Claims:We Claim:
1. A distributor type fuel injection pump (10), the pump (10) comprising:
a drive shaft (130) for receiving rotary input from an engine;
a delivery plunger (120) for delivery of fuel from the pump (10);
a control collar (135) for regulating delivery of fuel;
characterized in that:
a stepper motor (140) with a shaft (130); and
a wedge shaped slider (150) engaged with the shaft (130), and capable of translating axially from a first position to a second position along the shaft (130),
wherein the slider (150) engages with the control collar (135) and enables regulating the delivery of fuel.

2. The distributor type fuel injection pump (10) as claimed in Claim 1, wherein the stepper motor (140) comprises an encoder, to provide feedback on a position of the shaft (130), to a control unit
, Description:FIELD OF THE INVENTION
[0001] This invention relates to a distributor type fuel injection pump.

BACKGROUND OF THE INVENTION
[0002] Fuel injection pumps pressurizes the diesel fuel to prepare for injection into the cylinders. The pump supplies fuel along high-pressure injection lines to the nozzle-and-holder assemblies that inject the fuel into the combustion chambers. Critical criteria that influence the combustion process are timing and duration of fuel injection, distribution pattern in the combustion chamber, point at which combustion starts, quantity of fuel injected for each degree of crankshaft travel and the total quantity of fuel supplied relative to the engine’s load factor. The distributor type injection pump with axial piston provides the advantages of maintenance friendliness, low weight and compactness. US2922371 discloses a distributor type fuel injection pump for internal combustion engines with a housing having a longitudinal bore, a rotor mounted for rotation in said bore, said rotor having pumping and distribution portions, said pumping portion having radial cylinder means and piston means mounted for reciprocation in said radial cylinder means, cam means operatively associated with said piston means for effecting reciprocation of, said piston means upon rotation of said rotor.

BRIEF DESCRIPTION OF DRAWINGS
[0003] Embodiments of this disclosure is explained in principle below with reference to the drawings. The drawings are:
[0004] FIGURE 1 shows a fuel injection pump with a stepper motor based arrangement.

DETAILED DESCRIPTION
[0005] FIGURE 1 shows a distributor type fuel injection pump 10 with a stepper motor based arrangement. The pump 10 is broadly divided into the following segments, a low pressure stage 105, a high pressure pump 110 with distributor and a control mechanism 115. The low pressure stage 105 generally takes in diesel fuel and pressurizes an inner chamber of the pump 10. The low pressure stage 105 also comprises a pressure control valve to control the pressure mentioned above. The low pressure stage 105 also comprises an overflow valve, which is adapted to return fuel to cool the pump 10. In the high pressure pump 110, a plunger 120 distributes the pressurized fuel to a delivery valve 125. The number of delivery valves 125 is the same as the number of cylinders in the engine. The general operation of the distributor type fuel injection pump is understood by a person of ordinary skill in the art. The control mechanism 115 will be described in detail hereinafter.
[0006] Moreover, the distributor type fuel injection pump 10 comprises a drive shaft 130 for receiving rotary input from the engine, the delivery plunger 120 for delivery of fuel from the pump 10 to the engine, a control collar 135 for regulating delivery of fuel from the pump 10, a stepper motor 140 with a shaft 145, a wedge shaped slider 150 engaged with the shaft 145, and capable of translating axially from a first position to a second position along the shaft 145, the slider 150 engaging with the control collar 135 and enables regulating the delivery of fuel to the engine. To elaborate, the control mechanism 115 comprises the stepper motor 140, the shaft 145 and the slider 150.
[0007] The shaft 145 mentioned above has a fine pitched threaded end, with which the slider 150 is engaged. As is evident from FIGURE 1, a wedged side 155 of the wedge shaped slider 150 butts against a portion of the control collar 135. The control collar 135 is spring loaded. The slider 150 is orientated with an elongated side of the slider 150 collinear to or parallel to an axis of the stepper motor 140 and the shaft 145. The rotation of the stepper motor 140 rotates the shaft 145, which enables the slider 150 to translate along the elongated side or length from the first position to the second position and alternately from the second position to the first position. As the slider 150 translates between the first position and the second position, the wedged side 155, by virtue of the angled orientation pushes the control collar 135 against the spring. To elaborate, as the slider 150 moves from the motor 140 side towards a center of the pump 10, the collar 135 is pushed towards the delivery side of the pump 10 and vice versa. The movement of the control collar 135 helps in regulating the fuel delivery from the pump 10.
[0008] The stepper motor 140 also comprises an encoder to provide feedback on a position of the shaft 145 to a control unit. The relationship between the movement of the control collar 135 and the regulation of fuel delivery is understood by a person of ordinary skill in the art.
[0009] The advantage of this arrangement is a reduction in cost and better fuel regulation. Better fuel regulation refers to better accuracy because of the use of a stepper motor. This arrangement also results in reduction in size.
[0010] This is suited for applications in diesel generator sets where steep speed drops are required. This arrangement can also be deployed in other diesel engines such as cars and commercial vehicles.
[0011] 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. Any modification in the embodiments are envisaged and form a part of this invention. The scope of this invention is limited only by the claims.