JP2001221055A - Engine generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine generator high in cooling efficiency and excellent in restartability in a hot state. SOLUTION: A cooling duct 24 storing an engine 2 in it and a cooling duct 25 storing a muffler 4 in it are separately formed on the leeward side of a cooling fan 5 on an engine generator storing the engine 2, a generator 3, the muffler 4 and the cooling fan 5 in a casing 1. The engine 2 and the muffler 4 are separately cooled in the different cooling ducts 24, 25, and it is possible to efficiently cool the muffler in comparison with the case of cooling both of them in the same duct. Additionally, even after the engine stops, preheating of the muffler 4 is not directly transmitted to the side of the engine 2 in the different cooling duct 24. Consequently, remaining heat of the muffler 4 is hardly transmitted to a carburetor 9, and it is possible to improve restartability in a hot state.

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 a housing containing an engine, a generator and a muffler, and more particularly to an engine generator for cooling the engine and the like by a cooling fan driven by the engine. .

[0002]

2. Description of the Related Art In a so-called engine generator in which an engine and a generator driven by the engine are integrally arranged,
In order to reduce driving noise, those in which an engine or the like is housed in a housing for sound insulation are widely used. In such an engine generator, it is necessary to make the opening as small as possible due to the requirement of quietness, but it is desirable that the opening be as large as possible in consideration of the cooling performance in the housing. Therefore, in order to satisfy these conflicting demands, a configuration is adopted in which a cooling fan driven by an engine is provided in the housing, air is taken in from the outside into the housing and forcedly circulated to improve the cooling efficiency of the engine and the like. Often.

[0003] Japanese Patent Application Laid-Open No. 11-36880 discloses an engine generator using such a cooling fan in which the cooling efficiency is improved, in which a generator, an engine, and a muffler are disclosed. A configuration has been proposed in which the cooling air is introduced from the duct side of the duct by arranging the cooling air in this order. In this case, the cooling air introduced from the outside cools the generator having a relatively low temperature first, then cools the engine and the muffler having a high temperature in order, and is discharged to the outside. Therefore, it is described that in the engine generator, the inside of the generator can be efficiently cooled by the cooling in the above order, and further, a double sound insulation effect is exhibited by the duct and the housing.

[0004]

However, even if the inside of the housing is forcibly cooled using a fan, the cooling operation does not work because the fan also stops after the engine stops. Therefore, the heat of the muffler, which is the hottest, diffuses into and out of the housing or duct. That is, as long as the engine and the muffler are cooled in the same space, even if the engine and the like are arranged in the duct, it is inevitable that the residual heat of the muffler is diffused into the casing. For this reason, there has been a problem that the residual heat of the muffler is transmitted to the carburetor after the engine is stopped, and the restartability in a warm state is deteriorated. Further, even if the carburetor is arranged outside the duct, heat is easily conducted to a portion separated by only one metal plate, and it cannot be said that the carburetor has a sufficient heat-insulating effect.

[0005] In the generator disclosed in the above-mentioned publication, since the muffler is cooled by air after cooling the engine, the cooling efficiency cannot be reduced as compared with the case where the muffler is directly cooled by outside air. There was also a problem that it could not be obtained.

An object of the present invention is to provide a high cooling efficiency,
An object of the present invention is to provide an engine generator that is excellent in restartability in a warm state.

[0007]

According to the present invention, there is provided an engine generator, an engine, a generator driven by the engine, a muffler disposed downstream of the engine, and a cooling fan driven by the engine. And an engine generator accommodating the engine in a housing, the engine generator accommodating the engine, formed on a leeward side of the cooling fan in the housing, and cooling the engine by cooling air supplied from the cooling fan. A first cooling duct, which is formed separately from the first cooling duct on the leeward side of the cooling fan in the housing to house the muffler, and cools the muffler by cooling air supplied from the cooling fan. And a second cooling duct for cooling.

According to the present invention, since the engine and the muffler are cooled in different cooling ducts, the muffler can be cooled more efficiently than a configuration in which both are cooled in the same duct. . In addition, even after the engine is stopped, the residual heat of the muffler is not directly transmitted to the engine side in a different cooling duct, so that it is possible to suppress the cooling of the engine from being hindered by the residual heat of the muffler having a high temperature. Furthermore, the residual heat of the muffler is less likely to be transmitted to the carburetor, and the temperature rise of the carburetor is suppressed,
The restartability at the time of a warm state is improved. In addition, with the formation of the first and second cooling ducts, the engine can be surrounded by the duct, the soundproofing effect on the engine is enhanced, and the noise of the entire generator is reduced.

