JP6197279B2 - Engine unit for motorcycle - Google Patents

Description

  The present invention relates to an engine unit in a vehicle such as a motorcycle, and particularly to the periphery of an intake system thereof.

In general, a motorcycle equipped with a parallel multi-cylinder engine has a smaller space for arranging an intake system than a four-wheeled vehicle. Therefore, in order to obtain a required intake pipe length, the intake pipe is extended to the inside of the air cleaner.
In order to prevent the output from decreasing due to intake air interference, the motorcycle employs an independent throttle body in which a throttle valve is provided for each cylinder. In order to improve the engine response due to the throttle operation, an arrangement in which the throttle valve is as close to the combustion chamber as possible is common.

  As this type of intake system, for example, one disclosed in Patent Document 1 or Patent Document 2 is known.

Japanese Patent Laid-Open No. 2002-256895 JP 2002-256896 A

  In the conventional engine, particularly in the intake system, the intake pipe is extended to the inside of the air cleaner. Therefore, the substantial air cleaner capacity that can be used in the intake stroke of the engine is reduced by the internal capacity of the intake pipe. In particular, in an engine that aims to improve the torque in the low and medium speed rotation range, the intake pipe length tends to be set longer. In such an engine, the air cleaner capacity is further reduced, resulting in a decrease in output (particularly transient performance).

  In addition, in the independent throttle body type layout, the inertia effect obtained in the throttle valve slightly open region is small. This is because in the throttle valve slightly open region, the actual intake pipe length is not the intake pipe length itself but the length from the intake valve to the throttle valve in the throttle body. As a result, the charging efficiency in the throttle valve slightly open region, which is the normal region, is low, and it is necessary to increase the rotational speed in order to obtain the required torque.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an engine unit of a motorcycle that can effectively achieve downsizing while ensuring a sufficient intake pipe length and air cleaner capacity.

The engine unit of the motorcycle according to the present invention has a plurality of cylinders arranged in parallel in the vehicle width direction and a clutch chamber arranged on either the left or right side in the vehicle width direction, between the cylinder block and the air cleaner above the crankcase. An intake manifold, a fuel injection device, a throttle body, and an intake pipe, wherein the throttle body is disposed on the opposite side of the clutch chamber in the vehicle width direction, and the intake manifold is A plurality of separated intake pipes connected to the cylinder head of each cylinder, and a manifold assembly formed in a bottomed cylindrical shape that integrally collects these intake pipes, and each of the intake pipes includes: It is formed in a curved shape so as to wrap around the throttle body and the upper part of the manifold assembly part in a side view, Serial manifold collecting portion is located between the cylinder and the cylinder head at a side view of the vehicle body and the air cleaner, positioned below each of said intake pipe a and the upper portion of the crankcase, each on its rear The intake pipe is connected, and the throttle body is connected to the manifold assembly.

Further, in the motorcycle engine unit according to the present invention, the throttle body is integrally fixed to the intake manifold, and the throttle bore central axis is substantially parallel to the vehicle width direction. provided so as to be positioned in front of the rear and the rear end of each of the intake pipes from the front end of the intake pipe, characterized in Rukoto.
In the engine unit of the motorcycle according to the present invention, the throttle body is disposed on the inner side in the vehicle width direction of the cylinder block.

In the engine unit of the motorcycle according to the present invention, each of the intake pipes is arranged such that the inclination of the manifold assembly portion with respect to the longitudinal direction is gradually increased or gradually decreased in a rear view .
In the motorcycle engine unit of the present invention, the intake pipe farthest from the clutch chamber overlaps the throttle body in a plan view.

  Further, in the motorcycle engine unit of the present invention, the engine is surrounded by a body frame of a seat rail at the top, a down tube at the front, and a body tube at the rear, and the cylinder block and the air cleaner below the seat rail. In the space surrounded by the crankcase, the fuel injection device, the intake pipe, the throttle valve, and the drive motor thereof are arranged in tandem in a substantially parallel manner with the cylinder axis line from above in a side view.

