JP7201025B2 - Hub unit bearings and vehicles - Google Patents

Description

The present invention relates to a hub unit bearing for rotatably supporting a wheel of a vehicle such as an automobile with respect to a suspension system, a manufacturing method thereof, a rocking damping device used for carrying out the manufacturing method, and a vehicle and its manufacturing method. It relates to a manufacturing method.

In a hub unit bearing, a hub, which is an inner ring member, is usually constructed by combining a plurality of parts including a first hub element and a second hub element fitted onto the first hub element. Also, in order to reduce the number of parts constituting the hub, a structure in which the first hub element and the second hub element are joined by a crimped portion without using separate parts such as bolts and nuts is becoming popular.

FIG. 15 is a cross-sectional view of a main portion showing an example of a hub formed by connecting a first hub element and a second hub element with a caulked portion. The hub 100 includes a first hub element 101 having a fitting shaft portion 102 and a tubular second hub element 103 . The first hub element 101 further has a caulking portion 105 formed by radially outwardly plastically deforming a cylindrical portion 104 extending from one axial end of the fitting shaft portion 102 to one axial side. The first hub element 101 and the second hub element 103 are coupled by pressing the side surface of the second hub element 103 on one side in the axial direction with the crimped portion 105 .

Further, as a device for forming the crimping portion 105 as described above, there is known a rocking crimping device 106 having a stamping die 107 as shown in FIG. Document 1), Japanese Patent Application Laid-Open No. 2007-153247 (Patent Document 2)). The stamping die 107 has a rotation axis L inclined by an angle α with respect to the reference axis C, and a machining surface portion formed by forming a concave portion having an arcuate cross section in an annular shape around the rotation axis L at the lower end portion. 108.

When forming the crimped portion 105, the center axis of the hub 100 is aligned with the reference axis C, and the machined surface portion 108 of the stamping die 107 is pressed against the cylindrical portion 104 of the second hub element 103 while the stamping die 107 is pressed. By rotating the hub 100 around the central axis C, the cylindrical portion 104 is processed into a crimped portion 105 . That is, a machining force directed downward in the vertical direction and outward in the radial direction is applied from the machining surface portion 108 of the stamping die 107 to a portion of the cylindrical portion 104 in the circumferential direction. Further, the position at which the machining force is applied is continuously changed in the circumferential direction of the cylindrical portion 104 as the stamping die 107 rotates about the central axis C of the hub 100 . As a result, the crimped portion 105 is formed by plastically deforming the cylindrical portion 104 radially outward.

Japanese Patent Application Laid-Open No. 2001-162338 JP 2007-153247 A

The rocking damping device 106 as described above has room for improvement in terms of reducing the manufacturing cost of the hub unit bearing. That is, in the illustrated swinging clamp device 106, the processing surface portion 108 of the stamping die 107 is formed by forming a concave portion having an arcuate cross section in an annular shape around the rotation axis L, and has a complicated shape. Therefore, the processing cost of the processing surface portion 108 is increased, and the stamping die 107 tends to be expensive. Therefore, the manufacturing cost of the hub unit bearing tends to increase accordingly.

SUMMARY OF THE INVENTION An object of the present invention is to realize a method of manufacturing a hub unit bearing that can reduce the manufacturing cost.

A hub unit bearing to be manufactured according to the present invention includes an outer ring having a double-row outer ring raceway on its inner peripheral surface, a hub having a double-row inner ring raceway on its outer peripheral surface, the double-row outer ring raceway and the double-row inner ring raceway. A plurality of rolling elements are arranged for each row between the inner ring raceway.
The hub is formed by connecting and fixing at least a first hub element and a second hub element.
The first hub element has, on its outer peripheral surface, a base portion having one inner ring raceway out of the double-row inner ring raceways, and a fitting portion extending from an end portion on one axial side of the base portion toward one axial side. and a joint shaft portion.
The second hub element is fitted onto the fitting shaft portion, has the other inner ring raceway of the double-row inner ring raceways on its outer peripheral surface, and has, on one side surface in the axial direction, It has a surface to be held that is inclined toward one side in the axial direction as it goes radially outward.

In the method of manufacturing the hub unit bearing of the present invention, in a state in which the second hub element is externally fitted to the fitting shaft portion, from the end portion on the one axial side of the fitting shaft portion toward the one axial side, With respect to the rotation axis, the pressing die is rotatably supported on the end face of the extending cylindrical portion on one axial side in the axial direction, and is rotatable about the rotation axis inclined with respect to the central axis of the first hub element. By rotating the stamping die about the central axis of the first hub element while pressing a portion of the convex curved machined surface portion having a linear generatrix inclined toward the center in the circumferential direction, the cylindrical portion is moved in the axial direction. forming a crimped portion by crushing the first hub element and the second hub element together by pressing the surface to be restrained by the crimped portion;

In one aspect of the present invention, in the step of coupling and fixing the first hub element and the second hub element, the cylindrical portion and the A contact portion with the machined surface portion is present on a straight line perpendicular to the central axis of the first hub element.

In one aspect of the present invention, in the step of coupling and fixing the first hub element and the second hub element, the apexes of the virtual conical surface including the machined surface portion are aligned with the central axis of the first hub element and the rotation axis. exists at the intersection of

In one aspect of the present invention, a test is performed to examine the relationship between the inclination angle of the rotation axis with respect to the central axis of the first hub element and the shape of the side surface of the crimped portion on the other side in the axial direction, and based on the results of the test. Then, the inclination angle is obtained so that the side surface on the other side in the axial direction of the crimped portion can be shaped along the surface to be held down. A step of coupling and fixing with the hub element is performed.

In one aspect of the present invention, the thickness of the cylindrical portion is radially inward along the working surface portion due to the stepped surface portion existing in the portion adjacent to the radially inner side of the working surface portion on the outer peripheral surface of the stamping die. A step of coupling and fixing the first hub element and the second hub element while suppressing the flow is performed.

In one aspect of the present invention, the second hub element further has a rotary flange protruding radially outward from a portion located on one axial side of the other inner ring raceway.

In one aspect of the present invention, the second hub element is externally fitted onto the fitting shaft portion without interference.

