JP2011051474A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel which has an excess thickness cut off to be thin-walled while restraining the lowering of rigidity of a wheel mounted flange, whereas improvement of the accuracy of surface deflection of a brake rotor mounting face is attempted. <P>SOLUTION: The bearing device for a wheel is such that bolt inserting holes 11 into which hub bolts are fittingly pressed in are formed circumferentially at equal intervals along a wheel mounted flange 6, while hub bolts are pressed fit into these bolt inserting holes 11 for mounting a wheel. A hub wheel 4 is formed by forging, while a belt-like rib 10 is formed in a protrusive manner at the time of forging on the outer peripheral surface corresponding to those bolt inserting holes 11 on the outer peripheral surface of the wheel mounted flange 6, whereas after the hub bolts are pressed fit into the bolt inserting holes, the outer peripheral surface of the rib 10 is formed into a circular arc shape by machining. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a wheel bearing device for supporting a wheel of an automobile or the like, and more particularly to a wheel bearing device capable of suppressing the occurrence of brake judder by increasing the surface runout accuracy of a wheel mounting flange.

  In general, disc brakes with excellent braking power have become widespread, but when braking with the disc brake rotor held between brake pads, vibration occurs especially when the vehicle is running at low speed, causing unpleasant noise at low frequencies. There are things to do. Such a phenomenon is called a brake judder, and in recent years, this analysis and improvement has attracted attention as a new technical problem as the performance and quietness of the vehicle are improved.

  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. This runout accuracy includes not only the runout accuracy of the brake rotor itself, but also the runout accuracy of the wheel mounting flange to which the brake rotor is mounted, the axial runout of the rolling bearing, and the assembly accuracy of the rolling bearing. Finally, the surface runout accuracy of the brake rotor side surface appears.

  In recent years, not only cost reduction, but also the pursuit of weight reduction to improve fuel consumption, the wheel bearing device is eliminated as much as possible to make it slimmer, and steering stability is improved. Therefore, the above-described countermeasures for the surface runout accuracy of the side surface of the brake rotor are taken while satisfying the contradictory requirements such as an increase in rigidity of the wheel bearing device.

The wheel bearing device shown in FIG. 10 is a typical one. This wheel bearing device includes an inner member 50, an outer member 51, and double-row balls 52, 52. The inner member 50 includes a hub ring 53 and a separate inner ring 54. The hub wheel 53 integrally has a wheel mounting flange 55 for mounting a wheel (not shown) at one end portion, and has one inner rolling surface 53a on the outer periphery and an axial direction extending from the inner rolling surface 53a. A cylindrical small-diameter step portion 53b is formed. Hub bolts 55a for fixing the wheels are planted at equal circumferential positions of the wheel mounting flanges 55. The inner ring 54 has the other inner rolling surface 54 a formed on the outer periphery, and is press-fitted and fixed to the small diameter step portion 53 b of the hub ring 53.

  On the other hand, the outer member 51 integrally has a vehicle body mounting flange 51b to be attached to the vehicle body (not shown) on the outer periphery, and the double-row inner rolling surfaces 53a and 54a of the inner member 50 on the inner periphery. Opposing double-row outer rolling surfaces 51a and 51a are formed integrally. Between these outer raceway surfaces 51a and 51a and the aforementioned inner raceway surfaces 53a and 54a, double rows of balls 52 and 52, which are circumferentially arranged by cages 56 and 56, are respectively accommodated so as to roll freely. .

  Seals 57 and 58 are attached to the opening portion of the annular space formed between the inner member 50 and the outer member 51 to prevent leakage of the lubricating grease sealed inside the bearing and to prevent rainwater from the outside. And intrusion of dust and the like.

