A high-response, low-return injector based on a two-position three-way valve

Abstract

The purpose of this invention is to provide a high-response, low-return injector based on a two-position three-way valve, belonging to the field of engine technology. It includes a fastening cap, a two-position three-way solenoid valve module, an injector body, and a nozzle. The injector body has a needle valve and a fuel injection channel. A control chamber is formed between the top of the needle valve and the two-position three-way solenoid valve. An injection orifice is opened at the lower end of the nozzle. The two-position three-way solenoid valve module consists of a ball valve and a cone valve, connected by a transmission spring. It utilizes the advantages of the ball valve (good dynamic sealing and self-centering) and the cone valve (suitable for high-flow sealing), allowing for independent inlet and outlet processes in the control chamber to reduce return flow and accelerate needle valve opening. Compared to a two-position three-way valve with a double cone valve design, it requires lower machining precision. Furthermore, this invention is equipped with a large-sized control chamber throttling orifice and return orifice to further improve the injector's opening and closing response, making it suitable for engines or industrial equipment requiring rapid start / stop and precise flow control.

Description

Technical Field

[0001] The present invention relates to an engine, specifically an engine fuel injector. Background Technology

[0002] With increasing environmental regulations and the introduction of carbon peaking and carbon neutrality goals, fuel injection systems need further optimization to improve engine efficiency and reduce emissions. The fuel injection return rate and response speed are crucial indicators of fuel injection system efficiency and performance, directly impacting engine combustion efficiency, power output, emissions levels, and control precision. Furthermore, the high response speed of the fuel injector is fundamental to achieving certain advanced combustion modes. Traditional electronic fuel injectors often use a two-position, two-way ball valve as the control valve. This type of control valve experiences continuous high-pressure fuel entering the control chamber during return, increasing the return rate and extending the needle valve opening response time. Moreover, to ensure proper needle valve opening, the inlet orifice diameter needs to be smaller than the return orifice diameter, thus limiting the improvement in needle valve closing response. Summary of the Invention

[0003] The purpose of this invention is to provide a high-response, low-return injector based on a two-position three-way valve, where the inlet and return oil processes are performed independently.

[0004] The objective of this invention is achieved as follows: This invention discloses a high-response, low-return injector based on a two-position three-way valve, characterized by comprising a two-position three-way solenoid valve module, an injector body, and a nozzle arranged from top to bottom. The two-position three-way solenoid valve module is fixed to the injector body by a fastening cap, which has an oil inlet and an oil return port respectively. The injector body and the nozzle are fixed by a fastening block. The injector body contains a needle valve and an injection fuel channel. A control chamber is formed between the top of the needle valve, the two-position three-way solenoid valve module, and the injector body. A protrusion is provided in the middle of the needle valve, and a needle valve return spring is fitted on the needle valve. The two ends of the needle valve return spring are the injector body and the protrusion, respectively. An oil reservoir is formed between the needle valve and the nozzle below the protrusion, and the oil reservoir is connected to the injection fuel channel. The nozzle contains a spray hole.

[0005] The present invention may also include: 1. The two-position three-way solenoid valve module includes a ball valve seat, a cone valve seat, and a solenoid valve seat. The cone valve seat and the solenoid valve seat form a main oil inlet passage, which is connected to the fuel injection channel. A ball valve and a cone valve are horizontally arranged in the cone valve seat. The ball valve and the cone valve are connected by a transmission spring. A ball valve return spring and a return oil throttling orifice are provided in the ball valve seat. The ball valve cooperates with the ball valve seat, the ball valve return spring, and the return oil throttling orifice. The return oil throttling orifice is connected to the return oil port. A return oil guide hole is provided at the outer end of the ball valve. An oil inlet guide hole is provided at the outer end of the cone valve. A cone valve return spring is sleeved on the cone valve. The cone valve return spring is located between the outer ring of the cone valve and the cone valve seat. The middle part of the cone valve cooperates with the cone valve seat. A control chamber throttling orifice is opened on the cone valve seat. The control chamber throttling orifice is located between the outer ring of the ball valve and the outer ring of the cone valve and communicates with the control chamber. An armature and an electromagnet are horizontally arranged in the solenoid valve seat. A coil is installed in the electromagnet. The end of the cone valve is connected to the armature.

