JP6308969B2 - Small vehicle fuel injection device arrangement structure - Google Patents

Description

  The present invention relates to an arrangement structure in a small vehicle of a fuel injection device that directly injects fuel into a combustion chamber of a cylinder head.

In an internal combustion engine mounted on a small vehicle such as a motorcycle, an example of a diesel engine includes a fuel injection device that directly injects fuel into a combustion chamber of a cylinder head (see, for example, Patent Document 1).
A fuel injection device that directly injects fuel into a combustion chamber requires high-pressure injection even in a gasoline engine.

Japanese Patent Laid-Open No. 7-166997

A fuel injection device that directly injects fuel into a combustion chamber of a cylinder head is attached to the cylinder head. In Patent Document 1, a fuel injection nozzle (fuel injection valve) of the main body of the fuel injection device is attached to the top of the cylinder head. A structure is disclosed.
Actually, the fuel injection valve of the main body is attached to the cylinder head as a fuel injection device in which a fuel supply system piping portion and an electrical control system connector portion are attached.

  In the specification and claims of the present application, the fuel injection device is a device in which a fuel injection valve as a main body is assembled with a fuel supply system piping part, an electrical control system connector part and others. That is.

When a fuel injection device in which a pipe part and a connector part are mounted on a fuel injection nozzle disclosed in Patent Document 1 is attached to a cylinder head, the internal combustion engine mounted horizontally on the body frame of the motorcycle is inclined forward. The fuel injection device protrudes greatly at the top of the cylinder head provided at the upper end of the standing cylinder.
As described above, the fuel injection device protruding from the top of the cylinder head has an open periphery, and is not sufficiently protected from external forces and flying objects such as flying stones due to external factors.

  Further, in order to control the fuel injection valve with high accuracy, if the fuel injection device is provided with a fuel pressure sensor that detects the pressure of the fuel that fluctuates with the injection, the fuel injection device protruding from the cylinder head is even larger. As a result, the protection from external forces becomes more difficult, and it is not easy to secure an arrangement space.

  The present invention has been made in view of such a point, and an object of the present invention is to cover the fuel injection device with an existing member by arranging the fuel injection device in an appropriate space along with the intake passage of the cylinder head. This is to provide a fuel injection device arrangement structure for a small vehicle that can protect against external forces and avoid an increase in the weight of the internal combustion engine.

In order to achieve the above object, a fuel injection device arrangement structure for a small vehicle according to the present invention includes:
In a fuel injection device arrangement structure for a small vehicle in which an internal combustion engine including a fuel injection device that directly injects fuel into a combustion chamber of a cylinder head is supported by a vehicle body frame,
A main frame extending rearward from the vehicle body front portion of the vehicle body frame passes above the cylinder head,
The internal combustion engine is supported by the main frame in a posture in which a cylinder block and a cylinder head protrude forward from a crankcase,
An intake passage for introducing intake air into the combustion chamber is provided extending from the cylinder head;
The fuel injection device is attached to an upper side surface of the cylinder head facing the main frame, and is disposed below the main frame, and is disposed side by side in the vehicle body width direction with the intake passage.
A fuel supply pump for supplying fuel to the fuel injection device;
A discharge hose extending from the fuel supply pump and connected to the fuel injection device;
The discharge hose is located between the internal combustion engine and the main frame, and is disposed within a width of the internal combustion engine in a vehicle body width direction in a plan view of the vehicle .

According to this configuration, the fuel injection device is attached to the side face of the cylinder head facing the main frame, and is arranged side by side in the intake passage and the vehicle body width direction. The injection device is covered by the existing intake passage, main frame, and cylinder head, and is protected from external forces and scattered objects. Suppressing the increase in size of the cylinder head without providing a separate protective cover, and increasing the weight of the internal combustion engine Can be avoided.
According to this configuration, the internal combustion engine is supported by the main frame in a posture in which the cylinder block and the cylinder head protrude forward from the crankcase, and the fuel injection device is attached to the upper side surface of the cylinder head and below the main frame. As a result, the fuel injection device is sandwiched from above and below by the upper main frame and the lower cylinder head, and is covered with an intake passage on one side, and is protected from external forces and scattered objects. The cylinder head effectively protects against flying objects such as flying stones.

In the above configuration,
The intake passage is provided at a position biased to one side of the vehicle body width direction with respect to a cylinder center vertical plane perpendicular to the vehicle body width direction including the cylinder axis of the cylinder,
The fuel injection device may be arranged on the side opposite to the side where the intake passage is biased.

