CN217421393U

CN217421393U - Fuel injection nozzle of dual-fuel engine

Info

Publication number: CN217421393U
Application number: CN202220322214.0U
Authority: CN
Inventors: 魏立江; 吕志涛; 张旭升
Original assignee: Shanghai Maritime University
Current assignee: Shanghai Maritime University
Priority date: 2022-02-17
Filing date: 2022-02-17
Publication date: 2022-09-13
Anticipated expiration: 2032-02-17

Abstract

The utility model relates to a dual-fuel engine fuel sprayer, which comprises a needle valve body, wherein an oil inlet channel is arranged in the needle valve body, an oil cavity communicated with the oil inlet channel, and an annular oil duct communicated with the oil cavity, and the bottom of the needle valve body is respectively provided with a first layer fuel spray hole and a second layer fuel spray hole which have different heights; the needle valve rod is movably arranged in the needle valve body, a boss is arranged on the needle valve rod, the first layer of oil injection hole is arranged at the sealing connection position of the boss and the inner wall of the annular oil duct, and the needle valve rod is axially moved to control the boss to open or close the first layer of oil injection hole; therefore, the first layer of oil injection holes and the second layer of oil injection holes are controlled to be opened simultaneously, or the second layer of oil injection holes are opened independently. The utility model discloses a two-layer orifice structure of fuel sprayer possesses better load adaptability.

Description

Fuel injection nozzle of dual-fuel engine

Technical Field

The utility model relates to an engine high pressure fuel sprays technical field, in particular to dual fuel engine fuel sprayer.

Background

Energy conservation and emission reduction are challenges faced by internal combustion engines at present, and in order to reduce emissions of nitrogen oxides, particles, carbon dioxide and the like, novel fuels such as natural gas, methanol and the like are started to be applied in large scale in the field of internal combustion engines. However, the fuels such as natural gas and methanol are difficult to be directly ignited in a diesel engine, and basically diesel is needed for ignition, so that dual-fuel combustion is realized. In the dual-fuel engines, the amount of ignition diesel oil required when the dual-fuel engines work in a dual-fuel mode is very small, and in order to realize stable injection of small amount of diesel oil, diesel oil nozzles equipped in the dual-fuel engines are often very small and cannot meet the injection requirement of large amount of diesel oil, so that once the dual-fuel engines are short in fuel supply such as natural gas or methanol, the dual-fuel engines can only work in a pure diesel oil mode in a small amount of oil, and the generated power cannot meet the normal power requirement of equipment.

In order to solve the problems, it is an alternative to separately add an oil injector for injecting a large amount of oil to the cylinder head to realize a pure diesel mode high-load operation. However, at least 2 diesel injectors need to be arranged on the cylinder cover, which causes difficulty in limited cylinder cover space, and simultaneously makes the structure of the cylinder cover of the engine more complex, and challenges are brought to the production and manufacturing processes of the engine, the structural strength reliability and the like; in addition, the fuel injection directions of the 2 fuel injectors are difficult to achieve the optimal state at the same time, and the performance of the engine in at least one of the dual-fuel or pure diesel working modes is greatly influenced.

SUMMERY OF THE UTILITY MODEL

The utility model provides a not enough to prior art, the utility model provides a novel dual fuel engine fuel sprayer, this fuel sprayer can spray the trace fuel that draws, can spray big oil mass again and satisfy pure diesel oil heavy load mode, only adopt a diesel injector, can practice thrift engine cylinder head space, simplify engine structure, practice thrift the cost.

In order to achieve the purpose, the utility model provides a dual-fuel engine oil nozzle, which comprises a needle valve body and a needle valve rod;

an oil inlet channel and an oil cavity communicated with the oil inlet channel are arranged in the needle valve body, and a first layer of oil injection holes and a second layer of oil injection holes which are different in height are respectively arranged at the bottom of the needle valve body;

the needle valve rod is movably arranged in the needle valve body, the outer surface of the upper end of the needle valve rod is connected with the inner surface of the needle valve body in a sealing mode, an annular oil duct is formed between the lower end of the needle valve rod and the needle valve body, and the annular oil duct is communicated with the oil cavity;

the needle valve rod is further provided with a boss, the first layer of oil injection hole is arranged at the sealing connection position of the boss and the inner wall of the annular oil duct, and the needle valve rod is moved axially to control the boss to open or close the first layer of oil injection hole, so that the first layer of oil injection hole and the second layer of oil injection hole are controlled to be opened simultaneously or the second layer of oil injection hole is controlled to be opened independently.

