JP2007296585A - Method of manufacturing bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a bearing device, which restrains the occurrence of grinding burning, improves stability in quality, and also improves product load capacity. <P>SOLUTION: The manufacturing method of the bearing device is provided for grinding ball transfer grooves 5 and 6 of an external member 4 of the bearing device, by rotating a grinding wheel member 3 having projecting grinding surface parts 1 and 2 around its axis. The ball transfer grooves 5 and 6 are ground by obliquely notching by the projecting grinding surface parts 1 and 2 in the direction forming a predetermined inclination to the axis of the external member 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a method for manufacturing a bearing device.

  The bearing device includes a wheel bearing device. The wheel bearing device is a so-called first generation or second generation in which a pair of inner rings are mounted (press-fitted) on a hub ring, and a raceway surface directly on the outer periphery of the hub ring. What is called the 3rd generation that formed (rolling surface), and what is called the 4th generation that formed the raceway surface (rolling surface) directly on the outer periphery of the outer joint member of the hub wheel and constant velocity universal joint, respectively. There is.

  For example, as shown in FIG. 7, the wheel bearing device called the third generation (Patent Document 1 and Patent Document 2) includes a hub wheel 102 having a flange 101 extending in the outer diameter direction, and a cylindrical portion 113 of the hub wheel 102. The bearing structure part 100 arrange | positioned at the outer peripheral side of this is provided. An outer joint member of a constant velocity universal joint (not shown) is fixed to the hub wheel 102.

  The hub wheel 102 has a cylindrical portion 113 and the flange 101, and a short cylindrical pilot portion in which a wheel and a brake rotor (not shown) are mounted on the outer end surface (wheel mounting surface) 114 of the flange 101. 115 protrudes. The pilot portion 115 includes a large-diameter first portion 115a and a small-diameter second portion 115b. A brake rotor is externally fitted to the first portion 115a, and a wheel is externally fitted to the second portion 115b.

  A notch 116 is provided on the opposite side to the flange portion of the cylindrical portion 113, and the inner ring 117 of the bearing structure portion 100 is fitted into the notch 116. Further, a bolt mounting hole 112 is provided in the flange 101 of the hub wheel 102, and a hub bolt 106 for fixing the wheel and the brake rotor to the flange 101 is mounted in the bolt mounting hole 112.

  The bearing structure unit 100 includes the inner ring 117, an outer member (outer ring) 105, and balls 122 as rolling elements. The outer member 105 is provided with two rows of outer raceway surfaces 120 and 121 on its inner periphery, and a flange (vehicle body mounting flange) 132 on its outer periphery. A first inner raceway surface 118 is provided in the vicinity of the flange on the outer peripheral surface of the tubular portion 113 of the hub wheel 102, and a second inner raceway surface 119 is provided on the outer peripheral surface of the inner ring 117.

  The first outer raceway surface (ball transfer groove) 120 of the outer member 105 and the first inner raceway surface (ball transfer groove) 118 of the hub wheel 102 face each other, and the second outer raceway surface 121 of the outer member 105. And the raceway surface 119 of the inner ring 117 face each other, and a ball 122 is interposed therebetween.

  By the way, the ball transfer grooves 120 and 121 of the outer member 105 are ground and formed by the grinding apparatus described in Patent Document 1. That is, as shown in FIG. 8, this grinding apparatus uses a grindstone member 128 having a shaft portion 125 and a pair of protruding grinding surface portions 126 and 127 disposed on the outer diameter portion of the shaft portion 125. Further, the grindstone member 128 has an inner diameter grinding surface portion 132 that grinds the inner diameter surface 131 of the outer member 105 between the ridge grinding surface portions 126 and 127.

  In this case, the outer member 105 is mounted on the base member 130, and if the base member 130 rotates about its axis L, the outer member 105 also rotates about this axis L. Further, the shaft center L of the grindstone member 128 is arranged at a position eccentric in parallel with the shaft center L.

