JP6512237B2 - Engine fuel injection system - Google Patents

Description

  The present invention relates to a fuel injection device for injecting fuel into an intake passage in an engine mounted on a vehicle such as a motorcycle.

  In this type of engine, a plurality of injectors may be arranged in the intake passage in order to stabilize combustion in the engine. For example, in the fuel injection device disclosed in Patent Document 1, while the intake pipe is mounted substantially horizontally to the engine, the fuel injection device is provided with two injectors, and these injectors are disposed at the upper and lower positions of the intake pipe. Be done.

JP-A-6-317239

  In the fuel injection device of Patent Document 1, since the injector is attached to the throttle body, the injector position is far from the cylinder head, and the mounting angle and position of the injector also depend on the size and shape of the throttle body. Therefore, the fuel is likely to be attached to the wall surface of the intake passage, and the combustion becomes unstable due to the lack of the fuel, the misfire due to the liquefied fuel and the like, and the fuel efficiency is deteriorated. In addition, if injectors are disposed above and below the throttle body, the intake system becomes large, which greatly affects the layout of peripheral parts.

Furthermore, there are cases where a plurality of injectors are disposed along the direction of the intake passage, but since the intake passage becomes longer, the opportunity for fuel to adhere to the wall surface of the intake passage also increases. In addition, the intake system also becomes larger. On the other hand, in order to reduce the fuel adhering to the intake passage, the injector can be directly attached to the cylinder head, but if the vibration of the engine body is large, the injector may be damaged as it is.
Also, there are cases where the fuel spray direction from the injector is divided into two and the fuel is supplied to the respective intake ports, but the fuel adhering to the wall surface of the intake passage increases at an angle near the combustion chamber.

  An object of the present invention is to provide a fuel injection system for an engine, in which the fuel combustion in the engine can be stabilized and the intake system can be compactly arranged.

A fuel injection system for an engine according to the present invention comprises an air cleaner disposed above a cylinder head, a fuel tank covering the rear from above the air cleaner, a throttle body extending in the vertical direction, the throttle body and the cylinder head an intake pipe, and two intake ports communicating with the combustion chamber and the combustion chamber are formed in the cylinder head, and two injectors for injecting fuel respectively into the two intake ports, in engines equipped with the 2 The intake pipe having a single intake passage communicating with two intake ports is curved backward, and the two injectors are mounted in parallel on the curved curved portion on the rear side of the intake pipe , The inner surface of the intake pipe on the throttle body side is a perfect circle, and the inner surface on the cylinder head side is elliptical. Has a shape, characterized that you have been gradually expanded tube toward the two intake ports in the curved portion.

  According to the present invention, in an engine typically employing a downdraft intake system, combustion of the engine can be achieved by arranging two injectors in parallel for each intake port in the intake pipe connecting the throttle body and the cylinder head. While being stabilized, the intake system can be arranged compactly.

It is a front view showing the whole composition of the engine unit concerning the fuel injection device in the example of the present invention. It is a rear perspective view of an engine unit concerning a fuel injection device in an example of the present invention. It is a left side view of an engine unit in an example of the present invention. It is a rear view of engine unit 10 in an example of the present invention. It is sectional drawing in alignment with the II line of FIG. It is sectional drawing which follows the II-II line of FIG. It is a perspective view showing a fuel injection device circumference in an example of the present invention. It is a top view around a fuel injection device in an example of the present invention. It is sectional drawing which follows the III-III line of FIG. 8A. It is a top view of the intake pipe in the example of the present invention. It is a front view of the intake pipe in the example of the present invention. It is a bottom view of the intake pipe in the example of the present invention. It is a rear perspective view of an engine unit concerning a fuel injection device in an example of the present invention.

