JPS6219092Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a magnet generator having an ignition signal generator for use in a non-contact ignition device.

FIG. 1 shows a conventional magnet generator. In the figure, 1 is a bowl-shaped flywheel driven by the engine, 2 is four first magnets fixed at equal intervals inside the flywheel 1, and 3 is a boss connected to the shaft of the engine. The boss is integrally fixed to the flywheel 1 with rivets, and this boss and the flywheel 1 constitute a rotating body. 4 is an I-shaped core installed to face the first magnet 2 and the boss 3; 5 is a signal coil wound around the core 4; and 6 is a generator installed to face each of the first magnets 2. It is electronic and consists of an iron core 6a and a power generating coil 6b which serves as an ignition power source or a lighting power source.

As is well known, the operation of this conventional device is such that when the flywheel 1 is rotated by the engine via the boss 3, the first magnet 2 is rotated. A voltage is generated, and the core 4 also receives a rotating magnetic field from the first magnet 2 to the boss 3, and the magnetic flux changes as it flows through the core 4, so the signal coil 5 receives a rotating magnetic field that is synchronized with the rotation as shown in FIG. A signal voltage waveform is generated.

As described above, since this conventional device has a four-pole structure, when the flywheel 1 rotates once, the ignition signal voltage is generated twice in the signal coil 5 as shown in FIG. However, normally an engine only needs to ignite once per revolution, and if the ignition signal voltage is generated twice per revolution, various problems will occur. That is, by igniting twice at 180-degree symmetrical angular positions during one revolution of the engine, for example, 4
In cycle engines, ignition occurs during the suction stroke other than the normal compression stroke, and in 2-stroke engines, especially outboard motors, the ignition timing is adjusted to lower the rotation speed of the 2-stroke engine for purposes such as trolling. It is sometimes set after top dead center, but in this case as well, ignition takes place during the intake stroke, which has a negative effect on the engine, particularly resulting in a drop in output.

This idea was made in order to eliminate the above-mentioned drawbacks.The core is provided with a winding part perpendicular to the direction of magnetic flux flowing from the first magnet fixed inside the flywheel, and the signal coil is attached to this winding part. By winding the magnet, the signal coil generates an ignition signal that is not affected by changes in the magnet from the first magnet, and provides a highly reliable magnet generator with a simple configuration and excellent strength. be.

Hereinafter, a detailed explanation will be given based on the embodiment shown in FIG.
In the figure, a pair of recesses 3a, 3b are formed on the outer circumferential surface of the cylindrical portion of the boss 3 at a predetermined interval in the axial direction, and furthermore, a pair of recesses 3a, 3b are formed on the central bottom surface of the recesses 3a, 3b, which are larger than the recesses 3a, 3b. Shallow positioning hole 3
c, 3d are formed. One magnet 7 and the other magnet 7 constituting the second magnet are fitted and attached to these positioning holes 3c and 3d. These magnets 7, 8 are cylindrical. 9 is to prevent magnets 7 and 8 from flying out due to rotational force.
In addition, for the purpose of protection from external forces etc., the recesses 3a and 3b are
a non-magnetic ring press-fitted into the boss 3 to cover the
10 is a pair of magnetic pole parts 10a, 10b and a winding part 10
The pair of magnetic pole parts 10a and 10b face one magnet 7 and 8 through a gap and a ring 9, and the magnets 7 and 8
The winding portion 10c is arranged so as to receive a change in the magnetic velocity of
The boss 3 is arranged parallel to the axial direction of the boss 3 so as to be orthogonal to the boss 3. Reference numeral 11 denotes a signal coil 11 wound around the winding portion 10c of this core 10.

The other magnets 7 and 8, which are the second magnets, are installed and fixed at one position on the boss 3 where an ignition signal is generated to the signal coil 11 in accordance with the ignition timing of the engine.

