Note: Descriptions are shown in the official language in which they were submitted.
08
1 The present invention relates to alternatcrs
of the type mainly used as automotive vehicle alter-
nators, and more particularly the invention relates to
an alternator of the type having a semiconductor voltage
regulator built into its end frame.
Conventional vehicle alternators have employed
voltage regulators such that the current supplied to the
field coil is controlled in accordance with the output
voltage of the stator coils so as to maintain the
output voltage of the generator constant~ Heretofore,
voltage regulators of the semiconductor type composed
of electronic circuitry using semiconductor devices
have been used and it has been usual to mount the
voltage regulator on the generator. In this case, the
usual practice has been such that the voltage regulator
is attached with small screws to the mount secured
to the outer wall of the generator end frame.
However, efforts have recently been made
toward decreasing the size and weight of alternators
designed for use on vehicles, particularly automotive
vehicles and thus the space available for mounting the
generator has in fact been decreased correspondingly.
As a result, in the case of the alternators having the
voltage regulators mounted on the outer side of the
generator frames in the conventional manner, there
1 have been cases where the outer diameters of the
alternators have been so large as to make their
mounting on some types of vehicles impossible.
While attempts have heretofore been made to
build the voltage regulators into the alternators, the
rectifier units have been mounted in the intended
locations of the built-ln voltage regulators with the
result that the incorporation of the ordinary prior
art voltage regulators has necessitated modification
of the rectifier units into special forms with the
resulting complication of construction and hence the
increase in the size of the rectifier units.
With a view to overcoming the foregoing
deficiencies in the prior art, it is the object of
the present invention to provide a compact alternator
with built~in rectifier unit and voltage regulator.
In accordance with the present invention there
is thus provided an improved alternator apparatus of
a type housing therein a voltage regulator assembly,
comprising: an alternator having frame means including
a substantially cup-shaped end frame; cooling fin means
attached inside of and parallel to bottom surface of
said end frame, and rectifier means including diodes
provided over said cooling fin means to rectify AC
voltage from said alternator into substantially DC
voltage; a voltage regulator assembly including a
semiconductor voltage regulator circuit for regulating
the output voltage of said alternator, said circuit being
1 disposed in a case, a connector having a plurality of
external terminals, and an assembly base means made
from an insulating material and having embedded thereln
a plurality of wiring means for connecting said voltage
regulator circuit to said external terminals, said
assembly being disposed between said cooling fin
means and bottom surface of said end frame.
The invention will now be described by way
of example with reference to the accompanying drawings,
in which:
Fig. 1 is a circuit diagram showing the
circuit construction of an alternator according to an
embodiment of the present invention;
Fig. 2 is a partially sectional front view
of the alternator of Fig. 1 as viewed from its rear
side;
Fig. 3 is a front view of the voltage
regulator assembly shown in Fig. l; and
Figs. 4 and 5 are respectively a side view and
a sectional view taken along the line V-V of Fig. 3.
Referring to Fig. 1, there is illustrated by
way of example a circuit diagram showing the connections
between an alternator of this invention and external
units. In the Figure, an alternator G comprises
three-phase stator coils 1, a field coil 2 wound on
a rotor, brushes 3a and 3b for supplying current to the
field coil 2, a rectifier unit 4 including three
pairs of (or six) diodes for full-wave rectifying the
-- 3 --
;208
1 AC output of the stator coils 1, a pair of (or two)
neutral diodes 5, three regulator excitation diodes 6,
an initial e~citation resistor 7 and a diode 8 connected
in series with the former, a battery terminal 9, a
voltage regulator circuit 10 and a connector 11 having
external terminals lla to llc. The battery terminal 9
is connected to a battery B, and the connector 11
has its first external terminal or voltage detecting
terminal lla connected to the battery B, the second
external terminal or lamp terminal llb to a relay R for
a charge indicator lamp L and the third external terminal
llc to a key switch S.
