JP2006273246A - Hub unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hub unit capable of preventing cracking of a hub flange caused by stress concentration, and reducing the cost and the weight thereof. <P>SOLUTION: A faucet part 7 formed on a hub flange 12 includes a faucet projecting part 8 formed from a main surface 18 so as to be projected to the vehicle outer side in the axial direction, and a stress mitigating recess 9 in which the predetermined position in the circumferential direction is flush with the main surface by reducing the projecting height from the main surface. In addition, the stress mitigating recess 9 is formed in an area on the circumference of the faucet part 7 on the line segment to connect the axis 16 of a through hole passing through a hub bolt 38 to the axis 17 of a hub wheel 3. The facing distance L of a pair of inner side faces 10 of the stress mitigating recess 9 is preferably identical or larger than the diameter D of the through hole 15 of the hub bolt. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hub unit to which a vehicle wheel is attached.

  An outer ring member that is attached to the vehicle body and supports the wheel as a hub unit that is non-rotatably attached to the vehicle body side, and is arranged concentrically with the outer ring member and is axially connected to the outer ring member via a plurality of rows of rolling elements. There is a thing provided with a hub wheel provided so that rotation is freely possible (patent documents 1).

  FIG. 6 shows a conventional example. The vehicle hub unit 100 includes an outer ring 22 attached to a vehicle body, and a hub wheel 103 attached to the inner side of the outer ring 22 via a plurality of balls 27. The hub wheel 103 includes a plurality of balls 27. Is supported rotatably around the axis.

  The hub wheel 103 is formed with a shaft portion 11 that rotates about an axis, and an annular hub flange 12 that protrudes in the radial direction at the end portion of the shaft portion 11 on the vehicle outer side. The insertion hole 15 is formed. Further, a guide portion (inlay portion) 101 that plays a role of positioning when the brake disc rotor and the tire wheel are attached is formed on the mounting surface on the outer side of the hub flange 12, and the brake disc rotor and the tire wheel are formed by the inlay portion 101. Then, the hub bolt 38 is inserted into the insertion hole 15, and the brake disc rotor and the tire wheel are fixed to the hub flange 12 by screwing the hub bolt 38 and the nut.

JP 2004-150483 A

  However, in recent years, due to the increase in tire size and the improvement in the lateral road surface grip force of the tire, the gravitational acceleration applied to the hub unit when the vehicle turns is increasing, and as shown in FIG. Stress was collected between the parts, causing a crack 105 in the hub flange. For this reason, the hub flange has been subjected to quenching treatment and thickening measures at the stress concentration portion against the load. However, by taking such measures, the hub unit tends to increase in cost, weight, and size.

  An object of the present invention is to provide a hub unit that prevents cracking of the hub flange due to stress concentration, and that reduces cost and weight.

Means for Solving the Problems and Effects of the Invention

The hub unit of the present invention for solving the above problems is
An outer ring member that is non-rotatably attached to the vehicle body side, and a hub that is disposed concentrically with the outer ring member and that is rotatably provided around the axis of the outer ring member via a rolling element and is attached to a vehicle wheel and rotates integrally. A hub unit comprising a wheel,
The hub wheel is provided with a flange portion that protrudes radially from an end portion of the outer peripheral surface of the hub wheel on the vehicle outer side, and the brake disk rotor and the tire wheel are arranged in this order on the main surface of the flange portion on the vehicle outer side. And has an inlay portion formed annularly to project from the main surface to the vehicle outer side for concentrically positioning the brake disc rotor and the tire wheel with respect to the central axis of the hub wheel. ,
A stress relaxation recess having a reduced protrusion height from the main surface is formed in a partial region of the inlay portion in the circumferential direction.

