Fuel common rail system and ship

Abstract

The present invention relates to the technical field of fuel injection, and particularly to a fuel common rail system and a ship. The fuel common rail system includes a fuel pump, a common rail pipe, and an electronically controlled injector, and further includes a flow limiting valve. The flow limiting valve is arranged between the common rail pipe and the electronically controlled injector. The inlet of the flow limiting valve is communicated with the outlet of the common rail pipe, and the outlet of the flow limiting valve is communicated with the inlet of the electronically controlled injector. The flow limiting valve is configured to provide a fixed amount of oil when the electronically controlled injector switches from the closed state to the open state, and to cut off the passage between the common rail pipe and the electronically controlled injector when the electronically controlled injector is in the normally open state. By providing the flow limiting valve, when the electronically controlled injector fails and becomes normally open, the passage between the common rail pipe and the electronically controlled injector can be cut off in time, so that no extra fuel enters the combustion chamber, avoiding the risk of safety accidents.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel injection, and particularly to a fuel common rail system and a ship. Background Art

[0002] The electronically controlled high-pressure common rail fuel injection technology is to deliver high-pressure fuel to the common rail pipe by a common rail fuel pump, and by precisely controlling the fuel supply pressure in the common rail pipe and the opening time of the electronically controlled injector, to achieve the purpose of respectively adjusting the injection pressure and the injection quantity according to the changes in the power and speed of the diesel engine, and precisely optimizing the combustion efficiency. It can improve the economy of the diesel engine, reduce emissions, and particularly optimize the low-speed performance of the diesel engine within the full operating range. Therefore, the electronically controlled high-pressure common rail system has been widely used in marine diesel engines.

[0003] In the prior art, the common rail pipe is directly connected to the injector. Once the injector fails due to damage or other reasons, the high-pressure fuel in the common rail pipe will enter the combustion chamber of the diesel engine from the injector uncontrollably, increasing the risk of safety accidents. Summary of the Invention

[0004] The purpose of the present invention is to provide a fuel common rail system and a ship, which can ensure that no excess fuel enters the combustion chamber when the electronically controlled injector fails, and avoid the risk of safety accidents.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A fuel common rail system, including a fuel pump, a common rail pipe, and an electronically controlled injector. The outlet of the fuel pump is communicated with the inlet of the common rail pipe, and the outlet of the common rail pipe is communicated with the inlet of the electronically controlled injector;

[0007] It further includes a flow limiting valve. The flow limiting valve is arranged between the common rail pipe and the electronically controlled injector. The inlet of the flow limiting valve is communicated with the outlet of the common rail pipe, and the outlet of the flow limiting valve is communicated with the electronically controlled injector. The flow limiting valve is configured to provide a fixed amount of oil when the electronically controlled injector switches from the closed state to the open state, and to cut off the passage between the common rail pipe and the electronically controlled injector when the electronically controlled injector is in the normally open state.

[0008] As an optional technical solution of the fuel common rail system, the flow limiting valve includes:

[0009] A valve body, which has a valve cavity. The valve cavity includes a first cavity and a second cavity that are communicated with each other, and the diameter of the first cavity is larger than that of the second cavity. A limiting portion is arranged in the first cavity;

[0010] A piston is slidably disposed in the first cavity. The force-receiving area on the side of the piston facing away from the second cavity is smaller than the force-receiving area on the side facing the second cavity. The limiting portion can limit the first extreme position where the piston moves away from the second cavity, and the connection surface between the first cavity and the second cavity can limit the second extreme position where the piston moves closer to the second cavity. The oil inlet of the flow restriction valve is communicated with the first cavity, and the oil inlet of the flow restriction valve is located on the side of the piston facing away from the second cavity when the piston is in the first extreme position. A through-hole is axially formed in the piston, and the oil outlet of the flow restriction valve is communicated with the second cavity. When the piston is located at the second extreme position, the piston can block the communication port between the second cavity and the first cavity.

[0011] As an alternative technical solution of the fuel common rail system, the end of the communication hole close to the second cavity is funnel-shaped.

[0012] As an alternative technical solution of the fuel common rail system, the flow restriction valve further includes a connecting rod. An axially through sliding hole is formed in the limiting portion, and the connecting rod is slidably inserted through the sliding hole. The piston is fixedly sleeved on the connecting rod.

[0013] As an alternative technical solution of the fuel common rail system, the end of the connecting rod facing the second cavity has a flange, and a snap ring is further arranged on the connecting rod. The piston is limited between the flange and the snap ring, and when the piston is located at the second extreme position, the flange can block the communication port between the second cavity and the first cavity.

