A dual fuel injector and engine

Abstract

The application discloses a dual-fuel injector and an engine. The dual-fuel injector is characterized in that a first core cavity, a second core cavity, a first communication hole and a second communication hole are formed in an injector body. A first valve rod is arranged in the first core cavity, and a first guide part of the first valve rod divides the first core cavity into a first pressure cavity and a second low-pressure cavity. A first feed passage is in communication with the first pressure cavity and the first low-pressure cavity. The first guide part is provided with a first flow channel in communication with the first pressure cavity and a second flow channel in communication with the second low-pressure cavity. A second valve rod is arranged in the second core cavity, and a second guide part of the second valve rod divides the second core cavity into a second pressure cavity and a third low-pressure cavity. A second feed passage is in communication with the third low-pressure cavity. The first communication hole and the second communication hole are both in communication with the second pressure cavity. The first communication hole can be in communication with the first flow channel, and the second communication hole can be in communication with the second flow channel. The dual-fuel injector can not cause mixing of materials, and the actual working pressure range of the first fuel is larger.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more particularly to a dual-fuel injector and engine. Background Technology

[0002] An engine is a machine that converts other forms of energy into mechanical energy and is widely used in various mechanical equipment. Dual-fuel engines, as one type of engine, can burn two fuels simultaneously and have a broad application market. The dual-fuel injector is the core component of a dual-fuel engine. It injects two fuel channels into the engine's combustion chamber for combustion. Existing dual-fuel injectors incorporate two core chambers, two valve cores, two feed channels, two nozzles, and a solenoid valve control assembly within the injector body. This allows for simultaneous control of two fuel injections via a single solenoid valve control assembly, resulting in a more compact overall engine structure, improved engine layout, and reduced manufacturing costs.

[0003] However, the aforementioned dual-fuel injector still has some problems. Specifically, since the first core cavity and the second oil passage of the injector body are connected in both the closed and open states of the dual-fuel injector, when the oil inlet pressure of the first feed channel is too high, the oil inlet pressure can still be transmitted to the push rod through the first core cavity and the second oil passage. This may result in the pressure in the second feed channel and the elasticity of the first return spring failing to push the push rod open or fully open, ultimately preventing the second fuel from being properly ejected from the second nozzle. Therefore, to ensure normal injection of the second fuel, this dual-fuel injector places high demands on the oil inlet pressure of the first feed channel, thereby limiting the injection pressure of the first fuel and resulting in a smaller actual operating pressure range for the first fuel. In addition, when the dual-fuel injector is in the open state, the fuel in the second oil passage cannot be discharged or completely discharged. Therefore, a small amount of fuel may enter the second discharge channel through the gap between the guide hole and the push rod, and then mix with the second fuel and be ejected from the second nozzle, causing abnormal engine operation. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-fuel injector and engine to solve the problems of existing dual-fuel injectors that place high requirements on the oil inlet pressure of the first feed channel, thereby limiting the injection pressure of the first fuel and resulting in a small actual operating pressure range of the first fuel, and the possibility that fuel from the second oil passage may enter the second discharge channel and mix with the first fuel before being sprayed out from the second nozzle, thus causing abnormal engine operation.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A dual-fuel injector includes an injector body and a control valve assembly. The injector body has a first feed channel, a second feed channel, a first low-pressure chamber, a first nozzle, and a second nozzle. The first feed channel is used to introduce fuel and is connected to the first low-pressure chamber and the first nozzle. The second feed channel is connected to the second nozzle. The control valve assembly is capable of selectively disconnecting or connecting the first feed channel and the first nozzle, and disconnecting or connecting the second feed channel and the second nozzle. It further includes:

[0007] A first core cavity and a first valve stem are provided. The first core cavity is formed in the injector body, and the first valve stem is movably disposed in the first core cavity. The first valve stem includes a first guide portion and a first main body portion. The shaft diameter of the first guide portion is larger than the shaft diameter of the first main body portion. The first guide portion divides the first core cavity into a first pressure cavity and a second low-pressure cavity that are not interconnected. The first feed channel is connected to the first low-pressure cavity through the first pressure cavity. The first guide portion has a first flow channel connected to the first pressure cavity and a second flow channel connected to the second low-pressure cavity. The first flow channel and the second flow channel are not interconnected.

[0008] The second core cavity and the second valve stem are provided. The second core cavity is opened in the injector body and is spaced apart from the first core cavity. The second valve stem is movably disposed in the second core cavity. The second valve stem includes a second guide portion and a second body portion. The second guide portion divides the second core cavity into a second pressure chamber and a third low-pressure chamber that are not connected. The second feed channel is connected to the third low-pressure chamber.

[0009] The first connecting hole and the second connecting hole are both opened in the injector body and are both connected to the second pressure chamber. The first connecting hole can be connected to the first flow channel, and the second connecting hole can be connected to the second flow channel.

[0010] In the closed state of the dual-fuel injector, the control valve assembly cuts off the communication between the first pressure chamber and the first low-pressure chamber. The first feed channel, the first pressure chamber, the first flow channel, the first connecting hole, and the second pressure chamber are connected. The second connecting hole is disconnected from the second flow channel. The hydraulic pressure of the first pressure chamber drives the first valve stem to cut off the communication between the first feed channel and the first nozzle. The hydraulic pressure of the second pressure chamber drives the second valve stem to cut off the communication between the second feed channel and the second nozzle. In the open state of the dual-fuel injector, the control valve assembly connects the first pressure chamber and the first low-pressure chamber. The first connecting hole is disconnected from the first flow channel. The second pressure chamber, the second connecting hole, the second flow channel, and the second low-pressure chamber are connected.

[0011] As a preferred embodiment of the above-mentioned dual-fuel injector, the first flow channel includes a first oil hole and a second oil hole. The first oil hole extends along the direction from the first pressure chamber to the first low-pressure chamber, and one end of the first oil hole is connected to the first pressure chamber, while the other end of the first oil hole is connected to the second oil hole. The second oil hole extends along the direction from the first pressure chamber to the second pressure chamber. In the closed state of the dual-fuel injector, one end of the second oil hole is connected to the first connecting hole.

