JP5692437B2 - Wheel support bearing unit - Google Patents

Description

  The present invention relates to, for example, a bearing unit for supporting such a wheel in various vehicles such as automobiles and railway vehicles that travel with wheels mounted thereon, and more specifically, a rotor (brake of a braking device assembled to the bearing unit). The present invention relates to a hub structure having radial flanges for preventing damage to the rotor.

FIG. 1 (a) shows an example of a structure around a wheel bearing of an automobile. As shown in FIG. 1 (a), an automobile wheel (not shown) includes, for example, a wheel (disc wheel) 42 formed by welding and assembling parts pressed with a steel plate, and a braking device formed by casting cast iron. Is supported rotatably by a bearing unit (wheel support hub unit bearing) A in which a rotor (brake rotor) 40 of this type is assembled.
FIG. 3A shows an example of the configuration of such a wheel supporting hub unit bearing (hereinafter also simply referred to as a hub unit bearing) A. As shown in FIG. 3A, the hub unit bearing A is disposed opposite to the stationary wheel 2 fixed to a vehicle body structural member (for example, a knuckle (not shown) of a suspension device). The rotating wheel 4 that rotates with the disk wheel 42 and the brake rotor 40 by fixing the wheel constituent members (the disk wheel 42 and the brake rotor 40), and the stationary wheel 2 and the rotating wheel 4 that are formed on the stationary wheel 2 and the rotating wheel 4 respectively face each other. A plurality of rolling elements (for example, balls) incorporated so as to be able to roll between the rows (two rows) of raceway grooves are provided. The rotating wheel 4 is composed of a hub 12 and an inner ring constituting body 16 that is externally fitted to the hub 12. The hub 12 includes a disc wheel 42 as shown in FIGS. And in order to assemble and fix the brake rotor 40, a flange portion (hub flange) 12f extending in the diameter increasing direction is provided on the outer peripheral portion.

  Conventionally, as such a hub 12, a hub flange 12f is continuously provided over the entire circumference of the outer peripheral portion in a disk shape, or provided intermittently over the entire circumference of the outer peripheral portion. Various types such as a type (see Patent Document 1), a hot-formed (forged) type, and a cold-formed (forged) type are known. Among these, the cold forging type hub formed with radial flanges by precision side extrusion has increased strength due to work hardening, so it has the excellent feature that it is easy to reduce the weight compared to the hot type hub. is there.

  Here, in a hub unit bearing (hereinafter assumed to be a hub unit bearing A shown in FIGS. 1 and 3) having a cold forging type hub having a radial flange, a disc wheel is provided with respect to the hub flange 12 f of the hub 12. 42 and the brake rotor 40 are fixed by a predetermined stud bolt (hub bolt) 14. At this time, the brake rotor 40 abuts on the hub flange 12f, and the disc wheel 42 and the brake rotor 40 are fixed to the hub flange 12f in a state where the disc wheel 42 abuts on the brake rotor 40. That is, the brake rotor 40 is fixed to the hub flange 12f in a state where the brake rotor 40 is interposed between the hub flange 12f and the disc wheel 42, and the disc wheel 42 is assembled via the brake rotor 40.

  The disc wheel 42 has a substantially flat surface at a mounting portion (specifically, a contact portion with the brake rotor 40) to the hub flange 12f, and a hole (hereinafter referred to as a wheel bolt) through which the hub bolt 14 is inserted into the flat surface. A hole 42h) is punched out by pressing so as to have substantially the same diameter as the hub bolt 14 and is subjected to cationic coating. On the other hand, the brake rotor 40 includes drilling (hereinafter, this hole is referred to as a rotor bolt hole 40h), and includes any of the attachment part to the hub flange 12f and the contact part with the disc wheel 42 (simply). Is machined on both sides). The hub flange 12f also has a hole (hereinafter referred to as a flange bolt hole 12h) through which the hub bolt 14 is inserted into a contact portion with the brake rotor 40 so as to communicate with the wheel stud 42h hole and the rotor bolt hole 40h. ing.

