A dual fuel injection device for multiple purposes

Abstract

The utility model aims at providing a kind of multipurpose dual fuel injection device, belong to engine field.The device includes by two by same core, coil, armature etc. composed of electromagnet, concentric, back to, stack between by main control valve body, main control valve stem etc. composed of main control valve and by pilot valve body, pilot valve stem etc. composed of pilot control valve, to pass through control main control chamber, pilot control chamber pressure.The utility model will main needle valve be completely enclosed in the cavity of main needle valve body, not only can be exempted from the erosion of high temperature, high pressure gas in cylinder, also solve the instantaneous impact force and vibration of engine burst pressure to main needle valve, ensure the accurate control and stable performance of needle valve in long-term operation, reduce failure rate and maintenance cost, to optimize the overall efficiency and reliability of engine.

Description

Technical Field

[0001] The present invention relates to an engine, specifically a fuel injection device. Background Technology

[0002] Against the backdrop of energy shortages and increasingly stringent emission limits, alternative fuel engines are showing unique advantages. Alternative fuels include both gaseous and liquid fuels. Currently, most gaseous fuel engines still use low-pressure injection technology. However, the low gas density of low-pressure injection results in a significant power density gap between alternative fuel engines and diesel engines. In this context, the market is calling for a new injection technology: dual-fuel injection technology that integrates diesel and alternative fuels through high-pressure direct injection. Engines utilizing this technology can achieve power densities comparable to diesel engines and also achieve stratified combustion, resulting in a smoother combustion process and better hydrocarbon emissions than diesel engines. The problem is that most alternative fuels have low cetane content, making compression ignition difficult. Therefore, using diesel compression ignition to ignite alternative fuels can solve the problem of insufficient power density at high compression ratios. Existing dual-fuel injection systems often employ a 1+3 four-needle valve structure, with the diesel needle valve in the center and three alternative fuel needle valves arranged radially around it. Not only are they structurally complex, but they are also extremely large. Except for a few large or super-large engines, medium- and low-displacement large engines cannot meet the required installation space due to the excessive size of the nozzles, especially their large diameter. Therefore, the development of miniaturization technology for dual-fuel injection devices has become crucial for breakthroughs. Due to the complexity of the structure, the current integrated diesel and alternative fuel in-cylinder high-pressure direct injection dual-fuel injection technology is not yet mature. Nevertheless, driven by urgent market demand, the development of miniaturized integrated diesel and alternative fuel in-cylinder high-pressure direct injection dual-fuel injection technology has become key to energy conservation and emission reduction.

[0003] refer to Figure 2In the prior art, the dual-fuel injection device includes: a main control valve, from top to bottom, consisting of a diesel inlet section 29, a main control valve body 43, a main control valve stem 44, an armature 33, an outer iron core 46, an inner iron core 48, a coil 47, and a valve stem spring 34; and a pilot control valve, consisting of a substitute fuel inlet section 37, a pilot valve body 31, a pilot valve stem 32, an armature 52, an outer iron core 46, an inner iron core 48, a coil 51, and a pilot valve stem spring 55, with the main control valve and the pilot control valve sequentially fixed together by an upper screw sleeve 54; and an injection actuator, consisting of a crimping block 39, a main needle valve body 43, a main needle valve 44, a pilot needle valve 45, an isolator 41, a main needle valve spring 42, a pilot needle valve spring 53, and a steel ball 57, with the injection actuator fixed to the lower end of the substitute fuel inlet section 37 by an upper screw sleeve 38. During operation, the pilot coil 51 is energized, and the armature 52 drives the pilot valve stem 32 to move upward and open. The high-pressure diesel in the pilot control chamber 441 flows into the low-pressure area through the pilot inlet / outlet metering hole 373, causing the pressure in the pilot control chamber 441 to drop. When the combined force of the diesel in the pilot control chamber 441 pressing down on the pilot needle valve 45 and the spring force of the pilot needle valve spring 53 pressing down on the pilot needle valve 45 is less than the upward force of the pressure in the diesel storage chamber 444 on the pilot needle valve 45, the pilot needle valve 45 moves upward and opens to inject. When the pilot coil 47 is energized, the armature 33 drives the main control valve stem 36 downward to open it. The high-pressure diesel in the main control chamber 391 flows into the low-pressure area through the main inlet / outlet metering hole 352, causing the pressure in the main control chamber 391 to drop. When the combined force of the pressure in the main control chamber 391 and the spring force of the main needle valve spring 42 on the downward pressure of the main needle valve 44 is less than the upward force of the pressure in the alternative fuel storage chamber 431 on the main needle valve 44, the main needle valve 44 moves upward to open and inject. When coil 51 is de-energized, the electromagnetic force disappears, pilot valve stem 32 closes, and high-pressure diesel fuel enters pilot control chamber 441 through pilot inlet port 314 and pilot annular metering gap 315. When the combined force of the downward pressure of diesel fuel in pilot control chamber 441 on pilot needle valve 45 and the spring force of pilot needle valve spring 53 on pilot needle valve 45 is greater than the upward force of pressure in diesel storage chamber 444 on pilot needle valve 45, pilot needle valve 45 descends and closes to stop injection. When coil 47 is de-energized, the electromagnetic force disappears, the main control valve stem 36 closes, and high-pressure diesel fuel enters the main control chamber 391 through the main inlet metering port 351 and the main inlet / outlet metering port 352. When the combined force of the downward pressure of the diesel fuel in the main control chamber 391 on the main needle valve 44 and the spring force of the main needle valve spring 42 on the main needle valve 44 is greater than the upward force of the pressure in the alternative fuel storage chamber 431 on the main needle valve 44, the main needle valve 44 descends and closes, stopping the injection.

