JPH0422301Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a rotation detection device, and particularly to an improved structure of a rotation detection device including a magnet, a pole, and an output coil.

[Conventional technology]

FIG. 3 shows an outline of a conventional rotation detecting device of this type having a structure similar to the device disclosed in Japanese Utility Model Application Publication No. 59-138768.

That is, in FIG. 3, reference numeral 1 indicates a pole made of a ferromagnetic material, 2 a magnet that supplies magnetic flux to this pole 1, 3 a spacer that increases the effective amount of magnetic flux of this magnet, 4 these poles 1, The magnet 2 and the spacer 3 are stacked one on top of the other in order from the distal end side, and the output coil 5 is wrapped around the outer circumference of the pole 1 on the distal end side, and a terminal is attached on the proximal end side. Support part 4
a, 4a are formed thereon, and 6, 6 are fitted into the terminal support parts 4a, 4a, and have external lead wires 7, 7, and are connected to the winding start, winding end 5a, and winding ends of the coil 5, respectively. A pair of terminals 5a are connected to the cap, and 8 is a cap that holds the external lead wires 7, 7 and the terminals 6, 6, and positions and fixes the pole 1, magnet 2, and spacer 3 in the bobbin 4. , 9 is coil 5
and an insulating tape wrapped around the outer periphery of connection with the terminals 6, 6, and 10 is a device housing made of a resin material such as nylon and injection molded so as to surround the outside of each of these members. For example, in order to fit and attach it to a transmission case of an automobile, the external shape is a fitting part 1 on the rear half of the proximal end of a coil 5 having a predetermined outer diameter.
0a, a small diameter portion 10b on the front half of the tip side of the coil 5 whose outer diameter is smaller than this, and a fitting portion 1.
It consists of a groove 10c of the O-ring 11 at 0a and a mounting flange 10d in which a locking bush 12 is arranged in the mounting hole.

However, in this conventional configuration, the device housing 10 is mounted on a mounting seat such as a transmission case of an automobile.
The fitting portion 10a of the pole 1 is fitted and the mounting flange portion 10d is used to properly attach and fix the pole 1, and in this attached state, the tip end surface of the pole 1 is positioned at equiangularly spaced positions of the rotating body to be detected (not shown). It is used by opposing each protrusion set in the rotation path through a slight magnetic gap outside the rotation locus.

As is well known here, as the rotating body to be detected rotates, the individual protrusions move toward the pole 1.
When the magnet 2 repeatedly approaches and separates from the pole 2, the magnetic resistance between them changes, and the amount of magnetic flux of the magnet 2 that returns from the pole 2 to the spacer 3 via the protrusion and the outside also changes. , this magnetic flux is the coil 5
, a signal voltage corresponding to the change in magnetic resistance is induced and output in the coil 5, and the period of change of this signal voltage is measured to determine the rotational speed of the rotating body to be detected, Furthermore, in this case, it is possible to detect the driving speed of the car.

[Problem that the invention attempts to solve]

As mentioned above, in the conventional device, the coil 5
Regarding the insertion and insertion of the pole 1, magnet 2, and spacer 3 into the bobbin 4, which is wound with Because it is necessary to absorb the stress applied to each lead wire 7, 7, an elastomer with properties similar to rubber is used as the material, and has a relatively low heat distortion temperature and large heat shrinkage. .

Due to the properties of the cap 8, when large vibrations are applied to the device itself at high temperatures, for example, the pressing force against the pole 1, magnet 2, and spacer 3 within the bobbin 4 will be reduced. There is a risk that the cap will become smaller, and the same cap 8
When a crushing margin greater than the amount of thermal deformation is given to the pressing part, the stress from the outside is directly applied to the pressing part, the thermal deformation temperature becomes lower, and the pressing force is similarly reduced. Therefore, each member is likely to become loose, and as a result, there is a problem in that noise is superimposed on the signal from the coil 5.

Therefore, the purpose of this invention is to insert poles, magnets, etc. into a bobbin wound with a coil in order from the front side, one on top of the other.
It is an object of the present invention to provide a rotation detecting device of this kind that has a means for positioning and holding the rotation detecting devices so that they are not loosened from each other.

[Means for solving problems]

In order to achieve the above object, the rotation detecting device according to the present invention is configured such that a portion of the bobbin is press-supported by a pole, a magnet, and a spacer cap, and the bobbin is provided with these poles, A communication port that communicates with the inside of the space between the press support surface of the back of the magnet and spacer and the front of the cap is opened, and resin is filled and solidified into the space through this communication port during injection molding of the device housing. .

[Effect]

In addition to pressure support using the pole, magnet, and spacer cap inside the bobbin, this invention
These pressing support surfaces on the back can be fixed at the pressing position by the filled resin part that is integrally formed with the device housing.

〔Example〕

Hereinafter, one embodiment of the rotation detection device according to this invention will be described in detail with reference to FIGS. 1 and 2.

FIG. 1 is a longitudinal cross-sectional view showing the main part configuration of the rotation detection device according to this embodiment, and FIG. 2 is a perspective view of the same bobbin. The same reference numerals as in the conventional structure indicate the same or corresponding parts.

