Fuel injection nozzle matching part of high-pressure common-rail fuel injector

Abstract

The invention discloses an oil nozzle matching part of a high-pressure common-rail oil injector, and relates to the technical field of oil nozzles, the oil nozzle matching part comprises a needle valve body and a first needle valve, an oil groove and a containing groove are formed in the needle valve body, the oil groove is located at the bottom of the containing groove, and an oil channel communicated with the oil groove is formed in the surface of the needle valve body; when a connecting block moves upwards, a guide column can be driven to move upwards, so that the guide column is inserted into a movable cavity from a round hole, acting force can be applied to a rubber ring, at the moment, the rubber ring deforms, and due to the fact that the rubber ring is O-shaped and located in a limited space in the movable cavity, under the pressure effect of the guide column, the rubber ring can be prevented from falling off. The rubber ring can deform transversely and longitudinally under the limitation of the movable cavity, so that impact force transmitted by the guide column is absorbed and buffered, the deformation of the rubber ring plays a buffering role, the impact force instantly borne by the spring is relieved, fatigue damage of the spring is reduced, and the working stability and durability of the oil nozzle matching part are improved.

Description

Technical Field

[0001] The invention relates to the technical field of fuel injection nozzles, in particular to a fuel injection nozzle pair of a high-pressure common rail fuel injector. Background Art

[0002] The injector assembly is a valve body installed in the fuel chamber of a diesel engine to control the oil inlet. Existing injector assemblies generally include a needle valve body and a needle valve. When working, the needle valve performs high-speed linear reciprocating motion in the needle valve body under the interaction of spring pressure and fuel pressure. In high-pressure common rail fast response injectors, the injector assembly is extremely critical, and it directly affects the injection atomization quality of the injector assembly and the response time during operation.

[0003] The current high-pressure common rail injector nozzle pair has been found to have at least the following technical problems:

[0004] First, during the operation of the high-pressure common rail injector, the internal spring of the injector is frequently subjected to strong impacts during operation, which is prone to fatigue damage. The existing injector of the high-pressure common rail injector lacks buffer protection for the spring, which shortens the service life of the spring and affects the normal use of the injector.

[0005] Second, in actual use, the existing high-pressure common rail injector nozzle pair lacks a limit on the movement of the needle valve, which may cause the needle valve to deviate or shake during frequent lifting and lowering movements, increasing the wear inside the nozzle pair and further affecting its service life and working reliability. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of the deficiencies in the prior art, the present invention provides a fuel injection nozzle pair for a high-pressure common rail fuel injector to solve the above-mentioned technical problems.

[0008] (II) Technical solution

[0009] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0010] A fuel injection nozzle pair of a high-pressure common rail injector comprises a needle valve body and a first needle valve, wherein an oil groove and a receiving groove are arranged inside the needle valve body, the oil groove is located at the bottom of the receiving groove, an oil passage communicating with the oil groove is opened on the surface of the needle valve body, a second needle valve is fixedly installed on the upper end of the first needle valve, a conical plugging portion is fixedly installed on the upper end of the second needle valve, a connecting block is fixedly installed on the upper end of the conical plugging portion, the conical plugging portion is used to block the connection between the oil passage and the oil groove, an upper end block is fixedly installed in the receiving groove, a guide sleeve is fixedly installed on the bottom end of the upper end block, a guide column is fixedly installed on the upper end of the connecting block, a spring is sleeved on the guide column, a circular hole is opened on the surface of the guide sleeve, an active cavity communicating with the guide sleeve is arranged inside the upper end block, a rubber ring is arranged in the active cavity, the connecting block is fixedly connected to the guide sleeve through the spring, a limiting assembly is arranged on the connecting block, and the limiting assembly comprises two limiting sliders.

[0011] Preferably: the connecting block is slidably installed in the accommodating groove, the two limiting sliding blocks are respectively fixedly installed on both sides of the connecting block, and limiting grooves are provided on both side inner walls of the accommodating groove, and the two limiting sliding blocks are respectively slidably installed in the limiting grooves.

[0012] Preferably, each of the limit sliders is of arc-shaped design, and a plurality of balls are mounted on each of the limit sliders. A thickened portion is fixedly connected to the middle of the bottom end of the rubber ring, and the thickened portion is aligned with the position of the circular hole.

