A mechanical oil circuit on / off control device and a mechanically controlled fuel injector

Abstract

This invention relates to the field of internal combustion engine fuel supply, specifically to a mechanical fuel circuit on / off control device and a mechanically controlled fuel injector. The mechanical fuel circuit on / off control device includes a plunger sleeve, a plunger, and a plunger cover. The plunger sleeve has an axial hole, an inlet port, and an outlet port. The plunger has an insertion portion inserted into the axial hole. Two channels are formed between the end face of the insertion portion and its circumferential surface. The plunger cover has a frustum inserted into the axial hole. The end face of the frustum adjacent to the insertion portion has a communicating groove. When the inlet port is connected to one of the channels on the insertion portion, the communicating groove is simultaneously connected to both channels, and the outlet port is connected to the other channel. This invention controls the on / off of the fuel circuit by the rotation of the plunger within the plunger sleeve. This control process does not rely on any electronic components, but is completed solely by the mechanical structure itself, thus avoiding failure due to electromagnetic interference.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine fuel supply, specifically to a mechanical fuel circuit on / off control device and a mechanically controlled fuel injector. Background Technology

[0002] Diesel engines are crucial power systems in modern agriculture, shipbuilding, and the military. With increasingly scarce energy resources and stringent emission regulations, energy conservation and emission reduction are becoming ever more important. Electronically controlled high-pressure common rail systems offer advantages such as precise fuel injection control, low fuel consumption and emissions, a wider load range, and lower noise, making them an important means of improving diesel engine combustion efficiency and reducing pollutant emissions.

[0003] The development of modern agriculture is inseparable from agricultural machinery. In 2019, the total power of agricultural machinery in China was 1.028 billion kilowatts, of which diesel engines accounted for 797 million kilowatts, or 77.55% of the total power. However, the promotion of electronically controlled high-pressure common rail systems in agriculture faces the following problems: First, the electronic control system is expensive and difficult to promote in the agricultural machinery field; second, the maintenance and replacement of the electronic control system and its components require professional personnel, which greatly reduces agricultural production efficiency and increases production costs; third, the working environment of agricultural machinery is harsh, and components are easily damaged in such an environment, especially the solenoid valves in the fuel injectors.

[0004] According to a report by the International Maritime Organization (IMO), approximately 95% of ships worldwide use diesel engines as their primary power source. In China, diesel engines are the most widely used marine propulsion system. Marine diesel engines are the heart of a ship's power system; a failure can have serious consequences, thus placing higher demands on the reliability of common rail systems. However, the lifespan of components in the electronic control system is unpredictable, and damage can be sudden. Furthermore, ships have numerous electromechanical devices, and the common rail system's electronic control unit is susceptible to strong electromagnetic interference. This places higher demands on the hardware anti-interference design of the high-voltage common rail system's electronic control unit, which not only increases the production cost of diesel engines but also introduces greater risks.

[0005] In my country's land-based military field, diesel engines are used in the power systems of tanks, infantry fighting vehicles, armored vehicles, and self-propelled artillery, as well as in the power generation systems of combat bases. In my country's naval field, diesel engines are also the mainstream power choice, used in the main engine power and power generation systems of various combat ships and support vessels.

[0006] Finally, the world's three major companies—Ford (USA), Bosch (Germany), and Denso (Japan)—produce high-pressure common rail systems for diesel engines, holding over 90% of the global market share. Furthermore, the high-pressure common rail pressure sensors are primarily manufactured by Bosch and Denso. Imported high-pressure common rail systems of the same type are 20%-30% more expensive than domestically produced ones. Therefore, my country urgently needs to develop a high-pressure common rail system with independent intellectual property rights.

