JP2009052599A - Bearing for wheel with rotating speed detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for a wheel with a rotating speed detector, maintaining the accuracy of speed detection over a long period of time, and enhancing the reliability of ABS. <P>SOLUTION: A cover 11 includes: a fitting part 11a press-fitted to the end of an outer member 5; a flange 11b extended from the fitting part 11a toward the radial inside and closely adhering to the end face 6c of the outer member 5; and a bottom 11c extended from the flange 11b toward the radial inside, wherein a cutout 19 is formed in a portion in the circumferential direction in the radial outside of the bottom 11c, a retaining part 12 is formed by integral molding over the whole periphery in the circumferential direction so that the outside diameter Dh has the same or a little smaller diameter as/than the outside diameter of the fitting part 11a of the cover 11 in a range from the flange 11b to the bottom 11c, a rotating speed sensor 20 is embedded in a part of the cutout 19, and the inner side surface of the holding part 12 is formed to uniformly substantially make flush with the whole periphery. <P>COPYRIGHT: (C)2009,JPO&INPIT

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.

  Generally, 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. 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 on the outer periphery, and double row outer rolling surfaces 51a and 51a are formed on the inner periphery.

  On the other hand, the inner member 52 has 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 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 plate 62. It consists of a second seal plate 63 facing the seal 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 slidably in contact with the cylindrical portion 63a.

  An annular 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 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 automobile finished product manufacturer. It is possible to prevent foreign matter such as magnetic powder from entering the detection unit from 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 sensor holder 69 is attached to the outer member 51, the holding portion 68 is integrally molded by protruding from the fitting tube 67 in the axial direction. 8, pressing the pressing jig against the inward flange 67 b of the fitting cylinder 67 in a state avoiding the synthetic resin holding portion 68, and press-fitting the sensor holder 69 into the outer member 51. become. However, since the arc-shaped holding portion 68 cannot be pressed directly, a gap is generated between the end surface of the outer member 51 and the inward flange portion 67b of the fitting cylinder 67, and the magnetic encoder 64, the rotational speed sensor 70, and the like. As a result, the air gap may become larger and the rotational speed detection accuracy may be reduced. Further, since the inward flange portion 67b of the fitting cylinder 67 is lifted without being in close contact with the outer member 51, the sealing performance is deteriorated and the fixing force of the fitting cylinder 67 is insufficient, and vibration or There is a possibility that the ABS may malfunction due to a slight movement of the sensor holder 69 in the axial direction or the circumferential direction due to an impact load or the like.

  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 comprising a synthetic resin holding portion in which a rotational speed sensor is embedded, and a magnetic encoder in which characteristics in the circumferential direction change alternately and at equal intervals on the outer diameter of the inner ring, In the wheel bearing device with a rotational speed detection device in which the magnetic encoder is opposed to the rotational speed sensor via a predetermined axial clearance, the cover is press-fitted into the outer periphery of the inner side end of the outer member. A cylindrical fitting portion; a flange portion extending radially inward from the fitting portion and closely contacting the end surface of the outer member; and a bottom portion extending further radially inward from the flange portion, A notch is formed at one place in the circumferential direction on the radially outer side of the bottom part, and the holding part is integrally molded over the entire circumference in the range of the flange part and the bottom part. The rotational speed sensor is embedded in Both the inner side surface of the holding portion is formed in a uniform substantially flush shape over the entire circumference.

  As described above, the sensor includes a ring-shaped cover press-fitted to the outer periphery of the inner side end of the outer member, and a sensor holder that is coupled to the cover and includes a synthetic resin holding portion in which the rotation speed sensor is embedded. In a wheel bearing device with a rotation speed detection device of an inner ring rotation type, a cover is press-fitted into the outer periphery of the inner side end of the outer member, and radially inward from the fitting portion. Extending and closely contacting the end face of the outer member, and a bottom portion extending further radially inward from the flange portion, a notch is formed in one circumferential direction radially outward of the bottom portion, The holding part is integrally molded over the entire circumference in the range of the collar part and the bottom part, the rotational speed sensor is embedded in the notch part, and the inner side surface of the holding part is Because it is formed in a uniform and substantially uniform shape over the The holding part can be uniformly pressed over the entire circumference, the stress generated in the holding part can be reduced to prevent deformation and breakage of the holding part, and the cover collar part can be completely applied to the end surface of the outer member. The airtightness is improved by tightly contacting the circumference, and the air gap between the magnetic encoder and the rotation speed sensor can be set to a predetermined value with high accuracy. Further, since the fixing force of the cover can be ensured, it is possible to reliably prevent the ABS from malfunctioning due to a slight movement of the sensor holder in the axial direction or in the circumferential direction due to vibration or impact load during traveling. In addition, the desired detection accuracy can be maintained and the reliability can be improved.

