Dual-fuel injector and engine assembly

Abstract

The invention belongs to the technical field of engines, and discloses a dual-fuel injector and an engine assembly.The dual-fuel injector is used for injecting first fuel and second fuel into an engine; the dual-fuel injector is provided with a first fuel cavity allowing first fuel to enter, a fuel injection opening used for communicating the first fuel cavity with an inner cavity of the engine at the same time, a second fuel cavity allowing second fuel to enter and a communicating opening used for communicating the first fuel cavity with the second fuel cavity at the same time. The dual-fuel injector further comprises a control valve, communication of the communication opening is controlled through the control valve, second fuel in the second fuel cavity can enter the first fuel cavity through the communication opening and be mixed with the first fuel, communication of the fuel injection opening is controlled through the control valve, and mixed gas can enter an inner cavity of the engine through the fuel injection opening. According to the dual-fuel injector, control over the communicating opening and the fuel injection opening can be completed at the same time only through one control valve, and the number of parts is small.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a dual-fuel injector and an engine assembly. Background Art

[0002] The dual fuel injector is used to inject a first fuel and a second fuel into the engine, wherein the first fuel is a main fuel and the second fuel is a pilot fuel used to ignite the main fuel so that the main fuel starts to burn.

[0003] However, current dual-fuel injectors usually require two solenoid valves to be set at the same time. For example, the prior art provides a fuel premix injector, which includes a main body, a first valve body slidably arranged inside the main body, and a second valve body slidably arranged inside the first valve body. The gap between the main body and the first valve body is used for the first fuel to enter, and the gap between the first valve body and the second valve body is used for the second fuel to enter. The first valve body has a second fuel outlet channel below it for allowing the second fuel inside the first valve body to flow outward, and the second fuel outlet channel can be closed under the action of the first solenoid valve. In addition, the main body has a first fuel outlet channel below it for allowing the first fuel or mixed gas inside the main body to flow outward, and the first fuel outlet channel can be closed under the action of the second solenoid valve, so that the injection of fuel is controlled by the first solenoid valve and the second solenoid valve. However, since it needs to set two solenoid valves at the same time, the number of components is large and the overall structure is complex. Summary of the invention

[0004] According to one aspect of the present invention, the present invention provides a dual-fuel injector to solve the problem that the prior art requires two solenoid valves to be provided simultaneously, resulting in a large number of components and a complex overall structure.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A dual-fuel injector for injecting a first fuel and a second fuel into an engine; the dual-fuel injector comprises a first fuel chamber for the first fuel to enter, a fuel injection port for simultaneously connecting the first fuel chamber with an inner chamber of the engine, a second fuel chamber for the second fuel to enter, and a connecting port for simultaneously connecting the first fuel chamber with the second fuel chamber; the dual-fuel injector further comprises a control valve for connecting or disconnecting the fuel injection port, and for connecting or disconnecting the connecting port.

[0007] As a preferred solution of the dual fuel injector, the dual fuel injector further comprises:

[0008] A shell, wherein the first fuel cavity is located inside the shell, and the fuel injection port is opened on the cavity wall of the first fuel cavity;

[0009] A needle valve body, the needle valve body comprising:

[0010] an outer needle, slidably disposed in the first fuel cavity along a first direction, the control valve being capable of driving the outer needle to move relative to the housing along the first direction so that the outer needle abuts against a cavity wall of the first fuel cavity to open or close the fuel injection port; the second fuel cavity is located inside the outer needle, and the communication port is opened in the cavity wall of the second fuel cavity;

[0011] The inner needle is slidably arranged in the second fuel cavity along a first direction, and the control valve can drive the inner needle to move relative to the outer needle along the first direction so that the inner needle abuts against the cavity wall of the second fuel cavity to open or close the communication port.

