Ejector and engine

Abstract

According to the injector and the engine, the injector body, the control valve assembly and the needle valve matching part are axially integrated, a top pressure storage cavity is divided into a fuel flow channel of a first branch flow and a fuel flow channel of a second branch flow, so that a control cavity and an oil containing groove can obtain stable fuel supply, the stability of injection pressure is guaranteed by means of the pressure storage cavity, and the stability of the injection pressure is improved. The needle valve is directly driven to act by controlling the pressure of the cavity, so that the precise control of opening and closing of the nozzle can be realized; and the valve core can complete pressure accumulation and pressure relief of the control cavity by sealing or opening the control flow channel without depending on an independent high-pressure control oil system and multi-medium matching, so that the internal flow channel layout and the overall structure are greatly simplified, the processing difficulty and the manufacturing cost are reduced, meanwhile, the risk of cross contamination of different media is avoided, and the service life of the valve core is prolonged. And the operation reliability of the ejector is improved.

Description

Technical Field

[0001] This disclosure relates to an injector and an engine. Background Technology

[0002] Methanol fuel is widely favored due to its significant carbon reduction potential. Comparing high-pressure and low-pressure methanol injection technologies, high-pressure direct methanol injection technology offers superior results: more complete methanol fuel atomization, more uniform air-fuel mixing, more complete combustion, higher thermal efficiency, and a higher substitution rate.

[0003] High-pressure direct injection technology further optimizes the combustion process, significantly reducing emissions. Simultaneously, due to methanol's high latent heat of vaporization, direct injection provides a cooling effect, effectively reducing the risk of knocking. Therefore, in the field of methanol injection, high-pressure methanol direct injection technology, especially high-pressure methanol-diesel dual direct injection technology, possesses unparalleled technological advantages.

[0004] The core component of high-pressure methanol direct injection technology is the high-pressure methanol injector. Currently, high-pressure methanol injectors generally use mechanical nozzles or solenoid valve-piloted hydraulic amplification structures to control the injection of methanol needle valves. Among them, mechanical high-pressure methanol injection systems based on mechanical methanol nozzles are similar to traditional diesel unit pump mechanical injection systems, and the control of injection pressure and injection timing is limited, and the injection stability cannot achieve ideal results.

[0005] For methanol injectors that use a solenoid valve-piloted hydraulic amplification structure, especially high-pressure methanol-diesel dual-fuel integrated injectors, the electromagnetic force of the solenoid valve is generally in the range of 100N to 300N due to limitations in structural size and space. This relatively small solenoid valve driving force results in a hydraulic structure that is "small horse pulling a large cart".

[0006] Meanwhile, methanol, with its low saturated vapor pressure and boiling point, is highly susceptible to vaporization and possesses a large latent heat of vaporization. At high temperatures, its high-pressure gradient decompression process causes abrupt changes in streamlines due to heat absorption and pressure reduction, easily generating cavitation and transcritical flow phenomena. While using methanol as a pilot medium allows for pressure gradient optimization and stability control during the decompression process, the relatively small solenoid valve driving force limits the possibility of related structural optimizations, thus restricting the use of methanol as a pilot medium. Currently, high-pressure methanol injectors commonly use lubricating oil or diesel as pilot control media. This necessitates an independent high-pressure control oil system, resulting in complex and interwoven fuel flow channels within the injector, cumbersome structural layout, reduced system efficiency, and a significant increase in injector cost. Furthermore, the pressure matching between the two media is extremely complex.

[0007] Therefore, there is a need in the art for new injectors and engines to at least partially solve the aforementioned technical problems. Summary of the Invention

[0008] The purpose of this disclosure is to provide an injector.

[0009] Another objective of this disclosure is to provide an engine.

