# US 2013/0156620 A1 · Fuel injection pump including a variable pressure compartment

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- Number: US 2013/0156620 A1
- Document ID: US20130156620A1
- Status: Published application
- Kind: A1
- Application number: 13/819,005
- Filed: 2011-03-21
- Published: 2013-06-20
- Earliest claimed: 2010-10-20
- Assignees: Hyundai Heavy Industries Co., Ltd.
- Inventors: Deuk-Jin Park; Ju-Tae Kim; Dong-Hun Kim; Wook-Hyeon Yoon; Byong-Seok Kim; Tae-Hyung Park; Eun Ha; Beom-Yong No
- Web page: https://patentgrep.com/patent/US20130156620A1

## CPC

- F04B 49/12: by varying the length of stroke of the working members
- F02M 59/022: {having an accumulator storing pressurised fuel during pumping stroke of the piston for subsequent delivery to the injector}
- F02M 59/20: Varying fuel delivery in quantity or timing
- F02M 59/205: {Quantity of fuel admitted to pumping elements being metered by an auxiliary metering device}
- F02M 59/22: Varying quantity {or timing} by adjusting cylinder-head space
- F02M 59/462: {Delivery valves}
- F04B 1/053: with actuating or actuated elements at the inner ends of the cylinders
- F04B 7/00: Piston machines or pumps characterised by having positively-driven valving
- F04B 11/0016: {with a fluid spring}
- F04B 11/0033: {with a mechanical spring}
- F04B 49/16: by adjusting the capacity of dead spaces of working chambers
- F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F)
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF

## Abstract

The present invention relates to a fuel injection pump having a variable pressure chamber which can adjust a fuel injection timing according to each engine load with a simple structure and a lower manufacture cost compared to the conventional injection pump without a separate apparatus for moving a barrel as well as not modifying a shape of a plunger. The fuel injection pump having the variable pressure chamber further includes a pressure adjustment means including a contact plug of which lower portion is inserted and installed in the upper cover; a cylinder of which lower portion is inserted and installed in the contact plug and having the variable pressure chamber formed inside thereof; a main fuel pressing hole formed in the upper cover and the barrel to connect the variable pressure chamber of the cylinder and a plunger insertion hole of the barrel; a piston installed in the variable pressure chamber of the cylinder to enable an upward and downward sliding motion thereof; and a manual pressure adjustment unit installed on an upper portion of the cylinder to enable a vertical height adjustment to elastically support the upper portion of the piston.

## Claims

### Claim 1

A fuel injection pump having a variable pressure chamber, comprising:
a barrel inserted and installed within a pump housing;
a plunger slidably coupled to an inside of the barrel; and
an upper cover coupled to an upper surface of the pump housing, wherein the plunger closes a discharge hole of the barrel to begin a pressure increase of fuel to inject high pressure fuel, the fuel injection pump further comprising:
a pressure adjustment means comprising:
a contact plug of which lower portion is inserted and installed in the upper cover;
a cylinder of which lower portion is inserted and installed in the contact plug and having the variable pressure chamber formed inside thereof;
a main fuel pressing hole formed in the upper cover and the barrel to connect the variable pressure chamber of the cylinder and a plunger insertion hole of the barrel;
a piston installed in the variable pressure chamber of the cylinder to enable an upward and downward sliding motion thereof; and
a manual pressure adjustment unit installed on an upper portion of the cylinder to enable a vertical height adjustment to elastically support an upper portion of the piston.

### Claim 2 (depends on 1)

The fuel injection pump of claim 1, wherein the pressure adjustment means further comprises:
an automatic pressure adjustment unit connected to an air inflow groove which penetrates the cylinder and the contact plug to be positioned above the piston and to automatically adjust a location of the piston.

### Claim 3 (depends on 2)

The fuel injection pump of claim 2, wherein the automatic pressure adjustment unit comprises:
an air pressure supplier connected to the air inflow groove, which penetrates the cylinder and the contact plug, through an air pressure supplier connection line to be located above the piston;
a variable pressure valve installed on the air pressure supplier connection line; and
an engine load signaling device connected to the variable pressure valve and an engine.

### Claim 4 (depends on 2)

The fuel injection pump of claim 2, wherein the manual pressure adjustment means comprises:
a pressure adjustment screw which is screw coupled to the upper portion of the cylinder to be located above the piston, a vertical height of the pressure adjustment screw being adjustable;
an elastic member interposed between the piston and the pressure adjustment screw to elastically support the piston with respect to the pressure adjustment screw; and
a fixing nut which closely contacts an upper surface of the cylinder and is screw coupled to an upper portion of the pressure adjustment screw to fix the pressure adjustment screw.