Title of Invention

"VEHICULAR STARTER/GENERATOR"

Abstract A vehicular starter/generator having starter coils 17 and generator coils 16 both wound round a stator core of an armature, in which a commutator brush mechanism 20 is disposed inside in a crank axis direction of an inner rotation type rotor 11 fitted on a crank shaft 6, a governor mechanism 30 is disposed outside in the crank axis direction, and a commutator and brushes of the commutator brush mechanism 20 are moved into contact with and away from each other by the governor mechanism 30.
Full Text The present invention relates to a starter/generator as an integral combination of an internal combustion engine starter and a generator both mounted on a vehicle. Particularly, the invention is concerned with a vehicular starter/generator provided with a governor mechanism.
A vehicular starter/generator provided with a governor mechanism has been filed by the same applicant as in the present case, which application has already been laid open (Japanese Patent Laid Open No.289520/96) and which is illustrated in Fig.3.
In the vehicular starter/generator, which is indicated at 01 and which is disposed sideways of a crank case 02, an inner rotor 04 is fitted on an end portion of a crank shaft 03, the inner rotor 04 being an inner rotation type rotor having six magnets 05 fitted on its outer periphery.
Around the inner rotor 04 is disposed an outer stator 06 while being supported by the crank case 02, with both generator coils 07 and starter coils 08 being wound round the outer stator 06.
A governor mechanism 010 is disposed outwardly laterally of the inner rotor 04. The governor mechanism 010 comprises a governor outer Oil integral with the inner rotor 04, a governor inner 012 which is axially movable integrally with a brush holder 021, and a ball 013 as a governor weight interposed between the governor outer Oil and the governor inner 012.
Still outside the governor mechanism 010 is disposed a commutator brush mechanism 020. In the commutator brush mechanism 020, brushes 022 are projected
from an outer surface of the brush holder 021 which is adapted to axially move integrally with the governor inner 012, and commutator segments 024 are disposed in a commutator holder 023 opposed to the brush holder.
At the time of start-up of the associated internal combustion engine, the brushes 022 and the commutator segments 024 are in contact with each other. In this state, an electric current supplied from a battery flows through the starter coils 08, generating a rotational torque in the inner rotor 04 and causing the crank shaft 02 to rotate to start the internal combustion engine.
As the rotational speed increases after start-up of the internal combustion engine, the ball 013 moves in the outer periphery direction by virtue of a centrifugal force, causing the governor inner 012 to slide in the crank axis direction, whereby the brushes 022 can be moved out of contact with the commutator segments 024 automatically.
[Problem to be Solved by the Invention]
According to the above conventional structure wherein the governor mechanism 010 and the commutator
brush mechanism 020 are disposed in this order outwardly laterally of the inner rotor 04, the amount of outward expansion in the crank axis direction is large.
The present invention has been accomplished in view of the above-mentioned problem and it is an object of the invention to provide a vehicular starter/generator having a governor mechanism in which the amount of outward expansion in the crank axis direction is made small.
[Means for Solving the Problem and Function and Effect]
In order to solve the above-mentioned object, according to the invention defined in claim 1 there is provided a vehicular starter/generator having starter coils and generator coils both wound round a stator core of an armature, in which a commutator brush mechanism is disposed inside in a crank axis direction of an inner rotation type rotor fitted on a crank shaft, a governor mechanism is disposed outside in the crank axis direction, and a commutator and brushes of the commutator brush mechanism are moved into contact with and away from each other by the governor mechanism.
Since the commutator brush mechanism is disposed inside in the crank axis direction of the inner rotation type rotor, while outside in the crank axis direction is disposed the governor mechanism separately from the commutator brush mechanism, it is possible to minimize the amount of outward expansion in the crank axis direction.
Besides, it is easy to protect the commutator brush mechanism from dust suspended in the outside air because the commutator brush mechanism is disposed inside in the crank axis direction of the rotor.
According to the invention defined in claim 2 there is provided, in combination with the invention defined in claim 1, a vehicular starter/generator wherein the state of winding of the starter coils and the generator coils on the stator core is offset inside in the crank axis direction with respect to the stator core to decrease the amount of an outward expansion of both coils.
Since the amount of an outward projection of the starter coils and the generator coils from the stator core is made small, it is possible to keep smaller the
amount of an outward expansion in the crank axis direction.
According to the invention defined in claim 3 there is provided, in combination with the invention defined in claim 1, a vehicular starter/generator wherein a rotor for detecting a crank angle position is mounted integrally with a rotating portion of the governor mechanism.
The rotor can be disposed easily by utilizing the rotating portion of the governor mechanism.
According to the invention defined in claim 4 there is provided, in combination with the invention defined in claim 3, a vehicular starter/generator wherein a forced air cooling fan for an internal combustion engine is integrally mounted outside in the crank axis direction of the rotor.