[0012] As a preferred solution of the dual fuel injector, the housing further comprises a first control chamber, the first fuel chamber and the first control chamber are separated by a plunger, the plunger can slide in a first direction relative to the housing, and the plunger can push the outer needle to move in a direction of closing the fuel injection port; a first elastic member is connected between the plunger and the housing, and the first elastic member is used to provide an elastic force that enables the plunger to push the outer needle to move in a direction of closing the fuel injection port;

[0013] The inner needle comprises a blocking block, the blocking block can slide relative to the outer needle along a first direction, the outer needle further comprises a second control chamber inside, the second fuel chamber and the second control chamber are separated by the blocking block; a second elastic member is connected between the blocking block and the plunger, the second elastic member is used to provide an elastic force to move the blocking block and the inner needle in a direction of closing the communication port;

[0014] The first control chamber is connected to the second control chamber, and the first control chamber is connected to the second fuel chamber through a control channel. The control valve has a return channel connected to the control channel, and the return channel is used to connect to the second fuel storage structure. The control valve is used to connect or cut off the connection of the return channel.

[0015] As a preferred solution of the dual-fuel injector, a push rod is connected to one end of the blocking block close to the plunger, and the push rod can abut against the plunger to push the plunger to move.

[0016] As a preferred solution of the dual-fuel injector, the housing is further provided with a first fuel channel communicating with the first fuel chamber, and the first fuel channel is used to connect to a first fuel source;

[0017] The shell is also provided with a second fuel channel, and the second fuel channel is used to connect to a second fuel source. The outer needle is also provided with a third fuel channel connected to the second fuel channel, and the third fuel channel is connected to the second fuel cavity, and the second fuel channel is connected to the control flow channel.

[0018] As a preferred solution for the dual fuel injector, the control valve includes a control valve body and a valve core arranged on the control valve body, the return flow channel is opened in the control valve body, and the valve core is used to connect or cut off the connection of the return flow channel.

[0019] As a preferred solution of the dual-fuel injector, the plunger is provided with a plunger flow channel, and the plunger flow channel is connected to the first control chamber and the second control chamber at the same time.

[0020] As a preferred solution of the dual fuel injector, the housing is provided with a communication flow passage, and the communication flow passage is connected to the first control chamber and the second control chamber at the same time.

[0021] As a preferred solution of the dual fuel injector, a plurality of fuel injection ports are provided, and the plurality of fuel injection ports are arranged in the housing at intervals along the circumferential direction of the housing; and / or,

[0022] A plurality of the communication ports are provided, and the plurality of the communication ports are arranged at intervals on the outer needle along the circumferential direction of the outer needle.

[0023] As a preferred solution for a dual fuel injector, the shell includes an upper shell and a lower shell, the upper shell is connected to the control valve, the first control chamber is opened in the upper shell, the first fuel chamber and the fuel injection port are both opened in the lower shell, the outer needle is slidably arranged in the lower shell along a first direction, and the upper shell and the lower shell are detachably connected.

[0024] As a preferred solution of the dual fuel injector, the housing further comprises a connecting piece, the connecting piece has an internal thread and is threadably matched with both the upper housing and the lower housing, and the upper housing abuts against surfaces of the lower housing.

[0025] According to another aspect of the present invention, an engine assembly is provided, comprising an engine and the above-mentioned dual-fuel injector, wherein the dual-fuel injector is used for injecting a first fuel and a second fuel into the engine.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a dual-fuel injector for injecting a first fuel and a second fuel into an engine; the dual-fuel injector has a first fuel chamber for the first fuel to enter, a fuel injection port for simultaneously connecting the first fuel chamber and the inner chamber of the engine, a second fuel chamber for the second fuel to enter, and a connecting port for simultaneously connecting the first fuel chamber and the second fuel chamber; the dual-fuel injector also includes a control valve, the control valve is used to connect or cut off the fuel injection port, and is used to connect or cut off the connecting port. By controlling the connecting port to be connected by the control valve, the second fuel in the second fuel chamber can enter the first fuel chamber through the connecting port and mix with the first fuel in the first fuel chamber. By controlling the fuel injection port to be connected by the control valve, the mixed gas of the first fuel and the second fuel in the first fuel chamber can enter the inner chamber of the engine through the fuel injection port, thereby completing the injection of the first fuel and the second fuel. The dual-fuel injector can simultaneously complete the control of the connecting port and the fuel injection port by only one control valve, and the number of parts is relatively small.

