JP2002309954A - Engine generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a cooling performance of a control unit in an engine generator. SOLUTION: A fan cover 53 of a cooling fan 52 used for cooling an engine of this engine generator is formed of aluminum. The fan cover 53 is provided with a slit 54 for introducing an outside air. An inverter unit 11 for controlling a generating voltage is mounted to a position facing the slit 54 in a state of being in directly contact with the fan cover 53. Accordingly, the fan cover 53 is utilized as a heat radiating member to improve a heat radiating performance, and a cooling air is applied to the inverter unit 11, thereby further improving cooling effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine generator having an engine and a generator driven by the engine, and more particularly to an engine generator employing an inverter system as a control system.

[0002]

2. Description of the Related Art Generally, an engine generator is provided with a control unit for controlling a generated voltage together with an engine and a power generator. Conventionally, the heat generated by the control unit is smaller than that of an engine, a muffler or the like, and does not greatly affect the operability thereof. Therefore, the unit itself has not been actively cooled. In particular, in a large engine generator in which an engine, a power generator, and the like are provided on a pipe frame, the unit itself is in contact with the outside air, and there is no particular problem with its cooling performance.

On the other hand, in recent years, high-precision voltage stability and frequency characteristics have also been required for engine generators, and an inverter generator has been increasingly used as a control system. In the inverter type generator, it is possible to obtain a higher output than a conventional so-called AVR type generator by driving a rotor having magnets of 20 poles or more at high rotation. However, on the other hand, the electronic components of the control unit become large, and the heat generation of the unit also becomes large. Therefore, the operation stability of the electronic components may be impaired due to the temperature rise. For this reason, in adopting the inverter system, the cooling performance of the control unit itself has become a major problem.

[0004]

SUMMARY OF THE INVENTION Therefore, for example,
As disclosed in Japanese Patent Application Publication No. 00-213361, a configuration has been proposed in which a control unit is disposed at or near the opening of the duct for introducing engine cooling air to improve cooling efficiency and ensure operation stability. However, the heat generated by the control unit in the inverter system is not always sufficiently dissipated by merely applying cooling air, and further improvement in cooling performance has been demanded.

An object of the present invention is to improve the cooling effect of a control unit in an engine generator.

[0006]

An engine generator according to the present invention has an engine and a power generator driven by the engine, and cools the engine by a cooling fan mounted on a crankshaft of the engine. A metal fan cover disposed outside the cooling fan, and attached to the fan cover, at least a part of which is in direct contact with the fan cover for generating voltage control. And a control unit.

In the engine generator, the fan cover is provided with a cooling air inlet for taking in outside air introduced into the fan cover by a cooling fan, and the control unit faces the cooling air inlet. You may arrange.

In the present invention, since the control unit is mounted in direct contact with the metal fan cover, the fan cover can be used as a heat radiation member, and the heat radiation of the control unit can be improved. It becomes possible. In particular, if the fan cover is formed of a metal having good heat conductivity such as aluminum, the heat of the control unit can be effectively dissipated. In addition, since the cooling air inlet is provided in the fan cover and the control unit is arranged so as to face the cooling air inlet, the cooling effect can be further improved.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a front view of an engine generator according to an embodiment of the present invention, FIG. 2 is a plan view of the engine generator shown in FIG. 1, and FIG. 3 is a rear view thereof.

The engine generator 1 according to the present embodiment is
As shown in FIGS. 1 to 3, a power generation unit 5 in which an engine 3 as a drive source and a power generator 4 are integrated on a support frame 2 formed by bending a pipe into a rectangular frame shape is provided with a plurality of support pieces 6. Elastically supported. The engine generator 1 employs an inverter system as a control system, and an inverter unit (control unit) 11 for generating voltage control is attached to a side portion (the rear side in FIG. 3) of the power generation unit 5 (see FIG. 3). (See FIG. 1).

As shown in FIG. 1, a control panel 7 is provided on the front of the apparatus. The control panel 7 is provided with switches such as an engine switch and an auto throttle switch, and output terminals such as an AC power terminal and a DC power terminal. A recoil knob 8a for driving a recoil starter 8 (see FIG. 8) is provided below the control panel 7, and the engine 3 is started by pulling the same.

Above the power generation unit 5, a fuel tank 9 for storing fuel supplied to the engine 3 is provided. A fuel supply port is provided substantially at the center of the upper surface of the fuel tank 9, and a fuel cap 10 is attached to the fuel supply port 9 so that it can be opened and closed.

