JP7835342B2 - wheel support structure - Google Patents

Description

This matter concerns a wheel support structure that supports the wheels of a vehicle.

Conventionally, wheel support structures are known in which a wheel is supported via a hub unit (wheel hub) on a spindle (non-rotating axle) provided on a vehicle. For example, a wheel support structure is known in which a spindle attached to the steering knuckle or the lower part of the suspension is fixed to the inner ring of a hub unit, an outer ring is provided on the outer circumference of the inner ring via a bearing, and the wheel is fixed to the outer ring. Furthermore, in such a structure, a cover member (dust cover) is attached to protect the brake disc rotor fixed to the wheel from flying stones, mud, water, etc. (see Patent Documents 1 and 2).

Japanese Patent Application Publication No. 11-311270 Patent No. 4239159

A wheel speed sensor is installed near the wheel to detect the wheel speed (angular velocity of the wheel). For example, a wheel speed sensor is known that derives the wheel speed by fixing a magnetic ring (magnetic encoder) to the outer ring of the hub unit and detecting the fluctuation period of the magnetic field with a magnetic detector (magnetic sensor head) positioned opposite the magnetic ring. On the other hand, with this type of wheel speed sensor, the accuracy of wheel speed detection may decrease due to the adhesion or interference of foreign matter (e.g., flying stones, muddy water, sand and dust, etc.) to the magnetic ring or magnetic detector. Furthermore, even if a cover member is attached to protect the brake disc rotor, foreign matter may enter through the gap between the brake disc rotor and the cover member, raising concerns about a decrease in the accuracy of wheel speed detection and the occurrence of damage.

One of the objectives of this invention is to provide a wheel support structure that addresses the above-mentioned problems, suppresses the adhesion and interference of foreign matter to the wheel speed sensor with a simple configuration, and improves the accuracy of wheel speed detection. Furthermore, in addition to this objective, other objectives of this invention include achieving effects and benefits that cannot be obtained with conventional technology, derived from the various configurations shown in the "Modes for Carrying Out the Invention" section below.

The disclosed wheel support structure can be realized in the embodiments (application examples) disclosed below, and solves at least some of the above-mentioned problems. Each of the embodiments from Embodiment 2 onward is an additional embodiment that can be appropriately selected and each of them is an embodiment that can be omitted. None of the embodiments from Embodiment 2 onward disclose any embodiments or configurations that are indispensable to this case.

Embodiment 1. The disclosed wheel support structure comprises a hub unit mounted on a spindle that has a base fixed to the vehicle and protrudes outward in the vehicle width direction, to which a wheel and a brake disc rotor are fixed; a magnetic ring provided in an annular shape along the outer circumferential surface of the hub unit; a back plate fixed to the base to which a brake caliper is attached; a magnetic detector fixed to the base and extending through the back plate to the vicinity of the magnetic ring; and a cylindrical cover means formed on the radially outer side of the hub unit to cover the outer circumferential surface of the magnetic ring and the magnetic detector.

Embodiment 2. In Embodiment 1 described above, it is preferable that the cover means has a flange portion in a shape that is close to the surface of the brake disc rotor in a portion close to the brake disc rotor.
Embodiment 3. In Embodiment 1 or 2 described above, it is preferable that the cover means has a cutout portion in which the portion located below the spindle is removed in a portion close to the brake disc rotor.
Embodiment 4. In any of embodiments 1 to 3 described above, it is preferable to have a dust shield that is sandwiched between the base and the back plate and is formed in the shape of a tray, covering the back plate, the brake disc rotor and the cover means.

Embodiment 5. In an embodiment combining embodiments 1, 2 and 4 described above, it is preferable that the brake disc rotor has a disc-shaped central portion sandwiched between the hub unit and the wheel, a cylindrical portion extending cylindrically from the radially outer end of the central portion toward the base, and a perforated disc-shaped peripheral portion extending radially outward from the base-side end of the cylindrical portion toward the hub unit. Furthermore, it is preferable that the flange portion is provided close to the cylindrical portion, and the outer edge of the dust shield is provided close to the peripheral portion.

Embodiment 6. In any of embodiments 1 to 5 described above, it is preferable that the cover means is formed separately from the back plate and fixed to the back plate.
Embodiment 7. In an embodiment that combines embodiments 1, 4 and 6 described above, it is preferable that the back plate has a first tapped hole with a screw groove formed on its inner circumferential surface, the dust shield and the back plate are integrally fixed via a first bolt that screws into the first tapped hole, and the cover means is integrally fixed to the dust shield and the back plate via the first bolt and a first nut that screws into it.

According to the disclosed wheel support structure, by providing a cylindrical cover means that covers the outer circumference of the magnetic ring and magnetic detector, the adhesion and interference of foreign matter to the wheel speed sensor (magnetic ring, magnetic detector) can be suppressed with a simple configuration, and the accuracy of wheel speed detection can be improved.

