JPH028483B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal generator including two magnet-generated signal generators in a housing.

This type of signal generator includes a housing; a drive shaft rotatably supported in the housing;
a signal rotor that is attached to the drive shaft within the housing and has one protrusion on its outer peripheral surface;
The stator includes an iron core that is installed in the housing and can face the protrusion of the signal rotor with a predetermined gap therebetween, a coil wound around the iron core, and a permanent magnet connected to the iron core. a first signal generator; a plurality of signal generators, for example, four signal generators attached to the drive shaft within the housing;
a signal rotor having a plurality of protrusions; an iron core installed in the housing and facing the protrusion of the signal rotor with a predetermined gap; a coil wound around the core; a second stator comprising a stator having coupled permanent magnets;
Some are equipped with a signal generator.

Since the first signal generator has one protrusion on the signal rotor, it faces the iron core once during one rotation of the drive shaft and generates one output signal _P1 as shown in Figure 3a. On the other hand, since the second signal generator has four protrusions on the signal rotor, they face the iron core once per rotation of the drive shaft and produce four outputs as shown in Figure 3b. Generate signal P ₂ . In this case, in both signal generators, the drive shaft is used as part of the magnetic path to form the magnetic path, so when the first signal generator is not generating an output signal, the second signal generator is When output signals are generated, those output signals leak to the first signal generator side and appear as a noise signal pn.

In the first signal generator, the operating voltage level V ₁ is set slightly higher than the zero voltage level in order to minimize the time lag.
When the noise signal pn appears within the operating voltage level of the first signal generator, there is a problem in that the first signal generator malfunctions upon sensing the noise signal.

In view of the above, the present invention sets the voltage level between the output signals of the first signal generator outside its operating voltage level, causes the noise signal to appear at that voltage level, and causes the first signal generator to malfunction. It is an object of the present invention to provide the signal generating device which avoids the above.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a housing, which consists of a housing body 2 made of aluminum die-cast and a cap 3 made of synthetic resin. A pair of upper and lower bearings 4 ₁ and 4 ₂ are fitted, and the drive shaft 5 is rotatably supported by these bearings 4 ₁ and 4 ₂ .

A driven gear 6 is fixed to the end of the drive shaft 5 that protrudes from the bearing tube 2a, and a drive gear (not shown) fixed to the camshaft of the internal combustion engine meshes with the driven gear 6, so that the drive shaft 5 is driven by the cam. It is designed to be driven by a shaft.

Inside the housing body 2, around the drive shaft 5, first and second signal generators G ₁ , G ₂ of a magnetic power generation type are arranged.
are arranged in two levels, upper and lower.

The first signal generator G ₁ generates a signal for detecting engine rotation speed or crank position, and connects a signal rotor 7 fitted to the inner end of the drive shaft 5 and a signal rotor fixed to the housing body 2 It consists of a stator 9 provided on a support plate 8. The stator 9
A permanent magnet plate 10 placed on a support plate 8, a coil holding plate 11 placed thereon, and an iron core 13 protruding from a projecting piece 12 of the coil holding plate 11.
and a coil 14 fitted into the iron core 13, and the permanent magnet plate 10 and coil holding plate 11 are
They are fixed to the support plate 8 by fixing screws 15 passing through them.

The protruding end of the iron core 13 from the coil 14 may face one protrusion 7a on the outer peripheral surface of the signal rotor 7 with a predetermined gap therebetween.

The signal rotor 7 rotates clockwise together with the drive shaft 5 as shown in FIG.
The gap between the outer circumferential surface and the iron core 13 can gradually increase as the iron core 13 rotates.

The second signal generator G ₂ generates, for example, a signal for fuel injection or ignition of the engine, and is connected to a signal rotor 16 fitted to the drive shaft 5 adjacent to the support plate 8 and fixed to the housing body 2. support plate 17
The stator 18 is fixed to the stator 18. The stator 18 is a permanent magnet plate 19 placed on the support plate 17.
, a coil holding plate 20 placed thereon, an iron core 22 protruding from the projecting piece 21 of the coil holding plate 20, and a coil 23 fitted to the iron core 22. 20 are fixed to the support plate 17 by fixing screws 24 passing through them.

The protruding ends of the iron core 22 from the coil 23 can face the four protrusions 16a on the outer peripheral surface of the signal rotor 16 in sequence with a predetermined gap therebetween.