Not only the mounting of the fan can be done easily but also the rotor shuts off the dust suspended in the outside air which is introduced by the fan, thereby preventing the entry of the dust into the commutator
brush mechanism.
Accordingly, the present invention relates to a vehicular starter/generator having starter coils and generator coils both wound round a stator core of an armature, characterized in that a commutator brush device is disposed inside in a crank axis direction of an inner rotation type rotor fitted on a crank shaft, a governor device is disposed outside in the crank axis direction and a commutator and brushes of said commutator brush device are moved into contact with and away from each other by said governor device.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 is a sectional view of a vehicular starter/generator according to an embodiment of the present invention;
Fig. 2 is a sectional view of the vehicular starter/generator which is in a state different from the state shown in Fig. 1; and
Fig. 3 is a sectional view of a conventional vehicular starter/ generator.
[Mode for Carrying Out the Invention] An embodiment of the present invention will be described hereinunder with reference to Figs.l and 2, which are sectional views in different states of a vehicular starter/generator 10 embodying the invention and provided in an internal combustion engine 1.
The internal combustion engine 1 is a two-cycle 1-cylinder type engine, in which a cylinder block 3, a cylinder head 4 and a cylinder head cover 5 are projected from a crank case 2, and a crank shaft 6, which is rotated by a crank mechanism, is journaled in the crank case 2 in the transverse and horizontal direction through a main bearing 7 .
The crank case 2 is in the shape of a bowl comprising a bottom wall and a cylindrical wall 2a extending sideways to the right. The main bearing 7 is fitted in and supported by the bottom wall of the crank case 2, with the crank shaft 6 projecting centrally of the bowl-shaped crank case and rightward from the main
bearing 7 .
An inner rotor (inner rotation type rotor) 11 is fitted on a tapered tip of the crank shaft 6 and is fixed thereto with nut 13 so as to rotate together with the crank shaft.
The outer peripheral surface of the inner rotor 11 is formed with six grooves of an arcuate section, and Nd-Fe-B(neodium iron boron) magnets 12 are respectively fitted in those grooves.
An outer stator 15 is disposed on the outer periphery of the inner rotor 11 and its outer peripheral edge portion is threadedly engaged with the cylindrical wall 2a of the crank case 2 using bolt 19 and is supported thereby.
A stator core of the outer stator 15 is formed by a laminate of thin steel sheets, and a plurality of yokes extend from an annular outer peripheral edge portion toward the center, with generator coils 16 and starter coils 17 being wound round the yokes.
The generator coils 16 and the starter coils 17
wound round the yokes are offset inside in the crank axis direction to decrease the amount of an axially outward projection of the coils, as shown in Fig.l.
The generator coils 16 and the starter coils 17 projecting through the cylindrical wall 2a of the crank case 2 to a larger extent in the axially inward direction than in the axially outward direction are in an annular shape, defining an inner space, in which is constituted a commutator brush mechanism 20.
Within the said inner space is disposed a brush holder 21 through which the crank shaft 6 extends. The brush holder 21 is fitted on the crank shaft 6 so as to permit only an axial slide thereof while inhibiting a relative circumferential rotation with respect to the crank shaft. A spring 23 is disposed between the brush holder 21 and the inner rotor 11 to urge the brush holder axially inward.
From the inner surface of the brush holder 21 are projected brushes 22 at plural positions while being urged by springs.
A commutator holder 25 is mounted in opposition to
the inner surface of the brush holder 21, with the crank shaft 6 passing through the center of the commutator holder, and its outer peripheral edge is fixed to and supported by the portions of the generator coils 16 and the starter coils 17 projecting largely in the foregoing axially inward direction.
On the surface of the commutator holder 25 opposed to the brush holder 21 are arranged commutator segments 26 concentrically at predetermined positions.
The brush holder 21 adapted to rotate together with the crank shaft 6 moves toward and away from the fixed commutator holder 25. When the brush holder 21 approaches the commutator holder 25, the brushes 22 come into contact with required commutator segments 26.
On the other hand, outside in the crank axis direction of the inner rotor 11, an inner cylindrical portion 31 which covers the surroundings of the nut 13 engaged threadedly with the tip of the crank shaft 6 and an outer cylindrical portion 32 which is concentric with the inner cylindrical portion 31 and which covers the outside of the inner cylindrical portion, are extended
axially outward. In this portion there is formed governor mechanism 30.
More specifically, the outer cylindrical portion 32, which has a tapered inner peripheral surface, constitutes a governor outer, and a governor inner 33 is fitted on the outer periphery of the inner cylindrical portion 31 in an axially slidable manner. Further, a ball 34 serving as a governor weight is disposed between the governor inner 33 and the outer cylindrical portion 32.
The governor inner 33 in the governor mechanism 30 is adapted to slide axially, and a connecting rod 35, which is fixed at one end thereof to the governor inner 33, extends through the inner rotor 11 in parallel with the crank shaft 6 and the tip thereof is fitted in the brush holder 21.
The connecting shaft 35 connects the governor inner 33 and the brush holder 21 integrally with each other and in this integrally connected state it is movable in the crank axis direction.
When the crank shaft 6 is at rest, as shown in

