Method for manufacturing riveted assembly part, and method for manufacturing vehicle

Abstract

A method for manufacturing a hub unit bearing (1) includes a step of forming a rivet portion (26) for an inner ring (22a, 22b) on a hub body (21) by applying an axial load to an axial end of the hub body (21), and adjusting the load based on at least one of first information obtained before the load is applied and second information obtained after the load is applied.

Description

Technical Field

[0001] The invention relates to a riveted assembly, a method for manufacturing a hub unit bearing and a method for manufacturing a vehicle.

[0002] This application claims priority based on Japanese Patent Application No. 2019-074550 filed on April 10, 2019, the contents of which are incorporated herein by reference. Background Art

[0003] In the past, a hub unit bearing is known, in which a hub that rotates with a wheel includes a hub body (hub ring) that fixes the wheel, and an inner ring that is externally fitted to the hub body, and the axial side surface of the inner ring is pressed by a rivet formed at the axial end of the hub body. For example, a wheel and a brake rotating body of an automobile are supported by a hub unit bearing so as to rotate freely relative to a suspension device. In the hub unit bearing, in order to improve its rigidity, a preload is applied to the rolling element based on the fact that at least the axial side surface of the inner ring is pressed by the rivet.

[0004] Japanese Patent Application Laid-Open No. 2005-195084 (Patent Document 1) describes, as a method for processing the axial end of the hub body into a rivet portion, a swing forging in which a forming die that swings and rotates around the central axis of the hub body is pressed against the axial end of the hub body. Furthermore, Japanese Patent Application Laid-Open No. 2005-195084 (Patent Document 1) also describes a method in which the swing forging is performed in two stages, and the shape of the forming die or the swing angle of the forming die is changed in the first stage and the second stage, thereby suppressing the radial outward load applied to the inner ring from the rivet portion.

[0005] In addition, Japanese Patent Application Publication No. 2017-18991 (Patent Document 2), Japanese Patent Application Publication No. 2017-67254 (Patent Document 3), and Japanese Patent Application Publication No. 2017-106510 (Patent Document 4) describe a method for processing a caulking portion in which no eccentric load is applied to the axial end of the hub body.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2005-195084

[0009] Patent Document 2: Japanese Patent Application Publication No. 2017-18991

[0010] Patent Document 3: Japanese Patent Application Publication No. 2017-67254

[0011] Patent Document 4: Japanese Patent Application Publication No. 2017-106510 Summary of the invention

[0012] The preload of the hub unit bearing will affect the driving stability of the car. In particular, when an electric motor is used as the power source of the car rather than an engine, it can be said that the preload of the hub unit bearing becomes larger. In order to achieve a more uniform driving stability of the car, it is also required to be able to adjust the preload according to the target in the manufacture of the hub unit bearing. The method described in Japanese Patent Gazette No. 2005-195084 (Patent Document 1) of dividing the processing for forming the riveted portion into two stages can be considered to be an effective method for adjusting the preload of the hub unit bearing. However, Japanese Patent Gazette No. 2005-195084 (Patent Document 1) does not record specific details such as how to adjust the preload.

[0013] The object of the present invention is to realize a method for manufacturing a riveted assembly capable of adjusting preload, a method for manufacturing a hub unit bearing, and a method for manufacturing a vehicle.

[0014] A method for manufacturing a riveted assembly according to one embodiment of the present invention comprises: a process of axially combining a first component and a second component, the second component having a hole for inserting the first component; and a process of forming a riveted portion for the second component on the first component by applying the axial load to the axial end of the first component, the process of forming the riveted portion including a process of adjusting the load based on at least one of (a) first information obtained before applying the load and (b) second information obtained in a state after applying the load.

[0015] In a method for manufacturing a hub unit bearing according to one embodiment of the present invention, the hub unit bearing comprises: an outer ring having an outer ring raceway; a hub having an inner ring raceway; and a plurality of rolling elements arranged between the outer ring raceway and the inner ring raceway, the hub having a hub body and an inner ring arranged outside the hub body and held on the hub body. The method comprises: a step of axially combining the hub body and the inner ring, the inner ring having a hole for inserting the hub body; and a step of forming a rivet portion for the inner ring on the hub body by applying the axial load to the axial end of the hub body, the step of forming the rivet 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 after the load is applied.

[0016] In one embodiment of the present invention, a hub unit bearing to be manufactured comprises: an outer ring having a plurality of rows of outer ring raceways on the inner circumference; a hub having a plurality of rows of inner ring raceways on the outer circumference; and rolling elements arranged between the plurality of rows of inner ring raceways and the plurality of rows of outer ring raceways in a manner of arranging a plurality of each row. The hub comprises a hub body, and an inner inner ring having an axially inner row of inner ring raceways among the plurality of rows of inner ring raceways on the outer circumference. The inner inner ring is externally fitted to the hub body and the axial inner side surface is pressed by a rivet portion, the rivet portion being formed by plastically deforming the axial inner end of the hub body while being compressed axially outward and expanded radially outward. At least the axial inner side surface of the inner inner ring is pressed by the rivet portion, thereby imparting a preload to the rolling element.

[0017] In one embodiment of the present invention, a manufacturing method for a hub unit bearing divides the processing for forming the rivet portion into multiple stages in a rivet portion forming process for forming the rivet portion, and in at least the last stage of the multiple stages, the axial load applied to the axial inner end of the hub body is determined using at least one of information obtained earlier than the current stage in the rivet portion forming process and information obtained in a process earlier than the rivet portion forming process.

[0018] For example, the caulking portion forming process includes a first process and a second process. The first process is a process of processing a cylindrical portion provided at the axial inner end of the hub body before forming the caulking portion into a caulking portion intermediate body. The second process is a process of processing the caulking portion intermediate body into the caulking portion.

[0019] For example, in the first step, the caulking portion intermediate body is not brought into contact with the axial inner side surface of the inner inner ring.

[0020] For example, in the first step, the cylindrical portion is processed into the rivet portion intermediate by swing forging in which a forming die that swings and rotates around the central axis of the hub body is pressed against the axial inner end of the hub body. Furthermore, the end time point of the swing forging in the first step is determined by the value of the torque for swinging and rotating the forming die, i.e., the forming die rotation torque.

[0021] In this case, for example, the end time point of the swing forging in the first process is set to the following time point: the time point when the rotation torque of the forming die first begins to stabilize at a substantially fixed value after the start of the swing forging; or the time point when the rotation torque of the forming die first begins to decrease after the rotation torque of the forming die first stabilizes at a substantially fixed value after the start of the swing forging.

[0022] For example, in the second step, the axial load to be applied to the axial inner end portion of the hub body is determined using the information acquired in the first step.

[0023] For example, in the first step, the cylindrical portion is processed into the rivet portion intermediate by swing forging in which a forming die that swings and rotates around the central axis of the hub body is pressed against the axial inner end of the hub body. In addition, the information acquired in the first step includes an axial load applied from the forming die to the axial inner end of the hub body, a forming die rotation torque for swinging and rotating the forming die, and an axial moving speed of the forming die.

[0024] For example, in the second step, the axial load applied to the axial inner end portion of the hub body is determined using information acquired in a step before the first step in addition to the information acquired in the first step.

[0025] In a case where the hub also includes an outer inner ring having an axially outer row of inner ring raceways among a plurality of rows of inner ring raceways on the outer peripheral surface, and the outer inner ring is embedded in the hub body, for example, information acquired in a process before the first process includes at least one of the fitting margins between the hub body and the inner inner ring and the outer inner ring, the press-fit loads of the inner inner ring and the outer inner ring relative to the hub body, and the axial clearance of the bearing.

[0026] In the case where the hub body has an axially outer row of inner ring raceways among the multiple rows of inner ring raceways on the outer peripheral surface, for example, the information acquired in the process before the first process includes the fitting margin between the hub body and the inner inner ring, the press load of the inner inner ring relative to the hub body, the row width between the multiple rows of outer ring raceways, the row width between the multiple rows of inner ring raceways, the diameter of each row of rolling elements, and at least one item of the pitch circle diameter of each row of rolling elements.

