JP2959853B2 - Rotation speed detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational speed detector for detecting a rotational speed of a rotating body such as a wheel speed sensor used in an anti-skid brake control system of an automobile.

[0002]

2. Description of the Related Art Generally, anti-skid brake control is
When it is detected that a wheel has become skid during braking, the braking force of that wheel is loosened to eliminate the skid condition, and then the braking force is increased again to stabilize the operation of the vehicle and reduce the braking distance. The brake control is performed so as to be as short as possible.

In an anti-skid brake control system for performing such a brake control, an electronic control unit (ECU) determines a skid tendency of a brake wheel based on a wheel speed signal from a wheel speed sensor serving as a rotation speed detector. Then, when the ECU determines that the braked wheels tend to skid, the ECU outputs a control signal to a modulator that adjusts the brake pressure. As a result, the modulator adjusts the brake pressure so that the skid state of the brake wheels is eliminated.

A conventional wheel speed sensor includes a body in which a cable for transmitting an electric signal of the wheel speed is embedded, and an exciter ring having a predetermined number of teeth and rotating integrally with the wheel. A rotation detection device that is attached and electromagnetically detects the rotation of the exciter ring to generate an electric signal, and a cylindrical cover made of a metal sleeve that is attached to the body by caulking so as to cover the rotation detection device. It is composed of In this case, a sealing member such as a rubber seal is provided at a caulking portion of the cover between the body and the rotation detecting device in order to prevent liquid such as water from entering the rotation detecting device from the body mounting portion of the cover. ing.

[0005]

However, in the conventional wheel speed sensor, since the cover is simply fitted and crimped on the circular projection of the body, the cover rotates. Sometimes. For this reason,
There is a problem that the sealing performance of the sealing member is reduced. In particular, since the wheel speed sensor in the anti-skid brake control system is disposed in a location near the wheels where movement is strong and is likely to be subjected to rainwater, the cover rotates so that rainwater or the like easily enters the rotation detection device. Thus, the sealing property of the sealing member is likely to be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to provide a caulking portion between a cover and a body sealing member so that the cover is attached to the body so as not to rotate. It is an object of the present invention to provide a rotational speed detector capable of preventing a decrease in the sealing performance of a seal member provided in a rotary member.

[0007]

According to a first aspect of the present invention, there is provided a body for holding a cable for transmitting an electric signal of a rotational speed of a rotating body, and a body facing the rotating body. And attached to this body,
A rotation detection device that detects the rotation of the rotating body and generates an electric signal, a cylindrical cover attached to the body by caulking so as to cover the rotation detection device, and the body and the rotation detection device. A seal member disposed at a caulking portion of the cover between the seal members to prevent foreign substances such as water from entering, and preventing a relative rotation of the cover with respect to the body, thereby preventing a decrease in sealing performance of the seal member. And means for performing the operation.

The cover is provided with a flange, and the means includes a notch provided in the flange,
A locking projection provided on the body to prevent the cover from rotating when the notch hits in the rotation direction.

[0009]

In the rotation speed detector according to the present invention, the cylindrical cover for covering the rotation detection device is rotated relative to the body by means for preventing the sealing member from being deteriorated in sealing performance. Is prevented, and a reduction in the sealing performance of the sealing member provided at the caulked portion between the cover and the body is more reliably prevented. In particular, as in the second aspect of the present invention, the means for preventing the sealing member from being deteriorated in sealing performance is constituted by a notch provided on the flange of the cover and a locking projection provided on the body. Is formed with a very simple structure.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view schematically showing an embodiment of a rotational speed detector according to the present invention, taken along line II in FIG. 2, and FIG. 2 is a bottom view of this embodiment.

As shown in FIG. 3, the body 3 includes a mounting portion 3a to which the rotation detecting device 4 is mounted, and a holding portion 3b extending from the mounting portion 3a and holding the cable 2. The holding portion 3a is formed with a hole 3c into which the mounting and fixing portion 4a of the rotation detecting device 4 is fitted, and the inner peripheral surface of the hole 3c is fitted into the groove 4b of the mounting and fixing portion 4a of the rotation detecting device 4. An annular projection 3d is formed. Although FIG. 3 shows that these holes 3c and the annular projections 3d are formed independently, actually, the holes 3c and the annular projections 3d are molded with a resin or the like so as to embed the attachment fixing portion 4a of the rotation detecting device 4 and the cable 2. Formed when the body is formed.

A cover 6 is attached to the mounting portion 3a of the body 3.
An annular projection 3e to which the open end of the fitting is fitted is formed, and a rectangular parallelepiped locking projection 3f
Are formed. The locking surface 3g of the locking projection 3f facing the annular projection 3e is flat.

As shown in FIGS. 4 and 2, the cover 6 comprises a bottomed cylindrical main body 6a and an annular flange 6b formed on the opening end side of the main body 6a. A linear notch 6c is formed. When the cover 6 is fitted with the annular projection 3e, the notch 6c
Is opposed to the locking surface 3g of the locking projection 3f with almost no gap.

