JP2005130700A - Alternator for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alternator for a vehicle, capable of maintaining stable cooling capability, even in a high-temperature environment over a long time. <P>SOLUTION: In this alternator for the vehicle, comprising a stator having a generating coil; a rotor rotating in the stator for supplying an alternating field to the stator; a control section for controlling power generation amount; a rectifying section for rectifying the power generation current; a plurality of brackets holding the stator and the rotor; and a coolant flowing passage for making the coolant flow into at least one bracket for transmitting heat generated from coil itself to the outside of the alternator, is provided with a tightening member which is formed out of a material having proper thermal conductivity and integrally fixes the control section and a heat sink of the control section to the bracket, at a position distant from the bracket, so as to transmit the heat of the control section to the bracket by the tightening member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an automotive alternator, and more particularly to a liquid-cooled automotive alternator.

Conventional AC generators for automobiles mainly use the “air-cooling” method, in which the amount of heat generated by the self-heating is dissipated into the air. As the temperature increases, there are cases where air cooling cannot completely dissipate heat.

However, although the control unit of the automotive alternator has a small amount of self-heating, its absolute heat resistance is also lower than that of the power generation coil, so ensuring sufficient cooling is an important issue.

In particular, against the background of the need for low noise and improved output and efficiency, automobiles in recent years have experienced high temperatures in the engine room due to the effects of higher engine density, higher engine efficiency, and lower emissions. In addition, radiant heat tends to increase due to high temperatures of the components in the engine room. As a result, the alternator is exposed to a high temperature atmosphere in the engine room for a long time, which leads to a decrease in performance and life as an automotive alternator.

There is also a method in which a heat shield plate or the like made of a low thermal conductivity member is disposed between the high-temperature component in the engine room and the automotive alternator to thermally shut it off. However, this method inevitably increases the air temperature in the entire engine room as the operation time becomes longer, and is less effective as a countermeasure for increasing the temperature of an automotive alternator.

As a countermeasure for increasing the temperature of such an AC generator for automobiles, for example, JP-A-7-19
Like the examples described in Japanese Patent No. 4060 and Japanese Patent Laid-Open No. 2000-245111,
Liquid-cooled vehicle alternators have been developed.

JP-A-7-194060, EP1041699A2, EP109664
In the AC generator described in 7A2, heat generated from the voltage regulator and the rectifying unit is dissipated through a heat sink, a rear housing, and the like to be cooled. Further, in the AC generator described in Japanese Patent Laid-Open No. 2000-245111, the heat generated from the voltage regulator and the rectifying unit is dissipated through a heat sink, a rear bracket on the side opposite to the pulley, a good heat conductor, a water cooling housing, and the like. It is configured to be cooled.

In the methods described in the above-mentioned JP-A-7-194060 and JP-A-2000-245111, in order to make the control unit water-cooled, the heat sink of the control unit must be in close contact with the rear housing and the rear bracket, There are restrictions on the arrangement of the control unit, the brush, the rectifier, and the like, which may cause structural problems and assembly problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automotive alternator arranged in a high-temperature engine room, a liquid-cooled automotive alternator having a high degree of freedom in the position of the control unit and sufficient cooling capacity. Is to provide.

The present invention includes a stator having a power generation coil, a rotor that rotates in the stator and supplies an alternating magnetic field to the stator, a control unit that controls the amount of power generation, and rectification of a generated current A plurality of brackets holding the rectification unit, the stator and the rotor;
In an automotive alternator comprising a coolant flow path for flowing a coolant into at least one of the brackets and transmitting heat generated by the power generation coil to the outside of the alternator. A fastening member formed of a conductive material and integrally fixing the control unit and the heat sink of the control unit to the bracket at a position away from the bracket; and the heat of the control unit by the fastening member It is characterized in that it is transmitted to the bracket.

