Oil injection control system for diesel engine

Abstract

An oil injection control system for a diesel engine comprises a multi-oil injection pump, an oil pumping mechanism, a driving mechanism and an oil supply amount adjusting mechanism, the oil pumping mechanism and the driving mechanism are arranged in a pump body, and the oil supply amount adjusting mechanism is arranged on the pump body; the oil pumping mechanism comprises a plunger which is driven by the oil supply amount adjusting mechanism to rotate, and a spiral line capable of adjusting the oil supply amount is arranged on the plunger. The driving mechanism comprises a hydraulic driving unit capable of driving the plunger to do linear reciprocating motion in the axial direction of the pump body. The oil injection pump device has the advantages that the oil injection pump device is simple in structure and easy to implement, the production and manufacturing cost can be greatly reduced, and the cost performance of a whole machine product is higher; the product is wider in application range and high in practicability; the control precision and strength are effectively improved, and the reliability and safety of products are guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of diesel engine equipment technology, and in particular to a fuel injection control system for diesel engines. Background Technology

[0002] In a diesel engine's fuel system, the fuel injection pump (high-pressure fuel pump) is an extremely important component, the most crucial part of the diesel fuel supply system. Often referred to as the "heart" of a diesel engine, the fuel injection pump assembly is typically a single unit comprised of the fuel injection pump, governor, and other components. The function of the fuel injection pump is to deliver high-pressure diesel fuel to the injectors at regular intervals and in measured quantities according to the diesel engine's load. The governor, on the other hand, ensures low-speed operation of the diesel engine and limits its maximum speed, maintaining a specific relationship between the injection quantity and engine speed.

[0003] In the existing technology, fuel injection pumps can be mainly divided into three types: plunger-type fuel injection pumps, fuel injection pump-injector, and rotor-distributor fuel injection pumps. Among them, plunger-type fuel injection pumps have the longest history and are the most widely used, with high reliability. For example, the existing Chinese utility model patent with patent number 201721032411.4, entitled "High Injection Pressure Fuel Injection Pump", discloses a high injection pressure plunger-type fuel injection pump, which includes a pump body, a delivery valve assembly, a plunger assembly, a plunger spring, a rack and pinion adjustment mechanism, and a transmission component. The upper part of the plunger is fitted inside the plunger sleeve, and a helical groove is provided on the upper part of the plunger. The rack and pinion adjustment mechanism includes a gear ring and a rack. The gear ring is fitted outside the plunger sleeve, and the rack and gear ring cooperate with each other. The fuel supply is adjusted by adjusting the helical groove on the upper part of the plunger (i.e., the plunger rotates by a certain angle).

[0004] However, the traditional plunger-type fuel injection pump in the aforementioned patent achieves plunger rotation through a rack and pinion adjustment mechanism and drives the plunger pump to achieve vertical linear motion using a mechanical cam mechanism. However, because the fuel supply pressure varies with the speed, especially at low speeds, the cam drive device is limited by the mechanical structure itself, resulting in low high-pressure fuel pump discharge pressure and poor fuel atomization. On the other hand, the implementation of the cam-driven mechanical device is relatively complex, and the fuel injection quantity, injection pressure, and injection timing driven by the high-pressure fuel pump cannot be precisely controlled, thus limiting the application of the fuel injection pump.

[0005] Currently, in order to improve the control precision of fuel injection pumps, Chinese utility model patent ZL202010374876.8, entitled "Low-speed diesel engine electronically controlled high-pressure fuel pump," discloses a low-speed diesel engine electronically controlled high-pressure fuel pump. This pump includes a fuel boosting unit, comprising a sleeve and a plunger fitted therein for piston movement to achieve fuel intake and pressurized discharge; a hydraulic drive unit, screwed to the fuel boosting unit, for driving the plunger movement; and a cylinder electronic control unit for receiving and sending electrical signals to control the process of the hydraulic drive unit driving the plunger and the process of the fuel boosting unit intakeing and discharging fuel. The fuel boosting unit is provided with a fuel inlet, an inlet channel, a discharge channel, and a fuel outlet.

[0006] The plunger in this patent eliminates the spiral groove structure; the plunger only moves up and down under piston drive without rotating. The patent uses a cylinder electronic control unit (CCU) to determine the plunger's displacement based on electrical signals transmitted from a plunger displacement sensor. After comparing the plunger's displacement signal with the required displacement signal, an electrical signal is transmitted to an electro-hydraulic directional valve. The electro-hydraulic directional valve (solenoid valve) further controls the plunger's movement and stop by controlling a hydraulic piston. While this control method can achieve precise control of the plunger's displacement and speed, it is generally only suitable for low-speed diesel engines. For high-speed diesel engines (speeds exceeding 1000 rpm / min), the response speed and control accuracy of most solenoid valves cannot meet the requirements, making this control method difficult or even impossible to implement. Because this control method places high demands on the solenoid valves, requiring high-precision, high-frequency response valves, these are currently generally imported from specialized foreign manufacturers and are very expensive, significantly increasing the overall manufacturing cost of the equipment, limiting its applicability, and reducing its practicality.

