JP2013117455A - Wheel bearing apparatus with rotation speed detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing apparatus with a rotation speed detection device in which a rotation speed sensor can be fixed surely with a little resin material and sealability is improved.SOLUTION: A cap 10 is formed from a steel plate of a non-magnetic substance by press working and includes a cylindrical fitting part 10a which is press-fitted into the inner circumference of an inner-side terminal portion of an outer member 2, and a bottom part 10c which extends from the fitting part 10a through a reduced diameter part 10b inwardly in a radial direction and covers an inner-side terminal portion of an inner member. An elastic member 19 comprised of a synthetic resin is bonded integrally to the reduced diameter part 10b by vulcanization adhesion, and the elastic member 19 includes an annular protrusion 19a which protrudes outside, in the radial direction, of an outer diameter of the fitting part 10a. A boss part 16 comprised of a synthetic resin is integrally bonded to a portion of the bottom part 10c of the cap 10, and a nut 17 is integrally bonded for fixing a rotation speed sensor 18 to the boss part 16.

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like with respect to a suspension device, in particular, a rotation speed detection device for detecting the rotation speed of the wheel, and a rotation speed for improving the sealing performance. The present invention relates to a wheel bearing device with a detection device.

  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 adjusting the air gap between the rotational speed sensor and the magnetic encoder and to achieve a more compact design, recently, a bearing for a wheel with a rotational speed detection device that also incorporates the rotational speed sensor in the bearing. A device has been proposed.

  A structure as shown in FIG. 9 is known as an example of such a wheel bearing device with a rotational speed detection device. This wheel bearing device with a rotational speed detection device is supported and fixed to a knuckle (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 inner member 52 includes a hub ring 55 and an inner ring 56 that is externally fitted to the hub ring 55.

  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 is formed with double-row inner rolling surfaces 55a and 56a facing the 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 shaft-shaped small-diameter step portion 55 b that extends in the axial direction from the inner rolling surface 55 a 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 crimped portion 58 is formed by plastically deforming the end portion of the small diameter step portion 55b radially outward. The inner ring 56 is fixed in the axial direction by the caulking portion 58. A seal 59 and a cover 63 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, or the like from the outside into the bearing. .

  A magnetic encoder 60 is press-fitted into the outer periphery of the inner ring 56. The magnetic encoder 60 is composed of a support ring 61 formed in an annular shape having a substantially L-shaped cross section by a magnetic metal plate, and an encoder body 62 attached to a side surface of the support ring 61. The encoder body 62 is made of a permanent magnet such as rubber mixed with ferrite powder, and S poles and N poles are alternately magnetized at equal intervals in the circumferential direction.

  The cover 63 is formed of a synthetic resin in a covered cylindrical shape, and its cylindrical portion 63a is press-fitted into the inner periphery of the outer side of the outer member 51, and the opening of the outer member 51 is closed by the lid 63b. Yes. A flange 64 that abuts the end surface of the outer member 51 is formed in the cylindrical portion 63 a, whereby the entire cover 63 is accurately positioned in the axial direction with respect to the outer member 51, and a sensor attached to the cover 63. 69 position management can be easily performed.

  Further, as shown in FIG. 10, a cylindrical sensor mounting portion 65 is formed on the lid portion 63b of the cover 63, and the insertion portion 69a of the sensor 69 is inserted into a sensor mounting hole 66 formed on the inner peripheral side thereof. ing. On the other hand, the cover 63 is integrally molded with a cored bar 67 formed in a covered cylindrical shape from the inner peripheral surface of the cylindrical portion 63a to the inner surface of the lid portion 63b. The metal core 67 includes a cylindrical portion 67a molded on the cylindrical portion 63a of the cover 63, and a lid portion 67b that forms the bottom of the cylindrical portion 67a, and is provided on the side facing the encoder main body 62 of the sensor mounting hole 66. The opening is closed.

  The core metal 67 is formed of a non-magnetic steel plate having a thickness of approximately 0.3 mm, and has a cover portion 67b, thereby increasing the strength of the cover 63 and being non-magnetic. Does not affect accuracy.

  The sensor 69 is attached to the cover 63 by inserting the insertion portion 69 a into the sensor attachment hole 66 of the cover 63. The insertion portion 69 a faces a part of the encoder main body 62 via a predetermined axial clearance across the lid portion 67 b of the core metal 67, and rotates the magnetic encoder 60 in the vicinity of the surface facing the encoder main body 62. The detector (not shown) which detects the magnetic field fluctuation | variation which generate | occur | produces by is incorporated. This detection unit outputs an electrical signal at one end of the output cable 68 in the sensor 69 via the cable 68.