[0010] According to the first aspect of this disclosure, the injector includes: an injector body, a control valve assembly, and a needle valve assembly; The top of the injector body has a pressure accumulator chamber, and the bottom is axially mounted to the control valve assembly. The control valve assembly includes a control valve body, a valve core, a pressure spring, and an actuator. One end of the control valve body is connected to the injector body and has a control chamber inside. The valve core and the pressure spring are installed in the control chamber. The actuator is located in the injector body with its output end facing the valve core. The pressure spring is located at the end of the valve core away from the actuator and elastically presses against the valve core. A control flow channel is formed between the valve core and the actuator. The needle valve assembly includes a needle valve body, a needle valve, and a nozzle. One end of the needle valve body is connected to the control valve body and has an oil reservoir inside. The nozzle is located at the end of the needle valve body away from the control valve body. The first end of the needle valve extends into the control chamber and is driven by the pressure of the control chamber. The second end of the needle valve extends into the oil reservoir and faces the nozzle. A fuel flow channel is provided between the injector body, the control valve assembly, and the needle valve assembly. One end of the fuel flow channel is divided into a first branch and a second branch via the accumulator chamber. The first branch flows through the injector body and the control valve body to the control chamber, while the second branch flows through the injector body, the control valve body, and the needle valve body to the fuel collection tank. The valve core is configured to seal the control passage to drive the needle valve to seal the nozzle; or, to open the control passage to depressurize the control chamber to drive the needle valve to open the nozzle.

[0011] The technical solution described above integrates the injector body, control valve assembly, and needle valve assembly axially. The top accumulator chamber is divided into two fuel flow channels: a first branch and a second branch. This allows the control chamber and the fuel tank to receive stable fuel supplies. The accumulator chamber ensures the stability of the injection pressure, and the pressure in the control chamber directly drives the needle valve, thus enabling precise control of nozzle opening and closing. Furthermore, the valve core can complete the pressure accumulation and depressurization of the control chamber by sealing or opening the control flow channel, eliminating the need for an independent high-pressure control oil system and multi-media coordination. This significantly simplifies the internal flow channel layout and overall structure, reduces processing difficulty and manufacturing costs, avoids the risk of cross-contamination between different media, and improves the operational reliability of the injector.

[0012] In one or more embodiments, the actuator is a piezoelectric actuator, and the output force of the piezoelectric actuator is at least greater than the electromagnetic force of the solenoid valve.

[0013] In one or more embodiments, the valve core is provided with a first annular sealing surface at one end facing the actuator, and the control valve body is provided with a second annular sealing surface corresponding to the first annular sealing surface along the circumferential circumference of the control flow channel. The actuator is configured to cooperate with the compression spring to open the first annular sealing surface and the second annular sealing surface in the power-on and power-off states, or to make the first annular sealing surface and the second annular sealing surface seal and fit together. When the actuator is powered on, the first annular sealing surface and the second annular sealing surface open to form a first annular conical throttling channel.

[0014] In one or more embodiments, the first annular sealing surface is a spherical surface or a conical surface.

[0015] In one or more embodiments, the actuator has a protrusion at one end facing the valve core. When the actuator is energized, the protrusion presses against the valve core and opens the control flow channel; when the actuator is de-energized, the protrusion disengages from the valve core, releasing the force applied to the valve core. When the actuator is powered on, a second annular cone-shaped throttling channel is formed between the protrusion and the injector body. The injector body is also provided with a fuel recovery channel, which is connected to the second annular cone-shaped throttling channel. The actuator is configured to dynamically adjust the flow area of ​​the first annular conical throttling channel and the second annular conical throttling channel under different drive voltages.

[0016] In one or more embodiments, the control flow channel is open at one end toward the actuator, and the protrusion has a decreasing cross-sectional size along the injector body axial direction toward the valve core.

[0017] In one or more embodiments, the valve core includes a sealing portion and a mounting portion along the axial direction of the control valve body, the sealing portion is disposed toward the protrusion, and the first annular sealing surface is disposed on the sealing portion; The mounting portion is housed within the control chamber, the radial dimension of the mounting portion is larger than that of the sealing portion, and a first buffer cavity is provided between the mounting portion and the top wall of the control chamber.

[0018] In one or more embodiments, the first branch is provided with a throttling mechanism; or... The first tributary includes a first flow segment and a second flow segment. One end of the second flow segment is connected to the first flow segment, and the other end of the second flow segment is connected to the control chamber. The inner diameter of the second flow segment is smaller than that of the first flow segment.

[0019] In one or more embodiments, the throttling mechanism is a throttling orifice.

[0020] An engine according to a second aspect of this disclosure includes an injector as described in the first aspect. Attached Figure Description

[0021] The above and other features, properties, and advantages of this disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always denote the same features. It should be noted that these drawings are merely illustrative and are not drawn to scale, and should not be construed as limiting the scope of protection actually claimed by this disclosure, wherein: Figure 1 This is a cross-sectional view of the injector of this disclosure from a first angle; Figure 2 This is a cross-sectional view of the injector of this disclosure from a second angle; Figure 3 This is a partial sectional view of the injector in this disclosure; Figure 4 for Figure 1 Enlarged structural diagram at point A; Figure 5 for Figure 4 Enlarged structural diagram at point B; Figure 6 This is a schematic diagram of one embodiment of the valve core disclosed herein.