Other features of the present invention include a stator having a power generation coil, a rotor that rotates in the stator and supplies an alternating magnetic field to the stator, a control unit that controls the amount of power generation, and a generated current A rectifying unit that rectifies the stator, a plurality of brackets that hold the stator and the rotor, a cover that covers the control unit and the rectifying unit, and a coolant that flows into at least one of the brackets to generate the power In the automotive alternator provided with a coolant flow path for transmitting heat generated by the coil to the outside of the alternator, the plurality of brackets and the cover are made of a metal having good heat conductivity. The rectifying unit is held by one of the brackets, and the cover is in metal contact with the one bracket at the outer periphery, and is formed of a material having good heat conductivity, and the control unit Heat of the control unit A fastening member that integrally fixes the link to the one bracket between the one bracket and the cover, and transmits the heat of the control unit to the one bracket by the fastening member. It is in.

According to the present invention, the control unit and the heat sink or the rectifying unit of the control unit are fixed to a position away from the bracket and the cover by the fastening member formed of a material having good heat conductivity. As a result, most of the heat generated by the control unit and the rectification unit is transmitted to the coolant flowing in the bracket. Therefore, the temperature of the control unit and the rectifying unit that are almost entirely covered by the cover and the bracket are mainly governed by the temperature of the coolant.
As a result, even when exposed to a high temperature atmosphere for a long time, it is no longer subject to external temperature and radiant heat from high temperature components in the vicinity of the outside. Therefore, it is possible to provide an automotive alternator that can obtain stable cooling performance.

According to the present invention, the control unit and the heat sink or the rectifying unit of the control unit are fixed to a position away from the bracket and the cover by a fastening member formed of a material having good heat conductivity. As a result, most of the heat generated by the control unit and the rectification unit is transmitted to the coolant flowing in the bracket. Therefore, the temperature of the control unit and the rectifying unit that are almost entirely covered by the cover and the bracket are mainly governed by the temperature of the coolant. As a result, even when exposed to a high temperature atmosphere for a long time, it is no longer subject to external temperature and radiant heat from high temperature components in the vicinity of the outside.

Further, since it is not necessary to bring the control unit into close contact with the housing, the degree of freedom of arrangement is improved.

One embodiment of the present invention is shown in FIGS. FIG. 1 is a longitudinal sectional view showing the overall configuration of a liquid-cooled automotive alternator according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the AC generator of FIG. FIG. 3 is a side view of the AC generator of FIG. 1 with the rear cover removed, and FIG. 4 is an external perspective view of the vicinity of the control unit with the rear cover removed. FIG. 5 is a circuit configuration diagram of the control unit.

The automotive alternator 100 includes a center bracket 102, a front bracket 103 disposed on the pulley side, a rear bracket 104 on the side opposite to the pulley, and a rear cover 110. The front bracket 103 is made of aluminum die casting and has a structure for holding the rotor shaft 101 via a bearing 132. The center bracket 102 is also made of aluminum die casting, and the shaft 10
1 is held via a rear bearing 134. A stator 105 is held on the inner periphery of the center bracket 102. A cooling water channel 150 through which the coolant flows is provided inside the center bracket wall and the rear bracket wall. A pulley 130 is attached to one end of the shaft 101, and a slip ring 128 is attached to the other end. The pulley 130 is connected to a pulley disposed on the output shaft of the engine via a belt. A rotor 107 is attached to the central portion of the shaft 101, and a pair of claw-shaped magnetic poles 108 having a claw-like shape are disposed on the outer periphery of the rotor. Center bracket 10
2 has a built-in stator core 105, and the inner peripheral surface of the stator core 105 is arranged at a slight distance from the surface of the claw-shaped magnetic pole 108 of the rotor. Teeth and slots are arranged in the stator core 105, and a stator winding 106 is wound in three phases in a slot corresponding to the concave portion of the stator core 105. A field winding (power generation coil) 109 is wound around the center of the rotor 107, and the claw-shaped magnetic pole 108 is magnetized by flowing a direct current from the brush 121 through the slip ring 128 to the field winding 109. When the rotor 107 is rotated by driving the engine, the stator winding 1
A three-phase induced voltage is generated at 06.

Fixed to the rear bracket 104 are a control unit 120 that adjusts the generated voltage, a brush holding unit 122, and a rectifying unit 124 that rectifies the generated current, and these are covered with a rear cover 110. The control unit 120 is composed of an integrated circuit or the like formed on a thin plate-like substrate, and is arranged so that a flat plate heat sink 127 for heat dissipation is in surface contact with the back surface of the substrate.

