JP2000153431A - Monitoring control method and device for tail stock of machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To previously prevent work failure by comparing a position detected by a position detecting means on an after completing the setting of a tail stock with a stored position, and detecting abnormality when the compared result is not coincident. SOLUTION: When a motor current becomes a designated value, in other words, when pressing force of a tail stock 13 becomes designated pressing force, a low speed advance of the tail stock 13 is stopped, the setting of the tail stock 13 is completed, an output signal of a u-axis rotary encoder 29 at this time is stored as a setting completing position, and an output value of an ammeter 31 at this time is stored as a setting completing electric current value. A tail stock position is monitored by a signal outputted by the u-axis rotary encoder 29, the tail stock position by the signal outputted by the u-axis rotary encoder 29 is compared with a stored setting completing position, and when the compared result is not coincident, abnormality is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for monitoring and controlling a tailstock of a machine tool, and more particularly to a method and apparatus for monitoring and controlling a tailstock used in a machine tool such as a lathe, a milling machine, and a grinding machine. It concerns the device.

[0002]

2. Description of the Related Art Machine tools such as lathes, milling machines, and grinders use a tailstock, which is disposed opposite to a main chuck, as a sub-chuck and mainly work by a pressing force designated by a forward drive of the tailstock. There is a type in which the work is supported by pressing the work from the opposite side of the chuck and pressing the work against a main chuck (face plate) by a tailstock.

[0003]

In the above-mentioned machine tool, since the work is pushed toward the main chuck by the tailstock, the work slides in the axial direction due to vibration or poor work holding on the main chuck, and the work position is reduced. The work is deformed due to a shift or a reduction in the work rigidity due to a reduction in the work wall thickness due to the processing, and as a result, a processing failure occurs. The occurrence of such processing defects hinders continuous processing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and detects the occurrence of a work position shift or a work deformation, and uses a machine tool tailstock for avoiding machining defects. It is an object of the present invention to provide a method and apparatus for monitoring and controlling a table.

[0005]

To achieve the above object, a method of monitoring and controlling a tailstock of a machine tool according to the first aspect of the present invention is to advance a tailstock arranged opposite to a main chuck. In a method for monitoring and controlling a tailstock of a machine tool for pressing a work from the opposite side of the main chuck by a pressing force specified by driving, a position of the tailstock is detected by position detection means, and the position of the tailstock is detected by the position detection means. Stores the position of the tailstock at the time of completion of the setting of the tailstock, and compares the position detected by the position detecting means with the stored position after the completion of the setting of the tailstock, If the comparison results in a mismatch, abnormality detection is performed.

According to a second aspect of the present invention, there is provided a method for monitoring and controlling a tailstock of a machine tool according to the first aspect. The pressing force at the time of completion of the setting of the tailstock is stored by the pressing force detected by the pressing force detecting means, and the pressing force detected by the pressing force detecting means after the setting of the tailstock is completed. The stored pressing force is compared with the stored pressing force, and if the comparison result does not match, an abnormality is detected.

According to a third aspect of the present invention, in the method of monitoring and controlling a tailstock of a machine tool according to the second aspect, the tailstock is driven to rotate by a servomotor. The pressing force detecting means is for detecting the torque of the servomotor.

According to a fourth aspect of the present invention, there is provided a method of monitoring and controlling a tailstock of a machine tool according to any one of the first to third aspects. After the rough positioning is completed, the tailstock is advanced at a low speed. If the setting is completed and the position detected by the position detecting means during the high-speed forward movement exceeds a specified rough position, abnormality detection is performed.

According to a fifth aspect of the present invention, there is provided a monitoring and controlling apparatus for a tailstock of a machine tool, wherein the tailstock is opposed to the main chuck by a tailstock opposed to the main chuck. In the monitoring and control device of the tailstock of the machine tool that presses the workpiece with the specified pressing force from the side,
Position detecting means for detecting the position of the tailstock; storing the position of the tailstock at the time of completion of the setting of the tailstock according to the position detected by the position detecting means; There is a monitoring control means for comparing the position detected by the detecting means with the stored position, and detecting an abnormality when the comparison result is inconsistent.

According to a sixth aspect of the present invention, in the monitor and control apparatus for a tailstock of a machine tool according to the fifth aspect of the present invention, the monitor and control apparatus for the tailstock of the machine tool detects the pressing force of the tailstock. The monitoring control means stores the pressing force at the time of completion of the setting of the tailstock by the pressing force detected by the pressing force detecting means, and after the completion of the setting of the tailstock, The pressing force detected by the pressing force detecting means is compared with the stored pressing force, and if the comparison result is inconsistent, abnormality is detected.

