JP2014190463A - Bearing device for wheel with rotating speed detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel with a rotating speed detecting device capable of securing detecting accuracy by preventing deformation of a sensor cap and defective fixing of a rotating speed sensor, and reducing costs by simplifying working manhours.SOLUTION: An inner cap 15 is fitted to an outer side of a sensor cap 16, the inner cap 15 is formed by press working of austenitic stainless steel plate, and a rotating speed sensor 21 is kept into contact with or close to the inner cap so as to be opposed to a magnetic encoder 14 through the inner cap 15. A fixing nut 23 includes a cylindrical portion 23b provided with a female screw 23a on its inner periphery, and fitted and inserted to a hole 22, and a flange portion 23c disposed on an end outer periphery of the cylindrical portion 23b. The fixing nut 23 is fitted and inserted to the hole 22 until the flange portion 23c is closely kept into contact with an inner-side side face of a bottom portion 16c of the sensor cap 16, and the flange portion 23c is integrally joined to the bottom portion 16c by welding or an adhesive agent.

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, and more particularly, to a wheel bearing device with a rotation speed detection device incorporating a rotation speed detection device for detecting the rotation speed of the wheel. It is about.

  A wheel bearing with a rotation speed detection 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. Conventionally, devices having various structures are known. As an example of this conventional structure, one shown in FIG. 13 is known.

  This wheel bearing device with a rotational speed detecting device integrally has a vehicle body mounting flange 50b for mounting on a suspension device (not shown) on the outer periphery, and double row outer rolling surfaces 50a, 50a on the inner periphery. An outer member 50 that is formed and serves as a fixed side member, and inner rolling surfaces 51a and 52a that are opposed to the double row outer rolling surfaces 50a and 50a are formed on the outer periphery, and an inner member 53 that serves as a rotating side member A double row of balls 55 and 55 accommodated between the rolling surfaces 50a and 51a and 50a and 52a via the cages 54 and 54, and the outer member 50 and the inner member 53. And seals 56 and 57 attached to the opening of the annular space formed therebetween.

  The inner member 53 integrally has a wheel mounting flange 58 for mounting a wheel (not shown) at one end, an inner rolling surface 51a on the outer periphery, and a small diameter extending in the axial direction from the inner rolling surface 51a. The hub wheel 51 is formed with a stepped portion 51b, and the inner ring 52 is press-fitted into the small-diameter stepped portion 51b of the hub wheel 51 and has an inner rolling surface 52a formed on the outer periphery. Then, an annular encoder 59 fixed to the outer diameter of the inner ring 52 and having the characteristics extending in the circumferential direction alternately and at equal intervals, and a steel plate fixed to the inner end opening of the outer member 50 And a holder 61 that is attached to the cover 60 and holds a sensor (not shown) facing the encoder 59.

  The cover 60 is formed in a bottomed cylindrical shape including a cylindrical portion 64 that is press-fitted into the inner end portion of the outer member 50 and a bottom plate portion 65 that forms the bottom portion of the cylindrical portion 64. Then, a collar portion 66 formed by superposing a part of the cylindrical portion 64 radially outward is abutted against the end surface of the outer member 50 to position the cover 60 in the axial direction.

  As shown in FIG. 14, an insertion hole 67 and a through hole 68 are formed in the bottom plate portion 65 of the cover 60, and the insertion hole 67 has an insertion portion 69 that holds a sensor at the tip of the holder 61. Has been inserted. Further, the holder 61 is provided with a mounting flange 71 in which a mounting hole 70 is formed, and a nut 73 for screwing a bolt 72 inserted through the mounting hole 70 is part of the bottom plate portion 65 at a through hole 68 portion. A technique for fixing at low cost without welding by fixing by plastic deformation is disclosed (for example, see Patent Document 1).

Japanese Patent Laying-Open No. 2005-249180

  In such a conventional cover 60, when the nut 73 is press-fitted into the cover 60, it is fixed by plastically deforming a part of the bottom plate portion 65 at the through hole 68 portion. However, as shown in FIG. 15 (a), from the state in which the protruding portion 73a of the nut 73 is opposed to the axially outward opening of the through hole 68, on the axially outer side surface of the bottom plate portion 65, a press machine or the like. As a result, the projecting portion 73a is deformed into the through hole 68 while plastically deforming the inner peripheral surface portion of the through hole 68 by a part of the bottom plate portion 65, as shown in FIG. It is pushed in until the axially outer side surface of the portion 65 and the axially inner end surface of the main body portion of the nut 73 abut, and the half of the tip of the projecting portion 73 a bites into the inner peripheral surface portion of the through hole 68. Accordingly, since the inner peripheral surface of the through hole 68 of the bottom plate portion 65 or its periphery is plastically deformed when the nut 73 is press-fitted into the cover 60, burrs and metal powder are generated on the mounting surface of the holder 61 that holds the sensor. However, there is a risk of inducing a fixing failure of the holder 61. Therefore, a removal process for removing the generated burrs and metal powder is necessary. In this case, there is a problem that the manufacturing process becomes complicated, the number of work steps increases, and the manufacturing cost increases.