[0012] As a preferred embodiment of the above-mentioned dual-fuel injector, the second flow channel includes a third oil hole and a fourth oil hole. Along the direction from the first pressure chamber to the second low-pressure chamber, the third oil hole is spaced apart from the second oil hole and is located near one end of the second low-pressure chamber. One end of the fourth oil hole is connected to the third oil hole, and the other end is connected to the second low-pressure chamber. In the open state of the dual-fuel injector, one end of the third oil hole is connected to the second connecting hole.

[0013] As a preferred embodiment of the above-mentioned dual-fuel injector, the second guide portion includes at least two guide shaft segments, and a connecting shaft segment with a diameter smaller than the guide shaft segment is connected between two adjacent guide shaft segments. The two adjacent guide shaft segments, the connecting shaft segment, and the inner wall of the second core cavity together form a fourth low-pressure chamber.

[0014] As a preferred embodiment of the above-mentioned dual-fuel injector, a first return spring is provided in the third low-pressure chamber, and a first abutting shaft section is provided in the second main body. One end of the first abutting shaft section is connected to the first return spring. In the open state of the dual-fuel injector, the elastic force of the first return spring can drive the second main body to move towards one end of the second pressure chamber to connect the second feed channel and the second nozzle.

[0015] As a preferred embodiment of the above-mentioned dual-fuel injector, the second guide portion and the second main body portion are separately formed. The end of the first abutting shaft segment away from the first return spring abuts against the second guide portion. Along the axial direction of the first abutting shaft segment, the projected shape of the first abutting shaft segment is elliptical. The large end of the shaft diameter of the first abutting shaft segment is clearance-fitted with the third low-pressure chamber, and the small end of the shaft diameter of the first abutting shaft segment forms a fuel flow channel with the inner wall of the third low-pressure chamber.

[0016] As a preferred embodiment of the above-mentioned dual-fuel injector, the dual-fuel injector further includes a nozzle assembly, the nozzle assembly including a first nozzle and a second nozzle, the first nozzle being sleeved on the end of the first valve stem extending out of the first core cavity, a first injection channel being formed between the inner wall of the first nozzle and the outer wall of the first valve stem, the first nozzle being disposed on the first nozzle and communicating with one end of the first injection channel, the first nozzle having a first discharge channel, one end of the first discharge channel communicating with the first feed channel, and the other end of the first discharge channel communicating with the other end of the first injection channel;

[0017] The second nozzle is sleeved on the first nozzle, and a second injection channel is formed between the inner wall of the second nozzle and the outer wall of the first nozzle. The second nozzle is disposed on the second nozzle and connected to one end of the second injection channel. The first nozzle also has a second discharge channel. One end of the second discharge channel can be connected to the third low-pressure chamber, and the other end of the second discharge channel is connected to the other end of the second injection channel.

[0018] As a preferred embodiment of the above-mentioned dual-fuel injector, the outer wall of the end of the second main body away from the second pressure chamber is provided with a first inclined surface in the circumferential direction, and the inner wall of the end of the second discharge channel communicating with the third low-pressure chamber is provided with a second inclined surface in the circumferential direction. In the closed state of the dual-fuel injector, the first inclined surface is attached to the second inclined surface to cut off the communication between the third low-pressure chamber and the second discharge channel.

[0019] As a preferred embodiment of the above-mentioned dual-fuel injector, a valve plate is provided in the first low-pressure chamber, and an oil passage hole and a connecting channel are provided on the valve plate. One end of the oil passage hole is connected to the first pressure chamber, and the control valve assembly can selectively block or open the other end of the oil passage hole. The first feed channel is connected to the first pressure chamber through the connecting channel.

[0020] As a preferred embodiment of the aforementioned dual-fuel injector, the control valve assembly includes an electromagnet, an armature, a needle valve, and a sealing ball. The armature is magnetically attracted to the electromagnet, the needle valve is located on the side of the armature away from the electromagnet, and the sealing ball is located at the end of the needle valve away from the armature. The sealing ball can block the end of the oil passage away from the first pressure chamber.

[0021] An engine comprising the aforementioned dual-fuel injector.

[0022] The beneficial effects of this invention are as follows:

[0023] This invention provides a dual-fuel injector and an engine. The dual-fuel injector includes an injector body and a control valve assembly. The injector body has a first feed channel, a second feed channel, a first low-pressure chamber, a first nozzle, and a second nozzle. The first feed channel is used to introduce fuel and can communicate with the first low-pressure chamber and the first nozzle. The second feed channel can communicate with the second nozzle. The control valve assembly can selectively disconnect or connect the first feed channel and the first nozzle, and disconnect or connect the second feed channel and the second nozzle.