As shown in FIGS. 3 and 4, the control unit 120 and the heat sink 127 are made up of the brush 1.
21 and the cage 122 formed integrally with the connector portion 126 for connection to the vehicle side.
Is held by. The control unit 120 and the heat sink 127 are the fastening member 1
36 is fixed to the rear bracket (or center bracket). That is, the support bracket 138 having a screw hole is provided in the rear bracket 104, and the mounting boss portion of the heat sink 127 is made to correspond to this, and the heat sink 127 is fixed to the rear bracket 104 by the long-axis bolt 136 as a fastening member. . In other words, the heat sink 127 of the control unit 120 is at a position away from the rear bracket 104 by the length of the support column 138 and the mounting boss part, and is also at a position away from the rear cover 110. The heat sink 127 of the control unit 120 is fixed so as to transmit heat to the rear bracket 104 by the fastening member 136.

The fastening member 136 is preferably made of iron or brass, and the thermal conductivity λ is 3
It is desirable that it is 0 W / mK or more. The rear bracket 104 and the rear cover 110 are both made of aluminum die casting, which is a good heat conductor.

Aluminum die casting is an example of a manufacturing method, and the rear bracket 104 and the rear cover 110 can be made, for example, from an aluminum plate material by press molding.

Note that the configuration of the fastening member is not limited to the combination of the long-axis bolt and the support column shown in the embodiment, and the control unit 120 and the heat sink 127 are positioned away from both the rear bracket 104 and the rear cover 110. What is necessary is just to hold | maintain and to efficiently transmit the heat | fever of the control part 120 to a rear bracket.

Further, the control unit 120, the rectifying unit 124 that rectifies the generated current, and the brush 121 for supplying current to the rotor are arranged on substantially the same plane.

The bearing 134 on the side opposite to the pulley is held by the center bracket 102 and is located inside the rear cover 110 on which the control unit 120, the rectifying unit 124 and the brush 121 are arranged.

In the present embodiment, the heat generated by the control unit 120 is transmitted through the heat sink 127 and is radiated to the coolant that circulates through the cooling water channel 150 via the fastening member 136. Since heat is dissipated through the fastening member 136, the heat sink 127 and the rear bracket 104
Even if the resin cage 122 is sandwiched between them, the heat transfer from the control unit 120 to the rear bracket 104 is good.

In this liquid-cooled AC generator, a cooling water channel 1 through which the coolant circulates in the AC generator.
50, one or both of the end faces of the annular recess 151 (see FIG. 2) extending in the axial direction of the center bracket are open, and these openings are the front bracket 10.
3 and the rear bracket 104 are respectively closed and configured as a sealed flow path. In this embodiment, an example is shown in which the cooling water channel is opened only in the rear. The cooling water channel 150 is formed in the coolant supply / drain hole 1 provided on the outer periphery of the center bracket 102.
52.

The heat of the heat sink of the control unit 120 that adjusts the generated voltage is fixed to the rear bracket 104 that constitutes a part of the cooling water channel 150 via the fastening member 136.
The heat of the control unit 120 is transmitted to the rear bracket 104 via the fastening member 136,
Cooled with cooling water to dissipate heat. The cooling water passage 150 communicates with a cooling water circulation path of the engine via a cooling liquid supply / drain hole 152 provided on the outer periphery of the center bracket 102. A radiator, a thermostat, and a pump are connected to the cooling water circulation path. The heat generated in the AC generator uses the liquid flowing through the cooling water circulation path as a refrigerant, and is heat-exchanged in the radiator to be radiated.

As shown in FIGS. 3 and 4, the control unit 120 is held by a brush 121 and a control unit holder 123 formed integrally with a vehicle-side connector unit 126. In addition, the control unit 120, the rectifying unit 124 that rectifies the generated current, and the brush 121 for supplying current to the rotor are arranged at substantially the same position, in other words, substantially the same plane when viewed in the axial direction. Reference numeral 125 denotes a diode constituting a rectifier circuit. The heat sink 127 of the control unit 120 is fixed and held so that the rear bracket 104 sandwiches the cage.