In one aspect of the present invention, there is a detent engaging portion between the first hub element and the second hub element that prevents relative rotation between the first hub element and the second hub element. there is

In one aspect of the present invention, the anti-rotation engaging portion includes a first face spline provided on the end surface of the base portion of the first hub element on one side in the axial direction and the other side in the axial direction of the second hub element. It is configured by meshing with a second face spline provided on the end face of the.

In one aspect of the present invention, the anti-rotation engaging portion is formed by engaging an engaging slit formed in the crimped portion of the first hub element and an engaging convex portion provided on the second hub element. It is configured by

In one aspect of the present invention, the anti-rotation engaging portion includes an engaging convex portion that protrudes radially outward from one axial end of the fitting shaft portion of the first hub element; It is configured by engaging with an engaging recess provided on two hub elements.

In one aspect of the present invention, the first hub element further has a rotary flange protruding radially outward from a portion located on the other side in the axial direction of the one inner ring raceway.

The rocking stop device of the present invention is rotatably supported about a reference axis arranged coaxially with the central axis of the first hub element and a rotation axis inclined with respect to the reference axis, and the reference It is rotatable about an axis and has a convex curved surface having a linear generatrix inclined with respect to the rotation axis, a part of the circumferential direction being an end surface of the cylindrical portion on one side in the axial direction. and a die having a working surface for pressing against.

In one aspect of the rocking stop device of the present invention, within a virtual plane containing the reference axis and the rotation axis, the contact portion between the cylindrical portion and the machined surface portion is a straight line orthogonal to the reference axis. exist above.

In one aspect of the rocking stop device of the present invention, the vertex of the imaginary conical surface including the machined surface portion exists at the intersection of the central axis of the first hub element and the rotation axis.

In one aspect of the rocking clamp device of the present invention, the stamping die further has a stepped surface portion on a portion of the outer peripheral surface adjacent to the inner side in the radial direction of the machined surface portion.

In one aspect of the rocking lock device of the present invention, the machined surface portion is a lathe machined surface.

A vehicle to be manufactured according to the present invention includes a hub unit bearing.
A vehicle manufacturing method of the present invention manufactures the hub unit bearing by the hub unit bearing manufacturing method of the present invention.

A hub unit bearing of the present invention comprises an outer ring having a double-row outer ring raceway on its inner peripheral surface, a hub having a double-row inner ring raceway on its outer peripheral surface, and the double-row outer ring raceway and the double-row inner ring raceway. A plurality of rolling elements are arranged between each row.
The hub is formed by connecting and fixing at least a first hub element and a second hub element.
The first hub element has, on its outer peripheral surface, a base portion having one inner ring raceway out of the double-row inner ring raceways, and a fitting portion extending from an end portion on one axial side of the base portion toward one axial side. and a joint shaft portion.
The second hub element is fitted onto the fitting shaft portion, has the other inner ring raceway of the double-row inner ring raceways on its outer peripheral surface, and has a cover on one side surface in the axial direction. It has a holding surface.
the first hub element further includes an annular one axial end portion adjacent to the one axial side of the fitting shaft portion, the one axial end portion projecting radially outward; Further, it has a caulked portion that holds down the surface to be held down, and an inward flange portion that is located on the inner diameter side of the caulked portion and protrudes radially inward.

In one aspect of the hub unit bearing of the present invention, one axial end portion of the one axial end portion of the first hub element, including the one axial end portion of each of the caulked portion and the inward flange portion, is provided. The side end surface is a flat surface perpendicular to the central axis of the first hub element.

A vehicle according to the present invention includes a hub unit bearing.
In particular, in the vehicle of the present invention, the hub unit bearing is the hub unit bearing of the present invention.

According to the present invention, the manufacturing cost of the hub unit bearing can be suppressed because the stamping die can be manufactured at low cost.

FIG. 1 is a cross-sectional view showing a state in which a hub unit bearing according to a first embodiment is assembled to a vehicle. FIG. 2 is a half cut perspective view of the hub wheel of the first example of the embodiment. FIG. 3 is a cross-sectional view showing a state at the start of processing for forming a caulked portion in relation to the first example of the embodiment. FIG. 4 is a cross-sectional view showing a state at the end of processing for forming a crimped portion in relation to the first example of the embodiment. FIG. 5 is a cross-sectional view showing the test assembly set in the rocking device in relation to the first example of the embodiment. 6A to 6D, the upper half is a partial plan view showing the contact portion S of the stamping die with respect to the test piece, and the lower half is the plastic working region V and the crimped portion of the test piece. It is a partial sectional view showing a shape. FIG. 7 is a cross-sectional view of a hub unit bearing to be manufactured in the second example of the embodiment. FIG. 8A is a cross-sectional view showing a state at the start of processing for forming a caulked portion in the second example of the embodiment, and FIG. FIG. 5 is a cross-sectional view showing a state at the end of machining; FIG. 9 is a cross-sectional view of a hub unit bearing to be manufactured in the third example of the embodiment. FIG. 10 is a partial cross-sectional view of a hub unit bearing showing a state immediately before performing processing for forming a caulked portion in relation to the third example of the embodiment. FIG. 11 is a cross-sectional view of a hub unit bearing to be manufactured in the fourth example of the embodiment. FIG. 12 is a cross-sectional view showing a state at the end of processing for forming a crimped portion in relation to the fourth example of the embodiment. FIG. 13 is a cross-sectional view showing a state at the end of processing for forming a crimped portion in relation to the fifth example of the embodiment. 14 is an enlarged view of part A in FIG. 13. FIG. FIG. 15 is a cross-sectional view of a main part showing an example of a conventional structure of a hub unit bearing. FIG. 16 is a cross-sectional view of essential parts showing a state in which a crimped portion is formed by a conventional method.

[First example of embodiment]
A first example of an embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG.

(Configuration of hub unit bearing 1)
FIG. 1 shows a hub unit bearing 1 to be manufactured in this example. A hub unit bearing 1 is for a driven wheel and includes an outer ring 2, a hub 3, and a plurality of rolling elements 4a and 4b.

Regarding the hub unit bearing 1, the axially outer side is the left side in FIG. 1 on the right side of FIG. Further, in this example, regarding the hub unit bearing 1, the axially outer side corresponds to one axial side, and the axially inner side corresponds to the other axial side.

