WO2018001788A1 - A backflow pipe assembly in a fuel injection system - Google Patents

A backflow pipe assembly in a fuel injection system Download PDF

Info

Publication number
WO2018001788A1
WO2018001788A1 PCT/EP2017/065028 EP2017065028W WO2018001788A1 WO 2018001788 A1 WO2018001788 A1 WO 2018001788A1 EP 2017065028 W EP2017065028 W EP 2017065028W WO 2018001788 A1 WO2018001788 A1 WO 2018001788A1
Authority
WO
WIPO (PCT)
Prior art keywords
backflow
injector
valve
fuel
backflow pipe
Prior art date
Application number
PCT/EP2017/065028
Other languages
French (fr)
Inventor
Laxminarayan MANJUNATH NAIK
George Prakash Anthony
Original Assignee
Robert Bosch Gmbh
Bosch Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch Gmbh, Bosch Limited filed Critical Robert Bosch Gmbh
Publication of WO2018001788A1 publication Critical patent/WO2018001788A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/002—Arrangement of leakage or drain conduits in or from injectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
    • F02M37/0011—Constructional details; Manufacturing or assembly of elements of fuel systems; Materials therefor
    • F02M37/0017—Constructional details; Manufacturing or assembly of elements of fuel systems; Materials therefor related to fuel pipes or their connections, e.g. joints or sealings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
    • F02M37/0011—Constructional details; Manufacturing or assembly of elements of fuel systems; Materials therefor
    • F02M37/0023—Valves in the fuel supply and return system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
    • F02M37/0047—Layout or arrangement of systems for feeding fuel
    • F02M37/0052—Details on the fuel return circuit; Arrangement of pressure regulators

Definitions

  • This invention relates to the field of backflow pipe connector for a fuel injector. Background of the invention
  • a fuel injector is a part of both low pressure circuit and high pressure circuit in a fuel injection system.
  • the high pressure circuit comprises at least a high pressure pump, accumulator, and the injector adapted to receive pressurized fuel from the accumulator.
  • the injector opens and closes for injecting fuel into the engine cylinder based upon signals from the ECU.
  • the un-injected volume of fuel that is left over in the injector due to factors like opening & closing of the injector and leakage through clearances, needs to be relieved from the injector to avoid secondary injection and un-necessary pressure build up in the injector so as to prevent damage to the components of the injector.
  • Located in the injector is a back flow path that opens into a pipe leading to a fuel tank.
  • the pressure at which un-injected fuel is relieved back to the fuel tank is generally referred to as back pressure.
  • the back pressure depends upon the dimensions of the pipe, material of the pipe and the like.
  • the back pressure of fuel is maintained to an acceptable level by having a check valve/ non-return valve in the fuel return pipe of the low pressure circuit.
  • FIG. 1 illustrates a backflow pipe for a fuel injector 100 used in the state of art.
  • the back flow pipe is a part of low pressure circuit in the fuel injection system.
  • the backflow pipe 106 connects the backflow connector 104 of the injector 100 to the fuel tank 108.
  • the un- injected fuel from the injector 100 is sent back to the fuel tank 108 through the back flow pipe 106.
  • the backflow pipe 106 has a one-way valve (check/ non-return valve) 102 that allows the fuel to flow through the backflow pipe in one direction only, i.e. from the backflow connector to the fuel tank and not the other way.
  • the diameter of the pipe and pipe characteristic influence the back pressure of the injector.