[0027] For example, in the second step, the axial load applied to the axial inner end of the hub body is determined by using the following relational expression, in which the axial load applied to the axial inner end of the hub body is set as a dependent variable, and the independent variables include each of the acquired information and the target value of the preload. In this case, for example, a relational expression obtained by multivariate regression analysis can be used as the relational expression.

[0028] For example, in the second process, the processing for forming the rivet portion from the rivet portion intermediate is divided into multiple stages, and after the processing of each stage is completed, the torque for rotating the outer ring, i.e., the outer ring rotation torque, is measured for the hub, and in each stage after the second stage, the axial load applied to the axial inner end of the hub body is determined using information on the outer ring rotation torque measured after the processing of each previous stage is completed.

[0029] 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 the state where the preload reaches the target value, the relationship between the difference between these values ​​and the axial load applied to the axial inner end of the hub body required to make the difference close to 0 is calculated in advance. Moreover, in each stage after the second stage, the value of the outer ring rotation torque measured after the processing of each previous stage is completed is set as the value of the outer ring rotation torque at the current time point, and the axial load applied to the axial inner end of the hub body is determined using this value and the relationship.

[0030] For example, in the second step, the caulking portion intermediate product is processed into the caulking portion by swing forging in which a forming die that swings and rotates about the central axis of the hub body is pressed toward the axial inner end of the hub body.

[0031] For example, in the second step, the rivet portion intermediate body is processed into the rivet portion while applying loads to a plurality of positions rotationally symmetrical about the central axis of the hub body at the axial inner end of the hub body. In this case, for example, a step of installing a sealing member between the outer ring and the inner inner ring is performed between the first step and the second step, and the sealing member closes the axial inner end opening of the internal space between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub.

[0032] For example, in the second step, a processing force directed radially inward is applied to the caulking portion at the final stage of processing for forming the caulking portion.

[0033] In one aspect of the present invention, a vehicle to be manufactured includes a hub unit bearing. A method for manufacturing a vehicle according to one aspect of the present invention manufactures the hub unit bearing by the method for manufacturing a hub unit bearing according to the above aspect.

[0034] Effects of the Invention

[0035] According to the aspect of the present invention, the preload of the hub unit bearing can be adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1This is a cross-sectional view showing an example of a state in which the hub unit bearing is assembled to a vehicle.

[0037] Figure 2 This is a block diagram for explaining the caulking portion forming step in the first embodiment.

[0038] Figure 3 (a) is a partial cross-sectional view showing a start state of a first step of the caulking portion forming step in the first embodiment, and (b) is a partial cross-sectional view showing a finish state of the first step.

[0039] Figure 4 is a figure showing the rotation torque T of the forming die when the caulking portion is formed by the caulking processing device used in the first step of the caulking portion forming step in the first embodiment. s A line graph of changes over time.

[0040] Figure 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 a finish state of the second step.

[0041] Figure 6 yes Figure 5 (b) Enlarged view of part A.

[0042] Figure 7 is a figure showing the mold rotation torque T in the first step of the caulking portion forming step in the second embodiment. s There is no change in the line graph before and after the riveting process.

[0043] Figure 8 The outer ring rotation torque T after the first stage of the caulking process is measured in the second step of the caulking portion forming process in the second embodiment. g A line graph of the situation.

[0044] Fig. 9 This is a line graph showing load conditions when performing caulking work in the second stage and thereafter, which is used in the second step of the caulking portion forming step in the second embodiment.

[0045] Fig.10 The outer ring rotation torque T after the second stage of the caulking process is measured in the second step of the caulking portion forming process in the second embodiment. g A line graph of the situation.

[0046] Fig.11 It is a cross-sectional view showing a hub unit bearing in a third embodiment.

[0047] Fig.12It is a partial cross-sectional view showing a finishing state of the second step of the caulking portion forming step in the fourth embodiment.

[0048] Fig.13 It is a partial schematic diagram of a vehicle equipped with a hub unit bearing (bearing unit).

[0049] Fig.14 This is a cross-sectional view showing an example of a hub unit bearing using tapered rollers. DETAILED DESCRIPTION

[0050] [First embodiment]

[0051] use Figures 1 to 6 A first embodiment of the present invention will be described. First, the structure of the hub unit bearing 1 to be manufactured will be described, and then a method for manufacturing the hub unit bearing 1 will be described.

[0052] <Structure of hub unit bearing 1>

[0053] Figure 1 An example of a hub unit bearing 1 is shown. 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 4b.

[0054] In addition, regarding the hub unit bearing 1, the axially outer side is the outer side in the width direction of the vehicle when the hub unit bearing 1 is assembled in the vehicle. Figure 1 The axial inner side is the side that becomes the center side in the width direction of the vehicle when assembled in the vehicle. Figure 1 on the right side.

[0055] The outer ring 2 has multiple rows of outer ring raceways 5a, 5b and a stationary flange 6. In one example, the outer ring 2 is made of a hard metal such as medium carbon steel. In other examples, the outer ring 2 can be formed of other materials. Multiple rows of outer ring raceways 5a, 5b are provided on the inner peripheral surface of the axial middle portion of the outer ring 2 over the entire circumference. The stationary flange 6 protrudes radially outward from the axial middle portion of the outer ring 2 and has support holes 7 as threaded holes at multiple locations in the circumferential direction.

[0056] The outer ring 2 is supported and fixed to the knuckle 8 by bolts 10 inserted through a through hole 9 of the knuckle 8 constituting a suspension device of a vehicle being screwed and fastened to the support hole 7 of the stationary flange 6 from the axial inside.

[0057] The hub (riveted assembly, riveted unit) 3 is coaxially arranged on the radial inner side of the outer ring 2. The hub 3 has multiple rows of inner ring raceways 11a, 11b and a rotating flange 12. The multiple rows of inner ring raceways 11a, 11b are provided over the entire circumference on the outer peripheral surface (outer surface) of the hub 3 in a portion that is opposite to the multiple rows of outer ring raceways 5a, 5b. The rotating flange 12 protrudes radially outward from a portion of the hub 3 that is axially outward relative to the outer ring 2, and has mounting holes 13 at multiple locations in the circumferential direction.

[0058] In the example shown in the figure, in order to connect and fix the brake rotating body 14 such as a brake disc or a brake drum to the rotating flange 12, the serration portion of the stud 15 near the base end is pressed into the mounting hole 13. In addition, the middle portion of the stud 15 is pressed into the through hole 16 of the brake rotating body 14. Furthermore, in order to fix the wheel 17 constituting the wheel to the rotating flange 12, the external thread portion of the front end of the stud 15 is inserted into the through hole 18 of the wheel 17, and the nut 19 is screwed and tightened to the external thread portion.

[0059] The rolling elements 4a and 4b are arranged between the multiple rows of outer ring raceways 5a and 5b and the multiple rows of inner ring raceways 11a and 11b in a manner that multiple rolling elements are arranged in 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 elements 4a and 4b can be formed of other materials. In addition, the rolling elements 4a and 4b are held by the retaining frames 20a and 20b so as to roll freely in each row. In addition, Figure 1 In the example, balls are used as rolling elements 4a and 4b, but sometimes Fig.14 The example shown uses tapered rollers.

