JP5884401B2 - Method for manufacturing outer ring member of rolling bearing for wheel - Google Patents

Description

  The present invention relates to a method for manufacturing an outer ring member of a wheel rolling bearing.

The manufacturing method of the rolling bearing for wheels is disclosed by patent document 1, for example.
In this, as shown in FIG. 6, the outer member 202 is formed by forging while leaving a predetermined turning allowance from a round bar, and in this forging process, double row outer rolling surfaces 202a, 202a are formed. Shoulder portions 217 and 217 are formed in a tapered shape that gradually decreases in diameter toward the central portion in the axial direction of the portion to be the double row outer rolling surfaces 202a and 202a. Then, a disc portion 218 is provided approximately in the middle between both tapered portions, and the disc portion 218 is deleted by punching, and then formed into a predetermined dimension by turning.
The outer member (outer ring member) 202 as a turned product also has a tapered shape that gradually decreases in diameter from the shoulder portions 217 and 217 of the double row outer rolling surfaces 202a and 202a toward the central portion in the axial direction. Is formed.
Therefore, according to the invention of Patent Document 1, the difference between the shape of the outer member 202 formed by the forging process and the shape of the outer member 202 as a product formed by the turning process is reduced. The turning allowance for turning the outer member 202 in the process is reduced.

JP 2008-45699 A

  Between this kind, the inner member (corresponding to the inner ring member) and the outer member 202 (corresponding to the outer ring member), the double row balls on the inner side and the outer side of the vehicle are on the same arrangement pitch circle. In a rolling bearing device for a wheel that is arranged so as to be able to roll, it is necessary to ensure a so-called “ball shoulder climbing prevention performance” that prevents the ball from riding on the shoulder edge of the outer ring raceway shoulder. The In order to ensure the ability to prevent the ball from climbing to the shoulder, a vertical line passing through the center 0 'of the arc of the outer rolling surface 202a (the vehicle outer outer ring raceway surface located on the right side in FIG. 6) from past usage results. An angle θ ′ formed by L1 ′ and a line L2 ′ connecting the shoulder edge portion P ′ of the shoulder portion 217 and the arc center 0 ′ is required to be set in a range of 70 to 85 degrees.

  In the invention of Patent Document 1, only the turning allowance for turning on the outer member is reduced, and the use of a material that takes into account the difference in the performance to prevent shoulder rise required for the balls in the vehicle outer row and the balls in the vehicle inner row No design has been made to reduce the amount to reduce the cost.

  Thus, the problem to be solved by the present invention is to reduce the amount of material used and reduce the cost while taking a manufacturing method for reducing the turning allowance of the turning of the outer ring member of the rolling bearing for the wheel. It is to ensure the performance of preventing the shoulder climbing.

In order to solve the above-mentioned problem, the outer ring member manufacturing method of the rolling bearing for wheel according to the present invention, the outer ring member has a vehicle inner outer ring raceway surface and a vehicle outer outer ring raceway surface, A forging step in which an outer ring forged product is formed by forging the material of the outer ring member, and a turning step in which the outer ring member is formed by turning the outer ring forged product. By forging the material of the member, in the outer ring forged product, the inner diameter of the portion that becomes the shoulder of the outer race surface of the vehicle inner side becomes larger than the inner diameter of the portion that becomes the shoulder of the race surface of the outer outer ring of the vehicle. The cross-sectional shape of the center hole that connects the portion that becomes the shoulder portion of the outer race surface of the vehicle outer surface and the portion that becomes the shoulder portion of the race surface of the inner outer ring surface has a tapered shape in which the hole diameter increases from the vehicle outer side toward the vehicle inner side. Before When the outer ring forged product is turned in the turning process, the inner diameter of the shoulder portion of the vehicle inner outer ring raceway surface of the member becomes larger than the inner diameter of the shoulder portion of the vehicle outer outer ring raceway surface, and the center hole The cross-sectional shape is a tapered shape in which the hole diameter increases from the vehicle outer side toward the vehicle inner side, and further, a vertical line passing through the center of the arc that is the cross-sectional shape of the vehicle outer outer ring raceway surface and the shoulder of the vehicle outer outer ring raceway surface the angle between the line connecting the edge portion is in the range of 85 degrees from 70 degrees, in the turning step, you and performing turning with respect to the central hole of the outer ring forgings in a straight shape.

