JP2015155130A - Synchronous control device of double-headed machining machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synchronous control device of a double-headed machining machine capable of enhancing surface accuracy of a machined surface and machining even a thin workpiece in a short machining time.

SOLUTION: In a double-headed machining machine including a first drive motor 14A and a second drive motor 14B corresponding to a pair of cutters 15A and 15B, respectively, a synchronous control device includes a first drive control section 21A corresponding to the first drive motor 14A; a second drive control section 21B corresponding to the second drive motor 14B; and a command control section 20 for transmitting a drive signal to the first drive control section 21A and the second drive control section 21B. The command control section 20 transmits a virtual axis to be a rotation-reference of the first drive motor 14A and the second drive motor 14B together with the drive signal. The drive signal with the single virtual axis from the command control section 20 can be output to the two first drive control section 21A and the second drive control section 21B. Accordingly, feed-forward controlling two motors 14A and 14B by the same drive signal and matching a rotation phase between the two cutters 15A and 15B without causing delay.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a synchronous control device for a double-headed machine. More specifically, the present invention relates to a synchronous control device for a double-headed processing machine that simultaneously processes two opposing surfaces of a workpiece.

The double-headed processing machine is a processing machine that simultaneously processes two surfaces of a workpiece by having a pair of processing cutters and driving them simultaneously.
Such a double-headed processing machine has a pair of cutters arranged to face each other, and includes a main shaft that drives each cutter and a driving device such as a motor.

The blade of the cutter is obtained by mounting a plurality of blades radially on a disk-shaped boss. Workpiece chatter is unlikely to occur when the blades are facing each other with a workpiece sandwiched between a pair of cutters, but if the blade of one cutter is facing between the blades of the other cutter, the workpiece is distorted. This is likely to occur, particularly when the workpiece is a thin plate.
Therefore, if the rotational phases of the pair of cutters do not match in a double-headed machine, the workpiece will be chattered and the parallelism and surface accuracy of the machined surface will be inferior. There is something.

The prior art of Patent Document 1 is one example, and is configured as follows.
An encoder is attached to each of the pair of spindles. The output values of the two encoders are compared, and if there is a deviation, feedback control is performed so that the deviation is returned to zero. This eliminates the rotational difference between the two cutters.

However, in the above-described prior art, when a deviation in the rotational speed occurs, feedback control is performed to eliminate the deviation. Therefore, in principle, it is impossible to prevent the deviation from occurring at all.
And when a workpiece | work is a thin plate, if the blade of the cutter which pinched the thin plate from the back and front both sides has shifted | deviated even a little angle, a thin plate will vibrate and a corrugated pattern will appear on a processing surface. Therefore, there has been a limit to improving the surface accuracy of the processed surface.
In addition, the thinner the plate, the weaker the resistance of the workpiece, so the thinner the plate, the more difficult it is to process, and there is also a problem that it takes a long time to process because the cutting thickness must be reduced.

Japanese Patent No. 4318443

  In view of the above circumstances, an object of the present invention is to provide a synchronous control device for a double-headed processing machine that can increase the surface accuracy of a processed surface and can process a thin workpiece in a short processing time.

A synchronization control device for a double-headed processing machine according to a first aspect of the present invention is a double-headed processing machine including a pair of cutters, a first drive motor and a second drive motor associated with the pair of cutters, and corresponds to the first drive motor. And a command control unit that sends a drive signal to the first drive control unit and the second drive control unit. The command control unit sends a drive signal to the first drive control unit and the second drive control unit. The control unit transmits a virtual axis that is a reference for rotation of the first drive motor and the second drive motor together with a drive signal.
According to a second aspect of the present invention, there is provided a synchronous control device for a double-head machine, wherein the first drive motor and the second drive motor are each provided with a rotational speed detector, and the rotational speed detector detects the rotational speed detector. The result is fed back to the first drive control unit and the second drive control unit.

