Injection device and engine

Abstract

The present invention relates to the technical field of power machinery, and the present invention provides an injection device and an engine. The valve assembly includes a guide rod and a valve core. The guide rod is slidably connected to the housing in the first cavity. The servo oil cavity and the first fuel cavity in the first cavity are respectively formed at the axial two ends of the guide rod. The guide rod is provided with a pressure relief channel. The valve core is slidably connected to the housing in the second cavity. The second fuel cavity and the third fuel cavity are respectively formed at the axial two ends of the valve core in the second cavity. Both the first fuel cavity and the third fuel cavity are communicated with the fuel inlet channel, and the second fuel cavity is communicated with the pressure relief channel. When the guide rod is in the first position, the first fuel cavity is communicated with the second fuel cavity and the pressure relief channel is blocked from the fuel return channel, and the injection cavity is blocked by the valve core from the third fuel cavity. When the guide rod is in the second position, the first fuel cavity is blocked by the guide rod from the second fuel cavity and the pressure relief channel is communicated with the fuel return channel, and the injection cavity is communicated with the third fuel cavity. Thus, the valve core can quickly respond to the start of the injection device.

Description

Technical Field

[0001] The present invention relates to the technical field of power machinery, and particularly relates to an injection device and an engine. Background Art

[0002] With the increasingly stringent ship emission standards, the research on alternative energy sources for marine engines has become increasingly important. Low-carbon fuel methanol and zero-carbon fuel ammonia, as emerging fuels, have relatively mature preparation technologies and broad market prospects. Relying on the original diesel engine structure, developing a flexible fuel engine can flexibly balance emissions and power performance. And the fuel injection device is an important part of the engine fuel system, so it is very necessary to develop a flexible fuel injection device accordingly.

[0003] In the existing injection device, a servo oil chamber, a first fuel chamber, a second fuel chamber, and an injection chamber are sequentially formed in a housing. A guide rod is slidably connected to the housing between the servo oil chamber and the first fuel chamber, and a valve core is slidably connected to the housing between the first fuel chamber and the second fuel chamber, and a part of the valve core can extend into the injection chamber to block the communication between the second fuel chamber and the injection chamber.

[0004] The specific injection process is as follows. First, fuel is introduced into the injection device, and the fuel will fill the first fuel chamber and the second fuel chamber. Among them, since the servo oil chamber is in an empty state at this time, when the first fuel chamber is gradually filled, it will move toward the side where the servo oil chamber is located against the guide rod and compress the servo oil chamber. At the same time, the fuel in the first fuel chamber also moves against the valve core toward the side where the second fuel chamber is located, so that the valve core blocks the second fuel chamber and the injection chamber. Then, when servo oil is injected into the servo oil chamber, the guide rod moves toward the side where the first fuel chamber is located and squeezes the fuel in the first fuel chamber, causing it to move toward the second fuel chamber, thereby increasing the pressure in the second fuel chamber. The fuel in this chamber acts on the valve core, causing the valve core to move toward the side where the first fuel chamber is located, and then the second fuel chamber is communicated with the injection chamber to complete the injection.

[0005] With such a setting, since there is always pressure in the first fuel chamber, the pressure in the second fuel chamber needs to be continuously increased until the pressure in the second fuel chamber is greater than the pressure in the first fuel chamber, so that the valve core can release the blockage of the injection chamber. Therefore, not only is it necessary to provide servo oil with a relatively high pressure in the servo oil chamber, but it also causes a delay time after the device is started and the fuel cannot respond in time.

[0006] Therefore, there is an urgent need for an injection device and an engine to solve the above technical problems. Summary of the Invention

[0007] The purpose of the present invention is to provide an injection device and an engine that can quickly respond to the start of the device.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] Injection device, comprising:

[0010] A housing, provided with a fuel inlet passage, a fuel return passage, a first cavity and a second cavity;

[0011] A nozzle, connected to the above-mentioned housing, and the above-mentioned nozzle is provided with an injection cavity;

