JPH11287168A - In-cylinder injection engine - Google Patents

Abstract

(57) [Problem] An in-cylinder injection engine capable of avoiding problems such as difficulty in securing a space for disposing a boss portion and narrowing of a water cooling jacket by eliminating a dedicated boss portion for mounting a fuel injection valve. I will provide a. A fuel injection valve for directly injecting fuel into a cylinder.
5 is attached to the cylinder head 3 and a fuel rail 16 for supplying fuel to the fuel injection valve 15 is connected to the fuel injection valve 15.
In the in-cylinder injection engine 1, a support stay 16 b extending toward the cylinder head 3 is provided on the fuel rail 16, and the support stay 16 b is connected to the cylinder head 3.
And a valve pressing member 20 for pressing and fixing the fuel injection valve 15 to the cylinder head 3 is held between the support stay 16b and the cylinder head 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-cylinder injection engine and, more particularly, to an improvement in a fuel injection valve for directly injecting fuel into a cylinder and an improved mounting structure for a fuel rail for supplying fuel to the fuel injection valve.

[0002]

2. Description of the Related Art Recently, an in-cylinder injection engine which directly injects and supplies fuel into a cylinder (in a cylinder bore) has attracted attention as an engine which can be expected to increase output, improve fuel efficiency, and purify exhaust gas. ing. This type of direct injection engine has a structure in which a fuel injection valve for directly injecting fuel into a cylinder is mounted on a cylinder head, and a fuel rail for supplying fuel to the fuel injection valve is connected to the fuel injection valve. .

[0003] As a structure for mounting the fuel injection valve and the fuel rail to the cylinder head, there is a conventional structure described in, for example, Japanese Patent Application Laid-Open No. 8-313503. In this conventional structure, the fuel rail is disposed so as to cover the fuel introduction portion of the fuel injection valve, and a support stay formed so as to project in the direction perpendicular to the axis of the fuel rail is fixed to the cylinder head by bolting, and The pressing member for fixing the fuel injection valve is fixed to the cylinder head with bolts, and the front end of the pressing member presses the flange portion of the fuel injection valve.

[0004]

In the above conventional engine, a rail mounting boss for mounting the fuel rail to the cylinder head and a valve mounting boss for mounting the fuel injection valve to the cylinder head are separately provided on the cylinder head. Although the structure is adopted, there is a problem that it is difficult to secure a space for arranging these two bosses in the cylinder head. In addition, since the fuel rail and the fuel injection valve are separately fixed, the number of assembly steps is reduced. There is a problem that there are many.

In particular, when the fuel injection valve is provided on the intake port side portion of the cylinder head so that the injection port is opened in the combustion recess, the fuel injection valve is connected to the cylinder block at the intake port side on the cylinder block side. However, it is difficult to form the two bosses on the cylinder head because there is almost no empty space from the beginning.

When a rail mounting boss and a valve mounting boss are formed on the cylinder head, screw holes for mounting bolts are required. The boss for providing the screw holes is provided with a water cooling jacket in the cylinder head. Side, so that the water cooling jacket becomes narrower and the flow of the cooling water may deteriorate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. By eliminating a dedicated boss for mounting a fuel injection valve, it is difficult to secure a space for disposing the boss, and the water cooling jacket is narrow. It is an object of the present invention to provide an in-cylinder injection engine that can avoid such problems as becoming.

[0008]

According to a first aspect of the present invention, a fuel injection valve for directly injecting fuel into a cylinder is mounted on a cylinder head, and a fuel rail for supplying fuel to the fuel injection valve is provided on the fuel injection valve. In the connected direct injection engine,
The fuel rail is provided with a support stay extending toward the cylinder head, the support stay is fixedly fastened to the cylinder head by bolts, and a valve pressing member for pressing and fixing the fuel injection valve to the cylinder head is provided between the support stay and the cylinder head. It is characterized by being sandwiched by.

A second aspect of the present invention is characterized in that, in the first aspect, the support stay is provided so as to be adjacent to one side of the fuel injection valve in the cam axis direction.

According to a third aspect of the present invention, in the first aspect,
A pair of left and right support stays are provided adjacent to both sides in the cam axis direction with the fuel injection valve interposed therebetween, and both end portions of the valve pressing member are held by the left and right support stays in the cylinder head. It is characterized by having.

