JP2015020598A - Engine generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine generator capable of driving a generator at an efficient rotational speed upon setting a rotational speed of an engine to a low speed to suppress noise and vibration, and ensuring excellent mountability in an electric vehicle.SOLUTION: An engine generator 10 that is mounted in an electric vehicle (1) running by a motor (4) using a secondary battery (6) as a main power supply and that serves as a power supply of the secondary battery (6) or the motor (4), comprises: an engine 11 including a crankshaft 24; a generator 12 including a rotary shaft 62 provided in parallel to the crankshaft 24; and a transmission mechanism (41, 65) provided between the crankshaft 24 and the rotary shaft 62, and increasing a rotational speed of the generator 12 relatively to a rotational speed of the engine 11, the generator 12 being provided opposite to a cylinder (13) across the crankshaft 24 in a view in an axial direction of the crankshaft 24, so that mountability of the engine generator 10 in the electric vehicle (1) improves.

Description

  The present invention relates to an engine generator that is mounted on an electric vehicle that runs on a motor that uses a secondary battery as a main power source and that is used as a power source for the secondary battery or the motor.

  As a mobile generator, apart from the first generator for starting provided at one end of the crankshaft of a drive engine mounted on a two-wheeled vehicle, a second generator used as a power source for purposes other than traveling purposes is used for the two-wheeled vehicle. It is mounted on the upper part of the drive engine so that the electric power generated by the second generator when parked can be taken out (see Patent Document 1).

  In addition, as a vibration reduction device for the engine, the rotation shaft of the starter generator is connected to the crankshaft so as to rotate in reverse with respect to the crankshaft, and the torque reaction force of the crankshaft is canceled by the inertia moment of the rotation shaft. A technique for reducing rolling vibration is known (see Patent Document 2).

JP 61-81877 A JP 2011-122666 A

  However, conventional engine generators are generally used in an auxiliary role, and no consideration is given to noise, vibration, cooling performance, and mountability at high output. The smaller the generator, the more advantageous in terms of mountability. However, in the conventional engine generator, since the generator is provided coaxially with the crankshaft of the engine and rotates at the same rotational speed as the crankshaft, a high output is drawn from the generator while keeping the engine speed low. If it tries to do so, the power generation efficiency will deteriorate, the amount of heat generated by the coil will increase, and the durability will be disadvantageous. In order to extract the output efficiently from a small generator, it is conceivable to increase the rotation speed of the generator by increasing the rotation speed of the crankshaft. However, there is a conflicting problem that it is desired to reduce the rotational speed of the crankshaft in terms of engine noise suppression and vibration suppression. In addition, when an engine generator in which an engine and a generator are integrated is mounted under the floor of a vehicle, it is necessary to consider the mountability in addition to the size. In particular, when an engine generator is mounted on a small electric vehicle or the like, sufficient consideration must be given to mountability.

  The present invention has been made in view of such a background, and it is possible to drive the generator at an efficient rotational speed while suppressing the noise and vibration by reducing the engine rotational speed, and to an electric vehicle. It aims at providing the engine generator excellent in the mounting property.

  According to one aspect of the present invention, such a problem is mounted on an electric vehicle (1) that runs on a motor (4) that uses a secondary battery (6) as a main power source, and the secondary battery (6) or An engine generator (10) used as a power source for the motor (4), comprising a cylinder (13), a piston (23) slidably inserted in the cylinder, and a crankshaft ( 24), a first generator (12) having a rotating shaft (62) provided in parallel with the crankshaft (24), the crankshaft (24) and the rotating shaft (62). And a transmission mechanism (41, 65) for increasing the rotational speed of the first generator (12) with respect to the rotational speed of the engine (11), the first generator (12) This is achieved by providing an engine generator provided on the side opposite to the cylinder (13) with respect to the crankshaft (24) in the axial direction of the crankshaft (24). .

