Methanol injector, dual-fuel injector and engine

Abstract

The invention provides a methanol injector, a dual-fuel injector and an engine. Wherein the methanol injector comprises a shell, a methanol flow channel and a control unit, a control cavity and an alcohol containing groove are formed in the shell, a methanol needle valve is arranged between the control cavity and the alcohol containing groove, the first end of the methanol needle valve is driven by the pressure of the control cavity, and the second end of the methanol needle valve is arranged corresponding to the methanol nozzle; the first end of the methanol flow channel is an alcohol inlet, the second end of the methanol flow channel is divided into a first branch and a second branch, the first branch is communicated with the control cavity, and the second branch is communicated with the alcohol containing groove; a connecting flow channel is arranged between the control unit and the control cavity, at least two communicated volume cavities are further arranged in the shell, the connecting flow channel is communicated with the volume cavities in an open state, and a discharging flow channel communicated with the volume cavities is further arranged in the shell. The control unit is configured to be capable of sealing or opening the connecting flow channel so as to cooperate with the control cavity to drive the methanol needle valve to close or open the methanol nozzle.

Description

Technical Field

[0001] This disclosure relates to a methanol injector, a dual-fuel injector, and an engine. Background Technology

[0002] Methanol fuel, being liquid at room temperature and convenient to store and transport, is considered a highly promising alternative fuel for achieving carbon reduction goals in high-power engines. However, the physicochemical properties of methanol fuel differ significantly from those of traditional fuels and natural gas. It possesses a high latent heat of vaporization, making it difficult to ignite or compressively ignite. Based on this, the industry generally adopts a diesel ignition technology, leading to the development of methanol-diesel dual-fuel injection systems. High-pressure methanol direct injection technology, which enables more complete methanol atomization, more uniform mixing with air, and more complete combustion, thereby improving thermal efficiency and methanol substitution rate, reducing pollution emissions, and leveraging the cooling effect of methanol's high latent heat of vaporization to reduce engine knock risk, has become the core technology direction for methanol dual-fuel systems.

[0003] The core component of high-pressure methanol direct injection technology is the high-pressure methanol injector, whose performance directly determines the methanol injection effect and engine operating quality. However, current technical solutions for high-pressure methanol injectors have significant drawbacks: due to the characteristics of methanol as a medium, methanol has a low saturated vapor pressure and a low boiling point, making it extremely easy to vaporize, and it also has a large latent heat of vaporization. Under high-temperature engine operating conditions, its high-pressure depressurization process will cause a sudden change in streamlines due to heat absorption and decompression, which can easily generate cavitation and transcritical flow, leading to problems such as inaccurate methanol injection metering and multi-frequency pressure coupling. At the same time, methanol has low viscosity, is easily vaporized, and has certain hazardous chemical properties, making its high-pressure sealing and lubrication of key moving parts difficult.

[0004] To address the aforementioned issues, existing technologies generally employ a separate high-pressure control medium, such as high-pressure lubricating oil or diesel fuel at 300-700 bar, for the methanol injection section. This is used to achieve pilot hydraulic control of methanol injection, mitigating the negative impacts of methanol cavitation and transcritical flow. Simultaneously, separate high-pressure sealing and lubrication media, such as high-pressure lubricating oil or diesel fuel at 300-700 bar, are also required to meet the high and low pressure sealing requirements of methanol and the lubrication needs of critical moving parts.

[0005] However, the above solution has led to a series of new problems: the independently set control oil, sealing oil, and lubricating oil, combined with the cooling oil medium required by various components inside the injector, result in a complex and intricate fuel flow path and a cumbersome structural layout inside the injector, significantly increasing the difficulty of engine belt arrangement and reducing system operating efficiency. At the same time, it significantly increases the processing complexity and manufacturing cost of the injector.

[0006] Furthermore, under different engine operating conditions (such as starting, idling, and high load) and start-stop conditions, it is necessary to accurately match the pressures of various media such as high-pressure control oil, high-pressure sealing oil, and methanol. The matching process is extremely complex, which severely restricts the freedom of methanol injection under different operating conditions and makes it difficult to achieve precise control of methanol injection. Moreover, the coexistence of multiple media inside the injector can easily lead to cross-contamination, which may not only affect the injection performance of the injector but also pose a potential threat to the operational safety of the engine.

[0007] Therefore, there is a need in the art for new methanol injectors, dual-fuel 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 a methanol injector.

[0009] Another object of this disclosure is to provide a dual-fuel injector.