FIG. 4 is a front view of a power generation unit 5 used in the engine generator of FIG. 1, FIG. 5 is a plan view thereof, FIG. 6 is a right side view of FIG. FIG. 8 is a cross-sectional view taken along the line ZZ in FIG. 5.

The power generation unit 5 includes the engine 3 and the power generator 4.
And the recoil starter 8. The engine 3 is an air-cooled single-cylinder OHV gasoline engine, and includes a crankcase 31 and a cylinder 32 above the crankcase 31, and a head cover 33 is attached to the cylinder 32. An ignition coil 37 integrated with a plug cap is attached to the cylinder 32. A carburetor 1 is provided on the intake side of the engine 3.
2 is provided, and outside air is introduced into the carburetor 12 via an air cleaner 36, where a mixture with gasoline is produced and supplied to the engine 3. On the other hand, a muffler 14 is connected to the exhaust side via an exhaust pipe 13. Exhaust from the engine 3 passes through the muffler 14 and is discharged from an exhaust port 15 provided on the left side of the apparatus in FIG. You.

The carburetor 12 is provided with a throttle valve 16 as shown in FIG. The throttle valve 16 is opened and closed by a cab throttle lever 17 provided above the carburetor 12. One end of a governor rod 18a is attached to the cab throttle lever 17, and the engine 3 is controlled by a mechanical governor so that the engine speed is constantly adjusted without being affected by load fluctuations.

That is, as shown in FIGS. 4 and 5, a governor shaft 19 is rotatably mounted on the crankcase 31, and a base end of a governor lever 20 is attached thereto. The governor lever 20 includes a tension coil spring 22 connected to a speed control lever 21.
The governor lever 20 is urged clockwise in FIG. 5 by the tension coil spring 22. One end of a governor rod 18 b is attached to the distal end of the governor lever 20, and the other end of the governor rod 18 b is connected to the control lever 23. The control lever 23 is connected to the power generation unit 5
Is rotatably supported by a plate 25 attached to the upper part of the. Further, the control lever 23 is provided with the other end of the governor rod 18 a having one end connected to the cab throttle lever 17. Therefore, when the governor lever 20 rotates about the governor shaft 19, the governor rod 18b, the control lever 23, and the governor rod 18a are interlocked, and the cab throttle lever 17 is operated.

In this case, the governor shaft 19 is engaged with a governor sleeve that is slidably mounted in an axial direction on a shaft that is rotationally driven by a crankshaft 34 of the engine 3. A rotating body is fixed to the shaft, and a plurality of governor arms are rotatably mounted on the end surface of the shaft at a predetermined radius from the center of rotation. And
Each governor arm is integrally provided with a governor weight, and these constitute a mechanical governor mechanism.

When the load of the engine 3 is reduced, the engine speed, that is, the crankshaft 3 is reduced by the reduced load.
The number of revolutions of 4 tries to increase temporarily. However, the centrifugal force applied to the governor weight decreases as the rotation speed decreases, and the governor arm closes, whereby the governor sleeve moves and the governor shaft 19 rotates to the low speed side. And
The governor lever 20 also rotates together with the governor shaft 19,
The movement is transmitted to the cab throttle lever 17 via the governor rod 18a and the like, and the throttle valve 16 is driven in the closing direction. Thus, the engine speed is reduced according to the load. On the other hand, when the engine load becomes high, the governor lever 20
Is turned in the opposite direction. Therefore, the engine speed is adjusted to be constant without being affected by the load fluctuation.

The engine 3 is provided with a crankshaft 34 incorporated in the crankcase 31 so as to extend in the left-right direction in FIG. In the power generation unit 5, one end side of the crankshaft 34 is an output shaft of the engine 3, and a flywheel 51,
The cooling fan 52, the recoil starter 8, and the power generator 4 are arranged in this order. That is, the flywheel 51 and the cooling fan 52 are attached to the next position of the engine 3, and the adapter 5 fixed to the flywheel 51 is provided.
5, a recoil starter 8 and a power generator 4 are provided at the end thereof. Thus, when the power generator 4 and the recoil starter 8 are arranged on the same side, the crankshaft 34 can be shortened, and both the power generator 4 and the engine 3 can be cooled by one cooling fan 52. Become.

