A high-pressure common rail fuel injector needle valve sealing performance reinforcing structure

Abstract

This invention relates to the field of new energy internal combustion engine technology, and particularly to a structure for enhancing the sealing performance of a high-pressure common rail injector needle valve. It includes an injector body, which comprises a housing. A second central cavity is formed at the center of the housing cavity, and a reinforcing mechanism is connected to the bottom of the second central cavity. A second annular cavity is concentrically arranged around the second central cavity, and a fuel delivery mechanism is disposed within the second annular cavity. Because the diameter of the adjusting rod is smaller than the top opening of the reinforcing channel, and the diameter of the upper needle valve rod is larger than the top opening of the reinforcing channel, the needle valve head can avoid excessive instantaneous fuel flow into the fuel discharge mechanism from the bottom, thus achieving flow control of the discharged fuel. When the upper needle valve rod falls back, it can compress the sealing limit rod, ensuring that it remains accurately locked at the top opening of the reinforcing channel regardless of the length of use, avoiding the oil leakage problem that occurs after prolonged use of traditional sealing rings, thereby enhancing the sealing effect of the needle valve.

Description

Technical Field

[0001] This invention belongs to the field of new energy internal combustion engine technology, and specifically relates to a structure for enhancing the sealing performance of a needle valve in a high-pressure common rail injector. Background Technology

[0002] Nowadays, new energy internal combustion engines are being used by more and more new energy vehicle manufacturers because of their low energy consumption and low pollution. As an essential component of new energy internal combustion engines, the needle valve inside the injector, which controls the sealing and fuel injection, is of paramount importance.

[0003] A search revealed a patent document with publication number CN120384827A, published on July 29, 2025, entitled "A High-Pressure Common Rail Injector." This document includes a housing, a solenoid valve, and a valve-controlled nozzle device. The solenoid valve is positioned above the valve-controlled nozzle device, and its energization and de-energization control the injection of fuel into the nozzle device. This pen-shaped high-pressure common rail injector has a small outer diameter, and the injector inlet is located at the top of the housing. A wiring channel is provided within the housing. A PCB wiring board is mounted on the housing, with two sets of wiring points and the same number of external connectors. Each set of wiring points is electrically connected to its corresponding external connector. The solenoid valve's wire extends out of the housing through the wiring channel and connects electrically to the wiring points on the PCB wiring board, thereby connecting to the external connectors. As shown in the figure, the solenoid valve requires only a minimal number of components, omitting a series of adapters, brackets, and other parts, and also eliminating the need for overall injection molding.

[0004] The above embodiments still have the following drawbacks: The needle valve in the above embodiment still uses the traditional sealing ring sealing method. After prolonged use, the sealing ring is easily deformed due to long-term high pressure and strong impact, which causes the sealing effect of the needle valve to decrease. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a structure for enhancing the sealing performance of a needle valve in a high-pressure common rail injector. The structure includes an injector body, which comprises a housing. A second intermediate cavity is formed at the center of the housing cavity, and a reinforcing mechanism is connected to the bottom of the second intermediate cavity. A second annular cavity is concentrically arranged around the second intermediate cavity. An oil delivery mechanism is disposed within the second annular cavity, and its output end is connected to the second intermediate cavity. An oil discharge mechanism is connected to the bottom of the reinforcing mechanism, and a needle valve mechanism is disposed within the second intermediate cavity. The reinforcing mechanism is used to control the sealing between the oil discharge mechanism and the second middle cavity, the needle valve mechanism is used to control whether oil is delivered, the oil discharge mechanism is used to control the amount of oil injected, and the oil delivery mechanism is used to deliver oil evenly into the second middle cavity to ensure that the pressure in the second middle cavity is balanced.

[0006] Furthermore, the oil delivery mechanism includes a spiral oil delivery pipe, which has a spiral structure. The input end of the spiral oil delivery pipe is connected to an oil inlet pipe, and the input end of the oil inlet pipe is connected to the main oil inlet. Several component oil pipes are arranged at equal intervals on the spiral oil delivery pipe, the same number as the number of oil inlets in the central cavity. The output end of each component oil pipe is connected to a corresponding set of oil inlets in the central cavity.

