JP2010116053A - Rolling bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device improved in the shape of a bolt installation hole of a hub flange to prevent deformation of the hub flange. <P>SOLUTION: A serration 9d with a tooth 9e having a predetermined tooth width W and an outer diameter which satisfies a predetermined tooth height H in a radial direction of a screw shaft portion 9a is formed on an outer circumferential surface 9c of a screw shaft portion 9a proximal to a head portion 9b of a hub bolt 9. On the other hand, a round bolt installation hole 3b1 with a predetermined penetration length L in which the screw shaft portion 9a of the hub bolt 9 is inserted and the serration 9d is pressed is formed in a hub flange 3b. The bolt installation hole 3b1 is a tapered hole whose diameter is gradually increased toward the downstream side in a press-in direction F during the press-in operation of the hub bolt 9. The tooth width W of the tooth 9e of the serration 9d is shorter than the penetration length L of the blot installation hole 3b1. A press-in distal end 9d1 in the press-in direction F of the serration 9d is positioned in the blot installation hole 3b1 after pressing the serration 9d in the blot installation hole 3b1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rolling bearing device in which a hub bolt for attaching a wheel is fixed to a hub flange.

  In a rolling bearing device used in a vehicle such as an automobile, a hub bolt having a serration formed larger than the inner diameter of the bolt hole is press-fitted and fixed to a bolt hole formed in the hub flange, and a predetermined slip torque is applied. What is satisfied is known (see Patent Document 1).

JP 2000-94902 A

  However, since the bolt hole of the hub flange in this rolling bearing device is a straight hole having the same inner diameter, when the hub bolt is press-fitted, the press-fitting allowance at the time of press-fitting does not change until the press-fitting is completed, so that the peripheral part of the bolt hole As a result, a large pressing force deforms the peripheral portion of the bolt hole on the protruding side of the hub bolt and the entire hub flange is deformed. As a result, the runout accuracy of the hub flange is deteriorated, the runout of the brake rotor attached to the hub flange is generated, and the contact between the brake pad and the brake rotor is uneven. There is a problem that sound, vehicle braking failure, etc. occur at the same time.

  In view of the above problems, an object of the present invention is to provide a rolling bearing device in which the shape of a bolt mounting hole of a hub flange is improved and deformation of the hub flange is prevented.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above-mentioned problems, a rolling bearing device according to the present invention is a rolling bearing device that is fixed to a hub flange and includes a hub bolt for mounting a wheel, and the hub bolt is screwed in a certain region from the tip. And a screw head portion formed at the base end of the screw shaft portion, and an outer peripheral surface of a region where the male screw of the screw shaft portion near the bolt head portion is not formed Is formed with a tooth width of a predetermined length in the axial direction of the screw shaft portion, and serrations having chevron teeth having tooth tips formed in parallel with the axis of the screw shaft portion, On the other hand, the screw shaft portion of the hub bolt passes through the hub flange, and the serrated tooth tip of the screw shaft portion is press-fitted with a predetermined press-fitting allowance, and is a round hole-shaped bolt mounting hole with a predetermined penetration length. The bolt mounting hole is A taper hole shape is formed so that the hole diameter gradually increases toward the downstream side in the press-fitting direction at the time of press-fitting the hub bolt, and the tooth width of the teeth of the serration is made larger than the penetration length of the bolt mounting hole. After the serration is formed short and the serration is press-fitted into the bolt mounting hole, the press-fitting tip portion of the serration in the press-fitting direction is located in the bolt mounting hole.

  With the above configuration, in the press-fitting process of the hub bolt, the press-fitting allowance set large at the initial press-fitting process becomes smaller as the press-fitting process proceeds, so the pressing force applied to the bolt mounting hole by the press-fitting allowance also becomes smaller, and After the press-fitting, since the press-fitting tip portion of the serration is located in the bolt mounting hole, plastic deformation hardly occurs downstream in the press-fitting direction, and plastic deformation on the flange surface side of the hub flange protruding side of the hub flange becomes small. As a result, the bulging deformation of the flange surface of the hub flange on the hub bolt projecting side can be eliminated or reduced, and deterioration of runout accuracy due to deformation of the hub flange can be prevented. Even if the press-fit tightening allowance at the initial press-fit time is set so as to satisfy a predetermined slip torque, plastic deformation in such a state can hardly occur on the flange face side of the hub flange on the hub bolt projecting side. It is possible to provide a rolling bearing device that can exhibit a sufficient fixing force (slip torque) at the end of press-fitting in a state where the deformation is suppressed.