Hereinafter, a preferred embodiment of a fuel injection system for an engine according to the present invention will be described based on the drawings.
A fuel injection system for an engine according to an embodiment of the present invention includes an air cleaner disposed above a cylinder head, a fuel tank that covers the rear from above the air cleaner, a throttle body extending in the vertical direction, and the throttle body. It has an intake pipe connecting the cylinder head, a combustion chamber formed in the cylinder head, two intake ports communicating with the combustion chamber, and two injectors injecting fuel to the two intake ports. In the engine, the intake pipe is curved backward, and the two injectors are mounted in parallel on the curved curved portion on the rear side of the intake pipe.

  In the fuel injection system of the engine of the present invention, by arranging two injectors in parallel for each intake port in the intake pipe connecting the throttle body and the cylinder head, the combustion of the engine is stabilized and the intake system is compactly arranged. be able to.

  FIG. 1 is a front view showing an entire configuration of an engine unit 10 according to a fuel injection device in an embodiment of the present invention, and FIG. 2 is a rear perspective view of the engine unit 10. First, the schematic configuration of the entire engine unit 10 will be described using these figures. The present embodiment is an example of the engine unit 10 mounted on a motorcycle, and in the drawings used in the following description, the direction in which the rider on the motorcycle looks at the front of the vehicle is the front, and the reverse direction thereof. As the back. Also, the right side of the rider is the right side, the left side is the left side, and these directions are shown by arrows as needed.

  Here, the motorcycle on which the engine unit 10 is mounted has, for example, a twin spar type vehicle body frame, and a fuel tank or the like is disposed above the engine unit unit 10 supported at substantially the center of the vehicle by this vehicle body frame. Be done.

  The engine unit 10 has an engine 11, and in the present embodiment, a water-cooled multi-cylinder four-stroke gasoline engine is used. The engine 11 is typically a parallel two-cylinder engine in which a first (# 1) cylinder and a second (# 2) cylinder are disposed side by side (in the vehicle width direction). A cylinder block 13, a cylinder head 14 and a cylinder head cover 15 are integrally connected to an upper portion of a crankcase 12 accommodating a crankshaft horizontally supported in the horizontal direction so as to sequentially overlap, and an oil pan 16 is attached to the lowermost portion. Ru. The crankcase 12 is composed of upper and lower upper cases 12A and lower cases 12B. The cylinder axis of the engine 11 is disposed in a forwardly inclined manner. The engine 11 is integrally coupled to the inside of the vehicle body frame by being suspended to the aforementioned vehicle body frame via a plurality of engine mounts, and acts as a rigid member of the vehicle body frame by itself.

  A transmission case 17 is coupled to the rear portion of the crankcase 12 (FIG. 2), and a countershaft (not shown) and a plurality of transmission gears are disposed in the transmission case 17. The power of the engine unit 10 is finally transmitted from the crankshaft through the transmission to the drive sprocket (not shown), which is the output end of the transmission unit, and this drive sprocket is transmitted through the power transmission chain to the rear wheel of the motorcycle. It is connected to a driven sprocket to rotationally drive the rear wheel.

  The crankcase 12 and the transmission case 17 are integrally coupled to each other to form a casing assembly of the engine unit 10 as a whole. A plurality of accessories such as a starter motor for starting an engine, a clutch device and the like are mounted or coupled to appropriate places of the casing assembly, and the entire engine unit 10 including these is supported by a vehicle body frame.

  The engine 11 further includes an intake system for supplying a mixture of air (intake air) and fuel respectively supplied from an air cleaner and a fuel supply apparatus, an exhaust system for discharging exhaust gas after combustion from the engine 11, and cooling the engine 11 And a control unit (ECU; Engine Control Unit) for controlling the operation of these units. A plurality of functional devices cooperate with the above-mentioned accessories etc. by control of a control device, and, thereby, smooth operation is achieved as the engine unit 10 whole.

