Range extender for storage battery electric automobile

Abstract

A range extender (1) for a BEV is provided with the power generation-dedicated engine (2) having two horizontally opposed cylinders, a generator (3), a fuel tank (4) for the power generation-dedicated engine (2), and a cooling device (8) for the power generation-dedicated engine (2). The power generation dedicated engine (2) is provided with the crankshaft (11) having a horizontal rotational center axis, two cylinders (12) disposed facing each other across the crankshaft (11), and pistons (13) disposed in the cylinders (12) so as to face each other across the crankshaft (11). The power generator (3) is disposed in a substantially central portion in the longitudinal direction of the power-generating-dedicated engine (2) such that the power-generating-dedicated engine (2) and the power generator (3) form a T-shape in plan view.

Description

Technical Field

[0001] The present invention relates to a range extender for a battery electric vehicle which is mounted on a battery electric vehicle having four or more wheels and is used to extend the cruising distance.

[0002] In this specification and claims, Figure 1 and Figure 4 The left and right of Figure 2 and Figure 3 The upper and lower parts of are called upper and lower parts. Figure 1 and Figure 4 The upper side ( Figure 2 The left side of the image is called the front, and the opposite side is called the rear. Background Art

[0003] In the major developed countries in the world, battery electric vehicles (hereinafter referred to as BEVs depending on the situation) equipped with batteries and driven only by a battery-driven motor are rapidly gaining popularity. BEVs are vehicles equipped with batteries and a battery-driven motor, and various types of BEVs have been developed, such as sedans, SUVs (sport utility vehicles), pickup trucks, and vans. However, in the case of any type of BEV, there are common problems such as short cruising range and long battery charging time due to the energy capacity of the battery that can be installed.

[0004] In order to solve such problems, various BEV range extenders have been proposed. For example, Patent Document 1 describes a BEV range extender, which includes a power generation engine, a generator that generates electricity by driving the power generation engine, a fuel tank for the power generation engine, and a cooling device for the power generation engine, and includes: a crankcase, which has a crankshaft arranged in a manner such that the rotation center axis is horizontal with the longitudinal direction facing the vehicle width direction; a cylinder liner (cylinder liner); The invention relates to a case having a cylinder disposed on only one side of the crankshaft in a manner that the axial direction is perpendicular to the vehicle width direction; and a piston driven in the cylinder in a direction perpendicular to the vehicle width direction, the generator being disposed at one end of the crankcase in the length direction in a manner that is arranged in a straight line with the crankcase, the cooling device being disposed at the other end of the crankcase in the length direction in a manner that is arranged in a straight line with the crankcase, the rotating shaft of the generator being connected to the crankshaft, the combination consisting of the crankcase, the generator and the cooling device and the cylinder sleeve forming a T shape when viewed from above, and the fuel tank being disposed in a space on either side of a space surrounded by a vertical plane where an end of the cooling device on the opposite side to the crankcase is located and a vertical plane where an end of the power generation engine on the opposite side to the crankcase is located so as to partially extend beyond the space.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2022-72237 Summary of the invention

[0008] However, in the range extender for BEV described in the above-mentioned patent document 1, since the crankshaft of the generator engine is configured with the length direction facing the vehicle width direction, the cylinder is arranged only on one side of the crankshaft in a manner that the axial direction faces the direction perpendicular to the vehicle width direction, and the piston is driven in the cylinder in the direction perpendicular to the vehicle width direction, the generator engine is an in-line engine and generates large vibrations. As a result, large vibrations are transmitted to the occupants.

[0009] The present invention aims to solve the above-mentioned problems and provide a range extender for BEV that can reduce the generated vibration and can also comply with automobile exhaust regulations and automobile collision safety standards so as to be usable in various BEVs with different body structures and / or sizes.

[0010] The present invention includes the following aspects in order to achieve the above-mentioned object.

