JP3575485B2 - Rubber magnet encoder for detecting rotation speed of vehicle wheel, method of manufacturing the same, and rolling bearing unit for vehicle wheel - Google Patents

Description

A rubber magnet encoder for detecting the rotational speed of a vehicle wheel according to the present invention, a method of manufacturing the same, and a rolling bearing unit for a vehicle wheel support the vehicle wheel rotatably with respect to a suspension device and rotate the wheel. The present invention relates to a rubber magnet encoder for detecting the rotational speed of a vehicle wheel, a method of manufacturing the rubber magnet encoder, and a rolling bearing unit for a vehicle wheel , which are incorporated in a rolling bearing unit with an encoder constituting a rotational speed detecting device for detecting a speed .

  In order to control the antilock brake system (ABS) or the traction control system (TCS), it is necessary to detect the rotational speed of the wheels. Therefore, a rolling bearing unit with a rotation speed detection device is required to rotatably support the wheel with respect to the suspension device and detect the rotation speed of the wheel. Conventionally, as such a rolling bearing unit with a rotation speed detecting device, one having a structure as described in Patent Documents 1 and 2, for example, is known.

  FIG. 8 shows a rolling bearing unit with a rotation speed detecting device described in Patent Document 2 among them. A pair of inner wheels 1, 1 each of which is a stationary wheel, when fitted into a suspension, is externally fitted and fixed to a non-rotating axle (not shown). On the outer peripheral surface of each of the inner rings 1, 1, which are stationary peripheral surfaces, inner ring raceways 2, 2, each of which is a stationary raceway surface, are formed. In addition, double rows of outer raceways 4, 4, each of which is a rotating raceway surface, are formed on the inner circumferential surface (rotating circumferential surface) of the hub 3, which is a rotating wheel that rotates during use. A plurality of balls 5, 5 as rolling elements are provided between the outer raceways 4, 4 and the inner raceways 2, 2, respectively, and the hub 3 is rotatably supported around the axle. are doing. The wheel is fixed to a flange (not shown) provided on the outer peripheral surface of the hub 3.

  Further, the inner end of the hub 3 (inside means a side closer to the center in the width direction of the vehicle when assembled to the vehicle, and the right side in the figure. The same applies to FIGS. The outer side in the width direction is referred to as an outer side.) A core metal 7 which is a holding ring constituting the seal ring 6 is fitted and fixed in the opening. That is, the cylindrical portion 8 formed on the outer peripheral edge of the metal core 7 is internally fitted and fixed to the inner end opening of the hub 3 by interference fitting. A sealing material 9 made of an elastic material such as rubber is connected and supported on the inner surface of the cored bar 7, and an encoder 10 is further connected and supported on the inner surface of the sealing material 9. The encoder 10 is constituted by a permanent magnet and is formed in an annular shape in which S poles and N poles are alternately arranged in the circumferential direction.

  On the other hand, a second holding ring 11 formed by bending a metal plate is externally fixed to the inner end of the inner inner ring 1 of the pair of inner rings 1. The tip edges of the plurality of seal lips 12 provided on the seal material 9 constituting the seal ring 6 are brought into sliding contact with the inner and outer peripheral surfaces and the outer surface of the second holding ring 11 so that the balls 5, 5 5 Prevents dust and rainwater from entering the installation area. Further, a sensor 13 is supported and fixed on a part of the second holding ring 11, and a detection portion of the sensor 13 is opposed to an inner surface of the encoder 10.

  In the case of the rolling bearing unit with the rotation speed detecting device as described above, the wheel fixed to the hub 3 can be rotatably supported on the axle on which the inner wheels 1, 1 are externally fitted. When the hub 3 rotates with the wheels, the output of the sensor 13 facing the inner surface of the encoder 10 fixed to the hub 3 changes. The frequency at which the output of the sensor 13 changes is proportional to the rotational speed of the wheel. Therefore, if the output signal of the sensor 13 is input to a controller (not shown), the rotation speed of the wheel can be obtained, and the ABS and TCS can be appropriately controlled.

JP-A-6-281018 U.S. Pat. No. 4,948,277

The present invention relates to a rubber magnet encoder for detecting the rotational speed of a vehicle wheel, a method of manufacturing the rubber magnet encoder, and an improvement of the rolling bearing unit for a vehicle wheel, which is incorporated in the above-described rolling bearing unit with encoder.