According to a fourth aspect of the present invention, there is provided a direct injection engine in which a fuel injection valve for directly injecting fuel into a cylinder is mounted on a cylinder head, and a fuel rail for supplying fuel to the fuel injection valve is connected to the fuel injection valve. Wherein the fuel rail is provided with a valve pressing stay extending toward the fuel injection valve, and the valve pressing stay presses a flange portion of the fuel injection valve when the fuel rail is mounted on a cylinder head.

According to a fifth aspect of the present invention, in the fourth aspect, a support stay is provided on the fuel rail so as to be adjacent to one side of the valve pressing stay in the cam axis direction, and the support stay is fixed to the cylinder head by bolting. The valve pressing stay presses the flange portion of the fuel injection valve.

The invention of claim 6 is characterized in that, in claim 4 or 5, the fuel injection valve and a portion of the fuel rail deviated in the cam axis direction are connected by a fuel supply pipe.

[0014]

According to the in-cylinder injection engine according to the first aspect of the present invention, the support stay provided on the fuel rail is fixedly fastened to the cylinder head by a bolt, and the fuel injection valve is fixed to the cylinder by the support stay and the cylinder head. Since the valve pressing member for pressing and fixing to the head is sandwiched, there is no need to provide a mounting boss dedicated to the fuel injection valve on the cylinder head,
Therefore, it is easy to secure a space for disposing the boss portion. Further, the fuel injection valve can be fixed to the cylinder head only by fixing the fuel rail to the cylinder head with the valve pressing member interposed therebetween, and the number of assembling steps can be reduced.

Further, since a mounting boss dedicated to the fuel injection valve is not required, the boss for providing the screw hole for the boss does not protrude into the water cooling jacket, and the water cooling jacket becomes narrower or cooler. Problems such as poor water flow can be avoided.

According to the second aspect of the present invention, since the support stay is provided adjacent to one side of the fuel injection valve in the cam axis direction, the positions of the fuel injection valve and the support stay in the direction perpendicular to the fuel rail axis are substantially the same. Because of the position, the space for disposing the support stay and the fuel injection valve in the direction perpendicular to the fuel rail axis can be reduced.

According to the third aspect of the present invention, since the pair of left and right support stays are disposed adjacent to both sides in the cam axis direction with the fuel injection valve interposed therebetween, the fuel rail of the support stay and the fuel injection valve is provided. In addition to requiring a small space in the direction perpendicular to the axis, the flange portion of the fuel injection valve can be evenly pressed by the valve pressing member, and the fuel injection valve can be securely fixed to the cylinder head.

According to the fourth aspect of the present invention, the fuel rail is provided with a valve pressing stay extending toward the fuel injection valve, and when the fuel rail is mounted on the cylinder head, the valve pressing stay is connected to the flange portion of the fuel injection valve. As in the first aspect of the present invention, it is possible to prevent the water cooling jacket from decreasing and secure the flow of cooling water, and to fix the fuel rail simultaneously with fixing the fuel rail. The assembly workability can be further improved without the necessity of interposing a member.

According to the fifth aspect of the present invention, a support stay is provided on the fuel rail so as to be adjacent to one side of the valve pressing stay in the cam axis direction, and when the support stay is fixed to the cylinder head by bolting, the valve stays. Since the pressing stay presses the flange portion of the fuel injection valve, the support stay, the valve pressing stay, and the fuel injection valve come at substantially the same position in the direction perpendicular to the fuel rail axis. In this case, a small space is required, and it is easy to secure an arrangement space.

According to the sixth aspect of the present invention, since the fuel injection valve and the portion of the fuel rail deviated in the cam axis direction are connected by the fuel supply pipe, the fuel rail is arranged close to the fuel injection valve. In addition, a large bending radius (radius of curvature) of the fuel supply pipe can be secured, the durability of the fuel supply pipe can be secured, and the flow resistance of the fuel can be reduced.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 9 are views for explaining a fuel injection type gasoline engine according to a first embodiment of the present invention, wherein FIG. 1 is a sectional side view, and FIG. 2 is an arrow II direction arrow in FIG. FIG. 3 is an arrow II direction arrow view of the cylinder head alone in FIG. 1, and FIG. 4 is an arrow in FIG.
FIGS. 5 and 6 are sectional views taken along lines VV and VI-VI in FIG. 2, and FIG. 7 is a schematic sectional view showing the mounting state of the fuel injection valve and the fuel rail in FIGS. FIG. 3 is a plan view and a cross-sectional side view showing a state where the fuel injection valve is mounted.