The outer ring 2 is made of a hard metal such as medium carbon steel, and includes double-row outer ring raceways 5 a and 5 b and a stationary flange 6 . The double-row outer ring raceways 5a and 5b are formed on the inner peripheral surface of the axially intermediate portion of the outer ring 2, and are conical concave surfaces inclined in a direction in which the diameter increases with increasing distance from each other in the axial direction. The stationary flange 6 protrudes radially outward from an axially intermediate portion of the outer ring 2 and has support holes 7, which are screw holes, at a plurality of locations in the circumferential direction.

The outer ring 2 is supported and fixed to the knuckle 8 by screwing the bolt 10 inserted through the through hole 9 of the knuckle 8 constituting the suspension system of the vehicle into the support hole 7 of the stationary flange 6 from the inside in the axial direction and tightening it. ing.

The hub 3 is arranged radially inside the outer ring 2 and coaxial with the outer ring 2 , and includes double-row inner ring raceways 11 a and 11 b , a rotating flange 12 , and a pilot portion 13 . The double-row inner ring raceways 11a and 11b are formed in a portion of the outer peripheral surface of the hub 3 that faces the double-row outer ring raceways 5a and 5b. It is a conical convex surface inclined to . The rotary flange 12 protrudes radially outward from an axially outer portion of the hub 3 positioned axially outwardly of the outer ring 2, and has mounting holes 14 at a plurality of locations in the circumferential direction. The pilot portion 13 is a cylindrical portion that extends axially outward from a portion of the axially outer portion of the hub 3 that is adjacent to the radially inner side of the rotary flange 12 .

Further, in the illustrated example, in order to connect and fix the braking rotor 15 such as a disk or drum to the rotary flange 12, the braking rotor 15 is externally fitted to the axially inner portion of the pilot portion 13, and the stud is mounted on the stud. A serration portion provided at a proximal end portion of the stud 16 is press-fitted into the mounting hole 14 , and an intermediate portion of the stud 16 is press-fitted into the through hole 17 of the braking rotor 15 . Furthermore, in order to fix the wheel 18 constituting the wheel to the rotating flange 12, the male thread provided at the tip of the stud 16 is attached to the wheel 18 while the wheel 18 is fitted on the axially outer side of the pilot portion 13. A nut 20 is screwed onto the male threaded portion while being inserted into the through hole 19 of 18 and tightened.

The rolling elements 4a, 4b are each made of a hard metal such as bearing steel or ceramics, and are arranged between the double-row outer ring raceways 5a, 5b and the double-row inner ring raceways 11a, 11b for each row. It is The rolling elements 4a and 4b are rotatably held by retainers 21a and 21b for each row. In this example, each of the rolling elements 4a and 4b is a tapered roller.

In this example, the hub 3 is formed by combining a shaft member 23 corresponding to a first hub element and a hub wheel 22 corresponding to a second hub element, each of which is made of hard metal such as medium carbon steel.

The hub wheel 22 has a cylindrical shape and has the axially outer inner ring raceway 11a of the double-row inner ring raceways 11a and 11b on the axially inner peripheral surface, and the rotary flange 12 on the axially outer side. and a pilot section 13 . That is, the hub ring 22, which corresponds to the second hub element, protrudes radially outward from a portion located axially outward, which is on one axial side, of the axially outer inner ring raceway 11a, which corresponds to the other inner ring raceway. It has a rotating flange 12 with a . The hub wheel 22 also has a center hole 24 that axially penetrates through the axially intermediate portion and the radially central portion of the inner portion of the hub wheel 22 . The inner peripheral surface of the center hole 24 is a cylindrical surface whose inner diameter does not change in the axial direction. Further, the hub wheel 22 is located radially inward of the pilot portion 13 in the axial outer side surface, and is a portion that connects the inner peripheral surface of the pilot portion 13 and the inner peripheral surface of the center hole 24 . , and has an inclined surface portion 25 that is inclined in the axially outward direction as it goes radially outward. Although the inclined surface portion 25 is a conical concave surface having a straight generatrix in the illustrated example, it may be a concave curved surface having a substantially arc-shaped generatrix. Further, the hub wheel 22 has a second face spline 27, which is an uneven portion in the circumferential direction, on an axially inner end surface 26 thereof.

The shaft member 23 has a cylindrical base portion 28 having an axially inner inner ring raceway 11b of the double-row inner ring raceways 11a and 11b on the outer peripheral surface, and extends axially outward from the radially inner portion of the base portion 28. It has a cylindrical fitting shaft portion 29 . The fitting shaft portion 29 has an outer diameter slightly smaller than the inner diameter of the center hole 24 of the hub wheel 22 . In addition, the shaft member 23 has a stepped surface 30 connecting the outer peripheral surface of the base portion 28 and the outer peripheral surface of the fitting shaft portion 29, which is the axially outer end surface of the base portion 28. It has one face spline 31 . The first face spline 31 can mesh with the second face spline 27 without backlash in the circumferential direction.

By inserting the fitting shaft portion 29 of the shaft member 23 into the center hole 24 of the hub wheel 22, the hub wheel 22 and the shaft member 23 are prevented from rattling in the radial direction of the fitting shaft portion 29. By externally fitting and meshing the first face spline 31 and the second face spline 27, the hub wheel 22 and the shaft member 23 are connected and fixed in a state of preventing relative rotation. Specifically, in this state, a crimped portion 33 is formed by axially crushing a cylindrical portion 32 (see FIG. 3) extending axially outward from the axially outer end of the fitting shaft portion 29. , the radially inner portion of the inclined surface portion 25 of the hub wheel 22 (the portion of the inclined surface portion 25 surrounding the axially outer opening of the central hole 24) to be held down, thereby holding down the hub wheel 22 and the shaft member. 23 are coupled and fixed. In other words, the shaft member 23 further includes a crimped portion 33 projecting radially outward at the annular axially outer end adjacent to the axially outer side of the fitting shaft portion 29 . Then, the hub wheel 22 and the shaft member 23 are coupled and fixed by pressing the pressed surface 59 of the hub wheel 22 with the caulked portion 33 . That is, the hub wheel 22 is coupled and fixed to the shaft member 23 while being axially sandwiched between the stepped surface 30 of the shaft member 23 and the crimped portion 33 . Further, in a state in which the hub wheel 22 and the shaft member 23 are coupled and fixed in this manner, a proper preload is applied to the rolling elements 4a and 4b. Further, in this example, the pressing surface 42 , which is the inner side surface in the axial direction of the crimped portion 33 and contacts the pressing surface 59 , has a shape along the pressing surface 59 . In the illustrated example, the shaft member 23 further includes an inward flange portion 41 projecting radially inward on the inner diameter side of the caulking portion 33 at the axially outer end portion. The axially outer end surface of the annular axially outer end of the shaft member 23 , including the axially outer ends of the caulked portion 33 and the inward flange portion 41 , is flat and perpendicular to the central axis of the shaft member 23 . surface 61;

