Mounting Structure for Fuel Injector

Field of Invention

The present invention relates to fuel injection systems, and more particularly relates to an improved fuel injector mounting structure for an internal combustion engine that can securely hold a fuel injector on to the injector mounting surface formed on the inlet path of the engine cylinder head.

Background of Invention

Fuel injection systems are provided for the internal combustion engines for obtaining more effective emission control, better fuel economy and, at the same time, continued high power output. In the common fuel injection systems used, fuel is injected into an intake air manifold. Fuel injection systems generally employ injector locator hole which are formed relative to the engine at the intake manifold on the cylinder head to direct the received fuel towards the intake of the engine cylinder at appropriate timed intervals.

Mounting devices for mounting fuel injectors on engines have previously been employed which include a sleeve and seal means for directly affixing the injector to an engine element such as the intake manifold on the cylinder head, also a pipe joint for joining the fuel injector to the fuel line. Such mounting devices often requires appropriate sealing configuration at the joints between the fuel injector and the engine cylinder head.

The mounting of the fuel injector with this normal seal configuration does not ensure secured location of fuel injector onto the cylinder head. At the extreme, the fuel injector can assume a noticeably skewed orientation relative to a central axis of the opening in which is mounted.

The requirement for effective seals is often the result of the difficult environment in which the injector is located. The injector itself vibrates during the injecting operation; also this vibration is transmitted to the joints with the engine and with the fuel receiving line causing undesirable loosening of the joints. Fuel is thus able to leak between components.

Due to low guidance of injector bottom portion on to the sleeve and absence of secondary mounting leads to dislocation and tilting of the injector causing leakage of fuel, and thereby preventing proper fuel injection and effecting engine performance and emission control.

Hence there exists a need for a mounting construction of the fuel injector that consistently produces an effective seal between fuel injector and the injector mounting surface on the inlet path formed in the engine cylinder head.

Objective of the Invention
The main objective of the present invention is to provide a rigid mounting construction for the fuel injector that consistently produces an effective sealing between fuel injector and the engine body.

Another objective of the present invention is to provide a fuel injector mounting structure which prevents dislocation and tilting of the fuel injector mounted on the engine cylinder head.

Another objective of the present invention is to provide rigid mounting of fuel injector which prevents leakage of fuel, and providing proper fuel injection with increase in engine performance and emission control.

Another objective of the present invention is to provide a fuel injector mounting structure which prevents ingress of dust and related particles even in the difficult environment in which the injector is located.

Summary of Invention
The objective of the present invention is to provide a rigid mounting construction for the fuel injector that consistently produces an effective sealing between fuel injector and the engine body, and thereby preventing the dislocation and tilting of the fuel injector mounted on the engine cylinder head.

The present invention is directed to a mounting structure for a fuel injector placed on the injector mounting surface formed on the inlet path of the engine cylinder head. In order to overcome the above stated problems, a sleeve with an extended profile is provided for covering the fuel injector and substantially guiding the injector.

The sleeve is also having a concentrically down stepped profile, where the lowest outer diameter locates into the hole provided in the cylinder head. The other end of the sleeve is provided with a stepped bore to mount a seal made of rubber like material. The sleeve is defined to have two stepped bores to accommodate two differentially profiled seals made of rubber like material.

The rubber seal placed on the top side of the sleeve includes an inverted U shaped profile with one shorter end and one longer end, located concentrically for partially covering both inner and outer diameter of the topside walls of the sleeve.

The rubber seal placed on the bottom side of the sleeve includes an inverted L shaped profile located concentrically between the second stepped bore and second bottom face of the injector.

The extended guidance for the fuel injector prevents the tilting of the injector, and thereby preventing the leakage of the fuel. The provision of the two seals around
the injector at two different locations prevents ingress of dust and ensures rigid placement of injector and also provide proper guidance for the injector.

With the employment of this injector mounting structure, the fuel injector is positively mounted, and allows preventing and isolating the vibrations from the injector. Additionally the positive sealing made from the present invention also provide advantageous features such as self-adjusting orientation of the injector within the mounting structure, simple in construction, an assembly which can be easily removed or positioned on an engine, and thermal shielding of the injectors components.

The objective of the present invention to provide an improved mounting structure for fuel injector on to the injector mounting surface formed on the inlet path of the engine cylinder head. Other and further objects and advantages will appear hereinafter.

Brief description of the Drawings
The features of this invention will now be described with reference to the drawings which are intended to illustrate and not to limit the invention.

FIG. 1 is a top plan view illustrating a mounting structure for fuel injector on an
engine cylinder head.

FIG. 2 is a cross-sectional view illustrating a fuel injector mounted on an engine
cylinder head.

FIG. 3 is a cross-sectional view illustrating a fuel injector in accordance to the
present invention.

Detailed Description of the Drawings
The present invention will be described with reference to the accompanying
drawings. Referring to Figure 1, a top plan view shows an improved fuel injector
mounting structure on an internal combustion engine that can securely hold a fuel injector (102) on to the injector mounting surface formed on the inlet path (201) of the engine cylinder head (101).

Referring to Figure 2, a cross-sectional view illustrating a fuel injector mounted on an engine cylinder head, the engine cylinder head (101) is provided with a fuel injector locator hole (203) formed on the inlet path (201) of the air inlet valve (202), The injector locator hole (203) is made on an injector locating boss (204), where the boss (204) is integrally formed over the inlet path (201) on the cylinder head. The bore of the injector locator hole (203) is made perpendicular to the face of the injector locating boss (204) formed on the cylinder head (101). The injector locating boss (204) formed on the cylinder head (101) is also provided with a stepped hole parallel to axis of the injector mounting hole (203) and perpendicular to injector mounting boss (204) surface on the cylinder head (101).