[0060] The wheel hub (riveted assembly) 3 is composed of a wheel hub body (wheel hub ring) 21, an inner inner ring 22a, and an outer inner ring 22b. In one example, the wheel hub body 21 is made of hard metal such as medium carbon steel. The inner inner ring 22a and the outer inner ring 22b are respectively made of hard metal such as bearing steel. In other examples, the wheel hub body 21, the inner inner ring 22a, and the outer inner ring 22b can be formed of other materials. The wheel hub (riveted assembly) 3 is substantially composed of the wheel hub body (first component) 21 and the inner rings (second components) 22a and 22b combined in the axial direction. The wheel hub 3 includes a wheel hub body 21 having an outer peripheral surface (outer surface) 23, and inner rings (second components) 22a and 22b arranged on the outer peripheral surface (outer surface) 23 of the wheel hub body 21 and held on the wheel hub body (first component) 21. The inner ring raceway 11a of the axial inner side row is provided on the outer peripheral surface of the inner inner ring 22a. The inner ring raceway 11b of the axially outer row is provided on the outer circumferential surface of the outer inner ring 22b. The rotating flange 12 is provided on the axially outer side of the hub body 21. The hub body 21 has a cylindrical fitting surface 23 on the outer circumferential surface of the middle portion in the axial direction, and has a step surface 24 facing the axial inner side at the axially outer end of the fitting surface 23. The inner inner ring 22a and the outer inner ring 22b are fitted on the fitting surface 23 of the hub body 21 by interference fit. Furthermore, the hub body 21 has a caulking portion 26 at the axially inner end. The caulking portion 26 is bent radially outward from the axially inner end of the portion of the hub body 21 where the inner inner ring 22a is fitted, and presses the axially inner side surface of the inner inner ring 22a. That is, the inner inner ring 22a and the outer inner ring 22b are prevented from being separated from the hub body 21 by being sandwiched between the step surface 24 of the hub body 21 and the caulking portion 26. In this state, the contact angle and preload of the back-combined type are given to the multi-row rolling elements 4a and 4b constituting the hub unit bearing 1. In one example, the hub body 21 has a rivet portion 26 for the inner rings 22a and 22b (the rivet portion 26 for holding the inner rings 22a and 22b). The hub body 21 is inserted into the hole 120 of the inner rings 22a and 22b. The rivet portion 26 having a bend extending in the circumferential direction and covering the axial end of the inner ring 22a is provided on the peripheral wall of the hub body 21.

[0061] The axially opposite openings of the internal space 27 between the inner circumference of the outer ring 2 and the outer circumference of the hub 3 are closed by sealing members 28 and 29. The axially inner sealing member 28 is assembled between the inner circumference of the axially inner end of the outer ring 2 and the outer circumference of the axially inner end of the inner inner ring 22a. The axially outer sealing member 29 is assembled between the inner circumference of the axially outer end of the outer ring 2 and the outer circumference of the axially outer end of the outer inner ring 22b. These sealing members 28 and 29 can prevent the grease sealed in the internal space 27 from leaking into the external space through the axially opposite openings of the internal space 27. In addition, foreign matter such as muddy water existing in the external space can be prevented from intruding into the internal space 27 through the axially opposite openings of the internal space 27.

[0062] <Method for manufacturing hub unit bearing 1>

[0063] In the present embodiment, the manufacturing method of the hub unit bearing 1 divides the rivet forming step of forming the rivet 26 into a first step and a second step so that the preload applied to the rolling elements 4a and 4b is close to the target value, and the information (second information) obtained in the first step is used in the second step. B , and information (first information) obtained in a process before the rivet forming process A The axial load applied to the axial inner end of the hub body 21 is determined (see Figure 2 The manufacturing method of the hub body 21 includes: a step of axially combining the hub body 21 with inner rings 22a and 22b having a hole 120 for inserting the hub body 21; and a step of forming a rivet portion 26 for the inner rings 22a and 22b on 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 rivet portion 26 includes: (a) obtaining first information I before applying the load (axial load); A , and (b) the second information I obtained after the load (axial load) is applied B In addition, the first step is to process the cylindrical portion 25 provided at the axial inner end of the hub body 21 before the caulking portion 26 is formed into a caulking portion intermediate body (intermediate caulking portion) 39 (see Figure 3 (a) and Figure 3 The second step is to process the rivet portion intermediate body 39 into the rivet portion 26 (see Figure 5 (a) and Figure 5 (b)). The process of forming the rivet portion 26 includes: a first process of forming the intermediate rivet portion 39 by a predetermined load; and a second process of forming the final rivet portion 26 by applying an adjusted load to the intermediate rivet portion 39.

[0064] In one example, the rivet intermediate (intermediate rivet) 39 is defined as the shape of the axial end of the hub body 21 that has been at least partially plastically deformed in the first process (e.g., from the start of load application to the completion of load adjustment (preload adjustment)). Alternatively, the rivet intermediate (intermediate rivet) 39 is defined as the shape of the axial end of the hub body 21 that has been at least partially plastically deformed at the time point when load adjustment (preload adjustment) is completed. For example, the rivet intermediate (intermediate rivet) 39 has the shape of the axial end of the hub body 21 at the time point when preload adjustment is completed, which will be described later. The adjusted load is fixedly applied to the intermediate rivet 39 to form the final rivet 26. In one example, the rivet intermediate (intermediate rivet) 39 does not substantially contact the inner ring 22a. In other examples, the rivet intermediate (intermediate rivet) 39 substantially contacts the inner ring 22a.

[0065] For example, in the manufacturing method of the hub unit bearing 1, specifically, in the first step, when the cylindrical portion 25 is processed into the caulking portion intermediate body 39, information (second information) indicating the degree of processing resistance, in other words, the degree of hardness of the hub body 21 is obtained. B . Information I B The information I includes information related to the physical properties of the hub body 21. In the second step, the information I B The axial load applied to the axial inner end of the hub body 21 required to make the preload close to the target value is determined. In one example, further, in the second step, in addition to the information (second information) obtained in the first step, B In addition, information (first information) related to factors affecting preloading, such as the dimensions of specific parts, among the information acquired in the process before the caulking portion forming process is also used. A The axial load applied to the axial inner end of the hub body 21 required to bring the preload close to the target value is determined. Information (first information) I A The first information includes information associated with the combination of the hub body 21 and the inner rings 22a and 22b. For example, the information (first information) I A The information obtained or measured when the hub body 21 and the inner rings 22a and 22b are combined is included. In one example, based on the first information I obtained before the load (axial load) is applied A , and the second information I obtained after the load (axial load) is applied B The axial load when the intermediate rivet portion 39 is processed into the final rivet portion 26 is determined by these two. In other examples, the axial load is substantially determined based only on the first information I obtained before the load (axial load) is applied. AThe axial load when the intermediate rivet portion 39 is processed into the final rivet portion 26 is determined. In another example, the second information I is substantially obtained only based on the state after the load (axial load) is applied. B The axial load when the intermediate rivet portion 39 is processed into the final rivet portion 26 is determined. In another example, the axial load when the intermediate rivet portion 39 is processed into the final rivet 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.

[0066] The following describes the information to be acquired in the steps before the caulking portion forming step. A , and I to be obtained in the first step B After specifying which information is which, how to use the information I in the second step A ,I B Determination of the axial load applied to the axial inner end portion of the hub body 21 required to bring the preload close to the target value will be described.

[0067] (Steps before the caulking portion forming step)

[0068] In this embodiment, as information I to be acquired in the process before the caulking portion forming process A And use three information. Information I A The first information included is information about the fitting margin S between the fitting surface 23 of the hub body 21 and the inner inner ring 22a and the outer inner ring 22b. Therefore, for example, the outer diameter dimension of the fitting surface 23 of the hub body 21 and the inner diameter dimension of the inner inner ring 22a and the outer inner ring 22b are measured in a process before the caulking portion forming process. The difference between the outer diameter dimension of the fitting surface 23 of the hub body 21 and the inner diameter dimension of the inner inner ring 22a and the outer inner ring 22b measured in this way, that is, the fitting margin S (information I A The first information contained).

[0069] Information I A The second information included is information about the bearing axial clearance Δa before the rivet 26 is formed. Information I A The third information included is related to the press-fitting load F for press-fitting the inner inner ring 22a and the outer inner ring 22b into the fitting surface portion 23. p The relevant information is obtained in the assembly process of the hub unit bearing 1 before the caulking portion 26 is formed. Figure 1 An example of an assembling method will be described.

