JPH11294302A - Fuel injection valve mounting structure of cylinder fuel injection engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve mounting structure of a cylinder fuel injection engine, which absorbs dimensional tolerance between a fuel injection valve and a valve mounting hole, can surely mount the fuel injection valve to the cylinder head without applying excessive pressing force, and can provide excellent assembly operating performance with no strict torque management required. SOLUTION: A fuel injection valve 15 is inserted in and disposed to a valve mounting hole which is so formed as to be opened to the inside of a combustion chamber, when the valve side position fixing part 15e of the fuel injection valve 15 abuts against the head side position fixing part 3j of the valve mounting hole, the flange part 15d of the fuel injection valve 15 is so positioned as to be lower than a valve mounting boss part 3k, and furthermore, the difference H in dimension (reference dimension ± tolerance) between the flange part 15 and the valve mounting boss part 3k, is so made as to be H>=0, and a leaf spring (valve pressing member) 20 is provided, which is formed out of a thin plate having both a stationary part and a pressing part having been folded by a specified amount, the stationary part is fixed to the valve mounting boss part 3k, and the fuel injection valve 15 is thereby fixed to the cylinder head 3 by fixing the stationary part to the valve mounting boss part 3k, and pressing the flange part 15d by means of the pressing part.

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 improved mounting structure of a fuel injection valve for directly injecting fuel into a cylinder.

[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 on a cylinder head, a structure disclosed in, for example, Japanese Patent Application Laid-Open No. H8-3125 is known.
No. 03 is disclosed. This conventional structure,
The fuel injection valve is provided with a flange portion and a sealing surface, and the upper surface of the flange portion is pressed by a high-rigidity valve pressing member fixed to the cylinder head to bring the lower surface of the flange portion into contact with the cylinder head side. The fuel injection valve is positioned and fixed to the cylinder head, and a gasket that is elastically compressively deformable is interposed between the sealing surface of the fuel injection valve and the sealing surface of the valve mounting hole of the cylinder head. It is configured to absorb the processing tolerance between the mounting hole and the pressing member.

[0004]

However, in the above-mentioned conventional engine, the fuel injection valve is pressed and fixed to the cylinder head by a high-rigidity pressing member. Therefore, the fuel injection valve itself and a valve mounting hole of the cylinder head are provided. There is a problem that the pressing force applied to the fuel injection valve greatly changes depending on the dimensional tolerance between the fuel injection valve and the fuel injection valve.

In the above-mentioned conventional engine, the dimensional tolerance is absorbed by elastic compression deformation of the gasket. However, the elastic compression change of the gasket is limited. Is difficult to completely absorb. Further, in the above-described conventional engine, the valve pressing member is formed of an elastic body, and the elastic force is applied to the fuel injection valve by adjusting the screwing amount of the mounting bolt of the valve pressing member to the engine side. In general, strict torque control using a special tool is necessary for the adjustment of the screwing amount, and there is a problem that the assembling workability is low.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a simple structure to absorb a dimensional tolerance between a fuel injection valve and a valve mounting hole on a cylinder head side, thereby ensuring the fuel injection valve. To provide a fuel injection valve mounting structure for a direct injection engine that can be mounted on a cylinder head quickly and without exerting an excessive pressing force, and does not require strict torque control or the like and has good assembling workability. Is an issue.

[0007]

According to a first aspect of the present invention, there is provided a fuel injector for a direct injection engine having a fuel injection valve for directly injecting fuel into a cylinder, and a fuel rail for supplying fuel to the fuel injection valve. In the injection valve mounting structure, the fuel injection valve is inserted and disposed in a valve mounting hole formed in the cylinder head so as to open into the combustion chamber, and the valve-side positioning portion formed in the fuel injection valve is connected to the valve mounting hole. When the fuel injection valve is brought into contact with the head-side positioning portion formed in the above, the difference between the flange portion of the fuel injection valve and the valve mounting boss portion (standard dimension) is lower than the valve mounting boss portion. (± tolerance) H is set to satisfy H ≧ 0, a thin plate valve pressing member having a fixed portion and a pressing portion bent by a predetermined amount from the fixed portion is provided, and the fixed portion is mounted on a cylinder head valve. After fixing to the mounting boss, press It is characterized in that to fix the fuel injection valve by pressing the flange portion to the cylinder head by parts.