  An annular groove 59 having a predetermined width including the hub bolt 55a is formed on the side surface 55b of the wheel mounting flange 55, and the side surface 55b other than the annular groove 59 is secondarily cut by a lathe after the hub bolt 55a is press-fitted. Yes. In this way, by forming the annular groove 59 on the side surface 55b, the influence of the deformation to the side surface 55b due to the press-fitting of the hub bolt 55a can be suppressed to the minimum, and after the press-fitting of the hub bolt 55a, the side surface 55b is further subjected to secondary cutting. By doing so, the surface runout of the side surface 55b increased by the press-fitting of the hub bolt 55a can be suppressed as much as possible (see, for example, Patent Document 1).

JP 2007-176485 A

  However, in the wheel bearing device described above, not only forming the annular groove 59 in the side surface 55b of the wheel mounting flange 55 but also performing secondary cutting of the side surface 55b after press-fitting the hub bolt 55 causes an increase in manufacturing cost. There was a problem. Further, in order to reduce the weight of the wheel bearing device in order to improve the fuel consumption, there is a tendency to reduce the rigidity while excluding the surplus of the wheel mounting flange 55 of the hub wheel 53 and suppressing the decrease in rigidity. In particular, in the case of a steel wheel formed by pressing, the accuracy of the mounting surface is worse than that of an aluminum alloy wheel formed by cutting, and depending on the depth and width of the annular groove 59, the wheel mounting flange 55 can be secured by tightening a nut. May tilt, which may deteriorate the surface runout accuracy of the brake rotor side surface (pad sliding contact surface).

  The present invention has been made in view of such circumstances, and while reducing the rigidity of the wheel mounting flange, the extra thickness is eliminated and the thickness is reduced, and the surface runout accuracy of the brake rotor mounting surface is improved. An object of the present invention is to provide a wheel bearing device.

  In order to achieve this object, the invention according to claim 1 of the present invention includes an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel attachment for attaching a wheel to one end. From a hub ring integrally having a flange and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring fitted to the small-diameter step portion of the hub ring or an outer joint member of a constant velocity universal joint An inner member having a double row inner rolling surface facing the outer row rolling surface of the double row on the outer periphery, and freely rollable via a cage between the inner member and the outer member. For a wheel having a bolt insertion hole into which a hub bolt is press-fitted in the circumferential direction of the wheel mounting flange, and a hub bolt for pressing the wheel into the bolt insertion hole. In the bearing device, the hub ring is formed by forging. Formed Te, strip-shaped ribs on the outer peripheral surface corresponding to the bolt insertion holes of the outer circumferential surface of the wheel mounting flange is formed to protrude at the time of the forging.

  In this way, in the wheel bearing device in which the hub bolt is press-fitted into the bolt insertion hole, the hub wheel is formed by forging, in which the bolt insertion hole into which the hub bolt is press-fitted is formed in the circumferential direction of the wheel mounting flange. A band-shaped rib is formed on the outer peripheral surface of the wheel mounting flange corresponding to the bolt insertion hole so as to protrude during forging. Therefore, the rigidity of the portion where the hub bolt of the wheel mounting flange is press-fitted is increased, and the hub bolt is press-fitted. When cutting the periphery of the bolt insertion hole, the outer peripheral surface can be prevented from being deformed into a concave shape. It is possible to provide a wheel bearing device that improves the surface runout accuracy of the rotor mounting surface.

  Further, as in the invention described in claim 2, an R-shaped notch is formed between the bolt insertion holes on the outer periphery of the wheel mounting flange so as to avoid the periphery of the bolt insertion holes. If the portion is formed so that its deepest portion is close to the pitch circle diameter of the bolt insertion hole, it is possible to prevent the bending rigidity of the wheel mounting flange from being lowered while reducing the weight.

  According to a third aspect of the present invention, the wheel mounting flange has an annular root portion having a width substantially the same as a portion where each bolt insertion hole is formed by notching a portion except the vicinity of the hub bolt insertion hole. If the ribs are formed on the outer peripheral surface around the bolt insertion holes of these partial flanges, the hub bolts can be made lighter and more compact. It is possible to increase the rigidity of the portion where the pressure is inserted.