[0007] Furthermore, the strengthening mechanism includes a strengthening channel with openings at the center of both the upper and lower ends; a third spring abuts against the inner wall of the top of the strengthening channel, and a pressing plate is fixedly installed at the bottom of the third spring. The pressing plate is fixedly sleeved on the rod of the needle valve mechanism located inside the strengthening channel.

[0008] Furthermore, the needle valve mechanism includes an upper needle valve rod, a second spring is fixedly installed on the top of the upper needle valve rod, and the top of the second spring abuts against the top inner wall of the second middle cavity; a middle adjusting rod is fixedly installed on the bottom of the upper needle valve rod, a needle valve head is fixedly installed on the bottom of the middle adjusting rod, and the bottom of the needle valve head extends into the oil discharge mechanism cavity and is fixedly sleeved with an oil-blocking sealing ring.

[0009] Furthermore, the top of the middle adjusting rod is located inside the reinforcing channel, and the bottom extends below the reinforcing channel; the diameter of the middle adjusting rod is smaller than that of the upper needle valve rod and the top opening of the reinforcing channel, and the diameter of the upper needle valve rod is larger than that of the top opening of the reinforcing channel; a sealing limiting rod is fixedly installed at the joint of the middle adjusting rod and the upper needle valve rod, and the outer wall of the sealing limiting rod is in contact with the inner wall of the top opening of the reinforcing channel.

[0010] Furthermore, the oil discharge mechanism includes an oil discharge channel that connects to the bottom of the second cavity. The sidewall of the oil discharge channel has a first oil discharge path, a second oil discharge path, and a third oil discharge path arranged at equal intervals from bottom to top. The paths of the first oil discharge path, the second oil discharge path, and the third oil discharge path are all fan-shaped structures.

[0011] Furthermore, a starting unit is fixedly installed at the end of the injector body away from the oil discharge mechanism. The starting unit includes a top cover, a first middle cavity is opened at the center of the top cover cavity, and a first annular cavity is concentrically arranged around the first middle cavity. A buffer cavity is connected at the bottom center of the first middle cavity, and a through groove is connected at the bottom center of the buffer cavity.

[0012] Furthermore, the bottom of the through groove is connected to a plunger cavity; the central axes of the first central cavity, the plunger cavity, the through groove, and the buffer cavity all coincide with the central axis of the top cover; one end of the upper oil passage is connected to the center of the bottom of the plunger cavity, and the other end of the upper oil passage is connected to the cavity of the injector body.

[0013] Furthermore, an injection unit is fixedly installed at the end of the injector body away from the starting unit. The injection unit includes an injection head, and an oil storage chamber is provided at the center of the injection head. A first oil receiving passage, a second oil receiving passage, and a third oil receiving passage are arranged at equal intervals from top to bottom on the side wall of the oil storage chamber. The tops of the first oil receiving passage, the second oil receiving passage, and the third oil receiving passage are all connected to the output end of the oil discharge mechanism.

[0014] Furthermore, a central fuel injection port is vertically connected at the bottom center of the oil storage chamber. Several sets of first side fuel injection ports are arranged in a ring array around the central fuel injection port. Several sets of second side fuel injection ports are arranged in a ring array around the first side fuel injection ports with the central axis of the central fuel injection port as the center. Both the first side fuel injection ports and the second side fuel injection ports are inclined.

[0015] The beneficial effects of this invention are: 1. During the overall upward movement of the needle valve mechanism, the rising of the needle valve head causes the sealing limit rod to disengage from the top opening of the reinforced channel, allowing oil in the second middle chamber to enter the oil discharge mechanism through the reinforced channel. Because the diameter of the middle adjusting rod is smaller than the top opening of the reinforced channel, and the diameter of the upper needle valve rod is larger than the top opening of the reinforced channel, the needle valve head can prevent excessive instantaneous oil flow into the oil discharge mechanism from the bottom, thus controlling the oil discharge flow. When the upper needle valve rod falls back, it compresses the sealing limit rod, ensuring it remains accurately locked at the top opening of the reinforced channel regardless of usage time. This avoids the oil leakage problems that occur with traditional sealing rings after prolonged use, thereby enhancing the sealing effect of the needle valve.