[0007] In a high-pressure common rail system, fuel injection control is undoubtedly the core of the control system. The solenoid valve, as the actuator of the injector, controls the injection timing and quantity by controlling the magnitude and duration of the current flowing through it. However, the solenoid valves and other components in the electronically controlled high-pressure common rail system are susceptible to electromagnetic interference, which can cause them to malfunction and fail to perform their intended actions. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a mechanical oil circuit on / off control device and a mechanically controlled fuel injector, so as to control the on / off of the oil circuit in a simple and reliable mechanical control method, thereby avoiding the influence of electromagnetic interference and ensuring that the fuel injection system can operate stably for a long time.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] A mechanical oil circuit on / off control device includes a plunger sleeve, a plunger, and a plunger cover; the plunger sleeve has an axial hole; the plunger sleeve also has an oil inlet and an oil outlet communicating with the axial hole; the plunger has an insertion part that is inserted into the axial hole and can rotate within the axial hole; there are two independent channels between the end face and the circumferential surface of the insertion part; the plunger cover has a frustum inserted into the axial hole; the end face of the frustum adjacent to the insertion part has a communicating groove; when the oil inlet is connected to one of the channels on the insertion part, the communicating groove is simultaneously connected to both channels, and the oil outlet is connected to the other channel.

[0011] As an optional implementation, it also includes a pressure cap and an elastic element; the pressure cap is connected to the end of the plunger sleeve away from the plunger; the pressure cap has a receiving cavity; the elastic element is disposed in the receiving cavity and provides compressive force to the plunger cap.

[0012] As an alternative implementation, the frustum portion is rotatable within the axial bore; the plunger cap has an axially protruding rotating handle at the end away from the plunger; and the pressure cap has a through hole through which the rotating handle passes.

[0013] As an optional implementation, the elastic element is a spring or an elastic rubber ring.

[0014] As an optional implementation, the insertion part has a first axial hole, a second axial hole, a first radial hole, and a second radial hole, wherein the first axial hole is located at the axis of the plunger, the first radial hole is connected to the first axial hole, and the second radial hole is connected to the second axial hole; the first radial hole is located in the circumferential direction of the oil outlet port corresponding to the insertion part; and the second radial hole is located in the circumferential direction of the oil inlet port corresponding to the insertion part.

[0015] As an optional implementation, the insertion portion has a circumferential groove at a position corresponding to the second radial hole.

[0016] As an optional implementation, the plunger also has a first mounting portion for assembling a bearing.

[0017] As an optional implementation, the plunger also has a second mounting portion for assembling gears.

[0018] As an optional implementation, the plunger sleeve has a connecting lug.

[0019] A mechanically controlled fuel injector includes a mechanical nozzle, a first tee connector, a second tee connector, a throttling device, and a mechanical fuel circuit on / off control device as described above. The first interface of the first tee connector is connected to an inlet pipe; the second interface of the first tee connector is connected to the inlet of the mechanical nozzle; the third interface of the first tee connector is connected to the first interface of the second tee connector via the throttling device; the second interface of the second tee connector is connected to the return port of the mechanical nozzle; and the third interface of the second tee connector is connected to the inlet port of the mechanical fuel circuit on / off control device.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention controls the opening and closing of the oil circuit by rotating the plunger in the plunger sleeve. This control process does not rely on any electronic components and is completed solely by the mechanical structure itself. Therefore, it will not be affected by electromagnetic interference and will ensure that the fuel injection system can operate stably for a long time. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the mechanical oil circuit on / off control device described in this invention.

[0022] Figure 2 This is a schematic diagram of the plunger in the mechanical oil circuit on / off control device of the present invention.

[0023] Figure 3This is a schematic diagram of the plunger sleeve in the mechanical oil circuit on / off control device of the present invention.

[0024] Figure 4 This is a schematic diagram of the plunger cover in the mechanical oil circuit on / off control device of the present invention.

[0025] Figure 5 This is a schematic diagram of the pressure cover in the mechanical oil circuit on / off control device of the present invention.

[0026] Figure 6 This is a cross-sectional view of the mechanical oil circuit on / off control device of the present invention when the oil inlet interface is connected to the second radial hole.

[0027] Figure 7 This is a cross-sectional view of the mechanical oil circuit on / off control device of the present invention when the oil outlet interface is connected to the first radial hole.

