JP2003133127A - Pulsar ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a flux generating density per unit area. SOLUTION: A pulsar ring 8 for constituting a rotation detector 10 with a magnet sensor 9 is composed of a nonmagnetic material and has a ring body forming an annular space into which a magnetic powder is press-fed. The magnetic powder in the annular space is magnetized so as to make different polarities alternately in a peripheral direction, and, the flux generating density per unit area is increased to improve the rotation detecting accuracy in the rotation detector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detecting device for detecting a wheel rotation speed, a rotation direction and the like in an anti-lock brake system of an automobile and the like, and to a pulser ring thereof.

[0002]

2. Description of the Related Art For example, in an anti-lock brake system for an automobile, a rotation detecting device is used for detecting the rotation speed and the rotation direction of wheels. This rotation detecting device includes a pulser ring and a magnetic sensor. Normal,
The pulsar ring is attached to the rotating side, and the magnetic sensor is attached to the fixed side. The pulsar ring and the magnetic sensor are arranged to face each other in the axial direction or the radial direction.

The pulsar ring in this rotation detecting device is provided with S poles and N poles alternately in the circumferential direction, and with the rotation thereof, magnetic fluxes of different polarities alternately corresponding to the rotation speed of the magnetic sensor with respect to the magnetic sensor. To occur. The magnetic sensor can detect the rotation state on the rotation side based on the generated magnetic flux.

The conventional pulser ring of this type is
An elastic material such as rubber containing magnetic powder is vulcanization-molded and adhered to the surface of the pulsar ring support, and magnetized (magnetized) into S poles and N poles alternately in the circumferential direction.

[0005]

The pulser ring in the above rotation detecting device tends to be smaller, and
The magnetic pole area tends to be reduced due to an increase in the number of magnetic poles such as S poles and N poles per unit installation area. Due to such a tendency, it is required to increase the generated magnetic flux density per unit area of those magnetic poles in order to maintain the highly accurate rotation detection accuracy.

However, in the above-mentioned conventional pulsar ring structure, the outer shape holding material is mainly composed of rubber that does not contribute to the generation of magnetic flux. Therefore, in order to increase the mixing ratio of the magnetic powder that contributes to the generation of magnetic flux. There is a limit, the magnetic flux density generated from the S pole and the N pole cannot be increased, and the above requirements cannot be met.

Therefore, it is an object of the present invention to make it possible to increase the magnetic flux generation density per unit area in such a pulser ring.

[0008]

(1) A first aspect of the present invention is a pulsar ring which constitutes a rotation detecting device in pairs with a magnetic sensor, wherein a magnetic powder is applied to the entire circumference of the annular portion of the annular body. Is attached to the magnetic substance, and the magnetic substance is magnetized to have different polarities alternately in the circumferential direction.

According to the first aspect of the present invention, since the entire magnetic pole in the circumferential direction is formed by layering magnetic powder in a layered form, unlike the conventional one in which magnetic powder is mixed with rubber as the main material, The amount of magnetic powder per unit area can be increased, which results in extremely high magnetic flux generation density. Therefore, even if the pulsar ring is downsized or the magnetic pole area is reduced due to an increase in the number of S poles or N poles installed per unit installation area, high-precision rotation detection accuracy can be maintained. You can

In the above case, when the magnetic substance is solidified into a layer by magnetic powder with an adhesive and is adhered to the ring by utilizing the adhesive force of the adhesive, the magnetic pole is surrounded. This is preferable because it can be stably held in a direction immovable state, the magnetic flux generated from the pulser ring can be made to correspond to the rotation on the rotation side with high accuracy, and the rotation detection accuracy is further improved.

In the above case, when the magnetic material is sintered in a layered form to be solidified and adhered to the ring body with an adhesive, the magnetic pole is stabilized in a circumferentially immovable state. This is preferable because it can be held and the magnetic flux generated from the pulser ring can be made to correspond to the rotation on the rotation side with high accuracy, and the rotation detection accuracy is further improved.

(2) A second aspect of the present invention is a pulsar ring which constitutes a rotation detecting device in pairs with a magnetic sensor, wherein magnetic powder is pressure-filled into the annular space of an annular body having an annular space. The magnetic powder in the annular space is magnetized to have different polarities alternately in the circumferential direction.

