Claims:We Claim

1. An automatic air bleeding structure (100) capable of being mounted on a high pressure fuel pump (102), said air bleeding structure (100) comprising:
a cylindrical housing (104) having a hexagonal shaped head and a threaded portion (104a) near to the bottom end of said housing (104), the threaded portion adapted for screwing the structure (100) onto the high pressure fuel pump (102), characterized in that, said structure (100) further comprises;
a sealing agent (105) positioned inside the cylindrical housing (104) and adapted to float in working fuel entering the structure (100);
a float guide (106) positioned below the sealing agent (105) and adapted to guide the movement of the sealing agent (105);
a spring element (107) mounted inside the float guide (106) and adapted to support the movement of the sealing agent (105).

2. The automatic air bleeding structure (100) in accordance with Claim 1, wherein said sealing agent (105) is made up of a material with a density lesser than the working fuel entering the structure (100).

3. The automatic air bleeding structure (100) in accordance with Claim 1, wherein said float guide (106) is further adapted to provide easy assembly of the sealing agent (105) within the cylindrical housing (104).

4. The automatic air bleeding structure (100) in accordance with Claim 1, wherein said structure 100 further comprises a filler piece (108) mounted inside the spring element (107) and is adapted to support and control the movement of the spring element (107).
, Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:

Field of the invention
[0001] The present invention relates to an automatic air bleeder structure for high pressure pumps, and more specifically to an automatic air venting screw for high pressure pump applications.

Background of the invention
[0002] In general, in fuel injection systems, the diesel engines have a high pressure pump that is connected to injection fuel lines. The high pressure pump helps pump fuel at a very high pressure. The fuel line carries the fuel from the fuel tank to the fuel injection system in a vehicle. Fuel lines are under high pressure. The high pressure fuel is then supplied into the engine cylinders through fuel injection lines. Whenever there is excess fuel, is then returned to the fuel tank with the help of valves, which is located on the fuel rail in most vehicles. During this process, air bubbles can be formed in the fuel injection system if the engine is running on low fuel or if there are fuel leaks in the fuel injection lines. For smooth engine function, it is important to bleed an injector pump of any air so that fuel can easily flow to the combustion chamber.

[0003] Existing Air bleeding tools in high pressure pump in fuel injection systems are manually operated. In general, the users of such systems have to do the air bleeding manually before starting the vehicle. However, the manual air bleeding in such systems, is a laborious process and is often subjective, especially when air bleeding calls for extra effort and time. In addition, it may be impractical for manual handling of such air bleeding issues in high pressure pumps as the feed pump used is vane pump, at higher speeds there is a higher probability of air bubbles getting generated within the pumps which cause cavitation at critical components.

[0004] A prior art patent document, US20160281662A1 describes an air separator having a vessel defining a hollow interior chamber. The chamber has an inlet configured for receiving fuel from a fuel source and an outlet configured for fluidic communication with an engine. The chamber also has an air-bleed configured for fluidic communication to a port through which unwanted gas is discharged, e.g., by communication with a return line in fluidic communication with a fuel tank so that undesired gas can be returned thereto. A filter media is positioned within the chamber for contact with fuel received in the chamber and a conduit is located within the filter media for delivering fuel passing through the filter media to the outlet. The air separator is configured to remove a quantity of undesired gas from the fuel prior to passage of the fuel through the outlet from the vessel to the engine, with such undesired gas passing through the air-bleed. The air-bleed optionally has a gas collection area, which may be, e.g., somewhat in the shape of a depression from the surrounding surface of the air bleed, where gas bubbles congregate before exiting. The air bleed further includes a fluidic mixing alcove specially configured to entrap a larger concentration of large and small gas bubbles upon entrance and retention within the alcove so that they exit the air-bleed into the discharge port while reducing resistance to fuel flow and pressure loss through the discharge port.

Brief description of the accompanying drawing
[0005] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0006] Figure 1 illustrates a schematic diagram of an automatic air bleeder structure that is positioned onto the housing of a high pressure fuel pump, according to an embodiment in the invention; and

[0007] Figure 2 illustrates position of the automatic air bleeder structure onto the housing of a high pressure fuel pump, according to an embodiment in the invention.

