WO2015050258A1

WO2015050258A1 - Production method for outer member for wheel bearing device

Info

Publication number: WO2015050258A1
Application number: PCT/JP2014/076619
Authority: WO
Inventors: 柴田　靖史
Original assignee: Ntn株式会社; 柴田　靖史
Priority date: 2013-10-04
Filing date: 2014-10-03
Publication date: 2015-04-09
Also published as: JP6224402B2; JP2015071183A

Abstract

Provided is a production method for an outer member for wheel bearing devices, using less material and having improved strength and improved rolling fatigue life. This production method comprises: a step in which a rod-shaped material has a center section thereof that is diameter-expanded and molded into a drum shape, by upsetting; a step in which a disc-shaped punched bore section (17) is molded by forging in substantially a center section, in the axial direction, between an outer circumferential section of an outer member (10), a cylindrical inner circumferential section including a plurality of rows of outside rolling surfaces (2a), and the plurality of rows of outside rolling surfaces (2a) in this inner circumferential section; and a step in which the punched bore section (17) is removed by punch boring using a punch. The distance (L1) from an end surface (17a) of the punched bore section (17) to the groove bottom of the outside rolling surfaces (2a) is set within a range of L1 = 0.15-0.4R, when R is the radius of curvature for the outer rolling surfaces (2a). When the thickness of the groove bottom section of the outside rolling surfaces (2a) is H1 and the thickness of the outer member (10) is H2, at the groove bottom position of the outside rolling surfaces (2a), H1 and H2 are set such that H2 = 1.3-2.0H1.

Description

Method for manufacturing outer member of wheel bearing device

The present invention relates to a hub wheel of a wheel bearing device that supports a wheel of an automobile or the like, more specifically, an outer surface of a wheel bearing device having a vehicle body mounting flange and having a double-row inner raceway formed directly on the inner periphery. The present invention relates to a method for manufacturing a rectangular member.

A power transmission device that transmits engine power of a vehicle such as an automobile to a wheel transmits power from the engine to the wheel, and also causes radial or axial displacement from the wheel that occurs when the vehicle bounces or turns when traveling on a rough road. For example, one end of a drive shaft interposed between the engine side and the wheel side is connected to the differential through a sliding type constant velocity universal joint and the other end is required to allow moment displacement. Is connected to the wheel via a wheel bearing device including a fixed type constant velocity universal joint.

Further, the wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device. Second generation structure in which body mounting flange or wheel mounting flange is formed directly on the outer periphery of the member, third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel, or hub wheel, etc. It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the speed universal joint.

Among these wheel bearing devices, a wheel bearing device referred to as a third generation is provided with a hub wheel integrally having a wheel mounting flange for mounting a wheel and having an inner rolling surface directly formed on the outer periphery. For example, after the hub wheel is generally formed by forging, the surface scale is removed by shot blasting, and functional parts such as the inner rolling surface are cut by a dedicated turning line, induction hardening process, grinding Moved to the process. The hub wheel formed by this forging process is mainly made of steel such as S53C, and the inner raceway surface and other parts are hardened by induction hardening.

By the way, the hub wheel of this third generation wheel bearing device has a function as a structure for rotatably supporting the wheel and a function as a race of a double row rolling bearing. Therefore, in order to improve the rolling fatigue life, which is an important performance of the bearing function of the wheel bearing device, the angle of the fiber flow on the inner rolling surface of the hub wheel is set to 15 ° or less, and the machining allowance of the inner rolling surface is reduced. There has been proposed a wheel bearing device that reduces the amount of material input and cuts the machining time.

Further, in the outer member 50 of such a conventional wheel bearing device (the shape after completion is indicated by a broken line, and the curve indicating the fiber flow F is indicated in the cross section), the minimum diameter is obtained as shown in FIG. Double-row outer

rolling surfaces

52 and 53 each having an arc-shaped cross section are provided on both sides of the cylindrical surface portion 51, respectively, and the double-row outer rolling surfaces 52 are extended from the double-row outer

rolling surfaces

52 and 53 to both ends. , 53 has a

cylindrical surface portion

54, 55 having a diameter slightly smaller than the maximum diameter.

The outer

row rolling surfaces

52 and 53 of the double row of the outer member 50 have a shape shown in an enlarged manner in FIGS. 15 (a) and 15 (b), respectively. The angle α of the fiber flow F with respect to the double row

outer raceway surfaces

52 and 53 of the outer member 50 is 15 ° or less, more preferably 10 ° or less.