  Preferably, as in the invention described in claim 2, if the outer diameter of the holding portion is formed to be the same as or slightly smaller than the outer diameter of the fitting portion of the cover, It is possible to reduce the stress generated in the holding portion by maximizing the pressing area and to prevent deformation and breakage.

  Further, as in the invention according to claim 3, 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 from a steel plate by pressing to have a substantially L-shaped cross section. The magnetic encoder is integrally joined to the inner side surface of the standing plate portion. The magnetic encoder is composed of a rubber magnet in which magnetic powder is mixed into the elastomer and the magnetic poles N and S are alternately magnetized in the circumferential direction, and the rotational speed sensor changes its characteristics according to the flow direction of the magnetic flux. Magnetic detection The device and the IC incorporating a waveform shaping circuit for adjusting the output waveform of the magnetic detection element via the lead wire can make the device compact and can detect the rotational speed with high reliability at low cost. it can.

  Further, as in the invention according to claim 4, the rotational speed sensor is not disposed in a range corresponding to at least the inner diameter of the end of the outer member from the outer diameter of the holding portion, and is disposed on the inner diameter side from this. If it is done, even if it presses with a press-fit jig | tool, it can prevent that a rotational speed sensor related component is damaged.

  Further, as in the invention described in claim 5, if a plurality of through holes are formed in the circumferential direction of the bottom portion of the cover, the molded synthetic resin flows into these through holes and the cover and the holding portion Can be firmly fixed without peeling.

  If the cover is formed by press working from an austenitic stainless steel plate as in the invention described in claim 6, the detection performance of the rotational speed sensor is not adversely affected, and the detection accuracy is maintained. The rusting of the cover can be suppressed and the reliability can be improved over a long period of time.

  If the slinger is formed of a ferromagnetic steel plate as in the invention described in claim 7, 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 part in which a rotational speed sensor is embedded, and a magnetic 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 in which an encoder is opposed to the rotational speed sensor via a predetermined axial clearance, the cover is press-fitted into the outer periphery of the inner side end of the outer member. A fitting portion extending radially inward from the fitting portion and closely contacting the end surface of the outer member, and a bottom portion extending further radially inward from the flange portion. A notch is formed at one place in the radially outer circumferential direction, and the holding part is integrally molded over the entire circumference in the range of the flange part and the bottom part, and the notch part As the rotational speed sensor is embedded Since the inner side surface of the holding part is formed in a substantially uniform shape over the entire circumference, the holding part can be uniformly pressed over the entire circumference by the press-fitting jig and held. This reduces the stress generated in the part and prevents deformation and breakage of the holding part, and the cover's collar closely adheres to the end surface of the outer member over the entire circumference to improve the sealing performance, and the magnetic encoder, rotational speed sensor, The air gap can be accurately set to a predetermined value. Further, since the fixing force of the cover can be ensured, it is possible to reliably prevent the ABS from malfunctioning due to a slight movement of the sensor holder in the axial direction or in the circumferential direction due to vibration or impact load during traveling. In addition, the desired detection accuracy can be maintained and the reliability can be improved.

