JPH11226855A - Internal periphery spherical surface grinding method for workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make grinding possible in a short time. SOLUTION: In a position that the axis of a rotary shaft 25a of a cup grinding wheel 25 includes the center of rotation of a workpiece W and is separated by the prescribed dimension d from a second plane P2 orthogonal to a first plane P1, internal grinding is performed by relatively moving the cup grinding wheel 25 or the workpiece W in an axial direction of the rotary shaft 25a, the cup grinding wheel 25 is brought into slide contact with an internal periphery spherical surface of the workpiece W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for grinding an inner peripheral spherical surface of a work.

[0002]

2. Description of the Related Art Conventionally, when grinding the inner peripheral spherical surface of a substantially cylindrical work, it is performed as shown in FIG.

That is, while rotating the work W in the circumferential direction, the cup grindstone 25 is rotated and disposed on the inner periphery of the work W. In this case, the cup grindstone 25 has its rotating shaft 25
a is located in a second plane P2 orthogonal to the first plane P1 including the rotation center Wa of the workpiece W. Then, the work W is translated toward the cup grindstone 25. Thereby, the cup grindstone 25 is placed on the inner spherical surface of the workpiece W.
The outer peripheral edge of the end surface is in sliding contact, and the inner peripheral surface of the work W is spherically ground.

[0004]

However, the outer edge of the end face of the cup grindstone 25 is in sliding contact with the inner spherical surface of the work W at two positions A and B at the same time. For this reason, the contact pressure per unit area decreases, and the sharpness of the grindstone 25 deteriorates. In addition, when the sharpness of the grindstone 25 becomes poor, the cutting feed speed cannot be increased, and the cutting time becomes longer, resulting in an increase in cost.

Accordingly, it is a first object of the present invention to provide a method of grinding an inner peripheral spherical surface of a work which can be ground in a short time.

It is a second object of the present invention to provide a method for grinding the inner peripheral spherical surface of a work which can also perform highly accurate grinding having a desired surface roughness.

[0007]

According to the present invention, as a means for solving the first problem, a work having a substantially cylindrical shape and a spherical inner peripheral surface is rotated in a circumferential direction, while the work is rotated. A cup grindstone is provided on the inner periphery and rotated so that the rotation axis of the cup grindstone is orthogonal to the first plane including the rotation center of the work, and the cup grindstone or the work is relatively moved in the axial direction of the rotation shaft. In the method of grinding the inner peripheral spherical surface of a work in which the cup grindstone is slidably brought into contact with the inner peripheral spherical surface of the work by internally moving, the inner grinding is performed by rotating the cup grinding wheel with an axis of the workpiece. And at a position separated by a predetermined distance from a second plane orthogonal to the first plane.

[0008] The present invention further provides means for solving the second problem, wherein before the inner surface grinding is completed,
The inner surface is ground by moving in parallel so that the axis of the rotation axis of the cup grindstone is located in the second plane.

[0009]

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

FIG. 1 is a schematic diagram of a grinding apparatus to which an inner peripheral spherical grinding method according to the present invention is applied. This grinding device
The work comprises a work support 2 provided on the upper surface of the base 1 and a grindstone support 3.

The work support 2 is driven by an infeed AC servomotor 4 to move on the base 1 in the X-axis direction (in FIG. 1,
The vertical direction is indicated by X and X '. ) Can be moved forward and backward. In this work support base 2, a substantially cylindrical work W is mounted on a mounting plate 6 provided on a main shaft 5 via a backing plate 7. The outer peripheral surface of the work W is rotatably supported by a support member 8 and a holding arm 9 as shown in FIG. The inner peripheral surface of the work W is formed in a spherical shape, and the inner diameter thereof is measured by a conventionally known sizing device 10.

The spindle 5 is driven to rotate by a spindle motor 12 via a belt 11. The backing plate 7 is cylindrical and has a built-in magnet (not shown) to attract and hold the work W at its tip. The support member 8 includes a pair of shoes 1.
Three. Each shoe 13 is provided so that the position in the circumferential direction and the amount of protrusion in the radial direction can be adjusted, abuts against the outer peripheral surface of the work W, and supports the lower side of the work W. On the other hand, the holding arm 9 is rotatably provided on the work support base 2 and has a pair of rollers 14 on the inner peripheral surface. The holding arm 9 rotates while the work W is supported on the lower side by each shoe 13 of the support member 8, and the upper side of the work W is supported by the rollers 14. In FIG. 1, reference numeral 15 denotes a dresser for restoring the sharpness of the cup grindstone 25 described later.

The grindstone support 3 is driven by an AC servo motor 16 for table to move the first table 17 on the base 1 forward and backward in the Z-axis direction (left-right direction in FIG. 1).
And a second table 19 capable of moving up and down on the first table 17 in the Y-axis direction (the direction orthogonal to the paper surface in FIG. 1) by driving the Y-axis servo motor 18.

On the side wall of one end of the first table 17,
As shown in FIG. 3, a screw member 20 that rotates by driving the Y-axis servo motor 18 is rotatably mounted via a bearing 21. Further, on the upper surface of the first table 17, a slide member 23 is provided in the Z-axis direction (in FIG. 2, left and right directions, indicated by Z and Z ') via a cap 22 with which the tip of the screw member 20 is screwed. It is arranged to be able to reciprocate freely. The upper surface of the slide member 23 is formed so as to gradually increase toward the left side in FIG. on the other hand,
The bottom surface of the second table 19 is gradually inclined upward toward the left in FIG. 2 so as to correspond to the upper surface of the slide member 23. Thus, when the Y-axis servo motor 18 is driven forward and reverse, the screw member 20 rotates forward and reverse, and the slide member 23 moves in the left-right direction in FIG.
The table 19 is moved in the Y-axis direction (vertical direction in FIG. 2, Y, Y ').
Indicated by Go to).

