JP6619253B2 - Engine generator - Google Patents

Description

  The present invention relates to an engine generator, and more particularly to an engine generator including an engine in which a crankshaft is disposed in a vertical axis direction.

  As an example of this type of engine generator, for example, an engine generator described in Patent Document 1 is known. The engine generator described in Patent Document 1 is a box-shaped package including a package (frame) that is partitioned from a first chamber to a fourth chamber in the vertical axis direction from the bottom to the top and takes air into the first chamber. A passage is arranged, a water-cooled engine in which the crankshaft is arranged in the direction of the vertical axis is arranged in the second chamber, a generator is arranged below it, and a radiator and its cooling air intake passage are arranged in the third chamber. A cooling air exhaust passage for cooling the muffler and the like is arranged in the fourth chamber.

  More specifically, in the engine generator described in Patent Document 1, a ventilation fan is disposed in the second chamber to suck air from below the first chamber, and to open and suck one side wall of the third chamber. It is configured to release the air that has been discharged. In addition, the other side wall of the third chamber is opened, a second fan is disposed, and the air sucked from the other is connected from the cooling intake passage to the cooling air exhaust passage of the fourth chamber. It is constituted so that it may discharge outside from the exit opened in the side wall.

Japanese Patent No. 2739186

  As described above, the engine generator described in Patent Document 1 is configured such that the cooling air is sucked from the lower part of the package and one of the side walls by the cooling fan and is discharged to the outside from the other side wall. It would flow sideways while colliding with the engine body and auxiliary equipment, and it was difficult to efficiently cool the engine body and generator, particularly the exhaust system of the engine such as a muffler with a large heat capacity.

  Accordingly, an object of the present invention is to solve the above-described problems and effectively cool an engine body, a generator, and an exhaust system of the engine in an engine generator having an engine in which a crankshaft is arranged in a vertical axis direction. It is to provide an engine generator configured as described above.

  In order to solve the above-described problem, in claim 1, an engine in which a crankshaft is arranged in a direction of a vertical axis, an engine in which the crankshaft is arranged in the direction of the vertical axis, and a rotor in the direction of the vertical axis, An engine generator comprising a generator fastened to a crankshaft of an engine, wherein the engine generator is arranged upward in the direction of the vertical axis, and has an exhaust system for exhausting the exhaust of the engine from above to the outside, and a generally skirt shape. The internal space is formed to include a shroud that accommodates the exhaust system and the engine in the internal space, and an intake duct that is disposed below the shroud in the direction of the vertical axis.

  The engine generator according to claim 1 is arranged upward in the direction of the vertical axis and exhaust system for exhausting the exhaust of the engine from above to the outside, and has an approximately skirt shape and its internal space. The air intake system is configured to include a shroud that houses the exhaust system and the engine, and an intake duct disposed below the shroud, so that air sucked from the lower intake duct remains as it is in the internal space of the shroud. The engine main body, the generator, and the exhaust system of the engine can be effectively cooled.

  More specifically, the cooling air cools the generator having a low exothermic temperature, then cools the engine body having a higher exothermic temperature than the generator, and then cools the exhaust system of the engine having the highest exothermic temperature to the outside. Released.

  That is, the air sucked from the lower intake duct gathers in the inner space of the shroud, in other words, the air flow is not hindered and hits the exhaust system having the largest heat capacity. In addition, the engine exhaust system can be effectively cooled.

  In addition, by providing a shroud (exhaust duct) with a large heat capacity in the upper part, natural convection phenomenon can be used, and the air sucked from below becomes vertical convection (thermal convection) as it is in the engine and generator. The engine main body, the generator, and the exhaust system of the engine can be cooled more effectively.

FIG. 1 is a front view of an engine generator according to an embodiment of the present invention. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is a top view of the engine generator shown in FIG. It is a bottom view of the engine generator shown in FIG. It is explanatory drawing of the cooling fan shown in FIG. FIG. 3 is an enlarged perspective view when the engine generator shown in FIG. 2 is viewed from below. It is a characteristic view which shows the characteristic of the flow volume Q and the pressure P with and without the case where the fin formed in the inner wall face of the air intake duct shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for implementing an engine generator according to the present invention will be described with reference to the accompanying drawings.

  1 is a front view of an engine generator according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. 5 is a bottom view.