[0012] A valve assembly, comprising a guide rod and a valve core, the above-mentioned guide rod is slidably connected to the above-mentioned housing in the above-mentioned first cavity, a servo oil cavity and a first fuel cavity in the above-mentioned first cavity are respectively formed at the axial two ends of the above-mentioned guide rod, the above-mentioned guide rod is provided with a pressure relief passage, the above-mentioned valve core is slidably connected to the above-mentioned housing in the above-mentioned second cavity, a second fuel cavity and a third fuel cavity are respectively formed at the axial two ends of the above-mentioned valve core in the above-mentioned second cavity, both the above-mentioned first fuel cavity and the above-mentioned third fuel cavity are communicated with the above-mentioned fuel inlet passage, and the above-mentioned second fuel cavity is communicated with the above-mentioned pressure relief passage;

[0013] When the above-mentioned guide rod is in the first position, the above-mentioned first fuel cavity is communicated with the above-mentioned second fuel cavity and the above-mentioned pressure relief passage is blocked from the above-mentioned fuel return passage, and the above-mentioned injection cavity is blocked by the above-mentioned valve core from the above-mentioned third fuel cavity; when the above-mentioned guide rod is in the second position, the above-mentioned first fuel cavity is blocked by the above-mentioned guide rod from the above-mentioned second fuel cavity and the above-mentioned pressure relief passage is communicated with the above-mentioned fuel return passage, and the above-mentioned valve core makes the above-mentioned injection cavity communicate with the above-mentioned third fuel cavity.

[0014] As a preferred technical solution of the above-mentioned injection device, a thread groove is provided on the outer peripheral wall of the above-mentioned valve core, and the above-mentioned fuel inlet passage is communicated with the above-mentioned third fuel cavity through the above-mentioned thread groove.

[0015] As a preferred technical solution of the above-mentioned injection device, the above-mentioned valve assembly further includes an elastic member, the above-mentioned elastic member is sleeved on the periphery of the above-mentioned valve core, and both ends of the above-mentioned elastic member are axially abutted against the above-mentioned housing and the above-mentioned valve core respectively, so that the above-mentioned valve core has a tendency to move towards the side where the above-mentioned injection cavity is located.

[0016] As a preferred technical solution of the above-mentioned injection device, a spacer block is detachably clamped between the above-mentioned elastic member and the above-mentioned housing and / or between the above-mentioned elastic member and the above-mentioned valve core.

[0017] As a preferred technical solution of the above-mentioned injection device, it further includes a common rail valve, the above-mentioned housing is provided with a servo oil inlet passage, the above-mentioned servo oil inlet passage is communicated with the above-mentioned servo oil cavity, and the above-mentioned common rail valve is installed on the above-mentioned servo oil inlet passage.

[0018] As a preferred technical solution of the above-mentioned injection device, in the above-mentioned first cavity of the above-mentioned guide rod, a sealed oil cavity is formed between a part of the peripheral side wall of the above-mentioned guide rod and a part of the peripheral side wall of the above-mentioned housing, and the above-mentioned sealed oil cavity is located between the above-mentioned first fuel cavity and the above-mentioned servo oil cavity.

[0019] As a preferred technical solution of the above injection device, a mixed oil chamber is formed between the guide rod and the housing. The mixed oil chamber is located between the servo oil chamber and the sealing oil chamber. The housing is further provided with a mixed oil discharge channel, one end of which is communicated with the mixed oil chamber, and the other end forms an outlet on the housing.

[0020] As a preferred technical solution of the above injection device, the housing includes a housing main body and a top cap. The top cap is fixed to the housing main body, and one end of the top cap extends into the first cavity, and the end face adjacent to the guide rod forms a servo oil chamber.

[0021] An engine is further provided, including the above injection device.

[0022] As a preferred technical solution of the above engine, it further includes a body. The injection device is inserted into the body. The housing of the injection device is further provided with a gas blowing channel, and the exhaust port of the gas blowing channel faces the connection position between the injection device and the body.

[0023] Advantages of the present invention:

[0024] The present invention provides an injection device, including a housing, a nozzle and a valve assembly. Among them, the housing is provided with a fuel inlet channel, a fuel return channel, a first cavity and a second cavity; the nozzle is connected to the housing, and the nozzle is provided with an injection cavity; the valve assembly includes a guide rod and a valve core. The guide rod is slidably connected to the housing in the first cavity. The servo oil chamber and the first fuel chamber in the first cavity are respectively formed at the axial two ends of the guide rod. The guide rod is provided with a pressure relief channel. The valve core is slidably connected to the housing in the second cavity. The second fuel chamber and the third fuel chamber are respectively formed at the axial two ends of the valve core in the second cavity. The first fuel chamber and the third fuel chamber are both communicated with the fuel inlet channel, and the second fuel chamber is communicated with the pressure relief channel; when the guide rod is in the first position, the first fuel chamber is communicated with the second fuel chamber and the pressure relief channel is blocked from the fuel return channel, and the injection cavity is blocked by the valve core from the third fuel chamber; when the guide rod is in the second position, the first fuel chamber is blocked by the guide rod from the second fuel chamber and the pressure relief channel is communicated with the fuel return channel, and the injection cavity is communicated with the third fuel chamber. With such a setting, when the injection device is started, the guide rod moves to the second position, and the pressure relief channel is communicated with the fuel return channel, realizing rapid pressure relief of the second fuel chamber, and further enabling the valve core to move more easily and quickly towards the side where the second fuel chamber is located, so that the fuel in the third fuel chamber is discharged from the injection cavity. Description of the drawings

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the content of the embodiments of the present invention and these drawings.

[0026] Figure 1 is a schematic structural diagram of an injection device provided by an embodiment of the present invention;

[0027] Figure 2 is a schematic structural diagram of a first fuel chamber and a second fuel chamber provided by an embodiment of the present invention;

[0028] Figure 3 is a schematic structural diagram of a mixed oil chamber provided by an embodiment of the present invention;

[0029] Figure 4 is a schematic structural diagram of an air blowing channel provided by an embodiment of the present invention.

[0030] In the figure:

[0031] 10. Housing; 11. Fuel inlet channel; 111. Fuel inlet; 12. Fuel return channel; 13. Servo oil chamber; 131. Servo oil inlet; 14. First fuel chamber; 141. First channel; 15. Second fuel chamber; 16. Third fuel chamber; 161. Second channel; 17. Sealing oil chamber; 171. Sealing oil inlet channel; 18. Mixed oil chamber; 181. Mixed oil discharge channel; 19. Air blowing channel;

[0032] 20. Nozzle; 21. Injection chamber;

[0033] 30. Guide rod; 31. Pressure relief channel; 311. First pressure relief pipeline; 312. Second pressure relief pipeline;

[0034] 40. Spool; 41. Elastic member; 50. Common rail valve. Detailed implementation manners

[0035] The following will further elaborate on the present invention in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the convenience of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0036] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0038] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and do not have special meanings.

[0039] As Figures 1 to 4 shown, the present invention provides an injection device, which includes a housing 10, a nozzle 20, and a valve assembly. Among them, the housing 10 is provided with a fuel inlet passage 11, a fuel return passage 12, a first cavity, and a second cavity; the nozzle 20 is connected to the housing 10, and the nozzle 20 is provided with an injection cavity 21; the valve assembly includes a guide rod 30 and a valve core 40. The guide rod 30 is slidably connected to the housing 10 in the first cavity. A servo oil cavity 13 and a first fuel cavity 14 in the first cavity are respectively formed at the axial two ends of the guide rod 30. The guide rod 30 is provided with a pressure relief passage 31. The valve core 40 is slidably connected to the housing 10 in the second cavity. A second fuel cavity 15 and a third fuel cavity 16 are respectively formed at the axial two ends of the valve core 40 in the second cavity. Both the first fuel cavity 14 and the third fuel cavity 16 are communicated with the fuel inlet passage 11, and the second fuel cavity 15 is communicated with the pressure relief passage 31.

[0040] When the guide rod 30 is in the first position, the first fuel chamber 14 communicates with the second fuel chamber 15, and the pressure relief passage 31 is blocked from the fuel return passage 12, and the injection chamber 21 and the third fuel chamber 16 are blocked by the valve core 40; when the guide rod 30 is in the second position, the first fuel chamber 14 and the second fuel chamber 15 are blocked by the guide rod 30, the pressure relief passage 31 communicates with the fuel return passage 12, and the injection chamber 21 communicates with the third fuel chamber 16.

