JPH1198753A - Alternator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool a heat sink, and also take the temperature balance of the heat sink. SOLUTION: This alternator is constituted by fixing both a heat sink 18P on positive side and a heat sink 18M on negative side, where diodes 15P and 15M are mounted, in confrontational attitude to the first bracket 35 and has a structure such that the first bracket 35 is covered with a rear cover 51, provided with plural pieces of cooling air introduction ports 99. In this case, a wall for distributing the cooling air introduced from a cooling air introduction port 99-1 is made of a cut and erected baffle plate 100-1, using at least one from among cooling air introduction ports 99, and also the bore of the heat sink 18M on the negative side is made smaller than that of the bore of the heat sink 18P on the positive side so that the cooling air hits directly upon the heat sink 18M on the negative side, and moreover the width of the cooling air introduction port 99 and the interval for ventilation to the tip of the baffle plate 100 are made into the same dimension.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternator, in particular, to efficiently cool both a plus side heat sink and a minus side heat sink each having a plurality of plus side diodes and minus side diodes for rectifying a voltage generated by a generating coil. In addition, the present invention relates to a cooling air introduction structure for a rear cover portion in which both heat sinks are balanced in temperature.

[0002]

2. Description of the Related Art A conventional structure for introducing cooling air to a rear cover portion employs a structure as shown in FIG.

In FIG. 1, a rear cover 51 is attached to a first bracket 35 of the alternator 11 so as to form a storage chamber 50 between the first bracket 35 and the outside of the first bracket 35, and a plurality of rectifying diodes are provided. The plus side heat sink 18P and the minus side heat sink 18M provided respectively are attached to the outer surface side of the first bracket 35 in the storage chamber 50 so as to be covered by the rear cover 51.

The plus side heat sink 18P and the minus side heat sink 18M are arc-shaped ones which support one end of the rotating shaft 40 and surround a part of the boss 38 provided on the first bracket 35, thereby reducing the weight. It is formed of an aluminum alloy in order to achieve the above. On the surface of the plus side heat sink 18P facing the minus side heat sink 18M, the plus side diode 15P (actually, the plus side diode 14P, 16P,
Are mounted at intervals in the circumferential direction such that one end thereof is soldered.
A negative diode 15M (actually four diodes including negative diodes 14M, 16M, and 17M) is spaced from the surface of the M facing the positive heat sink 18P in the circumferential direction by soldering one end thereof. Installed.

[0005] The rear cover 51 is provided with a plurality of cooling air introduction holes 99 and a plurality of air guide plate portions 100 which extend to the inward side respectively connected to the edges of the cooling air introduction holes 99.

[0006]

However, in the conventional cooling air introduction structure for the rear cover shown in FIG. 6, for example, the cooling air introduced from the cooling air introduction hole 99 is supplied to the plus side heat sink as shown by the arrow in FIG. There has been a drawback in that sufficient consideration has not been given to the cooling structure, such as a small amount of cooling air flowing to the 18P side and a small amount of cooling air flowing to the minus side heat sink 18M, resulting in imbalance in cooling temperature.

[0007] In recent years, there has been an increasing movement to reduce the cost of production costs, which has led to a reduction in the number of components and a reduction in the cost of raw materials. In view of the above, conversion from an aluminum alloy to an iron plate has been demanded. In converting the material from the aluminum alloy to the iron plate, it is desired to improve the cooling property.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and in converting a material from an aluminum alloy to an iron plate, the cooling air introduction structure of the rear cover portion has been reviewed to efficiently cool the heat sink, It is an object of the present invention to provide an alternator having a cooling air introduction structure for a rear cover portion in which the temperature of a heat sink is balanced.

