Information
-
Patent Grant
-
6429556
-
Patent Number
6,429,556
-
Date Filed
Friday, May 12, 200024 years ago
-
Date Issued
Tuesday, August 6, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Ramirez; Nestor
- Le; Dang Dinh
Agents
-
CPC
-
US Classifications
Field of Search
US
- 310 71
- 310 688
- 310 263
- 363 142
- 363 144
- 363 146
-
International Classifications
-
Abstract
An AC generator for a vehicle includes a plurality of output lead wires having a generally rectangular cross-section with longer sides being parallel to a radial direction of the rotor and a rectifier unit having a pair of positive and negative metal heat sinks with a plurality of pairs of a positive rectifier element welded to the heat sinks and a terminal member. The terminal member has a plurality of metal terminals for connecting the rectifier elements so as to provide a structure for provisionally holding the rectifier unit only by the lead wires.
Description
CROSS REFERENCE TO RELATED APPLICATION
The present application is based on and claims priority from Japanese Patent Application Hei 11-153929 filed Jun. 1, 1999, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an AC generator for a vehicle, and particularly to a rectifier arrangement of an AC generator.
2. Description of the-Related Art
As disclosed in JP-A-9-19119, a rectifier unit is comprised of a plurality of pairs of positive and negative diodes which are respectively welded to positive and negative heat sinks, a circuit board having a plurality of insert terminals to which output lead wires extend to be welded thereto, a terminal member having a plurality of metal terminals which connect the diodes to form a rectifying bridge circuit, an insulator disposed between the heat sinks, and a DC output terminal. The output lead wires have a round cross section, and the heat sinks are made of aluminum-based alloy.
The circuit board is fixed by screws to connect the metal terminal of the terminal member to the insert terminal of the circuit board.
Thus, two connection steps, a step of connecting the output lead wires and the circuit board and a step of fixing the circuit board to the terminal member, are necessary to connect the output lead wires and the diodes. Since the. output lead wire has a round cross section, it is difficult to support the rectifier unit by itself during the manufacturing steps. This necessitates additional supporting steps or tools.
SUMMARY OF THE INVENTION
A main object of the invention is to provide an inexpensive and easy-manufactured AC generator for a vehicle.
In the AC generator according to a main feature of the invention, lead wires of a stator winding have a generally rectangular cross section with longer sides extending in parallel to a radial direction of said rotor, and a terminal member of a rectifier unit has a plurality of metal terminals for connecting rectifier elements to provide a structure for provisionally holding the rectifier unit only by said lead wires.
The metal terminals are preferably disposed at circumference of heat sinks of the rectifier unit in an arc range θ that is larger than 180°. The terminal member may include a plurality of resin guide members having axially extending rectangular holes at the outer peripheral portion of the heat sink to guide the lead wires therein, and the metal terminals may include U-shaped terminal portions respectively disposed at the plurality of guide members to connect the lead wires.
The heat sinks may include a pair of arc-shaped aluminum alloy members having a plurality of recesses at circumference of heat sinks, and the metal terminals comprise U-shaped terminal portions respectively disposed in the plurality of recesses.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and characteristics of the present invention as well as the functions of related parts of the present invention will become clear from a study of the following detailed description, the appended claims and the drawings. In the drawings:
FIG. 1
is a partially cross-sectional side view of an AC generator for a vehicle according to a first embodiment of the invention;
FIG. 2
is a front view of a rectifier unit of the AC generator according to the first embodiment;
FIG. 3
is a rear view of the rectifier unit shown in
FIG. 2
;
FIG. 4
is a schematic circuit diagram of the AC generator according to the first embodiment;
FIG. 5
is an exploded view illustrating a step of assembling the rectifier into a stator of the AC generator according to the first embodiment;
FIG. 6
is an insert metal terminal of a terminal member of the AC generator according to the first embodiment;
FIG. 7
is a fragmentary side view of the stator of the AC generator according to the first embodiment;
FIG. 8
is a schematic view illustrating location of output lead wires of an AC generator according to a second embodiment of the invention;
FIG. 9
is a schematic side view illustrating a rectifier unit being assembled into a stator of the AC generator according to the second embodiment;
FIG. 10
is a rear view of a rectifier unit of an AC generator according to a third embodiment of the invention;
FIG. 11
is a cross-sectional side view of the rectifier unit cut along line XI—XI in
FIG. 10
;
FIG. 12
is an enlarged perspective view illustrating a portion of the rectifier unit according to the third embodiment;
FIG. 13
is a rear view of a rectifier unit of an AC generator according to a fourth embodiment of the invention;
FIG. 14
is a schematic circuit diagram of the AC generator according to the fourth embodiment;
FIG. 15
is a perspective view of a variation of a insert metal terminal;
FIG. 16
is a perspective view of a variation of a insert metal terminal;
FIG. 17
is a fragmentary side view of a variation of the stator;
FIG. 18
is an exploded view illustrating a step of assembling the rectifier into a variation of the AC generator according to the first embodiment;
FIG. 19
is a schematic cross-sectional view of an output lead wire illustrated in
FIG. 18
;
FIG. 20
is a schematic circuit diagram of an AC generator according to a fifth embodiment of the invention; and
FIG. 21
is a schematic diagram illustrating a variation of a portion of the terminal member shown in FIG.
