A high-pressure common-rail fuel injector nozzle pair

Abstract

The application discloses a nozzle pair of a high-pressure common rail oil injector and relates to the technical field of oil injectors. The nozzle pair comprises a needle valve body and a first needle valve. The inside of the needle valve body is provided with an oil groove and a containing groove. The oil groove is located at the bottom of the containing groove. The surface of the needle valve body is provided with an oil channel which is communicated with the oil groove. When the connecting block moves upward, the guide column is inserted into the movable cavity from the round hole, and an acting force is applied to the rubber ring. At this time, the rubber ring is deformed. Since the rubber ring is O-shaped and the internal space of the movable cavity is limited, the rubber ring is deformed in the horizontal and vertical directions under the pressure of the guide column and the limitation of the movable cavity, so that the impact force transmitted by the guide column is absorbed and buffered. The deformation of the rubber ring plays a buffering role, reduces the impact force suffered by the spring instantaneously, helps to reduce the fatigue damage of the spring, and improves the working stability and durability of the nozzle pair.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel injection nozzle, in particular to a fuel injection nozzle assembly of high-pressure common rail fuel injector. BACKGROUND

[0002] The fuel injection nozzle assembly is a valve body installed in the fuel chamber of a diesel engine for controlling the fuel injection. The existing fuel injection nozzle assembly generally comprises a needle valve body and a needle valve. During operation, the needle valve reciprocates linearly in the needle valve body at high speed under the interaction of spring pressure and fuel pressure. In the high-pressure common rail fuel injector, the fuel injection nozzle assembly is extremely critical, which directly affects the fuel injection atomization quality and response time during operation.

[0003] The current fuel injection nozzle assembly of high-pressure common rail fuel injector has at least the following technical problems:

[0004] Firstly, the spring in the fuel injection nozzle assembly of high-pressure common rail fuel injector is subjected to frequent and strong impact during operation, which is prone to fatigue damage. The existing fuel injection nozzle assembly of high-pressure common rail fuel injector lacks protection for the spring, which shortens the service life of the spring and affects the normal use of the fuel injection nozzle assembly.

[0005] Secondly, the existing fuel injection nozzle assembly of high-pressure common rail fuel injector lacks limit for the movement of the needle valve during actual use, which may cause the needle valve to deviate or shake during frequent lifting and lowering, thereby increasing the wear of the fuel injection nozzle assembly and further affecting its service life and working reliability. SUMMARY

[0006] (I) Technical problems solved

[0007] In view of the above technical problems, the present application provides a fuel injection nozzle assembly of high-pressure common rail fuel injector.

[0008] (II) Technical solutions

[0009] To achieve the above purposes, the present application is implemented by the following technical solutions:

[0010] The utility model provides a kind of high-pressure common rail fuel injector's fuel nozzle coupling, including needle valve body and first needle valve, the inside of the needle valve body is provided with oil groove and accommodating groove, the oil groove is located the bottom of accommodating groove, the surface of the needle valve body is provided with oil channel with oil groove, the upper end of the first needle valve is fixedly installed with second needle valve, the upper end of the second needle valve is fixedly installed with conical plugging part, the conical plugging part upper end is fixedly installed with connecting block, the conical plugging part is used to block the communication of oil channel and oil groove, the accommodating groove is fixedly installed with upper end block, the bottom of the upper end block is fixedly installed with guide sleeve, the upper end of the connecting block is fixedly installed with guide column, the guide column is sleeved with spring, the surface of the guide sleeve is provided with round hole, the inside of the upper end block is provided with movable cavity with guide sleeve, the movable cavity is provided with rubber ring, the connecting block is fixedly connected with guide sleeve by spring, the connecting block is provided with limiting assembly, and the limiting assembly includes two limiting sliders.

[0011] Preferably: the connecting block is slidingly installed in the accommodating groove, the two limiting sliders are fixedly installed on the two sides of the connecting block respectively, the inner walls of the two sides of the accommodating groove are provided with limiting grooves respectively, and the two limiting sliders are slidingly installed in the limiting grooves respectively.

[0012] Preferably: each of the limiting sliders is arc-shaped, and a plurality of balls are installed on each of the limiting sliders; the bottom of the rubber ring is fixedly connected with a thickened portion, and the thickened portion is aligned with the position of the round hole.

[0013] Preferably: the surfaces of the two sides of the upper end block are provided with exhaust holes respectively, the two exhaust holes are communicated with the inner cavity of the movable cavity respectively, the inside of the needle valve body is provided with two air holes, the two air holes are communicated with the exhaust holes and the accommodating groove respectively, the bottom of the needle valve body is provided with a spray head, and the surface of the spray head is circumferentially provided with a plurality of oil injection holes.