[0011] 1) A range extender for a battery electric vehicle, comprising a dedicated power generation engine, a generator for generating power by driving the dedicated power generation engine, a fuel tank for the dedicated power generation engine, and a cooling device for the dedicated power generation engine, and supplying power to a driving battery of the battery electric vehicle, wherein the range extender for the battery electric vehicle comprises:

[0012] The dedicated power generation engine is a horizontally opposed engine, comprising: a crankshaft with a horizontal central axis of rotation; a total of an even number of cylinders, which are arranged in the same number on both sides of the crankshaft in a manner opposite to each other with the crankshaft interposed therebetween; and pistons, which are arranged in each of the cylinders in a manner opposite to each other with the crankshaft interposed therebetween. The generator is arranged in the approximate center of the length direction of the dedicated power generation engine in a manner such that the dedicated power generation engine and the generator are in a T-shape when viewed from above, and the rotating shaft of the generator is horizontally arranged on the same axis as the crankshaft or on an axis parallel to the crankshaft, and is connected to the crankshaft.

[0013] 2) The range extender for a battery electric vehicle according to 1) above, wherein the rotating shaft of the generator is connected to the crankshaft via a transmission device, and the rotating shaft is accelerated or decelerated by the transmission device and rotated by the rotation of the crankshaft.

[0014] 3) The range extender for a battery electric vehicle according to 1) above, wherein the dedicated power generation engine is a horizontally opposed two-cylinder, four-cylinder or six-cylinder engine, and the cylinders are arranged on both sides of the crankshaft with their lengths facing left and right.

[0015] 4) A range extender for a battery electric vehicle according to 1) above, wherein the fuel tank is configured to be entirely contained within a space, i.e., at least one of two spaces surrounded by a vertical plane where both ends of the dedicated power generation engine in the length direction are located and a vertical plane where the top end of the generator protruding from the dedicated power generation engine is located.

[0016] 5) The range extender for a battery electric vehicle according to 1) above, wherein the fuel tank is configured to be entirely contained in the following space, i.e., a space on either side of two spaces surrounded by the vertical plane where the two ends of the dedicated power generation engine in the length direction are located and the vertical plane where the top end of the generator protruding from the dedicated power generation engine is located, and the cooling device is configured to be at least partially contained in the other of the two spaces.

[0017] 6) The range extender for a battery electric vehicle according to 1) above, wherein the power generation engine comprises: a cylinder block, which is arranged on both sides of the crankshaft in a manner of clamping the crankshaft and forms the cylinders; a cylinder head, which is provided on the cylinder block and forms a combustion chamber corresponding to each of the cylinders, and two intake ports and two exhaust ports facing each of the combustion chambers; two intake valves, which open and close the two intake ports of each of the combustion chambers; two exhaust valves, which open and close the two exhaust ports of each of the combustion chambers; and a valve mechanism, which opens and closes all of the intake valves and all of the exhaust valves,

[0018] The valve mechanism is composed of a first valve unit that opens and closes all the intake valves, and a second valve unit that opens and closes all the exhaust valves.

[0019] The first valve unit includes a first camshaft that rotates around a horizontal rotation center axis through the crankshaft, a first push rod driven by a cam of the first camshaft, and a first rocker arm driven by the first push rod, and transmits input based on the cam of the first camshaft to all the intake valves.

[0020] The second valve unit includes a second camshaft that rotates around a horizontal rotation center axis through the crankshaft, a second push rod driven by a cam of the second camshaft, and a second rocker arm driven by the second push rod, and transmits input based on the cam of the second camshaft to all the exhaust valves.

[0021] One of the first camshaft and the second camshaft is arranged at a height position above the cylinder, and the other is arranged at a height position below the cylinder.

[0022] 7) A range extender for a battery electric vehicle according to 6) above, wherein the cylinder of the power generation engine is formed on the cylinder body in a manner such that the length direction faces the left-right direction, the two intake ports are formed in a front-to-back arrangement on the upper side of the combustion chamber, and the two intake valves are arranged in a front-to-back arrangement, the two exhaust ports are formed in a front-to-back arrangement on the lower side of the combustion chamber, and the two exhaust valves are arranged in a front-to-back arrangement, and the two intake valves are arranged above the two exhaust valves,

[0023] The first camshaft of the first valve unit is arranged at a height position above the cylinder and directly above the crankshaft, and two of the first push rods and two of the first rocker arms are provided for each of the cylinders.