  According to the above configuration, the inlay portion formed in the flange portion of the hub wheel has a function of concentrically positioning the brake disc rotor and the tire wheel with respect to the flange portion. Since the stress relief recess is formed in a partial region in the circumferential direction of the inlay portion, when the brake disk rotor and the tire wheel are attached to the flange portion, the flange portion, particularly in the vicinity of the inner peripheral region thereof. The generated stress can be relaxed. For this reason, the hub unit can be reduced in weight and manufacturing cost can be reduced without performing a quenching process on the flange part or taking measures such as increasing the thickness of the flange part.

  The stress relaxation recesses are formed at a predetermined interval in the circumferential direction of the spigot part. By forming the stress relaxation recesses at a predetermined interval, the stress generated in the flange portion can be efficiently diffused.

Further, the flange portion has an insertion hole in which a hub bolt projects so as to penetrate through the mounting holes formed in each of the brake disk rotor and the tire wheel from the vehicle outer side of the flange portion,
The stress relaxation recess is formed including a region on the circumference of the spigot portion and on a line segment connecting the central axis of the hub wheel and the central axis of the hub bolt insertion hole.

  Stress with reduced protrusion height from the main surface on the circumference of the spigot section and on the line segment connecting the center axis of the hub wheel and the center axis of the hub bolt insertion hole as in the above configuration By using the relief recess, when the brake disc rotor and the tire wheel are attached to the flange portion, the stress generated in the inner peripheral region of the flange portion near the hub bolt insertion hole can be diffused. That is, the stress generated in the flange portion can be dissipated by forming the same number of stress relaxation recesses as the insertion holes corresponding to the insertion holes of each hub bolt. Conventionally, the brake disc wheel and the tire hole fixed to the inlay part have a particularly large load on the area around the inlay part and on the line segment connecting the center axis of the hub wheel and the center axis of the hub bolt insertion hole. Although it was easy to concentrate and cracks etc. were prone to occur in the vicinity of this area, this area is made a stress relaxation recess with reduced protrusion height from the main surface, so that the stress to this area is dissipated. Therefore, it is not necessary to take measures such as conventional hardening processing and thickening of the flange portion. Therefore, it is possible to reduce the weight of the hub unit and reduce the manufacturing cost.

  And the opposing distance of a pair of inner surface of a stress relaxation recessed part is good to be the same as or larger than the diameter of the insertion hole of a hub bolt. By forming in this way, the stress which generate | occur | produces in the inner peripheral area | region of the insertion part vicinity of a flange part can be relieve | moderated efficiently.

  Furthermore, the bottom surface of the stress relaxation recess is formed flush with the main surface of the flange portion. Thus, by forming the bottom surface of the stress relaxation concave portion flush with the main surface of the flange portion, the stress in that region of the flange portion can be diffused.

  Moreover, the outer peripheral surface of the spigot part can be formed as a non-coating surface. Although the outer peripheral surface of the spigot portion is a fixed surface to which the brake disc rotor and the tire wheel are fixed, in order to prevent them from adhering to the spigot portion, conventionally, painting has been applied, but stress is applied to the spigot portion. Since the relief recess is formed and the contact area between the brake disc rotor and the tire wheel is reduced, the brake disc rotor and the tire wheel can be removed even if formed as a non-painted surface. Thus, since the outer peripheral surface of the spigot part can be a non-painted surface in which the coating for preventing sticking is omitted, the manufacturing cost can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the hub unit 1 in the present embodiment. In the figure, the right side is the vehicle outer side, and the left side is the vehicle inner side. As shown in FIG. 1, the hub unit 1 includes a rolling bearing (outer ring member) 2 and a hub wheel (inner ring member) 3 arranged concentrically with the rolling bearing 2.

  The hub wheel 3 has a shaft portion 11 and a hub flange 12 for fixing the wheel and the brake disc. A rolling bearing 2 formed of an angular ball bearing is mounted on the outer periphery of the shaft portion 11. The hub flange 12 is formed so as to protrude in the radial direction from the end portion of the outer peripheral surface of the hub wheel 3 on the vehicle outer side.

