CLIAMS:I claim,
1. A fuel inlet connector pipe (12) for a fuel pump (10), said fuel inlet connector pipe (12) comprising:
a bore (14) defined within the fuel inlet connector pipe (12), the bore (14) supplies fuel to the fuel pump (10); characterized in that
an opening (15) extending radially from the bore (14) to an outer surface (16) of the fuel inlet connector pipe (12).
2. The fuel inlet connector pipe (12) in accordance with Claim 1 wherein the opening (15) comprises a first constriction (17) extending from the bore (14) partially through the fuel inlet connector pipe (12), the opening (15) further comprises a second constriction (18) extending from one end the first constriction (17) to said outer surface (16) of said fuel inlet connector pipe (12).
3. The fuel inlet connector pipe (12) in accordance with Claim 2 wherein a diameter of the first constriction (17) is smaller than a diameter of the second constriction (18).
4. The fuel inlet connector pipe (12) in accordance with Claim 2 wherein the second constriction (18) is in flow communication with a cross feed supply line (20) of the fuel pump (10).
5. (it is enough to have this in the description)A fuel pump (10), said fuel pump (10) comprising:
a fuel inlet connector pipe (12) coupled to said fuel pump (10), said fuel inlet connector pipe (12) comprising a bore (14) defined within said fuel inlet connector pipe (12), the bore (14) supplies fuel to the fuel pump (10); characterized in that
an opening (15) extending radially from the bore (14) to an outer surface (16) of the fuel inlet connector pipe (12).
6. The fuel pump (10) in accordance with Claim 6 wherein the opening (15) comprises a first constriction (17) extending from the bore (14) partially through the fuel inlet connector pipe (12), the opening (15) further comprises a second constriction (18) extending from the first constriction (17) to said outer surface (16) of said fuel inlet connector pipe (12).
7. The fuel pump (10) in accordance with Claim 7 wherein a diameter of the first constriction (17) is smaller than a diameter of the second constriction (18).
8. The fuel pump (10) in accordance with Claim 7 wherein the second constriction (18) is in flow communication with a cross feed supply line (20) of said fuel pump (10).
,TagSPECI:Field of the invention
[0001] This invention relates to a fuel inlet connector pipe, and more particularly to a method and apparatus for connecting the fuel inlet connector pipe to a fuel pump.
Background of the invention
[0002] A fuel pump has a fuel inlet connector pipe coupled to an inlet of the fuel pump. During a pressure stroke of the fuel pump, the pressure developed by the fuel in the fuel inlet connector pipe causes the fuel to be channeled to a bore of the fuel pump via a cross feed fuel supply line. Consequently, the fuel may mix with the lubrication oil within the bore of the fuel pump thereby diluting the fuel. A constriction defined in the fuel inlet connector pipe causes the quantity of fuel escaping from the fuel inlet connector pipe to the bore of the fuel pump to substantially decrease.
[0003] U.S. Patent Number 6,688,269 describes a fuel supply system (1) for injecting liquefied vapour under high pressure, such as liquefied petroleum gas into a combustion chamber (3-6) of an internal combustion engine (2). The fuel supply system (1) comprises a fuel supply system for supplying liquefied vapour connected to a high pressure pump (11) via a duct. The high pressure pump (11) has a high pressure chamber (105) which is embodied thereby to increase the pressure of the liquefied vapour. A high pressure discharge of the high pressure pump (11) is connected to a high pressure rail (7) which comprises one or several injectors for injecting liquefied vapour into a combustion chamber. According to the invention, the fuel supply system (1) is provided with a discharge unit (20) for purging fuel, in particular fuel vapour, between the high pressure chamber and the combustion chamber.
Brief description of the accompanying drawings
[0004] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:
[0005] Figure 1 illustrates the fuel inlet connector pipe coupled to an inlet of the fuel pump.
[0006] Figure 2 illustrates an exploded section of fuel inlet connector pipe shown in Figure 1.
Detailed description of the embodiments
[0007] Figure 1 illustrates a fuel inlet connector pipe 12 coupled to an inlet of a fuel pump 10. The fuel inlet connector pipe 12 comprises a bore 14 defined within the fuel inlet connector pipe 12, the bore 14 supplies fuel to the fuel pump 10. An opening 15 extends radially from the bore 14 to an outer surface 16 of the fuel inlet connector pipe 12.
