JPH09138240A - Detection apparatus for rotational speed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a detection apparatus in which the number of components is reduced, whose assembling operation can be made easy and whose costs can be reduced. SOLUTION: A detection apparatus is provided with a magnet rotor 12, with a circuit board 15 on which a Hall element 15a arranged so as to face the magnet rotor 12 is mounted and with a lead wire 17a which is connected to the circuit board 15. The magnet rotor 12 is arranged and installed so as to be rotatable inside a rotor mounting block 11. On the other hand, the circuit board 15 and one end of the lead wire 17a which is connected to the circuit board 15 are buried and installed inside a resin member 14 so as to constitute a sensor block 13, and the sensor block 13 and the rotor mounting block 11 are integrated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational speed detecting device, and more particularly to a rotational speed detecting device connected to a transmission of an automobile and used for detecting a vehicle speed input to a speedometer or a navigation system. .

[0002]

2. Description of the Related Art FIG. 3 is an exploded perspective view schematically showing a conventional rotational speed detecting device of this type, in which 32 is a rotor mounting portion. The rotor mounting portion 32 is formed in a substantially thick cylindrical shape, and a screw portion 32a is formed at one end of the rotor mounting portion 32, and a wire cable (not shown) is inserted into the screw portion 32a. The cap 33 in which the hole 33a is formed is screwed. A magnet rotor (both not shown) is rotatably disposed in the rotor mounting portion 32 via a bearing portion, and the magnet rotor is magnetized into a plurality of poles or a plurality of permanent magnets (see FIG. (Not shown) is attached. A transmission (not shown) is connected to one end of the magnet rotor, and the other end of the magnet rotor is connected to a speedometer (not shown) via the wire cable. . A substantially box-shaped housing 34 extends from the upper part of the rotor mounting portion 32, and a hollow portion 34a into which an inner case 36 is inserted, a first end portion of a bush 36b, and a protection portion are provided at predetermined locations of the housing 34. Cavity portion 34b into which the collar portion 37b of the tube 37c is inserted
Are formed. These rotor mounting portion 32, housing 34
The device main body 31 is configured to include the
Are integrally formed by, for example, a die casting method.
On the other hand, as described above, a substantially box-shaped inner case 36 is inserted in the cavity 34a, and a circuit in which a hall element (not shown) or the like is mounted in the inner case 36. The board 36a and the other end of the rubber bush 36b, through which the lead wire 37a is inserted, are provided. The Hall element is arranged so as to face the magnet rotor, and one end of a lead wire 37a is connected to the circuit board 36a. Further, a resin member 36c is potted inside the inner case 36 so as to cover the hall element, the circuit board 36a, the lead wire 37a, and the other end of the bush 36b, and the hall element and the circuit board 36a are covered by the resin member 36c. It is protected from moisture. The sensor unit 35 is configured to include the inner case 36, the circuit board 36a, the resin member 36c, the hall element, and the like. A protective tube 37c having a flange 37b at one end thereof is wound around the lead wire 37a, and the other end of the lead wire 37a is connected to a connector 37d.
Is connected to a navigation device (not shown). These lead wires 37a, protection tube 37
The harness 37 is configured to include c, the connector 37d, and the like. Further, the cover 3 is provided above the sensor unit 35.
8 is provided, a mounting portion 38a is formed at a predetermined position of the cover 38 having a substantially flat plate shape, and the cover 3
A crimp portion 38b is formed by bending from a predetermined portion of 8. The rotation speed detection device 30 is configured by including the device body 31, the sensor unit 35, the harness 37, the cover 38, the magnet rotor, the wire cable, and the like.

In the case of such a rotation speed detecting device 30,
First, the magnet rotor is mounted on the bearing portion in the rotor mounting portion 32, one end of the wire cable inserted into the insertion hole 33a is connected to the other end of the magnet rotor, and then the cap 33 is screwed into the screw portion 32a. Tighten and fix to. Next, the sensor unit 35, the bush 36b,
The collar portion 37b of the protection tube 37c is connected to the cavity portion 3 of the housing 34.
4a and 34b, respectively, and mounting portion 38a
After the cover 38 is attached to the apparatus main body 31 via the, the lower portion of the caulking portion 38b is caulked to fix the flange portion 37b of the protective tube 37c to the apparatus main body 31, the rotational speed detecting device 30 is assembled and manufactured.

