Nested double-needle-valve electronic control fuel injector with variable fuel injection rule

Abstract

The invention aims to provide a nested double-needle-valve electronic control fuel injector with a variable fuel injection rule, and belongs to the field of internal combustion engines. Comprising a fastening cap, an upper fastening cap and a lower fastening cap, the fastening cap is fixed outside the upper fastening cap, the upper end of the lower fastening cap is fixed at the lower end of the lower fastening cap, and a pressure storage cavity wall, a control valve fastening block, an upper metering orifice plate and a middle metering orifice plate are sequentially arranged in the upper fastening cap from top to bottom. A lower metering orifice plate, a double-needle valve and lift conversion valve control cavity module and a nozzle are sequentially arranged in the lower tightening cap from top to bottom, and a double-electromagnetic valve control assembly is arranged in the control valve fastening block. Accurate control over the three control cavities is achieved through the two electromagnetic valves, and the fuel circulation area between the inner needle valve and the valve seat can be changed through the maximum lift switching function of the inner needle valve; the switching opening function of the inner needle valve and the outer needle valve can change the types of the spraying holes, the oil spraying rule is indirectly influenced through different types of the spraying holes, combustion in a diesel engine cylinder can be improved, and discharged pollutants are reduced.

Description

Technical Field

[0001] The present invention relates to an internal combustion engine, in particular to a fuel injector of the internal combustion engine. Background Art

[0002] Electronic fuel injectors have many technical advantages. They can precisely control the amount of fuel injected, making fuel injection more accurate and thus improving fuel utilization; the injection timing can be precisely controlled to optimize the combustion process; they can also achieve multiple injections to reduce pollutant emissions; they have a fast response speed and can quickly adjust the injection parameters according to the engine operating conditions to enhance the engine's power performance and stability.

[0003] The variable adjustment of the injection pattern is currently mainly achieved by changing the fuel pressure, specifically by adding a fuel booster valve in the fuel supply line, which is activated when needed to change the fuel supply pressure and thus change the curve of the injection pattern. However, in this solution, in order to ensure the effective operation of the hydraulic device, a large amount of return oil is often required to drive the oil pressure regulating component to work, thereby adjusting the pressure of the fuel in the injection device, which seriously affects the efficiency and economy of the entire injection system. Summary of the invention

[0004] The purpose of the present invention is to provide a nested double-needle valve electronically controlled fuel injector with variable injection pattern that can adapt to more complex diesel engine cylinder fuel supply and spray requirements and meet more actual working conditions of internal combustion engines.

[0005] The object of the present invention is achieved in that:

[0006] The invention discloses a nested double-needle valve variable injection rule electronically controlled fuel injector, which is characterized by comprising a fastening cap, an upper fastening cap and a lower fastening cap, wherein the fastening cap is fixed on the outside of the upper fastening cap, the upper end of the lower fastening cap is fixed on the lower end of the lower fastening cap, the upper fastening cap is provided with a pressure storage chamber wall, a control valve fastening block, an upper orifice plate and a middle orifice plate in order from top to bottom, the lower orifice plate, a double needle valve and a lift conversion valve control chamber module and a nozzle in order from top to bottom in the lower fastening cap, and a double solenoid valve control assembly is provided in the control valve fastening block; a pressure storage chamber is provided in the pressure storage chamber wall, a left fuel inlet oil circuit and a right fuel inlet oil circuit are respectively provided in the control valve fastening block, an orifice plate pressure storage chamber is provided in the middle orifice plate, the left fuel inlet oil circuit is connected to the pressure storage chamber and the orifice plate pressure storage chamber respectively, the right fuel inlet oil circuit is connected to the pressure storage chamber, and an interface connected to the pressure storage chamber is provided in the fastening cap.

[0007] The present invention may also include:

[0008] 1. The dual solenoid valve control assembly includes a control valve housing and an upper solenoid valve, a lower solenoid valve, and a nested slide valve assembly in the control valve housing. The upper solenoid valve includes an upper solenoid valve armature, a control valve core, and an upper solenoid valve return spring. The lower solenoid valve includes a lower solenoid valve stem, a lower solenoid valve armature, and a lower solenoid valve return spring. The control valve core and the lower solenoid valve stem are arranged relatively to each other. The nested slide valve assembly is located between the control valve core and the lower solenoid valve stem. The upper solenoid valve armature is installed on the top of the control valve core, and the lower solenoid valve armature is installed on the bottom of the lower solenoid valve stem. The control valve core is sleeved with an upper solenoid valve return spring, the lower solenoid valve stem is sleeved with a lower solenoid valve return spring, the control valve housing is provided with a first flange of the control valve housing, a second flange of the control valve housing, and a third flange of the control valve housing, respectively, the upper and lower ends of the upper solenoid valve return spring are the first flange of the control valve housing and the control valve core, respectively, and the upper and lower ends of the lower solenoid valve return spring are the second flange of the control valve housing and the third flange of the control valve housing; the nested slide valve assembly comprises a nested slide valve housing, a nested slide valve inner The nested slide valve shell is located between the control valve core and the lower solenoid valve stem, the nested slide valve inner core is located in the nested slide valve shell, a nested slide valve inner core oil return channel is formed between the nested slide valve inner core and the control valve core, a nested slide valve middle cavity is formed between the nested slide valve inner core, the control valve core and the nested slide valve shell, a nested slide valve bottom oil unloading through hole is formed between the nested slide valve inner core and the nested slide valve shell below, and a control valve core upper chamber, a control valve core middle chamber and a control valve core lower chamber are formed between the control valve core and the control valve housing. An internal oil circuit of the control valve core is arranged in the valve core, and the internal oil circuit of the control valve core is connected to the middle chamber of the control valve core and the oil return flow channel of the inner core of the nested sliding valve respectively, and the oil return flow channel of the inner core of the nested sliding valve is connected to the middle chamber of the nested sliding valve, the upper solenoid valve and the control valve component housing form an upper oil return chamber, and the lower solenoid valve and the control valve component housing form a lower oil return chamber, an upper oil return hole communicating with the upper oil return chamber and a lower oil return hole communicating with the lower oil return chamber are arranged in the control valve component housing, the oil unloading through hole at the bottom of the nested sliding valve is connected to the lower oil return chamber, and an oil groove for the valve stem of the lower solenoid valve is processed in the nested sliding valve housing.

