JP2007263299A - Manufacturing method of bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a bearing device for a wheel of fourth generation structure, for reducing weight and size of the device, increasing bearing stiffness, and reducing the number of processing steps. <P>SOLUTION: Trial assembly of double-rows of balls 6a, 6b to double-rows of outer rolling surfaces 4a, 4b of an outward member 4 is performed through retainers 9a, 9b. Then, seals 10, 10 are installed to both end parts of the outer member 4. A hub wheel 1 and an outer joint member 14 are respectively inserted from both sides of the outward member 4, a serration 20a of the shaft part 20 of the outer joint member 14 is fitted to a serration 1c of the hub wheel 1. With a state where a predetermined pre-load is applied to the double-rows of rolling bearings 2, an abutting part between the hub wheel 1 and the shaft part 20 is preheated, the hub wheel 1 and the shaft part 20 are integrally joined at a joint part 11 by joining, and then post heating is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a wheel bearing device for rotatably supporting a wheel of an automobile or the like with respect to a suspension device, and in particular, to reduce the weight and size of the device, increase the bearing rigidity, and reduce the machining process. The present invention relates to a method for manufacturing a four-generation wheel bearing device.

  The wheel bearing device for rotatably supporting the wheel of an automobile or the like is a second generation having a body mounting flange integrally with an outer member from a structure in which a double row rolling bearing called a first generation is used independently. In addition, the third generation in which one inner rolling surface of the double row rolling bearing is integrally formed on the outer periphery of the hub ring integrally having the wheel mounting flange, and further, the constant velocity universal joint is provided on the hub ring. Have been developed to the fourth generation in which the other inner rolling surface of the double row rolling bearing is integrally formed on the outer periphery of the outer joint member constituting the constant velocity universal joint.

Hereinafter, the prior art will be described with reference to the drawings.
FIG. 8 is a cross-sectional view showing a conventional wheel bearing device. The wheel bearing device shown in FIG. 8 is a typical example of a third generation structure. The wheel bearing device shown in FIG. 8 includes an inner member 50, an outer member 60, and a constant velocity universal joint 70 as a unit.

  The inner member 50 includes a hub ring 51 and a separate inner ring 52 that is press-fitted into the hub ring 51. The hub wheel 51 integrally has a wheel mounting flange 53 for mounting a wheel (not shown), and a hub bolt 54 for fixing the wheel is planted at a circumferentially equidistant position of the wheel mounting flange 53. ing. The inner ring 52 is pulled out in the axial direction by the crimping portion 56 in which the inner ring 52 is press-fitted into the small-diameter step portion 55 formed in the hub wheel 52 and the end of the small-diameter step portion 55 is plastically deformed radially outward. Is preventing.

  The outer member 60 integrally has a vehicle body mounting flange 61 for mounting to a vehicle body (not shown) on the outer periphery, and forms double-row rolling surfaces 60a and 60a on the inner periphery. On the other hand, the inner member 50 is formed integrally with the hub wheel 51 and the inner ring 52 with double row rolling surfaces 51a, 52a facing the rolling surfaces 60a, 60a of the outer member 60, respectively. Double row rolling elements (balls) 62, 62 are accommodated between 60a, 51a and 60a, 52a. The holders 63 and 63 hold the double-row rolling elements 62 and 62 in a rollable manner. Further, seals 64 and 65 are attached to the end portion of the outer member 60 to prevent leakage of the lubricating grease enclosed in the bearing, and to prevent rainwater and dust from entering from the outside.

  The constant velocity universal joint 70 includes an outer joint member 71, a joint inner ring 72, a cage 73, and a torque transmission ball 74. The outer joint member 71 has a cup-shaped mouth portion 75 and a shaft portion 76 extending in the axial direction from the mouth portion 75, and a curved track groove 71 a extending in the axial direction is formed on the inner periphery of the mouth portion 75. ing. On the other hand, a curved track groove 72 a is formed on the outer periphery of the joint inner ring 72 so as to face the track groove 71 a. The centers of curvature of the track grooves 71a and 72a are offset from each other by an equal distance in the axial direction with respect to the joint center. Therefore, the torque transmission ball 74 accommodated between the track grooves 71a and 72a is always held on a bisector of the operating angle at any operating angle, so that the speed is constant.

The shaft portion 76 of the outer joint member 71 is fitted into the hub wheel 51 through the serration 76a so that torque can be transmitted, and the caulking portion 56 and the shoulder portion 78 of the outer joint member 71 are in contact with each other by the fixing bolt 77. Thus, the inner member 50 and the outer joint member 71 are detachably fastened.
JP 2003-72308 A JP 2003-74569 A

  However, in such a conventional wheel bearing device, when fastening with fixing bolts, nuts, etc. or end face caulking / fixing is adopted, it is necessary to provide an extra screw part or caulking part. It was. In recent years, it has been desired to further improve durability and bearing rigidity while reducing the weight and size in order to improve the vehicle fuel efficiency and the motion performance by reducing the unsprung weight and weight. Furthermore, in a conventional wheel bearing device, if a fastening method using a fixing bolt, a nut or the like is employed, the number of processing steps tends to increase.

