JP2007147079A - Method of manufacturing hub ring and outward member of wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a hub ring and an outward member of a wheel bearing device for improving the rolling life of the raceway surface and reducing the machining allowance of the raceway surface, resulting in a less weight of material to be charged and a shorter cutting time. <P>SOLUTION: The method of manufacturing the hub ring 1 of the wheel bearing device whose hub ring 1 has a wheel mounting flange 5 and the raceway surface 10 comprises a forging step of forging a raw material formed by cutting a steel bar material into a predetermined size, and a grinding step of grinding the raceway surface of the raw material after completely forged. In the forging step, heating, rough shaping, finish shaping and inner-diameter removal are performed in sequence. In the forging step, the shape of the raw material after completely forged is made to approximate a final shape so that the angle of a fiber flow to the raceway surface of the hub ring in the final shape of the hub ring is 15° or smaller. In the method of manufacturing the outward member, not illustrated, similarly to the case of the hub ring 1, the shape of a raw material after completely forged is made to approximate a final shape so that the angle of a fiber flow to the raceway surface is 15° or smaller. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a hub wheel and an outer member in a wheel bearing device that supports a wheel of an automobile.

A hub wheel and an outer ring in a wheel bearing device such as a hub unit type are manufactured by turning after forging. As a forging process, for example, after cutting a carbon steel bar material having a carbon content of 0.4 to 0.8% in the cross-sectional direction, it is heated to around 1100 ° C., upsetting, rough forming, finish forming, and It is common to remove the inner diameter.

Japanese Patent Publication No. 5-66215

Since it is forged as described above, the fiber flow of the bar material is as shown in FIG. 11 for the hub wheel and the outer ring as shown in FIG. 13 after forging. In the figure, the finished shape of the hub wheel 81 or the outer ring 84 after turning is indicated by a broken line.
FIG. 12 shows an enlarged cross section of a portion A where the raceway surface 90 is formed by turning the hub wheel 81 in FIG. 14 (A) and 14 (B) show enlarged cross sections of portions A and B where the raceway surfaces 92 and 93 are formed by turning the outer ring 84 shown in FIG. 13, respectively. 12 and 14, the cross section of the fiber flow F from the groove curvature center O is in the range from the bottom edge X to the shoulder edge Y where the curvature of the grooved raceway surfaces 90, 92, and 93 occurs. The points up to the deposited point P are connected by a straight line L, a tangent line T is drawn at the intersection point P of the straight line L and the raceway surface, and angles α with respect to the tangent line T1 of the fiber flow F are obtained. This angle was defined as the angle α of the fiber flow F with respect to the raceway surface.
The fiber flow angle α is related to the size of machining allowance (difference between the forged contour shape of the raceway surface and the turning finish shape), and the fiber machining angle α tends to increase as the machining allowance increases. Yes, the hub wheel 81 has 15 ° <α <20 °, and the outer ring 84 has a large machining allowance and varies in a range of 15 ° <α <80 °.

  The fiber flow F is a material flow that occurs during molding of the bar material, and there are some impurities that cannot be removed during steelmaking, and the impurities exist along the fiber flow F. In general, the starting point of rolling fatigue life under normal lubrication conditions is considered to be impurities in the material, especially oxidation-type impurities, and the longer the impurity is, the longer the length, and the greater the number, the shorter the life. It has been broken.

  Although it is a test result in the test piece, there is a correlation between the angle of the fiber flow with respect to the raceway surface and the rolling life, and it is known that the rolling life decreases as the angle increases. In addition, even in the wheel bearing device, there is a description that the production from the round bar material is lighter than the production from the pipe material (for example, Patent Document 1).

  However, conventional wheel bearing devices satisfy the currently required rolling fatigue life, so fiber flow is basically not considered, and the material shape before turning is determined only by the ease of forging. Was. However, the material shape before turning, which is easy to forge, has a large machining allowance and increases the number of turning processes. As a result, the manufacturing cost increases and the cost of the product does not decrease. On the other hand, although the rolling life is sufficiently satisfied at present, it is conceivable that the wheel bearing device which is an automobile part used under severe conditions will be required to have a more severe rolling fatigue life in the future. In the above-mentioned Patent Document 1, there is a description that the production of a round bar material can reduce the fiber flow division more than the production of the pipe material, but there is a device for reducing the fiber flow division and the angle of the fiber flow. No consideration has been given. Moreover, the manufacturing method described in Patent Document 1 is a manufacturing method for an outer ring that does not have a hook, and it is unclear whether it can be applied or applied to a hub ring or an outer ring with a hook.