[0024] The dual-fuel injector also includes a first core cavity, a first valve stem, a second core cavity, a second valve stem, a first connecting hole, and a second connecting hole. The first core cavity is located in the injector body. The first valve stem is movably disposed in the first core cavity. The first valve stem includes a first guide portion and a first main body portion. The shaft diameter of the first guide portion is larger than the shaft diameter of the first main body portion. The first guide portion divides the first core cavity into a first pressure cavity and a second low-pressure cavity that are not interconnected. The first feed channel is connected to the first low-pressure cavity through the first pressure cavity. The first guide portion has a first flow channel connected to the first pressure cavity and a second flow channel connected to the second low-pressure cavity. The first flow channel and the second flow channel are not interconnected. The second core cavity is located in the injector body and is spaced apart from the first core cavity. The second valve stem is movably disposed in the second core cavity. The second valve stem includes a second guide portion and a second main body portion. The second guide portion divides the second core cavity into a second pressure cavity and a third low-pressure cavity that are not interconnected. The second feed channel is connected to the third low-pressure cavity. The first connecting hole and the second connecting hole are both located in the injector body and are both connected to the second pressure cavity. The first connecting hole can connect to the first flow channel, and the second connecting hole can connect to the second flow channel. In the closed state of the dual-fuel injector, the control valve assembly cuts off the connection between the first pressure chamber and the first low-pressure chamber. The first feed channel, the first pressure chamber, the first flow channel, the first connecting hole, and the second pressure chamber are connected, while the second connecting hole is disconnected from the second flow channel. The hydraulic pressure in the first pressure chamber drives the first valve stem to cut off the connection between the first feed channel and the first nozzle. The hydraulic pressure in the second pressure chamber drives the second valve stem to cut off the connection between the second feed channel and the second nozzle. In the open state of the dual-fuel injector, the control valve assembly connects the first pressure chamber and the first low-pressure chamber. The first connecting hole is disconnected from the first flow channel, while the second pressure chamber, the second connecting hole, the second flow channel, and the second low-pressure chamber are connected. Specifically, when the dual-fuel injector is closed, fuel from the first feed channel can enter the first pressure chamber and then enter the second pressure chamber through the first flow channel and the first connecting hole. At this time, both the first and second pressure chambers are high-pressure chambers. Therefore, under the action of the first pressure chamber, the first valve stem cuts off the connection between the first feed channel and the first nozzle, and under the action of the second pressure chamber, the second valve stem cuts off the connection between the second feed channel and the second nozzle. When the dual-fuel injector is in the open state, the second pressure chamber is connected to the first low-pressure chamber. The first valve stem is pressured and moves towards the first low-pressure chamber. The first fuel passage is connected to the passage of the first nozzle, and the first nozzle begins to inject fuel. The first connecting hole is disconnected from the first flow channel, and the second connecting hole is connected to the second flow channel. At this time, the second pressure chamber is a low-pressure chamber. The second valve stem is pressured and moves towards the first low-pressure chamber. The second fuel passage is connected to the passage of the second nozzle, and the second nozzle begins to inject fuel, which drives the fuel in the second pressure chamber to enter the second low-pressure chamber through the second connecting hole and the second flow channel.

[0025] When the control valve assembly connects the first pressure chamber and the first low-pressure chamber in this dual-fuel injector, the first connecting hole is disconnected from the first flow channel. At this time, the first pressure chamber is no longer connected to the second pressure chamber, and the oil inlet pressure of the first feed channel can no longer be transmitted to the second pressure chamber through the first pressure chamber. Therefore, compared with the prior art, this dual-fuel injector does not have an excessively high limitation on the oil inlet pressure of the first feed channel, thus making the actual operating pressure range of the first fuel wider. Furthermore, when the control valve assembly connects the first pressure chamber and the first low-pressure chamber, the second connecting hole is connected to the second flow channel. Most of the fuel in the second pressure chamber can enter the second low-pressure chamber through the second connecting hole and the second flow channel. Thus, the fuel in the second pressure chamber will not enter the third low-pressure chamber, avoiding the situation where the fuel in the second pressure chamber is sprayed out together with the second fuel through the second nozzle. Therefore, compared with the prior art, this dual-fuel injector will not have the first fuel and the second fuel mixed. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a dual-fuel injector provided in Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the injector body of a dual-fuel injector provided in Embodiment 1 of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the first valve stem of a dual-fuel injector provided in Embodiment 1 of the present invention;

[0029] Figure 4 yes Figure 3 Enlarged view of point C in the middle;

[0030] Figure 5 yes Figure 1 Enlarged view of point A in the middle;

[0031] Figure 6 This is a schematic diagram of the structure of the second valve stem of a dual-fuel injector provided in Embodiment 1 of the present invention;

[0032] Figure 7 yes Figure 1 Enlarged view of point B in the middle;

[0033] Figure 8 This is a partial structural schematic diagram of the first nozzle of a dual-fuel injector provided in Embodiment 1 of the present invention;

[0034] Figure 9 This is a schematic diagram of the structure of the second valve stem of a dual-fuel injector provided in Embodiment 2 of the present invention;

[0035] Figure 10 yes Figure 9A top view of the second main body section.

[0036] In the picture:

[0037] 1. Injector body; 11. First feed channel; 12. Second feed channel; 13. First low-pressure chamber; 14. First core chamber; 141. First pressure chamber; 142. Second low-pressure chamber; 15. Second core chamber; 151. Second pressure chamber; 152. Third low-pressure chamber; 153. Fourth low-pressure chamber; 161. First connecting hole; 162. Second connecting hole; 171. First connecting oil passage; 172. Second connecting oil passage;

[0038] 2. Control valve assembly; 21. Electromagnet; 22. Armature; 23. Needle valve; 24. Sealing ball;

[0039] 31. First valve stem; 311. First guide portion; 312. First main body portion; 3121. Second abutting shaft section; 313. First flow channel; 3131. First oil hole; 3132. Second oil hole; 3133. First annular groove; 314. Second flow channel; 3141. Third oil hole; 3142. Fourth oil hole; 3143. Second annular groove; 32. Second valve stem; 321. Second guide portion; 3211. Guide shaft section; 3212. Connecting shaft section; 322. Second main body portion; 3221. First abutting shaft section; 3222. First inclined surface;

[0040] 41. First return spring; 42. First washer; 43. Second return spring; 44. Second washer;

[0041] 51. First nozzle; 511. First nozzle opening; 512. First spray channel; 513. First discharge channel; 514. Second discharge channel; 5141. Second inclined plane; 52. Second nozzle; 521. Second nozzle opening; 522. Second spray channel;

[0042] 6. Valve plate; 61. Oil passage hole; 62. Connecting channel. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0044] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0047] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0048] Existing dual-fuel injectors, because the first core cavity and second oil passage of the injector body are connected in both the closed and open states, can still transmit excessive oil pressure through the first core cavity and second oil passage to the push rod when the oil pressure in the first feed channel is too high. This can lead to situations where the pressure in the second feed channel and the elasticity of the first return spring fail to push the push rod open or fully open, ultimately preventing the second fuel from being properly ejected from the second nozzle. Therefore, to ensure proper second fuel injection, this dual-fuel injector places high demands on the oil pressure in the first feed channel, thus limiting the injection pressure of the first fuel and resulting in a smaller actual operating pressure range for the first fuel. Furthermore, when the dual-fuel injector is open, fuel in the second oil passage cannot be discharged or completely discharged. Therefore, a small amount of fuel may enter the second discharge channel through the gap between the guide hole and the push rod, mixing with the second fuel and being ejected from the second nozzle, causing abnormal engine operation.

