阅读说明：本技术 铆接装配件的制造方法、轮毂单元轴承的制造方法及车辆的制造方法 (Method for manufacturing riveted assembly, method for manufacturing hub unit bearing, and method for manufacturing vehicle ) 是由 萩原信行 于 2020-02-20 设计创作，主要内容包括：轮毂单元轴承(1)的制造方法包括通过对轮毂主体(21)的轴端施加轴向上的荷载而在轮毂主体(21)上形成针对内圈(22a、22b)的铆接部(26)的工序。基于在施加荷载之前获取到的第一信息、和在施加荷载后的状态下获取到的第二信息的至少一个来调整荷载。(A method for manufacturing a hub unit bearing (1) includes a step of forming a clinched portion (26) to inner rings (22a, 22b) on a hub body (21) by applying an axial load to an axial end of the hub body (21). The load is adjusted based on at least one of first information acquired before the load is applied and second information acquired in a state after the load is applied.)

1. A method for manufacturing a swaged fitting, comprising:

a step of combining a first member and a second member in an axial direction, the second member having a hole into which the first member is inserted; and

and a step of forming a caulking portion to the second member by applying a load at least along the axial direction to an axial end of the first member, the step of forming the caulking portion including a step of adjusting the load based on at least one of (a) first information acquired before the application of the load and (b) second information acquired in a state after the application of the load.

2. The method of manufacturing a riveted assembly according to claim 1,

the first information includes information associated with the combination of the first component and the second component,

the second information includes information associated with a physical characteristic of the first component.

3. The method of manufacturing a riveted assembly according to claim 1 or 2, wherein the first information includes information measured at the time of the combination of the first member and the second member.

4. A method of manufacturing a riveted assembly according to any one of claims 1 to 3, characterized in that the rivet is formed at least temporarily using a pendulum riveting method.

5. A method of manufacturing a riveted assembly according to any one of claims 1 to 4, wherein the step of forming the riveted portion includes: a first step of forming an intermediate caulking part by a predetermined load; and a second step of forming the caulking portion by applying the adjusted load to the intermediate caulking portion.

6. The method of manufacturing a riveted assembly according to claim 5, wherein the riveted portion is formed by using a different method or a different device between the first step and the second step, or

The caulking portion is formed in the first step and the second step by using the same method or the same apparatus.

7. A method of manufacturing a hub unit bearing,

the hub unit bearing includes:

an outer ring having an outer ring raceway;

a hub having an inner race raceway; and

a plurality of rolling elements disposed between the outer ring raceway and the inner ring raceway,

the hub has a hub main body and an inner ring disposed outside the hub main body and held by the hub main body,

the method for manufacturing a hub unit bearing includes:

a step of axially combining the hub main body and the inner ring, the inner ring having a hole into which the hub main body is inserted; and

and a step of forming a clinched portion with respect to the inner ring on the hub main body by applying a load in the axial direction to an axial end of the hub main body, the step of forming the clinched portion including a step of adjusting the load based on at least one of (a) first information acquired before the load is applied and (b) second information acquired in a state after the load is applied.

8. A method of manufacturing a hub unit bearing, the hub unit bearing comprising:

an outer ring having a plurality of rows of outer ring raceways on an inner circumferential surface;

a hub having a plurality of rows of inner raceway on an outer circumferential surface; and

rolling elements disposed between the inner ring raceways and the outer ring raceways in a plurality of rows,

the hub includes a hub main body, and an inner ring having an inner ring raceway of an axially inner row among the inner ring raceways on an outer circumferential surface,

the inner ring is externally fitted to the hub main body and is pressed against the axially inner side by a caulking portion formed by plastically deforming an axially inner end of the hub main body so as to be pressed and expanded radially outward while being crushed axially outward,

at least the axially inner surface of the inner ring is pressed by the caulking portion to thereby impart a preload to the rolling elements,

the method of manufacturing a hub unit bearing is characterized in that,

in the caulking portion forming step of forming the caulking portion, the work for forming the caulking portion is performed in a plurality of stages, and at least at the last stage of the plurality of stages, the axial load applied to the axially inner end portion of the hub main body is determined using at least one of information acquired earlier than the present stage in the caulking portion forming step and information acquired in a step earlier than the caulking portion forming step.

9. The method of manufacturing a hub unit bearing according to claim 7, wherein the caulking portion forming step includes a first step and a second step,

the first step is a step of processing a cylindrical portion provided at an axially inner end of the hub main body before the formation of the caulked portion into a caulked portion intermediate body,

the second step is a step of processing the intermediate to be caulked portion into the caulked portion.

10. The method of manufacturing a hub unit bearing according to claim 9, wherein in the first step, the caulking portion intermediate body is not brought into contact with an axially inner surface of the inner ring.

11. The method of manufacturing a hub unit bearing according to claim 9, wherein in the first step, the cylindrical portion is machined into the intermediate swaged portion by swaging in which a forming die that rotates while swinging about a center axis of the hub main body is pressed against an axially inner end portion of the hub main body,

the end time point of the oscillating forging in the first step is determined by a value of a mold rotation torque, which is a torque for oscillating and rotating the molding die.

12. The method of manufacturing a hub unit bearing according to claim 11, wherein the finish time of the forging in the first step is set to be: after the oscillating forging is started, the forming die rotational torque first starts to stabilize at a point of time of a substantially fixed value; or a point in time at which the forming die rotational torque starts to decrease after the forming die rotational torque is first stabilized at a substantially fixed value after the oscillating forging starts.

13. The method of manufacturing a hub unit bearing according to any one of claims 9 to 12, wherein in the second step, an axial load applied to an axially inner end portion of the hub main body is determined using the information acquired in the first step.

14. The method of manufacturing a hub unit bearing according to claim 13, wherein in the first step, the cylindrical portion is machined into the intermediate swaged portion by swaging in which a forming die that rotates while swinging about a center axis of the hub main body is pressed against an axially inner end portion of the hub main body,

the information acquired in the first step includes an axial load applied from the molding die to the inner end portion of the hub main body in the axial direction, a molding die rotational torque for rotating the molding die in a swinging manner, and a moving speed of the molding die in the axial direction.

15. The method of manufacturing a hub unit bearing according to claim 13 or 14, wherein in the second step, an axial load applied to the axially inner end portion of the hub main body is determined using information acquired in a step preceding the first step in addition to information acquired in the first step.

16. The method of manufacturing a hub unit bearing according to claim 15, wherein (a) the hub further includes an outer inner ring having an inner ring raceway of an axially outer row of the inner ring raceways on an outer circumferential surface, the outer inner ring being externally fitted to the hub main body, and the information acquired in the step before the first step includes at least one of a fitting margin between the hub main body and the inner and outer inner rings, a press-fit load of the inner and outer inner rings with respect to the hub main body, and a bearing axial gap, or

(b) The hub main body includes an inner ring raceway of an axially outer row of a plurality of rows of the inner ring raceways on an outer circumferential surface, and information acquired in a step before the first step includes at least one of a fitting margin between the hub main body and the inner ring, a press-in load of the inner ring with respect to the hub main body, a row-to-row width of the outer ring raceway, a row-to-row width of the inner ring raceway, a diameter of each row of the rolling elements, and a pitch circle diameter of each row of the rolling elements.

17. The method of manufacturing a hub unit bearing according to any one of claims 13 to 16, wherein in the second step, the axial load applied to the axially inner end portion of the hub main body is determined using a relational expression in which the axial load applied to the axially inner end portion of the hub main body is set as a dependent variable and each of the acquired information and the target value of the preload is included in the dependent variable.

18. The method of manufacturing a hub unit bearing according to claim 17, wherein the relational expression is a relational expression obtained by a multiple regression analysis.

19. The method of manufacturing a hub unit bearing according to any one of claims 9 to 12, wherein in the second step, the machining for forming the caulking portion from the caulking portion intermediate body is performed in a plurality of stages, and after the machining at each stage is completed, an outer ring rotational torque that is a torque for rotating the outer ring is measured with respect to the hub, and at each stage after the second stage, an axial load applied to the axially inner end portion of the hub main body is determined using information of the outer ring rotational torque measured after the machining at each preceding stage is completed.

20. The method of manufacturing a hub unit bearing according to claim 19, wherein when the value of the outer ring rotation torque at the present time point is smaller than the value of the outer ring rotation torque in a state where the preload reaches the target value, a relationship between a difference between these values and an axial load applied to the axially inner end portion of the hub main body required to bring the difference close to 0 is obtained in advance,

in each stage after the second stage, the value of the outer ring rotation torque measured after the machining in each preceding stage is completed is set to the value of the outer ring rotation torque at the current time point, and the axial load applied to the axially inner end portion of the hub main body is determined using the value and the relationship.

21. The method of manufacturing a hub unit bearing according to any one of claims 9 to 20, wherein in the second step, the intermediate swaged portion is processed into the swaged portion by swaging in which a forming die that is rotated while being oscillated about a center axis of the hub main body is pressed against an axially inner end portion of the hub main body.

