A piston type booster pump and a high-response variable injection law fuel injection system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HARBIN UNIV OF SCI & TECH
- Filing Date
- 2026-04-23
- Publication Date
- 2026-06-16
Smart Images
Figure CN122215980A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an engine, specifically a fuel injection system. Background Technology
[0002] Applying green fuels such as methanol and ammonia to internal combustion engines is one of the effective ways to achieve efficient, clean, and low-carbon combustion. Diesel ignition and direct injection of green fuels into the cylinder can effectively reduce emissions and improve thermal efficiency. However, due to the low calorific value and high latent heat of vaporization of green fuels, it is difficult to achieve efficient and stable combustion at high substitution rates. Variable injection patterns within the cycle are an effective measure to solve this problem; for example, boot-shaped injection can effectively improve combustion and reduce emissions. Summary of the Invention
[0003] The purpose of this invention is to provide a piston-type booster pump capable of variable injection and a high-response variable injection pattern fuel injection system.
[0004] The objective of this invention is achieved as follows: This invention discloses a piston-type booster pump, characterized by comprising a green fuel inlet block, a booster pump body, and a booster pump solenoid valve. The green fuel inlet block is fixed to the top of the booster pump body, and the booster pump solenoid valve is fixed to the side of the booster pump body. The green fuel inlet block is provided with a green fuel inlet. The booster pump body is provided with a booster pump diesel inlet, a booster pump return port, and a booster pump outlet. A booster piston is provided inside the booster pump body, with the upper part of the booster piston being the large end and the lower part being the small end. A booster pump check valve and an internal flow channel are provided inside the booster piston. The booster pump check valve is fixed to the booster piston. A control chamber is formed between the lower end face of the large end and the booster pump body, and a booster chamber is formed between the lower end face of the small end and the booster pump body. A first hole and a third hole are provided around the control chamber. A displacement sensor is installed in the first hole, the second hole cooperates with the booster pump solenoid valve so that when the booster pump solenoid valve is open, it connects the control chamber and the booster pump return port, and the third hole connects to the booster pump diesel inlet.
[0005] The piston-type booster pump of the present invention may further include: 1. An annular groove is provided at the connection between the large end and the small end. When the booster piston is in the initial position, the displacement sensor recognizes the feature groove.
[0006] 2. A pressure sensor is installed at the bottom of the booster pump body to detect the pressure inside the booster chamber. The pressure sensor is located vertically between the booster chamber and the booster pump outlet.
[0007] A high-response variable injection pattern fuel injection system is characterized by comprising an electronically controlled unit pump, an injector, a green fuel high-pressure rail, a diesel storage tank, a green fuel storage tank, and the aforementioned piston-type booster pump. The electronically controlled unit pump includes an electronically controlled unit pump solenoid valve, an electronically controlled unit pump inlet, and an electronically controlled unit pump return port. The injector includes an injection solenoid valve, an injector inlet, and an injector return port. Diesel fuel flows from the diesel storage tank to the electronically controlled unit pump inlet, enters the booster pump diesel inlet under the control of the electronically controlled unit pump solenoid valve, and then flows back to the diesel storage tank through the booster pump return port under the control of the booster pump solenoid valve. The electronically controlled unit pump return port is connected to the diesel storage tank. Green fuel in the green fuel high-pressure rail enters the piston-type booster pump through the green fuel inlet, and then enters the injector inlet through the booster pump outlet. It is injected under the control of the injector solenoid valve, and the injector return port is connected to the green fuel storage tank.
[0008] The present invention may also include: 1. The boosting pressure of the electronically controlled unit pump is greater than the pressure inside the high-pressure rail for green fuel.
[0009] 2. A check valve is installed between the electrically controlled unit pump and the piston booster pump.
[0010] 3. Install rail pressure sensors on the high-pressure rails for green fuel.
