A methanol fuel injector for an engine

Abstract

This invention relates to a methanol fuel injector for an engine, comprising an injector body, a solenoid valve, a needle valve rod, a needle valve spring, and a needle valve. The solenoid valve is disposed on the top of the injector body. The solenoid valve includes a valve body, an electromagnet, and a solenoid valve spring. A control oil accumulator chamber is formed between the valve body and the needle valve spring. A control oil inlet is provided on one side of the injector body, communicating with the control oil accumulator chamber. A low-pressure chamber is formed between the valve body and the injector body. A control oil return port is provided on one side of the injector body, communicating with the low-pressure chamber. A methanol inlet passage is formed between the needle valve rod and the injector body. A methanol fuel accumulator chamber is formed between the needle valve and the injector body. A methanol inlet and return port is provided on one side of the injector body, communicating with the methanol inlet passage. This invention solves the problem of rapid wear of the control valve and effectively controls the upward leakage of methanol by introducing a piston structure.

Description

Technical Field

[0001] This invention relates to the field of fuel injector technology, and more particularly to a methanol fuel injector for engines. Background Technology

[0002] With the development of science and technology, environmental issues have attracted increasing attention. Compared to non-renewable fossil fuels, renewable low-carbon energy sources such as methanol, ammonia, and hydrogen have significant advantages. Methanol fuel, in particular, can be produced through carbon dioxide capture and extraction, offering advantages such as wide availability, a large economic scale, and sustainable development across the entire industrial chain. Furthermore, methanol fuel boasts low emissions and low toxicity. In the national standard "Classification of Occupational Exposure to Toxic Substances" (GBZ230-2010), the toxicity hazard index of methanol, calculated based on classification and evaluation criteria, is 20, while that of gasoline is 28. Therefore, methanol is currently a relatively ideal new renewable energy source.

[0003] Currently, the mainstream methanol injection technology is low-pressure port injection. This method achieves a methanol substitution rate (the ratio of methanol energy consumed in a single cycle to total fuel energy consumed) of only 50%. Simultaneously, the internal combustion engine's thermal efficiency is low, only around 40%. To improve the methanol substitution rate and internal combustion engine thermal efficiency, a diesel micro-injection ignition system for direct methanol injection has been proposed. The requirements for methanol injectors have also increased from 5 bar for low-pressure port injection to 35 MPa. However, existing electromagnetic injectors cannot handle the high-pressure injection of methanol. Methanol is a low-viscosity liquid with poor lubrication properties; it cannot effectively lubricate the injection device while injecting fuel, thus easily causing problems such as rapid wear of the control valve in electromagnetic injectors. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a methanol fuel injector for engines, thereby solving the problem that methanol fuel easily causes wear on the solenoid valve port of traditional electromagnetic injectors.

[0005] The technical solution adopted in this invention is as follows:

[0006] This invention discloses a methanol fuel injector for an engine, comprising an injector body, a solenoid valve, a needle valve rod, a needle valve spring, and a needle valve. The solenoid valve is located at the top of the injector body. The solenoid valve includes a valve body, an electromagnet, and a solenoid valve spring. The solenoid valve spring is located at the upper end of the valve body. The electromagnets are respectively located on both sides of the upper part of the valve body. The needle valve rod is located in the lower middle region inside the injector body. The needle valve is located at the bottom end of the needle valve rod. The needle valve spring is located at the top end of the needle valve rod and corresponds to the bottom end of the solenoid valve. The valve body and the needle valve... A control oil accumulator chamber is formed between the springs; a control oil inlet hole communicating with the control oil accumulator chamber is provided on one side of the injector body; a low-pressure chamber is formed between the valve body and the injector body; a control oil return hole communicating with the low-pressure chamber is provided on one side of the injector body; a methanol inlet oil passage is formed between the needle valve rod and the injector body; a methanol fuel accumulator chamber is formed between the needle valve and the injector body; characterized in that: a methanol inlet and return oil hole is provided on one side of the injector body, and the methanol inlet and return oil hole is communicating with the methanol inlet oil passage.

[0007] Furthermore, a sealing assembly is provided on the needle valve stem at the bottom of the needle valve spring, the sealing assembly being a piston or plunger; a sealing structure is formed between the sealing assembly and the inner wall of the injector body.

[0008] Furthermore, the needle valve stem and the sealing plate assembly can be either separate or integrated.

[0009] Furthermore, the solenoid valve is a ball valve.

[0010] Compared with the prior art, the present invention has the following advantages:

[0011] The present invention reduces the machining difficulty caused by adding pistons by introducing piston assembly threads, and further reduces the design and layout difficulty of cylinder head.

