JPH03118750A - Permanent-magnet generator with built-in signal generator - Google Patents

Abstract

PURPOSE:To dispense with an exclusive use of magnetic shielding member and to prevent invasion of leakage magnetic flux into a signal generator built in a generator by allowing the permanent magnet for the signal generator to have a structure in which leakage magnetic flux from a generation part is magnetically shielded by its own magnetic field. CONSTITUTION:A magnetic flux passing the core 12 of a pickup coil of a signal generator 10 is excited by a permanent magnet 13 for a signal generator interposed between a pickup coil 11 and a generation part 4 to vary each time it is opposed to the core 12 by the rotation of a rotational shaft 1. The magnet 13 for the signal generator is interposed between the coil 11 and a generation part 14 of the original generator. Thus, the magnet 13 for the signal generator prevents the magnetic flux leaked from the generation part 4 from entering the core 12 of the pickup coil of the signal generator side by its own ferromagnetic field.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a permanent magnet generator with a built-in signal generator.

[Conventional technology]

Traditionally, in the field of engines such as automobiles, a pickup-type signal generator has been built into a permanent magnet generator to generate a rotation signal (pulse signal) for ignition timing control and other signals related to engine rotation. The technology is known.

An example of this type of generator is Utility Model Publication No. 62-19092.

As disclosed in Japanese Patent Publication No. 63-3151, etc., a rotor of a generator is constituted by a bowl-shaped flywheel, and a permanent magnet for power generation and a power generation coil can be relatively rotated inside this flywheel. In addition to being built into the flywheel, a signal generator is also placed inside the flywheel.

Generally, an electromagnetic pickup type signal generator is used, in which a pickup coil with an iron core is fixed to a base, and a permanent magnet for exciting the iron core of the pickup coil is attached to the outer periphery of the boss in the center of the flywheel ( A method is adopted in which this boss portion is provided on a shaft connected to a rotating shaft of a generator driven by an engine. Namely.

In the case of this method, a permanent magnet provided on the boss of the flywheel rotates together with the boss and periodically faces the iron core of the pickup coil, which changes the magnetic flux passing through the iron core of the pickup coil and generates a rotation signal. (pulse) is generated.

[Problem to be solved by the invention]

By the way, when a signal generator is built into a permanent magnet generator, even if there is a slight air gap between the power generation section, which performs the original function of the generator, and the pickup of the signal generator, no consideration must be taken. , leakage magnetic flux from the power generation section becomes noise and enters the iron core of the pickup coil, deteriorating the S/N of the rotation signal generated from the signal generator. Therefore, in order to be less susceptible to leakage magnetic flux from the power generation section, consideration has been given to the positional relationship between the components of the power generation section and the signal generator, and the pickup coil is magnetically shielded with a box made of steel plate or the like. ing.

However, in the former case, it is not possible to adequately deal with the increase in leakage magnetic flux for power generation due to the high output of a single generator and the high density of the entire device, and in addition, there are positional restrictions when installing parts. Ta. In the latter case, although magnetic shielding can be effectively performed, it requires a special magnetic shielding member made of a TTG board or the like shaped into a box, which increases the number of parts.
This increases the number of assembly steps and costs.

The present invention has been made in view of the above points, and its purpose is to create a permanent magnet generator that is equipped with both a power generation section and a signal generator without using a dedicated magnetic shielding member. , effectively prevents leakage magnetic flux from the power generation section from entering the signal generator side, and improves the S/N.
The object of the present invention is to output a rotation signal with an excellent ratio, and also to reduce the cost and simplify the structure of this type of generator.

[Means to solve the problem]

In order to achieve the above object, the present invention proposes the following basic problem solving means (corresponding to the first claim).

