JP2007333394A - Magnetic encoder and wheel bearing with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic encoder that can prevent abrasions from generating the a surface of a multipole magnet at a transport. <P>SOLUTION: The magnetic encoder 11 is provided with a cored bar 12, and the multipole magnet 13. The cored bar 12 is provided with an inverted L-shape cross section having a cylindrical section 12a, and a standing plate section 12b, extending from one end of the cylindrical section 12a to an inside diameter. The multipole magnet 13 is provided on the outer face of the standing plate section 12b in the cored bar 12, and is formed alternately with magnetic poles, in the circumferential direction. The outside diameter ϕA of the multipole magnet 13 is smaller than the inside diameter ϕB of the cylindrical section 12a of the cored bar 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetic encoder used in a rotation detection device or the like of a bearing portion that relatively rotates, and a wheel bearing device including the same.

2. Description of the Related Art Conventionally, for example, in an antilock braking system for an automobile, a rotation encoder for a wheel bearing device is provided on a rotating wheel side of the wheel bearing device and on a fixed wheel side or a vehicle body of the wheel bearing device. In general, the magnetic sensor is configured to be used as a pair.
In the rotation detection device having such a configuration, the magnetic encoder is generally used in an integrated manner with a bearing seal provided to prevent foreign matter from entering the inside of the bearing (for example, Patent Documents 1 and 2). The bearing seal may be abolished and only the magnetic encoder alone may be provided on the bearing due to the peripheral structure. When used in an integrated manner with a bearing seal, in an annular cored bar having an L-shaped cross-section, which is a slinger for the bearing seal, alternately in the circumferential direction on the outer surface of the standing plate portion extending radially from one end of the cylindrical portion A multipolar magnet having magnetic poles formed thereon is provided, and the cylindrical portion of the annular cored bar is fitted to the rotating wheel of the bearing. Even when used as a single magnetic encoder, the multi-pole magnet is provided on the outer surface of the upright portion of the annular cored bar having an L-shaped cross section. As a multipolar magnet of a magnetic encoder, a magnetic rubber or the like in which magnetic poles are formed on an elastic member mixed with magnetic powder is generally used (for example, Patent Document 1). In the magnetic encoder disclosed in Patent Document 2, a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder is used as a multipolar magnet.

FIG. 6 shows a cross-sectional view of an example of a third-generation type wheel bearing device to which a conventional magnetic encoder is attached. In this wheel bearing device, in addition to the bearing seal 28, a magnetic encoder 31 is fitted on the outer diameter surface of the inner ring 30 in the rotation side wheel 22 composed of the hub wheel 29 and the inner ring 30 fitted to the outer diameter surface thereof. Can be installed together. In this case, as shown in a half sectional view in FIG. 7, the magnetic encoder 31 includes an annular cored bar 32 having an inverted L-shaped cross section having a standing plate portion 32b extending to the inner diameter side at one end of the cylindrical portion 32a. The multi-pole magnet 33 is provided on the outer surface of the standing plate portion 32 b of the annular core metal 32, and the cylindrical portion 32 a of the annular core metal 32 is fitted and attached to the outer diameter surface of the inner ring 30.
Japanese Patent No. 2816783 JP 2004-037441 A JP 2003-269476 A

When transporting the single unit of the magnetic encoder 31, generally, the magnetic encoder 31 is packed and transported in an overlapped state as shown in FIG. However, in the conventional magnetic encoder 31, as shown in FIG. 7, the multipolar magnet 33 is provided over the entire radial range on the outer surface of the standing plate portion 32 b of the core metal 32. Since the outer diameter φA is larger than the inner diameter φB of the cylindrical portion 32a (φA> φB), when the magnetic encoder 31 is stacked as shown in FIG. The end surface of 32a will be in the state which contacted the multipolar magnet 33 of the magnetic encoder 31 located below. For this reason, when the multipolar magnet 33 is made of magnetic rubber or the like, the multipolar magnet 33 and the end surface of the cored bar cylindrical portion 32a are rubbed due to vibration or the like generated during transportation, and the surface of the multipolar magnet 33 is scratched. This may not only deteriorate the quality of appearance but also lead to deterioration of magnetic properties.
Even in the case where the magnetic encoder 31 is integrated with the bearing seal, the magnetic encoder 31 flows through the process in a single state in the manufacturing process.