  According to this engine generator, since the first generator is connected to the engine via the speed change mechanism, it is possible to reduce the engine rotation speed necessary for obtaining a desired output and to suppress engine noise and vibration. In addition, since the first generator is provided so that the rotating shaft is parallel to the crankshaft and located on the side opposite to the cylinder with respect to the crankshaft, the size of the engine generator is about the cylinder axis direction. Although it becomes large, it becomes small about the direction orthogonal to this, and the mounting property to an electric vehicle can be improved.

  Further, according to one aspect of the present invention, the first generator (12) is configured so that the engine (11) has a direction perpendicular to the cylinder axis (13X) when the crankshaft (24) is viewed in the axial direction. It can be set as the structure provided in the position which has a dimension (H12) smaller than a dimension (H11), and does not protrude from the said engine (11).

  According to this configuration, since the size of the engine generator does not increase due to the presence of the first generator in the direction orthogonal to the cylinder axis direction, the mounting property to the electric vehicle is improved and mounting under the floor or the like is possible. It becomes easy.

  Further, according to one aspect of the present invention, the speed change mechanism (41, 65) is provided on the large gear (41) provided on the crankshaft (24) and the rotary shaft (62). A small gear (65) meshing with the gear, and a damper (elastic portion 68) provided on the large gear (41) or the small gear so as to prevent separation and collision of the tooth surfaces of the two gears (41, 65). , Elastic members 73 and 85) and the large gear (41) or the small gear (65) provided with the damper (68) so as to suppress vibration due to torque fluctuation of the engine (11). And a weight (outer portions 67 and 84, weight 75).

  According to this configuration, the transmission mechanism can be prevented from generating noise and vibration.

  According to another aspect of the present invention, the cooling fan (55) provided integrally with the crankshaft (24) and the cooling fan (55) are provided so as to be exposed to the cooling air, And a radiator (56) for circulating cooling water for the engine (11), wherein the first generator (12) is provided in the cooling air passage (91).

  According to this configuration, the first generator can be cooled using the cooling fan for cooling the engine, and the first generator can be downsized.

  In addition, according to one aspect of the present invention, it is possible to further include a second generator (50) provided on the crankshaft (24) integrally with the cooling fan (55).

  According to this configuration, since the engine generator can be configured by attaching the first generator to an engine with a starter motor that is widely used in motorcycles and the like, the manufacturing cost of the engine generator can be suppressed.

  As described above, according to the present invention, the engine can be driven at an efficient number of revolutions while suppressing the noise and vibration by reducing the engine rotation speed, and the engine has excellent mountability in an automobile. A generator can be provided.

1 is a schematic perspective side view of an electric vehicle equipped with an engine generator according to a first embodiment. Plan sectional view of the engine generator shown in FIG. III-III sectional view in FIG. Position explanatory drawing of the 1st generator in the engine generator shown in FIG. The principal part plane sectional view of the engine generator concerning the modification of a 1st embodiment. The principal part plane sectional view of the engine generator concerning other modifications of a 1st embodiment. Plan sectional view of the engine generator according to the second embodiment VIII-VIII sectional view in FIG. Plan sectional view of an engine generator according to a modification of the second embodiment

  Hereinafter, an engine generator 10 according to the present invention will be described in detail with reference to the drawings with two embodiments and modifications thereof.

<< First Embodiment >>
First, the engine generator 10 according to the first embodiment will be described with reference to FIGS. As shown in FIG. 1, the engine generator 10 is mounted and used in an automobile 1. The automobile 1 has four wheels 3 (3f, 3r) on the front, rear, left, and right of a vehicle body 2, and is driven by two motors 4 that are coaxially provided on both front wheels 3f. It is an electric four-wheeled vehicle. A battery 6, which is a secondary battery, is mounted below the floor 5 of the automobile 1, and a charger 7 for charging the battery 6 from an external power source such as a home AC power source is mounted. On the other hand, the engine generator 10 is installed in an engine room 8 formed below the floor 5 in the rear part of the vehicle body 2 of the automobile 1. The in-wheel motor 4 is a three-phase AC motor, and drives the AC power converted from the DC power supplied from the battery 6 through an inverter (not shown) as a main power source.