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

[0015] Preferably: the rubber ring is O-shaped, for relieving the impact on the spring, and the top end of the guide column is slidingly inserted into the round hole.

[0016] (Three) beneficial effects

[0017] I: When the connecting block moves up, it will drive the guide column to move up, so that the guide column is inserted into the movable cavity from the round hole. At this time, the rubber ring is deformed. Since the rubber ring is O-shaped and located in the limited internal space of the movable cavity, under the pressure of the guide column, the rubber ring will deform horizontally and vertically under the limitation of the movable cavity, thereby absorbing and buffering the impact force transmitted by the guide column. The deformation of the rubber ring plays a buffering role, reduces the impact force on the spring at the moment, helps to reduce the fatigue damage of the spring, improves the working stability and durability of the fuel nozzle pair.

[0018] II: The thickened part is arranged at 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, it will directly apply force to the thickened part at the middle of the bottom end of the rubber ring. Since the material thickness of the thickened part is increased, it can withstand greater pressure and deformation, improve the buffering performance of the rubber ring, and more effectively reduce the strong impact generated by the movement of the guide column, reduce the wear and fatigue between parts, and prolong the service life of the fuel nozzle pair.

[0019] III: The limiting sliding blocks are fixedly installed at both side ends of the connecting block. Each limiting sliding block is slidingly installed in the limiting groove, and is used for limiting the lifting of the first needle valve and the second needle valve. A guiding effect is provided to prevent deviation or shaking during lifting, improve the stability during lifting of the first needle valve and the second needle valve, and prolong the service life.

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

[0021] V: The cooling channel is arranged in the needle valve body and is designed in a spiral shape and surrounds the oil tank periphery. The cooling liquid or cooling medium enters the cooling channel through the liquid inlet, flows along the spiral shape, fully exchanges heat with the components around the oil tank, and then flows out from the liquid outlet after absorbing heat, thereby reducing the working temperature of the fuel nozzle pair, preventing overheating, ensuring normal operation within the normal working temperature range, optimizing the fuel injection process, and prolonging the service life of the fuel nozzle pair.

[0022] VI: The exhaust holes are arranged on the both side surfaces of the upper end block and are communicated with the air holes. When the connecting block and the guide column rise, the air in the movable cavity is compressed and discharged through the exhaust holes and the air holes. When the connecting block and the guide column descend, negative pressure is formed in the movable cavity, and external air enters the movable cavity through the air holes and the exhaust holes, so as to balance the internal and external air pressures, ensure the smoothness of the lifting of the connecting block and the guide column, and avoid affecting the movement due to air pressure problems. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above description is only a summary of the technical scheme of the present application. In order to make the technical means of the present application more clearly understood and implemented according to the content of the description, the preferred embodiments of the present application are described in detail as follows with reference to the accompanying drawings.

[0024] Figure 1 Figure 1 is a structure diagram of the whole nozzle assembly of the high-pressure common rail fuel injector of the present application;

[0025] Figure 2 Figure 2 is a structure diagram of the needle valve body of the present application;

[0026] Figure 3 Figure 3 is a structure diagram of the limiting groove of the present application;

[0027] Figure 4 Figure 4 is a structure diagram of the cooling channel of the present application;

[0028] Figure 5 Figure 5 is a structure diagram of the connecting block of the present application;

[0029] Figure 6 Figure 6 is a structure diagram of the upper end block of the present application;

[0030] Figure 7 Figure 7 is a structure diagram of the limiting sliding block of the present application;

[0031] Figure 8 Figure 8 is a structure diagram of the present application; Figure 1 Figure 9 is an enlarged structure diagram of position A in Figure 8;

[0032] Figure 9 Figure 10 is an enlarged structure diagram of position B in Figure 8. Figure 2

[0033] Legend: 1, needle valve body; 11, oil groove; 12, spray head; 13, fuel injection hole; 14, air hole; 2, first needle valve; 21, second needle valve; 22, conical sealing part; 23, connecting block; 24, guide column; 25, spring; 3, limiting sliding block; 31, ball; 4, oil channel; 5, accommodating groove; 51, limiting groove; 6, upper end block; 61, guide sleeve; 62, circular 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 embodiments of the present application are described in further detail below in combination with the accompanying drawings and examples. The following examples are used to illustrate the present application but cannot be used to limit the scope of the present application.