[0028] Figure 8 This is a schematic diagram of the connection structure of the mechanically controlled fuel injector described in this invention.

[0029] The labels in the diagram are as follows: 1. Plunger, 11. Insertion part, 12. First assembly part, 13. Second assembly part, 14. First axial hole, 15. Second axial hole, 16. First radial hole, 17. Second radial hole, 18. Circumferential groove, 19. Keyway, 2. Plunger sleeve, 21. Axial hole, 22. Threaded connection hole, 23. Connecting ear plate, 24. Oil inlet port, 25. Oil outlet port, 3. Plunger cover, 31. Frustum, 32. Rotating handle, 33. Connecting groove, 4. Pressure cover, 41. Receiving cavity, 42. Through hole, 43. Bolt connection hole, 5. Elastic element, 6. Mechanical oil circuit on / off control device, 7. Second tee connector, 8. Throttling device, 9. First tee connector, 10. Mechanical nozzle. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0031] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0032] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, while "above," "below," "within," etc. are understood to include the stated number. If terms such as "first," "second," etc., are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0033] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0034] Example 1

[0035] like Figure 1 As shown in the figure, this application embodiment introduces a mechanical oil circuit on / off control device, including a plunger sleeve 2, a plunger 1 and a plunger cover 3.

[0036] Among them, such as Figure 3 As shown, the plunger sleeve 2 has an axial hole 21 to accommodate a portion of the plunger 1 and the plunger cover 3. The plunger sleeve 2 also has an oil inlet port 24 and an oil outlet port 25 communicating with the axial hole 21.

[0037] like Figure 2 As shown, the plunger 1 has an insertion part 11 that can be inserted into and rotate within the axial hole 21. The end face and circumferential surface of the insertion part 11 have two independent channels that are not connected to each other.

[0038] like Figure 4 As shown, the plunger cap 3 has a frustum portion 31 that can be inserted into the axial hole 21. The end face of the frustum portion 31 adjacent to the insertion portion 11 has a communicating groove 33.

[0039] The insertion portion 11 of the plunger 1 and the frustum portion 31 of the plunger cover 3 are closely fitted together within the axial hole 21 of the plunger sleeve 2, as shown. Figure 6 and Figure 7As shown, when the plunger 1 rotates within the plunger sleeve 2 until the inlet port 24 connects with one of the channels on the insertion part 11, the connecting groove 33 simultaneously connects with both channels, and the outlet port 25 connects with the other channel. In this way, the inlet port 24 and the outlet port 25 are connected through the two channels within the plunger 1 and the connecting groove 33 on the plunger cover 3, allowing fuel to flow freely between them. When the plunger 1 continues to rotate within the plunger sleeve 2 until the inlet port 24 and the corresponding channel on the insertion part 11 are misaligned and not connected, the connecting groove 33 is not simultaneously connected with both channels, and the outlet port 25 is also misaligned and not connected with its corresponding channel.

[0040] In this embodiment, the oil circuit is controlled by the rotation of the plunger 1 within the plunger sleeve 2. This control process does not rely on any electronic components and is completed solely by the mechanical structure itself. Therefore, it will not be affected by electromagnetic interference and will ensure that the fuel injection system can operate stably for a long time.

[0041] To ensure that the insertion portion 11 of the plunger 1 and the frustum portion 31 of the plunger cover 3 remain close and tightly fitted together within the axial hole 21 of the plunger sleeve 2, such as Figure 1 , Figure 6 and Figure 7 As shown in the embodiment of this application, a mechanical oil circuit on / off control device may further include a pressure cap 4 and an elastic element 5. The pressure cap 4 is connected to the end of the plunger sleeve 2 away from the plunger 1, such as... Figure 5 As shown, the pressure cap 4 has a receiving cavity 41. The elastic member 5 is disposed in the receiving cavity 41 and provides a squeezing force to the plunger cap 3, so that the plunger cap 3 always tends to move in the direction of the plunger 1, thereby ensuring that the frustum portion 31 of the plunger cap 3 can always be close to and tightly pressed against the insertion portion 11 of the plunger 1, so as to ensure the sealing effect when the connecting groove 33 is connected to the two channels.