[0004] like Figure 2The problem with the prior art injection device shown is that, because the lower end of the main needle valve 44 is directly exposed inside the engine cylinder, it is subjected to the impact of cylinder explosion pressure. The explosion pressure during engine operation can reach as high as 140 bar or even higher. Under the action of this cylinder explosion pressure, the main needle valve 44 is subjected to an upward force of up to 260 N or even greater. This upward force obstructs the closing process of the main needle valve 44, increasing the closing delay time and causing a surge in the injection volume of that cycle. Since the nozzle's opening and closing movement is under closed-loop control, this leads to a sharp decrease in the injection volume in the next cycle. This repeated, drastic change in injection volume results in significant oscillations in engine torque.

[0005] like Figure 2 The problem with the prior art injection device shown is that its structure requires the upper dynamic sealing diameter of the main needle valve 44 to be concentric with the guide hole of the main needle valve body 43, and the main needle valve sealing ridge 442 at the lower end of the main needle valve 44 to be concentric with the tapered seat surface at the lower end of the main needle valve body 43. Furthermore, it requires the lower step diameter of the main needle valve 44 to be concentric with the corresponding dynamic sealing hole at the lower end of the main needle valve body 43. This is clearly an over-positioning structure. To ensure that the first two pairs of fits meet the requirements of the mating parts, the concentricity between the lower step diameter of the main needle valve 44 and the dynamic sealing hole at the lower end of the main needle valve body 43 must be relaxed in these three pairs of fits. The only way to widen the concentricity between the lower step diameter of the main needle valve 44 and the dynamic seal orifice at the lower end of the main needle valve body 43 is to increase the annular gap between them. This results in the vertically downward annular jet generated along the annular gap altering the concentration field distribution within the combustion chamber when the substitute fuel is injected simultaneously. Furthermore, when diesel and substitute fuel are injected simultaneously, the vertically downward annular jet formed by the substitute fuel injection acts like an annular wall, blocking part of the pilot diesel spray within the space defined by the annular jet and affecting the ignition effect.

[0006] like Figure 2The problem with the existing injection device shown is that, because the diesel injection orifice 434 is located on the main needle valve 44, while the alternative fuel injection orifice 435 is located on the main needle valve body 43, the two sets of injection orifices are not on the same part. During operation, it is impossible to ensure a relatively uniform distribution between the axes of the two sets of injection orifices. Therefore, the existing technology sets an axial keyway on the left shoulder of the upper central hole of the main needle valve body 43, and creates a ball socket at the corresponding position on the main needle valve 44. A steel ball 57 is placed in the ball socket and keyway, and moves only axially along the keyway, restricting circumferential rotation. However, in reality, for smooth movement, a large gap must be left between the ball socket and guide groove and the steel ball, causing a shift in the relative positions of the alternative fuel injection and diesel injection lines projected onto the combustion chamber plane, resulting in misaligned spray intervals and adverse combustion. Furthermore, when diesel injection and alternative fuel injection occur simultaneously, the main needle valve 44 moves upward by one stroke compared to diesel injection alone, which also affects the optimal matching relationship of diesel injection. Furthermore, the limited sealing length of the coupling is shortened due to the guide groove made on the upper left shoulder of the alternative fuel needle valve body 43.

[0007] like Figure 2 The shortcomings of the prior art injection device shown are that: the pilot valve body 31 is installed on the countersunk seat surface of the alternative fuel inlet section 37, and the high-pressure hard seal formed by the connection between the countersunk seat surface of the alternative fuel inlet section 37 and the lower plane of the pilot valve body 31 should have a sealing capacity of nearly 1,000 bar. Therefore, the flatness and roughness of the countersunk seat surface of the alternative fuel inlet section 37 are required to be very strict, which leads to processing difficulties and increased manufacturing costs.

[0008] like Figure 2 The problem with the prior art injection device shown is that the two electromagnets driving the pilot valve stem 32 and the main control valve stem 36 share a single inner iron core, which causes some mutual interference during operation.

[0009] like Figure 2 The problem with the prior art injection device shown is that, apart from sharing an inner core, the two electromagnets driving the pilot valve stem 32 and the main control valve stem 36 both use a combination of three iron cores made of different materials with different magnetic permeability. Since both the pilot valve body 31 and the main control valve body 35 have high hardness requirements, the magnetic permeability will be affected. Moreover, the gaps in the combined iron cores will greatly increase the magnetic resistance of the magnetic circuit, which will greatly weaken the dynamic response speed that the switching electromagnet should have.