  In such a structure, when the circumferential width of the hub flange 12f (the distance w shown in FIGS. 1B and 3B) is narrow, the rotor bolt hole of the brake rotor 40 is rotated when the wheel rotates. Stress is generated around 40h, and radial cracks may occur in a region from the rotor bolt hole 40h to the contact portion between the brake rotor 40 and the disc wheel 42. This is because the phases of the contact portion between the disc wheel 42 and the brake rotor 40 and the contact portion between the brake rotor 40 and the hub unit bearing A (specifically, the hub flange 12f) are offset.

  In other words, the attachment portion of the brake rotor 40 to the hub flange 12f (in the vicinity of the rotor bolt hole 40h) is machined on both sides as described above. Similarly, flatness is ensured by machining and precision side extrusion. The hub flange 12f is in contact with the flange bolt hole 12h. On the other hand, for example, when the disc wheel 42 is made of steel, if the wheel bolt hole 42h is punched by pressing as described above, the material is drawn into the die by the punch at the time of punching, or the material due to the influence of plate pressing The flatness around the wheel bolt hole 42h is unavoidable due to the thinning of the surface. Therefore, there is a difference in accuracy between the flatness around the rotor bolt hole 40h on the disc wheel 42 side of the brake rotor 40 and the flatness around the wheel bolt hole 42h of the disc wheel 42. The abutting position is a position slightly away from the wheel bolt hole 42h (in other words, the rotor bolt hole 40h).

  Therefore, the contact portion between the disc wheel 42 and the brake rotor 40 and the contact portion between the brake rotor 40 and the hub unit bearing A (specifically, the hub flange 12f) are offset, and the rotor bolt hole It causes the generation of stress around 40 h, and thus the generation of cracks as described above.

JP 2005-59832 A

  Such inconveniences can be avoided, for example, by increasing the thickness of the brake rotor (thickening) or improving rigidity (higher strength) by selecting material components or heat treatment. However, these measures simultaneously lead to an increase in the mass and manufacturing cost of the hub unit bearing, and are not necessarily good measures.

  The present invention has been made in order to solve such problems, and the object thereof is to make contact between the disc wheel and the brake rotor, the brake rotor and the bearing unit (specifically, without increasing the mass and cost). In particular, for wheel support equipped with a rotating wheel (for example, a cold forging type hub) having a radial flange that can reliably prevent the phase of the contact portion of the flange portion) from being offset. It is to provide a bearing unit.

  In order to achieve such an object, a wheel support bearing unit according to the present invention includes a stationary wheel that is fixed to a vehicle body component member and maintained in a non-rotating state, and is disposed to face the stationary wheel. And rotating wheels that rotate together with the wheel constituent members, and a plurality of rolling elements that are formed on these stationary wheels and the rotating wheels, respectively, and are rotatably incorporated between the mutually facing raceway grooves. A wheel bearing unit bearing, wherein the rotating wheel is constituted by a hub that fixes a rotor of a braking device that is the wheel constituting member and rotates together with the rotor, and an inner ring constituting body disposed on the hub. The hub has a plurality of flat-plate-shaped flange portions radially projecting in the diameter increasing direction on the outer peripheral portion thereof, and is formed by side extrusion of cold forging, The rotor and The wheel of the wheel, which is a wheel component member, is fixed through the rotor while being in contact, and has a through-hole in the vicinity of the tip portion that is perforated to pass through the fastening member when the rotor and the wheel are fixed. The wheel is made of steel, has a through hole that can be communicated with the through hole of the flange portion, and is punched by press working, and a thinning region is provided around the through hole of the wheel. The outer diameter end of the flange portion is formed so as to hang over the thinned region of the wheel, and the wheel is fixed to the flange portion via a fastening member in contact with the rotor, and the wheel And the contact portion of the rotor, and the matching range of phases of the contact portion of the rotor and the flange portion exist on the inner diameter side and the outer diameter side of the flange portion, and the matching range of the outer diameter side is Divided into two in the direction, the wheel, one point at the inner diameter side, characterized in that it is supported at three points as the two points outside diameter side.