Preferably, the boss is connected with the inner wall of the needle valve body in an annular sealing manner to divide the annular oil duct into an upper oil duct and a lower oil duct; the needle valve rod is also provided with a needle valve oil duct at the boss position, and the upper oil duct is communicated with the lower oil duct through the needle valve oil duct.

Preferably, the bottom end of the needle valve rod is provided with a conical surface, the bottom of the needle valve body is provided with a ring groove in sealing connection with the conical surface, and a pressure chamber is arranged below the ring groove; and the second layer of oil injection holes are arranged in the pressure chamber.

Preferably, the needle valve oil passage is obliquely arranged inside the needle valve stem.

Preferably, the aperture of the first layer of oil spray holes is larger than that of the second layer of oil spray holes.

Preferably, the number of the first layer of oil spray holes and the number of the second layer of oil spray holes are 4-10.

Preferably, the first layer of oil spray holes and the second layer of oil spray holes are distributed along the circumferential direction of the needle valve body.

Preferably, the first layer of oil spray holes and the second layer of oil spray holes are distributed in a staggered mode in the vertical direction.

Preferably, when the needle valve rod is moved to enable the conical surface to be separated from the annular groove and the boss covers the position of the first layer of oil injection hole, the second layer of oil injection hole is independently opened; when the needle valve rod is moved to separate the conical surface from the annular groove and the boss is moved away from the position of the first layer of oil spray hole, the first layer of oil spray hole and the second layer of oil spray hole are simultaneously opened

Compared with the prior art, the utility model, have following advantage:

the utility model adopts a two-layer spray hole structure of the oil nozzle, has better load adaptability, can realize the switching of two oil spray modes by independently opening the oil spray hole of the second layer and simultaneously opening the oil spray holes of the first layer and the second layer; the fuel injection nozzle can inject a trace amount of pilot fuel, can also inject a large amount of fuel to meet the pure diesel high-load working mode, only needs to arrange one diesel fuel injector, can reduce the arrangement quantity of the fuel injectors on the cylinder cover of the dual-fuel engine, and simplifies the cylinder cover structure.

Drawings

FIG. 1 is a schematic structural view of the fuel injection nozzle of the dual-fuel engine of the present invention;

FIG. 2 is a schematic structural view of the needle valve body of the present invention;

FIG. 3 is a schematic view of the structure of the needle valve stem of the present invention;

fig. 4 and fig. 5 are schematic structural diagrams of the two-layer nozzle hole distribution of the present invention.

Detailed Description

The fuel injection nozzle of the dual-fuel engine according to the present invention will be described in detail with reference to the accompanying drawings and embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are not to precise scale, and are provided for convenience and clarity in order to assist in describing embodiments of the present invention. To make the objects, features and advantages of the present invention more comprehensible, please refer to the attached drawings. It should be understood that the structure, ratio, size and the like shown in the drawings attached to the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by those skilled in the art, and are not used for limiting the limitation of the implementation of the present invention, so that the present invention does not have the essential significance in the technology, and any modification of the structure, change of the ratio relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the function and the achievable purpose of the present invention.