[0041] Specifically, a first cavity and a second cavity are sequentially formed in the housing 10 along the first direction. The first cavity and the second cavity are communicated through a first passage 141, and the diameter of the first passage 141 is smaller than the diameters of the first cavity and the second cavity. A guide rod 30 is slidably disposed in the first cavity along the first direction. One axial end of the guide rod 30 and the inner wall of the first cavity enclose a servo oil chamber 13. The end face of the other axial end of the guide rod 30 can block the connection port of the first passage 141 and the first cavity. A flat groove is formed on the circumferential side of this end of the guide rod 30. The bottom wall of the flat groove, a part of the circumferential side wall of the first cavity, and a part of the axial end face of the first passage 141 enclose the first fuel chamber 14. One end of the housing 10 connected to the nozzle 20 forms a second passage 161 communicating with the injection chamber 21. One end of the second cavity facing away from the first cavity can communicate with the second passage 161 along the first direction, and the diameter of the second passage 161 is smaller than the diameter of the second cavity. A valve core 40 is slidably disposed in the second cavity along the first direction. One end of the valve core 40 and the end face of the first passage 141 and the circumferential side wall of the second cavity form a second fuel chamber 15. The other end of the valve core 40 forms a conical sealing surface. One end of the second passage 161 forms a conical hole cooperating with the conical sealing surface. The part of the conical sealing surface close to the second fuel chamber 15 and a part of the circumferential side wall of the second cavity enclose a third fuel chamber 16. A part of this end of the valve core 40 can extend into the second passage 161, and the communication between the third fuel chamber 16 and the second passage 161 is blocked by the cooperation of the conical sealing surface and the conical hole. Along the first direction, a servo oil inlet 131 and a fuel inlet 111 are formed at one end of the housing 10 close to the first cavity, and the other end is connected to the nozzle 20.

[0042] Further, a servo oil inlet channel, a fuel inlet channel 11, and a fuel return channel 12 are also provided in the housing 10. Among them, the servo oil inlet channel communicates the servo oil inlet 131 with the servo oil chamber 13. One end of the fuel inlet channel 11 is connected to the fuel inlet 111, and the other end is respectively communicated with the first fuel chamber 14 and the second chamber. The fuel entering the second chamber can flow into the third fuel chamber 16 along the gap between the side wall of the valve core 40 and the side wall of the second chamber. An injection chamber 21 is provided in the nozzle 20, and the injection chamber 21 is communicated with the second channel 161. The axial movement of the valve core 40 can selectively communicate the third fuel chamber 16 with the second channel 161 to conduct the third fuel chamber 16 and the injection chamber 21, or disconnect from the second channel 161 to disconnect the third fuel chamber 16 and the injection chamber 21.

[0043] Further, a pressure relief channel 31 is provided in the guide rod 30. The pressure relief channel 31 includes a first pressure relief pipeline 311 and a second pressure relief pipeline 312. Among them, the first pressure relief pipeline 311 is axially provided along the guide rod 30, and one end of the first pressure relief pipeline 311 is communicated with the first channel 141, and the other end is communicated with the second pressure relief pipeline 312. The second pressure relief pipeline 312 is along the radial direction of the guide rod 30, and the second pressure relief pipeline 312 can be communicated with the fuel return channel 12 provided in the housing 10.

[0044] When in the idle state, under the action of gravity, the first fuel chamber 14 and the second fuel chamber 15 are blocked by the guide rod 30, and the injection chamber 21 and the third fuel chamber 16 are blocked by the valve core 40.

[0045] When performing injection operations, first inject fuel into the injection device. The fuel enters the housing 10 from the fuel inlet channel 11 and is divided into two branches. One branch enters the first fuel chamber 14 from the fuel inlet channel 11. As the fuel is introduced, the pressure in the first fuel chamber 14 is denoted as F 1燃 , and it also increases accordingly and acts on the guide rod 30. At this time, the servo oil chamber 13 is in an empty state, and the guide rod 30 moves towards the side where the servo oil chamber 13 is located under the action of F 1燃 . In this way, the first fuel chamber 14 and the second fuel chamber 15 are communicated. After the fuel enters the second fuel chamber 15, a pressure denoted as F 2燃 is applied to the valve core 40, causing the valve core 40 to move towards the side where the third fuel chamber 16 is located and blocking the communication between the third fuel chamber 16 and the injection chamber 21. The other fuel branch flows along the circumferential side wall of the valve core 40 into the third fuel chamber 16, and a pressure denoted as F 3燃 is applied to the valve core 40, causing the valve core 40 to have a tendency to move towards the side where the second fuel chamber 15 is located. When F 2燃 > F 3燃 , such that the resultant force of the two points towards the side where the nozzle 20 is located, and the valve core 40 continuously blocks the communication between the third fuel chamber 16 and the injection chamber 21 under the action of the resultant force.