In FIG. 5, the control unit 120 uses a diode 12 to charge the battery.
The field winding current is controlled so that the DC voltage rectified in 5 is maintained at a constant voltage of about 14.3V. The plus fin of the diode 125 is connected to the plus electrode of the battery 130, and the minus fin has the same potential as the AC generator 100 and is electrically connected to the minus terminal side of the battery 130. These diodes perform full-wave rectification on the AC induced voltage generated in the stator winding 106 and convert it into a DC voltage.

In the present embodiment, when the rotor 107 rotates with a magnetic field inside the stator 105 of the AC generator, a generated current flows through the stator 105, and the generated current is rectified to DC by the rectifying unit 124. The The field current that gives a magnetic field to the rotor 107 is controlled by the control unit 120.

Further, the field winding (power generation coil) 109 has an outer periphery that is center bracket 10.
It is in contact with 2. The center bracket 102 is made of a good heat conductor having a heat conductivity of 80 W / mK or more, such as aluminum die casting, for example, and the coolant is caused to flow through the cooling water channel 150 provided in the wall. Therefore, most of the heat generated by the self-heating of the field winding 109 power generation coil can be dissipated into the coolant.

Further, the control unit 120 has a relatively small amount of heat generation, and therefore the amount of heat to be dissipated is small. However, since the absolute heat resistance is relatively low, the influence of the environmental temperature is large. In the present invention, the periphery of the control unit 120 and the rectifying unit 124 is covered with a cover 110 made of a good thermal conductor having a thermal conductivity of 80 W / mK or more, such as aluminum die casting. Further, the outer periphery of the cover 110 is fixed to the center bracket 102 via a rear bracket 104, which is also made of a good thermal conductor having a thermal conductivity of 80 W / mK or more, like aluminum die casting. . The control unit 120 is in thermal contact with the heat sink 127, and the heat sink 127 is fixed to the rear bracket 104. And the heat sink is comprised with the good heat conductor whose heat conductivity is 80 W / mK or more. Therefore, the control unit 120 and the rectifying unit 124 can transmit the self-heating to the center bracket 102 and dissipate it through the coolant.

In the present invention, brackets (102, 102) for holding the stator 105 and the rotor 107 are used.
103, 104) are made of a metal with good thermal conductivity having a thermal conductivity of 80 W / (mK) or more. In addition, most of the heat generated by the field winding (power generation coil) 109 is self-generated.
It has a structure that transmits the coolant flowing in the bracket.

Further, the rear cover 110 that covers the control unit 120, the brush holding unit 122, and the rectifying unit 124 is formed of a metal having a good thermal conductivity with a thermal conductivity of 80 W / (mK) or more, and most of the outer peripheral portion thereof is formed with the bracket. It is a structure that makes metal contact.

Then, most of the heat generated by the control unit 120 is transmitted to the coolant flowing into the rear bracket 104 brackets (102, 103, 104) via the fastening member 136. As described above, the rear cover 110 and the brackets (102, 103, 104) are configured to transmit most of the heat generated by the rectifying unit 120 to the coolant flowing in the brackets (102, 103, 104). The temperatures of the control unit 120 and the rectification unit 124 that are almost entirely covered by the main body are mainly governed by the temperature of the coolant.

As a result, even when the AC generator is exposed to a high temperature atmosphere for a long time, it is not controlled by the external temperature and the radiant heat from the high temperature components in the vicinity of the outside.

As described above, in the method in which the heat sink of the control unit is in close contact with the housing on the water channel side, the arrangement of the control unit, the brush, the rectifier, and the like are restricted, which causes structural problems and assembly problems. May occur. According to the present invention, by adopting a structure for transferring the heat of the control unit to the housing via the fastening member 136, it is not necessary to make the control unit 120 tightly contact with the housing, so that the arrangement of the control unit, brush, rectifier, etc. The degree of freedom is improved.

