JPS5941348Y2 - Signal generator for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal generating device that generates signals for controlling the loading and unloading of a non-contact ignition device for an internal combustion engine.

Non-contact ignition devices for internal combustion engines require a signal to determine the ignition position.

Furthermore, when detecting the rotational speed of the engine electrically, a signal with a frequency proportional to the rotational speed of the engine is required.

As a conventional signal generating device for obtaining such a signal, there is one in which a magnet is embedded in the outer periphery of a rotating body that rotates synchronously with the engine, and a signal generator that cooperates with the magnet is attached near the rotating body.

FIG. 1 shows an example in which the flywheel of a flywheel magnet generator is used as the rotating body. In the figure, reference numeral 1 denotes a permanent magnet 3.3. It is a flywheel magnet rotor made up of...

A magnet rotor 1 is usually added to the output shaft of an engine and constitutes a magnet generator together with a stator (not shown).

A recess 4 is formed on the outer periphery of the flywheel 2, a magnet 5 is disposed at the center of the recess, and a space between the magnet 5 and the inner peripheral surface of the recess 4 is filled with a non-magnetic member 6.

In the vicinity of the flywheel 2, a signal generator 9 consisting of a signal coil 8 wound around an iron core 7 facing the magnet 5 and having a magnetic pole part is added to a location 1 such as an engine case or cover. A signal force is induced in the signal coil 8 each time the magnet 5 passes the position of the magnetic pole of the signal generator 9 as the flywheel 2 rotates.

However, in such a structure, since the non-magnetic member 6 is required separately from the magnet 5, there is a drawback that not only the number of parts increases, but also a large number of man-hours are required to attach the magnet and the non-magnetic member.

In this case, it may be possible to omit the non-magnetic member 6 and adhere the magnet 5 to the center of the recess 4, but in this case, since the magnet is exposed, iron powder etc. may adhere to its sides. There was a risk that the two poles of the magnet would be magnetically shorted and the performance would deteriorate.

An object of the present invention is to provide a signal generator for an internal combustion engine that does not require a separate non-magnetic member from the magnet and in which the magnet is magnetically short-circuited by iron powder or the like.

The present invention will be explained in detail below with reference to the illustrated embodiments.

FIG. 2 shows an embodiment of the present invention, in which the same parts as in FIG. 1 are given the same reference numerals.

A boss 22 is attached to the center of the bottom wall portion 2a of the flywheel 2 constituting the flywheel magnet rotor 1 by a rivet 21.
This boss 22 is fitted onto a rotating shaft (usually an output shaft of the engine), not shown.

A recess 4 with a circular cross section provided on the outer periphery of the flywheel 2
Inside, as shown in FIG. 3A, there is a magnetic pole component 1 made of a cylindrical anisotropic magnetic material whose outer diameter is equal to the inner diameter of the recess 4.
It is fully fitted and secured with adhesive.

Magnetic pole component 10b. Almost the entire area is disposed within the recess 4, and the peripheral area outside the broken line in the figure (the area adjacent to the inner peripheral surface of the recess 4) is in an unmagnetized state π, and only the area inside the broken line is in an unmagnetized state π. It is magnetized in a direction perpendicular to the axial direction of the flywheel (radial direction of the flywheel).

The iron core 7 of the signal generator 9 is formed in a U-shape, and this iron core is arranged so that its magnetic pole parts 7a and 7b are lined up in the circumferential direction of the flywheel 2 and face the outer periphery of the flywheel with a gap therebetween. It is fixed to a fixed position on the engine case, cover, etc. by screws 11.

The spacing between the magnetic pole parts 7a and 7b of the iron core 7 is set such that when one magnetic pole part faces the magnetized part 10a of the magnetic pole component 10, the other magnetic pole part faces the outer peripheral surface of the flywheel 2, In this way, when the iron core 7 faces the magnetized portion 10a of the magnetic pole component 10 and the outer periphery of the flywheel 2, the magnetized portion 10a-iron core 7-flywheel 2-magnetized portion 1
The magnetic flux is designed to flow in the magnetic path 0a.