In this case, the rotating wheel includes a hub that fixes the rotor of the braking device and rotates together with the rotor, and an inner ring structure that is disposed on the hub. What is necessary is just to have a flange part and to comprise by cold forging.
Further, the wheel may be made of steel, and may be configured to have a through hole that can be communicated with the through hole of the flange portion and is punched out by pressing.

  According to the wheel support bearing unit of the present invention, specifically, a hub unit bearing provided with a hub having a radial flange (for example, a cold forging type), the weight is reduced without increasing the mass and cost. While maintaining the effect and reducing costs, offset the phase of the contact portion between the disc wheel and the brake rotor and the phase of the contact portion between the brake rotor and the hub unit bearing (specifically, the hub flange). It can be reliably deterred. Thereby, generation | occurrence | production of the stress around the rotor bolt hole of a brake rotor and by extension, generation | occurrence | production of the crack around the said rotor bolt hole can be prevented effectively.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the wheel support bearing unit which concerns on one Embodiment of this invention, Comprising: (a) shows the contact state of a disk wheel and a brake rotor, and the contact state of the said brake rotor and hub flange. Cross-sectional perspective views of main parts, (b) and (c) are enlarged views showing the contact state. It is a figure which shows the transmission area | region of the compressive stress acted on from a hub bolt in a hub flange. It is a figure which shows the structural example of a bearing unit, (a) is sectional drawing of the whole structure, (b) is a top view which shows the structure of a hub from the direction of the arrow 3b of the same figure (a), (c) These are sectional drawings which show the structure of a hub along the arrow 2c of the same figure (b).

  Hereinafter, a wheel support bearing unit (hereinafter also simply referred to as a bearing unit or a bearing) of the present invention will be described with reference to the accompanying drawings. In addition, the bearing unit according to the present invention can be applied as a bearing unit that rotatably supports the wheels in various vehicles that travel by wearing tires, such as automobiles and railway vehicles. The case where it is applied as a bearing unit which supports the wheel of a motor vehicle is assumed as an example. The wheels of the automobile supported by the bearing unit are driven wheels (front wheels of front engine rear wheel drive (FR) vehicles and rear engine rear wheel drive (RR) vehicles, front engine front wheel drive (FF) vehicles). Rear wheels) or driving wheels (rear wheels of FR and RR vehicles, front wheels of FF vehicles, and all wheels of four-wheel drive vehicles) may be used.

1 and 3 show the configuration of a wheel support bearing unit (a bearing unit for supporting a driven wheel of an automobile) A according to an embodiment of the present invention. In the following description, when the bearing unit A is mounted on a vehicle, the side corresponding to the outside of the vehicle body (the wheel side (left side in FIG. 3A)) is referred to as the outboard side, and vice versa. The side, that is, the side corresponding to the inside of the vehicle body (the right side in the figure) is called the inboard side.
The bearing unit A is fixed to a vehicle body structural member (for example, a knuckle (not shown) of a suspension device) and is maintained in a non-rotating state, and is disposed to face the stationary wheel 2, and a wheel structural member (for example, The rotating wheel 4 that rotates together with the disc wheel 42 of the wheel and the rotor (brake rotor) 40) of the braking device, and the double row (two rows) formed on the stationary wheel 2 and the rotating wheel 4 and facing each other. A plurality of rolling elements 18 are provided so as to roll between the raceway grooves 2s and 4s and between the raceway grooves 2t and 4t. That is, in this case, the bearing unit A is configured such that the outer ring side is the stationary ring 2 and the inner ring side is the rotating wheel 4. The rolling elements 18 roll between the raceway grooves 2 s and 4 s and between the raceway grooves 2 t and 4 t in a state where the rolling elements 18 are rotatably held one by one in pockets formed in an annular cage 20. The rolling element may be a ball as shown in FIG. 3A, or may be various types of rollers (cylindrical roller, tapered roller, spherical roller, etc.). Moreover, what is necessary is just to apply arbitrary types for a holder | retainer according to the kind of rolling element. For example, when the rolling element is a ball, types such as an inclined type (FIG. 3 (a)), a crown type and a corrugated type can be applied, and the rolling element can be various rollers (conical roller, cylindrical roller and spherical roller). Etc.), types such as a punching die, a comb die and a cage die can be applied.