[0011] 4. It also includes an electronic control unit, which is connected to the solenoid valve of the electronically controlled unit pump, the solenoid valve of the booster pump, the pressure sensor, the displacement sensor, the rail pressure sensor, and the injection solenoid valve.
[0012] 5. When the piston-type booster pump is boosting, the electronic control unit (ECU) controls the booster pump solenoid valve to open and simultaneously controls the electronically controlled unit pump solenoid valve to close. Only fuel flows out of the booster pump control chamber, and no fuel flows in. The pressure in the booster pump control chamber decreases, and the booster piston moves down to boost pressure. When the booster piston returns to its original position, the ECU controls the booster pump solenoid valve to close and simultaneously controls the electronically controlled unit pump solenoid valve to open. The electronically controlled unit pump boosts pressure, and high-pressure fuel flows into the booster pump control chamber from the electronically controlled unit pump. The fuel pressure in the booster pump control chamber is greater than the green fuel pressure at the top of the booster piston, and the booster piston returns to its original position until the displacement sensor detects the feature groove. At this point, the ECU controls the electronically controlled unit pump solenoid valve to de-energize.
[0013] 6. In base pressure injection mode, the piston booster pump does not pressurize during the entire injection process; in boot-shaped injection mode, the piston booster pump pressurizes during the injection process and resets the booster piston after injection is completed; in boosted injection mode, the piston booster pump pressurizes before the injection begins and resets the booster piston after injection is completed.
[0014] The advantages of this invention are: 1. Use diesel fuel as the control oil for the piston booster pump to reduce the corrosion of the internal pipelines and solenoid valves of the piston booster pump caused by green fuel.
[0015] 2. Unlike conventional booster pump control chambers, where high-pressure fuel continuously enters during the return fuel process, this patented booster pump's solenoid valve opens for return fuel while the electronically controlled unit pump remains inactive. At this time, only fuel flows out of the control chamber, with no fuel flowing in, causing the pressure inside the control chamber to drop rapidly. This accelerates the booster pump's boosting process, enabling more precise shoe-shaped injection. It also allows for shoe-shaped injection with a smaller injection pulse width, effectively preventing situations where boosting is not completed after injection. This achieves variable injection patterns with small fuel volumes, improving engine performance.
[0016] 3. The diesel pressure boosted by the electronically controlled unit pump is greater than the pressure of the green fuel at the large end of the booster piston. This makes it the control oil for the piston-type booster pump, effectively accelerating the return of the booster piston and allowing the pressure entering the injector to recover quickly, resulting in more precise injection. It also effectively ensures the next boosting process and prevents the piston-type booster pump from failing due to insufficient piston displacement caused by repeated failures to return to full position. In addition, it is equipped with a displacement sensor that can close the solenoid valve of the electronically controlled unit pump when the booster piston returns to full position, preventing excessive pressure in the booster pump control chamber and effectively ensuring the response speed of the next boosting process. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the fuel injection system of the present invention; Figure 2 This is a left-side view of a piston booster pump. Figure 3 This is a front view of a piston booster pump. Figure 4 This is a cross-sectional view and a partial enlarged view of the left side of the piston booster pump along the AA direction. Figure 5 This is a cross-sectional view along the BB direction below the main view of the piston booster pump.