In the drawing, reference numeral 1 denotes a water-cooled four-cycle series 3
The engine 1 has a cylinder head 3 and a head cover 4 stacked on a cylinder block 2, a piston 5 is slidably inserted into a cylinder bore 2 a of the cylinder block 2, and the piston 5 is connected to a connecting rod. 6 is a schematic structure connected to a crankshaft (not shown).

The head 5a of the piston 5 projects in a pent roof shape, and a spray recess 5b into which fuel is injected and supplied from a fuel injection valve 15 described later is formed in the head 5a. When the piston 5 rises to the top dead center, the electrode 11a of the ignition plug 11 is located in the spray recess 5b.

In this embodiment, one of a pair of left and right intake ports (the left intake port in this embodiment) is closed by a switching valve 13a described later in a low intake air amount operation region such as an idling operation region. Air is introduced into the cylinder only from the intake port on the right side, and swirl (lateral vortex) is generated in the introduced air. Therefore, fuel injected and supplied into the spray recess 5b is supplied to the spray recess 5b.
It is biased against one side inside.

A combustion recess 3a, which forms a combustion chamber with the head 5a of the piston 5, is provided in the cylinder head 3 on the cylinder block side. In the combustion recess 3a,
Two intake valve openings 3b and two exhaust valve openings 3c are open. The intake valve opening 3b is led out to the front wall 3e of the cylinder head 3 by an intake port 3d, and the exhaust valve opening 3c
Is led out to the rear wall 3g by the exhaust port 3f.

The intake port 3d extends upward so that its axis Ci forms an angle of 40 to 60 degrees clockwise with respect to the cylinder axis C, and the exhaust port 3f has its axis Ce aligned with the cylinder axis C. 75 counterclockwise
It extends substantially horizontally to form an angle of up to 95 °.

The external connection port 3d 'of the intake port 3d is provided with an intake system 13 and the external connection port 3d of the exhaust port 3g.
The exhaust system 14 is connected to g '. The intake system 13 includes a connection pipe 13b having a switching valve 13a for opening and closing the intake port 3d on the left side when viewed from the front of the vehicle, an intake pipe 13c, and a surge tank 13d in the external connection port 3d '.
And an air cleaner (not shown) are sequentially connected. 3p is a fixing bolt hole for the connection pipe 13b. The exhaust system 14 has a configuration in which an exhaust manifold 14a, an exhaust pipe 14b, a muffler (not shown) and the like are connected to the external connection port 3g '.

Each of the intake valve openings 3b has an intake valve 7
An exhaust valve 8 is arranged in each of the exhaust valve openings 3c, and the intake valve 7 and the exhaust valve 8 are driven to open and close by an intake valve operating mechanism 9 and an exhaust valve operating mechanism 10. The intake-side and exhaust-side valve operating mechanisms 9 and 10 urge the intake valve 7 and the exhaust valve 8 to the closing side by valve springs 9a and 10a, and intake air through lifters 9b and 10b mounted on the upper end. , Exhaust camshaft 9
It is configured to be opened and closed by c and 10c.

The fuel supply device 12 of the engine 1 includes a fuel injection valve 15 disposed one by one for each cylinder, one fuel rail 16 common to the three fuel injection valves 15, The fuel supply system includes a high-pressure fuel pump 27 for supplying high-pressure fuel to the fuel cell 16 and a fuel pipe (not shown).

The fuel injection valve 15 is disposed at the center (boundary portion) of the left and right intake ports 3d, 3d in the cam axis direction when viewed from the front of the vehicle, and when viewed in the cam axis direction, its axis B is aligned with the intake port 3d. Are arranged substantially parallel to the axis Ci of the intake port 3 and closer to the axis Ci of the intake port 3d. That is, the portion near the boundary between the bottom walls of the left and right intake ports 3d, 3d is formed so as to bite into the intake port, and the fuel injection is made into the arrangement space a obtained by providing the bite portion 3n. A valve 15 is arranged.

In the present embodiment, the above-described arrangement in which the fuel injection valve 15 is displaced toward the intake port 3d side is employed, so that the fuel injection valve 15 is connected to the intake port 3d while the cylinder head 3 is made compact around the fuel injection valve. And the injection nozzle can face the combustion recess 3a. By the parallel arrangement of the fuel injection valve 15 and the intake port 3d, the fuel and the air can flow into the cylinder in the same direction, so that the stratification of the fuel and the air can be realized, and the lean air-fuel ratio combustion can be achieved. It can be stabilized.