According to the second aspect of the present invention, the amount of the magnetic powder that can be filled in the annular space of the ring body is increased by pressurizing and filling the annular space of the ring body with the magnetic powder so that the amount of the magnetic powder per unit area is increased. By increasing the number, the magnetic flux generation density can be made extremely high. Therefore, even if the pulsar ring is downsized or the magnetic pole area is reduced due to an increase in the number of S poles or N poles installed per unit installation area, high-precision rotation detection accuracy can be maintained. In addition, it is possible to stably hold the magnetic pole in a circumferentially immovable state by the pressure filling, and the magnetic flux generated from the pulser ring can be corresponded to the rotation on the rotation side with high accuracy, and the rotation detection accuracy is improved. .

In the above case, the annular body is a cylindrical member having an annular plate portion at one axial end along the radial direction, and the annular plate portion of the cylindrical member is palm-joined to form an annular body for filling magnetic powder. When configured by an annular plate member that creates a space, the annular plate portion of the cylindrical member and the annular plate portion that is palm-joined to this can generate magnetic flux from the magnetic poles in the circumferential direction at high density in the axial direction. Therefore, it is possible to contribute to further improvement of the rotation detection accuracy in the rotation detection device in which the magnetic sensor is arranged to face the pulser ring in the axial direction, which is preferable.

In the above case, the ring member is a first cylindrical member and a second cylindrical member which is concentrically polymer-bonded to the peripheral surface of the first cylindrical member to form an annular space for filling magnetic powder. With this configuration, since the magnetic flux from the magnetic poles in the circumferential direction is generated at a high density in the radial direction by the first cylindrical member and the second cylindrical member, the rotation detection in which the magnetic sensor is radially opposed to the pulser ring is detected. This is preferable because it can contribute to further improvement of the rotation detection accuracy in the device.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described based on the embodiments shown in the drawings.

The present invention will be described by applying it to a rotation detecting device incorporated in a hub unit which is a bearing device for a vehicle.

1 to 3 relate to the present embodiment, FIG. 1 is a vertical cross-sectional view of a hub unit, FIG. 2 is an enlarged cross-sectional view of the periphery thereof including the rotation detecting device of FIG. 1, and FIG. It is a partial front view of the pulser ring in the rotation detection apparatus of FIG.
The left side of the hub unit shown in FIG. 1 is the vehicle outer side, and the right side is the vehicle inner side. Also,
In FIG. 1, the illustration of the pulser ring that constitutes the rotation detection device is omitted.

Referring to FIG. 1, 1 is a hub unit, 2
Is an axle, 3 is an axle case, 4 is a hub wheel, 5
Are rolling bearings, and 6 and 7 are sealing devices.

The hub unit 1 has a hub wheel 4 and a rolling bearing 5.

The hub wheel 4 has a radially outward flange 41 to which a wheel (not shown) is attached, and a hollow shaft portion 4.
2 and. The rolling bearing 5 is a double-row outward angular ball bearing externally fitted and mounted on the outer diameter surface of the shaft portion 42 of the hub wheel 4, and is press-fitted and externally fitted on the small diameter outer diameter surface of the shaft portion 42 of the hub wheel 4. One inner ring 51, a single outer ring 52 having two rows of raceway grooves, and a plurality of balls 53 arranged in two rows.
And two crown-shaped cages 54, 54. The large-diameter outer diameter surface of the shaft portion 42 of the hub wheel 4 is used for the other inner ring of the rolling bearing 5.

A radially outward flange 55 is provided on the outer periphery of the outer ring 52 of the rolling bearing 5, and the rolling bearing 5 is fixed to the axle case 3 via this flange 55.

A sealing device is provided in each of the annular space between the large-diameter outer surface of the shaft portion 42 of the hub wheel 4 and the outer ring 52 of the rolling bearing 5 and the annular space between the inner ring 51 and the outer ring 52 of the rolling bearing 5. 6 and 7 are arranged and the annular space is sealed from the outside.

Referring to FIG. 2, in the present embodiment, a pulsar ring 8 is integrally provided on the sealing device 7 on the inner side of the vehicle. The pulsar ring 8 constitutes a rotation detecting device 10 together with a magnetic sensor 9 arranged to face each other in the axial direction.

In this embodiment, the pulsar ring 8 has the following features. First, the configuration of the sealing device 7 will be described. The sealing device 7 includes a first annular cored bar 71 mounted in a press-fitted state on the inner diameter surface of the outer ring 52 of the rolling bearing 5.
And a second annular cored bar 72 attached in a press-fitted state on the outer diameter surface of the inner ring 51. Both ring cores 71, 72
Are opposed to each other in the axial direction. The first annular core metal 71 has an upper half cross-sectional shape in a reverse L shape, and an annular elastic material 73 is fitted to the inner surface thereof. This annular elastic material 73 is
The side lip 74 slidingly contacting the inner surface of the annular core metal 72, the main lip 75 and the auxiliary lip 7 slidingly contacting the outer diameter surface of the inner ring 51.
6 and.