[0008] In addition, a fuel pump 10 is described. The fuel pump 10 comprises a fuel inlet connector pipe 12 coupled to the fuel pump 10. The fuel inlet connector pipe 12 comprises a bore 14 defined within the fuel inlet connector pipe 12, wherein the bore 14 supplies fuel to the fuel pump 10. An opening 15 extends radially from the bore 14 to an outer surface 16 of the fuel inlet connector pipe 12.
[0009] Figure 1 is a schematic representation of a fuel inlet connector pipe 12 for a fuel pump 10. The fuel inlet connector pipe 12 includes a bore 14 to channel fuel within the fuel inlet connector pipe 12. The fuel from the fuel inlet connector pipe 12 is supplied to an inlet of the fuel pump 10. From an inlet of the fuel pump 10, the fuel is channelled to a bore 22 of the fuel pump 10 where it is pressurized and delivered to an outlet of the fuel pump 10.
[00010] A cross feed supply line 20 is provided between the bore 22 of the fuel pump 10 and an inlet portion of the fuel pump 10. The cross feed line 20 allows fuel from the bore 22 of the fuel pump 10 back to an inlet of the fuel pump 10 during the pressure stroke.
[00011] During the suction stroke of the fuel pump 10, the flow of fuel from the fuel inlet connector pipe 12 to the bore 22 of the fuel pump 10 via the cross feed supply line 20 is reduced. In accordance with an embodiment of the invention, an opening 15 is defined between the cross feed supply line 20 and the bore 14 of the fuel inlet connector pipe 12. The opening 15 defined between the cross feed supply line 20 and the bore 14 of the fuel inlet connector pipe 12 causes the quantity of fuel that leaks from the bore 14 of the fuel inlet connector pipe 12 to the cross feed supply line 20 to be reduced. During the suction stroke of the fuel pump 10, the fuel from the inlet connector 12 is supplied to the bore 22 due to the pressure difference between the inlet connector 12 and the bore 22.
[00012] The opening 15 includes a first constriction 17 and a second constriction 18. The first constriction 17 of the opening 15 has a diameter that is smaller than that of the second constriction 18. The first constriction 17 of the opening 15 is in flow communication with the cross feed supply line 20. The diameter of the first constriction 17 and the diameter of the second constriction 18 may be decided based on the volume of fuel flow through the fuel pump 10. The second constriction 18 may be a conically shaped member. Alternatively, the second constriction 18 may be of any geometrical shape that enables the second constriction 18 to function in a manner as described in the following sections. By optimizing the diameter of the first constriction 17 and the second constriction 18, it is possible to control the flow of fuel from the bore 14 of the inlet connector 12 to the bore 22.
[00013] The principle of working of the fuel inlet connector pipe 12 coupled to an inlet of the fuel pump 10 is now explained as an example. When fuel flows through the fuel inlet connector pipe 12, the fuel is channelled into the fuel pump 10 during the suction stroke of the fuel pump 10. After the suction stroke of the fuel pump 10 is complete, the pressure of fuel in the fuel inlet connector pipe 12 builds up. The first constriction 17 and the second constriction 18 defined between the cross feed supply line 20 and the bore 14 of the fuel inlet connector pipe 12 causes the quantity of fuel that leaks from the bore 14 of the fuel inlet connector pipe 12 to the cross feed supply line 20 to be reduced. Therefore, the mixing of fuel with the lubrication oil within the fuel pump 10 is reduced. Moreover, the fuel present in between a plunger of the fuel pump 10 and a housing of the fuel pump 10 is at a higher temperature than the fuel in the fuel inlet connector pipe 12. Therefore, the ease of fuel flowing from the bore 22 to the fuel inlet connector pipe 12 via the cross feed supply line 20 is better owing to its lower viscocity.
[00014] Using the system of the present invention, reduction in the flow of fuel from the bore 14 of the fuel inlet connector pipe 12 to the cross feed supply line 20 is accomplished in a cost effective manner. This is important since the mixing of fuel with lubrication oil within the bore 22 of the fuel pump 10 is required to be reduced.
[00015] The above described fuel inlet connector pipe 12 for a fuel pump 10 facilitates reducing fuel leakage from the bore 14 out of the fuel inlet connector pipe 12, thereby increasing the efficiency of the fuel pump 10.
[00016] It must be understood that the embodiments explained in the above detailed description is only illustrative and does not limit the scope of this invention. The scope of this invention is limited only by the scope of the claims. Many modification and changes in the embodiments aforementioned are envisaged and are within the scope of this invention.