At the time of groove grinding, the outer member 105 is rotated around the axis L, and the grindstone member 128 is rotated around the axis L1 in the opposite direction or the same direction as the rotation direction of the outer member 105. Accordingly, the ball transfer grooves 120 and 121 can be ground by the ridge grinding surface portions 126 and 127 of the grindstone member 128. Further, when the ball transfer grooves 120 and 121 are ground, the inner diameter surface 131 between the protruding grinding surface portions 126 and 127 is ground by the inner diameter grinding surface portion 132.
JP 2005-325903 A Japanese Utility Model Publication No. 2004-52784

  However, as described above, conventionally, as shown in FIG. 6, since the ridge grinding surface portion is cut in a direction perpendicular to the axis of the outer member 105, the machining allowance (cutting allowance) is X 0 at the groove center position. In some cases, the allowance (cutting allowance) of the groove shoulder 121a is X1. At this time, X1> X0.

  By the way, in such a bearing device, it is necessary to deepen the ball transfer groove in order to improve the load capacity. For this reason, if the ball transfer groove is deepened by the conventional method as described above, the allowance (cutting allowance) of the groove shoulder 121a is further increased. For this reason, an increase in grinding cycle time and grinding burn occur. Further, in order to prevent grinding burn, it is necessary to provide a margin for the cutting position, resulting in a cycle time reduction and inferior productivity.

  Thus, as shown in FIG. 5, (H / D) is generally limited to 0.38 when the groove depth is H and the ball diameter (diameter) is D due to grinding burn and cycle time restrictions. It is said. However, in order to improve the product load capacity, it is necessary to increase (H / D).

  In view of the above problems, the present invention provides a method of manufacturing a bearing device that can suppress the occurrence of grinding burn, improve the stability of quality, and improve the product load capability.

  A method for manufacturing a bearing device according to the present invention is a method for manufacturing a bearing device in which a grindstone member having a ridge grinding surface portion is rotated around its axis to grind a ball transfer groove of an outer member of the bearing device, The ball transfer groove is ground by cutting in a slanting direction at the ridge grinding surface along a direction forming a predetermined inclination angle with respect to the axis of the outer member.

  In the bearing device manufacturing method of the present invention, the ball transfer groove is ground by cutting obliquely at the ridge grinding surface along the direction forming a predetermined inclination angle with respect to the axis of the outer member. The machining allowance (cutting allowance) of the shoulder can be made comparable to the machining allowance (cutting allowance) at the groove center position, and the allowance (cutting allowance) of the shoulder can be reduced.

  The grindstone member has a pair of ridge grinding surface portions, and the axial arrangement pitch of the pair of ridge grinding surface portions is made larger than the axial arrangement pitch of the ball transfer groove to be ground, so that one projection After grinding one ball transfer groove at the ridge grinding surface portion and simultaneously grinding the counter bore portion of the other ball transfer groove at the other ridge grinding surface portion, the other ball transfer groove is formed at the other ridge grinding surface portion. At the same time as grinding, the counter bore portion of one ball transfer groove can be ground by one ridge grinding surface portion.

  When grinding one ball transfer groove at one ridge grinding surface, the counterbore portion of the other ball transfer groove can be ground, and the other ball at the other ridge grinding surface When grinding the transfer groove, it is possible to grind the counterbore part of one ball transfer groove at one ridge grinding surface part. As a result, two rows of ball transfer grooves can be formed simultaneously. In addition, by using a grindstone member in which the axial arrangement pitch of the pair of ridge grinding surfaces is larger than the axial arrangement pitch of the ball transfer groove to be ground, a predetermined inclination with respect to the axis of the outer member is obtained. It is possible to cut stably and surely at the ridge grinding surface along the direction forming the angle.

  According to the method for manufacturing a bearing device of the present invention, the allowance for the shoulder (cutting allowance) can be reduced. For this reason, it is possible to reduce the cutting speed, suppress the occurrence of grinding burn, and stabilize the quality of the product to be ground (in this case, the outer member). Even when the cutting speed is reduced, the shoulder allowance (cutting allowance) is small, so that the overall processing time (grinding time) can be shortened, the work time can be shortened, and the productivity is excellent. Furthermore, since the depth of the groove can be increased and H / D (groove depth / ball diameter) can be increased, the product load capacity is improved.