22. The method of manufacturing a hub unit bearing according to any one of claims 9 to 20, wherein in the second step, the intermediate caulked portion is processed into the caulked portion while applying a load to a plurality of portions rotationally symmetric about a central axis of the hub main body with respect to an axially inner end portion of the hub main body.

23. The method of manufacturing a hub unit bearing according to claim 22, further comprising a step of attaching a seal member between the outer ring and the inner ring between the first step and the second step, the seal member closing an axial inner end opening of an internal space existing between an inner peripheral surface of the outer ring and an outer peripheral surface of the hub.

24. The method of manufacturing a hub unit bearing according to any one of claims 9 to 23, wherein in the second step, a machining force directed radially inward is applied to the caulked portion at a final stage of machining for forming the caulked portion.

25. A method of manufacturing a vehicle provided with a hub unit bearing, characterized in that the hub unit bearing is manufactured by the method of manufacturing a hub unit bearing according to any one of claims 7 to 24.

Technical Field

The present invention relates to a clinch fitting, a method of manufacturing a hub unit bearing, and a method of manufacturing a vehicle.

The present application claims priority based on japanese patent application No. 2019-074550 filed on 4/10/2019, and the contents thereof are incorporated herein by reference.

Background

Conventionally, there is known a hub unit bearing in which a hub rotating together with a wheel includes a hub main body (hub ring) for fixing the wheel and an inner ring fitted to the hub main body, and an axial side surface of the inner ring is pressed by a caulking portion formed at an axial end portion of the hub main body. For example, a wheel and a braking rotor of an automobile are rotatably supported by a suspension device through a hub unit bearing. In the hub unit bearing, preload is applied to the rolling elements based on at least the axial side surface of the inner ring being pressed by the caulking portion in order to increase the rigidity thereof.

Jp 2005-195084 a (patent document 1) describes, as a method of processing an axial end portion of a hub body into a caulking portion, a rocking forging in which a forming die that rocks and rotates about a central axis of the hub body is pressed against the axial end portion of the hub body. Further, japanese patent application laid-open No. 2005-195084 (patent document 1) describes a method of performing the oscillating forging in two stages, and changing the shape of the forming die or the oscillation angle of the forming die in the first stage and the second stage, thereby suppressing a radially outward load applied from the clinch portion to the inner ring.

Further, in japanese patent laid-open nos. 2017 and 18991 (patent document 2), 2017 and 67254 (patent document 3), and 2017 and 106510 (patent document 4), a method of not applying an eccentric load to an axial end portion of a hub body is described as a method of processing a caulking portion.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-195084

Patent document 2: japanese patent laid-open publication No. 2017-18991

Patent document 3: japanese patent laid-open publication No. 2017-67254

Patent document 4: japanese patent laid-open publication No. 2017-106510

Disclosure of Invention

The pre-compression of the hub unit bearing affects the driving stability of the vehicle. In particular, when an electric motor is used as a power source of an automobile as compared with a case where an engine is used, it can be said that the influence of the preload of the hub unit bearing is large. In order to achieve more uniform running stability of the automobile, it is also required to adjust the preload as intended in the manufacture of the hub unit bearing. The method of dividing the process for forming the clinch portion into two stages as described in japanese patent application laid-open No. 2005-195084 (patent document 1) is considered to be effective also for adjusting the preload of the hub unit bearing. However, japanese patent application laid-open No. 2005-195084 (patent document 1) does not describe specific details such as how to adjust the preload.

The invention aims to realize a manufacturing method of a riveting assembly capable of adjusting prepressing, a manufacturing method of a hub unit bearing and a manufacturing method of a vehicle.

A method for manufacturing a swaged fitting according to an aspect of the present invention includes: a step of combining a first member and a second member in an axial direction, the second member having a hole into which the first member is inserted; and a step of forming a caulking portion to the second member by applying a load in the axial direction to an axial end of the first member, the step of forming the caulking portion including a step of adjusting the load based on at least one of (a) first information acquired before the load is applied and (b) second information acquired in a state after the load is applied.

In a method of manufacturing a hub unit bearing according to an aspect of the present invention, the hub unit bearing includes: an outer ring having an outer ring raceway; a hub having an inner race raceway; and a plurality of rolling elements disposed between the outer ring raceway and the inner ring raceway, the hub having a hub main body, and an inner ring disposed outside the hub main body and held by the hub main body. The method comprises the following steps: a step of axially combining the hub main body and the inner ring, the inner ring having a hole into which the hub main body is inserted; and a step of forming a clinched portion with respect to the inner ring on the hub main body by applying a load in the axial direction to an axial end of the hub main body, the step of forming the clinched portion including a step of adjusting the load based on at least one of (a) first information acquired before the load is applied and (b) second information acquired in a state after the load is applied.

In one aspect of the present invention, a hub unit bearing to be manufactured includes: an outer ring having a plurality of rows of outer ring raceways on an inner circumferential surface; a hub having a plurality of rows of inner raceway on an outer circumferential surface; and rolling elements disposed between the inner ring raceways and the outer ring raceways in a plurality of rows. The hub includes a hub main body, and an inner ring having an inner ring raceway of an axially inner row of the inner ring raceways on an outer circumferential surface. The inner ring is externally fitted to the hub main body and is pressed against the axially inner side by a caulking portion formed by plastically deforming an axially inner end of the hub main body so as to be pressed and expanded radially outward while being crushed axially outward. At least the axially inner surface of the inner ring is pressed by the caulking portion, thereby imparting preload to the rolling elements.

In the method of manufacturing a hub unit bearing according to one aspect of the present invention, the process for forming the caulking portion is performed in a plurality of stages in the caulking portion forming step of forming the caulking portion, and at least at the final stage of the plurality of stages, the axial load applied to the axially inner end portion of the hub main body is determined using at least one of information acquired earlier than the current stage in the caulking portion forming step and information acquired in a step earlier than the caulking portion forming step.

For example, the caulking portion forming step includes a first step and a second step. The first step is a step of processing a cylindrical portion provided at an axially inner end of the hub main body before the formation of the caulked portion into a caulked portion intermediate body. The second step is a step of processing the intermediate to be caulked portion into the caulked portion.

For example, in the first step, the intermediate caulking portion is not brought into contact with the axially inner surface of the inner ring.

For example, in the first step, the cylindrical portion is machined into the caulking portion intermediate body by swaging in which a forming die that is rotated while being oscillated about a central axis of the hub main body is pressed against an axially inner end portion of the hub main body. The end time point of the oscillating forging in the first step is determined by a value of a mold rotation torque, which is a torque for oscillating and rotating the molding die.

In this case, for example, the end time of the oscillating forging in the first step is set as follows: after the oscillating forging is started, the forming die rotational torque first starts to stabilize at a point of time of a substantially fixed value; or a point in time at which the forming die rotational torque starts to decrease after the forming die rotational torque is first stabilized at a substantially fixed value after the oscillating forging starts.

For example, in the second step, the axial load applied to the axially inner end portion of the hub main body is determined using the information acquired in the first step.

For example, in the first step, the cylindrical portion is machined into the caulking portion intermediate body by swaging in which a forming die that is rotated while being oscillated about a central axis of the hub main body is pressed against an axially inner end portion of the hub main body. The information acquired in the first step includes an axial load applied from the molding die to the inner end portion of the hub main body in the axial direction, a molding die rotational torque for rotating the molding die in a swinging manner, and a moving speed of the molding die in the axial direction.

For example, in the second step, the axial load applied to the axially inner end of the hub main body is determined using information acquired in a step prior to the first step in addition to information acquired in the first step.

In the case where the hub further includes an outer inner ring having an inner ring raceway of an axially outer row of the inner ring raceways on an outer peripheral surface thereof, and the outer inner ring is externally fitted to the hub main body, for example, information acquired in a step prior to the first step includes at least one of fitting margins between the hub main body and the inner and outer inner rings, press-fitting loads of the inner and outer inner rings with respect to the hub main body, and a bearing axial clearance.

In the case where the hub main body has, on the outer peripheral surface, an inner ring raceway of an axially outer row of the inner ring raceways, for example, the information acquired in the step before the first step includes at least one of a fitting margin between the hub main body and the inner ring, a press-in load of the inner ring with respect to the hub main body, an inter-row width of the outer ring raceway, an inter-row width of the inner ring raceway, a diameter of the rolling elements in each row, and a pitch circle diameter of the rolling elements in each row.

For example, in the second step, the axial load applied to the axially inner end of the hub main body is determined using a relational expression in which the axial load applied to the axially inner end of the hub main body is set as a dependent variable and each of the acquired information and the target value of the preload is included in the dependent variable. In this case, for example, a relational expression obtained by a multiple regression analysis can be used as the relational expression.

