JP2869729B2 - Processing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a processing machine, particularly to a processing machine provided with a magnetic bearing spindle.

[Summary of the Invention]

The present invention makes it possible to easily and precisely control and machine a workpiece to a desired shape by electrically controlling the magnetic force of an electromagnet of a magnetic bearing spindle and reciprocating a rotating spindle in a cutting direction. .

[Conventional technology and problems]

In a conventional processing machine, for example, a grinder, for example, as shown in FIG. 13, when there is a concave portion 2 such as a hole in a part of the inner peripheral hole 1a in the circumferential direction of the work 1, There is a problem that the inner peripheral surfaces 4a and 4b before and after the concave portion 2 are excessively shaved and sagged, so that the entire inner peripheral hole 1a of the work 1 cannot be ground to a perfect circle.

As a countermeasure against such a problem, there is a method in which the following is provided on the work table side or the grindstone table side.

(1) Use a hydraulic piston to cut the grindstone, so that the grindstone escapes only at the recess 2 in synchronization with the rotation of the work.
Change hydraulic pressure.

(2) The cam mechanism is used to cut the grindstone, and the cam is used to change the cut so that the grindstone escapes only at the concave portion 2 in synchronization with the rotation of the work.

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

However, such a method has the following disadvantages. That is, in the above method (1), it is complicated and expensive to perform the cutting control in units of microns, and smooth movement cannot be realized due to the viscous resistance of the oil and the stick-slip of the oil seal. .

In the method (2), it is necessary to precisely rotate the camshaft in order to properly adjust the eccentricity and the rotation angle of the cam, which increases the cost. Further, a delay due to the inertia of the cam occurs, and the response of the control is reduced.

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

[Means for solving the problem]

Therefore, a processing machine according to the present invention includes a magnetic bearing spindle having a rotary spindle that is levitated and supported by an electromagnet to solve the above-described problem, and a processing machine provided with a tool at an end of the rotary spindle. A reciprocating means for electrically controlling the magnetic force of the electromagnet to reciprocate the rotary spindle in a machining cutting direction based on a control signal is provided.

[Action]

According to the processing machine having such a configuration, the work can be easily controlled to a predetermined shape by performing the processing while electrically controlling the magnetic force of the electromagnet of the magnetic bearing spindle and reciprocating the rotating spindle in the processing cutting direction. The workpiece can be precisely machined into a desired shape.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 7 are views showing a first embodiment of a processing machine according to the present invention.

In the internal grinding machine 10 shown in FIG. 1, reference numeral 11 denotes a magnetic bearing spindle, and the magnetic bearing spindle 11 is fixedly supported on a grindstone table 14. The grindstone table 14 is slidable in the axial direction by a motor 23 along a rail 17 on a bed frame 19. Reference numeral 20 denotes a chuck device for fixedly supporting the work 21. The work 21 fixed to the chuck device 20 is driven to rotate by a motor 24, and the chuck device 20 is fixed and supported on a work table 22. Work table 22 is rail 18 on bed frame 19
Is slidable in a direction perpendicular to the grinding wheel table 14 by a motor 25 along the axis.

Next, in the magnetic bearing spindle 11 shown in FIG.
Reference numeral 12 denotes a main body constituting the outer shape, and a rotary spindle 13 is disposed on an axis of the main body 12. Around the both ends of the rotary spindle 13, radial electromagnets 15, 16 for magnetically levitating the rotary spindle 13 to support the bearing are provided on the main body 1.
It is provided on two sides. A motor 28 for rotationally driving the rotary spindle 13 is provided at an intermediate portion in the longitudinal direction of the rotary spindle 13.
A pair of axial electromagnets 31 and 32 for restricting axial displacement of the rotary spindle 13 via a flange portion 30 of the rotary spindle 13 are provided on the main body 12 side.

