JPS6311828A - Balancer - Google Patents

Abstract

PURPOSE:To reduce the balance adjusting time requiring no skill for adjustment along with a higher accuracy of balance adjustment, by providing a support means to maintain a spindle non-contact against the inner wall surface of a bearing hole. CONSTITUTION:A flange B is mounted on a grinding wheel A machined and balancing pieces E are arranged roughly at equal intervals. A pressure source 40 is operated to supply compressed air into a bearing hole 20 through paths 44 and 43 or the like so that a spindle 30 is maintained in non-contact with the inner wall surface of the bearing hole 20 and then, an adjusting screw 11 is turned to keep the spindle 30 horizontal. Thereafter, a tapered hole C of the flange B is fitted onto a mounting section 33 and the grinding wheel A is fixed 33 by screwing 34 a nut 36. Here, screws of pieces E are kept loose. If so, the grinding wheel A turns with the gravity center downward and comes to a stop. One of the pieces E is moved upward and the piece E is moved again with the turning of the grinding wheel A. By repeating this operation, the pieces E are adjusted so that the grinding wheel A comes to a rest at any position of rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a balancer for adjusting the weight balance of a grindstone used, for example, in a machine tool.

[Conventional technology]

A grindstone used in a surface grinder or the like must have a well-balanced weight around its axis in order to achieve stable rotation. For this purpose, the grindstone is attached to a flange that has a circumferential groove surrounding the axis, and within this circumferential groove, a plurality of balancing pieces are movably provided, and the weight balance is adjusted by moving these balancing pieces. It has become so. This balance adjustment work involves inserting a shaft into the axial center of the flange, arranging a pair of rails with edges on the upper surface in parallel, and placing the shaft on these rails and rolling it to ensure smooth movement. This is done by moving the balancing piece so that

[Problem that the invention seeks to solve]

In the edge-type balance adjustment described above, it is necessary to repeatedly visually observe the transfer of the grindstone and move the balancing piece, and it takes time to judge whether the transfer of the grindstone has become smooth. Also, skill is required to make accurate judgments.

Furthermore, since the transfer of the grinding wheel is affected by the friction between the shaft and the rail, there is a certain limit to the accuracy of balance adjustment. The present invention aims to solve such problems.

[Means for solving problems]

The balancer according to the present invention includes a housing having a bearing hole, and a mounting device that is inserted into the bearing hole and rotatably supported around an axis, with one end protruding from the housing and fixing an object to be inspected to the protruding portion. a spindle in which a portion is formed;
and support means for maintaining the spindle in a substantially non-contact state with respect to the inner wall surface of the bearing hole. The object to be inspected is rotated around the axis of the spindle so that its center of gravity is located downward, and the center of gravity is thereby measured.

〔Example〕

The present invention will be explained below with reference to illustrated embodiments.

FIG. 1 shows a first embodiment of the invention. In this diagram,
The housing 10 has an adjustment screw 11 at the bottom, and the horizontality with respect to the base T can be adjusted by rotating the adjustment screw 11.

Inside the housing 10 is a cylindrical bearing 1 extending horizontally.
2 is attached, the rear of the bearing 12 (right side in the figure) is covered by a rear cover 13, and the front of the bearing 12 (left side in the figure) is covered by a front cover 14. However, the bearing 12,
A bearing hole 20 is formed by the rear cover 13 and the front cover 14.

The spindle 30 is inserted into the bearing hole 20 and supported rotatably around the axis. The spindle 30 has a main body part 31, a small diameter part 32 connected to the front side of the main body part 31, a mounting part 33 connected to the small diameter part 32, and a threaded part 34 formed at the tip of the mounting part 33. 6 The main body portion 31 has a cylindrical shape, and its cylindrical outer circumferential surface 31 a is located within the bearing 12 .

The small diameter portion 32 is the front air chamber 1 formed by the front cover 14.
5, and the tip of the small diameter portion 32 is located in the hole 1 of the front cover 14.
Projects outward from 6. The diameter of the attachment portion 33 decreases linearly from the small diameter portion 32 toward the tip, and the diameter of the threaded portion 34 is approximately equal to the minimum diameter of the attachment portion 33 . On the other hand, a flange portion 35 having a larger diameter than the main body portion 31 is formed on the rear side of the main body portion 31 . The flange portion 35 is accommodated within the rear air chamber 16 formed by the rear cover 13.

