JPH0640435Y2 - Multi-pole magnet generator for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a multi-pole magnet generator for an internal combustion engine used in an ignition device for an internal combustion engine.

[Conventional technology]

Conventionally, in a multi-pole magnet generator, the negative half-wave output of an ignition power supply coil is used as an ignition signal to
Since it is ignited once per revolution, 3
Some poles of the salient pole, which are continuously magnetized to the same pole or more and have the ignition power supply capacitor charging coil wound thereon, have a larger angle than the pole per pole of the magnet (for example,
JP-A-58-248369).

[Problems to be solved by the invention]

However, in the above-mentioned conventional one, it is common to arrange a plurality of permanent magnets, which are magnetized separately in the circumferential direction in the circumferential direction, with three or more poles respectively separated by a gap. In such a case, the same-polarized portion is formed across two permanent magnets, and the magnetic pole magnetized at the end of the permanent magnet has a smaller magnetic force than the magnetic pole at the central portion. Noise voltage is generated in the charging coil for the ignition power supply capacitor in the gap,
This noise voltage causes a problem of erroneous ignition.

Therefore, the present invention is intended to prevent erroneous ignition even if the same-polarized portion is formed across two permanent magnets.

[Means for solving problems]

Therefore, the present invention has a magnet rotor having a plurality of permanent magnets, which are rotationally driven in a predetermined rotation direction by an internal combustion engine and are arranged in a ring shape with gaps formed in adjacent portions in the circumferential direction, and a magnetic pole at the tip. A plurality of salient poles, one of which is formed as an ignition salient pole whose angle is larger than that of the other salient pole, and at least one of which is wound around the ignition salient pole. An ignition power source capacitor charging coil, and a stator having an output coil wound around the other salient pole, and the plurality of permanent magnets respectively have a predetermined angle range along the rotation direction as one magnetic pole. Has a range of three or more poles, and an alternating magnetized portion in which different magnetic poles alternately appear on the circumference along the rotation direction and a homopolar continuously magnetized portion in which the same magnetic pole appears continuously in three or more poles. Wear to split The magnet is magnetized and is arranged such that only one gap is located in the homopolar continuous magnetized portion, and the front is located forward of the gap in the homopolar continuous magnetized portion in the rotation direction. Magnetic poles for one or two poles forming the homopolar continuous magnetized portion are magnetized to the permanent magnet, and the homopolar continuous magnetized portion is provided to the rear permanent magnet located behind the gap in the rotation direction. The technical means of a multi-pole magnet generator for an internal combustion engine, characterized in that the remaining magnetic poles forming the magnet are magnetized and the homopolar continuous magnetized portion ends in the rear permanent magnet.

[Action]

 The operation of the present invention described above will be described.

According to the multi-pole magnet generator for an internal combustion engine of the present invention, when the magnet rotor is driven to rotate by the internal combustion engine, a voltage is induced in the output coil provided in the stator and also in the capacitor charging coil for the ignition power source. One rotation of the magnet rotor induces one positive voltage and one negative voltage.

Here, one of the positive voltage and the negative voltage is used for charging the capacitor, and the other is used for the ignition signal, which is provided for inducing a voltage in the capacitor charging coil for the ignition power supply. Since the pole-continuous magnetized portion has the only gap between the magnets in it, the magnetic flux decreases in this gap, and the capacitor charging coil for the ignition power supply has the same direction as the voltage for the ignition signal. Noise voltage is generated. However, according to the structure of the present invention, since the magnetic poles for one or two poles forming the homopolar continuous magnetized portion are formed in the permanent magnet in front of the gap in the rotational direction, the homopolar continuous magnetized portion rushes into the homopolar continuous magnetized portion. Since a noise voltage is generated immediately after that, the noise voltage is pulled in by the half-wave output of the capacitor charging voltage generated when the magnetic pole continuously enters the magnetized portion, and the noise voltage is suppressed. Moreover, since the continuously magnetized portion of the same pole is terminated by the permanent magnet located behind the gap in the rotational direction, the noise voltage is generated only in the gap. As described above, according to the present invention, the influence of the noise voltage generated in the gap between the permanent magnets in the homopolarized magnetized portion on the ignition signal is suppressed.

