JP3473166B2 - Rotation sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation sensor for detecting rotation of a rotating body or a rotating member, and more particularly to a rotation sensor provided at a wheel shaft end of a vehicle.

[0002]

2. Description of the Related Art Conventionally, it has been promoted to directly detect the rotation of a wheel shaft of a vehicle and utilize it for vehicle control. Since the rotation sensor mounting portion for the wheel shaft is outdoors, it is necessary to have a waterproof structure, and a durable electromagnetic pickup is often used as the sensor body. This electromagnetic pickup is mounted on the cover at the end of the wheel shaft or in the vicinity of the cover. When the electromagnetic pickup is mounted on the cover, the electromagnetic pickup including the magnet, the pickup coil and its spool, and the core is integrally molded with the cover to form a sensor module. This sensor module is mounted on the bearing fixed side of the wheel shaft end, and forms a rotation sensor by pairing with a signal chopper such as a comb-teeth rotor or a windowed rotor that generates a signal for an electromagnetic pickup.

The sensor module provided with the electromagnetic pickup on the cover is in a fixed state, and the sensor module is mounted so as to face the rotating signal chopper on the fixed side of the bearing. It is necessary to maintain clearance and coaxiality. Therefore, the opening, which is the fitting portion on the bearing fixed side, is formed so as to be coaxial with the rotation shaft, and at the same time, the fitting margin of the fixed cover of the electromagnetic pickup is configured to be coaxial with the rotation shaft. Since the sensor module is designed to be as small as possible, the cover fitting area is located in the external space area of the signal chopper arranged on the outer circumference of the electromagnetic pickup.
In this case, in order to securely fix the electromagnetic pickup to the cover and maintain the coaxiality with the rotation shaft, the electromagnetic pickup is preferably covered with resin.

[0004]

FIG. 3 is a sectional view showing the structure of the rotation sensor structure applied to the present invention when the prior art is applied. In the rotation sensor structure shown in FIG. 3, since the mold resin 8 is in contact with the inner peripheral surface of the fitting margin 61 portion of the cover 6, the fitting margin 61 is not easily deformed. Therefore, when the cover 6 is press-fitted to the fixed bearing side 3, it must be press-fitted with a strong pressure.
There is a problem that the mold resin 8 receives pressure due to the deformation of the fitting margin 61, and the position of the electromagnetic pickup 5, which is the sensor body, is displaced.

Therefore, an object of the present invention is to provide a rotation sensor with a structure that does not affect the sensor body when the cover provided with the sensor body is press-fitted into the bearing fixing side.

[0006]

In order to solve the above-mentioned problems, the structure of the present invention has a sensor main body arranged coaxially with the rotary shaft in a cover which covers the shaft end of the rotary shaft and is fitted to the bearing fixed side. Is mounted by being molded with a molding resin, and a signal chopper for periodically generating a rotation signal is arranged on the outer periphery of the sensor body with a predetermined clearance, and the fitting margin of the cover is
Located in the outer peripheral portion of the signal chopper in the outer peripheral portion of said sensor body, have a gap between the fitting margin and the inside of the mold resin, the voids root portion of the fitting allowance
Has been formed, and the mold resin is in contact with the fitting margin.
That is, it is configured not to touch . Another aspect of the present invention is a chamfer in which the end of the opening on the side where the bearing is fixed is a corner.
The inner diameter is slightly expanded due to the
The base of the shoulder does not directly contact the end of the opening,
Deformation of the root part hardly occurs due to insertion
It is characterized by Alternatively, the sensor body may be an electromagnetic pickup, and the signal chopper may be a toothed or window rotor or a comb tooth rotor made of a magnetic material.

[0007]

In the rotation sensor of the configuration example (FIG. 1) of the present invention, since the gap 63 exists between the inner peripheral surface of the fitting margin 61 of the cover 6 and the mold resin 8, the opening 3 of the bearing fixed side 3 is formed.
When the cover 6 is press-fitted into the cover 1, the fitting margin 61 is slightly deformed inward (toward the rotation axis) and fits therein. Even if deformation occurs, the void 63 acts as a buffer, and no force is applied to the electromagnetic pickup 5 inside. On the other hand, the electromagnetic pickup 5, which is the sensor main body, is securely fixed to the cover 6 by the molding resin 8 so that the electromagnetic pickup 5 maintains a predetermined clearance while being coaxial with the rotating shaft. Further, the base portion 6 of the fitting margin 61
There is a gap 63 up to 4 and the mold resin 8 contacts
Since it is configured so that it does not
No force is exerted on Pup 5. Or, as shown in Figure 2,
The opening end 32 of the bearing fixed side 3 is chamfered at the corner.
The inner diameter is slightly expanded, and the fitting margin 61 is
The root portion 64 should be in direct contact with the opening end 32.
However, the press-fitting hardly deforms the root portion 64.
It may not be generated.