  The object of the present invention is to reduce the machining allowance of the raceway surface, thereby improving the rolling life of the raceway surface, reducing the weight of the material and shortening the cutting time, and the hub wheel and the outer side of the wheel bearing device. It is providing the manufacturing method of a member.

The hub wheel manufacturing method in the wheel bearing device of the present invention includes an outer member having a double-row raceway surface formed on the inner periphery and a double-row raceway surface facing the raceway surface of the outer member. An inner member, and the inner member has a hub wheel formed with one raceway surface and a wheel mounting flange, and the hub wheel in a wheel bearing device for rotatably supporting a wheel with respect to a vehicle body A manufacturing method of
Including a forging process for forging a material obtained by cutting a steel bar material into a predetermined dimension, and a turning process for turning the raceway surface with respect to the forged material, and the angle of the fiber flow with respect to the raceway surface of the hub ring It is 15 degrees or less.
The method of manufacturing the outer member in the wheel bearing device of the present invention includes an outer member having a flange on the outer periphery and a double-row raceway surface formed on the inner periphery, and a compound facing the raceway surface of the outer member. An inner member formed with a raceway surface of a row, in a wheel bearing device for rotatably supporting a wheel with respect to a vehicle body, the method for manufacturing the outer member,
Including a forging step of forging a material obtained by cutting a steel bar material into a predetermined size, and a turning step of turning the raceway surface with respect to the forged material, and an angle of the fiber flow with respect to the raceway surface of the outer member Is 15 ° or less.
Each of the raceway surfaces may be an arc-shaped surface corresponding to a rolling element made of a ball, or may be a tapered surface corresponding to a rolling element made of a tapered roller.

  There is a correlation between the angle of the fiber flow with respect to the raceway surface and the rolling life, and the rolling life decreases as the angle increases. From the viewpoint of the life ratio of both the inner member and the outer member, it has been found that a rolling life almost equal to the fiber flow angle of zero can be obtained by setting the fiber flow angle to 15 ° or less. Further, when the fiber flow is set to 15 ° or less, the machining allowance of the raceway surface is reduced, and the material input weight and the cutting time can be shortened.

In this invention, even if the angle of the fiber flow is restricted as described above only for either the hub ring or the outer member, the effect is obtained for the hub ring or the outer member. For both, it is more preferable to regulate the angle of the fiber flow as described above.
The angle of the fiber flow with respect to the raceway surface of the hub wheel and the angle of the fiber flow with respect to the raceway surface of the outer member are both preferably 10 ° or less. In particular, the angle of the fiber flow with respect to the raceway surface of the hub wheel is preferably set to 10 ° or less. Therefore, for example, the angle of the fiber flow with respect to the raceway surface of the outer member may be 15 ° or less, and the angle of the fiber flow with respect to the raceway surface of the hub wheel may be 10 ° or less.

The hub wheel manufacturing method for a wheel bearing device according to the present invention is also applicable to a type in which the outer member does not have a flange on the outer periphery.
That is, an outer member in which a double row raceway surface is formed on the inner periphery, an inner member in which a double row raceway surface facing the outer member raceway surface is formed, and a composite member interposed between both raceway surfaces. A bearing device for a wheel having a rolling element in a row and a sealing device at both ends between an outer member and an inner member and rotatably supporting the wheel with respect to the vehicle body. In the case where a hub ring having a mounting flange is formed, the angle of the fiber flow with respect to the raceway surface of the hub ring may be 15 ° or less. Also in this case, the angle of the fiber flow with respect to the raceway surface of the hub wheel is more preferably 10 ° or less.