  • the back pressure to injector can be affected by the material of the back flow pipe, diameter/length and layout of the low pressure circuit in the fuel injection system.
  • FIG. 1 illustrates a backflow pipe for a fuel injector used in state of art
  • FIG. 2 illustrates a backflow pipe assembly in a fuel injection system.
  • FIG. 2 illustrates a backflow pipe assembly 200 in a fuel injection system.
  • the backflow pipe assembly 200 is adapted to send un-injected fuel from an injector to a fuel tank, and comprises at a backflow connector 202 engaged to a back flow outlet of the injector.
  • the backflow connector 202 is removably fitted to the injector in the fuel injection system.
  • a valve 208 is located within the back flow connector 202, the valve 208 is adapted to throttle un-injected fuel received from the backflow outlet 104 of the injector into the backflow pipe 206.
  • the valve 208 is integrated with the backflow connector 202.
  • the valve 208 may also be removably fitted to the back flow connector 202.
  • the valve 208 is a one-way valve, and is at least one, from a combination comprising at least a ball valve, a pin type valve, a pintle valve.
  • the backflow pipe assembly 200 with backflow connectors 202 is located in the low pressure circuit of the fuel injection system.
  • the backflow connector 202 is attached to the backflow outlet of the injector 104 and the other end of the backflow pipe connector 202 opens backflow pipe 206.
  • Each injector has such an arrangement, comprising the backflow connector 202 attached to the backflow outlet of the injector (For the purpose of simplicity only one injector with back flow connector is shown in FIG.2).
  • Backflow fuel flow from the injectors via the back flow connector 202 and to the backflow pipe 206 back into the fuel tank.
  • the backflow connector 202 is removably fitted to the backflow pipe 206 in the fuel injection system.
  • the injector 210 receives fuel for injection into the engine cylinder, from the accumulator.
  • the ECU through signals to the injector, decides the quantity of fuel that needs to be injected into the engine cylinder.
  • the injector opens and closes, during fuel delivery.
  • the un-injected fuel generally comprises leakage from injector (clearances in injector components, dead volume) and the control quantity used to enable injection of fuel in the injector.
  • the un-injected fuel flows through the fuel return path present in the injector to reach the backflow outlet of the injector.
  • the function of the fuel return path is to allow un-injected fuel present within the injector to flow back to the backflow pipe 206 present in the low pressure circuit.
  • the valve 208 that is located in the backflow pipe connector 202 throttles un-injected fuel and maintains the required back pressure to the injector, the fuel now flows through the backflow pipe 206 to reach the fuel tank. Since, the valve 208 is a one-way valve, flow of fuel is only possible from the backflow pipe to the fuel tank 220. As the fuel is throttled in the backflow pipe connector 202 itself, the need for a separate valve 102 (as disclosed in the detailed description of FIG. 1) in the back flow pipe 206 is not required anymore (in comparison to FIG.l in state of art).
  • This arrangement largely removes the influence of the low pressure pipe 206, on the injection quantity. Additionally, the requirements on the backflow pipe 206 is reduced in terms of pressure capability and retaining material properties within a close band.
  • back flow pipe pressure also referred to a as back pressure can be eliminated in the low pressure circuit.
  • the back flow pipe assembly with the proposed back flow connector gives greater flexibility in designing the low pressure circuit.