[0006] 2. When the ball valve and the ball valve seat are in a sealing fit, the ball valve compresses the ball valve return spring and blocks the return oil throttle hole. At this time, the middle part of the cone valve does not contact the cone valve seat. When the middle part of the cone valve and the cone valve seat are in a sealing fit, the middle part of the cone valve is attached to the cone valve seat. At this time, the ball valve and the ball valve seat do not contact each other.

[0007] 3. During the injection phase, the coil is energized, the electromagnet attracts the armature, and the armature drives the cone valve to sit on the cone valve seat, forming a line seal. The ball valve leaves the ball valve seat under the combined action of the transmission spring and the ball valve return spring. The high-pressure fuel in the control chamber returns through the control chamber throttle orifice, return oil guide orifice, return oil throttle orifice and return oil port, and the pressure in the control chamber decreases until the hydraulic pressure at the lower end of the needle valve is greater than the sum of the hydraulic pressure in the control chamber and the elastic force of the needle valve return spring. The needle valve opens, and the high-pressure fuel is injected from the injection hole.

[0008] 4. During the injection stop phase, the coil is de-energized, the electromagnet no longer attracts the armature, and the cone valve moves away from the cone valve seat under the action of the cone valve return spring. At the same time, the ball valve moves through the transmission spring, overcoming the spring force of the ball valve return spring. The ball valve sits on the ball valve seat, forming a line seal. High-pressure fuel enters the control chamber through the inlet, main inlet passage, inlet guide hole, and control chamber throttling hole. The pressure in the control chamber continuously increases until the needle valve sits on the nozzle under the combined action of the needle valve return spring preload and hydraulic force, and the high-pressure fuel injection stops.

[0009] 5. Both the control cavity throttling orifice and the return oil throttling orifice are large-sized throttling orifices.

[0010] The advantages of this invention are: 1. The valve core of the two-position three-way solenoid valve of the present invention is completely immersed in oil, which has pressure balance characteristics and enables the valve core to have the ability to move at high speed.

[0011] 2. When the injector returns oil, the ball valve opens and the cone valve sits and seals, preventing oil from entering the control chamber; when the injector enters oil, the cone valve opens and the ball valve sits and seals, preventing oil from returning to the control chamber; the oil entry and return processes of the control chamber are carried out independently, which can significantly reduce the amount of oil returning, reduce the waste of high-pressure fuel, and accelerate the opening of the needle valve.

[0012] 3. The oil inlet and outlet processes of the control chamber are carried out independently. The oil return speed can be accelerated by increasing the diameter of the oil return throttle orifice without increasing the oil return volume. Furthermore, the oil inlet of the control chamber can be accelerated by increasing the diameter of the control chamber throttle orifice, thereby improving the closing response of the needle valve without causing the needle valve to fail to open normally.

[0013] 4. The two-position three-way solenoid valve, which combines a ball valve and a cone valve, can fully utilize the advantages of ball valves, such as simple structure, self-centering, and good dynamic sealing, as well as the suitability of cone valves for high-flow sealing. Furthermore, the control valve and the ball valve are connected by a spring, which effectively prevents the cone valve from shifting when the ball valve is self-centering, ensuring the sealing performance when the cone valve is seated. Compared with the two-position three-way solenoid valve with a double cone valve, it has lower processing precision requirements and less complexity in manufacturing and assembly. Compared with the piezoelectric control type two-position three-way solenoid valve, it has a simpler process and lower cost. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the overall structure during the injection cessation phase; Figure 3 This is a schematic diagram of the two-position three-way solenoid valve module during the injection phase; Figure 4 This is a schematic diagram of the two-position three-way solenoid valve module during the injection stop phase. Figure 5 This is a schematic diagram of the fuel pressure distribution in the two-position three-way solenoid valve module during the injection phase. Figure 6 This is a schematic diagram of the fuel pressure distribution in a two-position three-way solenoid valve module during the injection stop phase.