  In this way, the opening of the cover 63 on the side facing the encoder main body 62 of the sensor mounting hole 66 is closed with the lid 67b of the cored bar 67 formed of a nonmagnetic steel plate in the shape of a covered cylinder. Since the mounting hole 66 does not penetrate the cover 63, there are few foreign substance intrusion paths into the apparatus, and the sealing performance of the entire apparatus is excellent (see, for example, Patent Document 1).

Japanese Patent No. 4286063

  In such a conventional wheel bearing device with a rotational speed detection device, the joint portion of the core metal 67 and the cover 63 made of synthetic resin, that is, the cylindrical portion 67a of the core metal 67, the cylindrical portion 63a of the cover 63, and the core metal. The joint portion between the cover portion 67b and the cover portion 67b of the cover 63 occupies a high proportion of the synthetic resin, so that the strength and rigidity of the cover 63 are reduced, and the cover 63 is peeled off due to a difference in linear expansion coefficient due to a temperature change due to a thermal shock or the like. As a result, it is difficult to maintain the initial sealing performance over a long period of time.

  The present invention has been made in view of such a conventional problem, and is capable of reliably fixing a rotational speed sensor with a small amount of resin material and having a rotational speed detection device-equipped wheel bearing with improved sealing performance. An object is to provide an apparatus.

  In order to achieve such an object, the invention described in claim 1 of the present invention has a vehicle body mounting flange for being attached to a knuckle on the outer periphery, and a double row outer rolling surface 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 formed of at least one inner ring that is press-fitted, and formed with a double-row inner rolling surface facing the double-row outer rolling surface on the outer periphery, and the inner member and the outer member. A double row rolling element housed in a freely rolling manner between the respective rolling surfaces, and a seal attached to an opening on the outer side of the annular space formed between the outer member and the inner member; The outer ring is fitted on the inner ring, and the characteristics are changed alternately and at equal intervals in the circumferential direction. A pulsar ring and a cup-shaped cap fitted to the inner side end of the outer member, and a rotational speed sensor disposed close to the cap is connected to the pulsar ring via the cap. In the wheel bearing device with a rotational speed detection device opposed to each other with a predetermined axial air gap, the cap is formed by pressing from a non-magnetic steel plate, and is formed on an inner side end of the outer member. A cylindrical fitting portion to be press-fitted and a bottom portion extending radially inward from the fitting portion and covering an inner side end portion of the inner member, and a part of the bottom portion is made of synthetic resin. A boss portion is integrally joined, and the rotational speed sensor is fixed to the boss portion.

  In this way, the pulsar ring that is externally fitted to the inner ring and whose characteristics are alternately changed at equal intervals in the circumferential direction, and a cup-shaped cap that is fitted to the end on the inner side of the outer member are provided. In the wheel bearing device with a rotational speed detection device, the rotational speed sensor disposed in the vicinity of the cap is opposed to the pulsar ring with a predetermined axial air gap through the cap. A cylindrical fitting portion formed by pressing from a magnetic steel plate and press-fitted into the inner side end portion of the outer member, and extending radially inward from the fitting portion to the inner side of the inner member And a boss part made of synthetic resin is integrally joined to the center of the bottom part, and the rotational speed sensor is fixed to the boss part. Securely fixed It is Rukoto can provide rotational speed detector equipped wheel support bearing assembly with improved sealing performance.

  Preferably, if the fitting portion of the cap is fitted to the outer member via an elastic member made of synthetic rubber as in the invention described in claim 2, the sealing performance is further improved. Can do.

  According to a third aspect of the present invention, a nut for fixing the rotational speed sensor to the boss portion is integrally joined by insert molding, and the boss portion is molded so that resin does not enter the end surface of the nut. If it does, when fixing a rotational speed sensor, it can prevent that the resin of a boss | hub part intervenes between the end surface of a nut, and an attachment member, and can improve the positioning accuracy of a rotational speed sensor.

  Further, as in the invention according to claim 4, if a concavo-convex portion is formed on the outer periphery of the nut and the resin of the boss portion wraps around the concavo-convex portion, not only the rotation of the nut but also the boss portion Can be prevented from falling off.

  Further, as in the invention described in claim 5, if an infinite number of minute dimples are formed on the surface of the bottom portion of the cap, the fixing force of the boss portion increases, and the nut can be stabilized over a long period of time. It can be fixed and reliability can be improved.