20
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(First Embodiment)
An AC generator for a vehicle according to a first embodiment of the invention is described with reference to
FIGS. 1-7
.
As shown in
FIG. 1
, AC generator
1
is comprised of stator
2
, rotor
3
, a pair of front frame
41
, and rear frame
42
, and rectifier unit
5
.
Stator
2
has a Y-connected stator winding
21
, which is comprised of three phase-windings. Each phase winding has output lead wires
211
for an output terminal to be connected to rectifier unit.
5
and a neutral point. Rotor
3
is comprised of shaft
31
, magnet core
32
having a plurality of claw poles, front cooling fan
331
and rear cooling fan
332
and cylindrically wound field coil
34
, slip ring
35
and others. Rectifier unit
5
has four input terminals respectively connected to four output lead wires
211
of stator winding
21
.
Shaft
31
carries pulley
8
, which is driven by an engine mounted in a vehicle, and magnetic pole
32
, which surrounds field coil
34
by the claw poles. Front and rear cooling fans
331
,
332
are respectively welded to the front and rear surface of magnet pole
32
to generate cooling air when rotor
3
rotates.
Front and rear frames
41
and
42
respectively have air-intake windows
411
and
421
at opposite end surfaces thereof and air-discharge windows
412
and
422
at peripheral portions thereof.
As shown in
FIGS. 2 and 3
, rectifier unit
5
is comprised of terminal member
52
, four positive diodes
501
, four negative diodes
502
, a pair of arc-shaped, positive copper heat sink
511
and negative copper heat sink
512
, and DC output terminal
53
. Positive diodes
501
are combined with positive heat sink
511
by welding, soldering, or press-fitting, and negative diodes
502
are combined with negative heat sink
512
in the manner stated above. DC output terminal
53
is fixed to positive heat sink
511
. Positive heat sink
511
has circumferentially dispersed four recesses at the outer periphery thereof.
Terminal member
52
is a resin mold member having four insert metal terminals
521
, which respectively connect the pairs of positive and negative diodes
501
and
502
to form a full-wave rectifying bridge circuit, as shown in FIG.
4
.
Terminal member
52
and the pair of arc-shaped heat sinks
511
and
512
spans more than 180° in angle so that output lead wires
211
can support rectifier unit
5
more easily. Each of terminal member
52
and the pair of heat sinks
511
and
512
has three dispersed common through holes
56
. Three insulation pipes
55
are disposed at the through holes between positive and negative heat sinks
511
,
512
, and pipe rivet
54
is inserted into each of insulation pipes
55
and each of through holes
56
to fix together.
The surface of terminal member
52
opposite rear cooling fan
332
has a fan-shroud portion providing a suitable gap between the surface and rear fan
332
.