[0016] 2. The spiral oil supply pipe has a spiral structure, and the oil inlets of each group of intermediate chambers are arranged along the spiral path, so that external oil can enter the second intermediate chamber evenly from different directions and heights. This prevents the second intermediate chamber under vacuum from experiencing instantaneous pressure imbalance due to traditional single-side single-point oil inlet, thereby protecting the injector body, reducing damage to it, and extending the service life of the device.

[0017] 3. When the plunger system rises, it creates a pressure differential, causing the needle valve mechanism to rise as a whole due to suction. This allows the oil-blocking seal rings to sequentially disengage from the first, second, and third oil discharge lines, enabling oil to enter the injection unit from each group of discharge lines. This ensures the sustainability and stability of the fuel injection process, preventing damage to the injection unit due to excessive instantaneous fuel volume. Furthermore, the rising amplitude of the needle valve mechanism can be adjusted by controlling the energizing time, thereby controlling the number of opening oil discharge lines. This not only extends the injection time and improves the injection effect but also allows for the regulation of the flow rate.

[0018] 4. By discharging through a high-voltage coil and utilizing electromagnetic attraction, a pathway can be instantly established between the upper oil circuit and the injector body. Under the influence of pressure differential, the needle valve system rises, thus completing the injection operation. As the pressure differential gradually reaches equilibrium, the plunger body gradually descends, and oil is gradually discharged. When the sealing head re-engages with the upper oil circuit, the oil is completely drained. This automates the entire oil inlet and outlet process, eliminating the need for manual discharge and improving the ease of use of the injector.

[0019] 5. Since the first and second side injection ports of each group of ring arrays are set at an angle, they cooperate with the central injection port to form a radial injection angle, which ensures the balance of injection and avoids the problem of excessive pressure difference caused by a single injection port.

[0020] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A cross-sectional schematic diagram of an injector according to an embodiment of the present invention is shown.

[0023] Figure 2 A cross-sectional schematic diagram of the start-up unit according to an embodiment of the present invention is shown.

[0024] Figure 3 A cross-sectional schematic diagram of the top cover according to an embodiment of the present invention is shown.

[0025] Figure 4 A schematic diagram of a plunger system according to an embodiment of the present invention is shown.

[0026] Figure 5 A cross-sectional schematic diagram of the injector body according to an embodiment of the present invention is shown.

[0027] Figure 6 A cross-sectional schematic diagram of the housing according to an embodiment of the present invention is shown.

[0028] Figure 7 A schematic diagram of the oil delivery mechanism according to an embodiment of the present invention is shown.

[0029] Figure 8 A schematic diagram of the reinforcing mechanism according to an embodiment of the present invention is shown.

[0030] Figure 9 A schematic diagram of the needle valve mechanism according to an embodiment of the present invention is shown.

[0031] Figure 10 A cross-sectional schematic diagram of an oil discharge mechanism according to an embodiment of the present invention is shown.

[0032] Figure 11 A cross-sectional schematic diagram of an injection unit according to an embodiment of the present invention is shown.

[0033] In the diagram: 100, starting unit; 110, top cover; 111, first annular cavity; 112, first intermediate cavity; 113, plunger cavity; 114, central groove; 115, buffer cavity; 120, high-voltage coil; 130, drain port; 140, plunger system; 141, middle rod; 142, first top plate; 143, first fixed plate; 144, first spring; 145, plunger body; 146, sealing head; 150, upper oil passage; 160, oil inlet passage; 170, oil outlet passage; 200, injector body; 210, housing; 211, second annular cavity; 212, second intermediate cavity; 213, intermediate cavity oil inlet; 214, main oil inlet; 220, oil delivery mechanism; 221, spiral oil delivery pipe; 222, oil inlet. 223. Oil distribution pipe; 230. Needle valve mechanism; 231. Upper needle valve rod; 232. Second spring; 233. Middle adjusting rod; 234. Sealing limit rod; 235. Needle valve head; 236. Oil baffle sealing ring; 240. Oil discharge mechanism; 241. Oil discharge channel; 242. First oil discharge path; 243. Second oil discharge path; 244. Third oil discharge path; 250. Reinforcing mechanism; 251. Reinforcing channel; 252. Third spring; 253. Extrusion plate; 300. Injection unit; 310. Injector head; 311. Oil storage chamber; 320. First oil receiving path; 321. Second oil receiving path; 322. Third oil receiving path; 330. Middle injection port; 340. First side injection port; 350. Second side injection port. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] This invention provides a structure for enhancing the sealing performance of a needle valve in a high-pressure common rail injector. For example,... Figure 1 As shown, it includes an injector body 200, and a starting unit 100 is fixedly installed at one end of the injector body 200. The inner cavity of the injector body 200 is connected to the inner cavity of the starting unit 100.