The rotation speed detecting device 3 having such a configuration
When 0 is used, when the rotation shaft of the transmission rotates, the magnet rotor and the wire cable rotate, and the vehicle speed obtained based on this rotation speed is displayed on the speedometer. At the same time, the direction of the magnetic force lines radiated from the plurality of permanent magnets changes in proportion to the rotation speed of the magnet rotor, and the change in the magnetic force lines is converted into an electric signal in the Hall element, and the circuit board 36a and the lead wire 37a. , The electrical signal is input to the navigation device via the connector 37d, and the vehicle speed is calculated.

[0005]

In the rotation speed detecting device 30 described above, the number of parts such as the casing 34, the inner case 36, and the cover 38 is large, and the assembling work of these parts including the caulking work under the caulking portion 38b is performed. Is troublesome,
There was a problem that the cost was high.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a rotation speed detecting device which can reduce the number of parts, facilitate the assembling work, and reduce the cost. Has an aim.

[0007]

Means for Solving the Problems and Effects Thereof In order to achieve the above object, a rotation speed detecting device according to the present invention comprises a magnet rotor, and a circuit board on which a hall element arranged opposite to the magnet rotor is mounted. A rotation speed detecting device including a lead wire connected to the circuit board,
While the magnet rotor is rotatably arranged in a rotor mounting block, the circuit board and one end of a lead wire connected to the circuit board are embedded in a resin member to form a sensor block, The sensor block and the rotor mounting block are integrated (1).

According to the above rotation speed detecting device (1), the magnet rotor is rotatably arranged in the rotor mounting block, while the circuit board and one end of the lead wire connected to the circuit board are provided. Part is embedded in a resin member to form a sensor block, and the sensor block and the rotor mounting block are integrated, so that the resin member causes one end of the circuit board or the lead wire to The Hall element is fixed in the sensor block, and the Hall element can be arranged at a predetermined position in the sensor block through the circuit board, and the Hall element and the circuit board can be protected from moisture and the like. Further, when the sensor block and the rotor mounting block are adhered to each other by using an adhesive or by connecting means such as a band, the sensor block and the rotor mounting block are easily integrated. In addition, parts such as a housing, an inner case, and a cover are not necessary, and assembling and caulking work of these parts can be omitted, and as a result, the cost can be reduced.

Further, the rotation speed detecting device according to the present invention comprises a magnet rotor, a circuit board on which a Hall element opposed to the magnet rotor is mounted, and a lead wire connected to the circuit board. In the speed detecting device, the rotor mounting block in which the magnet rotor is rotatably arranged therein, the circuit board, and one end of a lead wire connected to the circuit board are integrally resin-molded. It is characterized by being (2).

According to the above rotation speed detecting device (2), the rotor mounting block in which the magnet rotor is rotatably arranged, the circuit board, and the lead wire connected to the circuit board are provided. Since one end is integrally resin-molded, it is troublesome to connect the rotor mounting block and the sensor block composed of the circuit board, the lead wire, the resin member and the like with an adhesive or a connecting means. Is omitted, and the cost can be further reduced as compared with the rotation speed detecting device (1).

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a rotation speed detecting device according to the present invention will be described below with reference to the drawings. Note that components having the same functions as those of the conventional example are denoted by the same reference numerals. FIG. 1 is an exploded perspective view schematically showing a rotation speed detecting device according to the first embodiment, and 11 in the drawing shows a rotor mounting block. Rotor mounting block 11
Is formed of, for example, an aluminum tube, and the cap 3 shown in FIG.
A screw portion 11a is formed on which 3 is screwed. Further, a rotary shaft 12a is rotatably disposed at a predetermined position in the rotor mounting block 11 via a bearing (not shown), and a substantially disk-shaped magnet rotor 1 is provided at one end of the rotary shaft 12a.
2 are formed. A plurality of permanent magnets 12b are arranged on the outer peripheral portion of the magnet rotor 12, and the magnetic poles N and S of the permanent magnets 12b are set to be alternately arranged. A rotary shaft 12c extends from one end surface of the magnet rotor 12, and one end of a wire cable 12d connected to a speedometer (not shown) is connected to one end of the rotary shaft 12c.