[0070] The hub unit bearing 1 before forming 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 retainer 20a are arranged radially inward of the outer ring raceway 5a of the axially inner row. The rolling elements 4b of the axially outer row held by the retainer 20b are arranged radially inward of the outer ring raceway 5b of the axially outer row. Next, the inner inner ring 22a is inserted from the axial inner side to the radial inner side of the outer ring 2. The outer inner ring 22b is inserted from the axial outer side to the radial inner side of the outer ring 2, thereby assembling the bearing assembly 34.

[0071] Next, the bearing axial clearance Δa (information I) of the bearing assembly 34 is measured as the bearing axial clearance before the caulking portion 26 is formed. A The second information included). Here, the bearing axial clearance is the internal clearance of the bearing related to the axial direction. The bearing axial clearance Δa of the bearing assembly 34 is the internal clearance of the bearing assembly 34 related to the axial direction in a state where the axial side surfaces of the inner inner ring 22a and the outer inner ring 22b constituting the bearing assembly 34 are in contact with each other. In one example, the bearing axial clearance Δa is positive (>0). Therefore, the bearing axial clearance Δa can be measured based on the condition that the inner inner ring 22a and the outer inner ring 22b are relatively moved in the axial direction with respect to the outer ring 2 in a state where the axial side surfaces of the inner inner ring 22a and the outer inner ring 22b are in contact with each other. In other examples, the bearing axial clearance Δa can be set to other values.

[0072] Next, the seal member 28 on the axially outer side is mounted on the bearing assembly 34. The seal member 28 on the axially inner side is not mounted at this stage but is mounted after the caulking portion 26 is formed.

[0073] Next, the inner inner ring 22a and the outer inner ring 22b constituting the bearing assembly 34 are moved from the axial inner side ( Figure 1 The inner inner ring 22a and the outer inner ring 22b are thus fitted onto the fitting surface 23 of the hub body 21 before the rivet portion 26 is formed. Thus, the inner inner ring 22a and the outer inner ring 22b are fitted onto the fitting surface 23 by interference fit, and the axial side surfaces of the inner inner ring 22a and the outer inner ring 22b facing each other are brought into contact with each other. In addition, by bringing the axial outer side surface of the outer inner ring 22b into contact with the step surface 24 of the hub body 21, the hub unit bearing 1 before the rivet portion 26 is formed can be obtained. At this time, the press-fit load F for press-fitting the inner inner ring 22a and the outer inner ring 22b into the fitting surface 23 is measured. p (Information I A The third information contained in it).

[0074] Furthermore, when the inner inner ring 22a and the outer inner ring 22b constituting the bearing unit assembly 34 are pressed into the fitting surface 23 of the hub body 21 before the caulking portion 26 is formed as described above, the inner inner ring 22a and the outer inner ring 22b are enlarged in diameter by an amount corresponding to the fitting margin S, and the bearing axial clearance changes from positive to negative. As a result, the bearing axial clearance Δa′ in this state is mostly negative. That is, in most cases, a certain degree of preload is applied to the hub unit bearing 1 before the caulking portion 26 is formed.

[0075] In the present embodiment, the preload is then increased by forming a rivet portion 26 and pressing the axial inner surface of the inner inner ring 22a with the rivet portion 26 (increasing the preload that has already been applied, or applying a preload that has not been applied before and increasing the preload), thereby bringing the preload close to the target value.

[0076] (First step of the caulking portion forming step)

[0077] In this embodiment, as the information I to be acquired in the first step B The three pieces of information are used. The three pieces of information are obtained during the processing of the first step. Therefore, the processing method in the first step will be described next.

[0078] In the first step, using Figure 3 (a) and Figure 3 The cylindrical portion 25 is processed into the caulking portion intermediate body 39 by swing forging using the first caulking processing device of the first forming die 30 shown in (b). In the following description, the up-down direction refers to the up-down direction in the drawings.

[0079] The first molding die 30 is disposed above the wheel hub 3 and has a rotation axis β that is inclined at a predetermined angle θ relative to the center axis α of the wheel hub 3. In addition, the first molding die 30 has a processing surface 31, which is an annular concave surface centered on the rotation axis β, at the lower end. The first molding die 30 can move in the vertical direction and swing and rotate centered on the center axis α of the wheel hub 3, and can freely rotate centered on the rotation axis β. The first molding die 30 is in a state before the processing starts. Figure 3 The position shown in (a) is located above and does not contact the cylindrical portion 25.

[0080] When the first forming die 30 is used to perform swing forging on the cylindrical portion 25, the outer ring 2 is rotated relative to the hub 3 while the hub body 21 is prevented from displacement, and the first forming die 30 is swing-rotated around the central axis α of the hub 3. In this state, the first forming die 30 is moved downward, and Figure 3 As shown in (a), the processing surface 31 of the first molding die 30 is pressed toward the cylindrical portion 25. As a result, Figure 3 (a) and Figure 3 As shown in (b), the rivet intermediate body 39 is formed. That is, a processing force is applied downward in the up-down direction and radially outward to a portion of the cylindrical portion 25 in the circumferential direction from the processing surface portion 31 of the first molding die 30. In addition, the position to which the processing force is applied is continuously changed in the circumferential direction of the cylindrical portion 25 as the first molding die 30 swings and rotates around the central axis α of the hub 3. Thus, the rivet intermediate body 39 is formed by plastically deforming the cylindrical portion 25 in a manner that it is pressed and expanded radially outward while being crushed axially outward.

[0081] In one example, the riveted portion intermediate body 39 is as follows Figure 3 (b) shows a shape in which the axially outer side surface does not contact the axially inner side surface of the inner inner ring 22a, or 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 does not deform. For example, the rivet portion intermediate body 39 is a shape in which the pre-pressure does not change with the formation of the rivet portion intermediate body 39. In one example, the swing forging is terminated at the time point when such a rivet portion intermediate body 39 is formed. Thereafter, the first molding die 30 is retracted upward relative to the hub body 21.

[0082] In this embodiment, in order to form the caulking portion intermediate body 39 as described above, the time point (timing) of ending the swing forging in the first step is based on the torque for swinging and rotating the first forming die 30, that is, the forming die rotation torque T s To decide. Figure 4 In addition, the mold rotation torque T s For example, it can be measured based on the current value of the electric motor for the molding die (not shown) for swinging and rotating the first molding die 30 .

[0083] Figure 4 The forming die rotation torque T is shown in FIG. 1 when the cylindrical portion 25 is processed into the rivet portion 26 by swing forging using only the first forming die 30. s In this case, the molding die rotation torque T s The first stage (period t1) after the start of swing forging gradually increases. In the subsequent second stage (period t2), the forming die rotation torque T s In the subsequent third stage (period t3), the mold rotation torque T s In the subsequent fourth stage (period t4), the molding die rotation torque T s Once again stabilized at a roughly fixed value.

[0084] The axial inner end of the hub body 21 subjected to swing forging is in a state of not contacting the axial inner side surface of the inner inner ring 22a in the first and second stages (periods t1 and t2). In the third stage (period t3), it is in a state of contacting the axial inner side surface of the inner inner ring 22a to the extent that the inner ring raceway 11a of the axial inner row will not deform. In the fourth stage (period t4), it is in a state of contacting the axial inner side surface of the inner inner ring 22a to the extent that the inner ring raceway 11a of the axial inner row will deform.

[0085] In this embodiment, while confirming the rotation torque T of the molding die s On the one hand, the swing forging in the first process is ended at any time point in the first stage to the third stage (time period t1, t2, t3). However, from the viewpoint of seeking efficiency in the formation operation of the riveted portion 26, it is desirable to ensure a certain degree of processing volume of the axial inner end portion of the hub body 21 in the first process. Therefore, with regard to the time point of ending the swing forging in the first process, it is desirable to end at any time point in the second stage (time period t2) or the third stage (time period t3) compared to the first stage (time period t1). As a specific ending time point in this case, for example, the time point just after the transition to the second stage (time period t2) or the time point just after the transition to the third stage (time period t3) can be listed. Here, the so-called time point just after the transition to the second stage (time period t2) refers to: after the start of the swing forging, the forming die rotation torque T s The time point when the first value begins to stabilize (e.g. Figure 4 In addition, the time point immediately after the transition to the third stage (period t3) refers to the time point immediately after the start of the swing forging and the time point when the forming die rotation torque T s After the first stable value, the mold rotation torque T s The time point when the decrease begins (e.g. Figure 4 point Q2 in the figure).

