JPS60257751A - Alternator - Google Patents

Abstract

PURPOSE:To obtain a stable generating amount over the entire rotating area of an internal-combustion engine by controlling a magnetic flux density varying mechanism for varying the magnetic flux density of a magnetic circuit in response to the rotating speed of the engine. CONSTITUTION:A pressure control circuit 28 recognizes the rotating speed of an engine by a detection signal applied from a rotating speed sensor 30. The control circuit 28, when recognizing the rotating speed of the engine, for example, at 1,000r.p.m. or lower by a detection signal applied from the sensor 30, controls penumatic pressure in a pressure chamber 26 so that the pneumatic pressure in the chamber 26 is atmospheric pressure. Thus, a magnetic valve yoke 16 is attracted by the attacting force of a permanent magnet 4 to a housing 15, and adhered to the housing 15. Thus, since the magnetic flux density of a magnetic circuit 10 increases, the generated electromotive force increases. As described above, the control circuit 28 can control the generating amount of an alternator in response to the rotating speed of the engine in a wide rotating speed range constantly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates generally to alternators, and more particularly to alternators whose field poles are permanent magnets.

[Prior Art] As is well known, an alternator is a charging device used as a power source for various electrical devices in an automobile, and a three-phase alternating current generator is used.

As is well known, the internal combustion engine of an automobile has a rotation range of 1
, 00 Or, p, m, ~ 6.0 O Or, l), m, which covers a fairly wide range, so for example, if the pulley ratio is 1:1, the alternator that is rotationally driven by the output of the internal combustion engine will also 1,000 r,p
, m, ~6, OOOr,l], m. Therefore, various attempts have been made to prevent the alternator rotor from flying off due to the centrifugal force that increases in the high rotation range.
The figure shows an example of such conventional technology.
This is an illustration of the proposal published in Publication No. 44.80. The outline of the proposal is as follows. That is, a vortex 2 is formed inside the field core so as to be in contact with the outer periphery of the yoke in the continuous portion of the field core 3 with claws integrated with the cylindrical yoke 1, and the vortex 2 is formed in the core 3 to interfere with the groove. A through hole 4 is arranged so that the field coil 7 is sandwiched between the iron core 3 and the field iron core 5 with claws.

In the above configuration, a brush 9 is provided in the housing 10 in order to feed excitation current to the field coil 7.

By the way, as there has been a recent demand for various types of compact and high-performance vehicle equipment, alternators installed in vehicles have no choice but to be made as small as possible. Therefore, for example, it is possible to reduce the number of dangerous parts and downsize the equipment by installing permanent magnets on the rotors and trochanters to serve as field poles and removing brushes, etc., which are a source of noise due to wear and friction. It will be done.

However, in the above-mentioned invention, since the permanent magnet is used as the field pole, the magnetic flux density of the magnetic circuit formed by the permanent magnet is always constant.

Therefore, when the engine is in a low speed range, the amount of power generated by the alternator is very small, and when the engine is in a high speed range, the amount of power generated by the alternator is much larger than necessary.

Therefore, not only is it not possible to obtain a stable amount of power generation over the entire rotation range of the engine, but the pressure resistance of the equipment must be made larger than necessary, and the durability of the equipment due to the high voltage applied must be increased. There has been a problem in that this may lead to a decrease in performance or damage.

Therefore, the present invention is aimed at resolving the two problems of the prior art.The purpose of the present invention is to obtain a stable amount of power generation over the entire rotation range of the engine, and to prevent deterioration in durability and damage to equipment. Our goal is to provide an alternator that is capable of.

[Structure] The features of the present invention to achieve the above object are that, in an alternator in which a permanent magnet has 1 and 11 poles, a magnetic flux density variable mechanism that changes the magnetic flux density of a magnetic circuit formed by the permanent magnet; A control means is provided to control the mechanism according to the rotational speed of the internal combustion engine (located in the alternator).

[Function] In the above configuration, when the rotational speed of the internal combustion engine is in a high rotational speed range, the control means controls the magnetic flux density variable mechanism to reduce the magnetic flux density of the magnetic circuit, and when the rotational speed of the internal combustion engine is in a low rotational speed range, the control means controls the magnetic flux density variable mechanism to reduce the magnetic flux density of the magnetic circuit. When the magnetic flux density is within the range, the control means controls the variable mechanism to increase the magnetic flux density of the magnetic circuit.

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

FIG. 1 is a side sectional view of an alternator according to a first embodiment of the present invention, FIG. 2 is a partial perspective view of an alternator according to a first embodiment of the present invention, and FIG. 3 is a first embodiment of the present invention. FIG. 4 is a perspective view showing the relationship between the permanent magnet, the yoke, and the magnetic circuit according to the first embodiment of the present invention; FIG.
The figure shows an equivalent circuit of the magnetic circuit formed in the alternator according to the first embodiment of the present invention, FIG. 6 is a side sectional view of the alternator according to the twelfth embodiment of the present invention, and FIG. 7 is a diagram illustrating the present invention. FIG. 3 is a front view of an alternator according to a second embodiment of the invention. In FIGS. 1 to 8, the same reference numbers indicate the same parts.