In the vicinity of the radial electromagnet 15, a position sensor 34 for detecting the position of the rotary spindle 13 in the radial direction is provided on the body 12 side.
A position sensor 35 for detecting the radial position of 13 is provided on the main body 12 side. In the vicinity of the step 13a formed on one end side (left end side in the figure) of the rotary spindle 13, a position sensor 36 for detecting the axial position of the rotary spindle 13 is provided on the main body 12 side.

Radial electromagnets 15, 16 are provided around the small diameter portion 13b on one end side and the small diameter portion 13c on the other end side of the rotary spindle 13, respectively.
When the power is turned off and the magnetic levitation force of the rotary spindle 13 is lost, protective bearings 38 and 39 that directly support the rotary spindle 13 via the small-diameter portions 13b and 13c are provided on the main body 12 side. At the tip of the small diameter portion 13b of the rotating spindle 13, the work is performed by rotating the rotating spindle 13.
A cylindrical grindstone 41 for grinding the 21 is provided.

As shown in FIG. 3, each of the radial electromagnets 15 and 16 is provided in the vicinity of the rotary spindle 13 in the upper, lower, left and right directions, one each, and a total of four (15a to 15d, 16a to 16d). Such a magnetic bearing spindle 11 is electrically controlled so that the magnetic forces of the left radial electromagnets 15b, 16b and the left radial electromagnets 15d, 16d are different, for example, so that the rotary spindle 13 can be rotated left or right in the drawing. The crab can be translated by a predetermined distance.

Internal grinding machine having such a magnetic bearing spindle 11
10, a synchronous detector 55 for detecting a predetermined rotational position of the work 21 and a signal from the synchronous detector 55 are input to perform a predetermined procedure, as shown in FIG. A CPU 50 that outputs a signal to a magnetic bearing control device 47 that controls the spindle 11 is provided.

Internal grinding machine equipped with such a magnetic bearing spindle 11
The ten control processing methods will be described with reference to the drawings. For example, as shown in FIG. 6, it is assumed that a hole 21b in the radial direction is drilled in the middle of the length of the annular work 21 in the longitudinal direction. As shown in FIG. 4, a projection 44 that rotates together 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 the hole 21b can be detected. A synchronization detector 55 for detecting proximity and passage is provided on the stationary work table 22 side.

First, the work 21 of the chuck device 20 is rotated by the motor 24, and the grindstone 41 is rotated by the rotation spindle 13 of the magnetic bearing spindle 11, and the grindstone 41 is rotated by the motor 23 through the magnetic bearing spindle 11. Face 21a
Let go inside. Next, the chuck device is driven by the motor 25.
The workpiece 21 is moved in the radial direction through the
Then, the work 21 is cut and the grinding operation is started. Since the workpiece 21 has the hole 21b, the inner peripheral surface 21a cannot obtain a good roundness due to the influence of merely grinding.

Therefore, first, the synchronization detector 55 detects the position of the hole 21b and inputs the detection timing to the CPU 50 (P1 in FIG. 5). The CPU 50 reads the return amount stored in advance based on the timing (P2 in FIG. 4), and outputs a signal corresponding to the return amount according to the value of the cutting amount accompanying the progress of the grinding cycle. Then, when the hole 21b of the work 21 comes to the grindstone 41, the CPU 50 sends the magnetic force of the electromagnets 15, 16 of the magnetic bearing spindle 11 to the magnetic bearing control device 47 so that the rotating spindle 13 returns to the center direction of the work 21 by a predetermined amount. Control (P3). Since the phase difference between the detection tip of the synchronization detector 55 and the grindstone 41 is set to a predetermined amount in advance, the rotation spindle 13 moves after a predetermined time elapses after the synchronization detector 55 detects the phase of the hole 21b. The CPU 50 controls the magnetic bearing control device 47.

