JP2001221047A - Engine generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a cooling property of an inverter unit on an engine generator to carry out inverter control by using an outer rotor type generator. SOLUTION: An inverter unit 17 is arranged in the neighborhood of a cooling air intake 26a and at a position in the windward of a generator 3 in a casing 1 on an engine generator to cool an engine 2 and the generator 3 by a cooling fan 5 arranged between the engine 2 and the generator 3 by controlling output by an inverter circuit by using the outer rotor type generator 3. When the engine 2 starts and the cooling fan 5 works, cooling air is introduced to the inside of the casing 1 from the cooling air intake 26a, and the inverter unit 17 arranged in the neighborhood of the cooling air intake 26a is first cooled down. Consequently, it is possible to efficiently cool the inverter unit 17 easy to have a heat, to maintain a function of the inverter circuit favorably and to improve power generating efficiency.

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, a generator and the like housed in a housing, 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 Conventionally, as a so-called engine generator for obtaining electric power by driving a generator by an engine, Japanese Patent Application Laid-Open Nos. 58-197415 and 58-197417 have been known.
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. H11-209, an engine and a generator are widely housed in a housing. FIG. 3 is an explanatory view showing the internal configuration of such a conventional engine generator, and FIG. 4 is an exploded perspective view of a main part thereof.

As shown in FIG. 3, a conventional engine generator has an engine 52 and an inner rotor type generator 53 arranged in a housing 51, and a rotor 55 is rotated by a crankshaft 54 to generate an electromotive force toward a stator 56. Is generated. A cooling fan 57 is provided between the engine 52 and the generator 53, and the crankshaft 5
With the rotation of 4, the cooling fan 57 rotates, and cooling air is introduced into the housing 51 as shown by an arrow, so that the engine 52 and the generator 53 are cooled.

[0004] The generator 53 and the cooling fan 57 are
Inside, it is further housed in a front housing 58 and a rear housing 59. Front housing 5
8 is attached to the side of an engine cover 60 that houses the engine 52, and has a cooling fan 57
Is housed. The rear housing 59 is attached to the left end of the front housing 58 in FIG. 3 with a stator 56 interposed therebetween, and the crankshaft 54 is rotatably supported at the left end. A recoil starter 62 having a clutch mechanism 61 is provided outside the rear housing 59.

When the engine 52 is started by the recoil starter 62 and the crankshaft 54 rotates, the rotor 55 rotates in the stator 56 to generate electric power. At this time, the cooling fan 57 also rotates at the same time, and air is introduced into the housing 51 from the outside, thereby cooling the engine 52, the generator 53, and the muffler (not shown) disposed on the near side in FIG. .

On the other hand, Japanese Patent Laying-Open No. 11-36880 discloses an air-cooled engine generator using such a cooling fan in which the cooling efficiency is improved. There, a generator, an engine, and a muffler are arranged in this order in a housing, covered with a duct, and cooling air is introduced from the generator side of the duct. 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, in the engine generator, it is described that the inside of the generator is efficiently cooled by the cooling in the above order, and a double sound insulation effect is exhibited by the duct and the housing.

[0007]

SUMMARY OF THE INVENTION Here, Japanese Patent Application Laid-Open No.
In the engine generator described in Japanese Patent No. 36880, an outer rotor type generator is used as the generator, and the power generation output is controlled by an inverter device, so that the generator can be downsized in addition to improving the cooling efficiency. ing.

Therefore, it is conceivable to reduce the size and weight of the engine generator of FIGS. 3 and 4 by using an outer rotor type generator and adopting a configuration in which the generation output is controlled by an inverter. However, since the inverter unit containing the inverter control circuit required for inverter control generates a considerable amount of heat during operation, the cooling performance of the inverter unit is considered in addition to the engine and muffler in the housing. Need to be done. On the other hand, in the generators shown in FIGS. 3 and 4, the cooling performance of such a unit is not taken into consideration.
Also in JP-A-80-80, no particular consideration is given to the cooling performance of the inverter unit.