[0028] The present invention also provides an engine assembly, including an engine and the above-mentioned dual-fuel injector, the dual-fuel injector is used to inject the first fuel and the second fuel into the engine, the dual-fuel injector can simultaneously control the connecting port and the fuel injection port through only one control valve, the number of parts is small, thereby simplifying the overall structure of the engine assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of a dual fuel injector in an embodiment of the present invention;

[0030] Figure 2 yes Figure 1 The enlarged view of point A in the middle;

[0031] Figure 3 is a partial structural schematic diagram of a dual-fuel injector in an embodiment of the present invention;

[0032] Figure 4 It is a partial structural schematic diagram of another dual-fuel injector in an embodiment of the present invention.

[0033] In the figure:

[0034] 1. Shell; 101. First fuel cavity; 102. Fuel injection port; 1021. First blocking surface; 103. First control cavity; 104. First fuel channel; 105. Second fuel channel; 106. Connecting flow channel; 11. Upper shell; 12. Lower shell; 13. Connecting piece;

[0035] 2. outer needle; 201. second fuel cavity; 202. connecting port; 2021. second blocking surface; 203. second control cavity; 204. control flow channel; 205. third fuel channel; 206. oil inlet throttling channel;

[0036] 3. inner needle; 31. blocking block; 32. ejector rod; 33. sliding block; 331. sliding block flow channel;

[0037] 4. Control valve; 401. Return flow channel; 402. Oil outlet throttling channel; 41. Control valve body; 42. Valve core; 421. Solenoid control rod; 422. Ball head;

[0038] 5. Plunger; 501. Plunger channel; 51. First elastic member; 52. Second elastic member. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0040] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0042] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0043] Current dual-fuel injectors usually require two solenoid valves to be set up at the same time. For example, the prior art provides a fuel premix injector, which includes a main body, a first valve body slidably arranged inside the main body, and a second valve body slidably arranged inside the first valve body. The gap between the main body and the first valve body is used for the first fuel to enter, and the gap between the first valve body and the second valve body is used for the second fuel to enter. The first valve body has a second fuel outlet channel below it for allowing the second fuel inside the first valve body to flow outward, and the second fuel outlet channel can be closed under the action of the first solenoid valve. In addition, the main body has a first fuel outlet channel below it for allowing the first fuel or mixed gas inside the main body to flow outward, and the first fuel outlet channel can be closed under the action of the second solenoid valve, so that the injection of fuel is controlled by the first solenoid valve and the second solenoid valve. However, since it needs to set up two solenoid valves at the same time, the number of components is large and the overall structure is complex.

[0044] In view of the above problems, this embodiment provides a dual fuel injector to solve the problem that the prior art requires two solenoid valves to be set simultaneously, has a large number of components, and has a complex overall structure. The dual fuel injector can be used in the field of engine technology.

[0045] Reference Figure 1-Figure 2 The dual fuel injection is used to inject a first fuel and a second fuel into the engine. In this embodiment, the first fuel is a main fuel, which can be a gaseous fuel such as natural gas, methanol, gasoline, hydrogen, dimethyl ether or ammonia, and the second fuel is a pilot fuel, which can be a liquid ignitable fuel such as diesel or gasoline. In other embodiments, the first fuel and the second fuel can also be set to other types of fuels as needed.

[0046] Continue to refer to Figure 1-Figure 2 The dual fuel injector has a first fuel cavity 101 for the first fuel to enter, a fuel injection port 102 for simultaneously connecting the first fuel cavity 101 with the inner cavity of the engine, a second fuel cavity 201 for the second fuel to enter, and a connecting port 202 for simultaneously connecting the first fuel cavity 101 with the second fuel cavity 201. The first fuel cavity 101 is connected to a first fuel source, the inlet end of the first fuel source is connected to a first fuel storage structure, the first fuel storage structure is used to store the first fuel, and the first fuel source is used to deliver the first fuel to the first fuel cavity 101; the second fuel cavity 201 is connected to a second fuel source, the inlet end of the second fuel source is connected to a second fuel storage structure, the second fuel storage structure is used to store the second fuel, and the second fuel source is used to deliver the second fuel to the second fuel cavity 201. In addition, the fuel injection port 102 is specifically connected to the inner cavity of the intake manifold of the engine, so that the first fuel and the second fuel can enter the intake manifold through the fuel injection port 102.

