JP2018188976A - Fuel injection device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection device for an engine which can stabilize fuel combustion in the engine, and can arrange an intake system in a compact manner.SOLUTION: An engine related to a fuel injection device of this invention includes an air cleaner 18 arranged above a cylinder head 14, a fuel tank covering the air cleaner 18 from an upper side to a rear side, a throttle body 36 extending in a vertical direction, an intake pipe 37 connecting the throttle body 36 with the cylinder head 14, a combustion chamber 33 formed in the cylinder head 14 and two intake ports 34 communicating with the combustion chamber 33, and two injectors 45 for injecting fuel to the two intake ports 34, respectively. The intake pipe 37 has a shape backwardly curved, and the two injectors 45 are attached to a curved portion 37a being curved at a rear side of the intake pipe 37 in parallel.SELECTED DRAWING: Figure 6

Description

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

  In this type of engine, in order to stabilize combustion in the engine, a plurality of injectors may be arranged in the intake passage. For example, in the fuel injection device disclosed in Patent Document 1, the intake pipe is attached to the engine substantially horizontally, while the fuel injection apparatus includes two injectors, and these injectors are arranged at positions above and below the intake pipe. Is 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 attachment angle and position of the injector are also affected by the size and shape of the throttle body. For this reason, the fuel easily adheres to the wall surface of the intake passage, and there is a problem that the combustion becomes unstable and the fuel consumption deteriorates due to a shortage of fuel or misfire due to the liquefied fuel. In addition, if the injectors are arranged 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 arranged along the direction of the intake passage, but since the intake passage becomes longer, the chance of fuel adhering to the wall surface of the intake passage increases. In addition, the intake system is also enlarged. 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. However, if the vibration of the engine body is large, the injector may be damaged as it is.
In some cases, the fuel spray direction from the injector is divided into two, and the fuel is supplied to each intake port. However, since the fuel flows at an angle in the vicinity of the combustion chamber, the fuel adhering to the wall surface of the intake passage increases.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an engine fuel injection device capable of stabilizing fuel combustion in an engine and arranging an intake system in a compact manner.

  The fuel injection device for an engine according to the present invention connects 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, and the throttle body and the cylinder head. In an engine including an intake pipe, a combustion chamber formed in the cylinder head, two intake ports communicating with the combustion chamber, and two injectors for injecting fuel to the two intake ports, The pipe has a curved shape rearward, and the two injectors are attached in parallel to the curved curved portion on the rear side of the intake pipe.

  According to the present invention, in an engine that typically employs a downdraft type intake system, two injectors are arranged in parallel for each intake port in an intake pipe that connects a throttle body and a cylinder head, thereby reducing engine combustion. In addition to stabilization, the intake system can be arranged compactly.

It is a front view which shows the whole structure of the engine unit which concerns on the fuel-injection apparatus in the Example of this invention. It is a back perspective view of the engine unit concerning the fuel injection device in the example of the present invention. It is a left view of the engine unit in the Example of this invention. It is a rear view of the engine unit 10 in the Example of this invention. It is sectional drawing which follows the II line | wire of FIG. It is sectional drawing which follows the II-II line | wire of FIG. It is a perspective view which shows the surroundings of the fuel-injection apparatus in the Example of this invention. It is a top view around the fuel injection device in the embodiment 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 this invention. It is a front view of the intake pipe in the Example of this invention. It is a bottom view of the intake pipe in the Example of this invention. It is a back perspective view of the engine unit concerning the fuel injection device in the example of the present invention.

Hereinafter, preferred embodiments of a fuel injection device for an engine according to the present invention will be described with reference to the drawings.
An engine fuel injection device according to an embodiment of the present invention includes an air cleaner disposed above a cylinder head, a fuel tank covering the rear from above the air cleaner, a throttle body extending vertically, and the throttle body. An intake pipe that connects the cylinder head, a combustion chamber formed in the cylinder head, two intake ports that communicate with the combustion chamber, and two injectors that inject fuel into the two intake ports, respectively. In the engine, the intake pipe has a rearward curved shape, and the two injectors are attached in parallel to the curved curved portion on the rear side of the intake pipe.