As shown in FIG. 9, the magnetic encoder 31A in which the standing plate portion 32b of the annular cored bar 32 extends from the one end of the cylindrical portion 32a to the outer diameter side is provided on the outer surface of the cored bar standing plate portion 32b. A multipolar magnet 33 having an inner diameter φC larger than an outer diameter φD of the cylindrical portion 32a (φC> φD) has been proposed (Patent Document 3).
In this case, even if the magnetic encoder 31A is stacked in a stacked state as shown in FIG. 10, the end surface of the cored bar cylindrical portion 32a of the magnetic encoder 31A located above is the multipolar magnet of the magnetic encoder 31A located below. Since it contacts the mandrel standing plate 32b without contacting 33, the surface of the multipolar magnet 33 can be prevented from being scratched.

  An object of the present invention is to provide a magnetic encoder capable of preventing the surface of a multipolar magnet from being scratched during transportation, and a wheel bearing device including the magnetic encoder.

The magnetic encoder of this invention is provided on the outer surface of the upright plate portion of the upright plate portion of the upright plate portion having an inverted L-shaped cross section having a cylindrical portion and a upright plate portion extending from one end of the cylindrical portion toward the inner diameter side. And a multi-pole magnet having magnetic poles alternately formed in the circumferential direction, wherein the outer diameter of the multi-pole magnet is smaller than the inner diameter of the cylindrical portion of the cored bar. To do.
According to this configuration, in the state where the magnetic encoder is stacked, the end surface of the cylindrical portion of the core metal of the magnetic encoder positioned above does not contact the surface of the multipolar magnet of the magnetic encoder positioned below, Will come into contact. Therefore, it is possible to avoid the occurrence of scratches on the surface of the multipolar magnet during transportation, and it is possible to prevent deterioration in appearance quality and magnetic characteristics.

  A wheel bearing device according to the present invention includes an outer member having a double row raceway surface on an inner peripheral surface, and a wheel mounting flange on an outer periphery of an outboard side end having a raceway surface facing each of the raceway surfaces. In the wheel bearing device having the inner member having the inner member and the double row rolling elements interposed between the outer member and the raceway surface of the inner member, the magnetic encoder according to the present invention includes the cylindrical portion of the core metal. The multi-pole magnet is attached to the outer diameter surface at the inboard side end of the side member so that the multipolar magnet faces the inboard side. In this wheel bearing device, the surface of the multipolar magnet is not scratched during the transportation of the magnetic encoder of the invention to be mounted, and there is no deterioration of the magnetic characteristics, so that it is possible to accurately detect the rotation of the wheel. it can.

Another wheel bearing device of the present invention includes an inner member having a double-row raceway surface on the outer peripheral surface, and a wheel mounting flange on the outer periphery of the outboard side end having a raceway surface facing each of the raceway surfaces. And a double row rolling element interposed between the inner member and the raceway surface of the outer member, the magnetic encoder according to claim 1, wherein the magnetic encoder is a cylinder of a cored bar. The shape portion is fitted to the outer diameter surface of the inboard side end of the outer member, and the multipolar magnet is attached so as to face the inboard side.
Even in this wheel bearing device, the surface of the multipolar magnet is not scratched during the transport of the magnetic encoder, and the magnetic characteristics are not deteriorated, so that the rotation of the wheel can be detected with high accuracy.

A magnetic encoder according to a first aspect of the present invention includes a cylindrical portion and a core bar having an inverted L-shaped cross section having a vertical plate portion extending from one end of the cylindrical portion toward the inner diameter side, and the vertical plate of the core metal In the magnetic encoder provided with the multipolar magnet provided on the outer surface of the portion and having the magnetic poles alternately formed in the circumferential direction, the outer diameter of the multipolar magnet is set to be larger than the inner diameter of the cylindrical portion of the cored bar. Since the size is reduced, it is possible to prevent the surface of the multipolar magnet from being scratched during transportation.
A wheel bearing device according to the present invention includes an outer member having a double row raceway surface on an inner peripheral surface, and a wheel mounting flange on an outer periphery of an outboard side end having a raceway surface facing each of the raceway surfaces. In the wheel bearing device having the inner member having the inner member and the double row rolling elements interposed between the outer member and the raceway surface of the inner member, the magnetic encoder according to the present invention includes the cylindrical portion of the core metal. Since the multi-pole magnet is fitted to the outer diameter surface of the inboard side end of the side member and the multi-pole magnet faces the in-board side, the surface of the multi-pole magnet is not scratched during transportation of the magnetic encoder, and the magnetic There is no deterioration of the characteristics, and the rotation of the wheel can be detected with high accuracy and reliability.
Another wheel bearing device of the present invention includes an inner member having a double-row raceway surface on the outer peripheral surface, and a wheel mounting flange on the outer periphery of the outboard side end having a raceway surface facing each of the raceway surfaces. And a double-row rolling element interposed between the inner member and the raceway surface of the outer member, the magnetic encoder according to the present invention includes a cylindrical portion of the metal core. Fitted to the outer diameter surface of the inboard side end of the outer member and attached so that the multipolar magnet faces the inboard side, no scratches occur on the surface of the multipole magnet during transportation of the magnetic encoder, There is no deterioration of the magnetic characteristics, and the rotation of the wheel can be detected accurately and reliably.