  Further, as in the invention described in claim 6, the fitting portion of the cap is press-fitted into the outer periphery of the end portion of the outer member, and a reduced diameter portion is formed between the fitting portion and the bottom portion. When the elastic member is integrally joined to the reduced diameter portion by vulcanization adhesion, and the elastic member has an annular projection protruding radially outward from the outer diameter of the fitting portion, the cap is fitted. Since the annular protrusion is sometimes elastically deformed and pressure-bonded to the outer member, the airtightness of the fitting portion of the cap is further increased, and the sealing performance can be improved.

  Further, as in the invention according to claim 7, if the elastic member is joined so as not to protrude to the inner side from the outer surface of the bottom portion, the elastic member is prevented from interfering with the rotational speed sensor, Detection accuracy can be increased.

  Further, as in the invention according to claim 8, the fitting portion of the cap is press-fitted into the outer periphery of the end portion of the outer member, and the elastic member is integrated with the inner periphery of the end portion of the fitting portion by vulcanization adhesion. If the bottom portion is in close contact with the end surface of the outer member, the cap positioning accuracy increases, and the detection accuracy can be increased.

  Further, as in the ninth aspect of the present invention, the fitting portion of the cap is press-fitted into the outer periphery of the end portion of the outer member, and a chamfered portion is formed in the outer periphery of the end portion of the outer member. The elastic member may be interposed in the chamfered portion.

  Further, as in the invention described in claim 10, if an annular thin portion is formed in a radially outer portion facing the magnetic encoder in the bottom portion of the cap, the strength and rigidity of the cap are reduced. Therefore, the air gap can be set small without increasing the detection accuracy.

  The wheel bearing device with a rotational speed detection device according to the present invention has an outer body integrally provided with a vehicle body mounting flange for being attached to a knuckle on the outer periphery, and an outer side 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 one press-fitted into the small-diameter step portion of the hub ring An inner member formed of two inner rings and formed on the outer periphery with a double-row inner rolling surface facing the double-row outer rolling surface, and the respective rolling surfaces of the inner member and the outer member A double-row rolling element housed in a freely rotatable manner between the outer member and the inner member, and a seal attached to an opening on the outer side of the annular space formed between the outer member and the inner member; Puls that are fitted and whose characteristics are changed alternately at equal intervals in the circumferential direction A ring-shaped cap and a cup-shaped cap fitted to the inner end of the outer member, and a rotational speed sensor disposed in proximity to the cap is connected to the pulsar ring via the cap. In the wheel bearing device with a rotational speed detection device opposed to each other with an axial air gap, the cap is formed by press working from a non-magnetic steel plate and is press-fitted into the inner end of the outer member. And a bottom portion that extends radially inward from the fitting portion and covers the inner side end of the inner member, and a boss made of synthetic resin in a part of the bottom portion Since the rotational speed sensor is fixed to the boss, the rotational speed sensor can be securely fixed with a small amount of resin material, and the rotational speed detection improves the sealing performance. It is possible to provide a bearing device for a location wheeled.

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 a side view of FIG. It is a principal part enlarged view which shows the modification of FIG. It is a principal part enlarged view which shows the other modification of FIG. It is a principal part enlarged view which shows the other modification of FIG. It is a principal part enlarged view which shows the modification of FIG. It is a side view which shows the modification of FIG. 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.

  A vehicle body mounting flange to be attached to the knuckle on the outer periphery, an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel mounting flange to mount a wheel on one end A hub wheel integrally formed and having an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub wheel An inner member formed of an inner ring that is press-fitted into a small-diameter step portion and has an inner rolling surface that is opposed to the other outer rolling surface of the double row on the outer periphery, and each of the inner member and the outer member. A double row of rolling elements accommodated between the rolling surfaces of the rolling member, and a seal attached to an opening on the outer side of the annular space formed between the outer member and the inner member; A pulsar which is fitted on the inner ring and whose characteristics are alternately changed at equal intervals in the circumferential direction. And a cup-shaped cap fitted to the inner side end of the outer member, and a rotational speed sensor disposed in the vicinity of the cap is connected to the pulsar ring via the cap. In the wheel bearing device with a rotational speed detection device opposed to each other with an air gap in the axial direction, the cap is formed from a non-magnetic steel plate by pressing, and is formed on the inner circumference of the inner side end of the outer member. A cylindrical fitting portion to be press-fitted, and a bottom portion extending radially inward from the fitting portion through a reduced diameter portion and covering an inner side end portion of the inner member; An elastic member made of synthetic rubber is integrally joined by vulcanization adhesion, and the elastic member has an annular projection protruding radially outward from the outer diameter of the fitting portion, and is thermoplastic at the center of the bottom portion. From synthetic resin Boss is joined together, a nut for fixing the rotational speed sensor on the boss portion are joined together by insert molding.