[0024] The second camshaft of the second valve unit is arranged at a height position below the cylinder and directly below the crankshaft, and two of the second push rods and two of the second rocker arms are provided for each of the cylinders.

[0025] 8) A range extender for a battery electric vehicle according to 6) above, wherein the dedicated power generation engine has an intake manifold for supplying intake air to the intake port provided on the cylinder head, and a pressure regulating tank and a branch pipe are provided on the intake air path of the intake manifold, and the pressure regulating tank of the intake manifold is arranged along the side surface of the dedicated power generation engine opposite to the side where the generator is arranged, and / or a portion of the upper surface of the dedicated power generation engine opposite to the side where the generator is arranged.

[0026] 9) The range extender for a battery electric vehicle according to 8) above, wherein a top end portion of the branch pipe of the intake manifold is connected to an upper surface of the cylinder head of the power generation-dedicated engine.

[0027] 10) According to the range extender for a battery electric vehicle described in 8) above, the dedicated power generation engine is a horizontally opposed twin-cylinder engine having one cylinder on the left and right of the crankshaft, that is, two cylinders on the left and right, and the top end of the branch pipe of the intake manifold is connected to the side of the cylinder head of the dedicated power generation engine.

[0028] Effects of the Invention

[0029] In the BEV range extenders of 1) to 10), since the power generation engine is a horizontally opposed engine, the vibration generated is relatively small, and the vibration transmitted to the occupants is also relatively small.

[0030] In addition, since the generator is arranged in the middle of the length direction of the dedicated engine so that the dedicated engine and the generator are T-shaped when viewed from above, two spaces are formed between the two ends of the dedicated engine in the length direction and the top of the generator protruding from the dedicated engine. The two spaces that are safe even in a collision, which are generated by the rigid dedicated engine and the rigid generator, can be effectively used as installation spaces for the entire fuel tank, a part of the cooling device of the dedicated engine, an inverter, etc. As a result, even in completely different body structures such as the monocoque structure that is the mainstream structure of a passenger car and the ladder frame structure that is the mainstream structure of a commercial truck or a pickup truck, it can be mounted without a special vehicle-mounted frame or a protection frame for safety considerations, and the necessary conditions as a power generation unit of various BEVs, namely, miniaturization, compactness, and lightness can be achieved.

[0031] In addition, since the dedicated power generation engine and generator are configured as described above, the area of ​​the fixing parts used when mounting the dedicated power generation engine and generator on the vehicle body can be enlarged. As a result, the rotational torque generated by the dedicated power generation engine and generator can be easily absorbed, and the transmission of the rotational torque to the vehicle body can be reduced.

[0032] According to the range extender for BEV in 6) and 7), in order to ensure the combustion level, it is necessary to ensure the same layout as the DOHC four-valve engine that has been completed to meet the automobile exhaust regulations in existing cars, for the elements that roughly determine the basic combustion and basic exhaust components that meet the automobile exhaust regulations, that is, the ratio of the value of the inner diameter (bore) of the combustion chamber to the stroke, the number, shape and position of the intake and exhaust ports, and the position of the spark plug. Among them, each cylinder has two intake ports and two intake valves and two exhaust ports and two exhaust valves, and ensuring the shape and position of the straight port and the central arrangement of the spark plug are necessary conditions for the valve transmission system.

[0033] In addition, in order to meet the miniaturization, compactness and lightness required of the power generation engine dedicated to the range extender for BEV, the power generation work during high-speed rotation that would transmit large vibrations to the occupants can be compensated by work below medium speed rotation. Therefore, the high-speed rotation element of the valve drive system is omitted, resulting in miniaturization, compactness and lightness.

[0034] Specifically, the two intake valves that open and close the two intake ports are operated by the first rocker arm, the first push rod and the first camshaft of the first valve unit arranged in the cylinder head and the cylinder liner, and the two exhaust valves that open and close the two exhaust ports are operated by the second rocker arm, the second push rod and the second camshaft of the second valve unit arranged in the cylinder head and the cylinder liner. As a result, two camshafts can be omitted from each of the left and right cylinder heads, that is, a total of four camshafts can be omitted in the left and right cylinder heads, and two (four left and right) cam sprockets of the valve drive system that drives each camshaft can also be omitted. As a result, the lubricating oil required in the cylinder head can be saved, and the overall miniaturization, compactness and lightness of the range extender can be sought. Moreover, the cost can also be reduced. In summary, on the basis of ensuring the same combustion level as the existing DOHC engine and meeting the automobile exhaust regulations, a small and compact range extender dedicated power generation engine with less vibration can be provided.

