All-mechanical high-pressure common rail injection system

Abstract

The application discloses a full-mechanical high-pressure common rail injection system and relates to the technical field of agricultural machinery. A full-mechanical control device is designed to replace a complex and expensive electric control system in a typical high-pressure common rail system, so that the operation is simplified and the maintenance is easier. The mechanical control device of the application replaces an existing ECU block, and the input end of the application is the same as the input end of the ECU, that is, the accelerator (foot pedal) and the engine speed. However, unlike the ECU, the accelerator opening degree and the speed are directly converted into mechanical control instructions through mechanical conversion, so as to control the opening degree of the oil quantity control valve, the adjusting pressure of the mechanical oil pressure adjusting valve and the injection timing and pulse width control of the injection timing control valve.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, and more specifically to a fully mechanical high-pressure common rail injection system. Background Technology

[0002] The high-pressure common rail system in diesel engines has advantages such as precise fuel injection control, low fuel consumption and exhaust emissions, a wider load output range, and lower noise, making it an indispensable part of modern engine technology.

[0003] A typical high-pressure common rail system generally includes: a high-pressure pump, a high-pressure fuel rail, injectors, a fuel tank, an electronic control system, and sensors.

[0004] However, in the field of agricultural machinery, typical high-pressure common rail systems suffer from disadvantages such as high production costs, complex operation, difficulty in maintenance, and susceptibility of electrical components to damage in harsh working environments. The main reason for these disadvantages is that typical high-pressure common rail systems require electronic control systems and components for operation. Summary of the Invention

[0005] To overcome the defects and shortcomings of the existing technology, the present invention provides a fully mechanical high-pressure common rail injection system. The purpose of the invention is to reduce the application cost of high-pressure common rail systems in agricultural machinery. Without abandoning the advantages of high-pressure common rail systems, the present invention designs a fully mechanical control device to replace the complex and expensive electronic control system in typical high-pressure common rail systems, simplifying operation and making maintenance easier.

[0006] To address the problems existing in the prior art, the present invention is achieved through the following technical solution.

[0007] This invention discloses a fully mechanical high-pressure common rail injection system, comprising an oil tank, an oil supply pipe, a mechanical oil pump, an oil quantity control valve, a common rail oil pipe, several mechanical nozzles, a common rail return oil pipe, a main return oil pipe, and a mechanical control device. The oil tank supplies oil to the mechanical oil pump through the oil supply pipe. The mechanical oil pump pressurizes the oil supplied through the oil supply pipe and delivers it to the common rail oil pipe. The oil quantity control valve is located between the mechanical oil pump and the common rail oil pipe to control the oil supply quantity from the mechanical oil pump to the common rail oil pipe. Several mechanical nozzles are connected in parallel on the common rail oil pipe. A mechanical oil pressure regulating valve is installed at the return end of the common rail oil pipe, and the output end of the mechanical oil pressure regulating valve is connected to the common rail return oil pipe. The system is interconnected, with injection timing control valves installed on the return oil lines of several mechanical nozzles to control the opening and closing of the return oil lines. The return oil lines of several mechanical nozzles are connected in parallel to the common rail return oil line. The common rail return oil line and the return oil line of the mechanical oil pump are both connected to the main return oil line. The main return oil line is connected to the oil tank. The return oil from the mechanical oil pump, the common rail oil line, and several mechanical nozzles all flows back to the oil tank through the main return oil line. The mechanical control device converts the throttle opening and engine speed into mechanical control commands through mechanical conversion, which respectively control the opening of the fuel quantity control valve, the regulating pressure of the mechanical oil pressure regulating valve, and the injection timing and pulse width control of the injection timing control valve. The mechanical control device includes a throttle opening mechanical conversion component and an engine speed mechanical conversion component. The throttle opening mechanical conversion component converts the displacement of the throttle pedal device into the mechanical adjustment amount of the fuel quantity control valve, the mechanical pressure adjustment amount of the mechanical oil pressure regulating valve, and the mechanical control amount of the fuel injection timing control valve through mechanical transmission. The engine speed mechanical conversion component converts the engine speed into the mechanical adjustment amount of the fuel quantity control valve, the mechanical pressure adjustment amount of the mechanical oil pressure regulating valve, and the mechanical control amount of the fuel injection timing control valve through mechanical transmission. The engine speed mechanical conversion assembly includes a drive shaft, a variable diameter flywheel assembly, a guide rod, and a connector. The drive shaft establishes a transmission relationship with the engine through a transmission gear II, and the drive shaft remains rotating. One end of the variable diameter flywheel assembly is fixedly connected to the drive shaft at both ends axially upwards, and the other end is fixedly connected to the drive shaft radially, allowing it to move axially along the drive shaft. The end of the variable diameter flywheel assembly that can move axially along the drive shaft is connected to the connector via the guide rod. The connector is equipped with a fuel quantity cam rail, a hydraulic pressure cam rail, and a fuel injection cam rail. The fuel quantity cam rail... A hydraulic quantity connecting rod is slidably mounted, a hydraulic pressure connecting rod is slidably connected to the hydraulic cam rail, and an injection connecting rod is slidably connected to the injection cam rail. When the drive shaft speed increases, the speed of the variable diameter flywheel assembly increases with the rotation of the drive shaft. Under the action of centrifugal force, the diameter of the variable diameter flywheel assembly increases and the axial distance decreases, thereby driving the connecting piece to move towards the variable diameter flywheel assembly. Under the action of the hydraulic quantity cam rail, the hydraulic pressure cam rail, and the injection cam rail, the movement of the connecting piece is respectively converted into the displacement of the hydraulic quantity connecting rod, the hydraulic pressure connecting rod, and the injection connecting rod.

[0008] More preferably, the throttle opening mechanical conversion assembly includes a connecting slide rod, a return spring, a fixed sleeve, and a connecting member. The upper end of the connecting slide rod is connected to the throttle pedal device, and the lower end of the connecting slide rod passes through the fixed sleeve and is connected to the connecting member. The return spring is sleeved on the connecting slide rod and the fixed sleeve, with its upper end fixedly connected to the connecting slide rod and its lower end fixedly connected to the fixed sleeve. The fixed sleeve is fixed. The connecting member is provided with an oil quantity connecting rod, an oil pressure connecting rod, and an injection connecting rod. The connecting slide rod is displaced by the transmission of the throttle pedal device, which drives the connecting member to displace, thereby driving the oil quantity connecting rod, the oil pressure connecting rod, and the injection connecting rod to displace.