The present invention relates to a rubber magnet encoder for detecting a rotational speed of a vehicle wheel, which is made of rubber in which a powder of a magnetic material is mixed in rubber, and in which an axial magnetization direction is alternately changed in a circumferential direction. And a method of manufacturing the same , and a rolling bearing unit for a vehicle wheel incorporating the rubber magnet encoder .

In particular, the rubber magnet encoder for detecting the rotation speed of the wheel of a vehicle according to claim 1 is formed by punching a rubber plate material into which the powder is mixed in a uniform degree of orientation into an annular shape . Things.
A method of manufacturing a rubber magnet encoder for detecting a rotation speed of a vehicle wheel according to claim 2 is a method of manufacturing a rubber plate material in which the powder is mixed in a degree of orientation by a rolling roll forming machine to form an entire ring. It is formed by punching.
Further, the rolling bearing unit for a vehicle wheel according to claim 3 has a stationary wheel that has a stationary raceway surface on a stationary peripheral surface and does not rotate during use, and has a rotating raceway surface on a rotating peripheral surface. A rotating wheel that rotates at times, a plurality of rolling elements provided between the stationary-side raceway surface and the rotating-side raceway surface, and the vehicle wheel according to claim 1 fixed to the rotating wheel. A rubber magnet encoder for detecting a rotation speed.

The rolling bearing unit for a vehicle wheel incorporating the rubber magnet encoder for detecting the rotation speed of the vehicle wheel of the present invention configured as described above supports the wheel rotatably and combines it with a sensor to form a rotating wheel. The operation itself for detecting the rotational speed of the fixed wheel is the same as that of the above-described rolling bearing unit for an automobile with an encoder, which constitutes the above-described rolling bearing unit with a rotational speed detecting device.

1 to 6 show a rolling bearing unit for a wheel of an automobile equipped with an encoder incorporating the rubber magnet encoder of the present invention as a first embodiment of the present invention. Contrary to the case of the first example of the conventional structure shown in FIG. 8 described above, the inner raceways 2 and 2 as the rotating raceways are formed on the outer circumferential surface as the rotating circumferential surface, each of which is a rotating wheel. The inner rings 1, 1 are externally fitted and fixed to a rotating axle during use. An outer ring 17, which is a stationary wheel that does not rotate during use, is arranged around the inner rings 1, 1 concentrically with the inner rings 1, 1. A plurality of rolling elements, which are formed on the inner peripheral surface of the outer race 17 which is the stationary peripheral raceway, are provided between the outer raceways 4 and 4 which are the stationary raceway surfaces and the inner raceways 2 and 2, respectively. The balls 5, 5 are provided, and the inner rings 1, 1 are rotatably supported inside the outer ring 17.

  A combination seal 18 is provided between the inner peripheral surface of the inner end portion of the outer ring 17 and the outer peripheral surface of the inner end portion of the inner ring 1 so as to provide a gap between the inner peripheral surface of the outer ring 17 and the outer peripheral surface of the inner ring 1. It closes the inner end opening of the existing space. Further, another combination seal 19 is provided between the inner peripheral surface of the outer end of the outer ring 17 and the outer peripheral surface of the outer end of the inner ring 1 so that the inner peripheral surface of the outer ring 17 and the outer peripheral surface of the inner ring 1 are provided. And the outer end opening of the space that exists between them.

  Of the two sets of combination seals 18 and 19, the combination seal 18 provided on the inner side includes a cored bar 21 and a seal ring 22 fitted and fixed on the inner peripheral surface of the inner end of the outer ring 17. The core metal 21 is a holding ring that is externally fitted and fixed to the outer peripheral surface of the inner end of the inner ring 1 in order to support the encoder 20. Then, the seal lips 24, 24 of the seal member 23 provided over the entire circumference of the seal ring 22 are slidably contacted with the core metal 21, so that the outer peripheral surface of the inner end of the inner inner ring 1 and The space between the outer ring 17 and the inner peripheral surface of the inner end is sealed. The core metal 21 is made of a magnetic metal plate such as a mild steel plate or a magnetic or non-magnetic metal plate such as a stainless steel plate and has an L-shaped cross section and is formed in a ring shape as a whole. That is, the core metal 21 is composed of a cylindrical portion 25 and a circular ring portion 26 that is bent at a right angle from the inner end edge of the cylindrical portion 25 outward in the diametrical direction. The inner ring 1 is externally fitted and fixed to the inner peripheral surface of the inner ring 1 by interference fit. The encoder 20 made of a rubber magnet is adhered and supported on the inner surface of the ring portion 26.