[0010] Another objective of this disclosure is to provide an engine.

[0011] According to the first aspect of this disclosure, a methanol injector includes: a housing, which has a control chamber and a methanol tank inside, a methanol needle valve is provided between the control chamber and the methanol tank, a first end of the methanol needle valve is driven by the pressure of the control chamber, and a second end of the methanol needle valve is provided corresponding to a methanol nozzle; The methanol flow channel has a first end as an inlet and a second end as a branch, the first branch being connected to the control chamber and the second branch being connected to the methanol tank. The control unit has a connecting channel between itself and the control chamber. The housing also has at least two communicating volume chambers. The connecting channel is in the open state and communicates with the volume chambers. The housing also has a discharge channel communicating with the volume chambers. The control unit is configured to seal or open the connecting channel to cooperate with the control chamber to drive the methanol needle valve to close or open the methanol nozzle.

[0012] The technical solution described above, by setting a control chamber, a methanol tank, and a methanol needle valve driven by the pressure of the control chamber within the housing, combined with a methanol flow channel with a first end as the methanol inlet and a second end splitting into a first branch connecting the control chamber and the methanol tank respectively, and further combined with a control unit connected to the control chamber via a connecting flow channel that can seal or open the connecting flow channel, as well as at least two volume chambers within the housing connected to the connecting flow channel in the open state and an outlet flow channel connected to the volume chambers, allows the injector to achieve pilot hydraulic control and high-pressure in-cylinder direct injection of methanol injection using only a single methanol medium, without the need for independent high-pressure control oil, sealing oil, or other media. This effectively avoids the problem of complex and intertwined internal flow channels caused by the high integration of multiple media in existing technologies, resulting in a simpler and more compact structure and a significant reduction in processing difficulty and manufacturing costs. Moreover, it eliminates the risk of cross-contamination between different media, ensuring the safe operation of the engine. It also eliminates the need to deal with the pressure matching limitations of multiple media, enabling free online control of methanol pressure and flow, significantly improving the freedom and precision of methanol injection control, and reducing the difficulty of injection control, especially in the event of security anomalies.

[0013] In one or more embodiments, the housing is provided with a receiving chamber, the control unit is placed in the receiving chamber, the output end of the control unit forms a sealing surface with the bottom wall of the receiving chamber, and when the sealing surface is open, the connecting flow channel communicates with the volume chamber.

[0014] In one or more embodiments, the control unit includes a solenoid valve and an armature, wherein the solenoid valve drives the armature to open or close the connecting flow channel when the solenoid valve is powered on or off; The sealing surface is formed between the end of the armature away from the solenoid valve and the bottom wall of the accommodating chamber.

[0015] In one or more embodiments, the sealing surface is a sealing cone surface.

[0016] In one or more embodiments, at least two connected volumetric cavities are arranged along the axial direction of the housing; Along the direction away from the control unit, the volume of the cavity closer to the control unit is smaller than the volume of the cavity farther from the control unit; The discharge channel is connected to the largest volume cavity.

[0017] In one or more embodiments, a throttling mechanism is provided on the flow channel between adjacent volume chambers, and one end of the discharge flow channel is connected to the throttling mechanism.

[0018] In one or more embodiments, the throttling mechanism is a throttling orifice.

[0019] In one or more embodiments, the first branch is connected to the control chamber via an alcohol inlet orifice; The connecting channel and the control chamber are connected via an alcohol dispensing orifice.

[0020] A dual-fuel injector according to a second aspect of this disclosure includes a diesel injector and a methanol injector as described above, wherein the diesel injector is integrated within the housing.

[0021] In one or more embodiments, the diesel injector is arranged side-by-side with the main structure of the methanol injector along the axial direction of the housing.

[0022] An engine according to a third aspect of this disclosure includes a methanol injector as described in the first aspect or a dual-fuel injector as described in the second aspect. Attached Figure Description

[0023] 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 schematic diagram of the dual-fuel injector of this disclosure at one angle; Figure 2 This is a structural schematic diagram of the dual-fuel injector disclosed in this invention from another angle; Figure 3 for Figure 2 Partial structural diagram; Figure 4 For Figure 1 Partial structural diagram; Figure 5 for Figure 1 Enlarged view of point I.

