Mechanical injection device of internal combustion engine and control method of mechanical injection device
By adopting mechanical injection devices and control methods in the internal combustion engine, the wear and corrosion problems of traditional solenoid valve injectors when used under extreme conditions are solved, and high-precision and highly adaptable fuel injection control is achieved, ensuring long-term stable operation and improving engine efficiency.
Patent Information
- Application Number
- CN202411462002.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2025-03-25
AI Technical Summary
When used under long-term and large-load conditions, traditional solenoid valve injectors are prone to wear and corrosion of needle valves and valve seats due to poor fuel dissolution and lubrication performance, which affects the reliability and durability of the injectors, and is difficult to meet the long-term stable operation requirements of the internal combustion engine under extreme conditions.
The mechanical injection device is adopted, including a fuel chamber, an air chamber and a mixture distribution chamber. The opening and closing of the injection hole is controlled through the piston rod and the servo. Combined with the heating and preheating technology of the air compressor and copper tube, the uniform mixing of fuel and air is achieved.
It improves the accuracy and adaptability of fuel injection control, avoids corrosion and wear of fuel on the injection system, ensures long-term stable and reliable operation in various complex and harsh environments, and improves the working efficiency and fuel utilization of the engine.
Smart Images
Figure CN119686864A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of fuel injection for internal combustion engines, and in particular to a mechanical injection device for an internal combustion engine and a control method thereof. Background Art
[0002] Since the advent of the internal combustion engine, it has been widely favored due to its excellent performance. After hundreds of years of development, the internal combustion engine has been used as the main power source in transportation, manufacturing, military and other industries, bringing convenience to people's lives. Non-renewable resources such as oil and natural gas have long been the main power source for traditional internal combustion engines. At present, the demand for traditional non-renewable energy sources in countries around the world is constantly increasing, while the surplus of oil energy is rapidly decreasing.
[0003] In order to ease the dependence on traditional fossil energy, all related fields have begun to further strengthen the research and engineering utilization of non-fossil energy. Driven by this force, research has found that methanol, ethanol, biofuel, dimethyl ether and hydrogen can be used as alternative fuels to petroleum and applied to internal combustion engines.
[0004] The working principle of the currently commonly used solenoid valve injector mainly involves the power on and off of the electromagnetic coil, and the opening and closing of the injector is controlled by the magnetic force generated. However, fuels such as methanol, ethanol, and biofuel have a dissolving effect, and their viscosity is lower than that of gasoline and diesel, and their lubrication performance is poor. When the solenoid valve injector works under long-term and high-load conditions, the electromagnetic coil is constantly powered on and off, and its needle valve is constantly lifted and pressed. Long-term use will cause wear and corrosion to the needle valve and valve seat of the solenoid valve injector, affecting the reliability and durability of the injector. In addition, sometimes internal combustion engines need to maintain long-term reliable and stable operation under various extreme conditions, and the currently commonly used solenoid valve injectors are difficult to meet their use requirements. Summary of the invention
[0005] In view of the above problems, the purpose of the present invention is to provide a mechanical injection device for an internal combustion engine and a control method thereof, so as to solve the problem of wear and corrosion of the fuel on the fuel injection system, and also ensure long-term stable and reliable operation in various complex and harsh environments. The technical solution is as follows:
[0006] A mechanical injection device for an internal combustion engine comprises a fuel chamber, an air chamber and a mixed gas distribution chamber; the fuel chamber and the air chamber are two adjacent chambers, a piston rod is provided at one end of the fuel chamber, and the piston rod and the inner wall of the fuel chamber are sealed by a sealing ring; a fuel chamber inlet for delivering fuel is provided at the other end of the fuel chamber; an oil pressure sensor is provided at the top of the fuel chamber, and a plurality of oil injection holes leading to the air chamber are opened at the bottom; the movement position of the piston rod is controlled by a steering gear, thereby controlling the opening and closing and the number of oil injection holes;
[0007] One end of the air cavity is provided with an air cavity inlet for inputting high-temperature and high-pressure air, and the other end is provided with an air cavity outlet connected to the mixed gas distribution cavity inlet, for conveying the mixed gas with air and fuel to the mixed gas distribution cavity; a pressure sensor and a temperature sensor are also provided in the air cavity;
[0008] A spiral air passage is provided at the entrance of the mixed gas distribution chamber, and the mixed gas is evenly mixed and then transported into the engine through the outlet of the mixed gas distribution chamber.