[0036] For example, an injection unit 300 is fixedly installed at one end of the injector body 200 away from the starting unit 100, and the inner cavity of the injection unit 300 is in communication with the inner cavity of the injector body 200.

[0037] For example, such as Figure 2 and Figure 3 As shown, the starting unit 100 includes a top cover 110. A first central cavity 112 is formed at the center of the top cover 110 cavity, and a first annular cavity 111 is concentrically arranged around the first central cavity 112. A buffer cavity 115 is connected to the bottom center of the first central cavity 112, and a central through groove 114 is connected to the bottom center of the buffer cavity 115. A plunger cavity 113 is connected to the bottom of the central through groove 114. The central axes of the first central cavity 112, the plunger cavity 113, the central through groove 114, and the buffer cavity 115 all coincide with the central axis of the top cover 110. One end of an upper oil passage 150 is connected to the bottom center of the plunger cavity 113, and the other end of the upper oil passage 150 is connected to the cavity of the injector body 200.

[0038] For example, one side of the plunger cavity 113 is connected to one end of the oil inlet passage 160, and the other end of the oil inlet passage 160 is connected to the cavity of the injector body 200. The side of the plunger cavity 113 away from the upper oil passage 150 is connected to the oil outlet passage 170, and the other end of the oil outlet passage 170 is connected to the drain port 130, the output end of the drain port extending to the outside of the top cover 110.

[0039] For example, a plurality of high-voltage coils 120 are arranged in a ring array within the first annular cavity 111, and a plunger system 140 is provided within the central through groove 114, with both ends of the plunger system 140 extending into the buffer cavity 115 and the upper oil passage 150, respectively. An electromagnetic block is provided within the first central cavity 112, and the high-voltage coils 120 and the electromagnetic block are electrically connected.

[0040] For example, such as Figure 4As shown, the plunger system 140 includes a central rod 141 and a first top plate 142. The first top plate 142 is fixedly installed on the inner wall of the top of the buffer cavity 115. The central rod 141 is located in the central groove 114, and the top of the central rod 141 extends through the first top plate 142 and is fixedly installed with a magnetic block. The magnetic block and the electromagnetic block are magnetically connected. A first fixing plate 143 is fixedly sleeved on one end of the central rod 141 in the buffer cavity 115. The top of the first fixing plate 143 abuts against a first spring 144, and the top of the first spring 144 abuts against the first top plate 142. The bottom of the central rod 141 extends into the plunger cavity 113 and is fixedly installed with a plunger body 145. A sealing head 146 is installed at the bottom of the plunger body 145. The bottom of the sealing head 146 extends movably into the upper oil passage 150, and its outer walls are tightly fitted with the inner walls of the upper oil passage 150.

[0041] When the high-voltage coil 120 is not working, the electromagnetic block has no attraction, and the sealing head 146 is located in the upper oil passage 150, which isolates the plunger cavity 113 from the injector body 200, with external oil located in the inlet passage 160. When injection is required, the high-voltage coil 120 is activated to energize the electromagnetic block, generating electromagnetic attraction between the electromagnetic block and the magnetic block, which lifts the plunger system 140 as a whole, connecting the plunger cavity 113 and the injector body 200. Since the injector body 200 contains oil, the instantaneous pressure difference lifts the needle valve system, allowing the oil in the injector body 200 to enter the injection unit 300, thus enabling injection. Oil also enters the plunger cavity 113. When the plunger cavity 113 is full of oil, the pressure difference returns to zero, the needle valve system resets, and injection stops. After the oil injection is completed, the oil in the plunger chamber 113 is discharged through the oil outlet 170 and the oil drain port 130.