  According to this configuration, the intake passage is provided at a position that is biased to one side in the vehicle body width direction with respect to the cylinder center vertical plane, so that the fuel that uses the space generated on the opposite side of the suction passage to the fuel is utilized. An injection apparatus can be arrange | positioned and the enlargement of a cylinder head can be suppressed.

In the above configuration,
The cylinder head has one intake port and one exhaust port,
On the ceiling surface of the combustion chamber of the cylinder head, an intake valve port and an exhaust valve port, which are openings facing the combustion chamber of the intake port and the exhaust port, are biased toward opposite sides with respect to the cylinder center vertical plane. As it is formed,
The fuel injection valve (51) of the fuel injection device (50) is formed in an empty portion generated on the opposite side due to the intake valve port (31o) being biased to one side with respect to the cylinder center vertical plane (Sv). An injection valve port (33) with a protruding tip is formed, and a plug port from which the tip of the spark plug (58) protrudes into an empty portion formed on the opposite side due to the exhaust valve port (32o) being biased to one side (34) may be formed.

  According to this configuration, on the ceiling surface of the combustion chamber of the cylinder head, the intake valve port and the exhaust valve port, which are openings facing the combustion chamber of the intake port and the exhaust port, are on opposite sides of the cylinder center vertical plane. An injection valve port that is formed in a biased manner and in which a tip of the fuel injection valve of the fuel injection device protrudes into an empty portion formed on the opposite side due to the intake valve port being biased to one side with respect to the cylinder center vertical plane Is formed in the empty part generated on the opposite side due to the exhaust valve port being biased to one side, so the tip of the spark plug protrudes, so the ceiling surface of the combustion chamber of the cylinder head Two relatively large openings, the intake valve port and the exhaust valve port, and two relatively small projecting ports, the injection valve port and the plug port, are distributed in a compact manner with good balance and space efficiency, respectively. It can be, in particular, it is possible to suppress the increase in size of the cylinder head of a small engine displacement of the engine.

In the above configuration,
The small vehicle may be configured such that a side opposite to the intake passage of the fuel injection device in the vehicle body width direction is opened.

  According to this configuration, since the small vehicle is open on the side opposite to the intake passage of the fuel injection device in the vehicle body width direction, from the opened side in a state where the internal combustion engine is mounted on the vehicle body frame. The fuel injection device can be accessed, the fuel injection device can be easily detached, and the maintenance is excellent.

In the above configuration,
The intake passage may be connected to an upper air cleaner that extends upward from an upper side surface of the cylinder head and is attached to the main frame.

  According to this configuration, since the intake passage extends upward from the upper side surface of the cylinder head, the intake passage and the fuel injection device are arranged side by side in the vehicle body width direction on the upper side surface of the cylinder head. Since it is connected to the upper air cleaner, the fuel injection device can be covered with the air cleaner on the upper side together with the main frame, and is more effectively protected from external force from above.

In the above configuration,
The main frame may be constituted by a single frame member having a rectangular cylinder with a vertically long cross section.

  According to this configuration, the main frame is formed of a single rectangular frame member having a rectangular shape with a vertically long cross section, and thus the rigidity of the frame is increased by extending the cross-sectional dimension of the frame member in the vertical direction. The spread in the vehicle body width direction can be suppressed.

In the above configuration,
The main frame may extend in a straight line from the front part of the vehicle body to the rear and obliquely downward, and then bend so that the inclination becomes gentle at a position after passing through the fuel injection device.

  According to this configuration, the main frame is inclined so as to be gradually inclined at a position after passing through the fuel injection device, after being inclined in a straight line while being inclined rearward and obliquely downward from the front portion of the vehicle body. The fuel injection device is space-efficient by bending the slanting rear of the fuel injection device attached to the upper side surface of the fuel injection device so that the inclination becomes gentle after the main frame passes straight and diagonally downward. And can be effectively protected by the mainframe.

  In the present invention, the fuel injection device is attached to the side face of the cylinder head facing the main frame and is arranged side by side in the intake passage and the vehicle body width direction. Therefore, the fuel injection device is arranged side by side in the intake passage and the vehicle body width direction. Is covered by the existing intake passage, main frame, and cylinder head and protected from external force and scattered objects, and without increasing the size of the cylinder head without providing a special protective cover, avoiding the increase in weight of the internal combustion engine be able to.