[0035] According to the BEV range extender described in 8) and 9) above, since the pressure regulating box of the intake manifold is arranged along the side surface of the dedicated power generation engine opposite to the side on which the generator is arranged, and / or the upper surface of the dedicated power generation engine opposite to the side on which the generator is arranged, the vertical dimension of the BEV range extender can be made smaller, and the installation space on the BEV can be miniaturized.

[0036] When a horizontally opposed two-cylinder, four-cylinder or six-cylinder engine is used as an engine to directly drive a vehicle, in order to increase the output from idling to the normal rotation area and the maximum allowable rotation, the passage resistance from the manifold of the intake system to the intake port located in the cylinder head of the engine has to be reduced. The intake manifold has no structure other than standing vertically from the cylinder head, connecting the left and right sides on the cylinder line, and forming a chamber in the center.

[0037] In contrast, in the case of a dedicated power generation engine for a range extender for BEV, it is necessary to ensure basic combustion and exhaust performance that complies with automobile exhaust regulations, suppress power generation work at high speeds that transmit large vibrations to passengers, and can be compensated by power generation work within the rotation range below medium speeds. As a result, the shape of the intake manifold does not need to be a structure that stands vertically from the cylinder head, and can be arranged at an angle or bent relative to the top of the cylinder head. That is, the intake manifolds of 8) and 9) above are equivalent to this.

[0038] Moreover, by improving the intake system as described in 8) and 9), even if a horizontally opposed engine with basically less vibration is used, the height dimension of the intake system can be reduced, and the vertical dimension of the range extender for BEV can be reduced. As a result, it can be configured at an appropriate arbitrary position in accordance with various body structures and various body sizes of BEV. Specifically, it can be mounted on BEVs of different structures and sizes such as sedans, SUVs, pickup trucks, and vans.

[0039] According to the BEV range extender described in 10), since the dedicated power generation engine is a horizontally opposed twin-cylinder engine having one cylinder on each side of the crankshaft, that is, two cylinders on the left and right sides, and the top end of the branch pipe of the intake manifold is connected to the side of the cylinder head of the dedicated power generation engine, the protruding height of the intake manifold relative to the upper surface of the dedicated power generation engine can be made lower than that of the BEV range extenders described in 8) and 9). BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic plan view showing the range extender for BEV of the present invention.

[0041] Figure 2 yes Figure 1 Schematic side view of a range extender for BEV.

[0042] Figure 3 yes Figure 1 Schematic front view of a range extender for BEV.

[0043] Figure 4 It is a schematic plan view showing the range extender for BEV of the present invention, with the intake manifold omitted.

[0044] Figure 5 It roughly indicates Figure 1 A diagram showing a portion of the structure of a dedicated power generation engine for a BEV range extender as viewed from the front.

[0045] Figure 6 Yes means Figure 1 A three-dimensional diagram of the valve train system of the power generation engine of the BEV range extender.

[0046] Figure 7 Yes means Figure 1 Front view of the valve train system of the dedicated power generation engine of the BEV range extender.

[0047] Figure 8 Yes means Figure 1 A top view of the valve train system of the dedicated power generation engine of the BEV range extender.

[0048] Fig. 9This is a front view showing a modified example of the intake manifold used in the power generation engine of the range extender for BEV of the present invention. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0050] In the following instructions, Figure 1 and Figure 4 The left and right of Figure 2 and Figure 3 The upper and lower parts of are called upper and lower parts. Figure 1 and Figure 4 The upper side ( Figure 2 The left side of the image is called the front, and the opposite side is called the rear.

[0051] In the following description, the same components and the same parts are denoted by the same reference numerals.

[0052] Figure 1 to Figure 4 The overall structure of the BEV range extender is schematically shown with some parts omitted. Figure 5 The schematic diagram shows a part of the structure of the dedicated power generation engine of the BEV range extender. Figure 6 to Figure 8 This shows the valve train system of the power generation engine of the range extender for BEV.