In this embodiment, a bobbin 14 and a cap 18 are used as members corresponding to the bobbin 4 and cap 8, and the cap 18 of the pole 1, magnet 2, and spacer 3 is inserted into the bobbin 14.
With regard to press support against the press support surface 3a on the back surface of the spacer 3, the protrusion 18b extending from the front surface 18a of the cap 18 is
The bobbin 14 is made to abut against a part of the press support surface 3a of the spacer 3, and the press support surface 3a of the spacer 3 and the cap 1
A communication port 14a that communicates with the inside of the space between the front surface 18a of the spacer 8 and the front surface 18a of the spacer 3 is opened, and during injection molding of the device casing 10 described above, the communication port 14a communicates with the inside of the space and, by extension, the press support surface 3a of the spacer 3. The back portion is filled with resin and solidified, and the solidified filled resin portion 10e positions and fixes the pole 1, magnet 2, and spacer 3 at their pressed positions.

An example of the specific shape and configuration of the bobbin 14 is shown in FIG. 2. That is, in the figure, 14a is a communication port for filling the molten resin as described above, and it is effective to make the openings in two symmetrical positions. Also 14
b, 14c are insertion holes 1 into which the pole 1, magnet 2 and spacer 3 are inserted and held in sequence;
4d is the winding groove of the coil 5, 14e, 14f
14g is an extraction groove for the external lead wire 7, and 14h is the filled resin portion 10e.
14i is the internal space filled with the pole 1,
This opening serves as an insertion port for the magnet 2 and spacer 3, and also serves as an opening for sealing the cap 18.

Therefore, when using this bobbin 14, after assembling and connecting each member as described above,
When the cap 18 is tightly sealed in the opening 14i, the protrusion 18b of the cap 18 abuts a part of the pressing support surface 3a of the spacer 3, and the pole 1, magnet 2, and spacer 3 are pressed inside the bobbin 14. Support is provided, and the front surface 18a and the pressing support surface 3
An internal space 14h that opens to the outside through a pair of communicating ports 14a, 14a formed opposite to each other is independently formed between the other portion of a.

Thereafter, the device housing 10 is made of a resin material, which has a relatively high heat distortion temperature and little heat shrinkage, for example, since the device itself is attached to an automobile transmission case and exposed to high temperatures. When injection molding is performed using a resin material such as glass fiber-filled nylon or RBT, the molten resin flows into the internal space 14h through the communication ports 14a, 14a and is filled and solidified, and the filled resin portion 10e obtained in this way , the pressed positions of the pole 1, magnet 2, and spacer 3 within the bobbin 14 are held in position.

In this case, if the mounting recesses 14e, 14f of the terminal 6 and its connecting end 6a are spaced apart from the communication ports 14a, 14a, the molten resin can be prevented from flowing into the mounting recesses 14e, 14f. , reliability at the connection end 6a is not impaired. Furthermore, since the filled resin portion 10e is connected through the respective communication ports 14a, 14a, it is filled and solidified in a cross-like manner on the pressing support surface 3a of the spacer 3, and its strength can be increased. be.

[Effect of idea]

As detailed above, according to this invention, each member of the pole, magnet, and spacer is pressed into the bobbin using a cap and is supported by a part of the support surface, and the bobbin is provided with each member. A communication port communicating with the inside of the space between the pressing support surface for the member and the front surface of the cap is opened, and resin is filled and solidified into the space from this communication port during injection molding of the device housing, so that the bobbin In addition to the pressure support of each member inside by the cap, the pressure support surface on the back can be fixed in the pressed position by the filled resin part, which makes it extremely stable with little temperature change in the usage environment and aging. A structure that can be obtained, and there is no risk of loosening between each member,
It has features such as being able to effectively avoid noise and the like, being relatively simple in structure, and being able to be implemented easily and inexpensively.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing the general configuration of an embodiment of the rotation detection device according to the invention, FIG. 2 is a perspective view showing the shape and configuration of the same bobbin, and FIG.
The figure is a longitudinal cross-sectional view showing a schematic configuration of a rotation detecting device according to the conventional example. 1...Pole, 2...Magnet, 3...Spacer,
3a...Press support surface of spacer, 5...Coil,
5a... Coil winding start, winding end, 6...
Terminal, 6a... Connection end of terminal, 7
... External lead wire, 9 ... Insulating tape, 1
0...Device casing, 10e...Filled resin portion of device casing, 14...Bobbin, 14a...Bobbin communication port, 14h...Inner space of bobbin, 18...Cap, 18a...Front surface of cap , 18b... protrusion of the cap.

Claims (1)

[Claims for Utility Model Registration] (1) At least a pole made of ferromagnetic material,
A magnet that supplies magnetic flux to this pole, a bobbin in which these poles and magnets are stacked and inserted sequentially from the front side, and a coil is wound around the corresponding part of the pole, and each has an external lead wire. It is equipped with a set of terminals to which the winding start and winding ends of the coil are connected, and a cap that holds each external lead wire and presses and supports the pole and magnet from the rear side, and is made by injection molding of resin material. In the rotation detection device in which a device housing is formed to surround these, the pole and the magnet are partially supported by the cap, and the bobbin is provided with a magnet. A communication port communicating with the inside of the space between the pressing support surface on the back and the front surface of the cap is opened, and when the device housing is injection molded,
A rotation detection device characterized in that a resin is filled and solidified into the space through the communication port to fix these poles and magnets at a pressed position. (2) The cap has at least two communication ports facing each other, and the pressure support surface on the back of the magnet has a
The rotation detection device according to claim 1, which is characterized in that the resin is filled and solidified in a cross-shaped manner.