In the hub unit bearing 1 of this example as described above, the fitting shaft portion 29 has an outer diameter slightly smaller than the inner diameter of the center hole 24 of the hub wheel 22 . Therefore, the hub wheel 22 is fitted onto the fitting shaft portion 29 without interference. In other words, the fitting shaft portion 29 is not press-fitted into the center hole 24, and the outer peripheral surface of the fitting shaft portion 29 and the inner peripheral surface of the center hole 24 are fitted without interference. . Therefore, when the fitting shaft portion 29 is inserted into the center hole 24, the double-row inner ring raceways 11a and 11b are not deformed (expanded) in the diameter-expanding direction. The crimped portion 33 presses a pressed surface 59 positioned radially inward of the axially outer side surface of the hub wheel 22 at a large distance from the double-row inner ring raceways 11a and 11b. Therefore, it is possible to sufficiently suppress deformation of the double-row inner ring raceways 11a and 11b in the diameter-expanding direction due to the formation of the caulked portion 33 . Therefore, in the hub unit bearing 1 of this example, it is easy to apply an appropriate preload to the rolling elements 4a and 4b.

In addition, in the hub unit bearing 1 of this embodiment, the second face spline 27 of the hub wheel 22 and the first face spline 31 of the shaft member 23 are engaged with each other, so that the hub wheel 22 and the shaft member 23 rotate relative to each other ( creep) can be prevented.

(Structure of rocker fitting device 34)
Next, a rocking clamping device 34 for forming the crimped portion 33 and coupling and fixing the hub wheel 22 and the shaft member 23 will be described with reference to FIG. The rocking clamp device 34 includes a vertical reference axis C and a stamping die 35 supported so as to be rotatable (or revolving) around the reference axis C. As shown in FIG.

The stamping die 35 is a tool for forming the caulking portion 33, has a rotation axis L inclined by an angle α (0<α<90°) with respect to the reference axis C, and has the rotation axis L as the center. Rotation (rotation) is freely supported. That is, the stamping die 35 is supported so as to rotate (revolve) about the reference axis C and freely rotate about the rotation axis L (rotation). As for the structure of the portion that supports the stamping die 35, various structures including the structure of a conventionally known rocking device can be employed. The stamping die 35 has, on its lower side, a machining surface portion 36 having a convex surface shape (conical convex surface shape centering on the rotation axis L) having a linear generatrix inclined with respect to the rotation axis L. A processing method for forming the processed surface portion 36 is not particularly limited. For example, the machined surface portion 36 can be a forged surface formed by forging or a turned surface formed by turning. In this example, the inclination angle β of the generatrix of the machined surface portion 36 with respect to the rotation axis L is (90°−α). That is, in this example, the portion (X portion in FIGS. 3 and 4) located at the lower end of the machined surface portion 36 within the virtual plane including the reference axis C and the rotation axis L is It exists on an orthogonal straight line. Further, in this example, the vertex of the virtual conical surface including the machined surface portion 36 is present at the intersection point P between the reference axis C and the rotation axis L. As shown in FIG.

(Manufacturing method of hub unit bearing 1)
Next, a method for forming the crimped portion 33 using the swing crimping device 34 when manufacturing the hub unit bearing 1 will be described.

The operation of forming the crimped portion 33 is performed in a state in which the hub unit bearing 1 is assembled before the crimped portion 33 is formed. Therefore, the hub unit bearing 1 is assembled in advance before forming the caulked portion 33 .

The hub unit bearing 1 before the caulking portion 33 is formed can be assembled by an appropriate procedure, and for example, it can be assembled by the following procedure. First, the rolling elements 4a of the axially outer row are arranged around the axially outer inner ring raceway 11a of the hub wheel 22 while being held by the axially outer retainer 21a. An outer ring 2 is arranged around it. Next, of the shaft member 23 before the caulking portion 33 is formed, the axially inner row of the rolling elements 4b is held around the axially inner inner ring raceway 11b by the axially inner retainer 21b. Deploy. Then, the fitting shaft portion 29 of the shaft member 23 is inserted into the center hole 24 of the hub wheel 22, and the first face spline 31 and the second face spline 27 are engaged with each other. Assemble the hub unit bearing 1 of .

When forming the crimped portion 33 using the rocking crimping device 34, first, as shown in FIG. With the central axis of the hub 3 (the central axis of the shaft member 23 corresponding to the first hub element, the central axis of the hub wheel 22 corresponding to the second hub element) aligned with the reference axis C, the shaft member 23 is It is supported by a holder (not shown). The angle α of the rocking clamping device 34 is adjusted in advance by a method described later so that the clamping surface 42 of the crimped portion 33 after completion has a shape along the clamped surface 59 .

Next, in this state, the work of processing the cylindrical portion 32 into the caulked portion 33 is started. That is, as shown in FIGS. 3 to 4, by moving the stamping die 35 downward or by moving the hub unit bearing 1 upward, a part of the machining surface portion 36 of the stamping die 35 in the circumferential direction is The cylindrical portion 32 is processed into the caulked portion 33 by rotating the stamping die 35 around the reference axis C while pressing the portion (X portion) located at the axially outer end surface of the cylindrical portion 32 of the shaft member 23 do. That is, in this example, the contact portion between the machining surface portion 36 and the cylindrical portion 32 is present on a straight line orthogonal to the reference axis C in a virtual plane including the reference axis C and the rotation axis L, thereby performing machining. A processing force directed downward in the vertical direction is applied from the surface portion 36 to a portion of the cylindrical portion 32 in the circumferential direction. Further, the position at which the machining force is applied is continuously changed in the circumferential direction of the cylindrical portion 32 as the stamping die 35 rotates about the reference axis C. FIG. Thereby, the crimped portion 33 and the inward flange portion 41 are formed by crushing the cylindrical portion 32 in the axial direction. In this example, since the contact portion between the machined surface portion 36 and the cylindrical portion 32 is present on a straight line perpendicular to the reference axis C within a virtual plane including the reference axis C and the rotation axis L, the caulked portion The axially outer end surface of the annular axially outer end portion of the shaft member 23 , which includes the axially outer end portions of each of the 33 and the inward flange portion 41 , is a flat surface 61 perpendicular to the central axis of the shaft member 23 . becomes.