[0007] In conclusion, to address the issues of low control precision and high manufacturing cost of current diesel engine fuel injection pumps, further improvements are needed in the design of existing fuel injection pump equipment to enhance product performance, reduce product prices, and meet the demands of market competition. Utility Model Content

[0008] The technical problem to be solved by this utility model is to provide a fuel injection pump device for existing diesel engines that has high control accuracy and low manufacturing cost, which addresses the problem of difficulty in balancing control accuracy and manufacturing cost in the existing technology.

[0009] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0010] A fuel injection control system for a diesel engine includes a fuel supply quantity regulating mechanism and a plurality of fuel injection pumps. Each fuel injection pump includes a pump body and a pumping mechanism disposed within the pump body. The pumping mechanism is connected to a drive mechanism for controlling the supply of fuel to the pump. The pumping mechanism includes a plunger housed in a pump chamber within the pump body. Each plunger is throttledly connected to the fuel supply quantity regulating mechanism. A helical groove is provided on the outer peripheral wall near the end of each plunger.

[0011] The fuel supply adjustment mechanism includes a rotary driver with an output gear at its output end. A plunger gear, coaxial with the plunger, is located on the outer peripheral wall of the plunger. The output gear meshes with the plunger gear. The rotary driver adjusts the rotation angle of the output gear according to changes in the diesel engine speed, thereby adjusting the position of the helical groove and the pressure relief oil passage on the pump body, and thus regulating the fuel supply of the injection pump. The change in diesel engine speed reflects the load on the diesel engine. When the actual working load of the diesel engine changes, the fuel demand also changes accordingly. Therefore, the diesel engine speed is used as the control factor for the fuel injection pump's output.

[0012] This utility model employs a fuel injection pump fuel supply adjustment design that differs significantly from conventional designs. It utilizes a rotary driver to output rotation, which is transmitted to the plunger via gears. The fuel injection pump fuel supply is adjusted by controlling the plunger's fixed-angle rotation. Notably, the pump body and plunger in this design utilize a common spiral groove structure on the plunger's outer circumferential wall to adjust the fuel supply. The pump body cavity has a pressure relief oil hole positioned to align with the spiral groove. The rotation of the plunger gear synchronously drives the plunger's rotation, adjusting the position where the spiral groove and pressure relief oil hole connect to change the fuel injection pump's pressure relief position, thereby adjusting the fuel injection quantity within one working stroke of the plunger.

[0013] This new structure is simple and easy to implement. Compared with the traditional structure that drives the plunger rotation through adjustment mechanisms such as gear rings, racks, shift forks, or levers, it is more simplified and compact in structure, and easier to install. It can effectively reduce control errors caused by transmission backlash, which not only improves control accuracy but also ensures the reliability of plunger rotation angle control. It can significantly reduce inaccurate fuel injection adjustment caused by control deviation, thus reducing fuel waste. The whole machine is more energy-efficient and environmentally friendly. Moreover, the rotary drive can be easily combined with electronic control, making operation more convenient and control more intelligent.

[0014] Furthermore, this fuel injection control system is a structural improvement based on the traditional pressure oil pump, avoiding the use of expensive solenoid valves to achieve fuel quantity control. This significantly reduces manufacturing costs and makes the overall product more cost-effective. The accuracy of fuel quantity adjustment is not affected by the performance of the solenoid valve, making it applicable to various types of diesel engines, thus broadening the product's applicability and enhancing its practicality. Compared to traditional cam mechanisms, the electronically controlled hydraulic drive unit has a simpler structure and ensures that the fuel discharge pressure is executed according to the set requirements, effectively improving control accuracy and strength, and guaranteeing the product's reliability and safety.

[0015] As a preferred embodiment, each plunger in the fuel injection pump is drivenly connected to one of the rotary actuators. This design is optimized for individual control of multiple fuel injection pumps within the system. Each fuel injection pump plunger is equipped with an individually controlled rotary actuator, employing a single power source and a single transmission structure. Firstly, this design allows for complete independent control. Single-pump-single-control ensures precise mechanical engagement between the rotary actuator structure and the plunger. Furthermore, errors caused by gear molding and assembly can be corrected through individual coding at the rotary actuator control terminal, resulting in more precise fuel injection quantity adjustment.