The bearing unit A may be provided with a sealing device for sealing the inside of the unit (the space surrounded by the stationary wheel 2 and the rotating wheel 4) from the outside to keep it sealed (airtight and liquid tight). desirable. By providing such a sealing device, it is possible to prevent foreign matter (e.g., muddy water and dust) from entering the inside of the unit, and a lubricant (e.g., grease) enclosed in the unit. And lubricating oil) can be prevented from leaking outside. Depending on the level of sealing (air tightness or liquid tightness) required according to the configuration of the bearing unit, the purpose of use or the conditions of use, the sealing device is a contact-type seal (for example, the whole of a metal core made of steel or Seals that are partially connected with various elastic materials, etc.), non-contact type seals and shields (for example, shields pressed from thin metal plates such as stainless steel plates and iron plates), or seals, slinger and cores A package-type seal (pack seal) having a structure in which gold is combined may be arbitrarily selected and used.
Then, a lubricant (grease, lubricant, etc.) is sealed in a space (inner space of the bearing unit A) surrounded by the sealing device, the stationary wheel 2 and the rotating wheel 4, so that the stationary wheel 2, the rotating wheel 4, It is possible to reduce the friction and wear at the parts where the rolling elements 18 and the cage 20 are in contact with each other, prevent seizure, or extend the fatigue life.

The stationary ring 2 is integrally formed with a fixing flange 2f that protrudes outward (in the diameter-enlarging direction) from the outer peripheral surface 2a, and a fixing bolt (not shown) is inserted into a fixing hole 2h that passes through the fixing flange 2f. ) And fastened to the vehicle body side, the stationary wheel 2 can be fixed to a knuckle (not shown) of a suspension device (suspension).
The rotating wheel 4 includes a hub 12 that fixes and rotates with the disc wheel 42 and the brake rotor 40, and an inner ring structure 16 that is disposed on the hub 12. In this case, the hub 12 is formed with a raceway groove 4s facing the outboard side raceway groove 2s of the stationary wheel 2 on the outer periphery thereof, and the inner ring component 16 has an inboard of the stationary wheel 2 on the outer periphery thereof. A track groove 4t facing the side track groove 2t is formed. Thus, in this embodiment, the bearing unit A is configured as a hub unit bearing.
In this case, after the inner ring constituting body 16 is press-fitted to the stepped portion 12 s that is recessed so as to reduce the diameter of the outer peripheral edge of the inboard side of the hub 12 over the entire circumference, the hub 12 By crimping the end portion on the inboard side, the positioning is fixed to the hub 12 while being sandwiched between the stepped portion 12s of the hub 12 and the crimped portion 12d. As a result, a predetermined preload is applied to the inner ring structure 16 (and consequently the bearing unit (hub unit bearing) A).
Instead of such caulking and fixing, for example, after the inner ring 16 is press-fitted and fitted to the step 12s of the hub 12, the hub 12 is tightened with a fastening member such as a nut from the inboard side or the outboard side. It is also possible to fix to the inboard side. FIG. 3A also shows a rotating wheel 4 that includes only one inner ring component 16 and is disposed on the inboard side of the hub 10 (for example, fixed by crimping after press-fitting). Although the structure is shown, two inner ring components are provided, and in these inner ring components, raceway grooves 4t and 4s facing the raceway grooves 2t and 2s of the stationary ring 2 are formed, and these inner ring components are hubs. It is also possible to adopt a configuration of rotating wheels that are respectively fixed to the inboard side and the outboard side.