  In the fuel injection device for an engine according to 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 arranged compactly. be able to.

  FIG. 1 is a front view showing an overall configuration of an engine unit 10 according to a fuel injection apparatus in an embodiment of the present invention, and FIG. 2 is a rear perspective view of the engine unit 10. First, the overall configuration of the engine unit 10 will be described with reference to these drawings. The present embodiment is an example of the engine unit 10 mounted on a motorcycle. In the drawings used in the following description, the direction in which a rider riding the motorcycle sees the front of the motorcycle is defined as the forward direction and the opposite direction, as necessary. Is the rear. Also, the rider's right side is on the right and the left side is on the left, and these directions are indicated by arrows as needed.

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

  The engine unit 10 has an engine 11, and in this embodiment, a water-cooled multi-cylinder four-cycle 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 arranged side by side in the left and right (vehicle width direction). A cylinder block 13, a cylinder head 14 and a cylinder head cover 15 are joined together so as to sequentially overlap above a crankcase 12 that houses a crankshaft that is horizontally supported in the left-right direction, and an oil pan 16 is attached to the lowermost part. The The crankcase 12 includes upper and lower upper cases 12A and a lower case 12B. In addition, the cylinder axis line of the engine 11 is arranged to be inclined moderately forward. The engine 11 is suspended and coupled to the above-described body frame through a plurality of engine mounts so as to be integrally coupled and supported on the inside of the body frame, and itself functions as a rigid member of the body frame.

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

  Note that the crankcase 12 and the transmission case 17 are integrally coupled to each other and constitute a casing assembly of the engine unit 10 as a whole. A plurality of auxiliary machines including a starter motor for starting the engine, a clutch device, and the like are mounted or coupled at appropriate positions of the casing assembly, and the entire engine unit 10 including these is supported by the vehicle body frame.

  The engine 11 further includes an air intake device that supplies air (intake air) and an air-fuel mixture supplied from an air cleaner and a fuel supply device, an exhaust device that discharges exhaust gas after combustion from the engine 11, and the engine 11 is cooled. A cooling device that lubricates the movable portion of the engine 11 and a control device (ECU; Engine Control Unit) that controls the operation thereof are also included. A plurality of functional devices cooperate with the above-mentioned auxiliary machines and the like under the control of the control device, and thereby the smooth operation of the engine unit 10 is performed as a 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. 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 unit 20 </ b> A of the supercharger 20 (turbocharger). Connected to the inlet pipe 21 connected to the. Here, in the present embodiment, an example of the engine 11 including the supercharger 20 will be described. However, 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 in front of the crankcase 12 and the cylinder block 13, and air supplied from the air cleaner 18 is compressed by the compressor unit 20A. Compressed air is discharged from an outlet pipe 22 connected to the compressor unit 20 </ b> A, and an outlet pipe 23 is connected to the outlet pipe 22. As shown in FIG. 1, the outlet pipe 23 extends to above the cylinder head cover 15 and is connected to the intercooler 24.

  An intercooler 24 is arranged on the upper right side of the cylinder head cover 15, and air compressed by the compressor unit 20 </ b> A is supplied to the intercooler 24 via the outlet pipe 23. The intercooler 24 is substantially juxtaposed with 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 supplied from a surge tank, which will be described later, to the throttle body. Since the air compressed by the compressor unit 20A of the supercharger 20 generates heat, the intake efficiency of the engine 11 is lowered as it is. The intake air efficiency can be effectively improved by cooling the air supplied from the supercharger 20 by the intercooler 24 on the intake upstream side of the throttle body. A hollow exhaust duct 25 extending rearward as shown in FIG. 2 is joined to the intercooler 24, and heat taken from the supplied air is exhausted as exhaust air through the exhaust duct 25. To be discharged.

