JPH01234161A - Processing machine - Google Patents

Abstract

PURPOSE:To process a work easily and precisely into a desired form by providing a reciprocatory motion means for controlling the magnetic force of an electromagnet of a magnetic shaft bearing spindle electrically and reciprocating a rotary spindle in a processing cut direction based on a control signal. CONSTITUTION:A synchronization detector 55 detects the position of a hole 21b of a work 21, and its detection timing is inputted to a CPU 50. This CPU 50 reads a preliminarily memorized return quantity based on the timing, and outputs a signal corresponding to a return quantity based on the value of a cut quantity following the advance of a cutting cycle. The CPU 50 operates a magnetic shaft bearing controller 47 for controlling the magnetic force of constant magnets 15, 16 of a magnetic shaft bearing spindle 11 electrically to make a rotary spindle 13 return toward the center of the work 21 for a predetermined quantity when the hole 21b of the work 21 gets to a grindstone 41. By this reciprocating the rotary spindle 13 of the magnetic shaft bearing spindle 11 in the processing cut direction, cutting work can be performed at a good roundness for an inner circumferential surface 21a of the hole 21b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a processing machine, in particular a processing machine with a magnetic bearing spindle.

[Summary of the invention]

The present invention electrically controls the magnetic force of the electromagnet of the magnetic bearing spindle to reciprocate the rotary spindle in the cutting direction, thereby making it possible to easily precisely control and machine a workpiece into a desired shape. .

[Conventional technology and problems]

In a conventional processing machine, for example, a grinding machine, if there is a hole-like recess 2 in a part of the inner peripheral hole 1a of the workpiece 1 in the circumferential direction as shown in FIG. There was a problem in that the inner circumferential surfaces 4a and 4b at the front and rear of the recess 2 were ground too much and became dull, making it impossible to grind the entire inner circumferential hole 1a of the workpiece 1 into a perfect circle.

As a countermeasure to this problem, there is a method of providing the following on the work table side or the grindstone table side.

(1) A hydraulic piston is used to cut the grinding wheel, and the hydraulic pressure is changed so that the grinding wheel escapes only at the recess 2 in synchronization with the rotation of the workpiece.

(2) Use a cam mechanism to cut the grindstone so that the grindstone only escapes from the recess 2 in synchronization with the rotation of the workpiece.1. The depth of cut is changed by a cam.

(3) A ball screw mechanism is used to cut the grindstone, and the direction of rotation of the ball screw is changed in synchronization with the rotation of the workpiece so that the grindstone escapes only at the recess 2.

However, the above method has the following drawbacks. In other words, in the method (1) above, if you try to control the cutting depth in micron units, it will be complicated.
It is expensive, and smooth movement cannot be achieved due to the viscous resistance of the oil and the stick-slip of the oil seal.

Furthermore, in the method (2) above, it is necessary to precisely rotate the camshaft in order to properly adjust the eccentricity I and rotation angle of the cam, which increases the cost. Furthermore, a delay occurs due to the inertia of the cam, resulting in a decrease in control responsiveness.

Furthermore, in the method (3) above, similarly to (2) above, a control response delay occurs due to the inertia of the ball screw. That is, it is difficult to move objects with a large mass such as a work table or a grindstone table in a short period of time.

[Means for solving problems]

Therefore, in order to solve the above problems, the processing machine according to the present invention is equipped with a magnetic bearing spindle having a rotating spindle that is floated by an electromagnet and supported by a bearing, and a tool is provided at the end of the rotating spindle. The apparatus is configured to include a reciprocating means for reciprocating the rotary spindle in the processing cutting direction based on a control signal by electrically controlling the magnetic force of the electromagnet.

[Effect]

According to the machining machine with such a configuration, the magnetic force of the electromagnet of the magnetic bearing spindle is electrically controlled and the rotary spindle is reciprocated in the direction of the machining cut while machining, thereby easily controlling the workpiece into a predetermined shape. The workpiece can be precisely machined into the desired shape.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1 to 7 are diagrams showing a first embodiment of a processing machine according to the present invention.

In the internal grinding machine 10 shown in FIG. 1, 11 is a magnetic bearing spindle, and this magnetic bearing spindle 11 is fixedly supported on a grindstone table 14. As shown in FIG. The grindstone table 14 can be slid along a rail 17 on a bed frame 19 in the axial direction by a motor 23. Reference numeral 20 denotes a chuck device that fixedly supports a workpiece 21. The workpiece 21 fixed to the chuck device 20 is rotationally driven by a motor 24, and the chuck device 20 is fixedly supported on a work table 22. work table 22
is the motor 2 along the rail 18 on the bed frame 19.
5 allows it to slide in the direction perpendicular to the grindstone table 14.