As described above, when a magnetic pole component made entirely of magnetic material is placed in the recess of the 7-light wheel and its peripheral portion is left unmagnetized, the magnetic pole component 10 is placed in the recess 4 of the housing.
This eliminates the need for a non-magnetic material to provide magnetic insulation between the magnet and the inner surface of the recess 4.

Therefore, not only can the number of parts be reduced, but also the magnetic pole constituent members can be easily attached.

In the above embodiment, the magnetic pole component was formed into a cylindrical shape and bonded inside the recess 4, but as shown in FIG. 3B,
After forming a chamfered portion 10b at one end of the cylindrical magnetic pole component 10 and inserting this magnetic pole component into the recess 4, the fourth
As shown in the figure, the recess 4v and the open end periphery 4a are chamfered into a
It may be fixed by applying a seaming force toward b.

The location where the assembled magnetic pole constituent members are arranged is not limited to the recess, but may be a hole.

Furthermore, the shape of the magnetic pole component is not limited to a cylindrical shape, but can be formed into any suitable shape.

FIG. 5 shows a modification of the mounting method of the magnetic pole component, in which a mounting hole 4 having a large diameter portion 41 and a small diameter portion 42 is provided in the flywheel 2, and the large diameter portion 10c and the mounting hole 4 are provided in the flywheel 2. 1
This is a case where a magnetic pole component having a diameter of 0d is inserted and fixed by adhesive or the like.

In this way, it is possible to prevent the magnetic pole component from flying out due to centrifugal force.

In the above embodiment, the outer surface of the magnetic pole member 10 is brought into close contact with the inner surface of the recess or hole, but a gap may be formed between the magnetic pole member and the inner surface of the recess or hole.

In this case, since the outer periphery of the magnetic pole member is a non-magnetized portion, there is no possibility that iron powder or the like will adhere to the outer periphery of the magnetic pole member and short-circuit the 14 poles.

When the magnetic pole component is composed of a rare earth magnet such as samarium cobalt, which has a large wandering magnetic energy product.

Although the present invention is not limited to the use of such magnet materials, it is also possible to use, for example, quartzite or plastic magnets.

In the above embodiment, the recess 4 is provided between the magnets of the flywheel magnet rotor, but the position of this recess or hole is arbitrary.

In the above embodiment, a flywheel magnet rotor was used as a rotating body that rotates synchronously with the engine, but this rotating body may be any type that rotates synchronously with the engine, such as a simple flywheel added to the engine or a fan. A belt pulley or the like can also be used as this rotating body.

As described above, according to the present invention, since the four parts of the magnetic pole component or the peripheral area adjacent to the inner circumference of the hole are left unmagnetized, a non-magnetic material for magnetically insulating the magnetic pole component can be used. In addition, the entire magnetic pole component can be placed inside the recessed housing or hole without using it.

Therefore, there is an advantage that a signal generating device for an internal combustion engine in which the magnetic pole component is arranged in a recess or hole of a rotating body to protect it can be easily assembled with a reduced number of parts.

[Brief explanation of drawings]

Fig. 1 is a half cross-sectional view showing a conventional example, Fig. 2 is a half cross-sectional view showing an embodiment of the present invention, and Figs. 3 A and B respectively show the shape of the magnetic pole component used in the present invention. FIGS. 4 and 5 are perspective views showing different examples, and sectional views of main parts showing different modifications in terms of how the magnetic pole component is attached. 1...Flywheel magnet rotor, 2...
・Flywheel, 3... Magnet, 9...
Signal generator, 10...Magnetic pole component, 10a...
...Electromagnetic part.

Claims (1)

[Scope of utility model registration request] A magnetic pole component made of a magnetic material is fixed in four parts or holes provided in a magnetic rotary body that rotates in synchronization with the internal combustion engine, and a magnetic pole component made of a magnetic material is fixed at a fixed position near the rotary body, facing the magnetized portion of the magnetic pole component. In a signal generator for an internal combustion engine, in which a signal generator is fixed, the signal generator is formed by winding a signal coil around an iron core having a drum pole part, and the inner periphery of the recess or hole of the magnetic pole component is For an internal combustion engine, wherein an adjacent peripheral area is unmagnetized, and only the area of the magnetic pole component excluding the peripheral area is magnetized in a direction perpendicular to the axial direction of the rotating body. Signal generator.