JP2016169850A - Hub unit bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hub unit bearing which enables cycle-up by decreasing a turning processing area without causing the lowering of the rigidity of an attachment flange, can reduce a tool cost, and can improve processing accuracy.SOLUTION: A hub unit bearing includes: an outer ring 15 at which a knuckle 43 and an attachment flange 17 which is fastened via an attachment bolt 21 are protrusively arranged; a hub ring 1 at which a hub housing 9 which is connected to a wheel side is protrusively arranged at an external peripheral face; and a rolling body 27 which is assembled between raceway surfaces 16, 16 of the outer ring 15 and raceway surfaces 11, 13 of the hub wheel 1. A bolt seat face 47 is formed at a face part side of the attachment flange 17 on which a bolt head 23 of the attachment bolt 21 abuts, a face part 17a of the attachment flange 17 at a bolt seat face forming side is forged in a state that a bolt seat face forming area A2 is raised in an axial direction rather than a face part region A1 including a corner R part 25 of a root portion, and the bolt seat face 47 is formed by turning only the forged bolt seat face forming region A2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hub unit bearing provided with a mounting flange for bolting an outer ring to a vehicle side.

  FIG. 3 shows a so-called third generation type hub unit bearing called HUBIII, which is an embodiment for a driving wheel for rotating an inner ring. A hub wheel 1 and an outer ring 15 arranged so as to be rotatable relative to each other. Have.

The hub ring 1 is formed in a cylindrical shape, and a stepped fitting surface 3 is provided around one end side of the outer peripheral surface, that is, the inboard side, and another inner ring 5 is fitted to the fitting surface 3. And integrated. Further, on the outboard side, a hub flange 9 fastened via a wheel 50, a brake rotor 60 and a hub bolt 7 is spaced apart from the central axis of the hub wheel 1 at a predetermined interval in the circumferential direction of the outer peripheral surface of the hub wheel 1. A plurality of protrusions are provided in a direction perpendicular to the rotation axis.
Then, double row inner ring raceway surfaces 11 and 13 provided in the circumferential direction of the outer peripheral surface of the hub wheel 1 and the outer peripheral surface of the separate inner ring 5, and double row outer ring provided in the circumferential direction of the inner peripheral surface of the outer ring 15. A plurality of balls 27 which are rolling elements are incorporated between the raceway surfaces 16 and 16.
In the figure, reference numeral 29 indicates a cage for holding a plurality of balls 27 in a freely rotatable manner, and reference numerals 31 and 33 indicate sealing devices for sealing the bearing internal space.

In addition, the side which is the outer side in the vehicle width direction (left side toward FIG. 3) is referred to as the outboard side, and the side which is the inner side (right side in FIG. 3) is referred to as the inboard side.
Further, a stem portion 39 of a constant velocity joint 37 is fitted to the inner periphery of the through hole 35 of the hub wheel 1, and its tip is fixed by a nut 41 outside the through hole 35 of the hub wheel 1. The hub wheel 1 (including the separate inner ring 5) is configured to be rotatable.

  The outer ring 15 is formed in a cylindrical shape having an inner diameter larger than that of the hub wheel 1 on the inboard side of the outer peripheral surface of the hub wheel 1, and a suspension device is provided on the outer peripheral surface of the outer ring 15, for example. A mounting flange (also referred to as a knuckle mounting flange) 17 connected to the constituting knuckle (vehicle side) 43 is spaced in the circumferential direction of the outer peripheral surface of the outer ring 15 in a direction perpendicular to the central axis of the outer ring 15. A plurality of protrusions (forging) are provided.

  The mounting flange 17 has a through-hole 19 for fastening a bolt to the knuckle 43 side. For example, a mounting bolt (also referred to as a knuckle bolt) 21 for fastening the mounting flange 17 and the knuckle 43 is provided. After being serrated from the outboard side of the mounting flange 17 into the through hole 19 and inserted into the connecting hole 45 of the knuckle 43, the nut is tightened from the inboard side with a nut (not shown). Further, it is also known that a mounting bolt 21 inserted through the through hole 19 from the outboard side of the mounting flange 17 is screwed into a female screw provided in a connecting hole of the knuckle 43 and fastened (FIG. 3). reference).

