JP5193562B2 - Wheel bearing device with rotation speed detector - Google Patents

Description

  The present invention relates to a wheel bearing device with a rotational speed detection device that rotatably supports a wheel of an automobile or the like and incorporates a rotational speed detection device that detects the rotational speed of the wheel.

  A wheel bearing with a rotation speed detecting device that rotatably supports a vehicle wheel with respect to a suspension device and controls an anti-lock brake system (ABS) to detect the rotation speed of the wheel. Devices are generally known. Conventionally, in such a wheel bearing device, a sealing device is provided between an inner member and an outer member that are in rolling contact with a rolling element, and a magnetic encoder in which magnetic poles are alternately arranged in a circumferential direction is provided as the sealing device. In addition, the rotational speed detecting device is constituted by a magnetic encoder and a rotational speed sensor that is arranged facing the magnetic encoder and detects a magnetic pole change of the magnetic encoder accompanying the rotation of the wheel.

  In general, the rotational speed sensor is attached to the knuckle after the wheel bearing device is attached to the knuckle constituting the suspension device. However, in order to eliminate the complexity of the air gap adjustment work between the rotation speed sensor and the magnetic encoder and to achieve further compactness, recently, a bearing apparatus for a wheel with a rotation speed detection device in which the rotation speed sensor is also incorporated in the bearing. Has been proposed.

  A structure as shown in FIG. 6 is known as an example of such a wheel bearing device with a rotational speed detection device. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 6), and the side closer to the center is referred to as the inner side (right side in FIG. 6).

  The wheel bearing device with a rotational speed detection device is supported and fixed to a suspension device (not shown), and is inserted into the outer member 51 serving as a fixing member and the outer member 51 via double rows of balls 53 and 53. And an inner member 52. The outer member 51 integrally has a vehicle body mounting flange 51b to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and double row outer rolling surfaces 51a and 51a are formed on the inner periphery. ing.

  On the other hand, the inner member 52 is formed with double-row inner rolling surfaces 55a and 56a facing the double-row outer rolling surfaces 51a and 51a of the outer member 51 described above. Of the double row inner rolling surfaces 55 a and 56 a, one inner rolling surface 55 a is integrally formed on the outer periphery of the hub wheel 55, and the other inner rolling surface 56 a is formed on the outer periphery of the inner ring 56. The inner ring 56 is press-fitted into a cylindrical small-diameter step portion 55b extending in the axial direction from the inner rolling surface 55a of the hub wheel 55. The double-row balls 53 and 53 are respectively accommodated between the rolling surfaces and are held by the cages 57 and 57 so as to be freely rollable.

  The hub wheel 55 integrally has a wheel mounting flange 54 for mounting a wheel (not shown) on the outer periphery, and a hub bolt 54 a for fixing the wheel is planted at a circumferentially equidistant position of the wheel mounting flange 54. It is installed. A serration 55c is formed on the inner periphery of the hub wheel 55, and a stem portion 61 of an outer joint member 60 constituting a constant velocity universal joint is fitted therein. The inner member 52 refers to the hub ring 55 and the inner ring 56. Seals 58 and 59 are attached to the end of the outer member 51 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater, dust, etc. into the bearing from the outside.

  As shown in an enlarged view in FIG. 7, the inner-side seal 59 is press-fitted into the inner periphery of the end of the outer member 51 and has a first seal plate 62 having an L-shaped cross section, and the first seal. It consists of a second seal plate 63 facing the plate 62 and having an L-shaped cross section. The second seal plate 63 has a cylindrical portion 63a fitted on the inner ring 56, and a standing plate portion 63b extending radially outward from the cylindrical portion 63a. The second sealing plate 63 is formed on the outer surface of the standing plate portion 63b. The magnetic encoder 64 is integrally vulcanized and bonded. The magnetic encoder 64 is made of a rubber magnet in which magnetic powder is mixed and magnetic poles N and S are alternately formed in the circumferential direction.

  On the other hand, the first seal plate 62 is a cored bar 65 having an L-shaped cross section and is integrally vulcanized and bonded to the cored bar 65 so that the inner surface of the upright plate part 63b of the second seal plate 63 is obtained. And a seal member 66 including a pair of radial lips 66b and 66c in sliding contact with the cylindrical portion 63a.