  1 to 5, reference numeral 10 denotes an engine generator. The engine generator 10 includes an engine (more specifically, an engine body) 12, a generator 14, a cooling fan 16, and an intake duct in order from the top in the direction of the vertical axis (the vertical direction in FIGS. 1 to 3). 20 and a shroud (exhaust duct) 22 and accommodated in a cylindrical frame 24 formed in a cylindrical shape around the direction of the vertical axis.

  In the cylindrical frame 24, a cylindrical surface (side surface) 24a and an upper surface 24b are fastened in an air-tight and liquid-tight manner. On the other hand, as shown in FIG. 5, the lower portion 24c is opened so that air can be sucked therefrom. More specifically, the cylindrical frame 24 includes circular pipes 24d and 24e arranged above and below, and three straight pipes 24f, 24g, and 24h that extend in the vertical axis direction and connect the circular pipes 24d and 24e.

  The upper circular pipe 24d is disposed away from the upper surface 24b, so that the operator can easily grip and transport the cylindrical frame 24, and the lower circular pipe 24e is shown in FIG. As described above, it functions as a grounding stand, thus enabling stable installation.

  The engine 12 is an ignition type air-cooled engine using gasoline as fuel, and a cylinder head 12a has one cylinder and a piston (both not shown) arranged laterally in FIGS. 2 and 3, and the crankshaft 12b is a vertical shaft. For example, a single cylinder engine arranged in the direction of the engine has a displacement of about 160 cc. As described above, the engine generator 10 is configured as a so-called “vertical generator” including the engine 12 in which the crankshaft 12b is arranged in the direction of the vertical axis (the vertical direction in FIGS. 1 to 3).

  The generator 14 disposed below the engine 12 in the direction of the vertical axis is disposed (fixed) on a rotor 14a that is fastened to the crankshaft 12b of the engine 12 and is rotatably provided at a central portion, and around the circumference thereof. And a stator 14b made of a magnetic material, and a dielectric electromotive force (power generation output) is generated by interlinking with the magnetic flux of the stator 14b as the rotor 14a is rotated by driving the engine 12. The stator 14b has, for example, 24 poles (any number is possible as long as the number of poles is a multiple of 3).

  The cooling fan 16 disposed below the generator 14 in the direction of the vertical axis is connected to the crankshaft 12b of the engine 12 via the rotor 14a of the generator 14, and with the rotation of the rotor 14a driven by the engine 12 Rotates and sucks air.

  More specifically, as shown in FIG. 6, the cooling fan 16 is fastened to the lower part of the rotor 14a and rotates together with the rotor 14a, and a plurality of cooling fans 16 that protrude downward from the base 16a in the direction of the vertical axis ( 8 blades 16b in the illustrated example.

  A recoil starter 18 for starting the engine 12 is provided below the cooling fan 16 in the vertical axis direction, and the operator operates the rope 18a to start the engine 12.

  As shown in FIG. 7, the intake duct 20 disposed below the cooling fan 16 in the direction of the vertical axis is a fin 20b formed of a spiral curve that rotates upward around the vertical axis over the entire circumference of the inner wall surface 20a. Are formed (12 in the illustrated example). Each fin 20b is configured to protrude from the inner wall surface 20a with a pitch angle of about 30 degrees.

  Next, the upper side of the intake duct 20 will be described. The housing 26 is connected to the upper side of the intake duct 20. The housing 26 protrudes from the lower end of the engine 12 in the direction intersecting the vertical axis, more specifically in the lateral direction, and then bends and inclines obliquely downward. 36 in 10 degree increments) and a large-diameter portion 26c which is connected to the lower end of the inclined surface 26a in the lower direction of the vertical axis and functions as an engine case cover. And is connected to the intake duct 20 at the large diameter portion 26c. The housing 26 and the intake duct 20 are formed in a cylindrical shape centered on the vertical axis. The housing 26 and the intake duct 20 are covered with a duct cover 20c as shown in FIG.

  Further, as described above, the engine 12, the generator 14, the cooling fan 16, and the intake duct 20 are accommodated in the cylindrical frame 24 formed in a cylindrical shape centering on the vertical axis. However, as shown in FIG. 5, the gravity axis of the cylinder constituting the intake duct 20 (and the housing 26) is above the crankshaft 12b of the engine 12 (shown at the center position of the recoil starter 18 for convenience of illustration), It is eccentric from the gravity axis (corresponding to line II-II in FIG. 1) of the cylinder constituting the cylindrical frame 24.