[0049] Example 1

[0050] To address the technical problems existing in current dual-fuel injectors, such as... Figures 1 to 8 As shown, Embodiment 1 of the present invention provides a dual-fuel injector, including an injector body 1 and a control valve assembly 2.

[0051] Among them, such as Figure 1 and Figure 7 As shown, the injector body 1 has a first feed channel 11, a second feed channel 12, a first low-pressure chamber 13, a first nozzle 511, and a second nozzle 521. The first feed channel 11 is used to introduce fuel. The first feed channel 11 can communicate with the first low-pressure chamber 13 and the first nozzle 511. The second feed channel 12 can communicate with the second nozzle 521. The control valve assembly 2 can selectively cut off or connect the communication between the first feed channel 11 and the first nozzle 511, and cut off or connect the communication between the second feed channel 12 and the second nozzle 521.

[0052] Specifically, such as Figures 1 to 6As shown, the injector body 1 also has a first core cavity 14, a second core cavity 15, a first connecting hole 161, and a second connecting hole 162. A first valve stem 31 is movably disposed in the first core cavity 14. The first valve stem 31 includes a first guide portion 311 and a first main body portion 312. The shaft diameter of the first guide portion 311 is larger than the shaft diameter of the first main body portion 312. The first guide portion 311 divides the first core cavity 14 into a first pressure cavity 141 and a second low-pressure cavity 142 that are not interconnected. The first feed channel 11 communicates with the first low-pressure cavity 13 through the first pressure cavity 141. The first guide portion 311 has a first flow channel 313 communicating with the first pressure cavity 141 and a second flow channel 314 communicating with the second low-pressure cavity 142. The first flow channel 313 and the second flow channel 314... 4. Not connected; the second core cavity 15 is opened in the injector body 1 and spaced apart from the first core cavity 14. The second valve stem 32 is movably disposed in the second core cavity 15. The second valve stem 32 includes a second guide portion 321 and a second body portion 322. The second guide portion 321 divides the second core cavity 15 into a second pressure cavity 151 and a third low-pressure cavity 152 that are not connected. The second feed channel 12 is connected to the third low-pressure cavity 152. The first connecting hole 161 and the second connecting hole 162 are both connected to the second pressure cavity 151. The first connecting hole 161 can be connected to the first flow channel 313, and the second connecting hole 162 can be connected to the second flow channel 314.

[0053] Specifically, such as Figures 1 to 7As shown, in the closed state of the dual-fuel injector, the control valve assembly 2 cuts off the connection between the first pressure chamber 141 and the first low-pressure chamber 13. The first feed channel 11, the first pressure chamber 141, the first flow channel 313, the first connecting hole 161, and the second pressure chamber 151 are connected. The second connecting hole 162 is disconnected from the second flow channel 314. The oil pressure of the first pressure chamber 141 drives the first valve stem 31 to cut off the connection between the first feed channel 11 and the first nozzle 511. The oil pressure of the second pressure chamber 151 drives the second valve stem 32 to cut off the connection between the second feed channel 12 and the second nozzle 521. In the open state of the dual-fuel injector, the control valve assembly 2 connects the first pressure chamber 141 and the first low-pressure chamber 13. The first connecting hole 161 is disconnected from the first flow channel 313. The second pressure chamber 151, the second connecting hole 162, the second flow channel 314, and the second low-pressure chamber 142 are connected. In detail, when the dual-fuel injector is in the closed state, the fuel in the first feed channel 11 can enter the first pressure chamber 141 and enter the second pressure chamber 151 through the first flow channel 313 and the first connecting hole 161. At this time, both the first pressure chamber 141 and the second pressure chamber 151 are high-pressure chambers. As a result, the first valve stem 31 cuts off the connection between the first feed channel 11 and the first nozzle 511 under the action of the first pressure chamber 141, and the second valve stem 32 cuts off the connection between the second feed channel 12 and the second nozzle 521 under the action of the second pressure chamber 151. When the dual-fuel injector is in the open state, the second pressure chamber 151 is connected to the first low-pressure chamber 13, the first valve stem 31 is pressured and moves towards the first low-pressure chamber 13, the first fuel passage is connected to the passage of the first nozzle 511, the first nozzle 511 begins to inject fuel, the first connecting hole 161 is disconnected from the first flow channel 313, the second connecting hole 162 is connected to the second flow channel 314, at this time, the second pressure chamber 151 is a low-pressure chamber, the second valve stem 32 is pressured and moves towards the first low-pressure chamber 13, the second fuel passage is connected to the passage of the second nozzle 521, the second nozzle 521 begins to inject fuel, and drives the fuel in the second pressure chamber 151 to enter the second low-pressure chamber 142 through the second connecting hole 162 and the second flow channel 314.

[0054] like Figures 1 to 7As shown in the figure, in the dual-fuel injector provided in Embodiment 1 of the present invention, when the control valve assembly 2 connects the first pressure chamber 141 and the first low-pressure chamber 13, the first connecting hole 161 is disconnected from the first flow channel 313. At this time, the first pressure chamber 141 will no longer be connected to the second pressure chamber 151, and the oil inlet pressure of the first feed channel 11 can no longer be transmitted to the second pressure chamber 151 through the first pressure chamber 141. Therefore, compared with the prior art, the dual-fuel injector does not have an excessively high limitation on the oil inlet pressure of the first feed channel 11, thereby making the actual operating pressure range of the first fuel larger. Furthermore, when the control valve assembly 2 connects the first pressure chamber 141 and the first low-pressure chamber 13, the second connecting hole 162 connects to the second flow channel 314. Most of the fuel in the second pressure chamber 151 can enter the second low-pressure chamber 142 through the second connecting hole 162 and the second flow channel 314. Therefore, the fuel in the second pressure chamber 151 will not enter the third low-pressure chamber 152, preventing the fuel in the second pressure chamber 151 from being sprayed out together with the second fuel through the second nozzle 521. Thus, compared to the prior art, this dual-fuel injector does not experience mixing of the first and second fuels.

