JPS62201043A - Inductor rotating type signal generator - Google Patents

Abstract

PURPOSE:To prevent the induction of a noise voltage caused by a deformed section, by forming a flux change reducing pole section close to the deformed section in the shape of producing a flux change which almost cancels the flux change generated at a signal ringer by the deformed section. CONSTITUTION:A rotor 1 is composed with an inductor pole section 3 provided on the outside circumference of a flywheel 2. When the rotor 1 rotates, a signal voltages is induced to a signal coil wound around an iron core 5 wherever the inductor pole section 3 passes through the position of the iron core 5 having a pole section of a signal ringer 3. In the meantime, on the circumferential wall of a flywheel 2 a hole 3c to fit a whirl-stop jig in connecting and disconnecting the flywheel 2. Further, a flux change reducing pole section 20 is provided to the position adjacent to this hole 2c which is composed of a projection in the shape of almost cancelling the flux change generated at a signal ringer 4 by the hole 2c. On this account, the induction of a noise voltage to a signal coil by the hole 2c (deformed section) is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inductor rotating signal generator suitable for obtaining a signal for determining the ignition timing of an ignition device for an internal combustion engine.

[Prior Art] As an inductor rotating signal generator that obtains a signal that determines the ignition timing of an ignition system for an internal combustion engine, many are used that have a rotor configured using a flywheel attached to an R lever. . Figures 3A and 3B show an example of this. In these figures, 1 is a cup-shaped iron flywheel 2 with an inductor magnetic pole part 3 formed on the outer periphery of an arcuate protrusion. 4 is a signal generator. The flywheel 2 has a well-known structure that is commonly used to constitute the rotor of a magnet generator. A flanged boss 2a is fixed to the bottom wall of the flywheel 2 with a rivet 2b. is fitted onto the output shaft of an internal combustion engine. Although not shown, a permanent magnet is attached to the inner periphery of the flywheel, and the permanent magnet and the flywheel 2 constitute a rotor of the magnet generator.

The signal generator 4 includes an iron core 5 having a magnetic pole part 5a facing the inductor magnetic pole part 3, a signal generator coil 6 wound around this iron core, and one vA pole in contact with the iron core 5. A signal magnet 7 that flows a magnetic flux and a bracket part 8 that is in contact with the other magnetic pole of the magnet 7 are enclosed by a case or a molded part 9, and the bracket part 8 that is magnetically coupled to the magnet 7 acts as a flywheel. The nearby generator is attached to the part (not shown).

) is fixed with screws.

When the flywheel 2 rotates due to opening and opening rotation, each time the inductor magnetic pole part 3 passes the position of the magnetic pole part 5a of the signal generator 3, the signal magnet 7→iron core 5→flywheel 2→bracket part 8 →A change occurs in the magnetic flux flowing in the path of the signal magnet 7, and a signal voltage is induced in the signal coil.

4A and 4B show another example of a conventionally used inductor rotating signal generator. In this example, an inductor magnetic pole portion 3' consisting of a concave portion is provided on the outer periphery of the flywheel 2-. It is being In addition, in this example, the boss part 2 of the flywheel
a' is integrally provided on the bottom wall portion of the flywheel 2'. Note that 10 is a permanent magnet fixed to the inner periphery of the flywheel 2', and 11 is an electric wire that constitutes a magnet generator together with a magnet rotor made up of the flywheel 2 and the permanent magnets 10.

[Problems to be Solved by the Invention] In addition to the inductor 3 or 3', an irregularly shaped part that changes the magnetic flux to the signal generator 4 may be provided near the peripheral wall of the flywheel attached to the internal combustion engine. There are many. For example, in the signal generator shown in FIGS. 3A and 3B, a hole 2C into which a detent tool is fitted when attaching or detaching the flywheel 20 is provided in the peripheral wall of the flywheel, and this hole 2C becomes an irregularly shaped part. When the hole 2C passes near the magnetic pole part 5a of the signal generator, a change is caused in the magnetic flux flowing through the iron core 5 of the signal generator 4, and a noise voltage is induced in the signal coil 6.

Furthermore, as shown in FIGS. 5A and 5B, when a ring gear 12 that engages the binion gear of the starter of the internal combustion engine is installed on the outer periphery of the bottom wall side of the flywheel 2' of the generator shown in FIG. , the teeth of this ring gear 12 become irregularly shaped portions, causing a change in magnetic flux in the signal generator 4, and causing a noise voltage in the signal coil 6.