  The present invention has been made in view of such conventional problems, and prevents deformation of the sensor cap and fixing failure of the rotation speed sensor to ensure detection accuracy, and also simplifies the work man-hours and reduces costs. It is an object of the present invention to provide a wheel bearing device with a rotational speed detecting device.

  In order to achieve such an object, the invention described in claim 1 of the present invention has a vehicle body mounting flange integrally attached to the vehicle body on the outer periphery, and a double row outer rolling surface is integrated 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 comprising at least one inner ring that is press-fitted and having a double-row inner rolling surface that is opposed to 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 accommodated between the rolling surfaces via a cage, a pulsar ring externally fitted to the inner ring, and a rotational speed opposed to the pulsar ring via a predetermined axial air gap. The sensor and the outer member are fitted on the inner side end. A cup-shaped sensor cap on which the rotational speed sensor is supported and fixed, and the nut for attaching the rotational speed sensor to the sensor cap. However, the internal thread is formed on the inner periphery, and a cylindrical portion that is inserted into the perforation, and a flange portion is provided on the outer periphery of the end portion of the cylindrical portion, until the flange portion is in close contact with the inner side surface of the bottom portion of the sensor cap. The fixing nut is fitted into the perforation, and the flange portion is integrally joined to the bottom portion of the sensor cap.

  In this way, the pulsar ring that is externally fitted to the inner ring, the rotational speed sensor that faces the pulsar ring via a predetermined axial air gap, and the rotational speed sensor that is fitted to the inner side end of the outer member. And a cup-shaped sensor cap that is supported and fixed. In the wheel bearing device with a rotational speed detection device to which a nut for attaching the rotational speed sensor is fixed to the sensor cap, the fixing nut has an internal thread on the inner periphery. A cylindrical portion is formed and inserted into the perforation, and a flange portion is provided on the outer periphery of the end portion of the cylindrical portion, and the fixing nut is inserted into the perforation until the flange portion is in close contact with the inner side surface of the bottom portion of the sensor cap. Since the flange part is integrally joined to the bottom part of the sensor cap, the contact area between the fixing nut and the bottom part is increased without generating burrs or metal powder, A wheel with a rotation speed detection device that can be firmly fixed and can prevent deformation of the sensor cap and rotation speed sensor fixing to ensure detection accuracy, simplifying the work and reducing costs. A bearing device can be provided.

  Preferably, in the invention described in claim 2, if the flange portion of the fixing nut is joined by spot welding or an adhesive, it is possible to reliably prevent deformation of the sensor cap and malfunction of fixing the rotational speed sensor.

  In addition, if the flange portion of the fixing nut extends to the vicinity of the insertion hole of the sensor cap as in the third aspect of the invention, the contact area between the fixing nut and the bottom portion is further increased, so In addition, the mounting member can be supported over substantially the entire surface, and the bending of the mounting member when the rotational speed sensor is fixed can be prevented, so that desired detection accuracy can be ensured. .

  According to a fourth aspect of the present invention, a circular concave portion is formed in the inner side surface of the bottom portion of the sensor cap, the perforation is formed in the concave portion, and the bottom portion of the outer cap and the fixing nut If the side surface of the flange portion is set to be substantially flush, the mounting member can be supported on the bottom of the sensor cap over substantially the entire surface, and the mounting member can be prevented from bending when the rotational speed sensor is fixed. be able to.

  Further, as in the invention described in claim 5, if the sensor cap is formed by pressing from a steel plate and a rust preventive film made of cationic electrodeposition coating is formed on the outer surface including the fixed nut, The rust preventive film does not easily peel off when pressed into the side member, and a smooth surface can be maintained by filling minute irregularities on the fitting surface, and the fitting portion of the sensor cap rusts over a long period of time. Can be prevented, and good airtightness can be obtained between the fitting portion of the outer member.

  Further, as in the invention described in claim 6, a bulge portion is formed on the side of the bottom portion of the sensor cap that is close to the radially outer road surface and protrudes from the bottom portion to the inner side by a predetermined dimension. If a drain penetrating in the radial direction is formed in the bulging part, even if foreign matter such as rainwater enters the sensor cap from the outside when the knuckle protrudes from the end face of the outer member to the inner side, this It can flow and drop to the bulging portion and easily and effectively discharge foreign matter to the outside without being disturbed by the knuckle.

