Information
-
Patent Grant
-
6525430
-
Patent Number
6,525,430
-
Date Filed
Tuesday, May 16, 200024 years ago
-
Date Issued
Tuesday, February 25, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Ramirez; Nestor
- Gonzalez; Julio
Agents
-
CPC
-
US Classifications
Field of Search
US
- 290 1 R
- 290 1 C
- 290 1 A
- 123 4156
- 123 4165
- 123 7
- 123 2
-
International Classifications
-
Abstract
An engine generator comprises a fan cover made of die-cast aluminum alloy, and a power control unit including an aluminum base sheet. The base sheet has a power control circuit formed thereon. The fan cover includes a mounting portion to be attached to the power control unit. When the power control unit is attached to the fan cover, a surface of the aluminum base sheet comes into intimate contact with an outer surface of the mounting portion. Heat generated at the unit is transmitted to the fan cover, and then released from the fan cover serving as a heat releasing member.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an engine generator suitable for preventing temperature rise in a power control unit of the generator.
2. Description of the Related Art
Engine generators are used outdoors as general-purpose power supplies. In recent years, there has been an increased demand for outputs of such engine generators to be controlled by a power control unit such as an inverter.
Such a power control unit includes a circuit board on which an electric circuit for controlling power supplied from an engine generator is provided. When the electric circuit is supplied with a large electric current, the board produces a large amount of heat. Therefore, it becomes necessary for the thus-heated board to be cooled down.
Technique for cooling the above-described circuit board is known from, for example, Japanese Utility Model Laid-Open Publication No. SHO-63-171632 entitled “PORTABLE ENGINE GENERATOR” and Japanese Utility Model Post-Exam Publication No. HEI-6-11535 entitled “ELECTRONIC COMPONENT UNIT”.
The engine generator disclosed in the Publication No. SHO-63-171632 includes an end surface cover forming therein openings for taking in air, and a box member having an outer surface facing towards the end surface cover. The box member accommodates therein a control circuit unit. On the cuter surface of the box member, there are provided a plurality of heat releasing fins. The adjacent fins define an intake passage therebetween. Air taken into the openings flows through the respective intake passages. With this arrangement, when the control circuit unit generates heat, the heat is transmitted to the box member. The box member is cooled by the air passing through the intake passages as described above.
The Publication No. HEI-6-11535 discloses an electronic component unit including a case of aluminum accommodating therein a base sheet on which plural electronic components are mounted. The case is filled with hardened resin to cover the base sheet. With this arrangement, heat generated by the base sheet is released by means of the case having improved thermal conductivity.
As disclosed in the Publication No. SHO-63-171632, the air is directed against the outer surface of the box member to thereby cool the box member having the control circuit accommodated therein. However, when the engine generator supplies large power to thereby cause the control circuit unit to generate a large amount of heat, the box member can not be sufficiently cooled because the outer surface of the box member having the fins provided thereon provides limited area. As a result, the control circuit unit is difficult to cool.
Also, when the electronic components as disclosed in the Publication No. HEI-6-11535 provide large power to thereby generate a large amount of heat, it is required that the surface of the case serving as a heat releasing sheet have an enlarged area or that a separate heat releasing sheet of large size be added to the base sheet such that the case can effectively release the heat therefrom. In such a case, however, the electronic component unit is inevitably made large in size.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an engine generator including a power control unit and a heat releasing member which is formed from an existent member to thereby downsize the unit and which is disposed to effectively cool the unit to thereby prevent the temperature of the unit from rising.
According to an aspect of the present invention, there is provided an engine generator carrying thereon an engine and a generator driven by the engine, the engine generator comprising: a cooling fan mounted on a rotational shaft of the generator; a fan cover for covering the cooling fan; a power control unit including an aluminum base sheet forming thereon a power control circuit for controlling an output from the generator; the fan cover being made of die-cast aluminum alloy; the power control unit being attached to the fan cover with a surface of the aluminum base sheet intimately contacting an outer surface of the fan cover.