[0014] As an alternative technical solution of the fuel common rail system, the valve body includes a valve housing, a limiting block and a valve cover. The limiting block includes a connecting portion and the limiting portion. The connecting portion is connected between the valve housing and the valve cover, and the limiting portion is arranged in the first cavity.

[0015] As an alternative technical solution of the fuel common rail system, the valve housing and the connecting portion are connected by a first bolt, and the valve cover and the connecting portion are connected by a second bolt.

[0016] As an alternative technical solution of the fuel common rail system, the valve body is connected to the common rail pipe by a third bolt.

[0017] As an alternative technical solution of the fuel common rail system, the fuel common rail system further includes a pressure control valve and a safety valve. Both the pressure control valve and the safety valve are connected to the common rail pipe. When the pressure in the common rail pipe exceeds the pressure setting value of the pressure control valve, the common rail pipe can return oil through the pressure control valve. When the pressure in the common rail pipe exceeds the safety value of the safety valve, the common rail pipe can return oil through the safety valve.

[0018] A ship includes the fuel common rail system according to any one of the above solutions.

[0019] Advantages of the present invention:

[0020] The fuel common rail system provided by the present invention includes a flow limiting valve. The flow limiting valve is arranged between the common rail pipe and the electronically controlled injector. The flow limiting valve is configured to provide a fixed amount of oil when the electronically controlled injector switches from the closed state to the open state, and to cut off the passage between the common rail pipe and the electronically controlled injector when the electronically controlled injector is in the normally open state. By providing the flow limiting valve, when the electronically controlled injector fails and becomes normally open, the passage between the common rail pipe and the electronically controlled injector can be cut off in time, so that no extra fuel enters the combustion chamber, avoiding the risk of safety accidents. Description of the drawings

[0021] Figure 1 is a schematic diagram of the principle of the fuel common rail system provided by an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of the structure of the flow limiting valve involved in an embodiment of the present invention;

[0023] Figure 3 is the front view of the flow limiting valve involved in an embodiment of the present invention;

[0024] Figure 4 is Figure 3 a cross-sectional view taken along the A-A direction in

[0025] In the figure:

[0026] 10, fuel pump; 20, common rail pipe;

[0027] 30, flow limiting valve; 31, valve body; 311, valve housing; 312, limit block; 3121, connecting portion; 3122, limiting portion; 313, valve cover; 314, valve cavity; 3141, first cavity; 3142, second cavity; 32, piston; 321, communication hole; 33, connecting rod; 331, flange; 34, first bolt; 35, second bolt; 36, third bolt;

[0028] 40, pressure control valve; 50, safety valve; 60, electronically controlled injector. Detailed implementation manners

[0029] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. Generally, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0030] Therefore, the detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0031] It should be noted that: like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0032] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0033] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "arranged" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include indirect contact between the first and second features through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is lower than that of the second feature.

[0035] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0036] As Figure 1 shown, an embodiment of the present invention provides a fuel common rail system, including a fuel pump 10, a common rail pipe 20, and an electronically controlled injector 60. The outlet of the fuel pump 10 is communicated with the inlet of the common rail pipe 20, and the outlet of the common rail pipe 20 is communicated with the inlet of the electronically controlled injector 60. The fuel common rail system provided in this embodiment further includes a flow limiting valve 30. The flow limiting valve 30 is disposed between the common rail pipe 20 and the electronically controlled injector 60. The inlet of the flow limiting valve 30 is communicated with the outlet of the common rail pipe 20, and the outlet of the flow limiting valve 30 is communicated with the inlet of the electronically controlled injector 60. The flow limiting valve 30 is configured to provide a fixed amount of oil when the electronically controlled injector 60 is switched from the closed state to the open state, and to cut off the passage between the common rail pipe 20 and the electronically controlled injector 60 when the electronically controlled injector 60 is in the normally open state. By providing the flow limiting valve 30, when the electronically controlled injector 60 fails and becomes normally open, the passage between the common rail pipe 20 and the electronically controlled injector 60 can be cut off in time, so that no excess fuel enters the combustion chamber, avoiding the risk of safety accidents.

