CN118188246A - Dual-fuel nozzle and dual-fuel injection system - Google Patents

Abstract

The invention belongs to the technical field of engine injection systems, and discloses a dual-fuel nozzle and a dual-fuel injection system, wherein the dual-fuel nozzle comprises a shell, an air injection needle valve, an oil injection needle valve and a separation ring, the shell is provided with an inner cavity, an oil injection hole and an air injection hole, the air injection needle valve is slidably arranged in the inner cavity and is provided with an inner hole, one end of the inner hole far away from the oil injection hole is plugged by a separation seat, the inner cavity, the air injection needle valve and the separation seat form a first control cavity, a first elastic piece is arranged in the first control cavity, the inner cavity and the air injection needle valve form an air storage cavity together, the oil injection needle valve, the inner hole and the separation seat form a second control cavity, the second control cavity is internally provided with a second elastic piece, the conical end surfaces of the oil injection needle valve, the inner hole and the inner cavity form an oil storage cavity, and the separation ring is used for separating the oil storage cavity and the air storage cavity; the dual fuel injection system includes the dual fuel nozzle described above. The dual-fuel nozzle has a simple structure, and effectively ensures the positioning accuracy of the included angle between the oil spray hole and the air spray hole.

Description

Dual-fuel nozzle and dual-fuel injection system

Technical Field

The invention relates to the technical field of engine injection systems, in particular to a dual-fuel nozzle and a dual-fuel injection system.

Background

Natural gas has a wider and wider application range as an alternative fuel because of its obvious advantages over diesel in terms of cost and particulate matter reduction. The conventional natural gas supply method is to pre-mix with air before entering the engine, and the compression ratio is limited to be increased due to the risk of knocking during the compression stroke, so that the premixed combustion engine has a gap in power and efficiency from a diesel engine with the same size, and therefore, the gas fuel needs to be directly injected into the combustion chamber. Natural gas requires higher temperatures for ignition work than diesel fuel, and can be ignited with small amounts of liquid fuel (e.g., diesel fuel), thus requiring two fuel injection valves that can be controlled individually. On the premise of changing the original cylinder cover as little as possible, the two fuel injection valves are designed in an integrated way, namely the design of the dual-fuel nozzle, so that the pilot fuel and the main fuel can be injected into the combustion chamber in a timing and quantitative way.

Currently, in the prior art, a number of dual fuel nozzles have been developed by those skilled in the art, for example, patent document CN103814208B, CN216788583U, CN113719388B, and the dual fuel nozzles disclosed by them are structurally arranged in a form of concentric arrangement of a fuel injection needle valve and a fuel injection needle valve, so that two fuel injection valves can be integrated to realize combined injection of two fuels. In the prior art, the fuel injection hole and the air injection hole on the dual-fuel nozzle are often arranged on the air injection needle valve and the nozzle shell respectively, namely, the fuel injection hole and the air injection hole are arranged on two parts, and if the air injection needle valve rotates relative to the nozzle shell, the included angle between the fuel injection hole and the air injection hole is changed, so that the accuracy of the included angle between the fuel injection hole and the air injection hole is affected. To solve the above-mentioned problem, in the patent document disclosed in CN103814208B, a keying member is provided inside the elongated groove passage of the air injection needle valve and the nozzle housing, so as to avoid rotation. In addition, the arrangement needs to additionally add a component to fix the included angle between the air injection needle valve and the nozzle shell, so that the assembly complexity of the assembly is increased, and the accuracy of the included angle is not easy to control accurately.

Disclosure of Invention

The invention aims to provide a dual-fuel nozzle, wherein an oil spray hole and an air spray hole are arranged on the same component, so that the problem of the change of the included angle between the oil spray hole and the air spray hole is avoided, a special positioning component is not required to be additionally arranged, and the dual-fuel nozzle is simple in structure and can effectively ensure the positioning precision of the included angle between the oil spray hole and the air spray hole.

To achieve the purpose, the invention adopts the following technical scheme:

a dual fuel nozzle comprising:

The shell is provided with an inner cavity, the inner wall of the lower end of the inner cavity is provided with a conical end face, and the conical end face is provided with an oil spraying hole and an air spraying hole;

the air injection needle valve is arranged in the inner cavity in a sliding manner, an inner hole is formed in the air injection needle valve along the axial direction of the air injection needle valve, one end of the inner hole, which is far away from the conical end face, is plugged through the isolation seat, the inner cavity, the air injection needle valve and the isolation seat jointly form a first control cavity, a first oil inlet hole and a first oil outlet hole which are communicated with the first control cavity are respectively formed in the shell, a first elastic piece is arranged in the first control cavity, the first elastic piece provides a force for forcing the air injection needle valve to tightly prop against the conical end face and plug the air injection hole, the inner cavity and the air injection needle valve jointly form an air storage cavity, and an air inlet hole communicated with the air storage cavity is formed in the shell;

The oil injection needle valve is arranged in the inner hole in a sliding manner, a second control cavity is formed by the oil injection needle valve, the inner hole and the isolation seat together, a second oil inlet hole and a second oil outlet hole which are communicated with the second control cavity are respectively formed in the shell, a second elastic piece is arranged in the second control cavity, and the second elastic piece provides force for forcing the oil injection needle valve to tightly prop against the conical end face and plug the oil injection hole; the oil injection needle valve, the inner hole and the conical end face jointly form an oil storage cavity, and the shell is provided with a third oil inlet communicated with the oil storage cavity;

The isolating ring is positioned in the oil storage cavity and is used for isolating the oil storage cavity from the gas storage cavity.