  The engine generator 10 includes an engine 11 and a generator 12 connected to the engine 11, and the generator 12 is driven by the engine 11 to generate electric power (AC power here). The electric power generated by the engine generator 10 is converted into direct current power through a converter (not shown), and the battery 6 is charged and used for driving the in-wheel motor 4 or directly used for driving the in-wheel motor 4. The In this sense, the vehicle 1 can be said to be a hybrid vehicle that travels using not only the electric power from the battery 6 but also the electric power from the engine generator 10 as a driving power source. Although not shown, the automobile 1 is also provided with a fuel tank, a fuel supply system for supplying fuel in the fuel tank to the engine generator 10, an intake system for supplying air to the engine generator 10, and the like. It has been. Further, the automobile 1 is equipped with an exhaust system 9 that guides exhaust gas from the engine generator 10 to the rear of the vehicle body 2, and the exhaust system 9 is provided with a silencer 9 a for reducing noise. .

  As shown in FIGS. 2 and 3, the engine 11 is a four-stroke single-cylinder SOHC reciprocating engine, and includes a cylinder block 13, a cylinder head 14 joined to one end of the cylinder block 13 in the axial direction, and a cylinder head 14. Joined to the opposite side of the cylinder block 13 and joined to the other end of the cylinder block 13 in the axial direction of the cylinder head cover 16 and the cylinder block 13 which cooperate with the cylinder head 14 to define the valve operating chamber 15. A crankcase 18 is provided.

  The cylinder block 13 is formed with one cylinder bore 21 and an intra-block water jacket 22. A piston 23 is slidably received in the cylinder bore 21, and a crankshaft 24 is rotatably provided in the crank chamber 17. The piston 23 and the crankpin of the crankshaft 24 are connected by a connecting rod 25, and the reciprocating motion of the piston 23 is converted into the rotational motion of the crankshaft 24.

  The engine generator 10 is mounted on the automobile 1 with the cylinder head 14 facing forward and the cylinder bore 21 extending substantially horizontally in the front-rear direction and the crankshaft 24 extending horizontally in the left-right direction. In the following, the description will be made in accordance with the front, rear, left, and right directions indicated by arrows in FIGS. 2 and 3 with reference to the mounting posture of the engine generator 10. As shown in FIG. 3, a cooling water inlet 26 for allowing cooling water to flow into the water jacket 22 in the block is formed on the lower surface of the cylinder block 13.

  On the other hand, a spark plug 30 (FIG. 2) is installed in the cylinder head 14, and an intake port 31 (FIG. 3), an exhaust port 32 (FIG. 3), and a water jacket 33 (FIG. 2) in the head are formed. Yes. As shown in FIG. 3, the cylinder head 14 is provided with an intake valve 34 and an exhaust valve 35 slidably so as to open and close the intake port 31 and the exhaust port 32, respectively. The valve operating chamber 15 includes a camshaft 36 extending in parallel with the crankshaft 24, and a valve operating system including rocker arms 37, 38 that are driven to swing by the camshaft 36 and open and close the intake valve 34 and the exhaust valve 35. 39 is accommodated. The in-head water jacket 33 (FIG. 2) is formed so as to communicate with the in-block water jacket 22, and the cooling water flowing through the in-block water jacket 22 flows into the in-head water jacket 33.

  The crankshaft 24 can be rotated by journals formed on both sides in the axial direction of the crankpin being supported by the crankcase 18 via ball bearings 40, respectively. One end of the crankshaft 24 protrudes leftward from the crankcase 18, and a large gear 41 larger than a small gear 65 described later is integrally attached to the left protruding portion of the crankshaft 24. A gear cover 42 is attached to the left side surface of the crankcase 18, and a gear chamber 43 is formed inside the gear cover 42. The gear chamber 43 extends far behind the engine 11 so as to accommodate the small gear 65 in addition to the large gear 41. A part of the gear chamber 43 is defined by the crankcase 18, but the crankcase 18 defines the right half of the gear chamber 43 and the gear case 44 supporting the generator 12 extends rearward or upward. Are integrally formed.