As mentioned above, the noise voltage generated by the irregularly shaped part of the flywheel is generated at a different position from the normal signal generated by the inductor magnetic pole part 3 or 3-. Problems such as ignition operation occurring at a timing other than the ignition timing may occur, such as a reduction in engine output.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inductor rotating signal generator that eliminates the possibility of noise voltage generation.

Means for Solving the Problems] The present invention, as seen in FIG. 1 showing an embodiment thereof,
A rotor 1 configured by providing an inductor magnetic pole part 3 on the outer periphery of a flywheel 2, and a magnetic pole part 5a facing the inductor magnetic pole part 3.
The flywheel 2 includes a signal generator 4 equipped with a signal coil 6 wound around the iron core 5 and a permanent magnet 7 through which the magnetic flux of the iron core 5 flows. In an inductor rotation type signal generator having an irregularly shaped part 2c that causes a change in magnetic flux in the generator, the irregularly shaped part 2C
This prevents noise voltage from being induced.

Therefore, in the present invention, the magnetic flux change reducing pole part 20 is formed in the vicinity of the irregularly shaped part 2C, having a shape that causes a magnetic flux change that almost cancels out the magnetic flux change caused in the signal generator 4 due to the irregularly shaped part.

[Operation 1 of the invention] With the above structure, the magnetic flux change caused in the signal generator due to the irregularly shaped portion is canceled by the magnetic flux change generated by the magnetic flux change reducing pole portion, or at least the magnetic flux generated in the signal generator due to the irregularly shaped portion is reduced. Since the change can be made slight, it is possible to prevent problematic noise from occurring due to the presence of the irregularly shaped portion.

[Example] The present invention will be described in detail below with reference to the accompanying drawings.

1A to 1C show an embodiment in which the present invention is applied to the signal generator shown in FIGS. At a position adjacent to the hole 2C of No. 2, a magnetic flux change reducing pole portion 20 is provided, which is a projection having a shape that substantially cancels out the magnetic flux change caused in the signal generator 4 by the hole 2C. Other points are similar to the examples shown in FIGS. 3A and 3B.

In the signal generator shown in FIGS. 3A and 3B, the waveform of the magnetic flux φ flowing through the iron core 5 of the signal generator 4 as the flywheel 2 rotates with respect to the rotation angle θ is as shown by the solid line in FIG. 6A. This includes a magnetic flux change φ1 caused by the inductor magnetic pole portion 3 and a magnetic flux change φ2 caused by the hole 2C. The waveform of the voltage induced in the signal coil 6 by these changes in magnetic flux is as shown by the solid line in Figure 6B, and the voltage induced in this signal coil is equal to the normal signal voltage 1, 1 generated by the change in magnetic flux φ1, and the magnetic flux. and a noise voltage V2 caused by the change φ2.

On the other hand, if the magnetic flux change canceling pole part 20 is provided in a shape that generates a magnetic flux change φ2゛ that almost cancels out the magnetic flux change φ2 caused by the hole 2c (unusual shaped part) as in the present invention, this magnetic flux change φ2° acts to cancel the magnetic flux change φ2, so
The noise voltage ■2° becomes almost zero as shown by the broken line in FIG. 6B.

When the irregularly shaped portion is a hole or a recess, the magnetic flux change reducing pole portion 20 may be a protrusion, and when the irregularly shaped portion is a protrusion, the magnetic flux change reducing pole portion may be a hole or a recess. The specific shape and location of the magnetic flux change reducing pole part are determined by conducting experiments in which protrusions or recesses of various shapes are provided near the abnormally shaped part in question and the output waveform of the signal generator is observed. can do.

FIG. 2 shows an embodiment in which the present invention is applied when the ring gear 12 is attached to the outer periphery of the flywheel 2' as shown in FIG. A magnetic flux change reducing pole portion 20 is provided on the bottom surface of the portion 3'. The magnetic flux change reducing pole portion 20 is provided at a shallow valley portion 20a provided at a position corresponding to the tooth ridge portion 12a of the ring gear 12 and a shallow valley portion 20a provided at a position corresponding to the tooth valley portion 12b of the ring gear 12. It consists of a low mountain part 20b. The depth of the valley portion 20a and the height of the peak portion 20b are set to have an appropriate serration to produce a magnetic flux change that cancels the magnetic flux change caused in the signal generator 4 by the teeth of the ring gear. The height of the peak portion 20b is set to be sufficiently smaller than the depth of the recessed portion constituting the inductor magnetic pole portion 3'.

