FIELD OF INVENTION:

The invention is related to a fuel injection pump for pumping fuel into an internal combustion engine (ICE).

BACKGROUND OF THE INVENTION:

It is well known that in an internal combustion engine (ICE) the fuel is injected into the combustion chamber at very high pressure. The pressurized fuel is generally an output of a fuel injection pump. The fuel injection pump draws the fuel from a fuel reservoir or a fuel tank and pumps the fuel out at a desired pressure and into the combustion chamber. There are several mechanisms within the fuel injection pump for controlling the pressure and amount of fuel that is pumped into the combustion chamber of the ICE.

DESCRIPTION OF THE INVENTION:

The core of the current invention is a fuel injection pump with a cam plate integrated to a plunger of the pump. Further, the fuel injection pump comprises a solenoid pump for controlling the amount of fuel that is injected into an internal combustion engine (ICE) from the fuel injection pump.

The fuel injection pump is electronically controlled by a control unit. The control unit operates the solenoid pump and controls the pressure of fuel that is injected and the amount of fuel that is injected into the internal combustion engine.

The control unit of the current invention advantageously helps in reducing the number of moving parts inside the fuel injection pump, thus increasing the stability of the pump.

The solenoid valve acts as a intermediary between the barrel in which the fuel is pressurized and a fuel reservoir in which the fuel is stored outside the pump. The solenoid valve controls the pressure and amount of fuel that is injected into the ICE x depending on the temperature inside the pump and the speed of operation of the pump.

The cam plate is integrated with the plunger of the fuel injection pump and is in stationary position. In one operation, the cam plate is in an oscillatory position thus advancing or retarding the timing of the fuel injection into the ICE. The cam plate is in the oscillatory position with respect to a drive shaft of the fuel injection pump. The fuel injection is advanced or retarded depending on the cam plate being moved in a clockwise direction or an anti-clockwise direction.

SHORT DESCRIPTION OF DRAWINGS:

Figure 1 shows a block diagram of a typical fuel pump;

Figure 2 shows a block diagram of the fuel injection pump of the current invention; Figure 3 shows the block diagram of the control unit of the current invention; and Figure 4a, 4b and 4c show example profiles of the cam, plunger and drive shaft respectively, according to the aspects of the current invention.

DESCRIPTION OF DRAWINGS:

Figure 1 shows a schematic of a typical fuel injection pump 100 used in pumping fuel into an internal combustion engine (ICE). The fuel injection pump 100 comprises a drive means 1 for operating the pumping action of the pump 100, an inlet and outlet pressure controller 2 for controlling the pressure of the inlet and outlet fuel, a pumping unit 3 comprising a barrel 30 and a plunger 300 enclosed within the barrel 30 and performing the actual pumping of the fuel, an injection control unit 4 for advancing or retarding the timing of the injection of the fuel from the pump 100 and a governor 5 for controlling the speed of operation of the pump depending on the speed of the vehicle and load on the engine. The pumping unit 3 comprises a delivery valve 31 which is in a fluid connection with the barrel 30 of the pumping unit and delivers the pressurized fuel into the internal combustion engine.

The governor 5 is a mechanical element and comprises lot of moving elements and is not entirely reliable in performing precise control of the speed of operation of the pump 100. The pump of the current invention (as shown in figure 2) comprises a solenoid valve 35 for controlling the pressure and amount of pressurized fuel that is pumped into the ICE through the delivery valve 31. The solenoid valve acts as a intermediary between the pumping unit 3 and a fluid reservoir 80 external to the pump. The solenoid valve 35 is electronically controlled. The solenoid valve 35 diverts the pressurized fuel from the pumping unit 3 into the fluid reservoir 80 and thus controlling the quantity and the pressure of the fuel injected into the ICE. The solenoid valve 35 provides precise operation of the pump and helps in delivering right quantity of fuel into the ICE.

The solenoid valve 35 is controlled by a control unit 70 and as shown in figure 3. The control unit 70 may also control the delivery valve 31 and the drive means 1. By controlling the delivery valve 31 by the control unit 70, the timing of the pump can be varied such that the injection of the fuel into the ICE is advanced or retarded. The drive means 1 can also be controlled by the control unit 70 such that the speed of pumping operation of the pump is varied according to the needs of the ICE.

The control unit 70 obtains input from a temperature sensing means 36 sensing a temperature inside the barrel 30 of the pumping unit 3 and a speed detection means 37 detecting the speed of operation of the plunger inside the pumping unit 3 before controlling the solenoid valve 35.

The solenoid valve 35 is advantageous in that the barrel 30 and the plunger 300 (as shown in figure 4b) can be simplistic in design. As shown in figure 4a and 4c, the cam plate 200 design and the drive shaft 400 design respectively can also be simplistic and manufactured such that so as to handle less mechanical stress. The cam plate 200 can have a profile such that it operates in a stationary or in an oscillatory motion and hence reducing the mechanical stress on the pump body. In one oscillating movement of the cam plate 200, the timing of the fuel pump can be advanced and in another direction of oscillation of the cam plate 200, the timing of the fuel pump can be retarded.

WE CLAIM:

1. A Fuel injection pump (100) for pumping fluid into an internal combustion engine (ICE) comprising,

- a cam plate (200) in connection with a barrel (30),

- a plunger (300) in a reciprocating motion within the barrel (30) and in correlation with said cam plate (200),

Characterized in,

said cam plate (200) being integrated with said plunger (300),

a solenoid valve (35) in connection with said barrel (30) and controlling the fluid pumped into said internal combustion engine.

2. The fuel injection pump (100) as claimed in claim 1, wherein said cam plate (200) integrated with said plunger is in a stationary position or in an oscillatory motion with respect to a drive shaft (400) of said fuel injection pump (100).

3. The fuel injection pump (100) as claimed in claim 1 and 2, wherein said cam plate (200) integrated with said plunger (300) in said oscillatory motion results in advancement or retardation in the timing of said fuel being injected into said ICE.

4. The fuel injection pump (100) as claimed in claim 1, wherein said solenoid valve (35) controls the pressure of the fluid pumped by said fuel injection pump (100).

5. The fuel injection pump (100) as claimed in claim 1 and 4, wherein said solenoid valve (35) diverts pressurized fluid into a fluid reservoir (80) external to said Fuel injection pump (100), thereby controlling the quantity of the fuel that goes into the ICE.

6. The fuel injection pump (100) as claimed in claim 1, wherein said solenoid valve (35) is operated by a control unit (70).

7. The fuel injection pump (100) as claimed in claim 1 and 6, wherein said control unit (70) operates said solenoid valve (35) in dependence of speed of operation (37) of said pump and temperature (36) inside said barrel (30) of said pump (100).