A magnetic encoder according to an embodiment of the present invention will be described with reference to FIGS. The magnetic encoder 11 includes a metal annular core 12 and a multipolar magnet 13 provided on the surface of the core 12 along the circumferential direction. The annular cored bar 12 has an inverted L-shaped cross section having a cylindrical portion 12a and a standing plate portion 12b extending from one end of the cylindrical portion 12a toward the inner diameter side. The multipolar magnet 13 is provided on the outer surface of the upright portion 12b of the core metal 12 and has magnetic poles alternately formed in the circumferential direction, and is made of, for example, a rubber magnet. The multipolar magnet 13 may be a plastic magnet.
In the magnetic encoder having this configuration, the outer diameter φA of the multipolar magnet 13 is made smaller than the inner diameter φB of the cylindrical portion 12a of the core metal 12 (φA <φB). The multipolar magnet 13 is fixed to the outer surface of the cored bar upright portion 12b by, for example, vulcanization adhesion.

  The magnetic encoder 11 is attached to a rotating member (not shown) such as a bearing rotating wheel, and a magnetic sensor (not shown) faces the multipolar magnet 13 to be used for rotation detection. The magnetic encoder 11 and the magnetic sensor constitute a rotation detection device.

  FIG. 2 is a half sectional view showing a state in which the magnetic encoders 11 are stacked in order to transport the magnetic encoder 11. As described above, in the magnetic encoder 11, the outer diameter φA of the multipolar magnet 13 is smaller than the inner diameter φB of the cored bar cylindrical portion 12a. The end surface of the cored bar cylindrical portion 12a of the magnetic encoder 11 positioned does not contact the surface of the multipolar magnet 13 of the magnetic encoder 11 positioned below, but contacts the cored bar standing plate 12b. Therefore, it is possible to avoid the occurrence of scratches on the surface of the multipolar magnet 13 of the magnetic encoder 11 during transportation, and it is possible to prevent the appearance quality and the magnetic characteristics from deteriorating.

FIG. 3 shows the above-described magnetic encoder 11 mounted on a wheel bearing device for supporting a driven wheel, which is a third-generation inner ring rotating type. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle with the wheel bearing device attached to the vehicle is referred to as the outboard side, and the side closer to the center of the vehicle is referred to as the inboard side.
The wheel bearing device includes an outer member 1 having a double row raceway surface 3 on an inner periphery, an inner member 2 having a raceway surface 4 facing each of the raceway surfaces 3, the outer member 1 and the inner member. A rolling element 5 having double rows interposed between the raceway surfaces 3 and 4 of the side member 2 is provided, and the wheels are rotatably supported with respect to the vehicle body. This wheel bearing device is a double-row outward angular ball bearing type, and the rolling elements 5 are formed of balls and are held by a cage 6 for each row. Both ends of the bearing space between the outer member 1 and the inner member 2 are sealed with seals 7 and 8, respectively.

The outer member 1 is a member on the fixed side, and has a flange 1a attached to the knuckle in the suspension device (not shown) of the vehicle body on the outer periphery, and the whole is an integral part.
The inner member 2 is a member on the rotation side, and is fitted on the outer periphery of the inboard side end of the hub wheel 9 and the hub wheel 9 having a flange 9a for wheel attachment on the outer periphery of the outboard side end. The inner ring 10 is combined. A wheel (not shown) is attached to the flange 9 a of the inner member 2 together with a brake rotor with a hub bolt 15. The hub ring 9 and the inner ring 10 are formed with the raceway surfaces 4 in each row.

  4 is an enlarged cross-sectional view of a portion IV in FIG. The magnetic encoder 11 is attached to the outer diameter surface of the inboard side end of the inner member 2. Specifically, the cylindrical portion 12a of the cored bar 12 in the magnetic encoder 11 is press-fitted into the outer diameter surface of the inner ring 10 in the inner member 2 so that the multipolar magnet 13 is inboard side. The magnetic encoder 11 is attached so as to face the direction. The magnetic encoder 11 and a magnetic sensor (not shown) installed on the vehicle body side, for example, so as to face the outward surface of the multipolar magnet 13 constitute a rotation detection device.

  In this wheel bearing device, the surface of the multi-pole magnet 13 is not scratched during the transportation of the magnetic encoder 11 mounted as described above, and there is no deterioration in magnetic characteristics. Can be done reliably.

