JPH0454906B1 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotational speed detection device that detects the rotational speed of a wheel in order to detect the running speed of a motorcycle.

Conventionally, this type of rotational speed detection device has either a device that detects the rotational speed of the brake disk by having a magnetic pick-up that detects changes in magnetic resistance facing the teeth provided on the outer periphery of the brake disk, or a device that detects the rotational speed of the brake disk by having a magnetic pickup that detects changes in magnetic resistance opposed to teeth provided on the outer periphery of the brake disk. A device has been proposed in which a gear-shaped tone wheel is fixed to a brake disk and the above-mentioned magnetic pickup is opposed to the teeth of the tone wheel, but in each device, the detection section is provided with waterproof and dustproof means. Not for water intrusion,
Detection failures occur due to mud adhesion, etc.

In order to solve such problems, the present invention provides a method for assembling a rotational speed detection device that detects the rotational speed of a wheel using changes in magnetic resistance to the front wheel of a motorcycle. By assembling one end of the hub into a housing that covers it, the rotational speed detection device is waterproof and dustproof, preventing detection failures, and also makes the rotational speed detection device more compact and increases the rigidity of mounting to the vehicle body. The purpose of this invention is to improve the performance of the user, and one embodiment thereof will be described below with reference to the drawings.

The drawing shows an example in which the rotational speed detection device 20 according to the present invention is applied to a front wheel W of a motorcycle,
1 and 2, reference numeral 11 is a front fork which is a member on the vehicle body side, reference numeral 12 is an axle fixed to the front fork 11, and reference numeral 13 is an axle 12.
The wheel hub of the front wheel is shown.
The rotational speed detection device 20 includes an internal gear-shaped tone wheel 21 fixed coaxially to the inner peripheral wall of one end of the wheel hub 13 by press fitting, and a spur gear-shaped tone wheel 21 made of magnetic sintered metal fixed to the inner end of a collar 23 made of mild steel. The stator 22 is provided with a stator 22. In such a configuration, the tooth portion 2 formed on the inner circumference of the tone wheel 21
A toothed portion 22a formed on the outer periphery of the stator 22 opposite to the stator 1a is arranged with a slight gap, and a collar 23 is disposed between the stepped portion of the axle 12 and the inner race 14a of the ball bearing 14 that supports the wheel hub 13. and is fitted and fixed to the axle 12.

Housing 24 fixed to the outer end of collar 23
is fixedly assembled in a predetermined position by fitting the collar 23 to the axle 12 as described above, and covers one end of the wheel hub 13, and the one end of the wheel hub 13 and the housing 24 The tone wheel 21 is located in a space surrounded by. Inside this housing 24, an annular mild steel magnetic pole member 2 fixed to the inner wall of the housing 24 is provided.
5 is disposed adjacent to one side of the tone wheel 21, and an annular permanent magnet 26 is interposed between the magnetic pole member 25 and the outer peripheral surface of the collar 23. Moreover, between the permanent magnet 26 and the stator 22, a magnetic pole member 2
An annular magnetoresistive detection coil 27 fixed to the inner peripheral surface of the collar 23 is molded with resin and fitted to the collar 23.

Thus, in this rotational speed detecting device 20, all the parts constituting the detecting section (namely, the tone wheel 21, the stator 22, the collar 2)
3. Magnetic pole member 25, permanent magnet 26 and coil 2
7) is housed inside the housing 24, and is sealed by an oil seal 28 interposed between the inner peripheral surface of the open end 24a of the housing 24 and the outer peripheral surface of one end of the wheel hub 13. In addition, in the above assembly structure, as shown by the two-dot chain line in FIG. A magnetic circuit surrounding the coil 27 is formed, and the tone wheel 21
As the magnetic resistance of this magnetic circuit changes due to the change in the gap between the teeth 21a and 22a as the wheel rotates, the magnetic flux generated in the magnetic circuit by the permanent magnet 26 also changes, and as a result, the coil 27 is controlled by the rotation of the front wheel. Generates an electrical signal representing speed.

As understood from the above description, the wheel rotation speed detection device for a motorcycle according to the present invention includes an axle fixed to the body side of the motorcycle;
a housing that covers one end of a wheel hub that is fixed to the axle and is pivotally supported by the axle; a fixed internal gear-like tone wheel, a stator fixed to the axle and having teeth facing the teeth on the inner periphery of the tone wheel, and a stator with a space between the teeth of the stator in the axial direction of the axle. a permanent magnet that is disposed and fixed to the axle and generates a magnetic flux in a magnetic circuit that passes between the tone wheel and the teeth of the stator; The coil is fixed to the magnetic circuit and generates an electrical signal that changes according to changes in the magnetic flux of the magnetic circuit.

In this type of rotational speed detection device, in order to obtain a predetermined detection accuracy, the distance from the axle center to the tone wheel teeth cannot be less than a predetermined value. Since the permanent magnets and coils are arranged in the axial direction of the teeth of the stator opposite to the teeth on the periphery, these members, that is, the stator, permanent magnets, and coils, do not protrude outward beyond the tone wheel. Therefore, the diameter of the rotational speed detection device as a whole becomes smaller and more compact, and the mounting rigidity of each of these members to the axle also increases.

Also, since the tone wheel is located in the space surrounded by one end of the wheel hub and the housing,
It is possible to reliably protect the space between the tone wheel, which is a relatively moving part, and each tooth part of the stator from water, mud, etc., and it is possible to prevent detection failures due to the adhesion of these things.

In the above embodiment, the collar 23 is made to serve as a strength member when tightening the axle and also serve as a magnetic circuit, so the components of the detection section can be assembled with a simple structure. can be attached, and the assembly work can be easily performed. In the above embodiment, an oil seal is used as the sealing means for the housing, but a labyrinth may be formed between the open end of the housing and the outer peripheral surface of one end of the wheel hub.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing an assembly position of a rotational speed detecting device according to the present invention, and FIGS. 2 and 3 are sectional views showing enlarged main parts of FIG. 1. Explanation of symbols, 12... Axle, 13... Wheel hub, 14... Ball bearing, 21... Tone wheel, 21a... Teeth, 22... Stator, 22a...
tooth portion, 23... collar, 24... housing, 25...
Magnetic pole member, 26... Permanent magnet, 27... Coil, 28
…Oil seal.

Claims (1)

[Claims] 1. An axle fixed to the body side of a motorcycle, a housing that covers one end of a wheel hub fixed to the axle and pivotally supported by the axle, and a housing surrounded by the one end of the wheel hub and the housing. an internal gear-like tone wheel located in a space and coaxially fixed to the wheel hub; a stator fixed to the axle and having teeth facing teeth on the inner circumference of the tone wheel; a permanent magnet that is fixed to the axle and is spaced apart from the tooth in the axial direction of the axle and generates a magnetic flux in a magnetic circuit that passes between the teeth of the tone wheel and the stator; A wheel rotation speed detection device for a motorcycle, comprising a coil that is disposed between teeth of the stator and fixed to the axle, and that generates an electrical signal that changes according to changes in magnetic flux of the magnetic circuit.