Next, in the magnetic bearing spindle 11 shown in FIG.
Reference numeral 12 denotes a main body that constitutes the outer shape of the main body 12. A rotary spindle 13 is disposed on the axis of the main body 12. The rotary spindle 13 is magnetically levitated and supported by bearings around both ends of the zero-rotation spindle 13. Radial electromagnet 15
．． A motor 28 for rotating the rotating spindle 13 and a motor 28 for rotating the rotating spindle 13 and a motor 28 for rotating the rotating spindle 13 at the intermediate portion in the longitudinal direction of the zero-rotating spindle 13 provided on the main body 12 side, and a motor 28 for rotating the rotating spindle 13 via a flange portion 30 of the rotating spindle 13 are provided. A pair of axial electromagnets 31 and 32 for regulating displacement in the axial direction are provided on the main body 12 side.

A position sensor 34 that detects the radial position of the rotating spindle 13 is provided on the main body 12 near the radial electromagnet 15, and a position sensor 34 that also detects the radial position of the rotating spindle 13 is provided near the radial electromagnet 16. 3
5 is provided on the main body 12 side. Also, a stepped portion 13a formed on one end side (left end side in the figure) of the rotating spindle 13
A position sensor 36 for detecting the axial position of the rotary spindle 13 is provided on the main body 12 near the main body 12 .

When the radial electromagnets 15, 16 are de-energized and the magnetically levitated blade of the rotating spindle 13 is lost, a small diameter portion 13b is formed around the small diameter portion 13b on one end side of the rotating spindle 13 and the small diameter portion 13c on the other end side, respectively. , 13c are provided on the main body 12 side with protective bearings 38 and 39 that directly support the rotary spindle 13. When the rotary spindle 13 rotates, A cylindrical grindstone 41 for grinding the workpiece 21 is provided.

As shown in FIG. 3, the radial electromagnets 15 and 16 are located near the top, bottom, left and right sides of the rotating spindle 13, respectively.
A total of four (15a to 15d, 16a to 16d) are provided. Such a magnetic bearing spindle 11 can be operated by electrically controlling the magnetic forces of the left radial electromagnets 15b, 16b and the right radial electromagnets 15d, 16d to make them different, so that the rotating spindle 13 can be rotated to either the left or right in the figure. It is possible to move in parallel by a predetermined distance.

As shown in FIG. 4, the internal grinding machine 10 having such a magnetic bearing spindle 11 further includes a synchronous detector 55 for detecting a predetermined rotational position of the workpiece 21, and a signal from the synchronous detector 55 is input. and a magnetic bearing control device 4 that controls the magnetic bearing spindle 11 after performing work in a predetermined procedure.
The computer 7 includes a CPU 50 that outputs a signal to the computer 7.

A method of controlling the internal grinding machine 10 equipped with such a magnetic bearing spindle 11 will be explained based on the drawings.

For example, suppose that an annular workpiece 21 with a radial hole 21b formed in the middle in the length direction is to be ground, as shown in FIG.

As shown in FIG. 4, a protrusion 44 that rotates with the workpiece 21 is provided at the same phase position as the hole 21b or at a position rotated by a predetermined phase so that such a hole 21b can be detected. A synchronization detector 55 for detecting the passing of a nearby object 9 is provided on the stationary work table 22 side.

First, the workpiece 21 of the chuck device 20 is rotated by the motor 24, and the grindstone 41 is rotated via the rotating spindle 13 of the magnetic bearing spindle 11.
The grinding wheel 41 is moved inside the inner peripheral surface 21a of the workpiece 21 via the magnetic bearing spindle 11. Next, the motor 25 moves the workpiece 21 in its radial direction via the chuck device 20, and At the same time, the workpiece 21 is cut and the grinding work begins. Since the workpiece 21 has the hole 21b, the inner circumferential surface 21a cannot obtain a good roundness by simply grinding.