  The other end of the crankshaft 24 also protrudes rightward from the crankcase 18. A crank sprocket 45 that rotates integrally with the crankshaft 24 is attached in the vicinity of the journal at the right side protruding portion of the crankshaft 24. A cam sprocket 46 is integrally attached to the camshaft 36 at a position corresponding to the crank sprocket 45 in the axial direction. An endless chain 47 is wound around the crank sprocket 45 and the cam sprocket 46, and the rotation of the crank sprocket 45 is transmitted to the cam sprocket 46 by the endless chain 47. The sprocket diameter of the crank sprocket 45 is ½ of the sprocket diameter of the cam sprocket 46, and the camshaft 36 is rotationally driven at a rotational speed ½ that of the crankshaft 24. A chain cover 48 is provided on the side surface of the crankcase 18 where the endless chain 47 is provided, and the endless chain 47 is accommodated in a chain chamber 49 defined by the crankcase 18 and the chain cover 48. .

  An AC generator 50 is provided coaxially with the crankshaft 24 at a portion of the crankshaft 24 to the right of the crank sprocket 45. The AC generator 50 includes an outer rotor 51 having a permanent magnet attached so as to rotate integrally with the crankshaft 24, and an inner stator 52 having an electromagnetic coil fixed to the crankcase 18. The AC generator 50 functions as a starter motor when the engine 11 is started, and can function as an auxiliary generator driven by the crankshaft 24 after the engine 11 is started.

  A centrifugal cooling fan 55 that rotates integrally with the crankshaft 24 is attached to an end of the crankshaft 24 that is further to the right than the AC generator 50. A radiator 56 for cooling the engine 11 is disposed on the side opposite to the AC generator 50 with respect to the cooling fan 55, that is, on a position away from the cooling fan 55 on the intake side of the cooling fan 55. The radiator 56 is attached to the right open end of a cylindrical radiator base 57 joined to the right side surface of the cylinder block 13 so as to be exposed to the cooling air generated by the cooling fan 55, and is integrated with the engine 11. . A radiator cover 58 in which an air introduction port 58 a is formed is attached to the radiator base 57 so as to cover the radiator 56, and the air introduced from the air introduction port 58 a passes through the radiator 56, so that the inside of the radiator 56 Heat exchange is performed between the cooling water and air. An air discharge port 57a is formed at the rear portion of the radiator base 57, and the air blown by the cooling fan 55 is discharged to the outside from the air discharge port 57a.

  In the present embodiment, the air outlet 57a is formed at a position that does not overlap the generator 12 in the left-right direction. In another embodiment, the air discharge port 57a is formed at a position overlapping the generator 12 in the left-right direction, and the air discharged to the outside from the air discharge port 57a is configured to cool the generator 12, in other words, You may comprise the generator 12 so that it may be located on the path | route of the cooling air from the cooling fan 55. FIG.

  The engine 11 having such a configuration is the same as the engine with a starter motor that is widely used for two-wheeled vehicles and the like except for the large gear 41 and the gear case 44. Therefore, the engine 11 of the embodiment can be configured by slightly modifying the general-purpose engine, and the engine generator 10 can be configured by attaching the generator 12 to the general-purpose engine. Manufacturing costs can be reduced.

  The generator 12 is disposed in parallel with the crankshaft 24 at a position separated from the crankcase 18 behind the engine 11. The generator 12 is mounted so as to rotate together with a housing 61 attached to the gear case 44, a rotary shaft 62 that is rotatably supported by the housing 61, and provided in parallel with the crankshaft 24, and the rotary shaft 62. The inner rotor 63 has a permanent magnet, and the outer stator 64 has an electromagnetic coil fixed to the housing 61. The rotating shaft 62 extends in parallel with the crankshaft 24, that is, horizontally in the left-right direction.