[0009] 2. The double needle valve and lift conversion valve control chamber module includes a lift conversion valve fastening block, an inner needle valve upper fastening block, an inner needle valve lower fastening block, a lift conversion valve, an inner needle valve, and an outer needle valve. The outer needle valve is located in the nozzle, the main body of the inner needle valve is located in the outer needle valve, the upper end of the inner needle valve passes through the inner needle valve lower fastening block and is located in the inner needle valve upper fastening block, the upper part of the lift conversion valve is located in the lift conversion valve fastening block, the lower part of the lift conversion valve is located in the inner needle valve upper fastening block, the upper part of the lift conversion valve is sleeved with a lift conversion valve reset spring, the upper part of the inner needle valve is sleeved with an inner needle valve reset spring, and the inner needle valve is located at the upper part of the outer needle valve. The part is sleeved with an outer needle valve return spring, the position of the lift conversion valve return spring forms a lift conversion valve control chamber, the position of the inner needle valve return spring forms an inner needle valve control chamber, and the position of the outer needle valve return spring forms an outer needle valve control chamber; the lift conversion valve control chamber is connected to the middle chamber of the control valve core through the lower orifice plate lift conversion valve return oil throttling hole, and the lift conversion valve control chamber is connected to the orifice plate pressure storage chamber through the lift conversion valve control chamber oil inlet throttling hole; the outer needle valve control chamber oil inlet oil circuit and the outer needle valve control chamber oil outlet oil circuit are respectively arranged in the fastening block on the inner needle valve, and the outer needle valve control chamber oil inlet oil circuit is connected to the orifice plate pressure storage chamber The outer needle valve control chamber oil inlet oil circuit is connected to the outer needle valve control chamber through the outer needle valve control chamber oil inlet throttle hole, the outer needle valve control chamber oil outlet oil circuit is connected to the upper chamber of the control valve core, the outer needle valve control chamber oil outlet oil circuit is connected to the outer needle valve control chamber through the outer needle valve control chamber outgoing throttle hole, the outer needle valve control chamber third oil drain hole is arranged in the inner needle valve lower fastening block, the outer needle valve control chamber third oil drain hole is connected to the outer needle valve control chamber outgoing throttle hole; the inner needle valve control chamber oil inlet oil circuit and the inner needle valve control chamber oil return oil circuit are arranged in the lift conversion valve fastening block, and a lift conversion valve oil storage tank is formed between the lift conversion valve and the lift conversion valve fastening block. An inner needle valve control chamber oil inlet throttling hole is arranged in the lift conversion valve, and the inner needle valve control chamber oil inlet oil circuit is connected to the orifice plate pressure storage chamber and the lift conversion valve oil storage tank, the inner needle valve control chamber oil inlet throttling hole is connected to the lift conversion valve oil storage tank and the inner needle valve control chamber, and the inner needle valve control chamber oil return oil circuit is connected to the lift conversion valve oil storage tank and the lower chamber of the control valve core; an outer needle valve oil storage tank is formed between the outer needle valve and the nozzle, the outer needle valve oil storage tank is connected to the orifice plate pressure storage chamber and the right fuel supply oil circuit, an oil storage chamber is formed between the inner needle valve and the outer needle valve, and a fuel connecting channel is arranged in the outer needle valve, and the fuel connecting channel is connected to the outer needle valve oil storage tank and the oil storage chamber.

[0010] 3. In the injection preparation stage, the coils of the upper solenoid valve and the lower solenoid valve shall not be energized and have no electromagnetic force. The upper chamber of the control valve core is seated on the lower end face of the second flange of the control valve housing under the action of the lower solenoid valve return spring. The control valve core as a whole is seated on the upper end face of the inner needle valve control chamber under the action of the upper solenoid valve return spring. The control slide valve module is in a completely locked state. The high-pressure fuel enters the orifice plate pressure storage chamber through the left fuel inlet oil passage, and then is divided into two paths. One path enters the oil storage chamber through the left fuel inlet oil passage to complete the oil supply; the other path completes the oil supply to the outer needle valve control chamber through the outer needle valve control chamber inlet oil passage. At this time, the upper chamber of the control valve core is closed, and the high-pressure fuel cooperates with the outer needle valve return spring in the outer needle valve control chamber to The outer needle valve applies downward pressure to make the outer needle valve seated, completing the sealing of the outer needle valve spray hole; one way is to flow into the inner needle valve control chamber through the inner needle valve control chamber oil inlet circuit, at this time the lower chamber of the control valve core is in a closed state, and the high-pressure fuel in the inner needle valve control chamber cooperates with the inner needle valve return spring to apply downward pressure to the inner needle valve to make the inner needle valve seated, completing the sealing of the inner needle valve spray hole; one way is to enter the lift conversion valve control chamber through the lift conversion valve control chamber oil inlet circuit and the lift conversion valve control chamber oil inlet throttle hole, at this time the control slide valve module is closed, and the high-pressure fuel in the lift conversion valve control chamber cooperates with the lift conversion valve return spring to apply downward pressure to the lift conversion valve to make the lift conversion valve seated on the upper end face of the flange of the fastening block on the inner needle valve.