[0042] The elastic element 5 here can be a spring, or an elastic rubber ring or other elastic element, as long as it can provide the corresponding elastic force.

[0043] The pressure cap 4 and the plunger sleeve 2 can be detachably connected. For example, multiple threaded connection holes 22 are provided on the end face of the plunger sleeve 2, and multiple corresponding bolt connection holes 43 are provided on the pressure cap 4. After the bolt passes through the bolt connection hole 43, it is connected to the corresponding threaded connection hole 22 to realize the detachable connection between the pressure cap 4 and the plunger sleeve 2.

[0044] To further control the duration and flow rate of oil circuit on / off, such as Figure 1 , Figure 4 , Figure 6 and Figure 7As shown in the embodiment of this application, in a mechanical oil circuit on / off control device, the frustum 31 of the plunger cover 3 can rotate within the axial hole 21, and the end of the plunger cover 3 away from the plunger 1 has an axially protruding rotating handle 32; the pressure cover 4 has a through hole 42 through which the rotating handle 32 passes. As previously mentioned, the frustum 31 of the plunger cover 3 has a communicating groove 33, and the communicating area between the communicating groove 33 and the two channels in the plunger 1 determines the duration and flow rate of the oil circuit on / off. When the frustum 31 is rotated by the rotating handle 32, the communicating area between the communicating groove 33 and the two channels in the plunger 1 changes. For example, if the communicating area decreases, the oil circuit connection time decreases, and its flow rate also decreases; conversely, if the communicating area increases, the oil circuit connection time increases, and its flow rate also increases.

[0045] As an optional implementation, the two channels within the plunger 1 can be configured as follows: Figure 2 As shown: The insertion portion 11 has a first axial hole 14 and a second axial hole 15 extending to the end face, with the first axial hole 14 located at the axis of the plunger 1. The insertion portion 11 also has a first radial hole 16 and a second radial hole 17 extending to the circumferential surface, with the first radial hole 16 communicating with the first axial hole 14 and the second radial hole 17 communicating with the second axial hole 15. Furthermore, the first radial hole 16 is located in the circumferential direction corresponding to the oil outlet port 25 in the insertion portion 11, and the second radial hole 17 is located in the circumferential direction corresponding to the oil inlet port 24 in the insertion portion 11.

[0046] The connecting groove 33 can be an elongated groove, with one end preferably located at the center of the frustum 31. The length of the entire connecting groove 33 is greater than or equal to the distance between the first axial hole 14 and the second axial hole 15 on the end face of the insertion part 11, and preferably equal in length. The width of the connecting groove 33 is preferably equal to the diameter of the first axial hole 14 / second axial hole 15. In this way, since the first axial hole 14 is located at the axis of the plunger 1 and one end of the connecting groove 33 is located at the center of the frustum 31, the first axial hole 14 can always be connected to the connecting groove 33, no matter how the plunger 1 rotates. At the same time, in order to ensure that the second radial hole 17 can always be connected to the oil inlet interface 24, a circumferential groove 18 can be machined on the insertion part 11 at the position corresponding to the second radial hole 17, and the second radial hole 17 is located in the circumferential groove 18. At this point, regardless of how the plunger 1 rotates relative to the plunger sleeve 2, the oil inlet port 24, the second radial hole 17, and the second axial hole 15 remain connected, as do the connecting groove 33, the first axial hole 14, and the first radial hole 16. During the rotation of the plunger 1, the state between the second axial hole 15 and the connecting groove 33 sequentially changes: initially partially connected, fully aligned, partially connected, and completely misaligned. Assume that it takes 1 second for the second axial hole 15 and the connecting groove 33 to go from initially partially connected to completely misaligned. Simultaneously, within this 1 second, the first radial hole 16 and the oil outlet port 25 also sequentially change: initially partially connected, fully aligned, partially connected, and completely misaligned. During this entire 1 second, the entire oil passage is connected, and fuel can pass smoothly. As the plunger 1 continues to rotate, the second axial hole 15 and the connecting groove 33 are no longer aligned, and the first radial hole 16 is no longer aligned with the oil outlet port 25. At this point, the oil passage is blocked, and fuel cannot pass through.

