JPH10318093A - Attaching structure for fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an attaching structure for an inner-cylinder injection type fuel injection valve which can attain sufficient sealability in respect to a cylinder head, and requires no excessive space. SOLUTION: A screw 26 is formed on an outer periphery of a housing 16 of a fuel injection valve 1 which injects fuel directly into a combustion chamber of an internal combustion engine. A female screw 27 is formed on an inner diameter part of an attaching hole 3 of the fuel injection valve 1 arranged on a cylinder head 2 of the internal combustion engine, and screwed with the screw 26 on the outer periphery of the housing 16. A seal member 28 is arranged between a bottom surface 5 of the attaching hole 3 and the fuel injection valve 1. The fuel injection valve 1 is fastened to the cylinder head 2 by screwing the screw 26 with the female screw 27. Load to be applied to the seal member 28 is thus adjusted to be a value optimum for sealing high pressure combustion gas in the combustion chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-cylinder fuel injection valve mounting structure for directly injecting fuel into a combustion chamber of an internal combustion engine.

[0002]

2. Description of the Related Art FIG. 6 is a configuration diagram showing a conventional in-cylinder fuel injection valve and its mounting structure. In the figure, reference numeral 1 denotes a fuel injection valve mounted in a mounting hole 3 of a cylinder head 2 of an internal combustion engine. The fuel injection valve 1 has a seal ring 6 between its valve holder 4 and a bottom surface 5 of the mounting hole 3 of the cylinder head 2. And a metal gasket 11 is interposed between the flange 8 provided on the housing 7 and the bottom surface 10 of the stepped portion 9 of the cylinder head 2 to be attached by a fork 12 which presses the flange 8 from its upper surface. Fork 1
2 is fixed to the cylinder head 2 by screws 13. In addition, 14 is a delivery pipe for supplying fuel to the fuel injection valve 1, and 15 is an O-ring that seals between the delivery pipe 14 and the fuel injection valve 1.

[0003] For example, gasoline as fuel is supplied to the fuel injection valve 1 from a delivery pipe 14, and the fuel injection valve 1 is opened by a signal given from a controller (not shown) to inject a predetermined amount of fuel directly into the combustion chamber of the internal combustion engine. It is configured to be. Such an in-cylinder injection system directly injects fuel into a combustion chamber in a high compression state, and a high combustion pressure is generated in the combustion chamber with combustion. A high sealing property is required between them, and in addition to selecting a sealing member such as a gasket, sufficient consideration must be given to the load applied to the sealing member.

[0004]

As described above, the fuel injection valve 1 in the conventional in-cylinder injection system includes the fork 12
The sealing ring 6 and the gasket 11
On the other hand, it is difficult to apply an appropriate load that can cope with a high combustion pressure, and there is a problem in sealing performance. When the fuel injection valve 1 is mounted on a cylinder head in which an intake / exhaust valve and an ignition plug are arranged, a fork 1
The fixing by the method 2 requires an unnecessarily large space, impairs the layout, and further affects the performance of the internal combustion engine.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. In a cylinder injection system, a sufficient sealing property is obtained with a minimum number of sealing members, and an extra space is required for mounting. It is an object of the present invention to obtain a fuel injection valve mounting structure that does not require a fuel injection valve.

[0006]

SUMMARY OF THE INVENTION A fuel injection valve mounting structure according to the present invention includes a screw provided on an outer periphery of a fuel injection valve housing for directly injecting fuel into a combustion chamber of an internal combustion engine, and a cylinder head of the internal combustion engine. A female screw is provided on the inner diameter of the mounting hole of the fuel injection valve provided on the housing, and is provided with a female screw that is screwed with a screw on the outer periphery of the housing, and a seal member interposed between the bottom surface of the mounting hole and the fuel injection valve. By setting the load applied to the seal member to the optimum load for sealing high-pressure combustion gas by tightening torque by screwing the screw and female screw of the mounting hole, the fuel injection valve is fastened to the cylinder head. It is.

Further, by forming the seal member from a gasket made of one of a metal plate, a metal laminate plate, a metal C-ring, a metal O-ring, a metal corrugated plate, and a graphite plate, a required fuel injection valve is provided. The seal member can be selected with respect to the tightening torque of the seal member and the value of the load applied to the seal member, and the metal gasket is coated with a fluorine resin such as Teflon, graphite, or a soft material. This makes it possible to improve the sealing performance.

Furthermore, when the fuel injection valve is mounted on the cylinder head, a contact surface is provided in which the two are in contact in the axial direction, and one or both of the contact surfaces are made of a fluorine-based resin such as Teflon, graphite, or the like. Alternatively, a soft material is coated, and the load applied to the coating layer is set to an optimum load for sealing the high-pressure combustion gas by a tightening torque by screwing a screw of the housing and a female screw of the mounting hole. Is fastened to the cylinder head.