  Preferably, as in the invention described in claim 4, if the rib is formed continuously over the root portion, the hub bolt of the wheel mounting flange is press-fitted while further reducing the weight and size. It is possible to increase the rigidity of the portion.

  More preferably, as in the invention described in claim 5, the thickness of the rib formed on the outer peripheral surface around the bolt insertion hole is set to be larger than the thickness of the rib formed on the root portion. If so, it is possible to further reduce the rigidity of the wheel mounting flange while reducing the weight and size.

  Further, as in the sixth aspect of the present invention, if a counterbore portion that accommodates the head portion of the hub bolt is formed in the opening portion on the inner side of the bolt insertion hole by forging, a wheel mounting flange It is possible to reduce the thickness by eliminating the surplus.

  If the outer peripheral surface of the rib is formed in an arc shape by machining as in the invention described in claim 7, it is possible to adjust the rotational balance of the hub wheel together with removal of burrs caused by forging. it can.

  Further, as in the invention according to claim 8, if the pitch circle diameter of the outer side rolling elements of the double row rolling elements is set larger than the pitch circle diameter of the inner side rolling elements. Further, while achieving light weight and compactness, the bearing rigidity of the outer side portion can be increased compared to the inner side, and the life of the bearing can be extended.

  Preferably, as in the invention described in claim 9, if the number of the outer side rolling elements is set to be larger than the number of the inner side rolling elements, the bearing rigidity of the outer side portion compared to the inner side is set. Can be further increased.

  Further, as in the invention described in claim 10, the inner rolling surface is directly formed on the outer periphery of the hub wheel, and a mortar-shaped recess extending in the axial direction at the outer side end portion of the hub wheel. If it is deeply formed to a position corresponding to the inner rolling surface by forging, and the thickness of the outer side of the hub wheel is set to be substantially uniform, it is possible to achieve light weight and compactness.

  The wheel bearing device according to the present invention integrally has an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for mounting the wheel on one end, and on the outer periphery. A hub ring formed with a small-diameter step portion extending in the axial direction, and 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 hub ring, the outer periphery of the double row on the outer periphery An inner member in which a double row of inner rolling surfaces facing the rolling surface is formed, and a double row of rolling elements housed between the inner member and the outer member via a cage so as to be freely rollable. In the wheel bearing device in which a bolt insertion hole into which a hub bolt is press-fitted is formed in the circumferential direction of the wheel mounting flange, and the hub bolt for fitting the wheel into the bolt insertion hole is press-fitted, the hub wheel is forged. Formed by machining, the wheel mounting frame A belt-like rib is formed on the outer peripheral surface of the outer peripheral surface corresponding to the bolt insertion hole so as to protrude during the forging process, so that the rigidity of the portion where the hub bolt of the wheel mounting flange is press-fitted is increased and the hub bolt is pressed When cutting the periphery of the bolt insertion hole, the outer peripheral surface can be prevented from being deformed into a concave shape. It is possible to provide a wheel bearing device that improves the surface runout accuracy of the rotor mounting surface.

(A) is a side view which shows 1st Embodiment of the wheel bearing apparatus which concerns on this invention, (b) is a longitudinal cross-sectional view of (a). It is a principal part enlarged view of Fig.1 (a). It is a principal part enlarged view of FIG.1 (b). (A) is a side view which shows the hub ring single-piece | unit of 2nd Embodiment of the wheel bearing apparatus which concerns on this invention, (b) is a longitudinal cross-sectional view of (a). It is a principal part enlarged view of Fig.4 (a). It is a principal part enlarged view of FIG.4 (b). It is a longitudinal cross-sectional view which shows 3rd Embodiment of the wheel bearing apparatus which concerns on this invention. (A) is the side view of FIG. 7, (b) is the cross-sectional view which followed the VIII-VIII line of (a). (A) is a side view which shows the hub ring single-piece | unit of 4th Embodiment of the wheel bearing apparatus which concerns on this invention, (b) is a longitudinal cross-sectional view of (a), (c) is (a). It is the cross-sectional view which cut along the IX-IX line. (A) is a side view which shows the conventional wheel bearing apparatus, (b) is a longitudinal cross-sectional view of (a).

