JP2004345517A - Axle unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axle unit that enables easy removal of a wheel from a wheel hub in changing a tire and can improve assembling work of the wheel to the wheel hub. <P>SOLUTION: The wheel hub 6 comprises a cylindrical part 6a coaxially arranged on the outer periphery of an axle shaft 2, and a flange 6b extending from one end of the vehicle outside of the cylindrical part in the direction orthogonal to the axial direction. A counter boring hole 22 is disposed on the vehicle outside of the inner diameter part of the flange, a hub cap 20 made of resin is engaged with the counter boring hole to cover the vehicle outside end of the axle. The outer peripheral surface 20c along the axial direction of the hub cap guides the inner peripheral side of the inner diameter part 14b disposed at the center position of the wheel 14, thereby providing a positioning part for matching a bolt 10 fixed to the flange with the position of a bolt through hole 14a formed in the wheel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an axle unit of an automobile, and relates to a structure for mounting a wheel on a flange of a wheel hub.
[0002]
[Prior art]
As a conventional axle unit, the structure of Patent Document 1 is known. In this axle unit, a brake drum and a wheel are mounted on a wheel hub arranged on the outer periphery of the axle by fastening bolts and nuts. That is, the wheel hub has a cylindrical portion rotatably supported on the outer periphery of the axle via a hub bearing, a disk-shaped flange provided at one end of the cylindrical portion outside the vehicle, and a vehicle from the inner diameter side of the flange. A cylindrical spigot part is provided that protrudes outward.
[0003]
The flange is provided with bolt through holes at predetermined intervals in the circumferential direction, and in these holes, the positions of the plurality of bolt insertion holes formed in the brake drum and the plurality of bolt insertion holes formed in the wheel match. The brake drum and the wheel are mounted on the wheel hub by tightening with bolts and nuts.
Here, the bolt insertion hole of the wheel matches the bolt insertion hole of the flange by guiding the inner peripheral surface of the inner diameter portion provided at the center position of the wheel to the outer periphery of the spigot portion of the hub. . That is, the spigot portion functions as a positioning portion for the bolt insertion hole of the wheel.
[0004]
[Patent Document 1]
JP 2000-142011 A
[Problems to be solved by the invention]
By the way, the wheel hub and the wheel are metal members, and when the inner diameter portion of the wheel and the spigot portion of the wheel hub are in contact with each other, they are stuck together due to rust, and when the tire is replaced, the wheel is replaced. May not easily come off the wheel hub.
[0006]
Also, inside the spigot part, a nut that gives preload to the hub bearing is screwed to the axle, but the workability is poor because the nut must be tightened in the narrow space inside the spigot part. There were challenges.
Therefore, the present invention has been made in view of the above circumstances, and an axle unit capable of easily removing a wheel from a wheel hub when replacing a tire and improving the operation of mounting the wheel to the wheel hub. It is intended to provide.
[0007]
[Means for Solving the Problems]
Therefore, the axle unit of the present invention is an axle unit in which a wheel is mounted on a flange of a wheel hub rotatably supported with respect to the axle, wherein the wheel hub has a cylindrical portion coaxially arranged on the outer periphery of the axle. A flange extending from one end of the cylindrical portion on the outside of the vehicle in a direction perpendicular to the axial direction, a counterbore hole is provided on the inside of the flange on the outside of the vehicle, and a cup shape made of non-metal. The opening edge of the hub cap is fitted in the counterbore to cover the outer end of the axle on the vehicle, and the outer peripheral surface of the hub cap along the axial direction is provided at the center position of the wheel. A positioning portion for guiding the position of the bolt and the bolt insertion hole by guiding the inner peripheral side of the inner diameter portion.
[0008]
In addition, a reduced diameter portion is provided at an opening edge portion of the hub cap, and a step surface perpendicular to an outer peripheral surface along the axial direction of the hub cap is provided at a base end portion of the reduced diameter portion, and the reduced diameter portion is provided. May be abutted on the side surface near the inner diameter portion of the flange while fitting into the counterbored hole.