On the other hand, a resin member 14 having a substantially rectangular parallelepiped shape is disposed above the rotor mounting block 11, and a substantially semi-cylindrical recess 14a into which the upper portion of the rotor mounting block 11 is inserted is provided below the resin member 14. Has been formed. In addition, a circuit board 15, a plurality of lead wires 17a connected to the circuit board 15, one end portions of a plurality of lead wires 17a, and a bush 16 having a substantially convex shape in which the lead wires 17a are inserted are provided at predetermined positions in the resin member 14. One end of the Hall element 15a is embedded and a Hall element 15a is mounted at a predetermined position below the circuit board 15 facing the magnet rotor 12. These resin members 14,
The sensor block 13 is configured to include the circuit board 15 and the Hall element 15a. The lead wires 17a are grouped together and covered with a protective coating 17b, and the other end of the lead wires 17a is connected to a navigation device (both not shown) via a connector. . The harness 17 is configured to include the lead wires 17a, the protective coating 17b, and the connector. The upper portion of the rotor mounting block 11 and the recess 14a of the sensor block 13 are bonded and integrated with an adhesive. The rotation speed detecting device 10 is configured by including the rotor mounting block 11, the magnet rotor 12, the wire cable 12d, the sensor block 13, the harness 17, and the like.

In the case of such a rotation speed detecting device 10,
First, the hall element 15a is mounted and the lead wire 17
a circuit board 15 to which one end of a is connected, and a bush 16
After setting one end of the bushing 16 at a predetermined position in a mold (not shown) and then injecting an epoxy resin into the mold by a low-pressure molding method, for example, the circuit board 15 and one end of the bush 16 become resin. It is embedded in the member 14. Next, when these are taken out from the mold and heated at a predetermined temperature, the resin member 1
4 reacts and cures to a predetermined strength in a relatively short time to form the sensor block 13. On the other hand, after the magnet rotor 12 is mounted in the rotor mounting block 11 via the bearing portion and the rotating shaft 12a and one end of the wire cable 12d is connected to one end of the rotating shaft 12c, as shown in FIG.
The cap 33 shown in is fastened and fixed to the screw portion 11a. Next, an adhesive is used to bond and integrate the upper portion of the rotor mounting block 11 and the recess 14a of the sensor block 13 to manufacture the rotation speed detecting device 10.

The rotation speed detecting device 1 configured as described above
When 0 is used, a transmission or the like is connected to the other end of the rotary shaft 12a,
When the magnet rotor 12 is rotated via a, the vehicle speed obtained based on this rotation speed is displayed on the speedometer, and at the same time, the hall speed is changed based on the magnetic field that changes in proportion to the rotation speed of the magnet rotor 12. Element 15
The electric signal detected and converted in a is the circuit board 15,
It is input to the navigation device side via the lead wire 17a and the vehicle speed is calculated.

As is apparent from the above description, in the rotation speed detecting device 10 according to the first embodiment, the magnet rotor 12 is rotatably arranged in the rotor mounting block 11, while the magnet rotor 12 is connected to the circuit board 15. , The one end of the lead wire 17a connected to the circuit board 15 is embedded in the resin member 14 to form the sensor block 13, and the sensor block 13 and the rotor mounting block 11 are integrated so that the resin member 14, the circuit board 15 and the lead wires 17
One end of a is fixed in the sensor block 13, and the Hall element 15a is fixed to the sensor block 13 via the circuit board 15.
In addition to being able to be placed in a predetermined position, the Hall element 15a and the circuit board 15 can be protected from moisture and the like. Also, the sensor block 13 and the rotor mounting block 1
When 1 and 1 are bonded with an adhesive, the sensor block 13
The rotor mounting block 11 is easily integrated with the rotor mounting block 11. In addition, parts such as the case, inner case, and cover are unnecessary,
Assembling and caulking work of these parts can be omitted, and as a result, the cost can be reduced.