[0047] Continue to refer to Figure 1-Figure 2The dual fuel injector also includes a control valve 4, which is used to connect or disconnect the fuel injection port 102, and to connect or disconnect the connecting port 202. By controlling the connecting port 202 through the control valve 4, the second fuel in the second fuel cavity 201 can enter the first fuel cavity 101 through the connecting port 202 and mix with the first fuel in the first fuel cavity 101. By controlling the fuel injection port 102 through the control valve 4, the mixed gas of the first fuel and the second fuel in the first fuel cavity 101 can enter the inner cavity of the engine through the fuel injection port 102, thereby completing the injection of the first fuel and the second fuel. The dual fuel injector can simultaneously control the connecting port 202 and the fuel injection port 102 through only one control valve 4, and the number of parts is relatively small.

[0048] Continue to refer to Figure 1-Figure 2 Specifically, the dual fuel injector further includes a housing 1 and a needle valve body, the first fuel chamber 101 is located inside the housing 1, and the fuel injection port 102 is opened in the chamber wall of the first fuel chamber 101. The needle valve body includes an outer needle 2 and an inner needle 3, the outer needle 2 is slidably arranged in the first fuel chamber 101 along a first direction, and the control valve 4 can drive the outer needle 2 to move relative to the housing 1 along the first direction so that the outer needle 2 abuts against the chamber wall of the first fuel chamber 101 to open or close the fuel injection port 102, specifically, the outer needle 2 has a first blocking surface 1021, and the first blocking surface 1021 can abut against the chamber wall of the first fuel chamber 101. The second fuel cavity 201 is located inside the outer needle 2, and the communication port 202 is opened in the cavity wall of the second fuel cavity 201; the inner needle 3 is slidably arranged in the second fuel cavity 201 along the first direction, and the control valve 4 can drive the inner needle 3 to move relative to the outer needle 2 along the first direction, so that the inner needle 3 abuts against the cavity wall of the second fuel cavity 201 to open or close the communication port 202. Specifically, the inner needle 3 has a second blocking surface 2021, and the second blocking surface 2021 can abut against the cavity wall of the second fuel cavity 201. With such a configuration, the main body of the dual-fuel injector adopts the form of a needle valve, which is easy to assemble.

[0049] Continue to refer to Figure 1-Figure 2The shell 1 also has a first control chamber 103 inside, and the first fuel chamber 101 and the first control chamber 103 are separated by a plunger 5. The plunger 5 can slide in a first direction relative to the shell 1, and the plunger 5 can push the outer needle 2 to move in the direction of the closed fuel injection port 102. Specifically, the end face of the plunger 5 abuts against the end face of the outer needle 2, so that the plunger 5 can push the outer needle 2 to move. In addition, a first elastic member 51 is connected between the plunger 5 and the shell 1, and the first elastic member 51 is used to provide an elastic force that enables the plunger 5 to push the outer needle 2 to move in the direction of the closed fuel injection port 102. The inner needle 3 includes a blocking block 31, and the blocking block 31 can slide in a first direction relative to the outer needle 2. The outer needle 2 also has a second control chamber 203 inside, and the second fuel chamber 201 and the second control chamber 203 are separated by the blocking block 31. In addition, a second elastic member 52 is connected between the blocking block 31 and the plunger 5, and the second elastic member 52 is used to provide an elastic force to move the blocking block 31 and the inner needle 3 toward the direction of the closed communication port 202. The first control chamber 103 is connected to the second control chamber 203, and the first control chamber 103 is connected to the second fuel chamber 201 through the control channel 204. The control valve 4 has a return channel 401 connected to the control channel 204, and the return channel 401 is used to connect to the second fuel storage structure. The control valve 4 is used to connect or cut off the connection of the return channel 401.