Detailed description of the embodiments
[0008] Figure 1 illustrates an automatic air bleeder structure 100 for a high pressure fuel pump 102, for a fuel injection hydraulic system. The automatic air bleeder structure 100 comprises a cylindrical housing 104 that is mounted on to housing of a high pressure fuel pump 102. The automatic air bleeder structure 100 comprises a cylindrical housing 104 with a through hole 101, which encloses all the components of the structure 100. The through hole 101 is having a stepped diameter inside for housing the other components of the structure 100. The other components of the structure 100 are further comprising a sealing agent 105, a float guide 106, and a spring element 107. Each component is described in further detail below.

[0009] The cylindrical housing 104 is having hexagonal shaped head and a threaded portion 104a. The threaded portion 104a of the housing 104 is adapted for screwing the structure 100 onto the high pressure fuel pump 102. Specifically the threaded portion 104a of the housing 104 is adapted for screwing the structure 100 onto housing of the high pressure fuel pump 102, implemented in a fuel injection system.

[0010] The sealing agent 105 is positioned at middle of the cylindrical housing 104 and adapted to float in working fuel entering the structure 100. In one embodiment, the sealing agent 105 is made up of a material with a density lesser than the working fuel entering the structure 100. In one exemplary embodiment the sealing agent 105 may be made of rubber. However, a variety of other material with lesser density may be envisaged for making sealing agent 105, for purposes of describing example embodiments.

[0011] The float guide 106 positioned onto the top of the sealing agent 105 and adapted to guide the movement of the sealing agent 105. Further, the float guide 106 is adapted to provide easy assembly of the sealing agent 105 within the cylindrical housing 104. In one embodiment, the structure of the float guide 106 is designed in order to accommodate the sealing agent 105 within the structure 100. In another embodiment, the float guide 106 may be either pressed/screwed on to the cylindrical housing 104 in order to provide easy assembly of the sealing agent 105.

[0012] The spring element 107 is mounted inside the float guide 106 and adapted to support the movement of the sealing agent 105. The spring element 107 is adapted to support the movement of the sealing agent 105 via a filler piece 108. The filler piece 108 mounted inside the spring element 107 and is adapted to support and control the movement of the spring element 107.

[0013] Figure 2 illustrates position of the automatic air bleeder structure 100 onto the housing of a high pressure fuel pump 102, according to an embodiment in the invention. In one embodiment, an overflow valve 200 is adapted to remove the air bubbles generated inside the system, however, since the overflow valve 200 and the bore towards the high pressure fuel pump 102 lies on the same horizontal level, chances are high that the air can go towards the high pressure fuel pump 102 bore. According to the present invention, automatic air bleeder structure 100 on to the high pressure fuel pump 102, the probability of air bubbles going inside the high pressure fuel pump bore is reduced.

[0014] In operation, the automatic air bleeder structure 100 is placed at the highest portion of the high pressure pump 102 for an easy escape of the air bubbles. In the starting, air flows from the tapered hole 101a in the hexagonal shaped head of the housing 104 towards the through hole 101. The flowing air will escape from the through hole 101 out to the atmosphere therefore venting the air automatically.

[0015] Once the fuel starts flowing through the high pressure pump 102. The fuel will pass through the tapered hole 101a at the bottom of the automatic air bleeder structure 100 and the fuel will start raising. Herein, the tapered hole 101a is adapted to dampen the velocity near the float thereby avoiding the sudden damages. When the fuel raises, the sealing agent 105 will float in order to raise with the fuel flow. Here, the float guide 106 will guide the movement of the sealing agent 105. This raised sealing agent 105 will create a region 101b created by a sealing surface, which in turn prevent further air to escape. The air will get trapped between the flowing fuels and region 101 b. The fuel will not raise upto the region 101b due to the air pressure created by the trapped air. When air bubbles are generated inside the high pressure pump 102, it will go to the automatic air bleeder structure 100 due to pressure difference. When the air bubble reaches the surface, the air inside the bubble gets dissipated into the air above the fuel causing a volume decrease in region 101c. This volume difference will cause the sealing agent 105 to move down with the help of the spring element 107 and it will release the sealing of region 101b causing the air to escape into the atmosphere. After this the fuel will raise again and the sealing agent 105 will seal the region 101b. So the automatic air bleeder structure 100 will remove air bubbles whenever it is created which reduces cavitation and thus improves the fatigue strength of the pump components.

[0008] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.