In the manufacturing method of the present invention, in the forged product of the outer ring member formed by forging in the forging process, the inner diameter before turning at a position that becomes the shoulder portion of the inner ring raceway surface after turning is the outer outer ring raceway after turning. The material of the outer ring member is forged so as to be larger than the inner diameter before turning at a portion that becomes the shoulder portion of the surface.
In the manufacturing method of the present invention, in the outer ring member that has been turned in the turning process, the inner diameter of the shoulder portion of the vehicle inner outer ring raceway surface is larger than the inner diameter of the shoulder portion of the outer outer ring raceway surface. The forged product of the outer ring member is turned.
For this reason, the difference between the shape of the forged product of the outer ring member and the shape of the outer ring member that has been turned is reduced. As a result, the turning allowance for turning is reduced. The “turning allowance” here refers to the turning allowance required to form a product shape portion of the outer ring member that requires accuracy by forging so that it is formed larger than the product shape and is accurately formed by turning. say.

  Next, the product shape of the outer ring member of the manufacturing method of the present invention is based on the outer ring raceway surface on the inner side of the vehicle, taking into account the difference in shoulder climbing prevention performance required for the balls in the outer row and the inner row. The inner diameter dimension of the shoulder edge portion of the track shoulder is set to be larger than the inner diameter dimension of the shoulder edge portion of the track shoulder portion of the outer ring raceway surface outside the wheel, and the shoulder edge portion outside the vehicle and the shoulder edge portion inside the vehicle The central hole that connects the two is gradually enlarged from the vehicle outer side toward the vehicle inner side. Thereby, the forged product shape formed by the forging process is also formed as a shape obtained by adding a turning allowance to the product shape. For this reason, in both of the forged product shape and the product shape in the present invention, the center hole that connects the shoulder edge portion on the outside of the vehicle and the shoulder edge portion on the inside of the vehicle gradually increases from the outside of the vehicle toward the inside of the vehicle. Compared with the case where the center hole connecting the shoulder edge on the outside of the vehicle and the shoulder edge on the inside of the vehicle, which is a conventional general shape, is formed in a cylindrical surface, which is a large diameter, from the outside of the vehicle. The amount of material used for the outer ring member can be reduced by the amount gradually formed toward the inside of the vehicle. And cost reductions, such as material cost corresponding to the reduction | decrease of this raw material usage-amount, can be aimed at.

  In addition, when the difference of the shoulder climbing prevention performance required for the balls in the vehicle outer row and the balls in the vehicle inner row, which the present inventor paid attention to, is described, the moment load generated when the vehicle turns turns the load on the vehicle outer row. By acting on the balls, the contact angle of the balls in the vehicle outer row becomes larger than the contact angle when the vehicle does not turn. For this reason, when the vehicle turns, the balls in the vehicle outer row easily ride on the shoulders on the vehicle outer track. Therefore, the angle formed by the vertical line passing through the center of the arc of the outer raceway surface of the vehicle outer surface and the line connecting the shoulder edge of the shoulder of the vehicle outer track and the center of the arc is also the shoulder edge of the vehicle outer row. Is preferably set larger than the angle of the shoulder edge portion of the vehicle interior row. In other words, even when the double rows of balls on the inside and outside of the vehicle are arranged on the same arrangement pitch circle, the angle of the shoulder edge portion is set closer to that of the inside row than the angle of the outside row. The angle can be set small, and the inner diameter of the shoulder edge of the track shoulder on the inner side of the vehicle is different from that of the outer row of the vehicle. It can be set small. The inventor has focused on this point and conceived of making the product shape of the present invention.