[0046] Then, servo oil is injected into the injection device. After the servo oil enters the servo oil chamber 13, a pressure F is applied to one end of the guide rod 30 伺 , at F 伺 > F 1燃 , the guide rod 30 moves toward the side where the first fuel chamber 14 is located under the action of the resultant force until the guide rod 30 blocks the first fuel chamber 14 from the second fuel chamber 15. As the guide rod 30 moves, the pressure relief channel 31 formed on the guide rod 30 communicates with the fuel return channel 12 formed on the housing 10. Since the pressure at the other end of the fuel return channel 12 is less than the pressure in the second fuel chamber 15, the fuel in the second fuel chamber 15 is discharged along the pressure relief channel 31 and the fuel return channel 12 at this time, realizing rapid pressure relief of the second fuel chamber 15. At this time, the pressure of the second fuel chamber 15 on the valve core 40 is denoted as F 2泄 , F 2泄 < F 3燃 , the valve core 40 moves toward the side where the second fuel chamber 15 is located under the action of the resultant force, and then the third fuel chamber 16 communicates with the nozzle chamber 21, and the fuel is ejected from the nozzle 20, regarded as completing one injection operation.

[0047] Optionally, the travel of the fuel from the fuel inlet channel 11 to the second fuel chamber 15 is less than the travel to the third fuel chamber 16. In this way, F 2燃 is applied to the valve core 40 before F 3燃 , avoiding fuel leakage.

[0048] Specifically, a threaded groove is formed on the outer peripheral wall of the valve core 40, and the fuel inlet channel 11 communicates with the third fuel chamber 16 through the threaded groove. With such a setting, on the one hand, the time for the fuel to enter the third fuel chamber 16 can be delayed through the threaded groove, so that F 2燃 can be applied to the valve core 40 before F 3燃 , and on the other hand, a groove structure is specially provided for the fuel to guide the flow, so as to ensure that the fuel can smoothly enter the third fuel chamber 16, avoiding blockage of the fuel due to impurities in the gap between the valve core 40 and the side wall of the second cavity.

[0049] Optionally, the valve assembly further includes an elastic member 41. The elastic member 41 is sleeved on the periphery of the valve core 40, and both ends of the elastic member 41 are axially abutted against the housing 10 and the valve core 40 respectively, so that the valve core 40 has a tendency to move toward the injection chamber 21. With such a setting, after the injection device completes one injection operation, the elastic member 41 can abut against the valve core 40 to more quickly block the communication between the third fuel chamber 16 and the injection chamber 21.

[0050] Specifically, the pressure exerted by the elastic member 41 on the valve core 40 is denoted as F 弹, when no fuel is introduced into the injection device, the spool valve 40 is only affected by the spring force F, blocking the communication between the third fuel chamber 16 and the injection chamber 21. When fuel starts to be introduced into the injection device, F 3燃 <F 弹 +F 2燃 , so the spool valve 40 remains in the blocked state. When servo oil starts to be introduced into the nozzle 20 device, F 2燃 decreases to F 2泄 , F 3燃 >F 弹 +F 2泄 , causing the spool valve 40 to move towards the side where the second fuel chamber 15 is located, and the third fuel chamber 16 communicates with the injection chamber 21. After the fuel is injected from the nozzle 20, F3 fuel rapidly decreases to F 3泄 , at this time F 弹 >F 3泄 , the spool valve 40 re-blocks the injection chamber 21, enabling the injection device to quickly close after completing one injection operation and preventing fuel leakage.

[0051] Furthermore, a spacer block is detachably clamped between the elastic member 41 and the housing 10 and / or between the elastic member 41 and the spool valve 40, intensifying the tendency of the spool valve 40 to move towards the injection chamber 21. With this arrangement, by adding the spacer block, the initial pre-tightening force of the elastic member 41 is changed, the movement range of the spool valve 40 is adjusted, and further, the opening size of the communication between the third fuel chamber 16 and the injection chamber 21 is changed to enhance the applicability of the injection device.