[0047] As mentioned earlier, in addition to switching the oil circuit on and off by rotating the plunger 1, the duration and flow rate of the oil circuit connection can also be adjusted by rotating the plunger cap 3. The specific process is as follows: After slightly rotating the frustum 31 by rotating the handle 32, when the plunger 1 is rotated at the same speed, assuming that the time taken for the first radial hole 16 and the oil outlet port 25 to go through the stages of initial partial connection, complete alignment connection, partial connection, and complete misalignment is still 1 second, the second axial hole 15 and the connecting groove 33 have not completely gone through the stages of initial partial connection, complete alignment connection, partial connection, and complete misalignment within this 1 second. It is possible that when the first radial hole 16 and the oil outlet port 25 are in the initial partial connection state, the second axial hole 15 and the connecting groove 33 have not yet started to connect; or when the first radial hole 16 and the oil outlet port 25 are in the complete misalignment state, the second axial hole 15 and the connecting groove 33 are still in the partial connection state. Therefore, the entire oil circuit connection time is no longer a full second, but less than one second, thus further controlling the oil circuit connection duration by rotating the frustum 31. Furthermore, when the first radial hole 16 and the oil outlet port 25 are fully aligned and connected, the second axial hole 15 and the connecting groove 33 may only be in a partially connected or initial state. At this time, the flow rate of the entire oil circuit can never reach its peak, thereby achieving oil circuit flow rate regulation.

[0048] like Figure 2 As shown, the plunger 1 is a stepped shaft, which is divided into three parts: an insertion part 11, a first assembly part 12, and a second assembly part 13. The first assembly part 12 can be used to assemble bearings, and the second assembly part 13 can be provided with a keyway 19 to assemble gears.

[0049] like Figure 3 As shown, several connecting lugs 23 can also be provided on the plunger sleeve 2 by welding or other means, so that the plunger sleeve 2 can be fixedly installed by the connecting lugs 23.

[0050] Example 2

[0051] This application describes a mechanically controlled fuel injector, such as... Figure 8 As shown, it includes a mechanical nozzle 10, a first tee connector 9, a second tee connector 7, a throttling device 8, and a mechanical oil circuit on / off control device 6 as described in Embodiment 1.

[0052] The first interface of the first tee connector 9 is used to connect to the oil inlet pipe of the high-pressure common rail. The second interface of the first tee connector 9 is connected to the oil inlet of the mechanical nozzle 10. The third interface of the first tee connector 9 is connected to the first interface of the second tee connector 7 through the throttling device 8. The second interface of the second tee connector 7 is connected to the oil return port of the mechanical nozzle 10. The third interface of the second tee connector 7 is connected to the oil inlet 24 of the mechanical oil circuit on / off control device 6. The oil outlet 25 of the mechanical oil circuit on / off control device 6 is used to connect to the oil return pipe of the high-pressure common rail.

[0053] In this embodiment, the plunger sleeve 2 in the mechanical oil circuit on / off control device 6 can be fixed to the high-pressure common rail bracket via the connecting lug 23, and the plunger 1 can be mounted on the high-pressure common rail bracket via the bearing on the first assembly part 12. Furthermore, the plunger 1 can also be connected to the crankshaft of the engine via the gear on the second assembly part 13, so that the crankshaft of the engine drives the plunger 1 to rotate. At the same time, the on / off of the oil circuit in the mechanical oil circuit on / off control device 6 is linked to the rotation of the crankshaft of the engine.