[0011] 4. When the outer needle valve is spraying independently, the lower solenoid valve coil is energized, and the upper solenoid valve coil remains de-energized. At this time, the lower solenoid valve armature is affected by the electromagnetic force and drives the lower solenoid valve stem to move downward. The control valve core as a whole is affected by the return spring of the upper solenoid valve and moves downward at the same time. The upper chamber of the control valve core is connected with the upper return oil chamber. The high-pressure fuel in the control chamber of the outer needle valve reaches the upper chamber of the control valve core through the oil outlet of the control chamber of the outer needle valve, and then drains through the upper return oil hole. At this time, the downward pressure of the high-pressure fuel in the control chamber of the outer needle valve on the outer needle valve is reduced. The oil leakage process is terminated, and the high-pressure fuel pressure at the bottom of the oil chamber causes the outer needle valve to rise, and the outer needle valve spray hole begins to spray fuel; when the lower solenoid valve loses power, the valve stem of the lower solenoid valve re-seats on the lower end face of the second flange of the control valve housing due to the action of the lower solenoid valve reset spring, and drives the control valve core to move up to its original position. At this time, the upper chamber of the control valve core is re-sealed by the upper end of the control valve core, the oil leakage process is terminated, and the high-pressure fuel re-fills the outer needle valve control chamber, and cooperates with the outer needle valve reset spring to make the outer needle valve seated, the outer needle valve spray hole is closed, and the injection process ends.

[0012] 5. When the inner needle valve is independently spraying, the upper solenoid valve coil is energized, and the lower solenoid valve remains de-energized. At this time, the upper solenoid valve armature is affected by the electromagnetic force and drives the control valve core to move upward as a whole. The seal of the lower chamber of the control valve core is released, and the oil return oil path of the inner needle valve control chamber in the control valve housing is connected with the lower oil return chamber. The high-pressure fuel in the inner needle valve control chamber reaches the lower oil return chamber through the oil return oil path of the inner needle valve control chamber, and then drains through the lower oil return hole; at this time, the downward pressure of the high-pressure fuel in the inner needle valve control chamber on the inner needle valve is weakened, and the high-pressure fuel pressure in the oil storage chamber overcomes the inner needle valve. The downward pressure generated by the needle valve return spring lifts the inner needle valve, and the fuel flows to the inner needle valve spray hole through the pressure chamber and starts to spray. At this time, the lift of the inner needle valve is limited by the lower bottom surface of the lift conversion valve; when the upper solenoid valve loses power, the control valve core as a whole is acted upon by the upper solenoid valve return spring, and the lower section of the control valve core is re-seated on the upper end surface of the nested slide valve assembly, and the lower return oil chamber is sealed by the lower section of the control valve core again, the oil leakage process is terminated, and the high-pressure fuel re-fills the inner needle valve control chamber, and the inner needle valve is seated with the inner needle valve return spring, the inner needle valve spray hole is closed, and the injection process ends.

[0013] 6. When the inner needle valve is in the boot-shaped injection mode, the upper solenoid valve coil is energized before the lower solenoid valve coil. The upper solenoid valve armature is affected by the electromagnetic force and drives the control valve core to move upward as a whole. At this time, the control slide valve module is closed, and the lower chamber of the control valve core is released. The inner needle valve starts to spray oil in the same injection mode as its independent injection. At this time, the upper limit of the lift of the inner needle valve is limited by the lower end face of the lift conversion valve; after the inner needle valve reaches the lift limit, the lower solenoid valve coil is energized, and the lower solenoid valve armature drives the lower solenoid valve stem and the nested slide valve housing to move downward. At this time, the inner core of the nested slide valve is connected to the lower return oil chamber, and the high-pressure fuel located in the control chamber of the lift conversion valve flows to the lower return oil chamber through the oil inlet path of the control chamber of the lift conversion valve, and then completes the oil leakage through the lower return oil hole. The lift conversion valve moves upward under the action of the inner needle valve and reaches the lower end face of the lower orifice plate to complete the lift conversion of the inner needle valve.

[0014] The advantages of the present invention are as follows: a nested double needle valve variable injection pattern electronically controlled injector of the present invention realizes precise control of three control chambers (i.e., inner needle valve control chamber, outer needle valve control chamber, and lift conversion valve control chamber) through two solenoid valves (i.e., upper solenoid valve and lower solenoid valve); the maximum lift switching function of the inner needle valve can change the fuel flow area between it and the valve seat; the switching opening function of the inner and outer double needle valves can change the type of spray hole (i.e., inner needle valve spray hole and outer needle valve spray hole), and indirectly affect the injection pattern through the different types of spray holes. Both can realize flexible and changeable injection pattern curve shape to meet a wider range of working conditions, which is beneficial to improving combustion in diesel engine cylinders and reducing emission pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention;

[0016] Figure 2 It is a schematic diagram of the structure of the dual electromagnetic control component;

[0017] Figure 3 It is a schematic diagram of the structure of the control valve slide valve assembly;

[0018] Figure 4 It is a schematic diagram of the double needle valve and lift conversion valve control chamber module. DETAILED DESCRIPTION

[0019] The present invention is described in more detail below with reference to the accompanying drawings:

[0020] Combination Figure 1-4 The present invention discloses a nested double needle valve variable injection pattern electronically controlled fuel injector comprising an interface 1, an upper tightening cap 2, a pressure storage chamber wall 3, a control valve fastening block 4, a fuel left oil inlet circuit 5, a lift conversion valve control chamber oil inlet circuit 6, a lift conversion valve return oil circuit 7, an orifice plate pressure storage chamber 8, an upper orifice plate 9, a lift conversion valve control chamber oil inlet throttle hole 10, an orifice plate 11, a lower orifice plate 12, a lower tightening cap 13, and a nozzle left oil supply circuit 14, nozzle 15, inner needle valve 16, pressure chamber 17, fastening cap 18, pressure storage chamber 19, double solenoid valve control assembly 20, control slide valve module 21, right fuel supply oil circuit 22, inner needle valve control chamber return oil circuit 23, lower orifice plate lift conversion valve return oil throttle hole 24, double needle valve and lift conversion valve control chamber module 25, outer needle valve 26, oil storage chamber 27, outer needle valve spray hole 28 and inner needle valve spray hole 29.