According to a seventh aspect of the present invention, there is provided a monitor and control device for a tailstock of a machine tool according to the sixth aspect, wherein the main tailstock is driven by a servomotor. This is performed by a driven feed screw mechanism, and the pressing force detecting means detects the torque of the servomotor.

According to an eighth aspect of the present invention, there is provided a tailstock monitoring and control apparatus for a machine tool according to any one of the fifth to seventh aspects. The tailstock is advanced at high speed to the specified rough position, and after the rough positioning is completed, the tailstock is advanced at low speed.If the tailstock pressure reaches the specified pressure, the tailstock is stopped at low speed and the tailstock is stopped. Tailstock control for completing the setting of the carriage is performed, and the monitoring control means performs abnormality detection if the position detected by the position detection means exceeds the designated rough position during the high-speed forward movement. is there.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a machine tool to which a tailstock monitoring and control apparatus according to the present invention is applied. This machine tool has an X-axis base (not shown) movable on the bed 1 in the X-axis direction, and a movable column 3 movable on the X-axis base in the Y-axis direction. Has a spindle holder 5 movable in the Z-axis direction, and a spindle head 7 is attached to the spindle holder 5.

A main chuck head 9 is fixedly arranged on one side of the base 1 in the X-axis direction. The main chuck head 9 has a face plate (main chuck) that is driven to rotate around the X-axis.
11 is attached.

A tailstock 13 is provided on the other side of the base 1 in the X-axis direction so as to be movable in the X-axis direction. Tailstock 1
2 is opposed to the face plate 11 and, as shown in FIG. 2, is driven forward and backward in the X-axis (= u-axis) direction by a feed screw mechanism 17 that is rotationally driven by a u-axis servomotor 15.

FIG. 2 shows a control system of the tailstock. This control system includes a numerical controller 21 and a sequence controller 2
3. Position control unit 25, u-axis servo amplifier 27, u
A u-axis rotary encoder (motor position detector) 29 attached to the shaft servomotor 15.

In this control system, as tailstock control, the numerical controller 21 outputs a rough position command to the position control unit 25, and the position control unit 25 calculates the rough position command and the signal output from the u-axis rotary encoder 29. A current command corresponding to the detected deviation from the tailstock position is output to the u-axis servo amplifier 27, and the u-axis servo amplifier 27 controls the power of the u-axis servo motor 15 based on the current command. As a result, the tailstock 13 moves forward at a high speed to the specified rough position.

When the rough position is completed, the sequence controller 23 outputs a constant torque pressing command to the numerical controller 21. Thereby, after the rough positioning is completed, the tailstock 1
3 moves forward at a low speed, and when the torque (motor current value) of the u-axis servomotor 15 reaches a specified value, in other words, the tailstock 13
When the pressing force of the tailstock 13 reaches the specified pressing force, the tailstock 13 stops moving at low speed and the setting of the tailstock 13 is completed. After the tailstock 13 has been set, the u-axis servomotor 15 continues to be driven with the specified torque. Thereby, the work is pressed from the opposite side of the face plate 11 by the pressing force specified by the forward drive of the tailstock.

The detection of the torque of the u-axis servo amplifier 27 is performed by detecting the u-axis servo motor current by an ammeter 31 incorporated in the u-axis servo amplifier 27.

The sequence control device 23 incorporates a monitoring control means 33. The monitoring control means 33 is actually embodied by execution of Soutwew,
During high-speed advance for rough positioning, if the tailstock position detected by the u-axis rotary encoder 29 exceeds the specified rough position, abnormality detection is performed.

The monitor control means 33 stores the position of the tailstock at the time of completion of the setting of the tailstock 13 based on the position of the tailstock detected by the u-axis rotary encoder 29, and completes the setting of the tailstock 13. Thereafter, the tailstock position detected by the u-axis rotary encoder 29 is compared with the stored tailstock position, and if the comparison results do not match, abnormality detection is performed.

Further, the monitoring control means 33 uses the u-axis servomotor current detected by the ammeter 31 when the tailstock 13 has been set, to detect the u-axis servomotor current (u-axis) when the tailstock 13 has been set. (Torque of the servomotor 15 = pressing force of the tailstock 13), and after the tailstock setting is completed, the u-axis servomotor current detected by the ammeter 31 serving as the pressing force detecting means and the stored current are stored. The current is compared with the current of the u-axis servo motor, and if the comparison result is inconsistent, abnormality is detected.

FIG. 3 shows the processing flow of tailstock monitoring control.