The fuel injection valve 15 has a small-diameter cylindrical nozzle portion 15a having an injection port, a large-diameter cylindrical main body portion 15b containing an electromagnetic coil and the like, and a cylindrical shape to which the fuel rail 16 is connected. And a fuel introduction section 15c. Further, a step portion between the large-diameter main body portion 15b and the fuel introduction portion 15c is a flange portion 15d for pressing and fixing the fuel injection valve 15 to the engine side, and furthermore, the main body portion 15b and the nozzle portion are formed. A tapered valve-side positioning portion 15e is formed at the boundary with 15a.

The nozzle portion 15a is inserted into a nozzle hole 3h of the valve mounting hole formed in the cylinder head 3 and opening into the combustion recess 3a, and its tip is located near the inner surface of the combustion recess 3a. Nozzle part 15a and nozzle hole 3
The space between h is sealed with a seal ring 15g. Further, the main body 15b is inserted into the holding hole 3i of the valve mounting hole, and the valve side positioning part 15e is in contact with a tapered head side positioning part 3j formed on the cylinder head. Thus, the fuel injection valve 15 is positioned in the valve mounting hole, and the combustion pressure is prevented from escaping to the outside.

The fuel rail 16 is a round pipe extending parallel to the camshaft.
When viewed in the direction of the axis B of the fuel injection valve 15 (see FIG. 4), the fuel introduction portion 15c of the fuel injection valve 15 is separated to a position where the fuel introduction portion 15c is not hidden under the fuel rail 16. Are located.

The fuel rail 16 is integrally formed with three fuel supply portions 16a and three support stay portions 16b. The fuel supply section 16a is connected to the fuel injection valve 15
Is extended rearward toward the engine front wall 3e so as to cover the fuel introduction portion 15c, and a fitting hole 16c formed at an extended end of the fuel supply portion 16a is formed in the fuel introduction portion 15c of the fuel injection valve 15. The introduction portion 15c and the fitting hole 1 are fitted.
6c is sealed with an O-ring 15f. In addition, 16e is the fuel rail 16 and the fitting hole 16c.
And a communication hole for communicating

The support stay 16b extends rearward toward the front wall 3e of the engine, and is attached to a rail mounting boss 3m formed on the cylinder head 3 and also serving as a fuel injection valve mounting boss. Flange 16 at the tip
d is a bolt 22 with a leaf spring (valve pressing member) 20 interposed therebetween.
It is tightened and fixed. The fuel injection valve 15 is pressed and fixed to the cylinder head 3 by the leaf spring 20.

The fixing bolts 22 of the fuel rail 16 are screwed in parallel with the injection valve axis B of the fuel injection valve 15 and counteracted by a straight line D parallel to the cam axis passing through the injection valve axis B by D1. The fuel injection valve 15 is disposed so as to be deviated toward the port 3 d and adjacent to the right side of the fuel injection valve 15.

Here, when the fuel injection valve 15 is inserted into the holding hole 3i of the cylinder head 3 and the valve side positioning part 15e is brought into contact with the head side positioning part 3j, the flange part 15d of the main body part 15b is formed. The difference H between the height of the rail and the height of the rail mounting boss 3m on the cylinder head 3 side slightly varies due to a machining error for each engine, but falls within a standard dimension ± tolerance. As described above, the leaf spring 20 as a valve pressing member is provided on the rail mounting boss 3m.
Is pressed and fixed, and the peripheral portion 2 at the tip of the leaf spring 20 is fixed.
0c presses the flange portion 15d so that the fuel injection valve 15 is connected to the cylinder head 3c.
It is fixed to.

The leaf spring 20 is connected to the support stay 16b.
Is pressed by the flange portion 16d of the
6d has high rigidity, so that the left and right tip portions 20c ', 20 of the arc-shaped peripheral portion 20c of the leaf spring 20 are formed.
The pressing force is applied uniformly to c '.