[0010] In conclusion, the numerous problems with existing spraying devices demonstrate that the technology is not yet mature enough, thus hindering its market application and promotion. Summary of the Invention

[0011] The purpose of this invention is to provide a multi-purpose dual-fuel injection device that is suitable for various alternative fuels, including gaseous fuels and liquid fuels, has a uniform atomization field, is not affected by cylinder pressure, has stable injection, and has better linearity of injection quantity gain.

[0012] The objective of this invention is achieved as follows: This invention discloses a multi-purpose dual-fuel injection device, characterized by comprising, from top to bottom, a diesel inlet section, a substitute fuel inlet section, a crimping block, and a main needle valve body. A control assembly is disposed between the diesel inlet section and the substitute fuel inlet section. The control assembly includes a pilot control valve and a main control valve, which are concentrically arranged, opposite to each other, and stacked. A disc gasket is installed between them. Inside the crimping block and the main needle valve body, from top to bottom, are a reducing vessel, an isolator, and a main needle valve. A pilot needle valve is disposed inside the main needle valve. A main needle valve spring is fitted on the lower part of the reducing vessel and the upper part of the isolator, and a [missing information - likely a device name or design] is fitted on the upper part of the pilot needle valve. The pilot needle valve spring has its top located below the isolator. The pressing block and the cavity under the isolator form the main control chamber. The cavities under the isolator, main needle valve, and pilot needle valve form the pilot control chamber. A diesel inlet is provided in the diesel inlet section. A diesel storage chamber is formed between the main needle valve and the pilot needle valve. The diesel inlet is connected to the diesel storage chamber through the diesel injection circuit. A substitute fuel inlet is provided in the substitute fuel inlet section. A substitute fuel storage chamber is formed between the main needle valve and the main needle valve body. The substitute fuel inlet is connected to the substitute fuel storage chamber through the substitute fuel injection circuit. The bottom of the main needle valve body is provided with a main injection hole and a pilot injection hole.

[0013] The present invention may also include: 1. The pilot control valve includes a pilot valve body, a pilot valve stem, a pilot core, and a pilot armature. The pilot valve body is located below the diesel inlet section, and the pilot core is located below the pilot valve body. A pilot coil is installed in the pilot core. The pilot valve stem is located inside the pilot valve body. The bottom of the pilot valve stem is connected to the pilot armature and extends into the pilot core. A pilot valve stem spring is fitted at the bottom of the pilot valve stem. A pilot radial annular cavity is formed between the pilot valve stem and the pilot valve body. The top of the pilot valve stem is a pilot valve stem conical surface. A low-pressure oil hole and a control oil circuit are provided in the diesel inlet section above the pilot valve stem conical surface. A diesel control oil circuit and a pilot inlet / outlet metering hole are respectively provided in the pilot valve body. The diesel control oil circuit is connected to the control oil circuit and the pilot radial annular cavity. The pilot inlet / outlet metering hole is connected to the pilot control chamber. The pilot valve stem conical surface controls the connection and disconnection between the pilot radial annular cavity and the low-pressure oil hole or the pilot inlet / outlet metering hole.

[0014] 2. The main control valve includes a main control valve body, a main control valve stem, a main control iron core, and a main control armature. The main control valve body is located above the alternative fuel inlet section, and the main control iron core is located above the main control valve body. A main control coil is installed inside the main control iron core. The main control valve stem is located inside the main control valve body. The top of the main control valve stem is connected to the main control armature and extends into the main control iron core. A main control valve stem spring is fitted on the top of the main control valve stem. A main control radial annular cavity is formed between the main control valve stem and the main control valve body. The bottom of the main control valve stem... The main control valve stem has a conical surface. A low-pressure return oil hole is provided in the alternative fuel inlet section below the main control valve stem conical surface. An alternative fuel control oil circuit and a main inlet / outlet oil metering hole are provided in the main control valve body. The alternative fuel control oil circuit is connected to the control oil circuit and the main control radial annular cavity respectively. The main inlet / outlet oil metering hole is connected to the main control chamber. The main control valve stem conical surface controls the connection and disconnection between the main control radial annular cavity and the main inlet / outlet oil metering hole or the low-pressure return oil hole. A disc gasket is installed between the pilot iron core and the main control iron core.

[0015] 3. A master-slave valve is installed below the pilot needle valve. The master-slave valve has a central hole inside, which is connected to the pilot injection hole. When the pilot needle valve is raised, the central hole of the master-slave valve is connected to the diesel storage chamber.

[0016] 4. When diesel fuel injection is activated, the pilot coil is energized, and the electromagnetic force acts on the pilot armature, driving the pilot valve stem connected to the pilot armature to move downward and open. The conical surface of the pilot valve stem controls the oil passage between the low-pressure oil hole and the pilot control chamber. The high-pressure oil in the pilot control chamber is depressurized through the upper valve face, causing the pilot needle valve to open for fuel injection. The high-pressure diesel in the pilot control chamber flows into the low-pressure area through the pilot return oil metering hole, the sealing line of the pilot valve stem end face of the pilot control valve stem, and the opening gap between the diesel inlet section, thus reducing the pressure in the pilot control chamber. When the upward lifting force of the high-pressure diesel in the high-pressure oil reservoir on the pilot needle valve is greater than the downward pressure of the high-pressure diesel in the pilot control chamber and the pilot needle valve spring on the pilot needle valve, the pilot needle valve moves upward and opens, and diesel is injected outward from the pilot injection hole through the central hole of the main and slave valve cores.

