A methanol injector for a methanol engine

Abstract

The utility model relates to methanol engine technical field discloses a methanol injector for methanol engine, including casing, valve seat, methanol input pipe, nozzle plate, valve rod, spring, solenoid and electromagnet, the casing both ends are equipped with valve seat and methanol input pipe respectively, the valve seat front end is equipped with nozzle plate, be equipped with guide cylinder in the casing, divide the casing into the first cavity of front part and the second cavity of rear part, the flow channel that is opened to the guide cylinder has communicated first cavity and second cavity, the valve rod slidingly arranged in the casing, and its front end forms sealed pair with valve seat.

Description

Technical Field

[0001] This utility model relates to the field of methanol engine technology, specifically to a methanol injector for a methanol engine. Background Technology

[0002] Methanol, as a clean alternative fuel, exhibits good economic and emission performance in engine applications. The methanol injector is a core component of the methanol engine fuel supply system, and its performance directly affects the engine's power and efficiency.

[0003] When a traditional solenoid valve injector is used with methanol fuel, the methanol oil film between the valve stem and the electromagnet is squeezed during the valve stem's engagement. This oil film generates a force that resists the reduction in thickness, creating a "squeezed oil film damping" effect. This results in an increased valve stem closing delay and a slower response speed, which affects the precise control of injection timing and consequently the engine's combustion efficiency.

[0004] Therefore, there is an urgent need for a methanol-specific injector that can effectively reduce oil film damping and improve response speed. Utility Model Content

[0005] To address the technical problems existing in the background art, this utility model proposes a methanol injector for a methanol engine.

[0006] This utility model discloses a methanol injector for a methanol engine, comprising a housing, a valve seat, a methanol input pipe, a nozzle plate, a valve stem, a spring, an electromagnetic coil, and an electromagnet. The housing has a valve seat and a methanol input pipe at its two ends, respectively. A nozzle plate is located at the front end of the valve seat. A guide cylinder is provided inside the housing, dividing the interior into a first cavity at the front and a second cavity at the rear. A flow channel connecting the first and second cavities is formed on the guide cylinder. The valve stem is slidably disposed within the housing, with its front end forming a sealing pair with the valve seat, and its rear end sliding through the guide cylinder and opposite the electromagnet, forming an oil film gap. A conical hole is provided inside the electromagnet, with the smaller diameter end communicating with the oil film gap and the larger diameter end facing the methanol input pipe. The spring acts on the valve stem, causing it to tend towards sealing the valve seat. When the electromagnetic coil is energized, it drives the electromagnet to generate magnetic force that attracts the rear end of the valve stem, overcoming the spring force and opening the valve stem. Addressing the issues of high oil film damping and long closing delay between the valve stem and electromagnet in traditional methanol injectors, which affect injection timing, this injector achieves a breakthrough through "conical orifice venting + dual-chamber pressure control." The guide cylinder separates the housing into a first chamber and a second chamber, ensuring smooth methanol flow. The valve stem and electromagnet form an oil film gap, and the conical orifice provides an efficient venting channel for the compressed oil film. When the electromagnet coil is energized, the electromagnet attracts the valve stem, and the compressed oil film is quickly discharged through the conical orifice, reducing oil film damping and closing delay. A spring maintains the valve stem's normally closed seal, and the dual chambers maintain a slight positive pressure of 0.3-0.5 MPa, ensuring rapid atomization and injection of methanol when the valve stem opens. This meets the high-frequency injection requirements of methanol engines, thereby improving combustion efficiency and reducing pollutant emissions.

[0007] As a further optimization of this utility model, the number of the tapered holes is multiple, and they are evenly distributed circumferentially on the electromagnet; Multiple circumferentially distributed conical holes can avoid oil interference during single-hole leakage, ensure uniform oil film discharge, increase the total leakage volume, further shorten the oil film squeezing time, and the circumferentially distributed design also balances the force on the electromagnet, avoids valve stem offset caused by unilateral leakage, ensures the sealing pair fit accuracy, and reduces methanol leakage.

[0008] As a further optimization of this utility model, the guide cylinder is cylindrical, and its inner hole is clearance-fitted with the valve stem to provide precise axial guidance for the valve stem, avoiding sealing failure or jamming caused by valve stem tilting. The clearance fit also reduces the sliding resistance of the valve stem, ensuring sensitive valve stem response, adapting to high-frequency start and stop, and improving the service life of the guide cylinder.

[0009] As a further optimization of this utility model, the number of flow channels is multiple, and they are evenly distributed circumferentially around the inner hole of the guide cylinder and extend axially. This ensures that the pressure loss is small when methanol flows from the second chamber to the first chamber, improves the pressure balance speed of the two chambers, and the flow channels are distributed around the inner hole of the guide cylinder. This does not affect the sliding of the valve stem, and at the same time avoids excessive local flow velocity caused by a single flow channel, prevents cavitation of methanol due to high-speed flow, and ensures stable injection volume.