1 to 5 illustrate an alternator according to a first embodiment of the present invention.

In FIG. 1, a rotor 2 is equipped with a permanent magnet 4 having a high holding force as a field pole, and is rotatably supported by a support shaft 6. The armature 8 is fixed to the housing 15 facing the permanent magnet 4.

The permanent magnet 4 is magnetized with the armature 8 side at the N pole and the opposite side at the S pole on the upper side C in FIG.
A magnetic circuit 10 consisting of a magnetic circuit 10b whose magnetic flux density changes by changing the annular groove 12 and a magnetic circuit 10a whose magnetic flux density is constant is formed between the magnetic circuit 10 and the housing 15 formed of a high magnetic permeability material. In the figure, the ◎ marks indicate the direction of magnetic flux towards the front of the paper, and the x marks indicate the direction of magnetic flux towards the back of the paper.

An annular groove 12 is formed from the outside at a position of the housing 15 where the magnetic flux is high. Opposed to the annular ring K 12 is a ring 1/I formed of a magnetic valve head with high magnetic permeability, such as a magnetic valve head, which has a circular shape as shown in FIG. 3. The valve head 14 is fixed to a ring plate 16, such as a magnetic valve yoke, for example, and the ring plate 16, that is, the magnetic valve yoke 16 is supported by a magnetic valve pin 18 so as to be slidable in the left and right direction in FIG. ing.

If the magnetic valve yoke 16 moves to the right in FIG. 2, the magnetic valve head 14 will fit into the annular groove 12,
Also, when the valve yoke 16 moves to the left in FIG.
The valve head 14 is configured to be spaced apart from the annular @12.

The magnetic valve head 14, the magnetic valve yoke 16, the magnetic valve bottle 18, and the diaphragm device 23 described later.
A magnetic flux density variable mechanism is constructed. The magnetic flux density is determined by the magnetic permeability of the material through which the magnetic flux passes, so when the magnetic valve head 14 is separated from the annular groove 12 by driving the diaphragm device 23, an air layer with low magnetic permeability is formed in the gap, and the magnetic flux density increases. This is because it is possible to make it smaller.

The diaphragm device 23 described above includes the diaphragm 22,
A pressure chamber 26 defined and formed by the tire flam 22
It is made up of. The tire flamm 22 is connected to a rod 24 and connected to the magnetic valve yoke 1 via the combination 24.
It is fixed at 6.

Control pressure from a pressure control circuit 28 is introduced into the pressure chamber 26 .

The pressure control circuit 28 is composed of, for example, a Fukui computer, etc., and based on a detection signal from a rotation speed sensor 30 that detects the engine rotation speed, the magnetic flux density decreases as the rotation speed increases. The pressure inside the pressure chamber 26 is controlled to decrease (t), and when the rotation speed decreases, the pressure inside the pressure chamber 26 is increased so that the magnetic flux density increases. The memory of the combi coater contains data such as tit, which indicates the relationship between the engine speed and the air FE2 in the pressure chamber 26, in advance.

The IC regulator 20 rectifies the three-phase induced electromotive force, that is, the three-phase AC voltage, generated in the armature 8 and supplies power to each scale vehicle equipment and battery. .

The external appearance of the alternator constructed as described above is shown in FIG.

The operation of the above configuration will be explained below using FIGS. 4 and 5 as VI.

A magnetic circuit 10 is formed by the permanent magnets 4 from the rotor 2 to the housing 15 as shown in FIG. When the engine starts driving, the rotor 2 starts rotating accordingly. As the rotor 2 rotates, a three-phase induced electromotive force is generated whose magnitude is determined by the rotational speed of the armature 81 and the magnetic flux density which varies depending on the width of the annular groove 12. The three-phase induced electromotive force, that is, the three-phase AC voltage is I
It is rectified by the C regulator 20 and supplied to various vehicle equipment and batteries.

The pressure control circuit 28 recognizes the engine speed based on the detection signal provided from the rotation speed sensor 30. When the control circuit 28 recognizes, for example, that the engine speed is 1°000 r, p, m or less based on a detection signal given from the rotation speed sensor 30, it sets the air pressure in the pressure chamber 26 to atmospheric pressure. The air pressure within the pressure chamber 26 is controlled accordingly. Therefore, the magnetic valve yoke 16 is attracted to the housing 15 by the attractive force of the permanent magnet 4 (=I
wear it. As a result, the magnetic flux density of the magnetic circuit 10 increases, so that the generated electromotive force becomes more severe.

The pressure control circuit 28 uses a detection signal given from the rotation speed sensor 30 to control the air pressure in the pressure chamber 26 to a negative pressure commensurate with the engine rotation speed as the engine rotation speed increases, for example. Predetermined operations such as opening and closing a valve mechanism (not shown) communicating with the intake manifold are performed. Since the air pressure in the pressure chamber 26 becomes negative as the engine speed increases, the driving force of the magnetic valve yoke 1G to the left in FIG. As a result, an annular vortex 12 is formed between the valve head 17'I and the housing 15. 3. As a result, the magnetic flux density of the magnetic circuit 1o is reduced, so that the generated electromotive force becomes smaller.

