JP2008049933A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a vehicle for suppressing the generation of brake judder, by securing the surface run-out accuracy of a wheel installing flange by reducing weight while reducing a material loss. <P>SOLUTION: This bearing device for the wheel has a hub wheel 17 having the wheel installing flange 19 at an outer side end by implanting a hub bolt 5 for installing a wheel in equal arrangement in the peripheral direction. The outer side side surface 20 of the wheel installing flange 19 is formed in a petal-like rib shape being a thick part in a part for pressing in the hub bolt 5. Since a recess 21 having a predetermined step height to the side surface 20 is formed at the outer edge of the wheel installing flange 19 by forging processing, even if a burr is formed by a hit mark when the outer diameter edge of the wheel installing flange 19 interferes with a mating part in carrying or assembling to a vehicle, the burr can be permitted by this recess part 21, and an adverse influence is not exerted on the surface accuracy of the side part 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing device for supporting a wheel of an automobile or the like. In particular, the material loss is reduced to reduce the weight, and the surface mounting accuracy of the wheel mounting flange is ensured to suppress the occurrence of brake judder. The present invention relates to a wheel bearing device.

  In general, the braking force has increased due to the widespread use of disc brakes. On the other hand, when braking is performed with the disc brake rotor held between brake pads, vibration occurs especially when the vehicle is running at low speed, causing low frequency unpleasant noise. There are things to do. Such a phenomenon is called a brake judder, and in recent years, this analysis and improvement have attracted attention as a new technical issue as the performance and silence of vehicles become higher.

  The exact mechanism of the brake judder has not yet been elucidated in detail, but one factor is the accuracy of the pad sliding contact surface of the brake rotor. As for this runout accuracy, not only the runout accuracy of the brake rotor alone, but also the surface runout accuracy of the wheel mounting flange to which the brake rotor is mounted, the axial runout of the rolling bearing, the accuracy of the rolling surface, the assembly accuracy of the rolling bearing, etc. are accumulated. Ultimately, it appears as the surface runout accuracy on the side of the brake rotor.

  Also, in recent years, it goes without saying that the cost has been reduced, and by pursuing weight reduction in order to improve fuel efficiency, the wheel bearing device has been slimmed down by eliminating excess material, and the wheels for steering stability. The rigidity of the bearing device for use has been increased. Various measures for the above-mentioned surface runout accuracy of the side surface of the brake rotor are taken while satisfying the requirements that contradict each other.

  FIG. 9 shows a conventional wheel bearing device, in which (a) is a side view and (b) is a longitudinal sectional view thereof. In the following description, the side closer to the outer side of the vehicle in the state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing).

  This wheel bearing device integrally has a wheel mounting flange 55 for attaching a wheel (not shown) to an end portion on the outer side, an inner side rolling surface 52a on the outer side on the outer periphery, and the inner side rolling surface. The hub wheel 52 is formed with a small-diameter step portion 54 extending in the axial direction from 52a, and the inner ring 53 is press-fitted into the small-diameter step portion 54 of the hub wheel 52 and has an inner side inner rolling surface 53a formed on the outer periphery. An inner member 51 and an outer member 60 integrally having a vehicle body mounting flange 61 for mounting to a vehicle body (not shown) on the outer periphery, and having double-row rolling surfaces 60a and 60b formed on the inner periphery And a plurality of balls 63, 63, which are circumferentially arranged by the cages 62, 62 and accommodated so as to roll between the rolling surfaces. Further, hub bolts 56 for fixing the wheels are planted at the circumferentially equidistant positions of the wheel mounting flanges 55.

  Seals 64 and 65 are attached to both ends of the outer member 60 to seal the annular space between the outer member 60 and the inner member 51, and leakage of the lubricating grease enclosed in the bearing to the outside and from the outside Rain water and dust are prevented from entering the bearing.