[0022] 1. Injector body; 11. Accumulator chamber; 12. Fuel recovery channel; 2. Fuel flow channel; 21. Fuel inlet; 22. First branch; 221. Throttling mechanism; 222. First flow section; 223. Second flow section; 23. Second branch; 24. First annular cone throttling flow channel; 3. Needle valve assembly; 31. Needle valve; 32. Needle valve body; 33. Nozzle; 34. Oil reservoir; 4. Control valve assembly; 41. Actuator; 411. Protrusion; 412. Second annular conical throttling channel; 42. Valve core; 421. First annular sealing surface; 422. Mounting part; 423. Sealing part; 424. First buffer chamber; 43. Compression spring; 44. Control valve body; 45. Control chamber; 46. Control channel; 47. Second annular sealing surface. Detailed Implementation

[0023] The present disclosure will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present disclosure. However, the present disclosure can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present disclosure. Therefore, the scope of protection of the present disclosure should not be limited by the content of this specific embodiment.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and foregoing description of the drawings of this disclosure are intended to cover non-exclusive inclusion.

[0025] Methanol, being a liquid at room temperature, widely available, and possessing carbon reduction potential, has become a core development direction in the engine field. High-pressure methanol direct injection technology, in particular, has become a key technological path due to its advantages such as thorough atomization, high combustion efficiency, and reduced knock risk. However, existing high-pressure methanol injectors suffer from significant technical bottlenecks: mechanical nozzles have limited control over injection pressure and timing, resulting in poor injection stability. The solenoid valve pilot hydraulic amplification structure is limited by size, with an electromagnetic force of only 100N~300N, creating a "small engine pulling a large load" hydraulic structure. This makes it impossible to directly use methanol as the pilot medium, requiring reliance on secondary media such as lubricating oil or diesel. This leads to complex internal flow channels within the injector, high processing costs, difficulties in matching pressures across multiple media, and the risk of cross-contamination, severely impacting system efficiency and engine operational safety.

[0026] Based on the above considerations, this disclosure proposes an injector and an engine.

[0027] refer to Figures 1 to 4As shown, the injector includes an injector body 1, a fuel flow channel 2, a needle valve assembly 3, and a control valve assembly 4. The injector body 1 has a pressure accumulator chamber 11 at the top and is axially mounted to the control valve assembly 4 at the bottom. The control valve assembly 4 includes an actuator 41, a valve core 42, a pressure spring 43, and a control valve body 44. One end of the control valve body 44 is connected to the injector body 1 and has a control chamber 45 inside. The valve core 42 and the pressure spring 43 are installed in the control chamber 45. The actuator 41 is located inside the injector body 1 with its output end facing the valve core 42. The pressure spring 43 is located at the end of the valve core 42 away from the actuator 41 and elastically presses against the valve core 42. A control flow channel 46 is formed between the valve core 42 and the actuator 41. The needle valve assembly 3 includes a needle valve 31, a needle valve body 32, and a nozzle 33. One end of the needle valve body 32 is connected to the control valve body 44 and has an oil reservoir 34 inside. The nozzle 33 is located at the end of the needle valve body 32 away from the control valve body 44. The first end of the needle valve 31 extends into the control chamber 45 and is driven by the pressure of the control chamber 45. The second end of the needle valve 31 extends into the oil reservoir 34 and faces the nozzle 33. A fuel flow channel 2 is provided between the injector body 1, the needle valve assembly 3, and the control valve assembly 4. One end of the fuel flow channel 2 is divided into a first branch 22 and a second branch 23 via the accumulator chamber 11. The first branch 22 flows through the injector body 1 and the control valve body 44 to the control chamber 45, and the second branch 23 flows through the injector body 1, the control valve body 44, and the needle valve body 32 to the fuel tank 34. The valve core 42 is configured to seal the control flow channel 46 to drive the needle valve 31 to seal the nozzle 33; or, to open the control flow channel 46 to depressurize the control chamber 45 to drive the needle valve 31 to open the nozzle 33.