[0021] The pressure accumulator chamber wall 3, the dual solenoid valve control assembly 20, the control valve fastening block 4, the upper orifice plate 9, the orifice plate 11, the lower orifice plate 12, the dual needle valve and lift conversion valve control chamber module 25, and the nozzle 15 are installed from top to bottom and connected by positioning pins, wherein the control valve fastening block 4 and the dual solenoid valve control assembly 20 are connected as a whole by threads. The fastening cap 18, the upper tightening cap 2 and the lower tightening cap 13 are all fastened together by threads. The inner needle valve 16 is nested in the outer needle valve 26 and placed in the nozzle 15. The diameter of the tail end of the inner needle valve 16 is reduced, and the inner diameter of the tail section 24 of the outer needle valve is increased, and cooperates with the nozzle 15 to form an oil storage chamber 27. The lower conical surface of the inner needle valve 16 and the concave surface processed in the bottom of the nozzle 15 are sealed to form a pressure chamber 17. The tail section of the nozzle 15 is processed with an outer needle valve spray hole 28, and the bottom end is processed with an inner needle valve spray hole 29.

[0022] During the high-pressure fuel supply process, the fuel first flows into the pressure storage chamber 19 from the interface 1, and then is divided into two paths, one path flows into the oil storage chamber 27 through 22 to complete the fuel supply; the other path enters the upper orifice plate pressure storage chamber 8 through the left fuel inlet oil path 5, and then reaches the oil storage chamber 27 through the left nozzle supply oil path 14 to complete the fuel supply. The other three paths of fuel drawn from 8 are respectively supplied to the control chambers of the valve components in the pilot control module 25.

[0023] The dual solenoid valve control assembly 28 includes an upper solenoid valve 30, a first flange 31 of a control valve housing, an upper solenoid valve return spring 32, a control valve housing 33, a middle chamber 34 of a control valve core, a nested sliding valve assembly 35, an internal oil circuit 36 ​​of a control valve core, a control valve core 37, a second flange 38 of a control valve housing, a third flange 39 of a control valve housing, a lower solenoid valve stem 40, an upper solenoid valve armature 41, an upper oil return chamber 42, an upper oil return hole 43, an upper chamber 44 of a control valve core, a lower chamber 45 of a control valve core, a lower oil return chamber 46, a lower oil return hole 47, an oil groove 48 of a lower solenoid valve stem, a lower solenoid valve return spring 49, a lower solenoid valve armature 50, a lower solenoid valve 51 and a lower oil return chamber 52.

[0024] The upper solenoid valve 30 is composed of an upper solenoid valve armature 41, a control valve core 37, an upper solenoid valve return spring 32 and a nested sliding valve assembly 35. The lower solenoid valve 51 is composed of a lower solenoid valve stem 40, a lower solenoid valve armature 50 and a lower solenoid valve return spring 49. The upper solenoid valve 30 and the lower solenoid valve 51 are symmetrically installed in the control valve housing 33.

[0025] The upper part of the control valve housing 33 is processed with a first flange 31 of the control valve housing, and the lower end surface thereof is provided with an upper solenoid valve return spring 32. The lower part of the control valve housing 33 is processed with a second flange 38 of the control valve housing and a third flange 39 of the control valve housing, and a lower solenoid valve return spring 49 is placed between the middle flange of the nested slide valve housing 57 and the third flange 39 of the control valve housing, and a lower solenoid valve stem oil groove 48 is processed in the nested slide valve housing 57. The upper solenoid valve 30 and the lower solenoid valve 51 are sealed with the control valve housing 33 to form two closed chambers, an upper oil return chamber 42 and a lower oil return chamber 52, respectively, in which an upper oil return hole 43 and a lower oil return hole 47 are processed respectively. The middle depression of the control valve core 37 cooperates with the control valve housing 33 to form a middle chamber 34 of the control valve core.

[0026] The nested slide valve assembly 35 includes a nested slide valve inner core oil return channel 53, a nested slide valve inner core bottom oil drain hole 54, a nested slide valve intermediate cavity 55, a nested slide valve inner core 56 and a nested slide valve housing nested slide valve housing 57. The nested slide valve 56 forms a seal with the top groove of the nested slide valve housing nested slide valve housing 57, and the nested slide valve housing 57 is processed with a nested slide valve inner core bottom oil drain hole 54 to avoid oil entrapment during the operation of the nested slide valve 56.

[0027] The double needle valve and lift change valve control chamber module 25 includes a lift change valve control chamber 58, an inner needle valve control chamber oil inlet circuit 59, a lift change valve fastening block 60, an outer needle valve control chamber oil inlet circuit 61, an inner needle valve control chamber oil inlet throttling hole 62, an inner needle valve control chamber 63, an inner needle valve return spring 64, an outer needle valve control chamber oil inlet throttling hole 65, an outer needle valve control chamber 66, a lift change valve return spring 67, an inner needle valve upper fastening block 68, a lift change valve 69, an inner needle valve upper fastening block flange 70, an inner needle valve lower fastening block 71, an outer needle valve control chamber oil outlet circuit 72, an outer needle valve control chamber oil outlet throttling hole 73, an outer needle valve control chamber third oil drain hole 74 and an outer needle valve return spring 75.