  A sensor holder 69 including a fitting cylinder 67 and a holding portion 68 coupled to the fitting cylinder 67 is attached to the end of the outer member 51. The fitting tube 67 includes a fitting tube portion 67a and an inward flange portion 67b extending radially inward from the fitting tube portion 67a, and is formed in an annular shape as a whole with an L-shaped cross section.

  The holding portion 68 is embedded therein with a rotational speed sensor 70 facing the magnetic encoder 64 via a predetermined air gap, and is integrally molded in a circular arc shape with a synthetic resin. The rotational speed sensor 70 incorporates a magnetic detecting element such as a Hall element, a magnetoresistive element (MR element) or the like that changes its characteristics according to the flow direction of the magnetic flux, and a waveform shaping circuit that adjusts the output waveform of the magnetic detecting element. It consists of IC.

Here, the labyrinth seal is configured by causing the end face of the inner ring 56 and the inward flange portion 67b of the fitting cylinder 67 to closely face each other through the minute gap 71. Thus, the magnetic encoder 64 and the rotational speed sensor 70 can be connected to each other even before the stem portion 61 of the outer joint member 60 is fitted to the inner diameter of the hub wheel 55, including when it is transported to the assembly line of the finished vehicle manufacturer. It is possible to prevent foreign matter such as magnetic powder from entering between the detection unit and the outside. Therefore, it is possible to improve the reliability of wheel rotation speed detection.
JP 2003-254985 A

  In such a conventional wheel bearing device with a rotational speed detection device, when the vehicle is running, foreign matter such as muddy water and pebbles is separated from the minute gap 71 between the end surface of the inner ring 56 and the inward flange portion 67b of the fitting cylinder 67 with the magnetic encoder 64. If it enters the gap between the holding portions 68, the surface of the encoder 64 and the mold surfaces of the holding portion 68 and the rotation speed sensor 70 may be damaged, and the detection of the vehicle speed may malfunction. In order to avoid this, a drain 72 is formed in the inward flange portion 67b of the fitting cylinder 67 (see FIG. 8). The drain 72 is disposed at a position closest to the road surface on the radially inward side so that foreign matter that has entered the inside flows easily by its own weight when the vehicle is stopped or the like.

  However, since the drain 72 is formed on the road surface side of the inward flange portion 67 b, it can be said that the pebbles and the like jumped up by the tire can easily enter from the opening of the drain 72. Then, intruded pebbles or the like are caught in the gap between the encoder 64 and the holding portion 68, and as a result, the encoder 64 and the rotation speed sensor 70 may be damaged, and the detection of the vehicle speed may malfunction or the operation of the ABS may be disabled. .

  The present invention has been made in view of such circumstances, and provides a wheel bearing device with a rotational speed detection device that maintains the accuracy of speed detection over a long period of time and has improved the reliability of ABS. It is aimed.

In order to achieve such an object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the suspension on the outer periphery, and a double row outer rolling surface integrally on the inner periphery. A hub wheel integrally formed with a formed outer member and a wheel mounting flange for mounting a wheel at one end, and having a small-diameter step portion extending in the axial direction on the outer periphery, and a small-diameter step portion of the hub ring An inner member having at least one inner ring that is press-fitted and having a double-row inner rolling surface facing the outer-rolling surface of the double-row on the outer periphery, and both the inner member and the outer member. A double row rolling element housed between the rolling surfaces so as to be freely rollable, a seal attached to an opening of an annular space formed between the outer member and the inner member, and the outer member An annular cover attached to the end of the inner side of the And a sensor holder composed of a synthetic resin holding portion in which a rotation speed sensor is embedded, and an encoder in which the characteristics regarding the circumferential direction change alternately and at equal intervals on the outer diameter of the inner ring, An outer joint of a constant velocity universal joint that is fitted to the inner diameter of the cover and the hub wheel in a wheel bearing device with a rotational speed detection device in which the encoder is opposed to the rotational speed sensor via a predetermined axial clearance. Between the members, the cover is a cylindrical fitting portion that is press-fitted into the outer periphery of the inner side end of the outer member, and extends radially inward from the fitting portion. A flange portion closely contacting the end surface of the outer member and a bottom portion extending radially inward from the flange portion, and the holding portion is integrally molded in an arc shape along a circumferential direction of the bottom portion, The phase where the holding part is arranged is While being arranged in the radius direction portion than the horizontal position of the cover, said part of the bottom of the cut and raised is formed drain of rectangular shape, one place in the circumferential direction of the drain is closest to the road surface of the bottom Is formed.

