A new type of methanol-diesel dual fuel injection system

Abstract

This patent relates to the field of internal combustion engine technology, specifically a new type of methanol-diesel dual-fuel injection system, several fuel injection mechanisms, pressure sensors, drive oil common rails and safety valves. Each of the fuel injection mechanisms includes a pump nozzle, a hydraulic drive device and an oil pipe. The hydraulic drive device is installed on the pump nozzle for controlling the pump nozzle. The hydraulic drive device is connected to the drive oil common rail through an oil pipe. The pressure sensor is installed at the oil inlet end of the drive oil common rail, and the safety valve is installed at the end of the drive oil common rail. The drive oil common rail can more effectively ensure the pressure stability of the drive oil, and the stability of the rail pressure can improve the pressure building speed and control flexibility at the pump end guide cylinder, thereby realizing the injection of methanol fuel and diesel fuel, and the pump end pressure can be adjusted according to the fuel characteristics to meet the fuel injection requirements.

Description

Technical Field

[0001] The invention relates to the technical field of internal combustion engines, in particular to a novel methanol-diesel dual-fuel injection system. Background Art

[0002] Nowadays, at a critical time of energy transformation, diesel and methanol will be used as the main fuels, but the existing dual-fuel systems do not adequately consider the characteristics of the two fuels, especially the differences in injection pressure and injection system requirements caused by the differences in the physical and chemical properties of the two fuels. Summary of the invention

[0003] The present invention aims to provide a novel methanol-diesel dual fuel injection system, which realizes the injection of methanol fuel and diesel fuel and can adjust the pump end pressure according to the fuel characteristics to meet the fuel injection requirements.

[0004] In order to achieve the above-mentioned object, the basic scheme of the present invention is as follows: a new type of methanol diesel dual fuel injection system, a plurality of fuel injection mechanisms, a pressure sensor, a driving oil common rail pipe and a safety valve, each of the fuel injection mechanisms includes a pump nozzle, a hydraulic drive device and an oil pipe, the hydraulic drive device is installed on the pump nozzle for controlling the pump nozzle, the hydraulic drive device is connected to the driving oil common rail pipe through the oil pipe, the pressure sensor is installed at the oil inlet end of the driving oil common rail pipe, and the safety valve is installed at the end of the driving oil common rail pipe;

[0005] The pump nozzle comprises a needle valve pair, a tight cap, an intermediate body, a lift limiting rod, a pressure regulating spring, an intermediate block, an injector body, a plunger, a plunger spring, a guide tube and a wire retaining ring. The injector body, the intermediate block, the intermediate body and the needle valve pair are installed in sequence from top to bottom, and the injector body, the intermediate block, the intermediate body and the needle valve pair are coaxially fixed by the tight cap. A cavity is provided in the intermediate body, and the upper end of the lift limiting rod is slidably connected to the cavity of the intermediate body. The pressure regulating spring is sleeved on the upper end of the lift limiting rod, and the bottom of the lift limiting rod is inserted into the needle valve pair. The injector body is a hollow structure, and the plunger is slidably connected to the injector body. In the body, an accommodating chamber is provided at the upper end of the injector body, the plunger spring is sleeved on the upper end of the plunger, and the plunger spring is located in the accommodating chamber, the lead cylinder is installed at the top end of the plunger, and the plunger spring is located in the lead cylinder, the lead cylinder is slidably connected in the accommodating chamber, a sealed oil return chamber is formed between the lower part of the lead cylinder and the injector body, a leakage return port is provided on the side of the injector body, a pump end pressure chamber is formed between the bottom surface of the plunger and the inner wall of the injector body, the pump end pressure chamber is connected to a fuel inlet, a high-pressure channel is provided in the intermediate block and the intermediate body, and the pump end pressure chamber is communicated with the inside of the needle valve pair through the high-pressure channel.

[0006] Furthermore, the hydraulic drive device is a normally closed two-position three-way solenoid valve, which includes a valve body, an armature, a coil, a valve sleeve, an inner valve core, a left valve core, a solenoid valve return spring and a right valve core. The top end of the injector body is slidably connected to the cavity at the bottom of the valve body, and a control oil chamber is formed between the valve body and the top surface of the guide tube.