The leaf spring 20 has a thickness of 0.5 to 3.0 m.
m is preferably made of a spring steel plate of about 1.5 mm, and is fixed by the flange portion 16d in plan view.
a and a pressing portion 20 protruding forward from the flange portion 16d.
b. The pressing portion 20b of the leaf spring 20 is bent downward along the line of the leading edge 16d 'of the flange portion 16d. The bending amount A of the pressing portion 20b is such that the difference H between the height of the flange portion 15d of the fuel injection valve 15 and the height of the rail mounting boss 3m on the cylinder head side has shifted to the (reference size + tolerance) side. In other words, when the difference dimension H is larger than the reference dimension, the leaf spring 20 undergoes elastic deformation, and when the difference dimension H swings to the (reference dimension-tolerance) side, that is, the difference dimension H When H becomes smaller than the reference size, the leaf spring 20 is set to undergo elastic deformation and further to cause plastic deformation. Thus, the fuel injection valve 15 can be securely fixed to the engine side, and the leaf spring 20 of the present embodiment is 0.5 to 3.0 m.
m, so that even if the leaf spring 20 is tightened to such an extent that the above-mentioned plastic deformation occurs, an excessive pressing force enough to damage the fuel injection valve 15 itself does not act.

In the case of the present embodiment, the bending amount A is specifically set, for example, in the following manner. That is, when the fuel injection valve 15 is inserted into the holding hole 3i and the valve side positioning part 15e is brought into contact with the head side positioning part 3j, the height of the flange part 15d and the height of the rail mounting boss part 3m are reduced. The difference dimension H is set to fall within a reference dimension of 0.3 mm ± 0.3 mm. The bending amount A is 0.95 ±
It is set to 0.25 mm. Therefore, the difference dimension H is 0 mm when the tolerance swings to the negative maximum value. In this case, the leaf spring 20 is deformed by about 0.95 mm, and is plastically deformed by about 0.4 mm. In addition,
The dimensions L1, L2, L3 in FIG.
mm.

According to the direct injection gasoline engine of this embodiment, the support stay 1 of the fuel rail 16 is provided.
Since the spring plate 20 for fixing the fuel injection valve is sandwiched and fixed between the flange portion 16d of the cylinder head 6b and the rail mounting boss portion 3m of the cylinder head 3, a dedicated boss portion for fixing the fuel injection valve can be eliminated. Accordingly, the necessary arrangement space can be reduced, the water cooling jacket can be enlarged by the amount that the bolt hole for the valve mounting boss is unnecessary, and the flow of the cooling water can be improved.

If the fuel rail 16 is fixed to the cylinder head 3 with the leaf spring 20 interposed, the fuel injection valve 15 can be attached at the same time, so that the number of assembling steps can be reduced and the assembling workability can be improved.

When viewed in the direction of the injection valve axis B, the fuel rail 16 is offset from the intake port 3d with the fuel injection valve 15 interposed therebetween.
The side rail mounting boss 3m is formed in a portion facing outward from between the intake port 3d and the fuel rail 16, so that the position of the fuel injection valve 15 and the mounting position of the fuel rail support stay 16b on the cylinder head side are reduced. Since the fuel rail 16 is located at substantially the same position in the direction perpendicular to the axis, the bending moment due to the reaction force of the fuel pressure is reduced, and the problem of increasing the weight to increase the rigidity of the support stay 16b can be avoided.

The support stay 16b and the fuel injection valve 1
5 is substantially the same as the position in the direction perpendicular to the axis from the fuel rail 16, so that the space required to dispose the support stay 16b and the fuel injection valve 15 in the direction perpendicular to the axis can be reduced. The fuel injection valve 15 is connected to the intake port 3d while making the surroundings compact.
Therefore, the degree of freedom in layout can be increased, for example, by arranging in substantially parallel with and close to the intake port 3d.

Further, since the fuel injection valve 15 can be disposed substantially parallel to the intake port 3d, fuel and air can flow into the cylinder in the same direction to promote stratification of fuel and air, and combustion at a lean air-fuel ratio can be achieved. Can be stabilized.

When viewed in the direction of the injection valve axis B, a rail mounting boss 3m is provided on the right side of the fuel injection valve 15 for fixing the fuel rail 16 to the cylinder head 3 with bolts.
And the rail mounting boss 3m is connected to the intake port 3
Since the fuel rail 16 faces outward from between d and the fuel rail 16, the fuel rail 16 itself does not hinder the mounting operation of the fuel rail 16, and the mounting workability is improved.