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. 4 is a main part enlarged view showing a modification of FIG. 2, FIGS. 5 and 6 are principal part enlarged views showing another modification of FIG. 2, and FIG. 7 is a modification of FIG. FIG. 8 is a side view showing a modification of FIG. 3. 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).

  The wheel bearing device with a rotational speed detection device shown in FIG. 1 is called a third generation for a driven wheel, and includes an inner member 1, an outer member 2, and double-row rolling elements (balls) 3a and 3b. Yes. The inner member 1 includes a hub ring 4 and a separate inner ring 5 fixed to the hub ring 4.

  The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and has one (outer side) inner rolling surface 4a on the outer periphery and the inner rolling surface. A small diameter step 4b extending in the axial direction from the surface 4a is formed. Hub bolts 6 a for fixing the wheels are planted at the circumferentially equidistant positions of the wheel mounting flanges 6.

  The inner ring 5 is formed with the other (inner side) inner raceway surface 5a on the outer periphery, and is press-fitted into the small-diameter step portion 4b of the hub ring 4 via a predetermined squeeze. And it fixes to the axial direction in the state to which the predetermined bearing preload was provided by the crimping part 4c formed by plastically deforming the edge part of the small diameter step part 4b to radial direction outward.

  The hub wheel 4 is made of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and includes an inner rolling surface 4a and an inner side of a wheel mounting flange 6 that becomes a seal land portion of a seal 9 to be described later. The surface hardness is hardened to a range of 58 to 64 HRC by induction hardening from the base 6b to the small diameter step 4b. The caulking portion 4c is an unquenched portion having a surface hardness of 25HRC or less after forging. Further, the inner ring 5 and the rolling elements 3a and 3b are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching.

  On the other hand, the outer member 2 integrally has a vehicle body mounting flange 2c to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and double row inner rolling of the inner member 1 on the inner periphery. Double row outer rolling surfaces 2a, 2b facing the surfaces 4a, 5a are integrally formed. The outer member 2 is formed of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, as in the case of the hub wheel 4, and at least the double-row outer raceway surfaces 2a and 2b are surfaced by induction hardening. Hardening is performed in the range of 58 to 64 HRC. And between these both rolling surfaces 2a, 4a and 2b, 5a, the double row rolling element 3a, 3b is accommodated via the holder | retainer 7,8 so that rolling is possible.

  Among the openings of the annular space formed between the outer member 2 and the inner member 1, a seal 9 is attached to the opening on the outer side, and a cap 10 is attached to the opening on the inner side. This prevents leakage of the enclosed lubricating grease to the outside and prevents rainwater and dust from entering the bearing from the outside.

  A pulsar ring 11 is press-fitted into the outer diameter of the inner ring 5. This pulsar ring 11 is formed into an L shape by press working from a ferromagnetic steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 series or the like) or a rust-proof cold-rolled steel plate, and has an annular shape as a whole. The formed support ring 12 and the magnetic encoder 13 integrally joined to the inner side surface of the support ring 12 by vulcanization adhesion or the like.

  The outer-side seal 9 includes a core metal 14 press-fitted through a predetermined shimeshiro to the inner periphery of the outer-side end of the outer member 2, and a seal member integrally joined to the core metal 14 by vulcanization adhesion 15 and an integral seal. The metal core 14 is formed into a substantially L-shaped cross section by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a cold rolled steel plate (JIS standard SPCC type or the like).

  On the other hand, the seal member 15 is made of a synthetic rubber such as NBR (acrylonitrile-butadiene rubber), and is formed so as to be inclined outward in the radial direction. A lip 15a, a dust lip 15b slidably in contact with a base portion 6b having a circular cross-section in a predetermined axial direction, and a slanted inward side of the bearing, and is formed on the base portion 6b via a predetermined radial direction. And a grease lip 15c in sliding contact.

  In addition to the exemplified NBR, the seal member 15 is made of, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc., which have excellent heat resistance, and heat resistance and chemical resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber, which are excellent in the above.