Therefore, the synchronization detector 55 first detects the position of the hole 21b and inputs the detection timing to the CPU 50 (
Pi in FIG. 5), the CPU 50 reads out the previously memorized return amount based on the timing.
2) A signal corresponding to the return amount is output in accordance with the value of the depth of cut as the grinding cycle progresses. and CPU50
When the hole 21b of the workpiece 21 reaches the grindstone 41, the magnetic force of the electromagnets 15 and 16 of the magnetic bearing spindle 11 is electrically applied to the magnetic bearing control device 47 so that the rotary spindle 13 returns a predetermined amount toward the center of the workpiece 21. Control (P3)
, since the phase difference between the detection tip of the synchronous detector 55 and the grinding wheel 41 is set to a predetermined amount, the synchronous detector 55
The CPU 50 controls the magnetic bearing control device 47 so that the rotary spindle 13 moves after a predetermined period of time has elapsed since the phase of the hole 21b was detected.

By reciprocating the rotary spindle 13 of the magnetic bearing spindle 11 in the cutting direction, the behavior of the axis of the rotary spindle 13 changes as shown in the serge waveform in FIG. The inner circumferential surface 21a can be ground with good roundness. Therefore, the synchronization detector 55. The CPU 50 constitutes a reciprocating means that reciprocates the rotary spindle in the processing cutting direction based on a control signal by electrically controlling the magnetic force of the electromagnet.

FIG. 8.9 shows a second embodiment of the present invention. In this second embodiment, as shown in FIG. Instead of the synchronization detector 55, the inner peripheral surface 2 of the workpiece 21
A fixed size bag w145 is provided to detect the size and shape of 1a. Then, the fixed size bag W45 is set so that the detection tip is located at a position where the arm 21c of the workpiece 21 can be detected.

In this second embodiment, the sizing device 45 first detects the eraser 21c and inputs the detection signal to the CPU 50 (9th
Pl in the figure), the CPU 50 uses the system 21 based on the signal.
In addition to calculating the cutting correction amount from the width of c (see P2 in the same figure), the rotary spindle 13 of the magnetic bearing spindle 11
The CPU 50 calculates the radial movement Ik (return amount) of the workpiece 21 (P3 in the figure), and based on the result, the CPU 50 outputs a signal to the magnetic bearing control device 47, so that the groove 21c of the workpiece 21 is aligned with the grindstone 41. The magnetic bearing control device 47 controls the electromagnets 15 and 16 of the magnetic bearing spindle 11 so that the rotary spindle 13 returns to the center of the workpiece 21 by a predetermined amount when the rotating spindle 13 reaches the specified position.
Electrically control the magnetic force of (P4 in the same figure), sizing device 4
Since the phase difference between the detection tip of No. 5 and the grinding wheel 41 is set by a predetermined person in advance, the CPU 50 controls the magnetic bearing control device so that the rotary spindle 13 is moved after a predetermined time has elapsed after the sizing device 45 detects the groove 21c. 47.

By reciprocating the rotary spindle 13 of the magnetic bearing spindle 11 in the cutting depth direction in this manner, the behavior of the axis of the rotary spindle 13 changes as shown in the serge waveform in FIG. 7J' in the direction of the center, making it possible to grind the inner peripheral surface 21a with good roundness. Therefore, in this second embodiment, the synchronization detector 55. CPtJ
Reference numeral 50 constitutes a reciprocating means for electrically controlling the magnetic force of the electromagnet to reciprocate the rotary spindle in the processing cutting direction based on a control signal.

10 to 12 show a third embodiment of the present invention,
As shown in FIG. 10, this third embodiment adds a rotary encoder 52 for detecting the rotation angle of the workpiece 21 to the second embodiment, and a CPU for grinding the workpiece 21 to obtain a predetermined shape. An input means 54 for memorizing and inputting 0 is additionally provided. This second embodiment, for example,
By giving the rotating spindle 13 a behavior similar to the Lissajous waveform shown in FIG.
The purpose is to grind the material into a predetermined shape (for example, a rice ball shape).

First, a predetermined shape (figure) desired to be obtained by grinding the workpiece 21 according to the axis locus of the rotating spindle 13 as shown in FIG. Call (P in Figure 11)
l) During the grinding process of the workpiece 21, the rotary encoder 52 detects the rotation angle of the workpiece 21 (see P in the same figure).
2) The sizing device 45 detects the dimensional change of the inner circumferential surface 21a of the workpiece 21 (P3 in the same figure), and sends each signal to the CPU.
50. The CPU 50 calculates the phase based on each signal (P4 in the same figure), the amount of cutting correction (P5 in the same figure), and further calculates the amount of movement of the rotating spindle 13 of the magnetic bearing spindle 11 in the radial direction of the workpiece 21. (P6 in the figure), and the CPU 50 outputs a signal to the magnetic bearing control device 47 based on the result, and causes the magnetic bearing control device 47 to control the magnetic field so that the inner peripheral surface 21a of the workpiece 21 has the desired predetermined shape. Bearing spindle 11
The magnetic force of the electromagnets 15 and 16 is electrically controlled (P7 in the same figure).