  The present invention can also be applied to a method for manufacturing an outer member in a wheel bearing device of the second generation type or the like. That is, an outer member having a flange on the outer periphery and a double-row raceway surface formed on the inner periphery, an inner member forming a double-row raceway surface facing the raceway surface of the outer member, and both raceway surfaces In a wheel bearing device comprising a double row rolling element interposed therebetween and a sealing device at both ends between the outer member and the inner member, the wheel bearing device rotatably supporting the wheel with respect to the vehicle body, the outer member described above The angle of the fiber flow with respect to the raceway surface may be 15 ° or less. The angle of this fiber flow is also preferably 10 ° or less. In the case of this wheel bearing device, either the outer member or the inner member may be on the rotating side. When the outer member is on the rotating side, the outer peripheral flange of the outer member is a wheel mounting flange, and when the inner member is on the rotating side, the outer peripheral flange of the outer member is a flange for mounting on the vehicle body. .

  The wheel bearing device to which the hub wheel and the outer member manufacturing method of the present invention is applied may be an inner ring in which the other raceway surface of the inner member is fitted to the outer periphery of the end portion of the hub wheel. That is, it may be a third generation wheel bearing device.

The wheel bearing device to which the outer member manufacturing method according to the present invention is applied has two inner rings in which the inner member has each row of raceways facing the double row raceway provided on the outer member. There may be. That is, it may be a second generation wheel bearing device. In this case, an outer ring rotating type or an inner ring rotating type may be used.
The wheel bearing device to which the hub wheel and outer member manufacturing method of the present invention is applied may be a fourth generation wheel bearing device.

In the manufacturing method of the hub wheel and the outer member in the wheel bearing device of the present invention, the material of the hub ring or the outer member that is the race ring that defines the angle of the fiber flow as described above is a bearing steel, a carburized steel, Alternatively, any carbon steel having a carbon content of 0.4 to 0.8% may be used.
In the case of these steel materials, the relationship between the angles of the raceways and the fiber flow was confirmed.

  In the wheel bearing device hub wheel manufacturing method and outer member manufacturing method of the present invention, the fiber flow angle with respect to the raceway surface of the hub wheel having the wheel mounting flange on the outer periphery is set to 15 ° or less, or the flange is formed on the outer periphery. Since the fiber flow angle with respect to the raceway surface of the outer member is 15 ° or less, the rolling life of the raceway surface can be improved and the machining allowance of the raceway surface can be reduced, reducing the material input weight. In addition, the effect of shortening the cutting time can be obtained.

  A first embodiment of the present invention will be described with reference to FIGS. This embodiment is an example applied to a third-generation ball type and drive wheel and an inner ring rotating type wheel bearing device. This wheel bearing device includes an inner member 3 composed of a hub wheel 1 and an inner ring 2 fitted to the outer periphery of the end of the inboard side of the hub wheel 1, and an outer member 4, and the wheel is mounted on the vehicle body. It is supported rotatably. The hub wheel 1 has a wheel mounting flange 5 at an end on the outboard side, and wheel mounting bolts 8 are press-fitted into bolt insertion holes 7 formed at a plurality of locations in the circumferential direction of the flange 5. . The hub wheel 1 is a cylindrical member through which the central hole 1a passes. A shaft portion of an outer joint member of a constant velocity universal joint (not shown) is fitted in the central hole 1a. The hub wheel 1 and the inner ring 2 are each provided with one of the double-row raceway surfaces 10 and 11. The outer member 4 is composed of a single outer ring, and has a flange 6 for attachment to the vehicle body on the outer periphery. Bolt insertion holes 9 are formed at a plurality of locations in the circumferential direction of the flange 6. The outer member 4 has double-row raceway surfaces 12 and 13 that face the raceway surfaces 10 and 11 of the hub wheel 1 and the inner ring 2, and between the raceway surfaces 10 and 12 that face each other and between the raceway surfaces 11 and 11. A rolling element 14 is interposed between 13. The raceway surfaces 10 to 13 are surfaces that cause a contact angle, and this bearing is of an angular type. The rolling element 14 is a ball such as a steel ball. These rolling elements 14 are held by a holder 29 for each row. Both ends of the bearing space between the inner member 3 and the outer member 4 are sealed by sealing devices 15 and 16. The sealing devices 15 and 16 are, for example, contact seals that are attached to the inner diameter surface of the outer member 4 so that the seal lip contacts the outer diameter surfaces of the hub wheel 1 and the inner ring 2.