  Further, as in the invention according to claim 7, an inner cap is fitted on the outer side of the sensor cap, and the inner cap is formed into a cup shape by pressing from a nonmagnetic austenitic stainless steel plate, A cylindrical fitting portion that is press-fitted into the inner periphery of the inner side end of the outer member, and a disc portion that extends radially inward from the fitting portion and faces the pulsar ring via a slight axial clearance. If the rotational speed sensor is abutted or brought close to this disc part and is disposed opposite to the pulsar ring via the inner cap, a desired air gap can be obtained, and complicated air gap adjustment can be performed. As a result, the assembly workability can be improved by omitting it, and the sealing performance of the bearing space can be improved without adversely affecting the sensing performance of the rotational speed sensor.

  Further, as in the invention described in claim 8, a reduced diameter portion is formed between the fitting portion of the inner cap and the disc portion, and an elastic member made of synthetic rubber is vulcanized and bonded to the reduced diameter portion. And the elastic member protrudes from the side surface of the disk portion of the inner cap to the inner side so as not to interfere with the rotational speed sensor, and is radially outer than the outer diameter of the fitting portion. If the annular protrusion protruding in the direction is provided, the annular protrusion is elastically deformed and pressure-bonded to the inner periphery of the end portion of the outer member when the inner cap is fitted, so that the airtightness of the fitting portion can be improved.

  A wheel bearing device with a rotational speed detection device according to the present invention has a vehicle body mounting flange integrally attached to a vehicle body 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 having an outer periphery formed with a double-row inner rolling surface opposite to the double-row outer rolling surface, and between both rolling surfaces of the inner member and the outer member. A double-row rolling element housed in a rollable manner via a cage; a pulsar ring externally fitted to the inner ring; a rotational speed sensor facing the pulsar ring via a predetermined axial air gap; Fitted to the end of the inner member on the inner side and rotated A cup-shaped sensor cap on which a degree sensor is supported and fixed, and a wheel bearing device with a rotational speed detection device in which a nut for attaching the rotational speed sensor to the sensor cap is fixed. An internal thread is formed on the inner periphery, and a cylindrical portion that is inserted into the perforation, and a flange portion is provided on the outer periphery of the end of the cylindrical portion, and the fixing is performed until the flange portion is in close contact with the inner side surface of the bottom portion of the sensor cap. Since the nut is inserted into the perforation and the flange portion is integrally joined to the bottom portion of the sensor cap, the contact area between the fixing nut and the bottom portion is increased without generating burrs or metal powder, and is firmly Can be fixed, and can prevent deformation of the sensor cap and malfunction of the rotation speed sensor to ensure detection accuracy, simplifying the work man-hours. It is possible to provide a wheel bearing device with rotational speed detection device which attained cost.

It is a longitudinal section showing one embodiment of a bearing device for wheels with a rotation speed detection device concerning the present invention. It is a principal part enlarged view which shows the bearing part of FIG. It is a principal part enlarged view which shows the detection part of FIG. It is a side view which shows the outer side cap of FIG. (A) is a principal part enlarged view which shows the junction part of the fixing nut of FIG. 1, (b) is a principal part enlarged view which shows the modification of (a). It is a principal part enlarged view which shows the drain part of FIG. It is a side view which shows the modification of the fixing nut of FIG. It is a principal part enlarged view which shows the junction part of the fixing nut of FIG. It is a side view which shows the other modification of the fixing nut of FIG. It is a principal part enlarged view which shows the junction part of the fixing nut of FIG. It is a side view which shows the modification of the outer side cap of FIG. It is a principal part enlarged view which shows the junction part of the fixing nut of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is a principal part enlarged view which shows the fixing | fixed part of the nut of FIG. (A), (b) is explanatory drawing which shows the fixing method of a nut.

  An outer member integrally having a vehicle body mounting flange to be attached to the vehicle body on the outer periphery, a double row outer rolling surface formed integrally on the inner periphery, and a wheel mounting flange for mounting 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 comprising an inner ring that is press-fitted into a small-diameter step portion and has an outer race formed with an inner race surface facing the other of the outer row raceways in the double row, and both the inner member and the outer member. A double row rolling element housed in a freely rolling manner between the rolling surfaces via a cage, a magnetic encoder externally fitted to the inner ring, and the magnetic encoder face each other via a predetermined axial air gap. The rotational speed sensor and the outer member are fitted to the inner side end, and the front A cup-shaped sensor cap on which a rotational speed sensor is supported and fixed. The sensor cap is a cylindrical fitting portion press-fitted into the inner periphery of the end portion of the outer member, and an inner side of the fitting portion. A bottom portion that extends radially inward from the end of the outer member and closes the opening on the inner side of the outer member, and the rotational speed sensor is inserted into the bottom portion at a horizontal position corresponding to the pulsar ring. A hole and a hole is formed in the vicinity of the insertion hole, a fixing nut is fixed to the hole, and the rotation speed sensor is fixed by fastening a fixing bolt to the fixing nut via an attachment member. In the wheel bearing device with a speed detection device, an inner cap is fitted on the outer side of the sensor cap, and the inner cap is pressed from a nonmagnetic austenitic stainless steel plate. It is formed in a cup shape by work, and the rotational speed sensor is abutted or brought close to the magnetic encoder via the inner cap, and the fixing nut is formed with an internal thread on the inner periphery for drilling. A cylindrical portion to be inserted, and a flange portion on the outer periphery of the end portion of the cylindrical portion, and the fixing nut is inserted into the perforation until the flange portion is in close contact with the inner side surface of the bottom portion of the sensor cap, The flange portion is integrally joined to the bottom portion of the sensor cap with an adhesive.