[0017] 5. When diesel fuel injection is shut off, the pilot coil is de-energized, the pilot valve stem moves upward under the action of the pilot valve stem spring, the conical surface of the pilot valve stem sits down, the connection between the pilot control chamber and the low-pressure oil port is disconnected, the oil inlet conical surface of the pilot valve stem opens, and high-pressure diesel fuel fills the pilot control chamber through the pilot inlet metering port and the pilot return metering port. When the diesel fuel pressure in the pilot control chamber and the downward pressure of the pilot needle valve spring on the pilot needle valve are greater than the upward lifting force of the diesel fuel in the high-pressure oil reservoir on the pilot needle valve, the pilot needle valve moves downward and closes, and the pilot injection port stops injecting.

[0018] 6. When low-carbon fuel injection is activated, the main control coil is energized, causing the lower main control armature to drive the main control valve stem upward and open. The conical surface of the main control valve stem controls the oil passage between the low-pressure return oil end and the main control chamber. The high-pressure diesel in the main control chamber is depressurized through the opening of the conical surface of the main control valve stem, causing the main needle valve to open for fuel injection. The high-pressure diesel in the main control chamber flows into the low-pressure area through the main return oil metering hole and the opening gap of the main control valve stem. When the upward lifting force of the high-pressure substitute fuel in the high-pressure oil storage chamber on the main needle valve is greater than the downward pressure of the diesel in the main control chamber and the main needle valve spring on the main needle valve, the main needle valve opens upward and injects substitute fuel outward from the main injection hole.

[0019] 7. When low-carbon fuel injection is shut off, the main control coil is de-energized. Under the action of the main control valve stem spring, the main control valve stem descends and closes. The conical surface of the main control valve stem sits down, and the connection between the main control chamber and the low-pressure return oil end is disconnected. High-pressure diesel fuel enters from the diesel inlet and fills the main control chamber through the main inlet metering hole and the main return oil metering hole. When the diesel fuel pressure in the main control chamber and the downward pressure of the main needle valve spring on the main needle valve are greater than the upward lifting force of the substitute fuel in the substitute fuel storage chamber on the main needle valve, the main needle valve closes and the main injection hole stops injecting.

[0020] The advantages of this invention are as follows: Since the main needle valve 22 is completely enclosed in the cavity of the main needle valve body 21, it is not only protected from the corrosion of high temperature and high pressure gas in the cylinder, but also solves the problem of instantaneous impact force and vibration of engine overpressure on the main needle valve 22, ensuring the accurate control and stable performance of the needle valve in long-term operation, reducing the failure rate and maintenance costs, and thus optimizing the overall efficiency and reliability of the engine.

[0021] Since the over-positioning problem of the main needle valve 22 has been solved, a vertically downward annular jet will not be generated as in the prior art, nor will a portion of the pilot-injected diesel spray be confined within the space covered by the annular jet, thus affecting the ignition effect.

[0022] By arranging the pilot nozzle 214 and the main nozzle 215 on the same part of the main needle valve body 21, both the accurate distribution of the spray axis and the sealing requirements can be met.

[0023] By using exposed surfaces for all parts that require planar hard seals, the process is simplified and costs are reduced.

[0024] By using two identical electromagnets and reducing additional magnetic resistance caused by the magnetic gap through the use of an integral iron core, the dynamic response speed of the electromagnets is not only improved and they are guaranteed not to interfere with each other, but the cost is also greatly reduced. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2This is a schematic diagram of the structure of an integrated diesel and alternative fuel nozzle in existing technology.