  Both the hub wheel 1 and the outer member 4 are manufactured by turning after forging. The material of the hub wheel 1 and the outer member 4 is, for example, bearing steel, carburized steel, or carbon steel having a carbon content of 0.4 to 0.8%. In the forging process, as shown in FIGS. 2A and 2B, the hub wheel 1 and the outer member 4 are cut by cutting the bar material W made of the above material into a predetermined size, heated to around 1100 ° C., and installed. , Rough forming, finish forming, and inner diameter removal. Through such a forging process, the hub wheel 1 is processed into the shape shown in FIG. 3, and the outer member 4 is processed into the shape shown in FIG. In the figure, the finished shape of the hub wheel 1 and the outer member 4 after turning is indicated by a broken line. Moreover, the curve which shows the fiber flow F was shown in the cross section of the same figure. The hub wheel 1 has a finished shape, and a seal contact surface 17 having an arcuate cross-sectional shape continues on the outboard side of the raceway surface 10 on the outer diameter surface, and the seal contact surface 17 continues to the side surface of the flange 5. Yes. The outer diameter surface portion on the inboard side with respect to the raceway surface 10 has a cylindrical surface shape with a linear cross section. The outer member 4 has raceway surfaces 12 and 13 each having an arcuate cross section on both sides of the cylindrical surface portion 18 having the smallest diameter, and the maximum diameter of the raceway surfaces 12 and 13 from both the raceway surfaces 12 and 13 to both ends. The cylindrical surface portions 19 and 20 having a slightly smaller diameter than the cylindrical surface portions 19 and 20 follow.

  The raceway surface 10 of the hub wheel 1 has an enlarged shape shown in FIG. The raceway surfaces 12 and 13 of the outer member 4 are enlarged and shown in FIGS. 6 (A) and 6 (B), respectively. As shown in FIG. 4, the angle α of the fiber flow F with respect to the raceway surface 10 of the hub wheel 1 is 15 ° or less, more preferably 10 ° or less. Further, as shown in FIGS. 6A and 6B, the angle α of the fiber flow F with respect to the raceway surfaces 12 and 13 of the outer member 4 is 15 ° or less, more preferably 10 ° or less.

  The angle α of the fiber flow F with respect to the raceway surfaces 10, 12, and 13 is defined as follows. That is, a straight line extends from the groove curvature center O to the point where the cross section of the fiber flow F is deposited in the range from the bottom edge X to the shoulder edge Y where the curvature of the raceway surfaces 10, 12, and 13 occurs. L is connected by L, and a tangent line T is drawn at the intersection point P between the straight line L and the raceway surfaces 10, 12, 13, and the angle formed by the tangent line T 1 of the fiber flow F at each intersection point P and the tangent line T of the raceway surfaces 10, 12, 13. α is an angle α of the fiber flow with respect to the raceway surface. When the raceway surface is a tapered surface, instead of the tangent line T, a straight line along the cross section of the tapered surface serving as the raceway surface, that is, a generatrix of the taper surface is used, and the generatrix and the tangent line T1 of the fiber flow F are The angle formed. Further, when the tapered surface is a crowning shape, T is the tangent line of the crowning curve.

  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 raceway surfaces 10, 12, and 13 and the rolling life, and the rolling life decreases as the angle increases. As a result of the test and research, in the hub wheel 1, the angle α of the fiber flow F is set to 15 ° or less, and in the outer member 4, the angle α of the fiber flow F is set to 15 ° or less. It has been found that the rolling life of the raceway surfaces 10, 12, and 13 can be significantly improved as compared with the prior art. 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 each of the raceway surfaces 10, 12, 13 can be improved more remarkably. In addition, the angle α of the fiber flow F can be reduced to 15 ° or less for the hub wheel and 15 ° or less for the outer member 4 as described above. Can be achieved. As a result, the machining allowance of the raceway surfaces 10, 12, and 13 is reduced, and the material input weight and the cutting time can be reduced.