This is an exploded perspective view of a wheel support structure as an example. This is a cross-sectional view of a wheel support structure as an example. Figure 1 is a perspective view of the spindle shown. Figure 1 is a perspective view of the backplate. Figure 1 is a perspective view of the dust cover. Figure 1 is a perspective view of the dust shield. Figure 1 is a perspective view of the brake disc rotor. This is an exploded perspective view illustrating the assembly method of the dust shield, backplate, and dust cover. (A) is a cross-sectional view showing the fastening state around the first tapped hole, and (B) is a cross-sectional view showing the fastening state around the second tapped hole.

The disclosed wheel support structure is implemented, for example, by the following embodiment. The wheel support structure of this embodiment is a structure that supports a wheel on a spindle (non-rotating axle) provided on a vehicle via a hub unit (wheel hub) with a built-in bearing, and is applied to a vehicle as a structure for the mounting points of the left wheel and the right wheel. The spindle is fixed to, for example, the steering knuckle or the arm of the suspension device (suspension arm) of the vehicle. The wheel of the wheel and the brake disc rotor of the disc brake device are fixed to the hub unit.

Regarding the definition of direction in this embodiment, the longitudinal direction is determined based on the forward and reverse direction of the vehicle, and the lateral direction (vehicle width direction) is determined based on that longitudinal direction. The vertical direction is determined based on the state in which the vehicle is stopped on a flat road surface. Furthermore, in the structure relating to the left wheel of the vehicle, the left side is the outside of the vehicle, and the right side is the inside of the vehicle. Similarly, in the structure relating to the right wheel of the vehicle, the right side is the outside of the vehicle, and the left side is the inside of the vehicle.

The hub unit according to this embodiment rotatably supports the driven wheels (non-driven wheels) of a vehicle. On the other hand, as in the structure described in Patent Document 1, it is also possible to rotatably support the driven wheels in the hub unit by inserting the drive shaft inside a hollow spindle. Therefore, the wheels to which the disclosed wheel support structure can be applied are not limited to driven wheels only, and the disclosed wheel support structure can be applied to the driven wheels. Furthermore, the disclosed wheel support structure can be applied to any wheel provided on a vehicle. For example, it may be applied to the front or rear wheels of a four-wheeled vehicle, or to the wheels of a vehicle with six or more wheels.

[1. Structure]
Figure 1 is an exploded perspective view of a wheel support structure 1 as an embodiment, and Figure 2 is a cross-sectional view of the wheel support structure 1. As shown in Figure 1, the wheel support structure 1 is provided with at least a hub unit 10, a wheel speed sensor including a magnetic ring 8 and a magnetic detector 9, a back plate 2, and a dust cover 3 (covering means). In addition, the wheel support structure 1 of this embodiment may include a dust shield 4 and a brake disc rotor 5.

The wheel speed sensor comprises a magnetic ring 8 fixed to the part of the hub unit 10 that rotates with the wheel (rotating side) and a magnetic detector 9 fixed to the vehicle-side part that does not rotate (non-rotating side). The magnetic ring 8 is a component formed including, for example, a magnetic material or a magnet, and is provided in an annular shape along the outer circumferential surface of the hub unit 10. If the wheel speed sensor is an electromagnetic induction type sensor, the magnetic ring 8 is formed in an annular shape by arranging multiple magnets in a circumferential direction so that the direction of the magnetic field alternates according to the rotation of the hub unit 10. If the wheel speed sensor is a magnetoresistive element type sensor, the magnetic ring 8 is formed in an annular shape with gear-like protrusions and recesses using, for example, some magnetic material.

The magnetic detector 9 is a device that detects the strength and direction of the magnetic field, which changes under the influence of the magnetic ring 8. The magnetic detector 9 is fixed to the vehicle so as to be in the vicinity of the magnetic ring 8 and facing the outer surface of the magnetic ring 8. If the wheel speed sensor is an electromagnetic induction type sensor, for example, a coil for capturing the direction and strength of the magnetic field is built into the magnetic detector 9. If the wheel speed sensor is a magnetoresistive element type sensor, for example, a magnet that generates a reference magnetic field and a semiconductor element (for example, an MR (Magneto-Resistance effect) element) that changes its resistance value according to the direction of the magnetic field that fluctuates under the influence of the magnetic ring 8 are built into the magnetic detector 9. Note that the position of the magnetic detector 9 in a side view of the vehicle may be located on the front side or rear side of the hub unit 10, or on the upper side or lower side of the hub unit 10.

[A] Hub Unit The hub unit 10 is a device that is mounted on a spindle 6 fixed to a vehicle and supports the wheel so that it can rotate. As shown in Figure 2, the hub unit 10 is provided with a hub inner ring 11 (inner race), a hub outer ring 12 (outer race), and a hub bearing 13 (bearing). The hub inner ring 11 is a member that is fixed to the spindle 6 so as not to rotate, and is formed, for example, in a hollow cylindrical shape. The inner circumferential surface of the hub inner ring 11 is formed in a cylindrical shape into which the spindle 6 fits, for example. On the other hand, the raceway surface of the hub bearing 13 is formed on the outer circumferential side of the hub inner ring 11.