Abstract

Disclosed herein is a backflow pipe assembly (200) in a fuel injection system. The backflow pipe assembly (200) is adapted to send un-injected fuel from an injector to a fuel tank, and, comprises at least a backflow connector (202) engaged to a back flow outlet of the (injector 210). A valve (208) is located within the backflow connector (202), the valve (208) is adapted to throttle un-injected fuel received from the backflow outlet (204) of the injector (210) into the backflow pipe (206).

Description

Description
TITLE:
A Backflow pipe assembly in a fuel injection system Field of the invention
This invention relates to the field of backflow pipe connector for a fuel injector. Background of the invention
A fuel injector is a part of both low pressure circuit and high pressure circuit in a fuel injection system. The high pressure circuit comprises at least a high pressure pump, accumulator, and the injector adapted to receive pressurized fuel from the accumulator. The injector opens and closes for injecting fuel into the engine cylinder based upon signals from the ECU. The un-injected volume of fuel that is left over in the injector, due to factors like opening & closing of the injector and leakage through clearances, needs to be relieved from the injector to avoid secondary injection and un-necessary pressure build up in the injector so as to prevent damage to the components of the injector. Located in the injector is a back flow path that opens into a pipe leading to a fuel tank. The pressure at which un-injected fuel is relieved back to the fuel tank is generally referred to as back pressure. The back pressure depends upon the dimensions of the pipe, material of the pipe and the like. In the current state of art, the back pressure of fuel, is maintained to an acceptable level by having a check valve/ non-return valve in the fuel return pipe of the low pressure circuit. In order to ensure the stability of the injection quantity over lifetime and for the robustness of the injector for lifetime, there is a need to make the backpressure of the fuel independent of the pipe characteristics.
FIG. 1 illustrates a backflow pipe for a fuel injector 100 used in the state of art. The back flow pipe is a part of low pressure circuit in the fuel injection system. The backflow pipe 106 connects the backflow connector 104 of the injector 100 to the fuel tank 108. The un- injected fuel from the injector 100, is sent back to the fuel tank 108 through the back flow pipe 106. The backflow pipe 106, has a one-way valve (check/ non-return valve) 102 that allows the fuel to flow through the backflow pipe in one direction only, i.e. from the backflow connector to the fuel tank and not the other way. It is observed that, in addition to the backflow valve, the diameter of the pipe and pipe characteristic influence the back pressure of the injector. The back pressure to injector can be affected by the material of the back flow pipe, diameter/length and layout of the low pressure circuit in the fuel injection system.
Brief description of the accompanying drawing
Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:
FIG. 1 illustrates a backflow pipe for a fuel injector used in state of art; and FIG. 2 illustrates a backflow pipe assembly in a fuel injection system. Detailed description of the embodiments
FIG. 2 illustrates a backflow pipe assembly 200 in a fuel injection system. The backflow pipe assembly 200 is adapted to send un-injected fuel from an injector to a fuel tank, and comprises at a backflow connector 202 engaged to a back flow outlet of the injector. The backflow connector 202 is removably fitted to the injector in the fuel injection system. A valve 208 is located within the back flow connector 202, the valve 208 is adapted to throttle un-injected fuel received from the backflow outlet 104 of the injector into the backflow pipe 206. The valve 208 is integrated with the backflow connector 202. The valve 208 may also be removably fitted to the back flow connector 202. The valve 208 is a one-way valve, and is at least one, from a combination comprising at least a ball valve, a pin type valve, a pintle valve.
The constructional details of backflow pipe assembly 200 with backflow connectors 202 will now be described in further detail. The backflow pipe assembly 200 with backflow connectors 202 is located in the low pressure circuit of the fuel injection system. The backflow connector 202 is attached to the backflow outlet of the injector 104 and the other end of the backflow pipe connector 202 opens backflow pipe 206. Each injector has such an arrangement, comprising the backflow connector 202 attached to the backflow outlet of the injector (For the purpose of simplicity only one injector with back flow connector is shown in FIG.2). Backflow fuel flow from the injectors via the back flow connector 202 and to the backflow pipe 206 back into the fuel tank. The backflow connector 202 is removably fitted to the backflow pipe 206 in the fuel injection system.
The working of fuel injector 210 with the valve 208 integrated in the backflow pipe connector 202 will now be explained in detail with reference to FIG. 2. The injector 210, receives fuel for injection into the engine cylinder, from the accumulator. The ECU through signals to the injector, decides the quantity of fuel that needs to be injected into the engine cylinder. The injector opens and closes, during fuel delivery. The un-injected fuel generally comprises leakage from injector (clearances in injector components, dead volume) and the control quantity used to enable injection of fuel in the injector. The un-injected fuel flows through the fuel return path present in the injector to reach the backflow outlet of the injector. The function of the fuel return path is to allow un-injected fuel present within the injector to flow back to the backflow pipe 206 present in the low pressure circuit. The valve 208 that is located in the backflow pipe connector 202 throttles un-injected fuel and maintains the required back pressure to the injector, the fuel now flows through the backflow pipe 206 to reach the fuel tank. Since, the valve 208 is a one-way valve, flow of fuel is only possible from the backflow pipe to the fuel tank 220. As the fuel is throttled in the backflow pipe connector 202 itself, the need for a separate valve 102 (as disclosed in the detailed description of FIG. 1) in the back flow pipe 206 is not required anymore (in comparison to FIG.l in state of art). This arrangement largely removes the influence of the low pressure pipe 206, on the injection quantity. Additionally, the requirements on the backflow pipe 206 is reduced in terms of pressure capability and retaining material properties within a close band. By having a separate back flow connector the influence of back flow pipe pressure also referred to a as back pressure can be eliminated in the low pressure circuit. The back flow pipe assembly with the proposed back flow connector gives greater flexibility in designing the low pressure circuit.
It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention in terms of and also the type of valve used. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.