[0037] Specifically, as Figures 2 to 4As shown, the flow limiting valve 30 includes a valve body 31 and a piston 32. The valve body 31 has a valve cavity 314. The valve cavity 314 includes a first cavity 3141 and a second cavity 3142 that communicate with each other. The diameter of the first cavity 3141 is larger than that of the second cavity 3142. A limiting portion 3122 is provided in the first cavity 3141. The piston 32 is slidably disposed in the first cavity 3141. The force-receiving area of the side of the piston 32 facing away from the second cavity 3142 is smaller than the force-receiving area of the side facing the second cavity 3142. The limiting portion 3122 can limit the first extreme position (i.e., Figure 4 the position shown) where the piston 32 moves away from the second cavity 3142. The connection surface between the first cavity 3141 and the second cavity 3142 can limit the second extreme position where the piston 32 moves towards the second cavity 3142; the oil inlet of the flow limiting valve 30 communicates with the first cavity 3141, and the oil inlet of the flow limiting valve 30 is located on the side of the piston 32 facing away from the second cavity 3142 when the piston 32 is in the first extreme position. A communication hole 321 that penetrates axially is provided on the piston 32. Preferably, the end of the communication hole 321 close to the second cavity 3142 is funnel-shaped to increase the flow rate of the oil; the oil outlet of the flow limiting valve 30 communicates with the second cavity 3142; when the piston 32 is in the second extreme position, the piston 32 can block the communication port between the second cavity 3142 and the first cavity 3141.

[0038] When the electronic control fuel injector 60 is in the closed state, the high-pressure fuel in the common rail 20 enters the space on the left side of the piston 32 in the first cavity 3141 through the oil inlet of the flow limiting valve 30, and flows through the communication hole 321 on the piston 32 to the space on the right side of the piston 32 in the first cavity 3141 and the second cavity 3142. Since the force-bearing areas on both sides of the piston 32 are different, the pressures on both sides of the piston 32 are different. In this embodiment, the force-bearing area on the side of the piston 32 facing away from the second cavity 3142 is smaller than the force-bearing area on the side facing the second cavity 3142, that is, the pressure on the side of the piston 32 facing away from the second cavity 3142 is smaller than the pressure on the side facing the second cavity 3142. Therefore, the piston 32 moves in the direction away from the second cavity 3142 under the action of the pressure difference on both sides until it abuts against the limiting portion 3122 and remains in this first limit position. When the electronic control fuel injector 60 is switched from the closed state to the open state, the pressure on the side of the piston 32 facing the second cavity 3142 disappears, and the piston 32 is pushed in the direction close to the second cavity 3142 to the second limit position. The fuel in the valve cavity 314 enters the electronic control fuel injector 60 through the oil outlet of the flow limiting valve 30. When the electronic control fuel injector 60 fails and is always open, the piston 32 will be always pushed to the second limit position and remain. At this time, the piston 32 can block the communication port between the second cavity 3142 and the first cavity 3141, the fuel is blocked, and will not flow into the electronic control fuel injector 60 through the flow limiting valve 30, so that no extra fuel will enter the combustion chamber, avoiding the risk of safety accidents.

[0039] Furthermore, the flow limiting valve 30 further includes a connecting rod 33. The limiting portion 3122 is provided with an axially penetrating sliding hole, and the connecting rod 33 slidably penetrates through the sliding hole. The piston 32 is fixedly sleeved on the connecting rod 33. By providing the connecting rod 33, it can play a guiding role in the movement of the piston 32. Preferably, one end of the connecting rod 33 facing the second cavity 3142 has a flange 331, and a snap ring is also provided on the connecting rod 33. The piston 32 is limited between the flange 331 and the snap ring, and when the piston 32 is in the second limit position, the flange 331 can block the communication port between the second cavity 3142 and the first cavity 3141. Due to the above structural setting of the connecting rod 33, it naturally makes the force-bearing areas on both sides of the piston 32 different, and by making the flange 331 block the communication port between the second cavity 3142 and the first cavity 3141, it can also reduce the contact area between the piston 32 and the abutting surface, making the movement of the piston 32 from the second limit position to the first limit position smoother.

[0040] In this embodiment, the valve body 31 includes a valve housing 311, a limiting block 312, and a valve cover 313. The limiting block 312 includes a connecting portion 3121 and a limiting portion 3122. The connecting portion 3121 is connected between the valve housing 311 and the valve cover 313, and the limiting portion 3122 is disposed in the first cavity 3141. Preferably, the valve housing 311 and the connecting portion 3121 are connected by a first bolt 34, and the valve cover 313 and the connecting portion 3121 are connected by a second bolt 35. With the above structural arrangement, the flow limiting valve 30 is convenient for disassembly, assembly, and maintenance. In addition, in this embodiment, the valve body 31 is connected to the common rail pipe 20 by a third bolt 36.

[0041] The fuel common rail system provided in this embodiment further includes a pressure control valve 40 and a safety valve 50. Both the pressure control valve 40 and the safety valve 50 are connected to the common rail pipe 20. The common rail pipe 20 maintains a constant pressure through the pressure control valve 40. When the pressure of the common rail pipe 20 exceeds the pressure set value of the pressure control valve 40, the common rail pipe 20 can return oil through the pressure control valve 40. When an accident occurs in the common rail pipe 20 and the pressure of the common rail pipe 20 exceeds the safety value of the safety valve 50, the common rail pipe 20 can return oil through the safety valve 50.

