Field of the invention
[0001]This invention relates to the field of a fuel injection pump.
Background of the invention
[0002]The function of a fuel injection pump is to deliver pressurized fuel to the common rail and in turn to the fuel injector. The fuel injection pump comprises a pressurizing chamber with a reciprocating plunger. The plunger has a helix cut. A control sleeve causes the helix to rotate. The control sleeve is in geared connection with a control rod, the control rod being driven by a governor in dependence of demand from the user of the vehicle. It is observed the there is a change in positional orientation of the control rod due to deformation in the housing of the fuel injection pump. This restricts the movement of control rod leading to a situation called stickiness of the control rod. Hence there is a need maintain positional orientation of the control rod within the housing of the fuel injection pump.
[0003]Prior art patent application US4753580 discloses a fuel injection pump for an internal combustion engine, in which fuel drawn into a pressure chamber is pressure delivered by reciprocating motion of a plunger. A control sleeve is slidably fitted on the plunger is axially moved by angular movement of a control rod to vary a prestroke of the plunger. The control rod is supported by a self-aligning bearing fixed in place by a tightening nut within one of a pair of fitting bores formed in a pump housing and a bush disposed within the other fitting bore.
Brief description of the accompanying drawing
[0004] Different modes of the invention are disclosed in detail in the description and
illustrated in the accompanying drawing:
[0005] FIG. 1 illustrates a fuel injection pump.
Detailed description of the embodiments

[0006] FIG. 1 illustrates a fuel injection pump 100. The fuel injection pump 100 comprises at least at least a housing 102, the housing 102 accommodates a plunger 104, a control rod 106 is mechanically engaged to the plunger 104 via a control sleeve 108. An actuator 110 is located in the housing 102, the actuator 110 is adapted to provide a force to a drive element 112 in order to continuously engage the control sleeve 108 and the control rod 106. The actuator 110 may be at least one of a spring based linear actuator 110, a piezo-electric actuator 110 and a mechanical actuator 110. The drive element 112 may be one of a piston and a spring. The actuator 110 receives a signal from either the control sleeve 108 or the control rod 106. The signal may be one a voltage, current and pulse width modulation
[0007]The constructional features of the fuel injection pump 100 will be explained in further detail. The function of the fuel injection pump 100 disclosed herein is to supply pressurized fuel to the common rail or the fuel injector. In order to achieve the above mentioned objective, the fuel injection pump 100 receives fuel from a fuel tank via an inlet (not shown). The fuel so received is pressurized in the fuel injection pump 100 due to reciprocating movement of the plunger 104 that is located in the housing 102 of the fuel injection pump 100. The plunger 104 needs to rotate in order to suck the fuel from the inlet. The rotational movement of the plunger 104 is achieved with the help of the control sleeve 108. The control rod 106 is mechanically engaged to the control sleeve 108. The movement of the control rod 106 is dependent on the demand for fuel and this is in turn controlled by the governor. The actuator 110 is located in the housing 102, the actuator 110 is adapted to provide a force to the drive element 112 in order to continuously engage the control sleeve 108 and the control rod 106. The drive element 112 may be a piston or a spring. The drive element 112 may be connected to the actuator 110, so as to receive the force from the actuator 110. The number of actuators and corresponding drive element 112 depends upon number of cylinder in the fuel injection pump 100. Thus for every plunger 104 in the fuel injection pump 100, a corresponding actuator 110 and drive element 112 is present in order to continuously engage the control sleeve 108 and said control rod 106, this ensures that all the plungers derive motion from the control sleeve 108.

[0008]During working of the fuel injection pump 100, fuel present in the fuel injection pump 100 needs to be pressurized. Fuel is sucked into the fuel injection pump 100 due to the movement of the plunger 104. The plunger 104 needs to rotate in order to suck the fuel from the inlet. The rotational movement of the plunger 104 is achieved with the help of the control sleeve 108 and the control rod 106. In order to keep the control sleeve 108 permanently engaged to the control rod 106, the actuator 110 is used along with a drive element 112. The actuator 110 adapted to provide a force to a drive element 112 in order to continuously engage the control sleeve 108 and the control rod 106. This ensures the control sleeve 108 and the control rod 106 are engaged in order to drive the plunger 104 of the fuel injection pump 100
[0009]It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention in terms of the type of plunger and the fuel injection pump. 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 fuel injection pump 100, comprising at least:
a housing 102, said housing 102 accommodating at least one plunger
104;
a control rod 106 mechanically engaged to said plunger 104 via a
control sleeve 108; characterized in that
an actuator 110 located in said housing 102, said actuator 110 adapted
to provide a force to a drive element 112 in order to continuously
engage said control sleeve 108 and said control rod 106.
2. The fuel injection pump 100 of claim 1, wherein said actuator 110 is at least one of a spring based linear actuator 110, a piezo-electric actuator 110 and a mechanical actuator 110.
3. The fuel injection pump 100 of claim 1, wherein said drive element 112 is one of a piston and a spring.
4. The fuel injection pump 100 of claim 1, further comprising receiving by said actuator 110 a signal from at least one of said control sleeve 108 and said control rod 106.
5. The fuel injection pump 100 of claim 4, wherein said signal is one a voltage, current and pulse width modulation.