[0028] The lift conversion valve fastening block 60 is processed with an inner needle valve control chamber oil inlet oil passage 59, and the lift conversion valve return spring 67 is placed in the lift conversion valve control chamber 58. The inner needle valve upper fastening block 68 is processed with an outer needle valve control chamber oil outlet oil passage 72, and the inner needle valve upper fastening block 68, the lift conversion valve 69 and the inner needle valve 16 together form the inner needle valve control chamber 63. The inner needle valve upper fastening block 68 is processed with an inner needle valve upper fastening block flange 70 for placing the inner needle valve return spring 64 and the lift conversion valve 69. The lift conversion valve 69 is processed with an inner needle valve control chamber oil outlet oil passage 23 and an inner needle valve control chamber oil inlet throttle hole 62. The inner needle valve lower fastening block 71 is machined with an outer needle valve control chamber oil outlet throttling hole 73, an outer needle valve control chamber oil inlet throttling hole 65 and an outer needle valve return spring 75, which together with the outer needle valve 15 and the nozzle 15 form an outer needle valve control chamber 66, and the outer needle valve return spring 75 is placed in the outer needle valve control chamber 66.

[0029] The electronically controlled fuel injector with nested double needle valves and inner needle valve dual lift variable injection pattern of the present invention can realize four basic injection modes: outer needle valve independent injection, inner needle valve small lift, inner needle valve large lift and inner needle valve boot-shaped injection. Different multiple injection modes can also be realized through the combination of the four basic injection modes. The working process of the four basic injection modes of the fuel injector is as follows:

[0030] During the injection preparation stage of the injector, the coils of the upper solenoid valve 30 and the lower solenoid valve 51 shall not be energized and have no electromagnetic force. Therefore, the upper chamber 44 of the control valve core is seated on the lower end surface of the second flange 38 of the control valve housing under the action of the lower solenoid valve return spring 49, and the control valve core as a whole 37 is seated on the upper end surface of the inner needle valve control chamber 63 under the action of the upper solenoid valve return spring 32, and the control slide valve module 21 is in a completely locked state. The high-pressure fuel enters the orifice plate pressure storage chamber 8 through the left fuel inlet oil circuit 5, and then is divided into four circuits. One circuit enters the oil storage chamber 27 through the left fuel inlet oil circuit 5 to complete the fuel supply; one circuit is completed through the outer needle valve control chamber oil inlet circuit 61 to complete the fuel supply to the outer needle valve control chamber 66. At this time, the upper chamber 44 of the control valve core is closed, and the high-pressure fuel in the outer needle valve control chamber 66 cooperates with the outer needle valve return spring 75 to apply downward pressure to the outer needle valve 26 so that the outer needle valve 26 is seated, completing the sealing of the outer needle valve spray hole 28; one circuit flows into the inner needle valve control chamber 63 through the inner needle valve control chamber oil inlet circuit 59. At this time, the lower chamber of the control valve core is closed. 45 is in a closed state, and the high-pressure fuel in the inner needle valve control chamber 63 cooperates with the inner needle valve return spring 64 to apply downward pressure to the inner needle valve 16 so that the inner needle valve 16 is seated, completing the sealing of the inner needle valve spray hole 29; one way enters the lift conversion valve control chamber 58 through the lift conversion valve control chamber oil inlet oil circuit 6 and the lift conversion valve control chamber oil inlet throttle hole 10. At this time, the control slide valve module 21 is closed, and the high-pressure fuel in the lift conversion valve control chamber 58 cooperates with the lift conversion valve return spring 67 to apply downward pressure to the lift conversion valve 69 so that the lift conversion valve 69 is seated on the upper end surface of the flange 70 of the inner needle valve upper fastening block.

[0031] When the injector is in the injection mode of independent injection of the outer needle valve, the coil of the lower solenoid valve 51 is energized and the coil of the upper solenoid valve 30 remains in a de-energized state. At this time, the lower solenoid valve armature 50 is affected by the electromagnetic force to drive the lower solenoid valve stem 40 to move downward, and the control valve core as a whole 37 is moved downward at the same time by the action of the upper solenoid valve reset spring 32. Therefore, the upper chamber 44 of the control valve core is connected to the upper return oil chamber 42, and the high-pressure fuel in the outer needle valve control chamber 66 reaches the upper chamber 44 of the control valve core through the outer needle valve control chamber oil outlet oil path 72, and then completes the oil leakage through the upper return oil hole 43. At this time, the downward pressure of the high-pressure fuel in the outer needle valve control chamber 66 on the outer needle valve 26 is weakened, and the high-pressure fuel pressure at the bottom of the oil chamber 27 causes the outer needle valve 26 to lift, and the outer needle valve spray hole 28 begins to spray fuel; when the lower solenoid valve 51 loses power, the lower solenoid valve stem 40 re-seats on the lower end surface of the second flange 38 of the control valve housing due to the action of the lower solenoid valve reset spring 49, and drives the control valve core 37 to move up to the original position. At this time, the upper chamber 44 of the control valve core is sealed again by the upper end of the control valve core 47, and the oil leakage process is terminated. The high-pressure fuel re-fills the outer needle valve control chamber 66, and cooperates with the outer needle valve reset spring 75 to make the outer needle valve 26 seated, the outer needle valve spray hole 28 is closed, and the oil injection process ends. During the whole process, the control slide valve module 21 is in a closed state. In order to prevent the outer needle valve control chamber 66 from being trapped in the inclined groove, a third oil leakage hole 74 of the outer needle valve control chamber is opened in the top inclined groove.