  The rubber magnet constituting the encoder 20 is obtained by mixing powders 14 of a ferromagnetic material such as ferrite into rubber, and is formed in an annular shape (ring shape) as a whole. The encoder 20 is magnetized in the axial direction (the left-right direction in FIGS. 1 and 2), and the magnetization direction is alternately changed in the circumferential direction. Therefore, S-poles and N-poles are alternately arranged at equal intervals in the circumferential direction on both axial side surfaces of the encoder 20.

In particular, in the case of the rolling bearing unit for a wheel of an automobile with an encoder according to the present embodiment, the encoder 20 cuts a rubber plate 29 having magnetic anisotropy mixed in advance with the orientation of the magnetic material powder being aligned. , By magnetizing. For example, as shown in FIG. 4, the rubber material 27 is rolled into a plate shape by a rolling roll forming machine 28 so that the directions of the magnetic material powders 14, 14 previously mixed into the rubber material 27 are changed. And the rolling direction (vertical direction in FIG. 4). Therefore, in the rubber plate 29 processed in this manner, both the front and back surfaces of the plate 29 itself and the flat portions 15, 15 (FIG. 9) of the powder are parallel. Therefore, the plate 29 has magnetic anisotropy in a direction perpendicular to both the front and back surfaces. Next, as shown in FIG. 5, for example, the rubber plate material 29 is punched into an annular shape by a shearing machine 30. Then, S-poles and N-poles are magnetized on both sides in the axial direction of the annularly formed rubber plate 29 so as to be arranged alternately and at equal intervals in the circumferential direction. The encoder 20 will be described. FIG. 6 shows the remaining material after punching out the encoder 20. Since the degree of orientation of the magnetic material powders 14 and 14 mixed in the plate material 29 for constituting the encoder 20 is previously aligned as described above, the magnetic force of the encoder 20 can be sufficiently increased, and will be described later. The density of the magnetic flux passing through the sensor 13 can be sufficiently increased. By increasing the magnetic flux density passing through the sensor 13 in this manner, the output of the sensor 13 can be increased, and the accuracy of detecting the rotational speed of the wheel can be improved.

  The encoder 20 configured as described above has one side (the left side in FIGS. 1 and 2) attached to one side (the right side in FIGS. 1 and 2) of the circular ring portion 26 constituting the cored bar 21 with an appropriate adhesive. It is supported on the inner surface of the cored bar 21 by adhesive bonding. Therefore, the processing and the magnetizing work of the encoder 20 are performed by a magnet maker, the encoder 20 is transported to a seal maker that manufactures the core metal 21, and the operation of bonding the encoder 20 to the core metal 21 is performed by a seal maker. It should be done by the manufacturer. There is no need to return any parts from the seal maker to the magnet maker.

A rolling bearing unit for a wheel of an automobile having an encoder incorporating the rubber magnet encoder of the present embodiment configured as described above is provided with an axle (not shown) for supporting the wheel inside a holding case 31 constituting a suspension device. Is rotatably supported, is supported by a part of the holding case 31, and is combined with the sensor 13 facing the inner surface of the encoder 20, so that the inner ring 1, 1 which is a rotating wheel that rotates together with the wheel. Detect the rotation speed. In particular, in the case of a rolling bearing unit with an encoder incorporating the rubber magnet encoder of the present embodiment, the encoder 20 is made of a rubber having magnetic anisotropy mixed by the magnet maker with uniform orientation of the magnetic material powders 14, 14. After punching and magnetizing the plate material 29 made of steel, it is only necessary to adhere and support the core metal 21 with a seal maker. For this reason, not only increase in equipment cost and transport cost can be suppressed, but also manufacturing operation can be simplified and increase in cost can be suppressed.

In the illustrated embodiment, the sensor 13 constituting the rotation speed detecting device together with the encoder 20 is installed in a holding case 31 outside the rolling bearing unit. However, the sensor 13 can also be supported on the outer wheel 17 which is a stationary wheel.
It is to be noted that unlike the present invention, when an encoder element 39, 39 cut into a belt shape is formed by bending to form an annular shape as shown in FIG. It is difficult in practice, and small discontinuities may occur. When an encoder having such a discontinuous portion is combined with a sensor, the detection signal output by the sensor becomes discontinuous at the discontinuous portion as the inner ring supporting the encoder rotates. There is a possibility that the rotation speed of the inner ring and the axle that externally supports the inner ring cannot be detected accurately.

