Claims:We claim:
1. A high pressure pump (10) assembly comprising at least:
a housing (22) , a barrel (16) and a valve holder (12), said barrel (16) and said valve holder (12) are located in said housing(22);
said barrel (16) having a collar (24) with a step (26) for sealing between said valve holder (12) and said barrel (16);
a washer (15) located on said step (26) of said barrel (16) ;
said valve holder (12) screw fitted into said housing (22) in a manner such that, at least a part of said valve holder (12) will rest against said washer (15).
2. The high pressure pump (10) assembly as claimed in claim (1), wherein when said valve holder (12) adapted to be screw fitted in said housing (22), a part of said valve holder (12) rests against a part of said housing (22).
3. The high pressure pump (10) assembly as claimed in claim (1), wherein said valve holder (12) is tightened into said housing (12) in such a way that, a part of the valve holder (12) will rest against the washer (15) and the movement of the washer (15) is restricted.
, Description:Field of the invention:
[0001] This disclosure relates to a high pressure pump assembly.
Background of the invention:
[0002] A typical high pressure pump may include a cylindrical body having a barrel with a central bore therein and a plunger reciprocating within the bore of the barrel. During an assembly of components of a high pressure pump, a washer is placed on barrel top which moves/shifts to one side and gets de-centralized if not guided properly. On tightening of a valve-holder in the housing, there is a possibility that the washer shifts to one end radially which results is non-uniform deformation of washer. A hydraulic sealing is achieved by the washer when placed between the barrel and the valve holder. The washer avoids a leakage of the fuel from the barrel.
[0003] An Indian Patent IN202798 discloses an external assembly orientation arrangement in a fuel injection pump. An external tool is inserted through an inlet hole of a pump housing and a barrel of an element is positioned in the pump housing. The external tool is withdrawn after a delivery valve holder is tightened in the pump housing to desired torque.

Brief description of the accompanying drawing s:
[0004] An embodiment of the disclosure is described with reference to the following accompanying drawings:
[0005] Figure 1 illustrates a high pressure pump assembly according to one embodiment of the invention.

Detailed description of the embodiments:

[0006] Figure 1 illustrates a high pressure pump 10 assembly in accordance with this disclosure. The high pressure pump 10 assembly comprises a housing 22 having a barrel 16 and a valve holder 12. The barrel 16 having a collar 24 with a step 26 for sealing between the valve holder 12 and the barrel 16. The pump 10 comprises a washer 15 located on the step 26 of the barrel 16. The valve holder 12 is screw fitted into the housing 22 in a manner such that, at least a part of the valve holder 12 will rest against the washer 15.
[0007] Further details about the construction of the fuel injection pump 10 and the components of the fuel injection pump 10 will be explained in the following description. During the assembly of the fuel injection pump 10, a plunger 14 which is placed in a bore of the barrel 16, is reciprocally driven into the barrel 16 by a rotating cam (not shown). The valve holder 12 is located on the barrel 16. In accordance with one embodiment of the valve 18, the valve 18 comprises two components a ball and a spring 20. During the construction of the fuel pump 10 the ball is located on the barrel 16. A part of the barrel 16 forms the valve seat where the ball rests. One end of the spring 20 abuts against the valve holder 12 while the other end of the spring 20 abuts the ball portion of the valve 18. Thus the valve 18 is a spring loaded ball valve. The spring 20 which is placed above the valve 18 is either compressed or expanded when the valve 18 is operated. The washer 15 present in the collar 24 of the barrel 16 is made of a material chosen from a group of materials like copper, steel or the like. During assembly, an inlet 32 of the barrel 16 will be at same height of an inlet path 30 of the housing 22. The valve holder 12 is adapted to be screw fitted in the housing 22 and a part of the valve holder 12 rests against a part of the housing 22.
[0008] The process of assembling of the components of the high pressure pump 10 is disclosed below. During the assembly of the high pressure pump 10, the barrel 16 is held above the housing 22 such that the inlet 32 of the barrel 16 is in line with the inlet path 30 of the housing 22 and then placed in the housing 22. During this process, the barrel 16 is positioned in the housing 22 in such a way that, the barrel 16 is tightly fixed in the housing 22, with no clearance between the inner surface of the housing 22 and the outer surface of the barrel 16. The washer 15 is placed on the barrel 16. The washer 15 is placed on the barrel 16 such that the washer is located on the step of the collar 24 of the barrel 16. The washer is fixed onto the collar 24 in such a way that, the movement of the washer 15 is restricted. As mentioned earlier, the valve 18 is then placed on a valve seat of the barrel 18. The spring is then located in a recess provided in the valve holder. The valve holder 12 along with the spring provided in the recess is then screw fitted into the housing 22. Plurality of threads are present in the inner circumference of the housing 22 and corresponding plurality of threads are present on the outer circumference of the valve holder 12. While screw fitting the valve holder the threads of the housing and the valve holder seal the two surfaces. While tightening the valve holder into the housing the step (26) provided on the barrel ensures that the part of the valve holder rests on the washer but there is no sliding or rubbing contact. As there is no sliding or rubbing contact the movement of the washer is restricted. Further the part of the valve holder 12 that rests on the washer 15 helps in stopping the leakage of the fuel from the barrel 16. Also as there is no sliding or rubbing contact between the valve holder and the washer, the washer 15 is not misaligned from a normal position during the screw fitting of the valve holder 12 into the housing 22. In accordance with another embodiment of this disclosure, in the high pressure pump assembly, the valve holder 12 is tightened in the housing 22 in such a way that, a part of the valve holder 12 rests directly against the area of the step 26 present at the collar 24 of the barrel 16. The part of the valve holder 12 is tightly secured directly onto the step 26 of the barrel 16 to stop the leakage of the fuel from the barrel 16.
[0009] With the above assembly process disclosed, the washer 15 is not misaligned from the collar 24 of the barrel 16 during the screw fitting of the valve holder 12 into the housing 22. Since, the step 26 at the collar 24 of the barrel 16 makes the valve holder 12 to park in a secured position, the movement in the valve 18 is restricted. The above process helps in ease assembly of the washer 15 in the collar 24 of the barrel 16 and also increase the effectiveness in sealing between the valve holder 12 and the barrel 16 in the housing 22.

[00010] 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.