As shown in
FIG. 5
, each output lead wire
211
has a rectangular cross-section and extends from stator winding
21
so that the longer side of the cross section become parallel with the radial direction of stator
2
. As shown in
FIGS. 5 and 6
, insert metal terminal
521
has U-shaped terminal portion
5211
, a pair of L-bent terminal portions
5212
to be connected to positive and negative diodes, and connection portion
5213
which is insert-molded with resin. Terminal member
52
has four hollow axially extending guide portions
522
respectively disposed in the recess of positive heat sink
511
. Each guide portion
522
has rectangular guide hole
523
formed under U-shaped terminal portion
5211
to which one of output lead wire
211
is inserted and welded or soldered to U-shaped terminal portion
5211
of insert metal terminal
521
. This provides a sufficient stiffness to provisionally hold rectifier unit
5
after output lead wires
211
are welded to terminal member
52
, while rectifier unit
5
is being fixed to, rear frame
42
.
Guide holes
523
and U-shaped terminal portions
5211
of terminal member
52
are disposed separate from each other so that output lead wires
211
can be inserted into guide portions
522
easily from below, as illustrated in
FIGS. 5 and 7
. Then output lead wires
211
are guided to terminal portions
5211
to be welded together, and rectifier unit
5
is placed on frame
42
. This structure provides a sufficient stiffness-to provisionally hold rectifier unit
5
, so that rectifier unit
5
can be fixed to rear frame
42
by bolts
6
, which are inserted into pipe rivets
54
, and nuts
7
.
(Second Embodiment)
U-shaped terminal portions
5211
of terminal member
52
can span in an arc range θ that is smaller than 180°, as shown in
FIG. 8
, if output lead wires
211
are stiff enough to support rectifier unit
5
. Rectifier unit
5
is fixed to stator
2
as illustrated in FIG.
9
.
(Third Embodiment)
An AC generator according to a second embodiment of the invention is described with reference to
FIGS. 10-12
.
Aluminum heat sinks
511
and
512
, which are lighter than the copper heat sinks of the first embodiment, are employed so that output lead wires.
211
can support rectifier unit
5
more easily. A plurality of outer radial slits
5110
are formed along the outer periphery of positive heat sink
511
, and a plurality of radial inner fins
5120
are also formed along the inner periphery of negative heat sink
512
.
(Fourth Embodiment)
As shown in
FIGS. 13 and 14
, neutral point terminal
521
e
is substituted for metal terminal
521
a
of the first embodiment. Neutral point terminal
521
e
has three U-shaped terminal portions
5211
to which three output lead wires
211
for the neutral point are respectively connected. The three U-shaped terminal portions
5211
of neutral point terminal
522
are respectively located at the outer peripheral portions of positive heat sink
511
together with the other three U-shaped terminal portions
5211
. This can reduce connection work time.
(Variations)
U-shaped terminal portions
5211
can have stopper
5214
to retain an end of output lead wire
211
, as shown in
FIG. 15
, or intermediate slit
5215
so that output lead wire
211
can be clamped easily, as shown in FIG.
16
.
As shown in
FIG. 17
, output lead wire
211
can be bent to have a radius of curvature R to provide a degree of freedom of location of rectifier unit
5
to be connected to output lead wires
211
.
As shown in
FIGS. 18 and 19
, end portion
2111
of rectangular output lead wire
211
is formed to be round in cross section to provide shoulder portion
2110
, and circular metal terminal
5216
is substituted for U-shaped terminal portion
5211
. Shoulder portion
2110
retains lead wires
211
as a stopper when output lead wire
211
is inserted into circular metal terminal
5216
.
(Fifth Embodiment)
As illustrated in
FIG. 20
, stator winding
21
is comprised of three phase-windings X, Y, and Z, and each phase winding X, Y or Z is comprised of a plurality of lap-wound coils. For example X-phase-winding has coils X
11
, X
12
, X
13
, and X
14
, each of which is wound in slots of the stator
2
at one-pole pitch. Each coil is made of a rectangular wire or a wire having an elliptic cross-section. Each coil can be formed by a plurality of U-shaped segments or I-shaped segments welded to form a lap winding. Each coil has opposite ends, both, extending from one end of stator
2
in the axial direction thereof so that longer sides of the wire extend in the radial direction thereof, as illustrated in FIG.
