JPS6044295A - Controller for reciprocating travelling - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION After finishing machining (the most common type is cutting), it is normal to retreat and return to the holding position. In order to switch back to the forward direction and perform the next process without returning to the home, the process of the processing machine is long, which not only makes the machine larger and more expensive, but also requires extremely complicated control. there were. Also, there was little need for that. However, recently, machining is no longer simple, and it has been devised that cutting, cutting, drilling, and notching can be done between runs by selecting a machining mold on one production line, and machines are becoming larger. Therefore, there is a need for control that allows the interval length between machining and the next machining to be set arbitrarily.

Numerical control has recently been used in many cases for conventional simple reciprocating processing machines, but the present invention introduces a new means to numerical control in the United States to achieve machining intervals that correspond to the above-mentioned arbitrary set length. The aim is to carry out forward servo control during these two steps, and to perform backward control in order to return the processing machine to its original position in between.

<Summary of the Invention> The purpose of the present invention is to provide a processing machine that moves back and forth along a moving material and performs traveling processing on the material at intervals of a set length. To provide a reciprocating travel control device that processes a material at intervals of a given set length, not only for a long set length that allows the user to return to the home, but also for a short set length that does not allow for return to the home.

According to this invention, a means is provided to compare the difference between the running speed signal of the material and the remaining length signal with the running speed signal of the processing machine, and to compare the dog/J\ including the sign, thereby controlling the forward servo of the processing machine. and reverse control.

<Example> Next, embodiments of this invention will be described with reference to the drawings.

FIG. 1 shows an example of a numerical control device for a reciprocating processing machine.

However, this is an example of a conventional control device that causes the vehicle to return to the home position every time. In FIG. 1, a material 11, for example a steel plate, is running into the swamp from the left in FIG. 1, as indicated by an arrow 12. A processing machine 13 is provided that travels along the material IJ and processes the material 11. A rack 14 parallel to the material 11 is attached to the processing machine 13, and the rack 1
The pinion 15 meshed with the DC motor 16 is rotated by the DC motor 16, and the processing machine 13 travels along the material 11. Depending on the direction of rotation of the DC motor 16, the processing machine 13 is rotated by the DC motor 16. l'$411
The vehicle travels in the traveling direction or in the skipping direction.

A length measuring roll 17 is rolled into contact with the material phase 11, and the length measuring roll 17
The length measuring encoder 18 is driven by 1, and a predetermined number of pulses are sent to the sub-length encoder 1 every time the phase material 11 moves by a unit length.
Occurs from 8. This nollus is counted by a length measuring counter J9, and a value L corresponding to the moving length of the material 11 is obtained. Further, pulses from the length measuring encoder 18 are supplied to a frequency-voltage converter 21, from which a traveling speed signal S1 of the material 110 is obtained. On the other hand, the processing machine encoder 22 is driven by the DC motor 16.
The predetermined number of pulses are generated every time the processing machine 13 moves by a unit length. These pulses are counted by a processing bar counter 23, and the number of pulses corresponding to the moving length of the processing bar 13 is 11.
IIL2 is obtained. The pulses of the processing machine encoder 22 are also counted by a reversible counter 24, and a value L3 corresponding to the position of the processing machine 13 is obtained from the counter 24, and this value L3 is converted into a negative analog signal by a DA converter 25. is,
This analog signal is used as a speed reference signal v3 when the processing machine 13 returns to the home. The pulses of the processing machine encoder 22 are supplied to the chest wave number voltage converter 26, and a traveling speed signal S2 of the cutting piece 13 is thereby obtained.