  In the present embodiment, the pitch circle diameter PCDo of the outer rolling element 3a row is set larger than the pitch circle diameter PCDi of the inner rolling member 3b row, and the outer rolling element 3a row of rolling elements. The diameter do is set to a smaller diameter (do <di) than the rolling element diameter di of the inner rolling element 3b row. Due to the difference between the pitch circle diameters PCDo and PCDi and the rolling element diameters do and di, the number of rolling elements Zo in the outer rolling element 3a row is set larger than the number of rolling elements Zi in the inner rolling element 3b row. (Zo> Zi). Thereby, the bearing rigidity of an outer side part can be increased compared with an inner side, and lifetime improvement of a bearing can be achieved. Here, the outer side rolling elements 3a and the inner side rolling elements 3b are illustrated as having different sizes. However, the present invention is not limited to this, and the same size may be used in both rows.

  In addition, although what was comprised here as the wheel bearing apparatus was comprised by the double row angular contact ball bearing which used the rolling elements 3a and 3b as a ball | bowl, not only this but a tapered roller was used for the rolling elements 3a and 3b. A double row tapered roller bearing may be used. Further, the third generation structure is illustrated, but a so-called second generation structure in which a pair of inner rings are press-fitted into the hub ring may be used.

  2, the support ring 12 of the pulsar ring 11 extends inward in the radial direction from the fitting portion 12a having a cylindrical shape that is press-fitted into the outer diameter of the inner ring 5. And a standing plate portion 12b. The magnetic encoder 13 is integrally joined to the inner side surface of the upright plate portion 12b. This magnetic encoder 13 constitutes a rotary encoder for detecting the rotational speed of a wheel by mixing magnetic powder such as ferrite in an elastomer such as rubber and alternately magnetizing magnetic poles N and S in the circumferential direction.

  In addition, although the pulsar ring 11 provided with the magnetic encoder 13 which consists of rubber magnets was illustrated here, it is not restricted to this, What is necessary is just the structure from which a characteristic changes alternately at equal intervals in a circumferential direction. It may be a pulsar ring made of steel plate in which through holes and irregularities are formed, or may be formed of a sintered alloy. Further, a plastic magnet may be joined.

  Here, the cap 10 is press-fitted into the inner periphery of the inner side end of the outer member 2 to close the inner side opening of the outer member 2. The cap 10 is formed by press working from a non-magnetic steel plate having corrosion resistance, for example, an austenitic stainless steel plate so as not to adversely affect the sensing performance of the rotational speed sensor 18 described later.

  The cap 10 has a cylindrical fitting portion 10a that is press-fitted into the inner periphery of the end portion of the outer member 2, and extends radially inward from the fitting portion 10a via the reduced diameter portion 10b. And a bottom portion 10c covering an end portion on the inner side. That is, the rotational speed sensor 18 is opposed to the magnetic encoder 13 through the cap 10 with a predetermined axial clearance (air gap). The rotational speed sensor 18 is made of injection-moldable synthetic resin such as PA66, and has a magnetic detecting element that changes characteristics according to the flow direction of magnetic flux, such as a Hall element and a magnetoresistive element (MR element), and the magnetic detecting element. An IC (not shown) or the like in which a waveform shaping circuit for adjusting the output waveform is embedded is embedded, and constitutes an automobile ABS that detects the rotational speed of the wheel and controls its rotational speed.

  The boss 16 is integrally joined to a part of the bottom 10c of the cap 10, for example, the center (see FIG. 3). Thereby, the position of the rotational speed sensor 18 to be described later becomes difficult to shift, and the detection accuracy can be improved. The boss portion 16 is made of a thermoplastic synthetic resin such as PA (polyamide) 66, and a nut 17 for fixing the rotation speed sensor 18 is integrally joined by insert molding. The boss portion 16 is formed so that the resin does not go around the end surface of the nut 17. As a result, the nut 17 can be securely fixed with a small amount of resin material, and when the rotational speed sensor 18 is fixed, the resin of the boss portion 16 is placed between the end surface of the nut 17 and an attachment member (not shown). Interposition can be prevented and the positioning accuracy of the rotation speed sensor 18 can be improved.

  In addition to the above-mentioned PA66, the material of the boss portion 16 may be a thermoplastic synthetic resin called so-called engineering plastic such as PA612, PPA (polyphthalamide), PBT (polybutylene terephthalate), or polyphenylene sulfide ( Thermoplastic synthetic resins called super engineering plastics such as PPS), polyetheretherketone (PEEK), polyamideimide (PAI) and the like, phenol resin (PF), epoxy resin (EP), polyimide resin (PI) Or other thermosetting synthetic resins. Further, it may be a biodegradable synthetic resin that reduces the environmental load. Examples of the components of this biodegradable synthetic resin include polylactic acid, polycaprolactone, polyglycolic acid, modified polyvinyl alcohol, and casein.