[0009]

In order to achieve the above object, an alternator according to the present invention comprises a rotor rotatably supported inside a stator held between first and second brackets. And a first bracket in which both the plus side heat sink and the minus side heat sink respectively provided with a plurality of plus side diodes and a plurality of minus side diodes for rectifying the voltage generated by the generator coil wound on the stator are opposed to each other. , Wherein the rear portion of the first bracket is covered with a rear cover provided with a plurality of cooling air introduction holes, wherein at least one of the plurality of cooling air introduction holes provided in the rear cover is provided. At the wind guide plate part of the cut and raised,
To form a wall for distributing the cooling air introduced from the cooling air introduction hole to the plus side heat sink and the minus side heat sink, and to directly blow the cooling air introduced from the cooling air introduction hole to the minus side heat sink. The inside diameter of the minus side heat sink attached to the first bracket is formed smaller than the inside diameter of the plus side heat sink, and the width a of the cooling air introduction hole and the ventilation gap b between the tip of the air guide plate portion of the cooling air introduction hole and Are characterized by having a structure in which both the plus side heat sink and the minus side heat sink are efficiently cooled.

The cooling air is blown directly to the minus heat sink side where the cooling air does not easily pass through the wall of the cooling air introduction hole at the wind guide plate portion, and the cooling air is introduced to the minus heat sink side where the cooling air does not easily pass. The temperature balance between the plus side heat sink and the minus side heat sink can be achieved.

Further, since the width a of the cooling air introduction hole and the ventilation gap b between the cooling air introduction hole and the tip of the air guide plate are made equal, it is possible to avoid a decrease in the cooling effect due to the diffusion of the ventilation. And cooling performance is improved.

[0012]

FIG. 1 shows an electric circuit diagram of an alternator. In the figure, an alternator 11 is a brushless alternator mounted on an automobile, and includes a stator coil 1 of three-phase power generation coils 12A, 12B, and 12C.
13 with 4 and four plus diodes 1
Each of the cathodes of 4P, 15P, 16P, and 17P is electrically connected in parallel, and the plus side heat sink 18P and four minus side diodes 14M, 15M,
A negative side heat sink 18M, in which the anodes of 16M and 17M are electrically connected in parallel and grounded, are mounted, a field coil 19, and a regulator 20.

Positive diodes 14P to 17P
Is connected to the output terminal 21 of the alternator 11 via the plus side heat sink 18P.
1, a field coil 19 and a regulator 20 are also connected. The output terminal 21 is connected to a positive terminal of a battery 23 via a fuse 22. The plus diode 14P and the minus diode 14
The power generation coil 12A is connected to the connection point between the positive side diode 15P and the negative side diode 15M, and the connection point between the positive side diode 16P and the negative side diode 16M. Is connected to the power generating coil 12C, and 3 is connected to a connection point between the plus side diode 17P and the minus side diode 17M.
The neutral points of the phase generating coils 12A, 12B, 12C are connected.

The regulator 20 includes capacitors 24 and 2
IC regulators 5 and 26 are attached, and four lead wires 27, 28 and 2 connected to the regulator 20 are provided.
Couplers 31 are provided at the ends of 9, 30. The lead wire 27 of the lead wires 27 to 30 is connected to the plus terminal of the battery 23 via the charge lamp 32 and the key switch 33, and the minus terminal of the battery 23 has minus diodes 14M, 15M,
The anodes 16M and 17M are connected to a minus heat sink 18M electrically connected in parallel.

The structure of the alternator 11 will be described below. Referring to FIG. 2, the stator 13 is formed by winding a stator coil 12 around an iron core formed by laminating a plurality of annular core plates. 13 is sandwiched between the first and second brackets 35 and 36. The first and second brackets 35 and 36 are fastened to each other by a plurality of through bolts 37, and sandwich the stator 13 between the first and second brackets 35 and 36.

At the center of the first and second brackets 35, 36, cylindrical bosses 38, 39 are provided coaxially, and at the boss 38 of the first bracket 35, a part of the rotary shaft 40 bears. It is rotatably supported by 41. Rotary axis 4
The other end of the pin 0 projects outward through the boss 39 of the second bracket 36, and a bearing 40 is interposed between the boss 39 and the rotating shaft 40.

A claw-pole type rotor 43 is fixedly mounted coaxially with the stator 13 on the rotating shaft 40 inside the stator 13, and a cylindrical field core 4 inserted into the rotor 43.
4 is fixed to the inner surface side of the first bracket 35 by a plurality of bolts 45. The field coil 19 is wound around the field core 44.