[0009] More preferably, a return spring is provided between the two ends of the variable diameter flywheel assembly to reduce the speed of the drive shaft, thereby reducing the centrifugal force on the variable diameter flywheel assembly. Under the action of the return spring, the diameter of the variable diameter flywheel assembly becomes smaller and the axial distance becomes larger.

[0010] More preferably, the throttle opening mechanical conversion component and the engine speed mechanical conversion component share the same connector. The connector is provided with left and right guide rails that cooperate with the connecting slide rod, and upper and lower guide rails that cooperate with the guide rod. Under the action of the left and right guide rails, when the connector is displaced by the variable diameter flywheel assembly, it slides left and right relative to the connecting slide rod; under the action of the upper and lower guide rails, when the connector is displaced by the connecting slide rod, it slides up and down relative to the guide rod.

[0011] More preferably, the oil quantity connecting rod is connected to the oil quantity control valve, and the displacement of the oil quantity connecting rod is the adjustment amount of the oil quantity control valve; the oil pressure connecting rod is connected to the mechanical oil pressure regulating valve, and the displacement of the oil pressure connecting rod is the oil pressure control amount of the mechanical oil pressure regulating valve; the fuel injection connecting rod is connected to the fuel injection timing control valve, and the displacement of the fuel injection connecting rod is the control amount of the fuel injection timing control valve, thereby realizing the control of the fuel injection timing control valve on the fuel injection timing and fuel injection pulse width.

[0012] More preferably, the injection timing control valve includes a sliding sleeve I, a sliding sleeve II, and a rotating shaft. The sliding sleeve I and the sliding sleeve II are axially sealed and connected to the rotating shaft, and the rotating shaft rotates relative to the sliding sleeve I and the sliding sleeve II. The sliding sleeve I is provided with a passage I that communicates with the return nozzle interface of the mechanical nozzle. An annular channel I is provided between the sliding sleeve I and the rotating shaft, and the passage I communicates with the annular channel I. The rotating shaft has a radial channel I that communicates with the annular channel I. An axial passage is provided inside the rotating shaft, and the radial channel I communicates with the axial passage. The sliding sleeve II is provided with a passage II that connects to the downstream of the return oil path of the mechanical nozzle. A passage III with a certain circumference is provided between the sliding sleeve II and the rotating shaft. A lever is provided on the passage III to change the length of the passage III. The passage II is connected to the passage III. The rotating shaft is provided with a radial channel II that is connected to the passage III. The radial channel II is connected to the axial passage.

[0013] More preferably, the paddle is connected to a mechanical control device via a mechanical connection structure. The mechanical control device converts the throttle opening and engine speed into mechanical control commands through mechanical conversion. By changing the position of the paddle through the mechanical connection structure, the length of passage III is changed, thereby realizing the control of the injection timing and pulse width of the injection timing control valve.

[0014] More preferably, a transmission gear I is fixedly mounted on the rotating shaft, and a transmission relationship is established with the engine through the transmission gear I, so that the rotating shaft keeps rotating.

[0015] More preferably, the mechanical nozzle includes a fuel injector body with an inlet pipe connector; a pressure regulating chamber is provided on the upper part of the fuel injector body, and a pressure regulating spring is provided in the pressure regulating chamber. The upper end of the pressure regulating spring is connected to a pressure regulating screw, which is threaded to the top of the fuel injector body. The lower end of the pressure regulating spring is fixed to a spring seat, and a push rod is connected to the bottom of the spring seat; a threaded sleeve is connected to the bottom of the fuel injector body, and a needle valve body is provided on the threaded sleeve. The bottom of the push rod is connected to a needle valve, which is located in the needle valve cavity within the needle valve body and forms a sealing pair with the inner wall of the needle valve cavity. A fuel injection hole communicating with the needle valve cavity is provided at the bottom of the needle valve body; the fuel injector body includes a fuel injection passage and a fuel return passage. Fuel entering the fuel injector body through the inlet pipe connector enters the needle valve cavity through the fuel injection passage, and a small portion enters the pressure regulating chamber through the fuel return passage. The pressure regulating chamber is connected to the fuel return nozzle interface.

[0016] More preferably, an oil filter is provided on the oil supply pipe.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows: 1. This invention designs a fully mechanical control device to replace the complex and expensive electronic control system in a typical high-pressure common rail system, simplifying operation and making maintenance easier. The mechanical control device of this invention replaces the existing ECU board. While the inputs of this invention are the same as those of the ECU (throttle pedal and engine speed), it does not use electrical signals. Instead, it directly converts the throttle opening and engine speed into mechanical control commands through mechanical conversion. These commands control the opening of the fuel quantity control valve, the regulating pressure of the mechanical fuel pressure regulating valve, and the injection timing and pulse width control of the injection timing control valve.

[0018] 2. The fuel injection timing control valve of this invention controls the injection timing and injection pulse width by adjusting the rotational speed of the rotating shaft and changing the length of passage III. When radial passage II on the rotating shaft is connected to passage III, it indicates that the fuel injector return path is open; when radial passage II on the rotating shaft is not connected to passage III, it indicates that the fuel injector return path is closed. Changing the shaft rotational speed determines the injection timing; the length of passage III represents the duration the fuel injector return path is open, i.e., the injection pulse width. This invention's fuel injection timing control valve mechanically controls the injection timing and injection pulse width.

[0019] 3. The mechanical control device of the present invention includes a throttle opening mechanical conversion component and an engine speed mechanical conversion component. The throttle opening mechanical conversion component converts the displacement of the throttle pedal device into the adjustment amount of the fuel quantity control valve, the oil pressure control amount of the mechanical oil pressure regulating valve, and the displacement amount of the paddle in the injection timing and pulse width control device, thereby achieving mechanical control of fuel quantity, oil pressure, injection timing, and pulse width. The engine speed mechanical conversion component converts the engine speed into a displacement amount through transmission ratio control, and then converts this displacement amount into the adjustment amount of the fuel quantity control valve, the oil pressure control amount of the mechanical oil pressure regulating valve, and the displacement amount of the paddle in the injection timing and pulse width control device, thereby achieving mechanical control of fuel quantity, oil pressure, injection timing, and pulse width.