  The engine unit 10 will be described more specifically. FIG. 3 is a left side view of the engine unit 10, and FIG. 4 is a rear view of the engine unit 10. As shown in FIG. In the intake system, an air cleaner 18 is disposed on the upper left side of the cylinder head cover 15. For example, a rubber inlet pipe 19 extends downward so as to pass through the left front of the cylinder head 14, and the compressor portion 20A of the turbocharger 20 (turbocharger) Connected to the inlet pipe 21 connected to the Here, although an example of the engine 11 provided with the supercharger 20 is described in the present embodiment, the present invention is not limited to this and the present invention can be applied to a naturally aspirated engine. A supercharger 20 is mounted on the front of the crankcase 12 and the cylinder block 13, and the air supplied from the air cleaner 18 is compressed by the compressor unit 20A. The compressed air is discharged from an outlet pipe 22 connected to the compressor unit 20A, and an outlet pipe 23 is connected to the outlet pipe 22. The outlet pipe 23 extends to the upper side of the cylinder head cover 15 as shown in FIG. 1 and is connected to the intercooler 24.

  An intercooler 24 is disposed on the upper right side of the cylinder head cover 15, and the air compressed by the compressor portion 20A is supplied to the intercooler 24 through an outlet pipe 23. The intercooler 24 is substantially juxtaposed to the air cleaner 18 in the left-right direction. The intercooler 24 cools the air supplied from the outlet pipe 23, and the cooled air is fed from a surge tank described later to the throttle body. Since the air compressed by the compressor portion 20A of the turbocharger 20 generates heat, the intake efficiency of the engine 11 is lowered as it is. By cooling the air supplied from the turbocharger 20 by the intercooler 24 on the intake upstream side of the throttle body, the intake efficiency can be effectively improved. A hollow exhaust duct 25 extending rearward as shown in FIG. 2 and the like is joined to the intercooler 24, and the heat taken from the supplied air is taken as the exhaust wind, and the vehicle aft through the exhaust duct 25. To be discharged.

  In the above case, referring to FIGS. 1 to 3, bypass valve 27 is provided to connect inlet pipe 21 and outlet pipe 22, bypassing turbocharger 20 via bypass hose 26. One end of the bypass hose 26 is connected to the bypass valve 27, and the other end is connected to the outlet pipe 22.

  As shown in FIGS. 3 and 4, a surge tank 29 having a horizontal width substantially corresponding to # 1 and # 2 cylinders is disposed at substantially the same height position behind the air cleaner 18 and the intercooler 24. . The surge tank 29 is connected to the intercooler 24 via the connection pipe 30 as shown in FIG. 2, and the air cooled by the intercooler 24 is supplied. As shown in FIG. 3, the fuel tank 28 is mounted so as to cover the air cleaner 18 and the surge tank 29 from above. Fuel is supplied from a fuel tank 28 to an injector described later. Here, FIG. 5 is a cross-sectional view taken along the line I-I of FIG. 3, and FIG. 6 is a cross-sectional view taken along the line II-II of FIG. A down draft type intake system is adopted for the engine 11, and a substantially vertical intake passage is formed from the surge tank 29 to an intake port described later of the cylinder head 14.

  Further, in the present embodiment, the engine 11 is a four-valve engine, and as shown in FIG. 5, both the # 1 and # 2 cylinders have two intake valves 31 and two exhaust valves 32 on the intake and exhaust sides, respectively. ing. Two intake valves 31 and two exhaust valves 32 in the # 1 and # 2 cylinders are disposed at a predetermined pitch width in the left-right direction. Further, as shown in FIG. 6, both the # 1 and # 2 cylinders have two intake ports 34 and two exhaust ports 35 communicating with the combustion chamber 33 formed in the cylinder head 14, and these intake ports 34 and exhaust ports The valves 35 are opened and closed by the intake valve 31 and the exhaust valve 32, respectively. As shown in FIG. 6, the surge tank 29, the throttle body 36 and the intake pipe 37 are connected in a substantially straight line, and a downdraft type intake passage is formed by these.

  Here, in the present embodiment, the engine 11 typically includes the supercharger 20, but a natural intake system can be applied. In this case, the air cleaner 38 is attached to the throttle body 36 as shown by the two-dot chain line in FIG. 6, and the clean side 38 a and the dirty side 38 b are divided by the air cleaner element 39. Air is supplied to the throttle body 36 from the clean side 38 a without passing through the turbocharger 20. The air cleaner 18 itself also has the clean side 18 a and the dirty side 18 b.