1 is an overall side view of a motorcycle according to an embodiment of the present invention. Fig. 2 is a side view of the main part of the motorcycle. FIG. 3 is a plan view of the main part of the motorcycle (a view taken along the arrow III in FIG. 1). FIG. 2 is a front view of a principal part of the motorcycle (a view taken along an arrow IV in FIG. 1), with a part omitted. It is a reverse view of a cylinder head. FIG. 3 is a partial side view of the motorcycle with a partial cross section of the internal combustion engine. It is a reverse view of the cylinder head concerning another embodiment.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 is a side view of a motorcycle 1 that is a straddle-type vehicle according to an embodiment to which the present invention is applied.
In the description of the present specification, the directions of front, rear, left and right are based on a normal standard in which the straight traveling direction of the motorcycle 1 according to the present embodiment is the front. In the drawings, FR is the front and RR is the rear. , LH indicates the left side, and RH indicates the right side.

The vehicle body frame 2 has one main frame 4 extending rearward and downward from the head pipe 3, and a pair of left and right pivot plates 5, 5 are suspended downward from the rear end of the main frame 4. A pair of left and right rear frames 6, 6 extend obliquely upward rearward from the rear, and subframes 7, 7 are installed between the main frame 4 and the rear frames 6, 6.
The main frame 4 is a frame member having a rectangular tube shape with a vertically long cross section (see FIG. 4).

A front wheel 10 is pivotally supported at the lower end of a front fork 9 which is attached to the head pipe 3 by a handle 8 so as to be steerable.
On the other hand, a swing arm 12 is pivotally supported on the pivot plate 11 by a pivot shaft 11 so as to be swingable up and down, and a rear wheel 13 is pivotally supported at the rear end of the swing arm 12.
A rear cushion 14 is interposed between the swing arm 12 and the upper rear frame 6.

  A storage box 15 is attached to the front of the pair of left and right sub-frames 7 and 7, and a fuel tank 16 is supported from the storage box 15 to the rear of the rear frames 6 and 6, and above the storage box 15 and the fuel tank 16. A seat (not shown) is attached so as to be freely opened and closed.

An internal combustion engine 20 is suspended by being supported by an engine hanger 17 and a pivot plate 5 that project downward from the rear of the center of the main frame 4.
The internal combustion engine 20 is a four-stroke cycle one-cylinder air-cooled internal combustion engine.

The internal combustion engine 20 is mounted on the vehicle body frame with a cylinder disposed substantially horizontally forward in a horizontal posture with the crankshaft 25 oriented in the left-right direction.
That is, the cylinder block 22, the cylinder head 23, and the cylinder head cover 24 are stacked in order and projecting from the crankcase 21 to the front and near the horizontal.
The left and right sides of the crankcase 21 are covered with a left case cover 28L and a right case cover 28R.

  One main frame 4 extending rearward from the head pipe 3 at the front portion of the vehicle body frame 2 is located within the left and right widths of the internal combustion engine 20 suspended downward in the plan view shown in FIG. It is within the horizontal width.

Referring to FIG. 6, a connecting rod 27 connects a piston 26 that slides in a cylinder (cylinder liner) 22c of a cylinder block 22 and a crank pin 25p that connects a pair of crank webs 25w and 25w of a crankshaft 25. ing.
A cylinder axis C, which is the central axis of the cylinder 22c in which the piston 26 reciprocates, extends forward and inclines slightly upward (see FIGS. 2 and 6).

An intake passage (intake pipe) 40 extends upward from an upper side surface 23u of the cylinder head 23 that projects forward from the crankcase 21. The intake passage 40 passes through the throttle body 41 on the way to the front end of the main frame 4. It is connected to an air cleaner 42 attached to the section (see FIG. 2).
The exhaust pipe 45 extending downward from the lower side surface of the cylinder head 23 is bent and extends rearward, and is connected to a muffler 46 disposed behind the crankcase 21 and on the right side of the rear wheel 13 (FIG. 1). reference).

  Referring to FIGS. 4 and 5, one intake port 31 extends upward from the intake valve port 31 o facing the combustion chamber 30 and downward from the exhaust valve port 32 o facing the combustion chamber 30 in the cylinder head 23. One exhaust port 32 is extended, the intake port 31 is connected to the intake passage 40, and the exhaust port 32 is connected to the exhaust pipe 45.

A fuel injection device 50 is attached to the upper side surface 23u of the cylinder head 23 from which the intake passage 40 extends upward (see FIG. 2) side by side with the intake passage 40.
As shown in FIGS. 3 and 4, the intake passage 40 is at a position biased to the left in the vehicle body width direction (left-right direction) with respect to the cylinder center vertical plane Sv perpendicular to the vehicle body width direction including the cylinder axis C. The fuel injection device 50 is provided on the side (right side) opposite to the side where the intake passage 40 is biased.