  An annular groove 57 is formed on the outer side surface 55a of the wheel mounting flange 55 by primary cutting such as a lathe. Bolt holes 58 are formed at equal intervals in the center of the groove width of the annular groove 57. Further, after a knurl 56a formed on the outer diameter of the hub bolt 56 is press-fitted and fixed in the bolt hole 58, the side surface 55a is secondarily cut by a lathe or the like.

Thus, in the conventional wheel bearing device, since the annular groove 57 is formed in the side surface 55a, the influence of the deformation of the side surface 55a due to the press-fitting of the hub bolt 56 can be suppressed to the minimum. At the same time, since the side surface 55a is secondarily cut after the hub bolt 56 is press-fitted, the surface runout of the side surface 55a increased by the press-fitting of the hub bolt 56 can be suppressed as much as possible.
JP 2003-154801 A

  However, in the conventional wheel bearing device described above, a dent is formed when the device interferes during transportation or assembly into a vehicle, and in particular, as shown in FIG. When the outer diameter portion of the non-wheel mounting flange 55 interferes with the mating component 66, as shown in (b), not only the surface accuracy of the side surface 55a is deteriorated but also the side surface 55a is braked. The rotor (not shown) tilts without being in close contact. Then, there is a risk that brake judder will occur due to the inclination of the brake rotor.

  The present invention was made in view of such circumstances, and reduced the material loss to reduce the weight, while ensuring the surface runout accuracy of the wheel mounting flange and suppressing the occurrence of brake judder. The purpose is to provide.

  In order to achieve such an object, the invention according to claim 1 of the present invention is such that an outer member having a double row outer raceway formed on the inner periphery and hub bolts for attaching wheels are equidistant in the circumferential direction. A hub wheel having a wheel mounting flange planted at one end and a small diameter step portion extending in the axial direction from the wheel mounting flange on the outer periphery, and at least fitted to the small diameter step portion of the hub wheel The inner member is composed of one inner ring or an outer joint member of a constant velocity universal joint, and an inner member in which a double row inner rolling surface facing the outer row rolling surface of the double row is formed on the outer periphery, and the inner member and the In a wheel bearing device including a double row rolling element that is rotatably accommodated between both rolling surfaces of an outer member, an outer side surface of the wheel mounting flange is provided at an outer edge portion of the wheel mounting flange. The relief part with a predetermined step is It has been made.

  Thus, since the relief part which has a predetermined level | step difference with respect to the outer side surface of the said wheel mounting flange is formed in the outer edge part of the wheel mounting flange by the forging process, material loss is reduced and weight reduction is achieved. At the same time, it is possible to provide a wheel bearing device that ensures the surface runout accuracy of the wheel mounting flange and suppresses the occurrence of brake judder.

  Preferably, as in the invention described in claim 2, if the step of the relief portion is set to at least 0.5 mm, the outer diameter edge of the wheel mounting flange is the counterpart part during transportation or assembly into the vehicle. Even if interference occurs and burrs due to the dents are generated, it can be tolerated by this escape portion, and the side surface accuracy is not adversely affected. Therefore, the brake rotor can be mounted in close contact with the side surface without inclination.

  Moreover, if the outer side surface of the wheel mounting flange is formed in a petal-like rib shape in which the portion into which the hub bolt is press-fitted is a thick portion as in the invention described in claim 3, braking is performed. The contact area with the brake rotor, which sometimes becomes hot, is reduced and heat conduction is suppressed, and a large space is formed between the brake rotor and the wheel mounting flange by the escape portion, so that a heat dissipation effect can be expected. Temperature rise can be suppressed. Therefore, it is possible to prevent the grease from deteriorating and extend the life of the bearing.

  According to a fourth aspect of the present invention, the outer side surface of the wheel mounting flange is a cutting surface that is cut after the hub bolt is press-fitted, and the surface runout of the side surface is restricted to 20 μm or less. As a result, the surface runout accuracy of the side surface of the brake rotor can be suppressed to a desired specified value, and the occurrence of brake judder can be suppressed.