[0009] Furthermore, it also includes an air compressor and a copper tube, one end of which is connected to the exhaust port of the air compressor, and the other end is connected to the inlet of the air cavity. The copper tube is wound and fixed to the outer wall of the exhaust pipe of the engine, and the compressed air is heated by the waste heat of the engine's exhaust gas.
[0010] Furthermore, the fuel chamber inlet is connected to the fuel tank through a fuel pressure regulating valve and a fuel pump in sequence, and the fuel return port of the fuel pressure regulating valve is connected to the fuel return port of the fuel tank.
[0011] Furthermore, the outlet of the mixed gas distribution chamber is a plurality of circumferential openings arranged at the nozzle of the mixed gas distribution chamber, and the number of the openings is the same as the number of engine cylinders.
[0012] A control method for a mechanical injection device of an internal combustion engine comprises the following steps:
[0013] Step 1: Fuel supply injection
[0014] After collecting the engine's speed and load signals, the ECU transmits a fuel injection signal to the servo. After receiving the electrical signal from the ECU, the servo rotates a specific angle in proportion, drags the piston rod to the left in the fuel chamber to the corresponding position in proportion, opens the corresponding number of fuel injection holes, and sprays the fuel in the fuel chamber into the air chamber from the fuel injection holes.
[0015] Step 2: Air pressurization preheating
[0016] The air is pressurized by an air compressor, and the pressure is lower than the fuel supply pressure; the pressurized air passes through the copper tube wound and fixed on the exhaust pipe, absorbs the waste heat of the engine exhaust gas, and then enters the air cavity to mix with the fuel sprayed from the fuel cavity. The obtained mixed gas is transported to the inlet of the mixed gas distribution cavity;
[0017] Step 3: Evenly distribute the mixture
[0018] The mixed gas is further evenly mixed through the spiral air passage at the inlet of the mixed gas distribution chamber, and then enters the mixed gas distribution chamber. The evenly mixed mixed gas finally enters the cylinder of the engine from the outlet of the mixed gas distribution chamber.
[0019] Furthermore, before step 1, the fuel injection amount is also calibrated, specifically:
[0020] Step a: Under a given injection pressure, the steering gear rotates proportionally to drag the piston rod to a certain position to the left, so that a spray hole is opened at the bottom of the fuel chamber. The amount of fuel sprayed is calculated based on the injection pressure, intake pressure difference and the cross-sectional area of the injection hole, as shown in the following formula:
[0021]
[0022] In the formula, q v is the volume flow rate, A is the flow cross-sectional area, ΔP is the pressure difference, ρ is the fluid density, C d The value is a constant, and v is the fluid flow rate;
[0023] Step b: The steering gear continues to rotate proportionally, the piston rod continues to move leftward, the holes at the bottom of the fuel chamber open in sequence, and the amount of fuel sprayed under different numbers of holes is calculated;
[0024] Step c: calibrate the required fuel amount of the engine under different speed ranges and loads, open the required number of injection holes according to the injection flow corresponding to the injection pulse width, and finally write it into the ECU program;
[0025] Step d: When the engine is running, the servo rotates proportionally according to the program written in the ECU, and the injection device injects fuel. The ECU adjusts the servo rotation angle through the collected intake pressure and intake temperature data to achieve real-time correction of the injection amount.
[0026] The beneficial effects of the present invention are:
[0027] (1) The present invention has high control accuracy and is a device that can convert an input electrical signal into a displacement in proportion to control the fuel flow rate. By controlling the position of the actuator, the fuel injection amount can be continuously and accurately controlled in proportion.
[0028] (2) The present invention has strong adaptability. The present invention can be applied to various liquid fuels as well as gaseous fuels, thereby avoiding corrosion and wear of the fuel injection system by the fuel, and can also operate stably and reliably for a long time under various working conditions.
[0029] (3) The present invention has an excellent atomization effect on the fuel, avoiding problems such as low engine combustion efficiency, difficulty in cold starting and engine wear caused by poor fuel atomization.
[0030] (4) The mixed gas of the present invention is formed more uniformly, and the airflow is caused to rotate through the spiral air passage to form a vortex, thereby intensifying its mixing and improving the working efficiency and fuel utilization rate of the engine.
[0031] (5) The present invention reduces the number of components and simplifies the oil circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 This is a schematic diagram of a mechanical fuel injection device.
