JPH0752007A - Rotary grinding machine and grinding method - Google Patents

Abstract

PURPOSE:To grind flat surfaces and cylindrical surfaces with high accuracy and at high efficiency in a rotary grinding machine having a grinding wheel spindle above a rotatable table by providing the grinding wheel spindle so that it can be tilted to the upper face of the table. CONSTITUTION:When a cylindrical surface W1 is ground, a nut 23 is released to tilt a grinding wheel spindle 17 to the upper face of a table 7 up to a specified angle and to fix it to a slider 16 by clamping the nut 23. In this state, a saddle shifting motor 6 is driven in order for the cylinder grinding-outer peripheral surface 20a of a grinding wheel 21 to contact the cylindrical surface W1 of a work W, and thus grind the cylindrical surface W1. Then, when surface grinding of the work W is performed, the grinding wheel spindle 17 is lowered in state where the grinding wheel spindle 17 is held parallel to the upper face of the table 7, and after the flat surface-grinding surface 20b is brought into contact with the flat surface W2 of the work W, a saddle 2 is moved to the left side. Thereafter, the grinding wheel 21 is moved along the direction of the periphery of the work W to grind the flat surface W2 of the work W.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary grinding machine in which a table on which a work is placed rotates and a grinding method for grinding a work with the rotary grinding machine.

[0002]

2. Description of the Related Art Generally, the rotary grinding machine is
The work is placed on a table that rotates with respect to the frame, and in the state where the table is rotated, the work is ground with a grindstone on a rotation axis that is substantially parallel to the upper surface of the table.

[0003]

However, the rotary grinding machine described above can only perform planar machining of a workpiece. That is, the rotary grinder can perform grinding only on the grindstone surface orthogonal to the grindstone axis. Therefore, in the conventional rotary grinder, the cylindrical surface cannot be ground despite the rotation of the table.

Further, when the end surface of the grindstone is forcibly used to grind the cylindrical surface of the work, it is very difficult to machine the work within a desired allowable range. Therefore, there is a problem that processing efficiency deteriorates.

Further, when a grindstone is clogged during grinding of a work and the grinding ability of the grindstone is lowered, the grindstone slides without grinding the work, that is, slides on the upper surface of the work. . Therefore, the workpiece thermally expands due to frictional heat with the grindstone, and the grindstone escapes upward. But,
Since the grindstone shaft that supports the grindstone is fixed, the grindstone cannot escape upward, and as a result, a large stress is applied to the contact surface between the grindstone and the work. As a result, distortion occurs on the ground surface of the work, which affects accuracy and surface roughness.

Further, when the diameter of the grindstone changes due to abrasion of the grindstone of the grindstone during grinding, waviness (unevenness) may occur on the ground surface of the work. In this case, even if the ground surface is subjected to finish grinding, the effect of pre-processing is exerted, and a desired finished surface cannot be obtained.

The present invention has been made to solve the above problems, and a first object thereof is to provide a rotary grinder capable of grinding a flat surface and a cylindrical surface with high accuracy and efficiency. A second object is to provide a grinding method that does not cause distortion on the ground surface of the work.

[0008]

In order to achieve the above object, according to the first aspect of the invention, in a rotary grinder having a grindstone shaft parallel to the upper surface of a rotatable table, the grindstone shaft is provided on the table upper surface. The main point is that it is tiltable.

The gist of the second invention is that the grindstone shaft can be tilted with respect to the upper surface of the table by rotating up and down about an axis. In the third invention, the tilting position of the grindstone shaft with respect to the table upper surface is
The gist thereof is to provide a fixing means for fixing at a predetermined position.

The gist of the fourth invention is that the grindstone shaft is preliminarily inclined and held with respect to the upper surface of the rotatable table. In the fifth invention, from the reference surface where the work on the table and the grindstone come into contact with each other, a predetermined amount of the grindstone is cut so that a part of the grindstone width comes into contact with the work, and a cutting step of grinding a part of the work, After finishing the cutting step, a grindstone returning step of raising the grindstone axis to separate the grindstone from the grinding surface of the work once, and a table moving step of moving the table in the axial direction of the grindstone axis after finishing the returning step. The gist is to grind the work piece intermittently by repeating the above three steps in sequence.