For example, in the second step, the machining for forming the caulking portions from the caulking portion intermediate body is performed in a plurality of stages, and an outer ring rotation torque that is a torque for rotating the outer ring is measured with respect to the hub after the machining in each stage is completed, and in each stage after the second stage, the axial load applied to the axially inner end portion of the hub main body is determined using information of the outer ring rotation torque measured after the machining in each preceding stage is completed.

For example, when the value of the outer ring rotation torque at the current time point is smaller than the value of the outer ring rotation torque in a state where the preload reaches the target value, a relationship between a difference between these values and an axial load applied to the axial inner end portion of the hub main body necessary to bring the difference close to 0 is obtained in advance. In each of the second and subsequent stages, the value of the outer ring rotation torque measured after the completion of the machining in each preceding stage is set to the value of the outer ring rotation torque at the current time point, and the axial load applied to the axially inner end portion of the hub main body is determined using the value and the relationship.

For example, in the second step, the intermediate caulking portion is machined into the caulking portion by swaging the molding die, which is rotated while swinging about the center axis of the hub body, so as to press the molding die against the axially inner end of the hub body.

For example, in the second step, the intermediate caulked portion is processed into the caulked portion while applying a load to a plurality of portions rotationally symmetric about the center axis of the hub main body with respect to the axially inner end portion of the hub main body. In this case, for example, a step of attaching a seal member that closes an axial inner end opening of an inner space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub between the outer ring and the inner ring is performed between the first step and the second step.

For example, in the second step, a machining force directed radially inward is applied to the caulked portion at a final stage of the machining for forming the caulked portion.

In one embodiment of the present invention, a vehicle to be manufactured includes a hub unit bearing. A method of manufacturing a vehicle according to an aspect of the present invention manufactures a hub unit bearing according to the above-described aspect.

Effects of the invention

According to the aspect of the invention, the preload of the hub unit bearing can be adjusted.

Drawings

Fig. 1 is a cross-sectional view showing an example of a state in which a hub unit bearing is assembled in a vehicle.

Fig. 2 is a block diagram for explaining a caulking portion forming process in the first embodiment.

Fig. 3 (a) is a partial cross-sectional view showing a start state of the first step of the caulking portion forming step in the first embodiment, and (b) is a partial cross-sectional view showing an end state of the first step.

Fig. 4 shows the mold rotation torque T in the case where the caulking portion is formed by the caulking device used in the first step of the caulking portion forming step in the first embodiment_sA line graph of time variation of (a).

Fig. 5 (a) is a partial cross-sectional view showing a start state of the second step of the caulking portion forming step in the first embodiment, and (b) is a partial cross-sectional view showing an end state of the second step.

Fig. 6 is an enlarged view of a portion a of fig. 5 (b).

FIG. 7 shows a mold rotation torque T in the first step of the caulking portion forming step in the second embodiment_sLine graphs which do not change before and after the caulking process.

FIG. 8 is a view illustrating the outer ring rotation torque T measured after the caulking process of the first stage in the second step of the caulking portion forming step in the second embodiment_gLine graph of the case (1).

Fig. 9 is a line graph showing load conditions used in the second step of the caulking portion forming step in the second embodiment when caulking is performed after the second stage.

FIG. 10 is a view illustrating the outer ring rotation torque T measured after the caulking process of the second stage in the second step of the caulking portion forming step in the second embodiment_gLine graph of the case (1).

Fig. 11 is a sectional view showing a hub unit bearing according to a third embodiment.

Fig. 12 is a partial cross-sectional view showing a state in which the second step of the caulking portion forming step in the fourth embodiment is completed.

Fig. 13 is a partial schematic view of a vehicle provided with a hub unit bearing (bearing unit).

Fig. 14 is a cross-sectional view showing an example of a hub unit bearing using tapered rollers.

Detailed Description

[ first embodiment ]

A first embodiment of the present invention will be described with reference to fig. 1 to 6. First, a structure of the hub unit bearing 1 to be manufactured will be described, and next, a method of manufacturing the hub unit bearing 1 will be described.

< construction of hub Unit bearing 1 >

Fig. 1 shows an example of a hub unit bearing 1. The hub unit bearing 1 is used for a driven wheel, and includes an outer ring 2, a hub 3, and a plurality of rolling elements 4a and 4 b.

Further, the axially outer side of the hub unit bearing 1 is the left side of fig. 1, which is the vehicle width direction outer side in the state of being assembled to the vehicle. The axially inner side is the right side of fig. 1, which is the vehicle width direction center side in the assembled state to the vehicle.

The outer ring 2 includes a plurality of outer ring raceways 5a and 5b and a stationary flange 6. In one example, the outer ring 2 is made of hard metal such as medium carbon steel. In other examples, the outer race 2 can be formed of other materials. The outer ring raceways 5a and 5b are provided on the inner peripheral surface of the outer ring 2 at the intermediate portion in the axial direction over the entire circumference. The stationary flange 6 protrudes radially outward from an axially intermediate portion of the outer ring 2, and has support holes 7 as threaded holes at a plurality of locations in the circumferential direction.

The outer ring 2 is supported and fixed to a knuckle 8 of a suspension system of a vehicle by screwing and fastening bolts 10 inserted through holes 9 of the knuckle 8 to support holes 7 of a stationary flange 6 from the axially inner side.

A hub (caulking fitting, caulking unit) 3 is disposed coaxially with the outer ring 2 on the radially inner side of the outer ring 2. The hub 3 includes a plurality of inner ring raceways 11a and 11b and a rotating flange 12. The multiple rows of inner ring raceways 11a, 11b are provided on the entire circumference at portions of the outer peripheral surface (outer surface) of the hub 3 that face the multiple rows of outer ring raceways 5a, 5 b. The rotary flange 12 protrudes radially outward from a portion of the hub 3 located axially outward of the outer ring 2, and has mounting holes 13 at a plurality of locations in the circumferential direction.

In the illustrated example, in order to couple and fix the braking rotor 14 such as a brake disc or a brake drum to the rotation flange 12, the serration provided in the portion of the stud 15 near the base end is press-fitted into the mounting hole 13. Further, the intermediate portion of the stud 15 is press-fitted into the through hole 16 of the braking rotor 14. Further, in order to fix the wheel 17 constituting the wheel to the rotary flange 12, the nut 19 is screwed and fastened to the external thread portion provided at the tip end portion of the stud 15 in a state where the external thread portion is inserted into the through hole 18 of the wheel 17.

The rolling elements 4a, 4b are disposed between the outer raceway rows 5a, 5b and the inner raceway rows 11a, 11b so as to be disposed in plural numbers for each row. In one example, the rolling elements 4a and 4b are made of hard metal such as bearing steel or ceramic. In other examples, the rolling bodies 4a, 4b can be formed of other materials. The rolling elements 4a and 4b are held by cages 20a and 20b so as to be rollable in each row. In the example of fig. 1, balls are used as the rolling elements 4a and 4b, but tapered rollers may be used as shown in the example of fig. 14.

The hub (clinch fitting) 3 is constituted by a hub main body (hub wheel) 21, an inner ring 22a, and an outer inner ring 22 b. In one example, the hub body 21 is made of hard metal such as medium carbon steel. The inner ring 22a and the outer inner ring 22b are made of hard metal such as bearing steel. In other examples, the hub main body 21, the inner ring 22a, and the outer inner ring 22b may be formed of other materials. The hub (clinch fitting) 3 is substantially configured by axially combining a hub main body (first member) 21 and inner rings (second members) 22a and 22 b. The hub 3 includes a hub main body 21 having an outer peripheral surface (outer surface) 23, and inner rings (second members) 22a and 22b arranged on the outer peripheral surface (outer surface) 23 of the hub main body 21 and held by the hub main body (first member) 21. The inner ring raceway 11a of the axially inner row is provided on the outer peripheral surface of the inner ring 22 a. The inner ring raceway 11b of the axially outer row is provided on the outer peripheral surface of the outer inner ring 22 b. The rotary flange 12 is provided at an axially outer side portion of the hub main body 21. The hub body 21 has a cylindrical fitting surface portion 23 on the outer peripheral surface of an intermediate portion in the axial direction, and a stepped surface 24 facing the axial inner side on the outer end portion in the axial direction of the fitting surface portion 23. The inner ring 22a and the outer inner ring 22b are fitted to the fitting surface portion 23 of the hub main body 21 by interference fit. Further, the hub main body 21 has a caulking portion 26 at an axially inner end portion. The caulking portion 26 is bent radially outward from an axial inner end portion of a portion of the hub main body 21 to which the inner ring 22a is fitted, and presses an axial inner side surface of the inner ring 22 a. That is, the inner ring 22a and the outer inner ring 22b are sandwiched between the stepped surface 24 and the caulking portion 26 of the hub main body 21, thereby preventing separation from the hub main body 21. In this state, a back contact angle and a preload are applied to the rows of rolling elements 4a and 4b constituting the hub unit bearing 1. In one example, the hub main body 21 has a caulking portion 26 for the inner rings 22a, 22b (the caulking portion 26 for holding the inner rings 22a, 22 b). The hub body 21 is inserted into the bore 120 of the inner rings 22a, 22 b. The hub body 21 has a caulking portion 26 extending in the circumferential direction and bent to cover the axial end of the inner ring 22 a.