[0015] The attached diagram is labeled as follows: 1. Fastening cap; 2. Oil inlet; 3. Two-position three-way solenoid valve module; 4. Oil return port; 5. Control chamber; 6. Injector body; 7. Injection fuel channel; 8. Fastening block; 9. Needle valve return spring; 10. Nozzle; 11. Needle valve; 12. Oil reservoir; 13. Spray hole; 3-1. Ball valve seat; 3-2. Ball valve return spring; 3-3. Transmission spring; 3-4. Cone valve; 3-5. Cone valve return spring; 3-6. Cone valve seat; 3-7. Main oil inlet channel; 3-8. Armature; 3-9. Electromagnet; 3-10. Coil; 3-11. Oil return throttle orifice; 3-12. Control chamber throttle orifice; 3-13. Oil return guide orifice; 3-14. Oil inlet guide orifice; 3-15. Detailed Implementation

[0016] The invention will now be described in more detail with reference to the accompanying drawings: Implementation method 1: Combination Figure 1-6 , Figure 1 As shown in the schematic diagram of the present invention, this embodiment includes, from top to bottom, a fastening cap 1, a two-position three-way solenoid valve module 3, an injector body 6, and a nozzle 10. The fastening cap 1 connects the two-position three-way solenoid valve module 3 and the injector body 6 along the axial direction. The fastening cap 1 has an axial oil inlet 2 at the top and a radial oil return port 4 on the side. The injector body 6 has a needle valve 11 and an injection fuel channel 7 inside. The top of the needle valve 11 and the two-position three-way solenoid valve module 3 form a control chamber 5. A needle valve return spring 9 is provided between the injector body 6 and the middle of the needle valve 11. The nozzle 10 and the injector body 6 are connected by a fastening block 8. The nozzle 10 has an oil collection tank 12 inside and a spray hole 13 at the lower end of the nozzle 10. High-pressure fuel can enter the oil collection tank 12 through the oil inlet 2, the two-position three-way solenoid valve module 3, and the injection fuel channel 7.

[0017] Implementation Method 2: Based on Implementation Method 1, Figure 3 This is a schematic diagram of the two-position three-way solenoid valve module during the injection phase. From left to right, it includes a ball valve seat 3-1, a ball valve 3-3, a cone valve 3-5, a cone valve seat 3-7, an armature 3-9, a coil 3-11, and an electromagnet 3-10. The ball valve seat is equipped with a return oil throttling hole 3-12 and a ball valve return spring 3-2. The ball valve 3-3 and cone valve 3-5 are respectively surrounded by a return oil guide hole 3-14 and an inlet oil guide hole 3-15. The ball valve 3-3 and cone valve 3-5... -5 is connected by a transmission spring 3-4. A cone valve return spring 3-6 is provided between the cone valve 3-5 and the cone valve seat 3-7. The lower side of the two-position three-way solenoid valve module is provided with a control chamber throttling orifice 3-13. The right side is provided with a main oil inlet channel 3-8 that runs through the entire two-position three-way solenoid valve. This structure design will allow the ball valve 3-3 to open when the cone valve 3-5 is sealed, and the cone valve 3-5 to open when the ball valve 3-3 is sealed, ensuring that the oil inlet and return processes of the control chamber 5 are carried out independently.

[0018] Implementation Method 3: Based on Implementation Method 1, a large-sized control chamber throttle orifice 3-13 and return oil throttle orifice 3-12 are provided to improve the opening and closing response of the injector.