  Further, according to the outer ring member manufacturing method of the present invention, the vertical line passing through the center of the arc of the outer raceway surface of the vehicle outer side and the line connecting the shoulder edge portion of the shoulder of the vehicle outer track and the center of the arc are Since the formed angle θ is formed in the range of 70 degrees to 85 degrees required from past use results, it is possible to ensure the performance of preventing the balls on the shoulder of the vehicle outside row from climbing. In the present specification, “the ability to prevent the ball from climbing on the shoulder” means that the ball does not ride on the shoulder edge of the shoulder portion of the outer ring raceway.

  According to the manufacturing method of the present invention described above, while using a manufacturing method for reducing the turning allowance for turning of the outer ring member of the wheel rolling bearing, the amount of material used is reduced, the cost is reduced, and the ball shoulder Raising prevention performance can be secured.

It is a longitudinal cross-sectional view which shows the rolling bearing device for wheels which concerns on Example 1 of this invention. It is a longitudinal cross-sectional view which similarly shows an outer ring member. It is a longitudinal section showing an outer ring forging corresponding to an outer ring member similarly. It is a longitudinal cross-sectional view which shows the outer ring member which concerns on Example 2 of this invention. It is a longitudinal section showing an outer ring forging corresponding to an outer ring member similarly. It is a longitudinal cross-sectional view which shows the conventional outer ring member.

  A mode for carrying out the present invention will be described according to an embodiment.

A first embodiment of the present invention will be described with reference to FIGS. FIGS. 1 and 2 show an example of a wheel bearing device of a final product shape produced by the manufacturing method of the present invention, FIG. 1 shows the whole, and FIG. 2 is an enlarged half cross section of an outer ring member. Show.
As shown in FIG. 1, a wheel bearing device (sometimes called a wheel hub unit)
An inner ring member 10 as a hub wheel, an outer ring member 60 disposed on the outer peripheral surface of the shaft portion 11 of the inner ring member 10 while maintaining an annular space, and an equivalent arrangement between both members 10 and 60 of the inner and outer rings. A double-row angular ball bearing is configured by including double-row balls 55 and 56 in the vehicle inner row and the vehicle outer row that are arranged so as to roll on a pitch circle.

The inner ring member 10 integrally includes a shaft portion 11 and a flange portion 20 formed on the outer peripheral surface of one end portion of the shaft portion 11.
Further, in the first embodiment, the shaft portion 11 of the inner ring member 10 is formed in a step shaft shape in which the flange portion 20 side has a large diameter and the distal end side has a small diameter. Further, a vehicle outer side inner ring raceway surface 51 is formed on the outer peripheral surface of the large diameter part 12 of the shaft part 11 of the inner ring member 10.
Further, the inner ring body 45 is fitted on the outer peripheral surface of the small diameter portion 13 of the shaft portion 11, and the tip portion of the shaft portion 11 is caulked outward in the radial direction to form the caulking portion 14. An inner ring body 45 is fixed to the outer peripheral surface. A vehicle inner ring raceway surface 50 is formed on the outer circumferential surface of the inner ring body 45.

In addition, a fitting shaft portion 30 having a diameter larger than that of the shaft portion 11 is formed in the center portion of the outer surface (vehicle width direction outer surface) of the flange portion 20 of the inner ring member 10. A brake rotor fitting portion is formed on the flange portion 20 side, and a wheel fitting portion having a slightly smaller diameter than the brake rotor fitting portion is formed on the distal end side.
A hub bolt 25 that presses and fixes a wheel with a brake rotor interposed therebetween is press-fitted and fixed to the flange portion 20 of the inner ring member 10.