  In the intake system, as shown in FIG. 6 and the like, the engine 11 is provided with a fuel injection device 40 which injects fuel to the intake port 34 and supplies the fuel. 7 is a perspective view showing the periphery of the fuel injection device 40, FIG. 8A is a top view thereof, and FIG. 8B is a cross-sectional view taken along the line III-III of FIG. 8A. First, two throttle bodies 36 corresponding to the # 1 and # 2 cylinders are integrally formed, and each throttle body 36 is formed with an intake passage 41 communicating with the surge tank 29, and from the surge tank 29 to the intake passage 41. Air flows into the Each intake passage 41 is provided with a throttle valve 43 rotatably supported around a valve shaft 42. Each intake passage 41 is opened and closed by a throttle valve 43. In this example, a drive motor 44 for opening and closing the throttle valve 43 is provided at the front of the # 1 cylinder of the throttle body 36, and the output shaft of the drive motor 44 and the valve shaft 42 are connected to each other via gears. Be done. The drive motor 44 is controlled by the ECU. As shown in FIG. 6, the drive motor 44 is disposed on the opposite side of the side where the injector 45 is disposed, that is, the front of the throttle body 36 and between the air cleaner 18 and the cylinder head 14.

  The intake pipe 37 is curved rearward as shown in FIGS. 6 and 8A, that is, it is convexly curved rearward at an appropriate R (curvature radius), and two injectors 45 are curved behind the intake pipe 37. It is attached in parallel in the left-right direction in the curved part 37a which curves by the side. 9A is a top view of the intake pipe 37, FIG. 9B is a front view thereof, and FIG. 9C is a bottom view thereof. Two intake pipes 37 corresponding to the # 1 and # 2 cylinders are integrally formed, and in each intake pipe 37, an intake passage 46 communicating with the intake passage 41 of the corresponding throttle body 36 is formed. The flange 47 connecting the two throttle bodies 36 and the flange 48 connecting the two intake pipes 37 are butted together, and both are fastened and fixed to each other by a bolt 49 or the like to be integrated. As shown in FIG. 9B, each intake pipe 37 has a flange 50 as shown in FIG. 9 and the flange 50 abuts the opening of the intake port 34 (see FIG. 10). It is concluded.

As shown in FIG. 9A, in the opening of the intake passage 46 on the flange 48 side of the intake pipe 37, a circumferential groove 46a for mounting a seal member such as an O-ring is formed. The circumferential groove 46a is a perfect circle. Further, as shown in FIG. 9C, in the opening of the intake passage 46 on the flange 50 side of the intake pipe 37, a circumferential groove 46b for mounting a seal member such as an O-ring is formed. The circumferential groove 46b has an elliptical shape whose major axis is in the left-right direction.
That is, the inner surface of the intake pipe 37 on the throttle body 36 side is a perfect circle, the inner surface on the cylinder head 14 is an elliptical shape, and the pipe is gradually expanded near the curved portion 37a.

  Further, an elastic member is inserted between the cylinder head 14 and the injector 45. Specifically, as shown in FIG. 8B, the rubber ring 52 is mounted so as to be sandwiched between the flange 50 and the lower portion of the curved portion 37a of the intake pipe 37 as shown in FIG. 7 or 9B. The rubber ring 52 is fixed to the intake pipe 37 by a baking process, and both are bonded with a strong bonding strength.

  As shown in FIG. 7, a delivery pipe 53 extending in the left-right direction is disposed in the vicinity of the rear side of the joint between the throttle body 36 and the intake pipe 37. That is, the upper end of the delivery pipe 53 is located behind the throttle body 36. As shown in FIGS. 9A and 9B, a delivery pipe attaching portion 54 for attaching the delivery pipe 53 is formed in a pedestal shape at a central rear portion of the flange 48 of the intake pipe 37. In this example, two delivery pipe mounting portions 54 are provided, and the delivery pipe 53 is fastened by bolts 55 to these delivery pipe mounting portions 54. A fuel supply port 53a is provided at the left end of the delivery pipe 53, and fuel is supplied from the fuel tank 28 via the fuel supply port 53a (see arrow F in FIG. 7). Fuel is further supplied to each injector 45 from the delivery pipe 53.

