A forced lubrication dual fuel injection pump

Abstract

The utility model discloses a kind of forced lubrication's dual-fuel injection pump, belong to internal combustion engine technical field.The injection pump includes pump body, and pump body is provided with methanol fuel supply unit, diesel fuel supply unit and volume cavity.Diesel plunger coupling's oil outlet end is communicated with volume cavity, and volume cavity is communicated with the cooperation gap of methanol plunger coupling by the lubricating oil channel being set on methanol plunger coupling.The utility model utilizes high-pressure diesel generated by diesel fuel supply unit, and by special oil circuit is led to the cooperation gap of methanol plunger coupling, forcibly lubricates it, effectively solve the plunger coupling wear and jam problem caused by methanol and other low lubricity fuel, improve the reliability of injection pump, simultaneously can satisfy the oil supply demand of dual-fuel engine.

Description

Technical Field

[0001] This utility model belongs to the field of fuel injection pump technology, and in particular relates to a dual-fuel fuel injection pump with forced lubrication. Background Technology

[0002] As emission regulations become increasingly stringent, clean energy alternatives to diesel have emerged. Among the many alternative energy sources, methanol stands out for its advantages such as safety, ease of production, and low cost. However, methanol's low viscosity and low lubricity are also prominent characteristics, making it crucial to address these issues. As is well known, during the operation of the fuel injection pump, the low-pressure fuel pump draws fuel from the fuel tank, pressurizes it, and after the pressure is limited by the overflow valve, the pressurized fuel is delivered to the fuel metering valve for fuel quantity control. The fuel then enters the plunger chamber through the inlet valve. Under the action of the camshaft, the plunger realizes reciprocating motion and pressurizes the fuel to form high-pressure fuel. The high-pressure fuel is provided to the injector for high-pressure injection under the one-way control of the delivery valve, and finally participates in combustion in the engine combustion chamber. During the reciprocating motion of the plunger assembly, the speed is relatively high, while methanol has very low lubricity. When the plunger assembly moves at high speed, it cannot provide sufficient lubrication conditions, resulting in abnormal wear and jamming of the plunger assembly. When traditional fuel injection pumps directly use methanol as the medium, they cannot solve the lubrication problem caused by the low viscosity and lubrication characteristics of the plunger assembly, which poses a risk to the reliability of the plunger assembly when it moves at high speed. Summary of the Invention

[0003] To address the problems existing in the prior art, this utility model provides a forced lubrication dual-fuel injection pump; an injection pump assembly suitable for methanol fuel, which solves the lubrication problem of the injection pump plunger assembly by forced lubrication of the methanol plunger.

[0004] This utility model is implemented as follows: a forced lubrication dual-fuel injection pump includes a pump body, characterized in that the pump body is provided with: at least one methanol fuel supply unit, which includes a methanol plunger assembly; at least one diesel fuel supply unit, which includes a diesel plunger assembly; a volumetric cavity disposed within the pump body; the oil outlet end of the diesel plunger assembly communicates with the volumetric cavity, and the volumetric cavity communicates with the methanol plunger assembly through a lubricating oil passage disposed on the methanol plunger assembly and a mating clearance of the methanol plunger assembly.

[0005] More preferably, the methanol plunger assembly has a diesel high-pressure leakage hole that communicates with the lubricating oil passage, and the diesel high-pressure leakage hole is connected to the pipeline before the oil inlet valve of the diesel fuel supply unit.

[0006] In a further preferred embodiment, the methanol plunger assembly is also provided with a high-pressure methanol leakage oil passage, which is connected to the methanol tank.

[0007] More preferably, the diesel fuel supply unit further includes a diesel fuel tank, a first filter, an electronic fuel pump, a second filter, an overflow valve, a fuel metering valve, a diesel fuel inlet valve, a plunger chamber of the diesel plunger assembly, and a diesel fuel outlet valve, which are connected in sequence along the fuel flow direction, and the diesel fuel outlet valve is connected to the volume chamber.

[0008] More preferably, the methanol fuel supply unit further includes a methanol tank, a third filter, a fuel pump, a fourth filter, an overflow valve, a fuel metering valve, a methanol inlet valve, a plunger chamber of the methanol plunger assembly, and a methanol outlet valve, which are connected in sequence along the methanol flow direction. The methanol outlet valve is used to connect to the injector.