On the upper surface of the second table 19, a wheel head 24 and a wheel head motor 26 are mounted. An arm 24a extends from the wheel head 24, and a grinding wheel shaft 25a is provided at the tip of the arm 24a. A bottomed cylindrical cup grinding wheel 25 is rotatably attached to the grinding wheel shaft 25a. The open end surface of the cup grindstone 25 is a ground surface, and is rotated in the circumferential direction via belts 27a and 27b by driving of a wheel head motor 26.

Next, the work W by the grinding apparatus having the above-described configuration is used.
The grinding of the inner spherical surface will be described.

That is, the spindle motor 12 is driven to rotate the work W, and the wheel head motor 2 is rotated.
6 is driven to rotate the cup grindstone 25. Then, the table AC servomotor 16 is driven to move the first table 17 in the Z direction in FIG. In addition, the AC servo motor for infeed 4
By driving the workpiece W in the X-axis direction and driving the Y-axis servo motor 18 to move the cup grindstone 25 in the Y-axis direction, as shown by a two-dot chain line in FIG. The cup grindstone 25 is positioned around the circumference. At this time, the axis of the rotation axis 25a of the cup grindstone 25 is orthogonal to the plane P1 including the rotation center Wa of the workpiece W, as shown in FIG.
The workpiece W is stopped at a position separated by a predetermined distance d from a plane P2 including the rotation center Wa of the work W and orthogonal to the plane P1.

Next, the inner peripheral spherical surface of the work W is made to approach the cup grindstone 25 by driving the cutting AC servomotor 4. As described above, since the position of the cup grindstone 25 is displaced by the predetermined dimension d with respect to the work W, the outer periphery of the cup grindstone 25 is limited to the work W
Is in sliding contact with the inner peripheral spherical surface. That is, the cup grindstone 25 hits the workpiece W only at the position A, and a large contact pressure is obtained. Therefore, even if the cutting feed amount by the cutting AC servomotor 4 is increased, a favorable grinding state is maintained, and the inner peripheral spherical surface of the work W can be efficiently ground.

The grinding process is continued in this way,
When a predetermined dimension up to the finishing dimension is reached by an input signal from the sizing device 10, the cutting AC servomotor 4 is driven to move the workpiece W in the X-axis direction and the Y-axis servomotor 18 to drive the cup grindstone 25. Translate in the Y-axis direction. Then, the rotating shaft 25a of the cup grindstone 25 is moved to the position shown in FIG.
As shown in the figure, it is located in the plane P2. In this case, the cup grindstone 25 is moved along the inner peripheral spherical surface of the work W. Further, the number of revolutions of the AC servomotor 4 for cutting is reduced to reduce the feed amount of cutting. As a result, the work W
The cup grindstone 25 on the inner spherical surface of FIG.
And the contact pressure is reduced, and the grinding amount per rotation of the cup grindstone 25 is suppressed, so that the finished surface accuracy (surface roughness) can be increased.

[0020]

As is apparent from the above description, according to the method for grinding the inner peripheral spherical surface of the work according to the present invention, the center of the rotation axis of the cup grindstone is ground at a position away from the second plane by a predetermined dimension. As a result, the cup grindstone comes into sliding contact with the inner peripheral spherical surface of the work only at one location, and it is possible to increase the contact pressure and perform efficient grinding.

Further, since the axis of the rotation axis of the cup grindstone is located in the second plane before the completion of the grinding, the cup grindstone comes into sliding contact with the inner peripheral spherical surface of the work at two places. It is possible to finish to the surface roughness.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a grinding device according to an embodiment.

FIG. 2 is a front view (a) of the work support base of FIG. 1 and a partial sectional view (b) thereof.

FIG. 3 is a cross-sectional view of the grinding wheel support of FIG. 1;

FIG. 4 is a front view showing a grinding state according to the embodiment.

FIG. 5 is a front view showing a grinding state according to a conventional example.

[Explanation of symbols]

 2 Work support 3 Grindstone support 25 Cup grindstone 25a Rotation axis P1 First plane P2 Second plane W Work Wa Rotation center

Claims (2)

[Claims] 1. A work, which is substantially cylindrical and has a spherical inner peripheral surface, is rotated in a circumferential direction, while a cup grindstone is provided on the inner periphery of the work, and a rotation axis of the cup grindstone includes a rotation center of the work. By disposing and rotating the cup grindstone or the workpiece relatively in the axial direction of the rotating shaft, the cup grindstone is slid in contact with the inner peripheral spherical surface of the workpiece by rotating the cup grindstone or the workpiece relatively to the first plane. In the method for grinding an inner peripheral spherical surface of a work to be internally ground, the inner surface grinding is performed by a predetermined process from a second plane in which an axis of a rotation axis of the cup grindstone includes a rotation center of the work and is orthogonal to the first plane. A method of grinding an inner peripheral spherical surface of a work, wherein the method is performed at a position apart by a dimension. 2. The internal grinding method according to claim 1, wherein before the internal grinding is completed, the cup grinding wheel is moved in parallel so that an axis of a rotating shaft of the cup grindstone is located within the second plane. Inner surface spherical grinding method of work.