  Further, the delivery pipe 53 is provided with a pulsation damper 56 as shown in FIG. 7 and the like, and the pulsation damper 56 is attached to the delivery pipe 53 between adjacent # 1 and # 2 cylinders. According to the pulsation damper 56, it is possible to suppress the fuel pressure fluctuation caused by the pressure drop in the delivery pipe 53 due to the fuel injection of the injector 45.

Further, at the curved portion 37a of each intake pipe 37, as shown in FIG. 9B, a pair of injector attachment portions 57 for attaching the injector 45 is formed in the center left-right distribution in a rear view of the intake pipe 37. Each injector mounting portion 57 is formed in a counterbore shape and has a through hole 57 a into which the nozzle of the injector 45 is inserted. As shown in FIG. 8B and the like, each injector 45 is attached with a coupler 45a protruding as a convex portion obliquely to the side from the body axis, and a drive control signal to the injector 45 is input through the coupler 45a.
Particularly, as shown in FIG. 10, the convex portions of the adjacent couplers 45a are directed away from each other. For example, in the example of the injector 45 of the # 1 cylinder in FIG. 10, the pair of couplers 45a are arranged to be separated from each other in the directions indicated by the arrows A and B.

  Next, in the exhaust system, two exhaust ports 35 (see FIG. 6) are opened on the front side of the cylinder head 14 for both the # 1 and # 2 cylinders in the above-mentioned embodiment, as shown in FIG. An exhaust pipe 58 is connected to 35. The exhaust pipe 58 of each cylinder extends downward from the exhaust port 35 once as shown in FIG. 1 and merges and integrates on the front side of the cylinder block 13. Thereafter, the exhaust pipe 58 wraps around to the lower right side of the crankcase 12 and extends further rearward as shown in FIGS. 2 and 3 through the right side of the oil pan 16. A muffler or the like is attached to the rear end of the exhaust pipe 58.

  In this embodiment, the drive unit side of the turbocharger 20, that is, the turbine unit 20B is disposed in the middle of the exhaust pipe 58, and the compressor unit 20A of the turbocharger 20 is rotationally driven by using the turbine unit 20B as a drive source. As described above, in the present embodiment, the exhaust flow of the engine 11 is used to pressurize the air supplied from the air cleaner 18, and a turbocharger that supplies the air to the intercooler 24 is adopted. Note that, as shown in FIG. 1, a waste gate valve 59 is attached to the supercharger 20, and the exhaust gas flows into the turbine portion 20B of the supercharger 20 by diverting a part of the exhaust gas. Adjust the amount. As a result, the rotational speed of the turbocharger itself is controlled to obtain a stable boost pressure.

  Although not shown in detail in the cooling system, a water jacket is formed around the cylinder block 13 and the cylinder head 14 so as to circulate cooling water. It is equipped with a radiator that cools the cooling water supplied to the water jacket, and is designed to cool the cooling water circulating in the cooling system.

  Furthermore, a lubricating system is provided to supply lubricating oil to the movable parts of the engine unit 10 to lubricate them. The lubrication system includes a valve gear configured in the crankshaft and the cylinder head 14, a cam chain connecting them, a transmission and the like. In the present embodiment, a normal oil pump is used for the lubricating system, but the lubricating oil sucked from the oil pan 16 is fed to the lubricating system by this oil pump.

  Here, the basic operation and the like in the present invention will be described. An intake port 34 opens on the rear side of the cylinder head 14 for both the # 1 and # 2 cylinders of the engine 11, and a throttle body 36 is connected to the intake port 34 via an intake pipe 37. A throttle valve 43 is attached to the throttle body 36 to open and close the intake passage 41 formed therein according to the accelerator opening degree, and the flow rate of air supplied from the air cleaner 18 is controlled.