In other words, it is a permanent magnet generator that rotates with the power of the engine.Inside the generator body, there are two power generating parts such as a relatively rotating permanent magnet (field) for power generation, and a power generation coil, as well as a one-rotation signal. In the signal generator, the signal generator is disposed inside the power generation section of the permanent magnet generator, and the signal generator is arranged between the pickup coil of the signal generator and the power generation section. A permanent magnet for a signal generator that excites the iron core of the pickup coil is interposed, and a magnetic shield is configured that blocks leakage magnetic flux from the power generation section from passing through to the iron core side of the pickup coil through the interposition of the permanent magnet for the signal generator. In addition, a signal portion that repeatedly faces the iron core of the pickup coil during rotation is disposed on the outer periphery of the rotating shaft of the permanent magnet generator or a boss portion that fits thereto, and when the signal portion passes, The pickup coil is configured to vary the excitation magnetic flux in the pickup coil iron core.

In addition, as a specific example of a means to solve this basic problem, we have developed a so-called rotating field type permanent magnet power generation system in which a bowl-shaped flywheel is used as a rotor and permanent magnets for power generation are arranged around the inner circumference of this flywheel. In this case, I would like to propose a system with a built-in signal generator as described in the above basic problem solving means. Note that this corresponds to the second claim, but since the details have been described in the embodiment, the explanation here will be omitted.

[Effect]

According to the present invention, the iron core of the pickup coil in the signal generator is connected to the pickup coil and the power generation section (
It is excited by a permanent magnet for a signal generator interposed between a permanent magnet for power generation (9) and a power generation coil. The magnetic flux that passes through the iron core of the pickup coil due to this excitation is generated every time the signal part disposed on the outer periphery of the rotating shaft of the generator or the boss part that fits thereto faces the iron core of the pickup coil due to its rotation. Change. Due to such changes in magnetic flux, a rotation signal is generated in the pickup coil as a pulse.

In addition, according to this problem-solving means, the permanent magnet for the signal generator is interposed between the pickup coil and the original power generation part of the generator, so that the permanent magnet for the signal generator is generated by its own strong magnetic field.

Blocks magnetic flux leaking from the power generation section from entering the iron core of the pickup coil on the signal generator side. In other words, the signal generator permanent magnet not only functions as a pulse generator magnet.

It also serves as a magnetic shield against leakage magnetic flux from the power generation section. Therefore, the S/N ratio of the signal (pulse output) of the signal generator can be improved without using a dedicated magnetic shield formed into a box shape of a steel plate or the like as in the past.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

FIG. 1 is a longitudinal cross-sectional view showing a first embodiment of the present invention, and FIG. 2 is a partial view of the same as viewed from direction P in FIG.

In these figures, 1 is a rotating shaft rotated by the power of the engine, 2 is a nut, and 3 is a flywheel that serves as the rotor of the generator. The flywheel 3 is formed of a magnetic material into a bowl shape, and a boss portion 3a is integrally provided at the center thereof. The flywheel 3 is fixed to the rotating shaft 1 by fitting the boss portion 3a onto the rotating shaft 1 and tightening the nut 2.

This generator is roughly divided into a power generation section 4 that performs the original function of the generator, and an electromagnetic pickup type signal generator 10 that generates a rotation signal (pulse) such as an ignition signal.

The power generation section 4 includes a power generation permanent magnet 5. It consists of a stator core, 6° generator coil 7, etc. The power generation permanent magnets 5 in this embodiment are arranged on the inner periphery of the flywheel 3 by the number of field poles, and rotate together with the flywheel 3 to form a rotating field. Inside the flywheel 3, a stator core 6 is fixed to a mounting base 8 via screws 9, facing the rotating field, and a power generating coil 7 is wound around the stator core 6. Symbols 7a, 'yb, 7c* 7d in Figure 2
... are elements of the power generation coil 7, and these coil elements are fitted into a radial core portion that becomes the stator core 6.

The signal generator 10 includes a pickup coil 11
．． an iron core 12 fitted within the pickup coil 11;
Permanent magnet 13 for exciting this iron core 12. It is composed of a protrusion (signal part) 14 for inducing changes in magnetic flux. The signal generator 10 is arranged inside the generator main body so as to be located inside the power generation section 4. Specifically, the pickup coil 11 is wound around the iron core 12,
A signal generator permanent magnet 13 is brought into close contact with this cored pickup coil 11, these elements are integrated with a mold 15, and this mold assembly is positioned inside the stator core 6 of one power generation section 4. It is fixed to base 8. When this mold assembly is fixedly arranged on the base 8, the signal generator permanent magnet 13 is set to be interposed between the power generation section 4 and the pickup coil 11. In this case, one side of the magnetic pole surface of the signal permanent magnet 13 faces one end of the iron core 12 on the signal generator side, and the other side faces the inner periphery of the stator iron core 6 on the power generation section 4 side.