[0013] Preferably: exhaust holes are provided on both side surfaces of the upper end block, and the two exhaust holes are communicated with the inner cavity of the active cavity; two vent holes are provided inside the needle valve body, and the two vent holes are respectively communicated with the exhaust hole and the accommodating groove; a nozzle is provided at the bottom end of the needle valve body, and a plurality of oil injection holes are equidistantly provided on the surface circumference of the nozzle.

[0014] Preferably: a cooling channel is arranged inside the needle valve body, the cooling channel is spiral-shaped, a liquid inlet and a liquid outlet are arranged inside the needle valve body, the liquid inlet and the liquid outlet are respectively connected to the upper port and the lower port of the cooling channel, and the cooling channel surrounds the periphery of the oil tank.

[0015] Preferably, the rubber ring is of O-shaped design to relieve the impact on the spring, and the top end of the guide column is slidably inserted into the round hole.

[0016] (III) Beneficial effects

[0017] 1. When the connecting block moves upward, it will drive the guide column to move upward, so that the guide column is inserted into the active cavity from the round hole, which will exert force on the rubber ring. At this time, the rubber ring is deformed. Since the rubber ring is O-shaped and the space inside the active cavity is limited, under the pressure of the guide column, the rubber ring will deform laterally and longitudinally under the restriction of the active cavity, thereby absorbing and buffering the impact force transmitted by the guide column. The deformation of the rubber ring plays a buffering role, reducing the instantaneous impact force on the spring, helping to reduce fatigue damage of the spring and improve the working stability and durability of the injector pair.

[0018] Second: A thickened portion is provided in the middle of the bottom end of the rubber ring. When the guide column moves with the movement of the second needle valve and the first needle valve, a force is directly applied to the thickened portion in the middle of the bottom end of the rubber ring. Since the material thickness of the thickened portion is increased, it can withstand greater pressure and deformation, thereby improving the buffering performance of the rubber ring, more effectively alleviating the strong impact caused by the movement of the guide column, reducing wear and fatigue between components, and extending the service life of the injector nozzle pair.

[0019] Three: Limit sliders are fixedly installed on both side ends of the connecting block, and each limit slider is slidably installed in the limit groove, which is used to limit the first needle valve and the second needle valve when they are lifted or lowered, and provides a guide to prevent them from shifting or shaking during the lifting process, thereby improving the stability of the first needle valve and the second needle valve when they are lifted or lowered, and extending their service life.

[0020] Four: Injection holes are equidistantly opened on the surface circumference of the nozzle. Each injection hole is designed in an arc-shaped strip, so that the fuel can be evenly sprayed in multiple directions and angles. The arc-shaped injection holes can guide the fuel to form a specific spray shape and trajectory, increase the contact area and mixing degree of the fuel and air, and thus form a good spray effect.

[0021] Five: A cooling channel is arranged inside the needle valve body. The cooling channel is designed in a spiral shape and surrounds the outer periphery of the oil tank. The coolant or cooling medium enters the cooling channel through the liquid inlet channel, flows along the spiral shape, fully exchanges heat with the components around the oil tank, and flows out from the liquid outlet after absorbing heat, thereby reducing the operating temperature of the fuel injector pair, preventing overheating, ensuring that it operates within the normal operating temperature range, optimizing the injection process, and extending the service life of the fuel injector pair.

[0022] Six: Exhaust holes are opened on both side surfaces of the upper end block, and the exhaust holes are connected with the vent holes. When the connecting block and the guide column rise, the air in the movable cavity is compressed, and the air is discharged through the exhaust holes and the vent holes; when the connecting block and the guide column descend, negative pressure is formed in the movable cavity, and the outside air enters the movable cavity through the vent holes and the exhaust holes, maintaining the balance of internal and external air pressure, ensuring the smoothness of the lifting and lowering of the connecting block and the guide column, and avoiding affecting their movement due to air pressure problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings.