Preferably, the isolating ring is sleeved on the oil injection needle valve, the outer peripheral wall of the isolating ring abuts against the hole wall of the inner hole and can slide relative to the hole wall of the inner hole, an oil passing gap is formed between the inner peripheral wall of the isolating ring and the oil injection needle valve, a third elastic piece is arranged between the isolating ring and the oil injection needle valve, and the third elastic piece provides force for forcing the isolating ring to abut against the conical end face between the air injection hole and the oil injection hole.

Preferably, a sealing groove is formed in the peripheral wall of the isolation ring, and a sealing ring is sleeved in the sealing groove.

Preferably, an abutting joint is arranged on the inner peripheral wall of the inner hole, the third elastic piece is sleeved on the oil injection needle valve, the first end of the third elastic piece abuts against the isolating ring, and the second end of the third elastic piece abuts against the abutting joint.

Preferably, a first sliding abutting part is arranged between the second control cavity and the oil storage cavity, a second sliding abutting part is correspondingly arranged in the inner hole, and the first sliding abutting part abuts against the second sliding abutting part and can slide relative to the second sliding abutting part;

The second elastic piece is sleeved on the oil injection needle valve, the first end of the second elastic piece is abutted against the first sliding abutting part, and the second elastic piece is abutted against the isolation seat.

Preferably, the first elastic piece is sleeved on the isolation seat, a first end of the first elastic piece abuts against the isolation seat, and a second end of the first elastic piece abuts against a cavity wall of the inner cavity.

Preferably, a first oil delivery ring groove is formed in the peripheral wall of the air injection needle valve, the first oil delivery ring groove is communicated with the second oil inlet hole and the second oil outlet hole, the length dimension of the first oil delivery ring groove in the axial direction of the air injection needle valve is larger than the aperture of the second oil inlet hole and the aperture of the second oil outlet hole, and a first oil delivery hole communicated with the second control cavity is formed in the first oil delivery ring groove.

Preferably, a second oil delivery ring groove is formed in the peripheral wall of the air injection needle valve, the second oil delivery ring groove is communicated with the third oil inlet hole, the length dimension of the second oil delivery ring groove in the axial direction of the air injection needle valve is larger than the aperture of the third oil inlet hole, and a second oil delivery hole communicated with the oil storage cavity is formed in the second oil delivery ring groove.

The invention also provides a dual-fuel injection system which comprises the dual-fuel nozzle, has a simple and reliable structure and effectively ensures the positioning accuracy of the included angle between the oil spray hole and the air spray hole.

A dual fuel injection system comprising the dual fuel nozzle of any of the above claims, the dual fuel injection system further comprising:

The oil supply mechanism comprises an oil tank, an oil pump, an oil supply pipeline, an oil return pipeline, an oil collecting device and a control valve group, wherein an oil inlet of the oil pump is communicated with the oil tank, an oil outlet of the oil pump is respectively communicated with the first oil inlet hole, the second oil inlet hole and the third oil inlet hole through the oil supply pipeline, the oil return pipeline comprises a first oil return pipe and a second oil return pipe, the first oil outlet is communicated with the oil collecting device through the first oil return pipe, the second oil outlet is communicated with the oil collecting device through the second oil return pipe, and the control valve group can control the opening degrees of the first oil return pipe and the second oil return pipe;

The air supply mechanism comprises a high-pressure air source and an air pipe, and the high-pressure air source is communicated with the air inlet hole through the air pipe.

Preferably, the control valve group comprises a first electromagnetic valve and a second electromagnetic valve, the first electromagnetic valve is arranged on the first oil return pipe, and the second electromagnetic valve is arranged on the second oil return pipe.

The beneficial effects are that:

according to the dual-fuel nozzle provided by the invention, under the initial assembly state, one end of the air injection needle valve, which faces towards the conical end face, is tightly abutted against the conical end face under the pretightening force of the first elastic piece, and meanwhile, a sealing ring belt is formed to seal the air injection hole. Under the pretightening force of the second elastic piece, one end of the oil injection needle valve, which faces the conical end face, is tightly abutted against the conical end face, and a sealing ring belt is formed to seal the oil injection hole. The isolating ring is positioned in the oil storage cavity and can always isolate the oil storage cavity from the air storage cavity.