[0012] The injection conditions of this invention are greater than 35 MPa. Under this condition, conventional fuel injectors will be damaged in a short time. However, this invention can significantly increase the service life of the injector by introducing a designed diesel passage to lubricate the existing structure.

[0013] To address the problem of rapid wear in control valves, this invention proposes an optimized solution that effectively controls upward leakage of methanol by introducing a piston structure.

[0014] This invention introduces a piston structure that further isolates methanol and diesel fuel, resulting in higher purity methanol and lower diesel fuel concentration compared to other technologies, thereby reducing pollutant emissions from diesel combustion at the source. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 A schematic diagram of a traditional electromagnetic fuel injector;

[0017] Figure 3 This is a schematic diagram of the separate structure of the piston body and the needle valve rod;

[0018] Figure 4 This is a schematic diagram of the integrated structure of the piston body and the needle valve rod;

[0019] Figure 5 This is a schematic diagram of a structure that uses a plunger as a sealing component.

[0020] In the attached drawings, the following reference numerals are used: 1-Injector body; 2-Valve body; 3-Electromagnet; 4-Solenoid valve spring; 5-Piston body; 6-Threaded structure; 7-Piston ring; 8-Needle valve rod; 9-Needle valve spring; 10-Needle valve; 11-Thread; 12-Plunger body; 13-Plunger sleeve; A1-Control oil inlet; A2-Control oil accumulator chamber; A3-Low pressure chamber; A4-Return oil hole; B1-Methanol inlet and return oil holes; B2-Methanol inlet oil passage; B3-Methanol fuel accumulator chamber. Detailed Implementation

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] It should be noted that in the description of this invention, the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not mean that the device or element must have a specific orientation, or be constructed and operated in a specific orientation.

[0023] See appendix Figure 1This invention provides a specific structure of an embodiment of a methanol fuel injector for an engine. The injector includes an injector body 1, a solenoid valve, a needle valve rod 8, a needle valve spring 9, and a needle valve 10. The solenoid valve is connected to the top of the injector body 1 via a thread 11; wherein, the solenoid valve is a ball valve, including a valve body 2, an electromagnet 3, and a solenoid valve spring 4; the valve body 2 is located on the upper side inside the injector body 1; the solenoid valve spring 4 is disposed at the upper end of the valve body 2; the electromagnets 3 are respectively disposed on both sides of the upper part of the valve body 2; the needle valve rod 8 is vertically disposed in the lower middle region inside the injector body 1; the needle valve 10 is disposed at the bottom end of the needle valve rod 8; the needle valve spring 9 is disposed at the top end of the needle valve rod 8 and corresponds to the bottom end of the solenoid valve body 2.

[0024] The valve body 2 and the needle valve spring 9 form a control oil accumulator chamber A2, and one side of the injector body 1 is provided with a control oil inlet hole A1 that communicates with the control oil accumulator chamber A2; the valve body 2 and the injector body 1 form a low-pressure chamber A3, and one side of the injector body 1 is provided with a control oil return hole A4 that communicates with the low-pressure chamber A3; the needle valve rod 8 and the injector body 1 form a methanol inlet oil passage B2; the needle valve 10 and the injector body 1 form a methanol fuel accumulator chamber B3; one side of the injector body 1 is provided with a methanol inlet and return oil hole B1, and the methanol inlet and return oil hole B1 communicates with the methanol inlet oil passage B2.

[0025] In this embodiment, a sealing assembly is provided on the needle valve rod 8 at the bottom of the needle valve spring 9. The sealing assembly is a piston or plunger. A sealing structure is formed between the sealing assembly and the inner wall of the injector body 1.

[0026] like Figure 1 As shown, the piston includes a piston body 5 and a piston ring 7. The piston ring 7 is sleeved on the outside of the piston body 5, and the piston body 5 is installed inside the injector body 1 through a threaded structure 6; a sealing structure is formed between the piston ring 7 and the inner wall of the injector body 1.

[0027] like Figure 5 As shown, the plunger includes a plunger body 12 and a plunger sleeve 13. The plunger sleeve 13 is fitted onto the outside of the plunger body 12, and the plunger body 12 is installed inside the injector body 1 through a threaded structure 6. A sealing structure is formed between the plunger sleeve 13 and the inner wall of the injector body 1.

[0028] The bottom of the sealing assembly and the needle valve stem 8 can be a separate structure, such as... Figure 3 As shown; a one-piece structure can also be used, such as Figure 4 As shown.