[0024] Figure 1 It is a structural diagram of the entire fuel injection nozzle assembly of the high-pressure common rail fuel injector of the present invention;

[0025] Figure 2 It is a cutaway structural diagram of the needle valve body of the present invention;

[0026] Figure 3 It is a structural diagram of the limiting groove of the present invention;

[0027] Figure 4 It is a structural diagram of the cooling channel of the present invention;

[0028] Figure 5 It is a structural diagram of the connection block of the present invention;

[0029] Figure 6 It is a structural diagram of the upper end block cut away in the present invention;

[0030] Figure 7 It is a structural diagram of the limit sliding block of the present invention;

[0031] Figure 8 For the present invention Figure 1 The enlarged structural diagram at A in the middle;

[0032] Fig. 9 For the present invention Figure 2 The enlarged structure diagram at point B in the middle.

[0033] Legend: 1. Needle valve body; 11. Oil groove; 12. Nozzle; 13. Oil injection hole; 14. Vent hole; 2. First needle valve; 21. Second needle valve; 22. Conical sealing part; 23. Connecting block; 24. Guide column; 25. Spring; 3. Limiting slider; 31. Ball; 4. Oil channel; 5. Receiving groove; 51. Limiting groove; 6. Upper end block; 61. Guide sleeve; 62. Round hole; 63. Movable cavity; 64. Exhaust hole; 7. Rubber ring; 71. Thickened part; 8. Cooling channel; 81. Liquid inlet; 82. Liquid outlet. DETAILED DESCRIPTION