The angle α of the fiber flow F with respect to the double row

outer raceway surfaces

52 and 53 is defined as follows. That is, the groove bottom X of the double row

outer raceway surfaces

52 and 53 in the completed state and the raceway curvature center O are connected by a straight line L ′. Next, let P (ball contact point) be a point tilted from the straight line L ′ around the center O by the ball contact angle, and let the straight line from the center O to the ball contact point P be the straight line L′ 2. And the tangent line T of the outer

rolling surfaces

52 and 53 at the ball contact point P is drawn. Subsequently, a tangent line T ′ of the fiber flow F at the ball contact point P is drawn. At this time, an angle α formed by the tangents T and T ′ is an angle α of the fiber flow F with respect to the outer

rolling surfaces

52 and 53.

The operation of the above configuration will be described. There is a correlation between the angle α of the fiber flow F with respect to the double row

outer raceway surfaces

52 and 53 and the rolling life, and the rolling life decreases as the angle increases. As a result of tests and researches, in the outer member 50, when the angle α of the fiber flow F is set to 15 ° or less, the rolling life of the double-row

outer raceway surfaces

52 and 53 is significantly improved as compared with the conventional case. It turns out that it is obtained. Further, it has been found that when the angle α of these fiber flows F is set to 10 ° or less, the rolling life of the double row outer

rolling surfaces

52 and 53 can be improved more remarkably. Further, reducing the angle α of the fiber flow F to 15 ° or less with the outer member 50 can be achieved by making the material shape after completion of forging extremely close to the final shape. As a result, the machining allowance of the double row

outer raceway surfaces

52 and 53 is reduced, and the material input weight and the cutting time can be reduced (for example, Patent Documents). 1).

JP 2005-083513 A

However, in practice, in the forging process, the outer member 50 includes a portion that forms the double-row outer

rolling surfaces

52 and 53 on the inner periphery, and a cylindrical surface-shaped portion on both ends from the outer

rolling surfaces

52 and 53. The

portions

54 and 55 are formed, and finish punching is performed with the inner diameter removed portion 56 remaining on the inner periphery (indicated by a two-dot chain line in the figure). Depending on the position of the inner diameter thinned portion 56, the fiber flow angle of the outer

rolling surfaces

52 and 53 increases, and as a result, the rolling life is affected.

In general, it is known that at a location where shear stress is applied, the fiber flow is stronger in terms of strength and fatigue than when the fiber flow passes in parallel to the direction in which the shear stress is applied.

The present invention has been made in view of such circumstances, and while reducing the amount of material input, also on the outer rolling surface of the wheel bearing device, the state of the fiber flow is as close as possible to the state described above, It aims at providing the manufacturing method of the outer member of the wheel bearing apparatus which improved the fatigue strength of the wheel bearing apparatus.

In order to achieve such an object, the method invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the vehicle body on the outer periphery, and a double row arc-shaped outer rolling on the inner periphery. A hub wheel having an integrally formed outer member, a wheel mounting flange for mounting a wheel at one end, and a small-diameter step portion extending in the axial direction on the outer periphery, and the hub wheel An inner member composed of at least an inner ring or an outer joint member of a constant velocity universal joint, which is press-fitted into a small-diameter step portion and has an arc-shaped inner rolling surface facing the outer rolling surface of the double row, In a method for manufacturing an outer member of a wheel bearing device comprising a member and a double row of balls accommodated in a freely rolling manner between both rolling surfaces of the outer member, a round bar-like material is formed by upsetting. The center part of the material is expanded and formed into a drum shape, Between the outer peripheral part of the outer member including the body mounting flange and the cylindrical inner peripheral part including the outer rolling surface of the double row by the manufacturing process, and the outer rolling surface of the double row of the inner peripheral part Grinding from at least one end face of the inner diameter punched portion, comprising a step of forming a disk-shaped inner diameter punched portion in the central portion in the axial direction and a step of removing the inner diameter punched portion by an inner diameter punching process using a punch. When the distance L1 to the groove bottom of the outer rolling surface on the end face side of the inner-diameter-extracted portion of the double row outer rolling surfaces is R, the radius of curvature of the outer rolling surface after grinding is , L1 = 0.15 to 0.4R.