According to the first invention, since the drive signal with a single virtual axis from the command control unit can be output to the two first drive control units and the second drive control unit, the two motors have the same drive signal. Feed-forward control is performed, and the rotation phase matches between the two cutters, so that no delay occurs.
For this reason, the surface accuracy of the finished surface of the workpiece is improved with the blade edges of the pair of cutters always having the same phase.
According to the second invention, even if a rotational position delay occurs between a pair of cutters, a rotational signal can be eliminated by outputting a correction signal from the detection result of the rotational position detector. Accuracy can be improved.

It is explanatory drawing of the synchronous control apparatus of the double-headed processing machine which concerns on one Embodiment of this invention. (A) is a photograph showing the processed surface of Example 1, and (B) is a photograph showing the processed surface of the comparative example. It is a side view of the double-headed processing machine to which this invention is applied. It is a top view of the double-sided processing machine shown in FIG. It is an enlarged view of a clamp part.

Next, an embodiment of the present invention will be described with reference to the drawings.
Although the present invention can be applied to various processing machines as long as the processing machine has a pair of processing heads, an embodiment applied to a double-sided side milling machine will be described below.

First, the basic configuration of a double-headed side milling machine will be described.
First, the basic configuration of the double-sided side milling machine according to this embodiment will be described with reference to FIGS.
Reference numeral 1 denotes a base. On the upper surface of the base 1, a processing table 2 is provided so as to be movable in the longitudinal direction (X-axis direction in FIGS. 3 and 4) with respect to the base 1. On the processing table 2, a lower jig 3 for placing the workpiece W is provided. An upper clamp cylinder 5 that moves together with the processing table 2 is provided above the lower jig 3. The upper clamp cylinder 5 has a rod disposed vertically downward. An upper jig plate 6 is provided at the tip of the rod.

  On the upper surface of the base 1, a pair of left and right heads 10, 10 are provided so as to be able to move toward and away from the workpiece in a direction orthogonal to the moving direction of the processing table 2 (Z-axis direction in FIG. 4). The headstocks 11 and 11 are attached to the pair of left and right heads 10 and 10, respectively.

A pair of main shafts 12 and 12 are rotatably supported on the pair of main shaft bases 11 and 11, respectively, and the pair of main shafts 12 and 12 are provided horizontally so that their axis centers coincide with each other. Yes. Cutters 15A and 15B are attached to one end portions of the pair of main shafts 12 and 12, respectively, and the other end portion of each main shaft 12 is a motor provided on the upper portion of the head stock 11 by a belt or the like. 14A and 14B.
For this reason, when the motors 14A and 14B are driven, the main shaft 12 rotates and the cutters 15A and 15B rotate.

  As shown in FIG. 5, the lower jig 3 on the processing table 2 is composed of a base part 3a having a substantially triangular cross-sectional shape and a support part 3b having a narrow central top surface and protruding upward. The width of the support portion 3b is made thinner than the finished dimension of the workpiece W to be cut. In other words, several types of lower jigs 3 are prepared according to the workpiece W, and the lower jig 3 having the support portion 3b narrower than the finished dimension is selected and used.

  For this reason, if the clamping cylinder 5 is extended, the workpiece W is sandwiched between the lower jig 3 and the upper jig plate 6, so that the workpiece W can be fixed to the processing table 2. In addition, if the work table 2 is moved back and forth (X-axis direction), the work W is moved back and forth (X-axis direction) while the work W is sandwiched between the upper jig 6 and the lower jig 3. Can do.

  According to the double-sided side milling machine of the above-described embodiment, the workpiece W is attached to the processing table 2 and the pair of heads 10 and 10 are moved toward the processing table 2 by the amount of processing the workpiece W. Then, when the cutter 15 is rotated by driving the motor and the workpiece W is sent in the cutter direction by the processing table 2, the front and back surfaces of the workpiece W can be cut at once by the cutters 15A and 15B.

Next, a synchronous control device that is a characteristic part of the present invention will be described.
In the following description, the motor associated with the cutter 15A will be described as the first drive motor 14A, and the motor associated with the cutter 15B will be described as the second drive motor 14B. ,
In FIG. 1, 20 is a command control unit, and 21A and 21B are a first drive control unit and a second drive control unit. The first drive control unit 21A is associated with the first drive motor 14A, and the second drive control unit 21B is associated with the second drive motor 14B.
Servo motors are used for the drive motors 14A and 14B in terms of controllability.