  The present invention has been made in view of such circumstances, and provides a method of manufacturing a fourth-generation wheel bearing device having a reduced weight and size, increasing bearing rigidity, and reducing processing steps. The purpose is to do.

  In order to achieve the object, the invention described in claim 1 of the present invention is a method of manufacturing a wheel bearing device in which a hub wheel, a double row rolling bearing, and a constant velocity universal joint are unitized. The double row rolling bearing has an outer member in which a double row outer rolling surface is formed on the inner periphery and a vehicle body mounting flange is formed on the outer periphery, and a wheel mounting flange is integrally formed on one end, and on the outer periphery. A hub wheel having one inner rolling surface facing the outer rolling surface of the double row, a small cylindrical step extending in the axial direction from the inner rolling surface, and a serration on the inner periphery; and And the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and the shaft portion extending in the axial direction from the inner rolling surface and having serrations formed integrally therewith. An inner member composed of an outer joint member of a universal joint, and both rotations of the inner member and the outer member. In a method of manufacturing a wheel bearing device including a double row ball group accommodated in a freely rolling manner between surfaces, a step of fitting the shaft portion to the hub wheel via serrations, and the fitting And a step of joining the butt portions of the portions together at a joint portion by joining.

  In this way, by adopting a method of fixing the shaft part to the hub wheel by serration fitting and welding, the screw part and the caulking part are extraneous compared to fastening with fixing bolts, nuts, etc. or end face caulking and fixing. Therefore, it is possible to realize light weight and compactness and to increase bearing rigidity. In addition, when so-called outboard welding is performed, it is not necessary to perform cleaning after joining.

  The invention according to claim 2 of the present invention is a method of manufacturing a wheel bearing device in which a hub wheel, a double row rolling bearing, and a constant velocity universal joint are unitized, and the double row rolling. The bearing has an outer member in which a double row outer rolling surface is formed on the inner periphery and a vehicle body mounting flange is formed on the outer periphery, and one inner rolling surface facing the double row outer rolling surface on the outer periphery. And the constant velocity universal joint formed with a cylindrical small-diameter step portion extending in the axial direction from the inner rolling surface, serrations on the inner periphery, and a wheel mounting flange at one end, An inner member formed of a hub ring formed with a shaft portion extending in the axial direction from the inner rolling surface and formed with a serration. The double row baud accommodated between the rolling surfaces of the inner member and the outer member so as to roll freely. In the method of manufacturing a wheel bearing device including a group, the shaft portion is fitted into the constant velocity universal joint via serrations, and the butted portion of the fitting portion is integrally formed by a joint portion by joining. And a process to be combined.

  By the way, 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 at the same time, the radial direction or axis from the wheel that occurs when the vehicle bounces or turns when traveling on a rough road. Because it is necessary to allow directional displacement and moment displacement, one end of the 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 Are connected to the wheel via a wheel bearing device including a fixed type constant velocity universal joint.

  It is known that a large torque is applied to a wheel of such a vehicle from the engine via a sliding type constant velocity universal joint when the engine rotates at a low speed, for example, when the vehicle starts, and the drive shaft is twisted. As a result, the double row rolling bearing supporting the drive shaft is also twisted. When the twist amount of the drive shaft is large, stick-slip noise due to a sudden slip is generated at the contact surface between the outer joint member constituting the fixed type constant velocity universal joint and the hub wheel.

  However, according to the above-described method, since the butted portion between the outer joint member constituting the constant velocity universal joint and the shaft portion of the hub wheel is fixed by bonding, stick-slip noise can be suppressed. Moreover, in what is called inboard side joining, since a junction part is not exposed outside, rust can be suppressed.

Further, as in the invention described in claim 3, the joining is preferably performed by laser welding, arc welding, or electron beam welding.
According to the present invention, the shaft portion of the constant velocity universal joint is fitted to the hub wheel via serration, or the shaft portion of the hub wheel is fitted to the constant velocity universal joint via serration to transmit the torque. Therefore, it is possible to adopt a welding method in which the load applied to the welded portion is relatively small and the heat effect is small. Therefore, it is possible to improve the rigidity and durability, and to improve the reliability of the joint portion between the constant velocity universal joint and the hub wheel.

Moreover, like the invention of Claim 4, the said joint part can also be performed by friction stir welding.
If the joint portion is joined by friction stir welding, it is possible to prevent the deformation of the bearing portion and the decrease in hardness by suppressing the thermal effect due to the joining.

Further, as in the invention described in claim 5, it is preferable to make the diameter of the joint portion larger than the diameter of the intermediate shaft fitted to the constant velocity universal joint.
By making the diameter of the joint part thicker than the diameter of the intermediate shaft, the load due to torque transmission applied to the joint part becomes relatively smaller than the load applied to the intermediate shaft, so that breakage at the joint part can be suppressed.

Further, as in the invention described in claim 6, the joint portion is offset in a traveling direction of a wheel at a large diameter portion of a butt portion between the hub wheel and the constant velocity universal joint, It is preferable to form in the state where the wall surface of the serration provided in the constant velocity universal joint abuts.
By joining the large diameter portion, it is possible to withstand a large load torque. Further, by joining in a state offset in the traveling direction, even if a load is applied in the traveling direction, the load can be received by the wall surface of the serration, so that the bearing rigidity can be increased.