In accordance with the present invention the
voltage regulator circuit 10 and the connector 11 are
made integral with each other to form a voltage regulator
assembly 12. The voltage regulator circuit lO is
responsive to the voltage of the battéry B to control
the flow of current to the field coil 2 and thereby to
regulate the output voltage of the generator and it is
in the form of a semiconductor circuit employing semi-
conductor devices. The circuit 10 includes four termi-
nals lOa to lOd. Of the four terminals of the voltage
regulator circuit 10, the first terminal lOa is connected
to the terminal lla of the connector 11 through a
wiring member lOa', the second terminal lOb to the
second terminal llb of the connector 11 and a brush
terminal 12b of the assembly 12 through wiring members
lOb' and lOb", respectively, the third terminal lOc
O~
1 to the other brush terminal 12c of the assembly 12
through a wiring member lOc' and the fourth terminal lOd
to a ground terminal 12d of the assembly 12 through a
wiring member lOd'. The brush terminals 12b and 12c
of the assembly 12 are respectively connected to the
brushes 3a and 3b, and the ground terminal 12d is
grounded.
Fig. 2 shows the construction of the principal
parts of the alternator according to the invention.
In the Figure, a rear end frame 20 is formed into sub-
stantially cup shape and it is coupled with a front
end frame (not shown) so as to hold therebetween the
stator (not shown) having the stator coils 1 (Fig. 1)
and form a generator housing. Disposed in the conven-
tional manner inside the rear end frame 20 are coolingfins 41 arranged substantially parallel to a side
portion 21 (corresponding to the bottom of the cup), and
the diodes of the rectifier unit 4 of Fig. 1 are mounted
on the cooling fins 41. Although not shown in detail,
the cooling fins 41 comprise a pair of p'ositive and
negative fins each in the form of a circular thin plate
and the fins 41 are circumferentially continuously
arranged to take the shape of horseshoe as a whole.
The three positive diodes of the rectifier unit 4 of
Fig. 1 are mounted in the conventional manner on the
positive fin and the other three negative diodes are
similarly mounted on the other negative fin. These
diodes are connected as shown in Fig. 1. If necessary,
o~
1 the neutral diodes 5 and the excitatlon diodes 6 of Fig.
1 may also be mounted on the cooling fins 41.
The voltage regulator assembly 12 including
the voltage regulator circuit 10 and the connector 11
made integral with each other as described in connection
with Fig. 1 is formed into substantially circular
arc shape and it is disposed between the side portion
21 of the rear end frame 20 and the cooling fins 41
so as to extend substantially parallel to the latter.
The voltage regulator assembly 12 is built into the
generator by attaching it to the end frame 20 by three
bolts 42 fitted to the cooling fins 41. In this case,
the connector section that will be described later is
located between the ends of the cooling fins 41 so as
to bridge these ends, and a brush holder 3 for holding
the brushes 3a and 3b of Fig. 1 is mounted on the back
side of the connector section (the inner side of the
generator).
Figs~ 3 to 5 show a detailed construction of
the voltage regulator assembly 12, and the assembly 12
includes an assembly base 13 made from an insulating
material such as PPS material (polyphenylene sulphide)
for assemblying the voltage regulator and the connector
as an integral unit. The base 13 includes a case 101
of the voltage regulator circuit 10 and the connector
11 and these components are molded in one piece. In
this case, five metal condùctors 14a to 14e of band
plate shape are embedded simultaneously in the base 13.
v~
1 The voltage regulator circuit case 101 is formed into
square box shape and the connector 11 is formed into a
shape having three connecting boxes llla to lllc.
The first metal conductor 14a embedded in
the base 13 comprises, as its integral parts, the first
terminal lOa of the voltage regulator circuit 10, the
wiring member lOa' and the first external terminal lla
of the connector 11 which are shown in Fig. 1, and
the metal conductor 14a has its one end projected
through an inner wall 102 of the case 101 to form the
first terminal lOa, its other end exposed inside the
first connecting box llla of the connector 11 to form
the first external terminal lla and its intermediate
portion formed into the connecting conductor lOa'.