Heat generated by the control circuit unit is transmitted to the fan cover made of die-cast aluminum alloy. The heat is then released from the fan cover. The fan cover intimately contacts the surface of the aluminum base sheet of the power control. The cooling fan directs cooling air against the fan cover.
Since the surface of the aluminum base sheet intimately contacts the fan cover, the heat generated by the power control circuit can be efficiently transmitted to the fan cover. In addition, the cooling fan directs cooling air against the fan cover during the operation of the power control unit. Thus, the heat can be effectively released from the fan cover to thereby prevent temperature of the power control unit from rising.
The fan cover for covering the cooling fan serves as a heat releasing member for the power control unit. This eliminates the need to provide the power control unit with a separate heat releasing member of large size such as the heat releasing fins. Thus, it becomes possible to downsize the power control unit as well as to make small the number of parts forming the engine generator. Consequently, the cost of the engine generator can be reduced.
In a preferred form of the invention, the fan cover has a thick mounting portion formed thereon, the mounting portion having a flat outer surface to be attached to the surface of the aluminum base sheet.
The heat generated at the unit is transmitted from the surface of the aluminum base sheet of the unit to the entire fan cover through the thick mounting portion having the flat outer surface.
Since the mounting portion of the fan cover is made thick to thereby increase heat capacity thereof, the transmission of the heat to the fan cover is improved. It thus becomes possible to prevent the temperature of the unit from rising.
Moreover, the flat mounting portion is advantageous in that the intimate contact between the unit and the surface of the aluminum base sheet can be readily effected, and in that the mounting portion can be easily formed.
In a further preferred form of the present invention, the generator has a flywheel structure including an outer rotor fixed to the rotational shaft, the outer rotor having the cooling fan mounted thereon, and the fan cover for covering the cooling fan has a cylindrical configuration and is opener at opposite end portions either of which is secured to the engine and discharges cooling air therefrom.
The cooling fan directs cooling air along the cylindrical fan cover towards the engine to thereby cool the engine.
The cooling air is continuously taken into the fan cover of cylindrical configuration. The fan cover has the inner surface exposed to the cooling air. Therefore, heat transmitted to the fan cover can be effectively released therefrom.
In a still further preferred form of the present invention, the outer rotor includes permanent magnets, the cooling fan is formed from a centrifugal fan, the outer rotor and an inner surface of the fan cover define a passageway therebetween, and the cooling air is forced to flow through the passageway towards the engine.
The outer rotor includes the permanent magnets and the cooling fan is formed from the centrifugal fan. With this arrangement, the cooling air is directed radially outwardly from inside the cooling fan. The air is then forced to flow through the passageway, defined between the outer rotor and the inner surface of the fan cover, towards the engine.
Thus, since a large amount of cooling air is directed against the inside of the peripheral surface of the fan cover, the fan cover can be effectively cooled.
In a still further preferred form of the present invention, the power control unit is a cycloconverter unit or an inverter unit for converting an output from the generator into a power having a predetermined frequency.
The inverter unit or the cycloconverter unit converts the output from the generator into a power having a predetermined frequency.
An inverter or cycloconverter generates a large amount of heat corresponding to power loss caused when controlling a large power supplied from the generator. It was therefore difficult to reduce the size of a conventional inverter or cycloconverter unit. However, since the present invention employs the unit attached to the fan cover, the size of the unit can be reduced to ½to ⅓of the size of the conventional unit.
BRIEF DESCRIPTION OF THE DRAWINGS
A certain preferred embodiment of the present invention will hereinafter be described in detail, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1
is a perspective view of an engine generator according to the present invention;
FIG. 2
is a front elevational view of the engine generator;
FIG. 3
shows the engine generator as viewed from a side on which a recoil starter is provided;
FIG. 4
is a top plan view of the engine generator;
FIG. 5
is a rear elevational view of the engine generator;
FIG. 6
shows the engine generator as viewed from a side on which an engine is provided;
FIG. 7
is a cross-sectional view taken along line
7
—
7
of
FIG. 3
;
FIG. 8
shows a cycloconverter unit of the engine generator with a converter cover removed;
FIG. 9
shows in perspective a fan cover and the cycloconverter unit exploded; and
FIG. 10
shows how the fan cover is operated to release heat generated by the cycloconverter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description is merely exemplary in nature and is in no way intended to limit the invention or its application or uses.