Further, the screw on the outer periphery of the housing is formed of a cylindrical screw member and is fitted and fixed on the outer periphery of the housing, so that the same screw member is changed regardless of the size of the female screw of the cylinder head. A fuel injection valve of a kind can be used for various internal combustion engines. Furthermore, by applying a coating of a fluorine-based resin such as Teflon, or graphite, or a soft material to the screw on the housing side, or the internal thread on the mounting hole side, or both, a double structure with a gasket or the like is provided. This makes it possible to increase the reliability.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 and 2 show a first embodiment of the present invention.
FIG. 1 is a cross-sectional view showing a mounting structure of a fuel injection valve, and FIGS. 2A to 2F are configuration examples of a gasket as a seal member used in the first embodiment.
In the figure, reference numeral 1 denotes a fuel injection valve mounted in a mounting hole 3 of a cylinder head 2 of an internal combustion engine. The fuel injection valve 1 includes a housing 16, a core 17 fixed to the housing 16 and forming a fuel passage 17a therein, and a housing. Solenoid 18 housed in 16 and energizing core 17 by a signal
A valve body 20 fixed to the housing 16 and having a valve seat 19 at one end, a valve body 21 for opening and closing the valve seat 19, and a suction force of the excited core 17 connected to the valve body and a pressing force of the spring 22. An armature 23 that moves the valve body 21, and a plate 24 that is disposed between the housing 16 and the valve body 20 and determines the amount of movement of the valve body 21.
The valve body 20 is provided with a revolving body 25 that gives a swirling flow to the injected fuel.

The housing 16 of the fuel injection valve 1 has a screw portion 26 on its outer diameter, and is screwed with a female screw 27 provided on the inner diameter of the mounting hole 3 of the cylinder head 2 to mount the fuel injection valve 1 thereon. The sealing member 2 interposed between the fuel injection valve 1 and the bottom surface 5 of the mounting hole 3 due to the tightening torque of the screw engagement.
8 is adjusted so that an optimum load for sealing the combustion gas is applied. For example, as shown in FIGS. 2A to 2F, the sealing member 28 includes a metal plate (FIG. 2A), a metal laminated plate (FIG. 2B), a metal C ring (FIG. 2C), a metal O ring (FIG. 2D), and a metal wave. Board (Figure 2
e), a gasket such as a graphite plate (FIG. 2f) is used, and the type is selected according to a required tightening torque when the fuel injection valve 1 is mounted. Further, among these gaskets, a metal gasket can be provided with a coating layer made of a fluorine-based resin such as Teflon, graphite, or a soft material on the surface to improve the sealing property. Reference numeral 15 denotes an O-ring disposed in a groove 29 provided at the upper end of the core 17, and reference numerals 30 and 31 denote backup rings of the O-ring 15 for sealing a joint between the fuel injection valve 1 and the delivery pipe 14. belongs to.

According to the fuel injector mounting structure of the first embodiment of the present invention, the housing 16
The axial load on the seal member 28 can be set to an optimum value by screwing the screw 26 having an outer diameter of 3 with the female screw 27 having an inner diameter of the mounting hole 3. Since no fork is used as in the conventional device, no extra space is required for mounting, and the layout of the cylinder head 2 is greatly improved. Further, when the tightening torque of the fuel injection valve 1 is changed by the internal combustion engine, the optimum seal member 28 can be selected according to the load by the tightening torque, and the sealing performance can be ensured.

Embodiment 2 FIG. FIG. 3 is a sectional view showing the configuration of the second embodiment of the present invention. Embodiment 2
Is formed by fitting a cylindrical screw member 33 having a screw 26 on the outer periphery to the outer periphery of the housing 16 and integrating the same by welding, caulking, press-fitting, or the like.
7 is screwed. Further, one or both of the screw 26 of the housing 16 and the female screw 27 of the mounting hole 3 is coated with a fluorine-based resin such as Teflon, graphite, or a soft material. is there.

In the fuel injection valve mounting structure of the second embodiment configured as described above, the screw member can be used for an internal combustion engine having a different size of the female screw 27 provided in the mounting hole 3 of the cylinder head 2. The same type of fuel injection valve can be used simply by replacing 33, and the standardization of the fuel injection valve becomes possible. In addition, the screw 26 or the female screw 27
Alternatively, by applying a coating of a soft material such as Teflon to both of them, the sealing performance at the threaded portion is improved, and the gasket 28 and the double structure can be sealed.

Embodiment 3 FIG. 4 is a cross-sectional view showing a configuration of a third embodiment of the present invention. This third embodiment is a fuel injection device configured to abut on the bottom surface 5 of the mounting hole 3 of the cylinder head 2. Housing 1 for valve 1
6, a coating layer made of a fluorine-based resin such as Teflon, or graphite, or a soft material is provided on the front end surface 34 or both of them. This is set by screwing with the internal thread 27, and by applying an appropriate load to the coating layer, high-pressure combustion gas is sealed. According to this embodiment, a seal member such as a gasket is not required, and the number of parts and cost can be reduced. Further, similarly to the second embodiment, the screw 26
Alternatively, the female screw 27 or both of them can be coated with a soft material such as Teflon to form a double seal structure.

