JP2908115B2 - Rotation sensor and method of manufacturing the same - 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 gear-shaped magnetic rotator and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a conventional rotation sensor disclosed in, for example, Japanese Utility Model Laid-Open No. 63-91294.
In FIG. 4, 1 is a case, 2 is a coil wound around a bobbin 3, 4 is a magnetic core inserted into the axis of the case 1, 5 is a bias magnet having one end of the magnetic core 1 close to, 6 Is a spacer for increasing magnetic flux, 7 is a grommet, 8 is a terminal, 9 is a cover, 10 is a lead wire connected to the terminal 8, and 11 is an O-ring.

FIG. 5 is a connection diagram of a conventional rotation sensor. In FIG. 5, 12 is a rotation sensor, 13 is a filter circuit, 14 is a Schmitt trigger circuit composed of a comparator and a switching element, and 15 is a computer unit.

Next, the operation will be described. In the conventional rotation sensor 12, since the magnetic core 4 and the spacer 6 are close to both end surfaces of the bias magnet 5, and the coil 2 is wound around the magnetic core 4, the rotation sensor 12 is close to the tip of the magnetic core 4. An AC voltage that is excited by the coil 2 as the gear-shaped magnetic rotating body rotates is output.

The AC voltage output has its noise attenuated by a filter circuit 13 and is converted into a pulse wave by a Schmitt trigger circuit 14. The computer unit 15 comprises:
The number of rotations of the gear-shaped magnetic rotator is calculated by measuring the period of the pulse wave.

[0006]

Since the conventional rotation sensor and its system are constructed as described above, there has been a problem that it is difficult to detect the low-speed rotation of the gear-shaped magnetic rotator to be detected.

This is a problem that occurs because the output of the rotation sensor 12 is proportional to the rotation speed of the gear-shaped magnetic rotator.
During low-speed rotation, the S / N ratio between the output of the rotation sensor and the noise decreases, and the rotation detection accuracy decreases. Further, since the output current of the rotation sensor is 1 mA or less, there is a problem that the contact resistance of the terminal fitting portion is liable to increase.

The first aspect of the present invention has been made to solve the above problems, and the output voltage level does not depend on the rotation speed of the gear-shaped magnetic rotator to be detected. An object of the present invention is to provide a rotation sensor that can be set to a high level and a low level so that low-speed rotation can be detected and the reliability of the terminal fitting portion is improved.

Another object of the present invention is to provide a method of manufacturing a rotation sensor which has a simple manufacturing process and can be manufactured at low cost.

[0010]

According to a first aspect of the present invention, there is provided a rotation sensor which is insert-molded in a base and has a magnetoelectric conversion element and an electronic component on a terminal used as a connector terminal, and a magnetoelectric conversion element on the base. And a permanent magnet fixed at a position close to the permanent magnet.

According to a second aspect of the present invention, there is provided a method for manufacturing a rotation sensor, comprising the steps of: pressing a terminal into a predetermined shape from a hoop material, insert-molding the terminal into a base, and cutting unnecessary joint portions; a step of soldering an electronic component for surface mounting to a predetermined position of the terminal as well as soldered by inserting a magnetoelectric transducer to provided the land, and fixing the permanent magnet with an adhesive to a predetermined position of the base over the scan, A step of inserting the base to the end of the case and subjecting the case end to heat caulking, and covering the heat caulked portion with a resin.

[0012]

According to the first aspect of the present invention, the magnetoelectric conversion element performs switching operation between the high and low states based on a predetermined hysteresis due to a change in magnetic flux, and depends on the rotation speed of the gear-shaped magnetic rotating body to be detected. Constant output without
Is obtained. Therefore, low-speed rotation detection of the detection target is possible, and the reliability of the connector terminal fitting portion is also improved.

According to the second aspect of the present invention, the pressed terminal is formed into a base by insert molding, and after cutting unnecessary connecting portions, an electromagnetic transducer is inserted into a land at the terminal end and soldered. the surface mount electronic components to a predetermined position by utilizing the vent hole formed in the base and reflow soldering, to insert the permanent magnets at a predetermined position of the base over the scan to the tip of the case the base in a state fixed with adhesive Then, heat staking is performed on the end of the case, and the heat staking portion is covered with a resin.

[0014]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of one embodiment of the present invention. In FIG. 1, reference numeral 16 denotes a case, 17 denotes a magnetoelectric conversion element, 18 denotes a base, 19 denotes a terminal formed by insert molding on the base, and 20 denotes a surface. Electronic components for mounting, 21 is a permanent magnet, 22 is an adhesive for fixing the permanent magnet 21 to the base, 23 is an O-ring, and 24 is a resin.

The magnetoelectric transducer 17 halls element or magnetoresistive element with built-in Schmitt trigger circuit is used,
In the case 16, it is disposed close to the end face of the permanent magnet 21, and detects a change in magnetic flux from the end face of the permanent magnet 21 toward a gear-shaped magnetic rotating body (not shown).