[0055] Specifically, such as Figures 1 to 5 As shown, the first flow channel 313 includes a first oil hole 3131 and a second oil hole 3132. The first oil hole 3131 extends along the direction from the first pressure chamber 141 to the first low-pressure chamber 13, with one end connected to the first pressure chamber 141 and the other end connected to the second oil hole 3132. The second oil hole 3132 extends along the direction from the first pressure chamber 141 to the second pressure chamber 151. In the closed state of the dual-fuel injector, one end of the second oil hole 3132 is connected to the first connecting hole 161. Specifically, in the closed state of the dual-fuel injector, fuel in the first pressure chamber 141 enters the second pressure chamber 151 sequentially through the first oil hole 3131, the second oil hole 3132, and the first connecting hole 161. In the open state of the dual-fuel injector, the second oil hole 3132 is disconnected from the first connecting hole 161, and at this time, the first pressure chamber 141 and the second pressure chamber 151 are no longer connected. Furthermore, a first annular groove 3133 extending circumferentially is formed on the outer periphery of the first guide portion 311, and the first annular groove 3133 is connected to both ends of the second oil hole 3132. With this configuration, even if the position of the first valve stem 31 is rotated a certain angle around the axial direction, causing one end of the second oil hole 3132 to be unable to directly connect with the first connecting hole 161, the fuel in the second oil hole 3132 can still enter the first connecting hole 161 through the first annular groove 3133. Specifically, in this embodiment, the specific opening position and opening angle of the first oil hole 3131 and the second oil hole 3132 are not limited, as long as the first pressure chamber 141 and the second pressure chamber 151 can be connected.

[0056] Specifically, such as Figures 1 to 5 As shown, the second flow channel 314 includes a third oil hole 3141 and a fourth oil hole 3142. Along the direction from the first pressure chamber 141 to the second low-pressure chamber 142, the third oil hole 3141 and the second oil hole 3132 are spaced apart and located near one end of the second low-pressure chamber 142. One end of the fourth oil hole 3142 is connected to the third oil hole 3141, and the other end of the fourth oil hole 3142 is connected to the second low-pressure chamber 142. In the open state of the dual-fuel injector, one end of the third oil hole 3141 is connected to the second connecting hole 162. Specifically, in the closed state of the dual-fuel injector, the third oil hole 3141 is disconnected from the second connecting hole 162, and the second pressure chamber 151 is not connected to the second low-pressure chamber 142. In the open state of the dual-fuel injector, fuel in the second pressure chamber 151 enters the second low-pressure chamber 142 sequentially through the second connecting hole 162, the third oil hole 3141, and the fourth oil hole 3142. Furthermore, a second annular groove 3143 extending circumferentially is provided on the outer periphery of the first guide portion 311, and the second annular groove 3143 is connected to both ends of the third oil hole 3141. With this configuration, even if the position of the first valve stem 31 is rotated a certain angle around the axial direction, causing one end of the third oil hole 3141 to be unable to directly connect with the second connecting hole 162, the fuel in the second through hole can still enter the third oil hole 3141 through the second annular groove 3143, and then enter the second low-pressure chamber 142 through the fourth oil hole 3142. Specifically, in this embodiment, the specific opening positions and angles of the third oil hole 3141 and the fourth oil hole 3142 are not limited, as long as the second pressure chamber 151 and the second low-pressure chamber 142 can be connected.

[0057] Preferably, such as Figure 2 , Figure 5 and Figure 6 As shown, the second guide section 321 includes at least two guide shaft segments 3211. A connecting shaft segment 3212 with a diameter smaller than the guide shaft segments 3211 connects two adjacent guide shaft segments 3211. The two adjacent guide shaft segments 3211, the connecting shaft segment 3212, and the inner wall of the second core cavity 15 together form a fourth low-pressure chamber 153. With this configuration, when fuel in the second pressure chamber 151 leaks towards the third low-pressure chamber 152 through the gap between the second valve stem 32 and the second core cavity 15, the fourth low-pressure chamber 153 can collect the leaked fuel, preventing it from entering the third low-pressure chamber 152 and mixing with the second fuel. Exemplarily, in this embodiment, two guide shaft segments 3211 and one connecting shaft segment 3212, i.e., one fourth low-pressure chamber 153, are used. Of course, the number of fourth low-pressure chambers 153 can be increased according to actual needs.

[0058] Specifically, such as Figure 1 , Figure 2 and Figure 7 As shown, the dual-fuel injector also includes a nozzle assembly, which includes a first nozzle 51 and a second nozzle 52. The first nozzle 51 is sleeved on the end of the first valve stem 31 that extends out of the first core cavity 14. A first injection channel 512 is formed between the inner wall of the first nozzle 51 and the outer wall of the first valve stem 31. A first nozzle 511 is disposed on the first nozzle 51 and communicates with one end of the first injection channel 512. The first nozzle 51 has a first discharge channel 513, one end of which can communicate with the first feed channel 11, and the other end of which communicates with the other end of the first injection channel 512. More specifically, the injector body 1 has a first connecting oil passage 171, one end of which communicates with the first feed channel 11, and the other end of which communicates with the first discharge channel 513. In detail, when the dual-fuel injector is working, fuel is injected sequentially through the first feed channel 11, the first connecting oil channel 171, the first discharge channel 513, the first injection channel 512 and the first nozzle 511.