  In the case where the mounting bolt 21 is inserted into the through hole 19 from the outboard side of the mounting flange 17 in this way, the bolt head portion 23 of the mounting bolt 21 abuts on the surface portion 17 a of the mounting flange 17 on the outboard side. The bolt seat surface 47 needs to be provided on the surface portion 17a of the mounting flange 17 on the outboard side.

  Conventionally, from the viewpoint of the strength of the mounting flange, since it is desired to leave a forged line (metal flow) formed by forging at the root portions 17c on both the outboard side and the inboard side of the mounting flange 17, The technique which processes a bolt seat surface to the attachment flange 17 is proposed (refer patent document 1).

  However, the counterbore is to be cut using a predetermined cutting tool (predetermined milling machine), and since it is necessary to process one by one, it takes time and has a problem in processing efficiency. In some cases, the processing cost increased.

  Therefore, in recent years, a technical means for processing a plurality of bearing surfaces at once by a turning process has also been proposed (see Patent Document 2).

However, the distance between the head of the mounting bolt and the outer surface of the outer ring is short, and as shown in FIG. 1B, turning is required up to the corner R portion 25 of the root portion 17c that connects the outer surface of the outer ring 15 and the mounting flange 17. Then, since the forging line is scraped even at the root portions 17c on both the outboard side and the inboard side of the mounting flange 17, the strength of the root portion 17c of the mounting flange 17 is likely to decrease. Had problems. In FIG. 1 (b), the area indicated by the two-dot chain line indicates the surface area on the outboard side of the mounting flange after forging, and the area indicated by the solid line indicates the area on the outboard side of the mounting flange formed by turning after forging. The surface area is shown.
In the above case, the turning surface is not a single surface, and it is necessary to use a diamond-shaped tip and a diamond-shaped tip holder (bite) that are inferior in durability and rigidity. There was also a problem that it was likely to cause a rise in the machining accuracy and a decrease in processing accuracy.

JP 2009-154601 A JP 2005-349982 A

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to reduce the turning area without reducing the strength of the mounting flange to be forged and cycle. Another object of the present invention is to provide a hub unit bearing that can be improved and that can reduce tool costs and improve machining accuracy.

In order to achieve such an object, the present invention comprises an outer ring having a mounting flange that is fastened to a vehicle side via a mounting bolt, projecting from the outer periphery,
A hub wheel that is arranged so as to be relatively rotatable with the outer ring, and a hub flange that is connected to the wheel side protrudes from the outer periphery;
Comprising at least a rolling element incorporated between the raceway surface of the outer ring and the raceway surface of the hub ring,
A hub unit bearing having a bolt seat surface on the surface side of the mounting flange with which the bolt head of the mounting bolt contacts,
The bolt bearing surface forming side surface portion of the mounting flange is forged into a state where the bolt seat surface forming region swells in the axial direction from the surface portion region of the root portion,
Only the forged bolt seat surface formation region is turned to form the bolt seat surface, thereby providing a hub unit bearing.

  According to the present invention, there is provided a hub unit bearing capable of reducing the machining area and improving the machining accuracy while reducing the turning area and reducing the cycle without increasing the strength of the mounting flange to be forged. Could be provided.

(A) is a schematic sectional drawing which shows one Embodiment of the outer ring | wheel employ | adopted as this invention hub unit bearing, (b) is sectional drawing of the outer ring | wheel used as the comparative example. It is a schematic side view which shows one Embodiment of the outer ring | wheel suitable for this invention hub unit bearing. It is a schematic sectional drawing which shows one Embodiment of the hub unit bearing which incorporates the outer ring | wheel which has the attachment flange bolted to a knuckle.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, this embodiment is only one embodiment of the present invention, and is not construed as being limited thereto, and can be appropriately modified within the scope of the present invention.