  In the engine unit of the motorcycle according to the present invention, the air cleaner is disposed in front of a body tube constituting a vehicle body frame, and the intake pipe that connects the throttle body and the air cleaner does not extend into the air cleaner. It is connected.

  According to the present invention, an integrated single electronically controlled throttle body is arranged in a marginal space on the rear side of the cylinder block opposite to the clutch chamber. With this arrangement, intake manifolds, which were impossible with conventional motorcycles, are gathered and the intake air amount is controlled by a single throttle body. As a result, it is possible to realize an intake system that can ensure a sufficiently long intake pipe length and an air cleaner capacity that is equal to or greater than that of the conventional one.

1 is a left side view showing a state where a power unit is mounted on a body frame in a motorcycle according to the present invention. 1 is a right side view showing a state where a power unit is mounted on a body frame in a motorcycle according to the present invention. 1 is a top view showing a state where a power unit is mounted on a body frame in a motorcycle according to the present invention. It is a back perspective view showing a power unit from which an intake system in an embodiment of the present invention was removed. It is a back perspective view showing the power unit which attached the intake system in the embodiment of the present invention. It is a top view which shows the power unit which attached the intake system in embodiment of this invention. It is a left view which shows the power unit which attached the intake system in embodiment of this invention. It is a rear view of the power unit which shows the structure of an intake system, an effect | action, etc. in embodiment of this invention. It is the front view and side view which show the structural example of the electronic throttle which concerns on this invention. It is a P arrow view of FIG.

Hereinafter, preferred embodiments of an engine unit of a motorcycle according to the present invention will be described with reference to the drawings.
1 is a left side view showing a state in which an engine unit is mounted on a body frame in a motorcycle according to the present invention, FIG. 2 is a right side view thereof, and FIG. 3 is a top view thereof. The area around the engine unit will be described with reference to FIGS. In the drawings used in the following description, the front of the vehicle is appropriately indicated by an arrow Fr and the rear of the vehicle is indicated by an arrow Rr as necessary, and the lateral right side of the vehicle is indicated by an arrow R. Are indicated by arrows L, respectively.

  In the motorcycle 100, a seat rail 101 made of steel or an aluminum alloy material is connected to the rear portion of the steering head pipe 102, and a pair of left and right branches into a bifurcated shape toward the rear, while temporarily widening from the steering head pipe 102. It extends diagonally downward. Also from the steering head pipe 102, the down tube 103 extends downward at a steep angle and curves backward at its lower end. Further, the body tube 104 extends obliquely downward from the vicinity of the rear portion of the seat rail 101, and the rear end portion of the seat rail 101 is connected to a side tube 105 that is moderately inclined rearwardly up, and the vehicle body frame is connected by these frames. Composed. The vehicle body frame has a generally bowl-like shape that forms a housing space for the engine unit 10 inside thereof, and the engine unit 10 is mounted as shown in the figure.

  Although not shown in the drawings, the overall configuration of the motorcycle 100 will be described briefly. Two left and right front forks supported by the steering head pipe 102 so as to be pivotable to the left and right are provided. A handle bar is fixed to the upper end of the front fork, and a front wheel is rotatably supported at the lower end portion thereof. A swing arm 106 (see FIG. 1 and the like) is coupled to the rear side of the engine unit 10 so as to be swingable, and a rear wheel is rotatably supported at the rear end thereof. The rear wheels are rotationally driven via a driven sprocket around which a chain for transmitting the power of the engine unit 10 is wound.

  A fuel tank is mounted above the engine unit 10 mounted on the vehicle body frame. Fuel is supplied from the fuel tank by a fuel supply device, and air is supplied from an air cleaner constituting an intake system described later. A mixture of these fuel and air is supplied to the engine unit 10 and exhaust gas after combustion in the engine is exhausted through the exhaust pipe.