[0007] Furthermore, a low-pressure sealing oil passage is provided in the injector body, the intermediate block and the intermediate body, and a low-pressure sealing oil ring groove is provided on the contact surface between the injector body and the intermediate block, the contact surface between the intermediate block and the intermediate body, and the contact surface between the intermediate body and the needle valve pair, and the low-pressure sealing oil ring groove is connected to the low-pressure sealing oil passage.

[0008] Furthermore, a leakage hole is provided on the side of the valve body, and the leakage hole is communicated with the leakage oil outlet on the pump nozzle.

[0009] The beneficial effects of this solution are as follows: (1) This solution provides the system with driving oil through a driving oil common rail pipe. The driving oil flows through the oil pipe and flows into the hydraulic driving device. Under the action of a normally closed two-position three-way solenoid valve, it flows into the pump nozzle and drives the plunger to pressurize the fuel and realize fuel injection, thereby realizing hydraulic drive replacing mechanical cam drive. The system adopts hydraulic drive and a common rail pipe to provide the hydraulic driving device with driving oil with stable pressure. The driving oil common rail pipe can more effectively ensure the pressure stability of the driving oil, and the stability of the rail pressure can improve the pressure building speed and control flexibility at the pump end lead cylinder; and through the pressure sensor and The safety valve can monitor and adjust the pressure of the driving oil in the common rail pipe in real time, and can be continuously adjustable to achieve continuous adjustment of the pump end pressure, which is flexible and controllable; through the electronically controlled hydraulic drive device, on the one hand, it is far away from the fuel, increasing the safety of the use of the solenoid valve, and on the other hand, it can increase the control flexibility and sensitivity of the oil supply characteristics and the oil supply duration, and can flexibly adjust the oil supply duration and the oil supply regularity, and can meet the pressure of the high-pressure oil during fuel injection by adjusting the liquid drive oil pressure, meet the fuel injection quality requirements of the injection process, and meet the injection pressure requirements of different fuel characteristics.

[0010] (2) This solution uses hydraulic flexible drive instead of cam rigid drive, eliminating the roughness of mechanical transmission and making the transmission process smoother and gentler. The hydraulic drive oil is provided in the form of a common rail pipe, which more effectively ensures the pressure stability of the drive oil, further improves the pressure building speed and control flexibility of the drive pressure, and can further simplify the engine structure and increase the flexibility of the engine fuel system layout.

[0011] (3) When the fuel is diesel, the driving oil pressure can be adjusted according to the characteristics of diesel, the injection pressure at the pump end can be increased, the injection atomization quality can be improved, and the combustion quality can be optimized; when the fuel is methanol, the driving oil pressure can be reduced according to the characteristics of methanol, and the pump end pressure can be reduced. On the one hand, it can meet the injection pressure requirements of methanol and reduce the workload of the system device, thereby improving the reliability and service life of the system. Before the end of methanol injection, the system can switch from methanol fuel to diesel fuel, which can not only achieve the cleaning of methanol in the system and prevent the escape after shutdown, but also avoid the problem of poor injection quality caused by fuel characteristics.

[0012] (4) In this scheme, the sealing ring groove will realize the sealing effect of high-pressure leakage. The low-pressure sealing oil comes from the sealing oil return chamber and flows back to the sealing oil return chamber and flows out from the leakage return port. When methanol fuel is used, the leaked methanol will be brought into the sealing oil return chamber by the sealing oil and flow out from the leakage return port. The centralized collection and treatment can effectively prevent the safety hazards caused by methanol leakage and improve the safety of the use of methanol fuel in the system.

[0013] (5) The driving oil and low-pressure sealing oil in this scheme are both lubricating oil of the engine, and the lubrication of the guide cylinder and the low-pressure sealing oil can both be the driving oil that leaks from the guide cylinder gap into the sealing oil return chamber. This can not only reduce the oil products and simplify the oil circuit layout, but also realize the recycling of control oil and low-pressure sealing oil, which is economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0015] Figure 2 is a schematic diagram of the specific structure of the pump nozzle in an embodiment of the present invention;

[0016] Figure 3 Schematic diagram of the structure of the low-pressure sealing oil passage in an embodiment of the present invention;