Fig.l, the brush holder 21 is moved axially inward with the biasing force of the spring 23, and the brushes 22 are in contact with commutator segments 26. Therefore, upon supply of an electric current from a battery, the electric current flows to the starter coils 17 through the contact between the brushes 22 and the commutator segments 26, producing a rotating torque in the inner rotor 11 to rotate the crank shaft 6, whereby the internal combustion engine 1 can be started.
As the engine speed increases, the ball 34 moves to the outer peripheral side on the tapered inner surface of the outer cylindrical portion 32, thereby causing the governor inner 33 to slide axially outward, so that the brush holder 21 also moves axially outward integrally through the connecting shaft 35, as shown in Fig. 2. When the engine speed exceeds a predetermined number of revolutions, the brushes 22 leave the commutator segments 26 automatically. Subsequently, power generation is performed by the generator coils 16 to charge the battery.
An inner peripheral edge of a crank angle detecting rotor 40, which is in the shape of an annular plate, is
integrally fitted on an outer peripheral edge of the outer cylindrical portion 32 as a constituent of the governor mechanism 30. In proximity to an outer peripheral edge of the rotor 40 is disposed a pulser 41 at a predetermined position, the pulser 41 being fixed to the crank case 2 .
The rotor 40 is adapted to rotate together with the crank shaft 6 through the inner rotor 11. Notches are formed in the outer peripheral edge of the rotor 40, and the pulser 41 detects the said notches and determines a crank angle.
The annular plate-like rotor 40 covers the generator coils 16 and starter coils 17 of the outer stator from the outside.
A forced air cooling fan member 45 for the internal combustion engine is integrally mounted axially outside of the rotor 40.
The fan member 45 has a central conical portion 45a, a skirt portion of which is fixed to the outer cylindrical portion 32 of the inner rotor 11 with bolt 46, and a fan 45b is erected on the said skirt portion
outwardly laterally of the rotor 40.
The fan member 45 is covered with a fan cover 48.
The fan cover 48 has an outside air inlet 48a formed outside the fan member 48 and also has a guide wall 48b for conducting intake air toward the cylinder head cover 5 .
In the vehicular starter/generator 10 of this embodiment constructed as above, the commutator brush mechanism 20 is disposed axially inside of the inner rotor 11, while the governor mechanism 30 is disposed axially outside of the inner rotor separately from the commutator brush mechanism 20, whereby the amount of an outward expansion in the crank axis direction is kept small.
Besides, since the state of winding of the generator coils 16 and the starter coils 17 on the yokes of the stator core of the outer stator 15 is offset inside in the crank axis direction to decrease the amount of an outward projection of the coils, the rotor 40 and the fan member 45 both located outside the coils can be
positioned in less outward expansion in the crank axis direction.
The outside air which has been introduced from the outside air inlet 48a of the fan cover 48 with rotation of the fan 45b spreads along the outer periphery of the central conical portion 45a, but the rotor 40 shuts off the introduced air and prevents the entry thereof into the vehicular starter/generator 10. Therefore, the outside air is difficult to get into the commutator brush mechanism 20 which is located in a more interior (axially inward) position than the starter/generator 10. Thus, the commutator brush mechanism 20 is prevented from being influenced by the dust contained in the outside air.
[Explanation of Reference Numerals]
1 ... internal combustion engine
2 ... crank case
3 ... cylinder block
4 ... cylinder head
5 ... cylinder head cover
6 ... crank shaft
7 ... main bearing