In this processing flow, first, the tailstock 13 is advanced at high speed for rough positioning (step S1).
0). In this rough positioning, the tailstock position is monitored by a signal output from the u-axis rotary encoder 29 (step S11). If the tailstock position exceeds the specified rough position (rough position over), abnormality detection determination is made. Do. In this case, an alarm for stopping the machine and outputting a rough position error is issued (step S12).

On the other hand, when the tailstock position stops at the rough position, in other words, when the rough positioning is completed, the tailstock 13 is advanced forward at a low speed (step S13). The motor current (torque) is monitored based on the detected u-axis servo motor current (step S1).
4).

When the motor current reaches the specified value, in other words, when the pressing force of the tailstock reaches the specified pressing force, the tailstock 13 is stopped at a low speed and the tailstock 13 is set. Upon completion (step S15), the output signal of the u-axis rotary encoder 29 at this time is stored as a set completion position (step S16), and the output value of the ammeter 31 at this time is stored as a set completion current value (step S16). Step S17).

Thus, thereafter, until machining is completed (step S21), the u-axis servomotor 15 is continuously driven at the specified current value, and the tailstock position is monitored by the signal output from the u-axis rotary encoder 29, and (Step S18), the motor current (torque) is monitored based on the u-axis servo motor current detected by the ammeter 31 (Step S19).

In tailstock position monitoring, the tailstock position based on the signal output from the u-axis rotary encoder 29 is compared with the stored set completion position, and if the comparison results do not match, an abnormality is detected. . In this case, a machine stoppage and tailstock position abnormality alarm output are performed (step S).
20).

In the motor current monitoring, the u-axis servo motor current detected by the ammeter 31 is compared with the set completion current value, and if the comparison results do not match, an abnormality is detected. Also in this case, the alarm output of the machine stoppage and the tailstock position abnormality is performed (step S20).

It should be noted that in this embodiment, abnormality detection by tailstock position monitoring and abnormality detection by motor current monitoring have an OR relationship.

By the monitoring control as described above, it is accurately detected that the work position is shifted or the work is deformed, and the processing defect is avoided.

In the above embodiment, the feed screw mechanism is used as the tailstock feed mechanism. However, the present invention is not limited to this. A feed mechanism such as a pinion type may be used.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to this, and various embodiments may be made within the scope of the present invention. The possibilities will be clear to the skilled person.

[0035]

As will be understood from the above description, according to the method and apparatus for monitoring and controlling a tailstock of a machine tool according to the first and fifth aspects of the present invention, the position of the tailstock is controlled by a rotary encoder. The position of the tailstock at the time of completion of the setting of the tailstock is stored by the position detected by the position detection means, and the position detected by the position detection means after the completion of the setting of the tailstock. Is compared with the stored position, and if the comparison result is inconsistent, an abnormality is detected. Therefore, it is accurately detected that the work position has been shifted or the work has been deformed, and the occurrence of machining defects is prevented beforehand. can do.

According to the method and the apparatus for monitoring and controlling a tailstock of a machine tool according to the second and sixth aspects, the pressing force of the tailstock is detected by the pressing force detecting means, and further detected by the pressing force detecting means. The pressing force at the time of the setting of the tailstock is stored by the pressing force to be applied, and the pressing force detected by the pressing force detecting means after the completion of the setting of the tailstock is compared with the stored pressing force. If the results do not match, abnormality detection is performed, so that a double check is performed to determine whether a work position shift or a work deformation has occurred, and the occurrence of processing defects can be more reliably avoided.

According to the method and the apparatus for monitoring and controlling a tailstock of a machine tool according to the third and seventh aspects, the tailstock is driven by a feed mechanism which is rotationally driven by a servomotor. Detection of servo motor torque (motor current)
Since the detection is performed by the detection, the pressing force can be accurately detected without requiring a special detector, and the monitoring control can be accurately performed.

According to the method and apparatus for monitoring and controlling a tailstock of a machine tool according to the fourth and eighth aspects, the tailstock is advanced at a high speed to a specified rough position, and after the rough positioning is completed, the tailstock is moved at a low speed. When the tailstock reaches the specified pressing force, the tailstock is stopped from moving forward at a low speed to complete the setting of the tailstock, and is detected by the position detecting means during the high speed movement. If the position exceeds the specified rough position, abnormality detection is performed, so that the occurrence of processing failure due to the rough position failure can be avoided.