Referring to
FIG. 1
, an engine generator
10
for use as a general-purpose power supply includes a frame
11
formed from a pipe frame, an engine
12
, a generator
13
(see
FIG. 7
) driven by the engine
12
, a fuel tank
14
for storing fuel for the engine
12
, an air cleaner
15
connected to the engine
12
, a muffler
18
(see
FIG. 5
) connected to the engine
12
and covered with an upper cover
16
, a recoil starter
21
for starting the engine
12
, a control box
22
to which an output from the generator
13
is input, and a cycloconverter unit
23
for use as a power control unit for converting an output from the generator
13
into a power having a predetermined frequency. The control box
22
accommodates therein an ignition control device
43
(see
FIG. 2
) for the engine
12
and the like. The air cleaner
15
is provided on an intake side of the engine
12
. The muffler
18
is provided on an exhaust side of the engine
12
. The power control unit may employ an inverter unit in lieu of the cycloconverter unit
23
. All the engine
12
, the generator
13
, the fuel tank
14
, the air cleaner
15
, the muffler
18
, the recoil starter
21
, the control box
22
, and the cycloconverter unit
23
are attached to the frame
11
.
As shown in
FIG. 1
, the engine generator
10
includes the control box
22
provided forwardly thereof.
The frame
11
comprises front and rear frames
31
,
32
provided forwardly and rearwardly of the engine generator
10
, respectively, lower longitudinal beams
33
,
34
each laid between the front and rear frames
31
,
32
, upper longitudinal beams
35
,
36
(best shown in
FIG. 4
) each laid between the front and rear frames
31
,
32
, a front lateral beam
37
(see
FIG. 2
) laid between upper portions of the front frame
31
, and a rear lateral beam
38
laid between upper portions of the rear frame
32
. The front and rear frames
31
,
32
have rectangular configurations.
The front frame
31
includes vertical portions
24
,
25
while the rear frame
32
includes vertical portions
26
,
27
. Reference numerals
28
,
28
denote positioning support portions provided on the front and rear frames
31
,
32
. By virtue of the positioning support portions
28
,
28
, a plurality of the engine generators
10
can be stacked with the support portions
28
,
28
engaged with the lower longitudinal beams
33
,
34
. Denoted by reference numeral
29
is a converter cover for use as a cover of the cycloconverter unit
23
.
With reference to
FIG. 2
, the control box
22
has an operational panel
41
attached to a front side thereof. On the panel
41
, there are mounted an engine switch
42
for an ignition system for placing the ignition system in an ON state, an ignition control device
43
for controlling ignition timing, a battery charge outlet
44
for providing a dc output to charge a battery disposed outside the engine generator
10
, a first outlet
45
for outputting a large alternating current, second outlets
46
,
46
for outputting small alternating currents each of which is smaller than the alternating current output from the first outlet
45
, a circuit breaker
47
for blocking the flow of currents which are output from the first and second outlets
45
,
46
and have levels exceeding a predetermined level, and a frequency switch
48
for switching to 50 or 60 Hz the frequencies of currents output from the first and second outlets
45
,
46
. A sticker
49
for showing the names of a manufacturer and a model of the control box
22
is stuck on the control box
22
. The control box
22
includes inner components electrically connected to the cycloconverter unit
23
through a wire
50
.
As shown in
FIG. 3
, the recoil starter
21
includes a pulley attached via a one-way clutch to a crankshaft
68
of the engine
12
provided behind the recoil starter
21
. The pulley has a wire wound thereon. The wire includes its end connected to a handle
51
. With this arrangement, when the handle
51
is pulled, the crankshaft
68
is rotated to thereby start the engine
12
. The recoil starter
21
includes its rotating part covered with a cover
52
. The cover
52
has plural slits
52
a
,
52
b
into which air is introduced.