[0054] The mechanical nozzle 10 here refers to a traditional mechanical nozzle, such as the injector assembly for the Changchai Changfa ZR175 / ZR180 direct injection diesel engine (6hp / 8hp). Fuel enters the mechanical nozzle 10 through the inlet pipe connector and flows into the upper and lower ends of the nozzle 10 via the first and second fuel passages. Due to the presence of a throttling orifice in the first fuel passage, less fuel enters the upper end of the mechanical nozzle 10 than the lower end. Therefore, under the same volume, the pressure at the lower end of the mechanical nozzle 10 is greater than the pressure at the upper end. To maintain the balance of the ejector rod of the mechanical nozzle 10 and keep the nozzle orifice closed, the pressure regulating spring inside the mechanical nozzle 10 needs to be adjusted to generate a downward force to balance the pressure at both ends, ensuring that the needle valve always blocks the nozzle orifice. When the return oil pipe passage of the mechanical nozzle 10 is open, the pressure of the fuel at the upper end is greater than the oil pressure in the return oil pipe. Therefore, fuel flows out of the return oil pipe, resulting in a decrease in the amount of fuel at the upper end and a decrease in pressure. This breaks the force balance of the push rod, causing it to move upwards, which in turn causes the needle valve body to move upwards, and fuel is injected from the lower nozzle. When the return oil pipe passage is closed, the pressure at both ends recovers, and the push rod returns to its original position. The above process constitutes the entire process of one fuel injection by the mechanical nozzle 10. Therefore, by controlling the opening and closing time of the return oil pipe, the timing of fuel injection can be controlled. By controlling the duration of the return oil pipe being open, the duration of fuel injection (i.e., the pulse width of fuel injection) can be controlled.

[0055] In this embodiment, a mechanical oil circuit on / off control device 6 is connected to the return port of the mechanical nozzle 10 to control the opening and closing time and duration of fuel injection from the mechanical nozzle 10. High-pressure fuel in the high-pressure common rail inlet pipe is divided into two branches via the first three-way connector 9, delivering high-pressure fuel to the upper and lower ends of the mechanical nozzle 10. One branch connects to the nozzle orifice of the mechanical nozzle 10, and the other branch connects to the return pipe of the mechanical nozzle 10 via a throttling device 8. The throttling device 8, also known as a throttle valve, limits and reduces the flow rate in its path, thereby creating a pressure differential. When high-pressure fuel enters the mechanical nozzle 10, the presence of the throttling device 8 causes the oil pressure at the top of the needle valve of the mechanical nozzle 10 to be lower than the oil pressure at the bottom (i.e., the end blocking the nozzle). Because a set of pressure-adjusting springs at the top of the needle valve of the mechanical nozzle 10 balances the pressure differential across the needle valve, the needle valve in the mechanical nozzle 10 remains balanced, ensuring that the needle valve always blocks the nozzle. When the oil circuit in the mechanical oil circuit on / off control device 6 is open, the fuel at the top of the needle valve will be discharged through the second three-way connector 7 and the mechanical oil circuit on / off control device 6 under its own pressure, all of which will be discharged into the high-pressure common rail return pipe and finally back to the fuel tank. At this time, the subsequent discharge from the top of the needle valve will cause the balance of the needle valve to be broken. Under the thrust of the oil pressure at the bottom of the needle valve, the needle valve will move away from the nozzle, the nozzle will open, and then the fuel will be sprayed out from the nozzle. When the oil circuit in the mechanical oil circuit on / off control device 6 is blocked, because the oil inlet pipe connector of the mechanical nozzle 10 is continuously injected, the needle valve will eventually restore its balance, and then the needle valve will block the nozzle again, stopping the injection. The above process is the fuel injection process of the mechanically controlled injector described in the embodiment of this application.

[0056] This application embodiment replaces the existing solenoid valve nozzle with a mechanically controlled injector, thereby avoiding electromagnetic interference during the injection process. By controlling the on / off time and duration of the oil circuit in the mechanical oil circuit on / off control device 6, the injection pulse width of the entire mechanically controlled injector can be controlled. By controlling the opening and closing of the oil circuit in the mechanical oil circuit on / off control device 6, the injection time can be controlled. By controlling the duration of the oil circuit in the mechanical oil circuit on / off control device 6, the injection pulse width of the mechanical nozzle 10 can be controlled.

