JP3050279B2 - Sensor ring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor ring, and more particularly to an anti-lock brake system (hereinafter referred to as AB).
S) of the present invention relates to an improvement in a sensor ring used for magnetically detecting a wheel speed.

[0002]

2. Description of the Related Art In general, various types of wheel speed detecting devices of this type have been proposed, including an optical type, an electromagnetic type and a semiconductor type. However, the optical type is vulnerable to mud, and the semiconductor type is vulnerable to high temperature and high humidity.

FIG. 4 shows a typical example of this electromagnetic wheel speed detecting device. This device comprises, for example, a sensor ring A formed by sintering magnetic metal powder into a gear shape, and a sensor ring A.
And a sensor portion B disposed near the ring A. The sensor section B includes a permanent magnet Ba, a pole piece Bb extending from the permanent magnet Ba, and a pole piece Bb.
And a coil Bc wound around the coil Bb.
The pole piece Bb is arranged so that a certain gap is formed between the tip face of the pole piece Bb and the tooth Aa of the sensor ring A.

In this device, a sensor ring A is mounted on a wheel of an automobile and rotates together with the wheel. When the sensor ring A rotates with the rotation of the wheel,
The teeth Aa of the sensor ring A face or do not face the tip surface of the lupus Bb, thereby causing a change in magnetic flux (Δφ) between the two and a voltage (V) generated in the coil Bc. I do. This output voltage is represented by Equation 1.
In the equation, N represents the number of turns of the coil Bc, and Δφ / Δt represents a rate of change of magnetic flux per unit time.

V = N (Δφ / Δt) 1 The frequency (f) of this output voltage is proportional to the number of teeth Aa passed per unit time, that is, the wheel rotation speed (w), and is expressed by equation (2). In the expression, z represents the number of teeth Aa of the sensor ring A.

F = w · z / 60 2 By measuring the above frequency (f), the wheel speed (v) can be obtained according to equation (3). In the equation, K
Represents a constant for each vehicle. v = f · K 3

[0007]

However, according to the detection device having the above-described sensor ring, although the wheel speed can be accurately measured without being affected by the use environment, the sensor ring A uses metal powder. There is a problem in that the cost is increased because it is manufactured by molding into a predetermined shape and sintering.

Therefore, in view of economy, a sensor ring C shown in FIG. 5 has been proposed. This sensor ring C
Is formed by punching openings Ca at predetermined intervals in a band-shaped magnetic metal (a fusible material) with a press machine, bending the openings Ca in a ring shape, and welding (Cb) both ends.

However, according to the sensor ring C, although the cost can be reduced as compared with the sensor ring of FIG. 4 , the welding of the ring end is troublesome, and the circularity of the ring is hardly obtained, and the There is a problem that speed detection accuracy is low.

[0010] Therefore, an object of the present invention is to provide a sensor ring capable of reducing the manufacturing cost with a relatively simple structure and increasing the detection accuracy of the wheel speed.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a ring-shaped member made of a non-magnetic member to achieve the above-mentioned object.
The formed ring body and a pair of
A plurality of magnetic members formed in the shape of
Multiple grooves on the circumferential surface of the
Form the magnetic member in this groove, the ring body with the holding piece
Are mounted so as to be pinched .

[0014]

Next, an embodiment of the present invention will be described with reference to FIG. In the figure, reference numeral 1 denotes a ring main body formed of a resin material (non-magnetic member) such as polypropylene, for example, in a circular shape. 2 are formed. In particular, the depth of the groove 2 is set substantially equal to the thickness of a magnetic member described later. The ring body 1 is appropriately mixed with a reinforcing material such as glass fiber or carbon fiber. On the other hand, magnetic members 3 are mounted in all the grooves 2 of the ring main body 1. The magnetic member 3 is formed by bending, for example, an iron-based metal piece having spring properties and magnetism into a substantially U-shape, and a pair of holding pieces 3a and 3b hold the ring main body in the groove 2.

According to this embodiment, since the ring body 1 is made of a resin material, the weight can be reduced and the cost can be reduced.

In addition, the magnetic member 3 can be assembled simply by being mounted in the groove 2 of the ring main body 1 so as to be held by the holding pieces 3a and 3b, so that the working efficiency is improved and the cost is reduced. .