  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 side end of the outer member, and coupled to the cover A sensor holder comprising a synthetic resin holding part in which a rotation speed sensor is embedded, and an inner seal of the seal is fitted into an inner side end of the outer member, and from a steel plate A metal core formed into a substantially L-shaped cross-section by pressing, and an annular seal plate formed integrally with the metal core 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, A rubber in which the magnetic encoder is integrally joined to the inner side surface of the standing plate portion of the slinger, and magnetic powder is mixed into the elastomer and the magnetic poles N and S are alternately magnetized in the circumferential direction. In the wheel bearing device with a rotational speed detection device that is made of stone and is opposed to the rotational speed sensor via a predetermined axial clearance, the cover is press-fitted into the outer periphery of the inner side end of the outer member. A cylindrical fitting portion, a flange portion extending inward in the radial direction from the fitting portion and closely contacting the end surface of the outer member, and a bottom portion extending further inward in the radial direction from the flange portion, A notch is formed at one place in the circumferential direction on the radially outer side of the bottom portion, and the holding portion is within the range of the flange portion and the bottom portion, and the outer diameter is the same or slightly smaller than the outer diameter of the fitting portion of the cover. The rotation speed sensor is embedded in the notch, and the side surface on the inner side of the holding portion extends over the entire circumference. And is formed in a substantially uniform surface.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 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 an enlarged view of a main part showing a detection unit of FIG. 1, and FIG. FIG. 4 is a side view of FIG. 1, FIG. 5 shows a single cover, (a) is a longitudinal sectional view, and (b) is a front view. In the following description, the side closer to the outside of the vehicle in the state assembled to the vehicle is referred to as an outer side (left side in FIG. 1), and the side closer to the center is referred to as an inner side (right side in FIG.

  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. Thereby, not only the wear resistance of the base portion 6b is improved, but also the fretting of the small-diameter step portion 1b which becomes 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 are 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.

  In addition, although the wheel bearing which comprises the double row angular contact ball bearing which used the rolling element 4 as the ball | bowl was illustrated here, it is not restricted to this, The double row tapered roller bearing which uses a tapered roller for a rolling element may be sufficient. . Here, the third-generation wheel bearing device is exemplified, but the present invention is not limited to this, and a second-generation structure in which the pair of inner rings 2 is press-fitted into the small-diameter step portion 1b of the hub wheel 1 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 in FIG. 2, the seal 9 is fitted into an end portion on the inner side of the outer member 5 and has an annular seal plate 13 having a substantially L-shaped cross section, and the seal plate 13. And a slinger 14 press-fitted into the outer diameter of the inner ring 2.

  The seal plate 13 is composed of a cored bar 15 fitted into the end on the inner side of the outer member 5 and a seal member 16 integrally joined to the cored bar 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 magnetic material powder such as ferrite is mixed in an elastomer such as rubber is integrally joined to the inner side surface of the standing plate portion 14b of the slinger 14 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.

  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 upright plate portion 14 b faces the seal plate 13 through a slight radial clearance to constitute 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 annular holding portion 12 integrally molded with the cover 11. 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. The holding portion 12 is integrally molded over the entire circumference in the range from the flange portion 11b to the bottom portion 11c. In this way, the cover 11 is fitted on the inner side end of the outer member 5 with the flange portion 11b in close contact with the end surface 5c of the outer member 5, so The holder 10 can be positioned and fixed easily and accurately, and the rotational speed of the wheel can be detected with high accuracy.

  As shown in FIG. 5, a notch 19 is formed at one place in the circumferential direction of the bottom 11 c of the cover 11 on the outer side in the radial direction (the side far from the road surface), here, the uppermost part in the radial direction. The rotational speed sensor 20 is embedded in A plurality of through holes 23 are punched in the circumferential direction of the bottom portion 11c. As a result, the molded synthetic resin flows into the through holes 23 and the cover 11 and the holding portion 12 are firmly fixed without being peeled off.

  Note that an eyebrow-shaped drain hole 22 is formed at one place in the circumferential direction closest to the road surface at the bottom 11c of the cover 11. By this drain hole 22, even if foreign matter such as muddy water or pebbles enters the bottom portion 11c during traveling of the vehicle, it 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 10 to 45 wt% of a fibrous reinforcing material made of GF (glass fiber). 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.