[0035] Example: as Figure 1 , Figure 2 , Figure 3 , Figure 4 ​, Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9As shown, in order to solve the problems in the prior art, the present application provides a kind of high-pressure common rail fuel injector's fuel injection nozzle couple, including needle valve body 1 and first needle valve 2, the inside of needle valve body 1 is provided with oil groove 11 and containing groove 5, oil groove 11 is located in the bottom of containing groove 5, the surface of needle valve body 1 is provided with oil channel 4 communicated with oil groove 11, the upper end of first needle valve 2 is fixedly installed with second needle valve 21, the upper end of second needle valve 21 is fixedly installed with conical plugging part 22, conical plugging part 22 upper end is fixedly installed with connecting block 23, conical plugging part 22 is used to block the communication of oil channel 4 and oil groove 11, containing groove 5 is fixedly installed with upper end block 6, the bottom end of upper end block 6 is fixedly installed with guide sleeve 61, the upper end of connecting block 23 is fixedly installed with guide column 24, guide column 24 is provided with spring 25, the surface of guide sleeve 61 is provided with round hole 62, the inside of upper end block 6 is provided with movable cavity 63 communicated with guide sleeve 61, movable cavity 63 is provided with rubber ring 7, connecting block 23 is fixedly connected with guide sleeve 61 by spring 25, connecting block 23 is provided with limiting assembly, limiting assembly includes two limiting sliding blocks 3, connecting block 23 is slidably installed in containing groove 5, two limiting sliding blocks 3 are fixedly installed on the two sides of connecting block 23, the inner wall of containing groove 5 is provided with limiting groove 51, two limiting sliding blocks 3 are slidably installed in limiting groove 51, each limiting sliding block 3 is arc design, each limiting sliding block 3 is installed with a plurality of ball bearings 31, the middle part of the bottom end of rubber ring 7 is fixedly connected with thickened part 71, thickened part 71 is aligned with the position of round hole 62, the surface of both sides of upper end block 6 is provided with exhaust hole 64, two exhaust holes 64 are communicated with the inner cavity of movable cavity 63, the inside of needle valve body 1 is provided with two air holes 14, two air holes 14 are communicated with exhaust hole 64 and containing groove 5 respectively, the bottom end of needle valve body 1 is provided with spray head 12, the surface of spray head 12 is provided with a plurality of oil injection holes 13 equidistantly, the inside of needle valve body 1 is provided with cooling channel 8, cooling channel 8 is spiral shape, the inside of needle valve body 1 is provided with liquid inlet channel 81 and liquid outlet channel 82 respectively, liquid inlet channel 81 and liquid outlet channel 82 are communicated with the upper end and lower end of cooling channel 8 respectively, cooling channel 8 is around the periphery of oil groove 11, rubber ring 7 is O design, for relieving the impact on spring 25, the top end of guide column 24 is slidably inserted in round hole 62, when high-pressure common rail fuel injector works, high-pressure fuel enters the inside of needle valve body 1 from oil channel 4, second needle valve 21, first needle valve 2 and conical plugging part 22 move up, connecting block 23 moves up by conical plugging part 22, oil channel 4 is no longer blocked by conical plugging part 22 moving up, oil channel 4 is communicated with oil groove 11 at this time, fuel is transported to oil groove 11 at this time, and is sprayed from spray head 12, connecting block 23 moves up and exerts force on spring 25, so that spring 25 is compressed under stress, when spring 25 drives conical plugging part 22 to reset, conical plugging part 22 blocks oil channel 4 again, oil channel 4 and oil groove 11 will not be communicated at this time, so there will be no oil injection,When the connecting block 23 moves up, the guide column 24 will move up, so that the guide column 24 is inserted into the movable cavity 63 from the round hole 62, and an action force is applied to the rubber ring 7, at this time the rubber ring 7 is deformed, because the rubber ring 7 is O-shaped and the internal space of the movable cavity 63 is limited, under the pressure of the guide column 24, the rubber ring 7 will be deformed horizontally and longitudinally under the limitation of the movable cavity 63, so as to absorb and buffer the impact force transmitted by the guide column 24, the deformation of the rubber ring 7 plays a buffering role, reduces the impact force received by the spring 25 instantaneously, helps to reduce the fatigue damage of the spring 25, improves the working stability and durability of the fuel nozzle pair, and the thickened part 71 is arranged at 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, the thickened part 71 at the middle of the bottom end of the rubber ring 7 is directly subjected to an action force, because the material thickness of the thickened part 71 is increased, it can bear greater pressure and deformation, improve the buffering performance of the rubber ring 7, can more effectively reduce the strong impact generated by the movement of the guide column 24, reduce the wear and fatigue between parts, prolong the service life of the fuel nozzle pair, the two side end portions of the connecting block 23 are fixedly installed with the limiting sliding blocks 3, each limiting sliding block 3 is slidably installed in the limiting groove 51, and is used for limiting the lifting of the first needle valve 2 and the second needle valve 21, provides a guiding effect, prevents deviation or shaking during lifting, improves the stability of the first needle valve 2 and the second needle valve 21 during lifting, and prolongs the service life, the surface of the nozzle 12 is equally spaced to be provided with the oil injection holes 13, each oil injection hole 13 is designed in an arc strip shape, so that the fuel can be uniformly injected in multiple directions and angles, the arc strip-shaped oil injection hole 13 can guide the fuel to form a specific spray shape and track, increase the contact area and mixing degree of the fuel and air, and thus form a good spray effect, the needle valve body 1 is provided with the cooling channel 8, the cooling channel 8 is designed in a spiral shape and surrounds the oil groove 11 periphery, the cooling liquid or cooling medium enters the cooling channel 8 through the liquid inlet 81, flows along the spiral shape, fully exchanges heat with the parts around the oil groove 11, flows out from the liquid outlet 82 after absorbing heat, thereby reducing the working temperature of the fuel nozzle pair, preventing overheating, ensuring that it operates within a normal working temperature range, optimizing the fuel injection process, and prolonging the service life of the fuel nozzle pair, when the connecting block 23 and the guide column 24 lift, the air in the movable cavity 63 is extruded, the two side surfaces of the upper end block 6 are provided with the exhaust holes 64, the exhaust holes 64 are communicated with the air holes 14, when the connecting block 23 and the guide column 24 rise, the air in the movable cavity 63 is compressed, and the air is discharged through the exhaust holes 64 and the air holes 14; when the connecting block 23 and the guide column 24 descend, a negative pressure is formed in the movable cavity 63, and the outside air enters the movable cavity 63 through the air holes 14 and the exhaust holes 64, so as to keep the air pressure balance inside and outside, ensure the smoothness of the lifting of the connecting block 23 and the guide column 24, and avoid affecting the movement due to air pressure problems.