When forming the caulking portion 33 and the inward flange portion 41 in this way, the stamping die 35 rotates around the rotation axis L based on the frictional force acting on the contact portion between the processing surface portion 36 and the cylindrical portion 32. . That is, the contact of the machined surface portion 36 with the cylindrical portion 32 is rolling contact. In particular, in this example, the vertex of the virtual conical surface including the machined surface portion 36 exists at the intersection point P between the reference axis C and the rotation axis L. As shown in FIG. Therefore, when the cylindrical portion 32 is processed into the caulked portion 33 and the inwardly directed flange portion 41, it is possible to prevent differential slippage from occurring at the contact portion between the machined surface portion 36 and the cylindrical portion 32 (the caulked portion 33 and the inwardly directed flange portion 41). can be prevented. Specifically, slippage in the circumferential direction can be prevented at any radial position of the contact portion. Therefore, wear and heat generation at the contact portion between the machined surface portion 36 and the cylindrical portion 32 (the crimped portion 33 and the inwardly directed flange portion 41) can be sufficiently suppressed.

In the method of manufacturing the hub unit bearing 1 of the present embodiment as described above, the machined surface portion 36 of the stamping die 35 constituting the rocker fitting device 34 is formed in a simple conical convex shape. Therefore, the processing cost of the processing surface portion 36 can be suppressed, and the stamping die 35 can be manufactured at low cost. Therefore, the manufacturing cost of the hub unit bearing 1 can be reduced accordingly.

Furthermore, since the machined surface portion 36 has a conical convex shape, the crimped portion can be formed using a common stamping die 35 even when manufacturing a plurality of hub unit bearings having different diameters of the crimped portion. can be done. For this reason, it is possible to omit troublesome work such as replacing the pressing die 35 of the rocker clamp device 34 every time the name number of the hub unit bearing to be manufactured changes. Therefore, from these aspects as well, the manufacturing cost of the hub unit bearing 1 can be suppressed.

(How to adjust the angle α)
Next, based on FIGS. 5 and 6, the angle α (and β=90° -α) will be described.

First, a plurality of stamping dies 35 with different angles α (and β) are prepared. Then, for each of the prepared stamping dies 35, a test for forming the crimping portion 33z (see FIGS. 6A to 6D) is performed using the rocking crimping device 34 including the stamping dies 35. FIG. The test can be performed, for example, using a test assembly 37 as shown in FIG.

The test assembly 37 is set below the stamping die 35 with respect to the rocking clamp device 34 and comprises a support base 38 , a support cylinder member 39 and a test piece 40 . The support base 38 is prevented from moving radially about the reference axis C. As shown in FIG. The support cylinder member 39 is arranged coaxially with the reference axis C and supported and fixed to the upper surface of the support base 38 . The test piece 40 is configured in a cylindrical shape, and is internally fitted and supported by the support cylinder member 39 without rattling in the radial direction. , and the upper end protrudes upward from the inner diameter side of the support cylinder member 39 . The material of the test piece 40 and the shape and size of the upper end portion of the test piece 40 are the same as those of the cylindrical portion 32 of the hub unit bearing 1 before the caulking portion 33 is formed.

For each of a plurality of stamping dies 35 with different angles α (and β), the rocking clamping device 34 including the stamping dies 35 is used to process the upper end portion of the test piece 40 constituting the test assembly 37 into a crimping portion 33z. When the test is performed, test results as shown in FIGS. 6A to 6D, for example, are obtained. As shown in the test results, the crimped portion 33z has different shapes depending on the angles α (and β). This is because the angle α (and β) changes the area (circumferential width) of the contact portion of the processed surface portion 36 with respect to the test piece 40 (range S marked with a diagonal grid), and accordingly, the test piece This is because the volume (depth in the axial direction) of the plastic deformation region (range V with diagonal grid) of 40 changes. This is because the volume (depth in the axial direction) of the plastically deformed region V becomes smaller accordingly. In particular, the pressing surface 42z of the caulked portion 33z is an inclined surface (substantially circular arc A convex curved surface having a linear generatrix and a tapered surface having a substantially linear generatrix), but the specific shape thereof varies depending on the angle α (and β).

Therefore, based on the test results as described above, the angle α (and β) at which the restraining surface 42z of the crimped portion 33z follows the restrained surface 59 of the hub wheel 22 is determined. That is, from the test results as described above, the angle α (and β) is selected so that the holding surface 42z of the crimped portion 33z follows the holding surface 59 of the hub wheel 22 . Then, the caulked portion 33 is formed when the hub unit bearing 1 is manufactured by adopting the angle α selected in this manner.

In this way, a sufficient contact area of the caulked portion 33 with the radially inner portion of the pressed surface 59 of the hub wheel 22 can be ensured, and the caulked portion 33 with respect to the radially inner portion of the pressed surface 59 of the hub wheel 22 can be secured. It is possible to prevent the contact pressure of the contact surface from becoming excessively large. Therefore, the strength of the connection between the hub wheel 22 and the shaft member 23 and the durability of the crimped portion 33 can be increased.

In this example, the processing surface portion 36 of the stamping die 35 has a conical convex shape, and the abutment portion between the processing surface portion 36 and the cylindrical portion 32 within a virtual plane including the reference axis C and the rotation axis L is Since it exists on a straight line orthogonal to the reference axis C, when the cylindrical portion 32 is processed into the crimped portion 33, the processed surface portion 36 crushes the cylindrical portion 32 in the axial direction, and the crushed meat is removed. A portion tends to flow radially inward along the machined surface portion 36 . This tendency increases as the angle α increases (in other words, as the shape of the contact portion S approaches a rectangle, further in other words, as the difference in the amount of deformation between the outer diameter side and the inner diameter side decreases). Then, as shown in FIGS. 6A to 6D, when the angle α reaches a predetermined value or more (15° or more in the illustrated example), the crimped portion 33 (33z) after completion is An inward flange portion 41 (41z) projecting radially inward is formed on the inner diameter side. 1 and 4 show an example in which such an inward flange 41 is formed. The inward flange portion 41 can function as a reinforcing rib for maintaining the shape of the caulked portion 33 . However, the inward flange portion 41 may be removed by cutting or the like as necessary.