[0011]

According to the first to fourth inventions, when grinding a work having a cylindrical surface, the grindstone shaft is tilted with respect to the upper surface of the table, and the outer peripheral surface of the grindstone for grinding the work is a cylindrical surface of the work. It is processed and formed by dressing work so as to face with. Then, the cylindrical surface of the work is ground with high precision and efficiency by grinding the cylindrical surface of the work with the outer peripheral surface of the grindstone that has been processed and formed.

According to the fifth aspect of the present invention, the grindstone is cut by a predetermined amount from the reference surface where the work on the table and the grindstone contact each other so that approximately half the width of the grindstone contacts the work. Then, after part of the work is ground, the table is moved in the grindstone axis direction with the grindstone once separated from the work. Then, a predetermined amount of the grindstone is repeatedly cut so that approximately half of the grindstone width comes into contact with the work again, and the work is surface-ground.

[0013]

【Example】

(First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a pair of guide rails 3 (only one of which is shown) extending in the left-right direction in the figure are provided on the upper surface of the frame 1. A saddle 2 is engaged with the guide rail 3, and the saddle 2 reciprocates left and right along the guide rail 3. A screw body 4 is provided on the lower surface of the saddle 2, and a screw shaft 5 is screwed on the screw body 4. One end of the screw shaft 5 projects to the outside of the frame 1 and is connected to the saddle moving motor 6 via a speed reducer (not shown). That is, the saddle 2 moves left and right with respect to the frame 1 based on the rotation of the saddle moving motor 6.

A table 7 is supported on the upper surface of the saddle 2 by a hydraulic motor (not shown) so as to be positively rotatable in a horizontal plane. The table 7 is an electromagnetic chuck and fixes the work W by an electromagnetic force. Frame 1
A column 10 is erected on the right side of the column 10, and a screw shaft 12 extending vertically is disposed below the column 10. A screw body 13 is screwed to the lower end of the screw shaft 12, and the screw body 13
Rotates as the lifting motor 14 is driven. On the other hand, a cylindrical slider 16 is connected to the upper end of the screw shaft 13 via a bearing 15. The slider 16 has a grindstone shaft 1
7 is inserted.

As shown in FIGS. 1 and 2, the grindstone shaft 1
The rotary shaft 18 is rotatably supported by the rotary shaft 18 with respect to the slider 16. An arc-shaped elongated hole 19 is formed on the side surface of the slider 16. A threaded rod 20 protruding from the grindstone shaft 17 is slidably engaged with the elongated hole 19. A nut 23 is screwed onto the screw rod 20 outside the slider 16. The screw rod 20 and the nut 23 constitute a fixing means.

By loosening the nut 23, the grindstone shaft 1
7 can be rotated clockwise from the horizontal state of FIG. Then, the whetstone shaft 17 can be fixed to the slider 16 by tightening the nut 23 at a desired position. In this embodiment, when the grindstone shaft 17 is held in the horizontal state shown in FIG. 1, the grindstone shaft 17 can be easily positioned with respect to the slider 16 by the interference between the elongated hole 19 and the screw rod 20. it can.

A grindstone 21 for grinding the work W is rotatably supported at the front end of the grindstone shaft 17. The grindstone 21 is positively rotated by a motor 22 attached to the rear end of the grindstone shaft 17. The slider 16 and the grindstone shaft 17 move up and down as the lifting motor 14 rotates forward and backward. That is, the distance between the grindstone 21 and the table 7 changes as the lifting motor 14 rotates forward and backward.