  The hub 12 has a plurality of flange portions (hereinafter referred to as hub flanges) 12f for fixing the brake rotor 40 while abutting against a rotor (brake rotor) 40 of a braking device, which is a wheel constituent member. The hub flange 12f protrudes radially from the outer peripheral portion of the hub 12 in the diameter increasing direction. In this embodiment, as shown in FIGS. 1 (a) and 3 (b), the four hub flanges 12f are equidistant (90 ° phase difference) in the circumferential direction, and the outer periphery of the hub 12 is A flat and radial projection is provided so as to extend beyond the stationary wheel 2 substantially perpendicularly from the outboard side along the diameter increasing direction. The hub 12 may be integrally formed with the hub flange 12f by cold forging. At that time, the number of protrusions and the protrusion interval of the hub flange 12f are not particularly limited, and can be set arbitrarily. Each hub flange 12f is a through-hole (hereinafter referred to as a flange bolt hole) 12h drilled so as to insert a fastening member (as an example, a stud bolt (hereinafter referred to as hub bolt 14)) when the brake rotor 40 is fixed. In the vicinity of the tip in the extending direction.

  On the other hand, the brake rotor 40 and the disc wheel 42 also have through holes (hereinafter referred to as rotor bolt holes 40h and wheel bolt holes 42h) that can communicate with the flange bolt holes 12h with respect to the respective disc portions 40a and 42a. The same number (four as an example) of flange bolt holes 12h are provided at equal intervals (as an example, a phase difference of 90 °). The flange bolt hole 12h, the rotor bolt hole 40h, and the wheel bolt hole 42h are all drilled with a hole diameter (diameter) substantially the same as the bolt diameter (diameter) of the hub bolt 14 to be inserted.

  Then, the hub rotor 14 is inserted into the rotor bolt hole 40h and the wheel bolt hole 42h from the flange bolt hole 12h and fastened with a hub nut (not shown), thereby positioning the brake rotor 40 and the disc wheel 42 with respect to the hub flange 12f. Can be fixed. In this case, the inboard side of the brake rotor 40 (specifically, the disc portion 40a) abuts on the outboard side of the hub flange 12f, and the disc wheel is placed on the outboard side of the brake rotor 40 (disc portion 40a). The disc wheel 42 and the brake rotor 40 are fixed to the hub flange 12f with the inboard side of 42 (specifically, the disk portion 42a) in contact therewith. That is, the brake rotor 40 is fixed to the hub flange 12f in a state in which the disc portion 40a is interposed (sandwiched) between the hub flange 12f and the disc portion 42a of the disc wheel 42. The disc portion 42a is fixed to the hub flange 12f in a state where the disc portion 42a is assembled via the disc portion 40a of the brake rotor 40.

In the present embodiment, the hub flange 12f is such that the circumferential width of the contact portion with the brake rotor 40 (specifically, the disc portion 40a) is not less than twice and not more than four times the diameter of the flange bolt hole 12h. (Hereinafter, this dimension is referred to as an appropriate dimension). 1 and 3 show a hub flange 12f having a circumferential width (distance w shown in FIGS. 1 (b) and 3 (b)) set to substantially the same dimension from the base in the extending direction to the tip. Although the configuration is shown as an example, if the circumferential width w of at least the contact portion with the brake rotor 40 (disk portion 40a) is set to the appropriate dimension, the circumferential width dimensions of other portions are arbitrary. You can set it to.
Note that a region that expands within twice the radius around the flange bolt hole 12h (a region that is the same center as the flange bolt hole 12h and has a diameter that is twice) is, for example, a steel disc wheel 42 via the brake rotor 40. Is fixed to the hub flange 12f, this corresponds to a region having the same phase as a flatness deterioration region (hereinafter referred to as a thinning region) on the disc wheel 42 that is generated when the wheel bolt hole 42h is punched out by press working. Further, the region that expands within 4 times the radius around the flange bolt hole 12h (the region that is the same center as the flange bolt hole 12h and has a diameter that is four times larger) is the axial dimension of the flange bolt hole 12h (around the flange bolt hole 12h). The thickness of the hub flange 12f) is approximately the same as the diameter (diameter) of the flange bolt hole 12h and the head diameter of the hub bolt 14 is twice the shaft diameter, the compression stress is 45 °. This corresponds to a region to be transmitted (hereinafter referred to as a compressive stress transmission region).
In the present embodiment, the hub flange 12f has a phase matching range between the contact portion with the brake rotor 40 and the phase of the contact portion between the brake rotor 40 and the disc wheel 42 with the inner diameter side of the hub flange 12f. It exists in the outer diameter side, respectively, and it comprises so that the matching range by the said outer diameter side may be divided into two in the circumferential direction.