When the present invention is carried out, the retaining ring may be made of a non-metal material such as a high-performance resin (engineering plastic) instead of being made of a metal plate like the core metal 21 (FIGS. 1 to 3). . For example, if the retaining ring is made by injection molding a high-performance resin, the material can be effectively used. Further, when the rotating wheel is an outer ring as in the conventional structure shown in FIG. 8, the holding ring is fixedly fitted to the rotating wheel. In this case, the annular portion is bent inward in the diameter direction from one end of the cylindrical portion. Further, in the first embodiment described above, an example was shown in which one side of the encoder 20 was adhered and fixed to one side of the annular portion 26 of the cored bar 21. However, when the cored bar 21 was made of a magnetic metal plate, Alternatively, the encoder 20 can be attracted to one side surface of the annular portion 26 by the magnetic force of the encoder 20 itself. In this case, it is not necessary to bond the encoder 20 to the metal core 21, and the manufacturing operation of the rolling bearing unit for the wheel of the vehicle with the encoder can be further simplified, and the cost can be further reduced.

FIG. 1 is a cross-sectional view illustrating a first embodiment of the present invention. The enlarged view of the A section of FIG. FIG. 2 is a cross-sectional view showing an encoder and a core that constitute the structure of FIG. 1. FIG. 4 is a schematic diagram showing an example of a method of rolling a rubber to produce a plate material and adjusting the degree of orientation of powder of a magnetic material mixed in the rubber. FIG. 7 is a schematic cross-sectional view showing one example of a method of forming a circular encoder by punching a rubber plate material mixed with a magnetic material powder. FIG. 6 is a plan view showing a remaining material after a plurality of encoders are punched by the method of FIG. 5. FIG. 3 is a plan view showing a state in which a rubber plate material mixed with a magnetic material powder is cut into a belt shape after magnetization unlike the present invention. Sectional drawing which shows an example of the conventional structure. FIG. 3 is a perspective view showing an easy magnetization direction of a magnetic material powder.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Inner ring track 3 Hub 4 Outer ring track 5 Ball 6 Seal ring 7 Core 8 Cylindrical part 9 Seal material 10 Encoder 11 Second holding ring 12 Seal lip 13 Sensor 14 Powder of magnetic material 15 Flat part 16 Encoder 17 Outer ring 18 , 19 Combination seal 20 Encoder 21 Core bar 22 Seal ring 23 Seal material 24 Seal lip 25 Cylindrical part 26 Ring part 27 Rubber material 28 Roll roll forming machine 29 Rubber plate material 30 Shearing machine 31 Holding case 39 Encoder piece

Claims (3)

A rubber magnet encoder for detecting a rotation speed of a wheel of an automobile made of rubber in which a magnetic material powder is mixed in rubber, wherein a magnetization direction in an axial direction is alternately changed in a circumferential direction, A rubber magnet encoder for detecting a rotation speed of a vehicle wheel, wherein the rubber plate material is formed by punching a whole of a rubber plate material into which the above-mentioned powders are mixed in a uniform degree of orientation into an annular shape . A method of manufacturing a rubber magnet encoder for detecting a rotation speed of a wheel of an automobile made of rubber in which a magnetic material powder is mixed into rubber, wherein magnetization directions in an axial direction are alternately changed in a circumferential direction. In addition, the above-mentioned powder is formed by punching a rubber plate material mixed with a uniform degree of orientation by a rolling roll forming machine into an annular shape for detecting the rotation speed of a wheel of an automobile. Manufacturing method of rubber magnet encoder.   A stationary wheel having a stationary raceway surface on the stationary peripheral surface and not rotating when used; a rotating wheel having a rotating raceway surface on the rotating peripheral surface and rotating during use; a stationary raceway surface and a rotating raceway surface A rolling bearing unit for a vehicle wheel, comprising: a plurality of rolling elements provided between the rolling element and the rubber magnet encoder for detecting the rotational speed of the vehicle wheel according to claim 1 fixed to the rotating wheel. .

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