The hub unit bearing of the present embodiment is configured to have substantially the same configuration as the hub unit bearing shown in FIG. 3, and is different in the configuration of the mounting flange 17 of the outer ring 15. Except for this, the configuration of FIG. 3 is used as it is. Therefore, in the present embodiment, the description of FIG. 3 is used, and a detailed description of the overall configuration of the hub unit bearing is omitted.
It should be noted that the configuration as the hub unit bearing is not construed as being limited to the illustrated form, and any other hub unit bearing configuration may be used as long as it has the configuration of the mounting flange 17 of the outer ring 15 of the present invention. It can be employed within the range, and the design can be changed as appropriate.

FIG. 1A shows an embodiment of the outer ring 15 incorporated in the hub unit bearing of the present invention.
In the present invention, as shown in FIG. 2, the rod-shaped mounting flange 17 protrudes from the outer diameter (outer peripheral surface) of the outer ring 15, that is, a shape in which stress is easily applied to both sides of the root portion 17 c of the mounting flange 17. It can be used suitably. The number of protrusions of the mounting flange 17 is not limited and is arbitrary.

  First, the outer ring 15 has a bolt seat surface forming region A2 in the axial direction (in FIG. 1) in the surface portion 17a on the outboard side bolt seat surface forming side of each mounting flange 17 rather than the surface portion region A1 of the root portion 17c. Forging is performed so as to be raised in the direction indicated by the arrow (a region indicated by a two-dot chain line in FIG. 1A).

  Specifically, the portion 25a closest to the inboard side in the corner R portion 25 of the root portion 17c of the mounting flange 17 is the bolt seat surface 47 (FIG. 1A) after the turning of the surface portion 17a on the outboard side is completed. The area A2 (area indicated by a two-dot chain line in FIG. 1A) that is closer to the inboard side than the surface (indicated by the solid line) and becomes the bolt seat surface 47 is more axial than the area A1 of the root portion 17c. Forging with a shape that rises to the outboard side.

  Next, only the bolt seat surface formation region A2 forged as described above is turned to form the bolt seat surface 47 (region indicated by a solid line in FIG. 1A).

  According to the present embodiment, as described above, only the bolt seat surface formation region A2 is turned to form the bolt seat surface 47, and the root portion 17c of the mounting flange 17 is not turned, and thus is formed at the root portion 17c. Since the forged flow line (melt flow) is not cut by turning (while leaving the forged surface), the bolt seating surface 47 can be turned, so that the thickness of the root portion 17c of the mounting flange 17 can be increased. Even if it falls a little, compared with the case where the forging line of the root part 17c of the mounting flange 17 is cut by turning as shown in FIG.

Further, in the case of the shape shown in FIG. 1A, since it is sufficient to perform the turning process only in the region A2 which becomes the bolt seating surface 47, the turning area is reduced as compared with the case of FIG. It is possible to up.
In addition, since the turning surface is only one plane (only in the axial direction), there is no need to use a diamond-shaped tip and a diamond-shaped holder (bite) that are inferior in durability or rigidity. Can be reduced and machining accuracy can be improved.

  The present invention can be used even for a hub unit bearing for a driven wheel, and can also be used for a hub unit bearing including a roller bearing. Further, even a so-called second generation type hub unit bearing called HUBII in which a plurality of single-row inner rings are arranged on the outer peripheral surface of the hub ring can be used.

1 Hub Wheel 9 Hub Flange 11, 13 Raceway 15 Outer Ring 16 Raceway 17 Mounting Flange 21 Mounting Bolt 23 Bolt Head 27 Rolling Element 43 Knuckle (Vehicle Side)
47 Bolt seating surface A1 Root portion surface region A2 Bolt seating surface formation region

Claims (1)

An outer ring having a mounting flange projecting on the outer periphery, which is fastened to the vehicle side via a mounting bolt;
A hub wheel that is arranged so as to be relatively rotatable with the outer ring, and a hub flange that is connected to the wheel side protrudes from the outer periphery;
Comprising at least a rolling element incorporated between the raceway surface of the outer ring and the raceway surface of the hub ring,
A hub unit bearing having a bolt seat surface on the surface side of the mounting flange with which the bolt head of the mounting bolt contacts,
The bolt bearing surface forming side surface portion of the mounting flange is forged into a state where the bolt seat surface forming region swells in the axial direction from the surface portion region of the root portion,
A hub unit bearing characterized in that the bolt seat surface is formed by turning only the forged bolt seat surface formation region.

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