FIG. 6 shows the experimental results regarding the cooling performance. FIG. 6 shows the temperature difference of the regulator case when the cooling method of the control unit is the air cooling state and the water cooling method via the fastening member. In the air cooling system, the control unit retainer was used in common with the air cooling alternator. The temperature difference in the graph indicates the effect of cooling through the fastening member 136. According to the water-cooled type through the fastening member of the present invention, the temperature of the regulator case is kept at 70 ° C. or lower. On the other hand, in the air cooling system, the temperature of the regulator case becomes a high temperature of 90 ° C to 120 ° C. Thus, as is clear from the example of FIG. 6, the cooling of the control unit and the degree of freedom of attachment can both be achieved by adopting the water cooling method via the fastening member of the present invention.

The automotive alternator 100 may be constituted by the front bracket 103, the rear bracket 104, and the rear cover 110, and the center bracket may be omitted. The control unit 120 is held by the rear bracket 104. In this case, cooling water channels through which the coolant flows are provided inside the walls of the front bracket 103 and the rear bracket 104. By omitting the center bracket, the number of parts can be reduced.

Next, FIG. 7 is a longitudinal sectional view showing the entire configuration of a liquid-cooled automotive alternator according to another embodiment of the present invention. In this embodiment, the control unit 120 is held by a brush 121 and a cage 122 that is integrally formed with the vehicle side and the connector 126 for connection. The heat sink 127 of the control unit 120 is fixed to the rear bracket 104 by a fastening member 136. The control unit 120, the rectification unit 124, and the brush 121 are arranged on substantially the same plane.

Even if the heat sink 127 is directly fixed to the rear bracket 104 by the fastening member 136 without sandwiching the cage as in the present embodiment, the same effect as in the previous embodiment can be obtained.

Next, FIG. 8 is a longitudinal sectional view showing the overall configuration of a liquid-cooled automotive alternator according to another embodiment of the present invention. FIG. 9 is an external perspective view of the vicinity of the control unit with the rear cover similarly removed. In this embodiment, the control unit 120 is disposed between the cage 122 and the rear bracket 104. The heat sink 127 of the control unit 120 is fixed to the rear bracket 104 by a fastening member 136. Also in this embodiment, the same effect as that of the above-described embodiment can be obtained.

Next, FIG. 10 is a longitudinal sectional view showing the entire configuration of a liquid-cooled automotive alternator according to another embodiment of the present invention. FIG. 11 is an external perspective view of the vicinity of the control unit with the rear cover similarly removed. In this embodiment, the automotive alternator 100 includes a front bracket 103, a rear bracket 104, and a rear cover 110. The control unit 120 is held by a brush 121 and a control unit holder 123 formed integrally with the vehicle side and the connector unit 126 for connection. Control unit 1
20 is arrange | positioned with respect to the rectification | straightening part 124 and the brush 121 along with the axial direction of an alternating current generator, and the outer side. The heat sink 127 and the fastening member 136 are made of a good heat conductor having a thermal conductivity of 80 W / mK or more. Therefore, the self-heating of the control unit 120 and the rectifying unit 124 is effectively transmitted to the center bracket 102 and dissipated through the coolant.

Further, the brush 121 and the control unit 120 are arranged in series with respect to the axial direction of the generator, so that the area in the circumferential direction of the cage 122 of the controller 120 is reduced, and other parts in the rear cover 110 are provided. The degree of freedom of arrangement of the parts can be improved.

Next, FIG. 12 is a longitudinal sectional view showing the overall configuration of a liquid-cooled automotive alternator according to another embodiment of the present invention. This embodiment differs from the previous embodiments in that the rotor slip-ring 128 is located inside the bearing 135 on the opposite pulley side. In other words, since the control unit 120 and the rectifying unit 124 can be disposed closer to the center bracket 102, their self-heating can be effectively transmitted to the center bracket 102 and cooled.

Further, since it is not necessary to bring the control unit into close contact with the housing, the degree of freedom of arrangement is improved.