[0050] The specific action process of the above structure is that first, the first fuel will enter the first fuel chamber 101, and the second fuel will enter the second fuel chamber 201. The first fuel in the first fuel chamber 101 will apply a thrust to the plunger 5 and the outer needle 2 to make the outer needle 2 move toward the direction of opening the fuel injection port 102, and the second fuel in the second fuel chamber 201 will apply a thrust to the blocking block 31 to make it move toward the direction of opening the connecting port 202.

[0051] If the control valve 4 cuts off the connection of the return flow channel 401, part of the second fuel will enter the first control chamber 103 through the control flow channel 204 and then enter the second control chamber 203. Since the return flow channel 401 is blocked, the liquid pressure in the first control chamber 103 and the second control chamber 203 is relatively large. Under the joint action of the thrust exerted by the second fuel in the first control chamber 103 on the plunger 5 and the elastic force of the first elastic member 51, the plunger 5 is pushed to move so that the outer needle 2 moves toward the direction of closing the fuel injection port 102; under the joint action of the thrust exerted by the second fuel in the second control chamber 203 on the blocking block 31 and the elastic force of the second elastic member 52, the blocking block 31 and the inner needle 3 are pushed to move toward the direction of closing the connecting port 202, so that both the fuel injection port 102 and the connecting port 202 are closed.

[0052] If the control valve 4 connects the return flow channel 401, part of the second fuel located in the control flow channel 204 will flow back to the second fuel storage structure through the return flow channel 401. At this time, the liquid pressure in the first control chamber 103 and the second control chamber 203 becomes smaller. When the thrust exerted by the second fuel in the first control chamber 103 on the plunger 5 and the elastic force of the first elastic member 51 are smaller than the thrust exerted by the first fuel in the first fuel chamber 101 on the outer needle 3 and the plunger 5, the first fuel in the first fuel chamber 101 pushes the plunger 5 and the outer needle 2 to move so that the outer needle 2 opens the fuel injection port 102; when the thrust exerted by the second fuel in the second control chamber 203 on the blocking block 31 and the elastic force of the second elastic member 52 are smaller than the thrust exerted by the second fuel in the second fuel chamber 201 on the blocking block 31, the second fuel in the second fuel chamber 201 pushes the blocking block 31 and the inner needle 3 to move so that the inner needle 3 opens the connecting port 202.

[0053] In this way, the on and off of the fuel injection port 102 and the connecting port 202 can be controlled by the control valve 4. In addition, by adjusting the elastic force of the two elastic members, the pressure threshold for the outer needle 2 to open the fuel injection port 102 and the pressure threshold for the inner needle 3 to open the connecting port 202 can be adjusted, and then the opening sequence of the fuel injection port 102 and the connecting port 202 can be adjusted, so that the two are opened at the same time, or the fuel injection port 102 is opened first and then the connecting port 202 is opened, or the connecting port 202 is opened first and then the fuel injection port 102 is opened.

[0054] It is understandable that in this embodiment, since the second fuel is a liquid fuel, its compressibility is weak and it can provide a large liquid pressure. In other embodiments, the first fuel chamber 101 can also be connected with the first control chamber 103 and the second control chamber 203, and the first fuel can provide a thrust to move the plunger 5 and the inner needle 3.

[0055] Optionally, the control flow channel 204 and the return flow channel 401 are connected through an oil outlet throttling channel 402, and the cross-sectional area of ​​the oil outlet throttling channel 402 is smaller than the cross-sectional area of ​​the control flow channel 204 and the cross-sectional area of ​​the return flow channel 401, so that only a part of the second fuel in the control flow channel 204 flows into the return flow channel 401, preventing excessive reflow of the second fuel.