[0042] By discharging through the high-voltage coil 120 and using electromagnetic attraction, a passage can be instantly formed between the upper oil passage 150 and the injector body 200. Under the action of pressure difference, the needle valve system rises, thus completing the fuel injection operation. As the pressure difference gradually approaches equilibrium, the plunger body 145 gradually descends, and the oil is gradually discharged. When the sealing head 146 re-contacts the upper oil passage 150, the oil is completely drained. This automates the entire fuel inlet and outlet process, eliminating the need for manual discharge and improving the ease of use of the injector.

[0043] For example, such as Figure 5 and Figure 6As shown, the injector body 200 includes a housing 210. A second central cavity 212 is formed at the center of the housing 210. Several sets of central cavity oil inlets 213 are arranged at equal intervals along a spiral path on the side wall of the second central cavity 212. The top of the second central cavity 212 is connected to the upper oil passage 150, and the bottom of the second central cavity 212 is connected to a reinforcing mechanism 250. A second annular cavity 211 is concentrically arranged around the second central cavity 212. A main oil inlet 214 is provided at the top edge of one side of the second annular cavity 211, and the input end of the oil passage 160 is connected to the main oil inlet 214. An oil delivery mechanism 220 is provided inside the second annular cavity 211. The input end of the oil delivery mechanism 220 is connected to the main oil inlet 214, and the output end of the oil delivery mechanism 220 is connected to each set of central cavity oil inlets 213. The bottom of the reinforcing mechanism 250 is connected to an oil discharge mechanism 240, and the output end of the oil discharge mechanism 240 is connected to the cavity of the injection unit 300. A needle valve mechanism 230 is provided in the second middle cavity 212.

[0044] For example, such as Figure 7 As shown, the oil delivery mechanism 220 includes a spiral oil delivery pipe 221, which has a spiral structure. The input end of the spiral oil delivery pipe 221 is connected to an oil inlet pipe 222, and the input end of the oil inlet pipe 222 is connected to the main oil inlet 214. Several component oil pipes 223, the same number as the number of central cavity oil inlets 213, are arranged at equal intervals on the spiral oil delivery pipe 221. The output end of each group of component oil pipes 223 is connected to a corresponding group of central cavity oil inlets 213.

[0045] For example, such as Figure 8 As shown, the strengthening mechanism 250 includes a strengthening channel 251, with openings at the center of both its upper and lower ends. A third spring 252 abuts against the inner wall of the top of the strengthening channel 251, and a pressing plate 253 is fixedly installed at the bottom of the third spring 252. The pressing plate 253 is fixedly sleeved on one end of the rod of the needle valve mechanism 230 located inside the strengthening channel 251.

[0046] For example, such as Figure 9 As shown, the needle valve mechanism 230 includes an upper needle valve rod 231. A second spring 232 is fixedly installed on the top of the upper needle valve rod 231, and the top of the second spring 232 abuts against the top inner wall of the second middle cavity 212. A middle adjusting rod 233 is fixedly installed on the bottom of the upper needle valve rod 231, and a needle valve head 235 is fixedly installed on the bottom of the middle adjusting rod 233. The bottom of the needle valve head 235 extends into the cavity of the oil discharge mechanism 240 and is fixedly fitted with an oil-blocking sealing ring 236.

[0047] Specifically, the top of the adjusting rod 233 is located within the reinforcing channel 251, and its bottom extends below the reinforcing channel 251. The diameter of the adjusting rod 233 is smaller than that of the upper needle valve rod 231 and the top opening of the reinforcing channel 251, while the diameter of the upper needle valve rod 231 is larger than that of the top opening of the reinforcing channel 251. A sealing limiting rod 234 is fixedly installed at the joint between the adjusting rod 233 and the upper needle valve rod 231, and the outer wall of the sealing limiting rod 234 moves in contact with the inner wall of the top opening of the reinforcing channel 251.