  The rotating shaft 62 penetrates the left wall of the housing 61 and the gear case 44 and enters the gear chamber 43, and a small gear 65 smaller in diameter than the large gear 41 is integrally attached near the end in the gear chamber 43. It has been. The small gear 65 is provided so as to always mesh with the large gear 41, and the rotation of the crankshaft 24 is transmitted to the rotating shaft 62. In the present embodiment, the reference pitch circle diameter of the small gear 65 is ½ of the reference pitch circle diameter of the large gear 41, and the rotary shaft 62 is driven to rotate at twice the rotational speed of the crankshaft 24. That is, the large gear 41 and the small gear 65 are interposed between the crankshaft 24 and the rotating shaft 62 to constitute a speed change mechanism that increases the rotational speed of the generator 12 with respect to the rotational speed of the engine 11. Yes.

  The small gear 65 includes an annular inner portion 66 fixed to the rotary shaft 62, an annular outer portion 67 having an inner diameter larger than the outer diameter of the inner portion 66, and teeth 65a formed on the outer peripheral surface thereof, A rubber-like elastic portion 68 that connects the inner portion 66 and the outer portion 67 is provided. The outer portion 67 has a larger axial dimension than the inner portion 66, and is provided so as to protrude toward the housing 61 of the generator 12 with respect to the inner portion 66. The outer portion 67 is rotatably supported on the gear case 44 by two ball bearings 69 provided in a portion protruding from the inner portion 66. The elastic portion 68 connects the inner portion 66 and the outer portion 67 so as to be relatively displaceable in the circumferential direction, and prevents separation and collision of the tooth surfaces of the large gear 41 and the small gear 65 caused by the presence of backlash. Functions as a damper.

  Further, the small gear 65 has a smaller diameter than the large gear 41 and thus rotates at a higher speed than the large gear 41, and the axial dimension of the outer portion 67 is increased, so that it is larger when the engine 11 is driven. Generates moment of inertia. Therefore, the small gear 65 suppresses changes in the rotational speed of the crankshaft 24 due to torque fluctuations of the engine 11 and suppresses rolling vibration of the engine generator 10. Further, since the elastic portion 68 is deformed by the torque fluctuation of the engine 11, the change in the rotation speed of the rotary shaft 62 is suppressed, and the power generation amount of the generator 12 is stabilized.

  In the present embodiment, the generator 12 is used for power generation when the engine 11 is driven. The electric power generated by the generator 12 is converted into DC power via a converter (not shown) as described above, and the battery 6 is charged to be used for driving the in-wheel motor 4 or directly driving the in-wheel motor 4. Used for Since the AC generator 50 that functions as a starter motor in the present embodiment is not an essential configuration, the AC generator 50 may be omitted. In this case, when the engine 11 is started. The generator 12 may be used as the starter motor.

  As shown in FIGS. 1 and 3, the engine generator 10 configured in this way is installed substantially horizontally in an engine room 8 formed under the floor 5 at the rear of the vehicle body 2 of the automobile 1. In the present embodiment, the axis of the cylinder block 13 (hereinafter referred to as the cylinder axis 13X (see FIG. 4)) faces the cylinder head 14 side upward so that no oil hammer is generated due to the oil collecting in the cylinder bore 21. The engine generator 10 is mounted in the engine room 8 while being inclined with respect to the horizontal plane. The floor 5 has a level difference to form the engine room 8, and the rear floor is higher than the front. The space above the raised rear part of the floor 5 is used as a rear seat installation space or a luggage room. Therefore, in order to enlarge the space on the floor 5, it is necessary to make the height of the engine room 8 as small as possible.