According to a second aspect of the present invention, in the first aspect, the pressing member is plastically deformed in a direction opposite to the bending direction when the fuel injection valve is fixed.

According to a third aspect of the present invention, in the second aspect, the valve pressing member includes a pressing portion for pressing two points on a straight line passing through the center of the annular flange portion of the fuel injection valve; And a fixing portion extending outward in the radial direction.The pressing portion is bent toward the flange portion side, and the amount of bending is when the tolerance of the reference dimension is a positive side. It is characterized in that it is set so as to generate elastic deformation, and further generate plastic deformation when it is on the negative side.

According to a fourth aspect of the present invention, in the second or third aspect, the valve pressing member has a fixing portion extending obliquely outward in the radial direction from one end of the pressing portion, and the valve pressing member is provided on the fixing portion. The valve mounting boss portion is bolted and fixed with a washer member having higher rigidity than the member, and the washer member extends to the other end of the pressing portion and extends from one end to the other end of the pressing portion. It is characterized in that it has an extension portion for applying a pressing force evenly across it.

According to a sixth aspect of the present invention, in the second or third aspect, the valve pressing member has a fixing portion extending symmetrically radially outward from both ends of the pressing portion. It is characterized in that the fixing portion is bolted and fixed to a valve mounting boss formed on both sides of the fuel injection valve.

[0012]

According to the fuel injection valve mounting structure of the direct injection engine according to the first aspect of the present invention, the fuel injection valve is mounted on the cylinder head by inserting the fuel injection valve into the valve mounting hole. The side positioning portion is brought into contact with the head-side positioning portion, and the flange portion of the fuel injection valve is fixed to a thin plate valve pressing member attached to the cylinder head to thereby lower the fuel injection valve from the fixing portion of the valve pressing member. The flange portion is pressed by the bent pressing portion, and the fuel injection valve is fixed to the cylinder. In this case, the dimensional tolerance between the flange portion of the fuel injection valve and the valve mounting boss portion of the cylinder head is absorbed by the elastic deformation of the thin plate pressing member (leaf spring).

According to the second aspect of the present invention, the pressing portion of the valve pressing member is elastically deformed and further plastically deformed.
When the dimensional tolerance is large, the elastic deformation is absorbed in the process of further plastic deformation. Further, since the valve pressing member is made of a thin plate, an excessive pressing force does not act on the fuel injection valve even if the pressing force is increased to such an extent that the thin plate is plastically deformed.

In the present invention, even if the mounting bolt is tightened to such an extent that the valve pressing member is plastically deformed according to the above-mentioned dimensional tolerance, excessive pressing force does not act on the fuel injection valve. It is not necessary to perform strict torque control as in the case where the valve pressing member made of a highly rigid and elastic body is pressed to the extent that a predetermined elastic force can be obtained, so that the assembling workability is good.

According to a third aspect of the present invention, the valve pressing member is
The fuel injection valve is made of a spring steel plate having a pressing portion for pressing a substantially half portion of an annular flange portion of the fuel injection valve, and a fixed portion extending radially outward from the pressing portion, and the pressing portion is formed on the side of the flange portion. And the amount of bending is set such that when the tolerance of the reference dimension is on the positive side, elastic deformation occurs, and on the negative side, further plastic deformation occurs. The deformation absorbs the dimensional tolerance, and the fuel injection valve can be securely fixed by simple operation without strict torque control and without applying excessive pressing force.

According to the fourth aspect of the present invention, the valve pressing member has a fixed portion extending obliquely outward in the radial direction from one end of the pressing portion, that is, a cantilever type. The valve mounting member is bolted and fixed to the valve mounting boss with a washer member having higher rigidity than the pressing member and having an extension extending to the other end of the pressing portion. The pressing force can be applied uniformly from one end to the other end of the pressing portion, and the fuel injection valve can be securely fixed to the cylinder head.