[Second example of embodiment]
A second example of the embodiment of the present invention will be described with reference to FIGS. 7 and 8. FIG.

In the hub unit bearing 1a to be manufactured in this example, the axially inner end surface 26a of the hub wheel 22a and the stepped surface 30a of the shaft member 23a are flat surfaces perpendicular to the axial direction, and are in plane contact with each other. are doing. That is, in this example, the configuration in which the end surface 26a and the stepped surface 30a are face-spline-engaged to prevent relative rotation between the hub wheel 22a and the shaft member 23a is not adopted.

In this example, of the shaft member 23a, the axially outer end portion (including the crimped portion 33a and the inward flange portion 41a) positioned axially outwardly of the fitting shaft portion 29 is provided at a plurality of locations in the circumferential direction, It has engagement slits (notches) 43 that are open on both radial sides and axially outward. In addition, the hub wheel 22a has engaging protrusions 44 at a plurality of circumferential locations aligned with the engaging slits 43 in the radially inner portion of the inclined surface portion 25a. The hub wheel 22a and the shaft member 23a are relatively rotated by engaging the engagement slit 43 of the crimped portion 33a and the engagement projection 44 of the inclined surface portion 25a without any play in the circumferential direction. prevent

In the manufacturing method of the hub unit bearing 1a of the present embodiment, before assembling the hub unit bearing 1a before forming the caulked portion 33a, the slanted surface portion 25a constituting the hub wheel 22a is provided at a plurality of locations in the circumferential direction on the inner side in the radial direction of the inclined surface portion 25a. Axial direction slits 45 (see FIG. 8(a)) extending in the axial direction are formed at a plurality of locations in the circumferential direction of the cylindrical portion 32a forming the shaft member 23a. Then, the hub unit bearing 1a is assembled before forming the caulked portion 33a. At this time, the engagement convex portion 44 of the hub wheel 22a and the axial slit 45 of the shaft member 23a are in phase with each other in the circumferential direction. Then, in this state, as shown in FIGS. 8(A) to 8(B), the cylindrical portion 32a is crushed in the axial direction by using the rocking clamp device 34. As shown in FIG. As a result, the crimped portion 33a and the inward flange portion 41a are formed, the axial slit 45 is used as the engaging slit 43, and the engaging convex portion 44 is engaged with the engaging slit 43 so that the hub wheel 22a and the shaft are connected. The member 23a is coupled and fixed.

In this example, the crimped portion 33a and the inward flange portion 41a are formed by axially crushing the cylindrical portion 32a having the axial slits 45 at a plurality of locations in the circumferential direction. Therefore, when forming the crimped portion 33a and the inward flange portion 41a, it is possible to prevent a large circumferential stress from being applied to the cylindrical portion 32a, thereby preventing damage such as cracks from occurring in the crimped portion 33a and the inward flange portion 41a. can be prevented more reliably.
Other configurations and effects are the same as those of the first embodiment.

[Third example of embodiment]
A third example of the embodiment of the invention will be described with reference to FIGS. 9 and 10. FIG.

In the hub unit bearing 1b to be manufactured in this example, the axially inner end surface 26a of the hub wheel 22b and the stepped surface 30a of the shaft member 23b are flat surfaces orthogonal to the axial direction, and are in plane contact with each other. are doing. That is, in this example, the configuration in which the end surface 26a and the stepped surface 30a are face-spline-engaged to prevent relative rotation between the hub wheel 22a and the shaft member 23a is not adopted.

In this example, the plurality of engagement recesses 46 provided on the hub wheel 22b and the plurality of engagement protrusions 47 provided on the shaft member 23b are engaged without backlash in the circumferential direction. Thus, the hub wheel 22b and the shaft member 23b are prevented from rotating relative to each other. The engaging recesses 46 are formed at a plurality of locations in the circumferential direction of the hub wheel 22b so as to open to the radially inner portion of the inclined surface portion 25b and the inner peripheral surface of the axially outer end portion of the center hole 24a. The engaging projections 47 are formed at a plurality of locations in the circumferential direction of the axial outer end of the fitting shaft portion 29 of the shaft member 23b so as to protrude radially outward. As will be described later, the engaging convex portion 47 is formed by subjecting the outer peripheral surface of the cylindrical portion 32b constituting the shaft member 23b before forming the caulked portion 33b to a tightening process. Therefore, of the axial inner surface of the caulked portion 33b formed by axially crushing the cylindrical portion 32b, the phase in the circumferential direction matches that of the engaging convex portion 47, and the engaging convex portion 47 A recessed groove 48 opening axially inwardly and radially outwardly is formed in the radial direction at a portion positioned radially outwardly of.

In the manufacturing method of the hub unit bearing 1a of this embodiment, before assembling the hub unit bearing 1b before forming the crimped portion 33b, the engaging recesses 46 are formed at a plurality of positions in the circumferential direction of the hub wheel 22b. Then, the hub unit bearing 1a is assembled before forming the caulked portion 33a. At this time, after the fitting shaft portion 29 of the shaft member 23b is inserted into the center hole 24a of the hub wheel 22b, or at the same time as the fitting shaft portion 29 is inserted into the center hole 24a, the shaft member Using a tool (not shown), a plurality of locations in the radially outer portion of the cylindrical portion 32b of the cylindrical portion 32b of the cylindrical portion 32b that are aligned with the engaging recesses 46 are pressed axially inward using a tool (not shown) to plastically deform them. process. As a result, as shown in FIG. 10, recessed grooves 48z are formed in each of the plurality of locations, and engaging protrusions 47 are formed by surplus material generated along with the formation of the recessed grooves 48z. The engaging convex portion 47 is engaged with the engaging concave portion 46 without looseness in the circumferential direction. After that, the cylindrical portion 32b is processed into the crimped portion 33b by using the rocking clamping device 34 (see FIGS. 3 and 4), and at the same time, the axially outer portion of the concave groove 48z is used as the concave groove 48, and the hub wheel 22b and the shaft are separated from each other. The member 23b is coupled and fixed.
Other configurations and effects are the same as those of the first embodiment.