Thus, an outer member integrally having a vehicle body mounting flange to be attached to the vehicle body on the outer periphery, a double row arc-shaped outer rolling surface formed integrally on the inner periphery, and a wheel on one end. A hub wheel integrally having a wheel mounting flange for mounting and having a small-diameter step portion extending in the axial direction on the outer periphery, and press-fitted into the small-diameter step portion of the hub wheel, facing a double row outer rolling surface An inner member formed of at least an inner ring or an outer joint member of a constant velocity universal joint formed with an arc-shaped inner rolling surface, and is rotatably accommodated between both rolling surfaces of the inner member and the outer member. In the method of manufacturing the outer member of the wheel bearing device provided with the double-row balls, a step of forming a round bar-shaped material into a drum shape by expanding the center of the material by upsetting and a forging process The outer peripheral part of the outer member including the body mounting flange A cylindrical inner peripheral portion including the outer rolling surface of the disk, and a step of forming a disk-shaped inner diameter punched portion in the axial central portion between the outer rolling surfaces of the double row of the inner peripheral portion; A step of removing the inner diameter punched portion by the inner diameter punching process, and outer rolling on the end face side of the inner diameter punched portion of the double row outer rolling surfaces after grinding from at least one end face of the inner diameter punched portion. The distance L1 to the groove bottom of the surface is set in a range of L1 = 0.15 to 0.4R, where R is the radius of curvature of the outer rolling surface after grinding, so the fiber flow is turned outward. It is possible to follow the shape of the running surface, the angle of the fiber flow with respect to the outer rolling surface can be made 15 ° or less, and the shape of the material after forging can be brought close to the final shape as much as possible. Reduce machining allowance on rolling surface and reduce material input weight In addition, it is possible to provide an outer member that can shorten the cutting time and that has improved strength and rolling fatigue life.

According to a second aspect of the present invention, a punch for forming the inner peripheral surface of the outer member includes an arc-shaped portion along the shape of the outer rolling surface after grinding, and the arc-shaped portion. Is formed in a two-stage arc shape forming an arc-shaped annular recess having substantially the same radius of curvature as the arc-shaped portion, and the inner diameter of the annular recess is the outer surface of the double row after completion. If the diameter is set to be smaller than the inner diameter of the shoulder portion, the fiber flow can be made to follow the shape of the outer rolling surface, and the angle of the fiber flow with respect to the outer rolling surface can be made 15 ° or less.

Preferably, as in the invention described in claim 3, the distance between the intersection of the arc-shaped portion and the annular recess and the intersection of the outer rolling surface and the shoulder after grinding is the curvature of the outer rolling surface. If the radius is set to be 0.08 to 0.5 times, an appropriate turning allowance can be secured to obtain a desired shape / dimension, and the occurrence of black skin residue after heat treatment can be prevented.

According to a fourth aspect of the present invention, a punch for forming the inner peripheral surface of the outer member includes an arc-shaped portion along the shape of the outer rolling surface after grinding, and the arc-shaped portion. If the radius of curvature of the arcuate portion is set larger than the radius of curvature of the outer rolling surface after grinding, the fiber flow is shaped to the outer rolling surface. The angle of the fiber flow with respect to the outer rolling surface can be made 15 ° or less.

Further, as in the invention according to claim 5, at the groove bottom position of the outer rolling surface after grinding, the thickness of the groove bottom portion of the outer rolling surface is H1, and the outer member after forging If H2 is set to H2 = 1.3 to 2.0H1, the material input weight can be reduced and the cutting time can be shortened, and the fiber flow F can be further reduced on the outer rolling surface. It can follow the shape.

According to a sixth aspect of the present invention, the vehicle body mounting flange is formed to protrude at a plurality of locations on the outer periphery of the outer member, and a convex portion is formed between the vehicle body mounting flanges. Is attached to the vehicle body side so as to be located on the opposite road surface side, the fiber flow flows through the vehicle body mounting flange and the convex portion during forging, so that the fiber flow angle α of the outer rolling surface is effectively 15 Can be less than °. In addition, by attaching the convex part to the vehicle body side so that it is located on the opposite road surface side, the outer rolling surface with a small fiber flow angle can be used at a severe position in terms of life, which is advantageous for rolling life. Become.

Further, as in the invention described in claim 7, the height from the axial center of the convex portion is ½ or more of the height of the outer diameter portion between the vehicle body mounting flanges and the height of the vehicle body mounting flanges. If so, the fiber flow of the outer member can be made to follow the outer rolling surface.

Further, as in the invention according to claim 8, the wall thickness of the convex portion is larger than the wall thickness of the vehicle body mounting flange, and the outer rolling surface after grinding from the knuckle mounting surface of the vehicle body mounting flange. It may be set larger than the distance to the groove bottom.