When the fuel oil pump is applied to a dual-fuel injection system, under the action of the fuel pump, fuel oil with certain pressure in the fuel tank is divided into three paths, and the first path of fuel oil sequentially enters the fuel storage cavity through the fuel inlet pipeline and the third fuel inlet hole; the second fuel oil sequentially enters the second control cavity through the fuel inlet pipeline and the second fuel inlet hole; the third fuel enters the first control cavity through the fuel inlet pipeline and the first fuel inlet hole in sequence. The high-pressure gas source sequentially enters the gas storage cavity through the gas pipe and the gas inlet hole by using high-pressure gas with certain pressure.

When the opening of the second oil return pipe is regulated by the control valve group, and the second oil return pipe is completely closed, the oil injection needle valve is tightly abutted against the conical end face and seals the oil injection hole under the combined action of the fuel pressure in the second control cavity and the pretightening force of the second elastic piece. When the control valve group opens the second oil return pipe, the fuel in the second control cavity can flow out from the second control cavity and sequentially flow into the oil collecting device through the second oil outlet, the pressure in the second control cavity is reduced at the moment, and the fuel injection needle valve can be lifted upwards under the action of the upward oil pressure of the oil storage cavity to overcome the pretightening force of the second elastic piece, so that the blocking of the fuel injection hole is relieved, the fuel injection hole is communicated with the oil storage cavity, and the fuel is sprayed out from the fuel injection hole to enter the combustion chamber of the engine.

When the opening of the first oil return pipe is regulated by the control valve group, and the first oil return pipe is completely closed, the air injection needle valve is tightly abutted against the conical end face and seals the air injection hole under the combined action of the internal combustion oil pressure of the first control cavity and the pretightening force of the first elastic piece. When the control valve group opens the first oil return pipe, fuel in the first control cavity can flow out from the first control cavity and sequentially flow into the oil collecting device through the first oil outlet, and at the moment, the pressure in the first control cavity is reduced, so that the air injection needle valve can be lifted upwards under the action of the upward air pressure of the air storage cavity to overcome the pretightening force of the first elastic piece, thereby blocking the air injection hole is relieved, the air injection hole is communicated with the air storage cavity, and then fuel gas is sprayed out from the air injection hole and enters the combustion chamber of the engine.

The isolating ring is always positioned in the oil storage cavity in the process, and can always isolate the oil storage cavity from the oil storage cavity, so that the effect of isolating fuel oil and fuel gas is achieved.

The dual-fuel nozzle is simple and ingenious in structure, the oil spraying holes and the air spraying holes are formed in the same component, the problem that the included angles of the oil spraying holes and the air spraying holes change is avoided, a special positioning component is not needed to be additionally arranged, and the positioning precision of the included angles between the oil spraying holes and the air spraying holes can be effectively guaranteed when the oil spraying operation is carried out.

Drawings

FIG. 1 is a structural cross-sectional view of a dual fuel nozzle provided by the present invention;

FIG. 2 is a partial structural cross-sectional view of a dual fuel nozzle provided by the present invention;

fig. 3 is a schematic diagram of the dual fuel system provided by the present invention.

In the figure:

1. a housing; 1001. a tapered end face; 101. a first control chamber; 102. a second control chamber; 103. an oil storage chamber; 104. a gas storage chamber; 11. an oil injection hole; 111. jetting a converging groove; 12. a gas injection hole; 13. a first oil inlet hole; 14. a first oil outlet hole; 15. a second oil inlet hole; 16. a second oil outlet hole; 17. a third oil inlet hole; 18. an air inlet hole;

2. A jet needle valve; 21. a separation seat; 22. a butt joint; 23. a second sliding abutment; 24. a first oil delivery ring groove; 241. a first oil feed hole; 25. the second oil delivery ring groove; 251. a second oil delivery hole;

3. A fuel injection needle valve; 31. a first sliding abutment;

4. a spacer ring; 401. an oil passing gap; 41. sealing grooves; 42. a seal ring;

51. a first elastic member; 52. A second elastic member; 53. A third elastic member;

61. An oil tank; 62. An oil collecting device;

7. an oil pump;

81. A first oil inlet pipe; 82. a second oil inlet pipe; 83. a third oil inlet pipe; 84. a first oil return pipe; 841. a first electromagnetic valve; 85. a second oil return pipe; 851. a second electromagnetic valve;