[0026] Figure reference numerals: 1. Wiring socket; 2. Diesel inlet section; 3. Pilot valve body; 4. Pilot valve stem; 5. Armature; 6. Spring washer; 7. Buffer spring; 8. Open gasket; 9. Valve stem spring; 11. Disc gasket; 12. Main control valve body; 13. Main control valve stem; 14. Alternative fuel inlet section; 15. Lower threaded sleeve; 16. Crimping block; 17. Reducer; 18. Isolator; 19. Main needle valve spring; 21. Main needle valve body; 22. Main needle valve; 23. Pilot needle valve; 24. Master-slave valve core; 25. Iron core; 26. Iron core coil assembly; 27. Pilot needle valve spring; 28. Wiring socket; 29. ​​Diesel inlet section; 31. Pilot valve body; 32. Pilot valve stem; 33. Armature; 34. Valve stem spring; 35. Main control valve body; 36. Main control valve stem; 37. Alternative fuel inlet section; 38. Lower threaded sleeve; 39. Crimping block; 41. Isolator 42 Main needle valve spring, 43 Main needle valve body, 44 Main needle valve, 45 Pilot needle valve, 46 Outer iron core, 47 Coil, 48 Inner iron core, 49 Iron core, 51 Pilot coil, 52 Armature, 53 Pilot needle valve spring, 54 Upper threaded sleeve, 55 Pilot valve stem spring, 56 Socket bend plate, 57 Steel ball, 121 Main inlet metering hole, 122 Main inlet and outlet metering hole, 123 Main control valve body cone hole sealing line, 131 Main control valve stem conical surface, 132 Main control valve stem lower end sealing line, 133 Main control valve stem upper end sealing line, 141 Alternative fuel inlet, 142 Low-pressure return oil hole, 143 Pilot inlet and outlet metering hole, 151 Low-pressure return oil hole, 161 Main control chamber, 162 Return oil hole, 201 Diesel inlet, 202 Low-pressure oil hole, 211 Alternative fuel 212 Main needle valve body conical hole seat surface, 213 Main and slave valve core conical hole seat surface, 214 Pilot injection hole, 215 Main injection hole, 221 Pilot control chamber, 222 Main needle valve sealing ridge, 223 Pilot needle valve conical hole seat surface, 224 Diesel fuel storage chamber, 231 Pilot needle valve dynamic seal diameter, 232 Pilot needle valve sealing ridge, 233 Oil passage groove, 241 Main and slave valve core sealing ridge, 242 Main and slave valve core central hole, 301 Pilot inlet metering hole, 302 Pilot inlet and outlet metering holes, 303 Pilot valve body conical hole sealing line, 304 Pilot inlet hole, 305 Pilot annular metering gap, 401 Pilot valve stem conical surface, 402 Pilot valve stem end face sealing line, 351 Main inlet metering hole, 352 Main inlet and outlet metering holes, 353 Main control valve 361 Main control valve stem conical surface, 362 Main control valve stem lower end sealing line, 363 Main control valve stem upper end sealing line, 371 Alternative fuel inlet, 372 Low-pressure return oil hole, 373 Pilot inlet / outlet metering hole, 381 Low-pressure return oil hole, 391 Main control chamber, 392 Return oil hole, 291 Diesel fuel inlet, 292 Low-pressure oil hole, 431 Alternative fuel storage chamber, 432 Main needle valve body conical hole seat surface, 433 Main and slave valve core conical hole seat surface, 434 Pilot injection hole, 435 Main injection hole, 441 Pilot control chamber, 442 Main needle valve sealing ridge, 443 Pilot needle valve conical hole seat surface, 444 Diesel fuel storage chamber, 451 Pilot needle valve dynamic seal diameter, 452 Pilot needle valve sealing ridge, 453 Oil passage groove, 311 Pilot inlet metering hole.312 Pilot inlet / outlet metering orifice; 313 Pilot valve body conical bore sealing line; 314 Pilot inlet port; 315 Pilot annular metering clearance; 321 Pilot valve stem conical surface; 322 Pilot valve stem end face sealing line. Detailed Implementation

[0027] The invention will now be described in more detail with reference to the accompanying drawings: Combination Figure 1-2 This invention includes two electromagnets, each composed of an identical iron core 25, coil 26, and armature 5, concentrically and oppositely stacked between a pilot control valve (composed of a pilot valve body 3 and a pilot valve stem 4) and a main control valve (composed of a main control valve body 12 and a main control valve stem 13). A disc-shaped gasket 11 supports the two electromagnets and provides a flow gap for cooling. An upper threaded sleeve 35 concentrically connects the pilot control valve and the main control valve between the diesel inlet section 2 and the alternative fuel inlet section 14, forming a control component for a dual-fuel injection device. An injection actuator assembly, consisting of a reducing container 17, a main needle valve spring 19, an isolator 18, a main needle valve 22, a pilot needle valve spring 34, a pilot needle valve 23, and a master-slave valve core 24, sequentially mounted in a pressing block 16 and a main needle valve body 21, is fixed to the lower plane of the alternative fuel inlet section 14 by a lower threaded sleeve 15. The cavity governed by the crimping block 16 and the isolator 18 constitutes the main control room 161, and the cavity governed by the isolator 18, the main needle valve 22, and the pilot needle valve 23 constitutes the pilot control room 221.