  Further, as in the invention according to claim 5, if the petal-like rib in which the portion into which the hub bolt is press-fitted is a thick portion is formed on the side surface on the inner side of the wheel mounting flange by forging, While achieving weight reduction, even if a large moment load is applied to the wheel mounting flange, strength and rigidity can be ensured and desired durability can be exhibited.

  The wheel bearing device according to the present invention includes an outer member having a double row outer raceway formed on the inner periphery, and a wheel mounting flange in which hub bolts for mounting the wheel are planted in a circumferentially equidistant manner. A hub wheel having a small-diameter step portion extending in the axial direction from the wheel mounting flange on the outer periphery, and at least one inner ring or constant velocity universal joint fitted to the small-diameter step portion of the hub wheel. An inner member formed of a joint member and having a double row inner rolling surface facing the outer row rolling surface of the double row on the outer periphery, and between both rolling surfaces of the inner member and the outer member In a wheel bearing device including a double row rolling element accommodated in a freely rolling manner, a clearance portion having a predetermined step on an outer edge portion of the wheel mounting flange with respect to an outer side surface of the wheel mounting flange. Is formed by forging, so materia With weight reduction by reducing the loss, it is possible to provide a wheel bearing apparatus which suppresses the occurrence of brake judder to ensure surface runout accuracy of the wheel mounting flange.

  An outer member that has a body mounting flange that can be attached to the vehicle body on the outer periphery, a double-row outer rolling surface is formed on the inner periphery, and hub bolts for mounting the wheels are planted in a uniform circumferential direction. The wheel mounting flange is formed at one end, and one inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a small diameter step portion extending in the axial direction from the inner rolling surface is formed. An inner member comprising a hub ring and an inner ring press-fitted into a small-diameter step portion of the hub ring and having the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and the inner member And an outer side surface of the wheel mounting flange is thicker at a portion where the hub bolt is press-fitted. It is formed in a petal-like rib shape that becomes a part and The outer edge of the flange, the relief portion having a predetermined step with respect to the outer side of the side face of the wheel mounting flange is formed by forging.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 2 is a view taken along arrow A in FIG. 1, and FIG. 3A is a wheel bearing according to the present invention. Explanatory drawing which shows the state which the apparatus interfered with the other party parts, (b) is a principal part enlarged view which shows the interference part of (a), FIG. 4 is B arrow directional view of FIG.

  The wheel bearing device includes an inner member 1, an outer member 10, and double-row rolling elements (balls) 6 and 6. The inner member 1 includes a hub ring 2 and a separate inner ring 3. The hub wheel 2 integrally has a wheel mounting flange 4 for attaching a wheel (not shown) to an end portion on the outer side, one (outer side) inner rolling surface 2a on the outer periphery, and this inner rolling. A small diameter step 2b extending in the axial direction from the surface 2a is formed. Hub bolts 5 for fixing the wheels are planted at equal circumferential positions of the wheel mounting flanges 4. On the other hand, the inner ring 3 is formed with the other (inner side) inner rolling surface 3a on the outer periphery, and is press-fitted into the small-diameter step portion 2b of the hub ring 2 through a predetermined squeeze. The end of the small-diameter step 2b is fixed in the axial direction by a caulking portion 2c formed by plastic deformation (rocking caulking) radially outward.

  The outer member 10 integrally has a vehicle body mounting flange 10b for mounting to a vehicle body (not shown) on the outer periphery, and a double row facing the inner rolling surfaces 2a, 3a of the inner member 1 on the inner periphery. The outer rolling surfaces 10a and 10a are integrally formed. And between these both rolling surfaces 2a, 10a and 3a, 10a, the double row rolling elements 6 and 6 equally distributed by the holder | retainers 7 and 7 are each accommodated so that rolling is possible. Seals 8 and 9 are attached to the opening of the annular space formed between the outer member 10 and the inner member 1, and leakage of lubricating grease sealed inside the bearing, rainwater, dust, etc. from the outside. It prevents entry into the bearing.