Further, as in the invention described in claim 7, it is preferable to perform preheating when the joining is performed.
By performing preheating, the cooling rate of the joined portion after joining is slowed, martensite formation can be prevented, and the occurrence of cold cracking can also be suppressed. In addition, when preheating is performed, the temperature gradient in the vicinity of the joint becomes gentle, so that the generation of deformation and residual stress can be reduced.

Moreover, it is preferable to carry out post-heating after the joining as in the invention described in claim 7.
If the temperature of 723 to 726 ° C or higher is lowered at a speed of less than 550 ° within 5 seconds, it will become martensite, so post-heating is performed so that the temperature gradient becomes gentler than that. . Thereby, the reliability of joining can be raised.

Moreover, it is preferable to implement the said welding, supplying a metal wire like invention of Claim 8.
In laser welding or the like, by welding while putting a metal wire, the wire is melted at the welded portion, the material of the welded portion is improved, and defects in the welded portion are suppressed. For example, by supplying a stainless steel wire, the amount of carbon is relaxed and austenite having a material composition remains, so that it is difficult to form martensite and weld defects can be prevented. Furthermore, there are advantages such as being less likely to rust.

  The method of manufacturing a wheel bearing device according to the present invention employs a method of fixing a shaft portion to a hub wheel by serration fitting and joining, and compared with fastening with fixing bolts, nuts, etc. or end surface caulking and fixing. In addition, it is not necessary to provide an extra screw part or caulking part, so that the weight and size can be reduced, the bearing rigidity can be increased, and the machining process can be reduced.

  A method for manufacturing a wheel bearing device according to the present invention is a method for manufacturing a wheel bearing device in which a hub wheel, a double-row rolling bearing, and a constant velocity universal joint are unitized, and the double-row rolling bearing includes: The outer member having a double row outer rolling surface formed on the inner periphery, the outer member having the vehicle body mounting flange formed on the outer periphery, and the wheel mounting flange at one end is integrally formed, and the outer surface of the double row is rolled on the outer periphery. One inner rolling surface facing the surface, a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, a hub ring formed with serrations on the inner circumference, and the double row on the outer circumference. From the outer joint member of the constant velocity universal joint in which the other inner rolling surface facing the outer rolling surface and the shaft portion extending in the axial direction from the inner rolling surface and having serrations are integrally formed. An inner member, and the inner member and the outer member can roll between both rolling surfaces. In a method for manufacturing a wheel bearing device including a double row ball group that is contained, a step in which the shaft portion is fitted to the hub wheel via serrations, and a butt portion of the fitting portion is formed by bonding. And a step of joining together at a joint.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view of an axle bearing device for explaining a first embodiment of a method for manufacturing a wheel bearing device of the present invention. In the following description, the side closer to the outer side of the vehicle in a state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing).

  In this wheel bearing device, a hub wheel 1, a double row rolling bearing 2 and a constant velocity universal joint 3 are configured as a unit. The double-row rolling bearing 2 includes an outer member 4, an inner member 5, and double-row balls 6 a and 6 b accommodated between these members. The inner member 5 includes a hub wheel 1 and an outer joint member 14 to be described later that is fitted into the hub wheel 1.

  The outer member 4 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 4c for mounting to the vehicle body (not shown) on the outer periphery. Arc-shaped double-row outer rolling surfaces 4a and 4b are formed. The double row outer rolling surfaces 4a, 4b are hardened to a surface hardness of 58 to 64 HRC by high frequency heat treatment.

  On the other hand, the hub wheel 1 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and has a wheel mounting flange 7 for mounting a wheel to an end portion on the outer side. A plurality of hub bolts 8 are planted at equal intervals in the circumferential direction. Further, on the outer periphery of the hub wheel 1, one arcuate inner rolling surface 1a (outer side) facing the double row outer rolling surfaces 4a and 4b, and an axial direction from the inner rolling surface 1a. An extending cylindrical small-diameter step portion 1b is formed. Further, a serration (or spline) 1 c is formed on the inner periphery of the hub wheel 1.

  And the surface hardness is hardened in the range of 58-64 HRC by induction hardening over the inner rolling surface 1a and the small diameter step portion 1b from the seal land portion 7a with which the outer seal 10 is in sliding contact. As a result, not only the wear resistance of the seal land portion 7a serving as the base portion of the wheel mounting flange 7 is improved, but also the hub has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 7. The durability of the wheel 1 is improved.

  The constant velocity universal joint 3 includes an outer joint member 14, a joint inner ring 15, a cage 16, and a torque transmission ball 17. The outer joint member 14 is made of medium carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and has a cup-shaped mouth portion 18, a shoulder portion 19 that forms the bottom portion of the mouth portion 18, and the shoulder portion 19. A shaft portion 20 extending in the axial direction from is integrally formed. On the outer periphery of the shoulder 19, the other (inner side) arcuate inner rolling surface 14 a facing the double row outer rolling surfaces 4 a, 4 b is formed.

  On the inner side of the shaft portion 20, a hollow portion 21 is formed so as to penetrate in a cylindrical shape in the axial direction. In this example, all of the inside of the shaft portion 20 is hollow, but only a part of the solid or the end portion of the shaft portion 20 may be hollow. A serration (or spline) 20 a is formed on the outer periphery of the shaft portion 20 and is fitted to the serration 1 c of the hub wheel 1.