[0024] 1. Outer shell; 11. Control chamber; 12. Methanol tank; 13. Methanol needle valve; 14. Methanol nozzle; 15. Volumetric cavity; 151. Throttling mechanism; 16. Discharge channel; 17. Containing chamber; 2. Methanol flow channel; 21. Methanol inlet; 22. First branch; 221. Methanol metering orifice; 23. Second branch; 3. Control unit; 31. Connecting flow channel; 311. Alcohol outlet orifice; 32. Sealing surface; 33. Solenoid valve; 34. Armature; 4. Diesel injector; 41. Diesel inlet; 42. Diesel pilot ball valve; 43. Diesel pilot ball valve armature; 44. Diesel needle valve; 45. Diesel control chamber; 46. Filling tank; 47. Diesel outlet orifice; 48. Diesel outlet flow channel; 49. Diesel inlet orifice; 491. Diesel nozzle. Detailed Implementation

[0025] Reference will now be made in detail to various embodiments of this disclosure, examples of which are shown in the accompanying drawings and described below. Although this disclosure will be described in conjunction with exemplary embodiments, it should be understood that this disclosure is not intended to be limited to those exemplary embodiments. Rather, this disclosure is intended to cover not only these exemplary embodiments, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of this disclosure as defined by the appended claims.

[0026] This disclosure uses specific terms to describe embodiments of the present disclosure. For example, "an embodiment" and / or "one embodiment" refers 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 "an embodiment" or "one embodiment" mentioned twice or more in different locations in this disclosure does 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.

[0027] In the following description, the terms "upper," "lower," "inner," "outer," "front," "rear," or other directional terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These are used solely for the convenience of describing this disclosure and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed in a specific orientation, or be implemented in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. In this disclosure, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying positional relationships or order of importance.

[0028] As introduced above, methanol, as a clean alternative fuel with mature technology, economic and social foundation, has high-pressure direct injection technology as a key direction for optimizing combustion efficiency and reducing emissions. As the core component of this technology, the high-pressure methanol injector currently requires independent high-pressure control medium, sealing medium and lubrication medium due to the easy vaporization and low viscosity of methanol. This results in complicated internal flow channels of the injector, high processing costs, and difficulty in motor belt layout. In addition, the pressure matching between different media is complicated and cross-contamination is easy to occur, which seriously limits the freedom of methanol injection and the safety of engine operation.

[0029] Based on this, refer to Figure 1 and Figure 2As shown, this disclosure proposes a methanol injector, which includes a housing 1, a methanol flow channel 2, and a control unit 3. The housing 1 contains a control chamber 11 and a methanol reservoir 12. A methanol needle valve 13 is provided between the control chamber 11 and the methanol reservoir 12. The first end of the methanol needle valve 13 is driven by the pressure of the control chamber 11, and the second end of the methanol needle valve 13 corresponds to a methanol nozzle 14. The first end of the methanol flow channel 2 is a methanol inlet 21, and the second end of the methanol flow channel 2 splits into a first branch 22 and a second branch 23. The first branch 22 communicates with the control chamber 11, and the second branch 23 communicates with the methanol reservoir 12. A connecting flow channel 31 is provided between the control unit 3 and the control chamber 11. The outer shell 1 is also provided with at least two connected volume chambers 15. The connecting flow channel 31 is connected to the volume chambers 15 when it is open. The outer shell 1 is also provided with a discharge flow channel 16 connected to the volume chambers 15. The control unit 3 is configured to seal or open the connecting flow channel 31 to cooperate with the control chamber 11 to drive the methanol needle valve 13 to close or open the methanol nozzle 14.

[0030] As described above, this disclosure provides a control chamber 11, a methanol tank 12, and a methanol needle valve 13 driven by the pressure of the control chamber 11 within the housing 1. This is complemented by a methanol flow channel 2 with a first end being an inlet 21 and a second end branching into a first branch 22 and a second branch 23 respectively connecting the control chamber 11 and the methanol tank 12. Furthermore, it incorporates a control unit 3 connected to the control chamber 11 via a connecting flow channel 31, which can seal or open the connecting flow channel 31. Additionally, it includes at least two volumetric cavities 15 connected to the open connecting flow channel 31 within the housing 1 and an outlet flow channel 16 connected to the volumetric cavities 15. This allows the methanol injector to achieve pilot hydraulic control and high-pressure direct injection of methanol using only a single methanol medium, eliminating the need for independent high-pressure control oil, sealing oil, or other media. This effectively avoids the complex and intertwined internal flow channels of the injector caused by the high integration of multiple media in existing technologies, resulting in a simpler and more compact structure and significantly reduced processing difficulty and manufacturing costs.

