JP2002002212A - Bearing unit for axels - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the bearing unit for axles to prevent the cracks on the edge corner of bolt holes on the opposite side of disc rotor of a radial flange without restriction of the plate thickness of the radial flange and the dimension of working through holes formed on a rotary member side. SOLUTION: On the bearing unit for axel provided with an inner ring member, outer ring member, rolling elements held in a holder which is disposed between the inner ring or outer ring member, and the radial flange equipped with the disc rotor of a disc brake on the side surface thereof, which is formed on the inner ring member or outer ring member as a rotary member, plural through holes 8 for bolts fixing the disc rotor are formed circumferentially on the radial flange 7 and working through holes through which the tool for installing the bearing unit for axle is inserted are formed in the area of the through holes 8, therefore, the peripheral edge corner part 15 of the through holes 11 on the apposite side of disc rotor becomes a work-hardening part 16 by compression deformation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for an axle to which a vehicle wheel is mounted.

[0002]

2. Description of the Related Art Conventionally, bearing devices for axles as shown in FIGS. 4 and 5 are known. That is, an outer ring member 41 attached to the vehicle body 43, an inner ring member 40 to which the disk rotor 42 of the disk brake device is attached, and a rolling element 45 held and interposed between the inner and outer ring members 40 and 41 by the retainer 44. It has. An annular radial flange 46 is provided at one end of the outer periphery of the inner ring member 40 on the side to be the rotating member, and a plurality of axially penetrating holes are provided in the radial flange 46 at equal circumferential intervals and at the same radial position. A bolt hole 47 is formed.
8 is inserted. Serrations 49 are formed in the lower part of the neck of the bolts 48 and bite into the inner peripheral surface of the bolt holes 47, whereby the bolts 48 are press-fitted and fixed in the bolt holes 47. The disc rotor 42 and a wheel member (not shown) are fitted and mounted on the bolt 48 projecting from the radial flange 46.

In the radial flange 46, working through holes 50 are formed in respective areas between the bolt holes 47 adjacent in the circumferential direction. This work through hole 5
Reference numeral 0 denotes a work tool such as a hexagon wrench (axle bearing) for attaching the outer ring member 41 to the vehicle body 43 by inserting a bolt 53 into a vehicle body mounting bolt through hole 52 formed in a radial flange 51 of the outer ring member 41. This is a hole through which an installation tool (tool for the installation location of the device) is inserted. The working through holes 50 are located at the same position in the radial direction.

[0004]

In the above-described bearing device for an axle, a bending moment is generated by a ground contact load from a tire when the vehicle turns, and a rotating torque is generated in the radial flange 46. At this time, high stress is generated in the work through hole, which is a large hole, and a crack may be generated in the peripheral corner portion 54 of the work through hole 50 on the side opposite to the disk rotor. As a measure to prevent this crack, a work through hole 50
Can be considered as small as possible, but in this case, there is a limit to making the size smaller than the size of the tool. Also,
It is conceivable to increase the thickness of the radial flange 46 of the inner race member 40. However, in this case, there is a limit in increasing the thickness of the inner ring member 40 due to interference between the bolt 48 and members around the disk rotor 42.

The present invention has been made to solve the above-mentioned problems, and is not limited by the thickness of the radial flange formed on the rotating member side and the dimensions of the working through hole. It is an object of the present invention to provide an axle bearing device that prevents a crack at a peripheral edge of a bolt hole on a side opposite to a disk rotor.

[0006]

As means for solving the above-mentioned problems, in claim 1, an inner ring member, an outer ring member, and a rolling element held by a retainer between the inner and outer ring members, An axle bearing device having a radial flange formed on the inner ring member or the outer ring member on the side to be a rotating member and having a disk rotor of a disk brake device mounted on a side surface thereof, wherein the radial flange has a disk rotor mounting bolt. A plurality of through holes are formed around the circumference, and a work through hole through which a tool for installation work for the axle bearing device installation location is inserted is formed in a region between the through holes, and is located on the side opposite to the disk rotor. The work through hole is characterized in that a peripheral edge portion of the work through hole is a work hardened portion by compression deformation.