[0010] As a further optimization of this utility model, the nozzle plate is provided with multiple uniformly distributed injection holes, which atomize the methanol in an umbrella shape and mix it more thoroughly with the air, avoiding the localized rich mixture phenomenon of traditional single-hole injection. The uniform distribution of injection holes also ensures the consistency of fuel injection in each cylinder, making it suitable for multi-cylinder methanol engines and improving the overall power stability of the engine.

[0011] As a further optimization of this utility model, an electronic control unit is also installed on the housing to control the energization and de-energization of the electromagnetic coil. The electronic control unit integrates an MCU and a driver chip to receive signals from the engine ECU and precisely control the energization duration and frequency of the electromagnetic coil to achieve quantitative methanol injection. The electronic control unit has built-in overcurrent and overvoltage protection functions to prevent the electromagnetic coil from burning out. It is compatible with vehicle power supplies and can be directly integrated into the injector housing to reduce external wiring harnesses.

[0012] As a further optimization of this utility model, the seal between the front end of the valve stem and the valve seat is a spherical seal. Compared with a planar seal, the seal is more reliable. Even if there is a slight offset of the valve stem, it can still effectively seal and prevent methanol leakage. The spherical seal also has a self-centering function. When the valve stem is reset, it can automatically correct its position, reduce the wear of the sealing pair, and extend the service life of the sealing pair.

[0013] As a further optimization of this utility model, the methanol input pipe is used to connect to the methanol output port of the methanol common rail pipe. The methanol common rail pipe is installed on the engine air supply pipe. The methanol common rail pipe has a methanol input port connected to the methanol fuel supply equipment and a methanol output port connected to the methanol input pipe to ensure a stable methanol supply. The common rail pipe can be connected to multiple cylinder injectors at the same time to achieve precise fuel supply to each cylinder. With the built-in pressure sensor of the common rail pipe, the ECU can adjust the fuel injection parameters in real time to adapt to different operating conditions, improve methanol utilization, and reduce engine fuel consumption.

[0014] The methanol injector for methanol engines proposed in this invention has the following beneficial effects: (i) The present invention provides an optimized drainage channel for the squeezed oil film between the valve stem and the electromagnet by opening a tapered hole inside the electromagnet. The tapered structure facilitates fluid outflow, significantly reduces the oil film damping effect, thereby shortening the valve stem closing delay time and improving the response speed of the injector. (ii) In the non-injection stage, the spring force ensures a tight seal between the valve stem and the valve seat. By maintaining the first chamber, the flow channel and the second chamber in a slightly positive pressure state, it is beneficial for the next rapid oil injection. (III) This utility model adopts a cylindrical electromagnet with good central symmetry, small high-pressure area, and a guide cylinder and its circumferentially distributed flow channel design, which ensures smooth flow of methanol from the second chamber to the first chamber and stable pressure. (iv) By maintaining a slight positive pressure in the first cavity and combining it with a porous nozzle plate, this utility model ensures that methanol can be well atomized when it is sprayed out, thereby improving combustion efficiency.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] Figure 1 This is a front sectional view of the present invention. Figure 2 This is a three-dimensional sectional view of the present invention. Figure 3 This is a schematic diagram of the structure of the guide cylinder of this utility model; Figure 4 This is a first-view perspective three-dimensional structural diagram of the present invention; Figure 5 This is a second-view perspective three-dimensional structural diagram of the present invention; Figure 6 This is a schematic diagram of the assembly structure of this utility model and the engine intake pipe.

[0017] Figure descriptions: 1. Housing; 2. Valve seat; 3. Methanol inlet pipe; 4. Nozzle plate; 5. Valve stem; 6. Spring; 7. Electromagnetic coil; 8. Electromagnet; 9. Conical orifice; 10. Guide tube; 11. First chamber; 12. Second chamber; 13. Flow channel; 14. Electrical control unit; 15. Inlet pipe; 16. Methanol common rail pipe; 17. Methanol inlet; 18. Methanol outlet; 19. Electrical control wiring harness. Detailed Implementation