A method for manufacturing an outer member of a wheel bearing device according to the present invention has a vehicle body mounting flange integrally attached to the vehicle body on the outer periphery, and a double-row arc-shaped outer rolling surface integrally formed on the inner periphery. A hub wheel integrally formed with a formed outer member and a wheel mounting flange for mounting a wheel at one end, and having a small-diameter step portion extending in the axial direction on the outer periphery, and a small-diameter step portion of the hub ring An inner member composed of at least an inner ring or an outer joint member of a constant velocity universal joint that is press-fitted and has an arcuate inner rolling surface that faces the outer rolling surface of the double row, and the inner member and the outer member In the method of manufacturing an outer member of a wheel bearing device including a double row of balls accommodated between two rolling surfaces of a side member, a central portion of the material is formed by upsetting a round bar-shaped material. The process of expanding into a drum shape and forging An outer peripheral portion of the outer member including the vehicle body mounting flange, a cylindrical inner peripheral portion including the double row outer rolling surface, and an axial center between the double row outer rolling surfaces of the inner peripheral portion A step of forming a disc-shaped inner diameter punched portion in the portion, and a step of removing the inner diameter punched portion by an inner diameter punching process using a punch, and after grinding from at least one end face of the inner diameter punched portion When the distance L1 to the groove bottom of the outer rolling surface on the end face side of the inner-diameter portion of the double row outer rolling surfaces is R, the radius of curvature of the outer rolling surface after grinding is L1. = 0.15-0.4R, the fiber flow can be made to follow the shape of the outer rolling surface, and the angle of the fiber flow with respect to the outer rolling surface can be made 15 ° or less. The shape of the material after the forging is completed to the maximum Provide an outer member that can approach the final shape, reduce the machining allowance of the outer rolling surface, reduce the material input weight and cutting time, and improve the strength and rolling fatigue life. be able to.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. It is sectional drawing which accumulated the forge process and completion state of the outer member of FIG. It is the figure which showed the principal part enlarged view and fiber flow of FIG. It is sectional drawing which shows the modification of FIG. It is the principal part enlarged view which considered the fiber flow of FIG. It is sectional drawing which shows the other modification of FIG. It is the principal part enlarged view which considered the fiber flow of FIG. It is a side view which shows the wheel bearing apparatus provided with the outward member of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. FIG. 10 is a side view of FIG. 9. It is a principal part enlarged view which shows the modification of FIG. It is a side view which shows the modification of the wheel bearing apparatus of FIG. It is a side view which shows the other modification of the wheel bearing apparatus of FIG. It is sectional drawing of the raw material of the forge completion state of the outer member in the conventional wheel bearing apparatus. (A) is an expanded sectional view of the A part of FIG. 14, (b) is an enlarged sectional view of the B part of FIG.

An outer member integrally having a vehicle body mounting flange to be attached to the vehicle body on the outer periphery, and a double row arc-shaped outer rolling surface formed integrally on the inner periphery, and a wheel for attaching the wheel to one end A hub wheel integrally having a mounting flange and formed with a small-diameter step portion extending in the axial direction on the outer periphery, and an arc-like shape that is press-fitted into the small-diameter step portion of the hub wheel and faces the double-row outer rolling surface An inner member composed of at least an inner ring or an outer joint member of a constant velocity universal joint formed with an inner rolling surface, and a plurality of rolling members accommodated between the rolling surfaces of the inner member and the outer member. In the manufacturing method of the outer member of the wheel bearing device provided with a row of balls, a step of forming a round bar-shaped material into a drum shape by expanding the diameter of the material center by upsetting, and the forging process The outer peripheral portion of the outer member including the vehicle body mounting flange A cylindrical inner peripheral portion including the double-row outer rolling surface, and a disk-shaped inner diameter punching portion formed at the axially central portion between the double-row outer rolling surfaces of the inner peripheral portion. And a step of removing the inner diameter punched portion by an inner diameter punching process using a punch, and a distance L1 from one end face of the inner diameter punched portion to the groove bottom of the outer rolling surface after grinding is determined by grinding. When the radius of curvature of the outer rolling surface after machining is R, it is set in a range of L1 = 0.15 to 0.4R, and at the groove bottom position of the outer rolling surface after grinding, When the thickness of the groove bottom portion of the outer rolling surface is H1, and the thickness of the outer member after forging is H2, H2 is set to 1.3 to 2.0H1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 2 is a sectional view in which a forging process and a completed state of the outer member in FIG. 1 are overlapped, and FIG. FIG. 4 is a cross-sectional view showing a modification of FIG. 2, FIG. 5 is an enlarged view of the main part of FIG. 4, and FIG. 6 is another view of FIG. 7 is a sectional view showing a modification, FIG. 7 is an enlarged view of a main part of FIG. 6, and FIG. 8 is a side view showing a wheel bearing device including the outer member of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

This wheel bearing device is referred to as a third generation structure on the driven wheel side, and includes a plurality of

balls

3, 3, which are accommodated so as to roll between the inner member 1 and the outer member 2, and both

members

1, 2. And. The inner member 1 includes a hub ring 4 and an inner ring 5 press-fitted into the hub ring 4.

The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and one (outer side) arcuate inner rolling surface 4a on the outer periphery. A small-diameter step 4b extending in the axial direction from the inner rolling surface 4a is formed. Hub bolts 6 a for attaching the wheels are planted at the circumferentially equidistant positions of the wheel attachment flanges 6.