[0028] The technical solution described above, by setting a control chamber 45 in the control valve body 44, and cooperating with the separately set first branch 22 and second branch 23, not only realizes the pressure drive control of the needle valve 31 by the control chamber 45, but also stabilizes the fuel pressure through the accumulator chamber 11, thus avoiding the complex structure of multiple media flow channels intersecting in the prior art.

[0029] Furthermore, the control valve assembly 4 achieves pressure relief of the control chamber 45 by sealing or opening the control flow channel 46 through the valve core 42, eliminating the need for multi-media control. This simplifies the overall structure of the injector, thereby reducing processing difficulty and cost. It also avoids the risk of cross-contamination between different media, which is beneficial for improving engine operating safety. Moreover, the needle valve 31 is directly driven by the pressure in the control chamber 45, resulting in a more direct response and significantly improving the injection control accuracy and stability of the injector, thus adapting to high-pressure fuel injection requirements.

[0030] In one or more embodiments, actuator 41 is a piezoelectric actuator, and the output force of the piezoelectric actuator is at least greater than the electromagnetic force of the solenoid valve. Optionally, the fuel in fuel channel 2 is high-pressure methanol, but is not limited thereto; for example, it can also be ammonia fuel.

[0031] This disclosure employs a piezoelectric actuator, which, by utilizing its precise proportional output characteristics, enables online proportional adjustment of the flow capacity of the control channel 46. This allows for precise proportional adjustment of the pressure accumulation and decompression process in the control chamber 45, thereby achieving online adjustment of the opening and closing process of the needle valve 31 and ultimately realizing online flexible control of the fuel injection rate curve.

[0032] Furthermore, the performance of piezoelectric actuators is adapted to high-pressure, single-fuel-medium control, without relying on a second control medium. This helps improve the reliability of high-pressure methanol injection and solves the control limitation problem caused by the "small engine pulling a large load" of traditional solenoid valves.

[0033] In one or more embodiments, please refer to Figures 4 to 6 The valve core 42 has a first annular sealing surface 421 at one end facing the actuator 41, and the control valve body 44 has a second annular sealing surface 47 corresponding to the first annular sealing surface 421 around the circumference of the control flow channel 46. The actuator 41 is configured to cooperate with the compression spring 43 to open the first annular sealing surface 421 and the second annular sealing surface 47 in the power-on and power-off state, or to make the first annular sealing surface 421 and the second annular sealing surface 47 seal against each other; wherein, in the power-on state, the first annular sealing surface 421 and the second annular sealing surface 47 are opened, forming a first annular conical throttling flow channel 24.

[0034] That is, the first annular sealing surface 421 and the second annular sealing surface 47 in this disclosure are designed to form a circumferentially uniform sealing structure when they are fitted together, thereby effectively preventing fuel from leaking from the control flow channel 46 during the pressurization process of the control chamber 45, thus ensuring the pressurization efficiency and pressure stability of the control chamber 45.

[0035] This application utilizes the actuator 41 to switch on and off in conjunction with the clamping spring 43 to control the first annular sealing surface 421 and the second annular sealing surface 47 to be in contact or open. The switching reliability is high, which can avoid the pressure fluctuation of the control chamber 45 caused by the unreliability of the sealing structure in the prior art, thereby ensuring the consistency of the opening and closing action of the needle valve 31 and improving the injection stability.

[0036] Moreover, the precise proportional output characteristics of the piezoelectric actuator can realize the online proportional adjustment of the flow capacity of the first annular conical throttling channel 24, which is conducive to the precise proportional adjustment of the pressure storage and depressurization process of the control chamber 45, and realizes the online adjustment of the opening and closing of the needle valve 31.

[0037] Optionally, the first annular sealing surface 421 is a spherical surface or a conical surface, and the second annular sealing surface 47 is a conical surface. For example, Figure 4 The first annular sealing surface 421 is spherical, while Figure 6The first annular sealing surface 421 is a conical surface. Both of the above settings are acceptable and are not limited here.

[0038] The present invention selects a first annular sealing surface 421 with a spherical or conical structure. Compared with a planar sealing surface, the contact pressure distribution with the second annular sealing surface 47 is more uniform, which can better adapt to the high pressure environment of the control chamber 45 and significantly improve the sealing reliability of high pressure methanol.

[0039] Moreover, the spherical and conical surfaces have better machining adaptability, which facilitates precise fitting with the second annular sealing surface 47, reduces wear on the sealing surface, and thus extends the service life of the valve core 42. At the same time, the spherical or conical seal has better guidance during opening and closing, which can reduce the risk of valve core 42 jamming and improve the smoothness of the switching between sealing and pressure relief.