[Effect of device]

According to the present invention described above, it is possible to suppress the influence of the noise voltage generated in the gap between the permanent magnets in the continuously magnetized portion of the same pole on the ignition signal. The ignition operation can be performed with a simple configuration without malfunction.

〔Example〕

The present invention will be described below with reference to the embodiments shown in the drawings. FIG. 1 is a partial cross-sectional plan view of a multi-pole magnet generator showing an embodiment of the present invention, in which 1 is a bowl-shaped rotor made of a magnetic material and 2a to 2d are gaps formed in adjacent portions in the circumferential direction. Then, four permanent magnets are fixed to the inner peripheral surface of the magnet 1 at equal intervals. Each of the magnets 2a to 2d is divided into three poles in the circumferential direction, and two of the permanent magnets 2a and 2b are magnetized. 5 poles are continuously magnetized to the S pole, and the same pole continuously magnetized portion is provided with 2 poles for the front magnet 2a in the rotation direction, and the remaining 3 poles are all for the rear magnet 2b. Except for the same-polarity continuously magnetized portion, N and S are alternately magnetized to become alternately magnetized portions.
The inner circumference of the magnet array shown in FIG. 1 is divided into the homopolar continuous magnetized portions and the alternating magnetized portions. Reference numeral 3 is a core forming a magnetic circuit, and ten salient poles 3b to 3k projecting at substantially equal intervals in the outer diameter direction.
And one ignition salient pole 3a. 4 is an ignition power supply capacitor charging coil wound around the salient pole 3a for ignition, 5 is an output coil used for charging a lamp or a battery, and the remaining 10 salient poles 3b to 3k are wound and connected in series. Has been done.
The rotor 1 and the magnets 2a to 2d are connected to a crankshaft of an internal combustion engine (not shown) and driven to rotate. The core 3 is fixed to the crankcase (not shown) of the internal combustion engine through a hole 31 by screwing or the like.

Further, among the salient poles 3a to 3k of the core 3, ten salient poles 3b to 3k provided at equal intervals have the same magnetic pole angle pitch of the magnet 30.
The salient poles 3b to 3k have a magnetic pole piece facing the magnetic poles of the magnets 2a to 2d at the tips.
The angle .theta.p per pole of .about.2d is smaller than 30.degree. In addition, the salient pole 3a for ignition has two salient poles 3b to 3k so that one salient pole is formed by two salient poles 3b to 3k.
45 ° to both salient poles 3b and 3k in the middle of 3b and 3k
The angle θc of the magnetic pole pieces facing the magnetic poles of the magnets 2a to 2d at the tip of the salient pole 3a for ignition is larger than the angle θp per magnetic pole of the magnets 2a to 2d θp = 30 °. 53
The size is about °.

The arrow in FIG. 1 indicates the rotation direction of the rotor 1.

FIG. 3 is an electric circuit diagram. 10, 13, 15 are rectifying diodes, 11 is an ignition capacitor, 12 is an ignition coil, 12a is its primary coil, 12b is its secondary coil, and 14 and 14a are resistors. ,
Reference numeral 16 is an ignition thyristor, and 17 is an ignition plug.

In the above configuration, when the rotor 1 rotates, the salient poles 3a of the capacitor charging coil 4 are set so that substantially two salient poles 3b to 3k of the output coil 5 become one pole, and the pole pieces thereof are arranged. Is larger than the angle per pole of the magnets 2a to 2d, the effective magnetic flux is linked to the coil 4 only when the same magnetism of the magnets 2a to 2d faces two or more consecutive magnetic poles.
In the portion where the magnetic changes are alternated between N and S, these adjacent magnetic poles are short-circuited by a wide magnetic pole piece, so that the effective magnetic flux does not become effective. Therefore, the magnetic flux change shown by (C) in FIG. 2 is used for ignition. A voltage shown by C in FIG. 2C is generated in the capacitor charging coil 4 by being generated in the salient pole 3a. Here, when the voltage indicated by V _c in FIG. 2 (C) generates a forward voltage in the coil 4, the diode 10 in FIG. 3 → the capacitor 11 → the ignition coil
12 primary coil 12a → diode 13 → ground → coil 4
In this circuit, the ignition condenser 11 is charged. Further, when the rotor 1 rotates and a negative voltage indicated by V _s in FIG. 2 (C) is generated in the coil 4, a current flows in the circuit of arm → resistor 14a, 14 → diode 15 → coil 4 to cause resistance 14 When the voltage between the terminals of, i.e., the gate-cathode voltage of the ignition thyristor 16 becomes equal to or higher than its trigger level, the thyristor 16 becomes conductive. When the thyristor 16 conducts in this way, the electric charge charged in the capacitor 11 is rapidly discharged in the circuit of the thyristor 16 → the primary coil 12a of the ignition coil 12 → the capacitor 11 to the secondary coil 12b of the ignition coil 12. A high voltage is generated and the spark plug 17 is ignited. By repeating the above operation, it is possible to obtain a non-contact ignition device that fires once per one revolution of the rotor 1.