[0019] Implementation Method 4: Based on Implementation Method 1, during the injection stage, coil 3-11 is energized, electromagnet 3-10 attracts armature 3-9, armature 3-9 drives cone valve 3-5 to sit on cone valve seat 3-7, forming a line seal, ball valve 3-3 leaves ball valve seat 3-1 under the combined action of transmission spring 3-4 and ball valve return spring 3-2; at this time, no high-pressure fuel flows into control chamber 5, and the high-pressure fuel in control chamber 5 will return through control chamber throttle orifice 3-13, return oil guide orifice 3-14, return oil throttle orifice 3-12 and return oil port 4, the pressure in control chamber 5 drops until the hydraulic pressure at the lower end of needle valve 11 is greater than the sum of hydraulic pressure in control chamber 5 and spring force of needle valve return spring 9, needle valve 11 opens, and high-pressure fuel is sprayed out from injection hole 13.

[0020] Implementation Method 5: Based on Implementation Method 1, during the injection stop phase, coil 3-11 is de-energized, electromagnet 3-10 no longer attracts armature 3-9, and cone valve 3-5 moves away from cone valve seat 3-7 under the action of cone valve return spring 3-6. At the same time, it drives ball valve 3-3 to move through transmission spring 3-4, overcoming the spring force of ball valve return spring 3-2, so that ball valve 3-3 sits on ball valve seat 3-1, forming a line seal. At this time, there is no more high-pressure fuel flowing out of control chamber 5, but high-pressure fuel will enter the control chamber through inlet 2, main inlet channel 3-8, inlet guide hole 3-15 and control chamber throttling hole 3-13, so that the pressure in control chamber 5 continues to rise until needle valve 11 sits on nozzle 10 under the combined action of needle valve return spring 9 and hydraulic force, and high-pressure fuel injection stops.

[0021] Combination Figure 3 and Figure 5 , Figure 5 This is a schematic diagram of the fuel pressure distribution in the two-position three-way solenoid valve module 3 during the injection phase. During the injection phase, the area of ​​cone valve 3-5 on the left side of the sealing line of ball valve 3-3 and cone valve 3-5 is completely immersed in the low-pressure zone, the middle area of ​​cone valve 3-5 is immersed in the high-pressure zone, and the right side area of ​​cone valve 3-5 is immersed in the low-pressure zone. At this time, the hydraulic pressure to the left and the hydraulic pressure to the right borne by the valve core are basically equal, and the valve core achieves hydraulic balance. When coil 3-11 is de-energized, ball valve 3-3 will quickly sit and close, and cone valve 3-5 will quickly open.

[0022] Combination Figure 4 and Figure 6 , Figure 6This diagram illustrates the fuel pressure distribution in the two-position three-way solenoid valve module 3 during the injection stop phase. During the injection stop phase, the ball valve 3-3 to the left of the sealing line is in the low-pressure zone, while the rest of the ball valve 3-3 and most of the cone valve 3-5 are immersed in the high-pressure zone. The rightmost part of the cone valve 3-5 is in the low-pressure zone. At this time, the hydraulic pressure to the left and the hydraulic pressure to the right borne by the valve core are basically equal, and the valve core achieves hydraulic balance. When the coil 3-11 is energized, the ball valve 3-3 will open quickly, and the cone valve 3-5 will close quickly.

[0023] As described above, the present invention achieves independent control of the oil inlet and return processes of the control chamber through a two-position three-way solenoid valve in the form of a ball valve combined with a cone valve. Compared with the traditional two-position two-way solenoid valve in the form of a ball valve, this not only reduces the return oil volume and speeds up the opening of the needle valve 11, but also further improves the opening and closing response of the injector by increasing the size of the control chamber throttling orifice 3-13 and the return oil orifice 3-12. In addition, the valve core of the two-position three-way solenoid valve is completely immersed in oil, which has pressure balance characteristics and enables the valve core to have the ability to move at high speed.