  An axially extending track groove 18 a having a curved portion is formed on the inner periphery of the mouse portion 18, and a track groove 15 a corresponding to the track groove 18 a is formed on the outer periphery of the joint inner ring 15. , 15a, a torque transmission ball 17 is accommodated via a cage 16. The surface hardness is hardened in the range of 58 to 64 HRC by high-frequency heat treatment from the outer peripheral surface where the track groove 18a and the inner side seal 10 are fitted to the inner rolling surface 14a and the shaft portion 20.

  Between the double row outer raceway surfaces 4a and 4b of the outer member 4 and the double row inner raceway surfaces 1a and 14a facing these, double row balls 6a and 6b are accommodated, and cages 9a and 9b are accommodated. It is held so that it can roll freely. Further, seals 10 and 10 are attached to the end portion of the outer member 4 to prevent leakage of the lubricating grease sealed inside the bearing and intrusion of rainwater, dust and the like into the bearing from the outside. These double-row rolling bearings 2 are so-called back-to-back type double-row angular contacts in which the acting lines of the acting directions of the forces applied to the rolling surfaces 4a, 1a and 4b, 14a are separated in the axial direction as they approach the axial center. It constitutes a ball bearing.

  In the present embodiment, the pitch circle diameter PCDi of the inner side ball 6b is set larger than the pitch circle diameter PCDo of the outer side ball 6a. The outer diameters of these double-row balls 6a and 6b are the same, but due to the difference in pitch circle diameters PCDo and PCDi, the number of inner-side balls 6b is set to be larger than the number of outer-side balls 6a. . In the case of this embodiment, by making the outer diameters of the double-row balls 6a and 6b the same, it is possible to eliminate the problem of misassembly in the assembly process, to reduce the manufacturing cost, and to improve the reliability of quality. To do.

  As described above, with the difference in pitch circle diameters PCDo and PCDi between the left and right balls 6a and 6b, in the inner member 5, the groove bottom diameter of the inner rolling surface 14a of the outer joint member 14 is changed to the inner rolling of the hub wheel 1. The diameter is larger than the groove bottom diameter of the running surface 1a. On the other hand, in the outer member 4, with the difference in pitch circle diameters PCDo and PCDi of the left and right balls 6a and 6b, the groove bottom diameter of the inner-side outer rolling surface 4b is the groove bottom of the outer-side outer rolling surface 4a. The diameter is larger than the diameter.

  In the wheel bearing device having such a configuration, the inner-side inner rolling surface 14a is directly formed on the outer periphery of the shoulder portion 19 of the outer joint member 14, so that the pitch circle diameter PCDi of the inner-side ball 6b is set to the outer side. The ball 6a can be set to have a larger diameter than the pitch circle diameter PCDo, and the number of balls 6b can be set to be larger on the inner side than on the outer side. In addition, the bearing rigidity can be increased and the bearing life can be extended.

Next, a method for unitizing the hub wheel 1, the double row rolling bearing 2 and the constant velocity universal joint 3 will be described.
First, the double row balls 6a and 6b are temporarily assembled to the double row outer rolling surfaces 4a and 4b of the outer member 4 via the cages 9a and 9b. Thereafter, the seals 10 and 10 are attached to both ends of the outer member 4. Next, the hub wheel 1 and the outer joint member 14 are respectively inserted from both sides of the outer member 4, and the serration 20 a of the shaft portion 20 of the outer joint member 14 is fitted into the serration 1 c of the hub wheel 1. Then, in a state in which a predetermined preload is applied to the double row rolling bearing 2, preheating is performed at the abutting portion between the hub wheel 1 and the shaft portion 20, and the hub wheel 1 and the shaft portion 20 are joined by joining. Are joined together, after which post-heating is performed. In addition, when joining, preheating and post-heating were implemented, but you may make it implement either pre-heating or post-heating.

Next, the joining method in the manufacturing method of the axle bearing device of the present invention will be described.
FIG. 2 is a view for explaining the joining method of the present invention. In FIG. 2, a hub wheel 1, a double row rolling bearing 2 and a constant velocity universal joint 3 are configured as a unit. The constant velocity universal joint 3 is composed of an outer joint member 14 and the like, and a hollow portion 21 is formed inside the end face of the shaft portion 20 so as to penetrate in a cylindrical shape in the axial direction. An intermediate shaft 26 is fitted to the joint inner ring 15 provided in the constant velocity universal joint 3.

  The laser beam 24 output from the laser welding machine 23 is applied to the abutting portion 22 between the hub wheel 1 and the shaft portion 20. Further, a rod-shaped nickel wire 25 is supplied to the tip of the laser beam 24 of the butting portion 22. While supplying the nickel wire 25 and applying the laser beam 24 to the butting portion 22, the condensing portion of the laser beam 24 of the laser welding machine 23 is formed in an annular shape along the butting portion 22 of the hub wheel 1 and the shaft portion 20. We will carry out welding by moving. In this way, the abutting portion 22 between the hub wheel 1 and the shaft portion 20 is integrally coupled by the welded portion 11 by welding. In addition to moving the condensing part of the laser beam 24 and welding, the apparatus can be welded by rotating the apparatus around the axis in the state where the laser beam 24 is applied. In addition, although the wire is supplied when welding, it can weld even if it does not supply a wire.