  Therefore, in the present embodiment, as shown in FIG. 4, the generator 12 is provided so as to be located on the side opposite to the cylinder block 13 with respect to the crankshaft 24 in the axial direction view of the crankshaft 24. More specifically, the generator 12 of this embodiment is disposed at a position where the rotary shaft 62 is at the same height as the crankshaft 24 of the engine 11. Here, the height dimension H12 of the generator 12 is smaller than the height dimension H11 of the engine 11. Therefore, the generator 12 is provided in the engine 11 so as not to protrude in the vertical direction from the engine 11, and the height dimension of the engine generator 10 is not increased by the installation of the generator 12. Therefore, the height dimension H of the engine room 8 can be reduced, and the engine generator 10 can be easily mounted under the floor 5 and the mountability of the engine generator 10 to the automobile 1 is improved.

  From this point of view, the generator 12 does not need to be arranged at the same height as the crankshaft 24, and is arranged at a position shifted upward or downward as indicated by an imaginary line in FIG. Is also possible. However, even when the generator 12 is installed at such a position, it is preferable to install the generator 12 at a position that does not protrude from the engine 11 in the vertical direction.

  Assuming that a reference line BL is a line extending in parallel to the cylinder axis 13X from the rotation center 24X of the crankshaft 24 to the side opposite to the cylinder block 13, in the present embodiment, the crankshaft 24 is positioned substantially on the cylinder axis 13X. Therefore, the reference line BL coincides with the cylinder axis 13X. The position of the generator 12 is such that the straight lines GL connecting the rotation center 24X of the crankshaft 24 and the rotation shaft 62 of the generator 12 are each 30 degrees or less in the vertical direction with respect to the reference line BL (cylinder axis 13X). Is set, the generator 12 can be installed so as not to protrude from the engine 11 in the vertical direction.

  When the position of the generator 12 is set to a position shifted in the vertical direction as shown by an imaginary line in FIG. 4, the longitudinal dimension of the engine generator 10 is slightly smaller than that of the present embodiment, and the engine room 8 The front-rear dimension L can be slightly reduced.

  In this way, the generator 12 is connected to the engine 11 via the large gear 41 and the small gear 65, so that the engine rotation speed necessary for obtaining desired power can be reduced, and the engine 11 Noise and vibration can be suppressed. Further, since the generator 12 is provided so that the rotary shaft 62 is parallel to the crankshaft 24 and is located on the side opposite to the cylinder block 13 with respect to the crankshaft 24, the longitudinal dimension of the engine generator 10 is provided. Although the (front-rear dimension L of the engine room 8) is increased, the height dimension of the engine generator 10 (height dimension H of the engine room 8) is decreased, and the mountability of the engine generator 10 on the automobile 1 is improved. .

<Modification 1>
Next, a modification of the first embodiment will be described with reference to FIG. As shown in FIG. 5, in this modification, a disk-like plate 71 is fastened to the rotating shaft 62 of the generator 12 by a nut 72 on the end face in the gear chamber 43 so as to be orthogonal to the rotating shaft 62. The small gear 65 is integrally attached to the rotary shaft 62 via the plate 71.

  A plurality of long holes 71a are formed in the plate 71 so as to extend in the circumferential direction, and a rubber-like elastic member 73 having a shape corresponding to the long holes 71a is attached to each long hole 71a. . A pin 74 is attached to the center of the elastic member 73 in the circumferential direction so as to penetrate the elastic member 73, and a small gear 65 is integrally provided on the pin 74. The small gear 65 has a larger axial dimension than the teeth 65a meshing with the large gear 41, and is rotatably supported by the gear case 44 by two ball bearings 69 provided at both ends in the axial direction. At a position offset in the axial direction from the teeth 65 a of the small gear 65, a weight 75 formed in an annular shape having a larger diameter than the small gear 65 is integrally attached.