By reciprocating the rotating spindle 13 of the magnetic bearing spindle 11 in the machining cutting direction in this manner, the behavior of the axis of the rotating spindle 13 is changed to the workpiece 21 at the hole 21b as shown in the Lissajous waveform in FIG. And the inner peripheral surface 21a can be ground with good roundness. Therefore, the synchronization detector 5
5. The CPU 50 constitutes reciprocating means for electrically controlling the magnetic force of the electromagnet to reciprocate the rotary spindle in the machining cutting direction based on the control signal.

8 and 9 show a second embodiment of the present invention. In the second embodiment, as shown in FIG. 8, the inner surface grinding machine 10 having the magnetic bearing spindle 11 is different from the first embodiment in that the synchronous detector 55 is replaced by the size of the inner peripheral surface 21a of the work 21. A sizing device 45 for detecting the shape and shape is provided. Then, the sizing device 45 is set such that the detection tip portion comes to a position where the groove 21c of the work 21 can be detected.

In the second embodiment, the sizing device 45 first detects the groove 21c and inputs the detection signal to the CPU 50 (P in FIG. 9).
1). The CPU 50 calculates the cut correction amount from the width of the groove 21c and the like based on the signal (P2 in the same figure), and also calculates the radial movement amount (return amount) of the rotating spindle 13 of the magnetic bearing spindle 11 of the work 21. (P3 in the same figure). Then, the CPU 50 outputs a signal to the magnetic bearing control device 47 based on the result, and when the groove 21c of the work 21 comes to the grindstone 41, the magnetic bearing control is performed so that the rotating spindle 13 returns to the center direction of the work 21 by a predetermined amount. Electromagnets 15 and 16 of the magnetic bearing spindle 11 in the device 47
Is electrically controlled (P4 in the same figure). Since the phase difference between the detection tip of the sizing device 45 and the grindstone 41 is set to a predetermined amount in advance, the CPU 50 moves the rotating spindle 13 a predetermined time after the sizing device 45 detects the groove 21c.
Controls the magnetic bearing control device 47.

By reciprocating the rotating spindle 13 of the magnetic bearing spindle 11 in the machining cutting direction in this manner, the behavior of the axis of the rotating spindle 13 is changed to the work 21 at the groove 21c as shown by the Lissajous waveform in FIG. And the inner peripheral surface 21a can be ground with good roundness. Therefore, in the second embodiment, the setting device 45 and the CPU 50 constitute reciprocating means for reciprocating the rotary spindle in the machining cutting direction based on the control signal by electrically controlling the magnetic force of the electromagnet.

10 to 12 show a third embodiment of the present invention. In the third embodiment, as shown in FIG. 10, a rotary encoder 52 for detecting the rotation angle of the work 21 and a predetermined shape to be obtained by grinding the work 21 are added to the CPU 50 of the second embodiment.
In addition, an input means 54 for storing and inputting the data is additionally provided. This third embodiment is intended to grind the inner peripheral surface 21a of the work 21 into a predetermined shape (for example, a diaper shape) by giving a behavior such as a Lissajous waveform shown in FIG. 12 to the rotary spindle 13. It is.

First, a rotating spindle 13 as shown in FIG.
A predetermined shape (figure) desired to be obtained by grinding the workpiece 21 is input according to the axis locus of the workpiece.
Calls that figure signal from (P1 in FIG. 11). Work 21
At the time of grinding, the rotary encoder 52 detects the rotation angle of the work 21 (P2 in the same figure), and the sizing device 45 detects the dimensional change of the inner peripheral surface 21a of the work 21 (P3 in the same figure). Is input to the CPU 50. The CPU 50 calculates the phase based on the respective signals (P4 in the same figure), calculates the amount of incision 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. Calculation (P6 in the same figure). The CPU 50 outputs a signal to the magnetic bearing control device 47 based on the result, and the magnetic bearing control device 47 sends the electromagnets 15, The 16 magnetic forces are electrically controlled (P7 in the same figure).