  The command control unit 20 can generate a single virtual axis together with the drive signal and transmit it to the first drive control unit 21A and the second drive control unit 21B. The virtual axis means an axis that serves as a reference for the rotational positions of the first drive motor 14A and the second drive motor 14B.

  The command control unit 20 transmits a drive signal with the same virtual axis to the two first drive control units 21A and the second drive control unit 21B. For this reason, each drive control part 21A, 21B starts from the axial center position of the same phase, and rotates while maintaining the same rotational phase. As described above, according to the synchronous control device of the present invention, feedforward control is performed, so that one of the pair of motors always rotates in synchronization with the phase without being delayed or accelerated.

  If synchronous control is performed in the present invention, the plurality of blades provided in the pair of cutters 15A and 15B are opposed to the respective blade edges during rotation, and the blade edge of one cutter is not the blade edge of the other cutter. There is no opposite. For this reason, since the same pressure is always applied to both surfaces of the workpiece, no corrugated pattern is generated on the cut surface.

  As described above, since the control according to the present invention is feedforward control, feedback of the output shaft is essentially unnecessary. However, it is necessary to correct when there is a feed in the rotational phase of one of the cutters for reasons such as overload. Therefore, in the present embodiment, a rotational speed detector is attached to each motor 14A, 14B.

Reference numerals 16A and 16B denote pulse generators which are examples of the rotational speed detector. When the detection signal of the pulse generator 16A is fed back to the first drive control unit 21A and the detection signal of the pulse generator 16B is fed back to the second drive control unit 21B and compared by the command control unit 20, one of the delays can be determined. .
If the delay is found, the command control unit 20 may output a speed increase signal or a speed decrease signal that eliminates the delay.

  According to the rotation synchronous control of the present invention, since feedforward control is performed, a control delay that is unavoidable in the prior art does not occur, and machining with high surface accuracy can be performed.

(Example)
The first embodiment is a processing machine in which the control device of FIG. 1 is incorporated in the double-sided side milling machine shown in FIGS.
As Comparative Example 1, the same processing machine as in Example 1 was prepared except that the synchronous control device was not incorporated.
In Example 1, a thin plate workpiece having a thickness of 5 mm, a width of 100 mm, and a length of 1000 mm could be processed. The thickness / width ratio is a thin plate having a large ratio of 1/20. In Comparative Example 1, the thickness / width ratio is from 1/2 to 1/5, and therefore the workpiece of the present invention can process a workpiece having a thickness / width ratio of 4 times or more.

Further, the processing time was 35 minutes in the comparative example 1, but 9 minutes in the example 1, so that the time is shortened by about ¼.
Furthermore, the smoothness of the processed surface could be finished to 15 μm or less, and the parallelism of both front and back surfaces could be finished to 10 μm or less. The photograph of a processed surface is shown to (A) and (B) of FIG. It can be easily determined by the presence or absence of ripples that the processed surface according to Example 1 shown in (A) is superior to the processed surface according to Comparative Example 1 shown in (B).

1 Base 14A, 14B Drive motor 15A, 15B Cutter 16A, 16B Pulse generator
20 Command controller 21A, 21B Drive controller

Claims (2)

In a double-headed processing machine comprising a pair of cutters, a first drive motor and a second drive motor associated with the pair of cutters,
A first drive controller associated with the first drive motor and a second drive controller associated with the second drive motor;
A command control unit that sends a drive signal to the first drive control unit and the second drive control unit;
The synchronous control device for a double-headed processing machine, wherein the command control unit transmits a single virtual axis that serves as a reference for rotational positions of the first drive motor and the second drive motor together with a drive signal. A rotation speed detector is attached to each of the first drive motor and the second drive motor,
2. The synchronous control apparatus for a double-headed processing machine according to claim 1, wherein a detection result of the rotation speed detector is fed back to the first drive control unit and the second drive control unit.