  An outer member integrally having a vehicle body mounting flange to be attached to the vehicle body on the outer periphery, a double row outer rolling surface formed integrally on the inner periphery, and a wheel mounting flange for mounting a wheel on one end A hub wheel integrally formed and having an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub wheel An inner member comprising an inner ring that is press-fitted into a small-diameter step portion and has an inner race surface formed opposite to the other outer race surface of the double row on the outer periphery, and is held between the inner member and the outer member. A plurality of rolling elements which are accommodated so as to be able to roll through a vessel, and bolt insertion holes into which hub bolts are press-fitted are formed at equal intervals in the circumferential direction of the wheel mounting flange, and the wheels are inserted into these bolt insertion holes. In the wheel bearing device in which the hub bolt to be fitted is press-fitted, After the hub wheel is formed by forging, a belt-like rib is formed protruding from the outer peripheral surface of the wheel mounting flange corresponding to the bolt insertion hole during the forging process, and the hub bolt is press-fitted. The outer peripheral surface of the rib is formed in an arc shape by machining.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1A is a side view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 1B is a longitudinal sectional view of FIG. 1A, and FIG. FIG. 3 is an enlarged view of a main part of FIG. 1B. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  The wheel bearing device includes an inner member 1, an outer member 2, and double-row rolling elements (balls) 3 and 3. The inner member 1 includes a hub ring 4 and a separate inner ring 5 fixed to the hub ring 4. The hub wheel 4 integrally has a circular wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, one (outer side) inner rolling surface 4a on the outer periphery, and the inner side. A cylindrical small diameter step portion 4b extending in the axial direction from the rolling surface 4a is formed, and a serration (or spline) 4c for torque transmission is formed on the inner periphery. A hub bolt 6a for fixing the wheel is planted at the circumferentially equidistant position of the wheel mounting flange 6, and a plurality of bolt holes 6c (two here) for temporarily fixing a brake rotor (not shown) are provided. ) Is formed. The inner ring 5 is formed with the other (inner side) inner raceway surface 5a on the outer periphery, and is press-fitted into the small-diameter step portion 4b of the hub ring 4 via a predetermined squeeze.

  On the other hand, the outer member 2 integrally has a vehicle body mounting flange 2b for mounting to the vehicle body (not shown) on the outer periphery, and double row inner rolling surfaces 4a, 5a of the inner member 1 on the inner periphery. Double row outer rolling surfaces 2a, 2a facing each other are integrally formed. Between these two rolling surfaces, double-row rolling elements 3 and 3 that are circumferentially arranged by a cage 7 are accommodated so as to roll freely.

  Seals 8 and 9 are attached to both ends of the outer member 2 to seal the opening of the annular space formed between the outer member 2 and the inner member 1, and leakage of the lubricating grease sealed inside the bearing As well as rain water and dust from the outside.

  The hub wheel 4 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner raceway surface 4a and the base portion 6b on the inner side of the wheel mounting flange 6 are connected to the small diameter step portion 4b. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. As a result, the hub wheel 4 has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 6 and the fretting resistance of the small-diameter step portion 4b serving as the fitting portion of the inner ring 5 is improved. Improves durability. Further, the inner ring 5 and the rolling element 3 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching.

  Similar to the hub wheel 4, the outer member 2 is formed of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and at least the double row outer raceway surfaces 2a and 2a have surface hardness by induction hardening. Is cured in the range of 58 to 64 HRC.

  In addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the rolling element 3 as the ball | bowl was illustrated here, it is not restricted to this but is comprised by the double row tapered roller bearing which used the tapered roller for the rolling element 3. It may be what was done. Moreover, although the 3rd generation structure was illustrated, it is not restricted to this, For example, the 1st generation-4th generation structure including the 2nd generation structure which press-fits a pair of inner ring | wheel to the hub ring may be sufficient.