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 bearing portion of FIG. 1, and FIG. FIG. 4 is a side view showing the outer cap of FIG. 1, FIG. 5 (a) is an enlarged view of a main part showing a joint portion of the fixing nut of FIG. 1, and FIG. FIG. 6 is a main part enlarged view showing the drain part of FIG. 1, FIG. 7 is a side view showing a modification of the fixing nut of FIG. 5, and FIG. FIG. 9 is a side view showing another modified example of the fixing nut shown in FIG. 5, and FIG. 10 is a main part showing the connecting portion of the fixing nut shown in FIG. FIG. 11 is an enlarged view, FIG. 11 is a side view showing a modified example of the outer cap of FIG. 4, and FIG. 12 is an enlarged view of a main part showing a joint portion of the fixing nut of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing device is called the third generation on the driven wheel side, and is a double row rolling element (ball) accommodated between the inner member 1 and the outer member 2 and between the members 1 and 2 so as to roll freely. 3 and 3. The inner member 1 includes a hub ring 4 and an inner ring 5 press-fitted into the hub ring 4 through a predetermined shimiro.

  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 6a are planted on the wheel mounting flange 6 at equal intervals in the circumferential direction.

  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 stepped portion 4b of the hub wheel 4 to form a back-to-back type double row angular contact ball bearing. The inner ring 5 is fixed in the axial direction in a state where a predetermined bearing preload is applied by a caulking portion 4c formed by plastically deforming the end portion of 4b. The inner ring 5 and the rolling elements 3 and 3 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching.

  The hub wheel 4 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 4a and an inner side of a wheel mounting flange 6 serving as a seal land portion of a seal 8 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. Note that the caulking portion 4c is left with a raw surface hardness after forging. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 6, the fretting resistance of the small-diameter step portion 4b serving as the fitting portion of the inner ring 5 is improved, and the minute There is no occurrence of cracks and the like, and the plastic working of the caulking portion 4c can be performed smoothly.

  The outer member 2 integrally has a vehicle body mounting flange 2b to be attached to the knuckle 9 on the outer periphery, and a cylindrical pilot portion 2c fitted to the knuckle 9 is formed on the inner side of the vehicle body mounting flange 2b. The outer outer rolling surface 2a facing the inner rolling surface 4a of the hub wheel 4 and the inner outer rolling surface 2a facing the inner rolling surface 5a of the inner ring 5 are integrally formed on the inner periphery. ing. Double-row rolling elements 3 and 3 are accommodated between these rolling surfaces and are held by the cages 7 and 7 so as to be freely rollable. A seal 8 is attached to the opening on the outer side of the annular space formed between the outer member 2 and the inner member 1, and an inner cap 15 described later is attached to the opening on the inner side. This prevents the grease sealed inside the bearing from leaking to the outside and prevents rainwater and dust from entering the bearing from the outside.

  The outer member 2 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 2a and 2a have a surface hardness of 58 to 64 HRC by induction hardening. Has been cured.

  As shown in an enlarged view in FIG. 2, the seal 8 includes a core metal 10 press-fitted into the inner periphery of the outer end of the outer member 2, and a seal member integrally joined to the core metal 10 by vulcanization adhesion. 11 and an integrated seal. The metal core 10 has 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 11 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, and is in sliding contact with the inner side surface 6c of the wheel mounting flange 6 with a predetermined axial direction. A side lip 11a, a dust lip 11b slidably in contact with a base 6b having a circular cross section in a predetermined axial direction, and a slanted inward side of the bearing, is formed on the base 6b via a predetermined radial direction. And a grease lip 11c in sliding contact. And the sealing member 11 wraps around and joins so that the outer surface of the metal core 10 may be covered, and what is called a half metal structure is comprised. Thereby, airtightness can be improved and the inside of a bearing can be protected.