[0028] The injector, from top to bottom, consists of a diesel inlet section 2, a pilot valve body 3, a main control valve body 12, a crimping block 16, and a main needle valve body 21. A pilot needle valve 23 sits on the main needle valve 22, forming a high-pressure reservoir 224. When not injecting fuel, high-pressure injected diesel and control diesel enter the injector through the diesel inlet 201. The diesel inlet is located at the far end of the nozzle and splits into two lines. The diesel injection line 39 (a newly added lead wire) passes sequentially through the pilot valve body 3, the main control valve body 12, the crimping block 16, the annular cavity connecting the main needle valve body 21 and the main needle valve 22, and then enters the high-pressure reservoir 224 within the main needle valve 22 through an oblique hole, awaiting injection. The diesel pipeline, serving as control oil circuit 40 (newly added lead), splits into two paths at the diversion groove where the diesel inlet section 2 connects to the pilot valve body 3. One path, diesel control oil circuit 41 (newly added lead), enters the upper solenoid valve of the dual solenoid valve through the pilot inlet metering hole 301, and then enters the radial annular cavity formed by the pilot valve stem 4 and the pilot valve body 3, acting on the pilot valve stem conical surface 401. When not in operation, the pilot valve stem 4, under oil pressure, sits on the lower plane of the diesel inlet section 2. The low-pressure oil hole 202 is not connected to the diesel inlet oil circuit. The high-pressure diesel in the radial annular cavity passes through the pilot valve stem conical surface 401, through another throttling hole in the pilot valve body 3 on the same plane, the main inlet / outlet metering hole 302, and sequentially through the main control valve body 12, the fuel inlet section 14, and the crimping block 16. The main needle valve 22 and the main needle valve body 21 have a radial annular cavity formed by grooves. After the diesel control oil enters this chamber, it enters the pilot control chamber 221 through the throttling orifice in the main needle valve body 21. The pilot control chamber 221 is formed by the lower plane of the isolator 18 and the upper planes of the main needle valve 22 and the pilot needle valve 23. The pressure in the pilot control chamber 221 acts on the pilot needle valve 23. Another methanol control oil circuit 42 (new lead wire) passes through the pilot valve body 3 and the main control valve body 12. The control oil enters the lower solenoid valve of the dual solenoid valve through the oil inlet metering hole 121 on the main control valve body 12. Both the main control valve stem 13 and the main control valve body 12 are grooved. The control oil enters the radial annular cavity formed by the grooves of the main control valve stem 13 and the main control valve body 12, and acts on the conical surface 131 of the main control valve stem. When not in operation, the main control valve stem 13 rests on the upper surface of the alternative fuel inlet section 14. The low-pressure return oil hole 142 is not connected to the diesel fuel inlet line. The high-pressure diesel fuel in the radial annular cavity passes through the conical surface 131 of the main control valve stem, through another throttling orifice 122 on the same plane in the main control valve body 12, and enters the crimping block 16 through the fuel inlet section 14. The crimping block 16 and the upper surface of the main needle valve body 21 form the main control chamber 161 through the isolator 18. The isolator 18 is fastened to the main needle valve body 21 by threads. Therefore, the pressure of the high-pressure diesel fuel in the main control chamber 161 also acts on the main needle valve body 21. Thus, the high-pressure diesel fuel fills the pilot control chamber 221, the main control chamber 161, and the high-pressure oil reservoir 224.

[0029] The high-pressure substitute fuel, filled with high-pressure low-carbon substitute fuel, enters the injector through the substitute fuel inlet 141 in the fuel inlet section 14, passes through the crimping block 16, and enters the fuel storage chamber 211 in the main needle valve body 21, waiting for injection. The fuel storage chamber 211 is an annular radial chamber formed by the main needle valve body 21 and the main needle valve 22. The high pressure in the fuel storage chamber 211 acts on the step of the main needle valve 22, forming a lifting force. In addition, it enters the lower end face of the main needle valve 22 through the annular gap, and the step in front of the sealing ridge 222 of the main needle valve also forms an upward lifting force.

[0030] When diesel fuel injection is initiated, the upper solenoid coil 26 of the dual solenoid valve is energized, and the electromagnetic force acts on the armature 5, driving the pilot valve stem 4 connected to the armature 5 to move downward and open. The seat surface of the valve stem 4 controls the opening and closing of the oil passage between the low-pressure oil port 202 and the pilot control chamber 221. The high-pressure oil in the pilot control chamber 221 needs to be depressurized through the upper valve surface, causing the pilot needle valve 23 to open for fuel injection. High-pressure diesel fuel in the pilot control chamber 221 flows into the low-pressure zone through the pilot return metering hole 302, the pilot valve stem end face sealing line 402 of the pilot control valve stem 4, and the opening gap between the diesel inlet section 2, thereby reducing the pressure in the pilot control chamber 221. At this time, the pressure in the high-pressure oil storage chamber 224 at the lower end of the pilot needle valve 23 is still in a high-pressure state. When the upward lifting force of the high-pressure diesel fuel in the high-pressure oil storage chamber 224 on the pilot needle valve 23 is greater than the downward pressure of the high-pressure diesel fuel in the pilot control chamber 221 and the pilot needle valve spring 34 on the pilot needle valve 23, the pilot needle valve 23 opens upward and injects diesel fuel outward from the pilot injection hole 214.

[0031] When diesel fuel injection is shut off, the upper solenoid coil 26 of the dual solenoid valve is de-energized, the electromagnetic force disappears, and the pilot valve stem 4 moves upward under the action of the valve stem spring 9. The conical surface of the pilot valve stem 401 sits down, and the connection between the pilot control chamber 221 and the low-pressure oil port 202 is disconnected. At the same time, the oil inlet conical surface of the pilot valve stem 401 opens, and high-pressure diesel fuel fills the pilot control chamber 221 through the pilot oil inlet metering port 301 and the pilot oil return metering port 302, causing the pressure in the pilot control chamber 221 to rise. When the diesel fuel pressure in the pilot control chamber 221 and the downward pressure of the pilot needle valve spring 34 on the pilot needle valve 23 are greater than the upward lifting force of the diesel fuel in the high-pressure oil reservoir 224 on the pilot needle valve 23, the pilot needle valve 23 moves downward and closes, and the pilot injection port 214 stops injecting.