[0040] It can be seen that the first annular sealing surface 421 and the second annular sealing surface 47 include a cone-to-cone surface and a spherical-to-cone surface. For the cone-to-cone surface, the sealing effect is better, but the coaxiality requirement is higher and the processing requirements are higher. For the spherical-to-cone surface, the two can be aligned, and the processing requirements are relatively low. The specific choice can be made according to actual needs, and no limitation is made here.

[0041] In one or more embodiments, please refer to Figure 4 and Figure 5 The actuator 41 has a protrusion 411 at one end facing the valve core 42. When the actuator 41 is energized, the protrusion 411 presses against the valve core 42 and opens the control flow channel 46. When the actuator 41 is de-energized, the protrusion 411 disengages from the valve core 42, releasing the force applied to the valve core 42. When the actuator 41 is energized, a second annular conical throttling flow channel 412 is formed between the protrusion 411 and the injector body 1. The injector body 1 also has a fuel recovery flow channel 12, which communicates with the second annular conical throttling flow channel 412. The actuator 41 is configured to dynamically adjust the flow area of ​​the first annular conical throttling flow channel 24 and the second annular conical throttling flow channel 412 under different driving voltages.

[0042] Please refer to Figure 4 and Figure 5 The control flow channel 46 is open at one end facing the actuator 41, and the protrusion 411 has a decreasing cross-sectional size along the axial direction of the injector body 1 and toward the valve core 42.

[0043] like Figure 5As shown, the control channel 46 is flared outward from the middle to both sides. One side is a second annular conical throttling channel 412 formed between the protrusion 411 and the injector body 1, and the other side is a first annular conical throttling channel 24 formed between the first annular sealing surface 421 and the second annular sealing surface 47 (existing when the actuator 41 is de-energized).

[0044] It is known that when the actuator 41 is energized, the protrusion 411 abuts against the valve core 42, while when the actuator 41 is de-energized, the protrusion 411 and the valve core 42 are spaced apart, forming a free stroke. Therefore, by utilizing the precise proportional output characteristics of the piezoelectric actuator and combining it with the free stroke setting, the initial proportional matching setting and online fine-tuning of the flow capacity of the second annular conical throttling channel 412 can be achieved. This allows for the optimization and online fine-tuning of the pressure gradient during the methanol depressurization process, keeping phenomena such as cavitation away from the first annular sealing surface 421 and the second annular sealing surface 47 during methanol depressurization, improving the reliability of the first annular sealing surface 421 and the second annular sealing surface 47, and creating conditions for using methanol as the guiding control medium.

[0045] The open design at one end of the control channel 46 facilitates the insertion of the protrusion 411 to form a circumferentially uniform second annular conical throttling channel 412, thereby stabilizing the fuel flow velocity and pressure distribution during the depressurization process and avoiding turbulent flow field caused by sudden changes in local pressure.

[0046] That is, by setting a circumferentially uniform second ring conical throttling channel 412, the consistency of the depressurization rate of the control chamber 45 under different operating conditions can be ensured, thereby stabilizing the pressure change of the control chamber 45, thus ensuring the consistency of the needle valve 31's action, improving injection accuracy, and adapting to the injection requirements of the engine under different loads.

[0047] The fuel recovery channel 12 set above is used to recover the fuel after depressurization, avoiding fuel waste and environmental pollution. At the same time, the recovered fuel can be recycled, improving the system's fuel utilization rate.

[0048] In one or more embodiments, please continue to refer to Figures 4 to 6 The valve core 42 includes a sealing part 423 and a mounting part 422 along the axial direction of the injector body 1. The sealing part 423 is disposed toward the protrusion 411, and a first annular sealing surface 421 is disposed on the sealing part 423. The mounting part 422 is housed in the control chamber 45. The radial dimension of the mounting part 422 is larger than that of the sealing part 423. A first buffer cavity 424 is provided between the mounting part 422 and the top wall of the control chamber 45.

[0049] It should be noted that the radial dimension of the mounting part 422 is larger than that of the sealing part 423, thereby enhancing the axial movement stability of the mounting part 422 along the control chamber 45. By increasing the contact area with the control chamber 45, local pressure concentration can be reduced, preventing the valve core 42 from deforming due to high-pressure fuel pressure.

