JPS6219093Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an ignition signal generator used in a contactless ignition device.

As a conventional device of this type, one shown in FIG. 1 is known.

In the figure, 1 is a bowl-shaped flywheel made of a magnetic material that is rotationally driven by the engine, 2 is a magnet attached to this flywheel 1 and used to generate power output for ignition or lighting, and 3 is a flywheel. A cylindrical boss made of a magnetic material is integrally connected to the flywheel 1 by a rivet 4, and is fitted onto the output shaft of the engine, and the flywheel 1 is rotationally driven by the engine via the boss 3. 5 is a magnet fixed to the outer periphery of the boss 3; 6 is a U-shaped core; one end faces the magnetic pole of the magnet 5 with a gap in between; the other end faces the outer periphery of the boss 3 through a gap; and face each other. Reference numeral 7 denotes a signal coil wound around this core 6, which together with the core 6 constitutes a generator that generates an ignition signal.

The operation of this device is such that when the magnet 5 rotates as the engine rotates, the core 6 receives changes in the magnetic flux of the magnet 5.
Signal coil 7 generates the ignition signal.

By the way, in such conventional devices, the magnet 5 is usually attached to the outer periphery of the boss 3 with adhesive, so if the adhesive is insufficient, it may move or move.
Furthermore, it had the disadvantage that it could fall off the boss 3.

Another drawback is that it is extremely difficult to position the magnet 5 with respect to the outer periphery of the boss 3, and the installation requires skill. Moreover, since the entire magnet 5 is exposed, there is a risk that the magnet 5 may chip, crack, or crack due to external force during transportation or use, and if the magnet 5 cracks, it may fly off and cause danger. There were flaws.

This idea was made to solve the above-mentioned drawbacks, and it allows the installation of magnets with a small and simple structure, prevents damage to the magnets, prevents the magnets from scattering, and provides sufficient signal strength. The present invention provides an ignition signal generator that can obtain output.

Hereinafter, a detailed description will be given based on the embodiment shown in FIGS. 2 to 4.

8 is a cylindrical magnet, and 9 is a circular positioning hole formed on the cylindrical outer circumferential surface of the boss 3, and has approximately the same diameter so that the cylindrical magnet 8 can be fitted therein.
Reference numeral 10 denotes a relief hole formed in the boss 3 concentrically with this positioning hole 9 and having a large diameter, and the depth of the positioning hole 9 is configured to be smaller than the depth of this relief hole. There is. A ring 11 is a non-magnetic member that closes the opening of the relief hole 10 and supports the magnet 8. The ring 11 is made of stainless steel, brass, etc., and is formed into a cylindrical shape so that it can be press-fitted onto the entire outer periphery of the boss 3. There is. Reference numeral 12 denotes a U-shaped core, one end and the other end of which face the magnetic pole of the magnet 8 and the outer periphery of the boss 3 via a gap and a ring 11, respectively. Reference numeral 13 denotes a signal coil wound around the core 12, which together with the core 12 constitutes a generator that generates an ignition signal. 14 is an adhesive filled in the escape hole 10. The other configurations are the same as those of the conventional device, and their explanation will be omitted.

By configuring as described above, the cylindrical magnet 8 is positioned simply by fitting into the positioning hole 9 of the boss 3, so the work of attaching the magnet 8 to the boss 3 is extremely easy, and the size is small. Moreover, if the magnet 8 is magnetized in advance, temporary fixing becomes possible by the magnetizing force. Furthermore, by making the escape hole 10 larger than the diameter of the magnet 8 and making the part buried in the positioning hole 9 shallower, leakage from one magnetic pole of the magnet 8 through the boss 3 to the other magnetic pole can be prevented. The magnetic flux can be reduced, and therefore, it is possible to suppress a decrease in the magnetic flux flowing through the core 12, and a sufficient output can be obtained from the signal coil 13.

Note that the ring 11 may have a width that completely covers the magnetic pole face of the cylindrical magnet 8 and the relief hole 10, but in this embodiment, the ring 11 is formed in a cylindrical shape, and the cylindrical A ring 11 is press-fitted into the boss 3 and covers the entire outer peripheral surface of the boss 3. Therefore, the magnet 8 is not directly subjected to external force, and chipping, cracking, cracking, etc. of the magnet 11 can be reliably prevented, and accidents such as the magnet 8 flying off from the boss 3 due to centrifugal force can also be reliably prevented. . Further, although this cylindrical ring 11 is made of a non-magnetic material, its thickness is extremely thin, so that the magnet 8 can be connected to the core 12.
Also, the magnetic resistance of the magnetic circuit to the boss 3 does not become large, and therefore a sufficient ignition signal can be obtained.

Furthermore, since the adhesive 14 securely holds the magnet 8 in the relief hole 10 that is closed by the ring 11, even if the magnet breaks due to vibration or the like, fragments will not be scattered, and the magnet 8 will not be scattered. Since sufficient effective magnetic flux can be obtained, the operation of the ignition signal generator is not affected.

In the above embodiment, the magnet 8 is attached to the boss 3, but a similar structure can be used for any rotating body that rotates with the engine, such as the outer periphery of the flywheel 1, and similar effects can be obtained. It will be done.

Further, the magnet 8 may be fixed to the positioning hole 9 with an adhesive, and the ring 11 may have a shape other than a cylindrical shape that covers only the opening of the relief hole 10. Further, each hole 9, 11 of the magnet 8 is not limited to a cylindrical shape, a circular shape, etc., and may have any shape.

As explained above, this invention allows the magnet to be easily attached to a rotating body with a small and simple configuration.
Moreover, it prevents the magnet from cracking or scattering due to external force.
Even if the magnet were to break during operation, it would not affect the operation, and furthermore, it has excellent practical effects, such as being able to effectively utilize magnetic flux to obtain a sufficiently large ignition signal.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional device, FIG. 2 is a sectional view showing an embodiment of the present invention, FIG. FIG. 3 is a plan view of the escape hole 10. FIG. In the figure, 1 is the flywheel, 2 is the magnet, and 3
is a boss, 4 is a rivet, 8 is a magnet, 9 is a positioning hole, 10 is an escape hole, 11 is a ring, 12 is a core,
13 is a signal coil, and 14 is an adhesive. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A rotating body rotationally driven by an engine, an escape hole formed on the outer peripheral surface of this rotating body, a positioning hole provided at the bottom of the escape hole and shallower and smaller in diameter than the escape hole, and a positioning hole that fits into the positioning hole. an ignition signal generating magnet that is fitted together and has a gap between it and the side surface of the escape hole and is disposed inside the outer peripheral surface of the rotating body; the ignition signal generating magnet and the side surface of the escape hole; An adhesive filled in the gap, an annular non-magnetic member press-fitted along the outer peripheral surface of the rotating body and closing the opening of the relief hole, and a rotating magnetic field based on the ignition signal generating magnet. Ignition signal generator with a generator that generates an ignition signal.