[0031] Because a single medium is used, the risk of cross-contamination between different media is eliminated, thereby ensuring the safe operation of the engine. Furthermore, there is no need to deal with the pressure matching limitations of multiple media, and methanol pressure and flow can be freely and online controlled, significantly improving the freedom and accuracy of methanol injection control. In particular, it can reduce the difficulty of injection control in the event of safety anomalies.

[0032] Moreover, the combination of the multi-volume cavity 15 and the discharge channel 16 can optimize the methanol depressurization process, reduce or even eliminate the impact of cavitation on the sealing surface 32 (see below), ensure metering stability, and further guarantee the overall operating performance and safety of the injector.

[0033] Please continue to refer to Figure 2The outer casing 1 has a receiving chamber 17. The control unit 3 is placed in the receiving chamber 17. The output end of the control unit 3 and the bottom wall of the receiving chamber 17 form a sealing surface 32. When the sealing surface 32 is open, the connecting channel 31 is connected to the volume chamber 15.

[0034] The inclusion chamber 17 provided inside the outer casing 1 can provide stable support and protection for the control unit 3, preventing the control unit 3 from shifting or being damaged by external vibration and temperature changes, thereby improving structural stability.

[0035] The sealing surface 32 can precisely control the opening and closing of the connecting channel 31, reduce methanol leakage in the gap between the control unit 3 and the accommodating chamber 17, ensure the accuracy of pressure regulation in the control chamber 11, thereby stabilizing the action of the methanol needle valve 13 and improving injection reliability.

[0036] Furthermore, the control unit 3 includes a solenoid valve 33 and an armature 34. When the solenoid valve 33 is powered on or off, it drives the armature 34 to open or close the connecting flow channel 31. The end of the armature 34 away from the solenoid valve 33 forms a sealing surface 32 with the bottom wall of the accommodating chamber 17.

[0037] That is, one end of the armature 34 extends to the bottom wall of the accommodating chamber 17 and forms a sealing surface 32 with the bottom of the accommodating chamber 17. Under the control of the solenoid valve 33, the armature 34 can move along the axial direction of the outer shell 1, thereby controlling the opening or closing of the sealing surface 32.

[0038] It is known that the structure of using solenoid valve 33 to drive armature 34 has the advantage of fast response speed, which can realize the rapid opening and closing of the connecting channel 31 and accurately control the pressure change state of control chamber 11 to ensure the timeliness and accuracy of methanol injection.

[0039] Optionally, the sealing surface 32 is a sealing cone surface.

[0040] Please refer to the details. Figure 2 The armature 34 has a conical bottom forming an annular conical surface. Correspondingly, the bottom of the receiving chamber 17 is a conical groove, and the conical surface of the armature 34 matches the conical groove. When the solenoid valve 33 is energized, the armature 34 moves upward, the sealing surface 32 opens, and the connecting flow channel 31 connects to the volume chamber 15. When the solenoid valve 33 is de-energized, the armature 34 moves downward according to the reset mechanism, and the sealing surface 32 closes.

[0041] The connection between the flow channel 31 and the volume cavity 15 is controlled by a conical surface, thereby achieving high-pressure sealing. At the same time, the conical surface structure balances the pressure, which can reduce wear caused by uneven force on the sealing surface 32.

[0042] In some other embodiments, the sealing surface 32 may also be a planar sealing surface or a sealing surface of other shapes, which is not limited here.

[0043] In one or more embodiments, reference may be made to Figure 2 At least two connected volume chambers 15 are arranged along the axial direction of the outer casing 1; in the direction away from the control unit 3, the volume of the volume chamber 15 closer to the control unit 3 is smaller than the volume of the volume chamber 15 farther from the control unit 3. One end of the discharge channel 16 is connected to the volume chamber 15 with the largest volume.

[0044] The axially arranged and gradually changing volumetric cavities 15 can form a multi-stage buffer pressure relief path. The small volumetric cavity 15 near the control unit 3 first receives the high-pressure methanol to slow down the initial pressure relief rate, while the large volumetric cavity 15 far away from the control unit 3 further expands and buffers to avoid cavitation caused by sudden pressure changes during the pressure relief process.

[0045] Optionally, the discharge channel 16 is connected to the largest volume chamber 15 (the lowest volume chamber 15 along the axial direction of the outer shell 1), which can ensure that the low-pressure methanol is discharged smoothly after depressurization, reduce flow field disturbance, stabilize the pressure change of the chamber 11, and thus ensure the smooth operation of the methanol needle valve 13 and improve the stability of the injection volume.