[0017] Figure 4 Schematic diagram of the specific structure of the hydraulic drive device in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The figure marks in the drawings of the specification include: pressure sensor 1, drive oil common rail pipe 2, safety valve 3, pump nozzle 4, hydraulic drive device 5, oil pipe 6, needle valve pair 7, tight cap 8, intermediate body 9, lift limiting rod 10, pressure regulating spring 11, intermediate block 12, injector body 13, plunger 14, plunger spring 15, guide cylinder 16, wire retaining ring 17, sealing oil return chamber 18, leakage return port 19, pump end pressure chamber 20, fuel inlet 21, high pressure channel 22, low pressure sealing oil channel 23, low pressure sealing oil ring groove 24, valve body 25, armature 26, coil 27, valve sleeve 28, inner valve core 29, left valve core 30, solenoid valve return spring 31, right valve core 32, leakage hole 33. Example

[0020] Basically as attached Figure 1 As shown: a new type of methanol diesel dual fuel injection system, a plurality of fuel injection mechanisms, a pressure sensor 1, a driving oil common rail pipe 2 and a safety valve 3, each fuel injection mechanism includes a pump nozzle 4, a hydraulic drive device 5 and an oil pipe 6, the hydraulic drive device 5 is installed on the pump nozzle 4 for controlling the pump nozzle 4, the hydraulic drive device 5 is connected to the driving oil common rail pipe 2 through the oil pipe 6, the pressure sensor 1 is installed at the oil inlet end of the driving oil common rail pipe 2, and the safety valve 3 is installed at the end of the driving oil common rail pipe 2;

[0021] Combination Figure 2 , Figure 3As shown, the pump nozzle 4 includes a needle valve pair 7, a tight cap 8, an intermediate body 9, a lift limiting rod 10, a pressure regulating spring 11, an intermediate block 12, an injector body 13, a plunger 14, a plunger spring 15, a guide cylinder 16 and a wire retaining ring 17. The injector body 13, the intermediate block 12, the intermediate body 9 and the needle valve pair 7 are installed in sequence from top to bottom, and the injector body 13, the intermediate block 12, the intermediate body 9 and the needle valve pair 7 are coaxially fixed by the tight cap 8. The body 9 is provided with a cavity, the upper end of the lift limiting rod 10 is slidably connected in the cavity of the intermediate body 9, the pressure regulating spring 11 is sleeved on the upper end of the lift limiting rod 10, the bottom of the lift limiting rod 10 is inserted into the needle valve pair 7, the injector body 13 is a hollow structure, the plunger 14 is slidably connected in the injector body 13, the upper end of the injector body 13 is provided with a receiving cavity, the plunger spring 15 is sleeved on the upper end of the plunger 14, and the plunger spring 15 is located in the receiving cavity, the guide tube 1 6 is installed on the top of the plunger 14, and the plunger spring 15 is located in the lead cylinder 16, the lead cylinder 16 is slidably connected in the accommodating cavity, a sealed oil return chamber 18 is formed between the lower part of the lead cylinder 16 and the injector body 13, a leakage return port 19 is provided on the side of the injector body 13, a pump end pressure chamber 20 is formed between the bottom surface of the plunger 14 and the inner wall of the injector body 13, and the pump end pressure chamber 20 is connected to the fuel inlet 21. The intermediate block 12 and the intermediate body 9 are provided with a high A high-pressure passage 22 is provided, and the pump-end pressure chamber 20 is communicated with the interior of the needle valve pair 7 through the high-pressure passage 22; a low-pressure sealing oil passage 23 is also provided in the injector body 13, the intermediate block 12 and the intermediate body 9, and a low-pressure sealing oil ring groove 24 is provided on the contact surface between the injector body 13 and the intermediate block 12, the contact surface between the intermediate block 12 and the intermediate body 9, and the contact surface between the intermediate body 9 and the needle valve pair 7, and the low-pressure sealing oil ring groove 24 is communicated with the low-pressure sealing oil passage 23.

[0022] Combination Figure 4 As shown, the hydraulic drive device 5 is a normally closed two-position three-way solenoid valve, which includes a valve body 25, an armature 26, a coil 27, a valve sleeve 28, an inner valve core 29, a left valve core 30, a solenoid valve return spring 31 and a right valve core 32. The top of the injector body 13 is slidably connected to the cavity at the bottom of the valve body 25, and a control oil cavity is formed between the valve body 25 and the top surface of the guide cylinder 16. A leakage hole 33 is also provided on the side of the valve body 25, and the leakage hole 33 is connected to the leakage oil outlet on the pump nozzle 4.