  According to this configuration, the elastic member 73 connects the pin 74 fixed to the small gear 65 and the plate 71 fixed to the rotary shaft 62 so as to be relatively displaceable in the circumferential direction, and is generated due to the presence of backlash. It functions as a damper that prevents separation and collision of the tooth surfaces of the large gear 41 and the small gear 65. In addition, since the weight 75 having a larger diameter than this is integrally attached to the small gear 65, the small gear 65 and the weight 75 generate a larger moment of inertia when the engine 11 is driven. Therefore, the change in the rotational speed of the crankshaft 24 due to the torque fluctuation of the engine 11 is more effectively suppressed, and the rolling vibration of the engine generator 10 is suppressed. Further, the power generation amount of the generator 12 is further stabilized.

<Modification 2>
With reference to FIG. 6, another modification of the first embodiment will be described. As shown in FIG. 6, in this modification, a small gear 65 is fixed to a gear chamber 43 side end of the rotating shaft 62 of the generator 12 by a nut 72, and the rotating shaft 62 is connected to a gear case by a ball bearing 69. 44 is rotatably supported. On the other hand, a pair of disc-shaped plates 81 and 82 are integrally attached to the left protruding portion of the crankshaft 24 so as to be orthogonal to the crankshaft 24, and are sandwiched between the pair of plates 81 and 82, thereby providing a large gear. 41 is held.

  The large gear 41 has an inner part 83 formed relatively thin and an outer part 84 formed integrally with the inner part 83 and relatively thick and having teeth 41a formed on the outer peripheral surface thereof. A plurality of long holes 83a are formed in the inner portion 83 so as to extend in the circumferential direction, and a rubber-like elastic member 85 having a shape corresponding to the long holes 83a is attached to each long hole 83a. Yes. A pin 86 is attached to the center of the elastic member 85 in the circumferential direction so as to penetrate the elastic member 85, and the pin 86 is fixed to the pair of plates 81 and 82.

  According to this configuration, the elastic member 85 connects the pin 86 fixed to the pair of plates 81 and 82 and the large gear 41 so as to be relatively displaceable in the circumferential direction, and the large gear generated by the presence of backlash. 41 and the small gear 65 function as a damper that prevents separation and collision of the tooth surfaces. Further, since the outer portion 84 of the large gear 41 is formed thick, a larger moment of inertia is generated when the engine 11 is driven. Therefore, the large gear 41 suppresses changes in the rotational speed of the crankshaft 24 due to torque fluctuations of the engine 11 and suppresses rolling vibration of the engine generator 10. Further, since the elastic member 85 is deformed by the torque fluctuation of the engine 11, changes in the rotation speed of the large gear 41 and the rotary shaft 62 are suppressed, and the power generation amount of the generator 12 is stabilized.

<< Second Embodiment >>
Next, the engine generator 10 according to the second embodiment will be described with reference to FIGS. 7 and 8. In addition, the same code | symbol is attached | subjected to the element which is the same or the same as that of 1st Embodiment, or a function, and the overlapping description is abbreviate | omitted.

  In the present embodiment, a generator cover 90 that covers the generator 12 (more specifically, the housing 61) is attached to the rear portion of the engine generator 10. The generator cover 90 is attached so that an air discharge port 57a formed in the radiator base 57 is opened inside. On the side of the generator cover 90 opposite to the air outlet 57 a of the radiator cover 58, an opening 90 a for discharging air that has circulated through the generator cover 90 is formed. In the present embodiment, the opening 90 a is a gap formed between the gear case 44. In another embodiment, it may be constituted by a through hole that penetrates the generator cover 90.

  By providing such a generator cover 90, the air (cooling air) generated by the cooling fan 55 and discharged from the air discharge port 57 a passes through the periphery of the generator 12 and passes from the opening 90 a to the radiator cover 58. Is discharged outside. That is, the generator cover 90 is a passage defining member that defines a cooling air passage 91 around the generator 12.