Here, in the case of a steel plate (for example, JIS G 3113 hot rolled steel plate for automobile structure and SAPH 310 to 440 of a steel strip) used for press processing of a disc wheel, the elastic limit is about half of the tensile strength. For this reason, for example, when the disc wheel 42 is made of steel such as the steel plate, when the wheel bolt hole 42h is punched by press working, the material is drawn into the die by the punch at the time of punching, or the material due to the influence of plate pressing The deterioration of the flatness around the wheel bolt hole 42h due to the thinning of the wheel occurs up to a region (thinning region) approximately twice the diameter of the wheel bolt hole 42h.
Accordingly, by bringing the hub flange 12f into contact with the disc wheel 42 via the brake rotor 40 outside the region of approximately twice the diameter of the wheel bolt hole 42h, the outer diameter side of the disc wheel 42 and the brake rotor 40 can be reduced. It is possible to eliminate the offset of the phase of the contact portion (region A42 shown in FIG. 1B) and the contact portion of the brake rotor 40 and the hub flange 12f (region A12 shown in FIG. 1B). Become. The region A42 exists on the outboard side of the disc portion 40a of the brake rotor 40, and the region A12 exists on the inboard side of the disc portion 40a. Here, it is assumed that these are on the same side. The position of the contact part is taken as a phase. The disc wheel 42 is also in contact with the inner diameter side of the brake rotor 40 (specifically, the outboard side of the disc portion 40a) (region A421 shown in FIG. 1B).

That is, the hub flange 12f has a circumferential width w of a contact portion with the brake rotor 40, which is 2 of the hole diameter of the flange bolt hole 12h (the distance d shown in FIGS. 1B, 3B, and 3C). In addition to setting the dimension to be twice or more (w ≧ 2 × d), the outer diameter (diameter dimension of the extended tip (the distance L shown in FIGS. 1B and 3B)) is set to the flange bolt hole 12h. By setting the pitch circle diameter (distance PCD shown in FIG. 3 (b)) to a dimension equal to or larger than the dimension obtained by adding twice the length of the hole diameter d of the flange bolt hole 12h (L ≧ PCD + 2 × d), The above-described offset can be eliminated. Thereby, when the wheel rotates, it is possible to effectively prevent the generation of stress around the rotor bolt hole 40h in the brake rotor 40, and hence the generation of cracks around the rotor bolt hole 40h.
The hub flange 12f may be chamfered with respect to the contact portion with the brake rotor 40, but even in this case, the set dimensions (w ≧ 2 × d, L ≧ PCD + 2 × d). ) Is set with the dimension of the flat part not including the chamfer.

  On the other hand, increasing the circumferential width w of the hub flange 12f unnecessarily increases the mass of the hub 12 (and hence the mass of the bearing unit (hub unit bearing) A), which is not preferable. In general, the axial dimension (flange thickness) of the bolt hole is about the same as the bolt hole diameter, and the head diameter (diameter) of the bolt (including the hub bolt 14) is 2 of the shaft diameter (diameter). It is set to about twice. Therefore, considering that the axial dimension (flange thickness) of the bolt hole is the same as the bolt hole diameter, the bolt head diameter is twice the shaft diameter, and the compressive stress increases at 45 ° (FIG. 2). It is sufficient to set the circumferential width w of the hub flange 12f (the flat portion not including the chamfer) to be about four times the hole diameter d of the flange bolt hole 12h (w ≦ 4 × d (compressive stress transmission region)). )). Similarly, the outer diameter L of the hub flange 12f (a flat portion not including the chamfer) is larger than the dimension obtained by adding a length four times the hole diameter d of the flange bolt hole 12h to the pitch circle diameter PCD of the flange bolt hole 12h. It is not necessary to set a large size (L ≦ PCD + 4 × d (compressive stress transmission region)).