The fuel injection device 50 is configured such that a fuel supply piping 51 and an electrical connector 54 are integrally assembled with a fuel injection valve 51 of the main body.
The piping portion 52 of the fuel supply system branches off from the vicinity of the end portion of the straight trunk pipe 52a to form a hose connection branch pipe 52b. The base end portion of the fuel injection valve 51 is held at the center of the trunk pipe 52a. A mounting base 52c is formed on the holding portion (see FIGS. 2, 3, and 4).

A fuel pressure sensor 53 is attached to the end of the pipe portion 52 opposite to the hose connection branch pipe 52b of the trunk pipe 52a.
When the fuel pressure sensor 53 is attached to the trunk pipe 52a, the trunk pipe 52a and the fuel pressure sensor 53 are linearly long.

The fuel injection valve 51 of the fuel injection device 50 is inserted from the upper side surface 23u of the cylinder head 23 toward the combustion chamber 30, and the tip of the fuel injection valve 41 from which fuel is injected faces the combustion chamber 30 (see FIG. 4, see FIG.
The fuel injection valve 51 of the fuel injection device 50 directly injects fuel into the combustion chamber 30 of the cylinder head 23.

  A trunk pipe 52a of the piping section 52 is assembled so as to intersect the fuel injection valve 51 at the base end portion, and a mounting base 52c at the center of the trunk pipe 52a is bolted to a mounting seat on the upper side surface 23u of the cylinder head 23. 2, as shown in FIG. 2, the straight trunk pipe 52 a and the fuel pressure sensor 53 are attached in a forward inclined posture with the fuel pressure sensor 53 on the upper side.

A hose connection branch pipe 52b branched from the vicinity of the lower end of the trunk pipe 52a of the piping section 52 protrudes rearward, and a fuel pressure sensor 53 extends from the upper end of the trunk pipe 52a.
As shown in FIGS. 3 and 4, in the trunk pipe 52 a and the fuel pressure sensor 53 of the piping section 52 configured linearly, the upper fuel pressure sensor 43 is inclined to the left in the vehicle body width direction.

A spark plug 58 is attached to the left side surface of the cylinder head 23.
The spark plug 58 is fitted into the combustion chamber 30 from the left side surface of the cylinder head 23, and the tip of the spark plug 58 faces the combustion chamber 30 (see FIGS. 3, 4, and 5).

The internal combustion engine 20 is a so-called direct injection system in which the fuel injection device 50 directly injects fuel into the combustion chamber 30 of the cylinder head 23. Since high pressure injection is required, the high pressure fuel is supplied to the fuel injection device 50. For this purpose, a high-pressure fuel supply pump 60 is provided.
The high-pressure fuel supply pump 60 is attached to the upper wall of the crankcase 21.

With reference to FIG. 6, the high-pressure fuel supply pump 60 is attached to the crankcase 21 by a pump attachment member 70.
The high-pressure fuel supply pump 60 is provided with a mounting flange 62f in the middle of a cylindrical base 62 that extends from a pump body 61 that houses a reciprocating piston (not shown).

A plunger 63 extending from the piston protrudes through the cylindrical base 62, and a slide member 64 is fixed to the tip of the plunger 63. A coil spring 66 is interposed between the slide member 64 and the end of the cylindrical base 62. It is wound around and installed.
A roller 65 is rotatably supported on the slide member 64, and a part of the roller 65 protrudes below the slide member 64.

The pump mounting member 70 fits the cylindrical base 62 of the high-pressure fuel supply pump 60, and a support sleeve portion 71 that accommodates the plunger 63, the slide member 64, the coil spring 66, and the like, and the support sleeve portion 71 is fixed to the crankcase 21. A mounting base 72 is integrally formed.
The support sleeve portion 71 of the pump mounting member 70 has an enlarged diameter portion 71f whose inner diameter and outer diameter are increased at the upper end portion, and a rectangular parallelepiped so as to protrude sideways from a part of the enlarged diameter portion 71f. A shaped mounting base 72 is formed.