  The hub wheel 2 is formed of medium and high carbon steel containing 0.40 to 0.80% by weight of carbon such as S53C, and the small diameter step portion 2b from the flange base portion 4a to which the outer seal 8 comes into sliding contact, including the inner rolling surface 2a. On the other hand, the surface is hardened in a range of 58 to 64 HRC by induction hardening. The caulking portion 2c is left as it is after forging. Such induction hardening improves the strength of the hub wheel 2, prevents fretting wear on the fitting surface of the inner ring 3, improves durability, facilitates plastic deformation, and causes cracks during swing caulking. It can be prevented from occurring.

  On the other hand, the inner ring 3 and the rolling element 6 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core by quenching. The outer member 10 is formed of medium and high carbon steel containing 0.40 to 0.80% by weight of carbon, such as S53C, similarly to the hub wheel 2, and the double row outer raceway surfaces 10a and 10a are formed by induction hardening. The surface hardness is set in the range of 58 to 64 HRC. In addition, although the double row angular contact ball bearing which used the ball for the rolling element 6 was illustrated here, not only this but the double row tapered roller bearing which used the tapered roller for the rolling element 6 may be sufficient.

  In the present embodiment, the outer side surface 11 of the wheel mounting flange 4 to which a brake rotor (not shown) is mounted is formed into a predetermined flat surface by primary cutting such as a lathe and the hub mounting bolt 4 is attached to the wheel mounting flange 4. After the press fitting, the side surface 11 is secondarily cut by a lathe or the like. And by this secondary cutting, the runout of the side surface 11 is regulated to 20 μm or less. Thereby, the surface runout accuracy of the side surface of the brake rotor mounted on the wheel mounting flange 4 can also be increased, and the occurrence of brake judder can be suppressed. The secondary cutting is not limited to a lathe, and may be cutting with a milling machine or a grinding machine.

  Before press-fitting the hub bolt 5, the side surface 11 may be subjected to primary cutting consisting of rough turning and intermediate finishing turning, followed by secondary cutting (finish turning) after press-fitting the hub bolt 5, or before the hub bolt 5 is press-fitted. Alternatively, the forged skin may be left without turning, and cutting (finish turning) may be performed after the hub bolt 5 is press-fitted. In other words, the number of cutting operations is not limited, and any cutting may be performed as long as the hub bolt 5 is pressed.

  Here, an annular relief portion 12 having a predetermined step δ with respect to the outer side surface 11 is formed on the outer diameter edge of the wheel mounting flange 4 by forging. The step δ of the escape portion 12 is set to at least 0.5 mm. As shown in FIG. 2, the outer diameter edge of the wheel mounting flange 4 is finished in a substantially uniform thickness continuously in the circumferential direction. By forming the escape portion 12, as shown in FIGS. 3 (a) and 3 (b), the outer diameter edge of the wheel mounting flange 4 interferes with the mating part 13 during transportation or assembly to the vehicle. Even if the burrs 14 due to the dents are generated, they can be allowed by the escape portion 12, and the surface accuracy of the side surface 11 is not adversely affected. Therefore, the brake rotor can be mounted in close contact with the side surface 11 without inclination, and the occurrence of brake judder can be prevented.

  Further, in the present embodiment, the wheel mounting flange 4 is formed thin in order to reduce the weight, and as shown in FIG. 4, a hub bolt is provided on the side surface 15 on the inner side of the wheel mounting flange 4 in the forging process. A petal-like rib 16 that is a thick-walled portion is formed at a portion where 5 is press-fitted. Thereby, strength and rigidity can be secured even when a large moment load is applied to the wheel mounting flange 4 while reducing the weight, and desired durability can be exhibited.

  FIG. 5 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, FIG. 6 is a view taken along arrow C in FIG. 5, and FIG. 7 is a brake rotor in the wheel bearing device in FIG. FIG. 8 is a modified example of the hub wheel shown in FIG. 6. This embodiment basically differs from the above-described embodiment (FIG. 1) only in the configuration of the hub wheel, and other parts having the same parts, the same parts, or the same functions are denoted by the same reference numerals and detailed. Description is omitted.