Further, a groove may be provided on a circumferential surface of the counterbored hole facing in the radial direction, and a convex portion which enters the groove may be provided on an outer periphery of an opening edge of the hub cap.
[0009]
Further, the wheel hub is rotatably supported on the axle via a hub bearing, and the hub bearing is fixed by being preloaded on the inside of the vehicle by a caulking portion formed on the outside of the axle on the vehicle. You may make it.
[0010]
【The invention's effect】
According to the axle unit of the present invention, the inner diameter portion of the wheel is in contact with the alignment portion of the hub cap, but since it becomes a contact portion between the metal member and the nonmetal member, no rust is generated, There is no problem such as difficulty in detaching the wheel from the wheel hub when changing tires.
[0011]
In addition, when the wheel is mounted, by contacting the positioning portion of the hub cap, the bolt fixed to the flange and the bolt insertion hole can be easily positioned, so that the wheel mounting operation is easily performed. be able to.
Also, since the wheel hub of the present invention does not have a portion that protrudes in the axial direction from the inner diameter portion of the flange, for example, when screwing a nut for disposing a hub bearing at the end of the axle on the vehicle outside, In addition, the nut can be tightened in a wide space, and the workability of assembling the axle unit can be improved.
[0012]
Furthermore, since the wheel hub according to the present invention has a short axial length, machining time such as cutting is shortened, and machining cost can be reduced.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a wheel support structure according to the present invention will be described with reference to the drawings.
FIG. 1 shows an axle unit according to a first embodiment applied to a driven wheel-side axle device. A cross section shown above an axis P of a driven axle (hereinafter, referred to as an axle) 2 is attached to a flange 6b described later. It is a cross section cut so as to include the axis of the fixed hub bolt 10, and a cross section below the axis P is a cross section including a portion of the flange 6b where the hub bolt 10 is not provided.
[0014]
A wheel hub 6 is rotatably supported on the outer periphery of the axle 2 via a hub bearing 4.
The hub bearing 4 is rotatably mounted on a double row of bearing inner rings 4a and 4b, a cylindrical portion 6a of a wheel hub 6 described below that functions as a bearing outer ring, and raceways of the inner rings 4a and 4b and the cylindrical portion 6a. And the rolling elements 4c held. By screwing an axle nut 8 to the male screw end of the axle 2 located on the outside of the vehicle, the hub bearing 4 is arranged with a preload applied to the inside of the vehicle, and the wheel hub 6 is mounted on the outer periphery of the axle 2. It is rotatably supported.
[0015]
The wheel hub 6 is a metal member, and has a cylindrical portion 6a coaxially arranged with respect to the axle 2 and a disk-shaped portion extending from one end of the cylindrical portion 6a outside the vehicle in a direction orthogonal to the axial direction. And a flange 6b. A counterbore hole 22 into which a hub cap 20 to be described later is fitted is formed outside the vehicle at the inner diameter portion of the flange 6b.
[0016]
A plurality of hub bolts 10 are fixed to the side surface of the flange 6b at a predetermined interval in the circumferential direction by press-fitting, and these hub bolts 10 are attached to bolt insertion holes 12a formed in the brake drum 12 of the drum brake device and tires. The brake drum 12 and the load wheel 14 are fixed to the flange 6b by being inserted into the bolt insertion hole 14a of the metal load wheel 14 and fastened together with the wheel nut 16. Note that a member indicated by reference numeral 18 facing the inner peripheral surface of the brake drum 12 is a brake shoe.
[0017]
The hub cap 20 described above is a cup-shaped member made of resin, and includes a cylindrical cap cylinder 20a and a lid 20b closing one end of the cap cylinder 20a. The opening edge of 20a fits into the counterbore 22 formed in the inner diameter of the flange 6b, thereby covering the tip of the axle 2. Here, when the hub cap 20 is fitted in the counterbore hole 22 of the wheel hub 6, a part 20c of the outer periphery of the cap tube portion 20a is a surface along the entire axis P of the wheel hub 6. . The inner peripheral surface of the inner diameter portion 14b formed at the center position of the load wheel 14 is guided by a part 20c of the outer periphery of the cap tube portion 20a, and the hub bolt 10 fixed to the flange 6b of the wheel hub 6; The four bolt insertion holes 14a are aligned with each other (the axes are aligned with each other). Therefore, when the hub cap 20 is attached to the wheel hub 6, a portion 20c of the outer periphery of the cap tube portion 20a becomes an alignment portion between the hub bolt 10 and the bolt insertion hole 14a (hereinafter, a portion of the outer periphery of the cap tube portion 20a). Is referred to as a positioning unit 20c).