[0057] The mechanically controlled injector described in this embodiment uses the same input signals as the electronic control system: throttle (foot pedal) and engine speed. However, unlike the electronic control system, it does not use electrical signals but directly uses throttle opening and engine speed as commands. The speed of plunger 1 can adjust the injection interval and timing, which can be adjusted according to the engine speed. The adjustment of the injection pulse width can apply the coupling result of throttle opening and engine speed to the rotating handle 32 of plunger cover 3 through mechanical transmission.

[0058] In summary, the embodiments of this application use a mechanical device with a longer lifespan, higher reliability, and lower cost to replace the function of the solenoid valve, eliminating the components and sensors included in the electronic control system, and fully utilizing mechanical language to control the injection timing and injection pulse width of the injector.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, various improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A mechanical oil circuit on / off control device, characterized in that: Includes plunger sleeve (2), plunger (1) and plunger cap (3); The plunger sleeve (2) has an axial hole (21); the plunger sleeve (2) also has an oil inlet (24) and an oil outlet (25) communicating with the axial hole (21). The plunger (1) has an insertion part (11) that is inserted into the axial hole (21) and can rotate within the axial hole (21); the end face of the insertion part (11) and the circumferential surface have two independent channels; The plunger cap (3) has a frustum (31) inserted into the axial hole (21); the end face of the frustum (31) adjacent to the insertion part (11) has a communicating groove (33). The oil passage between the oil inlet port (24) and the oil outlet port (25) is opened and closed by the rotation of the plunger (1) inside the plunger sleeve (2); It also includes a pressure cap (4) and an elastic element (5); the pressure cap (4) is connected to the end of the plunger sleeve (2) away from the plunger (1); the pressure cap (4) has a receiving cavity (41); the elastic element (5) is disposed in the receiving cavity (41) and provides a compressive force to the plunger cap (3); The frustum portion (31) is rotatable within the axial hole (21); the plunger cap (3) has an axially protruding rotating handle (32) at the end away from the plunger (1); the pressure cap (4) has a through hole (42) through which the rotating handle (32) passes. The insertion part (11) has a first axial hole (14), a second axial hole (15), a first radial hole (16), and a second radial hole (17). The first axial hole (14) is located at the axis of the plunger (1). The first radial hole (16) is connected to the first axial hole (14), and the second radial hole (17) is connected to the second axial hole (15). The first radial hole (16) is located in the circumferential direction of the oil outlet (25) corresponding to the insertion part (11); the second radial hole (17) is located in the circumferential direction of the oil inlet (24) corresponding to the insertion part (11); The insertion part (11) has a circumferential groove (18) at the position corresponding to the second radial hole (17).

2. The mechanical oil circuit on / off control device as described in claim 1, characterized in that: The elastic element (5) is a spring or an elastic rubber ring.

3. The mechanical oil circuit on / off control device as described in claim 1, characterized in that: The plunger (1) also has a first assembly part (12) for assembling the bearing.

4. The mechanical oil circuit on / off control device as described in claim 1, characterized in that: The plunger (1) also has a second assembly part (13) for assembling gears.

5. The mechanical oil circuit on / off control device as described in claim 1, characterized in that: The plunger sleeve (2) has a connecting lug (23).

6. A mechanically controlled fuel injector, characterized in that: It includes a mechanical nozzle (10), a first tee connector (9), a second tee connector (7), a throttling device (8), and a mechanical oil circuit on / off control device (6) as described in any one of claims 1-5; The first interface of the first tee connector (9) is used to connect to the oil inlet pipe. The second interface of the first tee connector (9) is connected to the oil inlet of the mechanical nozzle (10). The third interface of the first tee connector (9) is connected to the first interface of the second tee connector (7) through the throttling device (8). The second interface of the second tee connector (7) is connected to the oil return port of the mechanical nozzle (10). The third interface of the second tee connector (7) is connected to the oil inlet (24) in the mechanical oil circuit on / off control device (6).

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