Referring to FIG. 6, the upper wall of the crankcase 21 is positioned on the right side of the pair of left and right crank webs 25w, 25w connected to the crankpin 25p of the crankshaft 25 at the longitudinal position near the cylinder block 22. A circular opening 21h is formed at the position of the web 25w in the vehicle body width direction (left-right direction), and the support sleeve portion 71 of the pump mounting member 70 is fitted into the circular opening 21h.
The mounting base 72 of the pump mounting member 70 is brought into contact with the flat right side surface of the raised portion 21L raised on the left upper surface of the crankcase 21 and is fixed to the crankcase 21 by fixing the front and rear with bolts 75 and 75. (See FIG. 3).

As shown in FIG. 6, the support sleeve portion 71 of the pump mounting member 70 fitted in a circular opening 21h formed at a predetermined position on the upper wall of the crankcase 21 is inclined forward and protrudes obliquely upward. .
A high-pressure fuel supply pump 60 is inserted into and supported by the support sleeve portion 71.

  As shown in FIG. 6, the plunger 63 and the coil spring 66 are inserted into the support sleeve portion 71 so that the slide member 64 of the high-pressure fuel supply pump 60 is slidably fitted. The cylindrical base portion 62 of the high-pressure fuel supply pump 60 is fitted into the enlarged diameter portion 71f, the mounting flange 62f of the high-pressure fuel supply pump 60 is brought into contact with the enlarged diameter portion 71f of the support sleeve portion 71, and both are fastened by the bolt 69, The high-pressure fuel supply pump 60 is fixedly supported by the pump mounting member 70.

  When the high-pressure fuel supply pump 60 is supported by the support sleeve portion 71 of the pump mounting member 70 and attached to the crankcase 21, the pump body 61 is inclined forward and upward from the support sleeve portion 71 as shown in FIG. The roller 65 protruding downward and exposed downward from the support sleeve portion 71 is pressed against the outer peripheral surface of the crank web 25w on the right side of the crankshaft 25 by the spring force of the coil spring 66.

The crank web 25w has a predetermined peripheral cam shape, and the roller 65 is pressed against the outer peripheral cam surface by the spring force of the coil spring 66.
Accordingly, as the crank web 25w rotates, the roller 65 advances and retreats along the central axis of the support sleeve portion 71 while rolling on the outer peripheral cam surface, and the piston is reciprocated via the plunger 63 to reciprocate the high pressure fuel supply pump 60. Drive.

A low-pressure fuel supply pump 59 that primarily supplies fuel to the high-pressure fuel supply pump 60 is provided in the fuel tank 16 (see FIG. 1).
The pump main body 61 of the high-pressure fuel supply pump 60 has a fuel suction portion 61i and a fuel discharge portion 61e protruding obliquely forward, and a suction hose 67 extending from the fuel suction portion 61i protruding leftward is The vehicle extends rearward and is connected to a low-pressure fuel supply pump 59 provided in the fuel tank 16 (see FIGS. 1 and 3).

  A discharge hose 68 extending from a fuel discharge portion 61e protruding forward right of the pump body 61 is connected to a hose connection branch pipe 52b of a piping portion 52 of a fuel injection device 50 attached to the upper side surface 23u of the cylinder head 23. (See FIGS. 2 and 3).

  Therefore, the high pressure fuel driven by the high pressure fuel supply pump 60 is pumped to the fuel injection device 50 and directly injected into the combustion chamber 30 of the cylinder head 23 by the fuel injection valve 51 at a required timing.

 The high-pressure fuel supply pump 60 is also offset to the right with respect to the main frame 4 and protrudes to the right from the main frame 4 in a plan view shown in FIG. A bracket 78 is provided with the upper end fixed to the main frame 4 so as to cover the portion protruding from 4 from the right side.

  As shown in FIGS. 2 and 3, the high-pressure fuel supply pump 60 attached to the upper wall of the crankcase 21 via a pump attachment member 70 is arranged side by side on the upper side surface 23 u of the cylinder head 23. It is located behind the intake passage 40 and the fuel injection device 50.

Referring to FIG. 5 which is a rear view of the cylinder head 23, a combustion chamber 30 is formed so as to be cut out on the mating surface of the cylinder head 23 with the cylinder block 22.
A chain chamber 38 is formed on the right side of the combustion chamber 30 to accommodate a chain that transmits power to the valve train.

  The dome-shaped ceiling surface 35 of the combustion chamber 30 of the cylinder head 23 has an intake valve port 31o that is an opening facing the combustion chamber 30 of the intake port 31 and an exhaust valve port that is an opening facing the combustion chamber 30 of the exhaust port 32 32o is formed, and an injection valve port 33 from which the tip of the fuel injection valve 41 into which fuel is injected projects and a plug port 34 from which the tip of the spark plug 58 projects are formed.