In this way, by reciprocating the rotating spindle 13 of the magnetic bearing spindle 11 in the machining cut direction, the behavior of the axis of the rotating spindle 13 is controlled like a Lissajous waveform in FIG. Can be ground to a predetermined shape. Therefore, in the third embodiment, the sizing device 45, the CPU 50, the rotary encoder 52, and the input means 54 reciprocate the rotary spindle in the machining cutting direction based on the control signal by electrically controlling the magnetic force of the electromagnet. And a reciprocating means for causing the reciprocating means.

In the above embodiment, the processing machine is described as an internal grinding machine, but may be used for an external grinding machine.
Further, the present invention may be applied to other processing machines such as a lathe and a milling machine other than the grinding machine.

Further, the predetermined shape of the inner peripheral surface of the work in the third embodiment may be any shape such as an ellipse or a square, in addition to a tapered shape.

〔The invention's effect〕

As described 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 processed in the processing cut direction while reciprocating based on the control signal. , It is possible to easily process the workpiece while controlling it to the specified shape.
The workpiece can be precisely machined into a desired shape.

[Brief description of the drawings]

1 to 7 are views showing a first embodiment of a processing machine according to the present invention. FIG. 1 is a perspective view of an internal grinding machine, FIG. 2 is a side sectional view of a magnetic bearing spindle, and FIG. Front sectional view, FIG. 4 is a side view of the internal grinding machine, FIG. 5 is a flowchart, FIG. 6 is a sectional front view of a workpiece to be machined,
FIG. 7 is a Lissajous waveform diagram showing the behavior of the axis of the rotating spindle of the magnetic bearing spindle, and FIGS.
FIG. 8 is a view showing an embodiment, FIG. 8 is a side view of an internal grinding machine, FIG. 9 is a flowchart, FIG. 10 to FIG. 12 are views showing a third embodiment of the present invention, FIG. FIG. 11 is a side view of the internal grinding machine, FIG. 11 is a flowchart, FIG. 12 is a Lissajous waveform diagram showing the behavior of the axis of the rotating spindle of the magnetic bearing spindle, and FIG. 13 is a sectional view of a conventional work. 10 Internal grinding machine 11 Magnetic bearing spindle 12 Body 13 Rotating spindle 13a Step 13b, 13c Small diameter section 14 Grinding stone table 15 (15a to 15d) Radial electromagnet 16 ( 16a to 16d) Radial electromagnets 17, 18 Rail 19 Bed bed 20 Chuck device 21 Work 21a Inner peripheral surface 21b Hole 21c Groove 22 Work table 23 to 25 , 28 Motor 30 Flange 31,32 Axial electromagnet 34-36 Position sensor 38,39 Protective bearing 41 Grindstone 44 Projection 45 Sizing device 47 Magnetic bearing Control device 50 CPU 52 Rotary encoder 54 Input means 55 Synchronous detector

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B24B 47/10-47/12 B24B 41/04 B23Q 15/013

Claims (4)

(57) [Claims] 1. A magnetic bearing spindle having a rotary spindle which is levitated and supported by an electromagnet, a tool provided at an end of the rotary spindle, and a workpiece having a concave portion on a part of a processing surface in a rotating state. A processing device that cuts the work with the tool, and that calculates and controls a cut amount according to a detection signal of the recess detection device. A CPU that outputs a control signal to control the floating position of the rotary spindle according to the output of the CPU. When input, a control signal for instructing a predetermined return amount to the magnetic bearing control device is output, and this output is provided at the end of the rotary spindle. A processing machine, wherein a floating position of the rotary spindle is controlled so that a tool escapes at the position of the concave portion. 2. The processing machine according to claim 1, wherein said recess detecting means is a synchronous detector. 3. The processing machine according to claim 1, wherein said recess detecting means is a sizing device. 4. A means for controlling a floating position of the rotary spindle so that a tool provided at an end of the rotary spindle escapes at the position of the recess is performed through a phase calculator. 4. The processing machine according to any one of claims 1 to 3.