[0023] The specific implementation process is as follows: the driving oil common rail pipe 2 provides driving oil for the system, and the driving oil flows through the oil pipe 6 and flows into the hydraulic driving device 5. Under the action of the normally closed two-position three-way solenoid valve, it flows into the pump nozzle 4 and drives the plunger 14 to pressurize the fuel and realize fuel injection, so as to realize hydraulic drive instead of mechanical cam drive. The system adopts hydraulic drive and adopts a common rail pipe to provide the hydraulic driving device 5 with driving oil with stable pressure. The driving oil common rail pipe 2 can more effectively ensure the pressure stability of the driving oil, and the stability of the rail pressure can improve the pressure building speed and control flexibility at the pump end lead cylinder 16; and through the pressure sensor 1 and The safety valve 3 and the like can monitor and adjust the pressure of the driving oil in the driving oil common rail pipe 2 in real time, and can be continuously adjustable to achieve continuous and flexible control of the pump end pressure; through the electronically controlled hydraulic drive device 5, on the one hand, it is far away from the fuel, thereby increasing the safety of the use of the solenoid valve, and on the other hand, it can increase the control flexibility and sensitivity of the oil supply characteristics and the oil supply duration, and can flexibly adjust the oil supply duration and the oil supply regularity, and can meet the pressure of the high-pressure oil during fuel injection by adjusting the liquid drive oil pressure, so as to meet the fuel injection quality requirements during the injection process, and can meet the requirements of different fuel characteristics for injection pressure.

[0024] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0025] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A new type of methanol diesel dual fuel injection system, characterized by: Several fuel injection mechanisms, pressure sensors, driving oil common rail pipes and safety valves, each of the fuel injection mechanisms includes a pump nozzle, a hydraulic drive device and an oil pipe, the hydraulic drive device is installed on the pump nozzle for controlling the pump nozzle, the hydraulic drive device is connected to the driving oil common rail pipe through the oil pipe, the pressure sensor is installed at the oil inlet end of the driving oil common rail pipe, and the safety valve is installed at the end of the driving oil common rail pipe; The pump nozzle comprises a needle valve pair, a tight cap, an intermediate body, a lift limiting rod, a pressure regulating spring, an intermediate block, an injector body, a plunger, a plunger spring, a guide tube and a wire retaining ring. The injector body, the intermediate block, the intermediate body and the needle valve pair are installed in sequence from top to bottom, and the injector body, the intermediate block, the intermediate body and the needle valve pair are coaxially fixed by the tight cap. A cavity is provided in the intermediate body, and the upper end of the lift limiting rod is slidably connected to the cavity of the intermediate body. The pressure regulating spring is sleeved on the upper end of the lift limiting rod, and the bottom of the lift limiting rod is inserted into the needle valve pair. The injector body is a hollow structure, and the plunger is slidably connected to the injector body. In the body, an accommodating chamber is provided at the upper end of the injector body, the plunger spring is sleeved on the upper end of the plunger, and the plunger spring is located in the accommodating chamber, the lead cylinder is installed at the top end of the plunger, and the plunger spring is located in the lead cylinder, the lead cylinder is slidably connected in the accommodating chamber, a sealed oil return chamber is formed between the lower part of the lead cylinder and the injector body, a leakage return port is provided on the side of the injector body, a pump end pressure chamber is formed between the bottom surface of the plunger and the inner wall of the injector body, and the pump end pressure chamber is connected to a fuel inlet, a high-pressure channel is provided in the intermediate block and the intermediate body, and the pump end pressure chamber is communicated with the inside of the needle valve pair through the high-pressure channel; The hydraulic drive device is a normally closed two-position three-way solenoid valve, which includes a valve body, an armature, a coil, a valve sleeve, an inner valve core, a left valve core, a solenoid valve return spring and a right valve core. The top of the injector body is slidably connected to the cavity at the bottom of the valve body, and a control oil cavity is formed between the valve body and the top surface of the guide cylinder; The injector body, the intermediate block and the intermediate body are also provided with low-pressure sealing oil passages, and the contact surfaces between the injector body and the intermediate block, the contact surfaces between the intermediate block and the intermediate body, and the contact surfaces between the intermediate body and the needle valve pair are all provided with low-pressure sealing oil ring grooves, and the low-pressure sealing oil ring grooves are all connected to the low-pressure sealing oil passages.

2. A novel methanol-diesel dual fuel injection system according to claim 1, characterized in that: A leakage hole is also provided on the side of the valve body, and the leakage hole is communicated with the leakage oil outlet on the pump nozzle.

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