  The rolling bearing 2 includes an inner ring 21 serving as a rotating track that is press-fitted into the outer periphery of the shaft 11 on the vehicle inner side and fixed by caulking 33, and an outer ring 22 serving as a fixed ring. In addition, two rows of ball groups 27 arranged so as to roll along the inner ring raceways 23 and 24 formed on the shaft 11 and the inner ring 21 and outer ring raceways 25 and 26 formed on the outer ring 22, and each row And a seal member 29 that is fixed to the outer ring 22 at the side of the hub flange 12 and interposed between the shaft portion 11 and the crown-shaped cage 28.

  The outer ring 22 is made of hot-forged machine structural carbon steel such as S55C, and an outer ring flange portion 30 having a bolt insertion hole 31 is provided on the outer peripheral surface, and an outer ring inlay portion is formed on the vehicle inner side. Yes.

  The hub unit 1 is fixed to the vehicle body by inserting bolts into the bolt insertion holes 31 of the outer ring flange portion 30 and fixing the outer ring 22 to the knuckle. Then, the wheel is rotatably supported with respect to the vehicle body via the rolling bearing 2.

  The inner ring on the vehicle outer (hub flange 12) side is formed integrally with the shaft portion 11 by forming an inner ring raceway 23 on the shaft portion 11 of the hub wheel 3. Further, the inner ring 21 on the vehicle inner side is formed separately from the shaft portion 11. The inner ring is made of high carbon chrome bearing steel such as SUJ2.

  The hub flange (flange portion) 12 of the hub wheel 3 is formed with an insertion hole 15 for inserting the hub bolt 38 at a predetermined position. The hub flange 12 is formed with an inlay portion 7 on the main surface on the vehicle outer side for guiding the radial mounting positions of the brake disc rotor and the tire wheel. The inlay portion 7 is formed in an annular shape so as to protrude from the main surface 18 toward the vehicle outer side in the axial direction and centering on the central axis 17 of the hub wheel 3. By fitting the brake disc rotor and the tire wheel to the inlay portion 7, the brake disc rotor and the tire wheel can be positioned concentrically with respect to the hub flange 12. The hub wheel 3 is formed by hot forging from carbon steel for mechanical structure such as S55C, and the inlay portion 7 is formed integrally with the hub wheel 3.

  The inlay portion 7 will be described with reference to FIGS. FIG. 2 is a front view of the hub wheel 3 from the vehicle outer side. 3 is a view taken in the direction of arrow A in FIG. 2 is a sectional view taken along line XX in FIG. The inlay portion 7 includes an inlay protrusion 8 formed so as to protrude from the main surface 18 toward the vehicle outer side in the axial direction, and a protrusion position from the main surface is reduced at a predetermined position in the circumferential direction. A unified stress relaxation recess 9 is formed. That is, the bottom surface 19 of the stress relaxation recess 9 is flush with the main surface 18 of the flange portion 12 on the vehicle outer side. The inlay portion 7 forms a predetermined gap in the circumferential direction, and the gap serves as a stress relaxation recess 9, and each stress relaxation recess 9 has the same formation length. In other words, the pair of inner side surfaces forming the stress relaxation recess 9 becomes the side surface portion 10 of the adjacent spigot protrusion 8. Moreover, each spigot protrusion part 8 has the same length. That is, the stress relaxation recesses 9 are formed at equal intervals. In addition, the stress relaxation recessed part 9 and the spigot protrusion part 8 do not need to be the same formation length.

  Further, the stress relaxation recess 9 is formed so as to include a region on the circumference of the spigot portion 7 on a line segment connecting the central axis 16 of the insertion hole 15 through which the hub bolt 38 is inserted and the central axis 17 of the hub wheel 3. Has been. That is, the stress relaxation recess 9 is formed on a line segment connecting the insertion hole 15 and the central axis 17 corresponding to each of the insertion holes 15 projecting from the hub bolt 38. That is, the stress relaxation recesses 9 and the insertion holes 15 are formed to have the same number. By setting this region as the stress relaxation recess 9 in which the protruding height from the main surface 18 is reduced, the stress in this region of the hub flange 12 can be dispersed.