[0056] Optionally, the inner needle 3 also includes a sliding block 33, which is slidably arranged in the second fuel chamber 201 inside the outer needle 2 to improve the sliding stability. The sliding block 33 divides the second fuel chamber 201 into two chambers. The sliding block 33 has a sliding block channel 331 for connecting the chambers located at both ends thereof, so that the two chambers of the second fuel chamber 201 are connected to each other.

[0057] As an alternative solution, the first control chamber 103 and the second control chamber 203 are no longer provided, but the control valve 4 directly adopts a structure similar to a stop valve, specifically, the control valve 4 includes a valve body and two valve cores arranged in the valve body and capable of synchronous movement.

[0058] Continue to refer to Figure 1-Figure 2 The end of the blocking block 31 close to the plunger 5 is connected with a push rod 32, which can abut against the plunger 5 to push the plunger 5 to move, so that when the inner needle 3 moves in the direction of opening the connecting port 202, it can push the plunger 5 to move, and at this time, the outer needle 2 can also move in the direction of opening the fuel injection port 102 under the thrust of the first fuel in the first fuel chamber 101. With this arrangement, when the connecting port 202 is opened, the fuel injection port 102 can be ensured to be opened at the same time, so as to prevent the first fuel in the first fuel chamber 101 from flowing into the second fuel chamber 201 only through the connecting port 202.

[0059] Reference Figure 1-Figure 3 The shell 1 is also provided with a first fuel channel 104 in communication with the first fuel cavity 101. The first fuel channel 104 is used to connect to a first fuel source, so that the first fuel can enter the first fuel cavity 101 through the first fuel channel 104. The shell 1 is also provided with a second fuel channel 105. The second fuel channel 105 is used to connect to a second fuel source. The outer needle 2 is also provided with a third fuel channel 205 in communication with the second fuel channel 105. The third fuel channel 205 is in communication with the second fuel cavity 201, so that the second fuel can enter the second fuel cavity 201 through the second fuel channel 105 and the third fuel channel 205 in sequence. The second fuel channel 105 is in communication with the control flow channel 204, so that the second fuel can enter the control flow channel 204 through the second fuel channel 105. Optionally, the second fuel channel 105 and the control channel 204 are connected via an oil inlet throttling channel 206, and the cross-sectional area of ​​the oil inlet throttling channel 206 is smaller than the cross-sectional area of ​​the second fuel channel 105 and the cross-sectional area of ​​the control channel 204, so that only a portion of the second fuel in the second fuel channel 105 flows into the control channel 204, so as to ensure that most of the second fuel can enter the second fuel chamber 201, thereby ensuring the pressure of the second fuel in the second fuel chamber 201.

[0060] Continue to refer to Figure 1-Figure 2The control valve 4 includes a control valve body 41 and a valve core 42 disposed on the control valve body 41. The return flow channel 401 is opened in the control valve body 41. The valve core 42 is used to connect or disconnect the return flow channel 401, thereby controlling the connection and disconnection of the return flow channel 401. Specifically, the valve core 42 includes an electromagnetic control rod 421 and a ball head 422. The electromagnetic control rod 421 can drive the ball head 422 to move synchronously under the action of electromagnetic force. The inner cavity of the return flow channel 401 is connected to a control port. The ball head 422 can open or close the control port, thereby connecting or disconnecting the return flow channel 401.

[0061] The communication between the first control chamber 103 and the second control chamber 203 can be achieved by the following two structures: Figure 1 As shown, the shell 1 is provided with a connecting flow channel 106, which connects the first control chamber 103 and the second control chamber 203 at the same time, so that the second fuel can enter and exit the first control chamber 103 and the second control chamber 203 through the connecting flow channel 106 inside the shell 1. Figure 4 As shown, the plunger 5 is provided with a plunger flow channel 501 , which is connected to the first control chamber 103 and the second control chamber 203 at the same time, so that the second fuel can enter and exit the first control chamber 103 and the second control chamber 203 through the plunger flow channel 501 inside the plunger 5 .