Next, the operation of this embodiment will be explained. When the engine is operated and both signal rotors 7 and 16 are rotated by the camshaft via the drive shaft 5 in the clockwise direction in _FIG . A magnetic flux is formed between the permanent magnet plate 10 → support plate 8 → drive shaft 5 → signal rotor 7 → iron core 13 → coil holding plate 11 → permanent magnet plate 10, and then the protrusion 7a intersects with the iron core 13. As the magnetic flux changes due to the difference, a pulse-like voltage is generated in the coil 14, and the number of pulse-like voltages is generated once at a predetermined rotational position per one revolution of the engine's camshaft, so this voltage signal By detecting this, the engine speed or crank position can be determined. On the other hand, in the second signal generator _G2 , when each projection 16a of the signal rotor 16 faces the iron core 22 in sequence, the permanent magnet plate 19→support plate 17→drive shaft 5→signal rotor 16→iron core 22→coil holding A magnetic flux is formed between the plate 20 and the permanent magnet plate 19, and then the protrusion 1
6a and the iron core 22 causes the magnetic flux to change, so that a pulse-like voltage corresponding to each cylinder of the engine is generated in the coil 23. Therefore, this voltage signal can operate a fuel injection device, an ignition device, etc.

In the first signal generator _G1 , when the protrusion 7a of the signal rotor 7 faces the iron core 13 and moves away from it, the gap between the outer circumferential surface of the signal rotor 7 and the iron core 13 does not suddenly increase, but gradually increases.
The voltage level V ₂ of the first signal generator G ₁ between the first output signal P ₁ and the next output signal P ₁ is higher than the zero voltage level by ΔV, so that both output signals P ₁ , P ₁ , the noise signal Pn caused by the output signal _P2 of the second signal generator _G2 appears at the voltage level _V2 , so the operating voltage level of the first signal generator _G1 is set to the zero voltage level. and the lower limit voltage of the noise signal Pn.
It is possible to avoid the problem that the signal generator _G1 senses the noise signal Pn and malfunctions.

As described above, according to the present invention, the shape of the outer peripheral surface of the signal rotor of the first signal generator excluding the protrusion is formed such that the gap between the outer peripheral surface and the iron core can gradually increase as the signal rotor rotates. Therefore, it is possible to set the voltage level of the first signal generator between the first output signal and the next output signal outside the operating voltage level of the first signal generator, so that the voltage level between the two output signals In this method, a noise signal caused by the output signal of the second signal generator is caused to appear at the voltage level, and malfunction of the first signal generator due to the noise signal can be prevented.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional side view of one embodiment of the present invention;
The figure is a plan view showing the relationship between the signal rotor and the iron core, Figure 3a is an output signal waveform diagram of the conventional first signal generator, Figure 3b is an output signal waveform diagram of the second signal generator, FIG. c is an output signal waveform diagram of the first signal generator in the present invention. _G1 , _G2 ...First and second signal generators, 1...Housing, 5...Drive shaft, 7...Signal rotor, 7a...Protrusion, 9...Stator, 10...
Permanent magnet plate, 13... Iron core, 14... Coil, 1
6...Signal rotor, 16a...Protrusion, 18
... Stator, 19 ... Permanent magnet plate, 22 ... Iron core, 23 ... Coil.

Claims (1)

[Claims] 1 a housing; a drive shaft rotatably supported by the housing; a signal rotor that is attached to the drive shaft within the housing and has one protrusion on its outer peripheral surface; and a signal rotor installed within the housing; A magnet-powered first signal generator comprising an iron core that can face the protrusion of the signal rotor with a predetermined gap therebetween, a coil wound around the iron core, and a stator having a permanent magnet connected to the iron core. a signal rotor that is attached to the drive shaft within the housing and has a plurality of protrusions on its outer peripheral surface; a signal rotor that is installed within the housing and has a predetermined gap with the protrusions of the signal rotor; A signal generating device comprising a magnet-powered second signal generator comprising an iron core that can face each other, a coil wound around the iron core, and a stator having a permanent magnet connected to the iron core. A signal generating device, wherein an outer circumferential surface of the signal rotor of the generator, excluding the protrusion, is shaped so that a gap between the outer circumferential surface and the iron core can gradually increase as the signal rotor rotates.