameter selecting means, P ... Machining position, W ... Work

Claims (1)

[Claims] 1. A table device in which a cross slide having a work holder is mounted on a carriage that moves forward and backward so as to move forward and backward in a direction orthogonal to the forward and backward directions, and a cross slide is provided to Y-axis servo control means for feedback-controlling the forward and backward movement of the carriage. A table control device for a plate material processing machine provided with parameter changing means for changing at least one of a velocity loop gain and a position loop gain according to the X-axis position.