The second metal conductor 14b comprises, as its integral
parts, the second terminal lOb, the wiring members lOb'
and lOb", the second external terminal llb and the
brush terminal 12b of the assembly 12 which are shown
in Fig. 1, and the conductor 14b has its one end or the
second terminal lOb projected through the inner wall
102 of the case 101, its other end or the second external
terminal llb exposed inside the second connecting box
lllb of the connector 11 and its other end or the brush
terminal 12b projected from the base 13 near the side
of the connector 11. The third metal conductor 14c
comprises, as its integral parts, the third terminal lOc,
the wiring member lOc' and the other brush terminal 12c
which are shown in Fig. 1, and the conductor 14c has its
;;208
1 one end or the third terminal 1.0c proJected through the
case inner wall 102 and the other end or the brush
terminal 12c projected through the outer wall of the
base 13 to extend parallel to the brush terminal 12b
The fourth metal conductor 14d comprises, as its integral
parts, the fourth terminal lOd, the wiring member lOd'
and the ground terminal 12d which are shown in Fig. 1
and it also serves as a stay for attaching the assembly
12 to the end frame 20. The fourth terminal lOd
portion is projected through the case inner wall 102
and the ground terminal 12d portion which is attached
to the end frame 20 by the bolt 42 is grounded. The
fifth metal conductor 14e has its one end exposed
inside the third connecting box lllc of the connector 11
and the other end projected to the back side of the
base 13. The diode 8 of Fig. 1 is connected to the
other end of the fifth metal conductor 14e.
The case 101 forming an integral part of the
base 13 includes an open side facing the side 21 of
the end frame 20 and a radiation fin 103 is fixed by
rivets 104 to the open side to cover it. Disposed
inside the case 101 in contact with the inner surface
of the radiation fin 103 is a wiring board 105 comprising
a ceramic substrate or the like. A semiconductor unit
106 is mounted on the wiring board 105 to form the voltage
regulator circuit of Fig. 1 and the circuit is connected
to the terminals lOa to lOd projected through the case
inner wall 102. A cover 107 is fixed to the other open
-- 8 --
~6ZO~
1 side of the case 101 which is opposite to the radiation
fin 103 and thus the terminals lOa to lOd, the wiring
board 105 and the unit 106 are enclosed by the case 101,
the radiation fin 103 ancl the cover 107. The unit 106
is coated with resin 108 with which the case 101 is
filled, thus protecting the unit 106 from moisture and
the like.
In accordance with the above-described
construction, mainly by virtue of the fact that the
voltage regulator assembly 12 is constructed as described
above, there is the advantage of practically causing
no increase in the size of the generator than previously
and making it possible to build the voltage regulator
circuit 10 into the body of generator. In other words,
since the base 13 is in thin plate form, by locating
the base 13 parallel to and along the cooling fins
41 (hence the side 21 of the end frame 20), it is
possible to locate the assembly 12 in the narrow
space between the cooling fins 41 and the end frame
side 21. Since the assembly 12 is mounted such that the
connector 11 forming a relatively large projected
part of the assemb~ly 12 is located in the space between
the ends of the horseshoe-shaped cooling fins 41 and
also the connector 11 projects from the end frame 20,
there is the effect of eliminating the need for any
additional space to receive the voltage regulator.
As a result, by simply projecting the end frame 20
axially to some extent as the occasion demands, it is
620~3
1 possible to build the voltage regulator into the
generator.
In addition, since the assembly 12 is comprised
of at least the voltage regulator circuitlO, the connector
11 and the assembly base 13, the components which are to
be interconnected at a large number of their portions,
that is, the voltage regulator circuit 10 and the con-
nector 11 can be connected to each other prior to the
mountlng of the assembly 12 to the genèrator, thus
simplifying the connecting operation, making it possible
to automate the performance test of the assembly as a
separate unit and increasing the reliability of the con-
nections. Further, since the wiring members lOa' to lOd'
for connecting the voltage regulator circuit 10 to
the external terminals lla to llc of the connector
11 can be embedded in the base 13 and also the case 101
and the connector 11 can be formed as integral parts
of the base 13, the assembly can be manufactured
inexpensively and the assembly can also be made small
and compact. Still further, since the terminals lOa
to lOd of the voltage regulator circuit 10 are located
inside the case 101, these terminals can be possitively
protected against e~ternal water splash and the like.
It is to be noted that by disposing the heat radiation
plate 103 on the end frame side, the radiation plate
103 can be cooled effectively by means of the cooling
air drawn into the generator.
It will thus be seen from the foregoing
-- 10 --
o~
1 description that the present invention has a great
advantage o~ providing an alternator with built-in
voltage regulator ~hich is small in size, simple in
construction and excellent in reliability.