91. A high pressure air source; 92. and an air pipe.

Detailed Description

The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

The present embodiment provides a dual fuel nozzle. Referring to fig. 1 to 3, the dual fuel nozzle includes a housing 1, a spray needle 2, a spray needle 3, and a spacer ring 4. Wherein the housing 1 has an inner cavity (not shown), the inner wall of the lower end of the inner cavity is provided with a tapered end surface 1001, and the tapered end surface 1001 is provided with an oil injection hole 11 and an air injection hole 12. The air injection needle valve 2 is slidably arranged in the inner cavity, an inner hole (not shown) is formed in the air injection needle valve 2 along the axial direction of the air injection needle valve 2, one end of the inner hole, far away from the conical end face 1001, is plugged through the isolating seat 21, the inner cavity, the air injection needle valve 2 and the isolating seat 21 jointly form the first control cavity 101, the first oil inlet 13 and the first oil outlet 14 communicated with the first control cavity 101 are respectively formed in the shell 1, the first elastic piece 51 is arranged in the first control cavity 101, the first elastic piece 51 provides force for forcing the air injection needle valve 2 to tightly prop against the conical end face 1001 and plug the air injection hole 12, the inner cavity and the air injection needle valve 2 jointly form the air storage cavity 104, and the air inlet 18 communicated with the air storage cavity 104 is formed in the shell 1. The oil injection needle valve 3 is arranged in the inner hole in a sliding manner, the oil injection needle valve 3, the inner hole and the isolation seat 21 jointly form a second control cavity 102, a second oil inlet hole 15 and a second oil outlet hole 16 which are communicated with the second control cavity 102 are respectively formed in the shell 1, a second elastic piece 52 is arranged in the second control cavity 102, the second elastic piece 52 provides force for forcing the oil injection needle valve 3 to tightly lean against the conical end face 1001 and blocking the oil injection hole 11, the oil injection needle valve 3, the inner hole and the conical end face 1001 jointly form an oil storage cavity 103, and a third oil inlet hole 17 communicated with the oil storage cavity 103 is formed in the shell 1. The isolating ring 4 is positioned in the oil storage cavity 103, and the isolating ring 4 is used for isolating the oil storage cavity 103 and the gas storage cavity 104.

For the dual fuel nozzle provided in this embodiment, this embodiment also provides a dual fuel injection system. The dual-fuel injection system comprises an oil supply mechanism, an air supply mechanism and the dual-fuel nozzle. The oil supply mechanism comprises an oil tank 61, an oil pump 7, an oil supply pipeline, an oil return pipeline, an oil collecting device 62 and a control valve group, wherein an oil inlet of the oil pump 7 is communicated with the oil tank 61, an oil outlet of the oil pump 7 is respectively communicated with the first oil inlet hole 13, the second oil inlet hole 15 and the third oil inlet hole 17 through the oil supply pipeline, the oil return pipeline comprises a first oil return pipe 84 and a second oil return pipe 85, the first oil outlet 14 is communicated with the oil collecting device 62 through the first oil return pipe 84, the second oil outlet 16 is communicated with the oil collecting device 62 through the second oil return pipe 85, and the control valve group can control the opening degrees of the first oil return pipe 84 and the second oil return pipe 85. The air supply mechanism comprises a high-pressure air source 91 and an air pipe 92, wherein the high-pressure air source 91 is communicated with the air inlet hole 18 through the air pipe 92.

In the present embodiment, in the initial assembly state of the dual-fuel nozzle, the air injection needle 2 is tightly abutted against the tapered end surface 1001 at one end thereof facing the tapered end surface 1001 under the pretightening force of the first elastic member 51, and a sealing ring belt is formed to seal the air injection hole 12. Under the pretightening force of the second elastic member 52, the end of the injection needle valve 3 facing the tapered end surface 1001 abuts against the tapered end surface 1001, and a seal ring belt is formed to seal the injection hole 11. The isolating ring 4 is positioned in the oil storage cavity 103, and can always isolate the oil storage cavity 103 from the gas storage cavity 104.

When the fuel oil pump is applied to a dual fuel injection system, under the action of the oil pump 7, fuel oil with certain pressure in the oil tank 61 is divided into three paths, and the first path of fuel oil sequentially enters the oil storage cavity 103 through the oil inlet pipeline and the third oil inlet hole 17; the second fuel enters the second control cavity 102 through the fuel inlet pipeline and the second fuel inlet hole 15 in sequence; the third fuel enters the first control cavity 101 through the fuel inlet pipeline and the first fuel inlet hole 13 in sequence. The high-pressure gas source 91 sequentially enters the high-pressure fuel gas with certain pressure into the gas storage cavity 104 through the gas pipe 92 and the gas inlet hole 18.

When the opening of the second oil return pipe 85 is adjusted by the control valve group, and the second oil return pipe 85 is completely closed, the fuel injection needle valve 3 abuts against the conical end face 1001 and seals the fuel injection hole 11 under the combined action of the fuel pressure in the second control cavity 102 and the pretightening force of the second elastic member 52. When the control valve group opens the second oil return pipe 85, the fuel in the second control cavity 102 can flow out from the second control cavity 102 and sequentially flow into the oil collecting device 62 through the second oil outlet hole 16, the pressure in the second control cavity 102 is reduced, and the fuel injection needle valve 3 can overcome the pretightening force of the second elastic piece 52 to lift up under the upward oil pressure action of the oil storage cavity 103, so that the blocking of the fuel injection hole 11 is relieved, the fuel injection hole 11 is communicated with the oil storage cavity 103, and the fuel is sprayed out from the fuel injection hole 11 to enter the combustion chamber of the engine.