The engine generator further includes a control unit such as an inverter unit for controlling the output from the generator, and at least a part of the control unit is disposed in the second cooling duct. Alternatively, the control unit may be cooled by the cooling air flowing through the second cooling duct.

As a result, the control unit can be actively cooled, the function of the control circuit can be maintained well, and the power generation efficiency can be improved.

Further, the first and second cooling ducts may be juxtaposed left and right along the horizontal direction of the engine generator, or may be juxtaposed vertically along the vertical direction of the engine generator. You may. In this case, if the cooling duct is arranged in the horizontal direction, the dimension in the height direction can be suppressed, and if the cooling duct is arranged in the vertical direction, the dimension in the width direction can be suppressed.

[0012]

(Embodiment 1) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing the internal configuration of the engine generator according to Embodiment 1 of the present invention when viewed from above, and FIG. 2 shows the internal configuration of the engine generator shown in FIG. 1 when viewed from the X direction. Explanatory diagram,
FIG. 3 is an explanatory diagram showing an outline of the inside of the engine generator in a cross section taken along line YY of FIG.

The engine generator according to the present embodiment is of a type in which a generator is driven by an engine.
The engine 2, the generator 3, the muffler 4, the cooling fan 5, and the like are housed in a housing 1 made of synthetic resin. In the generator, two cooling ducts are formed by the inner covers A and D and the partition walls B and C on the rear side of the cooling fan 5, and the engine 2 and the muffler 4 are arranged in different ducts respectively and individually cooled. It is supposed to be.

The housing 1 comprises a main body cover 1a made of polypropylene, a rear cover 1b made of nylon, and a maintenance door 1c. In this case, the engine 2, the generator 3, and the cooling fan 5 are generally provided in the main body cover 1 a.
The muffler 4 is mainly accommodated in the rear cover 1b. Further, a base 6 made of sheet metal is attached to the bottom of the main body cover 1a. An anti-vibration material 7 is provided on the base 6, and the engine 2 is mounted on the anti-vibration material 7.

The engine 2 is a four-cycle gasoline engine. The air taken in through the air cleaner 8 is used as a mixture with fuel in a carburetor 9 and the mixture is burned.
The engine is exploded to obtain a rotational output from the crankshaft 10. Then, the rotation of the crankshaft 10 drives the generator 3, which is an outer rotor type multipolar generator arranged on the right side of the engine 2 in FIG. 1, to generate electric power. On the other hand, the exhaust gas discharged from the engine 2 is sent to a muffler 4 arranged on the left side of the engine in FIG. 1, and after the exhaust noise is reduced, the exhaust gas is discharged from the exhaust port 4a to the outside of the device. You.

The generator 3 generates electric power by rotating a bottomed cylindrical outer rotor 11 integrally fixed to the crankshaft 10 and also functioning as a flyhole around the coil 13 on the stator 12 side. The outer rotor 11 is disposed in a state where the engine 2 side is open, and a plurality of magnets 14 are attached to the inner peripheral surface of the peripheral wall along the circumferential direction. Further, the stator 12 has a stator core 15 in which a coil 13 is wound around a plurality of yokes protruding radially. Stator core 15
Is fixed to the crankcase side wall 16 of the engine 2,
It is housed on the inner peripheral side of the outer rotor 11.

The electromotive force generated in the coil 13 is sent to an inverter unit (control unit) 17, converted into an alternating current having a predetermined frequency, and output from a control panel 18. In this case, in the generator, since the power is supplied by converting the frequency in the inverter unit 17, it is not necessary to keep the engine speed constant regardless of the magnitude of the load in order to maintain the output frequency. For this reason, the engine 2 can be operated under optimal conditions as appropriate according to the load, so that the engine speed can be suppressed to a lower level than before, except at the time of a heavy load, and the driving noise can be reduced and the fuel efficiency can be improved. It becomes possible.

The back of the bottom wall of the outer rotor 11 (engine 2
The cooling fan 5 is mounted on the opposite side to the cooling fan 5. In the generator, the cooling fan 5 is housed in the fan cover 19 together with the generator 3. The cooling fan 5
As the crankshaft 10 rotates, it rotates integrally with the outer rotor 11, and takes in outside air from the right side of the fan cover 19 in FIG.

Further, a recoil starter 20 is provided outside the fan cover 19. The recoil starter 20 has a clutch mechanism 23 for connecting and releasing between a wheel 22 on which a rope 21 is wound and the cooling fan 5.
Is provided. Then, the rope 22 is rotated by manually pulling the rope 21, whereby the clutch mechanism 23 is connected and the cooling fan 5 rotates. Thereby, the crankshaft 10 is rotated, and the engine 2
Is started.