[0020] 4. The throttle opening mechanical conversion component of the present invention has a simple structure and a sensitive transmission structure; the engine speed mechanical conversion component of the present invention can convert the engine speed into a displacement amount, and then convert the displacement amount into the adjustment amount of the oil quantity control valve, the oil pressure control amount of the mechanical oil pressure regulating valve, and the displacement amount of the paddle, respectively, with a simple structure.

[0021] 5. The throttle opening mechanical conversion component and the engine speed mechanical conversion component of the present invention can share a single connector, thereby simplifying the structure of the mechanical control device. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the fully mechanical high-pressure common rail system of the present invention.

[0023] Figure 2 This is a schematic diagram of the fuel injection timing control valve of the present invention.

[0024] Figure 3 This is a cross-sectional view of the sliding sleeve I and the rotating shaft in the fuel injection timing control valve of the present invention.

[0025] Figure 4 This is a cross-sectional view of the sliding sleeve II and the rotating shaft in the fuel injection timing control valve of the present invention.

[0026] Figure 5 This is a schematic diagram of the mechanical control device of the present invention.

[0027] Figure 6 This is a schematic diagram of the mechanical nozzle of the present invention.

[0028] Reference numerals: 1. Fuel tank; 2. Fuel supply pipe; 3. Mechanical oil pump; 4. Fuel quantity control valve; 5. Common rail fuel line; 6. Mechanical nozzle; 7. Common rail return line; 8. Main return line; 9. Mechanical control device; 10. Mechanical oil pressure regulating valve; 11. Return line; 12. Injection timing control valve; 13. Fuel pump return line; 14. Sleeve I; 15. Sleeve II; 16. Rotating shaft; 17. Return nozzle interface; 18. Passage I; 19. Annular passage I; 20. Radial passage I; 21. Axial passage; 22. Passage II; 23. Passage III; 24. Paddle shifter; 25. Radial passage II; 26. Transmission gear I; 27. Throttle opening mechanical conversion assembly; 28. Engine speed mechanical conversion assembly. 29. Connecting slide rod; 30. Return spring; 31. Fixing sleeve; 32. Connecting piece; 33. Oil quantity connecting rod; 34. Hydraulic connecting rod; 35. Injection connecting rod; 36. Drive shaft; 37. Variable diameter flywheel assembly; 38. Guide rod; 39. Transmission gear II; 40. Oil quantity cam rail; 41. Hydraulic cam rail; 42. Injection cam rail; 43. Left and right guide rails; 44. Upper and lower guide rails; 45. Injector body; 46. Oil inlet pipe connector; 47. Pressure regulating chamber; 48. Pressure regulating spring; 49. Pressure regulating screw; 50. Spring seat; 51. Push rod; 52. Screw sleeve; 53. Needle valve; 54. Needle valve body; 55. Needle valve chamber; 56. Injection hole; 57. Injection oil passage; 58. Return oil passage; 59. Oil filter. Detailed Implementation

[0029] The following are exemplary embodiments of the invention as defined by the claims and their equivalents, taken in conjunction with the accompanying drawings, to aid in a comprehensive understanding. The specific details described herein are to be considered exemplary only and not to limit the scope of the invention. Therefore, those skilled in the art can make various changes and modifications to the embodiments without departing from the scope and spirit of the invention.

[0030] Example 1: As a preferred embodiment of the present invention, please refer to the appendix to the specification. Figure 1As shown, this embodiment discloses a fully mechanical high-pressure common rail injection system, including an oil tank 1, an oil supply pipe 2, a mechanical oil pump 3, an oil quantity control valve 4, a common rail oil pipe 5, several mechanical nozzles 6, a common rail return oil pipe 7, a main return oil pipe 8, and a mechanical control device 9. The oil tank 1 supplies oil to the mechanical oil pump 3 through the oil supply pipe 2. The mechanical oil pump 3 pressurizes the oil supplied by the oil supply pipe 2 and then delivers it to the common rail oil pipe 5. The oil quantity control valve 4 is located between the mechanical oil pump 3 and the common rail oil pipe 5 to control the oil supply quantity from the mechanical oil pump 3 to the common rail oil pipe 5. Several mechanical nozzles 6 are connected in parallel on the common rail oil pipe 5. A mechanical oil pressure regulating valve 10 is provided at the return end of the common rail oil pipe 5. The output end of the mechanical oil pressure regulating valve 10 is connected to the common rail return oil pipe 5. The pipe 7 is connected, and the return oil passage 11 of several mechanical nozzles 6 is equipped with an injection timing control valve 12 to control the opening and closing of the return oil passage 11. The return oil passage 11 of several mechanical nozzles 6 is connected in parallel to the common rail return oil pipe 7. The common rail return oil pipe 7 and the oil pump return oil pipe 13 of the mechanical oil pump 3 are both connected to the main return oil pipe 8. The main return oil pipe 8 is connected to the oil tank 1. The return oil from the mechanical oil pump 3, the common rail oil pipe 5, and several mechanical nozzles 6 all flow back to the oil tank 1 through the main return oil pipe 8. The mechanical control device 9 converts the throttle opening and engine speed into mechanical control commands through mechanical conversion, and controls the opening of the fuel quantity control valve 4, the regulating pressure of the mechanical oil pressure regulating valve 10, and the injection timing and pulse width control of the injection timing control valve 12, respectively.

[0031] In this embodiment, the aforementioned fully mechanical high-pressure common rail injection system comprises three subsystems: an oil supply system, an oil return system, and a mechanical control system.

[0032] The fuel supply system consists of three steps: ① The fuel tank 1 supplies clean, impurity-free fuel to the mechanical fuel pump 3; ② The mechanical fuel pump 3 supplies high-pressure fuel to the common rail fuel line 5; ③ The common rail fuel line 5 supplies fuel at the same pressure to each mechanical nozzle 6.

[0033] Specifically: ① Fuel enters the fuel tank 1 through the fuel filter 59, then flows through the fuel supply pipe 2 into the mechanical fuel pump 3 and is pressurized. ② It then flows from the fuel supply pipe 2 into the common rail fuel line 5 through the fuel quantity control valve 4 and is temporarily stored. ③ The common rail fuel line 5 is connected to the mechanical nozzle 6. The high-pressure fuel in the common rail fuel line 5 is injected into the injector body 45 through the inlet pipe connector 46 of the mechanical nozzle 6 and splits into two ends. One end is temporarily stored in the needle valve chamber 55, ready for injection; the other end is connected to the return fuel line 11 of the mechanical nozzle 6.

