JPH0788750A - Cage window grinding machine - Google Patents

Abstract

PURPOSE:To support in high rigidity a grinding wheel shaft of relatively weak strength by providing the three grinding wheel shafts rotatably about the axis of a main spindle, also providing the grinding wheel shafts radially with an equal space by interposing the axis of the main spindle, and rotatably supporting the grinding wheel shaft by a fluid bearing. CONSTITUTION:Three quills 47 to 49 are provided rotatably about the axis of a main spindle 9, also provided radially with an equal space by interposing the axis of the main spindle 9, and supported rotatably by a fluid bearing 52a. As a result, by supporting in high rigidity the quills 47 to 49 of relatively weak strength, reaction force, received by grinding wheels 44 to 46 from a dresser 26 or a cage 13 at dressing time or grinding time, is reduced. Consequently, generating an escape between the grinding wheels 44 to 46 and the dresser 26 and between the grinding wheels and the cage 13 is prevented, and proper dressing and heavy grinding can be performed. As a result, grindability of a cage window 13a can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cage window grinder for grinding a cage window of a cage of a constant velocity ball joint.

[0002]

2. Description of the Related Art Generally, a constant velocity joint used for a driving force transmitting portion such as a rear drive of an automobile or a propeller shaft is provided with a cage, and a cage window for supporting a ball portion is formed in the cage. There is. When this cage window is ground, as shown in FIG. 4, one side surface Wa located on one side of the six cage windows Wp and the other side surface Wb located on the other side thereof are in the same planes A and B, respectively. Inside, the six cage windows Wa must be machined to the same size.

As a conventional grinding method of this type, for example, there is a method in which six grinding wheel shafts each having a grinding wheel are provided. This tool rotates the grindstone in the same direction when dressing the grindstone, and
Dressing only up to ~ 5μm, and by alternately changing the rotation direction of the grindstone shaft when grinding the cage window (3 normal rotation, 3 reverse rotation), the grinding direction to the cage is the same direction and the workpiece is rotated. The cage window is efficiently grinded in a short time while preventing the above.

Further, as another grinding method, for example, there is a method described in JP-A-56-89469. This one is provided with two grindstone shafts sandwiching a cage mounted on the main shaft, and the grindstones mounted on the grindstone shafts are cut in opposite directions to the cage window, that is, one grindstone 4 one of the cage windows Wa is ground at the same time as the other of the cage windows Wb is ground by the other grindstone.
By grinding the cage window, it is possible to prevent variations in the dimensions of the cage window and to grind the cage window with high accuracy.

[0005]

However, in the former grinding method, the rotation directions of the grindstone shafts are alternately varied when grinding the cage window so that the reaction forces of the grindstone shafts cancel each other out. At times, up-cutting and down-cutting occurred and the grinding conditions changed. Also,
Since the grindstone was rotated in the same direction during dressing of the grindstone, a grindstone rotating in the opposite direction to that during dressing was generated during grinding, and the grinding direction was opposite to the dressing direction. As a result, there is a problem that the grinding accuracy varies and the processing accuracy deteriorates.

Further, since it has six grindstone shafts, the grinding machine becomes large and its space increases, and at the same time,
There is a problem that the cost of the grinder increases.
Further, in the latter grinding method, since the grindstones are cut in the cage windows in opposite directions, it is necessary to index the cage windows six times in order to grind the cage windows. It took a lot of time to grind
There was a problem that productivity of the cage deteriorates.

In both grinding methods, a grindstone is attached to the tip of the grindstone shaft. However, since this grindstone shaft generally has a small diameter and low rigidity, the dresser is dressed by the reaction force of the dresser during dressing. In addition, there is a problem that proper dressing cannot be performed because escape occurs between the dressers. In addition, grinding is performed with a grindstone that is not properly dressed, and since the grindstone receives a large reaction force against the cage during grinding, heavy grinding cannot be performed and grinding performance deteriorates. was there.

Therefore, according to the first aspect of the present invention, the grindstone shaft is rotatably supported by the fluid bearing, so that the reaction force received from the dresser and the cage during dressing and grinding is reduced, and proper dressing and heavy grinding are performed. It is possible to improve the grinding performance and obtain the same productivity as the one using the six grinding wheel shafts, and prevent the grinding accuracy from being deteriorated by making the grinding condition and the dressing condition the same. An object of the present invention is to provide a compact, low-cost cage window grinder that can be manufactured.