The outer ring member 60 is disposed on the outer peripheral surface of the shaft portion 11 of the inner ring member 10 while maintaining an annular space.
On the inner peripheral surface of the outer ring member 60, the inner and outer outer raceway surfaces 70 and 71 corresponding to the inner and outer race inner raceway surfaces 50 and 51 of the inner ring member 10 are maintained at predetermined intervals in the axial direction. Is formed.
Between the inner ring raceway surfaces 50 and 51 on the inner side and the outer side of the inner ring member 10 and the outer ring raceway surfaces 70 and 71 on the inner side and the outer side of the outer ring member 60, The double rows of balls 55 and 56 are arranged so as to roll while being held by the cages 57 and 58.
Further, on the outer peripheral surface of the outer ring member 60, a body side member, for example, a knuckle supported by a vehicle suspension device (not shown), or a fixing flange 61 fastened by a bolt to a mounting surface of a carrier is integrally formed. ing.

When a moment load generated when the vehicle turns turns acts on the balls 56 in the outer row, the contact angle of the balls 56 in the outer row when the vehicle turns makes the contact angle of the outer row when the vehicle does not turn. The contact angle of the ball 56 becomes larger. For this reason, when the vehicle turns, the balls 56 in the vehicle outer row can easily ride on the shoulders 75 on the vehicle outer track. The ability to prevent this ball from climbing on the shoulder edge of the outer ring raceway shoulder is referred to as “shoulder climbing prevention performance”.
In view of the above, in order to secure the shoulder climb prevention performance of the balls 56 in the vehicle outer side row, as shown in FIG. 2, it passes through the center 0 of the arc of the vehicle outer side outer ring raceway surface 71 of the outer ring member 60. The angle θ formed by the vertical line L1 and the line L2 connecting the shoulder edge portion 76 of the vehicle outer track shoulder 75 and the center 0 of the arc is set in the range of 70 to 85 degrees.

In order to reduce the amount of material used, that is, the weight of the outer ring member 60, the inner diameter dimension B of the shoulder edge portion 73 of the inner track shoulder 72 of the vehicle inner outer ring raceway surface 70 is the outer side of the vehicle outer outer raceway surface 71. The inner diameter dimension A of the shoulder edge portion 76 of the track shoulder portion 75 is set to be larger. The center hole 65 connecting the shoulder edge portion 76 of the vehicle outer track shoulder 75 and the shoulder edge portion 73 of the vehicle inner track shoulder 72 is gradually formed in a large diameter from the vehicle outer side toward the vehicle inner side. Yes.
In the first embodiment, the center hole 65 that connects the shoulder edge portion 76 of the vehicle outer track shoulder 75 and the shoulder edge portion 73 of the vehicle inner track shoulder 72 gradually increases from the vehicle outer side toward the vehicle inner side. It is formed in the taper hole formed in the large diameter.

The wheel rolling bearing device according to the first embodiment is configured as described above.
Therefore, the angle θ formed by the vertical line L1 passing through the arc center 0 of the outer outer raceway surface 71 and the line L2 connecting the shoulder edge portion 76 of the outer race shoulder 75 and the arc center 0 is set to 70 degrees. By setting the angle within the range of ˜85 degrees, it is possible to secure the shoulder climb prevention performance of the balls 56 in the vehicle outer row.
And the center hole 65 which connects the shoulder edge part 76 of the vehicle outer side track shoulder 75 and the shoulder edge part 73 of the vehicle inner side track shoulder 72 is gradually formed in a large diameter from the vehicle outer side toward the vehicle inner side. As a result, the center hole 65 is gradually formed to have a larger diameter from the vehicle outer side toward the vehicle inner side as compared with the case where the center hole 65 is formed in the cylindrical surface with the size of the inner diameter A of the shoulder edge portion 76 on the vehicle outer side. It is possible to reduce the amount of material used, that is, the weight by the amount of the generated material, thereby reducing the material cost and reducing the weight of the entire apparatus.

  Further, when the center hole 65 that connects the shoulder edge portion 76 of the vehicle outer track shoulder 75 and the shoulder edge portion 73 of the vehicle inner track shoulder 72 is formed into a tapered hole, the turning process is performed in a straight shape. This makes it easy to turn the center hole 65.