  Here, as shown in FIGS. 2 and 3 in an enlarged manner, a rib 10 is formed on the outer diameter surface of the outer diameter surface of the wheel mounting flange 6 where a hub bolt (not shown) is press-fitted. The rib 10 is formed in a strip shape protruding outward in the radial direction by forging. This increases the rigidity of the outer diameter surface of the wheel mounting flange 6 where the hub bolt 6a is press-fitted, and when the hub bolt is press-fitted, the outer diameter surface is deformed into a concave shape by scraping the periphery of the bolt insertion hole 11. To provide a wheel bearing device that can reduce the thickness of the mounting surface of the brake rotor while reducing the rigidity of the wheel mounting flange 6 and reducing the thickness of the mounting surface of the brake rotor. Can do.

  Furthermore, in this embodiment, in order to adjust the rotational balance of the hub wheel 4 together with removal of burrs generated by forging, the hub bolt 6a is press-fitted and then the outer peripheral surface of the rib 10 (indicated by a two-dot chain line in the figure). ) Is formed in an arc shape by machining such as turning.

  FIG. 4A is a side view showing a single hub wheel of a second embodiment of the wheel bearing device according to the present invention, FIG. 4B is a longitudinal sectional view of FIG. 4A, and FIG. The principal part enlarged view of a) and FIG. 6 are the principal part enlarged views of FIG.4 (b). Note that the same parts and parts as those in the above-described embodiment or parts and parts having the same functions are denoted by the same reference numerals, and detailed description thereof is omitted.

  The hub wheel 12 integrally has a flower-shaped wheel mounting flange 13 at an end portion on the outer side, one inner rolling surface 4a on the outer periphery, and a small cylindrical diameter extending in the axial direction from the inner rolling surface 4a. A step 4b is formed, and a serration 4c for torque transmission is formed on the inner periphery. Bolt insertion holes 11 for press-fitting hub bolts (not shown) are formed in the circumferentially equidistant positions of the wheel mounting flange 6, avoiding the periphery of these bolt insertion holes 11 and between the bolt insertion holes 11, 11. , An R-shaped notch 14 is formed on the outer periphery of the wheel mounting flange 13.

  The notch portion 14 is formed so that the deepest portion 14 a is close to the pitch circle diameter PCDb of the bolt insertion hole 11. As a result, the weight rigidity of the wheel mounting flange 13 is prevented from being lowered while reducing the weight.

  Here, as shown in FIG. 5 and FIG. 6 in an enlarged manner, a counterbore portion 15 that accommodates the head of a hub bolt (not shown) is formed in the opening on the inner side of the bolt insertion hole 11 by forging. At the same time, a rib 16 is formed on the outer diameter surface of the wheel mounting flange 13 corresponding to the bolt insertion hole 11. The rib 16 is formed in a strip shape protruding outward in the radial direction by forging. Thereby, the rigidity of the portion where the hub bolt of the wheel mounting flange 13 is press-fitted is increased, and when the hub bolt is press-fitted, it is possible to prevent the outer peripheral surface from being deformed into a concave shape by scraping the periphery of the bolt insertion hole 11. It is possible to reduce the rigidity of the wheel mounting flange 13 while eliminating the surplus thickness and reducing the thickness and improving the surface runout accuracy of the brake rotor mounting surface.

  Further, in order to adjust the rotational balance of the hub wheel 12 together with the removal of burrs generated by forging, the outer peripheral surface of the rib 16 (shown by a two-dot chain line in the figure) is turned into a machine such as a turning machine after the hub bolt is press-fitted. It is formed in an arc shape by processing.