According to a second aspect of the present invention, the work hardened portion formed by compressive deformation of the peripheral edge of the working through hole is formed on both left and right sides in the circumferential direction of a radial line passing through the center of the bolt hole and the center of the working through hole. It is characterized in that it is formed in a region.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of the present invention will be described with reference to FIGS. The vehicle includes an outer ring member 2 attached to a vehicle body 4, an inner ring member 1 to which a disk rotor 3 of a disk brake device is attached, and a rolling element 6 interposed between the inner and outer ring members 1 and 2 held by a retainer 5. ing. An annular radial flange 7 is provided at one end of the outer periphery of the inner ring member 1 on the side to be a rotating member,
A plurality of axially penetrating bolt holes 8 are formed in the radial flange 7 at equal circumferential positions and at the same radial position, and bolts 9 are inserted into the bolt holes 8. Serrations 10 are formed in the lower part of the neck of the bolt 9 and bite into the inner peripheral surface of the bolt hole 8, whereby the bolt 9 is press-fitted and fixed in the bolt hole 8. The disk rotor 3 and a wheel member (not shown) are fitted and mounted on the bolt 9 protruding from the radial flange 7.

In the radial flange 7, working through holes 11 are formed in respective regions between the bolt holes 8 adjacent in the circumferential direction. This work through hole 11
A work tool such as a hexagon wrench (axle bearing device) This is a hole through which an installation tool for the installation location is inserted. This work through hole 11
Are at the same radial position. The position, the number, and the size of the work through hole 11 can be arbitrarily increased or decreased as necessary. Further, the working through hole 11 is provided with a peripheral corner 15 on the side opposite to the disk rotor.
As shown in FIG. 3, the corners are erased by compression deformation with a punch 17 or the like, and the work hardened portion 16 is brought into a state. As a result, the work hardened portion 16 is formed by the compression deformation, so that the tensile strength is partially improved. In addition, by removing the peripheral corner portion 15, it is possible to reduce stress concentration. Therefore, by the improvement of the tensile strength and the relaxation of the stress concentration, the occurrence of a crack in the peripheral corner 15 of the working through hole 11 on the side opposite to the disk rotor is prevented.

The work hardening portion 16 formed in the working through hole 11 is provided between the center O of the bolt hole 8 and the working through hole 1.
One portion is formed in each of left and right circumferential regions of a radial line OX passing through one center O1. This is because torque is generated in the rotational direction about the center O of the bolt hole 8 and OX
This is because high stress occurs in the left and right regions in the circumferential direction of the line, which is effective in alleviating the stress. If necessary, a work hardened portion 16 may be formed on the entire periphery 15 of the peripheral edge if there is a portion where stress can be easily concentrated.

[0011]

According to the present invention, there is provided an axle bearing device in which a radial flange for mounting a disk rotor is formed on an inner ring member or an outer ring member serving as a rotating member. The work through-hole is formed in the area of, and the peripheral edge of the work through-hole on the side opposite to the disk rotor is formed as a work hardened part by compression deformation, so that partial tensile strength improvement and stress concentration Is prevented, and a crack is prevented at the corner of the bolt hole peripheral edge of the radial flange on the side opposite to the disk rotor.

[Brief description of the drawings]

FIG. 1 is a sectional view of an axle bearing device according to an embodiment of the present invention.

FIG. 2 is a plan view of a radial flange as viewed from an A side in FIG. 1;

FIG. 3 is a schematic view of forming a work hardened portion of a working through hole of a radial flange in FIG. 1;

FIG. 4 is a sectional view of a conventional axle bearing device.

FIG. 5 is a plan view of the radial flange as viewed from the side B in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner ring member 2 Outer ring member 3 Disk rotor 4 Body 5 Cage 6 Rolling element 7 Radial flange 8 Bolt hole 9 Bolt 10 Serration 11 Working through hole 12 Radial flange 13 Body mounting bolt through hole 14 Bolt 15 Peripheral edge 16 Work hardening part 17 Punch

Claims (2)

[Claims] 1. A disk brake formed on an inner ring member, an outer ring member, a rolling element held by a retainer between the inner and outer ring members, and the inner ring member or the outer ring member on the side to be a rotating member. An axle bearing device having a radial flange on the side of which the disk rotor of the device is mounted,
A plurality of circumferentially formed through holes for disc rotor mounting bolts are formed in the radial flange, and a work through hole through which a tool for installation work for an axle bearing device installation location is inserted in a region between the through holes. A bearing device for an axle, characterized in that a peripheral edge of the working through hole on the side opposite to the disk rotor is formed as a work hardened portion by compression deformation. 2. A work hardened portion formed by compressive deformation of a corner of a peripheral edge of the working through hole is formed at a position on both left and right circumferential directions of a radial line passing through the center of the bolt hole and the center of the working through hole. A bearing device for an axle.