[0008]

When the cover 6 is press-fitted into the bearing fixing side 3, no force is applied to the internal molding resin 8 by the deformation of the fitting margin 61, so that the molding resin 8 is not peeled off, cracked or deformed. Further, since no force is applied to the electromagnetic pickup 5 which is the sensor body, the displacement of the electromagnetic pickup 5, especially the displacement of the core 13 and the pickup coil 11 does not occur. Therefore, the rotation sensor is mounted on the axle bearing so as to reliably detect the signal.

[0009]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 (a) is a sectional view of the configuration of a wheel bearing portion 1 to which a rotation sensor according to the present invention is attached. Axle hub 2, which is the rotating shaft, has bearing 4 on bearing fixed side 3.
It is rotatably fixed by. In the cover 6 that covers the three ends of the fixed bearing side, the fitting margin 61 is the opening 31.
It is press-fitted into (a space portion indicated by the inner diameter of the broken line arrow on the bearing fixing side 3) and fitted into the stopper portion 62 provided on the outer periphery of the bottom of the cover 6. An electromagnetic pickup 5 which is fitted into a cylindrical comb tooth rotor 9 for generating a rotation sensor signal provided at an end portion of the axle hub 2 in the opening 31 with a predetermined clearance is formed on the cover 6 by a molding resin. It is attached at 8 to form a rotation sensor together with the comb toothed rotor 9. The comb toothed rotor 9 is a signal chopper, and functions as a magnetic flux chopper near the gap 14 of the core 13 on the outer peripheral surface of the electromagnetic pickup 5.

The rotation sensor has an electromagnetic pickup 5 fixed to a cover 6 by a mold resin 8 as a sensor body. A portion including the cover 6 to which the electromagnetic pickup 5 is attached and the connector 7 and fitted into the opening 31 is referred to as a sensor module 10. The electromagnetic pickup 5 includes a pickup coil 11 and a magnet 1.
2, the core 13 and other parts, electromagnetic pickup 5
Signal is taken out by the connector 7 provided in a part of the cover 6, and the connector terminal 71 is taken out from the pickup coil 11. The mold resin 8 is filled with resin integral molding in which both the parts of the electromagnetic pickup 5 and the cover 6 are incorporated into a mold (not shown). By this resin integral molding, the connector 7 is formed, the electromagnetic pickup 5 is fixed to the cover 6, and the sensor module 1
It becomes 0. Further, the inner peripheral surface of the fitting margin 6 of the cover 6 is, as shown in FIG. 1 (b), a base portion 64 of the fitting margin 61.
A void 63 is formed up to this point so that the mold resin 8 does not come into contact with it. The bottom portion 65 of the gap 63 is the inner surface of the stopper portion 62 of the cover 6.

A fitting margin 61 that fits into the opening 31 on the fixed side 3 of the bearing is cylindrical and is press-fitted to the stopper 62. Since the opening 31 is formed coaxially with the axle hub 2, the cylindrical fitting allowance 61 maintains coaxiality with the axle hub 2. Further, when the electromagnetic pickup 5 is molded on the cover 6 with the molding resin 8, the electromagnetic pickup 5 and the fitting margin 61 are coaxially fixed and become the sensor module 10, so that the sensor module 10 is fitted in the opening 31. Even when the electromagnetic pickup 5 is press-fitted, the electromagnetic pickup 5 can maintain coaxiality with the rotor 9 with the comb teeth. Therefore, in the space around the outer periphery of the electromagnetic pickup 5, the rotor 9 with comb teeth is arranged coaxially with the gap 14 of the core 13 while maintaining a predetermined clearance.

The outer diameter of the fitting margin 61 press-fitted into the opening 31 is slightly larger than the inner diameter of the opening 31,
The design value is such that the fitting is loose and will not come off after press fitting. Therefore, a certain amount of pressure is required at the time of press fitting, and the fitting margin 61 is slightly deformed toward the inner peripheral side as the fitting margin 61 is press fitted into the opening 31.

