CN110939538A

CN110939538A - Fuel filter in fuel injection system

Info

Publication number: CN110939538A
Application number: CN201910899945.4A
Authority: CN
Inventors: G.P.安东尼
Original assignee: Robert Bosch GmbH; Bosch Ltd
Current assignee: Robert Bosch GmbH; Bosch Ltd
Priority date: 2018-09-21
Filing date: 2019-09-23
Publication date: 2020-03-31
Anticipated expiration: 2039-09-23
Also published as: CN110939538B

Abstract

A fuel filter (102) in a fuel injection system is disclosed. The fuel filter (102) is located upstream of the fuel tank (104) and downstream of the high pressure pump (106), and includes a first flow path (108) in flow communication with the fuel tank (104). The fuel filter (102) comprises at least a second flow path (110), the second flow path (110) being in flow communication with an electric feed pump (111) located in the fuel tank (104). A solenoid (112) is positioned along the second flow path (110), the solenoid (112) adapted to open the second flow path (110) to either of the fuel filter (102) and the dosing injector (114).

Description

Fuel filter in fuel injection system

Technical Field

The present invention relates to the field of fuel filters in fuel injection systems.

Background

In a fuel injection system, an electrically powered feed pump located in a fuel tank is used during an engine start-up state to supply fuel to a high-pressure fuel injection pump via a feed pump located in the vicinity of the high-pressure fuel injection pump. Once the engine accelerates, the electric feed pump is switched "off" and the feed pump driven by the engine receives sufficient force to draw fuel from the fuel tank. During operation of this feed pump, it is necessary to ensure that fuel initially supplied by the electric feed pump does not flow back to the fuel tank during the engine start-up state.

Drawings

Various modes of the invention are disclosed in detail in the specification and illustrated in the accompanying drawings:

FIG. 1 illustrates a fuel filter in a fuel injection system during an engine start phase;

FIG. 2 illustrates a fuel filter in a fuel injection system during engine operation; and

FIG. 3 illustrates a fuel filter in a fuel injection system during hydrocarbon injection (HCI) dosing, and illustrates a graph showing filter status during fuel injection system operation.

Detailed Description

FIG. 1 illustrates a fuel filter 102 in a fuel injection system during an engine start phase. The fuel filter 102 is located upstream of the fuel tank 104 and downstream of the high pressure pump 106, and includes a first flow path 108. The first flow path 108 is in flow communication with the fuel tank 104. The fuel filter 102 includes at least a second flow path 110, the second flow path 110 being in flow communication with an electric supply pump 111 located in the fuel tank 104, and a solenoid 112 being positioned along the second flow path 110, the solenoid 112 being adapted to open the second flow path 110 to either of the fuel filter 102 and the dosing injector 114. In one embodiment, the solenoid 112 is actuated by an electronic control unit. A flow control valve 109 is located at the interface of the first flow path 108 and the second flow path 110.

Consider the situation during the engine start phase. When the engine starts, the electric supply pump 111 is switched "on", and the electric supply pump 111 delivers fuel to the fuel filter 102 through the second flow path 110, which then reaches the interface 105 of the first flow path 108 and the second flow path 110. The pressure of the fuel causes the flow control valve 109 to block the first flow path 108. Now, the fuel flows within the fuel filter 102 and reaches the high pressure pump 106.

Fig. 2 illustrates a fuel filter 102 in a fuel injection system during engine operation. When the engine starts driving the feed pump 107, the electric feed pump 111 is switched "off", and the suction force generated by the feed pump 107 causes the fuel to flow through the flow path 108. The pressure of the fuel lifts the flow control valve 109, causing the fuel to flow within the fuel filter 102 and to the high pressure pump 106.

FIG. 3 illustrates a fuel filter 102 in a fuel injection system during hydrocarbon injection (HCI) dosing. Consider the situation when there is a dosing requirement along the discharge flow path. In order to enable dosing, the fuel in the fuel tank 104 needs to flow at a pressure which is controlled by a valve 105 present in the fuel tank 104. Alternatively, the valve may be between the electric supply pump 111 and the first flow path 108. When the electric feed pump 111 is switched "on" and the solenoid 112 is actuated by the electronic control unit. The solenoid 112 blocks the second flow path 110 and fuel from the electric feed pump 111 flows along the dosing flow path 107 to reach the dosing injector 114. The metering injector then injects fuel along the discharge path. During dosing, the first flow path 108 provides fuel to the high-pressure pump 106.

Thus, by using the above-described fuel filter 102 having multiple flow paths (first flow path 108 and second flow path 110), fuel can now be supplied during various demands such as dosing, engine start-up, and during normal engine operation.

Fig. 3 illustrates a diagram showing the state of the filter 102 during operation of the fuel injection system. During the start-up phase, the electric feed pump 111 is kept "on", the feed pump 107 being kept "on" during normal operation of the engine and during HCI dosing. The flow control valve 109 is closed during the engine start phase. During operation of the fuel injection system 100, the valve 113 remains "open". The port 115 is opened with the solenoid valve (i.e., solenoid valve) 112 only during the time when HCI dosing is required.

In the context of the present disclosure, "adapted" or "arranged" refers to a technical property or technical capability of a component, with respect to which the term "adapted" or "arranged" is used to perform or execute a specified action or actions, when such is required. Furthermore, the use of the terms "adapted to" or "arranged" herein is with reference to the normal technical performance or capability of the component as conferred by the design or structure or composition of the component, and not with reference to any special or extraneous performance or capability beyond the scope of the normal technical performance or capability. Therefore, a solution to this problem is required.

It should be understood that the embodiments explained in the above description are merely illustrative and do not limit the scope of the invention in terms of the type of solenoid or fuel filter used. Many such embodiments, as well as other modifications and variations of the embodiments explained in this specification, are contemplated. The scope of the invention is limited only by the scope of the claims.

Claims

1. A fuel filter (102) in a fuel injection system (100), the fuel filter (102) being located upstream of a fuel tank (104) and downstream of a high pressure pump (106) and comprising a first flow path (108), the first flow path (108) being in flow communication with the fuel tank (104), characterized in that:

the fuel filter (102) comprises at least a second flow path (110), the second flow path (110) being in flow communication with an electric feed pump (111) located in the fuel tank (104); and a solenoid (112) positioned along the second flow path (110), the solenoid (112) adapted to open the second flow path (110) to any one of the fuel filter (102) and a dosing injector (114).

2. The fuel filter (102) of claim 1, wherein the solenoid is actuated by an electronic control unit.

3. The fuel filter (102) of claim 1, wherein a flow control valve (109) is located at an interface of the first flow path (108) and the second flow path (110).