As described above, the sensor holder includes an annular cover press-fitted on the outer periphery of the inner side end of the outer member, and a synthetic resin holding part that is coupled to the cover and in which the rotation speed sensor is embedded. In the inner ring rotation type wheel bearing device with a rotation speed detection device, an opening is formed between the cover and the outer joint member of the constant velocity universal joint fitted to the inner diameter of the hub ring, and the cover is an outer member. A cylindrical fitting portion that is press-fitted into the outer periphery of the inner side end portion, a flange portion that extends radially inward from the fitting portion and is in close contact with the end surface of the outer member, and a diameter further from the flange portion. A holding portion is integrally molded in an arc shape along the circumferential direction of the bottom portion, and the phase in which the holding portion is disposed is higher in the radial direction than the horizontal position of the cover. Placed and rectangular with a part of the bottom cut out This drain is formed at one place in the circumferential direction closest to the road surface at the bottom, so this cut-and-raised piece acts as a protective part to close the drain opening and drive the vehicle With a rotational speed detection device that makes it difficult for foreign matter such as muddy water and pebbles splashed by tires to enter from the opening of this drain, maintaining accuracy of speed detection over a long period of time, and improving the reliability of ABS A wheel bearing device can be provided.

  Preferably, as in the invention described in claim 2, if a plurality of the drains are formed in the circumferential direction of the bottom portion, even if the mounting position of the holding portion is changed with respect to the outer member, The sensor holder can be used, and the cost can be reduced without increasing the types of sensor holders.

  According to a third aspect of the present invention, the drain is formed in a substantially rectangular shape, and a slit is formed leaving the inner diameter side, and the bottom portion is cut and raised from the slit to the inner side so that the protective portion is formed. Further, as in the invention described in claim 4, the drain is formed in a substantially rectangular shape, and a slit is formed leaving both end portions in the circumferential direction, and the bottom portion is formed from the slit. The protection part may be configured by cutting and raising the inner side.

  In addition, as in the invention described in claim 5, the inner seal of the seal is fitted into the inner end of the outer member, and is formed into a substantially L-shaped cross section by pressing from a steel plate. An annular seal plate made of a cored bar and a seal member integrally joined to the cored bar, a cylindrical part disposed opposite to the seal plate and press-fitted into the outer diameter of the inner ring, and the cylindrical part It has a standing plate portion extending radially outward, and is formed of a slinger formed into a substantially L-shaped cross section by pressing from a steel plate. If the encoder is disposed on the side surface of the standing plate portion, the compact Thus, a seal with improved sealing performance can be obtained.

  According to a sixth aspect of the present invention, the encoder is integrally joined to the inner side surface of the upright plate portion, and magnetic powder is mixed into the elastomer so that the magnetic poles N and S are alternately arranged in the circumferential direction. Is a magnetized rubber magnet, and an IC in which the rotational speed sensor incorporates a magnetic detection element whose characteristics change according to the flow direction of the magnetic flux, and a waveform shaping circuit for adjusting the output waveform of the magnetic detection element The apparatus can be made compact and the rotation speed can be detected at low cost and with high reliability.

  Preferably, as in the seventh aspect of the invention, if the slinger is formed of a ferromagnetic steel plate, the output signal of the magnetic encoder becomes strong and stable detection accuracy can be ensured.

Further, as in the invention described in claim 8 , if the holding portion is made of a non-magnetic synthetic resin, it does not adversely affect the sensing performance of the rotation speed sensor, has excellent corrosion resistance, and lasts for a long time. It is possible to improve strength and durability.

Preferably, as in the invention described in claim 9 , if the holding portion is filled with 10 to 45 wt% of a fibrous reinforcing material made of glass fiber, the semi-crystalline material is heated to a temperature exceeding its glass transition temperature. Therefore, the heat resistance is improved, and the rigidity is increased by increasing the elastic modulus while achieving dimensional stability.