According to the fifth aspect of the present invention, the valve pressing member has a fixing portion extending symmetrically in a radially outward direction from both ends of the pressing portion. The pressing force can be applied evenly,
The fuel injection valve can be securely fixed to the cylinder head.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 10 are views for explaining a fuel injection type gasoline engine according to a first embodiment of the present invention. FIG. 1 is a sectional side view, and FIG. 2 is a direction of an arrow II in FIG. FIG. 3 is a view of the cylinder head alone in FIG. 1 as viewed in the direction of arrow II, FIG. 4 is a view of FIG. 1 as viewed in the direction of arrow IV, and FIGS.
8, VI-VI, VII-VII sectional views, FIG. 8 is a schematic sectional view showing the mounting state of the fuel injection valve and the fuel rail, FIG. 9 and FIG. FIG.

In the drawing, 1 is 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 has a recess 5b into which fuel is injected and supplied from a fuel injection valve 15 described later. 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 to be 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 for each cylinder, one fuel rail 16 common to the three fuel injection valves 15, and a fuel rail 16. 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, since the above-described fuel injection valve 15 is displaced toward the intake port 3d side, 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 the tip thereof 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 hole-shaped head side positioning part 3j formed in 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 stay portions 16b. The fuel supply portion 16a extends rearward toward the engine front wall 3e so as to cover the fuel introduction portion 15c of the fuel injection valve 15, and a fitting hole 16c formed at an extended end of the fuel supply portion 16a. Are fitted in the fuel introduction part 15c of the fuel injection valve 15, and the introduction part 15c and the fitting hole 16c
Is sealed with an O-ring 15f. In addition,
Reference numeral 16e denotes a communication hole for communicating the fuel rail 16 with the fitting hole 16c.

The stay 16b is provided on the front wall 3 of the engine.
e, a flange 16d at the tip of the stay 16b is bolted to a rail mounting boss 3m on the engine side formed on the cylinder head 3 so as to protrude in the direction of the axis B of the fuel injection valve 15 on the cylinder head 3. 22 is fixed. The fuel rail fixing bolt 22 and a fuel injector mounting bolt 19 described later are screwed in parallel with the injector axis B of the fuel injector 15 and are straight lines D parallel to the cam axis passing through the injector axis B. And D1 and D2 from the intake port 3d side, and are disposed on both sides 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 cylinder head 3 and the height of the valve mounting boss 3k on the side of the cylinder head 3 slightly varies due to a machining error for each engine, but falls within a reference dimension ± tolerance. A leaf spring 20 as a valve pressing member is pressed and fixed to the valve mounting boss 3k with a mounting bolt 19 over a washer member 21.
The left and right tip portions 20c 'press the flange portion 15d, whereby the fuel injection valve 15 is fixed to the cylinder head 3.

The leaf spring 20 and the washer member 21 are fixed by brazing.
A fixing portion 21 made of a high-rigidity steel plate thicker than the plate spring 20 (preferably 3 mm or more in thickness) and fixed by bolts 19
a, a contact edge 20 formed in an arc shape of the leaf spring 20
c and left and right distal end portions 20c ', 20c'.

The leaf spring 20 and the washer member 21
It is also possible to adopt a method in which brazing is not performed, whereby the brazing step can be omitted. In the case where this method is adopted, the cylinder head 3 is moved as shown by a two-dot chain line in FIG.
A protruding portion P for positioning is provided on the
Of the pressing portion 20b of the fuel injection valve 15 (a point on the line R passing through the center of the fuel injection valve). be able to.