A sleeve (205) is press fitted co-axially into the injector mounting hole (203) for receiving the fuel injector (102) on its inner diameter. The sleeve (205) partially covers the bottom portion of the injector (102) exposing various portions. The fuel injector (102) is located on to the sleeve (205) press fitted on the engine cylinder head (101). A fuel intake adaptor (207) is slidably fitted on the fuel receiving end of the fuel injector (102).

The top portion of the fuel injector (102) is provided with the fuel intake adaptor (207) made of resin like material. The fuel intake adaptor (207) has a fuel receiving sprout (208) with an inner bore of suitable diameter which connects to fuel receiving end of the fuel injector. The fuel intake adaptor (207) is also provided with an extended rectangular U shaped wall section (209) perpendicular to the axis of the fuel injector (102).

Referring to Figure 3, a cross-sectional view illustrating a fuel injector (102) in accordance to the present invention, the top extreme end of the extended rectangular U shaped wall (209) has a mounting hole formed parallel to the axis of fuel injector (102), and where a metallic insert (301) is enmolded in the mounting hole of the U shaped wall section (209).

A metallic spacer (302) is provided between the injector mounting boss surface coaxially placed on the tapped hole and the other end of the spacer towards the bottom wall of the U shaped extended wall section (209). A metallic screw (303) of the suitable length is inserted and fastened on to cylinder head (101) for securing rigid placement of fuel injector (102) on to the cylinder head.

In order to achieve the objectives of the present invention, the sleeve (205) is provided with an extended profile for covering the fuel injector (102) and substantially guiding the injector as clearly shown in Figure 2. The sleeve (205) is also includes a concentrically down stepped profile, where the lowest outer diameter locates into the mounting hole provided in the cylinder head (101). The other end of the sleeve is provided with a stepped bore to mount seals made of rubber like material. The sleeve (205) is defined to have two stepped bores to accommodate two differentially profiled seals (210, 211) made of rubber like material.

The rubber seal (210) placed on the top side of the sleeve (205) includes an inverted U shaped profile with one shorter end and one longer end, located concentrically for partially covering both inner and outer diameter of the topside walls of the sleeve (205).

The rubber seal (211) placed on the bottom side of the sleeve (205) includes an inverted L shaped profile located concentrically between the second stepped bore and second bottom face of the injector (102).

The extended guidance provided for the fuel injector (102) enables for consistently providing an effective sealing between fuel injector and the engine body, and thereby preventing the tilting of the fuel injector, which results in prevention of leakage of the fuel.

The provision of the two seals (210, 211) around the injector (102) at two different locations prevents dislocation and tilting of the fuel injector mounted on the engine cylinder head (101). The placement of rubber seals (210, 211) also prevents ingress of dust and related particles even in the difficult environment in which the injector is located.

With the employment of this injector mounting structure, the fuel injector (102) is positively mounted, and allows for preventing and isolating the vibrations of the fuel injector. Also the positive sealing made from the present invention also provides advantageous features such as self-adjusting orientation of the fuel injector within the mounting structure.

The simple mounting construction allows for easy removal as well as positioning of the fuel injector (102) on the injector mounting surface on the engine cylinder head (101). The structure also provides for effective thermal shielding of the injectors components, thereby increasing the life and reliability of the fuel injector.

Although this invention has been described in terms of a certain preferred embodiment, other embodiments apparent to those of ordinary skill in the art are also within the scope of this invention. Accordingly, the scope of the invention is intended to be defined only by the claims that follow.

We Claim:

1. A mounting structure for fuel injector mounted on engine cylinder head comprises of;
an injector locating boss (204) integrally formed over the inlet path of cylinder head (101);

a fuel injector mounting hole (203) formed on the inlet path injector locating boss(204);

an extended sleeve (205) fitted co-axially into the injector mounting hole (203) provided in the boss (204), covering the fuel injector (102) wherein the said sleeve (205) has a concentrically down stepped profile with lowest outer diameter locating into the fuel injector mounting hole and the other end is provided with a stepped bores ;

a seal (210) located concentrically for partially covering both inner and outer diameter of the topside walls of the sleeve (205); and a seal (211) located concentrically between the second stepped bore and second bottom face of the injector.

2. The mounting structure as claimed in claim 1, wherein the said seal (210) is preferably of inverted U shape.

3. The mounting structure as claimed in claim 1, wherein the said seal (211) is preferably of inverted L shape

4. The mounting structure as claimed in claim 2, wherein the said inverted U shaped seal has one shorter end and one longer end where shorter end is placed outside.

5. The mounting structure as claimed in claim 1, wherein the said injector locating boss (204) is provided with a stepped hole parallel to axis of injector mounting hole.

6. The mounting structure as claimed in claim 1, wherein the said sleeve (205) is press fitted co axially into the fuel injector mounting hole (203) of the injector locating boss (204).

7. The mounting structure as claimed in claim 1, wherein the said sleeve (205) partially covers the bottom portion of the injector exposing various portions.

8. The mounting structure as claimed in claim 1, wherein the said seal (210) and
seal (211) is preferably of polyeurethene material or rubber material.