  In addition to the exemplified NBR, the material of the seal member 11 includes, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc. having 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 addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling elements 3 and 3 was illustrated here, it is not restricted to this but is comprised by the double row tapered roller bearing using a tapered roller It may be what was done. In addition, the third generation structure wheel bearing device in which the inner raceway surface 4a is directly formed on the outer periphery of the hub wheel 4 is illustrated. However, the present invention is not limited to this. A so-called second generation structure in which the inner ring is press-fitted and fixed may be used.

  In the present embodiment, the pulsar ring 12 is press-fitted into the outer periphery of the inner ring 5. As shown in an enlarged view in FIG. 3, the pulsar ring 12 includes a support ring 13 formed in an annular shape and a magnetic encoder 14 integrally joined to the support ring 13 by vulcanization adhesion or the like. . This magnetic encoder 14 is 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 magnetizing magnetic poles N and S alternately in the circumferential direction.

  The support ring 13 is formed into a substantially L-shaped cross section by pressing 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. A cylindrical portion 13a that is press-fitted into the outer diameter surface 5b, and a standing plate portion 13b that extends radially outward from the cylindrical portion 13a. The magnetic encoder 14 is joined to the inner side surface of the upright plate portion 13b.

  Here, the inner cap 15 is attached to the outer member 2 to close the opening on the inner side of the outer member 2. The inner cap 15 is pressed from a non-magnetic austenitic stainless steel plate so as to improve the sealability of the bearing space and have corrosion resistance so as not to adversely affect the sensing performance of the rotational speed sensor 21 described later. And a cylindrical fitting portion 15a that is formed into a cup shape and press-fitted into the inner periphery of the inner side end of the outer member 2, and a slight amount from the fitting portion 15a to the magnetic encoder 14 via the reduced diameter portion 15b. A bottom portion 15e that covers an inner side end portion of an inner member (not shown) via a disk portion 15c facing each other through an axial clearance and a bent portion 15d bulging outward from the disk portion 15c. It has.

  In the inner cap 15, an elastic member 18 made of synthetic rubber such as NBR is integrally joined to the reduced diameter portion 15b by vulcanization adhesion. The elastic member 18 protrudes inward from the side surface of the disk portion 15c of the inner cap 15 so as not to interfere with the rotational speed sensor 21, and is an annular shape protruding radially outward from the outer diameter of the fitting portion 15a. A protrusion 18a is provided. The annular protrusion 18a is elastically deformed and pressure-bonded to the inner fitting surface 19 of the outer member 2 when the inner cap 15 is fitted, thereby improving the airtightness of the fitting portion 15a.

  In the present embodiment, an outer cap (sensor cap) 16 is further attached to the inner side of the inner cap 15. Specifically, an outer fitting surface 20 formed of an annular groove is formed on the opening side (inner side) of the inner fitting surface 19 of the outer member 2 via a predetermined step 19a, and the outer cap 16 is disposed outside the outer cap 16. The fitting surface 20 is press-fitted through a predetermined scissors. The outer fitting surface 20 is simultaneously ground by the double row outer rolling surfaces 2a, 2a, the inner fitting surface 19 into which the inner cap 15 is press-fitted, and a general-purpose grindstone. As a result, the stroke when the inner cap 15 is press-fitted into the inner fitting surface 19 of the outer member 2 is minimized to improve the assembly workability, and the roundness and coaxiality of each fitting surface 19, 20 are improved. Accuracy such as degree is improved, and airtightness of the fitting portion is increased. Further, the number of processing steps can be reduced by simultaneous grinding, and the cost can be reduced.

  The outer cap 16 is formed into a cup shape by press working from a rust-proof cold-rolled steel plate, and is fitted into a cylindrical fitting portion 16a that is press-fitted into the inner periphery of the inner side end of the outer member 2. A flange portion 16b that overlaps and extends radially outward from the portion 16a and adheres to the inner end face 2d of the outer member 2, and extends radially inward from the flange portion 16b to the inner side of the outer member 2 And a bottom portion 16c for closing the opening. An insertion hole 17 is formed in a horizontal position corresponding to the magnetic encoder 14 in the bottom portion 16 c of the outer cap 16, and the rotational speed sensor 21 is inserted into the insertion hole 17. As described above, since the outer cap 16 includes the flange portion 16b that is in close contact with the end surface 2d of the outer member 2, the strength and rigidity of the outer cap 16 can be increased and the positioning accuracy of the rotational speed sensor 21 can be improved. At the same time, the insertion hole 17 is formed in a horizontal position, and the rotational speed sensor 21 is mounted in the insertion hole 17 so that the outer member 2 and the inner member 1 are relatively moved by a lateral load from the wheel. Even in a tilted state, fluctuations in the air gap between the rotation speed sensor 21 and the magnetic encoder 14 can be suppressed, and stable detection accuracy can be obtained.