  Here, the diameter of the portion to which the welded portion 11 is applied is made larger than the diameter of the intermediate shaft 26 fitted to the constant velocity universal joint 3. By carrying out like this, since the load by torque transmission concerning a welding part becomes relatively smaller than the load concerning an intermediate shaft, destruction in a welding part can be controlled.

  In addition, welding can also be performed over the perimeter of the butt | matching part 22 of the hub wheel 1 and the axial part 20, and can also be implemented in multiple places on the circumference like intermittent welding and spot welding. Laser welding is performed in a range of width 1 to 3 mm and depth 7 to 8 mm.

  As the wire 25, various types of stainless steel wires such as a chrome wire can be used in addition to a nickel wire. By supplying a wire to a keyhole formed during welding by laser irradiation, the material composition of the welded portion can be improved, and defects generated in the welded portion can be prevented.

  Examples of the welding method include arc welding, electron beam welding and the like in addition to laser welding. Laser welding uses laser light as a heat source, condenses the laser with a parabolic mirror, lens, etc., irradiates the metal in a high energy density heat source, and joins the metal by locally melting and solidifying it. The welding method is excellent in monochromaticity, directivity, and coherence, and is characterized in that high power and high energy density can be obtained for welding by focusing with a parabolic mirror or lens.

  Arc welding is a method in which an arc (spark) is generated between a base material and a welding rod or wire, and the joint and the welding rod or wire are melted and welded by the heat generated at that time. The conversion efficiency to 70% or higher is high, and the energy density is low.

  Electron beam welding is a welding method that uses impact heat generation by irradiating materials generated by accelerating electrons generated in a vacuum to 2/3 the speed of light with a high voltage. It has a high density heat source and can perform high-speed welding and deep penetration welding. Further, since welding is performed in a vacuum, there is no oxidation of the welded portion. Furthermore, there is a feature that the width of the welded portion is narrow and the welding distortion is extremely small.

  Further, since the serration 20a of the shaft portion 20 of the outer joint member 14 is fitted to the serration 1c of the hub wheel 1 and torque can be transmitted via the serration, the load applied to the welded portion 11 is small, and the heat effect is reduced. Fewer welding methods can be employed. Therefore, it is possible to improve the rigidity and durability, and to improve the reliability of the joint portion between the outer joint member 14 of the constant velocity universal joint 3 and the hub wheel 1.

  Here, medium carbon steel is used for the hub wheel 1 and the outer joint member 14, and the surface is hardened by high-frequency heat treatment, but not limited thereto, for example, case-hardened steel such as SCr415 is used, Carburizing and quenching may be performed. In this case, the end portion of the fitting portion between the hub wheel 1 and the shaft portion 20 of the outer joint member 14 is preliminarily coated with a carburizing inhibitor and welded after heat treatment. As a result, forging processability is improved and the problem of cracking due to welding can be reliably solved.

Next, another manufacturing method will be described.
FIG. 3 is an explanatory view showing another manufacturing method. The so-called fail-safe mechanism at the joint between the hub wheel 1 and the outer joint member 14 is not limited to the joint 11 by such laser welding, but is joined by friction stir welding, so-called FSW (Friction Stir Welding) as shown in FIG. May be. In addition, the same code | symbol is attached | subjected to the site | part which has the same components same site | part or the same function as embodiment mentioned above, and the detailed description is abbreviate | omitted.

  This FSW is one of the solid-phase bonding methods, in which the rotor 27 with the probe 27a at the tip is rotated and pushed into the butt joint, and the members softened by frictional heat are agitated (plastic fluidized) and joined. is there. Since FSW is a solid phase bonding, the residual stress and deformation due to bonding can be suppressed as compared with general arc welding or the like, and the metal structure of the joint 11 becomes a fine crystal structure of the joint 11. Strength can be increased. Further, the member to be joined may be any material that is softer than the probe 27a, and the member to be joined has a feature that different metals can be joined.

Next, a method for joining the hub wheel 1 and the outer joint member 14 will be described.
First, the pin-shaped probe 27a is brought into contact with the opening in the abutting portion 22 of the hub wheel 1 and the outer joint member 14 with a predetermined contact pressure. The probe 27 a is made of a heat-resistant material that is harder than the joining member, here, the hub wheel 1 and the outer joint member 14, and resists frictional heat generated during joining, and projects on the end axis of the cylindrical rotor 27. Are integrally formed. Then, by rotating the rotor 27 at a high speed, the probe 27a is also rotated at a high speed, and the contact portion is softened and plasticized by frictional heat due to the contact. Further, the probe 27 a is pressed and inserted into the abutting portion 22.

  Thereafter, the probe 27 a is moved in the circumferential direction along the abutting portion 22. Then, due to the rotation of the probe 27a, the vicinity of the contact portion with the probe 27a is softened and agitated by frictional heat, and the softened stirring portion is subjected to the advance pressure of the probe 27a by the movement of the probe 27a and passes through the probe 27a. The probe 27a plastically flows so as to wrap around the recessed portion so as to fill the recessed portion. Then, the frictional heat is rapidly lost, and the joint portion 11 is cooled and solidified. This state is sequentially repeated with the movement of the probe 27a, and the hub wheel 1 and the butted portion 22 of the outer joint member 14 are joined over the entire circumference.