  Next, a configuration example of the engine unit 10 in the present embodiment will be described. As shown in FIG. 4, the engine unit 10 of this example includes a cylinder 12, a cylinder head 13, and a cylinder head cover 14 that are integrally connected to an upper portion of a crankcase 11 in order to form a cylinder block. The cylinder block is disposed in a moderately forward tilted posture. Further, the engine unit 10 is integrally supported and supported by the vehicle body frame by being suspended on the down tube 103 or the like via a plurality of engine mounts. In this example, four cylinders 12 are juxtaposed in the left-right (vehicle width) direction, and pistons are fitted into the cylinder bores of the respective cylinders 12 so as to be slidable in the cylinder axial direction. Note that the cylinders are numbered 1 (# 1), 2 (# 2), 3 (# 3), and 4 (# 4) in order from the left. A center line in the vehicle front-rear direction (FIG. 3, vehicle center line Y) is set so as to pass between approximately # 2 cylinder and # 3 cylinder.

  In the crankcase 11, an upper crankcase and a lower crankcase which are divided into upper and lower halves are coupled to each other, and a shaft such as a crankshaft 15 is supported on a mating surface thereof. In the crankcase 11, a crankshaft 15 (abbreviated by a one-dot chain line in FIG. 4) is arranged in the vehicle width direction. In this case, the plurality of journal portions of the crankshaft 15 are pivotally supported by the plurality of journal bearing portions set on the mating surfaces of the crankcase 11. A generator including a generator coil and a generator rotor is arranged at the left shaft end of the crankshaft 15. In this case, the generator coil is attached and supported inside the magnet cover 16. A sprocket for driving the cam of the valve gear is attached to the right shaft end of the crankshaft 15.

  The cylinder head 13 accommodates a valve operating device that controls opening and closing of the intake valve and the exhaust valve. These valves are driven by an intake cam and an exhaust cam provided on the intake camshaft and the exhaust camshaft, respectively. Each cylinder has an intake port 18 that opens to the rear of the cylinder head 13, and the air-fuel mixture supplied from the intake system to the intake port 18 is controlled by the intake valve to flow into the combustion chamber.

  The rear portion of the crankcase 11 also serves as a transmission case 19, and a transmission gear is accommodated therein. In the transmission case 19, the countershaft 20 (abbreviated by a one-dot chain line in FIG. 4) is spaced apart in parallel with the crankshaft 15, and the drive shaft 21 (the one-dot chain line in FIG. 4) is further spaced rearward and downward. Is abbreviated as). Among these, the countershaft 20 is supported on the mating surface of the crankcase 11. Further, a transmission device (transmission) having a predetermined number of stages is arranged between the counter shaft 20 and the drive shaft 21 in the transmission case 19, and the rotation of the counter shaft 20 is shifted to the drive shaft 21 via the transmission device. Is transmitted. A drive sprocket is attached to the left shaft end of the drive shaft 21, and the rear side of the engine unit 10 is connected to the drive sprocket via a chain wound between the drive sprocket and a sprocket mounted on the rear wheel axle. Power is transmitted to the wheel.

  A clutch device is mounted on the right shaft end of the countershaft 20 in the clutch chamber 22. The clutch device is covered with a clutch cover 17. In the clutch device, a plurality of drive plates and driven plates having a radius in a direction orthogonal to the axial direction of the countershaft 20 are disposed in the clutch housing so as to alternately overlap. And the clutch device itself is bulky and requires a considerable arrangement space. In this example, the breather case 23 is adjacent to the left side of the clutch device.

  Here, as can be seen from FIG. 4, a space is secured in the upper part of the crankcase 11 on the rear side of the cylinder block in combination with the cylinder block being in a moderately inclined posture. The transmission case 19 projects rearward from the main body of the crankcase 11 in the middle of the # 2 cylinder or in the range from the # 3 cylinder to the # 4 cylinder in the vehicle width direction. Therefore, the transmission case 19 corresponding to the # 1 cylinder in general. A space is also secured in the left side area. These spaces are shown as spaces S in FIG.