When the opening of the first oil return pipe 84 is adjusted by the control valve group, and the first oil return pipe 84 is completely closed, the air injection needle valve 2 abuts against the conical end face 1001 and seals the air injection hole 12 under the combined action of the fuel pressure in the first control cavity 101 and the pretightening force of the first elastic member 51. When the control valve group opens the first oil return pipe 84, the fuel oil in the first control cavity 101 can flow out from the first control cavity 101 and sequentially flow into the oil collecting device 62 through the first oil outlet hole 14, and at this time, the pressure in the first control cavity 101 is reduced, so that the air injection needle valve 2 can overcome the pretightening force of the first elastic piece 51 to lift up under the action of the upward air pressure of the air storage cavity 104, thereby removing the blocking of the air injection hole 12, enabling the air injection hole 12 to be communicated with the air storage cavity 104, and further enabling the fuel gas to be ejected out from the air injection hole 12 and enter the engine combustion chamber.

In the process, the isolating ring 4 is always positioned in the oil storage cavity 103, and can always isolate the oil storage cavity 103 from the gas storage cavity 104, so that the effect of isolating fuel oil and fuel gas is achieved.

The dual-fuel nozzle is simple and ingenious in structure, the oil spray hole 11 and the air spray hole 12 are formed in the same component, the problem that the included angle between the oil spray hole 11 and the air spray hole 12 changes is avoided, a special positioning component is not needed to be additionally arranged, and the positioning precision of the included angle between the oil spray hole 11 and the air spray hole 12 can be effectively guaranteed when oil spraying is performed.

In this embodiment, the tapered end surface 1001 is disposed to extend obliquely downward, and is disposed in a funnel shape in fig. 1 to 3. Correspondingly, the lower end face of the injection needle valve 2 is arranged by downwards inclining and extending from the outer side wall to the inner hole side wall, the lower end face of the isolating ring 4 is arranged by downwards inclining and extending from the outer side wall to the inner side wall, and the lower end face of the injection needle valve 3 is also arranged to be a conical surface which downwards inclines and extends.

In this embodiment, the inner cavity extends along the axial direction of the housing 1. The air injection needle valve 2 is slidable in the extending direction of the inner chamber. The injection needle valve 3 is slidable in the axial direction of the bore. The extending direction of the inner cavity, the axial direction of the air injection needle valve 2 and the axial direction of the air injection needle valve 3 are arranged in parallel.

In this embodiment, the inner cavity, the injection needle valve 2 and the injection needle valve 3 are coaxially arranged.

In this embodiment, the housing 1 includes an injector body and a needle valve body arranged in this order from top to bottom. The first oil inlet hole 13 and the first oil outlet hole 14 are formed in the injector body, and the second oil inlet hole 15, the second oil outlet hole 16, the third oil inlet hole 17, the air inlet hole 18, the oil injection hole 11 and the air injection hole 12 are formed in the needle valve body respectively.

In this embodiment, the center of the conical end surface 1001 is provided with the injection converging groove 111, and the plurality of injection holes 11 are provided, and the plurality of injection holes 11 are uniformly distributed at intervals along the axial direction of the housing 1 and are communicated with the injection converging groove 111. Specifically, the injection converging groove 111 is arranged in a positive alignment with the plugging abutting end of the injection needle valve 3, and the injection needle valve 3 abuts against the conical end face 1001 and plugs the injection converging groove 111 under the combined action of the fuel pressure in the second control cavity 102 and the pretightening force of the second elastic member 52, so that the plurality of injection holes 11 are plugged. When the injection needle valve 3 is lifted up, the blocking of the injection converging groove 111 can be released, so that the plurality of injection holes 11 are communicated with the oil storage cavity 103 through the injection converging groove 111, and further, the fuel is sprayed out of the injection holes 11 and enters the engine combustion chamber.

In the present embodiment, the number of the gas injection holes 12 is plural, and the plural gas injection holes 12 are uniformly spaced apart in the axial direction of the housing 1.

In this embodiment, the spacer ring 4 is sleeved on the fuel injection needle valve 3, the outer peripheral wall of the spacer ring 4 abuts against the hole wall of the inner hole and can slide relative to the hole wall of the inner hole, a fuel passing gap 401 is formed between the inner peripheral wall of the spacer ring 4 and the fuel injection needle valve 3, a third elastic member 53 is arranged between the spacer ring 4 and the fuel injection needle valve 2, and the third elastic member 53 provides a force forcing the spacer ring 4 to abut against the conical end face 1001 between the fuel injection hole 12 and the fuel injection hole 11.

Specifically, in the initial assembly state of the dual-fuel nozzle, the spacer ring 4 is pressed against the tapered end surface 1001 at one end thereof facing the tapered end surface 1001 under the pre-tightening force of the third elastic member 53, and simultaneously forms a sealing ring belt to seal the tapered end surface 1001 at the portion between the gas injection hole 12 and the fuel injection hole 11.