[0009] The advantages and technical effects of this utility model are as follows: This utility model provides a forced-lubrication dual-fuel injection pump, which, through structural innovation, successfully solves the global problem of plunger wear caused by the use of low-lubricity fuels such as methanol in injection pumps. Its core lies in the creative addition of a diesel fuel supply unit, which uses the high-pressure diesel fuel it generates to forcibly lubricate the methanol plunger assembly through a shared volumetric chamber and a dedicated lubrication channel. This design not only greatly improves the reliability and durability of the injection pump when burning low-lubricity fuels, avoiding jamming and wear failure, but also achieves coordinated supply and management of diesel and methanol dual fuels within the same pump body, meeting the emission optimization and energy diversification requirements of dual-fuel engines. The entire system has a compact structure, clear oil circuit separation, and recyclable lubricating medium, exhibiting significant advantages such as high reliability, strong practicality, and ease of implementation. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the methanol plunger assembly in this utility model; Figure 2 This is a hydraulic schematic diagram of the fuel injection pump assembly of this utility model.

[0011] 1. Methanol plunger assembly; 2. Diesel plunger assembly; 3. Volume chamber; 4. Methanol fuel tank; 5. Diesel fuel tank; 6. First filter; 7. Electronic fuel pump; 8. Second filter; 9. Overflow valve; 10. Fuel metering valve; 11. Lubricating oil passage; 12. Diesel high-pressure leak hole; 13. Methanol high-pressure leak passage; 14. Diesel inlet valve; 15. Diesel outlet valve; 16. Third filter; 17. Fuel pump; 18. Fourth filter; 19. Overflow valve; 20. Fuel metering valve; 21. Methanol inlet valve; 22. Methanol outlet valve. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0013] Please see Figures 1 to 2 A forced-lubrication dual-fuel injection pump includes a pump body, which houses at least one methanol fuel supply unit, including a methanol plunger assembly 1; at least one diesel fuel supply unit, including a diesel plunger assembly 2; and a volumetric cavity 3 disposed within the pump body. The oil outlet end of the diesel plunger assembly 2 communicates with the volumetric cavity 3, and the volumetric cavity 3 communicates with the methanol plunger assembly 1 via a lubrication passage 11 disposed on the methanol plunger assembly 1 and a clearance between the two components. The number of diesel plunger assemblies 2 is determined based on the number of methanol plunger assemblies 1 and the pressure and flow rate required for lubrication.

[0014] Working Principle: The core of this invention is the forced lubrication of the methanol plunger assembly using diesel fuel. High-pressure diesel fuel generated by the diesel fuel supply unit is output through the diesel fuel outlet valve 15 and converges into a shared volume chamber 3. Subsequently, the high-pressure diesel fuel is forcibly transported through the lubrication oil passage 11 connected to the volume chamber 3 to the precision-fitted gap of the methanol plunger assembly 1, forming a lubricating film therein, thereby solving the problem of insufficient lubricity of methanol fuel itself. The lubricated diesel fuel and leaked methanol are returned to their respective fuel tanks through independent circuits, avoiding mixing of the two fuels.

[0015] This solution creatively solves the core problem of poor lubricity of methanol fuel by introducing an independent diesel lubrication circuit. High-pressure diesel fuel forms a stable lubricating film in the mating gap of the methanol plunger assembly, effectively reducing friction and wear. This fundamentally avoids plunger jamming and abnormal wear, significantly improving the reliability and service life of the injection pump when using low-lubricity fuels. Simultaneously, the compact structure enables the coordinated management of both fuels within the same pump body.

[0016] More preferably, the methanol plunger assembly 1 is provided with a diesel high-pressure leakage hole 12 that communicates with the lubricating oil passage 11, and the diesel high-pressure leakage hole 12 is connected to the pipeline before the oil inlet valve of the diesel fuel supply unit.

[0017] The diesel high-pressure leak hole 12 forms a diesel fuel recycling loop. Diesel fuel that has completed its lubrication function can leak through this hole and flow back to the main pipeline before the diesel inlet valve, re-participating in subsequent pressurization and lubrication cycles. This not only achieves the recycling of the lubricating medium, improves system efficiency, and avoids diesel fuel waste, but also helps maintain the pressure stability of the diesel pipeline system and removes some of the heat generated by friction.