[0086] In this embodiment, the swing forging in the first step is performed while measuring the following information: the axial load P1 applied from the first forming die 30 to the axial inner end of the hub body 21; the forming die rotation torque T for swinging and rotating the first forming die 30; s and the axial moving speed V of the first molding die 30 s The axial load P1 can be measured based on, for example, the hydraulic pressure in a hydraulic mechanism (not shown) for moving the first molding die 30 in the axial direction. s For example, it can be measured using a linear scale (not shown).

[0087] In this embodiment, as the information I to be acquired in the first stepB The three pieces of information included are the axial load P1, the forming die rotation torque T, and the time point at which the swing forging in the first step is completed. s and moving speed V s In addition, information I B Other information can be included instead of or in addition to the information described above.

[0088] (Second step of forming caulking portion)

[0089] In the second step, first, using the information I acquired in the step before the caulking portion forming step, A , and the information I obtained in the first step B The axial load P applied to the axial inner end of the hub body 21 required to bring the preload close to the target value is determined. 2x In one example, the axial load P is calculated using the following formula (1): 2x In formula (1), the axial load P 2x In addition, in formula (1), the independent variable includes information I A The information included (fitting allowance S, bearing axial clearance Δa, press-fit load F p ), Information I B The information included (axial load P1, mold rotation torque T s and moving speed V s ), and the target value X of the preload.

[0090] P 2x =k1×S+k2×Δa+k3×F p +k4×P1+k5×T s +k6×V s +k7×X……(1)

[0091] Here, k1, k2, k3, k4, k5, k6, and k7 are coefficients. These coefficients are obtained in advance by multiple regression analysis. In addition, these coefficients can also be obtained by various experiments or simulations other than multiple regression analysis.

[0092] In the formula (1), the target value X of the preload can be set to any value. In the hub unit bearing 1, the outer ring rotation torque T is the torque for rotating the outer ring 2 relative to the hub 3. g Therefore, in the formula (1), the outer ring rotation torque T corresponding to the target value of the preload can be input to the target value of the preload X. g , that is, the target outer ring rotation torque T gx In addition, the outer ring rotation torque T gThe current can be measured based on the current value of the outer ring electric motor (not shown) for rotating the outer ring 2 relative to the hub 3 .

[0093] As described above, the axial load P applied to the axial inner end of the hub body 21 required to bring the preload close to the target value can be calculated. 2x Next, using the axial load P 2x The caulking portion intermediate product 39 is processed into the caulking portion 26. In one example, the caulking portion 39 is formed using different methods and / or different devices between the first step and the second step. This point will be described in detail below.

[0094] In the second step, a device different from the first riveting processing device used in the first step is used, specifically including Figure 5 (a) and Figure 5 The second riveting processing device of the second forming die 32 shown in (b) is used to process the riveted portion intermediate body 39 into the riveted portion 26 by swing forging. Figure 5 (a) and Figure 5 As shown in (b), the riveted portion 26 is formed by preventing the hub body 21 from displacing and by causing the outer ring 2 to rotate relative to the hub 3 while the processed surface 33 of the second molding die 32 that swings and rotates around the central axis α of the hub 3 is pushed toward the axial inner end (riveted portion intermediate body 39) of the hub body 21.

[0095] By this swing forging, when forming the caulking portion 26, the axial load P2 applied from the second molding die 32 to the axial inner end portion of the hub body 21 is gradually increased. Thus, by advancing the downward movement of the second molding die 32, the shape of the axial inner end portion of the hub body 21 is made closer to the shape of the caulking portion 26 after completion. In this example, the upper limit value of the axial load P2 is set in advance to the axial load P2. 2x Therefore, for example, in the hydraulic mechanism (not shown) for moving the second molding die 32 in the axial direction, the hydraulic pressure value set by the control valve to generate the axial load P2 does not exceed the value corresponding to the axial load P2. 2x As a result, in this example, when the axial load P2 reaches the axial load P 2x At the time point of , the increase of the axial load P2 stops, and at the same time, the downward movement of the second forming die 32 stops. After that, if necessary, the swing forging in the second step is ended after the swing rotation of the second forming die 32 is continued for only a predetermined time. The preload is increased by the formation operation of the rivet portion 26, and the preload is brought close to the target value.

[0096] In addition, in this embodiment, the processing surface 33 of the second molding die 32 has Figure 5In the final stage of the swing forging shown in (b), a working force F directed downward in the vertical direction and radially inward can be applied to the rivet portion 26. s The shape (refer to Figure 6 ). In other words, the processing surface portion 33 of the second molding die 32 has a concave curved surface shape in which Figure 5 The portion that presses the caulking portion 26 in the final stage of the swing forging shown in (b) is inclined in a direction toward the lower side in the vertical direction as it goes toward the radial outer side.

[0097] Thus, in the present embodiment, in the final stage of the swing forging in the second step, a processing force F is applied downward in the vertical direction and radially inward from the processing surface portion 33 of the second forming die 32 to the caulking portion 26. s Therefore, if Figure 5 As shown by the arrow λ in (b), material will escape from the caulking portion 26 to the inner diameter side of the fitting surface portion 23, and a force with a large axial component will be applied to the inner inner ring 22a from the caulking portion 26. As a result, it is possible to prevent an excessive force from being applied to the inner inner ring 22a in the radial direction outward from the caulking portion 26, and to prevent the occurrence of undesirable situations such as deterioration in the shape accuracy of the inner ring raceway 11a in the axial inner row.

[0098] In addition, in other examples, the same method or the same device is used in the first process and the second process to form the rivet portion 39. For example, the same shape of the forming die can be used in the first process and the second process. In this case, by increasing the inclination angle of the rotation axis of the forming die relative to the central axis of the hub, that is, the swing angle θ, in the second process compared with the first process, it is also possible to apply a processing force downward in the vertical direction and radially inward from the processing surface of the forming die to the rivet portion in the final stage of the swing forging in the second process. Alternatively, the swing angle and the swing center can be made the same in the first process and the second process.

[0099] As described above, according to the method for manufacturing the hub unit bearing of the present embodiment, the preload can be adjusted, and specifically, the preload can be brought close to the target value.

[0100] In addition, in the present embodiment, the formation operation of the riveted portion 26 is divided into a first process and a second process, and different riveting processing devices are used to perform the first process and the second process. Therefore, the production efficiency of the hub unit bearing 1 can be improved. That is, if the formation operation of the riveted portion 26 is divided into a first process and a second process, the riveting processing time of each process can be shortened, and after the riveting processing of the first process is completed, the riveting processing of the first process of the next hub unit bearing can be started during the riveting processing of the subsequent second process. Therefore, the production efficiency of the hub unit bearing 1 can be improved accordingly. Regarding the use of different methods and / or different devices to form the riveted portion 39 between the first process and the second process, for example, it is beneficial to set processing conditions suitable for the first process and the second process respectively. Regarding the use of the same method and / or the same device to form the riveted portion 39 in the first process and the second process, for example, it is beneficial to simplify the processing system.

[0101] [Second embodiment]

[0102] use Figure 7 to Figure 10 A second embodiment of the present invention will be described.

[0103] In the second embodiment, the caulking portion forming step of forming the caulking portion 26 also includes a first step and a second step. The first step is a step of processing the cylindrical portion 25 provided at the axial inner end portion of the hub body 21 before forming the caulking portion 26 into a caulking portion intermediate body 39 (see Figure 3 (a) and Figure 3 The second step is to process the rivet portion intermediate body 39 into the rivet portion 26 (see Figure 5 (a) and Figure 5 (b)).