  Here, it is preferable that the shoulder 27b of the rotor 27 is brought into contact with the opening of the butting portion 22 in a state where the probe 27a is inserted. As a result, the softening can be promoted by the contact of the shoulder portion 27b, so that the scattering of the material in the softened portion being joined is suppressed, and the uniform joined portion surface 11 is obtained.

Next, the processed shape of the butt portion in the method for manufacturing an axle bearing device of the present invention will be described.
FIG. 4 is a view showing the shape of the butt portion of the present invention. 4 (a) shows an example in which the butt portion is not processed, FIG. 4 (b) shows an example in which the butt portion is processed into a groove shape, and FIG. 4 (c) shows that the butt portion is processed into a groove shape. An example is shown.

  In the example in which the butt portion 22 in FIG. 4A is not processed, laser welding with less bead swell is suitable. In this example, it is not necessary to perform processing, so that the processing process can be simplified.

  The example in which the butt portion 22 in FIG. 4B is processed into a groove shape is suitable for welding while supplying a wire. This is because swell of the beads can be suppressed by performing welding while supplying the wire to the groove portion of the butt portion 22.

  An example in which the butt portion 22 in FIG. 4C is processed into a groove shape is also suitable for welding while supplying a wire. Moreover, since it is necessary to provide a groove in the member to be joined by arc welding, it is suitable for arc welding when processing into a groove shape.

Next, the preheating / postheating method in the method of manufacturing an axle bearing device of the present invention will be described.
FIG. 5 is a diagram showing thermal changes of preheating and postheating. Fig.5 (a) is a figure which shows the heat pattern of a welding part, FIG.5 (b) is a figure which shows the heat pattern in the position of 20 mm deep from a welding location.

  FIG. 5 (a) shows a heat pattern P1 when only laser welding is performed and a heat pattern P2 by laser welding when preheating is performed. In this example, in the heat pattern P2, preheating for 10 seconds is performed before laser welding is performed, and the temperature at that time reaches 300 ° C. Thereafter, by performing laser welding, the temperature rises to about 2200 ° C., and when the welding is finished, the temperature slowly falls.

  As a preheating method, for example, an annular high-frequency generator is disposed opposite to the butting portion 22 in FIG. 2 and high-frequency heating is performed for 10 to 15 seconds to preheat the butting portion 22 to a range of about 10 mm. Can be added. As a preheating method, there is a method such as a gas burner in addition to a high frequency.

  On the other hand, the heat pattern P1 when only laser welding is performed starts laser welding at the time point of 10 seconds in the figure, and the temperature rises to about 2000 ° C. at a stretch. After that, when welding is finished, the temperature decreases.

  Here, when comparing the heat pattern P2 when preheating is performed and the heat pattern P1 when preheating is not performed, the gradient from the start of welding to the temperature rise is almost the same, but the welding is finished. The descending slope from is different. That is, it can be seen that the temperature after welding is lowered more slowly when preheating is performed. Like the heat pattern P2, it is possible to prevent martensite by slowly lowering the temperature. As described above, it is preferable that the laser welding is performed after the laser welding is finished or is cooled with air, and then the post-heating is performed slowly.

  FIG. 5B shows a heat pattern P3 when arc welding is performed, a heat pattern P4 when laser welding is performed, and a heat pattern P5 when electron beam welding is performed. The heat pattern P4 by laser welding and the heat pattern P5 by electron beam welding are less affected by temperature than the heat pattern P3 by arc welding.

  According to the present invention, since the serration 20a of the shaft portion 20 of the outer joint member 14 is fitted to the serration 1c of the hub wheel 1 and torque can be transmitted via the serration, the load on the welded portion is relatively low. It is possible to employ a welding method that is small and has little thermal influence as described above. Therefore, it is possible to improve the rigidity and durability, and to improve the reliability of the joint portion between the constant velocity universal joint and the hub wheel.

Next, the welding site | part in the manufacturing method of the axle bearing apparatus of this invention is demonstrated.
FIG. 6 is a diagram showing a welding site in the method of manufacturing an axle bearing device of the present invention. FIG. 6 shows an enlarged view of a fitting portion between the hub wheel 1 and the shaft portion 20 of the outer joint member 14. A serration 1c is formed on the inner surface of the hub wheel 1, and a serration 20a is formed on the outer surface of the shaft portion 20, and both are fitted.

  There is a gap between the serration 1c and the serration 20a. In this example, as shown by the arrow, the hub wheel 1 is rotated clockwise and the shaft portion 20 is rotated counterclockwise so that the wall surface of the serration contacts. The joint portion 11 is formed in an offset state so as to contact. The direction of the arrow indicates the traveling direction of the wheel. Since the load can be applied to the entire wall surface of the serration while the vehicle is traveling, the bearing rigidity can be increased.

  The joint surface 11 is not formed in the recess of the serration 20 a of the shaft portion 20 but in the recess of the serration 1 c of the hub wheel 1. That is, as shown in this figure, it is possible to withstand a large load torque by welding the large diameter portion of the butt portion between the hub wheel 1 and the outer joint member 14.