The hub outer ring 12 is a member that is rotatably supported by the hub inner ring 11 via a hub bearing 13, and is formed in a hollow cylindrical shape, for example, having an inner diameter larger than the outer diameter of the hub inner ring 11. The raceway surface of the hub bearing 13 is formed on the inner circumference side of the hub outer ring 12. The outer circumference surface of the hub outer ring 12 is formed in the shape of a frustoconical pyramidal surface, which is narrower on the vehicle side and wider on the vehicle side, as shown in Figure 2, for example. The wheel 19, brake disc rotor 5, and magnetic ring 8 are fixed to the hub outer ring 12. The magnetic ring 8 is provided in an annular shape along the outer circumference surface of the hub outer ring 12 at the vehicle side end of the hub outer ring 12.

The hub bearing 13 is, for example, a ball bearing, roller bearing, or fluid bearing, and is interposed between the hub inner ring 11 and the hub outer ring 12. The hub bearing 13 shown in Figure 2 is a ball bearing. A retainer (not shown) may be provided around the hub bearing 13 to prevent contact between the hub bearings 13. Note that the structure of the hub bearing 13 shown in Figure 2 is merely one example of a possible configuration and can be replaced with a wide variety of other bearing structures.

The hub unit 10 in this embodiment is a so-called second-generation hub unit. A second-generation hub unit is a common term for a hub unit 10 in which a hub flange 14 is provided on the hub outer ring 12. The hub flange 14 is a part that extends in a planar shape (record-like) from the hub outer ring 12 toward the radially outward direction of the hub unit 10. General second-generation hub units include those in which the hub flange 14 is fixed to the wheel 19 (the hub outer ring 12 rotates together with the wheel) and those in which the hub flange 14 is fixed to the vehicle side (the hub inner ring 11 rotates together with the wheel, and the hub outer ring 12 does not rotate). The hub unit 10 in this embodiment is the former.

Multiple hub bolt holes 15 are drilled in the hub flange 14. Each hub bolt hole 15 is positioned so that it is at an equal distance from the rotation axis of the hub outer ring 12 and at equal intervals in the circumferential direction relative to the rotation axis. The shape of the hub bolt holes 15 is circular. In addition, multiple spline grooves extending in the thickness direction of the hub flange 14 are engraved on the inner circumferential surface of the hub bolt holes 15. Similar spline grooves are engraved on the outer surface of the hub bolts 16 to correspond to the uneven shape of these spline grooves.

The hub bolts 16 are driven into each hub bolt hole 15 from the inside of the vehicle (left side of the page) to the outside of the vehicle (right side of the page) in Figure 2, and fixed in place, for example, before the hub unit 10 is mounted on the spindle 6. Although five hub bolts 16 are shown as an example in Figure 1, the number of hub bolts 16 is not limited to this and depends on the type of vehicle, wheel diameter, etc. The wheel 19 and brake disc rotor 5 are fastened and fixed to the hub flange 14 via the hub bolts 16 and hub nuts (wheel nuts) (not shown).

[B] Spindle As shown in Figure 3, the spindle 6 is provided with a base 61, a hub unit support portion 62, a threaded portion 63, and a fixing hole 64. The base 61 is a plate-shaped portion that is fixed to the vehicle. In this embodiment, the base 61 is flat and is fixed to the outer side of the suspension arm 7. The surface of the base 61 is vertical, and its normal extends horizontally outward in the vehicle width direction. In this embodiment, the back plate 2, dust cover 3, dust shield 4, and magnetic detector 9 are fixed to the base 61.

The hub unit support portion 62 is an axial portion that extends horizontally outward from the base portion 61 in the vehicle width direction. In this embodiment, the hub unit support portion 62 is formed in a cylindrical shape having an outer diameter corresponding to the inner circumferential surface of the hub inner ring 11. The axial length of the hub unit support portion 62 is set to correspond to the axial length on the inner circumferential surface of the hub inner ring 11.

The threaded portion 63 is a cylindrical part that is thinner and coaxial with the hub unit support portion 62, and has screw grooves engraved on its outer surface. The central axes of the hub unit support portion 62 and the threaded portion 63 coincide with the rotation axis of the hub unit 10 (the rotation axis of the wheel). The hub unit 10 is fixed to the spindle 6 by fastening a center nut 17 that screws onto the threaded portion 63 while the hub unit support portion 62 is inserted inside the inner ring 11 of the hub (fitted).