[0046] Please continue to refer to Figure 2 , Figure 2 The diagram shows two volumetric cavities 15, with the lower volumetric cavity 15 having a larger volume than the upper volumetric cavity 15. Figure 2 The example only uses two volumetric cavities 15 as an example and does not limit the specific number of volumetric cavities 15.

[0047] Furthermore, a throttling mechanism 151 is provided on the flow channel between adjacent volume chambers 15, and one end of the discharge flow channel 16 is connected to the throttling mechanism 151.

[0048] By setting up the throttling mechanism 151, the flow rate and velocity of methanol between adjacent volume chambers 15 can be precisely controlled. This prevents cavitation caused by excessively fast methanol flow leading to localized low pressure. Simultaneously, it slows down the pressure drop rate in the control chamber 11, resulting in a smoother opening and closing process for the methanol needle valve 13 and reducing impact wear between the needle valve and the methanol nozzle 14. Furthermore, the throttling mechanism 151 can balance the pressure within each volume chamber 15, ensuring a stable pressure relief process and improving the accuracy of methanol injection metering.

[0049] In one or more embodiments, the throttling mechanism 151 is a throttling orifice.

[0050] Because the throttling orifice has a simple structure, low processing difficulty, and controllable cost, this invention selects the throttling orifice as the throttling mechanism 151 and precisely matches the methanol flow characteristics by adjusting the orifice size to adapt to the pressure relief requirements under different working conditions.

[0051] By setting throttling orifices in the flow channels between adjacent volume chambers 15, the methanol flowing between the volume chambers 15 can be limited and stabilized. On the one hand, it can slow down the flow velocity of methanol between the volume chambers 15, avoiding flow field turbulence caused by excessive flow velocity and effectively suppressing turbulence generation. On the other hand, it can prevent a sudden pressure drop after methanol enters the volume chamber 15 from the control chamber 11, reducing the probability of cavitation caused by pressure change. At the same time, the throttling orifice can also ensure the continuity and stability of methanol flow between the control chamber 11 and the volume chamber 15, thereby ensuring the stability of methanol flow in the pilot valve inlet and outlet orifices (connecting the control chamber 11 and the connecting channel 31, and connecting the flow channel 31 and the volume chamber 15). The stable methanol flow can make the pressure change in the control chamber 11 smooth and precise, driving the methanol needle valve 13 to achieve smooth and precise opening and closing action, effectively improving the methanol injection metering accuracy, while reducing the erosion of the sealing surface 32 by cavitation and the risk of methanol leakage. Combined with the advantage of avoiding cross-contamination with a single methanol medium, it further ensures the safety of injector operation.

[0052] In some other embodiments, the flow channels between adjacent volume cavities 15 may be narrowed to form a throttling mechanism 151. The specific form of the throttling mechanism 151 is only an example and is not limited.

[0053] Please refer to Figure 3 The first branch 22 is connected to the control chamber 11 through the alcohol inlet orifice 221; the connecting channel 31 is connected to the control chamber 11 through the alcohol outlet orifice 311.

[0054] By setting the methanol inlet orifice 221, the methanol flow rate into the control chamber 11 can be stabilized, avoiding instability in the initial pressure of the control chamber 11 due to fluctuations in the methanol inlet flow rate.

[0055] The methanol outlet orifice 311, in conjunction with the throttling mechanism 151, controls the methanol outflow rate when the control chamber 11 is depressurized, and works with the methanol inlet orifice 221 to achieve precise pressure regulation in the control chamber 11. Together, they reduce pressure fluctuations in the control chamber 11, ensure consistent operation of the methanol needle valve 13, improve the repeatability and metering accuracy of methanol injection, and meet the flow control requirements of high-pressure methanol direct injection.

[0056] The operating principle of the methanol injector is explained below: High-pressure methanol from the high-pressure methanol common rail system first enters the methanol flow channel 2 through the methanol inlet 21 on the outer casing 1. If the methanol flow channel 2 integrates a high-pressure methanol accumulator chamber (optional depending on the system architecture, such as...), Figure 2In the design, methanol flow channel 2 has a branch on the left side. The upward branch flows to the high-pressure methanol accumulator chamber (the location of the methanol accumulator chamber is not specified here). The high-pressure methanol can first be accumulating and stabilizing in the accumulator chamber, and then it splits into two paths along the main path of methanol flow channel 2: one path serves as the first branch 22, which flows precisely into the control chamber 11 inside the outer shell 1 through the methanol inlet orifice 221, providing methanol with stable pressure to the control chamber 11. The other path serves as the second branch 23, which flows directly into the methanol holding tank 12 inside the outer shell 1, so that the methanol pressure in the methanol holding tank 12 is consistent with the common rail system pressure. A methanol needle valve 13 that can move up and down is provided between the control chamber 11 and the methanol holding tank 12. The first end of the methanol needle valve 13 is connected to the control chamber 11 to receive pressure drive, and the second end is sealed to the methanol nozzle 14.