[0048] For example, such as Figure 10 As shown, the oil discharge mechanism 240 includes an oil discharge channel 241, which is connected to the bottom of the second cavity 212. The sidewall of the oil discharge channel 241 has a first oil discharge path 242, a second oil discharge path 243 and a third oil discharge path 244 arranged at equal intervals from bottom to top. The paths of the first oil discharge path 242, the second oil discharge path 243 and the third oil discharge path 244 are all fan-shaped structures, and their output ends are all connected to the cavity of the injection unit 300.

[0049] Preferably, the oil discharge mechanism 240 may further include multiple sets of oil discharge paths; three sets are selected as a preferred embodiment here.

[0050] External oil enters the second intermediate cavity 212 evenly from different directions and heights through the main oil inlet 214, the spiral oil delivery pipe 221, and the branch oil pipe 223. This prevents the second intermediate cavity 212 under vacuum from experiencing instantaneous pressure imbalance due to traditional single-sided, single-point oil inlet, thus protecting the injector body 200, reducing damage, and extending the device's service life. When the plunger system 140 rises, creating a pressure difference, the needle valve mechanism 230 rises as a whole due to suction, allowing the oil-blocking sealing rings 236 to sequentially disengage from the first oil discharge passage 242, the second oil discharge passage 243, and the third oil discharge passage 244. This allows oil to enter the injection unit 300 from each set of oil discharge passages, ensuring the sustainability and stability of the injection operation. This prevents damage to the injection unit 300 due to excessive instantaneous oil volume, extends the injection time, and improves the injection effect.

[0051] During the overall upward movement of the needle valve mechanism 230, the rising of the needle valve head 235 causes the sealing limit rod 234 to disengage from the top opening of the reinforced channel 251, allowing oil in the second middle cavity 212 to enter the reinforced channel 251 and then flow into the oil discharge mechanism 240. Because the diameter of the middle adjusting rod 233 is smaller than that of the upper needle valve rod 231 and the top opening of the reinforced channel 251, and the diameter of the upper needle valve rod 231 is larger than that of the top opening of the reinforced channel 251, the needle valve head 235 can prevent excessive instantaneous oil flow into the oil discharge mechanism 240 during oil discharge. When the upper needle valve rod 231 falls back, it compresses the sealing limit rod 234, ensuring that it remains accurately locked at the top opening of the reinforced channel 251 regardless of usage time, thus preventing oil leakage problems that occur after prolonged use of traditional sealing rings and enhancing the sealing effect of the needle valve.

[0052] For example, such as Figure 11 As shown, the injection unit 300 includes an injection head 310, and an oil storage chamber 311 is provided at the center of the injection head 310. A first oil inlet passage 320, a second oil inlet passage 321, and a third oil inlet passage 322 are arranged at equal intervals from top to bottom on the side wall of the oil storage chamber 311. The tops of the first oil inlet passage 320, the second oil inlet passage 321, and the third oil inlet passage 322 are respectively connected to the output ends of the first oil outlet passage 242, the second oil outlet passage 243, and the third oil outlet passage 244.

[0053] For example, the oil storage cavity 311 has a central oil injection port 330 connected vertically at the bottom center. Several sets of first side oil injection ports 340 are arranged in a ring around the central oil injection port 330. Several sets of second side oil injection ports 350 are arranged in a ring around the central axis of the central oil injection port 330. Both the first side oil injection ports 340 and the second side oil injection ports 350 are inclined.

[0054] Since the first side injection port 340 and the second side injection port 350 of each group of ring arrays are inclined, they cooperate with the middle injection port 330 to form a radial injection angle, which ensures the balance of injection and avoids the problem of excessive pressure difference caused by a single port.