  FIG. 7A shows a test result of a rolling fatigue test piece obtained by cutting the raceway surface from the bar, and the fiber flow angles with respect to the raceway surface are 0 °, 15 °, 30 °, 45 °, 90 °. The result of each case is shown. FIG. 5B shows the relationship between each test piece and the axial direction of the bar. From the figure (A), the rolling life ratio shows that when the fiber flow angle is 0 ° (ideal), the rolling life ratio can be substantially equivalent when the fiber flow angle is 15 ° or less. Recognize.

A method for measuring the fiber flow will be described.
1. Fiber Flow Precipitation Procedure (1) A sample is prepared by cutting the hub wheel and outer ring in one axial direction with a cutter.
(2) A sample is put into a hydrochloric acid solution (hydrochloric acid 50% + water 50%) heated to 75 to 80 ° C.
(3) Immerse the sample for 10-15 minutes.
(4) Take out the sample, wash with water, dry and rust.
2. Determination of Fiber Flow Take a cross-sectional photograph of the raceway surface portion of the fiber flow deposited by the above procedure, and determine the angle of the deposited fiber flow from the bottom of the raceway surface to the shoulder at a magnification of 2 to 5.

  In the above embodiment, the inner ring 2 is press-fitted or fixed to the hub wheel 1 with a bolt (not shown). However, as shown in FIG. The inner ring 2 may be fixed to the hub wheel 1 by a caulking portion 21 provided in the portion. Further, as shown in FIG. 8B, a wheel bearing device for a driven wheel may be used. The wheel bearing device shown in the figure is the same as the example shown in FIG. 8A except that the hub wheel 1 does not have the central hole 1a.

  Moreover, although each said embodiment demonstrated as the case where all were applied to the 3rd generation wheel bearing apparatus, this invention can also be applied to the 2nd generation or the 4th generation wheel bearing apparatus.

  FIG. 9A is an example of the outer ring rotation type in the second generation. In this wheel bearing device, an outer member 30 composed of a single outer ring has double-row raceway surfaces 31 and 32 on the inner periphery, and raceway surfaces 33 and 34 facing these double-row raceway surfaces 31 and 32 are provided. The inner member 35 is provided between the raceway surfaces 31 and 33 facing each other, and the rolling elements 36 interposed between the raceway surfaces 32 and 34. The inner member 35 includes inner rings 35A and 35B having raceway surfaces 33 and 34 for each row. In the case of the second generation outer ring rotating type, a wheel mounting flange 5 </ b> A is formed on the outer peripheral outboard side of the outer member 30. In this example, the angle of the fiber flow (not shown) with respect to the raceway surfaces 31 and 32 of the outer member 30 is set to 15 ° or less, more preferably 10 ° or less.

  FIG. 9B is an example of the inner ring rotation type in the second generation. This wheel bearing device includes an inner member 45 having double-row raceway surfaces 43 and 44 opposed to double-row raceway surfaces 41 and 42 provided on an outer member 4A having a flange 6A, and opposing both rows. And rolling elements 46 interposed between the raceway surfaces 41 and 43 and between the raceway surfaces 42 and 44. The inner member 45 includes inner rings 45A and 45B having raceway surfaces 43 and 44 for each row. In this embodiment, the angle of the fiber flow (not shown) with respect to the raceway surfaces 41 and 42 of the outer member 4A is 15 ° or less, and more preferably 10 ° or less. In the case of this second generation inner ring rotating type, the inner rings 45A and 45B are generally fitted to the outer periphery of a hub ring having a wheel mounting flange (not shown).