A bearing device for a wheel with a rotational speed detection device according to the present invention has a vehicle body mounting flange integrally attached to a suspension device on the outer periphery, and an outer surface in which a double row outer rolling surface is integrally formed on the inner periphery. And a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end thereof and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least press-fitted into the small-diameter step portion of the hub ring An inner member composed of one inner ring and formed on the outer periphery with a double row inner raceway facing the double row outer raceway, and between the inner member and both outer raceway surfaces of the outer member A double row rolling element housed in a freely rolling manner, a seal mounted in an opening of an annular space formed between the outer member and the inner member, and an inner side of the outer member An annular cover attached to the end, and integrally joined to this cover A sensor holder comprising a synthetic resin holding portion in which a rotation speed sensor is embedded, and an encoder in which characteristics in the circumferential direction change alternately and at equal intervals on the outer diameter of the inner ring. In a wheel bearing device with a rotational speed detection device opposed to the rotational speed sensor via a predetermined axial clearance, and an outer joint member of a constant velocity universal joint fitted to the inner diameter of the cover and the hub wheel, between which are opened, said cover includes a cylindrical fitting portion which is press-fitted into the inner side of the outer circumference of the end portion of the outer member extends from the fitting portion radially inwardly, the outwardly A hook part closely contacting the end surface of the member and a bottom part extending further radially inward from the hook part, and the holding part is integrally molded in an arc shape along the circumferential direction of the bottom part, and the holding part Is arranged in a phase It is arranged at the upper part in the radial direction than the horizontal position of the bar, and a rectangular drain is formed by cutting and raising a part of the bottom, and this drain is at one place in the circumferential direction closest to the road surface of the bottom. Because it is formed, this cut-and-raised piece acts as a protective part to block the opening of the drain, and it is difficult for foreign matter such as muddy water and pebbles jumped up by the tire while the vehicle is running to enter the drain Thus, it is possible to provide a wheel bearing device with a rotational speed detection device that maintains the accuracy of speed detection over a long period of time and has improved ABS reliability.

An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, a double row outer rolling surface formed integrally on the inner periphery, and a wheel mounting flange for attaching a wheel to one end A hub ring formed on the outer periphery with an inner rolling surface facing one of the outer rolling surfaces of the double row, and a cylindrical small diameter step portion extending in the axial direction from the inner rolling surface, An inner member comprising an inner ring that is press-fitted into a small-diameter step portion of the hub wheel and has an inner rolling surface opposed to the other of the outer circumferential rolling surfaces of the double row, and the inner member and the outer member. A double row rolling element accommodated between both rolling surfaces of the side member, and a seal attached to an opening of an annular space formed between the outer member and the inner member; An annular cover attached to the inner end of the outer member, and coupled to the cover A sensor holder made of a synthetic resin holding portion in which a rotational speed sensor is embedded, and an inner seal of the seal is fitted into an inner end of the outer member, and a steel plate A core metal having a substantially L-shaped cross section by press working, an annular seal plate integrally joined to the core metal and having a side lip and a radial lip, and disposed opposite to the seal plate A cylindrical portion press-fitted into the outer diameter of the inner ring, and a standing plate portion extending radially outward from the cylindrical portion, and a slinger formed into a substantially L-shaped cross section by pressing from a steel plate, The magnetic encoder is integrally joined to the inner side surface of the standing plate portion of the slinger by vulcanization adhesion, and the magnetic encoder mixes magnetic powder into the elastomer so that the magnetic poles N and S are alternately arranged in the circumferential direction. Together consist of magnetized rubber magnets, in the rotational speed sensor the rotational speed detector equipped wheel support bearing assembly which is opposed via a predetermined axial clearance, be fitted to the inner diameter of the said cover hub wheel A space between the outer joint member of the constant velocity universal joint is opened, and the cover is press-fitted into the outer periphery of the inner side end of the outer member, and a diameter from the fitting portion. And a bottom portion extending further inward in the radial direction from the flange portion, and substantially rectangular drains at a plurality of locations in the circumferential direction of the bottom portion. The drain is formed and a slit is formed leaving the inner diameter side, and the bottom portion is cut and raised from the slit to the inner side to form a protective portion.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device with a rotational speed detection device according to the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 (a) is an enlarged view of a main part of FIG. Fig. 4 (b) is a view taken along arrow III in (a), Fig. 4 (a) is an enlarged view of a main part showing a modification of Fig. 3, and (b) is a view taken along arrow IV in (a). 5 (a) is an enlarged view of a main part showing another modification of FIG. 3, and FIG. 5 (b) is a view taken along the arrow V in FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing device with a rotational speed detection device is called a third generation for driving wheels, and includes an inner member 3 composed of a hub wheel 1 and an inner ring 2, and double row rolling elements (balls) on the inner member 3. 4 and 4 and an outer member 5 that is inserted through 4 and 4.