FIG. 5 is a double-row outward angular contact ball bearing type that is classified as a second generation type, in which the magnetic encoder 11 described above is attached to a wheel bearing device that is an outer ring rotating type and supports a driven wheel. . This wheel bearing device includes an outer member 1 also serving as a hub wheel having double rows of raceway surfaces 3 on the inner periphery, an inner member 2 having raceway surfaces 4 respectively facing these raceway surfaces 3, and these double rows. A plurality of rolling elements 5 interposed between the raceway surfaces 3 and 4. The outer member 1 has a wheel mounting flange 1b on the outer periphery of the outboard side end. A wheel (not shown) is attached to the flange 1 b of the outer member 1 with a hub bolt 15 together with a brake rotor. The inner member 2 includes a split inner ring in which two bearing inner rings 2A each having a raceway surface 4 are arranged in the axial direction. The rolling elements 5 are formed of balls and are held by the cage 6 for each row. Both ends of the annular space formed between the inner and outer members 2 and 1 are sealed with a pair of seals 7A and 8A.
The magnetic encoder 11 is attached to the outer diameter surface at the inboard side end of the outer member 2. Specifically, the cylindrical portion 12a of the cored bar 12 is fitted to the outer diameter surface of the inboard side end of the outer member 2 so that the multipolar magnet 13 faces the inboard side. 11 is attached.

  Also in the case of this wheel bearing device, the surface of the multipolar magnet 13 is not scratched during the transportation of the magnetic encoder 11 to be mounted, and there is no deterioration of the magnetic characteristics. It can be done well.

  In the above-described embodiment, the third generation type in which the inner member 2 includes the hub wheel 9 and the inner ring 10 in one row, and the second generation type wheel bearing device of the outer ring rotation type have been described. The invention is an inner ring rotation type, and a first and second generation type wheel bearing device in which a hub and a bearing are independently provided, that is, a first generation type in which a double row rolling bearing is provided on the outer periphery of the shaft portion of the hub. The second generation type in which the outer ring of the double row rolling bearing is provided with a flange for mounting the vehicle body, or the fourth generation type wheel bearing device in which the inner member is a hub ring and an outer ring of a constant velocity joint, The present invention can be applied. Moreover, in these, it can apply also to any angular ball bearing type | mold and a taper roller type | mold wheel bearing apparatus.

1 is a half sectional view showing an embodiment of a magnetic encoder of the present invention. It is a half part sectional view showing the state where the magnetic encoder was piled up. It is sectional drawing which shows an example of the wheel bearing apparatus which attached the magnetic encoder. It is an expanded sectional view of the IV section in FIG. It is sectional drawing which shows the other example of the wheel bearing apparatus which attached the same magnetic encoder. It is sectional drawing of an example of the wheel bearing apparatus which attached the conventional magnetic encoder. FIG. 2 is a half sectional view of the magnetic encoder. It is a half part sectional view showing the state where the magnetic encoder was piled up. It is a half sectional view of another conventional magnetic encoder. It is a half part sectional view showing the state where the magnetic encoder was piled up.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 1b ... Wheel mounting flange 2 ... Inner member 3 ... Outer member raceway surface 4 ... Inner member raceway surface 5 ... Rolling element 9a ... Wheel attachment flange 11 ... Magnetic encoder 12 ... Core metal 12a ... Cylindrical part 12b ... Standing plate part 13 ... Multipolar magnet

Claims (3)

A cylindrical bar and an inverted L-shaped core bar having a vertical plate part extending from one end of the cylindrical part to the inner diameter side, and an outer surface of the vertical plate part of the core bar are alternately provided in the circumferential direction. In a magnetic encoder comprising a multipole magnet having magnetic poles formed on
A magnetic encoder, wherein an outer diameter of the multipolar magnet is smaller than an inner diameter of a cylindrical portion of the cored bar.   An outer member having a double-row raceway surface on the inner peripheral surface, an inner member having a raceway surface facing each of the raceway surfaces and having a wheel mounting flange on the outer periphery of the outboard side end, and these outer members 2. The wheel bearing device having a member and a double row rolling element interposed between the raceway surfaces of the inner member, the magnetic encoder according to claim 1, wherein the cylindrical portion of the core metal is on the inboard side of the inner member. A wheel bearing device fitted to an outer diameter surface of the end and attached so that the multipolar magnet faces the inboard side.   An inner member having a double-row raceway surface on the outer peripheral surface, an outer member having a raceway surface facing each of the raceway surfaces and having a wheel mounting flange on the outer periphery of the outboard side end, and these inner members And a double-row rolling element interposed between the raceway surfaces of the outer member, the magnetic encoder according to claim 1, wherein the cylindrical portion of the core metal has an inboard side end of the outer member. The wheel bearing device is fitted to the outer diameter surface of the wheel and attached so that the multipolar magnet faces the inboard side.

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