[0059] Specifically, such as Figure 1 , Figure 2 and Figure 7 As shown, the second nozzle 52 is fitted onto the first nozzle 51, and a second injection channel 522 is formed between the inner wall of the second nozzle 52 and the outer wall of the first nozzle 51. A second nozzle 521 is disposed on the second nozzle 52 and connected to one end of the second injection channel 522. The first nozzle 51 also has a second discharge channel 514, one end of which is connected to the third low-pressure chamber 152, and the other end of which is connected to the other end of the second injection channel 522. Specifically, when the dual-fuel injector is operating, the second fuel can be sequentially ejected through the third low-pressure chamber 152, the second discharge channel 514, the second injection channel 522, and the second nozzle 521.

[0060] Preferably, such as Figure 1 , Figure 6 and Figure 8 As shown, the outer wall of the second main body 322 of the second valve stem 32, away from the second pressure chamber 151, is provided with a first inclined surface 3222 along the circumference. The inner wall of the end of the second discharge channel 514 that communicates with the third low-pressure chamber 152 is provided with a second inclined surface 5141 along the circumference. In the closed state of the dual-fuel injector, the first inclined surface 3222 fits against the second inclined surface 5141 to cut off the communication between the third low-pressure chamber 152 and the second discharge channel 514. With this configuration, when the second valve stem 32 is inserted into one end of the second discharge channel 514, the cooperation of the first inclined surface 3222 and the second inclined surface 5141 can better achieve a sealing effect, preventing the second fuel from leaking into the second discharge channel 514.

[0061] Specifically, the first guide portion 311 of the first valve stem 31 is clearance-fitted with the first core cavity 14, and the clearance range is 1μm to 4μm. The second guide portion 321 of the second valve stem 32 is clearance-fitted with the second core cavity 15, and the clearance range is 1μm to 4μm.

[0062] Specifically, such as Figure 1 , Figure 5 , Figure 6 and Figure 8 As shown, a first return spring 41 is provided in the third low-pressure chamber 152, and a first abutting shaft section 3221 is provided in the second main body 322. One end of the first abutting shaft section 3221 is connected to the first return spring 41. When the dual-fuel injector is in the open state, the elastic force of the first return spring 41 can drive the second main body 322 to move towards one end of the second pressure chamber 151 to connect the second feed channel 12 and the second nozzle 521. More specifically, the first return spring 41 is sleeved on the second main body 322 of the second valve stem 32, and one end of the first return spring 41 abuts against the first abutting shaft section 3221, while the other end of the first return spring 41 abuts against the upper wall of the first nozzle 51. In detail, in the closed state of the dual-fuel injector, the oil pressure in the second pressure chamber 151 causes the first return spring 41 to be in a compressed state, and the first inclined surface 3222 at one end of the second main body 322 abuts against the second inclined surface 5141 of the second discharge channel 514, and the third low-pressure chamber 152 is disconnected from the second discharge channel 514; in the open state of the dual-fuel injector, the elastic restoring force of the first return spring 41 drives the second valve stem 32 to move towards the end closer to the first low-pressure chamber 13, so as to move the first inclined surface 3222 away from the second inclined surface 5141, and the third low-pressure chamber 152 is connected to the second discharge channel 514. Preferably, the second main body 322 is fitted with a first gasket 42, and one end of the first return spring 41 abuts against the first abutment shaft section 3221 through the first gasket 42.

[0063] Specifically, such as Figure 1 , Figure 3 , Figure 5 and Figure 7As shown, a second return spring 43 is provided in the second low-pressure chamber 142, a second abutment shaft section 3121 is provided in the first main body 312, and an abutment shoulder is provided in the second low-pressure chamber 142. One end of the second return spring 43 is connected to the second abutment shaft section 3121, and the other end is connected to the abutment shoulder. Specifically, in the closed state of the dual-fuel injector, the oil pressure in the first pressure chamber 141 causes the second return spring 43 to be in a stretched state; in the open state of the dual-fuel injector, the elastic restoring force of the second return spring 43 drives the first valve stem 31 to move towards the first pressure chamber 141, so that the first nozzle 511 can inject fuel. Preferably, a second gasket 44 is sleeved on the second abutment shaft section 3121 of the first valve stem 31, and one end of the second return spring 43 is connected to the second abutment shaft section 3121 through the second gasket 44.

[0064] Specifically, such as Figure 1 and Figure 5 As shown, a valve plate 6 is provided in the first low-pressure chamber 13. The valve plate 6 has an oil passage hole 61 and a connecting channel 62. One end of the oil passage hole 61 is connected to the first pressure chamber 141. The control valve assembly 2 can selectively block or open the other end of the oil passage hole 61. The first feed channel 11 is connected to the first pressure chamber 141 through the connecting channel 62. More specifically, a second connecting oil passage 172 is also provided on the injector body 1. The second connecting oil passage 172 is used to connect the first feed channel 11 and the connecting channel 62 of the valve plate 6. By setting the valve plate 6 and opening the oil passage hole 61 and the connecting channel 62 on the valve plate 6, it is possible to avoid the situation where the first valve stem 31 blocks the connecting channel 62 when moving, thus preventing fuel from entering the first pressure chamber 141.

[0065] Specifically, such as Figure 1 , Figure 5 and Figure 7As shown, the control valve assembly 2 includes an electromagnet 21, an armature 22, a needle valve 23, and a sealing ball 24. The armature 22 can be magnetically attracted to the electromagnet 21. The needle valve 23 is located on the side of the armature 22 away from the electromagnet 21. The sealing ball 24 is located at the end of the needle valve 23 away from the armature 22. The sealing ball 24 can block the end of the oil passage 61 away from the first pressure chamber 141. In detail, when the dual-fuel injector is closed, the electromagnet 21 is de-energized and has no magnetism. The armature 22 is separated from the electromagnet 21. The sealing ball 24 located at one end of the needle valve 23 blocks the oil passage 61. The first pressure chamber 141 and the first low-pressure chamber 13 are disconnected. Both the first pressure chamber 141 and the second pressure chamber 151 are high-pressure chambers. The first valve stem 31 is pressured by the first pressure chamber 141 to cut off the connection between the first feed channel 11 and the first nozzle 511. The second valve stem 32 is pressured by the second pressure chamber 151 to cut off the connection between the second feed channel 12 and the second nozzle 521. When the dual-fuel injector is in the open state, the electromagnet 21 is energized, and the magnetism of the electromagnet 21 attracts the armature 22, which in turn drives the sealing ball 24 located at one end of the needle valve 23 away from the oil passage 61. The first pressure chamber 141 is connected to the first low-pressure chamber 13, the first feed channel 11 is connected to the first nozzle 511, the second feed channel 12 is connected to the second nozzle 521, and the first nozzle 511 and the second nozzle 521 begin to inject fuel.