  As shown in FIG. 2, the rotational speed sensor 20 faces the magnetic encoder 17 through a predetermined axial clearance (air gap) and responds to the flow direction of magnetic flux, such as a Hall element or a magnetoresistive element (MR element). The IC portion 20a and the lead wire 20b are integrated with a magnetic detection element that changes the characteristics and a waveform shaping circuit that adjusts the output waveform of the magnetic detection element. Then, the output of the rotational speed sensor 20 is taken out by the harness 21, extends in the circumferential direction of the holding portion 12, and sent to an ABS controller (not shown). As a result, the apparatus can be made compact and the rotational speed can be detected at low cost and with high reliability.

  In this embodiment, the part in which the rotational speed sensor 20 is embedded is formed in a substantially rectangular cross section, and the part pressed by the press-fitting jig when mounted on the outer member 5, that is, the outer diameter of the holding portion 12. In the range L corresponding to at least the end portion inner diameter Do of the outer member 5 from Dh, the rotational speed sensor 20 related parts such as the IC portion 20a and the lead wire 20b are not disposed, and are disposed on the inner diameter side from this. Thereby, even if it presses with a press-fit jig | tool, it can prevent that the rotational speed sensor 20 related components are damaged.

  Further, as shown in FIG. 3, the portions other than the portion in which the rotational speed sensor 20 is embedded are molded with a thin inner diameter portion 12a on both sides of the bottom portion 11c of the cover 11, and the diameter from the inner diameter portion 12a. A thick outer diameter portion 12b protrudes in the axial direction over the outer side in the direction and is molded. And when the plate | board thickness of the cover 11 is set to t, the outer diameter Dh of the holding | maintenance part 12 is formed so that it may become the same diameter as the outer diameter of the fitting part 11a of the cover 11, or a slightly small diameter (Dh <= Da + 2t). Thereby, the pressing area of the holding part 12 can be maximized to reduce the stress generated in the holding part 12, and deformation and breakage of the holding part 12 can be prevented.

  Furthermore, the side surface on the inner side of the holding portion 12 is formed in a substantially uniform shape that is uniform over the entire circumference. Thereby, as shown by hatching in FIG. 4, the pressing range L of the holding portion 12 can be uniformly pressed over the entire circumference by the press-fitting jig, and the stress generated in the holding portion 12 is reduced and held. While preventing the deformation | transformation and damage of the part 12, the collar part 11b of the cover 11 closely_contact | adheres to the end surface 5c of the outer member 5, a sealing performance improves, and the air gap between the magnetic encoder 17 and the rotational speed sensor 20 is a predetermined value. Can be set with high accuracy. Further, since the fixing force of the cover 11 can be secured, it is possible to reliably prevent the ABS from malfunctioning due to the fine movement of the sensor holder 10 in the axial direction or the circumferential direction due to vibration or impact load during traveling, Reliability can be enhanced while maintaining desired detection accuracy over a long period of time. Note that the term “substantially equal” as used herein means, for example, a design target value that is substantially free of steps, that is, a step caused by a processing error or the like should be allowed.

  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 rotational speed detection device according to the present invention includes a cover attached to an end portion of an outer member, and a resin-made holding portion that is coupled to the cover and in which the rotational speed sensor is embedded. The present invention can be applied to a wheel bearing device provided with a sensor holder.