[0018]
According to the axle unit of the present embodiment, the inner diameter portion 14b of the road wheel 14 is in contact with the positioning portion 20c of the hub cap 20, but the contact portion between the metal member and the non-metal resin member is As a result, no rust is generated, and there is no problem such as difficulty in detaching the road wheel 14 from the wheel hub 6 at the time of tire replacement.
[0019]
In addition, when the load wheel 14 is mounted, the hub bolt 10 and the bolt insertion hole 14a can be easily positioned by being brought into contact with the positioning portion 20c of the hub cap 20, thereby facilitating the mounting operation of the road wheel 14. Can be done.
Further, the wheel hub 6 of the present embodiment does not have a portion that protrudes from the inner diameter portion of the flange 6b to the outside of the vehicle unlike the conventional device (the spigot portion of Patent Document 1). When the nut 8 is screwed, the work of tightening the axle nut 8 can be performed in a wide space, and the workability of assembling the axle unit can be improved.
[0020]
Furthermore, since the wheel hub 6 of the present embodiment, which does not have a portion protruding from the inner diameter portion of the flange 6b, has a short axial length, the processing time such as cutting is reduced, and the processing cost is reduced. be able to.
Next, FIG. 2 shows an axle unit according to a second embodiment of the present invention. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
[0021]
In the present embodiment, a reduced diameter portion 20d having a smaller outer diameter than other cap cylinder portions 20a is provided at the opening edge of the cap cylinder portion 20a of the hub cap 20. The reduced diameter portion 20d is fitted in a counterbore hole 22 formed in the inner diameter portion of the flange 6b.
In addition, since the reduced diameter portion 20d is formed, a step surface 20e is provided at the base end of the reduced diameter portion 20d of the hub cap 20, and this positioning surface 20e is provided on the outer periphery of the hub cap 20. It is formed as a plane perpendicular to 20c.
[0022]
For this reason, even if the depth dimension of the spot facing hole 22 is not formed with high precision, the positioning function of the hub bolt 10 and the bolt insertion hole 14a can be achieved by abutting the step surface 20e on the side surface on the inner diameter side of the flange 6b. The provided hub cap 20 is attached to the wheel hub 6.
Therefore, the wheel hub 6 can be machined without requiring highly precise dimensions, so that the machining cost can be further reduced.
[0023]
Next, FIG. 3 shows a main part of an axle unit according to a third embodiment of the present invention.
In the present embodiment, an annular groove portion 22b is formed on a circumferential surface 22a of the counterbore hole 22 facing in the radial direction. Further, an annular convex portion 20f is provided on the outer periphery of the reduced diameter portion 20d of the hub cap 20. When the reduced diameter portion 20d of the hub cap 20 is fitted into the counterbored hole 22 of the flange 6b, the annular projection 20f is fitted into the annular groove 22b.
[0024]
When the hub cap 20 is attached to the wheel hub 6 as described above, the annular projection 20f of the hub cap 20 engages with the annular groove 22b. 20 can be prevented from being loosened.
The configuration is not limited to the configuration of the present embodiment. For example, a structure in which a groove is provided intermittently in the circumferential direction of the peripheral surface 22a and a convex portion is provided intermittently on the outer periphery of the reduced diameter portion 20d, or The same effect can be obtained even in a structure in which the annular groove 22b is provided on the surface 22a and the convex portion is provided intermittently on the outer periphery of the reduced diameter portion 20d.
[0025]
FIG. 4 shows a main part of an axle unit according to a fourth embodiment of the present invention.
In the present embodiment, the caulking portion 26 is formed at the end of the axle 2 on the outside of the vehicle, so that the hub bearing 4 is arranged with a preload applied to the inside of the vehicle.