  The formation length of the stress relaxation recess 9 will be described with reference to FIG. In order to dissipate the stress concentrated on the hub flange 12, the opposing distance L between the inner peripheries of the pair of inner side surfaces (side surfaces of the spigot protrusions 8) 10 a and 10 b of the stress relaxation recess 9 is such that the insertion hole 15 of the hub bolt 38 is inserted. It is desirable that the diameter is the same as the diameter D or slightly larger as shown in FIG. And the some stress relaxation recessed part 9 is formed in the same length, respectively. By forming the stress relaxation recess 9 in such a length, the stress in this region of the hub flange 12 can be efficiently dissipated. This eliminates the need for quenching or thickening the hub flange 12 to prevent cracking in the hub flange 12.

  The outer peripheral surface 7s of the inlay portion 7 serves as a fixed surface to which the brake disc rotor and the tire wheel are fixed, but can be formed as a non-painted surface. Since the stress relief recess 9 is formed in the inlay portion 7, the contact area between the brake disk rotor and the tire wheel and the outer peripheral surface 7 s decreases (the brake disc rotor and the tire wheel in the stress relaxation recess 9 are Even if the outer peripheral surface 7s is formed as a non-painted surface, the brake disc rotor and the tire wheel are prevented from adhering to the outer peripheral surface 7s, or even if there is a slight adhering, The wearing force is weak and the brake disc rotor and tire wheel can be removed. Thus, since the stress relaxation recessed part 9 is formed, the outer peripheral surface 7s can be formed as a non-coating surface, and manufacturing cost can be reduced.

  Then, the brake disc rotor is brought into contact with the inlay portion 7 as described above to position the brake disc rotor with respect to the hub flange 12, and the tire wheel is brought into contact with the inlay portion 7 to be positioned with respect to the hub flange 12 of the tire wheel. The A plurality of hub bolts 38 inserted through the insertion holes 15 of the hub wheel 3 are inserted into the respective mounting holes formed in the brake disc rotor and the tire wheel, and a plurality of hub nuts are screwed into the respective hub bolts 38. The tire wheel is fixed to the hub wheel 3 together with the brake disc rotor.

  Next, an embodiment of the spigot portion 7 in the case where four insertion holes 15 for the hub bolt 38 are formed in the hub flange 12 will be described. FIG. 5 is a front view of the hub wheel 3 from the vehicle outer side. Similar to the above-described embodiment, the inlay portion 7 includes an inlay protrusion 8 formed so as to protrude from the main surface 18 toward the vehicle outer side in the axial direction, and a predetermined position in the circumferential direction is a protrusion height from the main surface 18. Is formed to form a stress relaxation recess 9 that is flush with the main surface 18. The inlay portion 7 forms a predetermined gap in the circumferential direction, and the gap serves as a stress relaxation recess 9.

  Similar to the above-described embodiment, the stress relaxation recess 9 is on the circumference of the spigot portion 7 on the line segment connecting the central axis 16 of the insertion hole 15 through which the hub bolt 38 is inserted and the central axis 17 of the hub wheel 3. Formed in position. In this embodiment, the insertion holes 15 are formed at four locations, and the same number of stress relaxation recesses 9 are formed corresponding to the respective insertion holes 15. By setting this region as the stress relaxation recess 9 in which the protruding height from the main surface 18 is reduced, the stress in this region of the hub flange 12 can be dispersed.

  The formation length of the stress relaxation recess 9 is the same as the above-described embodiment, and the opposing distance L between the inner circumferences of the pair of inner side surfaces 10a and 10b of the stress relaxation recess 9 is the same as the diameter D of the insertion hole 15 of the hub bolt or FIG. As shown in FIG. By forming the stress relaxation recess 9 in such a length, the stress in this region of the hub flange 12 can be efficiently dissipated.