[0034] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] Embodiment: Figure 1 , Figure 2 , Figure 3 , Figure 4, Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9As shown, in view of the problems existing in the prior art, the present invention provides a fuel injection nozzle pair of a high-pressure common rail injector, comprising a needle valve body 1 and a first needle valve 2, wherein an oil groove 11 and a receiving groove 5 are arranged inside the needle valve body 1, the oil groove 11 is located at the bottom of the receiving groove 5, an oil passage 4 communicating with the oil groove 11 is opened on the surface of the needle valve body 1, a second needle valve 21 is fixedly installed on the upper end of the first needle valve 2, a conical plugging portion 22 is fixedly installed on the upper end of the second needle valve 21, a connecting block 23 is fixedly installed on the upper end of the conical plugging portion 22, and the conical plugging portion 22 is used to block the connection between the oil passage 4 and the oil groove 11, an upper end block 6 is fixedly installed in the receiving groove 5, a guide sleeve 61 is fixedly installed on the bottom end of the upper end block 6, a guide column 24 is fixedly installed on the upper end of the connecting block 23, and a guide post 24 is fixedly installed on the upper end of the connecting block 23. A spring 25 is sleeved on the column 24, a circular hole 62 is provided on the surface of the guide sleeve 61, an active cavity 63 communicating with the guide sleeve 61 is provided inside the upper end block 6, a rubber ring 7 is provided in the active cavity 63, the connecting block 23 is fixedly connected to the guide sleeve 61 through the spring 25, a limiting component is provided on the connecting block 23, the limiting component includes two limiting sliders 3, the connecting block 23 is slidably installed in the accommodating groove 5, the two limiting sliders 3 are respectively fixedly installed on both sides of the connecting block 23, the inner walls on both sides of the accommodating groove 5 are provided with limiting grooves 51, the two limiting sliders 3 are respectively slidably installed in the limiting grooves 51, each limiting slider 3 is of arc design, a plurality of balls 31 are installed on each limiting slider 3, and a thickened portion 7 is fixedly connected to the middle of the bottom end of the rubber ring 7 1, the thickened portion 71 is aligned with the position of the circular hole 62, exhaust holes 64 are provided on both sides of the upper end block 6, and the two exhaust holes 64 are communicated with the inner cavity of the active cavity 63, and two vent holes 14 are provided inside the needle valve body 1, and the two vent holes 14 are communicated with the exhaust hole 64 and the receiving groove 5 respectively, and a nozzle 12 is provided at the bottom end of the needle valve body 1, and a plurality of oil injection holes 13 are equidistantly provided on the surface circumference of the nozzle 12, and a cooling channel 8 is provided inside the needle valve body 1, and the cooling channel 8 is spiral-shaped, and a liquid inlet channel 81 and a liquid outlet channel 82 are respectively provided inside the needle valve body 1, and the liquid inlet channel 81 and the liquid outlet channel 82 are communicated with the upper port and the lower port of the cooling channel 8 respectively, and the cooling channel 8 surrounds the outer periphery of the oil groove 11, and the rubber ring 7 is an O-type design, which is used to relieve the elastic The top end of the guide column 24 is slidably inserted into the circular hole 62 by the impact of the spring 25. When the high-pressure common rail injector is working, the high-pressure fuel enters the needle valve body 1 from the oil passage 4, and the second needle valve 21, the first needle valve 2 and the conical plugging portion 22 move upward. The conical plugging portion 22 moves upward and drives the connecting block 23 to move upward. The conical plugging portion 22 moves upward and will no longer block the oil passage 4. At this time, the oil passage 4 is connected with the oil groove 11. At this time, the fuel is transported to the oil groove 11 and sprayed out from the nozzle 12. When the connecting block 23 moves upward, it will exert a force on the spring 25, so that the spring 25 is compressed. When the spring 25 drives the conical plugging portion 22 to reset, the conical plugging portion 22 will block the oil passage 4 again. At this time, the oil passage 4 and the oil groove 11 will not be connected, and the fuel will not be sprayed.When the connecting block 23 moves upward, it will drive the guide column 24 to move upward, so that the guide column 24 is inserted into the active cavity 63 from the circular hole 62, and a force will be applied to the rubber ring 7. At this time, the rubber ring 7 is deformed. Since the rubber ring 7 is O-shaped and has a limited internal space in the active cavity 63, under the pressure of the guide column 24, the rubber ring 7 will deform laterally and longitudinally under the restriction of the active cavity 63, thereby absorbing and buffering the impact force transmitted by the guide column 24. The deformation of the rubber ring 7 plays a buffering role, reducing the impact force instantly received by the spring 25, helping to reduce fatigue damage of the spring 25, and improving the working stability and durability of the fuel injection nozzle pair. A thickened portion 71 is provided in the middle of the bottom end of the rubber ring 7. When the guide column 24 moves along with the second needle valve 21 and the first When a needle valve 2 moves due to movement, a force will be directly applied to the thickened portion 71 in the middle of the bottom end of the rubber ring 7. Since the material thickness of the thickened portion 71 increases, it can withstand greater pressure and deformation, thereby improving the buffering performance of the rubber ring 7, and can more effectively reduce the strong impact caused by the movement of the guide column 24, reduce wear and fatigue between components, and extend the service life of the injector nozzle pair. The limiting sliders 3 are fixedly installed on both side ends of the connecting block 23, and each limiting slider 3 is slidably installed in the limiting groove 51, which is used for limiting the first needle valve 2 and the second needle valve 21 when they are lifted and lowered, providing a guiding effect to prevent them from deflecting or shaking during the lifting process, thereby improving the stability of the first needle valve 2 and the second needle valve 21 when they are lifted and lowered, and extending the service life of the injector nozzle pair. The service life is improved. The surface circumference of the nozzle 12 is equidistantly provided with injection holes 13. Each injection hole 13 is designed in an arc strip shape, so that the fuel can be uniformly sprayed in multiple directions and angles. The arc strip injection hole 13 can guide the fuel to form a specific spray shape and trajectory, increase the contact area and mixing degree of the fuel and the air, thereby forming a good spray effect. A cooling channel 8 is arranged inside the needle valve body 1. The cooling channel 8 is designed in a spiral shape and surrounds the outer periphery of the oil groove 11. The coolant or cooling medium enters the cooling channel 8 through the liquid inlet channel 81, flows along the spiral shape, fully exchanges heat with the components around the oil groove 11, and flows out from the liquid outlet channel 82 after absorbing heat, thereby reducing the working temperature of the nozzle pair and preventing Prevent overheating, ensure that it operates within the normal operating temperature range, optimize the injection process, and extend the service life of the injector pair. When the connecting block 23 and the guide column 24 are raised or lowered, the air in the active cavity 63 will be squeezed. Exhaust holes 64 are provided on both sides of the upper end block 6. The exhaust holes 64 are connected to the vent 14. When the connecting block 23 and the guide column 24 rise, the air in the active cavity 63 is compressed, and the air is discharged through the exhaust holes 64 and the vent 14; when the connecting block 23 and the guide column 24 fall, negative pressure is formed in the active cavity 63, and the outside air enters the active cavity 63 through the vent 14 and the exhaust hole 64, maintaining the balance of internal and external air pressure, ensuring the smoothness of the lifting and lowering of the connecting block 23 and the guide column 24, and avoiding the influence of air pressure problems on their movement.

