High-pressure fuel pipe

Patent metadata

Field	Value
Publication number	US-11719206-B2
Application number	US-202017795756-A
Country	US
Kind code	B2
Filing date	Feb 28, 2020
Priority date	Feb 28, 2020
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A high-pressure fuel pipe is a pipe disposed between an injector and a high-pressure fuel pump, the high-pressure fuel pump is provided on a downstream side of a low-pressure fuel pump, an engine is a single cylinder or a two-cylinder, the high-pressure fuel pump is a plunger type that performs pressurization once or twice per rotation in synchronization with a camshaft of the engine, and a volume of the high-pressure fuel pipe is k×Q/ΔP/1000×n or less, where k is a volume modulus of fuel, Q is a maximum discharge amount of the fuel in one reciprocation of the high-pressure fuel pump, ΔP is a difference between a target fuel pressure boosted by the high-pressure fuel pump and a feed fuel pressure boosted by the low-pressure fuel pump, and n is the number of times of boosting in one rotation of the high-pressure fuel pump.

First claim

The invention claimed is:

1. A high-pressure fuel pipe applied to a cylinder injection type engine that directly injects fuel into a combustion chamber with an injector, wherein
the high-pressure fuel pipe is a pipe disposed between the injector and a high-pressure fuel pump,
the high-pressure fuel pump is provided on a downstream side of a low-pressure fuel pump,
the engine is a single cylinder or a two-cylinder,
the high-pressure fuel pump is a plunger type that performs pressurization once or twice per rotation in synchronization with a camshaft of the engine, and
a value of a volume of the high-pressure fuel pipe is k×Q/ΔP/1000×n or less, where k is a volume modulus of fuel, Q is a maximum discharge amount of the fuel in one reciprocation of the high-pressure fuel pump, ΔP is a difference between a target fuel pressure boosted by the high-pressure fuel pump and a feed fuel pressure boosted by the low-pressure fuel pump, and n is a number of times of boosting in one rotation of the high-pressure fuel pump.

2. The high-pressure fuel pipe according to claim 1 , wherein the value of the volume of the high-pressure fuel pipe is q/0.6 or more, where q is an amount of the fuel pressure-fed by the high-pressure fuel pump in one second.

3. The high-pressure fuel pipe according to claim 1 , wherein the value of the volume of the high-pressure fuel pipe is q/0.4 or more, where q is an amount of the fuel pressure-fed by the high-pressure fuel pump in one second.

4. The high-pressure fuel pipe according to claim 3 , wherein the volume of the high-pressure fuel pipe is calculated by a following arithmetic expression q/0.4≤Vt≤k×Q/ΔP/1000×n, where Vt is the volume of the high-pressure fuel pipe.

5. The high-pressure fuel pipe according to claim 4 , wherein
the volume of the high-pressure fuel pipe includes a pre-orifice volume on an upstream side and a post-orifice volume on a downstream side across an orifice, and
a value of the pre-orifice volume is q/3.0 or more.

6. The high-pressure fuel pipe according to claim 4 , wherein
the engine is a single cylinder engine,
k as the volume modulus of the fuel is 1300 MPa,
Q as the maximum discharge amount of the fuel in one reciprocation of the high-pressure fuel pump is 26.12 mm 3 /stroke, and
n as the number of times of boosting is one.

7. The high-pressure fuel pipe according to claim 4 , wherein
the engine is a two-cylinder engine,
k as the volume modulus of the fuel is 1300 MPa,
Q as the maximum discharge amount of the fuel in one reciprocation of the high-pressure fuel pump is 120.00 mm 3 /stroke, and
n as the number of times of boosting is two.

Assignees

• Honda Motor Co Ltd

Inventors

• Konuma Takayuki
• TABUCHI Aoi

Classifications

• F02M55/025 Primary

  Common rails · CPC title

• F02M59/025

  characterised by a single piston · CPC title

• F02M59/16

  characterised by having multi-stage compression of fuel · CPC title

• F16L55/027

  Throttle passages · CPC title

• F02M59/02 Primary

  of reciprocating-piston {or reciprocating-cylinder} type · CPC title