[0053] exist Figure 1 to Figure 5 In the invention, a range extender (1) for BEV includes a dedicated power generation engine (2), a generator (3) for generating power by driving the dedicated power generation engine (2), a fuel tank (4) for the dedicated power generation engine (2), a cooling device (5) for the dedicated power generation engine (2), and a fixing member (not shown) used when the range extender (1) for BEV is mounted on a vehicle.

[0054] It should be noted that, although not shown in the figure, the BEV range extender (1) includes electrical equipment required for power generation such as an inverter.

[0055] The power generation engine (2) is a horizontally opposed engine, comprising: a crankshaft (11) having a horizontal rotation center axis extending in the front-rear direction; an even number of cylinders (12), two in this embodiment, arranged in equal numbers on the left and right sides of the crankshaft (11) in a manner opposite to each other across the crankshaft (11); pistons (13) arranged in each cylinder (12) in a manner opposite to each other across the crankshaft (11) on the left and right sides of the crankshaft (11); and an intake manifold (14). The cylinders (12) are arranged in equal numbers on the left and right sides of the crankshaft (11) in a manner with their length directions oriented in the left-right direction.

[0056] The power generation engine (2) comprises two left and right cylinder blocks (15) arranged on the left and right sides of a crankshaft (11) and two left and right cylinder heads (16) provided on each cylinder block (15). The crankshaft (11) is rotatably supported by the two cylinder blocks (15) in a state of being clamped by the two cylinder blocks (15). The left and right pistons (13) are respectively connected to the crankshaft (11) via connecting rods (13a). The crankshaft (11) rotates around the rotation center axis by the reciprocating motion of the two pistons (13). The cylinder block (15) and the cylinder head (16) may be formed separately and fixed to each other or may be formed integrally.

[0057] A cylinder (12) is formed in each cylinder block (15) of a power generation engine (2), and a combustion chamber (17) corresponding to the cylinder (12) and two intake ports (18) and two exhaust ports (19) facing the combustion chamber (17) are formed in each cylinder head (16). The two intake ports (18) of each cylinder head (16) are opened and closed by intake valves (21), and the two exhaust ports (19) are opened and closed by exhaust valves (22). The two intake ports (18) are formed in a front-to-back arrangement at the upper side of the combustion chamber (17), and the two intake valves (21) that open and close the two intake ports (18) are arranged in a front-to-back arrangement. In addition, the two exhaust ports (19) are formed in a front-to-back arrangement at the lower side of the combustion chamber (17), and the two exhaust valves (22) are arranged in a front-to-back arrangement. The two intake valves (21) are arranged above the two exhaust valves (22). That is, the power generation engine (2) has two cylinders (12) and two combustion chambers (17), four intake ports (18) and four exhaust ports (19), and four intake valves (21) and four exhaust valves (22).

[0058] like Figures 5 to 8As shown, the intake valves (21) for opening and closing four intake ports (18) and the exhaust valves (22) for opening and closing four exhaust ports (19) are operated by a valve mechanism (23). The valve mechanism (23) is composed of a first valve unit (24) and a second valve unit (25). The first valve unit (24) operates all the intake valves (21) for opening and closing two intake ports (18) facing the left and right combustion chambers (17), and the second valve unit (25) operates all the exhaust valves (22) for opening and closing two exhaust ports (19) facing the left and right combustion chambers (17). The first valve unit (24) comprises: a first camshaft (26) which is arranged at a height position above the cylinder (12), preferably directly above the crankshaft (11), and rotated around a horizontal rotation center axis by the crankshaft (11); two first push rods (28) on the left and right, a total of four, two of which are provided for each cylinder (12) and driven by two first cams (27) mounted on the first camshaft (26); and two first rocker arms (29) on the left and right, a total of four, two of which are provided for each cylinder (12) and driven by the first push rods (28). The first valve unit (24) transmits input based on the first cam (27) of the first camshaft (26) to all intake valves (21). The first camshaft (26) is arranged at a height position above the two cylinders (12) and directly above the crankshaft (11). The second valve unit (25) comprises: a second camshaft (31) which is arranged at a height position below the cylinder (12), preferably directly below the crankshaft (11), and rotated around a horizontal rotation center axis through the crankshaft (11); two second push rods (33) on the left and right, a total of four, two of which are provided for each cylinder (12) and driven by two second cams (32) mounted on the second camshaft (31); and two second rocker arms (31) on the left and right, a total of four, two of which are provided for each cylinder (12) and driven by the second push rods (33). The second valve unit (25) transmits input based on the second camshaft (27) to all exhaust valves (22). The second camshaft (31) is arranged at a height position below the two cylinders (11) and directly below the crankshaft (11).