  The hub wheel 1 integrally has a wheel mounting flange 6 for attaching a wheel (not shown) to an end portion on the outer side, and hub bolts 6 a are implanted at circumferentially equidistant positions of the wheel mounting flange 6. Yes. Further, an outer side (one) inner rolling surface 1a and a cylindrical small-diameter step portion 1b extending in the axial direction from the inner rolling surface 1a are formed on the outer periphery, and a torque transmission serration ( Or a spline) 1c is formed. An inner ring 2 is press-fitted and fixed to the small-diameter step portion 1b of the hub wheel 1 through a predetermined shimiro. An inner side (other side) inner rolling surface 2 a is formed on the outer periphery of the inner ring 2.

  The hub wheel 1 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes an inner rolling surface 1a and an inner side of a wheel mounting flange 6 that serves as a seal land portion of an outer seal 8. The surface hardness is set in the range of 58 to 64 HRC by induction hardening from the base 6b to the small diameter step 1b. As a result, not only the wear resistance of the base portion 6b is improved, but also the fretting of the small-diameter step portion 1b serving as the fitting surface of the inner ring 2 is suppressed, and the rotational bending load applied to the wheel mounting flange 6 is suppressed. Thus, the hub wheel 1 has sufficient mechanical strength. The inner ring 2 and the rolling element 4 are made of a high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core by quenching.

  The outer member 5 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 5b for attaching to a knuckle (not shown) on the outer periphery. The inner member 3 is integrally formed with double row outer rolling surfaces 5a, 5a facing the double row inner rolling surfaces 1a, 2a. Then, at least the double row outer raceway surfaces 5a and 5a are subjected to a hardening process in a range of 58 to 64 HRC by induction hardening.

  Between the double-row outer rolling surfaces 5a, 5a of the outer member 5 and the inner rolling surface of the hub wheel 1 and the inner rolling surface 2a of the inner ring 2 facing these, the double-row rolling elements 4, 4 are respectively accommodated and held by the cages 7 and 7 so as to be freely rollable. In addition, seals 8 and 9 are attached to the opening of the annular space formed between the outer member 5 and the inner member 3, and leakage of lubricating grease sealed inside the bearing and the inside of the bearing from the outside. Prevents intrusion of rainwater and dust.

  Here, the wheel bearing device constituted by a double row angular contact ball bearing in which the rolling element 4 is a ball is illustrated, but the present invention is not limited to this, and a double row tapered roller bearing using a tapered roller for the rolling element 4 is used. May be. In addition, here, the wheel bearing device having the third generation structure is illustrated, but the present invention is not limited thereto, and for example, the second generation structure and the 2.5th generation structure may be used.

  The outer-side seal 8 is configured as an integrated seal having a plurality of lips attached to the outer member 5 and in sliding contact with the base 6b on the inner side of the wheel mounting flange 6. On the other hand, the inner seal 9 is a so-called pack seal. As shown in an enlarged view of FIG. 3A, the seal 9 is fitted into the inner end of the outer member 5 and has an annular seal plate 13 having a substantially L-shaped cross section. A slinger 14 is disposed opposite to the seal plate 13 and press-fitted into the outer diameter of the inner ring 2.

  The seal plate 13 is composed of a core metal 15 press-fitted into the inner periphery of the inner side end of the outer member 5 and a seal member 16 integrally joined to the core metal 15 by vulcanization adhesion or the like. The core 15 is formed by pressing from a corrosion-resistant steel plate, for example, an austenitic stainless steel plate (JIS standard SUS304, etc.) or a rust-proof cold rolled steel plate (JIS standard SPCC, etc.). The cross section is substantially L-shaped. On the other hand, the seal member 16 is made of an elastic member such as synthetic rubber and has a side lip 16a, a grease lip 16b, and an intermediate lip 16c.

  The slinger 14 is pressed from a ferromagnetic steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC or the like). It has a cylindrical portion 14a that is formed into a substantially L-shaped cross section by processing and is press-fitted into the inner ring 2, and a standing plate portion 14b that extends radially outward from the cylindrical portion 14a. A magnetic encoder 17 in which a magnetic substance powder such as ferrite is mixed in an elastomer such as rubber is integrally joined to the side surface on the inner side of the standing plate portion 14b by vulcanization adhesion or the like. The magnetic encoder 17 is composed of a rubber magnet having magnetic poles N and S alternately magnetized in the circumferential direction, and constitutes a rotary encoder for detecting the rotational speed of the wheel. Since the slinger 14 is formed of a ferromagnetic steel plate, the output signal of the magnetic encoder 17 becomes strong, and stable detection accuracy can be ensured.