  As described above, since the rotary shaft 62 is rotationally driven at twice the rotational speed of the crankshaft 24, the power generation amount of the generator 12 is increased, while the outer stator 64 having a coil is likely to generate heat. In the present embodiment, since the generator 12 is provided in the cooling air passage 91, the cooling air flows around the generator 12 and the heat dissipation efficiency of the generator 12 is improved. That is, since the generator 12 can be cooled by using the cooling fan 55 for cooling the engine 11, it is possible to employ a small generator 12 having a large heat generation energy per output. Can be downsized.

<Modification>
Finally, a modification of the second embodiment will be described with reference to FIG. As shown in FIG. 9, in this modification, the radiator cover 58 and the generator cover 90 of the second embodiment are configured as an integral cover member 95, and the same power generation as the exhaust opening 90a of the second embodiment. An opening formed on the left rear side of the machine 12 is an air inlet 95a. The cooling air sucked from the air introduction port 95 a by the cooling fan 55 and passed through the radiator 56 is discharged to the outside from the air discharge port 57 a formed in the front portion of the radiator base 57. Note that the air discharge port 57 a is naturally formed at a position that opens outside the inside of the cover member 95. Even if the engine generator 10 is configured in this manner, the same effects as those of the second embodiment can be obtained.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above embodiment, the engine 11 is a single-cylinder SOHC engine, but it may be a multi-cylinder engine or a DOHC engine. In the above-described embodiment, the rotation shaft 62 is configured to rotate at twice the rotational speed of the crankshaft 24 by the speed change mechanism. However, if the speed is increased, the speed change magnification is limited to twice. It is not a thing. Further, a belt or a chain may be used as the speed change mechanism. In addition, the specific configuration, arrangement, quantity, angle, and the like of each member and part can be changed as appropriate without departing from the spirit of the present invention. On the other hand, all the components of the engine generator 10 shown in the above embodiment are not necessarily essential, and can be appropriately selected.

1 Car (electric car)
4 In-wheel motor 6 Battery (secondary battery)
10 engine generator 11 engine 12 generator (first generator)
13 Cylinder block (cylinder)
13X Cylinder axis 23 Piston 24 Crankshaft 41 Large gear (transmission mechanism)
50 AC generator (second generator)
55 Cooling fan 56 Radiator 62 Rotating shaft 65 Small gear (transmission mechanism)
67 Outer part (weight)
68 Elastic part (damper)
73 Elastic member (damper)
75 Weight 84 Outer part (weight)
85 Elastic member (damper)
H Height dimension of engine room 8 H11 Height dimension of engine 11 H12 Height dimension of generator 12

Claims (5)

An engine generator that is mounted on an electric vehicle that runs on a motor that uses a secondary battery as a main power source, and that serves as a power source for the secondary battery or the motor,
An engine having a cylinder, a piston slidably inserted into the cylinder, and a crankshaft coupled to the piston;
A first generator having a rotating shaft provided in parallel with the crankshaft;
A speed change mechanism interposed between the crankshaft and the rotation shaft and increasing the rotation speed of the first generator with respect to the rotation speed of the engine;
The first generator is provided on the side opposite to the cylinder with respect to the crankshaft when viewed from the axial direction of the crankshaft.   The first generator is provided at a position that has a dimension smaller than the dimension of the engine and does not protrude from the engine in a direction orthogonal to a cylinder axis when viewed in the axial direction of the crankshaft. The engine generator according to claim 1. The transmission mechanism is
A large gear provided on the crankshaft;
A small gear provided on the rotating shaft and meshing with the large gear;
A damper provided on the large gear or the small gear so as to prevent separation and collision of tooth surfaces of the two gears;
2. The engine generator according to claim 1, wherein the large gear or the small gear provided with the damper includes a weight provided so as to suppress vibration due to torque fluctuation of the engine. 3. A cooling fan provided integrally with the crankshaft;
A radiator that is provided to be exposed to cooling air generated by the cooling fan, and that circulates cooling water for the engine;
The engine generator according to claim 1 or 2, wherein the first generator is provided in a passage of the cooling air.   The engine generator according to claim 4, further comprising a second generator provided on the crankshaft integrally with the cooling fan.

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