A machining setting length is set in the setting device 27, and this machining setting length L
O and the count values Lz and L2 of the counters 19 and 23 are input to the digital adder 28, and the remaining length signals LO-L1+I and 2 indicating the remaining length after processing are obtained from the tezotal adder 28. This remaining length signal is converted by the DA converter 29 into an analog remaining length signal Vc. The difference 5l-VC between this remaining length signal Vc and the output S1 of the frequency-voltage converter 21 is taken by the analog adder 31, and this difference output Vf-"S
1-Vc becomes a speed reference signal when the processing machine 13 moves forward (advances) in the moving direction of the material 11a. The output Vf of the analog adder 31 and the output of the DA converter 3'A unit 25■
3 are switched by a switch 32, and one of them is supplied to an analog adder 33 as a speed reference signal. On the other hand, the polarity of the output of the frequency-voltage converter 26 is inverted by a sign inverting circuit 36, and the output is supplied to an analog adder 33 as a speed feedback signal. This analog adder 3
The output of No. 3 is used as a speed deviation signal for power control of the DC motor 16 by the drive circuit 37.

To explain the repetitive control of reciprocating travel starting from the end of machining, at this time the processing machine 13 is servoed to the material.I) Vcf
jlJ, analog Lo-L1+L2 is a value corresponding to zero. When an external signal indicating the completion of machining is received, the counter 19.23 is cleared and the next set length], 0, is obtained from the setter 27. Conventionally, LO is large, so V c' 1111, analog LO-L 1
+L2 becomes larger and Vf becomes negative. Code discriminator 34
When it is determined that Vf is negative, the switch 32 is turned over, and the speed reference signal of the DC motor is switched from Vf to the output (3) of the D/A converter 25. 1 because the negative analog signal v3 generated from the advance length L3 of the processing machine 13 serves as the speed reference.
．． Processing machine 13 and motor 1 due to current limitation by drive circuit 37
Depending on the inertia of 6, it decelerates at 5=constant acceleration and accelerates in the backward direction. Since Va is limited to the rated rotational speed of the DC motor 16, after acceleration ends, the motor moves backward at the rated speed, and then when L3 approaches zero, V3 decreases and it decelerates to a stop. Hold at zero and continue stop positioning control at the home.

Meanwhile, as the material 11 travels and Ll increases, Vc decreases, and when Vc decreases by Sz, Vf
=Sma1-Vc changes from negative to positive, so the sign discriminator 34
The switch 32 is switched and the speed reference returns from 3 to Vf again. After that, Vc decreases as the material travels,
As Vf increases, the DC motor 16 begins to accelerate, and the processing machine 13 begins to move forward, finally synchronizing with the material speed S1, that is, Vc waits for the end of processing while continuing the positioning control during the run that maintains the sozero.

The waveform of the motor speed S2 during this period is shown in FIG. 3A. The figure also shows a selection section in which the speed reference is Vf or V3. After processing is completed, the above steps are repeated.

The above is an example of a conventional control device that returns to the home every time. By the way, when the LO is not large enough as in the past, the Vf sign discriminator 34 sets the speed standard to v3.
After switching to Vf, for example, Vf changes from negative to positive even while the processing machine 13 is retracting at a rapid speed. Therefore, the code discriminator 34 switches the speed reference from v3 to Vf again.

At this time, the speed reference Vf starts from zero, but since the motor is already rotating in reverse, it cannot suddenly follow Vf due to the inertia of the machine and the torque limit of the motor, and the forward servo may be out of order or adjusted. I wake up and can't get into sync.

Therefore, according to the present invention, a comparator 38 is newly provided in place of the code discriminator 34 as shown in FIG. 2, and the speed reference is thereby switched to either 3 or Vf. Vf and the traveling speed S2 of the processing machine are used as inputs to the comparator 38, and algebraically when Vf≧82, the speed reference of Vf is used, and when Vf<82, algebraically, v3 is used as the speed reference. However, Sz
is the case when it is assumed to be positive in forward movement. For example, processing machine 13
is backward, and when Sz is negative, Vc decreases, that is, Vf increases, and when it increases with the same negative value as Sz, the speed reference is switched from v3 to Vf. In this way, from that point on, the motor speed will continuously and smoothly change to Vf according to Vf.
It is possible to start deceleration in reverse rotation and acceleration in forward rotation by following the decrease in c, that is, by following the movement of the material.