Next, a method for manufacturing the outer ring member used in the wheel rolling bearing device according to the first embodiment will be described.
The manufacturing method of the outer ring member of Example 1 includes a forging process, a turning process, a heat treatment process, and a polishing process. In this embodiment, the forging process will be described as including a forging process as the first process and a punching process as the second process. If the predetermined forged product shape can be formed only by the forging process in the first step, the punching process in the second step can be omitted.
First, in a forging process (first process of the forging process), a round bar is forged by hot forging or cold forging, and an outer ring forged product 80 having a shape corresponding to the outer ring member 60 is manufactured.
As shown in FIG. 3, when the outer ring forged product 80 corresponding to the outer ring member 60 is manufactured by forging, both the inner ring connecting portions 90 are left at both ends of the outer ring forged product 80, A vehicle exterior recess 87 is formed.
Further, the inner peripheral wall surface of the inner recess 85 is formed into a tapered surface 88 (taper surface having an angle larger than the draft angle of the forging die) while securing a turning allowance 70a on the inner peripheral side of the inner outer raceway surface 70. Is done.
Further, the inner peripheral wall surface of the outer-side recess 87 is formed in a shape close to a cylindrical surface having a turning allowance 71a on the inner peripheral side of the outer-wheel outer ring raceway surface 71 and having a draft angle of a forging die.
Next, in the punching process (second process of the forging process), a turning allowance 82 is secured on the inner peripheral surface of the center hole 65 of the outer ring member 60, and the intermediate connecting wall 90 of the outer ring forged product 80 is punched by a punch. .

Thereafter, in the turning process, each of a turning allowance 70a for the inner outer raceway surface 70, a turning allowance 71a for the outer outer raceway surface 71, a turning allowance 82 for the center hole 65, and another turning allowance 84 are provided. Turn.
Next, in the heat treatment step, the outer ring raceway surfaces 70 and 71 on the vehicle inner side and the vehicle outer side are heat-treated (quenched).
Finally, in the polishing process, the outer ring member 60 is manufactured by polishing the outer ring raceway surfaces 70 and 71 on the vehicle inner side and the vehicle outer side.

The outer ring member 60 to be a product can be easily manufactured through the above-described steps.
In particular, in the forging process, the inner peripheral wall surface of the inner recess 85 of the outer ring forged product 80 is formed as a tapered surface 88 that secures a turning allowance 70 a on the inner peripheral side of the inner outer raceway surface 70. As a result, the cylindrical surface of the inner peripheral wall surface is formed with the minimum diameter of the tapered surface compared to the case where the inner peripheral wall surface of the inboard recess 85 is formed on the cylindrical surface, so that the material is reduced by the taper shape. As a result, the outer ring forged product 80 can be formed with a high material yield, and the turning allowance, particularly the turning allowance 70a for the inner inner ring raceway surface 70, can be reduced. As a result, material costs and turning costs can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, the shape of the center hole 165 that connects the shoulder edge portion 176 of the vehicle outer track shoulder 175 and the shoulder edge portion 173 of the vehicle inner track shoulder 172 of the outer ring member 160 is changed.
That is, as shown in FIG. 4, the center hole 165 that connects the shoulder edge portion 176 of the vehicle outer track shoulder 175 of the outer ring member 160 and the shoulder edge portion 173 of the vehicle inner track shoulder 172 is formed from the vehicle outer side to the vehicle inner side. Are gradually formed with a large diameter, and the vicinity of the shoulder edge portion 176 of the vehicle outer track shoulder 175 and the vicinity of the shoulder edge portion 173 of the vehicle inner track shoulder 172 are respectively cylindrical surfaces 165a and 165b (axial direction). And a cylindrical surface having a cylinder length of 0.3 mm or more.

Further, the surface connecting the outer cylindrical surface 165b and the inner cylindrical surface 165a is a tapered hole 165c having a constant taper angle or a curved tapered surface 165d in which the taper angle gradually changes (see the two-dot chain line in FIG. 4). ).
Other configurations of the second embodiment are configured in the same manner as the first embodiment.
The outer ring member 160 described above is in the same order as the outer ring member manufacturing method described in the first embodiment in the order of the forging process (including the punching process), the turning process, the heat treatment process, and the polishing process. It is manufactured after.