[0052] Optionally, the injection device further includes a common rail valve 50. The servo oil inlet passage communicates with the servo oil chamber 13, and the common rail valve 50 is installed in the servo oil inlet passage. Specifically, the servo oil inlet passage includes a first pipe and a second pipe. One end of the first pipe forms a servo oil inlet 131 on the housing 10, and the other end communicates with the common rail valve 50. One end of the second pipe communicates with the common rail valve 50, and the other end communicates with the servo oil chamber 13. In this way, the servo oil is sprayed into the servo oil chamber 13 through the common rail valve 50, making the pressure in the servo oil chamber 13 independent of the engine speed, and can greatly reduce the degree of change of the diesel fuel supply pressure with the engine speed. Further, the common rail valve 50 can flexibly adjust the oil pressure in the servo oil chamber 13 according to the engine load condition and the requirements of economy and emissions, especially optimizing the low-speed performance of the engine.

[0053] Optionally, the housing 10 is further provided with a servo oil drain passage, one end of which communicates with the common rail valve 50, and the other end forms a servo oil drain port on the housing 10. When it is necessary to relieve the pressure of the servo oil chamber 13, the drain passage communicates with the common rail valve 50, and the servo oil returns from the servo oil chamber 13 along the second pipe to the common rail valve 50 and then is discharged from the housing 10 along the servo oil drain passage.

[0054] Optionally, the guide rod 30 is located within the first cavity, and its peripheral sidewall forms a sealed oil cavity 17 with a part of the peripheral sidewall of the housing 10. The sealed oil cavity 17 is located between the first fuel cavity 14 and the servo oil cavity 13. Specifically, the housing 10 is provided with a sealed oil inlet passage 171, one end of which communicates with the sealed oil cavity 17, and the other end forms a sealed oil hole on the housing 10. Lubricating oil is injected into the sealed oil cavity 17 through the sealed oil inlet passage 171. On the one hand, since the lubricating oil has better lubricity than the fuel, this can improve the lubrication condition, prevent the guide rod 30 and the housing 10 from being severely worn under the corrosion of the fuel, extend the time of maintenance, and improve the system life. On the other hand, the pressure of the sealed lubricating oil is greater than the pressure of the pressure relief passage 31 to ensure that the fuel in the second fuel cavity 15 will not move along the gap between the guide rod 30 and the housing 10 to the side where the servo oil cavity 13 is located and enter it to mix with the servo oil. A small amount of lubricating oil will pass through the first fuel cavity 14, the second fuel cavity 15 and the third fuel cavity 16 along the sidewall of the housing 10 all the way, and be sprayed into the cylinder together with the fuel in the third fuel cavity 16 to participate in injection and combustion.

[0055] Furthermore, since the guide rod 30 is slidably arranged in the first cavity, during its sliding process, it is inevitable to bring some lubricating oil into the servo oil cavity 13, or when squeezing the servo oil cavity 13, some servo oil enters the sealed oil cavity 17 along the gap between the guide rod 30 and the housing 10. Thus, the two kinds of oil fluids are mixed, and the mixed oil fluid cannot participate in the cycle, but needs to be stored separately and wait for further treatment.

[0056] Based on this, optionally, in this embodiment, a mixed oil cavity 18 is formed between the guide rod 30 and the housing 10. The mixed oil cavity 18 is located between the servo oil cavity 13 and the sealed oil cavity 17. The housing 10 is further provided with a mixed oil discharge passage 181, one end of which communicates with the mixed oil cavity 18, and the other end forms an outlet on the housing 10.

[0057] Specifically, the first cavity is in a stepped shape including a large-diameter section and a small-diameter section. The guide rod 30 correspondingly includes a large-diameter rod and a small-diameter rod. The large-diameter rod slides in the large-diameter section, a part of the small-diameter rod extends into the large-diameter section, and the other part slides in the small-diameter section. The end face of the large-diameter rod facing away from the small-diameter rod forms the servo oil cavity 13 with the end face of the housing 10, and the other end forms the mixed oil cavity 18 with the end face of the small-diameter section. The mixed oil cavity 18 is used to receive the servo oil escaping from the servo oil cavity 13 and the sealed lubricating oil escaping from the sealed oil cavity 17. The mixed oil fluid is discharged from the mixed oil discharge passage 181 to prevent it from escaping again and spreading the pollution area.

[0058] Optionally, the housing 10 includes a housing main body and a top cap. The top cap is fixed to the housing main body, and one end of the top cap extends into the first cavity, and the end face adjacent to the guide rod 30 forms the servo oil cavity 13.

[0059] The present invention also provides an engine, including the above-mentioned injection device.