  Innumerable minute dimples (not shown) are formed on the surface of the bottom 10c of the cap 10 by shot peening or the like. The unevenness of the dimple is set in the range of Rz2 to 4 in terms of surface roughness. Thereby, the fixing force of the boss | hub part 16 increases, the nut 17 can be fixed stably over a long period of time, and reliability can be improved. Here, Rz refers to the ten-point average roughness of the JIS roughness shape parameter (JIS B0601-1994).

  In this embodiment, the elastic member 19 made of synthetic rubber such as NBR is integrally joined to the reduced diameter portion 10b of the cap 10 by vulcanization adhesion. The elastic member 19 protrudes inward from the outer surface of the bottom portion 10c of the cap 10 and is joined so as not to interfere with the rotational speed sensor 18, and an annular protrusion 19a that protrudes radially outward from the outer diameter of the fitting portion 10a. It has. The annular protrusion 19a is elastically deformed and crimped to the inner periphery of the end of the outer member 2 when the cap 10 is fitted, and the height of the irregularities on the inner periphery of the end of the outer member 2 serving as the fitting surface of the cap 10 is increased. Is restricted to chatter of 3 μm or less. Thereby, the airtightness of the fitting part 10a of the cap 10 increases, and the wheel bearing device with a rotational speed detection device that aims to improve the sealing performance can be provided.

  FIG. 4 shows a modification of the boss portion 16 of the cap 10 shown in FIG. This embodiment is basically the same as the above-described embodiment (FIG. 2) except that the shape of the nut 17 is only partially different. Are denoted by the same reference numerals, and redundant description is omitted.

  The boss portion 20 is made of a thermoplastic synthetic resin such as PA66, and a nut 21 for fixing the rotation speed sensor 18 (indicated by a two-dot chain line in the figure) is integrally joined by insert molding. The nut 21 is formed with an uneven portion 21a on the outer periphery, and the resin wraps around the concavo-convex portion 21a and the resin does not wrap around the end surface. Thereby, it is possible not only to prevent the nut 21 from rotating, but also to prevent the nut 21 from falling off.

  FIG. 5 shows another modification of the cap 10. Note that this embodiment is basically different from the above-described embodiment (FIG. 2) only in part of the cap configuration, and is the same as the above-described embodiment in the same parts or parts having the same functions. Are given the same reference numerals and redundant description is omitted.

  The cap 22 has corrosion resistance and is press-molded with a non-magnetic austenitic stainless steel plate so as not to adversely affect the sensing performance of the rotational speed sensor 18 (indicated by a two-dot chain line in the figure). A cylindrical fitting portion 10a that is press-fitted into the inner periphery of the inner side end of the outer member 2, and a reduced diameter portion in which an elastic member 19 made of synthetic rubber is integrally joined from the fitting portion 10a. And a bottom 23 extending radially inward via 10b.

  An annular thin portion 23 a is formed in a radially outer portion of the bottom 23 that faces the magnetic encoder 13. The thickness H1 of the thin portion 23a is 0.2 to 1.0 mm, whereas the thickness H0 of the other portion is 1.0 to 1.5 mm. As a result, the air gap can be set small without reducing the strength and rigidity of the cap 22, and the detection accuracy can be increased. If the thickness H1 is less than 0.2 mm, it is difficult to accurately shape the shape of the thin portion 23a, and desired magnetic characteristics cannot be obtained, resulting in a decrease in detection accuracy.

  FIG. 6 shows another modification of the cap 10 described above. Note that this embodiment is basically different from the above-described embodiment (FIG. 2) only in part of the cap configuration, and is the same as the above-described embodiment in the same parts or parts having the same functions. Are given the same reference numerals and redundant description is omitted.

  The cap 24 is formed into a cup shape by press-molding an austenitic stainless steel plate having corrosion resistance, and a cylindrical fitting portion 24a that is press-fitted into the outer periphery of the inner side end of the outer member 2, and the fitting portion. A bottom portion 24b that extends radially inward from 24a and is in close contact with the end surface 2d on the inner side of the outer member 2 is provided. And the boss | hub part 16 is integrally joined to a part of bottom 24b of this cap 24, for example, center part.