Specifically, when the fuel injection needle valve 3 is lifted up, the fuel in the fuel reservoir 103 can flow to the fuel injection hole 11 through the fuel gap 401.

Specifically, to ensure that the air injection needle 2 can be in sufficiently reliable abutment with the tapered end surface 1001, the pretension force F1 of the first elastic member 51 is required to be greater than the sum of the pretension force F2 of the second elastic member 52 and the pretension force F3 of the third elastic member 53, that is, F1 > f2+f3.

In this embodiment, no matter what working state the dual-fuel nozzle is in, the spacer ring 4 is at the initial assembly position under the pretightening force F3 of the third elastic member 53 and the action of the upper and lower oil liquids, i.e. is abutted against the tapered end face 1001, so that the part between the air injection hole 12 and the oil injection hole 11 is effectively blocked, and the effect of isolating fuel oil and gas is achieved.

In the present embodiment, the first elastic member 51, the second elastic member 52, and the third elastic member 53 are each provided as a spring.

Further, a sealing groove 41 is formed in the outer peripheral wall of the isolation ring 4, and a sealing ring 42 is sleeved in the sealing groove 41. The sealing ring 42 can further play a role in isolating fuel, and the fuel in the oil storage cavity 103 is prevented from flowing into the gas storage cavity 104 through a gap between the isolating ring 4 and the air injection needle valve 2. Specifically, the seal ring 42 is an elastic energy storage seal ring 42, and the opening direction of the elastic energy storage seal ring is upward toward the fuel side.

Further, the inner peripheral wall of the inner hole is provided with an abutting joint 22, the third elastic piece 53 is sleeved on the oil injection needle valve 3, the first end of the third elastic piece 53 abuts against the isolation ring 4, and the second end of the third elastic piece 53 abuts against the abutting joint 22. Specifically, the provision of the abutment 22 provides a good abutment for the third elastic member 53. The third elastic piece 53 is in clearance fit with the fuel injection needle valve 3, and the third elastic piece 53 is sleeved on the fuel injection needle valve 3, so that the third elastic piece 53 is reliably and stably installed.

In this embodiment, the fuel injection needle valve 3 is provided with a first sliding contact portion 31 between the second control chamber 102 and the oil storage chamber 103, and a second sliding contact portion 23 is correspondingly provided in the inner bore, and the first sliding contact portion 31 is in contact with the second sliding contact portion 23 and can slide relative to the second sliding contact portion 23. The sliding fit between the first sliding abutment portion 31 and the second sliding abutment portion 23 can ensure reliable and stable relative sliding between the injection needle valve 3 and the injection needle valve 2.

The second elastic member 52 is sleeved on the fuel injection needle valve 3, the first end of the second elastic member 52 abuts against the first sliding abutting portion 31, and the second elastic member 52 abuts against the isolation seat 21.

Specifically, the first sliding abutment 31 can also provide a good abutment for the second elastic member 52. The second elastic piece 52 is in clearance fit with the oil injection needle valve 3, and the second elastic piece 52 is sleeved on the oil injection needle valve 3, so that reliable and stable installation of the second elastic piece 52 is ensured.

In the present embodiment, the isolation seat 21 and the air injection needle valve 2 are fixedly connected by a fastener such as a screw.

In this embodiment, the first elastic member 51 is sleeved on the isolation seat 21, the first end of the first elastic member 51 abuts against the isolation seat 21, and the second end of the first elastic member 51 abuts against the wall of the inner cavity. The first elastic member 51 is sleeved on the isolation seat 21, so that reliable and stable installation of the first elastic member 51 can be effectively ensured.

Specifically, the oil feed line includes a first oil feed pipe 81. Both ends of the first oil inlet pipe 81 are respectively communicated with the first oil inlet hole 13 and the oil pump 7.

Further, a first oil delivery ring groove 24 is formed in the outer peripheral wall of the air injection needle valve 2, the first oil delivery ring groove 24 is communicated with the second oil inlet hole 15 and the second oil outlet hole 16, the length dimension of the first oil delivery ring groove 24 in the axial direction of the air injection needle valve 2 is larger than the aperture of the second oil inlet hole 15 and the aperture of the second oil outlet hole 16, and a first oil delivery hole 241 communicated with the second control cavity 102 is formed in the first oil delivery ring groove 24. Specifically, the oil inlet pipeline comprises a second oil inlet pipe 82, and two ends of the second oil inlet pipe 82 are respectively communicated with the second oil inlet hole 15 and the oil pump 7. The fuel oil can enter the second control cavity 102 through the second oil inlet pipe 82, the second oil inlet hole 15, the first oil delivery ring groove 24 and the first oil delivery hole 241 in sequence, and the fuel oil can flow into the oil collecting device 62 through the first oil delivery ring groove 24, the second oil outlet hole 16 and the second oil return pipe 85 in sequence. And through setting up the length dimension of first oil transportation annular 24 in the axial direction of jet needle valve 2 and being greater than the aperture of second inlet port 15 and the aperture of second oil outlet port 16, when jet needle valve 2 slides about relative casing 1, can always keep reliable effective intercommunication state between first oil transportation annular 24 and second inlet port 15 and the second oil outlet port 16.