[0032] When low-carbon fuel injection is initiated, the lower solenoid coil 32 of the dual solenoid valve is energized, causing the lower armature 33 to drive the main control valve stem 13 upwards. The main control valve stem seat 132 controls the oil passage between the low-pressure return oil end 142 and the main control chamber 161. The high-pressure diesel fuel in the main control chamber 161 needs to be depressurized by opening the main control valve stem seat 132, causing the main needle valve 22 to open for fuel injection. The high-pressure diesel fuel in the main control chamber 161 flows into the low-pressure area through the main return oil metering hole 122 and the opening gap of the main control valve stem 13, reducing the pressure in the main control chamber 161. At this time, the pressure in the substitute fuel storage chamber 211 is still high. When the upward force of the high-pressure substitute fuel in the high-pressure storage chamber 211 on the main needle valve 22 is greater than the downward force of the diesel fuel in the main control chamber 161 and the main needle valve spring 19 on the main needle valve 22, the main needle valve 22 opens upwards, injecting substitute fuel outwards from the main injection hole 215.

[0033] When low-carbon fuel injection is shut off, the lower solenoid coil 32 of the dual solenoid valve is de-energized, the electromagnetic force disappears, and under the action of the pilot valve stem spring 36, the main control valve stem 13 descends and closes, the conical surface of the main control valve stem 13 sits down, and the connection between the main control chamber 161 and the low-pressure return oil end 142 is disconnected. At the same time, the oil inlet conical surface of the main control valve stem 13 opens, i.e., the sealing line 123 of the conical hole of the main control valve body. High-pressure diesel enters from the diesel inlet 201 and fills the main control chamber 161 through the main oil inlet metering hole 121 and the main oil return metering hole 122, causing the pressure in the pilot control chamber 161 to rise. When the diesel pressure in the main control chamber 161 and the downward pressure of the main needle valve spring 19 on the main needle valve 22 are greater than the upward lifting force of the substitute fuel in the substitute fuel storage chamber 211 on the main needle valve 22, the main needle valve 22 closes, and the main injection hole 215 stops injecting.

Claims

1. A multi-purpose dual-fuel injection device, characterized in that: The system includes, from top to bottom, a diesel inlet section, a substitute fuel inlet section, a crimping block, and a main needle valve body. A control assembly is installed between the diesel inlet section and the substitute fuel inlet section. The control assembly includes a pilot control valve and a main control valve, which are concentric, opposite to each other, and stacked. A disc gasket is installed between them. Inside the crimping block and the main needle valve body, from top to bottom, are a reducing vessel, an isolator, and a main needle valve. A pilot needle valve is installed inside the main needle valve. A main needle valve spring is fitted on the lower part of the reducing vessel and the upper part of the isolator, and a pilot needle valve spring is fitted on the upper part of the pilot needle valve. The top of the spring is located below the isolator. The pressing block and the cavity under the control of the isolator form the main control chamber. The cavities under the control of the isolator, the main needle valve, and the pilot needle valve form the pilot control chamber. A diesel inlet is provided in the diesel inlet section. A diesel storage chamber is formed between the main needle valve and the pilot needle valve. The diesel inlet is connected to the diesel storage chamber through the diesel injection oil circuit. A substitute fuel inlet is provided in the substitute fuel inlet section. A substitute fuel storage chamber is formed between the main needle valve and the main needle valve body. The substitute fuel inlet is connected to the substitute fuel storage chamber through the substitute fuel injection oil circuit. The bottom of the main needle valve body is provided with a main injection hole and a pilot injection hole.

2. The multi-purpose dual-fuel injection device according to claim 1, characterized in that: The pilot control valve includes a pilot valve body, a pilot valve stem, a pilot core, and a pilot armature. The pilot valve body is located below the diesel inlet section, and the pilot core is located below the pilot valve body. A pilot coil is installed in the pilot core. The pilot valve stem is located inside the pilot valve body. The bottom of the pilot valve stem is connected to the pilot armature and extends into the pilot core. A pilot valve stem spring is fitted at the bottom of the pilot valve stem. A pilot radial annular cavity is formed between the pilot valve stem and the pilot valve body. The top of the pilot valve stem is a pilot valve stem conical surface. A low-pressure oil hole and a control oil circuit are provided in the diesel inlet section above the pilot valve stem conical surface. The pilot valve body is provided with a diesel control oil circuit and a pilot inlet / outlet metering hole. The diesel control oil circuit is connected to the control oil circuit and the pilot radial annular cavity. The pilot inlet / outlet metering hole is connected to the pilot control chamber. The pilot valve stem conical surface controls the connection and disconnection between the pilot radial annular cavity and the low-pressure oil hole or the pilot inlet / outlet metering hole.