With respect to the rotor 43, the first bracket 3
A cooling fan 46 is fixed to the rotating shaft 40 on the side opposite to the side 5, in this embodiment, outside the second bracket 36. Further, on the outer side of the cooling fan 46,
A pulley 47 is fixed on the pulley 47, and a V-belt for transmitting power from an engine (not shown) is wound around the pulley 47.

Referring to FIGS. 3, 4, and 5, a rear cover 51 is attached to the first bracket 35 so as to form a storage chamber 50 between the first bracket 35 and the outside of the first bracket 35. Each diode 14P to 17P and 14
A heat sink assembly 52 having a plus side heat sink 18P and a minus side heat sink 18M having M through 17M, respectively, and a regulator 20 are covered with a rear cover 51 so as to be disposed on the outer surface side of the first bracket 35 in the storage chamber 50. Installed.

The plus side heat sink 18P and the minus side heat sink 18M are arc-shaped, which support one end of the rotating shaft 40 and surround a part of the boss 38 provided on the first bracket 35. It is made of an aluminum alloy to achieve the change. The surface of the plus side heat sink 18P facing the minus side heat sink 18M is provided with the plus side diodes 14P to 17P.
P is attached at a circumferential interval so as to solder one end thereof.
On the surface facing the plus side heat sink 18P, minus side diodes 14M to 17M are mounted at intervals in the circumferential direction such that one end thereof is soldered. That is, the positive side diodes 14P to 17P
Is mounted in a state of being electrically connected in parallel to the plus side heat sink 18P, and the minus diodes 14M to 17M are mounted in a state of being electrically connected in parallel to the minus side heat sink 18M. Moreover, the plus-side diodes 14P to 17P and the minus-side diodes 14M to 17M, which are connected in parallel,
At the positions corresponding to each other, they are attached to both heat sinks of the plus side heat sink 18P and the minus side heat sink 18M.

In the rear cover 51, a plurality of cooling air introduction holes 99, 99-1, 99-2 are provided.
And a plurality of baffle plates 100 extending inward in a manner connected to the edges of the baffle. The leading end of the air guide plate 100-1 in the cut and raised portion of the cooling air introduction hole 99-1 extends to the vicinity of the plus side heat sink 18P (see FIGS. 4 and 5). 99-1,
The ventilation introduced from 99-2 is the wind guide plate part 100-1.
Acts so that the wind direction can be changed. That is, the air guide plate 100-1 is provided with the cooling air introduction hole 9.
It acts on the ventilation introduced from 9-2 so as to flow through between the plus side heat sink 18P and the minus side heat sink 18M, and also prevents the ventilation introduced from the cooling air introduction hole 99 below it. It acts to flow to the rear cover 51 side of the plus side heat sink 18P. That is, the air guide plate 100-1 in the cut and raised portion of the cooling air introduction hole 99-1 forms a wall for distributing ventilation toward the gap between the plus side heat sink 18P and the minus side heat sink 18M. It has become.

In forming the air guide plate portion 100-1, the size of the cooling air introduction hole 99-1 is made larger than that of the other cooling air introduction holes 99, and the cut and raised portion is formed. The air guide plate portion may be formed to be long, and the size of the cooling air introduction hole 99-1 is the same size as the other cooling air introduction holes 99 and the like, and the cut-and-raised portion is formed. The extension plate may be added to the air guide plate portion.

The inside diameter of the minus side heat sink 18M attached to the first bracket 35 is formed smaller than the inside diameter of the plus side heat sink 18P.
That is, it is formed in such a shape that the ventilation introduced from the cooling air introduction hole 99-1 on the rotating shaft 40 side and guided by the air guide plate portion 100-1 is directly blown to the minus side heat sink 18M. Therefore, a part of the minus side heat sink 18M to which the ventilation is directly blown has larger heat dissipation than other parts, and the other part of the minus side heat sink 18M has a cooling effect by heat conduction.

The width a of the cooling air introduction hole 99 and the ventilation gap b between the cooling air introduction hole 99 and the front end of the air guide plate 100 are made to have the same size, so that the ventilation is not diffused. The heat is sprayed onto the surface of the side heat sink 18P, and a cooling effect can be provided by this equal dimensional relationship.