Further, a second oil delivery ring groove 25 is formed in the outer peripheral wall of the air injection needle valve 2, the second oil delivery ring groove 25 is communicated with the third oil inlet hole 17, the length dimension of the second oil delivery ring groove 25 in the axial direction of the air injection needle valve 2 is larger than the aperture of the third oil inlet hole 17, and a second oil delivery hole 251 communicated with the oil storage cavity 103 is formed in the second oil delivery ring groove 25. Specifically, the oil inlet pipeline comprises a third oil inlet pipe 83, and two ends of the third oil inlet pipe 83 are respectively communicated with the third oil inlet hole 17 and the oil pump 7. The fuel oil can enter the oil storage cavity 103 through the third oil inlet pipe 83, the third oil inlet hole 17, the second oil delivery ring groove 25 and the second oil delivery hole 251 in sequence. And the length dimension of the second oil delivery ring groove 25 in the axial direction of the air injection needle valve 2 is larger than the aperture of the third oil inlet hole 17, so that when the air injection needle valve 2 slides up and down relative to the shell 1, the second oil delivery ring groove 25 and the third oil inlet hole 17 can always maintain a reliable and effective communication state.

In this embodiment, the first oil inlet pipe 81, the second oil inlet pipe 82, and the third oil inlet pipe 83 flow back to the oil inlet manifold together, and the oil pump 7 is disposed on the oil inlet manifold.

In this embodiment, the control valve set includes a first solenoid valve 841 and a second solenoid valve 851, the first solenoid valve 841 is disposed on the first oil return pipe 84, and the second solenoid valve 851 is disposed on the second oil return pipe 85. Specifically, the opening and closing of the first solenoid valve 841 can be controlled correspondingly to the opening and closing of the first oil return pipe 84, and the opening and closing of the second solenoid valve 851 can be controlled correspondingly to the opening and closing of the second oil return pipe 85.

In this embodiment, the first oil inlet pipe 81, the second oil inlet pipe 82, the first oil return pipe 84, and the second oil return pipe 85 are all provided with throttles. Specifically, in order to ensure that the injection needle valve 2 and the injection needle valve 3 can work normally, the above throttle valve needs to be provided. Specifically, when the flow rate of the first oil inlet pipe 81 is made smaller than the flow rate of the first oil return pipe 84 under the control of the throttle valve, the fuel entering the first control chamber 101 is smaller than the fuel flowing out when the first electromagnetic valve 841 is opened, the pressure in the first control chamber 101 is reduced, the air injection needle valve 2 is lifted, and air injection is started. Under the control of the throttle valve, the flow rate of the second oil inlet pipe 82 is also smaller than the flow rate of the second oil return pipe 85, when the second electromagnetic valve 851 is opened, the fuel entering the second control cavity 102 is smaller than the fuel flowing out, the pressure in the second control cavity 102 is reduced, the oil injection needle valve 3 is lifted, and oil injection is started.

It is to be understood that the above examples of the present invention are provided for clarity of illustration only and are not limiting of the embodiments of the present invention. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the invention. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.

Claims (10)

1. A dual fuel nozzle, comprising:

The shell (1) is provided with an inner cavity, the inner wall of the lower end of the inner cavity is provided with a conical end face (1001), and the conical end face (1001) is provided with an oil spraying hole (11) and an air spraying hole (12);

The air injection needle valve (2) is arranged in the inner cavity in a sliding manner, an inner hole is formed in the air injection needle valve (2) along the axial direction of the air injection needle valve, one end of the inner hole, which is far away from the conical end face (1001), is plugged through the isolation seat (21), the inner cavity, the air injection needle valve (2) and the isolation seat (21) jointly form a first control cavity (101), a first oil inlet hole (13) and a first oil outlet hole (14) which are communicated with the first control cavity (101) are respectively formed in the shell (1), a first elastic piece (51) is arranged in the first control cavity (101), the first elastic piece (51) provides force for forcing the air injection needle valve (2) to tightly prop against the conical end face (1001) and plug the air injection hole (12), the inner cavity and the air injection needle valve (2) form an air storage cavity (104) together, and the shell (1) is provided with an air inlet hole (18) communicated with the air storage cavity (104);

The oil injection needle valve (3) is arranged in the inner hole in a sliding manner, the oil injection needle valve (3), the inner hole and the isolation seat (21) form a second control cavity (102) together, the shell (1) is respectively provided with a second oil inlet hole (15) and a second oil outlet hole (16) which are communicated with the second control cavity (102), the second control cavity (102) is internally provided with a second elastic piece (52), and the second elastic piece (52) provides force for forcing the oil injection needle valve (3) to tightly lean against the conical end face (1001) and sealing the oil injection hole (11); the oil injection needle valve (3), the inner hole and the conical end face (1001) jointly form an oil storage cavity (103), and the shell (1) is provided with a third oil inlet hole (17) communicated with the oil storage cavity (103);

The isolating ring (4) is positioned in the oil storage cavity (103), and the isolating ring (4) is used for isolating the oil storage cavity (103) and the gas storage cavity (104).