On the other hand, in the engine generator according to the present invention,
As shown in FIG. 1, two cooling ducts 24 and 25 are provided on the leeward side (left side in FIG. 1) of the cooling fan 5 by the inner covers A and D, the partition walls B and C, and the inverter unit 17. I have. In this case, an inner cover D and an inner cover A to which the engine 2 and the muffler 4 are covered and the inverter unit 17 is attached are provided in the housing 1. Partitions B and C are further provided inside the inner covers A and D.
Thereby, the inside of the inner covers A and D is divided into two chambers, and the cooling ducts 24 and 25 are formed by the respective sections. That is, in the engine generator, the cooling duct 2
4, 25 will be juxtaposed along the horizontal direction when the engine generator is normally installed.

FIG. 4 is an explanatory view schematically showing the structure of the cooling ducts 24 and 25. The cooling duct 24 (first cooling duct) is formed by the inner cover A and the partition walls B and C, and extends from the left end of the fan cover 19 in FIG. 1 to the rear end of the housing 1 (the left end in FIG. 1). Extending. The engine 2 is provided therein. On the other hand, the cooling duct 25 (second cooling duct) includes the inner cover D, the partition walls B and C, and the inverter unit 17.
And extends from the upper left end of the fan cover 19 to the rear end of the housing 1 in FIG. The muffler 4 is provided therein.

Therefore, in the engine generator, the cooling air supplied from the cooling fan 5 is, as shown in FIG.
The fan cover 19 is divided into two flow paths and circulates in the housing 1 to individually cool the members in each flow path. That is,
The cooling air supplied to the cooling duct 24 cools the engine 2 and is discharged from the rear end of the housing 1. On the other hand, the cooling air supplied to the cooling duct 25 is first supplied to the inverter unit 1.
After cooling the muffler 7, the muffler 4 is cooled and discharged from the rear end of the housing 1. For this reason, in this engine generator, it becomes possible to cool the muffler 4 more efficiently than in a configuration in which the muffler is cooled in the same duct together with the engine.

Further, even after the engine stops, the residual heat of the muffler 4 diffuses in the cooling duct 25 and is not directly transmitted to the engine 2 side. Therefore, it is possible to prevent the cooling of the engine 2 from being hindered by the residual heat of the muffler 4 having a high temperature. Further, in the generator, the carburetor 9 is disposed outside the inner cover A, so that two partition walls and the cooling duct 24 exist between the muffler 4 and the carburetor 9. Therefore, the residual heat of the muffler 4 is less likely to be transmitted to the carburetor 9, and a rise in the temperature of the carburetor 9 is suppressed, so that it is possible to improve the restartability in a warm state.

On the other hand, in the engine generator, when forming the cooling duct 25, the inverter unit 17 is used as a part of the cooling duct, and the inverter unit 17 is arranged so as to face the inside of the cooling duct 25. The inverter unit 17 is a device that relatively easily has heat. If the heat radiation is reduced, the function of the circuit may be impaired. Therefore, in the present engine generator, the inverter unit 17 is actively cooled by the cooling duct 25 to maintain the inverter circuit in a good condition and improve the power generation efficiency.

In the housing 1, the cooling ducts 24, 2
With the formation of 5, the wall surrounding the engine 2 is doubled by the inner covers A and D and the partition walls B and C. For this reason, the soundproofing effect on the engine 2 is enhanced, and the noise of the entire generator is reduced.

(Embodiment 2) By the way, the engine generator according to the present invention has a structure in which the engine 2 and the muffler 4 are individually cooled. The arrangement of components such as the muffler 4 can be changed as appropriate. That is, since there is no restriction on the arrangement order of the engine 2 and the muffler 4,
The degree of freedom for their arrangement is increased.

Therefore, as a second embodiment, an example in which the cooling ducts 24 and 25 are arranged vertically and the inverter unit 17 is arranged below the engine 2 will be described. FIG. 5 is an explanatory diagram showing the configuration of the engine generator according to the second embodiment. The same members, parts, and the like as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the engine generator shown in FIG. 5, a partition Q is provided in the inner cover P for vertically dividing the inside into two chambers, and a cooling duct 24 is provided above the partition Q.
Further, a cooling duct 25 is formed below the cooling duct.
That is, the cooling ducts 24 and 25 are arranged in the housing 1 along the vertical direction when the engine generator is normally installed. The engine 2 is disposed in the cooling duct 24 as in the first embodiment, and the muffler 4 and the inverter unit 17 are disposed in the cooling duct 25. In this case, the entire inverter unit 17 is housed in the cooling duct 25.