  The rotation speed sensor 21 is an IC incorporating a magnetic detection element such as a Hall element, a magnetoresistive element (MR element) or the like that changes characteristics according to the flow direction of magnetic flux and a waveform shaping circuit that adjusts the output waveform of the magnetic detection element. The anti-lock brake system of the motor vehicle which consists of these etc. and detects the rotational speed of a wheel and controls the rotation speed is comprised. The rotation speed sensor 21 is inserted until it abuts on or approaches the disc portion 15c of the inner cap 15. As a result, a desired air gap can be obtained, and the assembly workability can be improved by omitting complicated air gap adjustment, and the inside of the bearing can be sealed by the inner cap 15, so that the sealing performance is improved. A bearing device can be provided.

  Here, a fixing nut 23 is fitted into a perforation 22 formed at the center of the outer cap 16. The rotational speed sensor 21 inserted into the insertion hole 17 of the outer cap 16 is fixed by fastening the mounting bolt 25 to the fixing nut 23 via the mounting member 24.

  The fixing nut 23 includes a cylindrical portion 23b having a female screw 23a formed on the inner periphery thereof, and a circular flange portion 23c on the outer periphery of the end portion of the cylindrical portion 23b. Then, the fixing nut 23 is fitted into the perforation 22 from the inner side until the flange portion 23c comes into close contact with the inner side surface of the bottom portion 16c of the outer cap 16. The “insertion” referred to here includes a state in which a clearance is inserted with a radial clearance and a light press-fit state. Then, the outer peripheral part of the flange part 23c is joined by spot welding. This increases the contact area between the fixing nut 23 and the bottom portion 16c without generating burrs or metal powder, and enables firm fixing, and also prevents deformation of the outer cap 16 and fixing of the rotational speed sensor 21. Therefore, it is possible to provide a wheel bearing device with a rotation speed detection device that can prevent detection and ensure the detection accuracy, simplify the work man-hours, and reduce the cost.

  As shown in FIGS. 4 and 5A, the joint P1 of the fixing nut 23 is set at a plurality of locations on the outer peripheral portion of the flange portion 23c. Thereby, the heat influence by spot welding can be suppressed to the minimum and the deformation | transformation of the bottom part 16c of the cap 16 can be prevented.

  The joining of the fixing nut 23 is not limited to spot welding, but may be joined by applying an adhesive to the contact portion between the bottom portion 16c and the flange portion 23c of the cap 16, as shown in FIG. The joint portion P2 made of an adhesive is set to be uniform in the circumferential direction with a predetermined width. Thereby, while being able to fix firmly, intrusion of muddy water etc. from the junction part P2 can be prevented. As this adhesive, an epoxy resin adhesive excellent in water resistance, chemical resistance, strength and heat resistance is used, but other than this, suitable for bonding between metals, for example, acrylic resin Examples thereof include synthetic adhesives such as polyurethane, urethane resin, vinyl chloride resin solvent, silicone, and phenol resin.

  The outer cap 16 has a rust preventive film formed on the outer surface including the fixing nut 23 by cationic electrodeposition after the fixing nut 23 is joined. The cationic electrodeposition coating is an anionic electrodeposition coating in which the product side is energized with the product side as the negative electrode while the positive electrode is energized with the product side as the positive electrode. Also good. This anion-type electrodeposition coating has the characteristics that the coating color stability and baking temperature can be set low, but this type of outer cap 16 is a powerful coating with excellent rust prevention and adhesion. Cationic electrodeposition coating made of an epoxy resin system or the like that can form a film is preferred.

  In the present embodiment, zinc phosphate treatment is applied as a base treatment (pretreatment) for cationic electrodeposition coating. Since the surface of the steel material as a raw material is roughened by a chemical reaction by this zinc phosphate treatment, the bite of the paint is improved and the adhesion is improved. Further, a sealer treatment may be performed after the zinc phosphate treatment. This sealer is a kind of metal surface treatment agent, for example, a so-called chemical conversion treatment in which a chemical conversion film can be formed by performing immersion for a short time of about 30 seconds to 2 minutes, or spray treatment. Excellent film adhesion can be secured, and a protective film of the material can be formed, and a strong rust prevention function and conductivity can be exhibited. In other words, the zinc phosphate treatment is applied as a base treatment for the cationic electrodeposition coating, and the sealer treatment is performed thereon to smooth the fine surface of the zinc phosphate coating, thereby causing the air during paint electrodeposition. Can be prevented. If air is involved, surface defects such as craters (uneven surfaces such as irregularities) may occur in the coating film, which is not preferable.

  Thus, in this embodiment, since the rust preventive film which consists of cationic electrodeposition coating is formed in the outer cap 16, and the zinc phosphate process is performed as a ground treatment of cationic electrodeposition coating, adhesion of a coating material is carried out. The rust preventive film is not easily peeled off during press-fitting into the outer member 2 and can maintain a smooth surface by filling minute concavities and convexities on the fitting surface 16a. Rusting over a long period of time can be prevented, and good airtightness can be obtained between the outer fitting surface 20 and the end surface 2d of the outer member 2.