The hub wheel 4 is made of medium and high carbon steel containing 0.40 to 0.80% by weight of carbon such as S53C, and includes an inner rolling surface 4a and an inner side serving as a seal land portion with which an outer side seal 8 to be described later comes into sliding contact. A hardened layer is formed in the range of 58 to 64 HRC by induction hardening from the base portion 6b to the small diameter step portion 4b.

The inner ring 5 is formed with the other (inner side) arcuate inner rolling surface 5a on the outer periphery, and is press-fitted into the small-diameter step portion 4b of the hub wheel 4 through a predetermined shimoshiro, so that the end portion of the small-diameter step portion 4b It is fixed in the axial direction in a state in which a predetermined bearing preload is applied by a caulking portion 4c formed by plastic deformation radially outward. The caulking portion 4c is an unquenched portion with the material hardness after forging. Further, the inner ring 5 and the ball 3 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching.

The outer member 2 integrally has a vehicle body mounting flange 2b for mounting to a vehicle body (not shown) on the outer periphery, and a double row facing the inner rolling surfaces 4a and 5a of the inner member 1 on the inner periphery. Arc-shaped outer rolling surfaces 2a and 2a are integrally formed. The vehicle body mounting flange 2b is formed to protrude at a plurality of locations (here, 4 locations) on the outer periphery of the outer member 2, and is formed with a screw portion 2c that is fastened to a knuckle (not shown). This outer member 2 is formed of medium and high carbon steel containing 0.40 to 0.80% by weight of carbon, such as S53C, as in the case of the hub wheel 4, and at least the double row outer rolling surfaces 2a and 2a are formed by induction hardening. The surface hardness is set in the range of 58 to 64 HRC. Then, double-

row balls

3 and 3 are accommodated between the rolling

surfaces

2a and 4a and 2a and 5a via the cages 7 and 7 so as to roll freely.

Seals

8 and 9 are attached to the opening of the annular space formed between the inner member 1 and the outer member 2 to prevent leakage of the lubricating grease sealed inside the bearing, and from the outside. It prevents rainwater and dust from entering the bearing. In the present embodiment, the third generation structure is illustrated in which the inner raceway surface 4a is directly formed on the hub wheel 4 and the inner ring 5 is press-fitted and fixed to the small diameter step portion 4b. What is necessary is just to provide the outer member with which the attachment flange was integrally formed, and the 2nd generation or the 4th generation structure wheel bearing apparatus may be sufficient.

In the present embodiment, as shown in FIG. 2, the outer member 10 is formed into a drum shape by rounding the center portion of the material by upsetting a round bar-shaped material (billet), and by rough forming or die forging. A disc-shaped inner diameter punching portion 17 is formed at the substantially central portion in the axial direction between the outer peripheral portion of the vehicle body mounting flange 2b and the like, the cylindrical inner peripheral portion, and the double row

outer rolling surfaces

2a, 2a by finish molding. . Finally, although not shown, the inner diameter punched portion is removed by an inner diameter punching process using a punch, and the forging process is followed by turning to manufacture. In other words, the outer member 10 has a predetermined turning allowance, with the body mounting flange 11 on the outer periphery and the

seal fitting portions

12 and 13 and the outer rolling surfaces 14 and 15 on the inner periphery, by finishing punching in the forging process. (In the figure, the shape of the outer member 2 after completion is indicated by a two-dot chain line).

Here, as shown in FIG. 3, the distance L1 from the outer end surface 17a of the inner diameter punching portion 17 to the groove bottom of the outer rolling surface 2a in the completed state is the outer rolling surface after grinding (completed state). When the radius of curvature of 2a is R, L1 = 0.15 to 0.4R is set. Thereby, the fiber flow F can be made to follow the shape of the outer side rolling surface 2a.

Specifically, the groove bottom X of the outer rolling surface 2a and the rolling surface curvature center O are connected by a straight line L '. Next, let P (ball contact point) be a point inclined by the ball contact angle from L ′ about the center O, and let the straight line from the center O to the ball contact point P be a straight line L′ 2. Then, a tangent line T of the outer rolling surface at the ball contact point P is drawn. Subsequently, a tangent line T1 of the fiber flow F at the ball contact point P is drawn. At this time, when the angle α formed by the tangent lines T and T1 is the angle α of the fiber flow with respect to the outer rolling surface 2a, the angle α can be set to 15 ° or less. That is, the material shape after completion of forging can be made extremely close to the final shape, the machining allowance of the outer rolling surface 2a can be reduced, the material input weight can be reduced, and the cutting time can be shortened. The outer member 2 having an improved rolling fatigue life can be provided.