[0034] The oil return system includes three return branches: ① Mechanical oil pump 3 return branch; ② Common rail oil pipe 5 pressure relief return branch; ③ Mechanical nozzle 6 return branch. Details are as follows: ① Mechanical oil pump return branch: Unused fuel in mechanical oil pump 3 is connected to oil pump return pipe 13 and eventually returns to oil tank 1.

[0035] ② Common Rail Fuel Line 5 Pressure Relief Return Branch: As fuel accumulates inside the common rail fuel line 5 over time, its internal pressure increases. To regulate the pressure in the common rail fuel line 5, a mechanical oil pressure regulating valve 10 is designed on it, and the common rail return line 7 is connected to this valve. When the oil pressure in the common rail fuel line 5 exceeds the threshold, the mechanical oil pressure regulating valve 10 opens, allowing fuel to enter the common rail return line 7.

[0036] ③ Mechanical nozzle 6 return oil branch: Mechanical nozzle 6 needs to return oil every time it injects. The return oil line 11 of each nozzle is connected to the common rail return oil pipe 7 through the injection timing control valve 12, and finally returns to the oil tank 1.

[0037] The mechanical control system includes three control valves and a mechanical control device 9 for implementing control. The three control valves are the oil quantity control valve 4, the mechanical oil pressure regulating valve 10, and the oil injection timing control valve 12.

[0038] The function of the fuel quantity control valve 4 is to control the amount of fuel supplied by the mechanical oil pump 3 to the common rail oil pipe 5; the principle is to control the fuel flow by adjusting the opening of the fuel quantity control valve 4.

[0039] The function of the mechanical oil pressure regulating valve 10 is to regulate the oil pressure in the common rail fuel line 5. The principle is as follows: when the common rail fuel line 5 is connected to the mechanical oil pressure regulating valve 10, if the oil pressure in the common rail fuel line 5 exceeds the threshold, the thrust of the pressure regulating spring 48 in the mechanical regulating valve is less than the oil pressure in the common rail fuel line 5, so the valve is opened, and the fuel in the common rail fuel line 5 flows into the common rail return line 7, and finally back to the fuel tank 1. When the oil pressure in the common rail fuel line 5 drops to the pressure of the pressure regulating spring 48, the valve closes again, and the oil pressure in the common rail fuel line 5 is thus regulated. Therefore, by simply changing the pressure of the pressure regulating spring 48, the upper limit of the oil pressure in the common rail fuel line 5 can be changed.

[0040] The fuel injection timing control valve 12 is used in this invention. First, the working principle of the mechanical nozzle 6 is introduced. The inlet of the mechanical nozzle 6 is connected to the common rail fuel line 5. High-pressure fuel enters the nozzle body 45 through the inlet pipe connector 46 and is split into two ends. The upper end is defined as the end opposite the nozzle, and the lower end is the nozzle end. A throttling orifice exists in the upper fuel passage, which results in less fuel injected into the upper end than into the lower end, meaning the fuel pressure at the lower end is greater than the pressure at the upper end. A pressure regulating spring 48 at the upper end of the nozzle balances the pressure difference between the upper and lower ends, keeping the push rod 51 in the middle of the nozzle balanced, ensuring the needle valve 53 always blocks the injection hole 56. The upper end of the mechanical nozzle 6 has a fuel outlet connected to the return fuel line 11. When the return fuel line 11 is open, the fuel at the upper end is completely discharged from the nozzle due to its own pressure, enters the return fuel line 11, and finally returns to the fuel tank 1. At this time, the discharge of fuel at the upper end causes the balance of the push rod 51 to be disrupted. Under the thrust of the lower oil pressure, the push rod 51 moves upward, causing the needle valve 53 to move upward, opening the injection hole 56 and injecting fuel. When the upper return oil pipe passage is closed, because fuel is continuously injected into the inlet oil pipe, the push rod 51 will return to balance, and the needle valve 53 will block the injection hole 56 again, thus completing the fuel injection. Therefore, a device is needed to control the opening time and duration of the nozzle return oil pipe, thereby controlling the injection timing and injection pulse width.

[0041] Example 2: As another preferred embodiment of the present invention, this embodiment is a further detailed description and supplement to the technical solution of the present invention based on the above-described embodiment 1. (Refer to the appendix of the specification.) Figure 5 As shown, this embodiment provides a structure for a mechanical control device 9, including a throttle opening mechanical conversion component 27 and an engine speed mechanical conversion component 28. The throttle opening mechanical conversion component converts the displacement of the throttle pedal device into the mechanical adjustment amount of the fuel quantity control valve 4, the mechanical pressure adjustment amount of the mechanical oil pressure regulating valve 10, and the mechanical control amount of the fuel injection timing control valve 12 through mechanical transmission conversion. The engine speed mechanical conversion component 28 converts the engine speed into the mechanical adjustment amount of the fuel quantity control valve 4, the mechanical pressure adjustment amount of the mechanical oil pressure regulating valve 10, and the mechanical control amount of the fuel injection timing control valve 12 through mechanical transmission conversion.

[0042] In this embodiment, the mechanical control device 9 has the same input terminals as the ECU, namely the throttle (foot pedal) and engine speed. However, unlike the ECU, it does not use electrical signals but directly uses the throttle opening and engine speed as commands. The mechanical control device 9 in this embodiment includes three parts: ① a throttle command receiving and conversion device; ② an engine speed command receiving and conversion device; and ③ a command processing and output device.

[0043] The throttle opening mechanical conversion component 27 includes a connecting slide rod 29, a return spring 30, a fixing sleeve 31, and a connector 32. The upper end of the connecting slide rod 29 is connected to the throttle pedal device, and the lower end of the connecting slide rod 29 passes through the fixing sleeve 31 and is connected to the connector 32. The return spring 30 is sleeved on the connecting slide rod 29 and the fixing sleeve 31. The upper end of the return spring 30 is fixedly connected to the connecting slide rod 29, and the lower end is fixedly connected to the fixing sleeve 31. The fixing sleeve 31 is fixed. The connector 32 is provided with an oil quantity connecting rod 33, an oil pressure connecting rod 34, and an injection connecting rod 35. The connecting slide rod 29 is displaced by the transmission of the throttle pedal device, which drives the connector 32 to displace, thereby driving the oil quantity connecting rod 33, the oil pressure connecting rod 34, and the injection connecting rod 35 to displace.