[0104] Unlike the first embodiment, in the second embodiment, the swing forging in the second step is performed in a plurality of stages. In addition, the outer ring rotation torque T is measured after the swing forging in each stage is completed. g In addition, in each stage after the second stage, the outer ring rotation torque T measured after the swing forging of each previous stage is used. g The axial load P2 applied to the axial inner end of the hub body 21 is determined based on the information. Thus, 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 confirmed. g Adjust the preload at the same time.

[0105] (First step of the caulking portion forming step)

[0106] In this embodiment, it is confirmed that the preload does not substantially change before and after the swing forging in the first step, that is, before and after the cylindrical portion 25 of the hub body 21 is processed into the rivet portion intermediate body 39. Therefore, specifically, the outer ring rotation torque T at the time point before the swing forging in the first step is measured. g (unprocessed), and the outer ring rotation torque T at the time point after the swing forging in the first step g (0) The outer ring rotation torque T measured in this way at each time point before and after the swing forging in the first step is confirmed. g (Unprocessed), T g (0) Figure 7 Shown are approximately equal sizes (T g (Unprocessed)≈T g (0)), in other words, even if there is a difference between the two sizes, it is confirmed that the difference falls within the allowable range. If this confirmation is completed, the transition is made to the subsequent second step.

[0107] (Second step of forming caulking portion)

[0108] In the second step, the oscillating forging for processing the caulking portion intermediate body 39 into the caulking portion 26 is performed in multiple stages. In this second step, the axial load P2(1) during the first stage of oscillating forging is adjusted to the outer ring rotation torque T after the first stage of oscillating forging is completed. g Less than the target outer ring rotation torque T gx In addition, the target outer ring rotation torque T gx The outer ring rotation torque T after the preload reaches the target value g , and decide on the same size for similar products to be produced.

[0109] When the first stage of the swing forging in the second process is performed, the upper limit of the axial load P2 applied from the second forming die 32 to the axial inner end of the hub body 21 is set to the axial load P2(1). With this setting, when the first stage of the swing forging is started, the axial load P2 gradually increases. As a result, by advancing the downward movement of the second forming die 32, the shape of the axial inner end of the hub body 21 becomes closer to the shape of the completed rivet portion 26. Moreover, at the time point when the axial load P2 reaches the axial load P2(1), the increase of the axial load P2 stops, and at the same time, the downward movement of the second forming die 32 stops. Thereafter, as required, the first stage of the swing forging is terminated after the swing rotation of the second forming die 32 is continued for only a specified time. Moreover, after the swing forging is terminated, the second forming die 32 is retracted upward relative to the axial inner end of the hub body 21, and the outer ring rotation torque T is measured. g (1). Moreover, Figure 8 As shown, the measured value T is obtained g (1) and target outer ring rotation torque T gx The difference ΔG(1) = T gx -T g (1).

[0110] In addition, in this embodiment, the Fig. 9 The relationship shown in the line graph is that with the axial load P2 ( Fig. 9 The relationship is the outer ring rotation torque T at the current time point. g (For example, T g (1)) is greater than the target outer ring rotation torque T gx When the value of is small, the difference between these values ​​ΔG = T gx -T g ( Fig. 9 ), and the value required to make the difference ΔG close to 0. Using this relationship and the difference ΔG(1) obtained as described above, the axial load P2(2) during the second stage of swing forging is obtained.

[0111] Under this axial load P2(2), the second stage of oscillating forging is performed in the same manner as in the first stage of oscillating forging, that is, the upper limit value of the axial load P2 applied from the second forming die 32 to the axial inner end of the hub body 21 is set as the axial load P2(2). After the oscillating forging is completed, the second forming die 32 is retracted upward relative to the axial inner end of the hub body 21, and the outer ring rotation torque T is measured. g (2) Fig.10 As shown, confirm that the measured value T g (2) Close enough to the target outer ring rotation torque T gx Specifically, confirm the measured value T g (2) and target outer ring rotation torque T gx The difference ΔG(2) = T gx -T g (2) It falls below a predetermined threshold.

[0112] In addition, it is assumed that the value T is measured in this confirmation operation. g (2) Target outer ring rotation torque T gx Small, and the measured value T g (2) and target outer ring rotation torque T gx The difference ΔG(2) exceeds a predetermined threshold value. In other words, when the preload is not within the allowable range, the use of Fig. 9The operation of calculating the axial load when performing the next stage of swing forging is performed based on the relationship of , and the operation of swing forging is performed using the calculated axial load until it is confirmed that the preload falls within the allowable range.

[0113] In addition, in the present embodiment, when the manufacturing method is implemented, in the second step, as the value of the axial load when the swing forging is performed in the second stage and later, it is also possible to use Fig. 9 The value obtained by multiplying the axial load P2 obtained by the relationship with the safety factor ε less than 1 (for example, 0.9≤ε<1) is obtained. In this way, the outer ring rotation torque T after the second stage of swing forging can be prevented. g and target outer ring rotation torque T gx Compared with the previous example, it can also make the outer ring rotate with torque T g Close enough to the target outer ring rotation torque T gx .

[0114] As described above, in this embodiment, the pre-pressure can be adjusted, and specifically, the pre-pressure can be brought close to the target value. The other structures and functions can be the same as those of the first embodiment.

[0115] [Third Embodiment]

[0116] use Fig.11 A third embodiment of the present invention will be described.

[0117] In the third embodiment, the hub unit bearing 1a to be manufactured is Figure 1 Compared with the hub unit bearing 1 shown in the figure, the inner ring raceway 11b of the axially outer row is provided on the outer peripheral surface of the axial middle portion of the hub body 21a constituting the hub 3a. In addition, 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 portion, and has a step surface 24a facing the axial inner side at the axially outer end of the fitting surface portion 23a. The inner 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 side surface is in contact with the step surface 24a. In this state, the axial inner side surface of the inner inner ring 22a is pressed by the caulking portion 26 provided at the axially inner end of the hub body 21a. In addition, since the hub unit bearing 1a is used for the drive wheel, a spline hole 35 for spline engagement of a drive shaft (not shown) is provided at the center of the hub body 21a.

[0118] The hub unit bearing 1a is assembled, for example, in the following order. First, the rolling elements 4a of the axial inner row held by the retainer 20a are arranged radially inside the outer ring raceway 5a of the axial inner row, and the rolling elements 4b of the axial outer row held by the retainer 20b are arranged radially inside the outer ring raceway 5b of the axial outer row. Furthermore, the axially outer sealing member 29 is mounted on the outer ring 2. Next, the axial middle portion and the inner portion of the hub body 21a before the caulking portion 26 is formed are inserted radially inside the outer ring 2. Next, the inner inner ring 22a is pressed into the fitting surface portion 23a so that the axial outer side surface of the inner inner ring 22a contacts the step surface 24a. After the hub unit bearing 1a before the caulking portion 26 is formed is assembled, the caulking portion 26 is formed. In addition, the axially inner sealing member 29 is mounted after the caulking portion 26 is formed.

[0119] In addition, the hub unit bearing 1a is given a certain degree of preload in the assembly state before the rivet portion 26 is formed, that is, in the assembly state after the axial outer side surface of the inner inner ring 22a is brought into contact with the step surface 24a as described above, and the axial inner side surface of the inner inner ring 22a is pressed by the rivet portion 26 formed later, thereby increasing the preload.

[0120] In this embodiment, the hub unit bearing 1a is used as a manufacturing object, and the same processing method of the rivet portion 26 as the first example of the embodiment is implemented. In this embodiment, the information I related to the factors affecting the preload obtained in the process before the first process used in the second process of the rivet portion forming process is used. A The fitting margin S between the fitting surface portion 23a and the inner inner race 22a and the press-fit load F of the inner inner race 22a with respect to the fitting surface portion 23a are assumed to be p , and the bearing axial clearance Δa in the assembled state before the caulking portion 26 is formed.