In the signal generator shown in FIG. 4, the waveform of the magnetic flux φA flowing through the iron core of the signal generator 4 is as shown in FIG. 7, and no noise signal is generated. However, when the ring gear 12 is attached to the flywheel 2 as shown in FIG. 5, fine pulsating magnetic flux changes occur due to the ring gear. That is, in a region of the outer peripheral surface of the flywheel 2' where the inductor magnetic pole part 3' is not provided and faces the magnetic pole part 5a of the signal generator, the magnetic pole part 5a and the outer periphery of the flywheel 2' Because the gap between the surfaces is small,
The magnetic flux emitted from the magnetic pole portion 5a is concentrated on the outer circumferential surface of the flywheel 2-, and hardly flows toward the ring gear 12 side. Therefore, although the ring gear's stiffness in this area is slight, in the area where the inductor magnetic pole part 3' faces the magnetic pole part 5a, the gap between the magnetic pole part 5a and the flywheel 2' becomes large. A large amount of magnetic flux flows to the ring gear 12 side, and many changes in magnetic flux due to the teeth of the ring gear 12 appear.

Therefore, the waveform of the magnetic flux φB of the signal generator of the signal generator shown in FIG. 5 becomes as shown by the solid line in FIG. This means that ripples are included in the magnetic flux changes that occur. When ripples are included in the magnetic flux φB of the signal generator in this way, a noise voltage 2 is generated in addition to the normal signal voltage v1, as shown in FIG. 7C.

On the other hand, if a magnetic flux change reducing pole part 20 is provided as in the embodiment shown in FIG. Therefore, the noise voltage (2) can be reduced to almost zero.

[Effect of the invention 1 As described above, according to the present invention, the magnetic flux change that occurs in the signal generator due to the irregularly shaped part other than the inductor polarization part provided on the flywheel is caused by the magnetic flux change reducing pole part. Since the change in magnetic flux can be canceled out or at least the change in magnetic flux caused in the signal generator due to the irregularly shaped portion can be made slight, there is an advantage that it is possible to prevent problematic noise from occurring due to the presence of the irregularly shaped portion.

[Brief explanation of drawings]

Figures 1 and B are a front view and a bottom view showing one embodiment of the present invention, respectively, Figure 1C is a 7-direction arrow view of Figure B, and
The figure is a perspective view showing the main part of the embodiment of the present invention, FIG. 3A
4A and B are a front view and a partially sectional bottom view of a conventional signal generator, respectively, and FIGS. 4A and 4B are a front view and a cross section taken along line A-A of another example of a conventional signal generator, respectively. figure,
A front view and B- showing an example in which a ring gear is attached to the flywheel of the signal generator shown in Fig. 4, respectively.
6 is a waveform diagram showing the magnetic flux waveform and signal voltage waveform of the signal generator in FIGS. 1 and 3, and FIG. 7 is a waveform diagram showing the signal generator in FIG.
FIG. 6 is a waveform diagram showing magnetic flux waveforms and signal voltage waveforms of the signal generators shown in FIGS. 4 and 5; FIG. 1...Rotor, 2.2'...Flywheel, 2C
... Hole (unusual shaped part), 3.3-... Inductor magnetic pole part, 4
...Signal generator, 5...Iron core, 5a...Magnetic pole part,
6...Signal coil, 7...Signal magnet, 12...
Ring gear, 12a... Mountain part of ring gear tooth (unusual part), 12b... Valley part of tooth of ring gear (unusual part),
20... Pole part for reducing magnetic flux change, 20a... Valley part, 2
0b...Yamabe. @1 Figure

Claims (1)

[Scope of Claims] A rotor configured by providing an inductor magnetic pole part on the outer periphery of a flywheel, an iron core having a magnetic pole part facing the inductor magnetic pole part, a signal coil wound around the iron core, and the iron core. a signal generator having a permanent magnet that causes a magnetic flux to flow, and the flywheel has an irregularly shaped part that causes a change in magnetic flux in the signal generator at a position different from the inductor magnetic pole part. In the shaped signal generator, a magnetic flux change reducing pole part having a shape that causes a magnetic flux change that almost cancels out the magnetic flux change caused in the signal generator by the irregularly shaped part is formed in the vicinity of the irregularly shaped part. Child-shaped signal generator.