[0044] The connecting slide rod 29 is combined with the fixed sleeve 31 so that the connecting slide rod 29 can move axially along the fixed sleeve 31 in a straight line. Then, one end of the return spring 30 is connected to the connecting slide rod 29 and the other end is fixed (it can be fixed to the fixed sleeve 31) so that the connecting slide rod 29 can return to its original position after the force is removed. A guide rail is designed on the connecting piece 32 so that the connecting slide rod 29 can move in the guide rail and the connecting piece 32 can move in a straight line with the connecting slide rod 29 (e.g., the guide rail is a left and right guide rail 43 and the connecting slide rod 29 moves up and down). The other end of the connecting slide rod 29 is connected to the accelerator (foot pedal).

[0045] The working principle is as follows: When the driver presses the accelerator pedal harder, the pedal is displaced. This displacement is processed (scaled, expanded, or directional) and transmitted to the connecting slide rod 29, causing it to also displace. Since the connecting piece 32 is also connected to it, it also displaces. When the driver releases the pressure on the accelerator pedal, the return spring 30 returns the connecting slide rod 29 to its original position, causing the connecting piece 32 to return to its original position as well. (The different displacement amounts mentioned above represent different signals, thus converting the accelerator opening into the displacement of the connecting piece 32. The conversion ratio between the pedal displacement, the connecting slide rod 29 displacement, and the final displacement of the connecting piece 32 can be obtained through scientific calculation.)

[0046] The engine speed mechanical conversion assembly 28 includes a drive shaft 36, a variable diameter flywheel assembly 37, a guide rod 38, and a connector 32. The drive shaft 36 establishes a transmission relationship with the engine through a transmission gear II 39, and the drive shaft 36 keeps rotating. One end of the variable diameter flywheel assembly 37 is fixedly connected to the drive shaft 36 in the axial direction, and the other end is fixedly connected to the drive shaft 36 in the radial direction, allowing it to move axially along the drive shaft 36. The end of the variable diameter flywheel assembly 37 that can move axially along the drive shaft 36 is connected to the connector 32 through the guide rod 38. The connector 32 is provided with a fuel quantity cam rail 40, a hydraulic pressure cam rail 41, and a fuel injection cam rail 42. A hydraulic quantity connecting rod 33 is slidably mounted on the 40, a hydraulic pressure connecting rod 34 is slidably connected on the hydraulic pressure cam rail 41, and an injection connecting rod 35 is slidably connected on the injection cam rail 42. When the rotational speed of the drive shaft 36 increases, the rotational speed of the variable diameter flywheel assembly 37 increases with the rotational speed of the drive shaft 36. Under the action of centrifugal force, the diameter of the variable diameter flywheel assembly 37 increases and the axial distance decreases, thereby driving the connecting piece 32 to move towards the variable diameter flywheel assembly 37. Under the action of the hydraulic quantity cam rail 40, the hydraulic pressure cam rail 41, and the injection cam rail 42, the movement of the connecting piece 32 is respectively converted into the displacement of the hydraulic quantity connecting rod 33, the hydraulic pressure connecting rod 34, and the injection connecting rod 35.

[0047] Transmission gear II 39 is fixed to a transmission shaft 36, and the engine is connected to it; one end of a variable diameter flywheel assembly 37 is fixed axially to the transmission shaft 36 (fixed both axially and radially), and the other end of the variable diameter flywheel assembly 37 is radially fixed to the transmission shaft 36, so that it can move axially on the transmission shaft 36; one end of the return spring 30 is fixed to the transmission shaft 36, and the other end is fixed to the end of the flywheel that can move axially (or the return spring 30 can be fixed to both ends of the variable diameter flywheel assembly 37); a sliding guide rod 38 is connected to the axially movable end of the variable diameter flywheel assembly 37 (the sliding guide rod 38 does not follow the flywheel to make a circular motion around the axis, but can move axially with the axially movable end of the flywheel); the other end of the sliding guide rod 38 is connected to the connector 32 through a guide rail (e.g., the guide rail is an upper and lower guide rail 44, and the sliding guide rod 38 moves left and right).

[0048] The working principle is as follows: Through transmission gear II 39, the engine speed is transmitted to the transmission shaft 36 (the transmission ratio is set according to actual needs, and the speed signal can be amplified or reduced). At this time, the variable-diameter flywheel assembly 37 on the transmission shaft 36, being radially fixed, also undergoes circular motion around the transmission shaft 36. Under the action of centrifugal force, the diameter of the variable-diameter flywheel assembly 37 increases. The end of the variable-diameter flywheel assembly 37 that is not axially fixed will overcome the tension (or thrust, depending on the installation position of the return spring 30) of the return spring 30 and move towards the other end of the variable-diameter flywheel assembly 37, thus generating displacement. Under the action of the sliding guide rod 38, the circular motion of the variable-diameter flywheel assembly 37 is not transmitted, but the displacement of the moving end of the variable-diameter flywheel assembly 37 is transmitted to the connecting piece 32, causing it to also displace. With different speeds, the centrifugal force generated by the flywheel varies, resulting in different final displacements of the connecting piece 32. When the rotational speed is zero, the variable diameter flywheel assembly 37 returns to its original state under the action of the return spring 30 (the different displacements mentioned above are different signals, thus converting the engine speed into the displacement of the connecting piece 32. The conversion ratio between the rotational speed of the engine drive shaft 36 to the rotational speed of another shaft; the displacement of the flywheel and the displacement generated by the final connecting piece 32 can be obtained through scientific calculation).

[0049] As mentioned above, connector 32 is subject to the combined action of the throttle command receiving and conversion device and the engine speed command receiving and conversion device. To prevent their movements from interfering with each other, two guide rails are designed. This allows the throttle opening mechanical conversion component 27 and the engine speed mechanical conversion component 28 to share a single connector 32, simplifying the structure.