  The side lip 16a of the seal member 16 is in sliding contact with the standing plate portion 14b of the slinger 14, and the grease lip 16b and the intermediate lip 16c are in sliding contact with the cylindrical portion 14a of the slinger 14, respectively. The outer edge of the standing plate portion 14 b faces the seal plate 13 through a slight radial clearance to form a labyrinth seal 18.

  Here, in this embodiment, the sensor holder 10 is attached to the inner end of the outer member 5. The sensor holder 10 includes a cover 11 formed in a cup shape, and an arc-shaped holding portion 12 integrally molded with the cover 11 (see FIG. 1). The cover 11 is formed by pressing a non-magnetic steel plate having corrosion resistance, for example, a stainless steel plate such as an austenitic stainless steel plate (JIS standard SUS304 or the like). Thereby, it is possible to maintain the detection accuracy without adversely affecting the sensing performance of the rotational speed sensor 20 described later, and to suppress the rusting of the cover 11 and improve the reliability over a long period of time.

  The cover 11 has a cylindrical fitting portion 11a that is press-fitted into the outer periphery of the inner side end portion of the outer member 5, and extends radially inward from the fitting portion 11a, and is in close contact with the end surface 5c of the outer member 5. And a bottom portion 11c extending further radially inward from the flange portion 11b, and is formed in an annular shape as a whole. And the holding | maintenance part 12 is integrally molded by the circular arc shape along the circumferential direction of the bottom part 11c, as shown in FIG. In this way, the cover 11 is fitted on the inner side end of the outer member 5 with the flange portion 11 b in close contact with the end surface 5 c of the outer member 5. The sensor holder 10 can be positioned and fixed easily and accurately, and the rotational speed of the wheel can be detected with high accuracy.

  The phase at which the rotational speed sensor 20 is arranged, that is, the phase at which the holding unit 12 is arranged is arranged at an upper portion in the radial direction (upper portion in the vertical direction in the drawing) than the horizontal position of the cover 11. The harness 21 is connected in the tangential direction. Thereby, the length of the harness 21 itself does not become longer than necessary, and it is easy to take out to the outer diameter side of the knuckle, so that the assembly workability is improved.

  Here, in the present embodiment, a plurality (three in this case) of rectangular drains 22 are formed on the bottom 11 c of the cover 11. As shown in FIGS. 3A and 3B, the drain 22 has arc-shaped slits 22a and 22b formed on the inner diameter side and the outer diameter side, respectively, leaving both ends, and is cut and raised on the inner side. Yes. And this cut-and-raised piece becomes the protection part 22c, and the opening part of the drain 22 is obstruct | occluded. The protective part 22c formed in this way makes it difficult for foreign matter such as muddy water and pebbles that are splashed up by the tires while the vehicle is running from the opening of the drain 22 to maintain speed detection accuracy over a long period of time. A wheel bearing device with a rotation speed detection device with improved ABS reliability can be provided.

  Here, even if a plurality of drains 22 are formed and the mounting position of the holding portion 12 is changed with respect to the outer member 5, the single sensor holder 10 can cope with it, and the number of types of sensor holders 10 is increased. However, the present invention is not limited to this, and the cover 11 may be formed at one location in the circumferential direction closest to the road surface of the bottom portion 11c. Even if foreign matter such as muddy water or pebbles enters the bottom portion 11c while the vehicle is running, the drain 22 is easily discharged to the outside and does not stay for a long time. Therefore, it is possible to prevent foreign matters from adhering when the vehicle is stopped and adversely affecting peripheral components.

  The holding part 12 is formed by injection molding from a non-magnetic special ether-based synthetic resin material such as polyphenylene sulfide (PPS) and is filled with a fibrous reinforcing material made of GF (glass fiber) in an amount of 10 to 45 wt%. As a result, the sensing performance of the rotation speed sensor 20 is not adversely affected, the corrosion resistance is excellent, and the strength and durability can be improved over a long period of time. Further, by filling GF, the semi-crystalline material can be used at a temperature exceeding its glass transition temperature, so that the heat resistance is improved and the rigidity is increased by increasing the elastic modulus.

  Regarding the GF filling amount, if less than 10 wt%, the effect is not sufficiently exerted, and if the filling amount exceeds 45 wt%, the fibers in the molded product cause anisotropy and the density increases, resulting in a dimension. Stability is lowered, which is not preferable. In addition to PPS, the holding part 12 can be exemplified by synthetic resins that can be injection-molded such as PA (polyamide) 66, PA 6-12, PBT (polybutylene terephthalate). Moreover, as a fibrous reinforcement, not only GF but CF (carbon fiber), an aramid fiber, a boron fiber, etc. can be illustrated.