[0016] As a preferred embodiment, the rotary drive is a servo motor, and each servo motor is connected to a first electronic control device. The first electronic control device adjusts the rotation direction and angle of the servo motor's output end according to the speed change of the diesel engine. This design provides a preferred rotary drive design. The servo motor, as the power source for rotary drive, has a simple control design, low structural and installation costs, and can achieve precise rotation angle control through the electronic control device. The electronic control device can control the fuel supply according to the actual operating conditions of the diesel engine, making the control more intelligent, resulting in better energy saving and emission reduction effects. Both production costs and future operating costs are lower, balancing practicality and cost-effectiveness.

[0017] As a preferred embodiment, the rotary actuator is a hydraulic motor or a pneumatic motor. This design provides another rotary actuator design parallel to the above design, offering an alternative rotary power source to replace the servo motor. The hydraulic motor or pneumatic motor design also offers the advantage of precise control.

[0018] As a preferred embodiment, the pumping mechanism further includes a plunger sleeve, an oil outlet valve, and an oil outlet connector. The plunger sleeve is fixedly disposed within the pump body, and the plunger is axially slidably inserted into the plunger sleeve. The plunger gear is sleeved on the outer peripheral wall of the plunger sleeve and is circumferentially fixedly engaged with the plunger sleeve. The oil outlet valve is disposed at the top of the plunger sleeve and is equipped with a valve core that can be opened in one direction and a first elastic reset unit for resetting the valve core. The oil outlet connector is fixedly disposed at the top of the oil outlet valve and is used to connect a high-pressure oil pipe for oil supply output. This design specifically optimizes the structure of the pumping mechanism. The plunger gear forms a circumferential fixed engagement with the plunger through the structure of the plunger sleeve, which provides stable circumferential positioning and facilitates assembly and fixation.

[0019] As a preferred embodiment, the plunger gear includes an integrally formed external gear ring and a cylindrical sleeve portion. The sleeve portion is coaxial with the external gear ring, which meshes with the output gear. The sleeve portion has an opening groove on its side wall, with the opening direction opposite to that of the external gear ring. The outer peripheral wall of the plunger has a convex wing structure that mates with the opening groove. The convex wing structure and the opening groove mate to circumferentially position the plunger gear and the plunger. This design provides a preferred plunger gear structure, whose basic structure is sleeve-shaped, facilitating installation and forming a stable structural fit with the plunger. The key-like fit structure with the opening groove and convex wing simplifies the assembly between the gear and the plunger and ensures accurate circumferential positioning.

[0020] As a preferred embodiment, a fixed base is provided on the outer wall of the pump body, and the servo motor is fixedly mounted on the fixed base. A long through-hole groove structure is provided on the side wall of the pump body at the position corresponding to the plunger gear. The rim of the output gear passes through the long through-hole groove structure and extends into the pump body to mesh with the plunger gear. This design integrates the rotary driver and the fuel injection pump structure, making the pump structure more compact, reducing the space occupied by the structure, and facilitating the installation and disassembly of the fuel supply adjustment mechanism. Furthermore, to adapt to the pump's structure and avoid an increase in the overall axial dimension of the structure due to the integrated connection of the rotary driver and the pump, the servo motor and the plunger pump are arranged parallel to each other, with their housings laterally connected. A long through-hole groove structure communicating with the inner plunger sidewall is provided on the pump body, allowing the rim of the output gear to pass through this groove structure and mesh with the inner plunger gear. The design is compact and has good transmission performance.

[0021] As a preferred embodiment, the rotary actuator has an end cover at one end connected to the output gear, the output gear is housed within the end cover, and the end cover is snapped and fixed to the outer wall of the pump body. This design optimizes the mating structure between the actuator and the pump, improves the overall structural integrity of both, and the end cover structure effectively protects the output gear structure.

[0022] As a preferred embodiment, the drive mechanism includes a hydraulic drive unit or a cam-linkage drive unit that abuts against the end of the plunger and drives the plunger to perform linear reciprocating motion along the axial direction of the pump body. The axial reciprocating motion of the plunger, in conjunction with the internal cavity of the pump body, extrudes and supplies oil. The fuel injection pump device also includes a second electronic control device that controls the operation of the hydraulic drive unit. This design optimizes the drive mechanism; the pumping action of the plunger is its axial reciprocating motion within the pump body cavity. This action can preferably be driven by either hydraulic or cam-linkage methods. Both of these drive structure designs offer good controllability and are easily automated and intelligently controlled by the second electronic control device.

[0023] As a preferred embodiment, the fuel injection control system further includes a speed sensor for detecting the diesel engine speed, which is communicatively connected to the first electronic control device. This design primarily aims to facilitate the monitoring and feedback of diesel engine speed changes to reflect real-time load variations. Through pump load detection and feedback, the accuracy and reliability of the product's operation are significantly improved, making the product more intelligent and achieving better energy-saving and emission-reduction effects. This results in a more optimized solution for both production and future operating costs, balancing practicality and cost-effectiveness. Attached Figure Description

[0024] Figure 1 This is one of the three-dimensional structural diagrams of the fuel injection pump according to an embodiment of the present utility model.