  Further, the outer peripheral surface 7s of the spigot portion 7 can be formed as a non-painted surface as in the above-described embodiment, thereby reducing the manufacturing cost.

  Further, the number of insertion holes 15 of the hub bolt 38 formed in the hub flange 12 is not limited to the above-described embodiment. Even in other cases where the number of the insertion holes 15 is different from 4 or 5, the circumference of the spigot portion 7 on the line segment connecting the central axis 16 of the insertion hole 15 and the central axis 17 of the hub wheel 3 The stress relaxation recess 9 is formed at a position where That is, the number of stress relaxation recesses 9 to be formed is the same as the number of insertion holes 15.

  As described above, by forming a stress relaxation recess in which the protrusion height from the main surface is reduced in a partial region in the circumferential direction of the spigot portion, the quenching treatment and thickness increase that have been conventionally applied to the hub flange are performed. There is no need to take countermeasures, and the hub unit can be reduced in weight and the manufacturing cost can be reduced. The stress relaxation recess is formed including a region on the circumference of the spigot portion and on a line segment connecting the center axis of the hub wheel and the center axis of the insertion hole of the hub bolt, and a pair of inner side surfaces of the stress relaxation recess It is more effective if the facing distance is formed to be the same as or larger than the diameter of the insertion hole of the hub bolt.

  The rolling bearing is not limited to an angular ball bearing, and may be a tapered roller bearing or the like.

Sectional drawing which shows the hub unit which is one Embodiment of this invention. The front view which shows a hub flange. The A arrow line view of FIG. 2 which shows a hub flange. The figure which shows the formation length of a stress relaxation recessed part. The front view which shows the 2nd Example of a hub flange. The figure which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub unit 2 Rolling bearing 3 Hub wheel 7 Inlay part 8 Inlay part 9 Stress relaxation recessed part 10 Side surface part 11 Shaft part 12 Hub flange (flange part)
15 Insertion hole 16 Insertion hole center axis 17 Hub wheel center axis 18 Main surface 38 Hub bolt

Claims (6)

An outer ring member that is non-rotatably attached to the vehicle body side, and a hub that is disposed concentrically with the outer ring member and that is rotatably provided around the axis of the outer ring member via a rolling element and is attached to a vehicle wheel and rotates integrally. A hub unit comprising a wheel,
The hub wheel is provided with a flange portion that protrudes in a radial direction from an end portion of the outer peripheral surface of the hub wheel on the vehicle outer side, and a brake disc rotor and a tire wheel are provided on a main surface of the flange portion on the vehicle outer side. The brake disc rotor and the tire wheel are annularly formed so as to protrude from the main surface toward the vehicle outer side in order to concentrically position the brake disc rotor and the tire wheel with respect to a central axis of the hub wheel. And has an inlay portion
A hub unit, wherein a stress relaxation recess having a reduced protrusion height from the main surface is formed in a partial region of the inlay portion in the circumferential direction.   The hub unit according to claim 1, wherein the stress relaxation recesses are formed at a predetermined interval in a circumferential direction of the spigot part. The flange portion has an insertion hole through which a hub bolt projects so as to penetrate through the mounting holes formed in each of the brake disc rotor and the tire wheel from the vehicle outer side of the flange portion,
The said stress relaxation recessed part was formed including the area | region which is on the circumference of the said spigot part, and on the line segment which connects the center axis line of the said hub wheel, and the center axis line of the said insertion hole of the said hub bolt. 2. The hub unit according to 2.   The hub unit according to claim 3, wherein the opposing distance between the pair of inner side surfaces of the stress relaxation recess is equal to or larger than the diameter of the insertion hole of the hub bolt.   The hub unit according to any one of claims 1 to 4, wherein a bottom surface of the stress relaxation recess is formed flush with the main surface of the flange portion. The hub unit according to any one of claims 1 to 5, wherein an outer peripheral surface of the spigot portion is formed as a non-coating surface.

Images