[0050] Three cam rails are designed on the connector 32: oil quantity cam rail 40, oil pressure cam rail 41 and oil injection cam rail 42; oil quantity cam rail 40 is connected to oil quantity control valve 4 through oil quantity connecting rod 33; oil pressure cam rail 41 is connected to mechanical oil pressure regulating valve 10 through oil pressure connecting rod 34; oil injection cam rail 42 is connected to oil injection timing control valve 12 through oil injection connecting rod 35.

[0051] The oil quantity connecting rod 33 is connected to the oil quantity control valve 4, and the displacement of the oil quantity connecting rod 33 is the adjustment amount of the oil quantity control valve 4; the oil pressure connecting rod 34 is connected to the mechanical oil pressure regulating valve 10, and the displacement of the oil pressure connecting rod 34 is the oil pressure control amount of the mechanical oil pressure regulating valve 10; the fuel injection connecting rod 35 is connected to the paddle 24 of the fuel injection timing control valve 12, and the displacement of the fuel injection connecting rod 35 is the displacement of the paddle 24, thereby adjusting the length of the passage Ⅲ23, thereby realizing the control of the fuel injection timing and fuel injection pulse width by the fuel injection timing control valve 12.

[0052] In this embodiment, the connector 32 receives displacements in two different directions. Furthermore, the relationships between oil pressure, fuel quantity, injection timing, engine speed, and throttle opening are not identical. Finally, the relationships between different parameters are not simply additive or canceling relationships. Therefore, it is necessary to scientifically calculate the changing trends of oil pressure, fuel quantity, and injection timing under different engine speeds and throttle openings. Different cam rails were designed to convert the displacements obtained from the connector 32 into the openings of different valves.

[0053] Example 3: As another preferred embodiment of the present invention, this embodiment is a further detailed description and supplement to the technical solution of the present invention based on the above-described Embodiment 1 or Embodiment 2. In this embodiment, refer to the appendix to the specification. Figure 2 As shown, this embodiment provides an injection timing control valve 12, including a sliding sleeve I 14, a sliding sleeve II 15, and a rotating shaft 16. The sliding sleeve I 14 and the sliding sleeve II 15 are axially sealed to the rotating shaft 16, and the rotating shaft 16 rotates relative to the sliding sleeve I 14 and the sliding sleeve II 15.

[0054] As per the instruction manual Figure 3 As shown, the sliding sleeve I14 is provided with a passage I18 that communicates with the oil return port 17 of the mechanical nozzle 6. An annular channel I19 is provided between the sliding sleeve I14 and the rotating shaft 16. The passage I18 communicates with the annular channel I19. The rotating shaft 16 has a radial channel I20 that communicates with the annular channel I19. An axial passage 21 is provided inside the rotating shaft 16. The radial channel I20 communicates with the axial passage 21. As per the instruction manual Figure 4 As shown, the sliding sleeve II15 is provided with a passage II22 that connects to the downstream of the return oil passage 11 of the mechanical nozzle 6. A passage III23 with a certain circumference is provided between the sliding sleeve II15 and the rotating shaft 16. A lever 24 for changing the length of the passage III23 is provided on the passage III23. The passage II22 is connected to the passage III23. The rotating shaft 16 is provided with a radial channel II25 that is connected to the passage III23. The radial channel II25 is connected to the axial passage 21.

[0055] The paddle 24 is connected to the mechanical control device 9 through a mechanical connection structure. The mechanical control device 9 converts the throttle opening and engine speed into mechanical control commands through mechanical conversion. By changing the position of the paddle 24 through the mechanical connection structure, the length of the passage Ⅲ23 is changed, thereby realizing the control of the injection timing and pulse width of the injection timing control valve 12.

[0056] A transmission gear I26 is fixedly mounted on the rotating shaft 16, and a transmission relationship is established with the engine through the transmission gear I26, so that the rotating shaft 16 keeps rotating.

[0057] In this embodiment, the nozzle return oil passage 11 is connected to a gear-driven rotating shaft 16 via a sliding sleeve I 14. The sliding sleeve I 14 is made into an annular channel I 19. The rotating shaft 16 is then perforated to form a radial channel I 20, with an internal axial passage 21 formed. This design ensures that the rotating shaft 16 remains connected to the return oil passage 11 during rotation. After a certain distance, the rotating shaft 16 is perforated again to form a radial channel II 25, which connects to the axial passage 21. Then, a sliding sleeve II 15 is fitted, and a passage III 23 of a certain circumference is made inside the sliding sleeve II 15. A lever 24 is inserted between the sliding sleeve and the rotating shaft 16, allowing the lever 24 to change the length of the passage III 23 inside the sliding sleeve II 15. When the rotating shaft 16 rotates, the radial channel II 25 on the rotating shaft connects with the internal passage III 23 of the sliding sleeve II 15, thus opening the nozzle return oil passage 11; when the radial channel II 25 is misaligned with the internal passage III 23 of the sliding sleeve II 15, the nozzle return oil passage 11 closes. By changing the rotational speed of the rotating shaft 16, the timing of oil injection can be determined; while the length of the internal passage III 23 of the sliding sleeve II 15 represents the duration for which the nozzle return oil passage 11 is open, i.e., the pulse width of oil injection.

[0058] Example 4: As another preferred embodiment of the present invention, this embodiment is a further detailed description and supplement to the technical solution of the present invention based on the above-described embodiments 1, 2, or 3. In this embodiment, a structure of a mechanical nozzle 6 is provided, as shown in the appendix to the specification. Figure 6 As shown, the mechanical nozzle 6 includes a nozzle body 45, on which an oil inlet pipe connector 46 is provided; a pressure regulating chamber 47 is provided on the upper part of the nozzle body 45, and a pressure regulating spring 48 is provided in the pressure regulating chamber 47. The upper end of the pressure regulating spring 48 is connected to a pressure regulating screw 49, which is threaded onto the top of the nozzle body 45. The lower end of the pressure regulating spring 48 is fixed to a spring seat 50, and a push rod 51 is connected to the bottom of the spring seat 50; a threaded sleeve 52 is connected to the bottom of the nozzle body 45, and a needle valve body 54 is provided on the threaded sleeve 52. The bottom of the push rod 51 is connected to the needle valve 53. The needle valve 53 is located in the needle valve cavity 55 inside the needle valve body 54 and forms a sealing pair with the inner wall of the needle valve cavity 55. The bottom of the needle valve body 54 is provided with an injection hole 56 that communicates with the needle valve cavity 55. The injector body 45 includes an injection passage 57 and a return passage 58. The fuel that enters the injector body 45 through the inlet pipe connector 46 enters the needle valve cavity 55 through the injection passage 57 and a small part enters the pressure regulating chamber 47 through the return passage 58. The pressure regulating chamber 47 is connected to the return nozzle interface 17.