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 has a fixing portion 20a having the same shape as the washer member 21 in plan view and a pressing portion 20b protruding forward from the washer member 21. The pressing portion 20b of the leaf spring 20 is bent downward at the line of the leading edge 21c of the washer member 21. The bending amount A of the pressing portion 20b
The difference H between the height of the flange portion 15d of the fuel injection valve 15 and the height of the valve mounting boss 3k on the cylinder head side swings to the (reference dimension + tolerance) side, that is, the difference dimension H is based on If it becomes larger than the size, the leaf spring 20
When the fuel injection valve 15 is fixed in the normal state, the leaf spring 20 is elastically deformed, and the difference dimension H swings to the (reference dimension−tolerance) side, that is, the difference dimension H becomes the reference dimension. When it becomes smaller, the leaf spring 20 is set to be elastically deformed and further to be plastically deformed. Accordingly, the fuel injection valve 15 can be securely fixed to the engine side by absorbing the dimensional tolerance, and the leaf spring 20 of the present embodiment is made of a thin plate having a thickness of about 0.5 to 3.0 mm. Even if the leaf spring 20 is tightened, no excessive pressing force enough to cause damage to the fuel injection valve 15 is applied.

Note that the bending amount A of the leaf spring 20 is
Even when the difference dimension H swings to the (reference dimension + tolerance) side, that is, when the difference dimension H becomes larger than the reference dimension, the leaf spring 20 is set to undergo elastic deformation and further plastic deformation. May be. The present invention includes the case where the amount of bending is set in this way.

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 valve mounting boss part 3k are reduced. The difference dimension H is set to be within a standard dimension 0.3 mm ± tolerance 0.3 mm. The bending amount A is 0.95 ±
It is set to 0.25 mm. Therefore, the height difference dimension H becomes 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.
The dimensions L1, L2, L3 in FIG. 9 are set to, for example, about 16, 7, 20 mm, respectively.

According to the direct injection gasoline engine according to the present embodiment, in order to mount the fuel injection valve 15 to the cylinder head 3, the fuel injection valve 15 is inserted into the valve mounting hole and the valve side positioning section 15e is mounted. The flange portion 15d of the fuel injection valve 15 is fixed to the head side positioning portion 3j by being pressed against the thin plate leaf spring 20 mounted on the cylinder head 3 by tightening the mounting bolt 19. In this case, the dimensional tolerance between the flange portion 15d of the fuel injection valve 15 and the valve mounting boss portion 3k of the cylinder head 3 is absorbed by the elastic deformation of the thin plate spring 20, and when the dimensional tolerance is large. Is absorbed in the process in which the leaf spring 20 elastically deforms and further plastically deforms. And the leaf spring 20
Is made of a thin plate, no excessive pressing force acts on the fuel injection valve even if the pressing force is increased to such an extent that plastic deformation occurs in the thin plate.

Further, no problem occurs even if the leaf spring 20 is tightened by the mounting bolt 19 to such an extent as to cause plastic deformation in accordance with the above-mentioned dimensional tolerance. It is not necessary to strictly control the torque as in the case where the pressing is performed to such an extent that the elastic force can be obtained, so that the assembling workability is good.

For example, in the present embodiment, the leaf spring 20 is made of a spring steel plate having a thickness of 1.0 to 3.0 mm, and the reference dimension is set so that the flange 15d is lower than the valve mounting boss 3k. .3 mm. In this case, when the tolerance becomes negative (for example, -0.3 mm), the difference H becomes smaller than the reference dimension (for example, 0 mm),
When the leaf spring 20 is pressed by tightening the mounting bolts 19, the leaf spring 20 made of a thin plate is elastically deformed and further plastically deformed, for example, by about 0.4 mm, and can be easily operated without strict torque control. The fuel injection valve 15 can be reliably fixed to the cylinder head 3 without exerting an excessive pressing force.

In the present embodiment, the leaf spring 20 is
One having a fixing portion 20a that extends obliquely outward in the radial direction from one end of the pressing portion 20b, that is, a cantilever type, in which the fixing portion 20a has higher rigidity than the leaf spring 20 and is provided at the other end of the pressing portion 20b Since the valve spring boss 3k is fastened and fixed to the valve mounting boss 3k with the bolt 19 while covering the washer member 21 having the extending extension 21b, the leaf spring 20 is a cantilever type while reducing the arrangement space while reducing the arrangement space.
A uniform pressing force can be applied to both tip portions 20c ', 20c' of the fuel injection valve 15 and the fuel injection valve 15 can be securely fixed to the cylinder head 3.