[0050] The first buffer chamber 424 can fill the volume of the control chamber 45, accelerate the pressure relief and storage process in the control chamber 45, and realize the rapid opening and closing of the needle valve 31.

[0051] Continue to refer to Figure 1 and Figure 2 In one or more embodiments, the first branch 22 is provided with a throttling mechanism 221; or, the first branch 22 includes a first flow segment 222 and a second flow segment 223, one end of the second flow segment 223 is connected to the first flow segment 222, the other end of the second flow segment 223 is connected to the control chamber 45, and the inner diameter of the second flow segment 223 is smaller than that of the first flow segment 222.

[0052] This disclosure, by setting a throttling mechanism 221 or a narrow-diameter second flow section 223, can precisely control the fuel flow rate of the first branch 22 entering the control chamber 45, thereby adjusting the pressure storage rate of the control chamber 45.

[0053] Specifically, the accumulation rate can be flexibly adjusted according to different engine operating conditions to avoid excessively rapid accumulation leading to sudden closure of the needle valve 31 and injection interruption, or excessively slow accumulation leading to injection delay, which helps improve the matching degree between injection and engine operating conditions. At the same time, precise flow control can ensure stable pressure in the control chamber 45, providing a stable pressure drive for the opening and closing of the needle valve 31, further improving the injection control accuracy.

[0054] Optionally, the throttling mechanism 221 is a throttling orifice. For example, the second flow section 223 is not configured as a narrow diameter, but is instead provided with a throttling orifice.

[0055] It should be noted that the throttling orifice structure is simple and the machining accuracy is easy to ensure, which enables stable control of the fuel flow of the first branch 22. Compared with other throttling structures, such as throttling valves, it has lower cost and lower failure rate, and is easy to mass-produce.

[0056] The orifice diameter can be precisely designed according to the injection pressure (300 bar~600 bar) of high-pressure fuels, such as high-pressure methanol, and the pressure storage requirements of control chamber 45, ensuring a stable pressure storage rate and avoiding pressure instability in control chamber 45 due to flow fluctuations. Moreover, the orifice has strong anti-clogging capabilities, adapts to the characteristics of methanol, reduces the risk of flow channel blockage, and ensures long-term reliable operation of the injection system.

[0057] The working principle of the ejector disclosed herein is explained below: High-pressure methanol enters the first branch 22 and the second branch 23 through fuel inlet 21. The throttling mechanism 221 or the narrow-diameter second flow section 223 on the first branch 22 can precisely control the methanol inlet flow rate, slowly delivering high-pressure methanol to the control chamber 45, laying the pressure foundation for subsequent pressurization in the control chamber 45. The second branch 23 is directly connected to the oil tank 34, which can quickly fill its internal space. The volume design of the oil tank 34 achieves pressure buffering and stabilization of high-pressure methanol, avoiding the impact of common rail system pressure fluctuations on injection stability.

[0058] When actuator 41 is energized, it generates a large downward output force based on the piezoelectric effect. This force can overcome the elastic force of the compression spring 43 and the pressure of the high-pressure methanol liquid already stored in the control chamber 45, pushing the valve core 42 to move downward along the axial direction of the injector body 1. During this process, the sealing part 423 at the end of the valve core 42 facing the actuator 41 moves downward synchronously, causing the first annular sealing surface 421 provided on the sealing part 423 to separate from the second annular sealing surface 47 circumferentially located in the control flow channel 46 of the injector body 1, and the control flow channel 46 is opened. Simultaneously, the protrusion 411 of the actuator 41 facing the valve core 42 forms an annular section second annular conical throttling channel 412 with the inner wall of the control flow channel 46. The high-pressure methanol in the control chamber 45 first flows upward through the gap between the mounting part 422 of the valve core 42 and the inner wall of the control chamber 45, and then enters the section second annular conical throttling channel 412 through the control flow channel 46. The section second annular conical throttling channel 412 can slow down the methanol flow rate, optimize the pressure gradient, and avoid cavitation or transcritical flow phenomena caused by the low saturated vapor pressure and high latent heat of vaporization of methanol. Subsequently, the methanol flows smoothly into the fuel recovery channel 12 on the injector body 1 through the control flow channel 46, realizing orderly recovery and recycling. As methanol continues to be discharged from the control chamber 45, the pressure in the control chamber 45 is rapidly reduced to below the threshold. At this time, the high-pressure methanol that has been stabilized in the oil tank 34 continues to act on the second end of the needle valve 31 (near the nozzle 33 end) through the second branch 23, forming an upward driving force that pushes the needle valve 31 to move upward along the axial direction of the injector body 1, eventually causing the needle valve 31 to move away from the nozzle 33 orifice, and the high-pressure methanol is ejected at high speed from the oil tank 34 through the nozzle 33 orifice.