[0018] The attached diagram contains the following labels: 1. Piston booster pump; 2. Electronic control unit; 3. Injector; 4. Green fuel storage tank; 5. Electronically controlled unit pump; 6. Filter; 7. Diesel storage tank; 8. Check valve; 9. Green fuel high-pressure rail; 1-1. Green fuel inlet; 1-2. Booster pump solenoid valve; 1-3. Booster pump return port; 1-4. Booster pump diesel inlet; 1-5. Displacement sensor; 1-6. Pressure sensor; 1-7. Booster pump outlet; 1-8. Booster piston; 1-9. Booster pump check valve; 1-10. Booster piston internal flow channel; 1-11. Control chamber; 1-12. Booster piston return spring; 1-13. Booster chamber; 3-1. Injector inlet; 3-2. Injection solenoid valve; 3-3. Electronically controlled unit pump inlet; 5-1. Electronically controlled unit pump return port; 5-2. Electronically controlled unit pump solenoid valve; 5-3. Rail pressure sensor; 9-1. Detailed Implementation
[0019] The invention will now be described in more detail with reference to the accompanying drawings: Implementation method 1: Combining Figure 2-5 The piston-type booster pump 1, from top to bottom, includes a green fuel inlet 1-1, a booster piston 1-8, a booster piston return spring 1-12, and a booster pump outlet 1-7. The booster piston contains a booster pump check valve 1-9 and an internal flow channel 1-10. The booster pump check valve 1-9 is fixed to the booster piston 1-8 by threads. The space between the lower end face of the large end of the booster piston 1-8 and the booster pump body is the control chamber 1-11 of the booster piston, and the space between the lower end face of the small end of the booster piston and the booster pump body is the booster chamber 1-13. Three holes are drilled around the control chamber 1-11, one of which is fitted with a displacement sensor 1-5. One hole connects to the booster pump solenoid valve 1-2, and another hole connects to the booster pump diesel inlet 1-4. When the booster pump solenoid valve 1-2 is open, it can connect the control chamber 1-11 and the booster pump return port 1-3. There is a narrow annular groove 1-8-1 at the connection between the large and small ends of the booster pump, which is the characteristic groove of the displacement sensor 1-5. When the booster piston 1-8 is in the initial position, the displacement sensor 1-5 can identify the characteristic groove. A pressure sensor 1-6 is installed at the lower end of the piston booster pump 1, located between the booster chamber 1-13 and the booster pump outlet 1-7, to detect the pressure in the booster chamber 1-13.
[0020] Implementation method 2: Combining Figure 1Based on Embodiment 1, the present invention provides a high-response variable injection pattern fuel injection system comprising a piston booster pump 1, an electronic control unit 2, an injector 3, a green fuel storage tank 4, an electronically controlled unit pump 5, a filter 6, a diesel storage tank 7, a one-way valve 8, and a green fuel high-pressure rail 9. The piston booster pump is equipped with a booster pump solenoid valve 1-2, a displacement sensor 1-5, and a pressure sensor 1-6. Diesel fuel enters the electronically controlled unit pump 5 from the diesel storage tank 7 via the filter 6 and the electronically controlled unit pump inlet 5-1. After being pressurized by the electronically controlled unit pump 5, it passes through the one-way valve 8 and the booster pump diesel inlet 1-4. As the control oil for the piston-type booster pump 1, when the solenoid valve 5-3 of the electronically controlled unit pump is not energized, diesel fuel will return to the diesel storage tank 7 through the return port 5-2 of the electronically controlled unit pump. When the solenoid valve 1-2 of the booster pump is energized, the high-pressure diesel fuel from the electronically controlled unit pump 5 will flow back to the diesel storage tank 7 through the return port 1-3 of the booster pump. The high-pressure green fuel is stored in the green fuel high-pressure rail 9. The base pressure green fuel from the green fuel high-pressure rail 9 enters the injector 3 through the green fuel inlet 1-1, the booster pump check valve 1-9, the booster piston internal flow channel 1-10, the booster chamber 1-13, and the booster pump outlet 1-7. The piston-type booster pump 1 can perform secondary pressurization on high-pressure green fuel to achieve variable injection patterns. During the injection process of injector 3, green fuel will flow back from injector return port 3-2 to green fuel storage tank 4. The boosting pressure of the electronically controlled unit pump 5 is greater than the pressure in the high-pressure rail 9 of green fuel. The booster pump solenoid valve 1-2, displacement sensor 1-5, pressure sensor 1-6, and injection solenoid valve 3-3, the electronically controlled unit pump solenoid valve 5-3, and the rail pressure sensor 9-1 are all connected to the electronic control unit 2 through signal paths. The electronic control unit 2 can receive and send signals through the signal paths. By receiving signals from the rail pressure sensor 9-1, booster pump pressure sensor 1-6, and displacement sensor 1-5, the electronic control unit 2 coordinates the control of the booster pump solenoid valve 1-2, the electronically controlled unit pump solenoid valve 5-3, and the injection solenoid valve 3-3 to enable the piston-type booster pump 1 to achieve a high-response boosting and reset process, thereby achieving a high-response variable injection pattern for green fuel.