[0025] Figure 2 This is the second three-dimensional structural diagram of the fuel injection pump according to an embodiment of the present utility model.

[0026] Figure 3 This is one of the cross-sectional views of the fuel injection pump in the embodiment of this utility model (fuel supply state).

[0027] Figure 4 This is a second cross-sectional view of the fuel injection pump according to an embodiment of the present invention (fuel inlet state).

[0028] Figure 5 This is a three-dimensional exploded view of the fuel injection pump according to an embodiment of the present utility model.

[0029] Figure 6 This is a cross-sectional view of the pump body structure of the fuel injection pump according to an embodiment of the present utility model.

[0030] Figure 7 This is a three-dimensional structural diagram of the plunger gear according to an embodiment of the present utility model.

[0031] Figure 8 This is an assembly cross-sectional view of the plunger gear, plunger, and plunger sleeve according to an embodiment of the present utility model;

[0032] Figure 9 A simplified system diagram of a fuel injection control system for a diesel engine with single-motor control and dual-injection-pump fuel supply regulation, provided by this utility model;

[0033] Figure 10 A simplified system diagram of a fuel injection control system for a diesel engine with single-motor control and three-fuel injection pump fuel supply regulation provided by this utility model;

[0034] Figure 11 A simplified system diagram of another single-motor controlled dual-injection-pump fuel supply regulation system for a diesel engine provided by this utility model;

[0035] Figure 12 A simplified system diagram of another single-motor controlled three-injection-pump fuel supply regulation system for a diesel engine provided by this utility model.

[0036] in, Figures 1-12 middle:

[0037] 1. Pump body; 21. Plunger; 211. Helical groove; 212. Protruding wing; 22. Plunger sleeve; 221. Flange; 3. Plunger gear; 31. External gear ring; 32. Opening groove; 33. Convex surface; 4. Oil outlet valve; 41. Valve core; 5. Oil outlet connector; 51. Injection hole; 52. Pressure plate; 6. First spring seat; 61. First spring; 71. Motor; 711. Cable interface; 72. Gear mechanism; 73. End cover; 81. Piston seat; 82. Piston; 821. 83. Retaining ring; 94. Displacement sensor; 95. Upper spring seat; 96. Lower spring seat; 97. Mounting hole; 98. Inner cavity; 99. Second spring; 10. Fuel inlet; 11. Fuel outlet; 12. Lubricating oil inlet; 13. Oil drain; 14. Anti-splash screw; 15. Stop screw; 16. First step surface; 177. Second step surface; 178. Third step surface; 189. Upper base; 180. Lower base; 181. Mounting rod; 19. Long through hole groove structure. Detailed Implementation

[0038] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0039] Before providing a detailed explanation of the working principle of this utility model, further clarification is needed regarding its description: In this description, terms such as "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or a welded connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0041] refer to Figures 1-12 The following examples illustrate this. Figure 1 This is one of the three-dimensional structural diagrams of the fuel injection pump according to an embodiment of the present utility model. Figure 2 This is the second three-dimensional structural diagram of the fuel injection pump according to an embodiment of the present utility model. Figure 3 This is one of the cross-sectional views of the fuel injection pump in the embodiment of this utility model (fuel supply state). Figure 4 This is a second cross-sectional view of the fuel injection pump according to an embodiment of the present invention (fuel inlet state). Figure 5 This is a three-dimensional exploded view of the fuel injection pump according to an embodiment of the present utility model. Figure 6 This is a cross-sectional view of the pump body structure of the fuel injection pump according to an embodiment of the present utility model. Figure 7 This is a three-dimensional structural diagram of the plunger gear according to an embodiment of the present utility model. Figure 8 This is an assembly cross-sectional view of the plunger gear, plunger, and plunger sleeve according to an embodiment of the present utility model; Figure 9 A simplified system diagram of a fuel injection control system for a diesel engine with single-motor control and dual-injection-pump fuel supply regulation, provided by this utility model; Figure 10 A simplified system diagram of a fuel injection control system for a diesel engine with single-motor control and three-fuel injection pump fuel supply regulation provided by this utility model; Figure 11 A simplified system diagram of another single-motor controlled dual-injection-pump fuel supply regulation system for a diesel engine provided by this utility model; Figure 12A simplified system diagram of another single-motor controlled three-injection-pump fuel supply regulation system for a diesel engine provided by this utility model.

[0042] The fuel injection control system for diesel engines provided in this embodiment is composed of multiple fuel injection pumps and a fuel supply quantity adjustment mechanism. The fuel injection pump includes a pump body 1, a pumping mechanism, and a drive mechanism. The pumping mechanism is located inside the pump body 1, and its most important component is a plunger 21. It should be noted that the fuel supply quantity adjustment mechanism can be shared by several fuel injection pumps, or each fuel injection pump can be equipped with a separate fuel supply quantity adjustment mechanism.