  In the cylindrical frame 24, in addition to the opening of the lower portion 24c, a cooling air intake slit 24i is locally drilled in the cylindrical surface 24a, and air flows directly from the side of the intake duct 20 to the engine 12 and the generator 14. Configured to cool them.

  Next, the exhaust system of the engine 12 will be described. As shown in FIG. 2 and the like, the front exhaust pipe 12c of the engine 12 once extends laterally from the cylinder head 12a and then turns upward to change the direction of the vertical axis. It extends and is cut at a position immediately after entering the muffler 12d formed above the engine 12. A larger-diameter rear exhaust pipe 12e is arranged to face the cut portion at a minute distance.

  Thus, the exhaust system of the engine 12 includes the front exhaust pipe 12c, the muffler 12d, and the rear exhaust pipe 12e. Therefore, the exhaust gas discharged from the engine 12 flows from the front exhaust pipe 12c to the muffler 12d, and then discharged to the outside through the rear exhaust pipe 12e. Even the rear exhaust pipe 12e is accommodated in the shroud 22.

  The shroud 22 extends upward in the direction of the vertical axis and extends in a lateral direction intersecting the vertical axis in the vicinity of a position exceeding the circular pipe 24d on the upper side of the cylindrical frame 24, and a tip opening 22a. A narrow portion 22b extending downward, an enlarged diameter portion 22c in the vicinity of the lower muffler 12d, and a larger diameter portion 22d therebelow. Inside the shroud 22, an internal space 22 e having a generally skirt shape is formed.

  In the shroud 22, the narrow portion 22b and the tip opening portion 22a are made to continue smoothly so as to reduce the airflow resistance when the cooling air flows. A wire mesh 22a1 is stretched at the opening of the tip opening 22a to prevent entry of foreign matter.

  2, 3, and 7, the lower end of the shroud 22 is fully opened, and an exhaust system (a front exhaust pipe 12 c, a muffler 12 d, and a rear exhaust pipe 12 e) and an engine ( The main body) 12 and the upper portion of the housing 26 are accommodated.

  A fuel tank 12 f that stores fuel (gasoline) of the engine 12 is disposed on the outer periphery of the shroud 22. The fuel tank 12f has a spherical shape in section as shown in FIG. 2 and the like, and also has a circular (annular) donut shape in top view as shown in FIG. 4, and the shroud 22 is formed in the central opening 12f1 of the donut shape. The enlarged diameter portion 22c is inserted.

  In FIG. 4, reference numeral 12fc indicates a cap of the fuel tank 12f. The cap 12fc is provided on the upper surface 24b of the cylindrical frame 24 to facilitate fuel injection. A heat insulating material 30 (shown only in FIG. 2) is arranged between the fuel tank 12f and the shroud 22 to block heat transfer from the shroud 22 to the fuel tank 12f.

  The shroud 22 is formed in a cylindrical shape centered on the vertical axis, and the engine 12, the generator 14, the shroud 22, and the intake duct 20 are accommodated in a cylindrical frame 24 formed in a cylindrical shape centered on the vertical axis. Is done. The engine generator 10 has a weight of, for example, about 30 kg when housed in the cylindrical frame 24. The size of the cylindrical frame 24 is, for example, 60 cm in diameter and 100 cm in height.

  In FIG. 2 and the like, reference numeral 32 denotes a control panel, and reference numeral 34 denotes an outlet for taking out electric power therein. In addition, illustration and description of the details of a power generation circuit such as an inverter or AVR connected to the outlet 34 and a control device that controls driving of the engine 12 are omitted.

  Here, the flow of the cooling air sucked from the lower portion 24c of the cylindrical frame 24 will be described. As shown by arrows in FIG. 2, the cooling air is generated by the cooling fan 16 and the fins 20b formed on the inner wall surface 20a of the intake duct 20. The air is sucked from the lower portion 24 c and flows through the intake duct 20.