An object of the present invention is to improve the cooling performance of an inverter unit in an engine generator that performs inverter control using an outer rotor type generator.

[0010]

An engine generator according to the present invention accommodates an outer rotor type generator having an engine and a magnet rotor driven by the engine in a housing, and attached to an output shaft of the engine. An engine generator, wherein cooling air for cooling the engine and the generator is introduced into the housing by a cooling fan disposed between the engine and the generator, and the output of the generator is A control circuit unit for converting the cooling air into an alternating current having a predetermined frequency is disposed in the housing in the vicinity of the cooling air intake.

According to the present invention, when the engine is started and the cooling fan is operated, cooling air is introduced into the housing from the cooling air inlet, and the control circuit unit disposed near the cooling air inlet is first provided with the first control circuit unit. Is cooled. For this reason, the control circuit unit which easily has heat can be efficiently cooled, the function of the inverter circuit can be maintained well, and the power generation efficiency can be improved.

In this case, the control circuit unit may be arranged between the generator and the cooling air intake provided on the windward side of the generator.

Further, the generator and the cooling fan can be housed in a single housing, and the number of parts can be reduced as compared with the case where the generator and the cooling fan are conventionally housed and held by a plurality of parts. it can.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing a configuration of an engine generator according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing an internal configuration when the engine generator of FIG. 1 is viewed from an X direction.

The engine generator according to the present embodiment is of a type in which the generator is driven by the engine.
As shown in FIGS. 1 and 2, an engine 2, a generator 3, a muffler 4, a cooling fan 5, and the like are housed in a housing 1 made of synthetic resin. In the generator, the cooling fan 5 is disposed between the engine 2 and the generator 3, and when the engine 2 is started, the cooling fan 5 rotates, and from outside the device through the cooling air inlets 26a to 26c. Cooling air is sucked into the housing 1.

Here, an outer rotor type generator is used as the generator 3, and its output is converted into an alternating current of a predetermined frequency by the inverter unit 17 and output. In the engine generator according to the present invention, the inverter unit 17 is arranged on the windward side of the generator 3 immediately after the cooling air inlet 26a to improve the cooling efficiency.

The housing 1 is formed by injection-molding a synthetic resin such as polypropylene. In FIG. 1, a cooling air inlet 26 is provided at the lower left end, the bottom, and the right end face, respectively.
a to 26c are provided. 1 and 2 in the housing 1
As shown in the figure, the engine 2
The generator 3 and the cooling fan 5 are housed in the housing 30.
Further, the mufflers 4 are housed in muffler covers 40, respectively. A cooling air passage 38 is formed outside the engine cover 29 and the housing 30 in the housing 1 so as to communicate with the cooling air inlets 26a to 26c, through which cooling air flows as the cooling fan 5 operates. Also, the engine cover 2
9, an engine cooling air passage 39 is provided in the housing 30.
Inside each are formed volute chambers 42, which also serve as cooling air flow passages.

Here, in this generator, an outer rotor type generator 3 is used in place of the inner rotor type generator 53 shown in FIGS. For this reason, it is possible to reduce the size and weight of the power generator as compared with the related art, and to arrange the inverter unit 17 in a space created by the downsizing. Therefore, it is possible to supply high-quality power using inverter control while using the same housing as the generator shown in FIGS.