[0033] Figure 2 It is a schematic cross-sectional view of a mechanical fuel injection device.
[0034] Figure 3 Schematic diagram of the piston rod of a mechanical oil injection device.
[0035] Figure 4 Schematic diagram of the mixture distribution chamber.
[0036] Figure 5 It is a schematic diagram of the cross-sectional view of the mixture distribution chamber.
[0037] Figure 6 It is a schematic diagram of the connection of various components of a specific implementation method.
[0038] Figure 7 This is a schematic diagram of the control logic of the mechanical fuel injection device.
[0039] In the figure: 1-fuel tank, 2-fuel pump, 3-fuel pressure regulating valve, 4-oil pressure sensor, 5-mechanical fuel injection device, 6-servo, 7-exhaust pipe, 8-copper tube, 9-air compressor, 10-mixed gas distribution chamber, 11-piston rod, 12-fuel chamber inlet, 13-oil pressure sensor interface, 14-air chamber inlet, 15-fuel injection hole, 16-air chamber outlet, 17-pressure sensor interface, 18-temperature sensor interface, 19-mixed gas distribution chamber inlet, 20-mixed gas distribution chamber outlet; 21-fuel chamber; 22-air chamber; 23-spiral airway; 24-sealing ring. DETAILED DESCRIPTION
[0040] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0041] The structure of the mechanical injection device for an internal combustion engine of the present invention is as follows Figure 1 and Figure 2 As shown, the components include: piston rod 11, sealing ring, fuel chamber 21, air chamber, and mixed gas distribution chamber; the fuel chamber is equipped with piston rod 11 at one end, piston rod 11 is connected to a steering gear 6, the piston rod and the fuel chamber are sealed by sealing ring 24, the other end of the fuel chamber is the fuel chamber inlet 12, the top of the fuel chamber is provided with a hole, connected to an oil pressure sensor 4, the bottom is provided with several oil injection holes 15, connected to the air chamber, one end of the air chamber is connected to the high-temperature and high-pressure air inlet, and the other end is connected to the mixed gas distribution chamber, the evenly mixed fuel enters the mixed gas distribution chamber, and finally is connected to each cylinder through the outlet of the mixed gas distribution chamber. The piston rod schematic diagram is shown as follows Figure 3 shown.
[0042] The working process of the mechanical injection device for an internal combustion engine of the present invention is as follows:
[0043] The fuel enters the fuel chamber from the fuel chamber inlet 12. When the ECU (Electronic control unit) collects the engine speed and load signals, it transmits a fuel injection signal to the servo. After the servo receives the electrical signal from the ECU, the servo 6 rotates a certain angle in proportion, and then drags the piston rod 11 to move a certain position to the left in proportion in the fuel chamber.
[0044] After the piston rod moves to the left to a certain position in proportion, a certain number of injection holes are opened at the bottom of the fuel chamber, and then the fuel in the fuel chamber is sprayed into the air chamber from the injection holes.
[0045] Fresh air of a certain temperature and pressure is introduced into the air cavity inlet 14, and the fresh air is mixed with the fuel injected from the fuel injection hole. After the fuel is mixed with the air of a certain temperature and pressure, it enters the mixed gas distribution cavity inlet 19 through the air cavity outlet 16. A pressure sensor and a temperature sensor are installed on the air cavity to collect the intake pressure and intake temperature.
[0046] like Figure 4 and Figure 5 As shown, the mixed gas passing through the air cavity enters the inlet of the mixed gas distribution chamber. The inlet of the mixed gas distribution chamber is a spiral air passage. After the mixed gas passes through the spiral air passage and is evenly mixed, it enters the mixed gas distribution chamber 10. The evenly mixed mixed gas finally enters the engine from the outlet 20 of the mixed gas distribution chamber.
[0047] This embodiment includes four parts: a fuel supply injection part, an air pressurization and preheating part, a uniform mixed gas distribution part, and a mechanical injection device control part. Figure 6 shown.
[0048] Fuel supply injection part: the fuel comes out of the fuel tank 1 and is connected to the fuel pump 2. The fuel is pressurized to a certain pressure by the fuel pump. The oil outlet of the fuel pump is connected to a fuel pressure regulating valve 3. The outlet of the fuel pressure regulating valve is connected to the inlet of the fuel chamber of the mechanical fuel injection device 12. The fuel pressure regulating valve 3 is used to provide a constant fuel supply pressure. The return port of the fuel pressure regulating valve is connected to the return port of the fuel tank. When the piston rod 11 moves to the left in the fuel chamber, the injection hole 15 at the bottom of the fuel chamber opens, and the fuel enters the air chamber through the injection hole at the bottom. The oil pressure sensor interface 13 at the top of the fuel chamber is connected to an oil pressure sensor for monitoring the injection pressure at all times.