As described above, in the second embodiment, as shown in FIG. 4, the shoulder edge portion 176 of the vehicle outer track shoulder 175 of the outer ring member 160 and the shoulder edge portion 173 of the vehicle inner track shoulder 172 are connected. In the center hole 165, the vicinity of the shoulder edge portion 176 of the vehicle outer track shoulder 175 and the vicinity of the shoulder edge portion 173 of the vehicle inner track shoulder 172 are formed in the cylindrical surfaces 165a and 165b, respectively.
For this reason, as shown in FIG. 5, in the punching process, the turning allowance 182 of the inner peripheral surface of the center hole 165 of the outer ring member 160 after the intermediate connecting wall 190 of the outer ring forged product 180 is punched is reduced. It becomes possible. Then, the turning process is facilitated by reducing the turning allowance 182 on the inner peripheral surface of the center hole 165 of the outer ring member 160.

  In addition, this invention is not limited to the said Example 1 and 2, In addition, it can implement with a various form.

DESCRIPTION OF SYMBOLS 10 Inner ring member 50 Car inner inner ring raceway surface 51 Car outer inner ring raceway surface 55 Car inner row ball 56 Car outer row ball 60 Outer ring member 65 Center hole 70 Car inner outer ring raceway 71 Car outer outer ring raceway surface 72 Car inner race shoulder Part 73 Shoulder edge part 75 Car outer side track shoulder part 76 Shoulder edge part 80 Outer ring forged product 85 Car inner side concave part 87 Car outer side concave part 90 Intermediate connecting wall

Claims (2)

A manufacturing method of the outer race member of the rolling bearing for car wheels,
The outer ring member has a vehicle inner outer ring raceway surface and a vehicle outer outer ring raceway surface,
The manufacturing method includes a forging step of forming an outer ring forged product by forging the material of the outer ring member, and a turning step of forming the outer ring member by turning the outer ring forged product,
In the forging process, the material of the outer ring member is forged in the forging step, so that the inner diameter of the portion that becomes the shoulder portion of the inner outer ring raceway surface is the shoulder portion of the outer outer ring raceway surface in the outer ring forged product. The cross-sectional shape of the central hole connecting the portion that becomes the shoulder portion of the outer raceway surface of the vehicle outer side and the location that becomes the shoulder portion of the raceway surface of the vehicle inner outer ring is larger than the inner diameter of the vehicle outer outer ring raceway surface. Becomes a tapered shape,
When the outer ring forged product is turned in the turning step, the inner diameter of the shoulder portion of the vehicle inner outer ring raceway surface of the member becomes larger than the inner diameter of the shoulder portion of the vehicle outer outer ring raceway surface, and the center hole The cross-sectional shape of the outer surface of the outer ring raceway is a tapered shape with a hole diameter increasing from the outside of the vehicle toward the inside of the vehicle. The angle formed by the line connecting the edges of the part is within the range of 70 degrees to 85 degrees,
In the turning step, turning the center hole of the outer ring forged product in a straight shape,
Manufacturing method of outer ring member of rolling bearing for wheel. It is a manufacturing method of the outer ring member of the rolling bearing for wheels according to claim 1,
In the turning process, the turning process in which the diameter of the center hole connecting the shoulder of the outer raceway surface of the vehicle outer surface and the shoulder of the outer raceway surface of the vehicle inner surface increases from the outside of the vehicle toward the inside of the vehicle, The vicinity of the shoulder edge portion of the shoulder portion of the raceway surface and the vicinity of the shoulder edge portion of the shoulder portion of the inner race surface of the vehicle inner side are respectively turned into a cylindrical surface, and the outer cylindrical surface and the inner cylindrical surface of the vehicle are The method of manufacturing an outer ring member of a rolling bearing for a wheel , wherein the connecting surface is a turning process formed in a straight tapered hole having a constant taper angle .

Images