Turning to
FIG. 4
, the fuel tank
14
and the muffler
18
are disposed in lateral alignment with each other.
The fuel tank
14
has front and rear parts thereof mounted to the front lateral beam
37
(see
FIG. 2
) and the rear lateral beam
38
, respectively. The fuel tank
14
includes an opening into which a fuel is poured. Such an opening is closed by a cap
54
.
Reference is made to FIG.
5
. The engine
12
has a cylinder head
56
attached to an exhaust pipe
57
. The exhaust pipe
57
is mounted to the muffler
18
. The engine
12
includes a head cover
58
.
The muffler
18
has an upper part thereof covered with a heatproof cover
17
disposed such that heat generated by the muffler
18
can not be transmitted to the fuel tank
14
and parts provided in the vicinity of the muffler
18
. The cover
17
includes an upper part thereof covered with the upper cover
16
.
As shown in
FIG. 6
, the engine
12
and the generator
13
are mounted to the lower longitudinal beams
34
,
33
through mounting brackets
61
.
The engine
12
has a cylinder portion
62
inclined rearwardly of the engine generator
10
. In other words, the cylinder portion
62
is inclined away from the control box
22
provided forwardly of the engine generator
10
. Also, the cylinder portion
62
is disposed below the muffler
18
. The cylinder portion
62
has upper and lower engine shrouds
63
,
64
mounted on upper and lower parts thereof, respectively. The shrouds
63
,
64
are disposed such that cooling air flows over the cylinder portion
62
and the cylinder head
56
. Reference character CL designates a cylinder axial line.
Since the cylinder portion
62
is inclined away from the control box
22
, heat generated by the cylinder portion
62
is not transmitted to the control box
22
.
The thus inclined cylinder portion
62
provides the advantage that the height of the engine
12
is made smaller to thereby make the overall height of the engine generator
10
smaller. Consequently, the engine generator
10
can be steadily disposed.
The muffler
18
has a front part thereof connected to an arm portion
66
by means of a stay
65
. The arm portion
66
extends forwardly from the engine
12
. A rear part of the muffler
18
is supported by an exhaust pipe
57
attached to the engine
12
.
The muffler
18
and the control box
22
are disposed closely to each other with a front panel
17
a
of the cover
17
provided therebetween.
An end cover
67
is provided for covering one end portion of the crankshaft
68
extending in a direction perpendicular to this sheet.
Reference is made to FIG.
7
. The generator
13
is a multipolar generator including an outer rotor
76
of flywheel structure. The outer rotor
76
has one end thereof fixed to the crankshaft
68
. More specifically, the generator
13
includes stators
72
attached to an end surface of the engine
12
by means of bolts
71
,
71
, a flange member
75
mounted on another end portion of the crankshaft
68
through a nut
74
, the cup-shaped outer rotor
76
mounted on the flange member
75
and disposed radially outwardly of and closely to the stator
72
, a cooling fan
77
mounted on a front part of the flange member
75
, and a substantially cylindrical fan cover
78
for covering the cooling fan
77
and the outer rotor
76
. The outer rotor
76
includes a front part forming therein apertures
76
a
(only one shown) through which air passes. The crankshaft
68
serves as a rotational shaft of the generator
13
.
The stator
72
includes a stator core
81
and a stator coil
82
wound on the stator core
81
. The stator core
81
has plural magnetic materials such as metal sheets laid one on the other.
The outer rotor
76
has permanent magnets
83
mounted on an inner peripheral surface thereof.
Since the generator
13
includes the outer rotor
76
thus arranged, it is unnecessary to provide wires to the outer rotor
76
. Thus, the outer rotor
76
becomes simple in structure.
The cooling fan
77
is a centrifugal fan including blades
84
. The rotation of the blades
84
of the fan
77
causes air to flow radially outwardly from inside the blades
84
.
The fan cover
78
is a die-cast product of aluminum alloy attached to the end surface of the engine
12
through bolts
85
(only one shown).
