JP3265961B2 - Work movement control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a workpiece movement control device for servo-controlling the work movement hand stage provided <br/> to Panchipure scan.

[0002]

2. Description of the Related Art Conventionally, as a work moving means for moving a work to a predetermined position, a servo control means for moving the work in accordance with a predetermined speed curve has been generally adopted. However, if the weights of the workpieces are variously different, followability with respect to the set speed curve cannot be obtained, and the positioning accuracy decreases. When the workpiece moving means is provided in a plate material processing machine or a general machine tool, a decrease in positioning accuracy leads to a decrease in processing accuracy. Decreasing the moving speed can increase the positioning accuracy, but
Productivity decreases. Taking a punch press as an example,
The movement of a plate material as a work is performed by a servo motor by a work curve with a speed curve such as trapezoidal control. In this case,
If the weight of the plate material is constant, by always setting a constant optimum speed loop gain, it is possible to optimally adjust the followability to the speed curve. However, it is often necessary to process plate materials of various sizes, thicknesses, and materials, and the weight of the plate materials differs depending on the size, material, and the like.
Further, even during the processing of one sheet material, the weight of the sheet material gradually changes due to the progress of punching. Therefore, if the control is performed with a constant speed loop gain, it is difficult to increase the processing accuracy corresponding to various plate materials.

An object of the present invention is to provide a work movement control device capable of moving a work with good followability to a set speed curve even if the weight of the work is variously different. Another object of the present invention is to improve the processing accuracy while maintaining the followability to a set speed curve even if the work weight is reduced by the progress of processing. Still another object of the present invention is to make it possible to optimally control the movement of a work in accordance with the type of the work transfer surface.

[0004]

The structure of the present invention will be described with reference to FIG. 1 corresponding to an embodiment. A work movement control device according to the present invention is a work movement control device for a punch press machine, and includes a servo control means (19) for controlling a movement means (3) for a work (W) made of a plate material, and a work control means for controlling a work weight. A storage means (31) for storing one or both of a speed loop gain (G _S ) and a position loop gain ( _GP ); and the storage means (31) according to a work weight.
And a setting means (30) for selecting the loop gain (G _S , G _P ) and setting the same in the servo control means (19). By setting the loop gain (G _S , G _P ) in this manner, speed control according to the work weight can be performed, and the ability to follow the set speed curve is improved. Therefore,
The positioning accuracy can be improved without unnecessarily lowering the moving speed. It said moving means (3) is Ru <br/> Ah in to move the workpiece (W) relative to the workpiece conveying surface (S). The storage means includes a plurality of types of work transfer surfaces (S)
About the loop gain (G _S , G
_P ) is stored, and the type of the work transfer surface (S) is stored for each machine.
Kind is the one to be selected. The type of the work transfer surface (S) refers to the type of the guide member when a guide member such as a free bearing or a sliding material is provided on the transfer surface (S). Thus, the loop gain (G _S ,
By setting G _P ), when this work movement control device is used for machines having various transfer surfaces, it is possible to cope with various types of machines simply by selecting the type of transfer surface for each machine. The setting means (30) includes a weight correspondence setting unit (30).
a), the weight correspondence setting unit (30a) calculates the weight of the work (W) from the material data instructed by the machining program (16). The setting means (30) includes in response to workpiece weight which is lighter by machining, the loop gain (G _S, G _P) of the servo control means (19) processing amount corresponding setting unit for changing the the (30b) It is good. Thereby, it is possible to always maintain a good state of following the set speed curve in response to a change in the weight of the workpiece with the progress of processing.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a plan view of a punch press, which is a plate processing apparatus to which the work movement control device is applied. A turret 2 is installed on the frame 1 and a punch driving mechanism (not shown) built in the frame 1
At the processing position P, the turret 2 is punched by a die. The work moving means 3 is for holding a work W made of a plate material with a work holder 8 and moving the work W on a work transfer surface S formed of a table upper surface. The work transfer surface S is provided with a free bearing or roller bearing made of iron, urethane rubber, or the like, or a guide member with good slip such as felt.

The table of the work moving means 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 advance and retreat in the front-rear direction (Y-axis direction) along with the carriage 4 on the rail 6 of the bed 5. A cross slide 7 is provided on the carriage 4 so as to be able to move back and forth in the left-right direction (X-axis direction).
Are mounted, and the work W on the work transfer surface S is gripped by the plurality of work holders 8 provided on the cross slide 7.

The advance and retreat of the carriage 4 is performed by a Y-axis servomotor 9 and a feed screw 11 installed on the bed 5,
The forward / backward drive of the cross slide 7 is performed by an X-axis servo motor 10 and a feed screw 12 installed on the carriage 4.
The Y-axis servomotor 9 has, as position detecting means and speed detecting means, a pulse coder 13 (FIG. 1) for generating a pulse at a fixed minute angle of the rotor and a zero-phase pulse. Is input to the feedback counter 14 which indicates The X-axis servo motor 10 also has a similar pulse coder (not shown).