[0021] Implementation Method 3: Based on Implementation Method 2, when booster pump 1 pressurizes, electronic control unit 2 controls booster pump solenoid valve 1-2 to open, and simultaneously controls electronically controlled unit pump solenoid valve 5-3 to close. At this time, only fuel flows out of booster pump control chamber 1-11 and no fuel flows in, causing the pressure in booster pump control chamber 1-11 to drop rapidly, and booster piston 1-8 moves down to boost pressure. When booster piston 1-8 needs to reset, electronic control unit 2 controls booster pump solenoid valve 1-2 to close, and simultaneously controls electronically controlled unit pump solenoid valve 5-3 to close. When 5-3 is activated, the electronically controlled unit pump 5 pressurizes the pump, and high-pressure fuel continuously flows from the electronically controlled unit pump 5 into the booster pump control chamber 1-11. At this time, the fuel pressure flowing into the booster pump control chamber 1-11 is greater than the green fuel pressure at the upper end of the booster piston 1-8. The booster piston 1-8 will quickly reset until the displacement sensor 1-5 identifies the feature groove 1-8-1. Then, the electronic control unit 2 controls the electronically controlled unit pump solenoid valve 5-3 to de-energize, preventing the pressure in the booster pump control chamber 1-11 from being too high and affecting the next boosting process.
[0022] Implementation Method 4: Based on Implementation Method 2, in the base pressure injection mode, the booster pump 1 does not increase pressure during the entire injection process of the injector 3; in the boot-shaped injection mode, the booster pump 2 increases pressure during the injection process of the injector 3, and resets the booster piston 1-8 after the injection is completed; in the boosted injection mode, the booster pump 1 increases pressure before the injection of the injector 3 begins, and resets the booster piston 1-8 after the injection is completed.
[0023] This invention uses an electronically controlled unit pump 5 to pressurize diesel fuel as the control oil for a piston-type booster pump 1. This not only generates high-pressure control oil to accelerate the return of the booster piston 1-8 and improve the reset response speed of the piston-type booster pump 1, but the electronic control unit 2 can also control the electronically controlled unit pump solenoid valve 5-3 with high responsiveness, thereby accurately determining whether to supply high-pressure fuel to the booster pump control chamber 1-11, thus improving the booster pump 1's boost response speed. At the same time, the piston-type booster pump 1 is equipped with a displacement sensor 1-5. When the return of the booster piston 1-8 is detected, the electronically controlled unit pump solenoid valve 5-3 is closed, and high-pressure fuel is no longer supplied to the booster pump control chamber 1-11, preventing excessive pressure in the booster pump control chamber 1-11 and ensuring the boost response for the next boost.
Claims
1. A piston-type booster pump, characterized in that: The system includes a green fuel inlet block, a booster pump body, and a booster pump solenoid valve. The green fuel inlet block is fixed to the top of the booster pump body, and the booster pump solenoid valve is fixed to the side of the booster pump body. The green fuel inlet block has a green fuel inlet. The booster pump body has a booster pump diesel inlet, a booster pump return port, and a booster pump outlet. A booster piston is installed inside the booster pump body. The upper part of the booster piston is the large end, and the lower part of the booster piston is the small end. A booster pump check valve and an internal flow channel are installed inside the booster piston. The booster pump check valve is fixed to the booster piston. A control chamber is formed between the lower end face of the large end and the booster pump body, and a booster chamber is formed between the lower end face of the small end and the booster pump body. A first hole and a third hole are set around the control chamber. A displacement sensor is installed in the first hole. The second hole cooperates with the booster pump solenoid valve so that when the booster pump solenoid valve is open, it connects the control chamber and the booster pump return port. The third hole connects to the booster pump diesel inlet.