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 principal part enlarged view which shows the detection part of FIG. It is explanatory drawing which shows the structure of the sensor holder of FIG. It is a side view of FIG. (A) is a longitudinal cross-sectional view which shows a cover single-piece | unit. (B) is a front view same as the above. 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 ・ ・ ・ ・ ・ ・ ・ ・ Serration 2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... Inner member 4 ... Rolling element 5 ... Outer member 5a ...・ ・ ・ ・ ・ ・ ・ ・ Outer rolling surface 5b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Car body mounting flange 5c ・ ・ ・ ・ ・ ・ ・ ・ End surface of outer member 6 ... Wheel mounting flange 6a ... Hub bolt 6b ... Base 7 on the inner side of the wheel mounting flange ... ····· Outer side seal 9 ········ Inner side seal 10 ············· Sensor holder 11 ··· ··········································································································· ......... Bottom part 12 ......... Holding part 12a ......... Inner diameter part 12b ... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Slinger・ ・ ・ ・ ・ ・ ・ ・ Cylindrical part 14b ・ ・ ・ ・ ・ ・ ・ ・ Standing plate 15 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Core 16・ ・ ・ ・ ・ ・ ・ ・ ・ Seal member 16a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Side lip 6b ... grease lip 16c ... intermediate lip 17 ... magnetic encoder 18 ··············································································· Rotation speed Sensor 20a ... IC part 20b ... Lead wire 21 ... Harness 22 ·············· Drain hole 23 ······································· Member 51a ... Outer rolling surface 51b ... Car body mounting flange 52 ...・ Inner member 53 Wheel 54 ... wheel mounting flange 54a ... hub bolt 55 ... Hub wheel 55a, 56a ... Inner rolling surface 55b ... Small diameter step 55c ... Serration 56 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·- ... outer joint member 61 ... stem part 62 ... first Seal plate 63 ... second seal plate 63a ... cylindrical part 63b ... ... Standing plate part 64 ... Magnetic Enco 65 ···················································································· Side lip 66b, 66c ... Radial lip 67 ... Fitting cylinder 67a ... Fitting cylinder part 67b ············································· 6 Holder 70 ············ Rotational speed sensor 71 ···············································・ Harness Da ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outside diameter of outer member Dh ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer diameter of holding part Do ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ End member inner diameter L ・ ・ ・ ・ ・ ・ ・ ・ ・The thickness of the pressing range t ··············· cover of the press-fitting jig

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 portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion 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 mounted on the inner side end of the outer member, and a sensor holder that is integrally coupled to the cover and includes a synthetic resin holding portion in which a rotation speed sensor is embedded;
A rotational speed detecting device in which a magnetic encoder whose characteristics in the circumferential direction change alternately and at equal intervals is provided on the outer diameter of the inner ring, and the magnetic encoder is opposed to the rotational speed sensor via a predetermined axial clearance. In the bearing device for wheel with
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 is in close contact with the end surface of the outer member. And a bottom portion extending further radially inward from the flange portion, a notch is formed in one circumferential direction radially outward of the bottom portion, and the holding portion is within the range of the flange portion and the bottom portion. The rotation speed sensor is integrally molded over the entire circumference in the circumferential direction, and the rotational speed sensor is embedded in the cutout portion, and the inner side surface of the holding portion is substantially uniform over the entire circumference. A wheel bearing device with a rotational speed detecting device, characterized in that it is formed in a single shape.   The wheel bearing device with a rotation speed detection device according to claim 1, wherein the outer diameter of the holding portion is formed to be the same as or slightly smaller than the outer diameter of the fitting portion of the cover.   Of the seals, an inner side seal is fitted into an inner side end of the outer member, and a metal core having a substantially L-shaped cross section formed by pressing from a steel plate, and integrally joined to the metal 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, It consists of a slinger that is formed from a steel plate by pressing and has a substantially L-shaped cross section. The magnetic encoder is integrally joined to the inner side surface of the upright plate portion, and magnetic powder is mixed into the elastomer. In addition, the rotational speed sensor includes a magnetic detection element that changes its characteristics in accordance with the flow direction of the magnetic flux, and a magnetic element via a lead wire. detection Rotational speed detector equipped wheel support bearing assembly according to claim 1 or 2 waveform shaping circuit for shaping the output waveform of the child consisting of IC incorporated.   4. The rotation speed sensor according to claim 1, wherein the rotation speed sensor is not disposed in a range corresponding to at least an inner diameter of an end portion of the outer member from an outer diameter of the holding portion, and is disposed on an inner diameter side from the range. Wheel bearing device with rotation speed detector.   The wheel bearing device with a rotational speed detection device according to claim 1, wherein a plurality of through holes are formed in a circumferential direction of a bottom portion of the cover.   The wheel bearing device with a rotational speed detection device according to any one of claims 1 to 5, wherein the cover is formed from an austenitic stainless steel plate by pressing.   The wheel bearing device with a rotational speed detection device according to any one of claims 1 to 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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