The pulsar ring 8 is fixed to a position facing the magnetic sensor 9 in the axial direction with respect to the outer surface of the second annular cored bar 72 of the sealing device 7.

This pulsar ring 8 has a second annular core metal 72.
And a ring-shaped case 82 having an upper half cross-section and a ring-shaped cover 81 having a substantially inverted L-shape, a magnetic body 83 made of magnetic powder hardened in layers by pressure filling is enclosed. . The second annular cored bar 72 has an inner diameter side cylindrical portion 72a, an annular plate portion 72b, and an outer diameter side cylindrical portion 72c as a cylindrical member or an annular plate member having an annular plate portion along the radial direction at one shaft end. And the annular cover 81 is a cylindrical member or an annular plate member having an annular plate portion along the radial direction at one axial end, and is an annular plate portion 81a.
And a cylindrical portion 81b constitute a ring body.

The annular plate portion 72 of the second annular core metal 72
The annular cover 82 is palm-joined to the b by bonding or the like to form the annular case 82 inside.
On the other hand, magnetic powder is filled under pressure and sealed as a layered magnetic body 83.

The second annular core metal 72 and the annular cover 82 are made of non-magnetic or magnetic metal or resin material. As non-magnetic metal, non-magnetic stainless steel (SU
S304 etc.), copper alloy, aluminum alloy, etc. The non-magnetic resin material includes synthetic resin such as ABS resin and elastomer such as rubber. Further, the magnetic metal includes carbon steel such as magnetic stainless steel (SUS430 and the like) and S55C, and the magnetic resin material includes ABS resin and the like mixed with magnetic powder. When a non-magnetic material is used for the core metal, the magnetic flux emitted from the magnetic body 83 can be used as it is. When a magnetic material is used,
Since the resistance in the magnetic flux loop emitted from the magnetic body 83 can be suppressed to be low and the magnetic flux received by the magnetic sensor 9 can be increased, the detection accuracy of the sensor can be improved. When used in locations where rusting is a problem, such as automobile hub units, which are prone to splashing with muddy water, rusting may occur when stainless steel or resin material is used, regardless of whether it is non-magnetic or magnetic. It can be prevented.

Now, a structure for press-filling the annular case 82 with the magnetic body 83 will be described with reference to FIGS. 3 and 4.
First, as shown in FIG. 3, the annular cover 81 and the second annular cored bar 72 are attached to the guide (jig) wall surfaces 100 and 101, respectively. In this attached state, the annular cover 81 and the second
A magnetic material 83 is filled between the opposed annular cores 72. This filling is carried out while applying vibration to the magnetic body 83, so-called tapping filling, to increase the filling rate. Then, as shown in FIG. 4, the annular cover 81 is pressed along the guide wall surface 100 to be bonded to the second annular core metal 72. In this way, a structure in which the magnetic body 83 is pressure-filled in the annular case 82 is obtained.

The magnetic body 83 is, as shown in FIG.
Before or after assembling the sealing device 7 to the hub unit 1, magnets are magnetized so that different poles, S poles and N poles, are alternately formed in the circumferential direction at a predetermined pitch in a pitch circle PCD.

Further, since the magnetic body 83 is formed by layering magnetic powder in a layered manner, it is made immovable in the circumferential direction in the annular case 82 by the pressure filling and the positional relationship between the S poles and the N poles. Does not shift in the circumferential direction.

As described above, according to the present embodiment, since the entire magnetic pole of the pulsar ring 8 is composed of the magnetic body 83 in which magnetic powder is hardened in layers, the magnetic powder is mixed with rubber as the main material. Unlike the conventional one, the magnetic flux generation density per unit area is high. Therefore, even if the pulsar ring 8 is downsized or the magnetic pole area is reduced due to an increase in the number of S poles or N poles installed per unit installation area, high precision rotation detection accuracy is maintained. be able to.

Further, since the magnetic body 83 is formed by layering the magnetic powder into the annular case 82 by pressure filling, the magnetic body 83 is sealed in the annular case 82 while being immobile in the circumferential direction. The N pole and N pole are not displaced in the circumferential direction, and their outer shapes are retained, so that highly accurate rotation detection accuracy can be maintained.