Both axial end openings of an inner space 27 existing between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3 are closed by seal members 28, 29. The axially inner seal member 28 is assembled between the inner peripheral surface of the axially inner end of the outer ring 2 and the outer peripheral surface of the axially inner end of the inner ring 22 a. The axially outer seal member 29 is assembled between the inner peripheral surface of the axially outer end of the outer ring 2 and the outer peripheral surface of the axially outer end of the outer inner ring 22 b. These seal members 28 and 29 can prevent the grease sealed in the internal space 27 from leaking into the external space through the openings at both ends in the axial direction of the internal space 27. In addition, foreign matter such as muddy water present in the external space can be prevented from penetrating into the internal space 27 through the openings at both ends in the axial direction of the internal space 27.

< method for manufacturing hub unit bearing 1 >

In the present embodiment, the hub unit bearing 1 is manufacturedIn the manufacturing method, the caulking portion forming step of forming the caulking portion 26 is performed by dividing the caulking portion forming step into a first step and a second step so that the preload applied to the rolling elements 4a and 4b approaches a target value, and the information (second information) I acquired in the first step is used in the second step_BAnd information (first information) I acquired in a step prior to the clinch portion forming step_AThe axial load applied to the axially inner end portion of the hub main body 21 is determined (see fig. 2). The method for manufacturing the hub body 21 includes: a step of axially combining the hub body 21 with the inner rings 22a and 22b having the hole 120 into which the hub body 21 is inserted; and a step of forming a caulking portion 26 to the inner rings 22a, 22b in the hub body 21 by applying a load (axial load) at least in the axial direction to the axial end of the hub body 21. The step of forming the clinched portion 26 includes a step of forming the clinched portion based on (a) first information I acquired before applying a load (axial load)_AAnd (b) second information I acquired in a state after a load (axial load) is applied_BAnd (3) adjusting the load (axial load). The first step is a step of processing the cylindrical portion 25 provided at the axially inner end of the hub main body 21 before the formation of the caulked portion 26 into a caulked portion intermediate body (intermediate caulked portion) 39 (see fig. 3a and 3 b). The second step is a step of processing the caulking portion intermediate 39 into the caulking portion 26 (see fig. 5 (a) and 5 (b)). The process of forming the caulking portion 26 includes: a first step of forming the intermediate caulking portion 39 with a predetermined load; and a second step of forming a final caulking portion 26 by applying the adjusted load to the intermediate caulking portion 39.

In one example, the rivet intermediate (intermediate rivet) 39 is defined as: the axial end shape of the hub main body 21 after at least partial plastic deformation in the first step (for example, from the start of application of a load to the completion of load adjustment (pre-load adjustment)). Or the rivet intermediate (intermediate rivet) 39 is defined as: the axial end shape of the hub main body 21 after at least partial plastic deformation at the time point when the load adjustment is completed (the preload adjustment is completed). For example, the caulking portion intermediate body (intermediate caulking portion) 39 has an axial end shape of the hub main body 21 at the time point when the preload adjustment described later is completed. The adjusted load is fixedly applied to the intermediate caulking portion 39, and the final caulking portion 26 is formed. In one example, the intermediate caulking portion (intermediate caulking portion) 39 does not substantially contact the inner ring 22 a. In other examples, the rivet intermediate (intermediate rivet) 39 substantially contacts the inner race 22 a.

For example, in the method of manufacturing the hub unit bearing 1, specifically, in the first step, when the cylindrical portion 25 is processed into the caulking portion intermediate 39, the information (second information) I indicating the degree of processing resistance, that is, the degree of hardness of the hub main body 21 is acquired_B. Information I_BContaining information associated with the physical characteristics of the hub body 21. In the second step, the information I is used_BThe axial load applied to the axially inner end of the hub main body 21 required to bring the preload close to the target value is determined. In one example, further, in the second process, in addition to the information (second information) I acquired in the first process, the information (second information) I is_BIn addition, information (first information) I regarding factors affecting the preload, such as the size of the specific part, among information acquired in a step prior to the rivet forming step is used_AThe axial load applied to the axially inner end of the hub main body 21 required to bring the preload close to the target value is determined. Information (first information) I_AContaining information associated with the combination of the hub body 21 and the inner rings 22a, 22 b. For example, information (first information) I_AContains information obtained or measured when the hub main body 21 is combined with the inner rings 22a, 22 b. In one example, based on the first information I acquired before the application of the load (axle load)_AAnd second information I acquired in a state where a load (axial load) is applied_BThese determine the axial load when the intermediate caulking portion 39 is processed into the final caulking portion 26. In other examples, the first information I acquired substantially only before the load (axial load) is applied is based on_AThe axial load at the time of machining the intermediate caulking portion 39 into the final caulking portion 26 is determined. In another example, the second information I is substantially based only on the second information I acquired in a state after the load (axial load) is applied_BTo decide to rivet the middleAxial load when the portion 39 is machined to form the final clinch 26. In another example, the axial load when the intermediate caulking portion 39 is machined to the final caulking portion 26 is determined based on at least one of the first information and the second information and information different from the first and second information.

Hereinafter, the information I to be acquired in the process before the caulking portion forming process will be described in order_AAnd I to be obtained in the first step_BAfter each specific type of information, the second process is directed to how to use the information I specifically_A、I_BThe axial load applied to the axially inner end of the hub main body 21, which is required to bring the preload close to the target value, is determined.

(step before the clinch formation step)

In the present embodiment, the information I is acquired in a step prior to the caulking portion forming step_ABut three pieces of information are used. Information I_AThe first information included is information on the fitting margin S between the fitting surface portion 23 of the hub main body 21 and the inner and outer inner rings 22a and 22 b. Therefore, for example, the outer diameter of the fitting surface portion 23 of the hub body 21 and the inner diameter of the inner and outer inner rings 22a and 22b are measured in a step before the caulking portion forming step. The fitting margin S (information I) which is the difference between the outer diameter of the fitting surface portion 23 of the hub body 21 and the inner diameter of the inner ring 22a and the outer inner ring 22b measured in this manner is obtained in advance_AThe first information contained).

Information I_AThe second information included is information relating to the bearing axial clearance Δ a before the formation of the caulking portion 26. Information I_AThe third information included is the press-fit load F for press-fitting the inner ring 22a and the outer inner ring 22b to the fitting surface portion 23_pInformation about this. These pieces of information are acquired in the assembly process of the hub unit bearing 1 before the formation of the caulked portion 26. Next, an example of the assembling method will be described with reference to fig. 1.

The hub unit bearing 1 before the formation of the caulking portion 26 is assembled, for example, in the following order. First, the rolling elements 4a of the axially inner row held by the cage 20a are arranged radially inward of the outer ring raceways 5a of the axially inner row. The rolling elements 4b in the axially outer row held by the cage 20b are arranged radially inward of the outer ring raceway 5b in the axially outer row. Next, the inner ring 22a is inserted radially inward of the outer ring 2 from the axially inner side. The bearing portion assembly 34 is assembled by inserting the outer inner ring 22b from the axially outer side to the radially inner side of the outer ring 2.

Next, the bearing axial clearance Δ a of the bearing portion assembly 34 was measured as the bearing axial clearance before the formation of the caulking portion 26 (information I)_AThe second information contained). Here, the bearing axial clearance is an internal clearance of the bearing with respect to the axial direction. The bearing axial clearance Δ a of the bearing portion assembly 34 is an internal clearance of the bearing portion assembly 34 in relation to the axial direction in a state in which the opposite axial side surfaces of the inner ring 22a and the outer inner ring 22b constituting the bearing portion assembly 34 are brought into contact with each other. In one example, the bearing axial clearance Δ a is positive (> 0). Therefore, the bearing axial clearance Δ a can be measured based on the case where the inner and outer inner rings 22a and 22b and the outer ring 2 are relatively moved in the axial direction in a state where the axial side surfaces of the inner and outer inner rings 22a and 22b facing each other are brought into contact with each other. In other examples, the bearing axial clearance Δ a can be set to other values.

Next, the bearing assembly 34 is attached to the axially outer seal member 28. The axially inner seal member 28 is not attached at this stage, but is attached after the caulking portion 26 is formed.

Next, the inner ring 22a and the outer inner ring 22b constituting the bearing portion assembly 34 are press-fitted from the axially inner side (the right side in fig. 1) to the fitting surface portion 23 of the hub main body 21 before the caulking portion 26 is formed. Thereby, the inner ring 22a and the outer inner ring 22b are fitted to the fitting surface portion 23 by interference fit, and the axial side surfaces of the inner ring 22a and the outer inner ring 22b facing each other are brought into contact with each other. Further, the hub unit bearing 1 before the caulking portion 26 is formed can be obtained by bringing the axially outer surface of the outer inner ring 22b into contact with the stepped surface 24 of the hub main body 21. At this time, the measurement is used to fix the inner ring 22a and the press-fitting load F of the outer inner ring 22b to the fitting surface portion 23_p(information I)_AThe third information contained).