In the engine generator shown in FIGS. 1 and 2, a four-cycle gasoline engine is used as the engine 2, and the engine 2 is mounted on a vibration isolator 7 provided at the bottom of the housing 1. I have. In the engine 2, air taken in via an air cleaner (not shown) is converted into a mixture with fuel by a carburetor (not shown), and the mixture is burned and exploded to obtain a rotational output from the crankshaft 10. ing. The rotation of the crankshaft 10 causes the generator 3 arranged on the left side of the engine 2 in FIG.
Is driven to generate power. On the other hand, the exhaust gas discharged from the engine 2 is sent to a muffler 4 arranged on the right side of the engine in FIG. 2, 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 is an outer rotor type multi-pole generator, and an outer rotor 11 which is a bottomed cylindrical magnet rotor fixed to a rotor drive shaft 28 is provided around a coil 13 on a stator 12 side. Power is generated by rotation. The outer rotor 11 is, as shown in FIG.
The rotor drive shaft 2 is disposed with the opposite side opened.
8 and the boss rotor 1
1a and a yoke 11b rivet-fixed. A plurality of magnets 14 are attached to the inner peripheral surface of the peripheral wall of the yoke 11b along the circumferential direction. Note that the outer rotor 11 also functions as a flyhole of the engine 2.

The stator 12 has a stator core 15 in which a coil 13 is wound around a plurality of yokes formed so as to project radially.
It is composed of The stator core 15 is fixed to a housing 30 attached to an engine cover 29, and the stator 12 is held by a single housing 30 without using two housings as in the related art.

On the other hand, the rotor drive shaft 28 of the generator 3 is connected to the crankshaft 10. That is, the rotor drive shaft 28 is formed in a hollow shape having a hollow portion 28b as shown in FIG. 1, and a tapered portion 28a is formed at the end on the engine 2 side. On the other hand, the tip of the crankshaft 10 (the generator 3 side) is
A tapered portion 10a having a diameter increasing toward the side is formed, and a screw hole 10b is provided at the tip along the central axis. Then, the two tapered portions 10a and 28a are fitted together, and the bolt 27 is inserted through the hollow portion 28b so that the screw hole 1 is formed.
By screwing the tapered portion 0b, the tapered portions 10a and 28a are crimped, and the crankshaft 10 and the rotor drive shaft 28 are connected.

The back of the bottom wall of the outer rotor 11 (engine 2
1, a double-sided suction cooling fan 5 having blades 5a and 5b on both left and right sides in FIG. 1 is provided. The cooling fan 5 includes the rotor drive shaft 28 and the crankshaft 1
0 and inserted into the crankshaft 10 by the key 37.
Fixed to Thereby, the cooling fan 5 rotates together with the outer rotor 11 with the rotation of the crankshaft 10, sucks the cooling air from both sides thereof, and the cooling air flows through the inside of the housing 1 as indicated by an arrow in FIG. 1.

A bearing 31 is attached to the left end side of the housing 30 in FIG. 1, and one end of the rotor drive shaft 28 is supported by the bearing 31. In the engine generator, the generator 3 is housed in the housing 30 together with the cooling fan 5.
That is, in the conventional generator, as shown in FIGS.
The housing (the front housing 58, the rear housing 59) constituted by the parts is replaced with the single housing 30.
The number of parts and the number of assembling steps are reduced.

The recoil starter 20 is provided outside the housing 30. The recoil starter 20 includes a wheel 22 on which a rope is wound, and a wheel 22.
A clutch mechanism 23 is provided for connecting and releasing between the motor and the rotor drive shaft 28. Then, by manually pulling the rope, the wheel 22 rotates, and accordingly, the clutch mechanism 23 is connected and the cooling fan 5 rotates.
Thus, the crankshaft 10 is rotated, and the engine 2 is started.

On the other hand, the electromotive force generated in the coil 13 is sent to an inverter unit (control circuit unit) 17,
The control panel 18 is converted to an alternating current having a predetermined frequency.
Output from 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. Therefore, the engine 2 can be operated under optimal conditions as appropriate according to the load, so that the engine speed can be kept lower than before, except at the time of a heavy load, and it is possible to reduce driving noise and improve fuel efficiency. Becomes

Further, in the engine generator according to the present invention, the inverter unit 17 is provided immediately above the cooling air inlet 26a provided on the windward side of the generator 3. That is, the inverter unit 17 is located on the front side (the control panel 18 side) of the recoil starter 20.
And the cooling air inlet 26a is disposed near the lower end thereof. For this reason, the outside air introduced into the housing 1 from the cooling air inlet 26 a with the rotation of the cooling fan 5 first flows around the inverter unit 17, and then flows toward the generator 3. That is, the generator employs a configuration in which the inverter unit 17 that easily has heat is cooled first by the outside air, and then the generator 3 is cooled. Therefore, the inverter unit 17 can be efficiently cooled, the function of the inverter circuit can be maintained satisfactorily, and the power generation efficiency can be improved.