  In order to solve the above problems, in the rolling bearing device of the present invention, the press-fitting between the serration and the bolt mounting hole within the tooth width of the serration after the serration is press-fitted into the bolt mounting hole. The taper hole diameter of the bolt mounting hole is formed so as to eliminate the tightening margin on the downstream side in the press-fitting direction, and the tooth width of the serration is located in the bolt mounting hole. Combined with this, the pressing force applied to the bolt mounting hole by the press-fitting allowance can be further separated from the flange surface on the hub bolt protruding side of the hub flange, and the bulging deformation on the flange surface side of the hub bolt protruding side can be further reduced, so the hub This is useful for preventing deterioration of runout accuracy due to deformation of the flange. In addition, since the scraps generated by the serration of the bolt mounting holes are reduced or eliminated as the press-fitting process proceeds, the surface of the hub flange or the like is prevented from being damaged by the scraps.

  In order to solve the above-mentioned problem, in the rolling bearing device of the present invention, when the serration is press-fitted into the bolt mounting hole, the inner peripheral surface of the bolt mounting hole is cut at the tooth press-fitting tip side of the serration. However, since the teeth of the serrations bite into the inner peripheral surface, in the press-fitting process of the hub bolt, the press-fitting allowance set large in the initial press-fitting process becomes smaller as the press-fitting process proceeds, and the press-fitting process is performed. Since the teeth can be bitten while cutting the inner peripheral surface of the bolt mounting hole in the press-fitting process in which the tightening margin is set large, the large press-fit tightening margin is substantially reduced and depends on the press-fit tightening margin. Since the pressing force applied to the bolt mounting hole is further reduced, the bulge deformation on the flange surface side of the hub flange protruding side of the hub flange is reduced. There is further reduced, thus preventing a drop in the accuracy deflection due to deformation of the hub flange.

  Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings. FIG. 1 is a cross-sectional view of a mounted state of a rolling bearing device according to the present invention. In FIG. 1, a rolling bearing device 1 includes an outer ring 2a as a fixed ring made of bearing steel, an inner ring 2b as a rotating ring, and a plurality of rows arranged between the inner ring 2b and the outer ring 2a. A rolling bearing 2 composed of a moving body 2c is provided.

  The inner ring 2b is formed integrally with the hub 3. A hub bolt 9 for fixing the hub 3 so as to be connected to a wheel (not shown) on the vehicle outer side is fixed. The hub bolt 9 is axially press-fitted into a bolt mounting hole 3b1 of a disk-shaped hub flange 3b protruding outward.

  The hub flange 3b is integrally formed by projecting outward in the radial direction X on the outer periphery of one end portion (vehicle outer side) of the shaft portion 2b1 constituting the inner ring 2b. A small-diameter portion 2b2 having an outer diameter that is one step smaller is formed at the other end portion (vehicle inner side) of the shaft portion 2b1. The small-diameter portion 2b2 is press-fitted and fixed with an inner ring divided body 2b4 that includes a rolling surface 2b3 that is formed as a separate body and on which one rolling element 2c whose outer peripheral surface is arranged in a plurality of rows rolls. A rolling surface 2b5 on which the other rolling elements 2c arranged in a plurality of rows roll is formed on the outer peripheral surface between one end and the other end of the shaft 2b1. Thus, the inner ring | wheel division body 2b4 is press-fit and integrated with the other end part of the axial part 2b1, and the inner ring | wheel 2b provided with the hub flange 3b in the one end part is comprised.

  The shaft portion 2b1 of the inner ring 2b is formed with a connection insertion hole 2b6 to which a drive shaft 4 as a drive shaft for transmitting power is splined. The drive shaft 4 is passed through the connecting insertion hole 2b6 so that power can be transmitted. Then, the shaft end surface 4a of the drive shaft 4 is brought into contact with the inner ring end surface 2b7 on the vehicle inner side of the inner ring divided body 2b4 facing the shaft end surface 4a so that the end of the drive shaft 4 on the extending side is It is fixed by screwing a nut 5 as a screw fastening means.

  The rolling bearing device 1 is connected to an attachment port 6a of a vehicle fixing member 6 such as a knuckle or axle housing on the vehicle inner side of a suspension device in a vehicle. In this connection, the outer ring 2a of the rolling bearing 2 is inserted and fitted into the mounting opening 6a, and the flange 2a1 protruding outward from the outer ring 2a is fixed to the vehicle via a fastening member 7 such as a bolt and a nut. The member 6 is fixed to the peripheral surface (vehicle outer side) of the attachment port 6a.

