JPS62225152A - Magneto-generator - Google Patents

Abstract

PURPOSE:To obtain high output characteristic in a low rotation range and suppress a temperature rise in a high rotation range, by providing the intermediate section of a stator coil with a change-over switch for switching the coilwinding direction to the forward direction or to the reverse direction. CONSTITUTION:A stator coil 3 is divided into a first coil 3a and a second coil 3b by a change-over switch 5 set at the intermediate section of the coil 3, and by switching the switch contact of the change-over switch 5, the same winding direction namely a forward winding state to be forward phase on the first coil 3a and the second coil 3b is contrived tc be switched to the reverse winding direction namely a reverse winding state to be reverse phase. By a rotational frequency detecting means 6 for detecting the rotational frequency of a fly- wheel, the change-over switch 5 is switched to the forward winding side in the low rotation range of the rotational frequency of the flywheel and to the reverse winding side in the high rotation range.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a magnet generator installed in an internal combustion engine of an automobile or the like.

[Prior Art and Problems to be Solved by the Invention] In general, this type of magnet generator uses a fixed-side magnet generator wrapped around the stator to supply load current for ignition and lighting of an internal combustion engine, battery charging, etc. It is constructed using a stator coil and a drive-side flywheel provided with a permanent magnet, and generates electricity by the rotation of the flywheel as one engine is driven. And in such a magnet generator.

There is a desire to be able to obtain high output characteristics even when the flywheel is rotating at low speeds. In order to meet this demand, the stator on the stationary side is made multipolar in a so-called star shape with coil windings extending radially to improve output characteristics.

However, although increasing the number of poles in the stator improves the output characteristics, it is necessary to reduce the wire diameter of the stator coil due to the restriction that the magnet generator cannot be made larger. For this reason, even if the output characteristics in the low rotation range can be improved by increasing the number of poles,
When the flywheel rotates at a high speed, the current density in the stator coil becomes high, causing a large temperature rise in the stator coil. As a result, the improvement of output characteristics through multipolarization is limited by the upper limit of temperature rise in the flywheel's high rotation range, and it is still not possible to fully meet the demand for higher output in the flywheel's low rotation range. There is a problem with this drawback.

[Means for solving the problem] In view of the above-mentioned circumstances, the present invention was devised for the purpose of providing a magnet generator that can eliminate these drawbacks. In a magnet generator using a stator coil on a fixed side and a flywheel on a driving side provided with a magnet, a changeover switch is provided in the middle of the stator coil that can change the winding direction forward or reverse, and the changeover switch is connected to the flywheel rotational speed detecting means so as to switch the rotational speed of the flywheel to the forward winding side in the low rotational speed range and to the reverse winding side in the high rotational speed range.

With this configuration, the present invention makes it possible to suppress the temperature rise in the high rotation range as much as possible even if the stator is multipolarized so that the output characteristics of the flywheel in the low rotation range are large. It is.

[Embodiment] Next, an embodiment of the present invention will be described based on the drawings. In the drawings, reference numeral 1 denotes a flywheel type magnet generator, and the generator 1 includes a stator 2 on the fixed side in which a plurality of winding parts 2a projecting radially are formed, and windings around the winding parts 2a. The flywheel 4 rotates in conjunction with the drive of an internal combustion engine (not shown). Everything is the same as before, including the fact that it is designed to generate electricity.

FIG. 2 shows a wiring diagram of the generator 1 including the stator coil 3. The stator coil 3 is divided into a first coil 3a and a second coil 3b by a changeover switch 5 provided in the middle. By switching the switch contacts 1 and 2 of the changeover switch 5, the first coil 3a and the second coil 3b (the number of turns of the first coil 3a is greater) are wound in the same direction, that is, in an order in which they become normal phase. It is possible to switch between a winding state and a reverse winding state in which the winding direction is reverse, that is, the phase is reversed. Furthermore, 6 is the flywheel 4
The detecting means 6 is connected to the changeover switch 5 and controls switching of the changeover switch 5 according to the rotational speed of the flywheel 4. That is, the rotation speed detection means 6 is
Rotation speed detection unit 6a that detects the rotation speed of the flywheel 4
and a control command section 6b that issues a control command to the changeover switch 5 based on the detection result, and when the rotation speed of the flywheel 4 is detected to be smaller than a preset value, When the changeover switch 5 is switched to the forward winding state side of the switch contact 1 and a rotation speed larger than the set value is detected, a switching control command is issued to switch the changeover switch 5 to the reverse winding state side of the switch contact 2. It is set. In addition, in the figure, 7 is a load part such as a light.

In the embodiment of the present invention configured as described above, the magnet generator 1 is connected to the flywheel 4 in conjunction with the drive of the internal combustion engine.
However, in the present invention, when the rotation speed of the flywheel 4 is in a lower rotation range than the set value.

Since the selector switch 5 is switched to the forward winding state, corresponding high output characteristics can be obtained.On the other hand, when the rotation speed of the flywheel 4 is in the high rotation range, the selector switch 5 is switched to the reverse winding state. Therefore, the output characteristic from the stator coil 3 is lower than that of the first coil 3a minus the second coil 3b.

In this manner, in the present invention, the stator coil 3
Since the coils b are connected in a sequentially wound state of the switch contact 1, the generated current has a high output characteristic that is the sum of the electromotive force generated by both the coils 3a and 3b. On the other hand, when the rotation of the flywheel 4 reaches a high rotation range, the coils 3a and 3b are connected in a reverse winding state by switching the switch contact 2 of the changeover switch 5. Power generation is achieved with low output characteristics by reducing the electromotive force of the second coil 3b. For this reason, even if the stator 2 is made multipolar and can obtain higher output in the low rotation range, the output characteristics will be lower in the high rotation range, and therefore the amount of heat generated in the high rotation range will decrease. This also makes it possible to reliably prevent unnecessary temperature rises.

It should be noted that the present invention is of course not limited to the above embodiments, and the forward/reverse switching according to the rotation speed of the stator coil may be performed in multiple stages as necessary, such as two stages instead of one stage. It is.

[Operations and Effects] In short, 1. Since the present invention is constructed as described above, the stator is multipolarized so that high output characteristics can be obtained even when the flywheel rotates in a low rotation range. However, when the flywheel rotates at a high speed, the rotation speed detecting means that detects this changes the changeover switch, and the stator coil is connected in a reverse winding state. Power will be generated with low output characteristics, which is offset by the difference. For this reason, even if the stator is made to have multiple poles so that the necessary high output characteristics can be obtained in the low rotation range, the output characteristics in the high rotation range will be low, the amount of heat generated will be small, and the temperature rise can be suppressed to a low level.

[Brief explanation of drawings]

The drawings show one embodiment of the magnet generator according to the present invention, in which Fig. 1 is a schematic plan view of the magnet generator, Fig. 2 is a circuit diagram of the stator coil, and Fig. 3 is an output characteristic diagram. It is. In the figure, 1 is a magnet generator, 2 is a stator, 3 is a stator coil, 4 is a flywheel, 5 is a changeover switch, and 6 is a rotation speed detection means. Patent applicant: Mitsuba Electric Manufacturing Co., Ltd.
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Claims (1)

[Claims] In a magnet generator using a fixed-side stator coil wound around a stator and a drive-side flywheel provided with a magnet, a changeover switch is provided in the middle of the stator coil to change the winding direction forward or backward. A magnet generator, characterized in that the changeover switch is connected to a flywheel rotational speed detecting means so as to switch the rotational speed of the flywheel to a forward winding side in a low rotational speed range and to a reverse winding side in a high rotational speed range.