  By using a grindstone member in which the axial arrangement pitch of the pair of ridge grinding surface portions is larger than the axial arrangement pitch of the ball transfer groove to be ground, a predetermined inclination angle is set with respect to the axis of the outer member. It is possible to stably and surely cut the protruding grinding surface portion along the formed direction, and to form two rows of ball transfer grooves at the same time. For this reason, it is possible to grind the two rows of ball transfer grooves of the outer member in an extremely short time, thereby improving productivity and reducing production cost.

  An embodiment of a method for manufacturing a bearing device according to the present invention will be described with reference to FIGS.

  FIG. 1 shows a method of manufacturing a bearing device according to the present invention. In this method, a grindstone member 3 having protruding grinding surface portions 1 and 2 is rotated around its axis L1, and the outer member 4 of the bearing device is rotated. The ball transfer grooves 5 and 6 are ground. The bearing device is, for example, a wheel bearing device as shown in FIG.

  That is, the outer member 4 has the ball transfer grooves 5 and 6 disposed on the inner diameter surface 21 thereof at a predetermined pitch P1 along the axial direction. The ball 9 as a rolling element (see FIG. 2) interposed between the opposing ball transfer groove on the hub wheel side and the ball transfer groove on the inner ring mounted on the hub ring is fitted on the hub ring and the inner ring. Is done.

  The grindstone member 3 has a pair of raised grinding surface portions 1 and 2 and an inner diameter grinding surface portion 8 formed on the raised grinding surface portions 1 and 2, and its axis L1 is rotated by a driving device (not shown). To rotate. That is, the grindstone member 3 includes a barrel portion 7 and the ridge grinding surface portions 1 and 2 made of a ring body having a semicircular cross section that protrudes from the outer diameter surface of the barrel portion 7. In addition, the inner diameter grinding surface portion 8 for grinding the inner diameter surface 21 between the grooves 5 and 6 of the outer member 4 is formed between the ridge grinding surface portions 1 and 2.

  Next, the grinding method using the said grindstone member 3 is demonstrated. In this grinding method, the base member 10 similar to the base member 130 shown in FIG. 8 is used. That is, the ring-shaped outer member 4 is attached to the base member 10. At this time, the base member 10 and the outer member 4 are arranged on the same axis L. The base member 10 is rotationally driven by a driving device (not shown).

  First, one ball transfer groove 5 is ground by one ridge grinding surface portion 1. At this time, the base member 10 is rotated about the axis L, and the grindstone member 3 is rotated about the axis L1 in the direction opposite to the rotation direction of the base member 10. Then, the grindstone member 3 is rotated around its axis L1 and obliquely along a direction (in the direction of arrow A in FIG. 1) that forms a predetermined inclination angle θ1 (for example, 45 degrees) with respect to the axis of the outer member 4. Cut into. As a result, as shown in FIG. 2, the allowance (cutting allowance) X1 of the shoulder portion 11 of the ball transfer groove 5 can be made substantially equal to the allowance (cutting allowance) X0 at the groove center position. The machining allowance (cutting allowance) X1 can be reduced.

  At this time, as shown in FIG. 1A, the counter bore portion (shoulder portion) 12 of the other ball transfer groove 5 is ground at the other protruding grinding surface portion 2.

  Next, the other ball transfer groove 6 is ground by the other protruding grinding surface portion 2. At this time, the grindstone member 3 is rotated along its axis L1 and obliquely along a direction (in the direction of arrow B in FIG. 2) forming a predetermined inclination angle θ2 (for example, 45 degrees) with respect to the axis of the outer member 4. Cut in the direction. As a result, the machining allowance (cutting allowance) X1 of the shoulder 13 of the ball transfer groove 6 can be made substantially equal to the allowance (cutting allowance) X0 at the groove center position. Can be small.