At the boundary between the pair of left and right intake ports 3d, 3d, an arrangement space a is provided so as to bite into the inside of the intake port 3d.
5, the fuel injection valve 15 can be arranged substantially parallel to the intake port 3d while making the area around the fuel injection valve 15 of the cylinder head 3 compact, and air and fuel are supplied into the cylinder in the same direction. To promote stratification of air and fuel, stabilize lean air-fuel ratio combustion, improve fuel efficiency,
It can promote purification of exhaust gas.

Further, since the fuel rail mounting bolt 22 is screwed in a direction parallel to the injection valve axis B, it is possible to avoid problems such as a tool hitting the fuel rail 16 when the bolt 22 is screwed in, thereby further improving the assembling workability. Can be improved.

FIGS. 11 to 13 are views for explaining a second embodiment according to the third aspect of the present invention. This embodiment is an example in which a pair of left and right support stays is provided, and the same reference numerals in FIGS. 1 to 10 denote the same or corresponding parts.

A pair of left and right support stays 16b, 16b are integrally formed on the fuel rail 16 so as to be adjacent to both sides of the fuel injection valve 15 in the cam axis direction, and flange portions 16d of the both support stays 16b are provided. This presses and fixes one leaf spring (valve pressing member) 25. This leaf spring 2
5 is made of a spring steel plate having a thickness of 0.5 to 3.0 mm, preferably about 1.5 mm, and a fixing portion 25a pressed by the pair of left and right flange portions 16d, 16d in plan view, and the flange portion. 16d, pressing portion 25b located between 16d
It has. The pressing portion 25b is connected to the flange 16
d is bent downward along the line of the leading edge 16d '. The bending amount A of the pressing portion 25b is such that the difference H between the height of the flange portion 15d of the fuel injection valve 15 and the height of the rail mounting boss 3m on the cylinder head side swings to the (reference size + tolerance) side. In this case, the leaf spring 25 is elastically deformed in the fixed state of the injection valve, and when it swings to the (reference dimension−tolerance) side, the plate spring 25 is elastically deformed in the fixed state of the injection valve, and furthermore, plastic deformation is generated. This is the same as in the first embodiment.

In the second embodiment, since both ends of the leaf spring 25 are pressed by the pair of left and right flange portions 16d, the flange portions 15d of the fuel injection valve 15 are surely made uniform by the leaf springs 25. The pressing force can be applied, and the fuel injection valve 15 can be reliably fixed to the cylinder head 3.

FIGS. 14 to 16 are views for explaining a third embodiment according to the fourth to sixth aspects of the present invention. The third embodiment is an example in which a fuel injection valve pressing member is integrally formed on a fuel rail itself, and the same reference numerals in FIGS. 1 to 13 denote the same or corresponding parts.

The fuel rail 16 is formed with three valve pressing stays 16h and two supporting stays 16i so as to be adjacent to each other. Support stay 1 on the left side of FIG.
6i is a valve pressing stay 1 of the fuel injection valve 15 of the leftmost cylinder.
6h, and the right support stay 1
6i is disposed at the center of the remaining two cylinders. By fixing each of the support stays 16i to the rail mounting boss 3m of the cylinder head 3 with bolts 22, each of the valve pressing stays 16h is connected to the flange 1 of each fuel injection valve 15.
5d is pressed.

A disc spring 15h is interposed between the valve pressing stay 16h and the flange 15d.
The disc spring 15h has the same function as the leaf springs 20, 25 in the first and second embodiments. By inserting the disc spring 15h, the flange portion 15 of the fuel injection valve 15 is provided.
The fuel injection valve 15 can be securely fixed to the cylinder head without absorbing an excessive pressing force on the fuel injection valve 15 by absorbing the tolerance of the height difference between the height d and the rail mounting boss 3m. it can.

The fuel introduction section 1 of each fuel injection valve 15
5c is the joint 2 at the downstream end of the fuel supply pipe 26.
6a is connected by screwing. The upstream end of each fuel supply pipe 26 is connected by a joint 26b to a portion of the fuel rail 16 deviated in the cam shaft direction by E from each fuel injection valve.

In the third embodiment, the fuel rail 1
6 is provided with a supporting test portion 16i and a valve pressing stay portion 16h. When the supporting stay portion 16i is attached to the cylinder head 3, each of the valve pressing stay portions 16h is connected to a flange of each of the fuel injection valves 15 via a disc spring 15h. Since the portion 15d is pressed, the water cooling jacket can be prevented from decreasing and the flow of cooling water can be secured, and the fuel injection valve 15 can be fixed at the same time when the fuel rail 16 is fixed to the engine side. Properties can be further improved.