[Fourth example of embodiment]
A fourth example of the embodiment of the present invention will be described with reference to FIGS. 11 and 12. FIG.

In the hub unit bearing 1c to be manufactured in this example, the hub 3a is formed by combining a hub ring 49 corresponding to the first hub element and an inner ring 50 corresponding to the second hub element.

In this example, regarding the hub unit bearing 1c, the axially inner side corresponds to the axially one side, and the axially outer side corresponds to the axially other side.

The hub wheel 49 has the axially outer inner ring raceway 11a of the double-row inner ring raceways 11a and 11b on the outer peripheral surface of the axially intermediate portion corresponding to the base portion, and the rotating flange 12 and the rotating flange 12 on the axially outer portion. It has a pilot section 13 . That is, the hub ring 49 corresponding to the first hub element protrudes radially outward from a portion located on the other side in the axial direction, i.e., the axially outer side of the axially outer inner ring raceway 11a corresponding to one inner ring raceway. It has a rotating flange 12 with a . Further, the hub wheel 49 has a fitting shaft portion 51 having a smaller outer diameter than the portion adjacent to the axially outer side in the axially inner portion positioned axially inwardly of the inner ring raceway 11a on the axially outer side. When carrying out the present invention, the axially outer inner ring raceway can also be formed on the outer peripheral surface of a separate inner ring externally fitted to the axially intermediate portion of the hub wheel. In this case, the hub ring and the separate inner ring correspond to the first hub element.

The inner ring 50 is configured in a tubular shape, and has the axially inner inner ring raceway 11b of the double-row inner ring raceways 11a and 11b on the outer peripheral surface. In addition, the inner ring 50 has a center hole 52 that axially penetrates the radial center portion of the inner ring 50 . In addition, the inner ring 50 has a pressed surface 53 on the radially inner portion of the axially inner side surface. The pressed surface 53 is an inclined surface that is inclined inward in the axial direction as it extends radially outward. The pressed surface 53 is a conical concave surface having a straight generatrix in the illustrated example, but may be a convex curved surface having an arcuate generatrix with a large radius of curvature.

The inner ring 50 is press-fitted onto the fitting shaft portion 51 with its axially outer end surface abutting against a stepped surface 54 present at the axially outer end portion of the outer peripheral surface of the fitting shaft portion 51 . . In this state, the cylindrical portion 55 extending axially inward from the axially inner end portion of the fitting shaft portion 51 is plastically deformed radially outward to form a crimped portion 56 (the shaft of the crimped portion 56). A held-down surface 53 of the inner ring 50 is held down by a held-down surface 60, which is the direction outer surface. In this state, a proper preload is applied to the rolling elements 4a and 4b.

In the case of this example as well, when manufacturing the hub unit bearing 1c, the swivel crimping device 34 is used to form the crimped portion 56. As shown in FIG. The operation of forming the crimped portion 56 is performed in a state where the hub unit bearing 1c is assembled before the crimped portion 56 is formed. Therefore, the hub unit bearing 1c is assembled in advance before forming the caulked portion 56. As shown in FIG.

The hub unit bearing 1c before the caulking portion 56 is formed can be assembled by an appropriate procedure, and for example, it can be assembled by the following procedure. First, in the hub wheel 49 before forming the caulked portion 56, the rolling elements 4a of the axially outer row are arranged around the axially outer inner ring raceway 11a in a state of being held by the axially outer retainer 21a. Further, the outer ring 2 is arranged around the axially intermediate portion of the hub wheel 49 . Next, the rolling elements 4b of the axially inner row are arranged around the axially inner inner ring raceway 11b of the inner ring 50 while being held by the axially inner retainer 21b. Then, by inserting the fitting shaft portion 51 of the hub wheel 49 before forming the caulked portion 56 into the center hole 52 of the inner ring 50 , the inner ring 50 is externally fitted to the fitting shaft portion 51 , and the shaft of the inner ring 50 is fitted. The direction outer end surface is brought into contact with the stepped surface 54 .

When forming the crimped portion 33 using the rocking crimping device 34, first, as shown in FIG. With the center axis of the hub 3a aligned with the reference axis C, the hub wheel 49 is supported by a holder (not shown).

Next, in this state, as in the case of the first embodiment, a part of the machining surface portion 36 of the stamping die 35 located at the lower end in the circumferential direction is pressed against the cylindrical portion 55 of the hub wheel 49. By rotating the stamping die 35 around the reference axis C, the cylindrical portion 55 is processed into a caulking portion 56 . In the case of this example as well, since the processing surface portion 36 of the stamping die 35 has a conical convex shape, when the cylindrical portion 55 is processed into the caulking portion 56, the cylindrical portion 32 is crushed in the axial direction by the processing surface portion 36. , a portion of the crushed meat flows radially inward along the processing surface portion 36 . As a result, an inward flange portion 57 projecting radially inward is formed on the inner diameter side of the crimped portion 56 after completion. Furthermore, in the case of this example as well, the axially inner end surface of the annular axially inner end portion of the hub wheel 49, which includes the axially inner end portions of the caulked portion 56 and the inward flange portion 57, It becomes a flat surface 62 perpendicular to the central axis.

In the manufacturing method of the hub unit bearing 1c of the present embodiment as described above, the machined surface portion 36 of the stamping die 35 constituting the rocking set device 34 is also formed in a simple conical convex shape. Therefore, the processing cost of the processing surface portion 36 can be suppressed, and the stamping die 35 can be manufactured at low cost. Therefore, the manufacturing cost of the hub unit bearing 1c can be reduced accordingly.

Also in the case of this example, as in the case of the first example of the embodiment, the inner ring 50 (pressed The contact surface area of the caulked portion 56 with respect to the surface 53) can be sufficiently ensured, and the contact surface pressure of the caulked portion 33 with respect to the inner ring 50 (the surface 53 to be held down) can be prevented from becoming excessively large. Therefore, the bonding strength between the hub wheel 49 and the inner ring 50 and the durability of the crimped portion 56 can be increased.
Other configurations and effects are the same as those of the first embodiment.

[Fifth example of embodiment]
A fifth example of the embodiment of the present invention will be described with reference to FIGS. 13 and 14. FIG.