  That is, if the circumferential width w and the outer diameter L of the hub flange 12f are set with these as the upper limit, the molding material of the hub 12 can be eliminated and an increase in its mass can be suppressed. In consideration of the balance between the strength around the flange bolt hole 12h and the strength of the hub bolt 14, the thickness around the flange bolt hole 12h (the axial width (distance T shown in FIG. 3 (c))) It is preferable to make the dimensions substantially the same as the hole diameter d of the bolt hole 12h. In this case, the thickness (axial width) of the hub flange 12f may be the same dimension (same thickness) from the base in the extending direction to the tip, but gradually decreases from the extending base to the extending tip. It is also possible to make it small (thin) or to make the vicinity of the extended base part larger (thick) than other parts. Further, the cross-sectional shape in the tangential direction of the hub flange 12f is not necessarily rectangular. For example, if such a cross section is trapezoidal and the crossing angle between the long side and the oblique side is larger than 45 °, the weight can be reduced without inhibiting the transmission of compressive stress from the head of the hub bolt 14. Become.

Here, in the present embodiment, the phase coincidence range of the contact portion between the disc wheel 42 and the brake rotor 40 and the contact portion between the brake rotor 40 and the hub flange 12f is the same as the inner diameter side and the outer diameter of the hub flange 12f. The matching range on the outer diameter side is divided into two in the circumferential direction, in other words, the matching range of the phases of these contact portions is one point on the inner diameter side (specifically, the region A matching range between A421 and region A12), and three-point support that assumes two points on the outer diameter side (specifically, a matching range between region A42 and region A12) is assumed. For example, when the hub 12 is too light in weight, if the circumferential width w of the hub flange 12f is too narrow, the phase matching range is only one point on the inner diameter side. Alternatively, in order to secure a contact area, the circumferential width w of the hub flange 12f is increased as the outer diameter side (area A42) and the inner diameter side (area A421) of the contact portion between the disc wheel 42 and the brake rotor 40 are connected. In this case, the mass of the hub 12 is increased. Further, when the outer diameter L of the hub flange 12f is extended, not only the mass is increased, but also the contact portion on the outer diameter side of the disk wheel 42 and the brake rotor 40 (region A42 divided into two in the circumferential direction). The phase matching range between the brake rotor 40 and the contact portion (region A12) of the hub flange 12f is supported by two points, one point on the inner diameter side and one point on the outer diameter side. Since the hub flange 12f and the surface of the brake rotor 40 (specifically, the disk portion 40a) have irregularities that are unavoidable for molding, they actually come into contact with somewhere in the contact portion. Depending on the combination of the contact portions (positions), the fastening state by the hub bolt 14 may become unstable or cause unnecessary stress.
Therefore, in order to effectively prevent the generation of stress around the rotor bolt hole 40h in the brake rotor 40, and hence the generation of cracks around the rotor bolt hole 40h, and to stabilize the fastening state by the hub bolt 14 It is desirable that the phase coincidence range is a three-point support with one point on the inner diameter side and two points on the outer diameter side.