When the inner and outer inner rings 22a and 22b constituting the bearing portion assembly 34 are press-fitted to the fitting surface portion 23 of the hub main body 21 before the caulking portion 26 is formed as described above, the inner and outer inner rings 22a and 22b are expanded in diameter by the fitting margin S, and the bearing axial gap changes from positive to negative. As a result, the bearing axial clearance Δ a' in this state is mostly negative. That is, in many cases, a certain degree of preload is applied to the hub unit bearing 1 before the caulking portion 26 is formed.

In the present embodiment, the caulking portion 26 is formed thereafter, and the axial inner surface of the inner ring 22a is pressed by the caulking portion 26 to increase the preload (increase the preload that has been applied, or apply the preload that has not been applied before and increase the preload), thereby bringing the preload closer to the target value.

(first step of the clinch formation step)

In the present embodiment, the information I is acquired in the first step_BBut three pieces of information are used. Three pieces of information are acquired in the processing of the first process. Therefore, the processing method in the first step will be described next.

In the first step, the cylindrical portion 25 is machined into the caulking portion intermediate 39 by the swaging using a first caulking machining apparatus including the first molding die 30 shown in fig. 3 (a) and 3 (b). In the following description, the vertical direction refers to the vertical direction in the drawings.

The first molding die 30 is disposed above the hub 3, and has a rotation axis β inclined by a predetermined angle θ with respect to a central axis α of the hub 3. The first molding die 30 has a processed surface portion 31, which is an annular concave surface centered on the rotation axis β, at a lower end portion. The first molding die 30 is movable in the vertical direction and swingable about the central axis α of the hub 3, and is capable of freely rotating about the rotation axis β. The first molding die 30 is located above the position shown in fig. 3 (a) in the state before the start of the processing, and does not contact the cylindrical portion 25.

When the cylindrical portion 25 is forged by rocking using the first molding die 30, the outer ring 2 is rotated relative to the hub 3 while the displacement of the hub main body 21 is prevented, and the first molding die 30 is rotated by rocking about the center axis α of the hub 3. Then, in this state, the first molding die 30 is moved downward, and the processing surface portion 31 of the first molding die 30 is pressed against the cylindrical portion 25 as shown in fig. 3 (a). As a result, as shown in fig. 3 (a) and 3 (b), the caulking portion intermediate 39 is formed. That is, a machining force directed downward in the vertical direction and outward in the radial direction is applied to a part of the cylindrical portion 25 in the circumferential direction from the machining surface portion 31 of the first molding die 30. The position to which the machining force is applied is continuously changed in the circumferential direction of the cylindrical portion 25 in accordance with the swing rotation of the first molding die 30 about the center axis α of the hub 3. Thus, the cylindrical portion 25 is plastically deformed so as to be pressed and spread outward in the radial direction while being crushed outward in the axial direction, thereby forming the caulking portion intermediate 39.

In one example, the caulking portion intermediate body 39 has a shape such that the axially outer side surface does not contact the axially inner side surface of the inner ring 22a as shown in fig. 3 (b), or the axially inner side surface of the inner ring 22a contacts the axially inner side surface of the inner ring raceway 11a of the axially inner row to such an extent that the inner ring raceway 11a is not deformed. For example, the caulking portion intermediate 39 has a shape in which the prepressing does not change with the formation of the caulking portion intermediate 39. In one example, the swing forging is finished at the time point when such a caulking portion intermediate body 39 is formed. Thereafter, the first molding die 30 is retracted upward with respect to the hub main body 21.

In the present embodiment, in order to form the caulking part intermediate body 39 as described above, the time point (timing) when the swing forging is ended in the first step is based on the mold rotation torque T which is a torque for swinging and rotating the first mold 30_sTo decide. This point will be described with reference to fig. 4. In addition, the forming die rotation torque T_sFor example, the measurement can be performed based on the current value of an electric motor for a mold, not shown, for oscillating and rotating the first mold 30。

FIG. 4 shows the mold rotation torque T in the case where the cylindrical portion 25 is formed into the caulking portion 26 by just the oscillating forging using the first mold 30_sA line graph of time variation of (a). In this case, the molding-die rotational torque T_sThe first stage (period t1) after the start of the swing forging is gradually increased. In the subsequent second stage (period T2), the forming die rotation torque T_sStabilized at a substantially fixed value. At the subsequent third stage (period T3), the forming die rotation torque T_sAnd gradually decreases. In the following fourth stage (period T4), the forming die rotation torque T_sAgain stabilizing at a substantially fixed value.

The axially inner end of the hub main body 21, which has been subjected to the swaging, is in a state of not contacting the axially inner side surface of the inner ring 22a in the first to second stages (periods t1, t 2). In the third stage (period t3), the inner ring raceway 11a of the axially inner row is brought into contact with the axially inner surface of the inner ring 22a to such an extent that it is not deformed. In the fourth stage (period t4), the inner ring raceway 11a of the axially inner row is in contact with the axially inner surface of the inner ring 22a to such an extent that it is deformed.

In the present embodiment, the mold rotation torque T is checked while_sThe swing forging in the first process is ended at any one time point of the first to third stages (periods t1, t2, t 3). However, from the viewpoint of improving the efficiency of the operation of forming the caulking portion 26, it is desirable to ensure the machining amount of the axially inner end portion of the hub main body 21 in the first step to some extent. Therefore, as for the point of time at which the swing forging in the first process is ended, it is desirable to end at any one point of time of the second stage (period t2) or the third stage (period t3) as compared with the first stage (period t 1). As a specific end time point in this case, for example, a time point immediately after the transition to the second stage (period t2) or a time point immediately after the transition to the third stage (period t3) can be cited. Here, the time point immediately after the transition to the second stage (period t2) is: after the start of the swing forging, the forming die rotation torque T_sFirst start to stabilizeAt a substantially constant time point (e.g., point Q1 in fig. 4). The time immediately after the transition to the third stage (period t3) is: after the start of the swing forging, the forming die is rotated by a torque T_sThe rotational torque T of the forming die is stabilized at a substantially fixed value for the first time_sThe point in time at which the decrease is started (e.g., point Q2 in fig. 4).

In the present embodiment, the oscillating forging in the first step is performed while measuring information including: an axial load P applied from the first molding die 30 to the axially inner end portion of the hub main body 21₁(ii) a Mold rotation torque T for swinging and rotating first mold 30_s(ii) a And a moving speed V in the axial direction of the first molding die 30_s. In addition, axial load P₁For example, the measurement can be performed based on the hydraulic pressure in a hydraulic mechanism, not shown, for moving the first molding die 30 in the axial direction. Further, the moving speed V_sFor example, the measurement can be performed using a linear scale not shown.

In the present embodiment, the information I is acquired in the first step_BThe three pieces of information contained in the first step are respectively associated with the axial load P at the time point when the oscillating forging in the first step is completed₁Forming die rotation torque T_sAnd a moving speed V_sInformation about this. In addition, information I_BOther information can be included instead of or in addition to the above information.

(second step of the clinch formation step)

In the second step, first, information I acquired in a step prior to the caulking portion forming step is used_AAnd information I acquired in the first step_BTo determine the axial load P applied to the axial inner end of the hub body 21 required for bringing the preload close to the target value_2x. In one example, the axial load P is calculated using the following equation (1)_2x. In the formula (1), an axial load P is applied_2xSet as dependent variable. In addition, in the formula (1), the argument includes information I_AThe information (fitting margin S, bearing axial clearance Delta a, press-in load F) included in the information_p) Information I_BThe individual information contained (axial load P)₁Forming die rotation torque T_sAnd a moving speed V_s) And a target value X for the preload.

P_2x＝k₁×S+k₂×Δa+k₃×F_p+k₄×P₁+k₅×T_s+k₆×V_s+k₇×X……(1)

Here, k₁、k₂、k₃、k₄、k₅、k₆、k₇Is a coefficient. These coefficients are obtained in advance by multiple regression analysis. These coefficients can also be obtained by various experiments or simulations other than the multiple regression analysis.

In the formula (1), the target value X of the pre-pressure can be set to an arbitrary value. In the hub unit bearing 1, an outer ring rotation torque T, which is a torque for rotating the outer ring 2 with respect to the hub 3_gIs a magnitude corresponding to the preload. Therefore, in equation (1), the outer ring rotation torque T corresponding to the target value of the preload can be input to the target value X of the preload_gI.e. target outer ring rotation torque T_gx. Further, outer ring rotation torque T_gThe measurement can be performed based on the current value of an electric motor for an outer ring, not shown, for rotating the outer ring 2 with respect to the hub 3.