In the rotation speed detecting device 10 according to the first embodiment, the case where the sensor block 13 and the rotor mounting block 11 are bonded and integrated with each other using an adhesive has been described, but in another embodiment. These may be connected and integrated by using a connecting means such as a band.

FIG. 2 is a perspective view schematically showing a rotation speed detecting device according to the second embodiment, and 11 in the drawing shows a rotor mounting block similar to that shown in FIG. A hall element 15a is arranged at a predetermined position above the rotor mounting block 11, and the hall element 15a is arranged on the circuit board 1
It is mounted on the bottom of the 5. Also, one end of a lead wire 17a is connected to the circuit board 15.
One end of 7a is inserted into a bush 16 having a substantially convex shape. One end of the bush 16 and the lead wire 17a,
The circuit board 15, the hall element 15a, and the central portion of the outer peripheral portion of the rotor mounting block 11 are integrally resin-molded by using a resin member 24 having a substantially rectangular parallelepiped shape. Since other configurations are similar to those shown in FIG. 1, detailed description of the configuration will be omitted here. These rotor mounting block 11, magnet rotor 12, wire cable 12d, circuit board 15, hall element 15a, harness 1
The rotation speed detection device 20 is configured including 7 and the like.

In the case of such a rotation speed detecting device 20,
First, the rotor mounting block 11 and the Hall element 15a are mounted, and the circuit board 15 to which one end of the lead wire 17a is connected and one end of the bush 16 are set at predetermined positions in a mold (not shown), respectively. After that, for example, when an epoxy resin is injected into the mold by a low pressure molding method, the rotor mounting block 11, the circuit board 15, and one end of the bush 16 are integrally resin-molded.

As is apparent from the above description, in the rotation speed detecting device 20 according to the second embodiment, the rotor mounting block 11 in which the magnet rotor 12 (FIG. 1) is rotatably arranged is provided. Since the circuit board 15 and one end of the lead wire 17a connected to the circuit board 15 are integrally molded with the resin 24, the rotor mounting block 11, the circuit board 15, the lead wire 17a, and the resin member 1 are formed.
The time and effort for connecting the sensor block 13 composed of 4 and the like (both shown in FIG. 1) with an adhesive or a connecting means are omitted,
The cost can be further reduced as compared with the rotation speed detecting device (1).

In the rotation speed detecting device 20 according to the second embodiment, the case where the rotor mounting block 11 is made of an aluminum tube is used. However, in another embodiment, slipping out is prevented. For this reason, an aluminum tube having a surface subjected to knitting knurling may be used.

[Brief description of the drawings]

FIG. 1 is a first embodiment of a rotation speed detection device according to the present invention.
It is an exploded perspective view which showed roughly.

FIG. 2 is a perspective view schematically showing a rotation speed detection device according to a second embodiment.

FIG. 3 is an exploded perspective view schematically showing a conventional rotation speed detection device.

[Explanation of Codes] 10 Rotational Speed Detection Device 11 Rotor Mounting Block 12 Magnet Rotor 13 Sensor Block 14 Resin Member 15 Circuit Board 15a Hall Element 17a Lead Wire

Claims (2)

[Claims] 1. A rotation speed detecting device comprising a magnet rotor, a circuit board on which a Hall element is arranged opposite to the magnet rotor, and a lead wire connected to the circuit board. While being rotatably disposed in the rotor mounting block, the circuit board and one end of a lead wire connected to the circuit board are embedded in a resin member to form a sensor block, and the sensor block and A rotation speed detecting device characterized in that the rotor mounting block is integrated. 2. A rotation speed detecting device comprising a magnet rotor, a circuit board on which a Hall element is arranged opposite to the magnet rotor, and a lead wire connected to the circuit board. Rotational speed detection, characterized in that the rotor mounting block rotatably arranged therein, the circuit board, and one end of a lead wire connected to the circuit board are integrally resin-molded. apparatus.