JPH06102054A - Magnetic rotation sensor - Google Patents

Abstract

PURPOSE:To obtain a magnetic rotation sensor in which manufacturing cost can be reduced by eliminating the work for securing a magnet, a coil, a terminal, and the like, inserted into a synthetic resin body, by means of screws or adhesive thereby reducing the manhours. CONSTITUTION:A magnet 2, a coil 7, a terminal 5, and the like are integrally molded of synthetic resin 8. Since these components are secured simultaneously, securing work using screws or adhesive is not required and thereby manhours are reduced resulting in manufacturing cost reduction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a magnetic type rotation sensor for magnetically detecting rotation or angle for an automobile.

[0002]

2. Description of the Related Art Conventionally, a magnetic type rotation sensor is known, for example, in Japanese Utility Model Laid-Open No. 60-53060. Generally, permanent magnets such as rare earths, neodymium, alnico, and ferrite are used as the types of magnets of the sensor.

The magnetic rotation sensor is assembled by previously inserting a magnet, a coil, a terminal, etc. into a predetermined molded body made of a synthetic resin and combining them to assemble them with screws or adhesives. It is fixed with an agent. In such a manufacturing method, in addition to the assembling work, there is a work of fixing with a screw, an adhesive, or the like. Therefore, it is difficult to reduce the number of work steps, and there is a problem that the manufacturing cost cannot be reduced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic rotation sensor which can reduce the manufacturing cost by eliminating the above-mentioned work of fixing with a screw, an adhesive or the like and reducing the number of work steps. Especially.

[0005]

In order to achieve the above-mentioned object, the present invention is one in which a magnet, a coil, a terminal and the like are integrally molded with a synthetic resin.

[0006]

[Function] When the magnet, the coil, the terminal and the like are integrally molded by the synthetic resin, they are fixed at the same time, so that the work of fixing them with screws or an adhesive is not necessary, and the number of work steps can be reduced, and the manufacturing The cost can be reduced.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a partial sectional view according to the present invention,
FIG. 2 shows a characteristic diagram of a permanent magnet.

The core 1, the magnet 2, the yoke 3, the terminal 5, and the mounting collar 4 on the engine side are set in a synthetic resin molding die, and the coupler 9 is also molded simultaneously with the synthetic resin 8 to integrate the bobbin 11. Turn into

A coil 7 is wound around the bobbin 11, and lead wires of a winding start 7a and a winding end 7b of the coil 7 are wound around the terminal 5 and connected by solder 6.

Thereafter, for protection of the coil portion, the epoxy resin 10 and the like are molded to complete the magnetic rotation sensor.

In recent years, a lightweight, compact and high output type sensor has been desired. Therefore, as a material of the magnet 2, rare earth (Sm, Co based) or neodymium tends to be adopted. However, neodymium causes high-temperature demagnetization due to its characteristics, so that the manufacturing method of integral molding with synthetic resin cannot be adopted.

The rare earth elements include those that cause high temperature demagnetization and those that do not cause high temperature demagnetization in the synthetic resin mold integral molding. In particular, some Sm, Co, 2-17 series rare earths do not cause high temperature demagnetization.

On the other hand, when molding the synthetic resin 8,
The resin melted at a temperature of 250 to 270 ° C. is filled in the mold by injection. At that time, the temperature around the magnet was 220 to 230 ° C. according to the experiments by the inventors,
It was found from the experimental results that even if the magnetic flux density B shown in FIG. 2 is high, irreversible demagnetization occurs when exposed to high temperature, and the coercive force IHC decreases.

For example, at room temperature, the magnetic flux density B is 10 kG.
And a coercive force IHC of 8 kOe was used for the magnet, and a synthetic resin mold was formed integrally, about 10
% Output has decreased.

As a result of various investigations, as a characteristic of the permanent magnet which does not cause high temperature demagnetization in the synthetic resin mold integral molding, it is a rare earth element of Sm, Co, 2-17 series and has a coercive force I.
18 kOe or more at normal temperature of HC, 11 kO at 300 ° C
It was found that e or more was required.

Based on the above examination, a magnet, a coil,
When terminals and the like are integrally molded with synthetic resin, they are fixed at the same time, so the work of fixing them with screws or adhesives is not required, and the number of work steps can be reduced, and the manufacturing cost can be reduced. .

Further, by using a rare earth permanent magnet having a characteristic that high temperature demagnetization does not occur in the synthetic resin mold integral molding as the magnet, the synthetic resin mold integral molding becomes possible.

[0019]

As described above, according to the present invention,
There is an effect that the work of fixing with a screw or an adhesive is unnecessary, the number of work steps can be reduced, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram of a permanent magnet.

[Explanation of symbols]

1 ... Core, 2 ... Magnet, 3 ... Yoke, 4 ... Color,
5 ... Terminal, 6 ... Solder, 7 ... Coil, 7a ... Coil winding start, 7b ... Coil winding end, 8 ... Synthetic resin, 9 ... Connector, 10 ... Epoxy resin, 11 ... Bobbin.

Claims (3)

[Claims] 1. A magnetic type rotation sensor characterized in that at least a magnetic circuit element such as a core, a magnet, a yoke, and a lead terminal are integrally molded of synthetic resin having a bobbin. 2. A rare earth element (Sm, Co) in which at least a magnetic circuit element such as a core, a magnet, a yoke, and a lead terminal are integrally molded of a synthetic resin having a bobbin, and which does not undergo high-temperature irreversible demagnetization under the temperature during molding. , 2-17 system) permanent magnets are used for the magnets. 3. At least a magnetic circuit element such as a core, a magnet and a yoke, and a lead terminal are integrally molded of a synthetic resin having a bobbin, and a permanent magnet having a coercive force IHC of 10 kOe or more at 300 ° C. A magnetic rotation sensor, which is used for the magnet.