3. A multi-purpose dual-fuel injection device according to claim 2, characterized in that: The main control valve includes a main control valve body, a main control valve stem, a main control iron core, and a main control armature. The main control valve body is located above the alternative fuel inlet section, and the main control iron core is located above the main control valve body. A main control coil is installed inside the main control iron core. The main control valve stem is located inside the main control valve body. The top of the main control valve stem is connected to the main control armature and extends into the main control iron core. A main control valve stem spring is fitted on the top of the main control valve stem. A main control radial annular cavity is formed between the main control valve stem and the main control valve body. The bottom of the main control valve stem is... The main control valve stem has a conical surface. A low-pressure return oil hole is provided in the alternative fuel inlet section below the main control valve stem conical surface. The main control valve body is provided with an alternative fuel control oil circuit and a main inlet / outlet oil metering hole. The alternative fuel control oil circuit is connected to the control oil circuit and the main control radial annular cavity respectively. The main inlet / outlet oil metering hole is connected to the main control chamber. The main control valve stem conical surface controls the connection and disconnection between the main control radial annular cavity and the main inlet / outlet oil metering hole or the low-pressure return oil hole. A disc gasket is installed between the pilot iron core and the main control iron core.

4. A multi-purpose dual-fuel injection device according to claim 1, characterized in that: A master-slave valve is installed below the pilot needle valve. The master-slave valve has a central hole inside, which is connected to the pilot injection hole. When the pilot needle valve is raised, the central hole of the master-slave valve is connected to the diesel storage chamber.

5. A multi-purpose dual-fuel injection device according to claim 2, characterized in that: When diesel fuel injection is initiated, the pilot coil is energized, and electromagnetic force acts on the pilot armature, driving the pilot valve stem connected to the pilot armature to move downward and open. The conical surface of the pilot valve stem controls the opening and closing of the oil passage between the low-pressure oil hole and the pilot control chamber. The high-pressure oil in the pilot control chamber is depressurized through the upper valve face, causing the pilot needle valve to open for fuel injection. The high-pressure diesel in the pilot control chamber flows into the low-pressure area through the pilot return oil metering hole, the sealing line of the pilot valve stem end face of the pilot control valve stem, and the opening gap between the diesel inlet section, thus reducing the pressure in the pilot control chamber. When the upward lifting force of the high-pressure diesel in the high-pressure oil reservoir on the pilot needle valve is greater than the downward pressure of the high-pressure diesel in the pilot control chamber and the pilot needle valve spring on the pilot needle valve, the pilot needle valve moves upward and opens, and diesel is injected outward from the pilot injection hole through the central hole of the main and slave valve cores.

6. A multi-purpose dual-fuel injection device according to claim 2, characterized in that: When diesel fuel injection is shut off, the pilot coil is de-energized, the pilot valve stem moves upward under the action of the pilot valve stem spring, the conical surface of the pilot valve stem sits down, the connection between the pilot control chamber and the low-pressure oil port is disconnected, the oil inlet conical surface of the pilot valve stem opens, and high-pressure diesel fuel fills the pilot control chamber through the pilot inlet metering port and the pilot return metering port. When the diesel fuel pressure in the pilot control chamber and the downward pressure of the pilot needle valve spring on the pilot needle valve are greater than the upward lifting force of the diesel fuel in the high-pressure oil reservoir on the pilot needle valve, the pilot needle valve moves downward and closes, and the pilot injection port stops injecting.

7. A multi-purpose dual-fuel injection device according to claim 3, characterized in that: When low-carbon fuel injection is activated, the main control coil is energized, causing the lower main control armature to drive the main control valve stem upwards and open. The conical surface of the main control valve stem controls the oil passage between the low-pressure return oil end and the main control chamber. The high-pressure diesel in the main control chamber is depressurized through the opening of the conical surface of the main control valve stem, causing the main needle valve to open and inject fuel. The high-pressure diesel in the main control chamber flows into the low-pressure area through the main return oil metering hole and the opening gap of the main control valve stem. When the upward lifting force of the high-pressure substitute fuel in the high-pressure oil storage chamber on the main needle valve is greater than the downward pressure of the diesel in the main control chamber and the main needle valve spring on the main needle valve, the main needle valve opens upwards and injects substitute fuel outwards from the main injection hole.

8. A multi-purpose dual-fuel injection device according to claim 3, characterized in that: When low-carbon fuel injection is shut off, the main control coil is de-energized. Under the action of the main control valve stem spring, the main control valve stem descends and closes. The conical surface of the main control valve stem sits down, and the connection between the main control chamber and the low-pressure return oil end is disconnected. High-pressure diesel fuel enters from the diesel inlet and fills the main control chamber through the main inlet metering hole and the main return oil metering hole. When the diesel fuel pressure in the main control chamber and the downward pressure of the main needle valve spring on the main needle valve are greater than the upward lifting force of the substitute fuel in the substitute fuel storage chamber on the main needle valve, the main needle valve closes and the main injection hole stops injecting.

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