[0018] Further preferably, the methanol plunger assembly 1 is also provided with a methanol high-pressure leakage oil passage 13, which is connected to the methanol fuel tank 4. The independent methanol high-pressure leakage oil passage 13 is a key safety and separation design. It directly guides the methanol fuel leaking from the gap in the methanol plunger assembly back to the methanol fuel tank 4, ensuring physical isolation between the two fuels and preventing the mixing of diesel and methanol along the leakage path. This ensures fuel purity, avoids cross-contamination that could adversely affect engine performance, and allows for the recovery of leaked methanol, meeting operational economy and environmental protection requirements.

[0019] Further preferably, the diesel fuel supply unit also includes, in sequence along the fuel flow direction, a diesel fuel tank 5, a first filter 6, an electronic fuel pump 7, a second filter 8, an overflow valve 9, a fuel metering valve 10, a diesel inlet valve 14, the plunger chamber of the diesel plunger assembly 2, and a diesel outlet valve 15, the diesel outlet valve 15 being connected to the volume chamber 3. This scheme constructs a complete, stable, and controllable diesel supply and lubrication system. The multi-stage filters ensure the cleanliness of the lubricating diesel fuel, preventing impurities from damaging the precision assemblies; the electronic fuel pump and overflow valve ensure stable system pressure; and the fuel metering valve enables precise control of the amount of lubricating diesel fuel, thereby optimizing system energy consumption while ensuring sufficient lubrication. The entire oil circuit design is rigorous, providing a reliable foundation for the forced lubrication function.

[0020] Further preferably, the methanol fuel supply unit also includes, in sequence along the methanol flow direction, a methanol tank 4, a third filter 16, a fuel pump 17, a fourth filter 18, an overflow valve 19, a fuel metering valve 20, a methanol inlet valve 21, the plunger chamber of the methanol plunger assembly 1, and a methanol outlet valve 22, the methanol outlet valve 22 being used to connect to the injector. This scheme constructs an independent and efficient main fuel supply system. It has complete filtration, pressurization, metering, and injection functions, ensuring that methanol fuel can be supplied to the engine at sufficient pressure and precise quantity. This unit works in conjunction with the diesel lubrication unit without interference, enabling the fuel injection pump to simultaneously meet the engine's demand for main fuel methanol and the forced lubrication demand for key friction pairs, truly achieving stable and reliable operation in dual-fuel mode.

[0021] In summary, the entire system has a compact structure, clear oil circuit separation, and recyclable lubricating medium, and has significant advantages such as high reliability, strong practicality, and ease of implementation.

[0022] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A forced-lubrication dual-fuel injection pump, comprising a pump body, characterized in that, The pump body is equipped with: At least one methanol fuel supply unit, which includes a methanol plunger assembly (1). At least one diesel fuel supply unit, which includes a diesel plunger assembly (2). A volumetric cavity (3) disposed within the pump body; The oil outlet end of the diesel plunger assembly (2) is connected to the volume chamber (3), and the volume chamber (3) is connected to the methanol plunger assembly (1) through the lubricating oil passage (11) provided on the methanol plunger assembly (1) through the fitting gap.

2. The forced lubrication dual-fuel injection pump according to claim 1, characterized in that, The methanol plunger assembly (1) is provided with a diesel high-pressure leakage hole (12) that communicates with the lubricating oil passage (11). The diesel high-pressure leakage hole (12) is connected to the pipeline before the oil inlet valve of the diesel fuel supply unit.

3. The forced lubrication dual-fuel injection pump according to claim 2, characterized in that, The methanol plunger assembly (1) is also provided with a methanol high-pressure leakage oil passage (13), which is connected to the methanol tank (4).

4. A forced lubrication dual-fuel injection pump according to claim 1, characterized in that, The diesel fuel supply unit also includes a diesel tank (5), a first filter (6), an electronic fuel pump (7), a second filter (8), an overflow valve (9), a fuel metering valve (10), a diesel inlet valve (14), the plunger chamber of the diesel plunger assembly (2), and a diesel outlet valve (15) connected in sequence along the fuel flow direction. The diesel outlet valve (15) is connected to the volume chamber (3).

5. A forced lubrication dual-fuel injection pump according to claim 1, characterized in that, The methanol fuel supply unit also includes a methanol tank (4), a third filter (16), a fuel pump (17), a fourth filter (18), an overflow valve (19), a fuel metering valve (20), a methanol inlet valve (21), the plunger chamber of the methanol plunger assembly (1), and a methanol outlet valve (22) connected in sequence along the methanol flow direction. The methanol outlet valve (22) is used to connect to the injector.

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