As described above, the axial load P applied to the axially inner end portion of the hub main body 21 required to bring the preload close to the target value can be calculated_2x. Then, using the axial load P_2xThe caulking portion intermediate 39 is processed into the caulking portion 26. In one example, the caulking portion 39 is formed between the first step and the second step by using a different method and/or a different apparatus. This point will be specifically described next.

In the second step, the intermediate caulked portion 39 is processed into the caulked portion 26 by the oscillating forging using a device different from the first caulking device used in the first step, specifically, a second caulking device including the second molding die 32 shown in fig. 5 (a) and 5 (b). That is, as shown in fig. 5a and 5b, the caulking portion 26 is formed by pressing the machined surface portion 33 of the second molding die 32, which is swingably rotated about the central axis α of the hub 3, against the axial inner end portion (the caulking portion intermediate body 39) of the hub main body 21 while preventing the displacement of the hub main body 21 and rotating the outer ring 2 relative to the hub 3.

By the oscillating forging, when the caulking portion 26 is formed, the axial load P applied from the second molding die 32 to the axial inner end portion of the hub main body 21 is caused to occur₂And gradually increases. Thus, by pushing the second molding die 32 downward, the shape of the axially inner end of the hub main body 21 is brought closer to the shape of the completed clinch 26. In this example, the axial load P is preliminarily applied at this time₂Is set to the axial load P_2x. Therefore, for example, in a hydraulic mechanism, not shown, for moving the second molding die 32 in the axial direction, the setting is made by the control valve for generating the axial load P₂Does not exceed the axial load P_2xThe corresponding value. As a result, in this example, the load P in the axial direction₂To achieve axial load P_2xTime point of (1), axial load P₂The upward movement of the second molding die 32 is stopped, and the downward movement is stopped. Thereafter, if necessary, the oscillating forging in the second step is terminated after the oscillating rotation of the second molding die 32 is continued for a predetermined time. By the operation of forming the caulking portion 26, the preload is increased and the preload is brought close to a target value.

In the present embodiment, the machined surface portion 33 of the second molding die 32 has a shape capable of applying a machining force F directed downward in the vertical direction and inward in the radial direction to the swaged portion 26 at the final stage of the oscillating forging shown in fig. 5 (b)_sThe shape of (see fig. 6). In other words, the machined surface portion 33 of the second molding die 32 has a concave curved surface shape in which the portion that presses the caulking portion 26 at the final stage of the oscillating forging shown in fig. 5 (b) is inclined in a direction toward the lower side in the vertical direction as going toward the radially outer side.

In this way, in the present embodiment, the maximum forging step in the second step is performed by the oscillating forgingAt the final stage, a machining force F directed downward in the vertical direction and radially inward is applied to the swaged portion 26 from the machining surface portion 33 of the second molding die 32_s. As a result, as indicated by an arrow λ in fig. 5 (b), the material escapes from the caulking portion 26 toward the inner diameter side of the fitting surface portion 23, and a force having a large axial component is applied to the inner ring 22a from the caulking portion 26. This prevents an excessive force from acting on the inner ring 22a from the caulking portion 26 toward the radial outer side, and prevents problems such as deterioration in the shape accuracy of the inner ring raceway 11a of the axially inner row.

In other examples, the caulking portions 39 are formed in the first step and the second step by the same method or the same apparatus. For example, a mold having the same shape can be used in the first step and the second step. In this case, even in the second step, the swing angle θ, which is the inclination angle of the rotation axis of the forming die with respect to the center axis of the hub, is made larger than in the first step, so that the machining force directed downward in the vertical direction and inward in the radial direction can be applied to the swaged portion from the machined surface portion of the forming die at the final stage of the swing forging in the second step. Alternatively, the swing angle and the swing center may be made the same in the first step and the second step.

As described above, according to the method of manufacturing a hub unit bearing of the present embodiment, the preload can be adjusted, and specifically, the preload can be made close to the target value.

In the present embodiment, the operation of forming the caulking portion 26 is performed in a first step and a second step, and the first step and the second step are performed using different caulking apparatuses. Therefore, the production efficiency of the hub unit bearing 1 can be improved. That is, if the operation of forming the caulking portion 26 is performed by dividing the first step and the second step, the caulking time per step can be shortened, and after the caulking process in the first step is completed, the caulking process in the first step in the next hub unit bearing can be started during the period in which the caulking process in the second step is performed. Therefore, the production efficiency of the hub unit bearing 1 can be improved accordingly. The formation of the caulking portion 39 by using a different method and/or a different device between the first step and the second step is advantageous, for example, in setting processing conditions suitable for the first step and the second step, respectively. The formation of the caulking portion 39 in the first step and the second step using the same working method and/or the same apparatus is advantageous, for example, in terms of simplification of a processing system.

[ second embodiment ]

A second embodiment of the present invention will be described with reference to fig. 7 to 10.

In the second embodiment, the caulking portion forming step of forming the caulking portion 26 also includes the first step and the second step. The first step is a step of processing the cylindrical portion 25 provided at the axially inner end of the hub main body 21 before the formation of the caulked portion 26 into a caulked portion intermediate body 39 (see fig. 3 (a) and 3 (b)). The second step is a step of processing the caulking portion intermediate 39 into the caulking portion 26 (see fig. 5 (a) and 5 (b)).

Unlike the first embodiment, the second embodiment divides the oscillating forging in the second step into a plurality of stages. Further, the outer ring rotation torque T was measured after the completion of the oscillating forging at each stage_g. In each of the second and subsequent stages, the outer ring rotation torque T measured after the completion of the wobbling forging in the previous stage is used_gDetermines the axial load P applied to the axially inner end of the hub body 21₂. Thereby, the preload is adjusted. That is, in the second embodiment, the outer ring rotation torque T that changes according to the magnitude of the preload is checked while_gThe pre-compression is adjusted.

(first step of the clinch formation step)

In the present embodiment, it is confirmed that the preload is not substantially changed before and after the swaging in the first step, that is, before and after the cylindrical portion 25 of the hub main body 21 is processed into the caulking portion intermediate 39. Therefore, specifically, the outer ring rotation torque T at the time before the wobbling in the first step is measured_g(unprocessed) and outer ring rotation torque T at the time point after the wobbling forging in the first step_g(0). Confirming the first work measured in this wayOuter ring rotation torque T at each time point before and after oscillating forging in sequence_g(raw), T_g(0) As shown in fig. 7, are of substantially equal size (T)_g(unprocessed) approximately equal to T_g(0) In other words, even if there is a difference in the size of both, it is confirmed that the difference falls within the allowable range. If the confirmation is completed, the process proceeds to the subsequent second step.

(second step of the clinch formation step)

In the second step, the swaging for processing the swaged part intermediate body 39 into the swaged part 26 is performed in a plurality of stages. In the second step, the axial load P is applied during the first-stage oscillating forging₂(1) After the end of the first-stage oscillating forging, the outer ring rotation torque T is adjusted_gLess than target outer ring rotation torque T_gx. Further, the target outer ring rotation torque T_gxIs the outer ring rotation torque T in the state after the pre-pressure reaches the target value_gAnd the same size is determined for the same kind of products to be produced.

When the oscillating forging in the first stage in the second step is performed, the axial load P applied from the second forming die 32 to the axial inner end portion of the hub main body 21 is applied₂Is set to the axial load P₂(1). With this setting, when the first-stage oscillating forging is started, the axial load P is applied₂Will gradually rise. Accordingly, by pushing the second molding die 32 downward, the shape of the axially inner end of the hub main body 21 is closer to the shape of the completed clinch 26. And, in the axial direction, load P₂To achieve axial load P₂(1) Time point of (1), axial load P₂The upward movement of the second molding die 32 is stopped, and the downward movement is stopped. Thereafter, if necessary, the swing forging in the first stage is terminated after the swing rotation of the second molding die 32 is continued for a predetermined time. After the completion of the oscillating forging, the second molding die 32 is retreated upward with respect to the axial inner end of the hub main body 21, and the outer ring rotation torque T is measured_g(1). Then, as shown in FIG. 8, the measured value T is obtained_g(1) Torque T of target outer ring rotation_gxA difference Δ G (1) ═ T_gx－T_g(1)。

In the present embodiment, the relationship shown in the line graph of fig. 9, that is, the axial load P at the time of performing the next-stage oscillating forging, is found in advance through experiments or simulations₂(value on the horizontal axis of the line graph of fig. 9). The relationship is the outer race rotation torque T at the present time point_g(e.g. T)_g(1) Value of) is less than the target outer ring rotation torque T_gxWhen the value of (a) is small, the difference Δ G ═ T between these values_gx－T_g(value on the abscissa of the line graph of fig. 9) and the difference Δ G required to make it close to 0. The axial load P at the time of performing the second-stage oscillating forging is determined from the difference Δ G (1) determined as described above by using the above-mentioned relationship₂(2)。

Under such axial load P₂(2) Next, similarly to the swing forging in the first stage, the axial load P applied from the second molding die 32 to the axial inner end portion of the hub main body 21 is applied₂Is set to the axial load P₂(2) And the second stage of oscillating forging is performed. After the completion of the oscillating forging, the second molding die 32 is retreated upward with respect to the axially inner end of the hub body 21, and the outer ring rotation torque T is measured_g(2). As shown in FIG. 10, the measurement value T was confirmed_g(2) Sufficiently close to target outer ring rotation torque T_gxSpecifically, the measured value T is confirmed_g(2) Torque T of target outer ring rotation_gxA difference Δ G (2) ═ T_gx－T_g(2) Becomes below a predetermined threshold.