[0009]

In order to achieve the above object, the invention according to claim 1 is such that a bed, a slide portion slidably provided on the bed and driven by a drive mechanism, and rotating in the slide portion. It has a chuck that is freely supported and holds a cage at one end, has a main shaft that is rotated by a rotating mechanism that is provided on a slide unit, and has a dresser on the chuck side that is rotatably supported by the main shaft. , A dresser mount rotatably driven by a dresser drive mechanism, and a tip end portion that is rotatably provided around a rotation axis line that is perpendicular to the rotation axis line of the main shaft and that is radially provided with the central axis of the main shaft interposed therebetween. Three grindstone shafts each having a grindstone, and provided on each of the grindstone shafts,
A feed device for moving the grindstone shaft in a direction perpendicular to the rotation axis direction of the main shaft, and a fluid bearing for rotatably supporting the grindstone shaft are provided.

[0010]

According to the invention described in claim 1, three grindstone shafts are rotatably provided around the axis of the main shaft and arranged at equal intervals radially with the central axis of the main shaft interposed therebetween, and the grindstone shafts are formed by the fluid bearing. It is rotatably supported. Therefore,
Since the grindstone shaft having a relatively low strength is supported with high rigidity, the reaction force received by the grindstone from the dresser or the cage during dressing or grinding is reduced, and no escape occurs between the grindstone and the dresser or cage. Therefore, proper dressing and heavy grinding are performed. As a result, the grinding performance of the cage window is improved. Further, since the reaction force received from the cage is small, heavy grinding is performed and the cage window is ground in a short time, and the productivity equivalent to that using the six grindstone shafts can be obtained.

Further, since the grinding is performed by the three grindstone shafts, it is not necessary to change the rotating directions of the grindstone shafts. Therefore, the grinding condition and the dressing condition are the same, and the processing accuracy is improved. In addition to this, since the number of grinding wheel shafts is small, it is possible to reduce the size and cost of the grinding machine.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of a cage window grinder according to the invention of claim 1. First, the configuration will be described.

In FIG. 1, reference numeral 1 is a bed of a grinding machine, and a cylindrical case 2 is fitted in the bed 1.
A slide portion 3 is slidably provided in the case 2, and the slide portion 3 includes a slide portion 4 slidably contacting an inner peripheral portion of the case 2 and an outer frame 5 attached to a lower portion of the slide portion 4. It is configured. A hollow member 6 is rotatably attached to the inner peripheral portion of the slide portion 3 via a bearing 7, and a shaft member 8 forming a main shaft 9 together with the hollow member 6 is attached to the inner peripheral portion of the hollow member 6. Is provided slidably, and a rod 10a protruding from the cylinder 10 is provided at the lower end of the shaft member 8.
Is installed.

The inside of the cylinder 10 is partitioned by a piston into a pair of cylinder chambers, and a rotary switching valve 11 provided at the bottom of the cylinder 10 supplies fluid to either one of the cylinder chambers so that the shaft member 8 is moved. The hollow member 6 is moved up and down. A chuck 12 is provided on the upper end portion (one end portion) of the shaft member 8, and the chuck 12 swings between a position shown in the figure around a fulcrum 12a and a position in which the tip portion is lowered from that position. Then, the cage 13 having the six cage windows 13a is gripped together with the hollow member 6 when in the position shown in the figure. A ball nut member 14 is attached to the outer frame 5, and one end of a ball screw 15 is screwed into the member 14. The ball screw 15 is rotatably attached to the frame 16 of the grinder, and the servo motor 17 is attached to the other end of the screw 15 and is driven by the motor 17.

Accordingly, the ball screw is driven by the motor 17.
When 15 is rotated, the outer frame 5 is moved through the ball nut member 14.
Moves up and down, so that the main shaft 9 moves up and down via the slide portion 3. This ball nut member 14, ball screw
The motor 15 and the motor 17 form a drive mechanism 18. Also,
A reducer 19 and an AC servomotor 20 are attached to the outer frame 5, and the reducer 19 includes a hollow member 6 via a pinion gear 21.
Meshes with an outer peripheral gear 22 attached to the lower end of the. Therefore, when the motor 20 is driven, this driving force
After being decelerated by 19, the pinion gear 21 and the peripheral gear 22
The main shaft 9 rotates with respect to the slide portion 3 because it is transmitted to the hollow member 6 via the. The speed reducer 19, the AC servomotor 20, the pinion gear 21, and the outer peripheral gear 22 are a rotating mechanism 23.
Are configured.