  The rotational speed sensor 20 is opposed to the magnetic encoder 17 through a predetermined axial clearance (air gap), and magnetic detection such as a Hall element, a magnetoresistive element (MR element), etc., that changes the characteristics according to the flow direction of the magnetic flux. It consists of an IC part and a lead wire integrated with an element and a waveform shaping circuit for adjusting the output waveform of the magnetic detection element. The output of the rotation speed sensor 20 is taken out by the harness 21 (see FIG. 2) and sent to an ABS controller (not shown). By adopting such a rotational speed sensor 20, the apparatus can be made compact and the rotational speed can be detected with low cost and high reliability.

  FIG. 4A shows a modification of the drain. It should be noted that the same components and parts as those in the above-described embodiment, parts having the same functions, and parts are denoted by the same reference numerals, and redundant description is omitted. The drain 23 is formed in a eyebrow shape on the bottom 11 c of the cover 11. As shown in (b), the drain 23 is formed with slits 23a and 23b on both ends and an outer diameter side, leaving an arcuate inner diameter side, and is cut and raised on the inner side to form a protective portion 23c. Yes. This protective part 23c makes it difficult for foreign matter such as muddy water and pebbles splashed up by the tire to enter from the opening of the drain 23, as in the above-described embodiment.

  FIG. 5A shows another modification of the drain. It should be noted that the same components and parts as those in the above-described embodiment, parts having the same functions, and parts are denoted by the same reference numerals, and redundant description is omitted. The drain 24 is formed in a substantially rectangular shape on the bottom 11 c of the cover 11. As shown in FIG. 4B, the drain 24 is formed with a slit 24a on the arcuate outer diameter side and cut and raised on the inner side to form a protective portion 24b. This protective portion 24b makes it difficult for foreign matter such as muddy water and pebbles splashed up by the tire to enter from the opening of the drain 24 as in the above-described embodiment.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  A wheel bearing device with a rotation speed detection device according to the present invention includes a steel plate cover attached to an end of an outer member, and a resin holding portion that is coupled to the cover and in which a rotation speed sensor is embedded. It can apply to the wheel bearing apparatus provided with the sensor holder which consists of these.

It is a longitudinal cross-sectional view which shows one Embodiment of the wheel bearing apparatus with a rotational speed detection apparatus which concerns on this invention. It is a side view of FIG. (A) is a principal part enlarged view of FIG. (B) is a III arrow directional view of (a). (A) is a principal part enlarged view which shows the modification of FIG. (B) is a IV arrow view of (a). (A) is a principal part enlarged view which shows the other modification of FIG. (B) is a V arrow view of (a). It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus with a rotational speed detection apparatus. It is a principal part enlarged view of FIG. FIG. 7 is a side view of FIG. 6.

Explanation of symbols

1 ... hub wheel 1a, 2a ... inner rolling surface 1b ... ·············· Small diameter step 1c・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner member 4 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・.... Rolling element 5 ... Outer member 5a ... ... Outer rolling surface 5b ......... Car body mounting flange 5c ... End face 6 ..... Wheel mounting flange 6a ........ Hub bolt 6・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Base 7 on the inner side of the wheel mounting flange ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 8 ... Seal on the outer side 9 ... Seal on the inner side 10 ... Sensor Holder 11 ... Cover 11a ... ·················· Fitting part 11b・ ・ ・ ・ ・ Bottom part 12 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Holding part 13 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal plate 14 ... Slinger 14a ... ... Cylinder part 14b ..... Standing plate part 15 ..... Core metal 16・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal member 16a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Side lip 16b ・ ・ ・ ・ ・ ・Grease lip 16c ... Intermediate lip 17 ... ... Magnetic encoder 18 ... Labyrinth seal 20 ... Rotation speed Sensor 21 ... Harness 22, 23, 24 ... Drain 22a, 22b, 23a, 23b, 24a ..Slits 22c, 23c, 24b ... Protection part 51 ... Outer member 51a ... .... Outer rolling surface 51b ..... Body mounting flange 52 ..... Inward Member 53 ... Ball 54 ... Wheel mounting flange 54a ... ························· Hub bolt 55 .... Inner rolling surface 55b ..... Small diameter step 55c ..... Serration 56 ..... Inner ring 57 ... ············ Retainer 58, 59 ················ Seal 60 Joint member 61... ... stem part 62... 2nd seal plate 63a ... Cylinder 63b ...・ ・ ・ ・ ・ ・ ・ ・ ・ Vertical plate 64 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Magnetic encoder 65 ・ ・ ・ ・ ・ ・············ Core 66 ···························· Sealing member 66a ... ..Side lip 66b, 66c ... Radial lip 67 ... ············································································ ...... ...... Inward collar 68 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Holder 69 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Sensor holder 70 ·················· Rotational speed sensor 71・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Drain