Further, since the magnetic member 3 is mounted in the groove 2 of the ring main body 1, it is possible to reliably prevent the magnetic member 3 from being displaced in the circumferential direction after mounting. Therefore, the sensor
The detection accuracy of the wheel speed by the unit can be improved.

In particular, when the magnetic member 3 is mounted on the ring main body 1, the magnetic member 3 is configured so as not to protrude from the outer peripheral surface of the ring main body 1. Can be avoided.

FIG. 2 shows another embodiment of the present invention, in which the magnetic member 3A has a substantially U-shape.
The opening width of the tip portions of the holding pieces 3a, 3b is formed to be slightly narrower than the root portion. The leading end portions of the holding pieces 3a and 3b have guide portions 3 that expand outward.
c and 3c are integrally formed.

The attachment of the magnetic member 3A to the ring main body 1 is performed as follows. First, as shown in FIG.
The magnetic member 3A is attached to the side of the ring main body 1, and the holding pieces 3a, 3
The guide portions 3c, 3c of “b” are positioned so as to face the groove portion 2. In this state, when the magnetic member 3A is brought closer to the ring main body 3A, the guide portions 3c, 3c abut on the side of the groove 2. When the magnetic member 3A is pressed, the guide portions 3c, 3
The holding pieces 3a and 3b are formed in the groove 2 by using the inclined portion of FIG.
Get on. When the magnetic member 3A is further pressed, the holding pieces 3a and 3b move along the groove 2 on the inner and outer peripheral surfaces as shown in FIG.

According to this embodiment, since the guide portions 3c, 3c are formed at the tips of the holding pieces 3a, 3b, the magnetic member 3A can be mounted smoothly when mounted on the ring main body 1. .

FIG. 3 shows another embodiment of the present invention, in which a magnetic member 3B is formed in a substantially U-shape, and a hemispherical or triangular shape is provided inside the distal end portions of the holding pieces 3a and 3b. Locking portions 3d, 3d are formed.

According to this embodiment, when the magnetic member 3B is mounted on the ring main body 1, as shown in FIG.
Since the locking portions 3d are locked so as to be hooked on the ends of the grooves 2, a stable mounting state is obtained.

The present invention is not limited to the above-described embodiment. For example, the non-magnetic member may use other non-magnetic materials such as ceramics in addition to the resin material. The groove of the ring body may be formed on the inner and outer peripheral surfaces, or may be formed on only one of the inner and outer peripheral surfaces. The magnetic member includes a permanent magnet.

[0026]

As described above, according to the present invention, since the ring main body is made of a non-magnetic member, for example, a resin material, the mass productivity is excellent and the weight is reduced. Therefore, cost can be reduced. Further, since the magnetic member is mounted in the groove of the ring main body, it is possible to reliably prevent the magnetic member from being displaced in the circumferential direction after the mounting. Therefore, the detection accuracy of the wheel speed by the sensor unit can be improved.

In addition, the magnetic member can be mounted on the ring main body by using the groove as a guide and can be assembled simply by being clamped by the clamping pieces, so that the working efficiency is improved and the cost is improved. Contribute to reduction.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2A is a side sectional view of an exploded state showing a second embodiment of the present invention, and FIG. 2B is a side sectional view of an assembled state.

3A is a side sectional view of a disassembled state showing a third embodiment of the present invention, and FIG. 3B is a side sectional view of an assembled state.

FIG. 4 is a schematic diagram of a conventional wheel speed detecting device.

FIG. 5A is a longitudinal sectional view showing another sensor ring according to the conventional example, and FIG. 5B is a bottom view of a main part thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ring main body 2 Groove part 3, 3A, 3B Magnetic member 3a, 3b Holding piece 3d Locking part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01P 3/488 B60T 8/00 G01D 5/245

Claims (1)

(57) [Claims] 1. A ring body formed of a non-magnetic member in a ring shape, and a plurality of magnetic members in which a pair of holding pieces having a spring property are formed in a substantially U-shape, wherein a peripheral surface of the ring body is provided. A sensor ring in which a plurality of grooves are formed at regular intervals in a circumferential direction, and a magnetic member is mounted in the grooves so that a ring main body is held between holding members.