Here, as shown in FIG. 1 (FIG. 2 (C)), the magnetized portions of the permanent magnets 2a to 2c that are continuously magnetized with the same polarity are magnetized as shown by φn in FIG. 2 (C). 2a,
The magnetic flux interlinking with the ignition salient poles 3a in the gap portion between 2b is slightly reduced only in the first half portion thereof. Thus, the capacitor charging coil 4 small noise voltage V _n Following positive voltage V _c as shown since the second diagram (C) is generated in a negative direction. Although this noise voltage V _n is generated in the low speed range, its value is very small, and as the engine speed increases, the value increases accordingly. However, the forward voltage V _c of the capacitor charging coil 4 is The inductance of causes the voltage waveform to lag as the engine speed increases,
In the medium speed range, the noise voltage V _n overlaps. Therefore,
The noise voltage V _n is the forward voltage V _c at rotational speeds higher than the medium speed range.
Is absorbed by the thyristor 16 and the noise voltage V _n
Will no longer be supplied to the gate. As described above, if the position where the noise voltage is generated (the position of the gap between the magnets 2a and 2b) comes immediately after the capacitor charging coil 4 charges the capacitor 11, the noise voltage V _n can be suppressed. .

2 (A) and 2 (B) show comparative examples of magnetized portions of the same polarity in the magnets 2a to 2c. FIG. 2 (A) shows the front magnet 2a.
Is magnetized to the S pole, and the magnet 2b behind it is magnetized to the S pole continuously in two poles. At this time, as shown by φn in FIG. The magnetic flux interlinking with is slightly reduced in the latter half. by this,
Since the noise voltage is generated in the negative direction after a while after the positive voltage is generated in the capacitor charging coil 4, this noise voltage cannot be suppressed at all, and the noise voltage causes the thyristor 16 to malfunction in the medium speed range. Figure 2 (B) shows 3
This is the case where the S pole is magnetized to the same pole across two magnets 2a to 2c. At this time, as indicated by φn in FIG. 2B, the magnetic flux interlinking with the ignition salient pole 3a is immediately after the leading edge. There is a slight decrease between the part and the part just before the trailing edge. As a result, a noise voltage V _n is generated in the negative direction immediately before the positive voltage V _c is generated in the capacitor charging coil 4 and immediately before the negative voltage V _s is generated. Voltage V _c
The noise voltage V _n generated immediately before the end of the noise generation is drawn by this positive direction voltage V _c , but the noise voltage V _n generated immediately before the negative direction voltage V _s is not suppressed at all, and this noise voltage Thyristor 16 malfunctions in the high speed range.

V _n A to V _n C of FIG. 4, the second view (A), (B), (C)
The noise voltage V _n in each magnetization state is shown with respect to the engine speed. In the embodiment of the present invention shown in FIG. 2C, the noise voltage V _n is the gate voltage of the thyristor 16. Although it can be maintained at a value sufficiently lower than the trigger level V _T , in the comparative example of FIGS. 2A and 2B, the noise voltage V _n
Becomes higher than the gate trigger level V _{T of} the thyristor 16, and the thyristor 16 malfunctions.

Although the magnets 2a to 2d are separately magnetized into three poles in the above-described embodiment, they may be separately magnetized into four or more poles.