Next, the plus side heat sink 1 of this embodiment
The cooling action of the cooling function will be described focusing on 8P and the minus side heat sink 18M as follows. That is, when the cooling fan 46 is operated by the rotation operation of the rotating shaft 40 accompanying the transmission of the driving force from the engine, the rear cover 5
The cooling air introduced from the first cooling air introduction hole 99-2 is directly blown to the minus heat sink 18M by the wall formed by the baffle plate 100-1.
The cooling air flows as indicated by the arrow in FIG. 4, and flows between the plus side heat sink 18P and the minus side heat sink 18M to remove the heat and flow toward the rotor 43 by the action of the cooling fan 46. In addition, the cooling air introduced from the cooling air introduction hole 99 also flows toward the rotor 43 while taking away the heat along the surface side of the plus side heat sink 18P.

Ventilation is distributed to the plus side heat sink 18P and the minus side heat sink 18M by the wind guide plate portion 100-1 forming the wall, and the inner diameter of the minus side heat sink 18M is larger than the inner diameter of the plus side heat sink 18P. By being formed small,
The tendency of the distribution of ventilation flowing to the rear cover 51 side of the conventional plus side heat sink 18P to be larger is corrected, and the plus side heat sink 18P and the minus side heat sink 18P
The temperature of the cooling with M is balanced.

Since the width "a" of the cooling air introduction hole 99 and the ventilation gap "b" between the cooling air introduction hole 99 and the tip of the air guide plate portion 100 are set to have the same size, the ventilation is diffused. The cooling effect due to the diffusion of the ventilation is not wasted.

[0028]

As described above, according to the present invention, the cooling air is blown directly to the minus heat sink side where the cooling air does not easily pass, and the cooling air is cooled to the minus heat sink side where the cooling air does not easily pass. Since the structure allows air to pass easily, the temperature balance between the plus side heat sink and the minus side heat sink can be achieved.

Further, since the width a of the cooling air introduction hole 99 and the ventilation gap b between the cooling air introduction hole 99 and the front end of the air guide plate portion 100 are made equal, the cooling effect is reduced by the diffusion of the ventilation. Can be avoided.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of an alternator.

FIG. 2 is an irregular vertical sectional view of an alternator.

FIG. 3 is a left side view thereof.

FIG. 4 is an explanatory view of a cooling air introduction structure according to an embodiment of the rear cover portion of the present invention.

FIG. 5 is an enlarged explanatory view of a cooling air introduction structure of the present invention.

FIG. 6 is an explanatory view of a conventional cooling air introduction structure for a rear cover portion.

[Explanation of symbols]

11 Alternator 14P, 15P, 16P, 17P Positive diode 14M, 15M, 16M, 17M Negative diode 18P Positive heat sink 18M Negative heat sink 35 First bracket 36 Second bracket 40 Rotating shaft 43 Rotor 46 Cooling fan 51 Rear cover 99 99-1,99-2 Cooling air introduction hole 100,100-1 Air guide plate

Claims (1)

[Claims] A plurality of rotors rotatably supported inside a stator sandwiched between first and second brackets and rectifying a voltage generated by a power generation coil wound around the stator. A rear cover having both a plus side heat sink and a plurality of minus side heat sinks to which a plus side diode and a plurality of minus side diodes are attached, respectively, is fixed to the first bracket in an opposed posture, and is provided with a plurality of cooling air introduction holes. An alternator having a structure in which the rear portion of the first bracket is covered, wherein at least one of the plurality of cooling air introduction holes provided in the rear cover is used to cut and raise the cooling air introduction portion. A wall for distributing the cooling air introduced from the holes to the plus side heat sink and the minus side heat sink is formed, and the cooling air is formed. The inner diameter of the minus heat sink attached to the first bracket is formed smaller than the inner diameter of the plus heat sink so that the cooling air introduced from the introduction hole blows directly to the minus heat sink. An alternator characterized in that the ventilation gap b between the air introduction hole and the tip of the air guide plate portion is made equal in size, so that both the plus side heat sink and the minus side heat sink are efficiently cooled.