[0066] Furthermore, an elastic element is provided between the electromagnet 21 and the armature 22. When the electromagnet 21 is energized, it attracts the armature 22 and compresses the elastic element. When the electromagnet 21 is de-energized, the elastic restoring force of the elastic element causes the sealing ball 24 located at one end of the needle valve 23 to block the oil passage 61, ensuring the sealing effect of the sealing ball 24. Preferably, the elastic element is a compression spring.

[0067] Embodiment 1 of the present invention also provides an engine including the aforementioned dual-fuel injector. During engine operation, the injection and cessation of both fuels can be achieved simultaneously through a single control valve assembly 2, eliminating the need for two control valves and two hydraulic control systems to control the injection and cessation of the two fuels. This results in a more compact engine structure, reducing the difficulty of engine layout and manufacturing costs. Furthermore, in an engine using the aforementioned dual-fuel injector, the oil inlet pressure of the first feed channel 11 is not affected by the pressure of the second feed channel 12, allowing for a wider range of actual operating pressure conditions and preventing the mixing of the two fuels, thus ensuring high stability and reliability.

[0068] Example 2

[0069] To avoid redundancy, this embodiment only introduces the technical features that differ from Embodiment 1, wherein the same or corresponding parts as in Embodiment 1 are referred to by the same reference numerals as in Embodiment 1.

[0070] Specifically, such as Figures 9 to 10 As shown, in this embodiment, the second guide portion 321 and the second main body portion 322 of the second valve stem 32 are separately formed. The end of the first abutting shaft section 3221 away from the first return spring 41 abuts against the second guide portion 321. Along the axial direction of the first abutting shaft section 3221, the projected shape of the first abutting shaft section 3221 is elliptical. The large end of the shaft diameter of the first abutting shaft section 3221 is clearance-fitted with the third low-pressure chamber 152, and the small end of the shaft diameter of the first abutting shaft section 3221 forms a fuel flow channel with the inner wall of the third low-pressure chamber 152. In detail, in the closed state of the dual-fuel injector, one end of the second guide portion 321 abuts against one end of the second main body portion 322, so that the other end of the second main body portion 322 can cut off the connection between the second feed channel 12 and the second nozzle 521; in the open state of the dual-fuel injector, under the elastic force of the first return spring 41, the second main body portion 322 can drive the second guide portion 321 to compress the second pressure chamber 151, and discharge the fuel in the second pressure chamber 151 into the second low-pressure chamber 142. This configuration reduces the difficulty of integrally manufacturing the second valve stem 32 and facilitates the disassembly and assembly of the second valve stem 32.

[0071] Preferably, the gap between the large end of the first abutting shaft section 3221 and the third low-pressure chamber 152 is in the range of 1μm to 4μm.

[0072] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A dual-fuel injector, comprising an injector body (1) and a control valve assembly (2), wherein the injector body (1) has a first feed channel (11), a second feed channel (12), a first low-pressure chamber (13), a first nozzle (511), and a second nozzle (521), the first feed channel (11) being used to introduce fuel, the first feed channel (11) being able to communicate with the first low-pressure chamber (13) and the first nozzle (511), the second feed channel (12) being able to communicate with the second nozzle (521), and the control valve assembly (2) being able to selectively disconnect or connect the communication between the first feed channel (11) and the first nozzle (511), and disconnect or connect the communication between the second feed channel (12) and the second nozzle (521), characterized in that, Also includes: The first core cavity (14) and the first valve stem (31) are provided. The first core cavity (14) is located in the injector body (1). The first valve stem (31) is movably disposed in the first core cavity (14). The first valve stem (31) includes a first guide portion (311) and a first main body portion (312). The shaft diameter of the first guide portion (311) is larger than the shaft diameter of the first main body portion (312). The first guide portion (311) divides the first core cavity (14) into a first pressure cavity (141) and a second low pressure cavity (142) that are not connected to each other. The first feed channel (11) is connected to the first low pressure cavity (13) through the first pressure cavity (141). The first guide portion (311) is provided with a first flow channel (313) connected to the first pressure cavity (141) and a second flow channel (314) connected to the second low pressure cavity (142). The first flow channel (313) and the second flow channel (314) are not connected. The second core cavity (15) and the second valve stem (32) are provided. The second core cavity (15) is opened in the injector body (1) and spaced apart from the first core cavity (14). The second valve stem (32) is movably disposed in the second core cavity (15). The second valve stem (32) includes a second guide portion (321) and a second body portion (322). The second guide portion (321) divides the second core cavity (15) into a second pressure chamber (151) and a third low-pressure chamber (152) that are not connected. The second feed channel (12) is connected to the third low-pressure chamber (152). The first connecting hole (161) and the second connecting hole (162) are both opened in the injector body (1) and are both connected to the second pressure chamber (151). The first connecting hole (161) can be connected to the first flow channel (313) and the second connecting hole (162) can be connected to the second flow channel (314). In the closed state of the dual-fuel injector, the control valve assembly (2) cuts off the communication between the first pressure chamber (141) and the first low-pressure chamber (13). The first feed channel (11), the first pressure chamber (141), the first flow channel (313), the first connecting hole (161), and the second pressure chamber (151) are connected. The second connecting hole (162) is disconnected from the second flow channel (314). The oil pressure in the first pressure chamber (141) drives the first valve stem (31) to cut off the communication between the first feed channel (11) and the first nozzle (151). When the second pressure chamber (151) is connected to the second pressure chamber (141), the oil pressure of the second pressure chamber (151) drives the second valve stem (32) to cut off the connection between the second feed channel (12) and the second nozzle (521). In the open state of the dual fuel injector, the control valve assembly (2) connects the first pressure chamber (141) and the first low pressure chamber (13), the first connecting hole (161) is disconnected from the first flow channel (313), and the second pressure chamber (151), the second connecting hole (162), the second flow channel (314) and the second low pressure chamber (142) are connected.