  In order to seal the space between the inner ring 2b and the outer ring 2a of the rolling bearing 2 from the outside, a sealing device 8 is provided on the outer side of the vehicle and the inner side of the vehicle. Regulates leakage of grease filled in

  Moreover, although this example is the rolling bearing device 1 for a drive wheel, in the case where the connecting insertion hole 2b6 is not formed in the shaft portion 2b1, the other end side of the shaft portion 2b1 is extended to the outside, and the other end It can also be used for a driven wheel by being fixed so as not to come off in the axial direction Z by a caulking portion formed by plastic deformation outward in the radial direction X so that the side is caulked.

  Next, as shown in FIG. 2, the bolt mounting hole 3b1 of the hub flange 3b is formed in a round hole shape in the thickness direction of the hub flange 3b as a press-fitting structure of the hub bolt 9 and the bolt mounting hole 3b1 of the hub flange 3b. , A predetermined penetration length L is included. The bolt mounting hole 3b1 is formed in a tapered hole shape so that the diameter of the hole gradually increases toward the downstream side in the press-fitting direction F from the inlet 3b2 to the outlet 3b3 when the hub bolt 9 is press-fitted.

  The hub bolt 9 has a screw shaft portion 9a that protrudes outward through the bolt mounting hole 3b1. A male screw is formed in a certain region from the tip of the screw shaft portion 9a. A bolt head portion 9b is formed at the proximal end of the screw shaft portion 9a. The bolt head portion 9b is seated on the flange surface (inlet 3b2 side) around the bolt mounting hole 3b1 of the hub flange 3b. A serration 9d that is press-fitted into the bolt mounting hole 3b1 is formed on the outer peripheral surface 9c in the region where the male screw of the screw shaft portion 9a near the bolt head portion 9b is not formed. The serration 9d has chevron teeth 9e provided in the circumferential direction. The teeth 9e of the serration 9d are formed with a tooth width W having a predetermined length in the axial direction of the screw shaft portion 9a and have a tooth tip 9e1 formed in parallel with the axis of the screw shaft portion 9a. That is, it is formed with an outer diameter (tooth tip circumferential diameter Φ) that satisfies a certain height of tooth depth H in the radial direction of the screw shaft portion 9a.

  Further, the tooth width W of the tooth 9e of the serration 9d of the hub bolt 9 is formed shorter than the penetration length L of the bolt mounting hole 3b1, and after the serration 9d of the hub bolt 9 is press-fitted into the bolt mounting hole 3b1, the bolt of the hub bolt 9 With the head 9b seated on the hub flange 3b, the press-fitting tip 9d1 of the serration 9d in the press-fitting direction F is positioned in the bolt mounting hole 3b1.

  Further, the inner diameter of the taper bolt-shaped bolt mounting hole 3b1 of the hub flange 3b and the tooth tip circle diameter Φ of the serration 9d of the hub bolt 9 have a predetermined press-fitting allowance X at the time of press-fitting. The press-fit tightening margin X is indicated by a broken line in the change diagram of the press-fit tightening margin X in FIG. 2 in the press-fitting direction F within the tooth width W of the serration 9d of the hub bolt 9 because the bolt mounting hole 3b1 has a tapered hole shape. In this way, in the state where the end portion W2 of the tooth width W is reached toward the downstream side in the press-fitting direction F, the press-fit tightening allowance X is gradually reduced to the remaining level instead of zero.

  In addition, as shown by the solid line in the variation diagram of FIG. 2, the press-fit tightening allowance X varies in the press-fit tightening allowance toward the downstream side in the press-fit direction F within the tooth width W of the serration 9 d of the hub bolt 9. The tapered hole mounting hole 3b1 can be formed so as to be small until X disappears. The place where the press-fit tightening allowance X disappears and becomes zero can be set at an arbitrary position within the tooth width W. For example, an intermediate W1 within the tooth width W or a downstream side in the press-fit direction F can be set. It can be set to the end W2 of the tooth width W.

  Further, as shown in FIG. 3, a predetermined chamfered portion 9d2 is formed at the press-fitting tip portion 9d1 of the serration 9d of the hub bolt 9 in this example, and the chamfered surface 9d3 of the chamfered portion 9d2 has a knife edge shape. The configuration has a sharp peripheral edge 9d4. Further, the teeth 9e of the serration 9d are preferably subjected to a hardening process such as induction hardening in order to cut the inner peripheral surface 3b4 of the bolt mounting hole 3b1 with the peripheral edge 9d4 and to bite the teeth 9e.