[0018] The embodiments of this utility model are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0019] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0020] Please see Figures 1-5A methanol injector for a methanol engine includes a housing 1, with a valve seat 2 and a methanol input pipe 3 installed at both ends of the housing 1, a nozzle plate 4 communicating with its inner cavity installed at the front opening of the valve seat 2, a guide cylinder 10 installed inside the housing 1, thereby forming a first cavity 11 inside the valve seat 2, and a second cavity 12 formed inside the rear end of the housing 1, and a flow channel 13 for connecting the first cavity 11 and the second cavity 12 is provided on the guide cylinder 10; A valve stem 5, aligned with a valve seat 2, is slidably disposed inside the housing 1. An electromagnetic coil 7 and an electromagnet 8 located within the inner ring of the electromagnetic coil 7 are installed inside the rear end of the housing 1. The front end of the valve stem 5 contacts the front opening of the valve seat 2 and is spherically sealed. The rear end of the valve stem 5 slides through the inner hole of the guide cylinder 10 and is opposite to the electromagnet 8 to form an oil film gap. A conical hole 9 is provided inside the electromagnet 8 to connect the oil film gap and the methanol input pipe 3. The small end of the conical hole 9 communicates with the oil film gap. A spring 6, abutting against the end face of the guide cylinder 10, is installed at the rear end of the valve stem 5. An electronic control unit 14, used to control the electromagnetic coil 7 and the electromagnet 8, is installed outside the housing 1. The electronic control unit 14 controls the electromagnetic coil 7 to be energized, causing the electromagnet 8 to generate electromagnetic attraction. The force attracts the valve stem 5, causing its rear end to fit against the electromagnet 8. The spring 6 compresses and deforms, squeezing the oil film in the oil film gap, reducing its thickness. The oil flows out through the small end of the conical hole 9 and the edge of the gap. The front end of the valve stem 5 separates from the valve seat 2, while the first chamber 11 remains under a slight positive pressure. This causes the methanol oil in the first chamber 11 to spray outward through the nozzle plate 4. After the power is cut off, the electromagnet 8 loses its electromagnetic attraction, and the valve stem 5 moves forward and resets under the elastic deformation of the spring 6. This causes the front end of the valve stem 5 to re-contact and seal the front opening of the valve seat 2. The methanol oil in the methanol input pipe 3 enters the oil film gap through the conical hole 9 to maintain the slight positive pressure in the second chamber 12, the flow channel 13, and the first chamber 11, facilitating re-spraying.

[0021] The external structure of the electromagnet 8 is cylindrical, which has better central symmetry and stronger fluidity than the square shape. The area of ​​the high-pressure zone is reduced compared to the square shape. The opening structure of the conical hole 9 has a better effect on improving the gap than the circular hole, which is better than the guide groove. The opening area of ​​the circular hole and the conical hole is the same, but the circular hole will generate jet interference and blockage. The eddy current of the conical hole is larger than that of the circular hole, which makes it easier to block the fluid out of the gap. Moreover, the conical hole structure can also reduce the influence of the squeezing flow in the gap of the solenoid valve, shorten the closing delay time, and increase the maximum injection pressure.

[0022] Specifically, such as Figures 1-3As shown, the guide cylinder 10 is cylindrical and its inner hole is clearance-fitted with the valve stem 5. There are multiple flow channels 13, which are evenly distributed around the inner hole of the guide cylinder 10 and extend axially. Both ends of the flow channels 13 are open to connect the first chamber 11 and the second chamber 12. The rear end of the methanol input pipe 3 is connected to the methanol supply pipeline. Methanol oil is injected into the second chamber 12 through the methanol input pipe 3 and the conical hole 9, and then flows to the first chamber 11 for storage through the flow channels 13, thereby maintaining a slightly positive pressure state in the first chamber 11. When the valve stem 5 is separated from the opening of the valve seat 2, under the action of slightly positive pressure, the methanol oil in the first chamber 11 is quantitatively sprayed out through the nozzle plate 4.

[0023] Specifically, such as Figure 2 and Figure 5 As shown, the nozzle plate 4 has multiple evenly distributed injection holes to ensure uniform injection of methanol oil.

[0024] Specifically, the electronic control unit 14 is a conventional electronic control component in the prior art, used to control the energization and start / stop of the electromagnetic coil 7 and the electromagnet 8.

[0025] In one embodiment, such as Figure 6 As shown, the methanol engine is equipped with an intake pipe 15, which has six branch pipes that are respectively connected to the six cylinders of the engine. A methanol common rail pipe 16 for methanol supply is installed on the branch pipes. The methanol common rail pipe 16 corresponds to multiple branch pipes. The upper end of the methanol common rail pipe 16 has a methanol inlet 17, and the lower end has multiple methanol outlets 18 that are connected to multiple branch pipes. The methanol inlet pipe 3 at the rear end of the methanol injector is connected to the methanol outlets 18. Methanol oil is supplied to the methanol common rail pipe 16 through the methanol inlet 17, and the methanol oil is injected into the corresponding methanol injector through the methanol outlets 18, thus realizing multi-cylinder injection of methanol. Furthermore, a sensor for measuring methanol pressure is installed inside the methanol common rail 16, and an electrical control harness 19 electrically connected to the sensor is installed on the methanol common rail 16. The methanol pressure inside the methanol common rail 16 is designed to be 0.3-0.5 MPa. The sensor monitors the pressure in the methanol common rail 16 in real time and feeds the data back to the engine ECU via the electronic control harness 19. The ECU dynamically controls the electronic control unit 14 based on the pressure signal, thereby dynamically adjusting the energizing time of the solenoid coil 7 to ensure that the injection pressure of each cylinder is stable at 0.3-0.5MPa. This pressure range ensures that methanol is fully atomized, while avoiding excessive pressure that could damage the injector seals or excessive pressure that could result in poor atomization, thus optimizing combustion efficiency.