[0121] However, when it is difficult to measure the bearing axial clearance Δa in the assembled state before the caulking portion 26 is formed, the width W between the rows of outer ring raceways 5a and 5b can be measured instead of the bearing axial clearance Δa. o , the width W between the rows of the inner ring raceways 11a and 11b i , the diameter D of the rolling elements 4a, 4b of each row a , D b , and the pitch circle diameter PCD of the rolling elements 4a, 4b of each row a 、PCD b , and use these measured values.

[0122] In addition, the width W between the rows of outer ring raceways 5a and 5b is oThe axial distance between the center position of the contact portion between the outer ring raceway 5a of the axial inner row and the rolling element 4a of the axial outer row, and the center position of the contact portion between the outer ring raceway 5b of the axial outer row and the rolling element 4b of the axial outer row. i It is the axial distance between the center positions of the contact portions between the axially inner row inner ring raceways 11a and the axially outer row rolling elements 4a and the center positions of the contact portions between the axially outer row inner ring raceways 11b and the axially outer row rolling elements 4b.

[0123] In this embodiment, the axial load P is also calculated in the second step using the same relational expression as the above-mentioned equation (1). 2x In this relational expression, the axial load P applied to the axial inner end of the hub body 21a required to bring the preload close to the target value is expressed as 2x Set as the dependent variable and include information I in the independent variables A The information included (fitting allowance S, press load F p , bearing axial clearance Δa (or row width W o , column width W i , the diameter D of the rolling elements 4a, 4b a , D b and pitch diameter PCD a 、PCD b )) Information I B The information included (axial load P1, mold rotation torque T s and moving speed V s ), and the target value of preload X. Using the axial load P calculated in this way 2x The rivet portion intermediate body 39 is processed into the rivet portion 26 .

[0124] Furthermore, when swing forging is performed, the contact portion of the forming die relative to the workpiece moves in the circumferential direction as the forming die swings and rotates, but the width of the contact portion in the circumferential direction becomes narrower as the swing angle θ of the forming die increases. In addition, the plastic deformation area of ​​the workpiece around the contact portion also becomes narrower. On the other hand, in the case of the above-mentioned hub unit bearing 1a for the drive wheel, when the rivet portion 26 is formed, the contact portion of the forming die relative to the hub body 21a is closer to the spline hole 35 in the second step than in the first step. Therefore, in particular in the second step, it is desired to increase the size of the second forming die 32 (refer to Figure 5 (a) and Figure 5 The other structures and effects can be the same as those of the first embodiment.

[0125] [Fourth Embodiment]

[0126] use Fig.12 A fourth embodiment of the present invention will be described.

[0127] In the fourth embodiment, in the manufacturing method of the hub unit bearing, after the first step of the caulking portion forming step is performed and before the second step of the caulking portion forming step is performed, the following step is performed: the sealing member 29 that closes the axial inner end opening of the internal 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 inner ring 22a. That is, in the present embodiment, the second step of the caulking portion forming step is performed in a state where the axial inner sealing member 29 is installed between the outer ring 2 and the inner inner ring 22a.

[0128] In addition, in the present embodiment, a second riveting processing device including a forming die 36 and a plurality of rollers 37 as shown in the figure is used in the second step of the riveting portion forming step. The forming die 36 is arranged above the hub body 21. In addition, the forming die 36 is composed of a plurality of forming die elements 38 arranged in parallel in the circumferential direction with the center axis α of the hub body 21 as the center and capable of moving independently in the up and down directions. A plurality of rollers 37 are arranged above the forming die 36. In addition, the rollers 37 are arranged in a plurality of locations less than the total number of the forming die elements 38 in the circumferential direction with the center axis α of the hub body 21 as the center. More specifically, the rollers 37 are arranged in a plurality of locations that are rotationally symmetrical with the center axis α of the hub body 21 as the center. In particular, in this example, the rollers 37 are arranged in a plurality of locations at equal intervals in the circumferential direction with the center axis α of the hub body 21 as the center.

[0129] When the second step of riveting processing, i.e., the second riveting processing for forming the riveted portion 26, is performed, the lower side surface of the molding die 36 is brought into contact with the axial inner side of the hub body 21, and the plurality of rollers 37 are transferred in the circumferential direction with the central axis α of the hub body 21 as the center while the plurality of rollers 37 are pressed against the upper side surface of the molding die 36. Thus, by sequentially pressing the plurality of rollers 37 against the upper side surface of the molding die element 38, the lower side surface of the molding die element 38 is sequentially pressed against the axial inner side of the hub body 21, thereby plastically deforming the axial inner side of the hub body 21 toward the radial outer side to form the riveted portion 26.

[0130] When the rivet 26 is formed in this way, the processing force applied from the molding die 36 to the axial inner portion of the hub body 21 is always applied to a plurality of locations that are rotationally symmetrical about the central axis α of the hub body 21. Therefore, the rivet 26 can be formed without substantially applying an eccentric load to the axial inner portion of the hub body 21. Therefore, after the rivet 26 is formed, it is easy to prevent the force applied from the rivet 26 to the inner inner ring 22a from being biased in the circumferential direction.

[0131] In addition, in the present embodiment, since the second process is performed in a state where the sealing member 29 that closes the axial inner end opening of the internal space 27 is installed, when the second process is performed, foreign matter can be prevented from intruding into the internal space 27 from the outside through the axial inner end opening of the internal space 27. Furthermore, in the present embodiment, when the rivet portion 26 is formed, since an eccentric load is substantially not applied to the axial inner side of the hub body 21, it is possible to prevent the inner inner ring 22a from being radially displaced relative to the outer ring 2 during the formation of the rivet portion 26, and to prevent the sealing member 29 from being damaged. In addition, when the present invention is implemented, the second process can be performed even when the sealing member 29 is not installed. Other structures and effects can be the same as those of the first embodiment.

[0132] The present invention can be implemented by appropriately combining the above-mentioned embodiments within a range where no contradiction occurs.

[0133] For example, the second embodiment and the fourth embodiment can be implemented in combination. Specifically, as in the fourth embodiment, a process of installing an axially inner sealing component is implemented between the first process and the second process of the rivet portion forming process. In addition, in the second process, for the axially inner end of the hub body, the rivet portion intermediate is processed into a rivet portion while applying loads to a plurality of portions that are rotationally symmetrical about the central axis of the hub body. When this method is adopted, preload adjustment can also be performed as in the second embodiment. In addition, in this case, the outer ring rotation torque T at the time point when the first process is completed is g (0) Compared with the outer ring rotation torque T at the time when the process of installing the axially inner seal member is completed, sg (0) is only increased by an amount corresponding to the sealing torque (sliding contact resistance) of the sealing component. Figure 8 and Fig.10 Outer ring rotation torque T before the first stage of machining g (0) Replace with T sg (0), or Fig. 9 The data becomes the relationship after the sealing component is installed, and as long as the outer ring rotation torque to be processed in the second step is changed to a value after considering the sealing torque, the preload adjustment described in the second embodiment can be appropriately performed.

[0134] In one embodiment, in the rivet forming step, the information I acquired in the first step is used in the second step. B The information contained in the process and the information obtained in the process before the caulking portion forming process A The information included can select appropriate information. In addition, it is also possible to use only information I in the second step. A and Information I B any party in .

[0135] In one embodiment, various methods known in the past can be used to perform riveting on the axial inner end of the hub body to form the riveted portion. In addition, as a riveting method that does not apply an eccentric load to the axial inner end of the hub body when forming the riveted portion, for example, a method of riveting while pushing a forming mold on the entire outer circumference of the axial inner end of the hub body, or a method described in Japanese Patent Publication No. 2017-18991 (Patent Document 2), Japanese Patent Publication No. 2017-67254 (Patent Document 3), and Japanese Patent Publication No. 2017-106510 (Patent Document 4) can be used.

[0136] In one embodiment, if Figure 5 (b) and Figure 6 As shown in FIG. 1 , the method of applying a processing force downward in the vertical direction and radially inward from the processing surface of the forming die to the rivet portion in the final stage of the rivet processing in the second step is not limited to the rivet processing device that performs swing forging. For example, the method of applying a processing force to the rivet portion can also be used in Fig.12 The invention can be applied to other riveting processing devices such as the riveting processing device shown in the figure.

