Claims:We Claim:
1. A sealing device (100) for a flow passage 104 in a fuel injection pump, said sealing device 100 comprising:
a plug (102) for insertion into said flow passage (104);
a seal ring (106) located around said plug (102) and for sealing said flow passage (104);
a resilient element (108) attached to an inner end of said plug (102) for biasing against an internal constriction (110) in said flow passage (104); and
at least one elastic projection (112) attached to a side of said plug (102) and proximal to said inner end of said plug (102), said at least one elastic projection (112) capable of being locked in place by corresponding at least one groove (114) on an inner side of said flow passage (104).

2. The sealing device 100 of claim 1, wherein said resilient element 108 is a spring.

3. The sealing device 100 of claim 1, wherein said seal ring 106 is an O-ring.

4. The sealing device 100 of claim 1, wherein said elastic projection 112 is integrated with said plug 102.
, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001]This invention relates to a device for sealing the housing of a fuel injection pump.

Background of the invention
[0002]A fuel injection pump is used to deliver pressurized fuel to an injector/ rail. The fuel injection pump comprises a housing with multiple flow passages within the housing. These passages serve to bring fuel into the fuel injection pump and also to direct fuel out of the fuel injection pump. The flow passages are created by drilling through the housing of the fuel injection pump. Upon creation of the flow passages, the openings present at the housing of the fuel injection pump are sealed. These openings get created during drilling operation for creation of flow passages. The sealing of these openings is through a press fit arrangement. It is observed that during working of the fuel injection pump, the pressure of the fuel flowing within the fuel injection pump can cause the sealing to break open, leading to loss of pressure of fuel within the fuel injection pump and leakage of fuel. Hence, there is a need to ensure tight sealing of the opening in the fuel injection pump.

Brief description of the accompanying drawing
[0003] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0004] FIG. 1 illustrates a sealing device for a fuel injection pump.

Detailed description of the embodiments
[0005] FIG. 1 illustrates a sealing device 100 for a fuel injection pump. The sealing device 100 comprises a plug 102 for insertion into the flow passage 104, a seal ring 106 is located around the plug 102 and for sealing the flow passage 104. The seal ring 106 may be an O-ring. A resilient element 108 is attached to an inner end of the plug 102 for biasing against an internal constriction 110 in the flow passage 104. In an embodiment the resilient element 108 may be a spring. At least one elastic projection 112 is attached to a side of the plug 102 and proximal to the inner end of the plug 102. In an embodiment the elastic projection 112 is integrated with the plug 102. The elastic projection 112 is capable of being locked in place by the corresponding groove 114 on an inner side of the flow passage 104.

[0006]The constructional features of the sealing device 100 will be explained in further detail. The sealing device 100 disclosed herein is used to seal the flow passage 104 in the fuel injection pump. The sealing device 100 comprises a plug 102, for insertion into the flow passage 104. The plug 102, for example, may be made from mild steel. The profile of the plug 102 is such that there is a fit that is established with respect to the diameter of the flow passage 104 during insertion of the plug 102 into the flow passage 104. The seal ring 106 is located around the plug 102 for sealing the flow passage 104. In an embodiment the seal ring 106 may an O-ring. The resilient element 108 is attached to an inner end of the plug 102 for biasing against an internal constriction 110 in the flow passage 104. The resilient element 108 may be a spring. The internal constriction 110 is established by providing a flow passage 104 with different diameter along the length of the flow passage 104, in other words by using drill bits of different diameter during drilling operation. The spring biases against one the internal constriction 110 so established. The elastic projection 112 is attached to the side of the plug 102 and is proximal to the inner end of the plug 102. The elastic projection 112 is capable of being locked in place by corresponding groove 114 on the inner side of the flow passage 104. The elastic projection 112 may be made of rubber or any other elastomeric material.

[0007] To insert the sealing device 100 into the flow passage 104, the plug 102 is inserted into the flow passage 104, once the elastic projection 112 contacts the groove 114 in the flow passage 104, the plug 102 gets locked, as further movement of the plug 102 within the flow passage 104 is not possible. The groove 114 restricts the movement of the plug 102, and the spring biasing against the internal constriction 110 maintains the position of the plug 102 during working of the fuel injection pump. Hence it is possible to ensure the positional accuracy of the sealing device 100 within the flow passage 104.

[0008] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.