[0043] refer to Figures 9-12 Note: When using a single fuel pump adjustment structure to synchronously control the rotation adjustment of the plungers 21 of two or more fuel injection pumps, the rotation of the rotary drive can be transmitted to each plunger 21 through a gear set mechanism or a rack and pinion gear meshing structure. The output end of the fuel pump adjustment structure can also use a gear set mechanism to achieve motion transmission. Optional structures include reversing gears, rack and pinion gear meshing structures, crank connecting rod meshing gear structures, etc.

[0044] The pump body 1 is used to house the plunger 21 and the drive mechanism; the oil pumping mechanism is used to realize the intake and pressurization of fuel and to supply fuel to the injector; the drive mechanism is used to drive the movement of the oil pumping mechanism to ensure the correct timing of fuel injection; the fuel supply adjustment mechanism can adjust the fuel supply of the injection pump in each working cycle according to the change of diesel engine speed.

[0045] The oil pumping mechanism in this embodiment includes:

[0046] The plunger 21 is provided with a spiral groove 211 or a beveled groove to adjust the oil supply; the plunger 21 rotates under the drive of the oil supply adjustment mechanism. The plunger sleeve 22 is fixedly installed inside the pump body 1, and the plunger 21 can move linearly along the axial direction of the plunger sleeve 22 within the sleeve. The plunger gear 3 is sleeved outside the plunger sleeve 22; driven by the oil supply adjustment mechanism, the plunger gear 3 rotates, which in turn drives the plunger 21 to rotate synchronously around its axis. The delivery valve 4 is located at the top of the plunger sleeve 22. The delivery valve 4 has a valve core 41 that can be opened in one direction and a first elastic reset unit that can reset the valve core 41. The delivery valve 4 is a one-way valve. Under the action of the first elastic reset unit, the valve core 41 and the valve seat of the delivery valve 4 are tightly fitted. Its function is to isolate the high-pressure oil pipe (or injector) from the upper cavity of the plunger 21 when the oil supply is stopped, preventing oil in the high-pressure oil pipe (or injector) from flowing back into the injection pump. The delivery connector 5 is fixedly located at the top of the delivery valve 4. The delivery connector 5 has an injection hole 51 for connecting to the high-pressure oil pipe. The delivery connector 5 can adopt various structures in the prior art and can be connected to the high-pressure oil pipe through various existing fixed connection methods.

[0047] In this embodiment, the oil outlet connector 5 is also provided with a cavity that communicates with the oil injection hole 51 and can accommodate the first elastic reset unit. The first elastic reset unit includes a first spring 61 and a first spring seat 6. The first spring 61 is sleeved outside the first spring seat 6. One end of the first spring seat 6 abuts against the valve core 41 of the oil outlet valve 4, and the other end abuts against the inner wall of the cavity of the oil outlet connector 5. Furthermore, the inner cavity shape of the oil outlet connector 5 near the oil injection hole 51 is adapted to the head shape of the first spring seat 6, so that the first spring seat 6 can be axially confined within the cavity of the oil outlet connector 5.

[0048] Among them, such as Figure 5 , Figure 7 and Figure 8 As shown, the plunger gear 3 is an integrally formed cylindrical sleeve. The head of the sleeve is formed into an external gear ring 31 that can mesh with the output gear 72. The sleeve has an opening groove 32 that opens towards the bottom of the sleeve. The opening grooves 32 are preferably arranged symmetrically in pairs. Correspondingly, the plunger 21 has a convex wing structure 212 that can be respectively locked in the opening grooves 32 of the sleeve body and rotate synchronously with the plunger gear 3. The circumferential positioning of the plunger gear 3 and the plunger 21 is achieved through the concave-convex cooperation between the two.

[0049] like Figure 3-5 As shown, the fuel supply adjustment mechanism of this embodiment includes a servo motor 71, an output gear 72 that rotates under the drive of the servo motor 71, and a first electronic control device that controls the operation of the servo motor 71. The servo motor 71 is provided with a cable interface 711, and the output end 712 of the servo motor 71 serves as a structure that circumferentially positions and cooperates with the output gear 72. The first electronic control device adjusts the rotation direction and rotation angle of the output end of the servo motor 71 according to the speed of the diesel engine, so as to accurately adjust the rotation angle of the plunger 21, that is, accurately adjust the cooperation position between the spiral groove 211 and the oil discharge hole on the pump body 1, and more accurately adjust the working fuel injection quantity of the fuel injection pump.