A grindstone A, which is an object to be inspected, is fixed to a mounting portion 33. The grindstone A has an annular shape, and the flange B is attached to the center thereof. The grinding wheel A is fixed to the mounting part 33 by fitting the tapered hole C formed in the flange B into the mounting part 33 and screwing the nut 36 onto the threaded part 34 . As shown in FIG. 2, a circumferential groove surrounding the axis is carved on the surface of the flange B, and three balancing pieces E, for example, are provided within this circumferential groove. The balancing piece E is movable along the circumferential groove, and is fixed at a predetermined position by screws or the like (not shown).

In order to keep the spindle 30 in contact with the inner wall surface of the bearing hole 20, compressed air is supplied between the bearing hole 20 and the spindle 30 in this embodiment. The outer diameter of the main body 31 of the spindle 30 is slightly smaller than the inner diameter of the bearing 12, so that a clearance is formed between the cylindrical outer peripheral surface 31a of the main body 31 and the cylindrical inner peripheral surface 21 of the bearing 12. Further, the length of the rear air chamber 16, that is, the axial dimension is larger than the thickness of the flange 35, and the front end surface 3 of the flange 35 is larger than the thickness of the flange 35.
5a and the rear end surface 35b can take a non-contact state with the front facing surface 16a and the rear facing surface 16b of the rear air chamber 16.

The bearing 12 includes a plurality of radial passages 41 that penetrate in the radial direction, and a circumferential passage 42 that is formed on the outer circumferential surface of the bearing 12, extends in the cylindrical direction, and connects the radial passages 41 located at the same axial position. The housing 10 has an axial i1M path 43 that is formed on the outer peripheral surface of the bearing 12 and extends in the axial direction and communicates with each of the radial passages 41 located at the lowest position. It has 44. The base passage 44 is connected to a pressure source 4.0 provided outside the housing 10. The pressure source 40 generates compressed air of 2 to 6 kg/cm2, and this compressed air passes through the base passage 44, the axial passage 43, the circumferential passage 42, and the radial passage 11 to the bearing 12.
is supplied between the cylindrical inner circumferential surface 21 and the cylindrical outer circumferential surface 31a of the main body portion 31. Thus, the main body portion 31 is maintained in a non-contact state with respect to the bearing 12. The compressed air supplied between the main body part 31 and the bearing 12 is supplied to the front air chamber 15 and the rear air chamber 1.
6 and is discharged to the outside through exhaust ports 17 and 18 formed in the front cover 14 and the rear cover 13, respectively. Note that some of the air is discharged through the space between the hole 16 and the small diameter portion 32, so that the small diameter portion 32 also does not come into contact with the hole 16.

Further, an annular passage 45 is formed in the housing 10 that surrounds the outer periphery of the bearing 12 and communicates with the axial passage 43. It communicates with a rear passage 46 that opens to the opposing surface 16b. The opening 47 on the opposing surface 16b of the rear passage 46 is arranged in an annular shape around the axis of the rear end surface 35b so that compressed air is uniformly supplied to the entire rear end surface 35b of the collar portion 35. Therefore, the front end surface 35a of the collar portion 35 is pressed by the compressed air flowing out from between the bearing 12 and the main body portion 31, and the rear end surface 35b is pressed by the compressed air flowing out from the opening 47.
As a result, the front and rear facing surfaces 16 of the rear air chamber 16
N1F is held in a non-contact state with respect to a and 16b.

In this way, the compressed air discharged from the pressure source 40 is transmitted to the cylindrical outer circumferential surface 31a of the main body 31 and the cylindrical inner circumferential surface 2 of the bearing 12.
1, between the front end surface 35a of the collar 35 and the front facing surface 16a of the rear air chamber 16, and between the rear end surface 3 of the collar 35.
5b and the rear facing surface 16b of the rear air chamber 16.
It is discharged to the outside through the gap between the As a result, the main body portion 31 is supported by the air film formed between the bearing 12 and is kept in a non-contact state with respect to the bearing 12.
2 is also kept in a non-contact state with respect to the hole 16, and the collar portion 35
a is supported by an air film formed between the front and rear facing surfaces 16a and 16b, and these facing surfaces 15a,
16b is maintained in a non-contact state.