As shown in fig. 1, fig. 2 and fig. 3, the utility model provides a dual-fuel engine fuel spray nozzle, which comprises a needle valve body 1 and a needle valve rod 4, wherein an oil inlet channel 2 is obliquely arranged inside the needle valve body 1, an oil cavity 3 is communicated below the oil inlet channel 2, and an annular oil passage 8 is communicated with the bottom of the oil cavity 3; the bottom of needle valve body 1 is provided with first layer nozzle opening 5 and the second floor nozzle opening 7 of difference in height respectively, and second floor nozzle opening 7 is located first layer nozzle opening 5 below. The needle valve rod 4 is movably arranged in the needle valve body 1 and can move along the axial direction of the needle valve body 1, a boss 10 is arranged on the needle valve rod 4, the boss 10 is connected with the inner wall of the annular oil duct 8 in an annular sealing mode to form an annular first sealing surface 11, so that the annular oil duct 8 is divided into an upper oil duct 81 and a lower oil duct 82, and a needle valve oil duct 6 for communicating the upper oil duct 81 with the lower oil duct 82 is further arranged on the needle valve rod 4; the two ends of the needle valve oil passage 6 are respectively positioned above and below the boss 10. The bottom end of the needle valve rod 4 is provided with a conical surface 12, the bottom of the needle valve body 1 is provided with an annular groove 13 which is hermetically connected with the conical surface 12, a pressure chamber 9 is arranged below the annular groove 13, the second-layer oil injection hole 7 is arranged in the pressure chamber 9, and the pressure chamber 9 is communicated with the lower oil duct 82 after the conical surface 12 of the needle valve rod 4 is removed from the annular groove 13. When the needle valve rod 4 is inserted into the needle valve body 1, the conical surface 12 is in sealing connection with the annular groove 13 of the needle valve body 1 to form a second sealing surface 14; the outer surface of the upper end of the needle valve rod 4 is connected with the inner surface of the needle valve body 1 in a sealing way to form a third sealing surface 15; when the needle valve rod 4 is inserted into the needle valve body 1, the first layer of oil injection holes 5 are formed in the position of the first sealing surface 11, at the moment, the first layer of oil injection holes 5 are sealed and closed by the boss 10, and the second layer of oil injection holes 7 are sealed and closed by the conical surface 12 and the annular groove 13; the conical surface 12 can be moved away from the annular groove 13 by axially moving the needle valve rod 4, so that the oil injection hole 7 of the second layer is opened, the boss 10 can be moved away from the position of the oil injection hole 5 of the first layer by continuously moving the needle valve rod 4 upwards, and the oil injection hole 5 of the first layer can be continuously opened.

When only the second-layer oil injection hole 7 is used for injecting oil, the lifting height of the needle valve rod 4 is controlled, so that the conical surface 12 of the needle valve rod 4 is separated from the annular groove 13 of the needle valve body 1, the annular oil duct 8 is communicated with the pressure chamber 9, fuel oil enters the annular oil chamber 3 through the inclined oil inlet channel 2, the fuel oil in the annular oil chamber 3 flows downwards into the annular oil duct 8, the fuel oil is blocked by the cylindrical first sealing surface 11 formed by the contact of the outer surface of the boss 10 and the inner wall of the needle valve body 1, the fuel oil in the upper oil channel 81 enters the lower oil channel 82 again through the needle valve oil duct 6, the second-layer oil injection hole 7 is communicated with the whole oil supply channel (namely, the fuel oil enters the oil chamber 3 and the oil duct of the annular oil duct 8 through the oil inlet channel 2), and the fuel oil is injected out through the second-layer oil injection hole 7 after entering the pressure chamber 9.

When the first layer of oil spray holes 5 and the second layer of oil spray holes 7 are used for spraying oil at the same time, the outer surface of the boss 10 is in contact with the inner wall of the needle valve body 1 to form a cylindrical first sealing surface 11 to seal the first layer of oil spray holes 5, the lifting height of the needle valve rod 4 needs to be controlled, so that the cylindrical first sealing surface 11 crosses the position of the first layer of oil spray holes 5, the lower oil duct 82 is communicated with the first layer of oil spray holes 5 at the moment, and the first layer of oil spray holes 5 are opened. The fuel that has entered the lower oil gallery 82 through the above-described oil supply passage is injected from the first-layer oil jet holes 5, and at the same time, the fuel that has passed through the above-described oil supply passage also flows into the pressure chamber 9 and is injected through the second-layer oil jet holes 7.

As shown in fig. 4 and 5, two layers of oil injection holes are circumferentially arranged on the needle valve body 1, the first layer of oil injection holes 5 and the second layer of oil injection holes 7 are uniformly distributed at the bottom of the needle valve body 1, and the two layers of oil injection holes are staggered in the vertical direction, more specifically, the first layer of oil injection holes 5 are arranged at the first sealing surface 11 of the needle valve body 1 and are large-aperture oil injection holes, and the number of the first layer of oil injection holes 5 is 4-10. The second layer of oil spray holes 7 are arranged at the pressure chamber 9 and are small-oil-mass oil spray holes for ignition, and the number of the second layer of oil spray holes 7 is 4-10.