Here, as can be seen from Table 1 showing the results of verifying the life and workability, when L1 is set to be less than 0.15 of the groove curvature radius R, the turning allowance is not uniform and the material input weight increases. At the same time, the cutting time increases and the manufacturing cost increases. Furthermore, the angle α of the fiber flow F is increased, and the shape of the outer rolling surface 2a is not met. Further, if L1 exceeds 0.4 of the groove curvature radius R, not only the turning allowance is not uniform, but also the turning allowance is reduced, and a desired shape dimension cannot be obtained.

Further, when the thickness of the groove bottom portion of the outer rolling surface 2a is H1 and the thickness of the outer member 10 after forging is H2 at the groove bottom position of the outer rolling surface 2a after completion, The thickness H2 of the member 10 is set in a range of 1.3 to 2.0 times the thickness H1 of the groove bottom portion of the outer rolling surface 2a (H2 = 1.3 to 2.0H1). As a result, the material input weight can be reduced and the cutting time can be shortened, and the fiber flow F can be made to follow the shape of the outer rolling surface 14.

FIG. 4 is a modification of the outer member 10 described above. The outer member 18 has a predetermined turning in a vehicle body mounting flange 11 on the outer periphery, seal

fitting portions

12 and 13 on the inner periphery, and outer rolling surfaces (arc-shaped portions) 14 and 19 by predetermined finishing in a forging process. Molded to leave the allowance. Here, the outer side rolling surface 19 on the inner side is formed in an arc shape along the shape of the outer side rolling surface 2 a after completion, and the outer side rolling surface 19 is formed on the inner diameter side of the outer side rolling surface 19. An arcuate annular recess 20 having substantially the same radius of curvature is formed. That is, a punch (not shown) that molds the inner peripheral surface on the inner side is formed in a two-stage arc shape that molds the outer rolling surface 2 a and the annular recess 20. Here, the inner diameter D2 of the annular recess 20 is set to be smaller than the inner diameter D1 of the shoulder 16 of the outer member 2 after completion (D2 <D1).

Further, as shown in FIG. 5, distances L2 and L3 between the intersection P1 of the outer rolling surface 19 and the annular recess 20 and the intersection P2 of the outer rolling surface 2a and the shoulder 16 after completion are the outer rolling surface 2a. Is set to be 0.08 to 0.5 times the curvature radius R of (L2, L3 = 0.08 to 0.5R). Thereby, the fiber flow F can be made to follow the shape of the outer rolling surface 19, and the tangent T1 of the fiber flow F and the tangent T of the outer rolling surface 2a at the ball contact point P are similar to the embodiment described above. The formed angle α can be 15 ° or less.

Here, if L2 and L3 are set to be less than 0.08 of the groove curvature radius R, not only the turning allowance is reduced and a desired shape / dimension cannot be obtained, but a black skin residue is generated after the heat treatment. If L2 and L3 exceed 0.5 of the groove curvature radius R, the turning allowance increases and the cutting time increases.

FIG. 6 shows another modification of the outer member 10 described above. The outer member 21 is formed by finish punching in the forging process, with the body mounting flange 11 on the outer periphery and the

seal fitting portions

12 and 13 and the outer rolling surfaces 14 and 15 on the inner periphery with a predetermined turning allowance. Has been. Here, the inner side outer rolling surface 15 is formed by an arcuate portion 15a along the shape of the outer rolling surface 2a after completion, and a tangent line 15b of the arcuate portion 15a. That is, a punch (not shown) for forming the inner peripheral surface on the inner side is formed in a spire shape constituted by an arcuate portion 15a and a tangent line 15b of the arcuate portion 15a.

Here, the curvature radius r of the arcuate portion 15a is set larger than the curvature radius R of the outer rolling surface 2a as shown in FIG. By forming the outer rolling surface 15 with the punch having such a shape, the angle α formed by the tangent T1 of the fiber flow F and the tangent T of the outer rolling surface 2a at the ball contact point P is the same as in the above-described embodiment. Can be made 15 ° or less.

Further, as shown in FIG. 8, the outer member 21 'has a convex portion 22 formed between the outer body mounting flanges 2b. The convex portion 22 is mounted on the vehicle body side so as to be located on the opposite road surface side, and the height L6 from the axial center of the convex portion 22 is the height L4 of the outer diameter portion between the vehicle body mounting flanges 2b and the vehicle body mounting flange. It is set to be 1/2 or more of the height L5 of 2b (L6 ≧ (L4 + L5) / 2). Thereby, the fiber flow in the position where life is severe can be effectively made to follow the outer rolling surface 2a.