In this embodiment, when viewed in the direction of the injection valve axis B, the fuel rail 16 is connected to the fuel injection valve 15.
Is placed on the opposite side of the intake port 3d with the
Since the rail mounting boss 3m on the cylinder head 3 side is formed in a portion facing outward from between the intake port 3d and the fuel rail 16, the position of the fuel injection valve 15 and the mounting of the fuel rail support stay 16b on the cylinder head side. The position is substantially at the same position in the direction perpendicular to the axis of the fuel rail 16, so that 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 is avoided. it can.

The support stay 16b and the fuel injection valve 15
The position of the support stay 16b and the fuel injection valve 15 in the direction perpendicular to the axis can be small because the position of the fuel rail 16 in the direction perpendicular to the axis is substantially the same. While reducing the size, the degree of freedom in layout can be expanded, for example, by arranging the fuel injection valve 15 substantially parallel to the intake port 3d 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 for fixing the fuel rail 16 to the cylinder head 3 with bolts on one side of the fuel injection valve 15.
On the other side, valve mounting boss portions 3k for bolting and fixing the fuel injection valve 15 to the cylinder head 3 are respectively arranged, and these face outward from between the intake port 3d and the fuel rail 16. As a result, the fuel rail 16 itself does not interfere with the mounting operation of the fuel rail 16, and the mounting workability is improved. Further, the space required for the support stay 16b of the fuel rail 16, the fuel injection valve 15, and the entire valve mounting boss 3k in the direction perpendicular to the axis of the fuel rail can be reduced. Fifteen layout degrees of freedom can be expanded.

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 rail mounting boss 3m is projected in the axial direction of the injector, the length of the support stay 16b on the fuel rail 16 side in the axial direction of the injector can be shortened. The rigidity can be increased while reducing the weight of the device.

Further, since the fuel rail mounting bolt 22 and the fuel injection valve mounting bolt 19 are screwed in a direction parallel to the injection valve axis B, there is a problem that the tool hits the fuel rail 16 when the bolts 22 and 19 are screwed. Can be avoided, and the assembling workability can be further improved.

FIGS. 11 to 14 are views for explaining a second embodiment according to the sixth aspect of the present invention. This embodiment is an example in which a leaf spring having a pair of left and right fixing portions is provided. ,
In the drawings, the same reference numerals as those in FIGS. 1 to 10 indicate the same or corresponding parts.

In this embodiment, the flange 15 d of the fuel injection valve 15 is pressed by one leaf spring 25. The leaf spring 25 has a plate thickness of 0.5 to 3.0 mm, preferably 1.
It is made of a spring steel plate of about 5 mm, and includes the pair of left and right fixing portions 25a, 25a and a pressing portion 25b located between the fixing portions 25a, 25a in plan view. This pressing part 2
5b is bent downward at the bending line n. 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 valve mounting boss portion 3k on the cylinder head side has shifted to the (reference size + tolerance) side. In the case, that is, when the difference dimension H is larger than the reference dimension, when the fuel injection valve 15 is fixed in a normal state by the leaf spring 25, the leaf spring 25 undergoes elastic deformation, and the difference dimension H H is (standard dimension-tolerance)
When the plate spring 25 swings to the side, that is, when the difference dimension H becomes smaller than the reference dimension, the leaf spring 25 is set to undergo further plastic deformation from elastic deformation. Accordingly, the fuel injection valve 15 can be securely fixed to the engine without damaging the fuel injection valve itself.

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 valve mounting boss part 3k are reduced. The difference dimension H is set so as to fall within a standard dimension 0.3 mm ± tolerance 0.3 mm. The bending amount A is 0.9
It is set to 5 ± 0.25 mm. Therefore, the height difference dimension H is 0 mm when the tolerance swings to the negative maximum value, and in this case, the leaf spring 25 is deformed by about 0.95 mm and plastically deformed by about 0.4 mm. Becomes The dimension L4 in FIG. 13 is 20 m as an example.
m.

In the second embodiment, as in the first embodiment, when the dimensional tolerance between the flange portion 15d of the fuel injection valve 15 and the valve mounting boss portion 3k of the cylinder head 3 is large, the leaf spring is used. 25 can be absorbed by being elastically deformed and further plastically deformed, and no excessive pressing force acts on the fuel injection valve, and it is not necessary to control the torque more strictly, so that the assembling workability is good. .