2. A dual-fuel injector according to claim 1, characterized in that, The first flow channel (313) includes a first oil hole (3131) and a second oil hole (3132). The first oil hole (3131) extends along the direction from the first pressure chamber (141) to the first low pressure chamber (13), and one end of the first oil hole (3131) is connected to the first pressure chamber (141), and the other end of the first oil hole (3131) is connected to the second oil hole (3132). The second oil hole (3132) extends along the direction from the first pressure chamber (141) to the second pressure chamber (151). In the closed state of the dual fuel injector, one end of the second oil hole (3132) is connected to the first connecting hole (161).

3. A dual-fuel injector according to claim 2, characterized in that, The second flow channel (314) includes a third oil hole (3141) and a fourth oil hole (3142). Along the direction from the first pressure chamber (141) to the second low pressure chamber (142), the third oil hole (3141) and the second oil hole (3132) are spaced apart and located near one end of the second low pressure chamber (142). One end of the fourth oil hole (3142) is connected to the third oil hole (3141), and the other end is connected to the second low pressure chamber (142). In the open state of the dual fuel injector, one end of the third oil hole (3141) is connected to the second connecting hole (162).

4. A dual-fuel injector according to claim 1, characterized in that, The second guide section (321) includes at least two guide shaft segments (3211), and a connecting shaft segment (3212) with a shaft diameter smaller than the guide shaft segment (3211) is connected between two adjacent guide shaft segments (3211). The two adjacent guide shaft segments (3211), the connecting shaft segment (3212) and the inner wall of the second core cavity (15) together form a fourth low-pressure cavity (153).

5. A dual-fuel injector according to claim 1, characterized in that, The third low-pressure chamber (152) is provided with a first return spring (41), and the second main body (322) is provided with a first abutting shaft section (3221). One end of the first abutting shaft section (3221) is connected to the first return spring (41). In the open state of the dual fuel injector, the elastic force of the first return spring (41) can drive the second main body (322) to move towards one end of the second pressure chamber (151) to connect the second feed channel (12) and the second nozzle (521).

6. A dual-fuel injector according to claim 5, characterized in that, The second guide portion (321) and the second main body portion (322) are separately formed. The end of the first abutting shaft section (3221) away from the first return spring (41) abuts against the second guide portion (321). Along the axial direction of the first abutting shaft section (3221), the projected shape of the first abutting shaft section (3221) is elliptical. The large end of the shaft diameter of the first abutting shaft section (3221) is clearance-fitted with the third low-pressure chamber (152), and the small end of the shaft diameter of the first abutting shaft section (3221) forms a fuel flow channel with the inner wall of the third low-pressure chamber (152).

7. A dual-fuel injector according to claim 1, characterized in that, The dual-fuel injector further includes a nozzle assembly, which includes a first nozzle (51) and a second nozzle (52). The first nozzle (51) is sleeved on one end of the first valve stem (31) that extends out of the first core cavity (14). A first injection channel (512) is formed between the inner wall of the first nozzle (51) and the outer wall of the first valve stem (31). The first nozzle (511) is disposed on the first nozzle (51) and connected to one end of the first injection channel (512). The first nozzle (51) has a first discharge channel (513). One end of the first discharge channel (513) can be connected to the first feed channel (11), and the other end of the first discharge channel (513) is connected to the other end of the first injection channel (512). The second nozzle (52) is sleeved on the first nozzle (51). A second injection channel (522) is formed between the inner wall of the second nozzle (52) and the outer wall of the first nozzle (51). The second nozzle (521) is disposed on the second nozzle (52) and connected to one end of the second injection channel (522). The first nozzle (51) is also provided with a second discharge channel (514). One end of the second discharge channel (514) can be connected to the third low-pressure chamber (152). The other end of the second discharge channel (514) is connected to the other end of the second injection channel (522).

8. A dual-fuel injector according to claim 7, characterized in that, The outer wall of the second main body (322) away from the second pressure chamber (151) is provided with a first inclined surface (3222) in the circumferential direction. The inner wall of the second discharge channel (514) communicating with the third low pressure chamber (152) is provided with a second inclined surface (5141) in the circumferential direction. In the closed state of the dual fuel injector, the first inclined surface (3222) is attached to the second inclined surface (5141) to cut off the communication between the third low pressure chamber (152) and the second discharge channel (514).

9. A dual-fuel injector according to any one of claims 1-8, characterized in that, A valve plate (6) is provided in the first low-pressure chamber (13). The valve plate (6) is provided with an oil passage hole (61) and a connecting channel (62). One end of the oil passage hole (61) is connected to the first pressure chamber (141). The control valve assembly (2) can selectively block or open the other end of the oil passage hole (61). The first feed channel (11) is connected to the first pressure chamber (141) through the connecting channel (62).

10. A dual-fuel injector according to claim 9, characterized in that, The control valve assembly (2) includes an electromagnet (21), an armature (22), a needle valve (23), and a sealing ball (24). The armature (22) is magnetically attracted to the electromagnet (21). The needle valve (23) is located on the side of the armature (22) away from the electromagnet (21). The sealing ball (24) is located at the end of the needle valve (23) away from the armature (22). The sealing ball (24) can block the end of the oil passage (61) away from the first pressure chamber (141).

11. An engine, characterized in that, Includes the dual-fuel injector as described in any one of claims 1-10.

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