[0062] Continue to refer to Figure 1-Figure 2 , a plurality of fuel injection ports 102 are provided, and the plurality of fuel injection ports 102 are arranged in the shell 1 at intervals along the circumferential direction of the shell 1, so that the mixed fuel in the first fuel chamber 101 can be sprayed to the surroundings of the shell 1 along the circumferential direction of the shell 1 through the plurality of fuel injection ports 102; and / or, a plurality of connecting ports 202 are provided, and the plurality of connecting ports 202 are arranged in the outer needle 2 at intervals along the circumferential direction of the outer needle 2, so that the second fuel in the second fuel chamber 201 can be sprayed to the surroundings of the outer needle 2 along the circumferential direction of the outer needle 2 through the plurality of connecting ports 202.

[0063] Continue to refer to Figure 1-Figure 2 The specific structure of the housing 1 is that it includes an upper housing 11 and a lower housing 12, the upper housing 11 is connected to the control valve 4, the first control chamber 103 is opened in the upper housing 11, the first fuel chamber 101 and the fuel injection port 102 are both opened in the lower housing 12, the outer needle 2 is slidably arranged in the lower housing 12 along the first direction, and the upper housing 11 and the lower housing 12 are detachably connected, so as to facilitate the assembly of the housing 1, the outer needle 2 and the inner needle 3 inside the housing 1. It can be understood that the above-mentioned first fuel channel 104, the second fuel channel 105 and the connecting flow channel 106 all pass through the upper housing 11 and the lower housing 12 at the same time.

[0064] Optionally, the shell 1 also includes a connecting piece 13, which has an internal thread and is threadably matched with the upper shell 11 and the lower shell 12. The surfaces of the upper shell 11 and the lower shell 12 abut against each other, so that the upper shell 11 and the lower shell 12 are fixedly connected through the connecting piece 13, and the connection between the two is detachable. The surfaces of the upper shell 11 and the lower shell 12 abut against each other, so that the various flow channels passing through the upper shell 11 and the lower shell 12 can be sealed at the same time to avoid leakage.

[0065] The present embodiment also provides an engine assembly, including an engine and the above-mentioned dual-fuel injector, the dual-fuel injector is used to inject the first fuel and the second fuel into the engine, the dual-fuel injector can simultaneously complete the control of the connecting port 202 and the fuel injection port 102 through only one control valve 4, the number of parts is small, thereby simplifying the overall structure of the engine assembly.

[0066] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A dual fuel injector, for injecting a first fuel and a second fuel into an engine; characterized in that: The dual-fuel injector comprises a first fuel chamber (101) for a first fuel to enter, a fuel injection port (102) for simultaneously connecting the first fuel chamber (101) with an inner chamber of the engine, a second fuel chamber (201) for a second fuel to enter, and a connecting port (202) for simultaneously connecting the first fuel chamber (101) with the second fuel chamber (201); the dual-fuel injector further comprises a control valve (4), the control valve (4) being used to connect or disconnect the fuel injection port (102), and to connect or disconnect the connecting port (202).

2. The dual fuel injector according to claim 1, characterized in that: The dual fuel injector further comprises: A shell (1), wherein the first fuel cavity (101) is located inside the shell (1), and the fuel injection port (102) is opened on the cavity wall of the first fuel cavity (101); A needle valve body, the needle valve body comprising: The outer needle (2) is slidably disposed in the first fuel cavity (101) along a first direction, and the control valve (4) is capable of driving the outer needle (2) to move relative to the housing (1) along the first direction so that the outer needle (2) abuts against the cavity wall of the first fuel cavity (101) to open or close the fuel injection port (102); the second fuel cavity (201) is located inside the outer needle (2), and the communication port (202) is opened in the cavity wall of the second fuel cavity (201); An inner needle (3) is slidably disposed in the second fuel chamber (201) along a first direction, and the control valve (4) is capable of driving the inner needle (3) to move relative to the outer needle (2) along the first direction so that the inner needle (3) abuts against the chamber wall of the second fuel chamber (201) to open or close the communication port (202).