  FIG. 7 is a longitudinal sectional view of a wheel bearing device for explaining a second embodiment of the method for manufacturing the wheel bearing device of the present invention. In this wheel bearing device, a hub wheel 31, a double row rolling bearing 32 and a constant velocity universal joint 33 are configured as a unit. The double-row rolling bearing 32 includes an outer member 34, an inner member 35, and double-row balls 6a and 6b accommodated between these members. The inner member 35 includes a hub ring 31 and an outer joint member 44 (described later) fitted in the hub ring 31.

  The outer member 34 integrally has a vehicle body attachment flange 34c for attachment to a vehicle body (not shown) on the outer periphery, and arc-shaped double-row outer rolling surfaces 34a and 34b are formed on the inner periphery.

  On the other hand, the hub wheel 31 has a wheel mounting flange 37 for mounting a wheel at an end on the outer side, and a plurality of hub bolts 8 are implanted in the circumferential direction of the wheel mounting flange 37. Further, on the outer periphery of the hub wheel 31, one (outer side) arcuate inner rolling surface 31a facing the double row outer rolling surfaces 34a, 34b, and the inner rolling surface 31a extend in the axial direction. A shaft portion 36 is formed. A serration 36 a is formed on the outer periphery of the shaft portion 36. A seal land portion 37 a is formed at the base portion of the wheel mounting flange 37.

  The constant velocity universal joint 33 includes an outer joint member 44, a joint inner ring 15, a cage 16, and a torque transmission ball 17. The outer joint member 44 includes a cup-shaped mouth portion 18 and a shoulder portion 49 that forms the bottom of the mouth portion 18. On the outer periphery of the shoulder 49, the other (inner side) arcuate inner rolling surface 44a facing the double row outer rolling surfaces 34a, 34b, and a cylindrical shape extending in the axial direction from the inner rolling surface 44a. The small diameter step 44b is formed. A serration 44c is formed on the inner surface of the small diameter step portion 44b of the constant velocity universal joint 33, and a serration 36a formed on the shaft portion 36 of the hub wheel 1 is fitted.

  Between the double row outer raceway surfaces 34a and 34b of the outer member 34 and the double row inner raceway surfaces 31a and 44a facing these, double row balls 6a and 6b are accommodated, and cages 9a and 9b are accommodated. It is held so that it can roll freely. Further, seals 10 and 10 are attached to the end of the outer member 34. In the present embodiment, the pitch circle diameter of the inner-side ball 6b and the pitch circle diameter of the outer-side ball 6a are set to be the same.

Next, a method of unitizing the hub wheel 31, the double row rolling bearing 32, and the constant velocity universal joint 33 will be described in detail.
First, the double row balls 6a and 6b are temporarily assembled to the double row outer rolling surfaces 34a and 34b of the outer member 34 via the cages 9a and 9b. Thereafter, the seals 10 and 10 are attached to both ends of the outer member 34. Next, the hub wheel 31 and the outer joint member 44 are respectively inserted from both sides of the outer member 34, and the serration 36 a on the outer periphery of the shaft portion 36 is formed on the serration 44 c on the inner surface of the small diameter step portion 44 b of the constant velocity universal joint 33. Mated. Then, in a state where a predetermined preload is applied to the double row rolling bearing 32, preheating is performed on the abutting portion between the small diameter step portion 44b and the shaft portion 36, and the small diameter step portion 44b and the shaft portion 36 are welded by welding. It couple | bonds together in the part 41, and after-heat is implemented after that. In addition, when welding, preheating and afterheating were implemented, but you may make it implement either preheating or afterheating.

  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.

  The wheel bearing device according to the present invention can be applied to a wheel bearing device having a fourth generation structure in which a hub wheel, a double row rolling bearing, and a constant velocity universal joint are unitized.

It is a longitudinal cross-sectional view of the axle bearing device for demonstrating 1st Embodiment of the manufacturing method of the wheel bearing device of this invention. It is a figure for demonstrating the welding method of this invention. It is explanatory drawing which shows the other manufacturing method. It is a figure which shows the shape of the butt | matching part of this invention. 4 (a) shows an example in which the butt portion is not processed, FIG. 4 (b) shows an example in which the butt portion is processed into a groove shape, and FIG. 4 (c) shows that the butt portion is processed into a groove shape. An example is shown. It is a figure which shows the heat | fever change of preheating and postheating. Fig.5 (a) is a figure which shows the heat pattern of a welding part, FIG.5 (b) is a figure which shows the heat pattern in the position of 20 mm from a welding location. It is a figure which shows the welding site | part in the manufacturing method of the axle bearing apparatus of this invention. It is a longitudinal cross-sectional view of the wheel bearing apparatus for demonstrating 2nd Embodiment of the manufacturing method of the wheel bearing apparatus of this invention. It is sectional drawing which shows the conventional wheel bearing apparatus.