[0060] Optionally, the engine further includes a body, the injection device is inserted into the body, and an air-blowing channel 19 is further formed in the housing 10 of the injection device. The exhaust port of the air-blowing channel 19 faces the connection position between the injection device and the body, and the exhaust port faces the side where the nozzle 20 is located. Commonly used fuels may be toxic. After the main engine stops working, if the residual fuel remaining in the body is not washed away and disposed of in time, it is likely to cause an explosion, posing a major accident endangering the lives of the staff. Therefore, in this embodiment, the air-blowing channel 19 is provided. After the main engine stops working, a rare gas can be introduced into the air-blowing channel 19 in the injection device to blow away the residual fuel in the body, thereby improving the safety performance of the main engine.

[0061] In addition, the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. Injection device, characterized in that, Comprising: A housing (10) provided with a fuel inlet passage (11), a fuel return passage (12), a first cavity and a second cavity; A nozzle (20) connected to the housing (10), the nozzle (20) being provided with an injection cavity (21); A valve assembly including a guide rod (30) and a valve core (40), the guide rod (30) being slidably connected to the housing (10) in the first cavity, a servo oil cavity (13) and a first fuel cavity (14) in the first cavity being respectively formed at two axial ends of the guide rod (30), the guide rod (30) being provided with a pressure relief passage (31), the valve core (40) being slidably connected to the housing (10) in the second cavity, a second fuel cavity (15) and a third fuel cavity (16) being respectively formed at two axial ends of the valve core (40) in the second cavity, the first fuel cavity (14) and the third fuel cavity (16) both being communicated with the fuel inlet passage (11), and the second fuel cavity (15) being communicated with the pressure relief passage (31); When the guide rod (30) is in a first position, the first fuel cavity (14) is communicated with the second fuel cavity (15) and the pressure relief passage (31) is blocked from the fuel return passage (12), and the injection cavity (21) is blocked from the third fuel cavity (16) by the valve core (40); when the guide rod (30) is in a second position, the first fuel cavity (14) is blocked from the second fuel cavity (15) by the guide rod (30) and the pressure relief passage (31) is communicated with the fuel return passage (12), and the valve core (40) communicates the injection cavity (21) with the third fuel cavity (16).

2. The injection device according to claim 1, characterized in that, The outer peripheral wall of the valve core (40) is provided with a thread groove, and the fuel inlet passage (11) is communicated with the third fuel cavity (16) through the thread groove.

3. The injection device according to claim 1, characterized in that, The valve assembly further includes an elastic member (41), the elastic member (41) being sleeved on the periphery of the valve core (40), and two ends of the elastic member (41) being axially abutted against the housing (10) and the valve core (40) respectively, so that the valve core (40) has a tendency to move towards the side where the injection cavity (21) is located.

4. The injection device according to claim 3, characterized in that, A spacer block is detachably clamped between the elastic member (41) and the housing (10) and / or between the elastic member (41) and the valve core (40).

5. The injection device according to claim 1, characterized in that, It further includes a common rail valve (50), the housing (10) being provided with a servo oil inlet passage, the servo oil inlet passage being communicated with the servo oil cavity (13), and the common rail valve (50) being installed in the servo oil inlet passage.

6. The injection device according to claim 1, characterized in that, In the first cavity, the peripheral side wall of the guide rod (30) and a part of the peripheral side wall of the housing (10) form a sealed oil cavity (17), and the sealed oil cavity (17) is located between the first fuel cavity (14) and the servo oil cavity (13).

7. The injection device according to claim 6, characterized in that A mixing oil chamber (18) is formed between the guide rod (30) and the housing (10). The mixing oil chamber (18) is located between the servo oil chamber (13) and the sealing oil chamber (17). The housing (10) is further provided with a mixing oil discharge channel (181) whose one end is communicated with the mixing oil chamber (18) and the other end forms an outlet on the housing (10).

8. The injection device according to claim 1, characterized in that, The housing (10) includes a housing body and a top cap. The top cap is fixed to the housing body, and one end of the top cap extends into the first cavity, and the end face adjacent to the guide rod (30) forms a servo oil chamber (13).

9. An engine, characterized in that, It includes the injection device according to any one of claims 1-8.

10. The engine according to claim 9, characterized in that, It further includes a machine body. The injection device is inserted into the machine body. The housing (10) of the injection device is further provided with a gas blowing channel (19), and the exhaust port of the gas blowing channel (19) faces the connection position between the injection device and the machine body.

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