  Next, the cooling air flows from the intake duct 20 through the housing 26, enters the shroud 22 through the vent hole 26b formed in the inclined surface 26a at the upper end, flows upward through the inner space 22e, passes through the narrow portion 22b, and then reaches the tip. It is discharged outside through the opening 22a. At this time, the cooling air cools the generator 14 having a low exothermic temperature, then cools the engine (main body) 12 having a higher exothermic temperature than the generator 14, and then the exhaust system (the muffler 12d, etc.) of the engine 12 having the highest exothermic temperature. ) Is cooled and released to the outside. Thus, the cooling air can flow all around the generator 14 and the engine 12, and can effectively cool them.

  Further, since the plurality of fins 20b each having a spiral curve that is rotated upward about the vertical axis over the entire circumference of the inner wall surface 20a of the intake duct 20 are formed, the center of the intake duct 20 is formed by the cooling fan 16. As a result of the rotation of the air introduced through the fins 20b, the pressure concentrates on the outer peripheral side (inner wall surface 20a side), and the central portion is in a low pressure state, creating a pressure difference with the outer peripheral side. In other words, since the intake duct 20 is in a negative pressure state, it is possible to suck more air and cool the engine (main body) 12, the generator 14, and the exhaust system such as the muffler 12d more effectively. can do.

  This will be described with reference to FIG. The figure is a characteristic diagram showing the relationship of the pressure P to the flow rate Q in the engine generator 10 according to this embodiment.

  As shown in the figure, as far as the inventors have found, in the engine generator 10 provided with the fin 20b according to this embodiment, as the flow rate Q increases as the engine speed increases, the case where the fin 20b is not provided. It has been found that the difference in ventilation resistance (in other words, the difference in pressure P) increases. This is because, as described above, the pressure on the center side where the fins 20b are not formed is reduced with respect to the entire circumference side where the fins 20b are formed in the intake duct 20, and a negative pressure state is caused to suck more air. Means you can. Since the engine 12 is for power generation, the engine 12 is driven in a basically constant rotation range during operation.

  Further, by providing a shroud (exhaust duct) 22 having a large heat capacity in the upper part, natural convection phenomenon can be used, and the air sucked from below becomes vertical convection (thermal convection) as it is with the engine 12. The air flows around the generator 14, and a smooth flow can be secured without causing heat accumulation, and the engine (main body) 12, the generator 14, and the exhaust system such as the muffler 12d are cooled more effectively. can do.

  As described above, in this embodiment, the crankshaft 12b is disposed below the engine 12 in the direction of the vertical axis, and the rotor 14a is disposed below the engine 12 in the direction of the vertical axis. In an engine generator 10 including a generator 14 fastened to 12 crankshafts 12b, an exhaust system (front) is disposed above in the direction of the vertical axis and exhausts the exhaust of the engine 12 from above to the outside. An exhaust pipe 12c, a muffler 12d, a rear exhaust pipe 12e), and a shroud (exhaust duct) for forming an internal space 22e having a generally skirt shape and accommodating the exhaust system and the engine 12 in the internal space 22e. ) 22 and an intake duct 20 disposed below the shroud 22 in the direction of the vertical axis. Therefore, the air sucked from the lower intake duct 20 flows as it is around the engine 12 and the generator 14 in the inner space 22e of the shroud 22, and the engine (main body) 12, the generator 14, and the exhaust system of the engine And can be effectively cooled.

  More specifically, the cooling air cools the generator 14 having a low exothermic temperature, then cools the engine (main body) 12 having a higher exothermic temperature than the generator 14, and then the muffler 12d of the engine 12 having the highest exothermic temperature. The exhaust system is cooled and released to the outside.

  That is, the air sucked from the lower intake duct 20 gathers in the inner space 22e of the shroud 22, in other words, hits an exhaust system such as the muffler 12d having the largest heat capacity without being blocked. Not only the engine (main body) 12 and the generator 14 but also the exhaust system such as the muffler 12d can be effectively cooled.

  Further, by providing a shroud (exhaust duct) 22 having a large heat capacity in the upper part, natural convection phenomenon can be used, and the air sucked from below becomes vertical convection (thermal convection) as it is with the engine 12. It flows around the generator 14, and the engine (main body) 12, the generator 14, and the exhaust system such as the muffler 12d can be cooled more effectively.

  The intake duct 20 is arranged below the generator 14 and has a cooling fan 16 connected to the crankshaft 12b of the engine 12 via the rotor 14a. In addition, air can be effectively sucked from below, and the engine 12 and the generator 14 can be effectively cooled.