The present invention is not limited to the above embodiment, and various applications and modifications can be considered. (1) In the case of the pulsar ring 8 of the above-mentioned embodiment, it is provided in the sealing device 7, but magnetic powder is layered in an annular space formed by a pair of annular plate members 11 and 12 as shown in FIG. The pulsar ring 8 in which the magnetic body 83 is sealed by pressure filling may be configured separately from the sealing device 7. The pulsar ring 8 is fixed to the outer peripheral surface of the inner ring 51 of the rolling bearing 5, and a non-contact sealed portion is formed between the outer diameter surface of the one annular plate member 11 and the inner diameter surface of the outer ring 52 of the rolling bearing 5. The pulsar ring 8 in which the sealing device 7 can be omitted can be formed by forming the minute gap S. In this case, the pulsar ring 8 is used as the rolling bearing 5
Fixed to the inner peripheral surface of the outer ring 52 of the rolling bearing 5
The pulsar ring 8 in which the sealing device 7 can be omitted may be formed by forming a minute gap that constitutes a non-contact sealing portion with the outer diameter surface of the inner ring 51.

(2) In the case of the pulsar ring 8 of the above embodiment, it is provided in the sealing device 7, but as shown in FIG. 7, it is assumed that the magnetic body 83 is obtained by solidifying magnetic powder in a layer form with an adhesive. The pulsar ring 8 may be configured to adhere to the annular portion of the annular plate member 13 that is an annular body by utilizing the adhesive force of the adhesive contained in the magnetic body 83, and may be separated from the sealing device 7. Good. This adhesive is a thermoplastic resin.

The pulsar ring 8 is fixed to the outer peripheral surface of the inner ring 51 of the rolling bearing 5, and a non-contact sealed portion is formed between the outer diameter surface of the annular plate member 13 and the inner diameter surface of the outer ring 52 of the rolling bearing 5. The pulsar ring 8 in which the sealing device 7 can be omitted can be formed by forming the minute gap S to be formed. In this case, the pulsar ring 8 is fixed to the inner peripheral surface of the outer ring 52 of the rolling bearing 5, and a minute gap forming a non-contact sealed portion is formed between the pulsar ring 8 and the outer diameter surface of the inner ring 51 of the rolling bearing 5, The pulsar ring 8 in which the sealing device 7 can be omitted may be used.

(3) In the case of the pulsar ring 8 of the above-mentioned embodiment, the pulsar ring 8 is provided in the sealing device 7. However, as shown in FIG. 8, the magnetic body 83 is obtained by sintering magnetic powder into a layer and solidifying it. Alternatively, the pulsar ring 8 may be configured such that it is adhered to the annular portion of the cylindrical member 15 by the adhesive agent 14 and separated from the sealing device 7. The pulsar ring 8 is fixed to the outer peripheral surface of the inner ring 51 of the rolling bearing 5, and the outer diameter surface of the cylindrical member 15 and the outer ring 52 of the rolling bearing 5 are fixed.
The pulsar ring 8 in which the sealing device 7 can be omitted by forming a minute gap S which forms a non-contact sealing portion between the inner peripheral surface and
Can be In this case, while fixing the pulsar ring 8 to the inner peripheral surface of the outer ring 52 of the rolling bearing 5,
A pulsar ring 8 in which the sealing device 7 can be omitted may be formed by forming a minute gap forming a non-contact sealing portion between the rolling bearing 5 and the outer diameter surface of the inner ring 51.

(4) In the case of the above embodiment, as shown in FIG. 9, the first cylindrical member 16 and the first cylindrical member 16 are provided on the outer peripheral surface of the inner ring 51.
The second cylindrical member 17 is concentrically fixed to the cylindrical member 16 to form an annular space for filling the magnetic powder between the opposed cylindrical members 16 and 17, and the magnetic body 83 is pressed into the annular space. By filling the pulsar ring 8, the pulsar ring 8 and the magnetic sensor 9 can be arranged to face each other in the radial direction to form the rotation detecting device 10.

In the embodiments shown in FIGS. 2, 6 and 9, the magnetic body 82 is obtained by pressure filling the magnetic body 82.
However, as shown in FIGS. 10 to 12, a plurality of ribs 102 that divide the annular space in the circumferential direction are formed in the annular space formed by the annular cover 81 and the second annular cored bar 72. It may be arranged radially and filled with the magnetic body 83 partitioned by the ribs 102 to prevent the magnetic body 83 from moving in the circumferential direction. The rib 102 is
It may be integrally formed on either one of the annular cover 81 and the second annular cored bar 72. 10 is a partial front view of the pulsar ring, FIG. 11 is a cross-sectional view taken along the line AA of FIG. 10, and FIG. 12 is used to explain the mounting of the annular cover 81 and corresponds to FIG. Is.