Next, the operation of this embodiment will be described.
First, the case where the work W is subjected to surface grinding will be described. First, the grindstone shaft 17 is held parallel to the upper surface of the table 7. That is, the inclination angle of the grindstone shaft 17 is set to 0 °. Then, after dressing the grindstone 21, the work W is placed on the upper surface of the table 7 and the table 7 is rotated. Then, the lifting motor 14 is driven to move the grindstone 21 to a predetermined cut position. After that, the saddle moving motor 6 is driven to bring the table 7 closer to the grindstone 21 side to start grinding the work W. Then, when the grindstone 21 reaches the rotation center position of the table 7, the grindstone 21 is further lowered to a predetermined cutting position, the saddle 2 is moved to the left side, and the grindstone 21 is moved to the outer peripheral side of the work W. By repeating the above operation a plurality of times, the work W
Surface grinding is completed.

Next, the grinding of the workpiece W having the cylindrical surface w1 shown in FIG. 3 will be described. First, the nut 23 is loosened and the grindstone shaft 17 is held in a rotating state with respect to the slider 16. Then, in FIG. 1, the grindstone shaft 17 is rotated clockwise to incline the grindstone shaft 17 to a predetermined angle with respect to the upper surface of the table 7. Then, the nut 23 is tightened to position the grindstone shaft 17 with respect to the slider 16.
In this state, the grindstone 21 is dressed, and the outer peripheral surface of the grindstone 21 is processed as shown in FIG. That is, the work W
The outer peripheral surface of the grindstone 21 is dressed according to the cylindrical surface w1 and the flat surface w2 of
a, a plane grinding surface 21b is formed.

In this state, the saddle moving motor 6 is driven to bring the cylindrical outer peripheral surface 21a of the grindstone 21 into contact with the cylindrical surface w1 of the work W to grind the cylindrical surface w1. After that, the grindstone shaft 17 is lowered to move the flat grinding surface 21b to the work W.
After being brought into contact with the flat surface w2, the saddle 2 is moved to the left and the grindstone 21 is moved in the outer peripheral direction of the work W. Thereby, the flat surface w2 of the work W is ground. In this way, the work W having the cylindrical surface w1 is ground.

As described above, according to this embodiment, the grindstone shaft 17 serving as the grindstone shaft is rotatably provided with respect to the slider 16 which moves up and down. Accordingly, the grindstone shaft can be tilted with respect to the upper surface of the table 7. Then, in this state, the outer peripheral surface of the grindstone 21 is processed into a predetermined shape, whereby the cylindrical surface of the work W can be processed.

When the workpiece W shown in FIG. 3 is ground, the grindstone shaft 1 is placed at that position after grinding the cylindrical surface w1.
By lowering 7, it is possible to grind the flat surface w2. That is, since the cylindrical surface w1 and the flat surface w2 of the work W can be easily ground by positioning the work W once with respect to the grindstone 21, more efficient grinding becomes possible.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to FIG. First, FIG.
As shown in (a), the outer peripheral surface of the grindstone 21 is brought into contact with the upper surface of the work W on the table 7. That is, the contacted position becomes the reference plane L. Next, as shown in FIG. 5B, the saddle 2 is moved to allow the grindstone 21 to escape outside the work W. Then, as shown in FIG.
The saddle 2 is moved until about half of the contact with the upper surface of the work W. Next, as shown in FIG. 5D, the grindstone 21 is lowered from that position by a predetermined amount to cut the work W (cutting step). Then, as shown in FIG. 5E, the grindstone 21 is separated from the ground surface w3 of the work W again (returning step).

Next, as shown in FIG.
The saddle 2 is moved until about half of the above is opposed to the reference surface L of the work W (table moving step). Then, as shown in FIG. 5G, the grindstone 21 is lowered by a predetermined amount from that position to cut the work W (cutting step). At this time, the cut amount of the grindstone 21 is the same as the cut amount in FIG. 5D. After that, the steps of FIGS. 5 (e) to 5 (g) are repeated, and the entire surface of the work W is ground. When performing the steps of FIGS. 5D and 5G, immediately after cutting the grindstone 21, the grindstone 21 and the work W are contacted with each other for several seconds without being separated from the work W immediately. By doing so, the accuracy of the ground surface at that portion is improved.