The rotation of blades
84
of the cooling fan
77
further causes the thus outwardly flowing air to flow through a passageway, defined between the outer rotor
76
and the fan cover
78
, towards the engine
12
. The generator
13
and the engine
12
can be therefore cooled.
Referring to
FIG. 8
, the cycloconverter unit
23
for use as a power control unit converts an output from the generator
13
(see
FIG. 7
) into a power having a predetermined frequency. For example, the frequency of an alternating-current output from the generator
13
is converted into a frequency of 50 or 60 Hz by the unit
23
. The cycloconverter unit
23
includes an aluminum base sheet
91
having electronic components mounted thereon, a case
92
for receiving the base sheet
91
therein, capacitors
93
,
94
having large capacitances, and the converter cover
29
for covering the case
92
and the capacitors
93
,
94
. More specifically, the case
92
and the capacitors
93
,
94
include a front side on which the electronic components are provided. Such a front side is covered with the cover
29
. The capacitors
93
,
94
are mounted to a lower part of the case
92
. The case
91
is filled with hardened resin to cover the electronic components mounted on the base sheet
91
.
Formed at the aluminum base sheet
91
is a power control circuit
95
(see
FIG. 9
) for controlling an output from the generator
13
. The base sheet
91
includes input terminals
96
,
97
,
98
provided on the front side. An output from the generator
13
is input to the terminals
96
,
97
,
98
. The base sheet
91
has a flat surface
112
(see
FIG. 9
) provided at a side opposite to the front side.
The case
92
includes case mounting holes
101
,
102
for use in attaching the cycloconverter unit
23
to the fan cover
78
.
The capacitors
93
,
94
serving as filters include output terminals
103
,
104
,
105
,
106
for providing outputs having frequencies converted by the unit
23
. These terminals
103
,
104
,
105
,
106
are connected to the first outlet
45
and the second outlets
46
,
46
as shown in FIG.
2
.
Although the cycloconverter unit
23
or the inverter unit serving as the power control unit generates a large amount of heat corresponding to loss caused by the conversion of power supplied from the generator
13
, the unit can be effectively cooled to thereby prevent the temperature of unit from rising. Moreover, the unit
23
can be made small in size.
Turning to
FIG. 9
, the fan cover
78
includes a curved side wall
107
and a bulged wall
108
. On the wall
107
, there are mounted boss portions
109
,
111
for use in attaching the unit
23
thereto, and a thick mounting portion
114
having a flat outer surface
113
. The outer surface
113
is flatten to intimately contact the surface
112
when the unit
23
is attached to the fan cover
78
. The boss portions
109
,
111
have internal threads
115
,
116
formed therein.
The converter cover
29
has cover mounting holes
117
,
118
formed therein. The cycloconverter unit
23
is attached to the fan cover
78
through two bolts
121
,
121
(only one shown). More specifically, for attachment of the unit
23
to the fan cover
78
, the one bolt
121
is screwed into the boss portion
115
through the holes
117
,
101
while the other bolt
121
is screwed into the boss portion
111
through the holes
118
,
102
to thereby bring the surface
112
into intimate contact with the outer surface
113
.
As described above, the power control circuit
95
for controlling an output from the generator
13
is formed at the aluminum base sheet
91
of the cycloconverter unit
23
. On the fan cover
78
, there is formed the mounting portion
114
having the flat outer surface
113
to be attached to the sheet surface
112
. Because the outer surface
113
is flat, the intimate contact between the surface
112
and the outer surface
113
can be easily effected. Further, the mounting portion
114
can be readily formed.
Discussion will be made as to operation of cooling the fan cover
78
having the cycloconverter unit
23
attached thereto in relation to FIG.
10
.
As indicated by arrows, heat generated by the unit
23
is transmitted from the surface
112
to the entire fan cover
78
through the mounting portion
114
and the outer surface
113
provided in intimate contact with the surface
112
. The heat is then released from the fan cover
78
into the air.