[0057] When the solenoid valve 33 in the control unit 3 is energized, the electromagnetic force generated by the solenoid valve 33 drives the armature 34 to move upward, causing the sealing surface 32 formed between the end of the armature 34 away from the solenoid valve 33 and the bottom wall of the housing 1 receiving chamber 17 of the outer casing 1 to open. At this time, the high-pressure methanol in the control chamber 11 enters at least two interconnected volume chambers 15 arranged axially in the outer casing 1 through the connecting flow channel 31 and the methanol outlet orifice 311. The throttling orifices on the flow channels between adjacent volume chambers 15 can slow down the methanol flow velocity, suppress the flow field turbulence, and avoid cavitation caused by sudden pressure changes during the depressurization process. After the high-pressure methanol is gradually depressurized in the multi-stage volume chambers 15, it finally flows into the low-pressure methanol return collection pipeline outside the machine through the discharge flow channel 16 connected to the largest volume chamber 15. At the same time, the methanol leaking from the gap of the methanol injection pilot control valve armature 34 is discharged through an independent gap leakage return port (not shown in the figure), which is not directly connected to the low-pressure methanol formed by the control depressurization, thus avoiding mutual interference. As the methanol in the control chamber 11 continues to depressurize, its pressure gradually decreases. When the pressure difference between the control chamber 11 and the methanol tank 12 is sufficient to overcome the resistance of the methanol needle valve 13, the high-pressure methanol in the methanol tank 12 pushes the methanol needle valve 13 upward, releasing the seal between the methanol needle valve 13 and the methanol nozzle 14. The methanol nozzle 14 opens, and the high-pressure methanol in the methanol tank 12 is injected into the engine cylinder through the nozzle orifice of the methanol nozzle 14 in a high-pressure direct injection form, achieving full atomization of methanol fuel.

[0058] Conversely, when the solenoid valve 33 is de-energized, the electromagnetic force disappears, and the armature 34 moves downward under the action of the reset mechanism, re-fitting with the bottom wall of the accommodating chamber 17 to close the sealing surface 32 and the connecting flow channel 31. At this time, the first branch 22 continues to supply high-pressure methanol to the control chamber 11 through the methanol inlet orifice 221, causing the pressure in the control chamber 11 to gradually rise. When the pressure rises to the target value, and sufficient downward driving force is formed under the action of the area difference between the upper and lower ends of the methanol needle valve 13, the methanol needle valve 13 is pushed downward and re-sealed with the methanol nozzle 14, closing the spray hole of the methanol nozzle 14, and the methanol injection process stops.

[0059] Please refer to Figure 1 , Figure 4 and Figure 5 The present disclosure also proposes a dual-fuel injector, including a diesel injector 4 and the aforementioned methanol injector, wherein the diesel injector 4 is integrated into the housing 1.

[0060] This disclosure integrates the diesel injector 4 and the methanol injector into the same housing 1, which avoids the problems of complex flow channels and difficult system layout in separate structures, simplifies the engine belt layout process, and improves system integration. At the same time, it can reduce the risk of cross-contamination between different fuel flow channels and ensure the independence and safety of diesel ignition and methanol injection.

[0061] Furthermore, the diesel injector 4 is arranged parallel to the main structure of the methanol injector along the axial direction of the housing 1.

[0062] It can be seen that the above-mentioned main structure refers to the structure of the methanol injector inside the housing 1, including but not limited to the methanol needle valve 13 and the control unit 3.

[0063] This disclosure, by axially arranging the methanol injector and diesel injector 4 side-by-side, allows for more centered spray patterns from both the diesel and methanol nozzles, facilitating matching with the engine combustion chamber and optimizing in-cylinder combustion organization. Simultaneously, the independent side-by-side arrangement of the diesel injector 4 and methanol injector bodies enables separate and independent control of both, avoiding mutual interference and improving the stability of diesel ignition with small fuel volumes and the freedom of methanol injection. Furthermore, the side-by-side arrangement further simplifies the internal flow channel design of the housing 1, reduces manufacturing difficulty, and enhances structural compactness.