To sum up, the utility model provides a pair of dual fuel engine fuel sprayer utilizes first, second floor nozzle opening can realize nimble fuel injection strategy, possess better load adaptability, can enough spray micro-pilot oil, can spray the heavy oil quantity again and satisfy pure diesel oil heavy load mode, only adopts a diesel oil sprayer, can reduce the quantity of arranging of sprayer on the dual fuel engine, practices thrift and utilizes the engine cylinder head space, satisfies current engine intensification's development requirement.

While the present invention has been described in detail with reference to the preferred embodiments thereof, it should be understood that the above description should not be taken as limiting the present invention. Numerous modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims

1. A dual fuel engine fuel injector, comprising: a needle valve body (1) and a needle valve rod (4); an oil inlet channel (2) and an oil cavity (3) communicated with the oil inlet channel (2) are arranged in the needle valve body (1), and a first layer of oil injection holes (5) and a second layer of oil injection holes (7) which are different in height are respectively arranged at the bottom of the needle valve body (1);

the needle valve rod (4) is movably arranged in the needle valve body (1), an annular oil duct (8) is formed between the needle valve rod and the needle valve body (1), and the annular oil duct (8) is communicated with the oil cavity (3);

the needle valve rod (4) is further provided with a boss (10), the first layer oil injection hole (5) is arranged at the sealing connection position of the boss (10) and the inner wall of the annular oil duct (8), and the needle valve rod (4) is moved axially to control the boss (10) to open or close the first layer oil injection hole (5), so that the first layer oil injection hole (5) and the second layer oil injection hole (7) are controlled to be opened simultaneously, or the second layer oil injection hole (7) is controlled to be opened independently.

2. The dual-fuel engine fuel injector of claim 1, characterized in that the boss (10) is connected with the inner wall of the needle valve body (1) in a ring-shaped sealing manner to divide the ring-shaped oil passage (8) into an upper oil passage (81) and a lower oil passage (82); the needle valve rod (4) is further provided with a needle valve oil duct (6) at the position of the boss (10), and the upper oil duct (81) is communicated with the lower oil duct (82) through the needle valve oil duct (6).

3. The dual-fuel engine fuel injection nozzle of claim 1, characterized in that the bottom end of the needle valve rod (4) is provided with a conical surface (12), the bottom of the needle valve body (1) is provided with a ring groove (13) hermetically connected with the conical surface (12), and a pressure chamber (9) is arranged below the ring groove (13); the second layer of oil spray holes (7) are arranged in the pressure chamber (9).

4. The dual fuel engine injector of claim 1, characterized in that the needle valve oil passage (6) is obliquely provided inside the needle valve stem (4).

5. The dual fuel engine injector of claim 1, characterized in that the first layer of injectors (5) has a larger bore diameter than the second layer of injectors (7).

6. The dual fuel engine injector of claim 1, characterized in that the number of the first layer of injectors (5) and the second layer of injectors (7) is 4-10.

7. The dual fuel engine injector of claim 1, characterized in that the first layer of injectors (5) and the second layer of injectors (7) are both distributed and distributed along the circumference of the needle valve body (1).

8. The dual fuel engine injector of claim 1, characterized in that the first layer of injectors (5) and the second layer of injectors (7) are staggered in the vertical direction.

9. The dual fuel engine injector of claim 1, characterized in that the outer surface of the upper end of the needle valve stem (4) is sealingly connected with the inner surface of the needle valve body (1).

10. The dual fuel engine fuel injector of claim 3, characterized in that when the needle valve stem (4) is moved to separate the conical surface (12) from the ring groove (13) and the boss (10) covers the position of the first layer of fuel injection holes (5), the second layer of fuel injection holes (7) are opened independently; when the needle valve rod (4) is moved to separate the conical surface (12) from the annular groove (13) and the boss (10) is moved away from the position of the first layer of oil spray holes (5), the first layer of oil spray holes (5) and the second layer of oil spray holes (7) are opened simultaneously.