Further, it is assumed that the measurement value T is measured in the confirmation operation_g(2) Specific target outer ring rotation torque T_gxSmall and measured value T_g(2) Torque T of target outer ring rotation_gxWhen the difference Δ G (2) of (a) exceeds a predetermined threshold value, in other words, when the preload does not fall within the allowable range, the operation of obtaining the axial load at the time of performing the oscillating forging in the next stage using the relationship in fig. 9 and the operation of performing the oscillating forging using the obtained axial load are repeated until it is confirmed that the preload falls within the toleranceWithin a certain range.

In the present embodiment, when the manufacturing method is performed, the axial load P obtained from the relationship shown in fig. 9 may be used as the value of the axial load in the second step and subsequent step of the oscillating forging step₂Is multiplied by a safety factor ε less than 1 (for example, 0.9 ≦ ε < 1). Thus, the outer ring rotation torque T after the second and subsequent stages of the rocking forging can be prevented_gTorque T of target outer ring rotation_gxIs larger than the prior art, and can also cause the outer ring to rotate the torque T_gSufficiently close to target outer ring rotation torque T_gx。

As described above, in the present embodiment, the preload can be adjusted, specifically, the preload can be made close to the target value. Other structures and functions can be the same as those of the first embodiment.

[ third embodiment ]

A third embodiment of the present invention will be described with reference to fig. 11.

In the third embodiment, the hub unit bearing 1a to be manufactured is provided with the inner ring raceway 11b of the axially outer row on the outer peripheral surface of the axially intermediate portion of the hub main body 21a constituting the hub 3a, as compared with the hub unit bearing 1 shown in fig. 1. The hub body 21a has a fitting surface portion 23a having a smaller diameter than the inner ring raceway 11b of the axially outer row on the outer peripheral surface of the axially inner side portion, and a stepped surface 24a facing the axially inner side on the axially outer end portion of the fitting surface portion 23 a. The inner ring 22a having the inner ring raceway 11a of the axially inner row on the outer peripheral surface is fitted to the fitting surface portion 23a by interference fit, and the axially outer surface is brought into contact with the step surface 24 a. In this state, the axial inner surface of the inner ring 22a is pressed by the caulking portion 26 provided at the axial inner end of the hub main body 21 a. The hub unit bearing 1a is used for a drive wheel, and therefore has a spline hole 35 in the center of the hub main body 21a for spline engagement of a drive shaft, not shown.

The hub unit bearing 1a is assembled, for example, in the following order. First, the rolling elements 4a in the axially inner row held by the cage 20a are arranged radially inward of the outer ring raceways 5a in the axially inner row, and the rolling elements 4b in the axially outer row held by the cage 20b are arranged radially inward of the outer ring raceways 5b in the axially outer row. Further, an outer seal member 29 is mounted on the outer ring 2. Next, the axial intermediate portion and the inner side portion of the hub main body 21a before the caulking portion 26 is formed are inserted radially inward of the outer ring 2. Next, the inner ring 22a is press-fitted to the fitting surface portion 23a, and the axially outer surface of the inner ring 22a is brought into contact with the stepped surface 24 a. The caulked portion 26 is formed after the hub unit bearing 1a before the caulked portion 26 is formed is assembled. Further, the axially inner seal member 29 is attached after the caulking portion 26 is formed.

In addition, the hub unit bearing 1a is given a certain degree of preload in an assembled state before the caulking portions 26 are formed, that is, in an assembled state after the axially outer side surface of the inner ring 22a is brought into contact with the stepped surface 24a as described above, and the axially inner side surface of the inner ring 22a is pressed by the caulking portions 26 formed later, whereby the preload is increased.

In the present embodiment, the same method of processing the caulking portion 26 as in the first example of the embodiment is performed for manufacturing the hub unit bearing 1 a. In the present embodiment, information I on factors affecting the preload, which is used in the second step of the caulking portion forming step and is acquired in a step preceding the first step, is used_ASetting as follows: fitting margin S between the fitting surface portion 23a and the inner ring 22a, and press-fitting load F of the inner ring 22a to the fitting surface portion 23a_pAnd a bearing axial clearance Δ a in an assembled state before the formation of the caulking portion 26.

However, when it is difficult to measure the bearing axial gap Δ a in the assembled state before the formation of the caulking portion 26, for example, the inter-row width W of the outer ring raceways 5a and 5b can be measured instead of the bearing axial gap Δ a_oAnd a row-to-row width W of the inner ring raceways 11a, 11b_iDiameter D of rolling elements 4a, 4b of each row_a、D_bAnd pitch circle diameters PCD of the rolling elements 4a, 4b of the respective rows_a、PCD_bAnd these measured values are used.

Further, a plurality of rows of outer ring rollersInter-column width W of tracks 5a, 5b_oThe axial distance is a distance between the center position of the contact portion between the outer ring raceway 5a of the axially inner row and the rolling elements 4a of the axially outer row and the center position of the contact portion between the outer ring raceway 5b of the axially outer row and the rolling elements 4b of the axially outer row. Further, the inter-row width W of the inner-row raceways 11a, 11b_iThe axial distance is a distance between the center position of the contact portion between the inner ring raceway 11a of the axially inner row and the rolling elements 4a of the axially outer row and the center position of the contact portion between the inner ring raceway 11b of the axially outer row and the rolling elements 4b of the axially outer row.

In the present embodiment, also in the second step, the axial load P is first calculated using the same relational expression as the above expression (1)_2x. In this relational expression, an axial load P to be applied to the axially inner end portion of the hub main body 21a, which is required to bring the preload close to the target value, is applied_2xSet as a dependent variable and include information I in the independent variable_AThe information (fitting margin S, press-in load F) included in the information_pBearing axial gap Deltaa (or width W between rows)_oWidth W between rows_iDiameter D of rolling elements 4a, 4b_a、D_bAnd pitch circle diameter PCD_a、PCD_b) Information I), information I_BThe individual information contained (axial load P)₁Forming die rotation torque T_sAnd a moving speed V_s) And a target value X for the preload. Using the axial load P thus calculated_2xThe caulking portion intermediate 39 is processed into the caulking portion 26.

Further, when the oscillating forging is performed, the contact portion of the forming die with respect to the workpiece moves in the circumferential direction as the oscillating rotation of the forming die, but the width in the circumferential direction of the contact portion becomes narrower as the oscillation angle θ of the forming die becomes larger. In addition, the plastic deformation region of the workpiece in the periphery of the contact portion is also narrowed. On the other hand, in the case of the hub unit bearing 1a for the driving wheel described above, when the caulking portion 26 is formed, the contact portion of the molding die with respect to the hub main body 21a is closer to the spline hole 35 in the second step than in the first step. Therefore, in the second step, in particular, it is desirable to increase the oscillation angle θ of the second molding die 32 (see fig. 5a and 5b) to such an extent that the plastic deformation region of the hub main body 21a does not reach the spline hole 35 during the oscillating forging. Other configurations and operation effects can be the same as those of the first embodiment.

[ fourth embodiment ]

A fourth embodiment of the present invention will be described with reference to fig. 12.

In a fourth embodiment, in the method of manufacturing a hub unit bearing, the following steps are performed after the first step of performing the caulking portion forming step and before the second step of performing the caulking portion forming step: a seal member 29 that closes an axial inner end opening of an inner space 27 existing between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3 is installed between the outer ring 2 and the inner ring 22 a. That is, in the present embodiment, the second step of the caulking portion forming step is performed in a state where the axially inner seal member 29 is attached between the outer ring 2 and the inner ring 22 a.

In the present embodiment, a second caulking apparatus including a mold 36 and a plurality of rollers 37 as shown in the figure is used in the second step of the caulking portion forming step. The molding die 36 is disposed above the hub body 21. The molding die 36 is composed of a plurality of molding die elements 38 which are arranged in parallel in the circumferential direction around the center axis α of the hub body 21 and are movable in the vertical direction independently of each other. The plurality of rollers 37 are disposed above the molding die 36. The rollers 37 are disposed at a plurality of locations less than the total number of molding die elements 38 in the circumferential direction around the center axis α of the hub body 21. More specifically, the rollers 37 are disposed at a plurality of positions that are rotationally symmetrical about the center axis α of the hub main body 21. In particular, in the present example, the rollers 37 are disposed at a plurality of positions at equal intervals in the circumferential direction around the center axis α of the hub main body 21.

