Field of the invention

This invention relates to a high pressure pump. More particularly, this invention relates to a valve cone of the high pressure pump.

Background of the invention

A valve cone in an injection pump is used to direct the fluid from a fluid passage of a barrel housing to an injector. During the reciprocating motion of a plunger in the barrel housing, the fuel that is received at the fuel gallery is directed towards the injector through a valve cone. During assembly of the valve cone in the injection pump, the force generated due to tightening of the valve holder on the barrel housing acts on the valve cone thereby creating an imbalance on the valve cone. Moreover, the fluid that is passing through the valve cone also causes instability in the valve cone. This imbalance of forces leads to eccentric loading of the valve cone that finally leads to breakage of valve cone, if the valve cone is used for longer periods of time under eccentric loading.

Hence there is a need for a valve cone that nullifies the effects of eccentric loading on the valve cone.

Figure 1 illustrates a conventional valve cone used in a high pressure pump. A valve cone in a high pressure pump is positioned between an injection valve holder and the barrel housing. The valve cone as disclosed in Figure 1, has a flat circular flange. During assembly, as the injection valve holder is tightened against the barrel housing, an eccentric force is generated on the flat circular flange leading to a reaction force that causes imbalance. This eccentric force coupled with the reaction forces will cause damage to the valve cone.

Object of the invention.

It is an object of the invention to prevent eccentric loading on the valve cone of a fuel injection pump.

Brief description of the accompanying drawings

Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawings:
Figure 1 illustrates a conventional valve cone used in a high pressure pump.
Figure 2 illustrates a high pressure pump in accordance with the present invention.
Figure 3 illustrates a valve holder assembly with the valve cone.
Detailed description of the embodiments
Figure 2 illustrates a high pressure pump 100 in accordance with the present invention. In a high pressure pump 100, fuel is pressurized in the fluid passage 102 by a plunger. The plunger in turn receives the drive from roller tappet that is driven by a cam.

The high pressure pump 100 comprises a barrel housing 101. A fluid passage 102 in the barrel housing 101 opens into and interfaces with a valve cone 103 of a valve holder 104 assembly. The high pressure fluid is received by the valve cone 103 during the forward stroke of the plunger. The fuel is then delivered to the injector via a constant pressure valve.

During assembly of the valve holder 104 assembly with the barrel housing 101, the valve holder 104 is tightened to a required torque by rotating the internal threads on the valve holder 104 against the external threads on the barrel housing 101. The valve cone 103 that is present in between the barrel housing 101 and the valve holder 104 experiences reactive forces. This reactive force is due to the tightening effect of valve holder 104 against the barrel housing 101. Moreover, during working of high pressure pump 100 the fluid passing through the valve cone 103, also pressurizes the valve cone 103.

To overcome the imbalance in the reactive force that is generated due to tightening of the valve holder 104, the valve cone 103 is provided with a spherical filleted profile 103a. The function of a valve cone 103 is to fluidly connect the fluid passage 102 to the injector. The valve cone 103 acts as a sealing unit between the valve holder 104 and the barrel housing 101. The valve cone 103 has a flange head 103b. The top surface of the flange head 103b contacts the valve holder 104 though the spherical filleted profile 103b. The contact point of the barrel housing 101 with the valve cone 103 is through the spherical filleted profile provided at the bottom of the valve cone 103.The valve cone 103 also contacts the constant pressure valve of the valve holder 104 assembly.

Figure 3 illustrates a valve holder assembly with the valve cone 103.The valve cone 103 has a flange head 103b. The spherical filleted 103a surface on the valve cone 103 provides the property of self alignment of the vale cone 103 when the valve cone 103 is assembled within the valve holder 104 and barrel housing 101.

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.

WE CLAIM:

1. A high pressure pump (100), comprising.

a barrel housing (101); a fluid passage (102) in said barrel housing (101) opening into and interfacing with a valve cone (103) of a valve holder (104) assembly.
characterized in that said valve cone (103) comprises a spherical filleted profile (103a).

2. The high pressure pump (100) of claim 1, wherein said valve cone (103) fluidly connects said fluid passage (102) to injector.

3. The high pressure pump (100) of claim 1, wherein said valve cone (103) has a flange head (103b).

4. The high pressure pump (100) of claim 2, wherein top surface of said flange head (103b) contacts the valve holder (104) though the spherical filleted profile (103b).

5. The high pressure pump (100) of claim 1, wherein the contact point of the barrel housing (101) with said valve cone (103) is through said spherical filleted profile (103a) provided at the bottom of said valve cone (103).

6. The high pressure pump (100) of claim 1, wherein the contact point of the valve holder (104) with said valve cone (103) is through said spherical filleted profile (103b) provided at the top of said valve cone (103).