  Further, since the intake duct 20 is configured to have a plurality of fins 20b each formed of a spiral curve that rotates upward around the vertical axis over the entire circumference of the inner wall surface 20a, a larger amount of air is sucked in. It is possible to cool the engine 12 and the generator 14 more effectively.

  Further, since the fuel tank 12f for storing the fuel of the engine 12 is arranged on the outer periphery of the shroud 22, in addition to the above effects, space can be effectively utilized.

  Further, the fuel tank 12f has a circular donut shape, and the shroud 22 is inserted into the donut-shaped central opening 12f1. In addition to the above effects, space is effectively utilized. be able to.

  Further, since the exhaust system of the engine 12 is accommodated in the inner space 22e of the shroud 22, the air sucked from the lower intake duct 20 is collected in the inner space of the shroud 22, in other words. Without impeding the flow, it hits the muffler 12d having the largest heat capacity, so that not only the engine (main body) 12 and the generator 14 but also the exhaust system such as the muffler 12d can be cooled effectively.

  Further, since the shroud 22 is configured to be formed in a cylindrical shape centered on the vertical axis, in addition to the above effects, air can be effectively blown from below to the engine 12 and the generator 14. Can cool them effectively.

  In addition, since the engine 12, the generator 14, the shroud 22, and the intake duct 20 are configured to be accommodated in a cylindrical frame 24 that is formed in a cylindrical shape centered on the vertical axis, In addition, the space can be used effectively, and the orientation of the front opening 22a and the rear exhaust pipe 12e of the shroud 22, for example, can be easily changed.

  In the above description, the frame for housing the engine generator 10 has a cylindrical shape. However, the frame is not limited thereto, and may have a square shape.

  Further, all numerical values such as the number of blades 16b of the cooling fan 16 and the number of fins 20b of the intake duct 20 are examples and are not limited thereto.

  Needless to say, the structures of the engine 12 and the generator 14 are not limited to those shown in the drawing. For example, a simple exhaust duct may be used instead of the shroud.

10 engine generator, 12 engine, 12a cylinder head, 12b crankshaft, exhaust system (12c front exhaust pipe, 12d muffler, 12e rear exhaust pipe), 12f fuel tank, 12f1 central opening, 14 generator, 14a rotor , 14b Stator, 16 Cooling fan, 16a pedestal, 16b Blade, 18 Recoil starter, 20 Intake duct, 20a Inner wall surface, 20b Fin, 22 Shroud (exhaust duct), 22a Tip opening, 22b Narrow part, 22c Wide diameter part, 22d large diameter part, 22e internal space, 24 cylindrical frame, 24a cylindrical surface, 24b upper surface, 24c lower part, 24d, 24e, 24f, 24g, 24h pipe, 26 housing, 26a inclined surface, 26b vent hole, 26c large diameter part, 30 Insulation

Claims (8)

  An engine generator comprising: an engine having a crankshaft disposed in a vertical axis direction; and a generator disposed below the engine in the vertical axis direction and having a rotor fastened to the crankshaft of the engine. And an exhaust system that is disposed upward in the direction of the vertical axis and exhausts the exhaust of the engine from above to the outside, and has an approximately skirt-like shape, and an internal space is formed, and the exhaust system is formed in the internal space And a shroud for housing the engine, and an intake duct disposed below the shroud in the direction of the vertical axis.   2. The engine generator according to claim 1, wherein the intake duct includes a cooling fan disposed below the generator and connected to a crankshaft of the engine via the rotor.   3. The engine generator according to claim 1, wherein the intake duct is formed with a plurality of fins each having a spiral curve extending upward while rotating around the vertical axis over the entire circumference of the inner wall surface. 4.   The engine generator according to any one of claims 1 to 3, wherein a fuel tank for storing fuel of the engine is disposed on an outer periphery of the shroud.   5. The engine generator according to claim 4, wherein the fuel tank has a circular donut shape, and the shroud is inserted through a central hole portion of the donut shape.   The engine generator according to any one of claims 1 to 5, wherein an exhaust system of the engine is accommodated in an inner space of the shroud.   The engine generator according to any one of claims 1 to 6, wherein the shroud is formed in a cylindrical shape centered on the vertical axis. 8. The engine according to claim 1, wherein the engine, the generator, the shroud, and the intake duct are accommodated in a cylindrical frame that is formed in a cylindrical shape centered on the vertical axis. Engine generator.

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