Because the surface
112
of the unit
23
is in intimate contact with the outer surface
113
of the die-cast fan cover
78
of aluminum alloy, heat is efficiently transmitted from the unit
23
to the fan cover
78
.
The mounting portion
114
of the fan cover
78
is made thick to thereby provide the mounting portion
114
with increased heat capacity thereof. Therefore, the heat generated by the unit
23
is transmitted to the fan cover
78
more satisfactorily through the thick mounting portion
114
than through a less thick mounting portion
114
.
The fan cover
78
has heat transmitted thereto in the above manner as the unit
23
is operated. However, since the peripheral surface of the fan cover
78
has a large area and the cooling fan
77
continuously directs cooling air against the inside of the peripheral surface when rotating, the fan cover
78
can be effectively cooled to prevent the temperature of the unit
23
from rising.
In other words, the thus arranged fan cover
78
for covering the cooling fan
77
serves as a heat releasing member for releasing heat generated by the unit
23
to thereby eliminate the need to provide the unit
23
with a separate heat releasing member. Thus, the number of parts forming the engine generator
10
can be made small to thereby reduce the cost of the engine generator
10
.
Turning back to
FIG. 7
, as the engine
12
is operated to rotate the cooling fan
77
, cooling air passes through a first passage. This means that the cooling air flows through the slits
52
a
,
52
b
and the recoil starter
21
into the fan cover
78
, whereafter the air is directed to the inside of the fan
77
and then flows radially outwardly from inside the fan
77
into passageways defined between the cooling fan
77
and an inner surface of the fan cover
78
and between the outer rotor
76
and the inner surface of the fan cover
78
, as indicated by arrows. After passing through these passageways, the air flows over an outer surface of the engine
12
. Also, the rotation of the fan
77
causes cooling air to pass through a second passage. This means that the cooling air flows radially outwardly from within the outer rotor
76
of the generator
13
through the apertures
76
a
(only one shown). Between the engine
12
and the generator
13
, there are formed intake openings (not shown). Through such openings, cooling air is introduced into the outer rotor
76
.
That is, the engine generator
10
is cooled by the cooling air passing through the first and second passages.
As described above, the rotation of the cooling fan
77
formed from the centrifugal fan forces the cooling air to flow towards the engine
12
through the passageway defined between the inner surface of the fan cover
78
and the outer rotor
76
.
With this arrangement, the first and second passages become simple in configuration. Since the thus arranged passages provide a reduced resistance to the flow of cooling air, the cooling air is efficiently directed to the generator
13
, the fan cover
78
, and the engine
12
. Therefore, the generator
13
, the fan cover
78
, and the engine
12
can be sufficiently cooled.
The cylindrical fan cover
78
for covering the cooling fan
77
has one end secured to the engine
12
. Therefore, the rotation of the cooling fan
77
causes cooling air to flow along the fan cover
78
towards the engine
12
. Further, heat generated by the engine
12
is transmitted directly to the fan cover
78
, whereafter the heat is released from the fan cover
78
. Consequently, it becomes possible to cool the engine
12
by means of both the cooling air and the fan cover
78
.
Obviously, various minor changes and modifications of the present invention are possible in the light of the above teaching. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described.
Claims
- 1. An engine-driven generator unit having an engine and an electric power generator driven by said engine, said engine-driven generator unit comprising:a cooling fan mounted on a rotational shaft of said electric power generator; a fan cover for covering said cooling fan, the fan cover being made of die-cast aluminum alloy; and a power control unit comprising an aluminum base sheet and a power control circuit provided thereon for controlling an output from said electric power generator, the power control unit being attached to said fan cover with a surface of said aluminum base sheet intimately contacting an outer surface of said fan cover.
- 2. An engine-driven generator unit according to claim 1; wherein said fan cover has a thick mounting portion, said mounting portion having a flat outer surface attached to said surface of said aluminum base sheet.