[0059] It should be noted that the number of intake ports and intake valves and the number of exhaust ports and exhaust valves are not limited to two. Furthermore, the valve mechanism for operating the intake valve and the exhaust valve is not limited to the above-mentioned mechanism, and the well-known SOHC (single overhead cam) type, DOHC (double overhead cam) type or OHV (overhead valve) type mechanism can be used.

[0060] Reference Figure 1 and Figure 4The generator (3) is arranged at a substantially central portion of the length direction of the dedicated power generation engine (2) in such a manner that the dedicated power generation engine (2) and the generator (3) are in a T-shape when viewed from above. The rotating shaft (3a) of the generator (3) is arranged horizontally on the same axis as the crankshaft (11) or on an axis parallel to the crankshaft (11), and is connected to the crankshaft (11) via a transmission device (35), and is accelerated or decelerated by the rotation of the crankshaft (11) and rotates.

[0061] The fuel tank (4) is arranged so as to be entirely accommodated in the following space, that is, at least one of the two spaces (36) and (37) surrounded by the vertical plane where the two ends of the dedicated power generation engine (2) in the longitudinal direction are located and the vertical plane where the top end of the generator (3) protruding from the dedicated power generation engine (2) is located, in this case, the right space (36). The arrangement position of the fuel tank (4) is not limited to this and can be appropriately changed.

[0062] The cooling device (5) is configured to be at least partially contained in the following space, that is, the space (37) on the opposite side of the space (36) on the right side where the fuel tank (4) is arranged, in the two spaces (36) and (37) surrounded by the vertical plane where the two ends of the dedicated power generation engine (2) in the longitudinal direction are located and the vertical plane where the top end of the generator (3) protruding from the dedicated power generation engine (2) is located. The configuration position of the cooling device (5) is not limited to this and can be appropriately changed. For example, the cooling device (5) can also be configured in a manner parallel to the longitudinal direction of the dedicated power generation engine (2) on the front side side of the dedicated power generation engine (2) of the BEV range extender (1) which is opposite to the side where the generator (3) is arranged.

[0063] In addition, there is a case where electrical equipment required for power generation, such as inverters, is arranged in the above-mentioned spaces (36) and (37).

[0064] The intake manifold (14) has a surge tank (surge tank) (38) and branch pipes (39) of the same number as the cylinders (12). The surge tank (38) of the intake manifold (14) is arranged along the front side portion of the upper surface of the dedicated power generation engine (2) from the front side opposite to the side where the generator (3) is arranged. The branch pipe (39) extends from the surge tank (38) in the left and right directions in a manner of communicating with the surge tank (38), and its top end is connected to the upper surface of the cylinder head (16) of the dedicated power generation engine (2). The left branch pipe (39) sends the intake air in the surge tank (38) to the intake port (21) facing the left combustion chamber (17), and the right branch pipe (39) sends the intake air in the surge tank (38) to the intake port (21) facing the right combustion chamber (17).

[0065] The above-mentioned BEV range extender (1) is installed at various positions of the BEV.

[0066] For example, in the case of a pickup truck, the BEV range extender (1) is arranged at the lower part of the engine compartment or below the cargo box. In the case of a van, the BEV range extender (1) is arranged at the lower part of the cargo compartment. In the case of a sedan, the BEV range extender (1) is arranged at the lower part of the engine compartment or below the luggage compartment. In the case of an SUV (sport utility vehicle), the BEV range extender (1) is arranged at the lower part of the engine compartment or below the trunk.