  FIG. 7 is a longitudinal sectional view showing a third embodiment of the wheel bearing device according to the present invention, FIG. 8A is a side view of FIG. 7, and FIG. 7B is a VIII-VIII line of FIG. FIG. Note that the same parts and parts as those in the above-described embodiment or parts and parts having the same functions are denoted by the same reference numerals, and detailed description thereof is omitted.

  This wheel bearing device is a third-generation wheel bearing device that rotatably supports a driven wheel, and includes an inner member 17 and an outer member 18, and an inner member 17 and an outer member 18. It has double row rolling elements 3 and 3 accommodated therein. Here, the inner member 17 refers to the hub wheel 19 and the inner ring 5 press-fitted into the hub wheel 19.

  The hub wheel 19 integrally has a wheel mounting flange 20 divided into a plurality (in this case, five) in the circumferential direction at the end on the outer side, one inner rolling surface 19a on the outer circumference, and this inner rolling. A small-diameter step portion 4b is formed through an axial portion 19b extending in the axial direction from the surface 19a. A mortar-shaped recess 21 extending in the axial direction is formed at the outer end of the hub wheel 19. The recess 21 is deeply formed by forging to a position corresponding to the outer side inner rolling surface 19a, and the thickness of the outer side of the hub wheel 19 is set to be substantially uniform.

  The inner ring 5 is formed with the other inner rolling surface 5a on the outer periphery and is press-fitted into the small-diameter stepped portion 4b of the hub wheel 19 to form a back-to-back type double-row angular ball bearing, and the end of the small-diameter stepped portion 4b. The inner ring 5 is fixed in the axial direction in a state in which a predetermined bearing preload is applied by a caulking portion 19c formed by plastic deformation of the.

  The hub wheel 19 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner raceway 19a and the inner side base portion 6b of the wheel mounting flange 20 to the small diameter step portion 4b. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. Note that the caulking portion 19c is left with a raw surface hardness after forging. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 20, and the fretting resistance of the small-diameter step portion 4 b serving as the fitting portion of the inner ring 5 is improved, and the minute There is no occurrence of cracks and the like, and the plastic working of the caulking portion 19c can be performed smoothly.

  The outer member 18 integrally has a vehicle body mounting flange 18 c on the outer periphery, an outer outer rolling surface 18 a facing the inner rolling surface 19 a of the hub wheel 19 on the inner periphery, and an inner rolling surface of the inner ring 5. An inner side outer rolling surface 18b opposite to 5a is integrally formed. Double-row rolling elements 3 and 3 are accommodated between these rolling surfaces and are held by the cages 7 'and 7 so as to be freely rollable. A seal 8 and a magnetic encoder 9 ′ are attached to the opening of the annular space formed between the outer member 18 and the inner member 17, and leakage of grease sealed inside the bearing to the outside Prevents rainwater and dust from entering the bearing from the outside.

  The outer member 18 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the double row outer rolling surfaces 18a and 18b have a surface hardness in the range of 58 to 64HRC by induction hardening. It has been cured.

  In this embodiment, the pitch circle diameter PCDo of the outer side rolling element 3 is set larger than the pitch circle diameter PCDi of the inner side rolling element 3. Due to the difference between the pitch circle diameters PCDo and PCDi, the number of rolling elements Zo of the outer three rolling elements is set larger than the number of rolling elements Zi of the inner three rolling elements (Zo> Zi). Accordingly, the bearing rigidity of the outer side portion can be increased as compared with the inner side while reducing the weight and size, and the life of the bearing can be extended. Here, the outer side rolling element 3 and the inner side rolling element 3 have the same size. However, the present invention is not limited to this example. For example, the outer diameter of the outer side rolling element 3 is set to the inner side rolling element. The outer diameter of 3 may be larger.

  Here, as shown in FIG. 8A, the wheel mounting flange 20 is cut out at a portion other than the vicinity of the hub bolt insertion hole 11, has a substantially same width as the formation portion of each bolt insertion hole 11, and has an annular root. It is formed so as to protrude radially from the portion 20b. That is, the wheel mounting flange 20 is divided into a plurality of partial flanges 20a that are separated in the circumferential direction.