[Brief description of the drawings]

FIG. 1 is a front view showing a machine tool to which a tailstock monitoring control device according to the present invention is applied;

FIG. 2 is a block diagram showing one embodiment of a tailstock control system to which the monitoring control device according to the present invention is applied;

FIG. 3 is a flowchart showing a processing flow of monitoring control in the tailstock monitoring control method and apparatus according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 bed 3 movable column 5 spindle holder 7 spindle head 9 main chuck head 11 face plate 13 tailstock 15 u-axis servomotor 17 feed screw mechanism 21 numerical controller 23 sequence controller 25 position control unit 27 u-axis servo amplifier 27 29 u-axis rotary encoder 31 ammeter 33 monitoring control means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaaki Mizozono 2068-3 Ooka, Numazu-shi, Shizuoka Toshiba Mechanical Company Numazu Office (72) Inventor Yu Ito 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo 1 Kobe Plant, Kawasaki Heavy Industries, Ltd. (72) Inventor Masahiro Awai 3-1-1, Higashikawasaki-cho, Chuo-ku, Kobe City, Hyogo Prefecture Inside Kobe Plant, Kawasaki Heavy Industries, Ltd. (72) Atsushi Maruyama, Chuo-ku, Kobe City, Hyogo Prefecture 3-1-1 Higashi-Kawasaki-cho, Kobe Plant, Kawasaki Heavy Industries, Ltd. (72) Inventor Hisanori Ichinomiya 3-1-1, Higashi-Kawasaki-cho, Chuo-ku, Kobe-shi, Hyogo F-term (reference) 3C001 KA01 KB01 SA01 TA01 TB01 TB06 3C045 FE01 HA05

Claims (8)

[Claims] 1. A tailstock monitor and control method for a machine tool in which a work is pressed from a side opposite to the main chuck by a pressing force designated by a forward drive of a tailstock disposed opposite to a main chuck, comprising: The position of the tailstock is detected by position detection means, and the position of the tailstock at the time of completion of setting of the tailstock is stored by the position detected by the position detection means. Comparing the position detected by the method with the stored position, and detecting an abnormality when the result of the comparison is inconsistent. 2. A tailstock press force is detected by a press force detecting means, and a press force at the time of completion of setting of the tailstock is stored by the press force detected by the press force detecting means. The method according to claim 1, wherein after the completion of the setting, the pressing force detected by the pressing force detecting means is compared with the stored pressing force, and when the comparison result is inconsistent, abnormality detection is performed. The method for monitoring and controlling a tailstock of a machine tool according to the above. 3. The tailstock is driven by a feed mechanism rotated by a servomotor, and the pressing force detecting means detects the torque of the servomotor. The method for monitoring and controlling a tailstock of a machine tool according to the above. 4. The tailstock is advanced at a high speed to a specified rough position, and after the rough positioning is completed, the tailstock is advanced at a low speed.
When the pressing force of the tailstock becomes the specified pressing force, the tailstock is stopped at a low speed to complete the setting of the tailstock, and the position detected by the position detecting means at the time of the high speed movement is determined. 4. The method of monitoring and controlling a tailstock of a machine tool according to claim 1, wherein an abnormality is detected if the specified rough position is exceeded. 5. A tailstock monitor and control device for a machine tool, wherein a work is pressed by a specified pressing force from a side opposite to the main chuck by a tailstock arranged opposite to the main chuck. A position detecting means for detecting the position of the tailstock at the time of completion of the setting of the tailstock by the position detected by the position detecting means, and is detected by the position detecting means after the completion of the setting of the tailstock. A monitor control means for comparing the position of the tailstock with the stored position and detecting an abnormality when the result of the comparison is inconsistent with each other. . 6. A pressing force detecting means for detecting a pressing force of the tailstock, wherein the monitoring control means detects the pressing force when the setting of the tailstock is completed by the pressing force detected by the pressing force detecting means. And comparing the pressing force detected by the pressing force detecting means with the stored pressing force after completion of the setting of the tailstock, and performing an abnormality detection if the comparison result is inconsistent. The monitor control device for a tailstock of a machine tool according to claim 5, characterized in that: 7. The tailstock is driven by a feed screw mechanism which is driven to rotate by a servomotor, and the pressing force detecting means detects a torque of the servomotor. 2. A monitor and control device for a tailstock of a machine tool according to claim 1. 8. The tailstock is advanced at a high speed to a designated rough position, and after the rough positioning is completed, the tailstock is advanced at a low speed.
When the pressing force of the tailstock reaches the specified pressing force, the tailstock control for stopping the low speed advancement of the tailstock and completing the setting of the tailstock is performed. 8. The monitor control of a tailstock of a machine tool according to claim 5, wherein an abnormality is detected when a position detected by said position detection means exceeds a designated rough position during forward movement. apparatus.