  On the other hand, injectors 45 for fuel injection are disposed on the downstream side of the throttle valve 43 of each throttle body 36, and fuel in the fuel tank 28 is supplied to these injectors 45 by the fuel pump. In this case, each injector 45 is connected at its upper side to a delivery pipe 53 which is transversely extended in the vehicle width direction, and fuel is distributed from the delivery pipe 53 connected to the fuel pump. Each injector 45 injects fuel into the intake port 34 at a predetermined timing under the control of the control system described above, as shown by the arrow F in FIGS. 5 and 6, and thereby into the combustion chamber 33 of the # 1 and # 2 cylinders. A mixture of a predetermined air-fuel ratio is supplied.

  Next, main actions and the like in the present invention will be described. First, by arranging two injectors 45 in parallel with the intake pipe 37 for each of the # 1 and # 2 cylinders, the injectors 45 can be brought closer to the engine 11. As a result, the fuel supply from the injector 45 becomes faster, and the fuel does not easily adhere to the wall surface of the intake passage 46 etc., so that the combustion is stabilized and the thermal efficiency is improved. Further, fuel consumption is also improved by reducing fuel adhering to the wall surface, and unburned gas is reduced by stabilizing combustion, whereby the exhaust gas value is improved. Furthermore, engine output and response are also improved.

  Even in the case of a downdraft type intake passage where it is generally considered that the intake flow has a low flow rate and the flow in the pipe can not be enhanced, combustion can be stabilized according to the present invention. In the downdraft type, since the air flow in the pipe is hard to be disturbed because the intake passage is straight, the turbulence in the combustion chamber tends to be weak and the combustion tends to be unstable when the flow rate is low and the flow rate is low. Even in such a case, the combustion can be stabilized. In addition, since there is no problem at the time of high flow which is a high load, the air flow in the pipe is fast, and the basic effect of the output improvement at the time of high addition by the down draft type is guaranteed.

Further, by arranging the two injectors 45 in parallel on the same side in each of the # 1 and # 2 cylinders, the intake passage 46 and the like can be shortened, and the intake system can be laid out in a compact manner. In this case, by bending the intake pipe 37, the throttle body 36 can be brought close to the engine 11, and the intake passage 46 and the like can be shortened. Also in this point, the intake system can be laid out in a compact manner.
Further, by arranging the injector 45 at the curved portion 37a of the intake pipe 37, it becomes easy to aim at the center of the intake port 34 as the fuel injection direction of the injector 45 (arrow F in FIG. 5 and FIG. 6) Can be reduced more effectively.

In addition, the intake passage 46 and the like can be configured to be short, and the degree of freedom of arrangement of the injector 45 is improved.
Furthermore, the space between the air cleaner 18 and the cylinder head 14 can be effectively utilized, and the drive motor 44 disposed in the space can be cooled by the traveling air. In addition, the capacity of the fuel tank 28 can be easily secured.

  Further, the inner surface of the intake pipe 37 particularly on the side of the cylinder head 14 has an elliptical shape, and the pipe is gradually expanded near the curved portion 37a. By expanding the intake pipe 37 in accordance with the spread of the spray of the fuel injected from the injector 45, it becomes easy to aim at the center of the intake port 34, and the adhesion of the fuel to the wall surface can be further suppressed.

Further, the pair of couplers 45a of the injector 45 are disposed apart from each other, so that the injector 45 can be brought close to the center of the intake port 34, and the adhesion of fuel to the wall surface can be further suppressed.
Further, by inserting a rubber ring 52 of an elastic member between the cylinder head 14 and the injector 45, the function and durability of the injector 45 up to the higher rotation region of the engine 11 while bringing the injector 45 closer to the cylinder head 14 Can be secured. Heat transfer to the injector 45 and the throttle body 36 can be suppressed, and their proper functions can be secured and maintained.

  Furthermore, by arranging the pulsation damper 56 in the space formed between the cylinders of the engine 11, the length of the delivery pipe 53 in the vehicle width direction can be reduced, and the fuel piping can be made compact. Etc.) can also be facilitated.