FIG. 1 is a block diagram showing a conceptual configuration of the work movement control device. The work movement control device is constituted by a part of a computer-based NC device 15, and includes an arithmetic control unit, a memory device, and the like, and an X-axis servo control unit 18 and a Y-axis servo control unit 19 comprising software servo, and a program decoding unit. The background processing unit 17 is configured. The program decoding / background section processing means 17 decodes the machining program 16 and
19 is a means for giving a command of the axis feed amount of the machining program 16 and a sequence command of the machining program to a programmable controller (not shown).

Each of the axis servo control means 18 and 19 has a position,
Speed, and includes each respective feedback control function of the current, as a variable gain, each providing a position loop gain G _P and the speed rules gain G _S variable. The X-axis and Y-axis servo control units 18 and 19 have the same configuration except that the set values such as the loop gain are different. Therefore, the following description will be made only for the Y-axis servo control unit 19.

The Y-axis servo control means 19 comprises a position control means 20, a speed control means 21, a current control means 22, a parameter setting means 30, and a feedback signal conversion means 35. Feedback signal conversion means 35
Is calculated based on the count value of the feedback counter 14 and the position feedback signal Yf and the speed feedback signal ω.
f and a means for calculating the rotor angle signal Lω.

The position control means 20 includes a position command generator 23
And a position control unit 24. The position command generator 23
In accordance with a command Y ₀ feed amount transferred from the program decryption and background portion processing means 17 is means for outputting a position command Yc at each time according to the speed curve a preset. The position control unit 24 includes a position feedback signal Yf and a position command Y.
is compared by the comparing unit 33, and the position error Ye is multiplied by the position error amplifier 25 times the position loop gain _GP to output the speed command ωc. The position feedback signal Yf is output from the pulse coder 1 of the Y-axis servomotor 9.
3 via the feedback signal conversion means 35.

The speed control means 21 outputs a speed feedback signal ωf obtained from the feedback signal conversion means 35.
And the speed command ωc is compared by the comparing unit 34, and the speed error Ye is multiplied by the speed loop gain G _S times by the speed error amplifying means 26 to output the torque command τc.

The current control means 22 includes a torque control means constituted by a program of the NC device 15, a D / A converter constituted by electric elements, a current loop power amplifier, and a current detector (all shown in FIG. Not shown). The torque control means is a means for outputting a current command according to the rotor angle of the Y-axis servomotor 9 in accordance with the torque command τc, and performs vector control when the Y-axis servomotor 9 is an AC servomotor or a synchronous motor. Do. In the case of a DC servomotor, a current command is output simply by multiplying the torque command τc by a constant.

The parameter setting means 30 includes a plurality of variable parameter tables 31a constituting the loop gain storage means 30, a parameter selection means 32, a weight correspondence setting part 30a, and a machining amount correspondence setting part 30b. Each variable parameter table 31a is provided for each type of the material of the free bearing of the work transfer surface S, and for each weight of the work W with respect to the work transfer surface S (for example, several types to ten-odd). For each weight category classified by species)
Position loop gain G _P and the velocity loop gain G _S optimum is set to. Parameter selection means 32 selects the position loop gain G _P and the velocity loop gain G _S of the variable parameter table 31a in accordance with the instruction of the weight corresponding setting unit 30a and the machining amount corresponding setting unit 30b, the position error amplifying means 25 and the speed loop gain G _P, each with its selected was the error amplifying section 26 is for setting the G _S.

The weight setting unit 30a calculates the weight of the work W from material data (eg, vertical and horizontal dimensions, plate thickness, material) specified at the beginning of the machining program 16, and selects a parameter according to the calculation result. 32 Ru means der to select a position loop gain G _P and the velocity loop gain G _S corresponding to the weight. Also, weight corresponding setting section 30a
Are servo control means 18 and 19 for each of the X axis and the Y axis.
For, to perform selection and setting of the position loop gain G _P and the velocity loop gain G _S of the.

The processing amount correspondence setting unit 30b calculates the weight reduction of the work weight due to punching at predetermined intervals during the punching of each work W. Each time the processing is performed, the work amount is set based on the variable parameter table 31a of the storage means 31. This is a means for causing the parameter selection means 32 to select the position loop gain _GP and the speed loop gain G _S and to set them in the position control means 20 and the speed control means 21. The calculation for the weight reduction is:
For example, it may be performed periodically by determining the number of punches or the like, or may be performed each time a tool is changed by rotating the turret. The calculation of the weight reduction is performed from the data of the punch hole position and the tool type in the machining program 17. The processing amount correspondence setting unit 30b also
The gain is changed for the servo control means 18 and 19 for both the X and Y axes. The processing amount corresponding setting unit 30b calculates the deviation of the workpiece weight by machining position of the punch holes, the loop gain G _P of X and Y axes in accordance with the deviation, was added a function to correct G _S It is good.