In the engine unit 10 of the present invention, first, as shown in FIG. 1 and the like, the engine itself is surrounded by the body frame of the seat rail 101 at the top, the down tube 103 at the front, and the body tube 104 at the rear. An intake system 24 is arranged at the top of the crankcase 11 and behind the cylinder block as shown in FIG. The intake system 24 includes an intake manifold 26, an injector 27 as a fuel injection device, a throttle body 28, and an intake pipe 29 between the cylinder block and the air cleaner 25 as shown in FIGS. .
In the present invention, in particular, the throttle body 28 is disposed on the opposite side to the clutch chamber 22 in the vehicle width direction, that is, on the left side of the crankcase 11 as shown in FIG. That is, the single throttle body 28 is arranged using the space S corresponding to approximately # 1 cylinder.

  In the specific configuration of the intake system 24, the air cleaner 25 is disposed in front of the body tube 104 constituting the vehicle body frame as shown in FIG. The air cleaner 25 can be supported at substantially the same height as the cylinder block by using a body frame such as the body tube 104. As shown in FIG. 6, the air cleaner 25 is a casing extending horizontally in the vehicle width direction from approximately # 1 cylinder to # 4 cylinder, and a suction portion 30 for taking in air is attached to the rear portion thereof. The A suction pipe 31 that opens rearward is attached to the suction portion 30, and air A is sucked from the suction pipe 31 as shown in FIG. 7. The suction pipe 31 may be inclined moderately rearward and downward as shown in FIG. A filter 32 is mounted between the air cleaner 25 and the suction portion 30 as shown in FIG. 7, and purified air is introduced into the air cleaner 25.

  As shown in FIG. 5, the intake manifold 26 is horizontally mounted adjacent to the front side of the air cleaner 25. As shown in FIG. 6, the intake manifold 26 extends horizontally in the vehicle width direction from approximately # 2 cylinder to # 4 cylinder. That is, the throttle body 28 can be disposed in the space S corresponding to the # 1 cylinder as described above.

  The intake manifold 26 integrally collects a plurality of separated and independent intake pipes 33 (33A, 33B, 33C, 33D) connected to the cylinder heads 13 of the respective cylinders # 1 to # 4, and these intake pipes 33. And a manifold assembly portion 34 formed in a bottomed cylindrical shape. The manifold collecting pipe 34 is formed of a hollow cylinder having a circular cross section, and in this example, has a bottomed structure in which the right end side is closed. It can be formed by synthetic resin or aluminum die casting.

  Each intake pipe 33A, 33B, 33C, 33D has a front end connected to the intake port 18 (see FIG. 4) as shown in FIG. 7 and the like, and a throttle from its front end as shown in a side view of FIG. The upper portion of the body 28 is formed in a curved shape so as to go back. The curved shape may typically be an arc shape, and each is smoothly connected to the rear side of the outer peripheral surface of the manifold collecting pipe 34. The base end side where each of the intake pipes 33A, 33B, 33C, 33D is coupled to the manifold collecting pipe 34 may be arranged at substantially the same pitch interval as the arrangement pitch of the cylinders, that is, the interval between the intake ports 18 in the vehicle width direction.

Further, the intake pipe 33 is arranged such that the inclination of the manifold assembly 34 with respect to the longitudinal direction gradually increases or decreases in the rear view. As shown in FIG. 8, the longitudinal axis line X of the manifold assembly 34 is used, and in this example, the inclination angles θ ₁ , θ ₂ , θ ₃ , θ _{4 with} respect to the axis line X of the intake pipes 33A, 33B, 33C, 33D are The size gradually increases from # 1 cylinder to # 4 cylinder. The inclination angle θ of the intake pipe 33 is not limited to the example shown in FIG. 8 and can be changed as appropriate according to the arrangement interval of the intake ports 18, the length of the manifold assembly portion 34, and the like.

  Here, among the intake pipes 33A, 33B, 33C, and 33D, the intake pipe 33A that is farthest from the clutch chamber 22 is disposed so as to overlap the throttle body 28 in plan view as shown in FIG. That is, the intake pipe 33A corresponding to the # 1 cylinder in which the throttle body 28 is disposed is disposed above the throttle body 28 (see FIG. 7 and the like).