[0067] These are merely examples, and the installation position of the vehicle range extender (1) is not limited to the position shown in the figure, and can be installed anywhere as long as the necessary space can be secured.

[0068] Furthermore, when the remaining power of the driving battery of a BEV equipped with a BEV range extender (1) decreases, the dedicated power generation engine (2) is driven to generate power by a generator (3), and the generated power is supplied to the driving battery of the BEV. As a result, the cruising range of the BEV is extended.

[0069] In the above embodiment, the surge tank (38) of the intake manifold (14) is arranged along the front side portion of the upper surface of the dedicated power generation engine (2) opposite to the side where the generator (3) is arranged, but the present invention is not limited to this.

[0070] For example, Fig. 9 As shown, the power generation engine (2) may also include: a surge tank (41) arranged along the front side of the power generation engine (2); and an intake manifold (40) including left and right branch pipes (42) extending from the surge tank (41) in the left and right directions and having the top end connected to the front side of the cylinder head (16) of the power generation engine (2). The left branch pipe (42) sends the intake air to the intake port (21) facing the left combustion chamber (17), and the right branch pipe (42) sends the intake air to the intake port (21) facing the right combustion chamber (17).

[0071] In addition, in the above-mentioned embodiment, the dedicated power generation engine (2) is a horizontally opposed engine having two cylinders (12), but it is not limited to this, and it can also be a horizontally opposed engine having four cylinders or a horizontally opposed engine having six cylinders. In these cases, the top end of the branch pipe of the intake manifold used in the dedicated power generation engine is connected to the upper surface of the cylinder head (16). In addition, in these cases, the same even-numbered cylinders are respectively arranged on both sides of the crankshaft (11), and the cylinders on both sides of the crankshaft (11) are formed in a cylinder block, and a cylinder head is installed on the cylinder block, and a combustion chamber corresponding to each cylinder and two intake ports and two exhaust ports facing the combustion chamber are formed in the cylinder head.

[0072] Description of Reference Numerals

[0073] (1): Range extender for automobile, (2): Engine for power generation, (3): Generator, (3a): Rotating shaft, (4): Fuel tank, (5): Cooling device, (11): Crankshaft, (12): Cylinder, (13): Piston, (14): Intake manifold, (15): Cylinder block, (16): Cylinder head, (17): Combustion chamber, (18): Intake port, (19): Exhaust port, (21): Intake valve, (22): Exhaust valve, (23): Valve train , (24): 1st valve unit, (25): 2nd valve unit, (26): 1st camshaft, (27): 1st cam, (28): 1st push rod, (29): 1st rocker arm, (31): 2nd camshaft, (32): 2nd cam, (33): 2nd push rod, (34): 2nd rocker arm, (36), (37): space, (38): pressure regulator box, (39): branch pipe, (40): intake manifold, (41): pressure regulator box, (42): branch pipe.

Claims

1. A range extender for a battery electric vehicle, comprising a dedicated power generation engine, a generator for generating power by driving the dedicated power generation engine, a fuel tank for the dedicated power generation engine, and a cooling device for the dedicated power generation engine, and supplying power to a driving battery of the battery electric vehicle, wherein the range extender for the battery electric vehicle is characterized in that: The dedicated power generation engine is a horizontally opposed engine, comprising: a crankshaft with a horizontal central axis of rotation; a total of an even number of cylinders, which are arranged in the same number on both sides of the crankshaft in a manner opposite to each other with the crankshaft interposed therebetween; and pistons, which are arranged in each of the cylinders in a manner opposite to each other with the crankshaft interposed therebetween. The generator is arranged in the approximate center of the length direction of the dedicated power generation engine in a manner such that the dedicated power generation engine and the generator are in a T-shape when viewed from above, and the rotating shaft of the generator is horizontally arranged on the same axis as the crankshaft or on an axis parallel to the crankshaft, and is connected to the crankshaft.

2. The range extender for a battery electric vehicle according to claim 1, characterized in that: The rotating shaft of the generator is connected to the crankshaft via a transmission device, and the rotating shaft is rotated at a higher speed or a lower speed through the transmission device due to the rotation of the crankshaft.