In addition, the protrusion 14 serving as the signal part for generating the 9-rotation signal is
It is arranged on the outer periphery of the boss portion 3a. The protrusion 14 is connected to the boss portion 3
a and rotation axis 1, and is set to periodically face one end of the signal generator 10.

Next, the operation of this embodiment will be explained.

When the flywheel 3 rotates together with the rotating shaft 1, on the power generation section 4 side, the magnetic flux 18 passing from the power generation permanent magnet 5 through the stator core 6 changes, so that an alternating current is generated in the power generation coil 7, and the power source It is taken out to the outside as.

Further, on the signal generator 10 side, the signal generator permanent magnet 13 excites the iron core 12 of the pickup coil 11, and the excitation magnetic flux 17 is transmitted to the protrusion 1 that rotates once.
4, the pickup coil 1
1, a rotation signal 20 as shown in FIG. 3 is generated.

However, in such a permanent magnet generator, when the permanent magnet 5 on the power generation section 4 side excites the stator core 6, leakage magnetic flux 19 is generated, which enters the iron core 12 on the signal generator 10 side. Noise 2 as shown in Figure 3
1, but in this embodiment, this leakage magnetic flux 1
9 from entering the signal generator 1o side is prevented as follows.

That is, in this embodiment, the stator core 6 of the power generation section 4 and the pickup coil core 1 of the signal generator 10 side
Since the signal generator permanent magnet 13 is interposed between the signal generator permanent magnet 13 and the signal generator permanent magnet 13, the leakage magnetic flux 19 is canceled by the strong magnetic field of the signal generator permanent magnet 13 and is blocked from passing through the pickup coil iron core 12. Therefore, leakage magnetic flux 19 does not affect the excitation of pickup coil core 12, noise generated in pickup coil 11 can be reduced, and a pulse generator with a high S/N ratio can be provided.

Further, since the signal generator is magnetically shielded by using the permanent magnet 13 of the signal generator itself, the number of parts can be reduced, the cost can be reduced, and the structure can be simplified.

Furthermore, in this embodiment, the pickup coil 11 of the signal generator 10. Since the permanent magnet 13 and the iron core 12 are integrally formed by molding, it has the advantage of being easy to attach.

FIG. 4 is a partial explanatory view of a second embodiment of the present invention viewed from the direction P in FIG. 1, and FIG. 5 is a partial longitudinal sectional view showing a third embodiment of the present invention. In FIGS. 4 and 5, the same reference numerals as those used in the first embodiment indicate the same or common elements.

In the second embodiment, the surface of the permanent magnet 13 of the signal generator 10 on the side facing the inner circumference of the stator core 6 of the power generation section 4 is formed into a curved surface so as to be parallel to the inner circumference of the stator core 6. In addition, the permanent magnet 13 is formed so as to have a U-shaped cross section in the horizontal direction so that both circumferential (horizontal) ends 13a of the permanent magnet 13 overlap part of the left and right side surfaces of the pickup coil 11.

In addition, in the third embodiment, the permanent magnet 13 of the signal generator 10 is arranged such that both longitudinal ends 13b thereof overlap a part of the upper and lower surfaces of the pickup coil 11.
3 is formed vertically so as to have a U-shaped cross section.

According to these embodiments, in addition to producing the same effects as the first embodiment, the permanent magnet 13 can further cancel out the magnetic fluxes 19a and 19b that come around from the pickup coil 11 side among the leakage magnetic flux 19. , - layer S/
A pulse generator with a large N ratio can be provided.

Although the signal generator structure of each of the above embodiments has been exemplified as a rotating field type generator in which the permanent magnet 5 of the power generation section 4 rotates together with the flywheel 3 and the rotating shaft 1, the signal generator structure is not limited to this. It is also applicable to a type of generator in which the magnet is fixed and the generator coil and its iron core rotate together with the rotating shaft.