The fixing holes 64 are holes through which fasteners for fixing the back plate 2, dust cover 3, dust shield 4, etc., to the base 61 (i.e., the vehicle) are inserted. Multiple fixing holes 64 are arranged around the periphery of the hub unit support portion 62 in a front view of the base 61. The fixing holes 64 shown in Figure 3 are screw holes with threaded grooves formed on their inner circumferential surface for screwing into flange bolts 27. The back plate 2, dust cover 3, dust shield 4, etc., are fastened and fixed in a sandwiched state between the base 61 and the flange of the flange bolt 27. Although Figure 3 shows four fixing holes 64 and flange bolts 27, the number of fixing holes 64 and flange bolts 27 is not limited to this.

[C] Back Plate The back plate 2 is a plate-shaped member fixed to the base 61 of the spindle 6 and to which the brake caliper 18 is attached. As shown in Figure 4, the back plate 2 is provided with a plate hole 21, a plate fixing hole 22, a caliper fixing hole 23, a first tapped hole 24, a second tapped hole 25, and a recessed portion 26. The plate hole 21 is formed to be larger than the magnetic ring 8 provided at least on the vehicle-side end of the hub unit 10.

The plate fixing holes 22 are circular holes through which flange bolts 27 are inserted, and are arranged in multiple locations surrounding the plate holes 21 when viewed from the front of the back plate 2. The positions of the plate fixing holes 22 are set to coincide with the positions of the fixing holes 64 when the back plate 2 is fixed to the base 61. The caliper fixing holes 23 are holes for fixing the brake caliper 18, and caliper fasteners (not shown) are inserted through these holes for fastening.

The first tapped hole 24 is a circular hole for integrating the dust shield 4 and the back plate 2 (making them an assembly) and for fixing the dust cover 3 to the back plate 2. A screw groove for screwing in the first bolt 28, which will be described later, is formed on the inner circumferential surface of the first tapped hole 24. The length of the threaded portion of the first bolt 28 is set to be at least longer than the thickness of the back plate 2. The first bolt 28 is inserted into the first tapped hole 24 from the inside of the vehicle and fastened in place when the dust cover 3 and the back plate 2 are stacked together. At this time, the portion of the first tapped hole 24 that protrudes from the outside of the vehicle is used as a threaded portion for fixing the dust shield 4 to the back plate 2.

The second tapped hole 25 is a circular hole into which a fastener for fixing the dust shield 4 to the back plate 2 is attached. A threaded groove for screwing into the second bolt 37 (described later) is formed on the inner circumferential surface of the second tapped hole 25. The second bolt 37 is inserted into the second tapped hole 25 from the inside of the vehicle and fastened in place. The length of the threaded portion of the second bolt 37 may be set to be longer than the thickness of the back plate 2, but it is preferably set to be shorter than the thickness of the back plate 2.

The recessed portion 26 is a part of the plate hole 21 whose edge is partially recessed to prevent interference between the magnetic detector 9 and the back plate 2 (in other words, a part of the plate hole 21 that is enlarged so that the magnetic detector 9 and the back plate 2 do not interfere with each other). The magnetic detector 9 is mounted so as to pass through the inside of the recessed portion 26, penetrate the back plate 2 from the inside of the vehicle to the outside of the vehicle, and extend to the vicinity of the magnetic ring 8. Note that it is not necessary to integrate the recessed portion 26 and the plate hole 21 into a single hole; the recessed portion 26 and the plate hole 21 may each be formed as independent holes.

[D] Dust Cover The dust cover 3 is an example of a covering means that covers the outer circumference of the magnetic ring 8 and magnetic detector 9 in order to prevent foreign matter from adhering to or interfering with the wheel speed sensor. The dust cover 3 is formed in a cylindrical shape that covers the outer circumference of the magnetic ring 8 and magnetic detector 9 on the radially outer side of the hub unit 10. In this embodiment, the dust cover 3 is formed separately from the back plate 2 and is fixed to the outer surface of the back plate 2. The back plate 2 and the dust cover 3 may be formed as a single unit. That is, a part having the same shape as the dust cover 3 in this embodiment may be formed on the back plate 2.

As shown in Figure 5, the dust cover 3 is provided with a cylindrical portion 31, a flange portion 32, a cover fixing portion 33, a first fixing hole 34, a second fixing hole 35, and a notch portion 36. The cylindrical portion 31 is a hollow cylindrical part formed coaxially with the rotation axis of the hub unit 10. The inner diameter of the cylindrical portion 31 is set to a size that allows the magnetic ring 8 and magnetic detector 9 to be completely housed inside the cylindrical portion 31. Furthermore, the axial length of the cylindrical portion 31 is set to a length that covers at least the area directly above and directly below the magnetic ring 8 and magnetic detector 9, as shown in Figure 2.

In this embodiment, the inner diameter of the cylindrical portion 31 is set to facilitate the attachment, removal, and replacement of the hub bolts 16 during vehicle maintenance. For example, the inner diameter of the cylindrical portion 31 is set to a size that completely accommodates the figure obtained by projecting the contours of all the hub bolts 16 onto the surface of the back plate 2 in the direction of the rotation axis of the hub unit 10 (preferably, a size slightly larger than that figure).