  The wheel bearing device shown in FIG. 5 is referred to as a third generation on the driven wheel side, and includes an inner member 18 including a hub wheel 17 and an inner ring 3 press-fitted and fixed to the hub wheel 17, and an outer member 10. A row of rolling elements 6, 6 is provided. The hub wheel 17 integrally has a wheel mounting flange 19 for mounting a wheel (not shown) at an end portion on the outer side, one (outer side) inner rolling surface 2a on the outer periphery, and this inner rolling. A small diameter step 2b extending in the axial direction from the surface 2a is formed.

  In the present embodiment, as shown in FIG. 6, the outer side surface 20 of the wheel mounting flange 19 is formed in a petal-like rib shape. That is, the portion into which the hub bolt 5 is press-fitted is formed to be a thick portion, and a relief portion 21 having a predetermined step δ with respect to the side surface 20 is formed by forging. The escape portion 21 is formed in an R shape formed between the hub bolts 5 avoiding the periphery of the annular portion 21a formed on the outer peripheral portion of the wheel mounting flange 19 (the outer peripheral side of the circumscribed circle diameter of the side surface 20) and the hub bolt 5. The notch portion 21b.

  The notch portion 21b is formed so that the deepest portion 21c is close to the string L connecting the center of the adjacent hub bolt 5 on the inner diameter side from the annular portion 21a. As a result, while reducing the material loss and reducing the weight, it is possible to prevent the bending rigidity of the wheel mounting flange 19 from being lowered, and, like the above-described embodiment, the wheel during transportation or assembly to the vehicle. Even if the outer diameter edge of the mounting flange 19 interferes with the mating part and burrs due to the dents are generated, the escape portion 21 can allow it.

  Furthermore, since the outer side surface 20 is formed in a petal-like rib shape, as shown in FIG. 7, the contact area with the brake rotor 22 that becomes high during braking is reduced, and heat conduction is suppressed, Since the escape portion 21 forms a large space between the brake rotor 22 and the wheel mounting flange 19, a heat dissipation effect can be expected, and the temperature rise of the bearing portion can be suppressed. Therefore, it is possible to prevent the grease from deteriorating and extend the life of the bearing.

  Note that when the hub wheel 17 is processed by a closed forging method, burrs of about several millimeters usually remain at the joint portion of the mold. However, since the burrs are allowed by the escape portion 21, the burrs are removed as in the prior art. Can be eliminated and the number of processing steps can be reduced.

  Further, as in the above-described embodiment, the outer side surface 20 of the wheel mounting flange 19 is formed into a predetermined flat surface by primary cutting such as a lathe and the hub bolt 5 is press-fitted into the wheel mounting flange 19. The side surface 20 is secondarily cut by a lathe or the like. And the surface runout of the side surface 20 is regulated to 20 μm or less by this secondary cutting.

  Here, the wheel mounting flange 19 whose outer periphery is formed in a circular shape is illustrated, but the present invention is not limited to this, and for example, it may be formed in a petal shape as shown in FIG. The wheel mounting flange 23 is formed in a polygonal shape (here, a pentagonal shape) whose apex angle is a portion into which the hub bolt 5 is press-fitted. And the relief part 25 which has the predetermined level | step difference (delta) with respect to the side surface 20 is formed by the forge process. The escape portion 25 includes a petal-like outer peripheral portion 25a formed on the outer peripheral portion of the wheel mounting flange 23 and an R-shaped cutout portion 21b formed between the hub bolts 5 while avoiding the periphery of the hub bolt 5. . As a result, the hub wheel 24 can be further reduced in weight and size, and the heat dissipation effect during operation can be enhanced to further suppress the temperature rise of the bearing portion.

  Although the embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and is merely an example. For example, an outer ring rotation having a wheel mounting flange on an outer member. Of course, it may be of a type and can be implemented in various forms without departing from the gist of the present invention. The scope of the present invention is defined by the terms of the claims, and includes the equivalent meanings of the claims and all modifications within the scope.