  In the above case, with reference to FIGS. 1 to 3, a bypass valve 27 that bypasses the supercharger 20 via the bypass hose 26 and connects the inlet pipe 21 and the outlet pipe 22 is provided. 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 FIG. 3 and FIG. 4, a surge tank 29 having a lateral width substantially corresponding to the # 1 and # 2 cylinders is arranged at the same height as the rear side of the air cleaner 18 and the intercooler 24. . As shown in FIG. 2, the surge tank 29 is connected to the intercooler 24 through the connection pipe 30, and 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 the fuel tank 28 to an injector described later. 5 is a cross-sectional view taken along the line II of FIG. 3, and FIG. 6 is a cross-sectional view taken along the line II-II of FIG. The engine 11 employs a downdraft type intake system, 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 this 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 side and the exhaust side, respectively. ing. The two intake valves 31 and the two exhaust valves 32 in the # 1 and # 2 cylinders are arranged 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 35 are provided. 35 are opened and closed by an intake valve 31 and an 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, thereby forming a downdraft type intake passage.

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

  In such an intake system, the engine 11 includes a fuel injection device 40 that injects and supplies fuel to the intake port 34 as shown in FIG. 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 line III-III in FIG. 8A. First, two throttle bodies 36 corresponding to the # 1 and # 2 cylinders are integrally configured, and an intake passage 41 communicating with the surge tank 29 is formed in each throttle body 36, and the intake passage 41 extends from the surge tank 29. Air flows into the. Each intake passage 41 is provided with a throttle valve 43 that is 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 side 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 a gear or the like. Is done. The drive motor 44 is controlled by the ECU. As shown in FIG. 6, the drive motor 44 is disposed between the air cleaner 18 and the cylinder head 14 on the side opposite to the side where the injector 45 is disposed, that is, the front portion of the throttle body 36.

  As shown in FIGS. 6 and 8A, the intake pipe 37 has a shape that curves backward, that is, it curves backward with an appropriate R (curvature radius), and two injectors 45 are located behind the intake pipe 37. It is attached in parallel in the left-right direction at the curved portion 37a that bends on 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 an intake passage 46 communicating with the intake passage 41 of the corresponding throttle body 36 is formed in each intake pipe 37. The flange 47 that connects the two throttle bodies 36 and the flange 48 that connects the two intake pipes 37 are brought into contact with each other. As shown in FIG. 9B, each intake pipe 37 has a flange 50 as shown in FIG. 9B. The flange 50 is abutted against the opening of the intake port 34 (see FIG. 10). It is concluded.

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

  An elastic member is interposed between the cylinder head 14 and the injector 45. Specifically, as shown in FIG. 8B, a rubber ring 52 is mounted at the lower portion of the curved portion 37a of the intake pipe 37 so as to be sandwiched between the flange 50 as shown in FIG. 7 or FIG. 9B. The rubber ring 52 is fixed to the intake pipe 37 by the 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 near the rear side of the coupling portion 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 mounting portion 54 for mounting the delivery pipe 53 is formed in a pedestal shape at the center rear portion of the flange 48 of the intake pipe 37. In this example, there are two delivery pipe mounting portions 54, and the delivery pipe 53 is fastened to the delivery pipe mounting portions 54 with bolts 55. 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 (FIG. 7, arrow F). Fuel is further supplied from the delivery pipe 53 to each injector 45.

  Further, the delivery pipe 53 includes 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, a pair of injector mounting portions 57 for mounting the injectors 45 is formed in the curved portion 37a of each intake pipe 37 in the center left / right distribution as seen from the rear surface of the intake pipe 37 as shown in FIG. 9B. Each injector mounting portion 57 is formed in a spot shape and has a through hole 57a into which the nozzle of the injector 45 is inserted. As shown in FIG. 8B and the like, each injector 45 is provided with a coupler 45a protruding as a convex portion obliquely laterally from the main body axis, and a drive control signal for the injector 45 is input through this coupler 45a.
In particular, as shown in FIG. 10, the convex portions of the adjacent couplers 45a face away from each other. For example, in the example of the # 1 cylinder injector 45 in FIG. 10, the pair of couplers 45a are arranged so as to be separated from each other in the directions indicated by arrows A and B.