  Next, in this embodiment, a so-called electronic throttle is used. FIG. 9 shows a schematic configuration example of the electronic throttle 35 according to the present embodiment. The throttle body 28 has a throttle bore through which intake air circulates, and a throttle valve 37 supported so as to be rotatable by a predetermined angle via a support shaft 36 is mounted in the throttle bore. The support shaft 36 is connected to be rotated by a drive motor 38, and the drive motor 38 rotates the support shaft 36 based on a signal from an in-vehicle ECU, thereby controlling the opening degree of the throttle valve 37. It is configured. The opening degree of the throttle valve 37 is detected by a throttle position sensor 39, and the detection signal is fed back to the ECU. These components are preferably assembled integrally with the base plate 40 and unitized.

  In such an electronic throttle, the throttle bore central axis X ′ (FIG. 9) of the throttle body 28 is set substantially parallel to the vehicle width direction and is integrally fixed to the intake manifold 26. More specifically, as shown in FIG. 5 and the like, it is fixed to the left end portion of the manifold assembly portion 34 of the intake manifold 26. The throttle bore of the throttle body 28 communicates with the inside of the manifold assembly portion 34. In this case, the throttle bore central axis X ′ can be preferably arranged so as to coincide with the axis line X of the manifold assembly portion 34 (see FIG. 10). ).

  As described above, throttle body 28 is arranged below intake pipe 33A corresponding to the # 1 cylinder. Therefore, the throttle body 28 is disposed on the inner side in the vehicle width direction of the cylinder block. As shown in FIG. 6, the cylinder block is basically disposed within the range of the width W in the vehicle width direction of the widest cylinder head cover 14 in the cylinder block.

  Further, as shown in FIG. 6, at the upper part of the intake pipes 33A, 33B, 33C, 33D, the intake air disposed in the inner part of the intake port 18 in the immediate vicinity of the intake port 18 to which each is connected. An injector 27 that injects fuel toward the back of the valve is mounted. Each injector 27 is connected to the main gallery 41 by piping so that the fuel supplied from the fuel pump to the main gallery 41 is distributed to each injector 27.

  Referring to FIG. 1, an injector 27, an intake pipe 33 (33A), a throttle valve 37, and a drive motor thereof are disposed in a space surrounded by a cylinder block, an air cleaner 25 and a crankcase 11 below a seat rail 101 from above. 38 are arranged in tandem substantially parallel to the cylinder axis Z.

  In the above case, the air cleaner 25 is disposed in front of the body tube 104, but the intake pipe 29 connecting the throttle body 28 and the air cleaner 25 does not extend into the air cleaner 25 as shown in FIG. The intake pipe 29 extends forward from the vicinity of the left end near the front surface of the air cleaner 25 as shown in FIGS. 66 and 7, and is connected to the throttle body 28 while curving to the right.

In the intake system 24 of the engine unit 10 having the above-described configuration, air A is sucked from the suction pipe 31 as shown in FIGS. 6 and 7, and then purified air is introduced into the air cleaner 25 by passing through the filter 32. Is done. The air in the air cleaner 25 is supplied to the throttle body 28 through the intake pipe 29 (FIG. 6, arrow A ₀ ). The air in the manifold collecting pipe 34 whose flow rate is controlled by the throttle valve 37 further passes through the intake pipes 33A, 33B, 33C, and 33D as indicated by arrows A ₁ , A ₂ , A ₃ , and A ₄ in FIG. Supplied to intake ports 18 of # 1 to # 4 cylinders, respectively.

Next, the characteristic operation effects of the present invention will be described. First, the throttle body 28 is disposed on the opposite side of the clutch chamber 22 in the vehicle width direction.
In the multi-cylinder engine as in the present embodiment, the distance between the intake port 18 and the upper surface of the crankcase 11 is widest on the side opposite to the clutch chamber 22 on the rear side of the cylinder head 13. That is, the clutch chamber 22 has a bulky structure as described above, and there is not much room for space above the clutch chamber 22 with the intake port 18. By effectively arranging the single throttle body 28 on the left side of the space S (see FIG. 4) offset from the clutch chamber 22, an effective space is provided between the cylinder 12 and the air cleaner 25. Can be secured. By securing this space, the air cleaner 25 and the intake manifold 26 can be assembled without reducing the capacity. In addition, a sufficient inertial effect can be obtained over the entire opening of the throttle valve 37 with a sufficient intake pipe length, so that it is possible to improve output, improve fuel consumption, reduce noise and improve clean efficiency.