  At this time, as shown in FIG. 1B, the counter bore portion (shoulder shoulder portion) 14 of the other ball transfer groove 5 is ground by the other protruding grinding surface portion 1.

  For this reason, on one ball transfer groove 5 side, as shown in FIG. 3, a first grinding surface 15 and a second grinding surface 16 (counter bore portion 14) are formed in the protruding grinding surface portion 1. That is, the first grinding surface 15 is formed along the first arc 15a, and the second grinding surface 16 is formed along the second arc 16a. In addition, the protrusion 17 formed between the 1st grinding surface 15 and the 2nd grinding surface 16 can be removed, and it can also form in straight.

  Further, also on the other ball transfer groove 5 side, as shown in FIG. 4, in the ridge grinding surface portion 2, the first grinding surface 18 formed along the first arc 18a and the second arc 19a. The second grinding surface 19 (counter bore portion 12) formed in this manner is formed. In addition, the protrusion 20 formed between the 1st grinding surface 18 and the 2nd grinding surface 19 can be removed, and it can also form in straight.

  Further, when the ball transfer grooves 5 and 6 are ground in this way, the inner diameter surface 21 of the outer member 4 is ground by the inner diameter grinding surface portion 8.

  By the way, for the grinding operation, for example, an NC device is used. That is, the control means for controlling the operation of the driving device for the base member 10 and the grindstone member 3 is digitally controlled by numerical commands programmed in advance.

  Thus, H / D can be increased by grinding. H is the depth of the groove, and D is the diameter (diameter) of the ball 9 (see FIG. 2). That is, as shown in FIG. 2, in one ball transfer groove 5, the allowance (cutting allowance) X <b> 1 of the shoulder 13 is set to be approximately the same as the allowance X <b> 0 of the groove center, thereby increasing the depth of the groove. And H / D can be increased. Also, in the other ball transfer groove 6, by making the allowance (cutting allowance) X <b> 1 of the shoulder portion 13 approximately the same as the allowance X <b> 0 of the groove center, the depth of the groove can be increased. D can be increased.

  In addition, as a grindstone used for the grindstone member 3, general things, such as a vitrified grindstone, can be used. Here, the vitrified grindstone is a grindstone using a porcelain binder having a strong abrasive grain retention. However, if such a vitrified grindstone is used, it is necessary to perform dressing. Dressing is an operation for removing abrasive grains that are clogged or clogged and regenerating the cutting edge.

If dressing is performed, the grinding wheel wear pitch increases, and accordingly, NC program correction is required. On the other hand, when the CBN electrodeposition grindstone is used, dressing is not required, and there is no need for NC program correction, which is advantageous in terms of cost. For this reason, it is preferable to use this CBN electrodeposition grindstone for the grindstone member 3.

  According to the method for manufacturing a bearing device of the present invention, the ball transfer grooves 5 and 6 are ground by cutting at the ridge grinding surface portions 1 and 2 along a direction forming a predetermined inclination angle with respect to the axis L of the outer member 4. Therefore, the machining allowance (cutting allowance) of the shoulder portions 11 and 13 of the ball transfer grooves 5 and 6 can be made to be approximately the same as the machining allowance (cutting allowance) at the groove center position. Can be made smaller. For this reason, the cutting speed can be reduced to suppress the occurrence of grinding burn, and the quality of the product to be ground (in this case, the outer member 4) can be stabilized. Even if the cutting speed is reduced, the machining allowance (cutting allowance) of the shoulder portions 11 and 13 is small, so that the overall machining time (grinding time) can be shortened, and the working time can be shortened, resulting in productivity. Excellent. Furthermore, since the depth of the groove can be increased and H / D (groove depth / ball diameter) can be increased, the product load capacity is improved.

  By using a grindstone member in which the pitch in the axial direction of the pair of ridge grinding surfaces 1 and 2 is larger than the pitch in the axial direction of the ball transfer grooves 5 and 6 to be ground, On the other hand, the ridge grinding surface portion can be stably and surely cut along the direction forming a predetermined inclination angle, and two rows of ball transfer grooves can be simultaneously formed. For this reason, it is possible to grind the two rows of ball transfer grooves of the outer member in an extremely short time, thereby improving productivity and reducing production cost.