5
.
Generally circular terminal member
52
A has three metal terminals R
1
, R
2
, and R
3
, one neutral point terminal N, and three connection groups X
2
, Y
2
, and Z
2
. Connection group X
2
includes three X-phase connection members X
21
, X
22
, and X
23
, which are disposed along the outer periphery of positive heat sink to respectively correspond to coils X
11
, X
12
, X
13
, and X
14
to connect the four X phase coils in series to form X-phasewinding. Connection group Y
2
includes three Y-phase connection members, which connect four Y-phase coils in series to form Y-phase-winding. connection group Z
2
includes three Z-phase connection members, which connect four Z-phase coils to form Z-phase-winding. This makes connection works more suitable for automation.
Terminal member
52
A can be formed into double circular members or a plurality of coaxially disposed arc members. For example, terminal member
52
A can be comprised of a first member having the phase connection members and a second member having the neutral point terminal and the metal terminals. The first member can be disposed near the stator, in this case.
The connection members, neutral point terminal and metal terminals can be stamped out from a lead frame.
Output lead wires of the respective phase windings are star-connected in the similar manner as illustrated in FIG.
14
. However, it is easy to connect the phase-windings in the delta-connection in a well-know manner.
(Variation)
The phase connection members (e.g. X
21
, X
22
, and X
23
) can be substituted by guide holes h formed in terminal member
52
B, as illustrated in
FIG. 21
,
In the foregoing description of the present invention, the invention has been disclosed with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made to the specific embodiments of the present invention without departing from the broader spirit and scope of the invention as set forth in the appended claims. Accordingly, the description of the present invention in this document is to be regarded in an illustrative, rather than restrictive, sense.
Claims
- 1. An AC generator for a vehicle, comprising:a rotor driven by an engine; a stator disposed around the rotor, the stator including a plurality of phase windings with a plurality of output lead wires extending in an axial direction of the rotor, the lead wires having a generally rectangular cross section with longer sides being parallel to a radial direction of the rotor; a pair of front and rear frames for supporting the rotor and the stator; and rectifier unit disposed between the pair of frames and connected to the plurality of output lead wires, the rectifier unit comprising: a pair of positive and negative metal heat sinks; a plurality of pairs of a positive rectifier element having one side combined with the positive heat sink and a negative rectifier element having one side combined with the negative heat sink; and a terminal member for respectively connecting the plurality of output lead wires and the positive and negative rectifier elements to form a bridge circuit, the terminal member having a plurality of metal terminals for connecting the other side of the positive and the negative rectifier elements, wherein the terminal member comprises a plurality of resin guide members having axially extending rectangular hole at the outer peripheral portion of the positive heat sink for guiding the lead wire therein, the metal terminals comprise U-shaped terminal portions, respectively disposed at the plurality of guide members, for connecting the lead wires, and each metal terminal comprises a stopper for retaining an end of the lead wire.
- 2. An AC generator for a vehicle comprising:a rotor driven by an engine; a stator disposed around the rotor, the stator including a plurality of phase windings with a plurality of output lead wires extending in an axial direction of the rotor, the lead wires having a generally rectangular cross section with longer sides being parallel to a radial direction of the rotor; a pair of front and rear frames for supporting the rotor and the stator; and a rectifier unit disposed between the pair of frames and connected to the plurality of output lead wires, the rectifier unit comprising: a pair of positive and negative metal heat sinks; plurality of pairs of a positive rectifier element having one side combined with the positive heat sink and a negative rectifier element having one side combined with the negative heat sink and terminal member for respectively connecting the plurality of output lead wires and the positive and negative rectifier elements to form a bridge circuit, the terminal member having a plurality of metal terminals for connecting the other side of the positive and the negative rectifier elements, wherein the pair of positive and negative heat sinks comprises a pair of arc-shaped aluminum alloy members having a plurality of recesses at circumference of the pair of positive and negative heat sinks, the metal terminals comprise U-shaped terminal portions respectively disposed in the plurality of recesses and, each metal terminal comprises a stopper for retaining an end of the lead wire.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-153929 |
Jun 1999 |
JP |
|
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