[0036] Working principle:

[0037] First, when the high-pressure common rail fuel injector is working, high-pressure fuel enters the inside of the needle valve body 1 from the oil channel 4, the second needle valve 21, the first needle valve 2 and the conical sealing part 22 move up, the connecting block 23 moves up by the conical sealing part 22 moving up, the oil channel 4 is no longer sealed by the conical sealing part 22 moving up, at this time the oil channel 4 is communicated with the oil groove 11, at this time the fuel is transported into the oil groove 11 and sprayed out from the nozzle 12, the connecting block 23 moves up and exerts force on the spring 25, so that the spring 25 is compressed under stress, when the spring 25 drives the conical sealing part 22 to reset, the conical sealing part 22 re-seals the oil channel 4, at this time the oil channel 4 and the oil groove 11 are not communicated, so there is no fuel injection, when the connecting block 23 moves up, the guide column 24 moves up, the guide column 24 is inserted into the movable cavity 63 from the round hole 62, and the rubber ring 7 is subjected to force, at this time the rubber ring 7 deforms, since the rubber ring 7 is O-shaped and the space inside the movable cavity 63 is limited, under the pressure of the guide column 24, the rubber ring 7 deforms horizontally and vertically under the limitation of the movable 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 instantaneously received by the spring 25, which helps to reduce the fatigue damage of the spring 25 and improve the working stability and durability of the fuel nozzle assembly.

[0038] Second, the thickened part 71 is arranged at the middle part 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, the thickened part 71 at the middle part of the bottom end of the rubber ring 7 is directly subjected to force, since the material thickness of the thickened part 71 is increased, it can withstand greater pressure and deformation, improving the buffering performance of the rubber ring 7, which can more effectively reduce the strong impact generated by the movement of the guide column 24, reduce the wear and fatigue between parts, and prolong the service life of the fuel nozzle assembly.

[0039] Third, the limiting slide block 3 is fixedly installed on both sides of the connecting block 23, each limiting slide block 3 is slidingly installed in the limiting groove 51, which is used for limiting the lifting of the first needle valve 2 and the second needle valve 21, provides a guiding effect, prevents deviation or shaking during lifting, improves the stability of the first needle valve 2 and the second needle valve 21 during lifting, and prolongs the service life.

[0040] Fourth, the oil injection holes 13 are equidistantly arranged on the surface of the nozzle 12, each oil injection hole 13 is designed in an arc strip shape, so that the fuel can be uniformly injected in multiple directions and angles, the arc strip-shaped oil 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 air, and thus form a good spray effect.

