Fuel supply pump

Abstract

A fuel supply pump, which is simple in construction and easy to produce and is capable of efficiently pressurizing a high flow rate of fuel, is provided. The fuel supply pump (50) includes a housing (52), a plunger barrel (53), a plunger (54) for pressurizing fuel, which is installed in the plunger barrel (53) so as to be allowed to move up and down, a cam (60) installed in rotation way below the plunger (54), a tappet structure body (6) installed between the cam (60) and the plunger (54) to transmitting the turning force, serving as a lifting force, from the cam shaft (3) to the plunger (54), a tappet structure body (6) installed between the cam (60) and the plunger (54) and provided for transmitting a upward or downward movement of the cam (60) caused by the rotation of the camshaft (3) to the plunger (54); and a return spring (68) for setting lowering force to the plunger (54), which is installed between the tappet structure body (6) and the plunger barrel (53).

Description

TECHNICAL FIELD [0001] The present invention relates to a fuel supply pump. Particularly, the present invention relates to a fuel supply pump suitable for an accumulator fuel injection device with a pressure-amplifying piston (APCRS: Amplified Piston Common Rail System) that requires a high flow rate of pressurized fuel. BACKGROUNDS [0002] A conventional fuel supply pump 250 has been constructed as shown in FIG. 16. The conventional fuel supply pump 250 comprises: a pump housing 252 having a cylindrical space opened from end to end in the vertical direction; a plunger barrel 253 installed in the upper opening portion of the pump housing 252; a plunger 254 for pressurizing fuel, which is installed in the plunger barrel 253 and the cylindrical space of the pump housing 252 so as to be allowed to move up and down; a cam 260 installed in a rotation way below the plunger 254 and integrated with a cam shaft 3 (not shown) inserted into the pump housing 252 in the longitudinal direction; a ...

AI Technical Summary

Benefits of technology

[0010] That is, as constructed above, the inner peripheral surface of the pump housing does not require a projection for supporting the upper end of the return spring. Thus, no obstacle is provided on the inner peripheral surface of the pump housing has, so that the respective structural components such as the tappet structure body, the plunger barrel, and the plunger can be temporarily preassembled and inserted into the cylindrical space of the housing from the upper portion of the pump housing. In addition, no floor plug for inserting the tappet structure body is required. Consequently, the fuel supply pump simple in construction and easy to produce can be provided.

[0024] Using such an accumulator fuel injection device, the pressurization of the fuel having a large flow rate can be easily carried out. Therefore, the accumulator fuel injection device attains a further increase in fuel efficient, so that a diesel engine will have a higher power and an increase in fuel consumption, while attaining a reduction in particulate matters, and so on.

Problems solved by technology

Consequently, in the conventional fuel supply pump, there are problems in that the assembly work is complicated and the production cost is not easily reduced.

However, the degree of pressurization and the flow rate of fuel are still insufficient to allow higher power of the diesel engine.

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