[0064] For the diesel injector 4, the diesel injector 4 is designed based on the high-pressure common rail technology to adapt to the ignition requirements of methanol injection. The diesel inlet 41 on its housing 1 is directly connected to the high-pressure common rail system to receive high-pressure diesel fuel at a stable pressure. The diesel flow channel integrated inside the housing 1 has been compacted and optimized. After entering the housing 1, the diesel flow channel is divided into two branches: one is the first flow channel, which has a diesel fuel inlet orifice 49 at its end. The high-pressure diesel fuel flows into the diesel control chamber 45 after being precisely limited by the diesel fuel inlet orifice 49, ensuring that the diesel control chamber 45 can obtain a continuous and stable fuel supply pressure. The other is the second flow channel, through which the high-pressure diesel fuel is directly delivered to the diesel fuel tank 46 inside the housing 1.

[0065] The upper part of the diesel control chamber 45 is provided with a diesel fuel outlet orifice 47 communicating with its interior. The opening and closing of the fuel outlet orifice is controlled by the diesel pilot ball valve 42, and the diesel pilot ball valve 42 is fixedly connected to the diesel pilot ball valve armature 43. The armature 34 is driven by electromagnetic force to move up and down. The outer shell 1 is also provided with an independent diesel fuel outlet channel 48. One end of the fuel outlet channel is connected to the diesel fuel outlet orifice 47, and the other end extends to the outside of the outer shell 1 and is connected to the external low-pressure diesel fuel return line.

[0066] When the solenoid valve 33 corresponding to the diesel pilot ball valve 42 is energized, the electromagnetic force overcomes the elastic force of the reset element (e.g., spring) and drives the armature 43 of the diesel pilot ball valve to move upward. Figure 1 (The direction is shown in the image). The diesel pilot ball valve armature 43 synchronously drives the diesel pilot ball valve 42 to open upward, so that the diesel fuel outlet orifice 47 at the top of the diesel control chamber 45 is fully connected to the diesel fuel outlet channel 48 in the outer casing 1. At this time, the high-pressure diesel fuel in the diesel control chamber 45 enters the diesel fuel outlet channel 48 through the diesel fuel outlet orifice 47 and gradually depressurizes to the low-pressure return oil line outside the engine. The pressure in the control chamber 11 decreases steadily during the depressurization process. When the pressure in the diesel control chamber 45 drops below the high pressure in the diesel fuel tank 46, the high-pressure diesel fuel in the tank 46 forms an upward thrust on the middle of the diesel needle valve 44. After overcoming the weight of the diesel needle valve 44 and the reset resistance, the thrust pushes the diesel needle valve 44 to move upward along the axis, thereby opening the sealing mating surface between the lower end of the diesel needle valve 44 and the diesel nozzle 491. The high-pressure diesel fuel in the tank 46 is then sprayed out in an atomized form through the nozzle orifice of the diesel nozzle 491. This injection process can achieve stable injection of a small amount of diesel fuel required for ignition by precisely controlling the energization time of the solenoid valve 33, thus providing a reliable ignition source for subsequent methanol combustion.

[0067] When the solenoid valve 33 corresponding to the diesel pilot ball valve 42 is de-energized, the electromagnetic force disappears, and the armature 43 of the diesel pilot ball valve gradually moves downward under the reset action of the reset element, driving the diesel pilot ball valve 42 to move downward synchronously until the pilot ball valve completely blocks the diesel outlet orifice 47, disconnecting the flow path between the diesel control chamber 45 and the diesel outlet flow channel 48. At the same time, the first flow channel continues to deliver high-pressure diesel to the diesel control chamber 45 through the diesel inlet orifice 49, causing the pressure in the control chamber 11 to gradually rise. When the pressure in the diesel control chamber 45 rises to a level higher than the oil pressure in the diesel filling tank 46, and the downward pressure on the top of the diesel needle valve 44 is greater than the upward thrust of the filling tank 46 on the middle of the needle valve, the diesel needle valve 44 moves downward axially, and its lower conical surface re-forms a sealing fit with the diesel nozzle 491, completely blocking the nozzle orifice of the diesel nozzle 491, and the diesel injection process stops.

[0068] Throughout the diesel injection process, the pressure changes in the diesel control chamber 45 are precisely controlled, which ensures the smooth operation of the diesel needle valve 44 and the accuracy of the injected fuel quantity. In particular, it is well-suited to the stable supply demand for igniting small amounts of diesel fuel in dual-fuel mode, laying the foundation for the efficient combustion of methanol fuel.