In the rear view of the cylinder head 23 in FIG. 5, a cylinder center vertical plane Sv that is orthogonal to the vehicle body width direction including the cylinder axis C is superimposed on the relative position with the cylinder head 23.
The intake valve port 31o and the exhaust valve port 32o are formed on the ceiling surface 35 of the combustion chamber 30 of the cylinder head 23 at positions that are biased on opposite sides with respect to the cylinder center vertical plane Sv.
The intake valve port 31o is formed on the left side where the intake passage 40 exists with respect to the cylinder center vertical plane Sv, and the exhaust valve port 32o is formed on the right side opposite to the intake passage 40.

  A fuel injection device is provided on the ceiling surface 35 of the combustion chamber 30 of the cylinder head 23 in the empty portion generated on the opposite side (right side) due to the intake valve port 31o being biased to the left side with respect to the cylinder center vertical plane Sv. A plug in which the tip of the spark plug 58 protrudes into an empty portion formed on the opposite side (left side) by forming the injection valve port 33 from which the tip of the 50 fuel injection valves 51 protrudes and the exhaust valve port 32o being biased to the right side A mouth 34 is formed.

As described above, the embodiment of the V-belt continuously variable transmission according to the present invention described in detail has the following effects.
As shown in FIG. 2, the fuel injection device 50 is attached to the upper side surface 23u, which is the side facing the main frame 4 in the cylinder head 23, and is arranged side by side with the intake passage 40 in the vehicle body width direction. The device 50 is covered with the existing intake passage 40, the main frame 4, and the cylinder head 23 and is protected from external force and scattered matter, and suppresses an increase in the size of the cylinder head 23 without providing a dedicated protective cover. A large weight of 20 can be avoided.

  As shown in FIGS. 3 and 4, the intake passage 40 is located at a position biased to one side in the vehicle body width direction with respect to the cylinder center vertical plane Sv perpendicular to the vehicle body width direction including the cylinder axis C of the cylinder 22c. Since the fuel injection device 50 is provided on the side opposite to the side where the intake passage 40 is biased, the intake passage 40 is provided at a position offset toward one side in the vehicle body width direction with respect to the cylinder center vertical plane Sv. As a result, the fuel injection device 50 can be arranged using the space generated on the side opposite to the side where the intake passage 40 is biased, and the increase in size of the cylinder head 23 can be suppressed.

  As shown in FIG. 5, the cylinder head 23 has one intake port 31 and one exhaust port 32, and the intake port 31 and the exhaust port 32 are formed on the ceiling surface 35 of the combustion chamber 30 of the cylinder head 23. An intake valve port 31o and an exhaust valve port 32o that are openings facing the combustion chamber 30 are formed so as to be biased to the opposite sides with respect to the cylinder center vertical plane Sv, and the intake valve port with respect to the cylinder center vertical plane Sv An injection valve port 33 from which the tip of the fuel injection valve 51 of the fuel injection device 50 protrudes is formed in an empty portion generated on the opposite side when 31o is biased to one side, and the exhaust valve port 32o is biased to one side. Thus, a plug port 34 from which the tip of the spark plug 58 protrudes is formed in an empty portion generated on the opposite side.

  Therefore, the ceiling surface 35 of the combustion chamber 30 of the cylinder head 23 has two openings, an intake valve port 31o and an exhaust valve port 32o, and two projecting ports, an injection valve port 33 and a plug port 34, in a space-efficient and compact manner. The cylinder heads 23 of the internal combustion engine having a small displacement can be suppressed in particular.

  As shown in FIGS. 2 to 4, the motorcycle 1 is open on the side opposite to the intake passage 40 of the fuel injection device 50 in the vehicle body width direction (right side). In the state where the internal combustion engine 20 is mounted, the fuel injection device 50 can be accessed from the opened side, and the fuel injection device 50 can be easily detached and is excellent in maintainability.

  As shown in FIGS. 2 and 3, the internal combustion engine 20 is supported by the main frame 4 in a posture in which the cylinder block 22 and the cylinder head 23 protrude forward from the crankcase 21, and the fuel injection device 50 includes the cylinder head 23. Since the fuel injection device 50 is sandwiched from above and below by the upper main frame 4 and the lower cylinder head 23, one side of the fuel injection device 50 is disposed in the intake passage. It is covered with 40 and protected from external forces and scattered objects, and the cylinder head 23 effectively protects against scattered objects such as flying stones from below.