  A wheel bearing device according to the present invention includes a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end via a brake rotor, and a double-row rolling bearing that rotatably supports the wheel. The present invention can be applied to all structures from the first generation to the fourth generation.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. It is A arrow directional view of FIG. (A) is explanatory drawing which shows the state which the wheel bearing apparatus of FIG. 1 interfered with the other party components. (B) is a principal part enlarged view which shows the interference part of (a). It is a B arrow line view of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. It is C arrow line view of FIG. It is a longitudinal cross-sectional view which shows the state with which the brake rotor was mounted | worn with the wheel bearing apparatus of FIG. It is a modification of the hub wheel shown in FIG. The conventional bearing device for wheels is shown, (a) is a side view and (b) is the longitudinal section. (A) is explanatory drawing which shows the state which the conventional wheel bearing apparatus interfered with the other party components. (B) is a principal part enlarged view which shows the interference part of (a).

Explanation of symbols

1, 18 ... inward members 2, 17, 24 ... hub wheels 2a, 3a ... inner rolling surface 2b ...・ ・ ・ ・ ・ Small diameter step 2c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Clamping portion 3 ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 4, 19, 23 ・ ・ ・ ・ ・ ・ Wheel mounting Flange 4a ... Flange base 5 ... Hub bolt 6 ... Rolling element 7 ········· Retainer 8, 9 ········ Seal 10 ········· Outside member 10a ··· Outer Rolling surface 10b ··· Body mounting flanges 11 and 20 · · · Wheel mounting flange outer side surfaces 12, 21, 25 ............ Part 14 ...・ ・ ・ Fly 15 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Side 16 on the inner side of the wheel mounting flange ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rib 21a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Ring 21b ... Notch part 22 ... Brake rotor 25a ... Outer peripheral part 51 ... ... Inward member 52 ... Hub wheels 52a, 53a ... Inner rolling surface 53 ... Inner ring 54 ... ······· Small diameter step 55 ············ Wheel mounting flange 55a ······ Side surface 56 ······· Hub bolt 56a ... Knurl part 57 ... Annular groove 58 ... Bolt hole 60 ... .... Outer members 60a, 60b ··· Outer rolling surface 61 ········ Body mounting flange 62 ·························· Ball 64, 65 ... Seal 66 ... Mating part 67 ... Kaeri L ... ..String δ connecting the center of hub bolts ...

Claims (5)

An outer member having a double row outer raceway formed on the inner periphery;
A hub wheel having a wheel mounting flange in which hub bolts for mounting a wheel are planted at equal intervals in the circumferential direction at one end, and a small-diameter step portion extending in the axial direction from the wheel mounting flange on the outer periphery, and the hub It consists of an outer joint member of at least one inner ring or a constant velocity universal joint fitted to the small-diameter step portion of the ring, and a double-row inner rolling surface facing the double-row outer rolling surface is formed on the outer periphery. An inner member;
In the wheel bearing device including the inner member and a double-row rolling element that is accommodated in a freely rolling manner between both rolling surfaces of the outer member,
A bearing device for a wheel, wherein a relief portion having a predetermined step with respect to an outer side surface of the wheel mounting flange is formed on an outer edge portion of the wheel mounting flange by forging.   The wheel bearing device according to claim 1, wherein the step of the relief portion is set to at least 0.5 mm.   The wheel bearing device according to claim 1 or 2, wherein a side surface on the outer side of the wheel mounting flange is formed in a petal-like rib shape in which a portion into which the hub bolt is press-fitted is a thick portion.   The wheel according to any one of claims 1 to 3, wherein a side surface on the outer side of the wheel mounting flange is a cut surface cut after the hub bolt is press-fitted, and a surface runout of the side surface is regulated to 20 µm or less. Bearing device.   The wheel bearing device according to any one of claims 1 to 4, wherein a petal-like rib in which a portion into which a hub bolt is press-fitted is a thick portion is formed on a side surface on the inner side of the wheel mounting flange by forging.

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