[0059] Fuel enters through the inlet pipe connector 46 and flows into the upper and lower ends of the nozzle via the injection passage 57 and the return passage 58. Because of the throttling orifice in the return passage 58, the amount of fuel entering the upper part of the nozzle is less than that entering the lower part; therefore, for the same volume, the pressure at the lower end is greater than that at the upper end. To maintain balance of the push rod 51, the injection orifice 56 is closed, causing the adjusting pressure spring 48 to generate a downward force, balancing the pressure at both ends and ensuring that the needle valve 53 always blocks the injection orifice 56. When the return passage 11 opens, the pressure of the fuel at the upper end is greater than the pressure within the return passage 11, causing fuel to flow out of the return passage 11. This reduces the amount of fuel at the upper end, decreasing the pressure, thus breaking the force balance of the push rod 51. The push rod 51 moves upward, causing the needle valve 53 to move upward, and fuel is injected from the lower injection orifice 56. When the return passage 11 closes, the pressure at both ends returns to normal, and the push rod 51 returns to its original position, completing one injection cycle. The timing of fuel injection can be controlled by controlling the opening and closing of the return oil passage 11. The duration of the return oil passage 11 being open can be controlled by controlling the pulse width of the fuel injection.

[0060] Although the inventive concept has been specifically shown and described with reference to exemplary embodiments thereof, those skilled in the art should understand that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the claims.

Claims

1. A fully mechanical high-pressure common rail injection system, characterized in that: The system includes an oil tank (1), an oil supply pipe (2), a mechanical oil pump (3), an oil quantity control valve (4), a common rail oil pipe (5), several mechanical nozzles (6), a common rail return oil pipe (7), a main return oil pipe (8), and a mechanical control device (9). The oil tank (1) supplies oil to the mechanical oil pump (3) through the oil supply pipe (2). The mechanical oil pump (3) pressurizes the oil supplied by the oil supply pipe (2) and then delivers it to the common rail oil pipe (5). The oil quantity control valve (4) is located between the mechanical oil pump (3) and the common rail oil pipe (5) to control the amount of oil supplied by the mechanical oil pump (3) to the common rail oil pipe (5). Several mechanical nozzles (6) are connected in parallel on the common rail oil pipe (5). A mechanical oil pressure regulating valve (10) is installed at the return end of the common rail oil pipe (5). The output end of the mechanical oil pressure regulating valve (10) is connected to the common rail return oil pipe (7). Several mechanical nozzles (6) are connected in parallel on the common rail oil pipe (5). A timing control valve (12) for controlling the opening and closing of the return oil path (11) of the mechanical nozzle (6) is provided on the return oil path (11). The return oil paths (11) of several mechanical nozzles (6) are connected in parallel on the common rail return oil pipe (7). The common rail return oil pipe (7) and the oil pump return oil pipe (13) of the mechanical oil pump (3) are both connected to the main return oil pipe (8). The main return oil pipe (8) is connected to the oil tank (1). The return oil from the mechanical oil pump (3), the common rail oil pipe (5), and several mechanical nozzles (6) all flow back to the oil tank (1) through the main return oil pipe (8). The mechanical control device (9) converts the throttle opening and engine speed into mechanical control commands through mechanical conversion, and controls the opening of the fuel quantity control valve (4), the regulating pressure of the mechanical oil pressure regulating valve (10), and the injection timing and pulse width control of the injection timing control valve (12), respectively. The mechanical control device (9) includes a throttle opening mechanical conversion component (27) and an engine speed mechanical conversion component (28). The throttle opening mechanical conversion component converts the displacement of the throttle pedal device into the mechanical adjustment amount of the fuel quantity control valve (4), the mechanical pressure adjustment amount of the mechanical oil pressure regulating valve (10), and the mechanical control amount of the fuel injection timing control valve (12) through mechanical transmission conversion. The engine speed mechanical conversion component (28) converts the engine speed into the mechanical adjustment amount of the fuel quantity control valve (4), the mechanical pressure adjustment amount of the mechanical oil pressure regulating valve (10), and the mechanical control amount of the fuel injection timing control valve (12) through mechanical transmission conversion. The engine speed mechanical conversion assembly (28) includes a drive shaft (36), a variable diameter flywheel assembly (37), a guide rod (38), and a connector (32). The drive shaft (36) establishes a transmission relationship with the engine through a transmission gear II (39), and the drive shaft (36) keeps rotating. One end of the variable diameter flywheel assembly (37) is fixedly connected to the drive shaft (36) in the axial direction, and the other end is fixedly connected to the drive shaft (36) in the radial direction, and can move axially along the drive shaft (36). The end of the variable diameter flywheel assembly (37) that can move axially along the drive shaft (36) is connected to the connector (32) through the guide rod (38). The connector (32) is provided with an oil quantity cam rail (40), an oil pressure cam rail (41), and an injection cam rail (42). A hydraulic quantity connecting rod (33) is slidably mounted on the rail (40), a hydraulic pressure connecting rod (34) is slidably connected on the hydraulic pressure cam rail (41), and an oil injection connecting rod (35) is slidably connected on the oil injection cam rail (42). When the rotational speed of the drive shaft (36) increases, the rotational speed of the variable diameter flywheel assembly (37) increases with the rotational speed of the drive shaft (36). Under the action of centrifugal force, the diameter of the variable diameter flywheel assembly (37) increases and the axial distance decreases, thereby driving the connecting piece (32) to move in the direction of the variable diameter flywheel assembly (37). Under the action of the hydraulic quantity cam rail (40), the hydraulic pressure cam rail (41), and the oil injection cam rail (42), the movement of the connecting piece (32) is converted into the displacement of the hydraulic quantity connecting rod (33), the hydraulic pressure connecting rod (34), and the oil injection connecting rod (35), respectively.