  In the present embodiment, as shown in FIG. 6, a drain 26 is formed on the radially outer side of the bottom 16 c of the outer cap 16. This drain 26 is formed in the bulging part 27 of the side close | similar to the road surface of the fitting part 16a and the bottom part 16b. The bulging portion 27 is formed so as to protrude from the bottom portion 16b to the inner side by a predetermined amount. This bulging portion 27 is effective when the knuckle 9 is not flush with the end face 2d of the outer member 2 but protrudes toward the inner side. That is, by forming the drain 26 through the bulging portion 27 of the outer cap 16 in the radial direction, even if foreign matter such as rainwater enters the outer cap 16 from the outside, it flows into the bulging portion 27 portion. The foreign matter can easily and effectively be discharged outside without being blocked by the knuckle 9.

  7 and 8 show a modified example of the fixing nut 23 described above. The fixing nut 28 includes a cylindrical portion 23b having an internal thread 23a formed on the inner periphery, and a rectangular flange portion 28a at the end of the cylindrical portion 23b. Then, the fixing nut 28 is fitted into the perforation 22 from the inner side until the flange portion 28a comes into close contact with the inner side surface of the bottom portion 16c of the outer cap 16. Then, the outer peripheral part of the flange part 28a is joined by spot welding.

  In the present embodiment, the flange portion 28 a is formed in a rectangular shape that extends to the vicinity of the insertion hole 17 of the outer cap 16. As a result, the contact area between the fixing nut 28 and the bottom portion 16c further increases, and the fixing member 28 can be firmly fixed, and the mounting member 24 can be supported over substantially the entire surface. Since the bending of the mounting member 24 can be prevented, desired detection accuracy can be ensured.

  9 and 10 show another modification of the fixing nut 23 described above. The fixing nut 29 includes a cylindrical portion 23b having an internal thread 23a formed on the inner periphery, and a circular flange portion 29a at the end of the cylindrical portion 23b. Then, the fixing nut 29 is fitted into the perforation 22 from the inner side until the flange portion 29a comes into close contact with the inner side surface of the bottom portion 16c of the outer cap 16. Then, the outer peripheral part of the flange part 29a is joined by spot welding.

  In the present embodiment, the flange portion 29 a is larger than the width of the mounting member 24, and the outer diameter thereof is formed in a circular shape that extends to the vicinity of the insertion hole 17 of the outer cap 16. As a result, the contact area between the fixing nut 29 and the bottom portion 16c further increases, and the fixing member 29 can be firmly fixed, and the mounting member 24 can be supported over substantially the entire surface. It is possible to prevent the mounting member 24 from being bent.

  11 and 12 show a modified example of the outer cap 16 described above. This outer cap 30 is formed in a cup shape by press working from a rust-proof cold-rolled steel plate, and is fitted into a cylindrical fitting portion 16a that is press-fitted into the inner periphery of the inner side end of the outer member 2. A flange portion 16b that overlaps and extends radially outward from the fitting portion 16a and is in close contact with the inner side end surface 2d of the outer member 2, and an inner side opening of the outer member 2 is closed from the flange portion 16b. And a bottom portion 30a.

  In the present embodiment, a circular recess 31 is formed on the inner side surface of the bottom 30 a of the outer cap 30, and a fixing nut 23 is fitted into the perforation 22 formed in the recess 31. Then, the rotational speed sensor 21 fastens the mounting bolt 25 to the fixing nut 23 via the mounting member 24 with the bottom 30a of the outer cap 30 and the side surface of the flange 23c of the fixing nut 23 set to be substantially flush with each other. It is fixed by 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 fixing nut 23 is inserted into the perforation 22, and the fixing nut 23 is inserted into the perforation 22 from the inner side until the flange portion 23 c comes into close contact with the inner side surface of the recess 31 of the outer cap 30. Then, the outer peripheral part of the flange part 23c is joined by spot welding.

  Thus, in this embodiment, since the circular recessed part 31 is formed in the bottom part 30a of the outer cap 30, and the fixing nut 23 is joined to this recessed part 31, the attachment member 24 is spread over substantially the whole surface, and the outer cap 30 can be supported by the bottom 30a, and the bending of the mounting member 24 when the rotation speed sensor 21 is fixed can be prevented.

  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 according to the present invention can be applied to an inner ring rotating type wheel bearing device of any structure such as a driven wheel and a rolling element of a ball, a tapered roller or the like.