[0055] The above embodiments have the following beneficial effects: 1. During the overall upward movement of the needle valve mechanism 230, the rising of the needle valve head 235 causes the sealing limit rod 234 to disengage from the top opening of the reinforced channel 251, allowing oil in the second middle chamber 212 to enter the oil discharge mechanism 240 via the reinforced channel 251. Since the diameter of the middle adjusting rod 233 is smaller than the top opening of the reinforced channel 251, and the diameter of the upper needle valve rod 231 is larger than the top opening of the reinforced channel 251, the needle valve head 235 can prevent excessive instantaneous oil flow into the oil discharge mechanism 240 from the bottom, thus controlling the oil discharge flow. When the upper needle valve rod 231 falls back, it can compress the sealing limit rod 234, ensuring it remains accurately locked at the top opening of the reinforced channel 251 regardless of usage time, preventing oil leakage problems that occur after prolonged use of traditional sealing rings, thereby enhancing the sealing effect of the needle valve.

[0056] 2. The spiral oil supply pipe 221 has a spiral structure, and the oil inlets 213 of each group of intermediate chambers are arranged along a spiral path, so that external oil can enter the second intermediate chamber 212 evenly from different directions and heights. This prevents the second intermediate chamber 212 under vacuum from experiencing instantaneous pressure imbalance due to traditional single-side single-point oil inlet, thereby protecting the injector body 200, reducing the damage to it, and extending the service life of the device.

[0057] 3. When the plunger system 140 rises, it creates a pressure difference, causing the needle valve mechanism 230 to rise as a whole due to suction. This allows the oil-blocking sealing ring 236 to sequentially disengage from the first oil discharge passage 242, the second oil discharge passage 243, and the third oil discharge passage 244, allowing oil to enter the injection unit 300 from each group of oil discharge passages. This ensures the sustainability and stability of the oil injection operation, preventing damage to the injection unit 300 due to excessive instantaneous oil volume. At the same time, the rising amplitude of the needle valve mechanism 230 can be adjusted by controlling the energizing time, thereby controlling the number of opening oil discharge passages. This not only extends the injection time and improves the injection effect but also achieves the function of adjusting the flow rate.

[0058] 4. By discharging through the high-voltage coil 120 and using electromagnetic attraction, a passage can be instantly formed between the upper oil passage 150 and the injector body 200. Under the action of pressure difference, the needle valve system rises, thus completing the fuel injection operation. As the pressure difference gradually approaches equilibrium, the plunger body 145 gradually descends, and the oil is gradually discharged. When the sealing head 146 re-contacts the upper oil passage 150, the oil is completely drained. This automates the entire fuel inlet and outlet process, eliminating the need for manual discharge and improving the ease of use of the injector.

[0059] 5. Since the first side injection port 340 and the second side injection port 350 of each group of ring arrays are set at an angle, they cooperate with the middle injection port 330 to form a radial injection angle, which ensures the balance of injection and avoids the problem of excessive pressure difference caused by a single port.

[0060] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A structure for enhancing the sealing performance of a needle valve in a high-pressure common rail injector, comprising an injector body (200), characterized in that: The injector body (200) includes a housing (210), a second intermediate cavity (212) is provided at the center of the housing (210), and a reinforcing mechanism (250) is connected to the bottom of the second intermediate cavity (212); a second annular cavity (211) is concentrically arranged around the second intermediate cavity (212); an oil delivery mechanism (220) is provided in the second annular cavity (211), and the output end of the oil delivery mechanism (220) is connected to the second intermediate cavity (212); an oil discharge mechanism (240) is connected to the bottom of the reinforcing mechanism (250), and a needle valve mechanism (230) is provided in the second intermediate cavity (212); The reinforcing mechanism (250) is used to control the sealing between the oil discharge mechanism (240) and the second middle cavity (212), the needle valve mechanism (230) is used to control whether oil is delivered, the oil discharge mechanism (240) is used to control the amount of oil injected, and the oil delivery mechanism (220) is used to deliver oil evenly into the second middle cavity (212) to ensure that the pressure in the second middle cavity (212) is balanced.

2. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 1, characterized in that: The oil delivery mechanism (220) includes a spiral oil delivery pipe (221), which has a spiral structure. The input end of the spiral oil delivery pipe (221) is connected to an oil inlet pipe (222), and the input end of the oil inlet pipe (222) is connected to the main oil inlet (214). Several component oil pipes (223) are arranged at equal intervals on the spiral oil delivery pipe (221), the same number as the number of central cavity oil inlets (213). The output end of each component oil pipe (223) is connected to the corresponding group of central cavity oil inlets (213).

3. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 1, characterized in that: The strengthening mechanism (250) includes a strengthening channel (251), which has openings at the center of both the upper and lower ends; a third spring (252) is abutting against the inner wall of the top of the strengthening channel (251), and a pressing plate (253) is fixedly installed at the bottom of the third spring (252). The pressing plate (253) is fixedly sleeved on one end of the rod of the needle valve mechanism (230) located in the strengthening channel (251).

4. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 3, characterized in that: The needle valve mechanism (230) includes an upper needle valve rod (231), a second spring (232) is fixedly installed on the top of the upper needle valve rod (231), and the top of the second spring (232) abuts against the top inner wall of the second middle cavity (212); a middle adjusting rod (233) is fixedly installed on the bottom of the upper needle valve rod (231), and a needle valve head (235) is fixedly installed on the bottom of the middle adjusting rod (233). The bottom of the needle valve head (235) extends into the cavity of the oil discharge mechanism (240) and is fixedly fitted with an oil-blocking sealing ring (236).

5. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 4, characterized in that: The top of the middle adjusting rod (233) is located inside the reinforcing channel (251), and the bottom extends below the reinforcing channel (251); the diameter of the middle adjusting rod (233) is smaller than the top opening of the upper needle valve rod (231) and the reinforcing channel (251), and the diameter of the upper needle valve rod (231) is larger than the top opening of the reinforcing channel (251); a sealing limiting rod (234) is fixedly installed at the joint of the middle adjusting rod (233) and the upper needle valve rod (231), and the outer wall of the sealing limiting rod (234) moves against the inner wall of the top opening of the reinforcing channel (251).

6. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 1, characterized in that: The oil discharge mechanism (240) includes an oil discharge channel (241) that connects to the bottom of the second cavity (212). The sidewall of the oil discharge channel (241) is provided with a first oil discharge path (242), a second oil discharge path (243), and a third oil discharge path (244) arranged at equal intervals from bottom to top. The paths of the first oil discharge path (242), the second oil discharge path (243), and the third oil discharge path (244) are all fan-shaped structures.

7. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 1, characterized in that: A starting unit (100) is fixedly installed at the end of the injector body (200) away from the oil discharge mechanism (240). The starting unit (100) includes a top cover (110). A first middle cavity (112) is opened at the center of the cavity of the top cover (110). A first annular cavity (111) is concentrically arranged around the first middle cavity (112). A buffer cavity (115) is connected at the bottom center of the first middle cavity (112). A central groove (114) is connected at the bottom center of the buffer cavity (115).

8. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 7, characterized in that: The bottom of the through groove (114) is connected to the plunger cavity (113); the central axis of the first central cavity (112), the plunger cavity (113), the through groove (114), and the buffer cavity (115) all coincide with the central axis of the top cover (110); one end of the upper oil passage (150) is connected to the center of the bottom of the plunger cavity (113), and the other end of the upper oil passage (150) is connected to the cavity of the injector body (200).

9. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 1, characterized in that: The injector body (200) is fixedly installed with an injection unit (300) at one end away from the starting unit (100). The injection unit (300) includes an injection head (310). An oil storage chamber (311) is provided at the center of the injection head (310). A first oil receiving passage (320), a second oil receiving passage (321), and a third oil receiving passage (322) are arranged at equal intervals from top to bottom on the side wall of the oil storage chamber (311). The tops of the first oil receiving passage (320), the second oil receiving passage (321), and the third oil receiving passage (322) are all connected to the output end of the oil discharge mechanism (240).

10. The structure for enhancing the sealing performance of a high-pressure common rail injector needle valve according to claim 9, characterized in that: The oil storage chamber (311) is connected to a central oil injection port (330) in a vertical direction at the bottom center. Several sets of first side oil injection ports (340) are arranged in a ring around the central oil injection port (330). Several sets of second side oil injection ports (350) are arranged in a ring around the central axis of the central oil injection port (330). Both the first side oil injection port (340) and the second side oil injection port (350) are inclined.

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