The throttle bore central axis X ′ of the throttle body 28 is set substantially parallel to the vehicle width direction and is integrally fixed to the manifold collecting pipe 34 of the intake manifold 26.
A throttle body 28 is disposed at a position offset in the vehicle width direction on the side opposite to the clutch chamber 22 from the vehicle center line Y, in this example, to the left. As a result, the throttle bore central axis X ′ is arranged substantially parallel to the vehicle width direction, so that the front-rear width (riding direction) of the entire intake system is effectively maintained while ensuring a sufficient intake pipe length and capacity of the air cleaner 25. Can be truncated. Therefore, it is possible to reduce the size of the entire vehicle.

Further, as shown in FIG. 6, the throttle body 28 is disposed on the inner side in the vehicle width direction of the cylinder block.
By arranging the throttle body 28 in this manner, the width of the entire intake system in the left-right direction can be made compact while ensuring a sufficient intake pipe length. By making the intake system slimmer and more compact, it is possible to prevent the rider's feet from coming into contact with the intake system in the riding state, and to improve the riding performance or the ride comfort. Incidentally, the range of movement of the rider's legs is outside the dotted line M in FIG. 3, and the intake system is compactly housed inside.

The intake manifold 26 includes a plurality of intake pipes 33 and a manifold assembly part 34 that integrally collects the intake pipes.
That is, the manifold assembly 34 is installed on the upper part of the crankcase 11 between the cylinder 12 and cylinder head 13 of the engine and the air cleaner 25, and is arranged downstream of the throttle body 28 and coaxially with the throttle bore central axis X ′. It is arranged inside the width of the cylinder head 13 in the vehicle width direction. Thereby, a sufficient intake pipe length and a sufficient capacity of the air cleaner 25 can be ensured.

  Each intake pipe 33A, 33B, 33C, 33D is formed in a curved shape so as to wrap around the upper part of the throttle body 28 in a side view, and the inclination of the manifold assembly 34 in the longitudinal direction gradually increases in the rear view. It arrange | positions so that it may reduce gradually.

  By piping the intake pipe 33 by such a piping method, the intake pipe length necessary for obtaining the inertia effect of the intake air at the target rotational speed is ensured and sufficient, and the front and rear width of the vehicle is minimized. Thus, the length for maintaining the synchronism of each cylinder can be adjusted, and a sufficient inertia effect can be obtained over the entire throttle valve opening.

In this example, as shown in FIG. 8, the inclination angles θ ₁ , θ ₂ , θ ₃ , and θ ₄ of the intake pipes 33A, 33B, 33C, and 33D are made smaller toward the side closer to the throttle body 28. The length becomes longer on the # 1 cylinder side. By inclining the intake pipe 33 in this way, the intake pipe length can be ensured while the throttle body 28 is moved toward the center of the engine in the vehicle width direction, and the entire width of the intake pipe 33 can be made compact. The intake manifolds 33A, 33B, 33C, and 33D can have substantially the same intake passage length in the intake manifold 26 as a whole, and balance can be achieved among the # 1 to # 4 cylinders. Become.

Further, the intake pipe 33A farthest from the clutch chamber 22 overlaps the throttle body 28 in a plan view.
That is, by arranging the intake pipe 33A above the throttle body 28, the width of the entire intake system can be made compact while maintaining a sufficiently long intake pipe length.

Further, as shown in FIG. 1, the injector 27, the intake pipe 33, the throttle valve 37, and the drive motor 38 are substantially the same as the cylinder axis Z in the space surrounded by the vehicle body frame, the crankcase 11 and the like as viewed from the side. They are arranged in tandem in parallel.
In this way, the entire intake system can be laid out in a compact manner by arranging the respective functional components in stages. In other words, as a method for securing a sufficiently long intake pipe length and a necessary air cleaner volume and reducing the front-rear width of the entire intake system, an extremely effective arrangement method in which functional parts are arranged in tandem substantially in parallel with the cylinder axis Z is realized. .