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 2a Outer rolling surface 2b Car body mounting flange 2c Pilot part 2d Inner side end surface 3 of outer member Rolling element 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step part 4c Clamping part 5 Inner ring 5b Outer diameter surface of inner ring 6 Wheel mounting flange 6a Hub bolt 6b Inner side base 6c of wheel mounting flange Side surface of inner side of wheel mounting flange 7 Cage 8 Seal 9 Knuckle 10 Core metal 11 Seal member 11a Side lip 11b Da Strip 11c Grease lip 12 Pulsar ring 13 Support ring 13a, 23b Cylindrical portion 13b Standing plate portion 14 Magnetic encoder 15 Inner cap 15a, 16a Fitting portion 15b Reduced diameter portion 15c Disc portion 15d Bending portion 15e Bottom portion 16, 30 Outer cap 16b 鍔Part 16c, 30a bottom part 17 fitting insertion hole 18 elastic member 18a annular projection 1 Inner fitting surface 19a Step 20 Outer fitting surface 21 Rotational speed sensor 22 Perforation 23, 28, 29 Fixing nut 23a Female thread 23c, 28a, 29a Flange portion 24 Mounting member 25 Mounting bolt 26 Drain 27 Swelling portion 31 Recess 50 Outward Member 50a Outer rolling surface 50b Car body mounting flange 51 Hub wheels 51a, 52a Inner rolling surface 51b Small diameter step 52 Inner ring 53 Inner member 54 Cage 55 Ball 56, 57 Seal 58 Wheel mounting flange 59 Encoder 60 Cover 61 Holder 64 Cylindrical portion 65 Bottom plate portion 66 Gutter portion 67 Insertion hole 68 Through hole 69 Insertion portion 70 Mounting hole 71 Mounting flange 72 Bolt 73 Nut 73a Nut protrusion

Claims (8)

An outer member integrally having a vehicle body mounting flange for being attached to the vehicle body 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 housed between the rolling surfaces of the inner member and the outer member so as to be freely rollable via a cage;
A pulsar ring fitted on the inner ring;
A rotational speed sensor facing the pulsar ring via a predetermined axial air gap;
A cup-shaped sensor cap that is fitted to the inner side end of the outer member and on which the rotational speed sensor is supported and fixed,
In the wheel bearing device with a rotational speed detection device in which a nut for attaching the rotational speed sensor to the sensor cap is fixed,
The fixing nut has an internal thread formed on the inner periphery thereof, a cylindrical portion that is inserted into the perforation, and a flange portion on the outer periphery of the end portion of the cylindrical portion, and the flange portion is provided on the inner side surface of the bottom portion of the sensor cap. The wheel bearing device with a rotational speed detecting device, wherein the fixing nut is inserted into the perforation until it comes into close contact, and the flange portion is integrally joined to the bottom portion of the sensor cap.   The wheel bearing device with a rotation speed detection device according to claim 1, wherein the flange portion of the fixing nut is joined by spot welding or an adhesive.   The bearing device for a wheel with a rotational speed detection device according to claim 1 or 2, wherein a flange portion of the fixing nut extends to the vicinity of an insertion hole of the sensor cap.   A circular concave portion is formed on the inner side surface of the bottom portion of the sensor cap, the perforation is formed in the concave portion, and the bottom surface of the outer cap and the side surface of the flange portion of the fixing nut are set substantially flush with each other. The wheel bearing device with a rotational speed detection device according to claim 1 or 2.   The wheel with a rotational speed detection device according to any one of claims 1 to 4, wherein the sensor cap is formed from a steel plate by press working, and a rust preventive film made of cationic electrodeposition coating is formed on an outer surface including the fixing nut. Bearing device.   A bulge is formed on the side of the bottom of the sensor cap that is close to the radially outward road surface by projecting a predetermined dimension from the bottom to the inner side, and a drain that penetrates in the radial direction is formed in the bulge. The wheel bearing device with a rotational speed detection device according to any one of claims 1 to 5.   An inner cap is fitted on the outer side of the sensor cap, and the inner cap is formed into a cup shape by pressing from a nonmagnetic austenitic stainless steel plate and is press-fitted into the inner periphery of the inner side end of the outer member. A cylindrical fitting portion and a disc portion extending radially inward from the fitting portion and facing the pulsar ring via a slight axial clearance, and the rotational speed sensor is provided on the disc portion. The wheel bearing device with a rotational speed detection device according to claim 1, wherein the two are opposed to or close to each other and are arranged to face the pulsar ring via the inner cap.   A reduced diameter portion is formed between the fitting portion of the inner cap and the disk portion, and an elastic member made of synthetic rubber is integrally joined to the reduced diameter portion by vulcanization adhesion. 8. An annular protrusion that protrudes inward from the side surface of the disk portion of the inner cap so as not to interfere with the rotational speed sensor and protrudes radially outward from the outer diameter of the fitting portion. 2. A bearing device for a wheel with a rotational speed detection device according to 1.

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