  And in this embodiment, the rib 22 is formed in the outer peripheral surface of the some partial flange 20a. As shown in (b), the rib 22 is formed in a belt shape so as to protrude from the outer peripheral surface around the bolt insertion hole 11 by forging. As a result, the rigidity of the portion where the hub bolt of the wheel mounting flange 20 is press-fitted is increased, and when the hub bolt is press-fitted, the outer peripheral surface can be prevented from being deformed into a concave shape by scraping the periphery of the bolt insertion hole 11. While reducing the rigidity of the wheel mounting flange 20, it is possible to reduce the thickness by eliminating the surplus, and to improve the surface runout accuracy of the brake rotor mounting surface.

  Further, in order to adjust the rotational balance of the hub wheel 19 together with removal of burrs caused by forging, after the hub bolt is press-fitted, the outer peripheral surface of the outermost diameter portion of the rib 22 (indicated by a two-dot chain line in the figure). ) Is formed in an arc shape by machining such as turning.

  FIG. 9A is a side view showing a single hub wheel of a fourth embodiment of the wheel bearing device according to the present invention, FIG. 9B is a longitudinal sectional view of FIG. 9A, and FIG. Is a cross-sectional view taken along line XI-XI. Note that this embodiment is basically different from the hub wheel of the third embodiment (FIG. 8) described above except that the configuration of the ribs is different, and other parts or parts having the same function or similar functions are used. The same reference numerals are assigned and detailed description is omitted.

  The hub wheel 23 integrally has a wheel mounting flange 24 divided into a plurality (in this case, five) in the circumferential direction at an end portion on the outer side, and has one inner rolling surface 19a on the outer circumference and the inner rolling surface. A small-diameter step portion 4b is formed through an axial portion 19b extending in the axial direction from the surface 19a. Further, a mortar-shaped recess 21 extending in the axial direction is formed at the outer side end of the hub wheel 23.

  Here, the wheel mounting flange 24 is formed so as to protrude radially from the annular root portion 20b with the same width as the formation portion of each bolt insertion hole 11 by notching a portion except the vicinity of the hub bolt insertion hole 11. Has been. That is, the wheel mounting flange 24 is formed by being divided into a plurality of partial flanges 24a separated in the circumferential direction.

  And in this embodiment, the rib 25 is formed in the outer peripheral surface of the some partial flange 24a. As shown in (b), the rib 25 is continuous from the rib 25a to the root portion 20b through the rib 25a formed in a band shape by projecting to the outer peripheral surface around the bolt insertion hole 11 by forging. And ribs 25b formed. In addition, the thickness of the rib 25a formed in the outer peripheral surface around the bolt insertion hole 11 is set to be thicker than the thickness of the rib 25b formed in the root portion 20b. This increases the rigidity of the portion of the wheel mounting flange 24 where the hub bolt is press-fitted while reducing the weight and size, and when the hub bolt is press-fitted, the periphery of the bolt insertion hole 11 is scraped to deform the outer peripheral surface into a concave shape. In addition to preventing the wheel mounting flange 24 from being lowered in rigidity, it is possible to reduce the thickness by eliminating the surplus thickness and improve the surface runout accuracy of the brake rotor mounting surface.

  Further, in order to adjust the rotational balance of the hub wheel 23 together with removal of burrs generated by forging, the outer peripheral surface of the outermost diameter portion of the rib 25 is formed into an arc shape by machining such as turning after the hub bolt is press-fitted. Is formed.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The present invention can be applied to a wheel bearing device having a first generation to a fourth generation structure including a hub ring integrally having a wheel mounting flange.