  2 and 3, since the intake passage 40 extends upward from the upper side surface 23u of the cylinder head 23, the intake passage 40 and the fuel injection device 50 are connected to the vehicle body on the upper side surface 23u of the cylinder head 23. Since the intake passages 40 are arranged side by side in the width direction and are connected to the upper air cleaner 42, the fuel injection device 50 can be covered with the air cleaner 42 together with the main frame 4 from the external force from above. More effectively protected.

  As shown in FIG. 4, the main frame 4 is composed of a single frame member having a rectangular tube shape with a vertically long cross section. Therefore, the main frame 4 is rigid by extending the cross-sectional dimension of the frame member vertically. The spread in the vehicle body width direction can be suppressed while increasing

  As shown in FIG. 2, the main frame 4 tilts rearward and obliquely downward from the head pipe 3 at the front of the vehicle body and extends linearly, and then the inclination of the main frame 4 becomes gentle at a position where it passes through the fuel injection device 50. Therefore, the fuel injector 50 attached to the upper side surface 23u of the cylinder head 23 is bent obliquely behind the main frame 4 so that the inclination becomes gentle after the main frame 4 passes straight and diagonally downward. As a result, the fuel injection device 50 can be arranged with high space efficiency and can be effectively protected by the main frame 4.

Next, a fuel injection device arrangement structure for a small vehicle according to another second embodiment will be described with reference to FIG.
In the second embodiment, the left and right arrangements of the intake passage 40 and the fuel injection device 50 arranged in the vehicle body width direction on the upper side surface 23u of the cylinder head 23 are reversed in the above embodiment. There is no difference from the above embodiment except for the differences.

FIG. 7 is a rear view of the cylinder head 80 according to the second embodiment.
On the domed ceiling surface 95 of the combustion chamber 90 of the cylinder head 80, an intake valve port 91o that is an opening facing the combustion chamber 90 of the intake port 91 and an exhaust valve port that is an opening of the exhaust port 92 facing the combustion chamber 90 92o is formed, and an injection valve port 93 from which a tip from which fuel of the fuel injection valve 101 is injected projects and a plug port 94 from which the tip of the spark plug 102 projects are formed.

In the rear view of the cylinder head 80 in FIG. 7, the cylinder center vertical plane Sv is superimposed on the relative position with the cylinder head 80.
In the ceiling surface 95 of the combustion chamber 90 of the cylinder head 80, the intake valve port 91o and the exhaust valve port 92o are on the same side (right side) in the vehicle body width direction with respect to the cylinder center vertical plane Sv, unlike the above embodiment. It is formed at a biased position.

  Therefore, the intake passage 85 extends from the upper side surface 80u of the cylinder head 80 on the right side with respect to the cylinder center vertical plane Sv where the intake valve port 91o is biased, and the fuel injection device ( A fuel injection valve 101) is provided.

  On the ceiling surface 95 of the combustion chamber 90 of the cylinder head 80, the fuel injection valve 101 has an empty portion formed on the opposite side (left side) due to the intake valve port 91o being biased to the right side with respect to the cylinder center vertical plane Sv. An injection valve port 93 with a projecting tip is formed, and a plug port 94 with a projecting tip of the spark plug 102 is formed in an empty portion formed on the opposite side (left side) when the exhaust valve port 92o is biased to the right side. .

  Two relatively large openings, intake valve port 91o and exhaust valve port 92o, are formed to be biased to the right, and two relatively small projecting ports, injection valve port 93 and plug port 94, are formed in the left empty part. In addition, space-efficient and compact arrangement is achieved, and in particular, an increase in the size of the cylinder head of a small displacement internal combustion engine can be suppressed.

  As mentioned above, although the fuel injection device arrangement structure of the small vehicle according to the two embodiments according to the present invention has been described, the aspects of the present invention are not limited to the above-described embodiments, and are various within the scope of the gist of the present invention. Including those implemented in various embodiments.

  For example, the vehicle of the present invention is not limited to the motorcycle 1 of the embodiment, and can be applied to various small vehicles such as a scooter type, a three-wheeled vehicle, and a four-wheeled buggy vehicle.

DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 3 ... Head pipe, 4 ... Main frame, 16 ... Fuel tank,
20 ... Internal combustion engine, 21 ... Crank case, 22 ... Cylinder block, 23 ... Cylinder head, 25 ... Crankshaft, 30 ... Combustion chamber, 31 ... Intake port, 31o ... Intake valve port, 32 ... Exhaust port, 32o ... Exhaust valve 33, injection valve port, 34 ... plug port, 35 ... ceiling surface, 40 ... intake passage, 42 ... air cleaner,
DESCRIPTION OF SYMBOLS 50 ... Fuel injection apparatus, 51 ... Fuel injection valve, 52 ... Piping part, 52b ... Hose connection branch pipe, 53 ... Fuel pressure sensor, 54 ... Connector part, 59 ... Low pressure fuel supply pump, 58 ... Spark plug, 60 ... High pressure fuel Supply pump,
80 ... Cylinder head, 90 ... Combustion chamber, 91 ... Intake port, 91o ... Intake valve port, 92 ... Exhaust port, 92o ... Exhaust valve port, 93 ... Injection valve port, 94 ... Plug port, 95 ... Ceiling surface,
101 ... Fuel injection valve, 102 ... Spark plug.

Claims (8)

Fuel injector arrangement structure for a small vehicle in which an internal combustion engine (20) having a fuel injection device (50) for directly injecting fuel into a combustion chamber (30) of a cylinder head (23) is supported by a vehicle body frame (2) In
The main frame (4) extending rearward from the vehicle body front portion of the vehicle body frame (2) passes above the cylinder head (23),
The internal combustion engine (20) is supported by the main frame (4) in a posture in which a cylinder block (22) and a cylinder head (23) protrude forward from a crankcase (21),
An intake passage (40) for introducing intake air into the combustion chamber (30) is provided extending from the cylinder head (23),
The fuel injection device (50) is attached to an upper side surface (23u) facing the main frame (4) in the cylinder head (23), and is disposed below the main frame (4), and the intake air Arranged side by side in the vehicle width direction with the passage (40),
A fuel supply pump (60) for supplying fuel to the fuel injection device (50),
A discharge hose (68) extending from the fuel supply pump (60) and connected to the fuel injection device (50);
The discharge hose (68) is located between the internal combustion engine (20) and the main frame (4), and is disposed within a width in the vehicle body width direction of the internal combustion engine (20) in a vehicle plan view. The fuel injection device arrangement structure for a small vehicle   The fuel supply pump (60) is attached to the upper wall of the crankcase (21),
  The discharge hose (68) is connected to the fuel supply pump (60) so as to extend toward the front side, and is connected to the fuel injection device (50) so as to extend toward the rear side. The fuel injection device arrangement structure for a small vehicle according to claim 1. The intake passage (40) extends upward from an upper side surface (23u) of the cylinder head (23) and is connected to an upper air cleaner (42) attached to the main frame (4). The fuel injection device arrangement structure for a small vehicle according to claim 1 or 2 . The fuel injection for a small vehicle according to any one of claims 1 to 3, wherein the main frame (4) is formed of a single frame member having a rectangular tube shape whose section is a vertically long rectangle. Device arrangement structure. The main frame (4) is slanted downward and obliquely downward from the front of the vehicle body and extends linearly, and then bends so that the inclination becomes gentle at a position after passing through the fuel injection device (50). The fuel injection device arrangement structure for a small vehicle according to claim 4, The intake passage (40) is provided at a position biased to one side in the vehicle body width direction with respect to the cylinder center vertical plane (Sv) perpendicular to the vehicle body width direction including the cylinder axis (C) of the cylinder (22c). ,
6. The fuel injection for a small vehicle according to any one of claims 1 to 5, wherein the fuel injection device (50) is disposed on a side opposite to a side where the intake passage (40) is biased. Device arrangement structure. The cylinder head (23) has one intake port (31) and one exhaust port (32).
In the ceiling surface (35) of the combustion chamber (30) of the cylinder head (23), an intake valve port (31o) is an opening facing the combustion chamber (30) of the intake port (31) and the exhaust port (32). ) And the exhaust valve port (32o) are formed to be biased to the opposite sides with respect to the cylinder center vertical plane (Sv), and
The fuel injection valve (51) of the fuel injection device (50) is formed in an empty portion generated on the opposite side due to the intake valve port (31o) being biased to one side with respect to the cylinder center vertical plane (Sv). An injection valve port (33) with a protruding tip is formed, and a plug port from which the tip of the spark plug (58) protrudes into an empty portion formed on the opposite side due to the exhaust valve port (32o) being biased to one side The fuel injection device arrangement structure for a small vehicle according to claim 6, wherein (34) is formed. 8. The small vehicle (1) according to any one of claims 1 to 7, wherein a side opposite to the intake passage (40) of the fuel injection device (50) in the vehicle body width direction is opened. 2. A fuel injector arrangement structure for a small vehicle according to claim 1 .

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