  Next, in the exhaust system, two exhaust ports 35 (see FIG. 6) are opened at the front side of the cylinder head 14 in both the # 1 and # 2 cylinders in the above-described embodiment. As shown in FIG. An exhaust pipe 58 is connected to 35. As shown in FIG. 1, the exhaust pipes 58 of the respective cylinders temporarily extend downward from the exhaust port 35, merge at the front side of the cylinder block 13, and are integrated. Thereafter, the exhaust pipe 58 goes around to the lower right part of the crankcase 12 and extends further rearward through the right side of the oil pan 16 as shown in FIGS. A muffler or the like is attached to the rear end of the exhaust pipe 58.

  In the present embodiment, the driving unit side of the supercharger 20, that is, the turbine unit 20B is disposed in the middle of the exhaust pipe 58, and the compressor unit 20A of the supercharger 20 is rotationally driven using the turbine unit 20B as a driving source. Thus, in this embodiment, a turbocharger that uses the exhaust flow of the engine 11 to pressurize the air supplied from the air cleaner 18 and supplies the air to the intercooler 24 is employed. As shown in FIG. 1, the supercharger 20 is provided with a waste gate valve 59, and the exhaust gas flows into the turbine section 20B of the supercharger 20 by diverting a part of the exhaust gas. Adjust the amount. Thereby, the rotation speed of the turbocharger itself is controlled, and a stable supercharging pressure can be obtained.

  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 that cooling water circulates. Equipped with a radiator that cools the cooling water fed to the water jacket, the cooling water circulating in the cooling system is cooled.

  Furthermore, a lubricating system for supplying lubricating oil to the movable parts of the engine unit 10 and lubricating them is configured. This lubrication system includes a valve operating device configured in the crankshaft and the cylinder head 14, and a cam chain, a transmission and the like for connecting them. In this embodiment, a normal oil pump is used for the lubrication system, and the lubricating oil sucked up from the oil pan 16 by this oil pump is supplied to the lubrication system.

  Here, the basic operation and the like in the present invention will be described. An intake port 34 is opened on the rear side of the cylinder head 14 in 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. The throttle body 36 is provided with a throttle valve 43 that opens and closes an intake passage 41 formed in the throttle body 36 according to the accelerator opening, and the flow rate of air supplied from the air cleaner 18 is controlled.

  On the other hand, injectors 45 for fuel injection are arranged 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 a fuel pump. In this case, each injector 45 is connected to a delivery pipe 53 horizontally mounted in the vehicle width direction on the upper side, 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 chambers 33 of the # 1 and # 2 cylinders. A mixture having a predetermined air-fuel ratio is supplied.

  Next, the 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 injector 45 can be brought closer to the engine 11. This speeds up the fuel supply from the injector 45 and makes it difficult for the fuel to adhere to the wall surface of the intake passage 46 and the like, so that combustion is stabilized and thermal efficiency is improved. Further, fuel consumption is improved by reducing the fuel adhering to the wall surface, and unburned gas is reduced and the exhaust gas value is improved by stabilizing the combustion. Furthermore, engine output and response are improved.

  Even in the case of a downdraft type intake passage, in which intake air is generally low and the flow in the pipe cannot be enhanced, combustion can be stabilized according to the present invention. In the downdraft type, since the intake passage is straight and the airflow in the pipe is not easily disturbed, the turbulence in the combustion chamber tends to be weak and the combustion tends to become unstable at a low flow rate with a low load. Even in such a case, combustion can be stabilized. It should be noted that there is no problem because the air flow in the pipe is fast at a high flow rate at a high load, and the basic effect of improving the output at the time of high addition by the downdraft type is guaranteed.