[0050] The output gear 72 and the plunger gear 3 can adopt various conventional gear systems in the prior art. Simply put, in this embodiment, the plunger gear 3 is connected to the output end 712 of the servo motor 71 through a single gear, namely the output gear 72. However, when a design is adopted in which a servo motor 71 drives multiple fuel injection pumps to adjust the fuel injection quantity, the output gear 72, in conjunction with an appropriate gear set structure design, transmits the rotational motion to the plunger gear 31 of each fuel injection pump.

[0051] The drive mechanism includes a hydraulic drive unit or cam linkage mechanism that can drive the plunger 21 to reciprocate linearly along the axial direction of the pump body 1, and a second electronic control device that can control the operation of the hydraulic drive unit. When the drive mechanism uses a hydraulic drive unit, it includes a piston seat 81 housed in the pump body 1 and a piston 82 that can reciprocate up and down along the piston seat 81. The top of the piston 82 directly abuts against the bottom of the plunger 21. The piston seat 81 is fixedly connected to the pump body 1. The piston 82 can move along the piston seat 81. The hydraulic drive unit also includes a second elastic reset unit disposed on the upper part of the piston seat 81 and capable of resetting the piston 82.

[0052] Preferably, a displacement sensor 83 that can detect the moving position of piston 82 can also be provided. The displacement sensor 83 is set on pump body 1 and is communicatively connected to the second electronic control device to transmit the displacement of piston 82 to the second control unit so as to realize feedback control and more accurately control the reciprocating oil pressing action of plunger 21.

[0053] like Figure 3-5 As shown, the second elastic reset unit includes an upper spring seat 91, a lower spring seat 92, and a second spring 93. The tail of the plunger 21 can extend beyond the plunger sleeve 22. The second spring 93 is sleeved outside the plunger gear 3, and the two ends of the second spring 93 abut against the upper spring seat 91 and the lower spring seat 92, respectively.

[0054] In this embodiment, the various components are fixed in position by various limiting structures and connection methods. Specifically, in order to fix the oil outlet connector 5, a pressure plate 52 is provided on the top of the oil outlet connector 5. The pressure plate 52 is fixedly connected to the pump body 1 by screws, so that the bottom end of the oil outlet connector 5 can always be tightly pressed against the valve body of the oil outlet valve 4.

[0055] like Figure 5 As shown, the pump body 1 has a fuel inlet 11, a fuel outlet 12, a lubricating oil inlet 13, and a fuel leakage outlet 14 at the bottom. The pump body 1 also has a set of symmetrically arranged anti-splash screws 15 and a stop screw 16 located below one of the anti-splash screws. Inside the pump body 1, from top to bottom, there are three stepped surfaces: a first stepped surface 171 with decreasing pipe diameter, a second stepped surface 172 with increasing pipe diameter, and a third stepped surface 173 with increasing pipe diameter. (See [reference]). Figure 6 ;

[0056] The top of the plunger sleeve 22 abuts against the bottom of the oil outlet valve 4, and the plunger sleeve 22 also has a flange 221 that abuts against the first step surface 171, thereby enabling the plunger sleeve 22 to achieve axial positioning; Figure 3 , Figure 4As shown, the top of the plunger gear 3 abuts against the second stepped surface 172. The plunger gear 3 further has a convex surface 33 that can abut against the upper spring seat 91 of the second elastic reset unit. The convex surface 33 is located at the lower part of the outer gear ring 31.

[0057] The upper spring seat 91 of the second elastic reset unit abuts against the third stepped surface 173. The bottom of the upper spring seat 91 abuts against one end of the second spring 93, and the other end of the second spring 93 abuts against the top of the lower spring seat 92. The lower spring seat 92 is frustum-shaped and is provided with a mounting hole 921 and an inner cavity 922 communicating with the mounting hole 921. The bottom of the plunger 21 can be inserted into the mounting hole 921 and fixed, and the end of the piston 82 can extend into the inner cavity 922 so that the end of the piston 82 abuts against the bottom of the plunger 21.

[0058] The piston seat 81 has a "convex" cross-section. Refer to Figure 5 , the protruding portion 811 of the piston seat 81 is accommodated in the inner cavity 922 of the lower spring seat 92 and is adapted to the size of the inner cavity 922. The piston 82 is movably inserted through the piston seat 81. Moreover, a radially outwardly protruding retaining ring 821 is formed on the head of the piston 82, and the retaining ring 821 abuts against the top of the piston seat 81 to achieve the axial limit of the piston 82.

[0059] In order to prevent dust, avoid external interference and damage, and ensure the working safety and working accuracy of the output gear 72, the fuel supply regulating mechanism further includes an end cover 73 provided on the top of the output gear 72 and adapted to the size of the output gear 72. The end cover 73 is fixed to the outer side wall of the pump body 1 and can accommodate the entire output gear 72 therein.