As described above, in this embodiment, about half the width of the grindstone 21 is used, and the grindstone 21 is cut into a predetermined amount. Then, once from the grinding surface w3 of the work W to the grindstone 21
The surface of the workpiece W was ground by repeating the process of moving the saddle 2 (the table 7) by a predetermined amount in the state where they were separated from each other and cutting the grindstone 21 again at that position. Therefore, according to the grinding method of the present embodiment, unlike the grinding method in which the entire width of the grindstone 21 is brought into contact with the work W and the saddle 2 (table 7) is moved in that state, the stress applied to the work W is reduced. Can be greatly reduced. As a result, it is possible to prevent distortion on the ground surface. The present invention is not limited to the above-mentioned embodiments, but may be configured as follows, for example, within the scope of the invention.

(1) When the grindstone shaft 17 is tilted, the operator may manually tilt the grindstone shaft 17 instead of driving the motor or a cylinder.

(2) In the first embodiment, when grinding the flat surface of the work W, the grindstone shaft 17 is set parallel to the upper surface of the table 7 (the tilt angle is 0 °), but the grindstone shaft 17 is tilted. The surface of the workpiece W may be machined in this state.

(3) The grindstone shaft 17 may be preliminarily tilted with respect to the upper surface of the table 7 and fixed to the slider 16 so as not to be tiltable. (4) In the first embodiment, when the grindstone shaft 17 is in the horizontal state, the slot 19 and the screw rod 20 interfere with each other so that the grindstone shaft 17 cannot be further rotated counterclockwise. did. On the other hand, by making the long hole 19 longer,
The grindstone shaft 17 may be configured to be rotatable in the counterclockwise direction from the horizontal state.

(5) In the first embodiment, the general-purpose rotary grinder is embodied, but it may be embodied by a rotary grinder or the like which processes a workpiece by NC control. (6) In the second embodiment, the work W is ground by using about half the width of the grindstone 21, but the used area may be changed appropriately.

[0031]

As described in detail above, according to the present invention,
Since the outer peripheral surface of the grindstone can be used to grind the flat surface and the cylindrical surface of the work, the excellent effect that grinding can be performed efficiently and with high accuracy is achieved. Further, it has an excellent effect that it is possible to prevent the occurrence of distortion on the ground surface.

[Brief description of drawings]

FIG. 1 is a front view of a rotary grinding machine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view of a work to be ground in FIG.

FIG. 4 is a front view of a rotary grinder when a grindstone shaft is tilted to grind a cylindrical surface of a work.

FIG. 5 is a schematic front view of a table, a work and a grindstone for explaining a grinding process in the second embodiment.

[Explanation of symbols]

7 ... Table, 17 ... Whetstone shaft, 18 ... Rotary shaft, 19 ... Elongation hole which comprises fixing means, 20 ... Screw rod which constitutes fixing means, 21 ... Whetstone, 23 ... Nut which constitutes fixing means, W
… Work, w3… Ground surface

Claims (5)

[Claims] 1. A rotary grinder having a grindstone shaft (17) above a rotatable table (7), wherein the grindstone shaft (17) is tiltable with respect to the upper surface of the table (7). A characteristic rotary grinder. 2. The table (7) is provided by rotating the grindstone shaft (17) up and down about an axis (18).
The device according to claim 1, wherein the device is tiltable with respect to the upper surface.
The rotary grinder described in. 3. The fixing means (19, 20, 23) for fixing the tilting position of the grindstone shaft (17) with respect to the upper surface of the table (7) at a predetermined position, according to claim 1 or 2. The described rotary grinder. 4. A rotary grinder characterized in that a grindstone shaft (17) is tilted and held in advance with respect to an upper surface of a rotatable table (7). 5. The grindstone (21) from the reference surface (L) where the work (W) on the table (7) and the grindstone (21) contact each other.
Grindstone (21) so that a part of the width contacts the work (W)
A predetermined amount of cutting to grind a part of the work (W), and after finishing the cutting process, the grindstone shaft (17) is lifted to temporarily grind from the grinding surface (w3) of the work (W). (21) separating the grindstone, and after finishing the returning step, the table (7) is moved to the grindstone shaft (17).
3. A grinding method characterized by intermittently grinding a work (W) by sequentially repeating three steps of a table moving step of moving the workpiece (W) in the axial direction.