[0041] Fifth, through the needle valve body 1 is provided with cooling channel 8 inside, cooling channel 8 is spiral shape design, and surrounds the oil tank 11 periphery, cooling liquid or cooling medium through the inlet 81 into the cooling channel 8, along the spiral shape flow, fully with oil tank 11 around the components heat exchange, after absorbing heat from the outlet 82, so as to reduce the working temperature of the nozzle pair, prevent overheating, ensure its operation in the normal temperature range, optimize the injection process, prolong the service life of the nozzle pair;

[0042] Sixth, when the connecting block 23 and guide column 24 lift, will extrude the air in the movable cavity 63, through the upper end block 6 both sides surface are provided with exhaust hole 64, exhaust hole 64 and air hole 14 communication, when the connecting block 23 and guide column 24 rise, compression movable cavity 63 in the air, air through the exhaust hole 64 and air hole 14 exhaust; When the connecting block 23 and guide column 24 down, movable cavity 63 form negative pressure, outside air through the air hole 14 and exhaust hole 64 into movable cavity 63, keep the internal and external air pressure balance, ensure the connecting block 23 and guide column 24 lift smoothness, avoid because of air pressure problem influence its movement.

[0043] Finally, it should be noted that: obviously, the above examples are merely for the sake of clarity made of the invention, and not limited to the implementation. For those of ordinary skill in the art, on the basis of the above description can also be made in other different forms of changes or variations. Here do not need to and can not all the implementation to be exhausted. The obvious changes or variations derived from still within the scope of the present invention.

Claims

1. A fuel injector assembly for a high-pressure common rail injector, comprising a needle valve body (1) and a first needle valve (2), characterized in that: The needle valve body (1) is provided with an oil groove (11) and a receiving groove (5) inside. The oil groove (11) is located at the bottom of the receiving groove (5). The surface of the needle valve body (1) is provided with an oil passage (4) that communicates with the oil groove (11). The upper end of the first needle valve (2) is fixedly installed with a second needle valve (21). The upper end of the second needle valve (21) is fixedly installed with a conical sealing part (22). The upper end of the conical sealing part (22) is fixedly installed with a connecting block (23). The conical sealing part (22) is used to seal the connection between the oil passage (4) and the oil groove (11). The upper end block (6) is fixedly installed in the receiving groove (5), the bottom end of the upper end block (6) is fixedly installed with a guide sleeve (61), the upper end of the connecting block (23) is fixedly installed with a guide post (24), a spring (25) is sleeved on the guide post (24), a round hole (62) is opened on the surface of the guide sleeve (61), and an active cavity (63) communicating with the guide sleeve (61) is provided inside the upper end block (6), and a rubber ring (7) is provided inside the active cavity (63). The connecting block (23) is fixedly connected to the guide sleeve (61) by a spring (25). The connecting block (23) is provided with a limit component, which includes two limit sliders (3). Both sides of the upper block (6) are provided with exhaust holes (64). Both exhaust holes (64) are connected to the inner cavity of the movable cavity (63). The needle valve body (1) is provided with two vent holes (14). The two vent holes (14) are connected to the exhaust holes (64) and the receiving groove (5) respectively. The top end of the guide post (24) is slidably inserted into the round hole (62).

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

3. The injector assembly of a high-pressure common rail injector according to claim 2, characterized in that: Limiting grooves (51) are provided on both sides of the inner wall of the receiving groove (5); The two limiting sliders (3) are respectively slidably installed in the limiting groove (51).

4. The injector assembly of a high-pressure common rail injector according to claim 3, characterized in that: Each of the limiting sliders (3) is an arc-shaped design, and each of the limiting sliders (3) is equipped with a number of balls (31).

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

6. The injector assembly of a high-pressure common rail injector according to claim 5, characterized in that: The bottom end of the needle valve body (1) is provided with a nozzle (12), and the surface of the nozzle (12) is provided with a plurality of oil injection holes (13) at equal intervals.

7. The injector assembly of a high-pressure common rail injector according to claim 6, characterized in that: The needle valve body (1) is provided with a cooling channel (8) inside, and the cooling channel (8) is spiral in shape; The needle valve body (1) is provided with an inlet channel (81) and an outlet channel (82) respectively. The inlet channel (81) and the outlet channel (82) are connected to the upper and lower ports of the cooling channel (8) respectively. The cooling channel (8) surrounds the oil tank (11).

8. The injector assembly of a high-pressure common rail injector according to claim 7, characterized in that: The rubber ring (7) is an O-shaped design to mitigate the impact on the spring (25).

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