FIG. 3 shows an example of an interrupt program constituting the Y-axis servo control means 19 of FIG. This interrupt program is to interrupt the main program of the program decoding / background processing means 17 and to interrupt periodically at a predetermined sampling time. The current control step (S4) in the interrupt program is a step that constitutes a torque control unit that is a part of the current control unit 22 in 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. The position control step (S2) is a step constituting the position control means 20, and is executed every time the speed control step (S3) is performed a set number of times. The feedback processing step (S1) is a step constituting the feedback signal conversion means 35 of FIG. 1, and is executed for each interruption.

The X-axis servo control means 18 in FIG. 1, for example, in each of the steps S1 to S4 in FIG. 3, performs the processing on the X-axis in the same manner as the Y-axis before or after the processing on the Y-axis. It is composed of a program designed to be used. Further, the machining amount correspondence setting unit 30b in FIG. 1 is configured by, for example, an interrupt program different from that in FIG.

The operation of the above configuration will be described. Storage means 31
The variable parameter table 31a selects a table 31a according to the configuration of the moving means 3 of the punch press machine before the actual operation, such as at the time of machine installation, and the table 31a
Is set to be read. At the time of workpiece machining, before starting machining by the machining program 16, the weight correspondence setting unit 30a calculates the workpiece weight based on the material data specified at the beginning of the machining program 16, and selects parameters for each of the X axis and the Y axis. through means 32 select the appropriate weight of the position loop gain G _P and the velocity loop gain G _S of the variable parameter table 31a, sets the position control means 20 and the speed control unit 21. Therefore, also the weight of the workpiece W is a variety of different results in the movement of the workpiece W is performed by the position loop gain G _P and the velocity loop gain G _S corresponding to the workpiece weight, perform positioning accurately the workpiece W. Therefore, high-precision punching can be performed. Further, the work W can be moved without unnecessarily lowering the work moving speed, and the speed of punching can be increased. Regarding the speed loop gain G _S ,
If the value is smaller than the optimum value, the ability to follow the speed curve a deteriorates. If the value is larger than the optimum value, the servomotor 9 oscillates and causes a failure. Such a problem is solved by setting according to the work weight. Further, when the punching is started, the weight of the work W is gradually reduced, and the reduced amount is periodically (for example, every 30 to 50 times of the set number of punches, or Calculated every certain set time)
The position loop gain G _P and the velocity loop gain G _S is changed to the optimum value, can be done better work moving the followability to further speed curve a, from the start to the end of the process,
High-precision punching can be performed.

In the above embodiment, the position loop gain G
_{Although both the P} and the speed loop gain G _S are changed, only one of the loop gains G _P and G _S may be changed. In the case of either one, it is desirable to change the speed loop gain G _S.
In the above-described embodiment, the variable gain is realized by the software servo.
26 may be configured by an electric circuit so that its gain can be changed.

[0021]

The work movement control device according to the present invention has a pan
A work movement control device for a chip press machine, comprising:
And servo control means for controlling the moving means of word over click consisting storage means for storing one or both of the speed loop gain and position loop gain according to the weight of the work, of the storage means in accordance with the workpiece weight Since there is provided a setting means for selecting a loop gain and setting it in the servo control means, the workpiece can be moved with good followability to the set speed curve even when the weight of the workpiece is variously varied. can Ru. The storage means is a loop gay according to the work weight.
Is stored for each type of work transfer surface.
Optimal work movement control according to the type of work transfer surface
Can be performed. Before Symbol setting means, in accordance with the workpiece weight, which is lighter by machining, the case of providing the processing amount corresponding setting unit for changing the loop gain to be set to the servo control unit, to a change in workpiece weight with the progress of machining Accordingly, the followability to the set speed curve can be maintained, and the processing accuracy can be improved.

[Brief description of the 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 flowchart of an interrupt program constituting the software servo.

[Explanation of symbols]

3 Work moving means, 4 Carriage, 7 Cross slide, 8 Work holder, 9 Y-axis servo motor, 10
... X-axis servo motor, 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, 2
2. Current control means, 25 Position error amplification means, 30 Parameter setting means, 30a Weight setting section, 30b
Machining amount correspondence setting unit, 31: storage means, 31a: variable parameter table, 32: parameter selecting means, P: machining position, S: transport surface, W: work

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23Q 15/00 B23Q 15/20 B21D 28/00 G05B 19/404 G05D 3/12

Claims (2)

(57) [Claims] 1. A work movement control device for a punch press machine, comprising: a servo control means for controlling a movement means of a work made of a plate; and one or both of a speed loop gain and a position loop gain according to a weight of the work. Storage means, and setting means for selecting a loop gain of the storage means according to the weight of the work, and setting the selected gain in the servo control means, wherein the moving means moves the work with respect to the work transfer surface. And the storage means has a plurality of
For each type of workpiece transfer surface,
Pregain is memorized, and the type of workpiece transfer surface for each machine
There are those selected, the setting means, have a weight corresponding setting section, weight corresponding setting section, the workpiece movement control device to calculate the weight of the workpiece from the material data command to the machining program. Wherein prior Symbol setting means, in accordance with the workpiece weight, which is lighter by machining, the workpiece movement according to claim 1, wherein loop gain are those with a working volume corresponding setting unit for changing the said servo control means Control device.