3. The dual fuel injector according to claim 2, characterized in that: The shell (1) further comprises a first control chamber (103) inside, the first fuel chamber (101) and the first control chamber (103) are separated by a plunger (5), the plunger (5) can slide in a first direction relative to the shell (1), and the plunger (5) can push the outer needle (2) to move in a direction of closing the fuel injection port (102); a first elastic member (51) is connected between the plunger (5) and the shell (1), and the first elastic member (51) is used to provide an elastic force that enables the plunger (5) to push the outer needle (2) to move in a direction of closing the fuel injection port (102); The inner needle (3) comprises a blocking block (31), the blocking block (31) being able to slide along a first direction relative to the outer needle (2), the outer needle (2) further comprising a second control chamber (203) inside, the second fuel chamber (201) and the second control chamber (203) being separated by the blocking block (31); a second elastic member (52) is connected between the blocking block (31) and the plunger (5), the second elastic member (52) being used to provide an elastic force causing the blocking block (31) and the inner needle (3) to move in a direction of closing the communication port (202); The first control chamber (103) is connected to the second control chamber (203), and the first control chamber (103) is connected to the second fuel chamber (201) via a control channel (204). The control valve (4) has a return channel (401) connected to the control channel (204), and the return channel (401) is used to connect to the second fuel storage structure. The control valve (4) is used to connect or cut off the connection of the return channel (401).

4. The dual fuel injector according to claim 3, characterized in that One end of the blocking block (31) close to the plunger (5) is connected to a push rod (32), and the push rod (32) can abut against the plunger (5) to push the plunger (5) to move.

5. The dual fuel injector according to claim 3, characterized in that The housing (1) is further provided with a first fuel channel (104) communicating with the first fuel cavity (101), and the first fuel channel (104) is used to connect to a first fuel source; The shell (1) is also provided with a second fuel channel (105), and the second fuel channel (105) is used to connect to a second fuel source. The outer needle (2) is also provided with a third fuel channel (205) connected to the second fuel channel (105), and the third fuel channel (205) is connected to the second fuel cavity (201), and the second fuel channel (105) is connected to the control flow channel (204).

6. The dual fuel injector according to claim 3, characterized in that The control valve (4) comprises a control valve body (41) and a valve core (42) arranged on the control valve body (41); the return flow channel (401) is opened in the control valve body (41); and the valve core (42) is used to connect or disconnect the return flow channel (401).

7. The dual fuel injector according to claim 3, characterized in that The plunger (5) is provided with a plunger flow channel (501), and the plunger flow channel (501) is connected to the first control chamber (103) and the second control chamber (203) at the same time.

8. The dual fuel injector according to claim 3, characterized in that The housing (1) is provided with a communication channel (106), and the communication channel (106) is connected to the first control chamber (103) and the second control chamber (203) at the same time.

9. The dual fuel injector according to claim 3, characterized in that A plurality of the fuel injection ports (102) are provided, and the plurality of the fuel injection ports (102) are arranged on the shell (1) at intervals along the circumferential direction of the shell (1); and / or, A plurality of the communication openings (202) are provided, and the plurality of communication openings (202) are arranged on the outer needle (2) at intervals along the circumferential direction of the outer needle (2).

10. The dual fuel injector according to any one of claims 3 to 9, characterized in that: The shell (1) comprises an upper shell (11) and a lower shell (12); the upper shell (11) is connected to the control valve (4); the first control chamber (103) is opened in the upper shell (11); the first fuel chamber (101) and the fuel injection port (102) are both opened in the lower shell (12); the outer needle (2) is slidably arranged in the lower shell (12) along a first direction; and the upper shell (11) and the lower shell (12) are detachably connected.

11. The dual fuel injector according to claim 10, characterized in that The housing (1) further comprises a connecting piece (13), wherein the connecting piece (13) has an internal thread and is threadably matched with the upper housing (11) and the lower housing (12), and the upper housing (11) abuts against the surface of the lower housing (12).

12. An engine assembly, characterized in that: The invention comprises an engine and a dual-fuel injector as claimed in any one of claims 1 to 11, wherein the dual-fuel injector is used for injecting a first fuel and a second fuel into the engine.

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