  As shown in FIG. 4, the hub bolt 9 is press-fitted into the bolt mounting hole 3b1 of the hub flange 3b as the press-fitted state of the hub bolt 9 in the rolling bearing device 1. The maximum press-fitting allowance on the inlet 3b2 side of the bolt mounting hole 3b1 In the press-fitting process from the initial press-fitting to the end of press-fitting, the press-fit tightening allowance X that is set large in the initial press-fitting process becomes smaller on the press-fitting tip 9d1 side of the serration 9d as the press-fitting process proceeds ( The pressing force applied to the bolt mounting hole 3b1 due to the press-fit tightening allowance X is also reduced. Moreover, after the press-fitting, the press-fitting tip 9d1 of the serration 9d is located in the bolt mounting hole 3b1, so that the plastic deformation of the metal material in the press-fitting direction F downstream is difficult to occur, and the outlet on the hub bolt protruding side of the hub flange 3b. The plastic deformation on the flange surface side on the 3b3 side is reduced, and as a result, the bulging deformation of the flange surface is reduced. Further, even if the press-fit tightening allowance X at the initial press-fit is set so as to satisfy a predetermined slip torque, plastic deformation in such a state can hardly occur on the flange face side of the hub bolt protruding side of the hub flange 3b. Thus, a sufficient fixing force (slip torque) at the end of press-fitting can be exhibited in a state where the bulging deformation of the material is suppressed.

  Further, depending on the size of the press-fitting allowance X, the shavings generated when the bolt mounting hole 3b1 is shaved on the press-fitting tip 9d1 side of the serration 9d can be reduced or eliminated as the press-fitting process proceeds. Further, in the press-fitting process of the hub bolt 9, the press-fitting allowance X set large in the initial press-fitting process becomes smaller as the press-fitting process proceeds, and the inner peripheral surface of the bolt mounting hole 3b1 in the press-fitting process in which the press-fitting allowance X is set larger. 3b4 can be made to bite the teeth 9e of the serration 9d while being cut at the peripheral edge 9d4 sharpened at the chamfered portion 9d2 of the chamfered portion 9d2 of the press-fitting tip 9d1 of the serration 9d, and the press-fit tightening margin X set large is substantially Becomes smaller.

Sectional drawing of the attachment state of the rolling bearing apparatus which concerns on this invention. The figure which shows the relationship between a hub bolt and a hub flange. Partial enlarged view of serration. The figure which shows the bolt attachment hole and the tooth | gear of a serration in a press-fit process.

Explanation of symbols

3b Hub flange 3b1 Bolt mounting hole 9 Hub bolt 9a Screw shaft 9b Bolt head 9c Outer peripheral surface 9d Serration 9d1 Press fit tip 9e Teeth 9e1 Teeth tip L penetration length F Press fit direction X Press fit allowance W Teeth width H Teeth

Claims (3)

A rolling bearing device fixed to a hub flange and provided with a hub bolt for mounting a wheel,
The hub bolt has a screw shaft portion in which a screw is formed in a certain region from the tip, and a bolt head portion formed at a base end of the screw shaft portion. A tooth tip formed on the outer peripheral surface of the region where the male screw is not formed with a tooth width of a predetermined length in the axial direction of the screw shaft portion and parallel to the axis of the screw shaft portion A serration is formed with chevron teeth having
On the other hand, the screw shaft portion of the hub bolt passes through the hub flange, and the serrated tooth tip of the screw shaft portion is press-fitted with a predetermined press-fitting allowance, and is a round hole-shaped bolt mounting hole with a predetermined penetration length. The bolt mounting hole is formed in a tapered hole shape so that its hole diameter gradually increases toward the downstream side in the press-fitting direction when the hub bolt is press-fitted,
The tooth width of the teeth of the serration is formed to be shorter than the penetration length of the bolt mounting hole, and after the serration is press-fitted into the bolt mounting hole, the press-fitting tip in the press-fitting direction of the serration is within the bolt mounting hole. A rolling bearing device characterized by being located in   In the tooth width of the serration after the serration is press-fitted into the bolt mounting hole, the bolting tightening margin between the serration and the bolt mounting hole is eliminated on the downstream side in the press-fitting direction. The rolling bearing device according to claim 1, wherein a taper hole diameter of the mounting hole is formed.   When the serration is press-fitted into the bolt mounting hole, the tooth of the serration is bitten into the inner peripheral surface while cutting the inner peripheral surface of the bolt mounting hole on the tooth press-fitting tip side of the serration. The rolling bearing device according to claim 2.

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