3. The range extender for a battery electric vehicle according to claim 1, characterized in that: The power generation engine is a horizontally opposed two-cylinder, four-cylinder or six-cylinder engine, and the cylinders are arranged on the left and right sides of the crankshaft with their length directions facing the left and right directions.

4. The range extender for a battery electric vehicle according to claim 1, characterized in that: The fuel tank is configured to be entirely accommodated in at least one of two spaces surrounded by a vertical plane where both ends of the dedicated power generation engine in the longitudinal direction are located and a vertical plane where a top end of the generator protruding from the dedicated power generation engine is located.

5. The range extender for a battery electric vehicle according to claim 1, characterized in that: The fuel tank is configured to be entirely housed in the following space, that is, a space of either one of the two spaces surrounded by the vertical plane where the two ends of the dedicated power generation engine in the length direction are located and the vertical plane where the top end of the generator protruding from the dedicated power generation engine is located, and the cooling device is configured to be at least partially housed in the other of the two spaces.

6. The range extender for a battery electric vehicle according to claim 1, characterized in that: The power generation engine comprises: a cylinder block, which is arranged on both sides of the crankshaft in a manner of clamping the crankshaft and forms the cylinders; a cylinder head, which is provided on the cylinder block and forms a combustion chamber corresponding to each of the cylinders, and two intake ports and two exhaust ports facing each of the combustion chambers; two intake valves, which open and close the two intake ports of each of the combustion chambers; two exhaust valves, which open and close the two exhaust ports of each of the combustion chambers; and a valve mechanism, which opens and closes all of the intake valves and all of the exhaust valves. The valve mechanism is composed of a first valve unit that opens and closes all the intake valves, and a second valve unit that opens and closes all the exhaust valves. The first valve unit includes a first camshaft that rotates around a horizontal rotation center axis through the crankshaft, a first push rod driven by a cam of the first camshaft, and a first rocker arm driven by the first push rod, and transmits input based on the cam of the first camshaft to all the intake valves. The second valve unit includes a second camshaft that rotates around a horizontal rotation center axis through the crankshaft, a second push rod driven by a cam of the second camshaft, and a second rocker arm driven by the second push rod, and transmits input based on the cam of the second camshaft to all the exhaust valves. One of the first camshaft and the second camshaft is arranged at a height position above the cylinder, and the other is arranged at a height position below the cylinder.

7. The range extender for a battery electric vehicle according to claim 6, characterized in that: The cylinder of the power generation engine is formed on the cylinder body in a manner that the length direction faces the left-right direction, the two intake ports are formed in the upper part of the combustion chamber in a front-to-back arrangement, and the two intake valves are arranged in a front-to-back arrangement, the two exhaust ports are formed in the lower part of the combustion chamber in a front-to-back arrangement, and the two exhaust valves are arranged in a front-to-back arrangement, and the two intake valves are arranged above the two exhaust valves, The first camshaft of the first valve unit is arranged at a height position above the cylinder and directly above the crankshaft, and two of the first push rods and two of the first rocker arms are provided for each of the cylinders. The second camshaft of the second valve unit is arranged at a height position below the cylinder and directly below the crankshaft, and two of the second push rods and two of the second rocker arms are provided for each of the cylinders.

8. The range extender for a battery electric vehicle according to claim 6, characterized in that: The dedicated power generation engine is provided with an intake manifold, which has a pressure regulating tank and a branch pipe on the intake air path, and supplies intake air to the intake port provided on the cylinder head. The pressure regulating tank of the intake manifold is arranged along the side surface of the dedicated power generation engine opposite to the side where the generator is arranged, and / or a portion of the upper surface of the dedicated power generation engine opposite to the side where the generator is arranged.

9. The range extender for a battery electric vehicle according to claim 8, characterized in that: A tip end portion of the branch pipe of the intake manifold is connected to an upper surface of the cylinder head of the power generation dedicated engine.

10. The range extender for a battery electric vehicle according to claim 8, characterized in that: The power generation engine is a horizontally opposed twin-cylinder engine having one cylinder on each side of the crankshaft, that is, two cylinders on the left and right sides, and the top end of the branch pipe of the intake manifold is connected to the side of the cylinder head of the power generation engine.

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