When the caulking process of the second step, i.e., the second caulking process for forming the caulking portion 26, is performed, the lower side surface of the molding die 36 is brought into contact with the axially inner side portion of the hub main body 21, and the plurality of rollers 37 are transferred in the circumferential direction around the center axis α of the hub main body 21 in a state where the plurality of rollers 37 are pressed against the upper side surface of the molding die 36. As a result, the plurality of rollers 37 are sequentially pressed against the upper side surface of the mold element 38, and the lower side surface of the mold element 38 is sequentially pressed against the axially inner side portion of the hub main body 21, whereby the axially inner side portion of the hub main body 21 is plastically deformed radially outward to form the caulking portion 26.

When the caulking portions 26 are formed in this manner, the machining force applied from the molding die 36 to the axially inner portion of the hub main body 21 is always applied to a plurality of portions that are rotationally symmetrical about the center axis α of the hub main body 21. Therefore, the caulking portion 26 can be formed without substantially applying an eccentric load to the axially inner side portion of the hub main body 21. Therefore, after the caulking portion 26 is formed, it is easy to prevent the force applied from the caulking portion 26 to the inner ring 22a from being biased in the circumferential direction.

In addition, in the present embodiment, since the second step is performed in a state where the sealing member 29 that closes the axial inner end opening of the internal space 27 is attached, when the second processing is performed, it is possible to prevent foreign matter from entering the internal space 27 from the outside through the axial inner end opening of the internal space 27. Further, in the present embodiment, since an eccentric load is not substantially applied to the axially inner portion of the hub main body 21 when the caulking portion 26 is formed, it is possible to prevent the inner ring 22a from being displaced in the radial direction with respect to the outer ring 2 during the formation of the caulking portion 26, and to prevent the seal member 29 from being damaged. In the practice of the present invention, the second step can be performed without the sealing member 29 attached. Other configurations and operation effects can be the same as those of the first embodiment.

The present invention can be implemented by appropriately combining the above embodiments within a range that does not contradict each other.

For example, the second embodiment can be combined with the fourth embodiment. Specifically, as in the fourth embodiment, the step of mounting the sealing member on the inner side is performed between the first step and the second step of the caulking portion forming step. In the second step, the axially inner end of the hub body is rotated about the central axis of the hub bodyEven in the case where the intermediate caulking portion is processed into the caulking portion while applying a load to a plurality of rotationally symmetrical portions, the preload adjustment can be performed as in the second embodiment. In this case, the outer ring rotation torque T at the time point when the first step ends is_g(0) In contrast, the outer ring rotation torque T at the time point when the process of mounting the sealing member on the inner side is finished is set to be smaller than the outer ring rotation torque T_sg(0) Only by an amount corresponding to the sealing torque (sliding contact resistance) of the seal member. Therefore, in this case, the outer ring rotation torque T before the first stage machining in fig. 8 and 10 is performed_g(0) Substitution to T_sg(0) Or the data of fig. 9 is a relationship after the sealing member is attached, the preload adjustment described in the second embodiment can be appropriately performed by changing the outer ring rotation torque to be processed in the second step to a value in consideration of the sealing torque.

In one embodiment, in the caulking portion forming step, the information I acquired in the first step used in the second step_BInformation contained therein, and information I acquired in a step prior to the caulking portion forming step_AThe contained information can be selected as appropriate information, respectively. In addition, only the information I may be used in the second step_AAnd information I_BAny one of the above.

In one embodiment, various methods known in the art can be employed as a method of caulking the axially inner end of the hub main body to form the caulked portion. Further, as a method of caulking without applying an eccentric load to the axial inner end portion of the hub main body when forming the caulking portion, for example, a method of caulking while pressing a molding die over the entire outer periphery of the axial inner end portion of the hub main body, or methods described in japanese patent laid-open nos. 2017 and 18991 (patent document 2), 2017 and 67254 (patent document 3), and 2017 and 106510 (patent document 4) can be adopted.

In one embodiment, as shown in fig. 5 (b) and 6, the method of applying the processing force directed downward in the vertical direction and inward in the radial direction to the swaged portion from the processing surface portion of the forming die at the final stage of the swaging processing in the second step is not limited to the swaging processing apparatus that performs the oscillating forging. For example, the method of applying the processing force to the caulking portion can be applied to other caulking processing apparatuses such as the caulking processing apparatus shown in fig. 12.

In one embodiment, in the second step of the caulking portion forming step, a method of forming a caulking portion and forming a face spline (surface spline) as an uneven portion in the circumferential direction on the inner side surface in the axial direction of the caulking portion may be employed.

In one embodiment, a method for manufacturing a clinch fitting includes: a step of axially combining a first member (21, 21a) and a second member (22a, 22b) having a hole (120) into which the first member (21, 21a) is inserted; and a step of forming a caulking portion (39, 26) to the second member (22a, 22b) on the first member (21, 21a) by applying a load in the axial direction to the shaft end of the first member (21, 21a), the step of forming the caulking portion including a step of adjusting the load based on at least one of (a) first information acquired before the load is applied and (b) second information acquired in a state after the load is applied.

In one example, the first information comprises information associated with the combination of the first component (21) and the second component (22a, 22b), and the second information comprises information associated with a physical characteristic of the first component (21, 21 a).

For example, the first information includes information measured at the time of the combination of the first member (21, 21a) and the second member (22a, 22 b).

In one example, the clinch (39, 26) is formed at least temporarily using a swing clinch method.

In one example, the step of forming the caulking portions (39, 26) includes: a first step of forming an intermediate caulking part (39) by a predetermined load; and a second step of forming the caulking section (26) by applying the adjusted load to the intermediate caulking section (39).

In one example, the caulking portions (39, 26) are formed by using different methods or different devices between the first step and the second step, or the caulking portions (39, 26) are formed by using the same method or the same device in the first step and the second step.

In one embodiment, a hub unit bearing (1, 1a) includes: an outer ring (2) having outer ring raceways (5a, 5 b); a hub (3, 3a) having an inner ring raceway (11a, 11 b); and a plurality of rolling elements (4a, 4b) arranged between the outer ring raceways (5a, 5b) and the inner ring raceways (11a, 11 b). The hub (3, 3a) has a hub main body (21, 21a), and an inner ring (22a, 22b) that is disposed outside the hub main body (21, 21a) and is held by the hub main body (21, 21 a). The method for manufacturing the hub unit bearing (1, 1a) comprises the following steps: a step of axially combining the hub main body (21, 21a) and the inner ring (22a, 22b) having a hole (120) into which the hub main body (21, 21a) is inserted; and a step of forming a clinched portion (39, 26) for the inner ring (22a, 22b) on the hub main body (21, 21a) by applying a load in the axial direction to the shaft end of the hub main body (21, 21a), the step of forming the clinched portion including a step of adjusting the load based on at least one of (a) first information acquired before the load is applied and (b) second information acquired in a state after the load is applied.

Fig. 13 is a partial schematic view of a vehicle 200 including a hub unit bearing (bearing unit) 151. The present invention can be applied to either a hub unit bearing for a driving wheel or a hub unit bearing for a driven wheel. In fig. 13, the hub unit bearing 151 is used for a drive wheel, and includes an outer ring 152, a hub 153, and a plurality of rolling elements 156. The outer ring 152 is fixed to a knuckle 201 of the suspension device using a bolt or the like. The wheel (and the braking rotor 22)202 is fixed to a flange (rotation flange) 153A provided on the hub 153 by bolts or the like. The vehicle 200 may have the same support structure as described above for the hub unit bearing 151 for the driven wheel.

The present invention is not limited to the hub of the hub unit bearing, and can be applied to other caulking fittings (caulking units) in which a first member and a second member having a hole into which the first member is inserted are combined in the axial direction.

Description of the reference numerals

1. 1a hub unit bearing

2 outer ring

3. 3a wheel hub

4a, 4b rolling element

5a, 5b outer ring raceway

6 static flange

7 bearing hole

8 steering knuckle

9 through hole

10 bolt

11a, 11b inner ring raceway

12 swivel flange

13 mounting hole

14 rotating body for braking

15 stud

16 through hole

17 wheel

18 through hole

19 nut

20a, 20b cage

21. 21a hub body (hub ring, first component)

22a inner ring (inner ring, second component)

22b inner ring (outer inner ring, second component)

23. 23a fitting face portion

24. 24a layer difference surface

25 cylindrical part

26 riveted part

27 inner space

28 sealing member

29 sealing member

30 first forming die

31 processing the face

32 second forming die

33 processing the face

34 bearing part assembly

35 spline hole

36 forming die

37 roller

38 forming die element

39 caulking the intermediate body (intermediate caulking portion).