[0032] When the injector is in the injection mode of independent injection of the inner needle valve, the coil of the upper solenoid valve 30 is energized and the lower solenoid valve 51 remains in a de-energized state. At this time, the upper solenoid valve armature 41 is affected by the electromagnetic force to drive the control valve core as a whole 37 to move upward, and the seal of the lower chamber 45 of the control valve core is released. The inner needle valve control chamber return oil path 23 in the control valve component housing 33 is connected to the lower return oil chamber 46, and the high-pressure fuel in the inner needle valve control chamber 63 reaches the lower return oil chamber 46 through the inner needle valve control chamber return oil path 23, and then completes the oil leakage through the lower return oil hole 47. At this time, the downward pressure of the high-pressure fuel in the inner needle valve control chamber 63 on the inner needle valve 16 is weakened, and the high-pressure fuel pressure in the oil holding chamber 27 overcomes the downward pressure generated by the inner needle valve return spring 64, so that the inner needle valve 16 is lifted, and the fuel flows to the inner needle valve spray hole 29 through the pressure chamber 17 and starts to spray. At this time, the lift of the inner needle valve is limited by the lower bottom surface of the lift conversion valve 69; when the upper solenoid valve 30 loses power, the control valve core as a whole 37 is controlled by the upper solenoid valve return spring 32, and the lower section 37 of the control valve core is re-seated on the upper end surface of the nested sliding valve assembly 35, and the lower return oil chamber 46 is again sealed by the lower section 37 of the control valve core, and the oil leakage process is terminated. The high-pressure fuel refills the inner needle valve control chamber 63, and cooperates with the inner needle valve return spring 64 to seat the inner needle valve 16, and the inner needle valve spray hole 29 is closed, and the injection process ends. Under this working condition, the nested slide valve inner core 56 will be displaced relative to the nested slide valve assembly 35 , but the displacement is limited, and the nested slide valve middle cavity 55 is always sealed by the nested slide valve assembly 35 during this process.

[0033] When the inner needle valve is in the boot-shaped injection mode, the coil of the upper solenoid valve 30 is energized before the coil of the lower solenoid valve 51. The upper solenoid valve armature 41 is affected by the electromagnetic force to drive the control valve core 37 to move upward. At this time, the control slide valve module 21 is closed, and the lower chamber 45 of the control valve core is released. The inner needle valve 16 starts to spray oil in the same independent injection mode. At this time, the upper limit of the lift of the inner needle valve 16 is limited by the lower end face of the lift conversion valve 69. After the inner needle valve 16 reaches the lift limit, the coil of the lower solenoid valve 51 is energized, and the lower solenoid valve armature 50 drives the lower solenoid valve stem 40 and the nested slide valve housing 57 to move downward. At this time, the nested slide valve inner core 56 is connected to the lower oil return chamber 46, and the high-pressure fuel in the lift conversion valve control chamber 58 flows to the lower oil return chamber 46 through the lift conversion valve control chamber oil inlet oil path 6, and then completes the oil leakage through the lower oil return hole 47. The lift conversion valve 69 moves upward under the action of the inner needle valve 16 and reaches the lower end surface of the lower orifice plate 12, completing the lift conversion of the inner needle valve 16.

[0034] Through external needle valve independent injection, internal needle valve small lift injection, internal needle valve large lift injection and internal needle valve boot-shaped injection mode, the injector can also realize multiple injection modes such as "external needle valve independent injection-internal needle valve boot-shaped injection" to meet the fuel spray needs under more actual working conditions of diesel engines.

Claims

1. A nested double needle valve variable injection pattern electronically controlled fuel injector, characterized by: It comprises a fastening cap, an upper fastening cap and a lower fastening cap. The fastening cap is fixed on the outside of the upper fastening cap. The upper end of the lower fastening cap is fixed on the lower end of the lower fastening cap. The upper fastening cap is provided with a pressure storage chamber wall, a control valve fastening block, an upper orifice plate and a middle orifice plate in order from top to bottom. The lower orifice plate, a double needle valve and a lift conversion valve control chamber module and a nozzle are provided in order from top to bottom in the lower fastening cap. A double solenoid valve control assembly is provided in the control valve fastening block. A pressure storage chamber is provided in the pressure storage chamber wall. A left fuel inlet oil circuit and a right fuel inlet oil circuit are respectively provided in the control valve fastening block. An orifice plate pressure storage chamber is provided in the middle orifice plate. The left fuel inlet oil circuit is connected to the pressure storage chamber and the orifice plate pressure storage chamber respectively. The right fuel inlet oil circuit is connected to the pressure storage chamber. An interface connected to the pressure storage chamber is provided in the fastening cap.