A dresser mount 25 is rotatably provided on the outer peripheral portion of the hollow member 6 via a bearing 24. A dresser 26 is mounted on the upper end of the mount 25 on the chuck 12 side. There is. An outer peripheral pulley 27 is provided at the lower end of the mounting base 25.
Is loosely inserted in the outer peripheral portion of the hollow member 6. The outer peripheral pulley 27 is connected to a pulley 29 via a belt 28, and the pulley 29 is attached to an upper end portion of a rotary shaft 30. An upper portion of the rotating shaft 30 is rotatably supported by a supporting member 31 attached to an upper end portion of the slide member 4, and a lower end side thereof is rotatably supported by the outer frame 5.

An output shaft 32a of an AC motor 32 is attached to the lower end of the rotary shaft 30, and the AC motor 32 has an outer frame 5a.
It is fixed to a motor support member 33 attached to. Therefore, when the AC motor 33 is driven, the pulley 29 is rotated via the rotating shaft 30 and the rotation of the pulley 29 is transmitted to the outer peripheral pulley 27 via the belt 28, so that the dresser mount 25 is attached to the dresser 26. Rotate with. These peripheral pulleys
27, belt 28, pulley 29, rotating shaft 30 and AC motor 33
Constitutes a dresser drive mechanism 34.

On the other hand, three grindstone bases 41 to 43 are arranged around the main shaft 9 as shown in FIG.
Numerals 43 are rotatably provided around a rotation axis that is perpendicular to the rotation axis of the main shaft 9, and are radially provided at equal intervals with the central axis of the main shaft 9 interposed therebetween, and a grindstone made of CBN at the tip end portion.
It has quills 47-49 as three grindstone shafts having 44-46.

The grindstone bases 41 to 43 are provided on the feed device 50 (since the grindstone mounts have the same structure, the grindstone mount 4
1 will be described), the grindstone base 41 is moved by the feeding device 50 in a direction perpendicular to the rotation axis direction of the spindle 9. Also, the chuck 12 of the feeding device 50
A guide member 51 is attached to the side, and as shown in FIG. 3, a dovetail groove 51a is formed in the guide member 51, and a moving member 52 is slidably fitted in the dovetail groove 51a. .
A fluid bearing 52a is provided above the moving member 52, and the fluid bearing 52a rotatably supports the quill 47.

A cylinder 53 is provided at the lower end of the guide member 51, a rod 53a protruding from the cylinder 53 is attached to the lower end of the moving member 52, and the moving member 52 is vertically moved by the cylinder 53. It has become so. Therefore, the quill 47 is configured to swing vertically by the moving member 52. Next, the operation will be described.

First, to mount the cage 13 on the main shaft 9,
After inserting the cage 13 into the shaft member 8 while tilting the chuck 12 around the fulcrum 12a toward the shaft member 8 side, the chuck 12
Is moved to the position shown in FIG. 1 around the fulcrum 12a.
Next, the cylinder 10 is operated to move the shaft member 8 downward so that the cage 13 is gripped between the chuck 12 and the hollow member 6.

Then, the servo motor 17 is operated to raise the slide member 4 via the ball screw 15 and the ball screw nut member 14 to move the dresser 26 to the vicinity of the grindstones 44 to 46. Next, the AC motor 32 is operated to rotate the rotary shaft.
By rotating the pulley 29 via 30 and driving the outer peripheral pulley 27 via the belt 28, the dresser mount 25
1 is rotated by the feed device 50 while rotating the grindstone shaft 47 toward the dresser 26 as shown in FIG.
By moving to the right inside, the outer circumference of the grindstone 44
Dress only 5 μm.

At this time, since the quill 47 is rotatably supported by the fluid bearing 52a, the reaction force received from the dresser 26 is small, and no escape occurs between the grindstone 44 and the dresser 26. At this time, Quill 48 and 49 are also Quill 47.
The same operation is performed, and the quills 47 to 49 at this time have the same rotation direction and rotation speed, and dressing is performed under the same conditions. Further, since the quills 48 and 49 perform the same operation as the grindstone shaft 47, the description of the operation will be omitted.

After dressing, the cylinder 53 is operated to raise the moving member 52 to swing the quill 47 upward, and then the feed device 50 moves the grindstone base 41 away from the dresser 26. The cylinder 53 is operated to lower the moving member 52 to return the quill 47 to the original position, that is, the position where the rotation axis of the quill 47 is orthogonal to the rotation axis of the main shaft 9.

Then, the servo motor 17 is rotated in the reverse direction,
The slide member 4 is moved downward until the grindstone 44 comes to a position facing the cage window 13a of the cage 13, and the AC servomotor 20 is driven to reduce the rotational force by the speed reducer 19. The hollow member 6 is rotated by way of, and three of the six cage windows 13a are indexed so as to be on the respective grinding stones 44 to 46 side.