10 ... vehicular starter/generator
11 ... inner rotor
12 ... magnet
13 ... nut

15 ... outer stator
16 ... generator coil
17 ... starter coil

20 ... commutator brush mechanism
21 ... brush holder
22 ... brush
23 ... spring

25 ... commutator holder
26 ... commutator segment

30 ... governor mechanism
31 ... inner cylindrical portion
32 ... outer cylindrical portion
33 ... governor inner
34 ... ball
35 ... connecting shaft

40 ... rotor
41 ... pulser

45 ... fan member
46 ... bolt
48 ... fan dover



WE CLAIM:
1. A vehicular starter /generator having starter coils (17) and generator coils
(16) both wound round a stator core of an armature, characterised in that:
a commutator brush device (20) is disposed inside in a crank axis direction of an inner rotation type rotor fitted on a crank shaft (6) ;
a governor device (30) is disposed outside in the crank axis direction; and
a commutator (26) and brushes (22) of said commutator brush device (20) are moved into contact with and away from each other by said governor device (30).
2. A vehicular starter /generator as claimed in claim 1, wherein the state of
winding of the starter coils (17) and the generator coils (16) on said stator core is
offset inside in the crank axis direction with respect to the stator core to decrease
the amount of an outward expansion of both said coils (16, 17).
3. A vehicular starter /generator as claimed in claim 1, wherein a rotor (40)
for detecting a crank angle position is mounted integrally with a rotating portion
of said governor device (30).
4. A vehicular starter /generator as claimed in claim 3, wherein said rotor
has a forced air cooling fan (45) integrally mounted outside in the crank axis
direction of said rotor.
5. A vehicular starter /generator substantially as hereinbefore described with
reference to the accompanying drawings.

Documents:

1651-del-1998-abstract.pdf

1651-del-1998-claims.pdf

1651-del-1998-correspondence-others.pdf

1651-del-1998-correspondence-po.pdf

1651-del-1998-description (complete).pdf

1651-del-1998-drawings.pdf

1651-del-1998-form-1.pdf

1651-del-1998-form-13.pdf

1651-del-1998-form-19.pdf

1651-del-1998-form-2.pdf

1651-del-1998-form-3.pdf

1651-del-1998-form-4.pdf

1651-del-1998-form-6.pdf

1651-del-1998-gpa.pdf

1651-del-1998-petition-137.pdf

1651-del-1998-petition-138.pdf

abstract.jpg


Patent Number 215318
Indian Patent Application Number 1651/DEL/1998
PG Journal Number 11/2008
Publication Date 14-Mar-2008
Grant Date 25-Feb-2008
Date of Filing 16-Jun-1998
Name of Patentee HONDA GIKEN KOGYO KABUSHIKI KAISHA
Applicant Address 1-1 MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO, JAPAN.
Inventors:
# Inventor's Name Inventor's Address
1 SHOJI MOTODATE C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN.
PCT International Classification Number F02N 7/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 HEI-9-182834 1997-01-08 Japan