2. The nested double needle valve variable injection pattern electronically controlled fuel injector according to claim 1 is characterized in that: The double solenoid valve control assembly comprises a control valve housing and an upper solenoid valve, a lower solenoid valve and a nested sliding valve assembly in the control valve housing. The upper solenoid valve comprises an upper solenoid valve armature, a control valve core and an upper solenoid valve return spring. The lower solenoid valve comprises a lower solenoid valve stem, a lower solenoid valve armature and a lower solenoid valve return spring. The control valve core and the lower solenoid valve stem are arranged relatively to each other. The nested sliding valve assembly is located between the control valve core and the lower solenoid valve stem. The upper solenoid valve armature is installed on the top of the control valve core, and the lower solenoid valve armature is installed on the bottom of the lower solenoid valve stem. The control valve core is sleeved with an upper solenoid valve return spring, and the lower solenoid valve stem is sleeved with a lower solenoid valve return spring. The control valve housing is provided with a first flange of the control valve housing, a second flange of the control valve housing and a third flange of the control valve housing respectively. The upper and lower ends of the upper solenoid valve return spring are respectively the first flange of the control valve housing and the control valve core, and the upper and lower ends of the lower solenoid valve return spring are respectively the second flange of the control valve housing and the third flange of the control valve housing; the nested sliding valve assembly comprises a nested sliding valve housing, a nested sliding valve inner core The nested slide valve housing is located between the control valve core and the lower solenoid valve stem, the nested slide valve inner core is located in the nested slide valve housing, a nested slide valve inner core oil return channel is formed between the nested slide valve inner core and the control valve core, a nested slide valve intermediate cavity is formed between the nested slide valve inner core, the control valve core and the nested slide valve housing, a nested slide valve bottom oil unloading through hole is formed between the nested slide valve inner core and the nested slide valve housing below, and a control valve core upper chamber, a control valve core middle chamber and a control valve core lower chamber are formed between the control valve core and the control valve housing respectively. An internal oil circuit of the control valve core is arranged in the core, and the internal oil circuit of the control valve core is connected to the middle chamber of the control valve core and the oil return flow channel of the inner core of the nested sliding valve respectively, and the oil return flow channel of the inner core of the nested sliding valve is connected to the middle chamber of the nested sliding valve, the upper solenoid valve and the control valve component housing form an upper oil return chamber, and the lower solenoid valve and the control valve component housing form a lower oil return chamber, and an upper oil return hole communicating with the upper oil return chamber and a lower oil return hole communicating with the lower oil return chamber are arranged in the control valve component housing, the oil unloading through hole at the bottom of the nested sliding valve is connected to the lower oil return chamber, and an oil groove for the valve stem of the lower solenoid valve is processed in the nested sliding valve housing.

3. The nested double needle valve variable injection pattern electronically controlled fuel injector according to claim 2 is characterized in that: The double needle valve and lift change valve control chamber module comprises a lift change valve fastening block, an inner needle valve upper fastening block, an inner needle valve lower fastening block, a lift change valve, an inner needle valve, and an outer needle valve. The outer needle valve is located in the nozzle, the main body of the inner needle valve is located in the outer needle valve, the upper end of the inner needle valve passes through the inner needle valve lower fastening block and is located in the inner needle valve upper fastening block, the upper part of the lift change valve is located in the lift change valve fastening block, the lower part of the lift change valve is located in the inner needle valve upper fastening block, the upper part of the lift change valve is sleeved with a lift change valve reset spring, the upper part of the inner needle valve is sleeved with an inner needle valve reset spring, and the inner needle valve is located at the upper part of the outer needle valve. There is an outer needle valve return spring in a separate sleeve, the position of the lift conversion valve return spring forms a lift conversion valve control chamber, the position of the inner needle valve return spring forms an inner needle valve control chamber, and the position of the outer needle valve return spring forms an outer needle valve control chamber; the lift conversion valve control chamber is connected to the middle chamber of the control valve core through the oil return throttle hole of the lower orifice plate lift conversion valve, and the lift conversion valve control chamber is connected to the orifice plate pressure storage chamber through the oil inlet throttle hole of the lift conversion valve control chamber; the outer needle valve control chamber oil inlet oil circuit and the outer needle valve control chamber oil outlet oil circuit are respectively arranged in the fastening block on the inner needle valve, and the outer needle valve control chamber oil inlet oil circuit is connected to the orifice plate pressure storage chamber The outer needle valve control chamber oil inlet oil circuit is connected to the outer needle valve control chamber through the outer needle valve control chamber oil inlet throttle hole, the outer needle valve control chamber oil outlet oil circuit is connected to the upper chamber of the control valve core, the outer needle valve control chamber oil outlet oil circuit is connected to the outer needle valve control chamber through the outer needle valve control chamber outgoing throttle hole, the outer needle valve control chamber third oil drain hole is arranged in the inner needle valve lower fastening block, the outer needle valve control chamber third oil drain hole is connected to the outer needle valve control chamber outgoing throttle hole; the inner needle valve control chamber oil inlet oil circuit and the inner needle valve control chamber oil return oil circuit are arranged in the lift conversion valve fastening block, and a lift conversion valve oil storage tank is formed between the lift conversion valve and the lift conversion valve fastening block. An inner needle valve control chamber oil inlet throttling hole is arranged in the lift conversion valve, and the inner needle valve control chamber oil inlet oil circuit is connected to the orifice plate pressure storage chamber and the lift conversion valve oil storage tank, the inner needle valve control chamber oil inlet throttling hole is connected to the lift conversion valve oil storage tank and the inner needle valve control chamber, and the inner needle valve control chamber oil return oil circuit is connected to the lift conversion valve oil storage tank and the lower chamber of the control valve core; an outer needle valve oil storage tank is formed between the outer needle valve and the nozzle, the outer needle valve oil storage tank is connected to the orifice plate pressure storage chamber and the right fuel supply oil circuit, an oil storage chamber is formed between the inner needle valve and the outer needle valve, and a fuel connecting channel is arranged in the outer needle valve, and the fuel connecting channel is connected to the outer needle valve oil storage tank and the oil storage chamber.