Then, the quill 47 is rotated, and the grindstone base 41 is moved toward the cage 13 by the feeding device 50 to insert the grindstone 44 into the cage window 13a. At this time, the quills 47 to 49 have the same rotation speed and rotation direction. Then, by driving the servo motor 17 in the position direction, the main shaft 9 is moved upward or downward, and the upper surface or the lower surface of the cage window 13a is ground. Also at this time, since the quill 47 is rotatably supported by the fluid bearing 52a, the reaction force received from the cage 13 is small,
No escape occurs between the grindstone 44 and the cage 13.

After grinding, the quill 47 is separated from the cage window 13a, the main shaft 9 is rotated by the motor 20, the remaining three cage windows 13a are indexed, and the cage window 13a is ground again as described above. . As described above, in the present embodiment, three quills 47 to 49 are rotatably provided around the axis of the main shaft 9 and radially equidistantly sandwiching the central axis of the main shaft 9, and the quill 47 to 49 are fluid bearings. Since it is rotatably supported by the 52a, the quill 47 with relatively weak strength
It can support 49 with high rigidity and can be used from dresser 26 or cage 13 to grindstone 44 during dressing or grinding.
The reaction force received by ~ 46 can be reduced. Therefore, it is possible to prevent escape from occurring between the grindstones 44 to 46 and the dresser 26 and the cage 13, and it is possible to perform proper dressing and heavy grinding. This results in cage windows
The grinding performance of 13a can be improved.

Further, since the reaction force received from the cage 13 can be reduced, heavy grinding can be performed to grind the cage window 13a in a short time, which is equivalent to the production using six quills. You can get sex. Further, since the grinding is performed by the three quills 47 to 49, it is not necessary to change the rotation directions of the quills 47 to 49, and the grinding condition and the dressing condition are the same to improve the machining accuracy. You can In addition to this, the grindstone shaft 47-
Since there are three 49, it is possible to reduce the size and cost of the grinding machine.

[0029]

According to the first aspect of the present invention, it is possible to support a grindstone shaft having a relatively low strength with high rigidity, and reduce a reaction force received by the grindstone from a dresser or a cage during dressing or grinding. You can Therefore, it is possible to prevent escape from occurring between the grindstone, the dresser, and the cage, and it is possible to perform proper dressing and heavy grinding. As a result, the grinding performance of the cage window can be improved.

Further, since the reaction force received from the cage can be reduced, the heavy grinding can be performed to grind the cage window in a short time, and the productivity equivalent to that using the six quills can be obtained. Obtainable. Further, since the grinding is performed by the three grindstone shafts, it is not necessary to change the rotating directions of the grindstone shafts to each other, and the grinding condition and the dressing condition can be made the same to improve the processing accuracy. In addition to this, since there are three grindstone shafts, it is possible to reduce the size and cost of the grinding machine.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a cage window grinder according to the invention described in claim 1, and is a configuration diagram thereof.

FIG. 2 is a view showing the arrangement of the grinding stone heads.

3 (a) is a sectional view taken in the direction of arrow A in FIG. 1, and FIG. 3 (b) is a sectional view taken in the direction of arrow BB in FIG. 3 (a).

4A and 4B are diagrams showing a configuration of a cage, in which FIG. 4A is a side view thereof, and FIG. 4B is a sectional view thereof.

[Explanation of symbols]

 1 Bed 3 Slide part 9 Spindle 12 Chuck 13 Cage 18 Drive mechanism 23 Rotation mechanism 25 Dresser mount 26 Dresser 34 Dresser drive mechanism 44 ~ 46 Grinding wheel 47 ~ 49 Quill (grinding wheel axis) 50 Feeder 52a Fluid bearing

Claims (1)

[Claims] 1. A bed, a slide portion slidably provided on the bed and driven by a drive mechanism, and a chuck rotatably supported in the slide portion and holding a cage at one end thereof, A main shaft rotated by a rotating mechanism provided on the slide portion, a dresser mount rotatably supported by the main shaft and having a dresser on the chuck side, and driven to rotate by a dresser drive mechanism, and the main shaft rotating. Three grindstone shafts that are rotatably provided around a rotation axis that is perpendicular to the axis and that are arranged at equal intervals radially with the central axis of the main shaft sandwiched between them, and that are provided on the grindstone shafts, respectively. A feed device for moving the grindstone shaft in a direction perpendicular to the axis of rotation of the main shaft, and a fluid bearing for rotatably supporting the grindstone shaft. Cage window grinding machine which is characterized.