  FIG. 10 shows an example applied to a fourth-generation wheel bearing device. In this wheel bearing device, an inner member 52 is constituted by a hub wheel 1B having a wheel mounting flange 5B, and a constant velocity joint outer ring 51 having a shaft portion 51a fitted to the inner periphery of the hub wheel 1B. Raceway surfaces 53 and 54 are formed on the wheel 1B and the constant velocity joint outer ring 51. The outer member 4B has a flange 6B for attachment to the vehicle body on the outer periphery, and track surfaces 55, 56 facing the track surfaces 53, 54 are formed on the inner periphery. A rolling element 57 is interposed between the facing raceway surfaces 53 and 55 and between the raceway surfaces 54 and 56. In this embodiment, the angle of the fiber flow (not shown) with respect to the raceway surfaces 55 and 56 of the outer member 4B is 15 ° or less. Further, the angle of the fiber flow (not shown) with respect to the raceway surface 53 of the hub wheel 1B is set to 10 ° or less. The angle of the fiber flow (not shown) with respect to the raceway surface 53 of the hub wheel 1B may be 15 ° or less, and the angle of the fiber flow (not shown) with respect to the raceway surfaces 55 and 56 of the outer member 4B is More preferably, it is 10 ° or less.

Each of the above embodiments is a ball type wheel bearing device, but the present invention can also be applied to a method of manufacturing a hub wheel and an outer member in a tapered roller bearing type wheel bearing device. it can.
In the present invention, both the requirement that the angle of the fiber flow with respect to the raceway surface is 15 ° or less, and the requirement that the angle of 10 ° or less are satisfied may be satisfied substantially over the entire circumference.

It is a fragmentary sectional view of the bearing device for wheels to which the manufacturing method concerning a 1st embodiment of this invention is applied. It is process explanatory drawing which shows the forge process of the hub ring and an outer ring | wheel. It is sectional drawing of the raw material of the forge completion state of the hub ring in the bearing apparatus for the wheels. It is an expanded sectional view of A part of FIG. It is sectional drawing of the raw material of the forge completion state of the outer ring | wheel in the wheel bearing apparatus. (A), (B) is an expanded sectional view of A part and B part of FIG. 5, respectively. (A) is a graph of a test result, respectively, (B) is explanatory drawing which shows the relationship of the direction of each test piece and the bar used as a raw material. (A), (B) is a fragmentary sectional view which shows the wheel bearing apparatus to which the manufacturing method concerning other embodiment of this invention is applied, respectively. (A), (B) is a fragmentary sectional view which shows the wheel bearing apparatus to which the manufacturing method concerning further another embodiment of this invention is applied, respectively. It is a fragmentary sectional view which shows the wheel bearing apparatus to which the manufacturing method concerning further another embodiment of this invention is applied. It is sectional drawing of the raw material of the forge completion state of the conventional hub ring. It is an expanded sectional view of A part of FIG. It is sectional drawing of the raw material of the forge completion state of the conventional outer ring | wheel. (A), (B) is an expanded sectional view of A part and B part of FIG. 13, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hub ring 2 ... Inner ring 3 ... Inner member 4 ... Outer member 5 ... Flange 6 ... Flange 10, 11 ... Track surface 12, 13 ... Track surface 14 ... Rolling element 15, 16 ... Sealing device F ... Fiber flow (alpha) …angle

Claims (2)

An outer member having a double-row raceway surface formed on the inner periphery, and an inner member having a double-row raceway surface facing the raceway surface of the outer member. A method of manufacturing the hub wheel in a wheel bearing device having a hub wheel formed with a surface and a wheel mounting flange, and rotatably supporting the wheel with respect to the vehicle body,
Including a forging process for forging a material obtained by cutting a steel bar material into a predetermined dimension, and a turning process for turning the raceway surface with respect to the forged material, and the angle of the fiber flow with respect to the raceway surface of the hub ring The manufacturing method of the hub ring of the wheel bearing apparatus characterized by being 15 degrees or less. An outer member having a flange on the outer periphery and having a double-row raceway surface formed on the inner periphery, and an inner member having a double-row raceway surface facing the raceway surface of the outer member, In the wheel bearing device for rotatably supporting the wheel, a method for manufacturing the outer member,
Including a forging step of forging a material obtained by cutting a steel bar material into a predetermined size, and a turning step of turning the raceway surface with respect to the forged material, and an angle of the fiber flow with respect to the raceway surface of the outer member The manufacturing method of the outward member of the bearing apparatus for wheels characterized by becoming 15 degrees or less.

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