4. The nested double needle valve variable injection pattern electronically controlled fuel injector according to claim 3 is characterized by: During the injection preparation stage, the coils of the upper solenoid valve and the lower solenoid valve shall not be energized and have no electromagnetic force. The upper chamber of the control valve core is seated on the lower end face of the second flange of the control valve housing under the action of the lower solenoid valve return spring, and the control valve core as a whole is seated on the upper end face of the inner needle valve control chamber under the action of the upper solenoid valve return spring, and the control slide valve module is in a completely locked state; the high-pressure fuel enters the orifice plate pressure storage chamber through the left fuel inlet oil passage, and then is divided into two paths, one path enters the oil storage chamber through the left fuel inlet oil passage to complete the oil supply; the other path completes the oil supply to the outer needle valve control chamber through the outer needle valve control chamber inlet oil passage. At this time, the upper chamber of the control valve core is closed, and the high-pressure fuel in the outer needle valve control chamber cooperates with the outer needle valve return spring to supply the outer needle valve. The valve applies downward pressure to make the outer needle valve sit, completing the sealing of the outer needle valve spray hole; one way is to flow into the inner needle valve control chamber through the inner needle valve control chamber oil inlet circuit, at this time, the lower chamber of the control valve core is in a closed state, and the high-pressure fuel in the inner needle valve control chamber cooperates with the inner needle valve return spring to apply downward pressure on the inner needle valve to make the inner needle valve sit, completing the sealing of the inner needle valve spray hole; one way is to enter the lift conversion valve control chamber through the lift conversion valve control chamber oil inlet circuit and the lift conversion valve control chamber oil inlet throttle hole, at this time, the control slide valve module is closed, and the high-pressure fuel in the lift conversion valve control chamber cooperates with the lift conversion valve return spring to apply downward pressure on the lift conversion valve to make the lift conversion valve sit on the upper end face of the flange of the fastening block on the inner needle valve.

5. The nested double needle valve variable injection pattern electronically controlled fuel injector according to claim 3 is characterized by: When the outer needle valve is independently spraying, the lower solenoid valve coil is energized and the upper solenoid valve coil remains in a de-energized state. At this time, the lower solenoid valve armature is affected by the electromagnetic force and drives the lower solenoid valve stem to move downward. The control valve core as a whole is also affected by the return spring of the upper solenoid valve and moves downward at the same time. The upper chamber of the control valve core is connected to the upper return oil chamber, and the high-pressure fuel in the control chamber of the outer needle valve reaches the upper chamber of the control valve core through the oil outlet of the control chamber of the outer needle valve, and then drains the oil through the upper return oil hole. At this time, the downward pressure of the high-pressure fuel in the control chamber of the outer needle valve on the outer needle valve is weakened , the high-pressure fuel pressure at the bottom of the oil chamber causes the outer needle valve to lift, and the outer needle valve spray hole begins to spray fuel; when the lower solenoid valve loses power, the valve stem of the lower solenoid valve re-seats on the lower end surface of the second flange of the control valve housing due to the action of the lower solenoid valve return spring, and drives the control valve core to move up to its original position. At this time, the upper chamber of the control valve core is re-sealed by the upper end of the control valve core, the oil leakage process is terminated, and the high-pressure fuel re-fills the outer needle valve control chamber, and cooperates with the outer needle valve return spring to make the outer needle valve seated, the outer needle valve spray hole is closed, and the injection process ends.

6. The nested double needle valve variable injection pattern electronically controlled fuel injector according to claim 3 is characterized by: When the inner needle valve is independently injected, the upper solenoid valve coil is energized and the lower solenoid valve remains in a de-energized state. At this time, the upper solenoid valve armature is affected by the electromagnetic force and drives the control valve core to move upward as a whole. The seal of the lower chamber of the control valve core is released, and the oil return oil path of the inner needle valve control chamber in the control valve housing is connected to the lower oil return chamber. The high-pressure fuel in the inner needle valve control chamber reaches the lower oil return chamber through the oil return oil path of the inner needle valve control chamber, and then the oil is drained through the lower oil return hole. At this time, the downward pressure of the high-pressure fuel in the inner needle valve control chamber on the inner needle valve is weakened, and the high-pressure fuel pressure in the oil storage chamber overcomes the inner needle valve. The downward pressure generated by the valve return spring lifts the inner needle valve, and the fuel flows to the inner needle valve spray hole through the pressure chamber and starts to spray. At this time, the lift of the inner needle valve is limited by the lower bottom surface of the lift conversion valve; when the upper solenoid valve loses power, the control valve core as a whole is acted upon by the upper solenoid valve return spring, and the lower section of the control valve core is re-seated on the upper end surface of the nested sliding valve assembly, and the lower return oil chamber is sealed by the lower section of the control valve core again, the oil leakage process is terminated, and the high-pressure fuel re-fills the inner needle valve control chamber, and the inner needle valve return spring is used to seat the inner needle valve, the inner needle valve spray hole is closed, and the injection process ends.

7. The nested double needle valve variable injection pattern electronically controlled fuel injector according to claim 3 is characterized by: When the inner needle valve is in the boot-shaped injection mode, the upper solenoid valve coil is energized before the lower solenoid valve coil, and the upper solenoid valve armature is affected by the electromagnetic force to drive the control valve core to move upward as a whole. At this time, the control slide valve module is closed, and the lower chamber of the control valve core is released. The inner needle valve starts to spray oil in the same injection mode as its independent injection. At this time, the upper limit of the lift of the inner needle valve is limited by the lower end face of the lift conversion valve; after the inner needle valve reaches the lift limit, the lower solenoid valve coil is energized, and the lower solenoid valve armature drives the lower solenoid valve stem and the nested slide valve shell to move downward. At this time, the inner core of the nested slide valve is connected to the lower return oil chamber, and the high-pressure fuel located in the control chamber of the lift conversion valve flows to the lower return oil chamber through the oil inlet path of the control chamber of the lift conversion valve, and then completes the oil leakage through the lower return oil hole. The lift conversion valve moves upward under the action of the inner needle valve to reach the lower end face of the lower orifice plate, completing the lift conversion of the inner needle valve.

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