After the speed reference is switched to V3, Vf is switched to Vf from ■3 because Vf≧82 even if the speed becomes larger than positive 82 during forward speed movement (deceleration).

After switching to V3, if the setting length is long as before, Sz will be zero because it will return to the home switch, and comparator 3
8 also serves as the code discriminator 34.

FIG. 3B shows so-called medium-length machining in which the machine switches to forward servo mode while retracting at a constant speed.

This collapse is the speed waveform when medium length machining and long length machining alternate. FIG. 3C shows a case where the processing machine switches between decelerating in the forward direction and accelerating backward. This collapse is the velocity waveform when a long length, short length, medium length, and short length are one cycle.

Part of the control, including the operation of the comparator 38, can be performed by an electronic computer. In that case, VaJ operates the electronic computer as shown in FIG. That is, when the power switch of the apparatus is turned on, it is checked in step S1 whether or not machining has been performed, and if machining has started, the counter 19 +' 23 is cleared in step S2 and the process moves to step S3.
If not processed in step S, immediately step S3
Move to. In step S3, it is checked whether the processing machine 13 has returned to the home. If it has returned to the home, the content L3 of the reversible counter 24 is set to a reference value, for example, a cello, in step S4, and the process moves to step S5. Processing machine 1 in step S3
3 has not returned to the home, the process moves to step S5. In step S5, each count value L of the counters 19, 23, 24
l, L2. L3, material speed signal S1, and processing machine speed signal S2 are taken in. Since this acquisition is performed as a digital signal, the material velocity signal S1 can be obtained, for example, by counting the pulses generated by the length measuring encoder 18 for a unit time and determining the frequency thereof. Similarly, the pulse frequency generated by the processing machine encoder 22 is measured to obtain the processing machine speed signal S2. Next, in step S6, a comparative test corresponding to the comparator 38 is performed, but in order to make the dimensions uniform, the maximum value of the interest speed is Smi, and the maximum value of the workpiece speed is Sm2.
Let Ec be the number of pulses generated by the processing machine encoder 22 while accelerating from the maximum speed during reverse rotation to the maximum speed during forward rotation. The first and second terms on the right side of this equation correspond to the output Vf of the analog adder 31, and the third term corresponds to the traveling speed of the processing machine. Step S
In step 7, it is checked whether the calculation result in step S6 is positive or negative.
)) is converted into an analog signal and supplied to the analog adder 35, and the process returns to step S1. Step S7
If D is not positive, the process moves to step S9, and the counter 24
The content of is converted into an analog signal and supplied to the analog adder 35, and the process moves to step s1. Note that the electronic computer uses the set length Lo for the next machining for each individual machining according to the programmed program, and also outputs machining commands, machining mold selection commands, etc.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional reciprocating travel control device, FIG. 2 is a block diagram showing an example of the present invention, and FIG. 3 is a diagram showing processing machine speed for explanation of its operation.
FIG. 4 is a flowchart showing an example of operation when an electronic computer is used as a part of the present invention. ]-1: A2 material, 13: Processing machine, 16: DC motor,
8: Length measurement encoder, 19: Length measurement counter, 21, 26
: Frequency voltage converter, 22: Encoder for processing machine, 2
3: Processing machine counter, 24: Reversible counter for processing machine position detection, 25, 29 = DA converter, 34: Sign discriminator, 38: Comparator patent applicant Nameco Co., Ltd. Agent Takuo Kusano 1 Figure 1 Force 2 Figure 3

Claims (1)

[Claims] (1) Obtain the remaining length signal at the next processing point 1 from the signal corresponding to the moving length of the material, the signal corresponding to the moving length of the processing machine, and the set length signal, and use the remaining length signal to In a reciprocating travel control device that controls the movement of a processing machine to process the material during traveling at intervals corresponding to the set length, the difference between the traveling speed signal of the restriction and the remaining length signal of the processing machine is A comparison means is provided to compare the magnitude of the signal with the traveling speed signal, including the sign.
A reciprocating travel control device characterized by switching between.