[0036] Working principle:

[0037] In the first step, when the high-pressure common rail injector is working, the high-pressure fuel enters the needle valve body 1 from the oil passage 4, and the second needle valve 21, the first needle valve 2 and the conical plugging portion 22 move upward. The conical plugging portion 22 moves upward to drive the connecting block 23 to move upward. The conical plugging portion 22 moves upward and will no longer block the oil passage 4. At this time, the oil passage 4 is connected with the oil tank 11. At this time, the fuel is transported to the oil tank 11 and sprayed out from the nozzle 12. When the connecting block 23 moves upward, it will exert a force on the spring 25, so that the spring 25 is compressed. When the spring 25 drives the conical plugging portion 22 to reset, the conical plugging portion 22 will re-block the oil passage 4. At this time, the oil passage 4 and the oil tank 11 will not be connected. At this time, no oil will be sprayed. When the connecting block 23 moves up, it will drive the guide column 24 to move up, so that the guide column 24 is inserted into the active cavity 63 from the round hole 62, and a force will be applied to the rubber ring 7. At this time, the rubber ring 7 is deformed. Since the rubber ring 7 is O-shaped and the internal space of the active cavity 63 is limited, under the pressure of the guide column 24, the rubber ring 7 will be deformed laterally and longitudinally under the restriction of the active cavity 63, thereby absorbing and buffering the impact force transmitted by the guide column 24. The deformation of the rubber ring 7 plays a buffering role, reducing the impact force instantly received by the spring 25, helping to reduce fatigue damage of the spring 25, and improving the working stability and durability of the injector pair.

[0038] In the second step, a thickened portion 71 is provided in the middle of the bottom end of the rubber ring 7. When the guide column 24 moves with the movement of the second needle valve 21 and the first needle valve 2, a force is directly applied to the thickened portion 71 in the middle of the bottom end of the rubber ring 7. Since the material thickness of the thickened portion 71 is increased, it can withstand greater pressure and deformation, thereby improving the buffering performance of the rubber ring 7, and can more effectively reduce the strong impact generated by the movement of the guide column 24, reduce wear and fatigue between components, and extend the service life of the injector nozzle pair.

[0039] In the third step, the limiting sliders 3 are fixedly installed on both side ends of the connecting block 23, and each limiting slider 3 is slidably installed in the limiting groove 51, which is used to limit the first needle valve 2 and the second needle valve 21 when they are lifted or lowered, and provides a guiding function to prevent them from shifting or shaking during the lifting process, thereby improving the stability of the first needle valve 2 and the second needle valve 21 when they are lifted or lowered, and extending their service life.

[0040] The fourth step is to open fuel injection holes 13 equidistantly on the circumference of the surface of the nozzle 12. Each fuel injection hole 13 is designed in an arc-shaped strip, so that the fuel can be evenly sprayed out in multiple directions and angles. The arc-shaped strip fuel injection holes 13 can guide the fuel to form a specific spray shape and trajectory, increase the contact area and mixing degree of the fuel and air, and thus form a good spray effect.

[0041] The fifth step is to provide a cooling channel 8 inside the needle valve body 1. The cooling channel 8 is designed in a spiral shape and surrounds the outer periphery of the oil groove 11. The coolant or cooling medium enters the cooling channel 8 through the liquid inlet 81, flows along the spiral shape, fully exchanges heat with the components around the oil groove 11, and flows out from the liquid outlet 82 after absorbing heat, thereby reducing the operating temperature of the fuel injection nozzle pair, preventing overheating, ensuring that it operates within the normal operating temperature range, optimizing the injection process, and extending the service life of the fuel injection nozzle pair;