The wheel hub 6 of the present embodiment does not have a portion that protrudes from the inner diameter portion of the flange 6b to the outside of the vehicle unlike the conventional device (the spigot portion of Patent Document 1). Exists. The caulked portion 26 can be easily formed using a caulking tool while utilizing this wide space. Therefore, also in this embodiment, the workability of assembling the axle unit can be improved.
[0026]
In addition, since the axial length of the axle 2 is reduced, the axial length of the hub cap 20 can be reduced to the minimum necessary for guiding the inner diameter portion 14b of the load wheel 14, and the hub cap 20 The size can also be reduced.
In all of the above embodiments, the hub cap 20 may be entirely made of resin, or may be coated with a metal hub cap with resin.
[0027]
In addition, the hub cap 20 can prevent the load wheel 14 from being easily detached from the wheel hub 6 if at least a portion that is in contact with the inner peripheral surface of the inner diameter portion 14b of the load wheel 14 is made of nonmetal. Further, if the contact portion with the metal parts other than the road wheel 14 is also non-metallic, it is possible to prevent the hub cap 20 from being rusted and fixed to the metal parts other than the road wheel 14.
[0028]
The hub cap 20 does not necessarily have to have hardness equivalent to metal as long as rigidity necessary for guiding the inner peripheral surface of the inner diameter portion 14b of the road wheel 14 is secured.
[Brief description of the drawings]
FIG. 1 is a view showing a first embodiment of an axle unit according to the present invention.
FIG. 2 is a view showing a second embodiment of the axle unit according to the present invention.
FIG. 3 is a view showing a third embodiment of an axle unit according to the present invention.
FIG. 4 is a view showing a fourth embodiment of an axle unit according to the present invention.
[Explanation of symbols]
2 Axle (axle)
Reference Signs List 4 hub bearing 4a bearing inner ring 4c rolling element 6 wheel hub 6a cylindrical portion 6b flange 8 axle nut 10 hub bolt (bolt)
12 Brake drum 12a Bolt insertion hole for brake drum 14 Road wheel (wheel)
14a Load wheel bolt insertion hole 14b Road wheel inner diameter portion 16 Wheel nut 20 Hub cap 20a Cap cylinder portion 20b Lid portion 20c Alignment portion 20d Reduced diameter portion 20e Step surface 20f Annular convex portion 22 Counterbore hole 22a Counterbore hole Circumferential surface 22b facing in the radial direction of annular groove 26 caulked portion

Claims (4)

An axle unit comprising a wheel mounted on a flange of a wheel hub rotatably supported on an axle,
The wheel hub has a cylindrical portion coaxially arranged on the outer periphery of the axle, and a shape including a flange extending in a direction perpendicular to the axial direction from one end of the cylindrical portion outside the vehicle,
A counterbored hole is provided on the outside of the vehicle at the inner diameter of the flange, and an opening edge of a cup-shaped hub cap made of non-metal is fitted into the countersunk hole to cover a vehicle outside end of the axle. An outer peripheral surface along the axial direction of the hub cap serves as an alignment portion that guides an inner diameter side provided at a center position of the wheel to match the positions of the bolt and the bolt insertion hole. Axle unit. A reduced diameter portion is provided at an opening edge of the hub cap, and a step surface perpendicular to an outer circumferential surface of the hub cap along the axial direction is provided at a base end of the reduced diameter portion, and the reduced diameter portion is provided. The axle unit according to claim 1, wherein the stepped surface abuts on a side surface near an inner diameter portion of the flange while being fitted into a counterbore hole. 3. The groove according to claim 1, wherein a groove is provided on a circumferential surface of the counterbored hole that faces in a radial direction, and a protrusion that enters the groove is provided on an outer periphery of an opening edge of the hub cap. 4. Axle unit. The wheel hub is rotatably supported on the axle via a hub bearing, and the hub bearing is fixed by being preloaded on the vehicle inside by a caulking portion formed on the vehicle outside of the axle. The axle unit according to any one of claims 1 to 3, wherein:

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