As described above, the cooling air introduced from the cooling air inlet 26 a into the housing 1 and cooling the inverter unit 17 flows into the housing 30 from the opening 30 a of the housing 30. Then, after cooling the generator 3, it is sucked into the blade 5 a side of the cooling fan 5 and flows into the volute chamber 42. Further, the cooling air introduced from the cooling air inlet 26b into the housing 1 also flows through the cooling air passage 38 and flows into the housing 30 from the opening 30a as described above.

On the other hand, the cooling air inlet 26c
The cooling air introduced into the inside flows through the engine cooling air passage 39 and the cooling air passage 38 and flows through the upper and lower portions of the engine 2, and then passes through the opening (not shown) of the engine cover 29, and then the cooling fan 5 is sucked into the wing 5 b side and flows into the volute chamber 42. Then, the cooling air flowing into the volute chamber 42 flows into the muffler chamber 41 through an opening (not shown) of the muffler cover 40, cools the muffler 4, and is discharged out of the apparatus.

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, the structure in which the cooling air inlet 26a is provided at the lower front side of the housing 1 has been described, but the cooling air inlet 26a is opposed to the inverter unit 17 on the front surface of the housing 1. Alternatively, it may be formed on a portion to be controlled, below the control panel 18, near the inverter unit 17 on the side of the housing 1, and the like. 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.

[0032]

According to the engine generator of the present invention, the output is controlled by the inverter circuit using the outer rotor type generator, and the engine and the generator are generated by the cooling fan disposed between the engine and the generator. In the engine generator for cooling the machine, since the inverter unit is arranged near the cooling air intake, the control circuit unit arranged near the cooling air intake is first cooled. Therefore, it is possible to efficiently cool the control circuit unit which easily has heat, to maintain the function of the inverter circuit satisfactorily, and to improve the power generation efficiency.

Further, since the inverter unit can be arranged in the space created by employing the outer rotor type generator, the conventional housing can be used without changing the basic layout of the engine and the like. It becomes possible. Therefore, it is possible to realize a reduction in size and weight, a stable power supply, an improvement in fuel efficiency, and the like while suppressing an increase in cost, without changing the molding die and individual parts, and it is possible to improve product quality.

Further, by employing the outer rotor type generator, the generator and the cooling fan can be accommodated in a single housing, and the number of parts can be reduced as compared with the conventional case.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an engine generator according to an embodiment of the present invention.

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 internal configuration of a conventional engine generator.

FIG. 4 is an exploded perspective view of a main part of the engine generator of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 housing 2 engine 3 generator 5 cooling fan 10 crankshaft (output shaft) 11 outer rotor 17 inverter unit (control circuit unit) 26 a to 26 c cooling air inlet 30 housing 38 cooling air passage

Claims (3)

[Claims] 1. An outer rotor type generator having an engine and a magnet rotor driven by the engine is housed in a housing, and is mounted on an output shaft of the engine and arranged between the engine and the generator. An engine generator in which cooling air for cooling the engine and the generator by an installed cooling fan is introduced into the housing, and a control circuit unit that converts an output of the generator into an alternating current having a predetermined frequency. The engine generator is disposed in the housing in the vicinity of the cooling air intake. 2. The engine generator according to claim 1, wherein the control circuit unit is arranged between the generator and a cooling air intake provided on the windward side of the generator. Engine generator. 3. The engine generator according to claim 1, wherein said generator and said cooling fan are housed in a single housing.