[0069] This disclosure also proposes an engine comprising the aforementioned methanol injector or dual-fuel injector.

[0070] In summary, the advanced technical effects of this disclosure include, but are not limited to, at least one of the following: By setting a control chamber 11, a methanol tank 12, and a methanol needle valve 13 driven by the pressure of the control chamber 11 within the outer casing 1, and cooperating with a methanol flow channel 2 whose first end is a methanol inlet 21 and whose second end is split into a first branch 22 and a second branch 23 respectively connecting the control chamber 11 and the methanol tank 12, and further combined with a control unit 3 connected to the control chamber 11 through a connecting flow channel 31 that can be sealed or opened, and at least two volume chambers 15 connected to the connecting flow channel 31 in the open state within the outer casing 1 and an outlet flow channel 16 connected to the volume chambers 15, the injector does not need to use independent high-pressure control oil, sealing oil, or other media. It can achieve pilot hydraulic control and high-pressure in-cylinder direct injection of methanol injection using only a single methanol medium. This effectively avoids the problem of complex and intertwined internal flow channels of the injector caused by the high integration of multiple media in the prior art. The structure is simpler and more compact, and the processing difficulty and manufacturing cost are greatly reduced. Moreover, it eliminates the risk of cross-contamination between different media, ensuring the safe operation of the engine. It also eliminates the need to deal with the pressure matching limitations of multiple media, enabling free online control of methanol pressure and flow, significantly improving the freedom and precision of methanol injection control, and reducing the difficulty of injection control, especially in the event of security anomalies.

[0071] 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 of this disclosure, shall fall within the protection scope defined by the claims of this disclosure.

Claims

1. A methanol injector, characterized in that, include: The outer shell contains a control chamber and a methanol tank. A methanol needle valve is provided between the control chamber and the methanol tank. The first end of the methanol needle valve is driven by the pressure of the control chamber, and the second end of the methanol needle valve is set to correspond to the methanol nozzle. The methanol flow channel has a first end as an inlet and a second end as a branch, the first branch being connected to the control chamber and the second branch being connected to the methanol tank. The control unit has a connecting channel between itself and the control chamber. The housing also has at least two communicating volume chambers. The connecting channel is in the open state and communicates with the volume chambers. The housing also has a discharge channel communicating with the volume chambers. The control unit is configured to seal or open the connecting channel to cooperate with the control chamber to drive the methanol needle valve to close or open the methanol nozzle.

2. The methanol injector as described in claim 1, characterized in that, The housing has a accommodating chamber, and the control unit is placed in the accommodating chamber. The output end of the control unit forms a sealing surface with the bottom wall of the accommodating chamber. When the sealing surface is open, the connecting channel communicates with the volume chamber.

3. The methanol injector as described in claim 2, characterized in that, The control unit includes a solenoid valve and an armature. When the solenoid valve is powered on or off, it drives the armature to open or close the connecting flow channel. The sealing surface is formed between the end of the armature away from the solenoid valve and the bottom wall of the accommodating chamber.

4. The methanol injector as described in claim 3, characterized in that, The sealing surface is a sealing cone surface.

5. The methanol injector as described in claim 2, characterized in that, At least two of the connected volumetric cavities are arranged along the axial direction of the outer casing; Along the direction away from the control unit, the volume of the cavity closer to the control unit is smaller than the volume of the cavity farther from the control unit; The discharge channel is connected to the largest volume cavity.

6. The methanol injector as described in claim 1, characterized in that, A throttling mechanism is provided on the flow channel between adjacent volume chambers, and one end of the discharge flow channel is connected to the throttling mechanism.

7. The methanol injector as described in claim 6, characterized in that, The throttling mechanism is a throttling orifice.

8. The methanol injector according to any one of claims 1-7, characterized in that, The first branch is connected to the control chamber via an alcohol inlet orifice; The connecting channel and the control chamber are connected via an alcohol dispensing orifice.

9. A dual-fuel injector, characterized in that, Includes a diesel injector and a methanol injector as described in any one of claims 1 to 8, wherein the diesel injector is integrated within the housing.

10. The dual-fuel injector as claimed in claim 9, characterized in that, The diesel injector is arranged parallel to the main structure of the methanol injector along the axial direction of the housing.

11. An engine, characterized in that, Includes a methanol injector as described in any one of claims 1-8 or a dual-fuel injector as described in any one of claims 9-10.

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