2. A piston-type booster pump according to claim 1, characterized in that: An annular groove is provided at the connection between the large and small ends. When the booster piston is in the initial position, the displacement sensor recognizes the feature groove.
3. A piston-type booster pump according to claim 1, characterized in that: A pressure sensor is installed at the bottom of the booster pump body to detect the pressure inside the booster chamber. The pressure sensor is located vertically between the booster chamber and the booster pump outlet.
4. A high-response variable injection law fuel injection system, characterized in that: The system includes an electronically controlled unit pump, an injector, a green fuel high-pressure rail, a diesel storage tank, a green fuel storage tank, and a piston-type booster pump as described in claim 1. The electronically controlled unit pump includes an electronically controlled unit pump solenoid valve, an electronically controlled unit pump inlet, and an electronically controlled unit pump return port. The injector includes an injection solenoid valve, an injector inlet, and an injector return port. Diesel fuel flows from the diesel storage tank to the electronically controlled unit pump inlet, enters the booster pump diesel inlet under the control of the electronically controlled unit pump solenoid valve, and then flows back to the diesel storage tank through the booster pump return port under the control of the booster pump solenoid valve. The electronically controlled unit pump return port is connected to the diesel storage tank. Green fuel in the green fuel high-pressure rail enters the piston-type booster pump through the green fuel inlet, and then enters the injector inlet through the booster pump outlet. It is injected under the control of the injector solenoid valve, and the injector return port is connected to the green fuel storage tank.
5. A high-response variable injection law fuel injection system according to claim 4, characterized in that: The boost pressure of the electronically controlled unit pump is greater than the pressure inside the high-pressure rail for green fuel.
6. A high-response variable injection law fuel injection system according to claim 4, characterized in that: A check valve is installed between the electrically controlled unit pump and the piston booster pump.
7. A high-response variable injection law fuel injection system according to claim 4, characterized in that: Rail pressure sensors are installed on the high-pressure rails for green fuel.
8. A high-response variable injection law fuel injection system according to claim 4, characterized in that: It also includes an electronic control unit, which is connected to the solenoid valve of the electronically controlled unit pump, the solenoid valve of the booster pump, the pressure sensor, the displacement sensor, the rail pressure sensor, and the injection solenoid valve.
9. A high-response variable injection law fuel injection system according to claim 8, characterized in that: When the piston-type booster pump boosts pressure, the electronic control unit (ECU) controls the booster pump solenoid valve to open and simultaneously controls the electronically controlled unit pump solenoid valve to close. Only fuel flows out of the booster pump control chamber, with no fuel flowing in. The pressure inside the booster pump control chamber decreases, and the booster piston moves downward to boost pressure. When the booster piston returns to its original position, the ECU controls the booster pump solenoid valve to close and simultaneously controls the electronically controlled unit pump solenoid valve to open. The electronically controlled unit pump then boosts pressure, and high-pressure fuel flows into the booster pump control chamber from the electronically controlled unit pump. The fuel pressure inside the booster pump control chamber is greater than the green fuel pressure at the top of the booster piston, causing the booster piston to return to its original position until the displacement sensor detects the feature groove. At this point, the ECU controls the electronically controlled unit pump solenoid valve to de-energize.
10. A high-response variable injection law fuel injection system according to claim 4 or 9, characterized in that: in In base pressure injection mode, the piston booster pump does not pressurize during the entire injection process; in boot-shaped injection mode, the piston booster pump pressurizes during the injection process and resets the booster piston after injection is completed; in booster injection mode, the piston booster pump pressurizes before the injection begins and resets the booster piston after injection is completed.