The balance adjustment of the grindstone using the balancer in this first embodiment will be explained.

First, the flange B is attached to the cut whetstone A, and the balancing pieces E are arranged at approximately equal intervals. Next, the pressure source 40 is activated to supply compressed air into the bearing hole 20, and the spindle 30 is lightly rotated by hand while keeping the spindle 30 in a non-contact state with the inner wall surface of the bearing hole 20. Check. Then, by enclosing the adjustment screw 11, the spindle 30 is adjusted so as to be horizontal or so that the mounting portion 33 side faces slightly upward. Thereafter, the taper hole C of the flange B is fitted into the attachment part 33, the nut 36 is screwed into the threaded part 34, and the grindstone A is fixed to the attachment part 33.

At this time, loosen the screw on balancing piece E.

Here, the grindstone A rotates and stands still so that its center of gravity is located downward. Move one of the balancing pieces E upwards,
Once the grindstone A has rotated, move the balancing piece E again. By repeating this operation, the balancing piece E is adjusted so that the grindstone remains stationary at any rotational position. The balance adjustment is then completed.

Then, remove the nut 36 and attach the grindstone A from the attachment part 33. At this time, the spindle 30 is also displaced to the left in the figure together with the grindstone A, but it stops at a position where the collar 35 abuts the front facing surface 16a, and the grindstone A is easily released from the attachment part 33.

As described above, since the spindle 30 does not substantially contact the bearing hole 20, the F! ! The friction becomes almost 0. Therefore, grindstone A rotates even if its center of gravity is slightly offset from the center, and balance adjustment can be performed with high precision, reducing errors to about 1/3 compared to conventional edge-type grindstones. can. Further, unlike the edge type, this embodiment does not involve observing the state of transfer to the grindstone, so balance adjustment can be carried out in a short time.

Furthermore, in this embodiment, the length of the rear air chamber 16 is
5, the thickness of the flange 35 is somewhat larger than the thickness of the flange 35, so if the flow rate of the compressed air ejected to the front and rear end surfaces 35a, 35b of the flange 35 is slightly different, the flange 35 will
6b, but these opposing surfaces 16a,
It is possible to maintain a non-contact state with respect to 16b.

FIG. 3 shows a second embodiment. In addition to the rear flange 35, the spindle 30 has a flange 37 between the main body 31 and the small diameter portion 32.
has. Front air chamber 15 from between main body 31 and bearing 12
The compressed air flowing to the side is connected to the rear end surface 37 of the front flange 37.
At point a, the compressed air flowing into the rear air chamber 16 side hits the front end surface 35a of the rear collar portion 35. That is, the compressed air is transmitted to the end surface 35a located inside the pair of flanges 35.37.
, 37a to urge them in mutually opposite directions,
The flanges 35 and 37 are maintained in a non-contact state with respect to the inner wall surface of the bearing hole 20. Other configurations and operations are similar to those of the first embodiment.

Note that the flange portion may be provided only in the front air chamber 15, or may be provided in the center of the spindle body portion 31.

FIG. 4 shows a third embodiment. In this third embodiment, the spindle 30 has a front end surface 31b of the main body 31, which has a flange.
Compressed air is supplied to the rear end surface 31c. That is, a front passage 48 and a rear passage 49 are formed in the housing 10 , and the front passage 48 extends from an axial passage 43 formed on the outer peripheral surface of the bearing 12 and connecting each radial passage 41 , and extends from the axial passage 43 that is formed on the outer peripheral surface of the bearing 12 and connects each radial passage 41 . The rear passage 49 extends from the axial passage 43 and reaches a portion of the main body portion 31 facing the rear passage 31c. Thus, the front and rear end surfaces 31b and 31C of the main body portion 31 are maintained in a non-contact state with the inner wall surface of the bearing hole 20.

The other configurations and operations are the same as in each of the above embodiments.

FIG. 5 shows a fourth embodiment. In this embodiment, an outer circumferential groove 3 is formed approximately in the center of the main body 31 of the spindle 30 over the entire circumference.
8 is carved, and the bearing 12 is formed with an annular raised portion 51 that fits into the outer circumferential groove 38 .