1, 17 Inner member 2, 18 Outer member 2a, 18a, 18b Outer rolling surface 2b, 18c Car body mounting flange 3 Rolling elements 4, 12, 19, 23 Hub wheel 4a, 5a, 19a Inner rolling surface 4b Small diameter Step portion 4c Serration 5 Inner ring 6, 13, 20, 24 Wheel mounting flange 6a Hub bolt 6b Base portion 6c on the inner side of the wheel mounting flange Bolt hole 7, 7 'Cage 8 Outer side seal 9 Inner side seal 9' Magnetic encoder 10, 16, 22, 25 Rib 11 Bolt insertion hole 14 Notch portion 14a Deepest portion 15 of the notch portion Spot facing portion 19b Shaft portion 19c Clamping portion 21 Recess 20a, 24a Partial flange 20b Root portion 25a Bolt insertion hole Rib 25b formed on the outer peripheral surface of the periphery of the rib 50b formed on the root portion Inner member 51 Outer member 51a Outer rolling surface 51b Car body mounting Lunge 52 Ball 53 Hub wheel 53a, 54a Inner rolling surface 53b Small diameter step 54 Inner ring 55 Wheel mounting flange 55a Hub bolt 55b Side surface 56 Cage 57, 58 Seal 59 Annular groove PCDb Pitch circle diameter PCDi Bolt insertion hole Pitch circle diameter of moving body PCDo Pitch circle diameter of outer rolling element Zi Number of inner rolling elements Zo Number of outer rolling elements

Claims (10)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end thereof and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring fitted to the small-diameter step portion of the hub ring Or an inner member formed of an outer joint member of a constant velocity universal joint and having a double-row inner rolling surface facing the double-row outer rolling surface on the outer periphery;
A double row rolling element housed in a freely rollable manner between the inner member and the outer member via a cage;
In a wheel bearing device in which bolt insertion holes into which hub bolts are press-fitted are formed at equal intervals in the circumferential direction of the wheel mounting flange, and hub bolts to which the wheels are attached to these bolt insertion holes are press-fitted,
The hub wheel is formed by forging, and a belt-like rib is formed on the outer peripheral surface of the wheel mounting flange corresponding to the bolt insertion hole so as to protrude during the forging process. Bearing device.   Around the outer periphery of the wheel mounting flange, an R-shaped notch is formed between each bolt insertion hole, avoiding the periphery of the bolt insertion hole, and this notch has a pitch circle diameter of the bolt insertion hole. The wheel bearing device according to claim 1, wherein the deepest portion is formed so as to be close to each other.   The wheel mounting flange is a plurality of partial flanges formed by cutting out portions excluding the vicinity of the hub bolt insertion holes and having substantially the same width as the formation portions of the respective bolt insertion holes and projecting radially from the annular root portion. The wheel bearing device according to claim 1, wherein the rib is formed on an outer peripheral surface of the partial flange around the bolt insertion hole.   The wheel bearing device according to claim 3, wherein the rib is formed continuously over the root portion.   The wheel bearing device according to claim 4, wherein a thickness of a rib formed on an outer peripheral surface around the bolt insertion hole is set to be thicker than a thickness of a rib formed at the root portion.   The wheel bearing device according to any one of claims 1 to 5, wherein a counterbore portion for accommodating a head portion of the hub bolt is formed in the opening portion on the inner side of the bolt insertion hole by forging.   The wheel bearing device according to any one of claims 1 to 5, wherein an outer peripheral surface of the rib is formed in an arc shape by machining.   2. The wheel bearing device according to claim 1, wherein a pitch circle diameter of an outer side rolling element of the double row rolling elements is set to be larger than a pitch circle diameter of an inner side rolling element.   The wheel bearing device according to claim 8, wherein the number of the outer-side rolling elements is set to be larger than the number of the inner-side rolling elements.   The inner rolling surface is directly formed on the outer periphery of the hub wheel, and a mortar-shaped recess extending in the axial direction at the outer side end of the hub wheel is moved to a position corresponding to the inner rolling surface by forging. The wheel bearing device according to claim 1, wherein the wheel bearing device is formed deep and has a substantially uniform thickness on the outer side of the hub wheel.

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