- 3. An engine-driven generator unit according to claim 1; wherein said electric power generator includes an outer rotor serving as a flywheel of the engine, said outer rotor having one end thereof fixed to said rotational shaft, said outer rotor having said cooling fan mounted thereon, and said fan cover for covering said cooling fan has a cylindrical configuration and is opened at opposite end portions either of which is secured to said engine and discharges cooling air therefrom onto an outer peripheral surface of the engine.
- 4. An engine-driven generator unit according to claim 3; wherein said outer rotor includes permanent magnets, said cooling fan is a centrifugal fan, an annular passageway is defined between said outer rotor and an inner surface of said fan cover, and said cooling air is forced to flow through said passageway towards said engine.
- 5. An engine-driven generator unit according to claim 1; wherein said power control unit comprises one of a cycloconverter unit and an inverter unit for converting an output from said electric power generator into a power having a predetermined frequency.
- 6. An engine-driven generator unit according to claim 3; wherein the cooling fan comprises a centrifugal cooling fan device that forces cooling air between the outer rotor and the fan cover so as to send the cooling air to the outer peripheral surface of the engine.
- 7. An engine-driven generator unit according to claim 1; wherein the fan cover has an opening at a first end proximate the engine, and the cooling fan has a first rotary blade member for drawing outside air and blowing the air to cool the engine and the electric power generator.
- 8. An engine-driven generator unit according to claim 1; wherein the electric power generator is a multipolar generator having a magnet rotor, and the power control circuit converts an output of the multipolar generator into an alternating current of a predetermined frequency.
- 9. An engine-driven generator unit according to claim 1; wherein the engine has a cylinder inclined sideways obliquely and a muffler disposed in a space above the cylinder.
- 10. An engine-driven generator unit according to claim 9; wherein the muffler is substantially cylindrical and elongated in a direction perpendicular to the output shaft of the engine.
- 11. An engine-driven generator unit according to claim 1; further comprising an engine shroud covering a portion of the engine and having one end disposed proximate the fan cover so that air blown out of the fan cover by the cooling fan passes between the engine shroud and the engine to cool the engine.
- 12. An engine-driven generator unit according to claim 1; wherein the fan cover has a first end disposed proximate the engine and a second end disposed remote from the engine; and further comprising a recoil starter for starting the engine attached to the second end of the fan cover.
- 13. An engine-driven generator unit comprising: an engine; an electric power generator driven by the engine; a cooling fan mounted to a rotary output shaft of the engine; a thermally conductive fan cover covering the cooling fan and the electric power generator; and a power control unit comprising a thermally conductive metallic base sheet and a power control circuit provided on the base sheet for controlling an output of the electric power generator, the power control unit being attached to the fan cover so that a surface of the base sheet is in direct contact with an outer surface of the fan cover.
- 14. An engine-driven generator unit according to claim 13; wherein the fan cover is formed of a die-cast aluminum alloy, and the base sheet is formed of aluminum.
- 15. An engine-driven generator unit according to claim 13; wherein the fan cover has a flat surface at a location where the base sheet of the power control unit is attached.
- 16. An engine-driven generator unit according to claim 13; wherein the electric power generator has an outer rotor serving as a flywheel of the engine, the outer rotor has one end fixed to the rotary output shaft, the cooling fan is mounted to the outer rotor, and the fan cover has a generally cylindrical shape and is opened at opposite ends thereof, one of the ends being disposed proximate the engine to discharge cooling air therefrom onto the engine.
- 17. An engine-driven generator unit according to claim 16; wherein the cooling fan is a centrifugal fan for drawing air from outside the electric power generator into the fan cover, through an annular passageway defined between the outer rotor and an inner surface of the fan cover, and out a discharge portion of the fan cover onto the engine.
- 18. An engine-driven generator unit according to claim 13; wherein the power control unit comprises one of a cycloconverter unit and an inverter unit for converting an output of the generator into a power having a predetermined frequency.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-140715 |
May 1999 |
JP |
|
US Referenced Citations (16)
Foreign Referenced Citations (3)
Number |
Date |
Country |
359108826 |
Jun 1984 |
JP |
63171632 |
Nov 1988 |
JP |
6-11535 |
Mar 1994 |
JP |