[0049] Air pressurization and preheating part: The air is pressurized by the air compressor 9. The air pressure after pressurization is lower than the fuel supply pressure. The pressurized air is passed through the copper tube 8 wound and fixed on the exhaust pipe 7, making it similar to the structure of a shell and tube heat exchanger. The waste heat of the engine exhaust gas is used to heat the fresh air, and the temperature of the fresh air can be heated to above 120°C. The high-temperature and high-pressure air enters the air cavity inlet 14 of the mechanical fuel injection device through the copper tube and is evenly mixed with the fuel sprayed from the fuel cavity. The air cavity outlet 16 is connected to the mixed gas distribution cavity inlet 19. The mixed gas after uniform mixing enters the mixed gas distribution cavity through the air cavity outlet 16. The main function of the air cavity 22 is to mix the fuel sprayed from the fuel cavity with the high-temperature and high-speed fresh air to achieve the purpose of heating and evaporation of the fuel droplets and secondary crushing. This greatly improves the atomization efficiency and mixing uniformity of the fuel and reduces the possibility of incomplete combustion.
[0050] Uniform mixture distribution part: The spiral air passage at the 19th section of the mixture distribution chamber entrance is used to rotate the mixed flow of fuel and air entering the mixture distribution chamber to form a vortex, so that the mixture is mixed more evenly. The more evenly the mixture is mixed, the better the working efficiency and fuel utilization of the engine will be. The nozzle of the mixture distribution chamber has several holes circumferentially, and the number of holes is selected according to the number of cylinders in the engine. The number of holes is the same as the number of cylinders. The circumferential holes are connected to the cylinders, and the uniform mixture entering the mixture distribution chamber enters the cylinder through the circumferential holes of the nozzle.
[0051] The control part of the mechanical injection device: The piston rod is connected to a servo, and the amount of fuel required by the engine is related to the engine speed and load. When the engine is operating at low speed and light load, the amount of fuel required is less, and the servo is controlled to make the piston rod displace less to the left, the number of injection holes opened at the bottom of the fuel chamber is less, and the amount of fuel entering the air chamber is also less; when the engine is at high speed and heavy load, the amount of fuel required is more, and the servo is controlled to make the piston rod displace more to the left, the number of injection holes opened at the bottom of the fuel chamber is more, and the amount of fuel entering the air chamber is more. The control logic diagram of the mechanical injection device is as follows. Figure 7 shown.
[0052] Before using the mechanical injection device, its injection amount needs to be calibrated. Under a given injection pressure, the steering gear 6 rotates proportionally to drag the piston rod 11 to a certain position to the left, and when a fuel injection hole 15 is opened at the bottom of the fuel chamber 21, the amount of fuel injected is calculated based on the difference between the injection pressure and the intake pressure and the cross-sectional area of the injection hole; when the steering gear continues to rotate proportionally, the piston rod continues to move to the left, and the holes at the bottom of the fuel chamber are continuously opened, the amount of fuel injected under different numbers of holes is calculated.
[0053] According to the flow formula q v (m 3 / s) is the volume flow rate, A (㎡) is the flow cross-sectional area, ΔP (pa) is the pressure difference, ρ (Kg / m 3 ) is the fluid density, C d The value is a constant, and v is the fluid flow rate.
[0054] The required amount of fuel for the engine under different speed ranges and loads is calibrated, and the required number of injection holes is opened according to the injection flow corresponding to the injection pulse width, and finally written into the ECU program.
[0055] When the engine is running, the servo can rotate proportionally according to the program written in the ECU, and the injection device sprays fuel. The ECU adjusts the servo rotation angle based on the collected intake pressure and intake temperature data to achieve real-time correction of the injection amount.