Furthermore, in this embodiment, the axial length of the cylindrical portion 31 is set to enhance the effect of preventing foreign matter from adhering to or interfering with the wheel speed sensor. For example, the axial length of the cylindrical portion 31 is set to such a length that, in the cross-section shown in Figure 2, the cylindrical portion 52 of the brake disc rotor 5 (described later) and the cylindrical portion 31 overlap in the vertical direction of the paper (for example, in the vehicle's longitudinal direction or vehicle's vertical direction, etc.) (that is, the length such that the outer end of the cylindrical portion 31 extends inside the cylindrical portion 52).

The flange portion 32 is a part of the dust cover 3 that is close to the brake disc rotor 5 and is formed in a shape that is close to the surface of the brake disc rotor 5. In other words, the flange portion 32 is a part that is formed in a shape that approaches the brake disc rotor 5 in the radial direction of the hub unit 10. In this embodiment, the flange portion 32 is provided at the outer end of the cylindrical portion 31 and is formed in a shape (record-like) that extends in a planar manner toward the radially outward direction of the cylindrical portion 31. As shown in Figure 2, a small gap is provided between the tip of the flange portion 32 and the brake disc rotor 5 (cylindrical portion 52).

The cover fixing portion 33 is a part of the dust cover 3 that is bent at the end furthest from the brake disc rotor 5 so as to follow the surface of the back plate 2. In this embodiment, the cover fixing portion 33 is provided at the vehicle-side end of the cylindrical portion 31 and is formed in a shape (record-like) that extends radially outward from the cylindrical portion 31. The cover fixing portion 33 and the back plate 2 are in surface contact. Alternatively, the cover fixing portion 33 may be formed in a shape that extends radially inward from the cylindrical portion 31.

The first fixing hole 34 and the second fixing hole 35 are circular holes for fixing the dust cover 3 to the back plate 2, and are provided in the cover fixing portion 33. The position of the first fixing hole 34 is set to coincide with the position of the first tapped hole 24 when the dust cover 3 is fixed to the back plate 2, and the position of the second fixing hole 35 is set to coincide with the position of the second tapped hole 25 when the dust cover 3 is fixed to the back plate 2.

The notch 36 is a portion of the dust cover 3 that is cut away from the area near the brake disc rotor 5, specifically the portion located below the spindle 6. The notch 36 functions as an outlet for foreign matter that enters the inside of the dust cover 3 to be discharged. In this embodiment, the notch 36 is formed by cutting out the cylindrical portion 31 from the outer end of the vehicle toward the inside of the vehicle. This notch 36 also functions as a working opening for removing the hub bolt 16 during vehicle maintenance. The width of the notch 36 in the vehicle's longitudinal direction is formed to be greater than the head width of the hub bolt 16. The length of the notch 36 in the vehicle's width direction is set to a length that ensures a gap between the hub bolt 16 and the hub flange 14 for the hub bolt 16 to pass through, for example, when the brake disc rotor 5 is removed. The position of the notch 36 in a side view of the vehicle may be directly below the spindle 6, or it may be shifted in the vehicle's longitudinal direction from directly below the spindle 6.

[E] Dust Shield The dust shield 4 is a component for protecting the brake disc rotor 5. The dust shield 4 is formed in a tray shape that covers the brake disc rotor 5, the back plate 2 and the dust cover 3, and is sandwiched between the base 61 of the spindle 6 and the back plate 2. As shown in Figure 6, the dust shield 4 is provided with a shield center portion 41, a shield outer edge portion 42, a caliper mounting portion 43, a shield hole 44, a shield fixing hole 45, a first fastening hole 46, a second fastening hole 47 and a sensor pass-through hole 48.

The central part 41 of the shield is a flat portion that is sandwiched and fixed between the base 61 and the back plate 2. The shield hole 44, shield fixing hole 45, first fastening hole 46, second fastening hole 47, and sensor pass-through hole 48 are provided in the central part 41 of the shield.
The shield outer edge portion 42 is a portion with a shape (conical surface) that extends from the outer edge of the shield central portion 41 toward the outer edge of the brake disc rotor 5. The shield outer edge portion 42 is formed to cover the inner and radially outer portions of the brake disc rotor 5. As shown in Figure 2, the outer edge of the shield outer edge portion 42 protrudes further outward than the outer edge of the brake disc rotor 5.

The caliper mounting portion 43 is the area where the brake caliper 18 is positioned. The shape of the caliper mounting portion 43 is formed to correspond to the outer shape of the brake caliper 18. The shield hole 44 is a hole through which the hub unit support portion 62 is inserted, and is formed to be larger than the hub unit support portion 62.
The shield fixing holes 45 are circular holes through which flange bolts 27 are inserted, and are arranged in multiple locations around the shield holes 44 when viewed from the front of the back plate 2. The positions of the shield fixing holes 45 are set to coincide with the positions of the fixing holes 64 when the dust shield 4 is fixed to the base 61.