1B and 1C, the circumferential width w and the outer diameter L of the hub flange 12f are set as described above (2 × d ≦ w ≦ 4 × d, PCD + 2 × d ≦ L ≦ PCD + 4 × d). ), Specific examples of the contact state between the disc wheel 42 and the brake rotor 40 and the contact state between the brake rotor 40 and the hub flange 12f are shown.
In the state shown in FIG. 1B, the circumferential width w of the hub flange 12f is approximately twice the hole diameter d of the flange bolt hole 12h (w = 2 × d (corresponding to the periphery of the thinned region of the disc wheel 42). ), And the outer diameter L of the hub flange 12f is set so as to be applied to the peripheral edge of the thinning region of the disc wheel 42. As a result, the phase matching range of the contact portion (region A42 and region A421) between the disc wheel 42 and the brake rotor 40 and the contact portion (region A12) between the brake rotor 40 and the hub flange 12f is one point on the inner diameter side. In addition, it can be a three-point support that is two points on the outer diameter side (three regions shown with hatching in the figure).
Further, in the state shown in FIG. 1C, the contact portion (region A42 and region A421) of the disc wheel 42 and the brake rotor 40 and the contact portion (region A12) of the brake rotor 40 and the hub flange 12f. The phase matching range is outside the thinning region of the disc wheel 42 and within a predetermined region within the compressive stress transmission region of the hub flange 12f (a region spaced about 2.5 times the radius d / 2 from the center of the flange bolt hole 12h). , And its vicinity), and a three-point support having one point on the inner diameter side and two points on the outer diameter side in the region (three regions shown with hatching in the figure).

As described above, according to the hub unit bearing A including the wheel support bearing unit A according to the present embodiment, specifically, the hub (for example, the cold forging type) 12 having the radial hub flange 12f, the mass and While maintaining the weight reduction effect and reducing the cost without incurring an increase in cost, the phase of the contact portion between the disc wheel 42 and the brake rotor 40, the brake rotor 40 and the hub unit bearing A (specifically, , The offset from the phase of the contact portion of the hub flange 12f) can be reliably suppressed.
Thereby, generation | occurrence | production of the stress around the rotor bolt hole 40h of the brake rotor 40 and by extension, generation | occurrence | production of the crack around the said rotor bolt hole 40h can be prevented effectively. Therefore, for example, even when the steel disc wheel 42 is assembled to the hub flange 12f (so-called cold forging type hub 12) radially projecting via the brake rotor 40, the rotor bolt hole 40h. It is possible to effectively prevent the generation of stress around and the generation of cracks.

12 Hub 12f Flange (hub flange)
12h Through hole (flange bolt hole)
14 Fastening member (hub bolt)
16 Inner ring component 18 Rolling body 40 Brake rotor 42 Disc wheel A Wheel support bearing unit A12 Contact portion A42 between the brake rotor and hub flange A421 Contact portion A421 between the disc wheel and the brake rotor Disc wheel and brake rotor L-side contact part L Hub flange outer diameter PCD Pitch circle diameter of the through hole (flange bolt hole) d Flange bolt hole diameter (diameter)
w Hub flange circumferential width

Claims (1)

A stationary wheel fixed to the vehicle body component and maintained in a non-rotating state;
A rotating wheel that is disposed opposite to the stationary wheel and that rotates with the wheel component member by fixing the wheel component member;
A wheel bearing unit bearing comprising a plurality of rolling elements formed on the stationary wheels and the rotating wheels, respectively, so as to be able to roll between the mutually facing raceway grooves,
The rotating wheel is composed of a hub that fixes a rotor of a braking device that is the wheel constituent member and rotates together with the rotor, and an inner ring constituent body disposed on the hub,
The hub has a plurality of flat-plate-shaped flange portions radially projecting in the diameter increasing direction on the outer peripheral portion thereof, and is formed by side extrusion of cold forging,
The flange portion fixes a wheel of a wheel that is a wheel constituent member through the rotor while abutting on the rotor, and is a through-hole that is drilled to insert a fastening member when the rotor and the wheel are fixed. In the vicinity of the tip,
The wheel is made of steel, can communicate with the through-hole of the flange portion, and has a through-hole punched out by pressing, and is provided with a thinning region around the through-hole of the wheel,
The outer diameter end of the flange portion is formed so as to hang over the thinned region of the wheel,
The wheel is fixed to the flange portion via a fastening member in contact with the rotor, and the phases of the contact portion between the wheel and the rotor and the contact portion between the rotor and the flange portion are matched. The range exists on the inner diameter side and the outer diameter side of the flange portion, and the matching range of the outer diameter side is divided into two in the circumferential direction. The wheel has one point on the inner diameter side and two points on the outer diameter side. The wheel support bearing unit is supported at three points.