In this example, the stamping die 35a that constitutes the rocking clamp device 34a has a stepped surface portion 58 facing radially outward about the rotation axis L at a portion adjacent to the radially inner side of the machining surface portion 36. As shown in FIG.

In this example, in the process of axially crushing the cylindrical portion 32 (see FIG. 12) by the processing surface portion 36 when forming the crimped portion 56 using the rocking crimping device 34a, part of the crushed meat flow radially inward along the machined surface portion 36 is suppressed by the stepped surface portion 58 . For this reason, the inward flange portion 57 projecting radially inward is not formed on the inner diameter side of the crimped portion 56 after completion, as indicated by the phantom line (two-dot chain line) in FIG. 14 .
Other configurations and effects are the same as those of the fourth example of the embodiment.

It should be noted that the present invention can be carried out by appropriately combining the configurations of the above-described embodiments within a range that does not cause contradiction.
Further, the present invention is not limited to hub unit bearings for driven wheels, and can also be applied to hub unit bearings for driving wheels.
Further, the present invention is not limited to hub unit bearings using tapered rollers as rolling elements, but can also be manufactured for hub unit bearings using balls as rolling elements.
Further, according to the present invention, when a cylindrical portion is processed into a crimped portion using a rocking crimping device, the abutting portion between the machined surface portion and the cylindrical portion is set as a reference in a virtual plane containing the reference axis and the rotation axis. It can also exist on a straight line inclined in a direction toward one side in the axial direction as it goes radially outward about the axis.

Reference Signs List 1, 1a, 1b, 1c, 1d Hub unit bearing 2 Outer ring 3, 3a Hub 4a, 4b Rolling element 5a, 5b Outer ring raceway 6 Stationary flange 7 Support hole 8 Knuckle 9 Through hole 10 Bolt 11a, 11b Inner ring raceway 12 Rotating flange 13 Pilot portion 14 Mounting hole 15 Braking rotor 16 Stud 17 Through hole 18 Wheel 19 Through hole 20 Nuts 21a, 21b Cage 22, 22a, 22b Hub wheel 23, 23a, 23b Shaft member 24, 24a Center hole 25, 25a, 25b Inclined surface portion 26, 26a End surface 27 Second face spline 28 Base portion 29 Fitting shaft portion 30, 30a Stepped surface 31 First face spline 32, 32a, 32b Cylindrical portion 33, 33a, 33b Crimp portion 34, 34a Pivoting device 35, 35a stamping die 36 machined surface portion 37 test assembly 38 support base 39 support cylindrical member 40 test piece 41, 41a inward flange 42 restraining surface 43 engagement slit 44 engagement projection 45 axial slit 46 engagement recess 47 engagement Convex portion 48, 48z Concave groove 49 Hub wheel 50 Inner ring 51 Fitting shaft portion 52 Center hole 53 Surface to be held 54 Stepped surface 55 Cylindrical portion 56 Crimped portion 57 Inward flange 58 Stepped surface 59 Surface to be held 60 Pressing surface 61 Flat Surface 62 Flat surface 100 Hub 101 First hub element 102 Fitting shaft portion 103 Second hub element 104 Cylindrical portion 105 Crimp portion 106 Oscillation crimping device 107 Stamping die 108 Machined surface portion

Claims (7)

an outer ring having a double-row outer ring raceway on its inner peripheral surface;
a hub having a double-row inner ring raceway on its outer peripheral surface;
A plurality of rolling elements are arranged for each row between the double-row outer ring raceway and the double-row inner ring raceway,
the hub has a first hub element and a second hub element,
The first hub element has, on its outer peripheral surface, a base portion having one inner ring raceway out of the double-row inner ring raceways, and a fitting portion extending from an end portion on one axial side of the base portion toward one axial side. and a joint shaft part,
The second hub element is fitted onto the fitting shaft portion, has the other inner ring raceway of the double-row inner ring raceways on its outer peripheral surface, and has a cover on one side surface in the axial direction. It has a suppressing surface,
the first hub element further includes an annular one axial end portion adjacent to the one axial side of the fitting shaft portion, the one axial end portion projecting radially outward; and a crimped portion that holds down the surface to be held down; and an inward flange portion that is located on the inner diameter side of the crimped portion and protrudes radially inward;
The first hub element and the second hub element are coupled by pressing the pressed surface of the second hub element with the crimped portion.
hub unit bearings. The axially one-side end surface of the axially one-side end portion of the first hub element, which includes the axially one-side end portions of the crimped portion and the inward flange portion, is defined by the first hub element. A flat surface perpendicular to the central axis,
A hub unit bearing according to claim 1. an outer ring having a double-row outer ring raceway on its inner peripheral surface;
a hub having a double-row inner ring raceway on its outer peripheral surface;
a rolling element arranged in each row between the double-row outer ring raceway and the double-row inner ring raceway,
The hub is
a first hub element having a first inner ring raceway;
a second hub element having a second inner ring raceway;
a coupling portion for coupling the first hub element and the second hub element together at least axially;
a detent for restricting relative rotation between the first hub element and the second hub element;
a shaft portion inserted through the first hub element or the second hub element;
has
The connecting part is
a caulking portion provided on the shaft portion and protruding radially outward;
a collar portion provided radially inward of the crimped portion in the shaft portion and projecting radially inward;
has
(a) the anti-rotation portion has a structure in which a first surface of the first hub element and a second surface of the second hub element, which face each other along the axial direction, engage with each other; (c) an engagement slit formed in the crimped portion and the first hub element or the or (d) the engaging projection protruding radially outward from the axial end of the shaft portion and the first hub element. having a configuration in which the hub element or the engaging recess provided in the second hub element engages,
hub unit bearings. The anti-rotation portion is arranged between the first inner ring raceway and the second inner ring raceway in the axial direction,
A hub unit bearing according to claim 3. The first inner ring raceway or the second inner ring raceway is arranged between the coupling portion and the anti-rotation portion in the axial direction,
A hub unit bearing according to claim 4. The connecting portion has a flat surface including an axial end surface of the crimped portion and an axial end surface of the flange portion,
A hub unit bearing according to any one of claims 3 to 5. A vehicle comprising a hub unit bearing,
The hub unit bearing is the hub unit bearing according to any one of claims 1 to 6,
vehicle.

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