  Here, the elastic member 25 made of synthetic rubber such as NBR is integrally joined to the inner periphery of the end of the fitting portion 24a of the cap 24 by vulcanization adhesion. The elastic member 25 includes an annular protrusion 25 a that protrudes radially inward from the inner diameter of the fitting portion 24 a. The annular protrusion 25 a is elastically deformed to the outer periphery of the end portion of the outer member 2 when the cap 24 is fitted. In addition to being crimped, the unevenness height of the fitting portion 24a of the cap 24 is restricted to chattering of 3 μm or less. As a result, the air tightness of the fitting portion 24a of the cap 24 can be improved, the sealing performance can be improved, and the bottom portion 24b is in close contact with the inner end face 2d of the outer member 2, so that the cap 24 The positioning accuracy is increased, and the detection accuracy of the rotation speed sensor 18 (indicated by a two-dot chain line in the figure) can be increased.

  FIG. 7 shows a modified example of the cap 24 described above. This embodiment is basically the same as the above-described embodiment (FIG. 6) except that the configuration of the cap and the outer member is partially different, and has the same parts and the same functions as those of the above-described embodiment. Parts and parts are denoted by the same reference numerals, and redundant description is omitted.

  The cap 26 is formed into a cup shape by press-molding an austenitic stainless steel plate having corrosion resistance, and a cylindrical fitting portion 26a that is press-fitted into the outer periphery of the inner side end portion of the outer member 2 ′. A bottom portion 24b that extends radially inward from the portion 26a and is in close contact with the inner end surface 2d of the outer member 2 ′ is provided.

  Here, a chamfered portion 27 is formed on the outer periphery of the inner side end portion of the outer member 2 ′, and an elastic member 28 made of an O-ring such as NBR is interposed in the chamfered portion 27. As a result, the airtightness of the fitting portion 26a of the cap 26 can be improved, the sealing performance can be improved, and the positioning accuracy of the cap 26 that is in close contact with the outer member 2 ′ is increased, and the rotational speed sensor 18 (FIG. The detection accuracy can be improved.

  FIG. 8 shows a modified example of the cap 10 described above. This embodiment basically differs from the above-described embodiment (FIG. 3) only in the mounting position of the rotational speed sensor, and other parts and parts having the same parts or the same functions as the above-described embodiments. Are denoted by the same reference numerals, and redundant description is omitted.

  A rotation speed sensor 18 (shown by a two-dot chain line in the figure) is attached to the bottom 10c of the cap 10 at a horizontal position corresponding to a magnetic encoder (not shown) with respect to the road surface. As described above, the rotational speed sensor 18 is disposed in a horizontal position, so that the rotational speed sensor 18 and the inner member 1 are relatively inclined with respect to the lateral load from the wheels. The air gap fluctuation of the magnetic encoder can be suppressed, and stable detection accuracy can be obtained.

  In the above-described embodiment, the boss portion made of a thermoplastic synthetic resin is joined to the bottom portion of the cap, and the nut that fixes the rotation speed sensor is integrally joined to the boss portion by insert molding. The invention is not limited to this. For example, a metal ring may be joined to the boss portion by insert molding, and a pin for fixing the rotation speed sensor may be press-fitted or welded to the ring. Alternatively, a hook portion may be provided on each of the boss portion and the rotation speed sensor, and both may be engaged to fix the rotation speed sensor to the cap. In general, in the present invention, the resin member occupying the entire cap is set to 50% or less, preferably 30% or less. As a result, the sealing performance can be maintained with a synthetic resin with few caps, and the strength and rigidity of the cap can be prevented from being lowered.

  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.

  The wheel bearing device with a rotational speed detection device according to the present invention is for a driven wheel and can be applied to an inner ring rotating type wheel bearing device having any structure such as a rolling element having a ball or a tapered roller.