2. The dual-fuel nozzle as claimed in claim 1, characterized in that the spacer ring (4) is sleeved on the fuel injection needle valve (3), the outer peripheral wall of the spacer ring (4) is propped against the hole wall of the inner hole and can slide relative to the hole wall of the inner hole, a fuel passing gap (401) is formed between the inner peripheral wall of the spacer ring (4) and the fuel injection needle valve (3), a third elastic piece (53) is arranged between the spacer ring (4) and the fuel injection needle valve (2), and the third elastic piece (53) provides a force for forcing the spacer ring (4) to be tightly propped against the conical end face (1001) between the air injection hole (12) and the fuel injection hole (11).

3. The dual fuel nozzle as claimed in claim 2, characterized in that the outer peripheral wall of the spacer ring (4) is provided with a sealing groove (41), and the sealing groove (41) is internally sleeved with a sealing ring (42).

4. The dual fuel nozzle as claimed in claim 2, characterized in that the inner peripheral wall of the inner bore is provided with an abutment (22), the third elastic member (53) is sleeved on the fuel injection needle valve (3), a first end of the third elastic member (53) abuts against the spacer ring (4), and a second end of the third elastic member (53) abuts against the abutment (22).

5. The dual fuel nozzle of claim 1, wherein the fuel injection needle valve (3) is provided with a first sliding abutment (31) between the second control chamber (102) and the fuel storage chamber (103), the inner bore is correspondingly provided with a second sliding abutment (23), and the first sliding abutment (31) abuts against the second sliding abutment (23) and can slide relative to the second sliding abutment (23);

the second elastic piece (52) is sleeved on the oil injection needle valve (3), the first end of the second elastic piece (52) is abutted against the first sliding abutting part (31), and the second elastic piece (52) is abutted against the isolation seat (21).

6. The dual fuel nozzle of claim 1, wherein the first elastic member (51) is sleeved on the isolation seat (21), a first end of the first elastic member (51) abuts against the isolation seat (21), and a second end of the first elastic member (51) abuts against a cavity wall of the inner cavity.

7. The dual fuel nozzle of claim 1, wherein a first oil delivery ring groove (24) is formed in an outer peripheral wall of the air injection needle valve (2), the first oil delivery ring groove (24) is communicated with the second oil inlet hole (15) and the second oil outlet hole (16), a length dimension of the first oil delivery ring groove (24) in an axial direction of the air injection needle valve (2) is larger than a bore diameter of the second oil inlet hole (15) and a bore diameter of the second oil outlet hole (16), and a first oil delivery hole (241) communicated with the second control cavity (102) is formed in the first oil delivery ring groove (24).

8. The dual-fuel nozzle according to claim 1, characterized in that a second oil delivery ring groove (25) is formed in the peripheral wall of the air injection needle valve (2), the second oil delivery ring groove (25) is communicated with the third oil inlet hole (17), the length dimension of the second oil delivery ring groove (25) in the axial direction of the air injection needle valve (2) is larger than the aperture of the third oil inlet hole (17), and a second oil delivery hole (251) communicated with the oil storage cavity (103) is formed in the second oil delivery ring groove (25).

9. A dual fuel injection system comprising the dual fuel nozzle of any of claims 1-8, the dual fuel injection system further comprising:

The oil supply mechanism comprises an oil tank (61), an oil pump (7), an oil supply pipeline, an oil return pipeline, an oil collecting device (62) and a control valve group, wherein an oil inlet of the oil pump (7) is communicated with the oil tank (61), an oil outlet of the oil pump (7) is respectively communicated with the first oil inlet hole (13), the second oil inlet hole (15) and the third oil inlet hole (17) through the oil supply pipeline, the oil return pipeline comprises a first oil return pipe (84) and a second oil return pipe (85), the first oil outlet hole (14) is communicated with the oil collecting device (62) through the first oil return pipe (84), the second oil outlet hole (16) is communicated with the oil collecting device (62) through the second oil return pipe (85), and the control valve group can control the opening degrees of the first oil return pipe (84) and the second oil return pipe (85).

The air supply mechanism comprises a high-pressure air source (91) and an air pipe (92), and the high-pressure air source (91) is communicated with the air inlet hole (18) through the air pipe (92).

10. The dual fuel injection system of claim 9 wherein the control valve bank includes a first solenoid valve (841) and a second solenoid valve (851), the first solenoid valve (841) being disposed on the first return line (84) and the second solenoid valve (851) being disposed on the second return line (85).