9 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, FIG. 10 is a side view of FIG. 9, and FIG. 11 is an enlarged view of a main part showing a modification of FIG. 12 is a side view showing a modified example of the wheel bearing device of FIG. 10, and FIG. 13 is a side view showing another modified example of the wheel bearing device of FIG. This embodiment basically differs from the above-described embodiment only in the configuration of the outer member, and the same reference numerals are used for other parts and parts having the same parts or the same functions as the above-described embodiments. Detailed description will be omitted.

This wheel bearing device is called a third-generation structure on the driven wheel side, and the double-

row balls

3, 3 are accommodated so as to roll freely between the inner member 1 and the outer member 23, and both

members

1, 23. And.

The outer member 23 integrally has a vehicle body mounting flange 2b on the outer periphery, and double row outer rolling surfaces 2a and 2a are integrally formed on the inner periphery. The outer member 2 is formed with a protruding portion 24 protruding from an outer diameter portion between the vehicle body mounting flanges 2b. The thickness H5 of the convex portion 24 is thicker than the thickness H3 of the vehicle body mounting flange 2b, and the distance from the knuckle (not shown) mounting surface 25 of the vehicle body mounting flange 2b to the groove bottom of the outer rolling surface 2a. It is set larger than H4. As a result, as in the above-described embodiment, it is possible to effectively cause the fiber flow at a position that is severe in life to follow the outer rolling surface 2a.

FIG. 11 shows a modification of FIG. The outer member 26 integrally has a vehicle body mounting flange 2b on the outer periphery, and a convex portion 27 is formed at an outer diameter portion between the vehicle body mounting flange 2b. The inner side surface 27a of the convex portion 27 is offset by ΔH to the outer side from the mounting surface 25 of the vehicle body mounting flange 2b. This offset amount ΔH is set to be thinner than the thickness H3 of the vehicle body mounting flange 2b. As a result, as in the above-described embodiment, it is possible to effectively cause the fiber flow at a position that is severe in life to follow the outer rolling surface 2a.

FIG. 12 shows a modification of FIG. The outer member 28 integrally has a vehicle body mounting flange 2b on the outer periphery, and a convex portion 29 is formed integrally with the vehicle body mounting flange 2b on the outer diameter portion on the opposite road surface side between the vehicle body mounting flanges 2b. Thereby, a fiber flow can be made to follow an outer side rolling surface combined with the effect of the convex part 24. FIG.

FIG. 13 shows another modification of FIG. The outer member 30 is formed by protruding vehicle

body mounting flanges

2b and 2b 'at four locations on the outer periphery, and the vehicle body mounting flange 2b' positioned on the opposite road surface side is formed protruding from the other vehicle body mounting flanges 2b. ing. A height L7 from the axis of the vehicle body mounting flange 2b 'located on the opposite road surface side is set higher than a height L5 of the other vehicle body mounting flange 2b. Thereby, a fiber flow can be made to follow an outer side rolling surface combined with the effect of the convex part 24. FIG.

The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

An outer member of a wheel bearing device according to the present invention has a second to fourth generation wheel bearing device having a body mounting flange integrally on the outer periphery and a double row outer rolling surface formed on the inner periphery. It can be applied to the outer member.

DESCRIPTION OF SYMBOLS 1 Inner member 2, 21 ', 23, 26, 28, 30 Outer member 2a Outer rolling surface 2b Car body mounting flange 2c Screw part 3 Ball 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step part 4c Caulking Part 5 Inner ring 6 Wheel mounting flange 6a Hub bolt 6b Base part on the inner side of the wheel mounting flange 7 Cage 8 Seal on the outer side 9 Seals on the inner side 10, 18, 21 Outer member 11 after forging Car body mounting flange 12 after forging Outer side seal fitting surface 13 after forging Inner side seal fitting surfaces 14, 15, 19 after forging Outer rolling surface 15 a after forging Arc-shaped portion 15 b Arc tangent 16 Shoulder portion 17 after completion Portion 17a Outer end surface 20 on the outer side of the inner diameter annular recess 22, 24, 27, 29 Convex portion 25 Mounting surface 27a of the vehicle body mounting flange Side surface 50 on the inner side of the convex portion Outer member 51 Cylindrical surface portion 52, 53 Outer rolling surface 54, 55 Small diameter cylindrical surface portion 56 Inner diameter removal portion D1 Shoulder inner diameter D2 Inner diameter of annular recess F Fiber flow H1 Thickness H2 of groove bottom portion of outer rolling surface Thickness of outer member after processing H3 Thickness of vehicle mounting flange H4 Distance from mounting surface of vehicle mounting flange to groove bottom of outer rolling surface H5 Thickness of convex portion L1 From outer side end surface of inner diameter removal portion Distance L2 to groove bottom of outer rolling surface Axial distance L3 between intersections P1 and P2 Radial distance L4 between intersections P1 and P2 Height of outer diameter portion between vehicle body mounting flanges L5 and L7 Height of vehicle body mounting flange L6 Height from the axis of the convex portion L ′ Rotate a line L′ 2 L ′ connecting the outer rolling surface groove bottom and the rolling surface curvature center O by a predetermined angle around the rolling surface curvature center O Line O Groove curvature center P Ball contact point P1 Outer rolling after forging Intersection P2 between the surface and the annular recess R Intersection R between the outer rolling surface and the shoulder after completion R The curvature radius r of the outer rolling surface T, T1, T 'Tangential ΔH Mounting of the convex portion Projection amount from surface X Rolling surface groove bottom Y Shoulder side edge α Angle formed by tangent of fiber flow and tangent of outer rolling surface