[0137] In one embodiment, in the second step of the caulking portion forming step, a method of forming a face spline, which is a circumferentially concave and convex portion, on the axially inner side surface of the caulking portion while forming the caulking portion may be adopted.

[0138] In one embodiment, a method for manufacturing a riveted assembly comprises: a step of axially combining a first component (21, 21a) and a second component (22a, 22b), the second component having a hole (120) for inserting the first component (21, 21a); ​​and a step of forming a riveted portion (39, 26) for the second component (22a, 22b) on the first component (21, 21a) by applying the axial load to the axial end of the first component (21, 21a), the step of forming the riveted portion including a step of adjusting the load based on at least one of (a) first information obtained before applying the load and (b) second information obtained after applying the load.

[0139] In one example, the first information includes information associated with the combination of the first component (21) and the second component (22a, 22b), and the second information includes information associated with physical characteristics of the first component (21, 21a).

[0140] For example, the first information includes information measured when the first component (21, 21a) and the second component (22a, 22b) are combined.

[0141] In one example, the rivets (39, 26) are at least temporarily formed using a swing rivet process.

[0142] In one example, the process of forming the rivet portion (39, 26) includes: a first process of forming the intermediate rivet portion (39) using a specified load; and a second process of forming the rivet portion (26) by applying the adjusted load to the intermediate rivet portion (39).

[0143] In one example, different methods or different devices are used to form the rivet portion (39, 26) between the first process and the second process, or the same method or the same device is used to form the rivet portion (39, 26) in the first process and the second process.

[0144] In one embodiment, a hub unit bearing (1, 1a) comprises: an outer ring (2) having an outer ring raceway (5a, 5b); a hub (3, 3a) having an inner ring raceway (11a, 11b); and a plurality of rolling elements (4a, 4b) arranged between the outer ring raceway (5a, 5b) and the inner ring raceway (11a, 11b). The hub (3, 3a) comprises a hub body (21, 21a) and an inner ring (22a, 22b) arranged outside the hub body (21, 21a) and held on the hub body (21, 21a). The manufacturing method of the hub unit bearing (1, 1a) comprises: a process of axially combining the hub body (21, 21a) and the inner ring (22a, 22b), the inner ring having a hole (120) for inserting the hub body (21, 21a); ​​and a process of forming a rivet portion (39, 26) for the inner ring (22a, 22b) on the hub body (21, 21a) by applying the axial load to the axial end of the hub body (21, 21a), the process of forming the rivet portion including the process of adjusting the load based on at least one of (a) first information obtained before applying the load and (b) second information obtained in a state after applying the load.

[0145] Fig.13 1 is a partial schematic diagram of a vehicle 200 having 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. Fig.13 In the embodiment, the hub unit bearing 151 is used for the driving wheel and includes an outer ring 152, a hub 153, and a plurality of rolling elements 156. The outer ring 152 is fixed to the knuckle 201 of the suspension device using bolts or the like. The wheel (and the brake rotating body 22) 202 is fixed to the flange (rotating flange) 153A provided on the hub 153 using bolts or the like. In addition, regarding the hub unit bearing 151 for the driven wheel, the vehicle 200 can have the same support structure as described above.

[0146] The present invention is not limited to the hub of the hub unit bearing, but can also be applied to other riveting assemblies (riveting units) in which a first component and a second component having a hole for inserting the first component are combined in the axial direction.

[0147] Description of Reference Numerals

[0148] 1.1a Hub unit bearing

[0149] 2 Outer ring

[0150] 3.3a ​​Wheel Hub

[0151] 4a, 4b rolling elements

[0152] 5a, 5b Outer ring raceway

[0153] 6 Stationary flange

[0154] 7 Support holes

[0155] 8 Steering knuckle

[0156] 9 Through Holes

[0157] 10 Bolts

[0158] 11a, 11b Inner ring raceway

[0159] 12 Swivel flange

[0160] 13 Mounting holes

[0161] 14 Braking rotor

[0162] 15 Studs

[0163] 16 Through Holes

[0164] 17 Wheels

[0165] 18 Through Holes

[0166] 19 Nut

[0167] 20a, 20b Cage

[0168] 21, 21a Hub body (hub rim, first component)

[0169] 22a Inner ring (inner inner ring, second component)

[0170] 22b Inner ring (outer inner ring, second component)

[0171] 23, 23a Chimeric face

[0172] 24, 24a Layer difference surface

[0173] 25 Cylinder

[0174] 26 Riveting

[0175] 27 Interior Space

[0176] 28 Sealing parts

[0177] 29 Sealing parts

[0178] 30 First molding die

[0179] 31 Processing face

[0180] 32 Second molding die

[0181] 33 Processing face

[0182] 34 Bearing assembly

[0183] 35 spline hole

[0184] 36 Forming mold

[0185] 37 Rollers

[0186] 38 Forming die components

[0187] 39 Riveted portion intermediate body (middle riveted portion).

Claims

1. A method for manufacturing a riveted assembly, characterized in that: The riveted assembly is a hub unit bearing having an outer ring with an outer ring raceway, a hub with an inner ring raceway, and a plurality of rolling elements arranged between the outer ring raceway and the inner ring raceway, wherein the hub has a hub body as a first component, and an inner ring as a second component arranged outside the hub body and held on the hub body, wherein the inner ring is composed of an inner inner ring and an outer inner ring. The manufacturing method of the riveted assembly comprises: a step of axially combining the first member and the second member, the second member having a hole into which the first member is inserted; and A rivet forming step including a first step and a second step, wherein a load is applied to an axial end of the hub body at least in the axial direction to form a rivet for the inner ring on the hub body, wherein the load in the second step is adjusted based on at least one of (a) first information acquired before the load is applied and (b) second information acquired in the first step after the load is applied. The first step of the caulking portion forming step is a step of processing a cylindrical portion provided at the axial inner end portion of the hub body before the caulking portion is formed into a caulking portion intermediate body by applying a predetermined load based on the swing of a first molding die that swings and rotates around the central axis of the hub body and presses the axial inner end portion of the hub body toward the axial inner end portion of the hub body, the caulking portion intermediate body becoming the shape of the axial end of the hub body and being at least partially plastically deformed in the first step. The second step of the caulking portion forming step is a step of processing the caulking portion intermediate product into the caulking portion by applying an adjusted load. In the second step, the rivet portion intermediate is processed into the rivet portion by swing forging in which a second molding die that swings and rotates around the central axis of the hub body is pressed toward the axial inner end of the hub body using at least one of the first information and the second information. The first information is acquired in a process before the first process of the rivet portion forming process, and includes at least one of (i), (ii) and (iii) information associated with the combination of the first component and the second component, wherein (i) a fitting margin between the fitting surface of the hub body and the inner inner ring and the outer inner ring, (ii) a pressing load for pressing the inner inner ring and the outer inner ring into the fitting surface, and (iii) an internal clearance of the bearing related to the axial direction before the rivet portion is formed, that is, an axial clearance of the bearing, The second information is obtained in the first process of the riveting portion forming process, and includes at least one of (iv), (v) and (vi) information associated with the physical properties of the first component obtained at the time point of ending the swing forging in the first process, wherein (iv) is an axial load applied to the axial inner end of the hub body from the first molding die, (v) is a molding die rotational torque used to swing and rotate the first molding die, and (vi) is an axial moving speed of the first molding die.

2. The method for manufacturing a riveted assembly according to claim 1, characterized in that: In the first step, the caulking portion intermediate body is not brought into contact with the axially inner side surface of the inner inner ring.

3. The method for manufacturing a riveted assembly according to claim 1 or 2, characterized in that: In the second step, the axial load applied to the axial inner end portion of the hub body is determined using the information acquired in the first step. 4 . A method for manufacturing a vehicle, the vehicle comprising a hub unit bearing, wherein the hub unit bearing is manufactured by the method for manufacturing a caulking assembly according to claim 1 .

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