The first fastening hole 46 is a circular hole for fixing the dust shield 4 to the back plate 2. The position of the first fastening hole 46 is set to coincide with the position of the first tapped hole 24 when the dust shield 4 is fixed to the back plate 2.
The second fastening hole 47 is a circular hole corresponding to the second tapped hole 25 provided in the back plate 2. However, if the length of the threaded portion of the second bolt 37 to be attached to the second tapped hole 25 is relatively short, the tip of the second bolt 37 will not reach the dust shield 4, and therefore the second fastening hole 47 may be omitted.

The sensor through-hole 48 is a hole formed to prevent interference between the magnetic detector 9 and the dust shield 4, and is provided at a position corresponding to the recess 26 of the back plate 2. The magnetic detector 9 is mounted so as to extend not only through the recess 26 but also through the inside of the sensor through-hole 48 to the vicinity of the magnetic ring 8. Note that it is not necessary to form the sensor through-hole 48 and the shield hole 44 as separate holes; the sensor through-hole 48 and the shield hole 44 may be integrated into a single hole.

[F] Brake Disc Rotor The brake disc rotor 5 is a component of a disc brake system for braking the wheel, and is a disc-shaped member that rotates integrally with the wheel. When the brake caliper 18 presses the brake pads against the brake disc rotor 5, braking force is generated on the wheel. As shown in Figure 7, the brake disc rotor 5 is provided with a central portion 51, a cylindrical portion 52, a peripheral portion 53, disc holes 54, and hub bolt holes 55.

The central portion 51 is a perforated disc-shaped part sandwiched between the hub unit 10 and the wheel 19. The disc holes 54 and hub bolt holes 55 are provided in the central portion 51. The outer diameter of the central portion 51 is set to be larger than the outer diameter of the hub flange 14. As shown in Figure 2, the central portion 51 is the part that is sandwiched and fixed between the hub flange 14 of the hub unit 10 and the wheel 19.

The cylindrical portion 52 is a part that extends cylindrically from the outer end of the central portion 51 (the radially outer end of the hub unit 10 when it is fixed to the hub unit 10) toward the base portion 61. The cylindrical portion 52 is close to the flange portion 32 of the dust cover 3. In the cross-section shown in Figure 2, the cylindrical portion 52 has a shape that extends in the direction of the central axis of the hub unit 10, and the flange portion 32 has a shape that extends in a direction perpendicular to the central axis of the hub unit 10.

The peripheral portion 53 is a perforated disc-shaped part that extends radially outward from the end of the cylindrical portion 52 on the base portion 61 side of the hub unit 10. The brake pads are pressed against the peripheral portion 53 by the brake caliper 18. The peripheral portion 53 is close to the edge of the shield outer edge portion 42. In the cross-section shown in Figure 2, the peripheral portion 53 has a shape that extends in a direction perpendicular to the central axis of the hub unit 10, and the edge of the shield outer edge portion 42 has a shape that extends in the direction of the central axis of the hub unit 10.

[G] Assembly
Figures 8 and 9(A) and (B) illustrate the assembly method of the dust shield 4, back plate 2, and dust cover 3. As shown in Figure 2, these components are fastened together as a single unit after being installed on the vehicle. On the other hand, if these three components are integrated before being installed on the vehicle, the ease of assembly on the vehicle may be reduced. Specifically, because the space between the flange bolt 27 and the dust cover 3 is narrow, the tool used to rotate the flange bolt 27 is likely to interfere with the dust cover 3, making it difficult to fasten the flange bolt 27.

Therefore, in this embodiment, considering ease of assembly, a first fastening structure for forming the assembly of the dust shield 4 and the back plate 2, and a second fastening structure for fixing the dust cover 3 to the assembly are provided separately. The first fastening structure is a part that is fastened and fixed before assembly to the vehicle, and the second fastening structure is a part that is fastened and fixed after assembly to the vehicle. Figure 9(A) shows a cross-section of the first fastening structure, and Figure 9(B) shows a cross-section of the second fastening structure.

The fasteners for the first fastening structure are a first bolt 28 and a first nut 29. As shown in Figure 9(A), the first bolt 28 is a bolt having a screw groove that engages with the first tapped hole 24 of the back plate 2. When the dust shield 4 and the back plate 2 are stacked together, the bolt 28 is inserted from the first fastening hole 46 side of the dust shield 4 and fastened to the first tapped hole 24. As a result, the tip of the threaded portion of the first bolt 28 protrudes from the first tapped hole 24. The first nut 29 is not yet attached to the first bolt 28 when the dust shield 4 and back plate 2 assembly is not yet attached to the vehicle.