The raised portion 51 has a central passage 5 communicating with the axial passage 43.
2 is bored, and the central passage 52 is located on the side surface 51a of the raised portion 51.
, 51b, and side wall surfaces 38a, 38b of the outer circumferential groove 38.
supply compressed air. Therefore, the side wall surface 3 of the outer circumferential groove 3B
8a and 38b are both side surfaces 51a and 51b of the annular raised portion 51
maintained in a non-contact state.

The other configurations and operations are the same as in each of the above embodiments.

FIG. 6 shows a fifth embodiment. This fifth embodiment is different from the above-mentioned embodiments in that in order to maintain the spindle 30 in a non-contact state with respect to the bearing hole 20 (R force is used. embedded, bearing 1
A magnet 62 is pushed into the inner circumference of the magnet 2 so that the same poles as the magnet 61 are close to each other. Thereby, the main body 31 of the spindle 30 is supported without contacting the inner peripheral surface of the bearing 12. A magnet 63 is also embedded in the collar portion 35, and magnets 64.65 are embedded in the opposing surface 163.16b of the rear air chamber 16 so that the same poles as the magnet 63 are close to each other. As a result, the flange portion 35 faces the opposing surface 16a.

16b is maintained in a non-contact state. Except for the structure of this magnet, the fifth embodiment has the same structure as each of the above-mentioned embodiments, and produces the same effects.

Note that the main body 31 of the spindle 30 may be maintained in a non-contact state with respect to the bearing hole 20 by compressed air, and only the collar portion 35 may be maintained in a non-contact state with the bearing hole 20 by magnetic force, or The compressed air and magnetic force may be reversed.

〔Effect of the invention〕

As described above, according to the present invention, since the friction with respect to the rotational displacement of the inspected object is almost zero, the accuracy of balance adjustment can be greatly improved, and the transfer state of the inspected object cannot be observed. Therefore, no skill is required for balance adjustment, and the adjustment time can be significantly shortened.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the first embodiment of the present invention, Fig. 2 is a front view showing the grindstone, Fig. 3 is a sectional view showing the second embodiment, and Fig. 4 is a sectional view showing the third embodiment. 5 is a sectional view showing the fourth embodiment, and FIG. 6 is a sectional view showing the fifth embodiment. DESCRIPTION OF SYMBOLS 10... Housing, 12... Bearing, 20... Bearing hole, 30... Spindle, 33... Mounting part, 40... Pressure source, 4I... Radial direction passage, 46... - Rear passage, 61.62, 63.64.65... Magnet. Sha 2 Figure 3 Figure Shu 4

Claims (1)

[Claims] 1. A housing having a bearing hole, which is inserted into the bearing hole and supported rotatably around an axis, with one end protruding from the housing, and an object to be inspected is fixed to the protruding portion. A spindle having a mounting portion formed thereon, and support means for maintaining the spindle substantially in a non-contact state with the inner wall surface of the bearing hole, and the object to be inspected is placed such that its center of gravity is located downward. rotationally displaced around the axis of the spindle,
A balancer characterized in that the center of gravity position is measured by this. 2. The spindle has a pair of end faces that are substantially orthogonal to the axis, and the bearing hole has a pair of opposing faces that respectively oppose the pair of end faces, and the support means supports the cylindrical outer peripheral surface of the spindle and the bearing. 2. The balancer according to claim 1, wherein a non-contact state is maintained between the cylindrical inner circumferential surface of the hole and between the end surface of the spindle and the facing surface of the bearing hole. 3. The balancer according to claim 2, wherein the pair of end surfaces are formed on a flange provided on the spindle. 4. The balancer according to claim 2, wherein the pair of end faces are inner end faces of a pair of flanges provided on the spindle. 5. The balancer according to claim 2, wherein the pair of end surfaces are formed at both ends of the main body of the spindle. 6. The balancer according to claim 2, wherein the pair of end surfaces are both side wall surfaces of the outer circumferential groove of the spindle. 7. The balancer according to claim 1, wherein the support means maintains the spindle and the bearing hole in a non-contact state using compressed air. 8. The balancer according to claim 1, wherein the support means maintains the spindle and the bearing hole in a non-contact state by magnetic force. 9. The balancer according to claim 1, wherein the support means maintains the spindle and the bearing hole in a non-contact state by compressed air and magnetic force.