As described above, the pressure control circuit 28 appropriately adjusts and closes the gap between the annular grooves 12 according to the engine speed, so that the amount of power generated by the alternator can be controlled to be substantially constant over a wide range of speeds.

The contents described above will be explained as follows based on the equivalent circuit of the magnetic circuit 10 shown in FIG.

The magnetic circuits 10 formed between the housing 15 and the magnetic valve head 1/I, which are separated by an annular groove 12, are called IOa and 10b, respectively, and the magnetic resistance of the magnetic valve head 14 is called RV, annular. The magnetic resistance due to the groove 12 is RA, the magnetic resistance of the permanent magnet 4 itself is Rg, the magnetic resistance when the magnetic flux crosses the housing 15 is r, the magnetic resistance inside the housing 15 is RH, and the magnetism j of the permanent magnet 4 is [In other words, an equivalent circuit as shown in FIG. 5 is formed.

-Ih Of the magnetoresistances mentioned above, Rp, r, In+ and R
V is a constant determined when designing the alternator.

In the above circuit, when the annular groove 12 is varied by the pressure horn control circuit 28, the magnitude of RA is varied, so the magnitude of the magnetic flux strain 2 passing through the magnetic circuit 1o changes. Therefore, the magnetic flux, which is the sum of the magnetic flux distortion 2 and the magnetic flux east 1 passing through the magnetic circuit 10a, also changes, so the output of the alternator changes.

Figures 6 and 7 illustrate an alternator according to a second embodiment of the present invention. [13] is connected to iron core 32. The iron core 32 is made of a material similar to, for example, a wire steel plate and is laminated in a spiral shape.
] - supported by Kuamab r□ 30. The yoke armature 36 is mounted on the play 1-guide 38 that touches the guide shaft 40 and moves in the axial direction.
A cutout groove 34 is formed with a width corresponding to the amount of movement of the iron core 32 as it moves in the direction of FIG. 6 of '3. An armature take-out line 42 is connected to the armature 8, and the armature take-out line 42 is marked with an R shown in the drawing. The armature lead-out wire 42 is made of copper wire with a diameter commensurate with the amount of movement. .

In the above-mentioned drawing, move the plate guide 38 by a predetermined amount /, k + J million id 1i 1140 direction according to the operating state of the engine (engine speed and ml, load density applied to 18). The armature 8 is then moved. As a result, the width of the gap formed between the armature 8 and the permanent magnet 4 is adjusted, and the magnetic flux density of the magnetic circuit formed from the permanent magnet 4 to the armature 8 is varied, thereby improving power generation efficiency. Try to improve.

13. FIG. 7 shows a front view of the A alternator shown in FIG. 6.

As explained above, in d3 of this embodiment, the magnetic bulge head 1 is moved while the armature 8 is fixed in the first embodiment.
Whereas the magnetic flux density was varied by moving the armature 4 in the direction of the guide shaft 6, in this embodiment the magnetic flux density was varied by moving the armature 8 in the direction of the guide shaft 40. d5 The above-mentioned content is limited to the first part according to the present invention.
, is related to the second embodiment, and does not mean that the present invention is limited only to the above content.

[Effect] As explained above, according to the present invention, the magnetic flux density ri changes the magnetic flux density of the magnetic circuit formed by the permanent magnet.
lJ variable mechanism All mechanisms T N1 '/according to the rotational speed of the combustion engine
Since i+1-d-2-1 above t: +, r-, it is possible to obtain stable power generation over the entire rotation of the engine and to prevent a decrease in durability and damage to the mechanical equipment.
Provide an alternator - it's too much. .

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a Δ-alternator according to a first embodiment of the present invention, FIG. 2 is a partial perspective view of an alternator according to the first embodiment of the present invention, and FIG. FIG. 4 is a perspective view of the relationship between the permanent magnet, yoke, and magnetic circuit according to the first embodiment of the present invention; FIG. 5 is an overall perspective view of the alternator according to the first embodiment of the present invention. FIG. 6 is a side sectional view of the alternator according to the second embodiment of the present invention, and FIG.
FIG. 8 is a front view of an alternator according to a second embodiment of the present invention, and FIG. 8 is a side half-sectional view C of an alternator according to the prior art.
be. 2... Rotor 8... Armature 4... Permanent magnet 10... Magnetic circuit 12... Annular groove 30... Rotation speed sensor 32... Iron core 14...
・Magnetic hub head 15...housing 34...
Notch groove 16...Magnetic valve 36...Yoke armature yoke 38...Play 1 to guide 22...Diaphragm /1. O...Guide shaft 2
4... Rod 7'I2... Armature lead wire 26
...Pressure chamber 28...Pressure control circuit agent Patent attorney Yoshiyasu YoYoshiyasu Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 42 vPS7 Figure 5

Claims (1)

[Claims] In an alternator in which a permanent magnet is used as a field pole, a magnetic flux density variable mechanism that changes the magnetic flux density of a magnetic circuit formed by the permanent magnet, etc., and a control means that controls the variable mechanism according to the rotational speed of an internal combustion engine. An alternator characterized by the following.