Explanation of symbols

1 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheel 1a, 14a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 1b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... Small diameter step 1c ... Serration 2 ... Double row rolling bearing 3 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Constant velocity universal joint 4 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer member 4a, 4b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・-Outer rolling surface 4c ... Body mounting flange 5 ... Inner members 6a, 6b ... ·········· Ball 7 ·············· Wheel mounting flange 7a ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub bolts 9a and 9b 10 ... Seal 11 ... Joint 14 ...・ Outer joint member 15 ..... Fitting inner ring 15a, 18a .... Track groove 16 ... ... Cage 17 ... Torque transmission ball 18 ... Mouse 19 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 20 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shaft 20a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Serration 21 ・ ・ ・ ・ ・ ・···························································· Laser welder 24・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Laser beam 25 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ Nickel wire 26 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Intermediate shaft 27 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rotor 27a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ Probe 27b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rotor shoulder 31 ・ ・ ・ ・ ・ ・ ・ ・ Hub wheels 31a, 44a ・ ・ ・.... Inner rolling surface 32 ... Double row rolling bearing 33 ... Constant speed Universal joint 34 ... Outer members 34a, 34b ... Outer rolling surface 34c ... ... Car body mounting flange 35 ... Inward member 36 ... Shaft part 36a ... ... Serration 37 ... ··· Wheel mounting flange 37a ····················· seal land portion 41 ··········· welded portion 44 ··· ······ Outer joint member 44b ············· Small diameter step 44c ······················· Serration 49 ... shoulder 50 ... inner member 51 ... hub wheel 51a・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling surface 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 52a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling Running surface 53 ・ ・ ・ ・ ・ ・ Wheel mounting flange 54 ・ ・ ・ ・ ・ ・ Hub bolt 55 ・ ・ ・ ・ ・ ・・ ・ ・ ・ Small diameter step 56 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Clamping section 60・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer member 60a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling surface 61 ・ ・ ・ ・ ・ ・ ・ ・ Car body mounting Flange 62 ... rolling element 63 ... cage 64 ... ... Seal 65 ... Seal 70 ... Constant velocity universal joint 71 ... ······ Outer joint member 71a ······················································· Track groove 73 ... Cage 74 ... Torque transmission ball 75・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse part 76 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・· Shaft portion 76a · · · · · · serration 77 · · · · · · Fixing bolts P1, P2, P3, P4, P5 · · · Heat Pattern PCDi: Pitch circle diameter of inner side ball PCDo: Pitch circle diameter of outer side ball

Claims (8)

A wheel bearing device manufacturing method in which a hub wheel, a double row rolling bearing and a constant velocity universal joint are unitized,
The double-row rolling bearing has an outer member in which a double-row outer rolling surface is formed on the inner periphery and a vehicle body mounting flange is formed on the outer periphery.
A wheel mounting flange is integrally formed at one end, one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and a cylindrical small-diameter step portion extending in the axial direction from the inner rolling surface; A hub ring having serrations on the inner periphery, the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and an axial direction extending from the inner rolling surface to form serrations An inner member composed of an outer joint member of the constant velocity universal joint integrally formed with the shaft portion,
In the manufacturing method of the wheel bearing device comprising this inner member and a double row ball group accommodated so as to roll between both rolling surfaces of the outer member,
A wheel bearing comprising: a step in which the shaft portion is fitted to the hub wheel via serrations; and a step in which a butted portion of the fitting portion is integrally joined at a joint portion by joining. Device manufacturing method. A wheel bearing device manufacturing method in which a hub wheel, a double row rolling bearing and a constant velocity universal joint are unitized,
The double-row rolling bearing has an outer member in which a double-row outer rolling surface is formed on the inner periphery and a vehicle body mounting flange is formed on the outer periphery.
One inner rolling surface facing the outer rolling surface of the double row on the outer periphery, a cylindrical small-diameter step portion extending in the axial direction from the inner rolling surface, and a serration formed on the inner periphery, etc. A speed universal joint, and a wheel mounting flange integrally formed at one end, the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and extending in an axial direction from the inner rolling surface; An inner member formed of a hub wheel formed with a shaft portion on which serrations are formed;
In the manufacturing method of the wheel bearing device comprising this inner member and a double row ball group accommodated so as to roll between both rolling surfaces of the outer member,
A wheel comprising: a step in which the shaft portion is fitted to the constant velocity universal joint via serrations; and a step in which a butt portion of the fitting portion is integrally joined at a joint portion by joining. Of manufacturing a bearing device for a vehicle.   The method for manufacturing a wheel bearing device according to claim 1 or 2, wherein the joining is performed by laser welding, arc welding, or electron beam welding.   3. The method for manufacturing a wheel bearing device according to claim 1, wherein the welded portion is formed by friction stir welding.   5. The method for manufacturing a wheel bearing device according to claim 1, wherein a diameter of the joint portion is made larger than a diameter of an intermediate shaft fitted to the constant velocity universal joint.   The joint is offset to the large diameter portion of the abutting portion between the hub wheel and the constant velocity universal joint in the traveling direction of the wheel, and abuts against the wall surface of the serration provided on the hub wheel and the constant velocity universal joint. 6. The method for manufacturing a wheel bearing device according to claim 1, wherein the wheel bearing device is formed in contact with the wheel bearing device.   The method for manufacturing a wheel bearing device according to any one of claims 1 to 6, wherein preheating and postheating are performed when the joining is performed. The method for manufacturing a wheel bearing device according to any one of claims 1 to 3, 5 to 7, wherein the welding is performed while supplying a metal wire.

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