The dust shield 4 and back plate 2 assembly are attached to the vehicle via flange bolts 27. Then, the first fixing hole 34 of the dust cover 3 is inserted through the tip of the threaded portion of the first bolt 28, and the first nut 29 is fastened to the first bolt 28.
Furthermore, the fastener for the second fastening structure is the second bolt 37. As shown in Figure 9(B), the second bolt 37 is a bolt having a screw groove that engages with the second tapped hole 25 of the back plate 2. When the dust cover 3, dust shield 4 and back plate 2 assembly are stacked together, the bolt 37 is inserted from the second fixing hole 35 side of the dust cover 3 and fastened to the second tapped hole 25.

[2. Action, Effects]
(1) The wheel support structure 1 of this embodiment comprises a hub unit 10, a magnetic ring 8, a back plate 2, a magnetic detector 9, and a dust cover 3 (covering means). The hub unit 10, to which the wheel 19 and brake disc rotor 5 are fixed, is mounted on a spindle 6 that has a base 61 fixed to the vehicle and protrudes outward in the vehicle width direction. The magnetic ring 8 is provided in an annular shape along the outer circumferential surface of the hub unit 10. The back plate 2 to which the brake caliper 18 is attached is fixed to the base 61. The magnetic detector 9 is fixed to the base 61 and extends through the back plate 2 to the vicinity of the magnetic ring 8. The dust cover 3 is formed in a cylindrical shape that covers the outer circumference of the magnetic ring 8 and the magnetic detector 9 on the radially outer side of the hub unit 10.

In this way, by providing a cylindrical dust cover 3 that covers the outer circumference of the magnetic ring 8 and magnetic detector 9, it is possible to prevent foreign matter from adhering to or interfering with the wheel speed sensor. In other words, it is possible to suppress the adhesion and interference of foreign matter to the wheel speed sensor (magnetic ring 8, magnetic detector 9) with a simple configuration, thereby improving the accuracy of wheel speed detection and preventing damage caused by foreign matter.

(2) A flange portion 32 may be formed on the dust cover 3. The flange portion 32 is formed in a shape that is close to the surface of the brake disc rotor 5, for example, in a part close to the brake disc rotor 5. With this configuration, the gap between the dust cover 3 and the brake disc rotor 5 can be reduced, and foreign matter can be prevented from entering the inside of the dust cover 3. Therefore, the adhesion of foreign matter to and interference with the wheel speed sensor can be further suppressed.

(3) A notch 36 may be formed in the dust cover 3 described above. The notch 36 is formed in a shape in which a portion located below the spindle 6 is cut out, for example, in a part close to the brake disc rotor 5. With this configuration, even if foreign matter enters the inside of the dust cover 3, that foreign matter can be naturally discharged to the outside of the dust cover 3. Therefore, the adhesion and interference of foreign matter to the wheel speed sensor can be further suppressed. Also, as shown in Figure 2, if a gap is secured between the hub flange 14 and the dust cover 3 that allows the hub bolt 16 to pass through, the work efficiency when removing the hub bolt 16 during vehicle maintenance can be improved.

(4) The wheel support structure 1 described above may be equipped with a dust shield 4. The dust shield 4 is sandwiched between, for example, the base 61 and the back plate 2 and is formed in a tray shape that covers the back plate 2, the brake disc rotor 5 and the dust cover 3. With such a configuration, the entry path of foreign matter from outside the vehicle to the wheel speed sensor can be made into a complex shape. Therefore, the adhesion and interference of foreign matter to the wheel speed sensor can be further suppressed.

(5) The brake disc rotor 5 described above may have a central portion 51, a cylindrical portion 52, and a peripheral portion 53. The central portion 51 is formed in the shape of a disc sandwiched between the hub unit 10 and the wheel 19. The cylindrical portion 52 is formed in the shape of extending cylindrically from the radially outer end of the hub unit 10 in the central portion 51 toward the base portion 61. The peripheral portion 53 is formed in the shape of a perforated disc extending radially outward from the end of the cylindrical portion 52 on the base portion 61 side toward the radially outer side of the hub unit 10.

Furthermore, the flange portion 32 may be positioned close to the cylindrical portion 52, and the outer edge portion 42 of the dust shield 4 may be positioned close to the peripheral edge portion 53. With this configuration, as shown in Figure 2, the proximity points of the flange portion 32 and the cylindrical portion 52 can be positioned further outward from the vehicle than the proximity points of the outer edge portion 42 and the peripheral edge portion 53, thereby forming a complex, intricate labyrinth structure. Therefore, the adhesion and interference of foreign matter to the wheel speed sensor can be further suppressed.

(6) The dust cover 3 described above can be formed separately from the back plate 2 and fixed to the back plate 2, for example, as shown in Figure 5. With this configuration, the structure of the back plate 2 and the dust cover 3 can be simplified, and the structure according to the present invention can be easily realized. In addition, by providing the back plate 2 and the dust cover 3 separately, the fastening work of the flange bolts 27 that fix the back plate 2 to the base 61 becomes easier.