2. The fully mechanical high-pressure common rail injection system as described in claim 1, characterized in that: The throttle opening mechanical conversion assembly (27) includes a connecting slide rod (29), a return spring (30), a fixed sleeve (31), and a connector (32). The upper end of the connecting slide rod (29) is connected to the throttle pedal device, and the lower end of the connecting slide rod (29) passes through the fixed sleeve (31) and is connected to the connector (32). The return spring (30) is sleeved on the connecting slide rod (29) and the fixed sleeve (31). The upper end of the return spring (30) is fixedly connected to the connecting slide rod (29), and the lower end is fixedly connected to the fixed sleeve (31). The fixed sleeve (31) is fixed. The connector (32) is provided with an oil quantity connecting rod (33), an oil pressure connecting rod (34), and an oil injection connecting rod (35). The connecting slide rod (29) is displaced by the transmission of the throttle pedal device, which drives the connector (32) to displace, thereby driving the oil quantity connecting rod (33), the oil pressure connecting rod (34), and the oil injection connecting rod (35) to displace.

3. The fully mechanical high-pressure common rail injection system as described in claim 1, characterized in that: A return spring (30) is provided between the two ends of the variable diameter flywheel assembly (37). The rotational speed of the drive shaft (36) is reduced, the centrifugal force on the variable diameter flywheel assembly (37) is reduced, and under the action of the return spring (30), the diameter of the variable diameter flywheel assembly (37) becomes smaller and the axial distance becomes larger.

4. The fully mechanical high-pressure common rail injection system as described in claim 1 or 2, characterized in that: The throttle opening mechanical conversion assembly (27) and the engine speed mechanical conversion assembly (28) share the same connector (32). The connector (32) is provided with left and right guide rails (43) that cooperate with the connecting slide rod (29) and upper and lower guide rails (44) that cooperate with the guide rod (38). When the connector (32) is displaced by the variable diameter flywheel assembly (37) under the action of the left and right guide rails (43), it slides left and right relative to the connecting slide rod (29); when the connector (32) is displaced by the connecting slide rod (29) under the action of the upper and lower guide rails (44), it slides up and down relative to the guide rod (38).

5. The fully mechanical high-pressure common rail injection system as described in claim 2 or 3, characterized in that: The oil quantity connecting rod (33) is connected to the oil quantity control valve (4), and the displacement of the oil quantity connecting rod (33) is the adjustment amount of the oil quantity control valve (4); the oil pressure connecting rod (34) is connected to the mechanical oil pressure regulating valve (10), and the displacement of the oil pressure connecting rod (34) is the oil pressure control amount of the mechanical oil pressure regulating valve (10); the fuel injection connecting rod (35) is connected to the fuel injection timing control valve (12), and the displacement of the fuel injection connecting rod (35) is the control amount of the fuel injection timing control valve (12), thereby realizing the control of the fuel injection timing control valve (12) on the fuel injection time and fuel injection pulse width.

6. The fully mechanical high-pressure common rail injection system as described in any one of claims 1-3, characterized in that: The injection timing control valve (12) includes a sliding sleeve I (14), a sliding sleeve II (15), and a rotating shaft (16). The sliding sleeve I (14) and the sliding sleeve II (15) are axially sealed and connected to the rotating shaft (16), and the rotating shaft (16) rotates relative to the sliding sleeve I (14) and the sliding sleeve II (15). The sliding sleeve I (14) is provided with a passage I (18) that communicates with the return nozzle interface (17) of the mechanical nozzle (6). An annular channel I (19) is provided between the sliding sleeve I (14) and the rotating shaft (16). The passage I (18) communicates with the annular channel I (19). The rotating shaft (16) is provided with a radial channel I (20) that communicates with the annular channel I (19). An axial passage (21) is provided inside the rotating shaft (16). The radial channel I (20) communicates with the axial passage (21). The sliding sleeve II (15) is provided with a passage II (22) connected to the downstream of the return oil passage (11) of the mechanical nozzle (6). A passage III (23) of a certain circumference is provided between the sliding sleeve II (15) and the rotating shaft (16). A lever (24) for changing the length of the passage III (23) is provided on the passage III (23). The passage II (22) is connected to the passage III (23). A radial channel II (25) connected to the passage III (23) is provided on the rotating shaft (16). The radial channel II (25) is connected to the axial passage (21).

7. The fully mechanical high-pressure common rail injection system as described in claim 6, characterized in that: The paddle (24) is connected to the mechanical control device (9) through a mechanical connection structure. The mechanical control device (9) converts the throttle opening and engine speed into mechanical control commands through mechanical conversion. By changing the position of the paddle (24) through the mechanical connection structure, the length of the passage Ⅲ (23) is changed, thereby realizing the control of the injection timing and pulse width of the injection timing control valve (12).

8. The fully mechanical high-pressure common rail injection system as described in claim 6, characterized in that: A transmission gear I (26) is fixedly mounted on the rotating shaft (16), and a transmission relationship is established with the engine through the transmission gear I (26), so that the rotating shaft (16) keeps rotating.

9. The fully mechanical high-pressure common rail injection system as described in any one of claims 1-3, characterized in that: The mechanical nozzle (6) includes a nozzle body (45), on which an oil inlet pipe connector (46) is provided; a pressure regulating chamber (47) is provided on the upper part of the nozzle body (45), and a pressure regulating spring (48) is provided in the pressure regulating chamber (47). The upper end of the pressure regulating spring (48) is connected to a pressure regulating screw (49), which is threaded onto the top of the nozzle body (45). The lower end of the pressure regulating spring (48) is fixed to a spring seat (50), and a push rod (51) is connected to the bottom of the spring seat (50); a threaded sleeve (52) is connected to the bottom of the nozzle body (45), and a needle valve body (54) is provided on the threaded sleeve (52). The bottom of the push rod (51) is connected to the needle valve (53). The needle valve (53) is located in the needle valve cavity (55) inside the needle valve body (54) and forms a sealing pair with the inner wall of the needle valve cavity (55). The bottom of the needle valve body (54) is provided with an injection hole (56) that communicates with the needle valve cavity (55). The injector body (45) includes an injection passage (57) and a return passage (58). The fuel that enters the injector body (45) through the inlet pipe joint (46) enters the needle valve cavity (55) through the injection passage (57) and a small part enters the pressure regulating chamber (47) through the return passage (58). The pressure regulating chamber (47) is connected to the return nozzle interface (17).

10. The fully mechanical high-pressure common rail injection system as described in any one of claims 1-3, characterized in that: An oil filter (59) is installed on the oil supply pipe (2).

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