An intake pipe 29 that connects the air cleaner 25 and the throttle body 28 is connected so as not to extend into the air cleaner 25.
By connecting the intake pipe 29 to the air cleaner 25 in this manner, the air cleaner capacity is not reduced, and as a result, the engine output is improved.

As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.
For example, although the manifold collecting pipe 34 has been described as having a circular cross-sectional shape, it may be formed into a cross-sectional shape such as an ellipse due to a spatial relationship with surrounding parts or members.
In contrast to the above embodiment, when the clutch is arranged on the left side of the engine, the throttle body is arranged on the right side on the opposite side.
The present invention can be effectively applied to the case where the number of cylinders of the engine unit is 3 cylinders or less or 4 cylinders or more.

10 Engine Unit, 11 Crank Case, 12 Cylinder, 13 Cylinder Head, 14 Cylinder Head Cover, 15 Crank Shaft, 16 Magnet Cover, 18 Intake Port, 19 Transmission Case, 20 Counter Shaft, 21 Drive Shaft, 22 Clutch Chamber, 24 Intake System , 25 Air cleaner, 26 Intake manifold, 27 Injector, 28 Throttle body, 29 Intake pipe, 30 Suction part, 31 Suction pipe, 33 Intake pipe, 34 Manifold collecting pipe, 35 Electronic throttle, 36 Support shaft, 37 Throttle valve, 38 Drive Motor, 39 throttle position sensor, 100 motorcycle.

Claims (7)

A plurality of cylinders are arranged in parallel in the vehicle width direction, a clutch chamber is arranged on either the left or right side in the vehicle width direction, an intake manifold between the cylinder block and the air cleaner at the upper part of the crankcase, a fuel injection device, A motorcycle engine unit in which a throttle body and an intake pipe are arranged,
The throttle body is disposed on the opposite side of the clutch chamber in the vehicle width direction,
The intake manifold includes a plurality of separated intake pipes connected to the cylinder head of each cylinder, and a manifold assembly portion formed in a bottomed cylinder shape that integrally collects the intake pipes.
Each of the intake pipes is formed in a curved shape so as to wrap around the throttle body and the upper part of the manifold assembly part in a side view,
The manifold assembly is located between the cylinder and the cylinder head and the air cleaner as viewed from the side of the vehicle body, and is located above the crankcase and below each intake pipe, and at each rear portion thereof. The intake pipe is connected;
The engine unit of a motorcycle, wherein the throttle body is connected to the manifold assembly.   The throttle body is integrally fixed to the intake manifold, and its throttle bore central axis is substantially parallel to the vehicle width direction, and is behind the front end of each intake pipe in a side view of the vehicle body and each intake pipe The engine unit for a motorcycle according to claim 1, wherein the engine unit is provided in front of the rear end of the motorcycle.   The engine unit of a motorcycle according to claim 1 or 2, wherein the throttle body is disposed on an inner side in a vehicle width direction of the cylinder block.   The engine of a motorcycle according to any one of claims 1 to 3, wherein each of the intake pipes is arranged so that an inclination of the manifold assembly portion with respect to a longitudinal direction gradually increases or decreases in a rear view. unit.   The engine unit for a motorcycle according to any one of claims 1 to 4, wherein the intake pipe farthest from the clutch chamber overlaps the throttle body in a plan view. The engine is surrounded by the body frame of the seat rail at the top, the down tube at the front, and the body tube at the rear,
In the space surrounded by the cylinder block, the air cleaner, and the crankcase below the seat rail, the fuel injection device, the intake pipe, the throttle valve, and the drive motor thereof are vertically aligned in parallel with the cylinder axis from above in a side view. The engine unit for a motorcycle according to any one of claims 1 to 5, wherein the engine unit is disposed.   The air cleaner is disposed in front of a body tube constituting a vehicle body frame, and the intake pipe connecting the throttle body and the air cleaner is connected without extending into the air cleaner. The motorcycle engine unit according to any one of claims 6 to 6.

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