Claims

1. A high-response, low-return injector based on a two-position three-way valve, characterized in that: The device includes a two-position three-way solenoid valve module, an injector body, and a nozzle arranged from top to bottom. The two-position three-way solenoid valve module is fixed to the injector body by a fastening cap, which has an oil inlet and an oil return port. The injector body and the nozzle are fixed by a fastening block. The injector body contains a needle valve and an injection fuel channel. The top of the needle valve forms a control chamber with the two-position three-way solenoid valve module and the injector body. A protrusion is provided in the middle of the needle valve, and a needle valve return spring is fitted on the needle valve. The two ends of the needle valve return spring are the injector body and the protrusion, respectively. An oil reservoir is formed between the needle valve and the nozzle below the protrusion. The oil reservoir is connected to the injection fuel channel. The nozzle has a spray hole.

2. The high-response, low-return injector based on a two-position three-way valve according to claim 1, characterized in that: The two-position three-way solenoid valve module includes a ball valve seat, a cone valve seat, and a solenoid valve seat. The cone valve seat and the solenoid valve seat form the main oil inlet passage, which connects to the fuel injection channel. A ball valve and a cone valve are horizontally arranged in the cone valve seat, and the ball valve and the cone valve are connected by a transmission spring. A ball valve return spring and a return oil throttling orifice are provided in the ball valve seat. The ball valve cooperates with the ball valve seat, the ball valve return spring, and the return oil throttling orifice. The return oil throttling orifice connects to the return oil port. A return oil guide hole is provided at the outer end of the ball valve, and an oil inlet guide hole is provided at the outer end of the cone valve. A cone valve return spring is fitted on the cone valve, located between the outer ring of the cone valve and the cone valve seat. The middle part of the cone valve cooperates with the cone valve seat. A control chamber throttling orifice is opened on the cone valve seat, located between the outer ring of the ball valve and the outer ring of the cone valve, and communicating with the control chamber. An armature and an electromagnet are horizontally arranged in the solenoid valve seat. A coil is installed in the electromagnet. The end of the cone valve is connected to the armature.

3. A high-response, low-return injector based on a two-position three-way valve according to claim 2, characterized in that: When the ball valve and the ball valve seat are in contact and sealing, the ball valve compresses the ball valve return spring and blocks the return oil throttle hole. At this time, the middle part of the cone valve does not contact the cone valve seat. When the middle part of the cone valve and the cone valve seat are in contact, the middle part of the cone valve is attached to the cone valve seat. At this time, the ball valve and the ball valve seat do not contact.

4. A high-response, low-return injector based on a two-position three-way valve according to claim 1, characterized in that: During the injection phase, the coil is energized, the electromagnet attracts the armature, and the armature drives the cone valve to sit on the cone valve seat, forming a line seal. The ball valve leaves the ball valve seat under the combined action of the transmission spring and the ball valve return spring. The high-pressure fuel in the control chamber returns through the control chamber throttle orifice, return oil guide orifice, return oil throttle orifice and return oil port, and the pressure in the control chamber decreases until the hydraulic pressure at the lower end of the needle valve is greater than the sum of the hydraulic pressure in the control chamber and the elastic force of the needle valve return spring. The needle valve opens, and the high-pressure fuel is injected from the injection hole.

5. A high-response, low-return injector based on a two-position three-way valve according to claim 1, characterized in that: in During the injection stop phase, the coil is de-energized, the electromagnet no longer attracts the armature, and the cone valve moves away from the cone valve seat under the action of the cone valve return spring. At the same time, the ball valve moves through the transmission spring, overcoming the spring force of the ball valve return spring. The ball valve sits on the ball valve seat, forming a line seal. High-pressure fuel enters the control chamber through the inlet, main inlet passage, inlet guide hole, and control chamber throttling hole. The pressure in the control chamber continuously increases until the needle valve sits on the nozzle under the combined action of the needle valve return spring preload and hydraulic force, and the high-pressure fuel injection stops.

6. A high-response, low-return injector based on a two-position three-way valve according to claim 1, characterized in that: Both the control chamber throttling orifice and the return oil throttling orifice are large-sized throttling orifices.

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