When the fitting margin 61 is deformed to the inner peripheral side by the press-fitting of the sensor module 10, there is a gap 63 on the inner peripheral surface of the fitting margin 61, so that the clearance 63 serves as a buffer and the fitting margin 61 is freely deformed. To do. Since the deformation is only a slight displacement, the electromagnetic pickup 5 and the rotor 9 with the comb teeth at the position where the predetermined clearance is maintained do not come into contact with the fitting margin 61.

The void 63 may be formed by any method, but it is convenient to form it simultaneously when the cover 6 and the electromagnetic pickup 5 are integrally molded with resin. That is, these electromagnetic pickup 5 parts (11, 12, 13)
The void 63 is easily formed by giving a mold for incorporating the void a shape for forming the void 63.

(Second Embodiment) The stopper portion 62 of the sensor module 10 is press-fitted and positioned at the opening end portion 32 of the bearing fixing side 3. Since the inner diameter of the opening end portion 32 is slightly expanded by chamfering the corner portion, the root portion 64 of the fitting margin 61 connected to the stopper portion 62 does not directly contact the opening end portion 32, and the root portion is pressed into the opening portion 32. Almost no deformation of the portion 64 occurs. Then, even if the mold resin 8 is present on the bottom portion 65 of the inner peripheral surface of the fitting margin 61 (mold resin 81), the fixing position of the electromagnetic pickup 5 is not affected, and even if there is deformation, the deformation does not occur. It stops only in the region of and does not affect the molding resin 8 inside.

The mold resin 81 is formed by the cover 6
By filling the inside of the mold resin 8 with the mold resin 8, the electromagnetic pickup 5 is more firmly fixed to the cover 6 as compared with the case shown in the first embodiment.

As the signal chopper, the comb toothed rotor, which is a magnetic flux chopper, is used in the above embodiment, but a magnetic flux chopper other than this, such as a toothed rotor or a windowed rotor, may be used. Although an example using an electromagnetic pickup as the sensor body of the rotation sensor is shown, a rotation signal generation sensor based on a detection principle other than this may be used.

[Brief description of drawings]

FIG. 1 is a structural sectional view of a rotation sensor of a first embodiment to which the present invention is applied.

FIG. 2 is a structural sectional view showing a fitting margin portion of a second embodiment.

FIG. 3 is a structural cross-sectional view showing a rotation sensor of a comparative example.

[Explanation of symbols]

1 Wheel bearing 2 axle hub 3 Bearing fixed side 31 opening 32 Opening end 4 bearings 5 Electromagnetic pickup (consisting of 11, 12, 13) 6 cover 61 Fitting fee 62 Stopper part 63 void 64 Root part of fitting margin 61 65 bottom 7 connector 71 connector pin 8,81 Mold resin 9 Rotor with comb teeth (signal chopper) 10 sensor module 11 Pickup coil (electromagnetic pickup) 12 Magnet (electromagnetic pickup) 13 cores (electromagnetic pickup) 14 Gap

─────────────────────────────────────────────────── --Continued from the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01P 3/488 G01D 5/245

Claims (3)

(57) [Claims] 1. A sensor main body arranged coaxially with the rotary shaft is mounted on a cover which covers the shaft end of the rotary shaft and is fitted to the bearing fixed side by being molded with a molding resin to periodically generate a rotation signal. In a rotation sensor in which a signal chopper is arranged on the outer periphery of the sensor body with a predetermined clearance, the fitting margin of the cover is located at the outer peripheral portion of the signal chopper at the outer peripheral portion of the sensor body, and the fitting margin is and have a gap between the interior of the mold resin, the gap is formed to a root portion of said fitting allowance
And the mold resin does not come into contact with the fitting margin.
A rotation sensor characterized by being configured as follows . 2. A sensor main body arranged coaxially with the rotary shaft is mounted on a cover which covers the shaft end portion of the rotary shaft and is fitted to the bearing fixed side by being molded with a molding resin to periodically generate a rotation signal. In a rotation sensor in which a signal chopper is arranged on the outer periphery of the sensor body with a predetermined clearance, the fitting margin of the cover is located at the outer peripheral portion of the signal chopper at the outer peripheral portion of the sensor body, and the fitting margin is and have a gap between the interior of the mold resin, the opening end of the bearing fixed side by chamfering the corners
The inner diameter is slightly expanded, and the base of the fitting margin is directly connected to the end of the opening.
There is almost no deformation of the root part due to press fitting without contact.
A rotation sensor characterized by the fact that it does not occur . 3. The rotation according to claim 1, wherein the sensor body is an electromagnetic pickup, and the signal chopper is a rotor with teeth or windows made of a magnetic material or a rotor with comb teeth. Sensor.