The seal member 7 is formed in an annular shape from a seal member such as a rubber seal, and the seal member 7 is fitted to a mounting fixing portion 4a of the rotation detecting device 4 between the mounting portion 3a and the rotation detecting device 4. You. The seal member 7 is for preventing liquid such as water from entering the rotation detecting device 4 from the portion of the cover 6 where the body 3 is attached. By preventing the infiltration of a liquid such as water, the rotation detecting device 4 operates reliably and the reliability of the rotation detector 1 is improved. As the seal member 7, other seal members such as an O-ring can be used in addition to the illustration. In the case of an O-ring, one or two O-rings can be provided. In the case of one O-ring, the O-ring is disposed on either the upper or lower side of the caulking portion 5 of the cover 6, and in the case of two The O-ring is disposed vertically above and below the caulking portion 5.

In the rotation detector 1 according to the present embodiment, the body 3 is formed integrally with the cable 2 and the rotation detection device 4 by, for example, molding resin. The cover 6 is fitted with the annular projection 3e of the body 3 so as to cover the rotation detecting device 4 and the seal member 7 so as to cover the rotation detecting device 4 and the seal member 7. In this case, the notch 6 c of the flange 6 b of the cover 6
To the locking surface 3g of the locking projection 3f. In this state, by crimping a portion of the cover 6 corresponding to the seal member 7, the cover 6 is fastened and fixed to the annular projection 3e. The sealing member 7 is compressed by the caulking portion 5 of the cover 6, so that the sealing is reliably performed between the attachment fixing portion 4 a, the cover 6, and the annular protrusion 3 e. Thus, the rotation detector 1 is formed.

In the rotation detector 1 thus formed, the notch 6c of the flange 6b of the cover 6 faces the locking projection 3f of the body 3, so that the cover 6 is relatively When the cover 6 is to be rotated, the edge of the notch 6c hits the locking surface 3g of the locking projection 3f, so that the cover 6 can hardly rotate relative to the body 3. Thereby, the seal member 7 provided on the caulking portion 5 between the cover 6 and the body 3 caused by the relative rotation between the cover 6 and the body 3
Is prevented from being deteriorated. Thus,
The notch 6c and the locking projection 3f constitute a means for preventing the sealing performance of the seal member of the present invention from lowering.

The rotation detector 1 according to the present embodiment can be used as a wheel speed sensor used for an anti-skid brake control system in an automobile, for example. In this case, as shown in FIG. 5, for example, the tip of the rotation detector 1 is opposed to the teeth 9a of the exciter ring 9 fixed to the hub 8a of the wheel 8, and the rotation detector 1 is mounted on the bracket near the wheel 8. 10 attached.

The rotation speed detector 1 of the present invention can be applied to any rotation detector for detecting rotation. In particular, the rotation detector of the present invention is most suitable as a rotation detector to be installed in a place where the movement is intense or where a liquid such as water is easily applied.

[0019]

As is apparent from the above description, according to the rotation detector according to the present invention, the cylindrical cover covering the rotation detection device is prevented from rotating relative to the body, so that the sealing member can be used. Since the deterioration of the sealing performance is prevented, the rotation detector can be operated more reliably and more stably, and the reliability of the rotation detector can be improved.

In particular, as in the second aspect of the present invention, the means for preventing the sealing member from being deteriorated in sealing performance is constituted by a notch provided on the flange of the cover and a locking projection provided on the body. This means can be formed in a very simple structure.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a rotation detector according to the present invention.
FIG. 3 is a sectional view taken along the line II in FIG. 2.

FIG. 2 is a bottom view of the embodiment.

FIG. 3 is a perspective view illustrating a body of a rotation detector according to the embodiment.

FIG. 4 is a perspective view illustrating a cover of a rotation detector according to the embodiment.

FIG. 5 is a perspective view partially showing an example of a mounted state of the rotation detector in the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotation detector, 2 ... Cable, 3 ... Body, 3a ... Mounting part, 3e ... Annular protrusion, 3f ... Locking protrusion, 3g ... Locking surface, 4 ... Rotation detecting device, 5 ... Caulking part, 6 ... Cover , 6
a: body, 6b: flange, 6c: notch, 7: seal member

Claims (2)

(57) [Claims] 1. A body for holding a cable for transmitting an electric signal of a rotation speed of a rotating body, and a body attached to the body so as to face the rotating body, and detecting the rotation of the rotating body to generate an electric signal. A rotation detection device to be generated, a cylindrical cover attached to the body by caulking so as to cover the rotation detection device, and a caulking portion of the cover between the body and the rotation detection device,
A sealing member for preventing foreign matter such as water from entering ,
By preventing the cover from rotating relative to the body
Means for preventing a reduction in the sealing performance of the seal member . 2. The cover is provided with a flange, and the means is provided in a notch provided in the flange and the body, and the notch hits in the rotation direction to prevent rotation of the cover. 2. The rotation speed detector according to claim 1, wherein said rotation speed detector comprises a locking projection.