As shown in FIG. 8, one end 34a of the crankshaft 34 of the engine 3 is
1 and is supported by a bearing 35 mounted on the bearing 1.
The other end of the crankshaft 34 is also supported by a bearing (not shown) on the opposite side.
1 is freely rotatable. One end 34a protrudes out of the crankcase 31, and a flywheel 51 for stabilizing the engine output such as the rotation speed and torque of the engine 3 is attached to the one end 34a. Flywheel 51
Is composed of a boss portion 51a fixed to the crankshaft 34 via a key, and a disk portion 51b extending radially from the boss portion 51a.

A cooling fan 52 is attached to the disk section 51b. The cooling fan 52 is a disk unit 52
a and a number of fan blades 52b provided integrally on the surface of the disk portion 52a. Cooling fan 5
2 is covered by a fan cover 53 fixed to the engine 3. The fan cover 53 is made of aluminum, and has a number of slits 5 on the side surfaces serving as cooling air intakes.
4 are provided. The fan cover 53 also has a function as a duct for guiding air. As shown in FIG. 8, as the cooling fan 52 rotates, outside air is introduced into the fan cover 53 from the slit 54 and the cooling air Is sent to the engine 3 side and guided.

A recoil starter 8 is disposed next to the flywheel 51. The recoil ring 5 is attached to the boss 51 a of the flywheel 51 via an adapter 55.
6, a recoil holder 57 in which the disk portion 57a and the cylindrical portion 57b are integrated is provided at the next position. A recoil pulley 59 around which a recoil rope 58 is wound is rotatably mounted outside the cylindrical portion 57b.

The recoil pulley 59 is provided with an engagement claw (not shown). When the recoil knob 8 a is pulled and the recoil pulley 59 is rotated by the recoil rope 58, the engagement claw is engaged with the recoil ring 56. Accordingly, the crankshaft 34 connected via the adapter 55 rotates, and the engine 3 is started. The recoil holder 57 is provided with a rewind spring (not shown), and the recoil rope 58 is rewound onto the recoil pulley 59 by a spring force.

The power generator 4 is disposed next to the recoil starter 8. In the engine generator 1, the power generator 4
Is an inner rotor type, and is composed of an inner rotor 41 and a stator 42. Inner rotor 41
Is composed of a rotor shaft 43 and a rotor disk 45, and the rotor shaft 43 is fixed to the tip of the boss 55 a of the adapter 55 by a through bolt 60. In this case, a tapered portion 55b is formed in the boss portion 55a, and the tapered portion 55b is
Is fitted to the tapered hole 43a provided in the first hole. On the other hand, the other end of the rotor shaft 43 is rotatably supported by a bearing 61 attached to the power generator rear cover 44. A stator 42 is provided outside the inner rotor 41. In this case, the stator 42 is attached so as to be sandwiched between a fan cover 53 and a power generator rear cover 44.

A plurality of magnets (not shown) are mounted on the outer peripheral surface of the inner rotor 41 along the circumferential direction. On the other hand, the stator 42 is provided with a core 62 formed by laminating a number of steel plates, and a coil 63 is wound therearound. And the crankshaft 34
As the magnet of the inner rotor 41 rotates inside the coil 63 with the rotation of, an electromotive force is generated in the coil 63 to generate power.

The power generator rear cover 44 has a disk portion 44a in which ventilation holes 64 are formed and a cylindrical portion 44b integrated therewith. The power generator rear cover 44 is fixed to the fan cover 53 at the cylindrical portion 44 b, and at this time, the stator 42 is held between the power cover and the fan cover 53. Then, as shown in FIG. 8, with the rotation of the cooling fan 52, outside air is introduced into the power generator rear cover 44 from the ventilation holes 64, and flows toward the engine 3 while cooling the stator 42 and the like.

On the other hand, on the side of the power generation unit 5, FIG.
As shown in FIG. 6, an inverter unit 1 for controlling the power generation output from the power generator 4 and converting the power into an alternating current having a predetermined frequency.
1 is attached. 9 is a sectional view taken along line AA of FIG. 4, FIG. 10 is a bottom view of the inverter unit 11,
FIG. 11 is a sectional view taken along the line BB of FIG.