(5) In the above embodiment, the inner ring 51 can be a shaft and the outer ring 52 can be a cylinder. The shaft body is on the rotating member side, and the tubular body is on the fixed member side.

In this case, the pulser ring 8 and the magnetic sensor 9
Need only have a relationship of relative rotation, one of the cylinder and the shaft is the fixed member side and the other is the rotary member side, and the pulsar ring 8 is provided on either the fixed member side or the rotary member side.
The magnetic sensor 9 may be provided on the other side. (6) In the above-described embodiment, the rotation detection device 10 is used as a hub unit for a drive axle of an automobile, but it can be used for a well-known hub unit for a driven axle, which is not shown. . Other than that, I will not give specific examples,
In short, the rotation detection device of the present invention can be used in a place where it is necessary to detect the rotation state of a member on the rotating side of a cylinder and a shaft that are concentrically arranged so as to be relatively rotatable, such as an industrial machine. You can

[0043]

As described above, according to the present invention, the magnetic body formed by layering magnetic powder is attached to the entire circumference of the annular portion of the non-magnetic material, and the magnetic body is attached. Since the pulsar ring is constructed by magnetizing magnets with different polarities alternately in the circumferential direction, it is possible to increase the magnetic flux generation density per unit area unlike the conventional one in which magnetic powder is mixed with rubber as the main material. Therefore, it is possible to contribute to the improvement of highly accurate rotation detection accuracy in the rotation detection device.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a hub unit according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view around a pulsar ring, which is a main part of FIG.

FIG. 3 is a view for explaining a structure for filling a magnetic body in an annular case.

FIG. 4 is a diagram for explaining a structure in which a magnetic body is filled in an annular case.

5 is a partial front view of the pulsar ring of FIG.

FIG. 6 is a sectional view of a main part according to another embodiment of the present invention.

FIG. 7 is a sectional view of a main part according to still another embodiment of the present invention.

FIG. 8 is a sectional view of a main part according to still another embodiment of the present invention.

FIG. 9 is a sectional view of a main part according to still another embodiment of the present invention.

FIG. 10 is a partial front view of a pulser ring according to still another embodiment of the present invention.

11 is a cross-sectional view taken along the line AA of FIG.

FIG. 12 is a view corresponding to FIG. 11, which is used for explaining the mounting of the annular cover 81.

[Explanation of symbols]

1 hub unit 2 axles 3 axle case 4 hub wheels 5 Rolling bearing 6,7 Sealing device 8 pulsar ring 9 Magnetic sensor 10 Rotation detector

Claims (6)

[Claims] 1. A pulsar ring, which constitutes a rotation detecting device in pairs with a magnetic sensor, wherein a magnetic body formed by layering magnetic powder in layers is attached to the entire circumference of an annular portion of the annular body. , A pulsar ring characterized in that the magnetic material is magnetized to have different polarities alternately in the circumferential direction. 2. The pulsar ring according to claim 1, wherein the magnetic material is obtained by solidifying magnetic powder into a layer with an adhesive, and the magnetic material is applied to the ring body by utilizing the adhesive force of the adhesive. A pulsar ring characterized by being worn. 3. The pulsar ring according to claim 1, wherein the magnetic body is solidified by sintering magnetic powder into a layer and is adhered to the ring body with an adhesive. Pulsar ring that is characterized. 4. A pulsar ring, which constitutes a rotation detecting device in pairs with a magnetic sensor, wherein magnetic powder is pressure-filled into the annular space of an annular body having an annular space, and the annular space. The pulsar ring is characterized in that the magnetic powder therein is magnetized to have different polarities alternately in the circumferential direction. 5. The pulsar ring according to claim 4, wherein the annular body is a cylindrical member having an annular plate portion along one end of the shaft and extending in the radial direction, and the annular member is palm-joined to the annular plate portion of the cylindrical member so as to be magnetic. A pulsar ring comprising an annular plate member forming an annular space for powder filling. 6. The pulsar ring according to claim 4, wherein the annular body is polymer-bonded concentrically with a first cylindrical member and a peripheral surface of the first cylindrical member to form an annular space for filling magnetic powder. A pulsar ring comprising a second cylindrical member.