As shown in FIG. 5, also in the second embodiment, the cooling air from cooling fan 5
4, 25 into which the engine 2, the inverter unit 17, the muffler 4 and the like are cooled and discharged out of the housing 1. Therefore, as described above, the engine 2 and the muffler 4 are individually cooled, and the cooling is performed efficiently. Further, even after the engine is stopped, the residual heat of the muffler 4 is not directly transmitted to the engine 2 side.

As described above, in the engine generator according to the second embodiment, since the cooling ducts 24 and 25 are arranged vertically, the dimension in the width direction can be suppressed, and a more slim generator can be provided. Becomes possible. In contrast, in the case of the configuration of the first embodiment, it is possible to reduce the dimension in the height direction as compared with the configuration of the second embodiment.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the embodiment and can be variously modified without departing from the gist of the invention. Needless to say,

For example, in the above-described embodiment, an example in which a four-cycle engine is used as an engine has been described. However, it goes without saying that a two-cycle engine may be used instead.

[0033]

According to the engine generator of the present invention, the first cooling duct containing the engine and the second cooling duct containing the muffler are separately formed on the leeward side of the cooling fan. The engine and the muffler can be individually cooled in different cooling ducts, and the muffler can be cooled more efficiently than a configuration in which both are cooled in the same duct. Therefore, the output of the engine can be improved, and at the same time, the noise and red heat of the muffler can be prevented, and the mechanical life of the muffler can be extended.

Further, even after the engine is stopped, the residual heat of the muffler is not directly transmitted to the engine side in a different cooling duct, so that it is possible to prevent the cooling of the engine from being hindered by the residual heat of the high-temperature muffler. Further, the residual heat of the muffler is less likely to be transmitted to the carburetor, the temperature of the carburetor is suppressed from rising, and the restartability in a warm state is improved. In addition, since the engine can be surrounded by the duct with the formation of the first and second cooling ducts, the soundproofing effect on the engine is enhanced, and the noise of the entire generator can be reduced.

On the other hand, by arranging the inverter unit facing the second cooling duct or in the second cooling duct, the inverter unit can be actively cooled by the second cooling duct. In addition, it is possible to maintain the function of the control circuit well and to improve the power generation efficiency.

Furthermore, by arranging the first and second cooling ducts side by side along the horizontal direction, the dimension in the height direction can be suppressed, and the first and second cooling ducts can be vertically aligned. By arranging them vertically along the width, dimensions in the width direction can be suppressed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an internal configuration when an engine generator according to a first embodiment of the present invention is viewed from above.

FIG. 2 is an explanatory diagram showing an internal configuration when the engine generator of FIG. 1 is viewed from an X direction.

FIG. 3 is an explanatory diagram showing an outline of the inside of the engine generator in a cross section taken along line YY of FIG. 1;

FIG. 4 is an explanatory diagram schematically showing a configuration of a cooling duct in the engine generator of FIG. 1;

FIG. 5 is an explanatory diagram showing a configuration of an engine generator according to Embodiment 2 of the present invention.

[Explanation of symbols]

 Reference Signs List 1 housing 2 engine 3 generator 4 muffler 5 cooling fan 17 inverter unit 24 cooling duct (first cooling duct) 25 cooling duct (second cooling duct) A, D inner cover B, C partition P inner cover Q partition

Claims (4)

[Claims] 1. An engine generator including an engine, a generator driven by the engine, a muffler disposed at a rear stage of the engine, and a cooling fan driven by the engine in a housing. And a first cooling duct formed on the leeward side of the cooling fan in the housing to house the engine and cools the engine by cooling air supplied from the cooling fan; and housing the muffler. And a second cooling duct formed separately from the first cooling duct on the leeward side of the cooling fan in the housing and cooling the muffler with cooling air supplied from the cooling fan. Characteristic engine generator. 2. The engine generator according to claim 1, wherein said engine generator further comprises a control unit for controlling an output from said generator, wherein said control unit has at least a part thereof being said second unit. An engine generator provided in a cooling duct of the first embodiment and cooled in the second cooling duct. 3. The engine generator according to claim 1, wherein the first and second cooling ducts are arranged right and left along a horizontal direction of the engine generator. Generator. 4. The engine generator according to claim 1, wherein the first and second cooling ducts are vertically arranged along a vertical direction of the engine generator. Generator.