[0059] When the actuator 41 is de-energized, the output force of the piezoelectric actuator disappears, and the valve core 42 resets axially upward under the action of two forces: one is the pressure of the high-pressure methanol liquid gradually rising in the control chamber 45 through the first branch 22, and the other is the elastic reset force of the compression spring 43. During this process, the first annular sealing surface 421 of the sealing part 423 of the valve core 42 precisely fits with the second annular sealing surface 47 of the injector body 1, and the pressure uniformity of the spherical or conical seal achieves a reliable seal of the control flow channel 46, blocking the connection between the control chamber 45 and the fuel recovery flow channel 12. Subsequently, high-pressure methanol is continuously injected into the control chamber 45 through the first branch 22, and the control chamber 45 begins to accumulate pressure at a preset rate. When the pressure in the control chamber 45 rises to a level that can overcome the upward driving force of the oil tank 34 on the needle valve 31, it pushes the needle valve 31 to move axially downward until the sealing end of the needle valve 31 tightly seals the nozzle 33's spray hole, and the injection process stops. Meanwhile, the oil tank 34 remains filled with high-pressure methanol, which provides stable pressure for rapid injection when the actuator 41 is powered on next time, ensuring the continuity and reliability of the injector response. Moreover, the entire process relies on methanol as the only medium for control and injection, without relying on lubricating oil, diesel or other secondary control media, effectively avoiding the risk of cross-contamination of multiple media and simplifying the flow channel structure and pressure matching difficulty.

[0060] An engine according to a second aspect of this disclosure includes an injector as described in the first aspect.

[0061] In summary, the advanced technical effects of this disclosure include, but are not limited to, at least one of the following: This disclosed injector directly uses methanol as the pilot medium, eliminating the need for pilot control with media such as diesel or lubricating oil. This effectively avoids the internal flow channel design of injectors that integrates multiple media such as methanol and control oil. The structure is simple and compact, and it can also better avoid cross-contamination between different media, effectively ensuring the safe operation of the engine. The processing difficulty and cost are also greatly reduced.

[0062] Meanwhile, by using only methanol fuel as the medium, the limitations of matching pressures of multiple media under different operating conditions and application scenarios are avoided. This allows for the full transfer of the advantages and control strategies of traditional diesel high-pressure common rail injection technology, achieving true online controllability of pressure, flow, etc. Especially under abnormal security conditions, the difficulty of injection control is reduced, and the freedom and accuracy of methanol injection control are greatly improved.

[0063] The actuator 41 disclosed herein is a piezoelectric actuator. Piezoelectric actuators possess rapid response characteristics and proportional output capability. They can freely adjust the output displacement according to the methanol rail pressure and actual engine operating conditions to precisely control the flow area of ​​the pressure relief cone surface at the pilot valve orifice. Combined with the throttling mechanism 221 on the first branch 22, it can adjust the pressure accumulation rate of the control chamber 45, achieving online configuration of the injection rate and precise control of the injection timing. Compared to the limitations of fixed injection parameters in mechanical nozzles 33 and the coarse control of solenoid valves, it can flexibly adapt to different operating conditions such as high load and low load of high-power engines, ensuring injection stability under various operating conditions.

[0064] This disclosure eliminates the existing components such as the alcohol outlet orifice, plunger assembly, and independent high-pressure control oil system. Furthermore, the inverted valve core 42 design significantly simplifies the internal structure of the injector while ensuring high-pressure sealing, reducing processing difficulty and component manufacturing costs. In addition, the compact structure allows for the installation of cooling channels, effectively controlling the operating temperature of core components such as the piezoelectric actuator and nozzle 33, extending component lifespan, and reducing maintenance frequency and costs.

[0065] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, the technical terms such as "installation", "connection", "joining", and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can also refer to a mechanical connection. For those skilled in the art, the specific meaning of the above terms in the embodiments of this disclosure can be understood according to the specific circumstances.

[0066] This disclosure uses specific terms to describe embodiments of the present disclosure. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the present disclosure. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the present disclosure can be appropriately combined.