[0042] In the sixth step, when the connecting block 23 and the guide column 24 are raised or lowered, the air in the active cavity 63 will be squeezed. Exhaust holes 64 are provided on both side surfaces of the upper end block 6, and the exhaust holes 64 are connected with the vent holes 14. When the connecting block 23 and the guide column 24 rise, the air in the active cavity 63 is compressed, and the air is discharged through the exhaust holes 64 and the vent holes 14; when the connecting block 23 and the guide column 24 descend, negative pressure is formed in the active cavity 63, and the outside air enters the active cavity 63 through the vent holes 14 and the exhaust holes 64, so as to maintain the balance of internal and external air pressure, thereby ensuring the smoothness of the raising and lowering of the connecting block 23 and the guide column 24 and avoiding the influence of air pressure problems on their movement.

[0043] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A fuel injection nozzle assembly of a high-pressure common rail fuel injector, comprising a needle valve body (1) and a first needle valve (2), characterized in that: An oil groove (11) and a receiving groove (5) are provided inside the needle valve body (1); the oil groove (11) is located at the bottom of the receiving groove (5); an oil passage (4) communicating with the oil groove (11) is provided on the surface of the needle valve body (1); a second needle valve (21) is fixedly mounted on the upper end of the first needle valve (2); a conical blocking portion (22) is fixedly mounted on the upper end of the second needle valve (21); a connecting block (23) is fixedly mounted on the upper end of the conical blocking portion (22); the conical blocking portion (22) is used to block the connection between the oil passage (4) and the oil groove (11); An upper end block (6) is fixedly installed in the receiving groove (5), a guide sleeve (61) is fixedly installed at the bottom end of the upper end block (6), a guide column (24) is fixedly installed at the upper end of the connecting block (23), a spring (25) is sleeved on the guide column (24), a circular hole (62) is opened on the surface of the guide sleeve (61), an active cavity (63) communicating with the guide sleeve (61) is arranged inside the upper end block (6), and a rubber ring (7) is arranged in the active cavity (63); The connection block (23) is fixedly connected to the guide sleeve (61) via a spring (25), and a limit assembly is provided on the connection block (23), wherein the limit assembly comprises two limit slide blocks (3).

2. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 1, characterized in that: The connecting block (23) is slidably mounted in the receiving groove (5), and the two limiting sliding blocks (3) are respectively fixedly mounted on both sides of the connecting block (23).

3. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 2, characterized in that: The inner walls on both sides of the containing groove (5) are provided with limiting grooves (51); Wherein, the two limiting slide blocks (3) are respectively slidably installed in the limiting grooves (51).

4. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 3, characterized in that: Each of the limit sliders (3) is of arc-shaped design, and a plurality of balls (31) are mounted on each of the limit sliders (3).

5. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 4, characterized in that: A thickened portion (71) is fixedly connected to the middle of the bottom end of the rubber ring (7), and the thickened portion (71) is aligned with the position of the circular hole (62).

6. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 5, characterized in that: The surfaces of both sides of the upper end block (6) are provided with exhaust holes (64), and the two exhaust holes (64) are communicated with the inner cavity of the active cavity (63); Wherein, two vent holes (14) are arranged inside the needle valve body (1), and the two vent holes (14) are respectively communicated with the exhaust hole (64) and the containing groove (5).

7. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 6, characterized in that: A spray head (12) is arranged at the bottom end of the needle valve body (1), and a plurality of oil spray holes (13) are equidistantly arranged on the surface circumference of the spray head (12).

8. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 7, characterized in that: A cooling channel (8) is provided inside the needle valve body (1), and the cooling channel (8) is in a spiral shape; The needle valve body (1) is provided with a liquid inlet channel (81) and a liquid outlet channel (82) respectively, the liquid inlet channel (81) and the liquid outlet channel (82) are respectively connected to the upper port and the lower port of the cooling channel (8), and the cooling channel (8) surrounds the outer periphery of the oil groove (11).

9. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 8, characterized in that: The rubber ring (7) is of O-shaped design and is used to alleviate the impact on the spring (25).

10. The fuel injection nozzle assembly of a high pressure common rail fuel injector according to claim 9, characterized in that: The top end of the guide column (24) is slidably inserted into the circular hole (62).

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