Now, in the operation of this embodiment, as the crankshaft of the engine rotates, the boss 3 and the other magnets 7 and 8 also rotate, so that the pair of magnetic pole parts 10a and 10b of the core 10 8, the magnetic flux flowing through the winding part 10c of the core 10 is maximum, and at a position where the pair of magnetic pole parts 10a, 10b do not face the magnets 7, 8, the magnetic flux becomes zero, so that the rotation of the engine The winding portion 10 of the core 10 in synchronization with
The flux linkage of c changes as shown in Figure 4a. Therefore, an ignition signal voltage as shown in FIG. 4b is generated in the signal coil 11 based on the above-mentioned change in interlinkage magnetic flux. As described above, the ignition signal voltage is generated in the signal coil 11 once per revolution of the engine. Further, since the other magnets 7 and 8 can be attached to any arbitrary position on the boss 3, the phase relationship between the first magnet 2 and the generator 6 can be set arbitrarily, and the requirements of the engine can be immediately met. Moreover, the signal coil 11 generates electricity in response to a change in magnetic flux in a direction perpendicular to the direction 12 of magnetic flux flowing from the first magnet 2 . That is, since the signal coil 11 is wound around the winding portion 10c of the core 10 that is perpendicular to the magnetic flux flow direction 12 from the first magnet 2, it is less susceptible to changes in the magnetic flux of the first magnet 2, and the ignition signal has a good S/N ratio. It has the advantage of providing voltage.

As described above, according to this embodiment, even if the ignition signal generation section having the signal coil 11 is arranged inside the flywheel 1, the signal coil 11 is not affected by the magnetic flux change of the first magnet 2 and is connected to the second magnet. On the other hand, since it receives only changes in the magnetic flux of the other magnets 7 and 8, it is possible to generate a sufficiently large ignition signal only once per revolution of the engine, and the engine can be ignited accurately at the regular ignition timing. , and stable ignition action can be obtained. Further, the configuration for this purpose can be easily achieved by simply making the winding portion 10c of the core 10 orthogonal to the magnetic flux flowing direction 12 from the first magnet. In addition, since the other magnets 7 and 8 are located inside the outer peripheral surface of the boss 3, there is no protruding part and the size can be reduced in the radial direction, and the non-magnetic ring 9 can be easily and firmly attached by press-fitting. can. Furthermore, since the concave portions in which the magnets 7 and 8 on one side and the other side are provided are closed by the non-magnetic ring 9, it is possible to protect the magnets 7 and 8 on the one side and the other side. , 8 are damaged, the broken pieces of one or the other magnets 7, 8 can be prevented from scattering, and damage to other members can also be prevented.

Furthermore, the positioning holes 3c and 3d are connected to the recesses 3a,
By making the depth smaller than the depth of magnet 7,
The leakage magnetic flux flowing from one pole of the signal coil 8 to the other pole through the boss 3 can be reduced, and a decrease in the output of the signal coil 11 can be prevented.

As explained above, this invention provides a recess on the outer circumferential surface of the boss and a positioning hole shallower than the recess.
The pair of second magnets are each positioned by the positioning holes, and the winding portion of the core around which the signal coil is wound is perpendicular to the direction of magnetic flux flowing from the first magnet fixed inside the flywheel. place,
Since the winding part is configured to apply magnetic flux changes from a pair of second magnets, it is possible to generate an ignition signal with an excellent S/N ratio and a sufficiently large ignition signal once per rotation with an extremely simple and inexpensive configuration. In addition, a highly reliable magnet generator with excellent strength can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a conventional device, and FIG.
FIG. 3 shows the voltage waveform generated in the signal coil 5 of the device.
The figure is a cross-sectional view showing one embodiment of the invention, and Fig. 4 is a waveform diagram showing the magnetic flux waveform and voltage waveform obtained by the device of the invention. In the figure, 1 is a flywheel, 2 is a first magnet, 3 is a boss, 3a and 3b are recesses, 3c and 3d are positioning holes, 6 is a generator, 7 and 8 are second magnets,
9 is a non-magnetic ring, 10 is a core, 10a, 10b
A magnetic pole portion is indicated by 10c, a winding portion is indicated by 11, and a signal coil is indicated by 12. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A boss having a cylindrical portion coupled to the shaft of the engine, a pair of recesses formed on the outer circumferential surface of the cylindrical portion, and a pair of positioning holes formed on the bottom surface of the recess and shallower than the recess; a flywheel integrally fixed to the boss; a first magnet fixed inside the flywheel facing the cylindrical portion of the boss;
A generator that generates electricity in response to changes in magnetic flux from the first magnet, a pair of second magnets that are fitted into the positioning holes of the boss and disposed within the recess, and A non-magnetic ring member press-fitted along the recess to cover the recess and support the second magnet, a pair of magnetic pole parts facing the second magnet via the ring member, and a magnetic flux from the first magnet. A magnet generator comprising: a core having orthogonal winding portions; and a signal coil wound around the winding portion of the core and generating an ignition signal in response to changes in magnetic flux from the second magnet.