Here, the drive motor 44 may be disposed between the fuel tank 28 and the injector 45 on the same side as the injector 45 is disposed. In this case, referring to FIG. 3, as indicated by the two-dot chain line in FIG. 3, drive motor 44 is located on the rear side of throttle body 36, and surge tank 29 (above FIG. As in the example, the injector 45 is disposed below, including the case of being the air cleaner 38). Also, particularly around the rear of the drive motor 44 is covered by the fuel tank 28 as shown in FIG.
By arranging the drive motor 44 on the same side as the injector 45, that is, on the rear side of the throttle body 36 as described above, the drive motor 44 can be separated from the engine 11, so that heat damage can be suppressed. It also makes it easy to secure

As mentioned above, although the present invention was explained with various embodiments, the present invention is not limited only to these embodiments, and can be changed within the scope of the present invention.
Further, although the example of the water-cooled parallel two-cylinder engine has been described in the above embodiment, the number of cylinders of the engine 11, the cooling method, and the like can be appropriately selected. is there.

10 engine unit, 11 engine, 12 crankcase, 13 cylinder block, 14 cylinder head, 16 oil pan, 17 transmission case, 18 air cleaner, 19 inlet piping, 20 supercharger, 21 inlet pipe, 22 outlet pipe, 23 outlet piping , 24 intercooler, 25 exhaust air duct, 26 bypass hose, 27 bypass valve, 28 fuel tank, 29 surge tank, 30 connection pipe, 31 intake valve, 32 exhaust valve, 33 combustion chamber, 34 intake port, 35 exhaust port, 36 throttle body, 37 intake pipe, 38 air cleaner, 39 air cleaner element, 40 fuel injection device, 41, 46 intake passage, 42 valve shaft, 43 throttle valve, 4 Drive motor, 45 injector, 47,48,50 flange, 52 rubber ring, 53 a delivery pipe, 54 a delivery pipe mounting portion, 56 pulsation damper, 57 injector attachment, 58 exhaust pipe, 59 waste gate valve.

Claims (7)

An air cleaner disposed above the cylinder head, a fuel tank covering the rear from above the air cleaner, a throttle body extending in the vertical direction, an intake pipe connecting the throttle body and the cylinder head, and the cylinder head An engine having a combustion chamber and two intake ports communicating with the combustion chamber, and two injectors injecting fuel into the two intake ports respectively;
The intake pipe having a single intake passage communicating with the two intake ports is curved backward, and the two injectors are attached in parallel to the curved portion at the back of the intake pipe. It is,
The throttle body side inner surface of the intake pipe has a circular shape, wherein the cylinder head-side inner surface is an elliptical shape, Rukoto been gradually expanded tube toward the two intake ports in the curved portion An engine fuel injection device characterized by   A delivery pipe for supplying fuel to the injector, wherein the delivery pipe is attached to the intake pipe, and the upper end of the delivery pipe is located behind the throttle body. Engine fuel injection system.   The throttle body is provided with a drive motor for opening and closing a throttle valve, and the drive motor is disposed between the air cleaner and the cylinder head on the side opposite to the side where the injector is disposed. The fuel injection device of the engine according to claim 1 or 2, characterized by   The throttle body is provided with a drive motor for opening and closing a throttle valve, and the drive motor is disposed between the fuel tank and the injector on the same side as the injector is disposed. The fuel injection device of the engine according to claim 1 or 2, characterized by The fuel injection of the engine according to any one of claims 1 to 4 , wherein a coupler is attached to the injector, and the convex portions of the adjacent couplers face in directions away from each other. apparatus. The engine fuel injection device according to any one of claims 1 to 5 , wherein an elastic member is interposed between the cylinder head and the injector. The engine according to any one of claims 1 to 6 , further comprising a pulsation damper, wherein the engine has a plurality of cylinders arranged in parallel, and the pulsation damper is attached to the delivery pipe between adjacent cylinders. The fuel injection device of the engine according to item 1.

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