Claims (9)

An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, and an outer rolling surface of a double row integrally formed on the inner periphery;
From a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and having a small-diameter step extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step of the hub ring An inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery,
A double row rolling element accommodated in a freely rolling manner between both rolling surfaces of the inner member and the outer member;
A seal attached to an opening of an annular space formed between the outer member and the inner member;
An annular cover attached to the inner side end of the outer member, and a sensor holder that is integrally coupled to the cover and includes a synthetic resin holder embedded with a rotation speed sensor;
A wheel with a rotational speed detection device in which an encoder whose characteristics in the circumferential direction are alternately and equally spaced on the outer diameter of the inner ring is disposed, and the encoder is opposed to the rotational speed sensor via a predetermined axial clearance. Bearing device for
An opening is formed between the cover and the outer joint member of the constant velocity universal joint fitted to the inner diameter of the hub wheel,
The cover has a cylindrical fitting portion that is press-fitted into the outer periphery of the inner side end portion of the outer member, and a flange portion that extends radially inward from the fitting portion and closely contacts the end surface of the outer member. And a bottom portion extending further radially inward from the flange portion, the holding portion is integrally molded in an arc shape along the circumferential direction of the bottom portion, and the phase in which the holding portion is disposed is A rectangular drain is formed by cutting and raising a part of the bottom portion from the horizontal position of the cover in the radial direction, and the drain is located at one circumferential position closest to the road surface of the bottom portion. A wheel bearing device with a rotational speed detection device, characterized in that the wheel bearing device is formed.   The wheel bearing device with a rotational speed detection device according to claim 1, wherein a plurality of the drains are formed in a circumferential direction of the bottom portion.   The rotation according to claim 1 or 2, wherein the drain is formed in a substantially rectangular shape, a slit is formed leaving an inner diameter side thereof, and the protective part is configured by cutting the bottom portion to the inner side from the slit. Wheel bearing device with speed detector.   3. The drain according to claim 1 or 2, wherein the drain is formed in a substantially rectangular shape, a slit is formed leaving both ends in the circumferential direction, and the bottom portion is cut and raised from the slit to the inner side. The bearing apparatus for wheels with a rotational speed detection apparatus of description.   Of the seals, an inner side seal is fitted into an inner side end of the outer member, and is formed by pressing a steel plate into a substantially L-shaped cross section, and integrally joined to the core. An annular seal plate made of a sealed member, a cylindrical portion that is disposed opposite to the seal plate and press-fitted into the outer diameter of the inner ring, and a standing plate portion that extends radially outward from the cylindrical portion, The wheel with a rotational speed detection device according to any one of claims 1 to 4, comprising a slinger having a substantially L-shaped cross section formed by pressing from a steel plate, wherein the encoder is disposed on a side surface of the standing plate portion. Bearing device.   The encoder is integrally joined to the inner side surface of the upright plate portion, and is composed of a rubber magnet in which magnetic powder is mixed in an elastomer and magnetic poles N and S are alternately magnetized in the circumferential direction, and the rotation 6. The speed sensor includes a magnetic detection element that changes characteristics according to a flow direction of magnetic flux, and an IC in which a waveform shaping circuit that adjusts an output waveform of the magnetic detection element is incorporated. A bearing device for a wheel with a rotational speed detection device according to claim 1.   The wheel bearing device with a rotation speed detection device according to claim 6, wherein the slinger is formed of a ferromagnetic steel plate.   The wheel bearing device with a rotational speed detection device according to any one of claims 1 to 7, wherein the holding portion is made of a nonmagnetic synthetic resin. The wheel bearing device with a rotational speed detection device according to any one of claims 1 to 8, wherein the holding portion is filled with 10 to 45 wt% of a fibrous reinforcing material made of glass fiber.

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