〔Effect of the invention〕

As described above, according to the present invention, the permanent magnet for the signal generator built into the generator has a structure that magnetically shields leakage magnetic flux from the power generation section side with its own magnetic field, so the SZN ratio of the signal generator is improved. Moreover, it does not require a dedicated magnetic shielding member like the conventional one.
It is possible to provide a permanent magnet generator with a built-in signal generator that is advantageous in terms of cost and has a simplified structure by reducing the number of parts.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of the present invention. FIG. 2 is a partial view of the first embodiment viewed from the direction P in FIG. 1, and FIG. 3 is a diagram of the output waveform of the signal generator.
FIG. 4 is a partial view of a second embodiment of the present invention as viewed from the direction P in FIG. 1, and FIG. 5 is a longitudinal cross-sectional view of a portion of a third embodiment of the present invention. be. 1... Rotating shaft, 3... Flywheel, 3a...
Boss part, 4... Power generation part, 5... Permanent magnet for power generation, 6
...Stator core, 7...Generating coil, 10...Signal generator, 11...Pickup coil,
12... Iron core of pickup coil, 13... Permanent magnet for signal generator, 14... Signal section (
Projections), 19...Leakage magnetic flux. Figure 81 East O Figure 2

Claims (1)

[Claims] 1. A permanent magnet generator that rotates with the power of the engine. Inside the generator body, there are power generation parts such as a relatively rotating permanent magnet (field) for power generation, and a power generation coil. In addition, in the device having a built-in pickup type signal generator for generating a rotation signal, the signal generator is arranged inside the power generation section of the permanent magnet type generator, and the pickup coil of this signal generator and the A permanent magnet for a signal generator that excites the iron core of the pickup coil is interposed between the power generating section and the magnetic flux leakage from the power generating section passes to the iron core side of the pickup coil. a signal portion that repeatedly faces the iron core of the pickup coil during rotation is disposed on the outer periphery of the rotating shaft of the permanent magnet generator or a boss portion that fits thereon; A magnetic generator with a built-in signal generator, characterized in that the excitation magnetic flux in the pickup coil iron core is changed by passage of the signal section. 2. A flywheel (rotor) is fitted and fixed to the rotating shaft rotated by the engine via the boss part, and a permanent magnet for power generation that becomes a rotating field is arranged on the inner periphery of the flywheel.
This is a permanent magnet generator in which a power generation coil with a stator iron core is fixedly placed on a mounting base facing the permanent magnet for power generation inside the flywheel, and an electromagnetic pickup type signal generator is installed inside the generator. In the built-in one, the signal generator is arranged inside the power generation permanent magnet and the power generation coil with a stator core, which serve as the power generation section of the permanent magnet generator, and the pickup coil of this signal generator and the power generation section A permanent magnet for a signal generator that excites the iron core of the pickup coil is interposed between the magnet and the magnet, and the permanent magnet for the signal generator blocks leakage magnetic flux from the power generation section from passing through to the iron core side of the pickup coil. A signal part that constitutes a magnetic shield and repeatedly faces the iron core of the pickup coil during rotation is disposed on the outer periphery of the boss part of the flywheel, and the passage of this signal part causes excitation in the pickup coil iron core. A magnetic generator with a built-in signal generator that is configured to change the magnetic flux. 3. A magnetic generator with a built-in signal generator according to claim 1 or 2, wherein the signal portion includes a protrusion disposed on the outer periphery of a rotating shaft or a boss portion that fits on the rotating shaft. 4. The magnetic generator with a built-in signal generator according to any one of claims 1 to 3, wherein the permanent magnet, pickup coil, and iron core constituting the signal generator are integrated by molding. 5. In any one of claims 1 to 4, the signal generator permanent magnet has at least one of its longitudinal and lateral ends located on the left and right sides and the top and bottom sides of the pickup coil. A magnetic generator with a built-in signal generator that has a U-shaped cross section and hangs on either side.