[0042] In addition, since the fuel may be heavy oil with high viscosity and poor fluidity, heating pipes are installed on the high-pressure oil pipes of the system to improve the fluidity of the fuel. Fuel drain ports are provided on each component and connected to a fuel drain pipeline, which is convenient for the system to drain excess fuel during maintenance.

[0043] An embodiment of the present invention further provides a ship, including the fuel common rail system as described above.

[0044] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A fuel common rail system, comprising a fuel pump (10), a common rail pipe (20) and an electronically controlled injector (60). An oil outlet of the fuel pump (10) is communicated with an oil inlet of the common rail pipe (20), and an oil outlet of the common rail pipe (20) is communicated with an oil inlet of the electronically controlled injector (60). It is characterized in that The system further includes a flow limiting valve (30). The flow limiting valve (30) is disposed between the common rail pipe (20) and the electronically controlled injector (60). An oil inlet of the flow limiting valve (30) is communicated with the oil outlet of the common rail pipe (20), and an oil outlet of the flow limiting valve (30) is communicated with the electronically controlled injector (60). The flow limiting valve (30) is configured to provide a fixed amount of oil when the electronically controlled injector (60) is switched from a closed state to an open state, and to cut off the passage between the common rail pipe (20) and the electronically controlled injector (60) when the electronically controlled injector (60) is in an always-open state. The flow limiting valve (30) includes: A valve body (31) having a valve cavity (314). The valve cavity (314) includes a first cavity (3141) and a second cavity (3142) that are communicated with each other. The diameter of the first cavity (3141) is larger than that of the second cavity (3142), and a limiting portion (3122) is disposed in the first cavity (3141). A piston (32) slidably disposed in the first cavity (3141). The force-receiving area of one side of the piston (32) facing away from the second cavity (3142) is smaller than the force-receiving area of the side facing the second cavity (3142). The limiting portion (3122) can limit a first extreme position where the piston (32) moves away from the second cavity (3142), and the connection surface between the first cavity (3141) and the second cavity (3142) can limit a second extreme position where the piston (32) moves towards the second cavity (3142). The oil inlet of the flow limiting valve (30) is communicated with the first cavity (3141), and the oil inlet of the flow limiting valve (30) is located on the side of the piston (32) facing away from the second cavity (3142) when the piston (32) is at the first extreme position. A through hole (321) axially penetrating is provided on the piston (32), and the oil outlet of the flow limiting valve (30) is communicated with the second cavity (3142). When the piston (32) is at the second extreme position, the piston (32) can block the communication port between the second cavity (3142) and the first cavity (3141), and one end of the through hole (321) close to the second cavity (3142) is funnel-shaped.

2. The fuel common rail system according to claim 1, characterized in that, The flow limiting valve (30) further includes a connecting rod (33). An axially penetrating sliding hole is provided on the limiting portion (3122), and the connecting rod (33) slidably penetrates through the sliding hole. The piston (32) is fixedly sleeved on the connecting rod (33).

3. The fuel common rail system according to claim 2, wherein One end of the connecting rod (33) facing the second cavity (3142) has a flange (331). A snap ring is also arranged on the connecting rod (33). The piston (32) is limited between the flange (331) and the snap ring. When the piston (32) is in the second extreme position, the flange (331) can block the communication port between the second cavity (3142) and the first cavity (3141).

4. The fuel common rail system according to claim 1, characterized in that, The valve body (31) includes a valve housing (311), a limit block (312) and a valve cover (313). The limit block (312) includes a connecting portion (3121) and a limiting portion (3122). The connecting portion (3121) is connected between the valve housing (311) and the valve cover (313), and the limiting portion (3122) is arranged in the first cavity (3141).

5. The fuel common rail system according to claim 4, characterized in that, The valve housing (311) and the connecting portion (3121) are connected by a first bolt (34), and the valve cover (313) and the connecting portion (3121) are connected by a second bolt (35).

6. The fuel common rail system according to claim 1, characterized in that, The valve body (31) is connected to the common rail pipe (20) by a third bolt (36).

7. The fuel common rail system according to claim 1, characterized in that, The fuel common rail system further includes a pressure control valve (40) and a safety valve (50). Both the pressure control valve (40) and the safety valve (50) are connected to the common rail pipe (20). When the pressure of the common rail pipe (20) exceeds the pressure set value of the pressure control valve (40), the common rail pipe (20) can return oil through the pressure control valve (40). When the pressure of the common rail pipe (20) exceeds the safety value of the safety valve (50), the common rail pipe (20) can return oil through the safety valve (50).

8. A ship, characterized in that, Comprising the fuel common rail system according to any one of claims 1-7.

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