In the second embodiment, a pair of left and right fixing portions 25a of the leaf spring 25 are fixed by bolts.
5c 'allows a more even pressing force to act on the flange portion 15d of the fuel injection valve 15, and the fuel injection valve 15 can be securely fixed to the cylinder head 3.

[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 sectional view taken along line VII-VII of FIG. 2;

FIG. 8 is a schematic diagram showing a mounting state of the fuel injection valve and the fuel rail according to the first embodiment.

FIG. 9 is a plan view showing a state where the fuel injection valve is mounted according to the first embodiment.

FIG. 10 is a cross-sectional side view showing the state of attachment of the fuel injection valve according to the first embodiment.

FIG. 11 is a front view of an engine according to a second embodiment of the invention.

FIG. 12 is a schematic cross-sectional side view showing a state where a fuel injection valve is mounted according to the second embodiment.

FIG. 13 is a plan view of a leaf spring according to the second embodiment.

FIG. 14 is a side view of the leaf spring according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 In-cylinder injection engine 3 Cylinder head 3a Combustion concave part (combustion chamber) 3i Holding hole (valve mounting hole) 3j Head side positioning part 3k Valve mounting boss part 15 Fuel injection valve 15d Flange part 15e Valve side positioning part 16 Fuel rail 20, 25 Leaf spring (valve mounting member) 20a, 25a Fixed portion 20b, 25b Pressing portion H Dimension from flange to valve mounting boss

Claims (5)

[Claims] 1. A fuel injection valve mounting structure for a direct injection engine having a fuel injection valve for directly injecting fuel into a cylinder and a fuel rail for supplying fuel to the fuel injection valve, wherein the fuel injection valve is opened into a combustion chamber. As described above, the fuel injection valve is inserted and arranged in the valve mounting hole formed in the cylinder head, and the valve-side positioning portion formed in the fuel injection valve corresponds to the head-side positioning portion formed in the valve mounting hole. When the fuel injection valve is brought into contact with the valve mounting boss, the flange portion of the fuel injection valve is lower than the valve mounting boss portion, and the difference dimension (standard dimension ±
Tolerance) H is set to satisfy H ≧ 0, a thin plate valve pressing member having a fixed portion and a pressing portion bent from the fixed portion by a predetermined amount of bending is provided, and the fixed portion is fixed to a cylinder head. A fuel injection valve mounting structure for a direct injection engine, wherein the fuel injection valve is fixed to a cylinder head by being fixed to a valve mounting boss portion and pressing the flange by the pressing portion. 2. The fuel injection valve mounting structure for a direct injection engine according to claim 1, wherein the pressing member is plastically deformed in a direction opposite to the bending direction when the fuel injection valve is fixed. 3. The valve pressing member according to claim 2,
It is made of a spring steel plate having a pressing portion for pressing two points on a straight line passing through the center of the annular flange portion of the fuel injection valve, and a fixed portion extending radially outward from the pressing portion,
The pressing portion is bent toward the flange portion side, and the amount of bending is set so as to generate elastic deformation when the tolerance of the reference dimension is on the positive side and further generate plastic deformation when on the negative side. A fuel injection valve mounting structure for a direct injection engine. 4. The valve pressing member according to claim 2, wherein the valve pressing member has a fixing portion extending obliquely outward in a radial direction from one end of the pressing portion, and the fixing portion has higher rigidity than the valve pressing member. The washer member is bolted and fixed to the valve mounting boss with the washer member put thereon, and the washer member extends to the other end of the pressing portion and pushes uniformly from one end of the pressing portion to the other end. A fuel injection valve mounting structure for a direct injection engine, comprising an extension for applying pressure. 5. The valve pressing member according to claim 2, wherein the valve pressing member has a fixing portion extending symmetrically in a radially outward direction from both ends of the pressing portion. A fuel injection valve mounting structure for a direct injection engine, which is fixed to a valve mounting boss formed on both sides of a valve by bolts.