Claims
1. A mechanical injection device for an internal combustion engine, characterized in that: The invention comprises a fuel chamber (21), an air chamber (22) and a mixed gas distribution chamber (10); the fuel chamber (21) and the air chamber (22) are two adjacent chambers; a piston rod (11) is provided at one end of the fuel chamber (21), and the piston rod (11) and the inner wall of the fuel chamber (21) are sealed by a sealing ring (24); a fuel chamber inlet (12) for delivering fuel is provided at the other end of the fuel chamber (21); an oil pressure sensor (4) is provided at the top of the fuel chamber (21), and a plurality of oil injection holes (15) leading to the air chamber (22) are provided at the bottom; the moving position of the piston rod (11) is controlled by a steering gear (6), thereby controlling the opening and closing and the number of the oil injection holes (15); The air cavity (22) is provided with an air cavity inlet (14) at one end for inputting high-temperature and high-pressure air, and an air cavity outlet (16) connected to the mixed gas distribution cavity inlet (19) at the other end for conveying the mixed gas of air and fuel to the mixed gas distribution cavity (10); a pressure sensor and a temperature sensor are also provided in the air cavity (22); A spiral air passage (23) is provided at the inlet (19) of the mixed gas distribution chamber, and the mixed gas is evenly mixed and then transported into the engine through the outlet (20) of the mixed gas distribution chamber.
2. The mechanical injection device for an internal combustion engine according to claim 1, characterized in that: It also includes an air compressor (9) and a copper tube (8), one end of the copper tube (8) is connected to the exhaust port of the air compressor (9), and the other end is connected to the air cavity inlet (14), and is wound around and fixed to the outer wall of the exhaust pipe (7) of the engine, so that the compressed air is heated by the waste heat of the engine's exhaust gas.
3. The mechanical injection device for an internal combustion engine according to claim 1, characterized in that: The fuel chamber inlet (12) is connected to the fuel tank (1) via a fuel pressure regulating valve (3) and a fuel pump (2) in sequence, and the fuel return port of the fuel pressure regulating valve (3) is connected to the fuel return port of the fuel tank (1).
4. The mechanical injection device for an internal combustion engine according to claim 1, characterized in that: The mixed gas distribution chamber outlet (20) is a plurality of circumferential openings arranged at the nozzle of the mixed gas distribution chamber (10), and the number of the openings is the same as the number of engine cylinders.
5. A control method for a mechanical injection device of an internal combustion engine according to claim 1, characterized in that: The following steps are involved: Step 1: Fuel supply injection After collecting the engine's speed and load signals, the ECU transmits a fuel injection signal to the servo. After receiving the electrical signal from the ECU, the servo rotates a specific angle in proportion, drags the piston rod to the left in the fuel chamber to the corresponding position in proportion, opens the corresponding number of fuel injection holes, and sprays the fuel in the fuel chamber into the air chamber from the fuel injection holes. Step 2: Air pressurization preheating The air is pressurized by an air compressor, and the pressure is lower than the fuel supply pressure; the pressurized air passes through the copper tube wound and fixed on the exhaust pipe, absorbs the waste heat of the engine exhaust gas, and then enters the air cavity to mix with the fuel sprayed from the fuel cavity. The obtained mixed gas is transported to the inlet of the mixed gas distribution cavity; Step 3: Evenly distribute the mixture The mixed gas is further evenly mixed through the spiral air passage at the inlet of the mixed gas distribution chamber, and then enters the mixed gas distribution chamber. The evenly mixed mixed gas finally enters the cylinder of the engine from the outlet of the mixed gas distribution chamber.
6. The control method according to claim 5, characterized in that: The step 1 also includes calibrating the fuel injection amount, specifically: Step a: Under a given injection pressure, the steering gear rotates proportionally to drag the piston rod to a certain position to the left, so that a spray hole is opened at the bottom of the fuel chamber. The amount of fuel sprayed is calculated based on the injection pressure, intake pressure difference and the cross-sectional area of the injection hole, as shown in the following formula: In the formula, q v is the volume flow rate, A is the flow cross-sectional area, ΔP is the pressure difference, ρ is the fluid density, C d The value is a constant, and v is the fluid velocity; Step b: The steering gear continues to rotate proportionally, the piston rod continues to move leftward, the holes at the bottom of the fuel chamber open in sequence, and the amount of fuel sprayed under different numbers of holes is calculated; Step c: calibrate the required fuel amount of the engine under different speed ranges and loads, open the required number of injection holes according to the injection flow corresponding to the injection pulse width, and finally write it into the ECU program; Step d: When the engine is running, the servo rotates proportionally according to the program written in the ECU, and the injection device injects fuel. The ECU adjusts the servo rotation angle through the collected intake pressure and intake temperature data to achieve real-time correction of the injection amount.