[0060] A fixed base is provided on the outer side wall of the pump body 1, including an upper base 181 and a lower base 182 that are separated in position and structure and are respectively used for connecting and fixing the two axial ends of the servo motor 71. The servo motor 71 is installed and fixed on the fixed base. Between the servo motor 71 and the fixed base, two mounting rods 183 are used for auxiliary fixation. Each mounting rod 183 is connected to the upper base 181 and the lower base 182 at both ends respectively, and the two mounting rods 183 are respectively pasted on both sides of the servo motor 71 axially; A long through-hole groove structure 19 is also provided on the side wall of the pump body 1 for the plunger gear 3 to be exposed and in transmission connection with the output gear 72.

[0061] Existing fuel supply adjustment mechanisms are mostly mechanical adjustment methods such as gear rings and racks, shift forks and levers. They are designed with a single power source driving each fuel injection pump adjustment mechanism through a complex mechanical transmission structure. During operation, the complex structure or large transmission clearance leads to low control accuracy. In this embodiment, both the fuel supply adjustment mechanism and the drive mechanism adopt electronic control. Each fuel injection pump can automatically adjust the fuel supply through an independent motor gear device via electronic control. This can effectively improve the control accuracy during operation, ensure the precision of the fuel supply, and reduce fuel waste caused by control deviations while ensuring normal equipment operation, thus achieving the goal of energy conservation and emission reduction.

[0062] The principle and working process of the fuel injection pump in this embodiment are as follows:

[0063] Oil intake process: The plunger 21 moves downward, and a vacuum is generated in the upper space of the plunger 21 (oil pump chamber I). When the upper end of the plunger 21 moves down to open the fuel inlet 11 on the plunger sleeve 22, fuel enters the oil pump chamber I. The plunger 21 runs to the bottom dead center, and the oil intake ends.

[0064] Fuel supply process: The plunger 21 moves upward, the fuel is compressed, and part of the fuel flows back to the upper oil chamber of the injection pump through the fuel outlet 12. When the upper end of the plunger 21 covers the upper edge of the fuel inlet 11 on the plunger sleeve 22, the pump chamber I at the top of the plunger 21 becomes a sealed oil chamber. As the plunger 21 continues to rise, the oil pressure in the pump chamber I rises rapidly. The fuel is compressed and then pressurized. When the fuel reaches a certain pressure, the outlet valve 4 is opened, and the high-pressure fuel enters the high-pressure fuel pipe from the injection port of the outlet connector 5 through the outlet valve 4 and is injected into the combustion chamber through the injector.

[0065] When the plunger 21 is supplying fuel upwards, when the spiral groove 211 (or oblique groove) on the plunger 21 is connected to the fuel outlet 12 on the plunger sleeve 22, the low-pressure oil circuit in the pump chamber I will be connected to the spiral groove 211 (or oblique groove) on the head of the plunger 21, forming an unloading channel. When the unloading channel appears, the fuel pressure at the top of the plunger 21 will be released, and the oil pressure will drop sharply. The oil outlet valve 4 will close quickly under the action of the first elastic reset unit, stopping the fuel supply. This is the return oil process. After that, the plunger 21 will continue to move upwards to the top dead center, thus completing one cycle.

[0066] Then, under the action of the second elastic reset unit, the plunger 21 begins to descend, and the next oil suction-oil supply-oil return cycle begins.

[0067] In the above-described cycle, this embodiment uses an electronic control method to control the rotation angle and vertical displacement of the plunger 21. Specifically:

[0068] The first electronic control device first sends a command to the servo motor 71 of the oil supply adjustment mechanism according to the preset working parameters (such as speed). After receiving the command, the servo motor 71 can control the plunger 21 to rotate to the specified angle. That is, after the equipment is started, the plunger 21 first rotates to the corresponding oil supply angle position according to the preset speed.

[0069] During the reciprocating motion of the plunger 21, the diesel engine speed is monitored in real time to determine the actual load on the engine. The first electronic control unit then calculates the required speed and corresponding fuel supply based on this actual load and feeds this information back to the servo motor 71. The servo motor 71 controls the plunger 21 to rotate at the appropriate angle, ultimately changing the return oil timing (i.e., altering the effective fuel injection stroke), thus regulating the fuel injection quantity. This fuel quantity regulation is a real-time dynamic adjustment process until the actual fuel supply matches the actual working load of the diesel engine.

[0070] The reciprocating motion of the plunger 21 is driven by a hydraulic drive unit or a cam linkage mechanism. The hydraulic drive unit uses a displacement sensor to detect and feedback the movement position of the piston 82 to ensure the correct stroke of the plunger 21 and the correct timing of oil injection. The specific control method for hydraulically controlling the piston movement can be implemented using various control algorithms in the prior art, which will not be elaborated in this application.

[0071] This utility model's fuel injection pump device, while ensuring product performance, achieves intelligent control of the product, improves control precision, and significantly reduces manufacturing costs and production difficulty. It highly integrates traditional mechanized structures with advanced control technology, making the product more widely applicable, with outstanding energy-saving and environmental protection performance, higher cost performance, and stronger market competitiveness.