Since the support stay 16i and the valve pressing stay 16h are provided adjacent to each other in the cam axis direction, the support stay 16i, the valve pressing stay 16h, and the fuel injection valve 15 are perpendicular to the fuel rail axis. Since they are located at substantially the same position in the direction, the space in the direction perpendicular to the axis of the fuel rail can be reduced, and the arrangement space can be easily secured.

Further, since each of the fuel injection valves 15 and the portion of the fuel rail 16 deviated in the cam axis direction are connected by the fuel supply pipe 26, the fuel rail 16 is arranged close to the fuel injection valve 15. In addition, a large bending radius (radius of curvature) of the fuel supply pipe 26 can be secured, the durability of the fuel supply pipe 26 can be secured, and the fuel flow path resistance can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional side view of a direct injection gasoline engine according to a first embodiment of the present invention.

FIG. 2 is a front view as seen from the direction of arrow II in FIG. 1;

FIG. 3 is a front view of the cylinder head unit of FIG. 1 viewed from the direction of arrow II.

FIG. 4 is a front view around the fuel rail as viewed from the direction of arrow IV in FIG. 1;

FIG. 5 is a sectional view taken along line VV of FIG. 2;

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 2;

FIG. 7 is a schematic diagram showing a mounting state of a fuel injection valve and a fuel rail of the engine.

FIG. 8 is a plan view showing a state in which a fuel injection valve is attached to the engine.

FIG. 9 is a sectional side view showing a state in which a fuel injection valve is attached to the engine.

FIG. 10 is a front view of a direct injection engine according to a second embodiment of the present invention.

FIG. 11 is a schematic cross-sectional side view showing a mounting state of a fuel rail and a fuel injection valve of the second embodiment.

FIG. 12 is a plan view of a fuel injection valve mounting leaf spring of the engine according to the second embodiment.

FIG. 13 is a side view of the leaf spring.

FIG. 14 is a front view of a direct injection engine according to a third embodiment of the present invention.

FIG. 15 is a sectional view taken along line XV-XV of FIG. 17;

16 is a sectional view taken along line XVI-XVI in FIG. 17;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 In-cylinder injection engine 3 Cylinder head 15 Fuel injection valve 15d Flange part 16 Fuel rail 16b, 16i Support stay 16h Valve pressing stay 20, 25 Leaf spring (valve fixing member) 26 Fuel supply pipe

Claims (6)

[Claims] 1. An in-cylinder injection engine in which a fuel injection valve for directly injecting fuel into a cylinder is attached to a cylinder head, and a fuel rail for supplying fuel to the fuel injection valve is connected to the fuel injection valve. A support stay extending toward the cylinder head is provided, the support stay is fixed to the cylinder head by bolting, and a valve pressing member for pressing and fixing the fuel injection valve to the cylinder head is sandwiched between the support stay and the cylinder head. An in-cylinder injection engine characterized in that: 2. The direct injection engine according to claim 1, wherein the support stay is provided so as to be adjacent to one side of the fuel injection valve in the cam axis direction. 3. The device according to claim 1, wherein a pair of left and right stays are provided on both sides in the cam axis direction with the fuel injection valve interposed therebetween, and both ends of the valve pressing member are left and right. An in-cylinder injection engine characterized by being held between a cylinder head by a right support stay. 4. An in-cylinder injection engine in which a fuel injection valve for directly injecting fuel into a cylinder is mounted on a cylinder head, and a fuel rail for supplying fuel to the fuel injection valve is connected to the fuel injection valve. And a valve pressing stay extending toward the fuel injection valve, wherein the valve pressing stay presses a flange portion of the fuel injection valve when the fuel rail is mounted on a cylinder head. 5. The valve pressing stay according to claim 4, wherein a supporting stay is provided on the fuel rail so as to be adjacent to one side of the valve pressing stay in the cam axis direction, and the supporting stay is fixed to a cylinder head by bolting. Presses a flange portion of the fuel injection valve. 6. An in-cylinder injection engine according to claim 4, wherein said fuel injection valve and a portion of said fuel rail deviated in the cam axis direction are connected by a fuel supply pipe.