Further, in the above-described embodiment, the homopolar continuous magnetized portion has 5 poles, but it may be 3 poles or more, and preferably 1 pole or 2 poles more than the number of divided magnetized poles for one magnet. 1
It is preferable that all of the two magnets are magnetized to the same pole, and that the one or two poles at the rear end of the magnet in front of the magnet are also magnetized to the same pole continuously.

Further, in the case where the number of magnetized poles is 4 poles, in FIG. 2 (B), if continuous magnetization of the same pole is completed at the magnet 2b portion and the subsequent magnet 2c is started from the N pole. Even if only one pole at the rear end of the front magnet 2a is made to be the S pole, malfunction due to noise voltage can be prevented.

As described above, in the embodiment of the present invention, the positive voltage V _c for charging the capacitor is first generated in the capacitor charging coil 4 for the ignition power source, and then the negative voltage corresponding to the gap between the permanent magnets is generated. A directional noise voltage is generated only once, and then a negative voltage V _s for the ignition signal is generated. And
In this embodiment, since the permanent magnet located in front of the gap in the rotational direction is provided with the two S poles, the noise voltage is generated immediately after the forward voltage V _c , especially in the middle speed range or higher of the internal combustion engine. Since the noise voltage is drawn in and absorbed by the positive-direction power supply V _c that is previously generated in the ignition power supply capacitor charging coil, the noise voltage in the same direction as the negative-direction voltage V _s for the ignition signal is suppressed. Even if the same-polarized portion is formed over the permanent magnet, there is an excellent effect that erroneous ignition can be surely prevented.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional plan view showing an embodiment of the generator of the present invention, FIGS. 2A and 2B are magnetized state diagrams of magnets in two comparative examples, and waveform diagrams of respective parts corresponding thereto. 2C is a magnetized state diagram of the magnet in the above embodiment and waveform diagrams of respective parts corresponding thereto, FIG. 3 is an electric circuit diagram showing an ignition device applied to the embodiment, and FIG.
The figure is a rotation speed-noise voltage characteristic diagram in the above-mentioned embodiment and each comparative example. 1 ... Rotor, 2a-2d ... Permanent magnet, 3 ... Core, 3a-3k ... Salient pole, 4
… Ignition power capacitor charging coil.

Claims (3)

[Scope of utility model registration request] 1. A magnet rotor having a plurality of permanent magnets, which are rotationally driven in a predetermined rotation direction by an internal combustion engine, and are arranged in a ring shape with gaps formed in adjacent portions in the circumferential direction, and a magnetic pole at a tip. A plurality of salient poles, each of which is formed as an ignition salient pole whose angle is larger than that of the other salient pole, and at least one of which is provided so as to face the permanent magnet. And a stator having an output coil wound around the other salient pole, wherein the plurality of permanent magnets have a predetermined angle range along the rotation direction as one magnetic pole, Each has a range of three poles or more, and alternate magnetized portions in which different magnetic poles alternately appear on the circumference along the rotation direction, and homopolar continuous magnetized portions in which the same magnetic pole appears continuously in three or more poles. Magnetized to divide into In addition, the front permanent magnet is arranged such that only one gap is located in the homopolar continuous magnetized portion, and is located forward of the gap in the homopolar continuous magnetized portion in the rotation direction. Magnetic poles for one pole or two poles forming the homopolar continuous magnetized portion are magnetized, and the homopolar continuous magnetized portion is formed on the rear permanent magnet located behind the gap in the rotation direction. The multi-pole magnet generator for an internal combustion engine, characterized in that the remaining magnetic poles are magnetized and the homopolar continuous magnetized portion is completed in the rear permanent magnet. 2. A utility model registration claim characterized in that more magnetic poles than the number of circumferentially magnetized magnets of one of the permanent magnets continuously appear in the homopolar continuously magnetized portion. A multi-pole magnet generator for an internal combustion engine according to the item. 3. A utility model characterized in that the number of magnetic poles in the circumferential direction for one permanent magnet is three, and five magnetic poles appear continuously in the homopolar continuously magnetized portion. A multi-pole magnet generator for an internal combustion engine according to claim 2.