1 is a longitudinal sectional view showing an overall configuration of a liquid-cooled automotive alternator according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the AC generator of FIG. It is the side view which removed the rear cover of the alternator of FIG. It is an external appearance perspective view of the control part vicinity in the state which removed the rear cover of FIG. It is a circuit block diagram of the control part of FIG. It is a figure which shows the experimental result regarding cooling performance. It is a longitudinal cross-sectional view which shows the whole structure of the liquid-cooled type | formula alternating current generator for motor vehicles used as the other Example of this invention. It is a longitudinal cross-sectional view which shows the whole structure of the liquid-cooled type | formula alternating current generator for motor vehicles used as the other Example of this invention. It is an external appearance perspective view of the control part vicinity in the state which removed the rear cover of FIG. It is a longitudinal cross-sectional view which shows the whole structure of the liquid-cooled type | formula alternating current generator for motor vehicles used as the other Example of this invention. It is an external appearance perspective view of the control part vicinity in the state which removed the rear cover of FIG. It is a longitudinal cross-sectional view which shows the whole structure of the liquid-cooled type | formula alternating current generator for motor vehicles used as the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100: AC generator for motor vehicles, 102: Center bracket, 103: Front bracket, 104: Rear bracket, 110: Rear cover, 120: Control part, 127: Heat sink, 136: Fastening member, 138: Support pillar.

Claims (8)

A stator having a power generation coil, a rotor that rotates in the stator and supplies an alternating magnetic field to the stator, a control unit that controls the amount of power generation, a rectification unit that rectifies the generated current, A plurality of brackets for holding the stator and the rotor, and a coolant for causing the coolant to flow in at least one of the brackets and transmitting heat generated by the power generation coil to the outside of the AC generator In an automotive AC generator with a flow path,
A fastening member that is formed of a material having good heat conductivity, and that fixes the control unit and the heat sink of the control unit to the bracket integrally at a position away from the bracket;
An automotive alternator characterized in that heat of the control unit is transmitted to the bracket by the fastening member. A stator having a power generation coil, a rotor that rotates in the stator and supplies an alternating magnetic field to the stator, a control unit that controls the amount of power generation, a rectification unit that rectifies the generated current, A plurality of brackets for holding the stator and the rotor; a cover for covering the control unit and the rectifying unit; and a flow of cooling fluid in at least one of the brackets to generate heat generated by the power generation coil. In an automotive alternator with a coolant flow path that transmits to the outside of the alternator,
The plurality of brackets and the cover are formed of a metal having good heat conductivity,
The rectifying unit is held by one of the brackets,
The cover is in metal contact with the one bracket at the outer periphery,
A fastening member that is formed of a material having good heat conductivity and that integrally fixes the control unit and the heat sink of the control unit to the one bracket between the one bracket and the cover;
An automotive alternator characterized in that heat of the control unit is transmitted to the one bracket by the fastening member. In claim 1 or 2,
A brush for supplying a current to the control unit, the rectification unit and the rotor;
An automotive alternator, which is disposed in substantially the same plane as viewed in the rotor axial direction. In any of claims 1 to 3,
The bracket comprises a center bracket, a front bracket disposed on the pulley side, and a rear bracket on the opposite side of the pulley,
The coolant flow path is formed at least in the center bracket and the rear bracket,
The bearing on the anti-pulley side is held by the center bracket,
The automotive alternator characterized in that the fastening member integrally fixes the control unit and the heat sink of the control unit to the one bracket between the one bracket and the cover. . In claim 4,
The automotive alternator, wherein the heat sink is directly fixed to the rear bracket by the fastening member. In claim 3,
The heat sink of the control unit and the brush holder that holds the brush are arranged side by side in the axial direction, and the control unit is fixed to the rear bracket by the fastening member with the rear bracket side. An automotive alternator characterized by that. In any of claims 1 to 3,
The bracket comprises a center bracket, a front bracket disposed on the pulley side, and a rear bracket on the opposite side of the pulley,
The coolant flow path is formed at least in the center bracket and the rear bracket,
An AC generator for an automobile, wherein a bearing on the side opposite to the pulley is held by the center bracket. In any one of Claims 1 thru | or 7,
The automotive alternator characterized in that the fastening member comprises a bolt for fixing a support pillar portion having a screw hole formed on an end face of the one bracket to an attachment boss portion provided in the heat sink. .

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