[0026] The working principle of this utility model is as follows: In the initial state without power: Under the elastic force of spring 6, the front end of valve stem 5 is pressed against valve seat 2 to form a seal, and the injector is closed. At this time, methanol fuel enters from methanol input pipe 3, passes through the conical hole 9 on electromagnet 8, the second chamber 12, and the flow channel 13 on guide cylinder 10 in sequence, and enters the first chamber 11, maintaining the entire flow path in a slightly positive pressure state. During the injection process, the electronic control unit 14 controls the solenoid coil 7 to be energized, and the electromagnet 8 generates electromagnetic force to attract the rear end of the valve stem 5. The valve stem 5 begins to move backward and compress the spring 6. During this process, the oil film gap between the rear end of the valve stem 5 and the end face of the electromagnet 8 decreases, and the methanol in it is squeezed. Since the electromagnet 8 has a conical hole 9, it provides a superior discharge path for the squeezed methanol. The conical structure is conducive to the fluid flowing out quickly to the large diameter end, which significantly reduces the damping effect of the oil film, so that the valve stem 5 can quickly and smoothly complete the suction movement and shorten the closing delay. When the front end of the valve stem 5 leaves the valve seat 2, the methanol fuel in the first chamber 11, which is under slight positive pressure, is immediately sprayed out through the injection hole on the nozzle plate 4 and enters the engine intake manifold. Power off when injection stops: The electronic control unit 14 cuts off the current to the electromagnetic coil 7, the electromagnetic force disappears, the valve stem 5 moves forward rapidly under the restoring force of the spring 6, and its front end re-seals the valve seat 2, the fuel injection stops, and at the same time, methanol fuel is replenished again through the conical hole 9 and other paths to prepare for the next injection.

[0027] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A methanol injector for a methanol engine, comprising a housing (1), a valve seat (2), a methanol inlet pipe (3), a nozzle plate (4), a valve stem (5), a spring (6), an electromagnetic coil (7), and an electromagnet (8), wherein the housing (1) is provided with a valve seat (2) and a methanol inlet pipe (3) at both ends, and the nozzle plate (4) is provided at the front end of the valve seat (2), characterized in that: The housing (1) is provided with a guide cylinder (10) which divides the interior of the housing into a first cavity (11) at the front and a second cavity (12) at the rear. The guide cylinder (10) is provided with a flow channel (13) that connects the first cavity (11) and the second cavity (12). The valve stem (5) is slidably disposed in the housing (1), its front end forms a sealing pair with the valve seat (2), and its rear end slides through the guide cylinder (10) and is opposite to the electromagnet (8) to form an oil film gap; The electromagnet (8) has a conical hole (9) inside. The small diameter end of the conical hole (9) is connected to the gap between the oil film and the large diameter end is directed toward the methanol input pipe (3). The spring (6) acts on the valve stem (5), causing the valve stem (5) to tend to seal towards the valve seat (2); When the electromagnetic coil (7) is energized, it drives the electromagnet (8) to generate magnetic force to attract the rear end of the valve stem (5), overcoming the spring force to open the valve stem (5).

2. A methanol injector for a methanol engine according to claim 1, characterized in that, The number of tapered holes (9) is multiple, and they are evenly distributed circumferentially on the electromagnet (8).

3. A methanol injector for a methanol engine according to claim 1, characterized in that, The guide cylinder (10) is cylindrical, and its inner hole is clearance-fitted with the valve stem (5).

4. A methanol injector for a methanol engine according to claim 1, characterized in that, The number of flow channels (13) is multiple, and they are evenly distributed around the inner hole of the guide cylinder (10) and extend along the axial direction.

5. A methanol injector for a methanol engine according to claim 1, characterized in that, The nozzle plate (4) has multiple uniformly distributed spray holes.

6. A methanol injector for a methanol engine according to claim 1, characterized in that, An electronic control unit (14) is also installed on the housing (1) to control the energization and de-energization of the electromagnetic coil (7).

7. A methanol injector for a methanol engine according to claim 1, characterized in that, The seal between the front end of the valve stem (5) and the valve seat (2) is a spherical seal.

8. A methanol injector for a methanol engine according to claim 1, characterized in that, The methanol input pipe (3) is connected to the methanol output port (18) of the methanol common rail pipe (16), which is installed on the engine air supply pipe (15).

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