[0067] While this disclosure has described above with reference to preferred embodiments, it is not intended to limit the scope of this disclosure. Any changes and modifications can be made by those skilled in the art without departing from the spirit and scope of this disclosure. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this disclosure, without departing from the content of the technical solution, fall within the protection scope defined by the claims of this disclosure.

Claims

1. An injector, characterized in that, Including the injector body, control valve assembly, and needle valve assembly; The top of the injector body has a pressure accumulator chamber, and the bottom is axially mounted to the control valve assembly. The control valve assembly includes a control valve body, a valve core, a pressure spring, and an actuator. One end of the control valve body is connected to the injector body and has a control chamber inside. The valve core and the pressure spring are installed in the control chamber. The actuator is located in the injector body with its output end facing the valve core. The pressure spring is located at the end of the valve core away from the actuator and elastically presses against the valve core. A control flow channel is formed between the valve core and the actuator. The needle valve assembly includes a needle valve body, a needle valve, and a nozzle. One end of the needle valve body is connected to the control valve body and has an oil reservoir inside. The nozzle is located at the end of the needle valve body away from the control valve body. The first end of the needle valve extends into the control chamber and is driven by the pressure of the control chamber. The second end of the needle valve extends into the oil reservoir and faces the nozzle. A fuel flow channel is provided between the injector body, the control valve assembly, and the needle valve assembly. One end of the fuel flow channel is divided into a first branch and a second branch via the accumulator chamber. The first branch flows through the injector body and the control valve body to the control chamber, while the second branch flows through the injector body, the control valve body, and the needle valve body to the fuel collection tank. The valve core is configured to seal the control passage to drive the needle valve to seal the nozzle; or, to open the control passage to depressurize the control chamber to drive the needle valve to open the nozzle.

2. The injector as claimed in claim 1, characterized in that, The actuator is a piezoelectric actuator, and the output force of the piezoelectric actuator is at least greater than the electromagnetic force of the solenoid valve.

3. The injector as claimed in claim 1, characterized in that, The valve core has a first annular sealing surface at one end facing the actuator, and the control valve body has a second annular sealing surface corresponding to the first annular sealing surface along the circumferential circumference of the control flow channel. The actuator is configured to cooperate with the compression spring to open the first annular sealing surface and the second annular sealing surface in the power-on and power-off states, or to make the first annular sealing surface and the second annular sealing surface seal and fit together. When the actuator is powered on, the first annular sealing surface and the second annular sealing surface open to form a first annular conical throttling channel.

4. The injector as claimed in claim 3, characterized in that, The first annular sealing surface is a spherical or conical surface.

5. The injector as claimed in claim 3, characterized in that, The actuator has a protrusion at one end facing the valve core. When the actuator is energized, the protrusion presses against the valve core and opens the control flow channel. When the actuator is de-energized, the protrusion disengages from the valve core, releasing the force applied to the valve core. When the actuator is powered on, a second annular cone-shaped throttling channel is formed between the protrusion and the injector body. The injector body is also provided with a fuel recovery channel, which is connected to the second annular cone-shaped throttling channel. The actuator is configured to dynamically adjust the flow area of ​​the first annular conical throttling channel and the second annular conical throttling channel under different drive voltages.

6. The injector as claimed in claim 5, characterized in that, The control flow channel is open at one end facing the actuator, and the protrusion has a decreasing cross-sectional size along the axial direction of the injector body and toward the valve core.

7. The injector as claimed in claim 5, characterized in that, The valve core includes a sealing part and a mounting part along the axial direction of the control valve body. The sealing part is disposed toward the protrusion, and the first annular sealing surface is disposed on the sealing part. The mounting portion is housed within the control chamber, the radial dimension of the mounting portion is larger than that of the sealing portion, and a first buffer cavity is provided between the mounting portion and the top wall of the control chamber.

8. The injector as claimed in claim 1, characterized in that, The first branch is equipped with a throttling mechanism; or, The first tributary includes a first flow segment and a second flow segment. One end of the second flow segment is connected to the first flow segment, and the other end of the second flow segment is connected to the control chamber. The inner diameter of the second flow segment is smaller than that of the first flow segment.

9. The injector as claimed in claim 8, characterized in that, The throttling mechanism is a throttling orifice.

10. An engine, characterized in that, Including the injector as described in any one of claims 1-9.

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