In addition, by arranging 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 layout. In this case, by bending the intake pipe 37, the throttle body 36 can be brought closer to the engine 11 and the intake passage 46 and the like can be shortened. In this respect as well, the intake system can be laid out in a compact layout.
Furthermore, by arranging the injector 45 in the curved portion 37a of the intake pipe 37, it becomes easier to aim at the center of the intake port 34 as the fuel injection direction of the injector 45 (arrow F in FIGS. 5 and 6), and the fuel adhering to the wall surface. Can be reduced more effectively.

In addition, the intake passage 46 and the like can be shortened, and the degree of freedom in arranging the injector 45 is improved.
Furthermore, the space between the air cleaner 18 and the cylinder head 14 can be used effectively, and the drive motor 44 disposed in the space can be cooled with the traveling wind. In addition, the capacity of the fuel tank 28 can be easily secured.

  Further, the inner surface of the intake pipe 37, particularly the cylinder head 14 side, is elliptical and is gradually expanded in the vicinity of the curved portion 37a. By expanding the intake pipe 37 in accordance with the spread of the spray of fuel injected from the injector 45, it becomes easier 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 arranged so as to be separated from each other, the injector 45 can be brought closer to the center of the intake port 34, and the fuel wall surface adhesion can be further suppressed.
In addition, a rubber ring 52 of an elastic member is interposed between the cylinder head 14 and the injector 45, so that the function and durability of the injector 45 can be increased to a higher rotation region of the engine 11 while the injector 45 is brought 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 disposing 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 suppressed, and the fuel pipe 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 side where the injector 45 is disposed. In this case, referring to FIG. 3, as shown by the two-dot chain line in FIG. 3, the drive motor 44 is located on the rear side of the throttle body 36, and the surge tank 29 (in FIG. The injector 45 is disposed below the air cleaner 38 as in the example. Further, particularly around the rear portion of the drive motor 44 is covered by the fuel tank 28 as shown in FIG.
By disposing the drive motor 44 on the same side as the injector 45, that is, on the rear side of the throttle body 36 in this way, the drive motor 44 can be separated from the engine 11, so that heat damage can be suppressed and the air cleaner 18 can be suppressed. It is easy to secure the capacity.

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.
In the above-described embodiment, the example of the water-cooled parallel two-cylinder engine has been described. However, the number of cylinders and the cooling method of the engine 11 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 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 (8)

An air cleaner disposed above the cylinder head, a fuel tank covering the rear from above the air cleaner, a throttle body extending vertically, an intake pipe connecting the throttle body and the cylinder head, and the cylinder head are formed. An engine having two combustion ports and two intake ports communicating with the combustion chambers, and two injectors for injecting fuel into the two intake ports,
The fuel injection device for an engine according to claim 1, wherein the intake pipe has a shape curved rearward, and the two injectors are attached in parallel to the curved curved portion on the rear side of the intake pipe.   The delivery pipe according to claim 1, further comprising a delivery pipe for supplying fuel to the injector, the delivery pipe being attached to the intake pipe, and an upper end of the delivery pipe being located behind the throttle body. Engine fuel injection device.   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 for an engine according to claim 1 or 2.   The throttle body is provided with a drive motor that opens and closes 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 for an engine according to claim 1 or 2.   The throttle pipe-side inner surface of the intake pipe has a perfect circle shape, the cylinder head-side inner surface has an elliptical shape, and is gradually expanded at a curved portion thereof. 5. The fuel injection device for an engine according to any one of 4 above.   The engine fuel injection according to any one of claims 1 to 5, wherein a coupler is attached to the injector, and convex portions of the adjacent couplers face away from each other. apparatus.   The engine fuel injection device according to any one of claims 1 to 6, wherein an elastic member is interposed between the cylinder head and the injector.   The pulsation damper is provided, 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 for an engine according to claim 1.

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