Claims

We Claim:
1. A backflow pipe assembly (200) in a fuel injection system, said backflow pipe
assembly adapted to send un-injected fuel from injector (210) to a fuel tank, and, said comprising at least: a backflow connector 202 engaged to a back flow outlet of said injector; characterized in that: a valve (208) located within said backflow connector 202, said valve (208) adapted to throttle un-injected fuel received from said backflow outlet 204 of said injector into said backflow pipe (206).
2. The backflow pipe assembly 200 of claim 1, wherein said valve (208) is integrated with said backflow pipe connector (200).
3. The backflow pipe assembly 200 of claim 1, wherein said valve 208 is removably fitted to said back flow pipe connector (200).
4. The backflow pipe assembly 200 of claim 1, wherein said valve (208) is a one-way valve.
5. The backflow pipe assembly 200 of claim 1 and 4, wherein said valve (208) is at least one chosen from a group comprising at least a ball valve, a pin type valve, a pintle valve.
6. The backflow pipe assembly 200 of claim 1, wherein said backflow connector 202 is removably fitted to said injector in said fuel injection system.
PCT/EP2017/065028 2016-06-29 2017-06-20 A backflow pipe assembly in a fuel injection system WO2018001788A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IN201641022333 2016-06-29
IN201641022333 2016-06-29

Publications (1)

Publication Number Publication Date
WO2018001788A1 true WO2018001788A1 (en) 2018-01-04

Family

ID=59078079

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2017/065028 WO2018001788A1 (en) 2016-06-29 2017-06-20 A backflow pipe assembly in a fuel injection system

Country Status (2)

Country Link
FR (1) FR3053410A1 (en)
WO (1) WO2018001788A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020153337A (en) * 2019-03-22 2020-09-24 ヤンマーパワーテクノロジー株式会社 engine

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4213434A (en) * 1978-01-18 1980-07-22 Robert Bosch Gmbh Fuel injection system
DE19941703A1 (en) * 1999-09-02 2001-03-08 Bosch Gmbh Robert Fuel injection valve for internal combustion engines
DE102004041215A1 (en) * 2004-08-26 2006-03-02 Robert Bosch Gmbh Pressure relief valve for use in common rail system, has throttle portion formed for accelerating valve element when valve is opened and when acceleration phase of flowing fuel is increased to maintain or increase pressure in return pipe

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4213434A (en) * 1978-01-18 1980-07-22 Robert Bosch Gmbh Fuel injection system
DE19941703A1 (en) * 1999-09-02 2001-03-08 Bosch Gmbh Robert Fuel injection valve for internal combustion engines
DE102004041215A1 (en) * 2004-08-26 2006-03-02 Robert Bosch Gmbh Pressure relief valve for use in common rail system, has throttle portion formed for accelerating valve element when valve is opened and when acceleration phase of flowing fuel is increased to maintain or increase pressure in return pipe

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020153337A (en) * 2019-03-22 2020-09-24 ヤンマーパワーテクノロジー株式会社 engine
WO2020195666A1 (en) * 2019-03-22 2020-10-01 ヤンマー株式会社 Engine

Also Published As

Publication number Publication date
FR3053410A1 (en) 2018-01-05

Similar Documents

Publication Publication Date Title
US7249593B2 (en) Injection system for an internal-combustion engine
US7509943B2 (en) Injection system for an internal-combustion engine
KR101696498B1 (en) Fuel system for an internal combustion engine
US7278399B2 (en) Injection system for an internal-combustion engine
CN105745430B (en) Overflow valve and fuel injection system for fuel injection system
KR101857376B1 (en) Pump arrangement and system for a motor vehicle
CN108138735A (en) For the flow restrictor of injector
WO2016088339A1 (en) High-pressure pump and fuel-supply system using same
US20140041635A1 (en) Fuel rail connector
EP3180510B1 (en) A fuel injection valve arrangement for internal combustion engine
US8302888B2 (en) Fuel injector
JP6202606B2 (en) Fuel injection valve
RU2621846C2 (en) Flow limiter with ball and throttle
US8348176B2 (en) Fuel injector with an integrated pressure booster
WO2018001788A1 (en) A backflow pipe assembly in a fuel injection system
US20090184183A1 (en) Fuel injection device for an internal combustion engine
US20120205469A1 (en) Dual Mode Fuel Injector
KR101687036B1 (en) Suction valve of a fuel supply system of an internal combustion engine
US20080018101A1 (en) Return line connector
CN109790807B (en) Throttling element, high-pressure pump, low-pressure circuit of fuel injection system
WO2014072678A4 (en) A pump assembly and a valve
US8899263B2 (en) Return line connector
CN109386415B (en) Fuel injection system
CN107448338A (en) Fuel injector
EP3146195B1 (en) Connecting element for fuel injection system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17731152

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17731152

Country of ref document: EP

Kind code of ref document: A1