Claims

An outer member integrally having a vehicle body mounting flange for being attached to the vehicle body on the outer periphery, and a double-row arc-shaped outer rolling surface formed integrally on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end, a small diameter step portion extending in the axial direction on the outer periphery, and a small diameter step portion of the hub wheel are press-fitted to the outside of the double row An inner member formed of an outer joint member of at least an inner ring or a constant velocity universal joint formed with an arc-shaped inner rolling surface facing the rolling surface;
In the method of manufacturing the outer member of the wheel bearing device including the inner member and a double row of balls accommodated in a freely rolling manner between both rolling surfaces of the outer member,
A process in which the center of the material is expanded by upsetting a round bar-shaped material and formed into a drum shape,
Between the outer peripheral portion of the outer member including the vehicle body mounting flange and the cylindrical inner peripheral portion including the outer rolling surface of the double row by forging, and the outer rolling surface of the double row of the inner peripheral portion A step of forming a disc-shaped inner diameter-extracted portion in the central portion in the axial direction;
A step of removing the inner diameter punched portion by an inner diameter punching process using a punch, and
The distance L1 from at least one end face of the inner diameter punched portion to the groove bottom of the outer rolling surface on the end face side of the inner diameter punched portion of the double row outer rolling surface after grinding is the above-mentioned after grinding. A method for manufacturing an outer member of a wheel bearing device, wherein a radius of curvature of an outer rolling surface is set to R, and is set in a range of L1 = 0.15 to 0.4R.
The punch for forming the inner peripheral surface of the outer member has an arc-shaped portion along the shape of the outer rolling surface after grinding and an inner diameter side of the arc-shaped portion, and is substantially the same as the arc-shaped portion. It is formed in a two-stage arc shape for forming an arc-shaped annular recess having a radius of curvature, and the inner diameter of the annular recess is set smaller than the inner diameter of the shoulder between the outer rolling surfaces of the double row after completion. The manufacturing method of the outward member of the wheel bearing apparatus of Claim 1.
The distance between the intersection of the arcuate portion and the annular recess and the intersection of the outer rolling surface and the shoulder after grinding is 0.08 to 0.5 times the radius of curvature of the outer rolling surface. The manufacturing method of the outer member of the wheel bearing apparatus of Claim 2 currently set.
The punch for forming the inner peripheral surface of the outer member is formed in a spire shape composed of an arc-shaped portion along the shape of the outer rolling surface after grinding and a tangent line of the arc-shaped portion, The manufacturing method of the outer member of the wheel bearing apparatus in any one of Claims 1 thru | or 3 with which the curvature radius of the circular arc-shaped part is set larger than the curvature radius of the said outer side rolling surface after grinding.
When the thickness of the groove bottom portion of the outer rolling surface at the groove bottom position of the outer rolling surface after grinding is H1, and the thickness of the outer member after forging is H2, H2 = 1. The method for manufacturing an outer member of a wheel bearing device according to any one of claims 1 to 4, wherein the outer member is set to 3 to 2.0H1.
The vehicle body mounting flange is formed to protrude at a plurality of locations on the outer periphery of the outer member, and a convex portion is formed between the vehicle body mounting flanges, and the convex portion is mounted on the vehicle body side so that it is located on the opposite road surface side. The manufacturing method of the outward member of the wheel bearing apparatus of Claim 1 currently used.
The height from the axial center of the said convex part is set so that it may become 1/2 or more of the height of the outer diameter part between the said vehicle body mounting flanges, and the height of the said vehicle body mounting flange. A method for manufacturing an outer member of a wheel bearing device.
The wall thickness of the convex portion is greater than the wall thickness of the vehicle body mounting flange, and is set to be larger than the distance from the knuckle mounting surface of the vehicle body mounting flange to the groove bottom of the outer rolling surface after grinding. Item 7. A method for manufacturing an outer member of the wheel bearing device according to Item 6.