Embodiment 4 FIG. 5 is a sectional view showing a configuration of the fourth embodiment of the present invention. Embodiment 4
Is provided with a flange 8 on the housing 16 of the fuel injection valve 1 and a contact surface 35 of the flange 8 with the cylinder head 2 or a contact surface 3 with the flange 8 of the cylinder head 2.
6 or a coating layer made of a fluorine-based resin such as Teflon or graphite or a soft material is provided on both of them, and the contact load between them is reduced by the housing 16.
And a high-pressure combustion gas is sealed by applying an appropriate load to the coating layer. The sealing member is the same as in the third embodiment. It is intended to obtain a good sealing property without using any. Further, similarly to the second embodiment, the screw 26 or the female screw 27 or both of them can be coated with a soft material such as Teflon to form a double seal structure.

[0017]

As described above, according to the fuel injection valve mounting structure of the present invention, a screw is provided on the outer periphery of the housing of the fuel injection valve, and is screwed to the female screw of the cylinder head of the internal combustion engine. Since the optimum load is applied to the sealing member or the coating layer by this tightening torque, high sealing performance can be obtained, and the setting of the load according to the type of the sealing member is not only easy, but also for mounting. Therefore, the layout of the cylinder head can be improved without requiring extra space and parts. Also, without using a seal member such as a gasket, it is also possible to provide a high sealing property by a coating layer on the contact surface between the fuel injection valve and the cylinder head, and furthermore, the screw on the outer periphery of the housing has a separate structure. Therefore, it is possible to reduce the number of parts, the type of the fuel injection valve, and the cost, and also to provide a sealing property to the screwing portion between the fuel injection valve and the cylinder head, thereby mounting a highly reliable fuel injection valve. A structure is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a first embodiment of the present invention.

FIG. 2 is a view showing a first embodiment and a second embodiment of the present invention;
FIG. 3 is a view showing a configuration of a gasket used for the present invention.

FIG. 3 is a sectional view showing a configuration of a second embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration of a third embodiment of the present invention.

FIG. 5 is a sectional view showing a configuration of a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram showing a mounting structure of a conventional in-cylinder fuel injection valve.

[Explanation of symbols]

1 fuel injection valve, 2 cylinder head, 3 mounting hole, 1
6 Housing, 17 cores, 18 solenoids, 19
Valve seat, 20 valve body, 21 valve body, 22 spring, 23
Armature, 24 plates, 26 screws, 27
Female screw, 28 seal member, 32 injection nozzle, 33
Screw member.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masayuki Aoda 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Mamoru Sumita 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 Rishi Electric Co., Ltd.

Claims (6)

[Claims] 1. A fuel injection valve for directly injecting fuel into a combustion chamber of an internal combustion engine, a screw provided on an outer periphery of a housing of the fuel injection valve, a mounting hole for a fuel injection valve provided on a cylinder head of the internal combustion engine, A female screw provided on the inner diameter of the mounting hole and screwing with the screw on the outer periphery of the housing, a seal member interposed between the bottom surface of the mounting hole and the fuel injection valve; A mounting structure for a fuel injection valve, wherein a load applied to a seal member is set to an appropriate load by a tightening torque by screwing, and the fuel injection valve is fastened to a cylinder head. 2. The gasket according to claim 1, wherein the seal member is a gasket formed of any one of a metal plate, a metal laminate, a metal C-ring, a metal O-ring, a metal corrugated plate, and a graphite plate. The mounting structure of the fuel injection valve described in the above. 3. The fuel injection valve mounting structure according to claim 2, wherein the metal gasket is coated with a fluorine-based resin such as Teflon, graphite, or a soft material. 4. A fuel injection valve for directly injecting fuel into a combustion chamber of an internal combustion engine, a screw provided on an outer periphery of a housing of the fuel injection valve, a mounting hole for a fuel injection valve provided on a cylinder head of the internal combustion engine, A female screw provided in the inner diameter of the mounting hole and screwed with the screw on the outer periphery of the housing, one of the contact surfaces of the cylinder head and the fuel injection valve, or a fluororesin such as Teflon coated on both, or A coating layer of graphite or a soft material is provided, and a load applied to the coating layer between the abutting surfaces is set to an appropriate load by a tightening torque by screwing a screw on the outer circumference of the housing and a female screw on the inner circumference of the mounting hole. A fuel injection valve mounting structure, wherein the fuel injection valve is fastened to a cylinder head. 5. The fuel injection valve mounting structure according to claim 1, wherein the screw on the outer periphery of the housing is formed of a cylindrical screw member and is fitted and fixed on the outer periphery of the housing. . 6. The screw on the housing side, the female screw on the mounting hole side, or both of them is coated with a fluorine-based resin such as Teflon, graphite, or a soft material. A mounting structure for a fuel injection valve according to any one of claims 1 to 5.