  In each of the ball transfer grooves 5 and 6, counter bore portions 12 and 14 are provided. This is because the ball 9 and the cage that supports the ball 9 are externally attached when the wheel bearing device is assembled. It is intended not to drop when temporarily assembled to the side member. For this reason, the ball transfer grooves 5 and 6 are formed along two arcs, so that there is a possibility that so-called “backlash” may occur. However, since the hub wheel is preloaded and incorporated, there is no “backlash”.

By the way, unlike the above embodiment, it is possible to form (grind) one groove after forming (grinding) one groove with a single grindstone. By using such a single grindstone, (H / D) can be increased (for example, about 4.5). However, grinding a groove with a single grindstone allows simultaneous grinding of two grooves and simultaneous grinding between grooves as compared to using an integral grinding wheel that can grind two grooves simultaneously. The cycle time becomes longer.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, as a bearing device, a wheel hub bearing (wheel bearing device) is used. The present invention is not limited to this, and various angular bearing devices used for various machine tools, hydraulic pumps, and the like may be used. In the embodiment, the wheel bearing device is also described on the premise of what is called the third generation in which the raceway surface (rolling surface) is directly formed on the outer periphery of the hub wheel, corresponding to FIG. The first generation or the second generation, in which a pair of inner rings are mounted (press-fitted) on the outer ring, and a fourth raceway surface (rolling surface) formed directly on the outer circumference of the outer joint member of the hub wheel and constant velocity universal joint. It may be called a generation.

  Further, as the cutting direction of the grindstone member 3, the allowance (cutting allowance) of the shoulder portions 11 and 13 of the ball transfer grooves 5 and 6 can be set to the same extent as the allowance (cutting allowance) at the groove center position. Various changes can be made. Further, in the embodiment, after grinding one ball transfer groove 5, the other ball transfer groove 6 is ground, but conversely, after grinding the other ball transfer groove 6, The transfer groove 5 may be ground.

1A and 1B show a manufacturing method of a bearing device according to an embodiment of the present invention, in which FIG. 1A is a cross-sectional view of a main part in a state where one ball transfer groove is ground, and FIG. FIG. It is explanatory drawing of the grinding direction of a grindstone member. It is a principal part expanded sectional view which shows one ball transfer groove ground by the grindstone member. It is a principal part expanded sectional view which shows the other ball | bowl transfer groove | channel ground by the grindstone member. It is a principal part expanded sectional view which shows the relationship between the depth of a groove | channel, and the diameter of a ball | bowl. It is explanatory drawing of the grinding direction of the conventional grindstone member. It is sectional drawing of the bearing apparatus for wheels. It is sectional drawing which shows the conventional grinding method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ridge grinding surface part 2 Ridge grinding surface part 3 Grinding wheel member 4 Outer member 5 Ball transfer groove 6 Ball transfer grooves 12, 14 Counter bore part

Claims (2)

A method of manufacturing a bearing device in which a grindstone member having a ridge grinding surface portion is rotated about its axis to grind a ball transfer groove of an outer member of the bearing device,
A method of manufacturing a bearing device, characterized in that a ball transfer groove is ground by cutting in an oblique direction at a ridge grinding surface along a direction that forms a predetermined inclination angle with respect to an axis of an outer member.   The grindstone member has a pair of ridge grinding surface portions, and the axial arrangement pitch of the pair of ridge grinding surface portions is made larger than the axial arrangement pitch of the ball transfer groove to be ground, so that one projection After grinding one ball transfer groove at the ridge grinding surface portion and simultaneously grinding the counter bore portion of the other ball transfer groove at the other ridge grinding surface portion, the other ball transfer groove is formed at the other ridge grinding surface portion. 2. The method of manufacturing a bearing device according to claim 1, wherein the counter bore portion of one ball transfer groove is ground at one ridge grinding surface portion at the same time as grinding.

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