In this way, by reciprocating the rotary spindle 13 of the magnetic bearing spindle 11 in the cutting direction, the behavior of the axis of the rotary spindle 13 is controlled as shown in the surge waveform in FIG. 12, and the inner circumferential surface 21a It becomes possible to grind the material into a predetermined shape. Therefore, in this third embodiment, the synchronization detector 55. C
PU50, rotary encoder 52. The input means 54 is
By electrically controlling the magnetic force of the electromagnet, a reciprocating means is configured to reciprocate the rotary spindle in the processing cutting direction based on a control signal.

In the above embodiments, the processing machine is an internal grinder, but it may be used as an external grinder, or may be used in other processing machines other than the grinder, such as a lathe or a milling machine.

Further, the predetermined shape of the inner circumferential surface of the workpiece in the third embodiment may be any shape such as an ellipse, a square, etc. in addition to a rice ball shape.

〔Effect of the invention〕

As explained above, according to the processing machine of the present invention, by electrically controlling the magnetic force of the electromagnet of the magnetic bearing spindle, the rotary spindle is reciprocated in the processing cutting direction based on the control signal. The workpiece can be easily controlled and machined into a predetermined shape, and the workpiece can be precisely machined into the desired shape.

[Brief explanation of the drawing]

1 to 7 are views showing a first embodiment of a processing machine according to the present invention, in which FIG. 1 is a perspective view of an internal grinder, FIG. 2 is a side sectional view of a magnetic bearing spindle, and FIG. 4 is a side view of the internal grinder, FIG. 5 is a flowchart, FIG. 6 is a sectional front view of the workpiece to be machined, and FIG. 7 is the axial center of the rotating spindle of the magnetic bearing spindle. The Lissajous waveform diagram showing the behavior, Figure 8.9, is the second waveform diagram of the present invention.
FIG. 8 is a side view of an internal grinder, FIG. 9 is a flowchart, FIGS. 10 to 12 are views showing a third embodiment of the present invention, and FIG. FIG. 11 is a flowchart diagram, FIG. 12 is a Lissajous waveform diagram showing the behavior of the axis of a rotating spindle of a magnetic bearing spindle, and FIG. 13 is a sectional view of a conventional workpiece. 10... Internal grinder 11... Magnetic bearing spindle 12... Main body 13... Rotating spindle 13a... Step parts 13b, 13c... Small diameter portion 14... Grindstone table 15 (15a to 15d)... Radial electromagnet 16 (1
6a-16d)...Radial electromagnet 17.18...
...Rail 19...Bed frame 20...Chuck device 21...Work 21a...Inner peripheral surface 21b...Hole 21c...Erase 22... ...Work table 23-25.28...Motor 30...Flange portion 31.32...Axial electromagnet 34-36.
...Position sensor 38.39...Protection bearing 41...
・Whetstone 44... Protrusion 45... Sizing device 47... Magnetic bearing control device 50... CPU 52... Rotary encoder 54...Input means 55...Synchronous detector patent applicant Agent of Seiko Seiki Co., Ltd.
Seiko Electronics Co., Ltd. 15c (16c) Front view Fig. 3 Fig. 1 Flow + yard of FPI Fig. 5 Cross-sectional front view of 7-7 ko (r ('%l('J - 2 large scale example flow + Mart Figure 3 Figure 3 Example flow + 〒- Figure 11 Sodium size - Shoe 5 Keiform figure Figure 12 Wharf cross section Figure 13

Claims (1)

[Claims] In a processing machine equipped with a magnetic bearing spindle having a rotating spindle that is floated and supported by an electromagnet, and a tool is provided at an end of the rotating spindle, the rotating spindle is controlled by electrically controlling the magnetic force of the electromagnet. 1. A processing machine, comprising: a reciprocating means for reciprocating in a processing cutting direction based on a control signal, and controlling and processing a workpiece into a predetermined shape while reciprocating the rotary spindle.