As is apparent from FIG. 1, the terminal 19 of the connector is formed in an "L" shape, and a magnetoelectric conversion element 17 is provided at the tip (right end in FIG. 1).
Further, an electronic component 20 for surface mounting is arranged at a predetermined position. The terminal 19 and the base 18 form the connector, and the permanent magnet 21
Are fixed by bonding with an adhesive 22.

The base 18 is surrounded by a case 16 except for a connector portion. That is, case 1
6, a magneto-electric conversion element 17, a permanent magnet 21, an electronic component 2
0 is stored, and the left end of the case 17 and the base 1
8 are connected by fitting. An O-ring 23 is provided on the base 1 to maintain the inside airtightness.
8 is mounted in the O-ring groove. Case 16
Is heated and caulked, and then covered with resin 24.

With this configuration, the magnetoelectric conversion element 17 performs a switching operation between the high state and the low state based on a predetermined hysteresis based on a change in magnetic flux directed to the gear-shaped magnetic rotating body. In addition, a change in magnetic flux of the gear-shaped magnetic rotator to be detected is detected. Therefore, the magnitude of the output of the magnetoelectric conversion element 17 does not depend on the rotation speed of the gear-shaped magnetic rotator, and low-speed rotation of the gear-shaped magnetic rotator to be detected can be detected.

Embodiment 2 FIG. Next, a method of manufacturing a rotation sensor according to the present invention will be described with reference to FIGS. 2 and 3 are plan views of main parts during the manufacturing process. As shown in FIGS. 2 and 3, first, the terminal 19 is pressed from a hoop material into a predetermined shape.

Next, the terminal 19 is insert-molded on the base 18, an unnecessary connecting portion is cut, and the land provided at the end of the terminal 19 is transferred to the magneto-electric conversion element 17.
Insert and solder. Next, an electronic component 20 for surface mounting is soldered to a predetermined position of the terminal 19.
At the time of this soldering, a connecting portion between the terminals 19 is formed and cut, and an electronic component 20 is mounted on the connecting portion.
Perform reflow soldering.

Next, an O-ring 23 (not shown in FIGS. 2 and 3) is mounted in the O-ring groove of the base 18, and
The permanent magnet 21 is fixed at a predetermined position with an adhesive 22. Next, the base 18 is inserted up to the tip of the case 16, and the end of the case 18 is heat caulked, and the heat caulked portion is covered and covered with the resin 24.

[0022]

As described above, according to the first aspect of the present invention, the substrate is discarded, the terminal for the connector and the base are integrally formed, and the magnetoelectric conversion element and the electronic circuit component for surface mounting are formed on the terminal. Since it is configured so as to be provided, it is possible to detect low-speed rotation. Further, there is an effect that the contact reliability of the terminal fitting portion is improved. Further, since the filter circuit and the Schmitt trigger circuit which are required for the conventional rotation sensor are not required, the applied system is inexpensive.

According to the second aspect of the present invention, a connecting portion between the terminals required for insert molding the terminal into the base is cut after molding, and an electronic component for surface mounting is mounted on the portion. With this configuration, reflow soldering can be performed using the holes provided in the base, the manufacturing process can be simplified, the cost can be reduced, and low-speed rotation detection of the detection target can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a rotation sensor according to an embodiment of the present invention.

FIG. 2 is a plan view of a member during a manufacturing process for explaining a method of manufacturing a rotation sensor according to a second embodiment of the present invention.

FIG. 3 is a plan view showing a main part of a member during a manufacturing process according to the second embodiment.

FIG. 4 is a cross-sectional view illustrating a configuration of a conventional rotation sensor.

FIG. 5 is a connection diagram of a conventional rotation sensor.

[Explanation of symbols]

 16 Case 17 Magnetoelectric conversion element 18 Base 19 Terminal 20 Electronic component 21 Permanent magnet 22 Adhesive 23 O-ring 24 Resin

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01P 1/00-3/80 G01D 5/00-5/62 G01B 7/30

Claims (2)

(57) [Claims] 1. A terminal of a connector comprising: a magnetoelectric conversion element for detecting a change in magnetic flux from an end face of a permanent magnet toward a magnetic rotating body; and a terminal provided with the magnetoelectric conversion element at a tip and having a surface mount electronic component at a predetermined position. When the rotation sensor and a case where the connector is formed together with the terminal insert molded, and wrapping a base permanent magnet is fixed, the portion excluding the connector part of the base. 2. A step of pressing a terminal from a hoop material into a predetermined shape, a step of insert-molding the pressed terminal into a base and cutting an unnecessary joint portion, and a step provided at the tip of the terminal. and performing soldering by inserting a magneto-electric transducer to land, to fix the steps of soldering a surface mount electronic component at a predetermined position of the terminal by an adhesive a permanent magnet in a predetermined position before SL base A method for manufacturing a rotation sensor, comprising the steps of: inserting the base up to the end of the case, heat caulking the case end, and covering the heat caulked portion with resin.