(7) The back plate 2 may have a first tapped hole 24 with a screw groove formed on its inner circumferential surface, as shown in Figure 4, for example. The dust shield 4 and the back plate 2 may be fixed together via a first bolt 28 that is screwed into the first tapped hole 24. On the other hand, the dust cover 3 may be fixed together with the dust shield 4 and the back plate 2 via a first bolt 28 and a first nut 29 that is screwed into it.

This configuration allows the back plate 2, dust cover 3, and dust shield 4 to be integrated using the first bolt 28, thereby reducing the number of parts. Furthermore, by forming screw grooves on the inner surface of the first tapped hole 24, the assembly of the dust shield 4 and back plate 2 can be assembled before the dust cover 3 is attached, improving work efficiency.

[3. Others]
The above embodiments are merely illustrative examples, and there is no intention to exclude various modifications or applications of techniques not explicitly stated in these embodiments. Each configuration of these embodiments can be modified in various ways without departing from their intended purpose. Furthermore, each configuration of these embodiments can be selected or omitted as needed, or combined with various configurations included in publicly known technologies as appropriate.

In the above embodiment, the dust shield 4 is a component whose shape can be changed and which can be omitted. Also, while the brake disc rotor 5 is assumed to be present in this embodiment, its shape can be changed. By providing at least the hub unit 10, magnetic ring 8, back plate 2, magnetic detector 9, and cover means (dust cover 3) in the wheel support structure 1, a structure that provides the same effects as in the above embodiment can be realized.

This invention can be used as a wheel support structure for supporting wheels on a vehicle, and is applicable to the vehicle manufacturing industry to which this wheel support structure is applied.

1. Wheel support structure 2. Back plate 3. Dust cover (covering mechanism)
4 Dust shield 5 Brake disc rotor 6 Spindle 7 Suspension arm 8 Magnetic ring 9 Magnetic detector 10 Hub unit 11 Hub inner ring 12 Hub outer ring 13 Hub bearing 14 Hub flange 15 Hub bolt hole 16 Hub bolt 17 Center nut 18 Brake caliper 19 Wheel 21 Plate hole 22 Plate fixing hole 23 Caliper fixing hole 24 First tapped hole 25 Second tapped hole 26 Recessed part 27 Flange bolt 28 First bolt 29 First nut 31 Cylindrical part 32 Flange part 33 Cover fixing part 34 First fixing hole 35 Second fixing hole 36 Notch part 41 Shield center part 42 Shield outer edge part 43 Caliper mounting part 44 Shield hole 45 Shield fixing hole 46 First fastening hole 47 Second fastening hole 48 Sensor through hole 51 Center part 52 Cylindrical part 53 Peripheral part 54 Disc hole 55 Hub bolt hole 61, base portion 62, hub unit support portion 63, threaded portion 64, fixing hole

Claims (3)

A hub unit is mounted on a spindle that has a base fixed to the vehicle and protrudes outward in the vehicle width direction, and to which the wheel and brake disc rotor are fixed,
A magnetic ring is provided in an annular shape along the outer circumferential surface of the hub unit,
A back plate fixed to the base and to which the brake caliper is attached,
A magnetic detector fixed to the base and extending through the back plate to the vicinity of the magnetic ring,
The hub unit comprises a cylindrical cover means that covers the magnetic ring and the outer circumference of the magnetic detector on the radially outer side,
The brake disc rotor has a disc-shaped central portion sandwiched between the hub unit and the wheel, and a cylindrical portion extending cylindrically from the radially outer end of the hub unit in the central portion toward the base.
The cover means is located inside the cylindrical portion and has a cutout in a shape that removes the portion located below the spindle in a part close to the brake disc rotor.
The cover means is formed separately from the back plate and fixed to the back plate.
A dust shield is provided, sandwiched between the base and the back plate, and formed in the shape of a tray, covering the back plate, the brake disc rotor, and the cover means.
The back plate has a first tapped hole with a screw groove formed on its inner circumferential surface,
The dust shield and the back plate are fixed together via a first bolt that is screwed into the first tapped hole,
The cover means is fixed integrally with the dust shield and the back plate via the first bolt and the first nut screwed thereto.
A wheel support structure characterized by the following features. The wheel support structure according to claim 1, characterized in that the cover means has a flange portion in a part close to the brake disc rotor that is shaped to be close to the surface of the brake disc rotor. The cover means has a flange portion in a shape that is close to the surface of the brake disc rotor in a portion close to the brake disc rotor,
The brake disc rotor has a perforated disc-shaped peripheral edge that extends radially outward from the base end of the cylindrical portion toward the hub unit,
The flange portion is provided in close proximity to the cylindrical portion,
The wheel support structure according to claim 1 , characterized in that the outer edge of the dust shield is provided in close proximity to the peripheral edge.