[0072] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A fuel injection control system for a diesel engine, comprising a fuel supply regulating mechanism and a plurality of fuel injection pumps, wherein the fuel injection pump comprises a pump body (1) and a pumping mechanism disposed within the pump body (1), the pumping mechanism being connected to a drive mechanism for controlling its fuel supply; the pumping mechanism comprises a plunger (21) housed in a pump chamber of the pump body (1), the plunger (21) being operatively connected to the fuel supply regulating mechanism, and a helical groove (211) being provided on the outer peripheral wall near the end of the plunger (21). Its features are, The fuel supply adjustment mechanism includes a rotary driver, the output end of which is provided with an output gear (72). The outer peripheral wall of the plunger (21) is provided with a plunger gear (3) coaxial with the plunger (21). The output gear (72) meshes with the plunger gear (3). The rotary driver is used to adjust the rotation angle of the output gear (72) according to the change of diesel engine speed, so as to adjust the position of the engagement between the spiral groove (211) and the pressure relief oil passage on the pump body (1), thereby adjusting the fuel supply of the fuel injection pump.

2. The fuel injection control system for a diesel engine according to claim 1, characterized in that, Each of the plungers (21) in the fuel injection pump is drivenly connected to one of the rotary actuators.

3. The fuel injection control system for a diesel engine according to claim 2, characterized in that, The rotation driver is a servo motor (71), and each servo motor (71) is connected to a first electronic control device. The first electronic control device adjusts the rotation direction and rotation angle of the output end of the servo motor (71) according to the speed change of the diesel engine.

4. The fuel injection control system for a diesel engine according to claim 2, characterized in that, The rotary drive is a hydraulic motor or a pneumatic motor.

5. The fuel injection control system for a diesel engine according to claim 3, characterized in that, The oil pumping mechanism also includes a plunger sleeve (22), an oil outlet valve (4), and an oil outlet connector (5); The plunger sleeve (22) is fixedly installed inside the pump body (1). The plunger (21) can be slidably inserted into the plunger sleeve (22) along the axial direction. The plunger gear (3) is sleeved on the outer peripheral wall of the plunger sleeve (22) and is fixedly engaged with the plunger sleeve (22) circumferentially. The oil outlet valve (4) is installed on the top of the plunger sleeve (22). The oil outlet valve (4) is provided with a valve core (41) that can be opened in one direction and a first elastic reset unit that realizes the reset of the valve core (41). The oil outlet connector (5) is fixedly installed on the top of the oil outlet valve (4). The oil outlet connector (5) is used to connect the high-pressure oil pipe for oil supply output.

6. The fuel injection control system for a diesel engine according to claim 5, characterized in that, The plunger gear (3) includes an integrally formed outer gear ring (31) and a cylindrical sleeve portion. The sleeve portion is coaxial with the outer gear ring (31). The outer gear ring (31) meshes with the output gear (72). An opening groove (32) with an opening direction opposite to the outer gear ring (31) is provided on the cylindrical side wall of the sleeve portion. A convex wing structure (212) that mates with the opening groove (32) is provided on the outer peripheral wall of the plunger (21). The plunger gear (3) and the plunger (21) are circumferentially positioned by the convex wing structure (212) and the opening groove (32).

7. The fuel injection control system for a diesel engine according to claim 6, characterized in that, A fixed base is provided on the outer side wall of the pump body (1), and the servo motor (71) is fixedly installed on the fixed base; a long through hole groove structure (19) is provided on the side wall of the pump body (1) at the position corresponding to the plunger gear (3), and the rim of the output gear (72) passes through the long through hole groove structure (19) and extends into the pump body (1) to mesh with the plunger gear (3).

8. The fuel injection control system for a diesel engine according to claim 6, characterized in that, The rotary drive is provided with an end cover (73) at one end connected to the output gear (72), the output gear (72) is accommodated in the end cover (73), and the end cover (73) is snapped and fixed to the outer wall of the pump body (1).

9. The fuel injection control system for a diesel engine according to claim 6, characterized in that, The drive mechanism includes a hydraulic drive unit or a cam linkage drive unit that abuts against the end of the plunger (21) and drives the plunger (21) to make linear reciprocating motion along the axial direction of the pump body (1). The reciprocating motion of the plunger (21) along the axial direction cooperates with the internal cavity of the pump body (1) to squeeze and supply oil. The oil injection pump device also includes a second electronic control device that can control the operation of the hydraulic drive unit.

10. The fuel injection control system for a diesel engine according to claim 3, characterized in that, The fuel injection control system also includes a speed sensor for detecting the diesel engine speed, and the speed sensor is communicatively connected to the first electronic control device.

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