As shown in FIG. 11, the inverter unit 11 has a structure in which an electronic board 72 is housed in an aluminum case 71, and mounting portions 73 are provided at four corners at the bottom. In the engine generator 1, the inverter unit 11 is directly fixed to the fan cover 53 made of aluminum. That is, the mounting portion 7
The fan cover 53 is mounted on the inverter unit mounting surface 53a of the fan cover 53 so that the edge 3 and the bottom edge 74 directly contact the aluminum surface. Therefore, the heat of the inverter unit 11 is conducted to the fan cover 53 made of aluminum having good thermal conductivity, diffused throughout the fan cover 53, and is quickly radiated.

The fan cover 53 has a slit 54 for introducing cooling air. Therefore, in the engine generator 1, the inverter unit 11 is connected to the slit 5
4 so as to blow cooling air to the inverter unit 11 as well. That is, the inverter unit 11 is mounted at a position where the bottom surface thereof faces the slit 54, and at this time, the bottom surface portion and the fan cover 53
Are arranged such that a space serving as a passage of the cooling air is generated between them. As shown by arrows P and Q in FIGS. 4 and 9, outside air flows into the slit 54 by the cooling fan 52.
Inverter unit 1 arranged facing slit 54
This airflow also flows in 1. Therefore, the inverter unit 11 is cooled by the introduced outside air including its bottom surface, and the cooling effect can be enhanced. In addition, since there is a space on the bottom surface side, the cooling air flows also on the mounting surface side that is hard to contact with the outside air, and the inverter unit 11 can be actively cooled from the mounting surface side.

The airflow Q in FIG. 9 indicates the airflow flowing from the near side to the far side of the drawing, that is, from left to right in FIG.

As described above, in the engine generator 1, the inverter unit 11 uses the aluminum fan cover 53 as a heat radiating plate to improve heat radiation. In addition, the cooling effect is further improved by providing the slit 54 in the fan cover 53 and providing the inverter unit 11 to face the slit 54.

On the other hand, the cooling air that has cooled the inverter unit 11 in this way merges with the cooling air that has been introduced from the ventilation holes 64 and has cooled the stator 42 and the like, and the fan cover 5
It is guided by the engine 3 and sprayed around the engine 3. That is, the cooling fan 52 causes the slit 54
Then, two systems of cooling air of the ventilation holes 64 are generated, whereby both the power generator 4 and the engine 3 are cooled. Then, the cooling air blown to the engine 3 goes behind the engine 3 to cool the muffler 14.

The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, the fan cover 53 is formed of aluminum in consideration of heat dissipation, light weight, cost, etc. However, other metals such as iron and copper may be used.

[0036]

According to the present invention, since the control unit is mounted in direct contact with the metal fan cover, the fan cover can be used as a heat radiating member, and the heat radiation of the control unit is improved. Becomes possible. Further, since the cooling air intake port is provided in the fan cover and the control unit is arranged so as to face the cooling air intake port, the cooling effect of the control unit can be further improved.

[Brief description of the drawings]

FIG. 1 is a front view of an engine generator according to an embodiment of the present invention.

FIG. 2 is a plan view of the engine generator of FIG. 1;

FIG. 3 is a rear view of the engine generator shown in FIG. 1;

FIG. 4 is a front view of a power generation unit used in the engine generator of FIG.

FIG. 5 is a plan view of the power generation unit of FIG.

6 is a right side view of FIG. 5 (in the X direction shown by an arrow).

FIG. 7 is a left side view of FIG. 4 (Y direction indicated by an arrow).

FIG. 8 is a sectional view taken along the line ZZ in FIG. 5;

FIG. 9 is a sectional view taken along line AA of FIG. 4;

FIG. 10 is a bottom view of the inverter unit.

FIG. 11 is a sectional view taken along line BB of FIG. 10;

[Explanation of symbols]

 Reference Signs List 1 engine generator 3 engine 4 generator 11 inverter unit (control unit) 34 crankshaft 52 cooling fan 53 fan cover 54 slit (cooling air intake)

Claims (2)

[Claims] 1. An engine generator comprising an engine and a power generator driven by the engine, wherein the engine is cooled by a cooling fan mounted on a crankshaft of the engine, wherein the engine generator is provided outside the cooling fan. An engine generator comprising: a metal fan cover provided; and a control unit for controlling a generated voltage, the control unit being attached to the fan cover and at least part of which is in direct contact with the fan cover. 2. The engine generator according to claim 1, wherein the fan cover has a cooling air intake for taking in outside air introduced into the fan cover by a cooling fan, and the control unit includes the cooling unit. An engine generator, which is disposed facing a cooling air intake.