DESCRIPTION OF SYMBOLS 1 Inner member 2, 2 'Outer member 2a, 2b Outer rolling surface 2c Car body mounting flange 2d Inner side end surface 3a of outer member Outer side rolling element 3b Inner side rolling element 4 Hub wheel 4a, 5a Inner side Rolling surface 4b Small diameter step 4c Caulking portion 5 Inner ring 6 Wheel mounting flange 6a Hub bolt 6b Base portion 7 and 8 on inner side of wheel mounting flange Cage 9 Seals 10, 22, 24, 26 Caps 10a, 12a, 24a, 26a Fitting portion 10b Reduced diameter portion 10c, 23, 24b Bottom portion 11 Pulsar ring 12 Support ring 12b Standing plate portion 13 Magnetic encoder 14 Core metal 15 Seal member 15a Side lip 15b Dustrip 15c Grease lip 16, 20 Boss portion 17, 21 Nut 18 Rotational speed sensors 19, 25, 28 Elastic members 19a, 25a Annular projection 21a Uneven portion 23a Thin portion 7 Chamfered portion 51 Outer member 51a Outer rolling surface 51b Car body mounting flange 52 Inner member 53 Ball 54 Wheel mounting flange 55 Hub wheel 55a, 56a Inner rolling surface 55b Small diameter step portion 56 Inner ring 57 Cage 58 Caulking portion 59 Seal 60 Magnetic encoder 61 Support ring 62 Encoder main body 63 Cover 63a Tube portion 63b, 67b Cover portion 64 Flange 65 Sensor attachment portion 66 Sensor attachment hole 67 Core metal 67a Tube portion 68 Cable 69 Sensor 69a Insertion portion A Air gap di Inner side Rolling element diameter do of the rolling element row of the outer side rolling element diameter H0 of the outer rolling element row H0 thickness of the cap H1 thickness of the thin part of the cap PCDi pitch circle diameter of the inner rolling element row PCDo outer rolling element row Pitch circle diameter Zi Number of rolling elements in inner side rolling element row Zo Outer side rolling element row The number of elements

Claims (10)

An outer member integrally having a vehicle body mounting flange for being attached to the knuckle on the outer periphery, and an outer rolling surface of a double row integrally formed on the inner periphery;
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 housed movably between the rolling surfaces of the inner member and the outer member;
A seal attached to an opening on the outer side of the annular space formed between the outer member and the inner member;
Pulsar ring that is externally fitted to the inner ring, and the characteristics are changed alternately and at equal intervals in the circumferential direction;
A cup-shaped cap fitted to the inner side end of the outer member;
In the wheel bearing device with a rotational speed detecting device, the rotational speed sensor disposed in proximity to the cap is opposed to the pulsar ring with a predetermined axial air gap through the cap.
The cap is formed by pressing from a non-magnetic steel plate, and is fitted into a cylindrical fitting portion that is press-fitted into the inner side end of the outer member, and extends radially inward from the fitting portion, A bottom portion that covers the inner side end of the inner member, a boss portion made of synthetic resin is integrally joined to a part of the bottom portion, and the rotational speed sensor is fixed to the boss portion. A bearing device for a wheel with a rotational speed detection device.   The wheel bearing device with a rotational speed detection device according to claim 1, wherein the fitting portion of the cap is fitted to the outer member via an elastic member made of synthetic rubber.   The rotation speed according to claim 1 or 2, wherein a nut for fixing the rotation speed sensor to the boss portion is integrally joined by insert molding, and the boss portion is formed so that resin does not go around the end surface of the nut. Wheel bearing device with detection device.   4. The wheel bearing device with a rotation speed detecting device according to claim 3, wherein a concavo-convex portion is formed on an outer periphery of the nut, and the resin of the boss portion wraps around the concavo-convex portion.   The wheel bearing device with a rotational speed detection device according to claim 1, wherein an infinite number of minute dimples are formed on the surface of the bottom of the cap.   A fitting portion of the cap is press-fitted into the outer periphery of the end portion of the outer member, a reduced diameter portion is formed between the fitting portion and the bottom portion, and the elastic member is integrated with the reduced diameter portion by vulcanization adhesion. The wheel bearing device with a rotation speed detection device according to claim 1, wherein the elastic member includes an annular protrusion that protrudes radially outward from the outer diameter of the fitting portion.   The wheel bearing device with a rotational speed detection device according to claim 6, wherein the elastic member is joined so as not to protrude from the outer side surface of the bottom portion to the inner side.   The fitting portion of the cap is press-fitted into the outer periphery of the end portion of the outer member, the elastic member is integrally joined to the inner periphery of the end portion of the fitting portion by vulcanization adhesion, and the bottom portion is the outer member. The wheel bearing device with a rotation speed detection device according to claim 1, which is in close contact with the end face of the wheel.   The fitting portion of the cap is press-fitted to the outer periphery of the end portion of the outer member, and a chamfered portion is formed on the outer periphery of the end portion of the outer member, and the elastic member is interposed in the chamfered portion. Item 2. A wheel bearing device with a rotational speed detection device according to Item 1.   The wheel bearing device with a rotational speed detection device according to any one of claims 1 and 5 to 9, wherein an annular thin portion is formed in a radially outer portion facing the magnetic encoder in a bottom portion of the cap. .

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