[0029] The specific differences between this invention and traditional electromagnetic fuel injectors are as follows:

[0030] The structure of a traditional high-pressure common rail electromagnetic injector, such as Figure 2 As shown, there is no piston body 5 and methanol inlet / outlet port B1. Methanol enters the nozzle directly through the control oil inlet port A1. When the electromagnet 3 is not energized, the preload of the solenoid valve spring 4 presses the solenoid valve body 2, so that the low-pressure chamber A3 and the control oil accumulator chamber A2 are not connected. Fuel can only accumulate in the control oil accumulator chamber A2, the methanol fuel accumulator chamber B3, and the methanol inlet passage B2 through the control oil inlet port A1. At this time, the pressure in the control oil accumulator chamber A2 is equal to that in the methanol fuel accumulator chamber B3. The needle valve rod 8 is pressed tightly against the needle valve seat under the preload of the needle valve spring 9, and the nozzle is in a non-injecting state.

[0031] When electromagnet 3 is energized, it generates magnetic force, and the armature on the solenoid valve body 2 is attracted by the magnetic force. When the electromagnetic force is greater than the spring force of the solenoid valve spring 4, the solenoid valve body 2 moves upward to its large diameter point and contacts the injector body 1. The solenoid valve body 2 rises, and the low-pressure chamber A3 and the control oil accumulator chamber A2 are connected. High-pressure methanol in the control oil accumulator chamber A2 leaks into the low-pressure chamber A3 and returns to the control oil tank through the return oil hole A4. The methanol pressure in the control oil accumulator chamber A2 decreases, and the needle valve rises upward against the pressure in the control oil accumulator chamber A2 and the preload force of the needle valve spring 9, and the injector begins to inject. Due to the poor lubrication characteristics of methanol, the contact surface between the solenoid valve body 2 and the injector body 1 will wear rapidly due to the vaporization and cavitation of methanol during repeated opening and closing.

[0032] The injector structure proposed in this invention, such as Figure 1 As shown, the introduction of methanol inlet / outlet port B1 allows control oil to lubricate the solenoid valve through control oil inlet port A1, significantly increasing the durability of the methanol injector. Simultaneously, the introduction of piston body 5 isolates the control oil in the control oil accumulator chamber A2 from the methanol inlet chamber B2. This is achieved through pressure control (P... A2 >P B2 This allows a small amount of control oil in the control oil accumulator chamber A2 to seep out through the piston body 5, forming an oil film between the piston body 5 and the inner wall of the injector body 1, thus increasing the durability of the piston body 5. Through these measures, methanol in the methanol inlet circuit B2 will not flow into the cavitation solenoid valve at the top of the injector, preventing rapid damage to the injector.

[0033] The working principle of this invention is as follows:

[0034] Methanol fuel enters the injector's internal methanol inlet circuit B2 through the methanol inlet / outlet port B1; when the needle valve 10 is opened, it is injected into the combustion chamber through the methanol fuel accumulator chamber B3 and the nozzle.

[0035] Methanol fuel and control oil are independent of each other, and piston body 5 serves to prevent methanol from leaking into the control oil;

[0036] When the solenoid valve is closed, the combined force of the pressure in the control oil accumulator chamber A2 and the preload of the needle valve spring 9 is greater than the pressure in the methanol fuel accumulator chamber B3, which causes the needle valve 10 to sit on the needle valve seat. At this time, the needle valve is closed and methanol is not injected.

[0037] When the solenoid valve opens, the high-pressure control oil in the control oil accumulator chamber A2 leaks into the low-pressure chamber A3 and returns to the control oil tank through the return oil hole A4. At this time, the control oil pressure in the control oil accumulator chamber A2 decreases, and the needle valve rises upward against the pressure of the control oil accumulator chamber A2 and the preload force of the needle valve spring 9, completing one methanol injection.

[0038] All matters not covered in this invention are common knowledge.

[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A methanol fuel injector for an engine, comprising an injector body, a solenoid valve, a needle valve rod, a needle valve spring, and a needle valve; the solenoid valve is disposed on the top of the injector body; the solenoid valve includes a valve body, an electromagnet, and a solenoid valve spring; the solenoid valve spring is disposed on the upper end of the valve body; the electromagnets are respectively disposed on both sides of the upper part of the valve body; the needle valve rod is disposed in the lower middle region inside the injector body; the needle valve is disposed at the bottom end of the needle valve rod; the needle valve spring is sleeved on the outer side of the top of the needle valve rod and corresponds to the bottom end of the solenoid valve; a control oil accumulator cavity is formed between the valve body and the upper end face of the needle valve rod; a control oil inlet hole communicating with the control oil accumulator cavity is provided on one side of the injector body; a low-pressure cavity is formed between the valve body and the injector body; a control oil return hole communicating with the low-pressure cavity is provided on one side of the injector body; a methanol inlet oil passage is formed between the needle valve rod and the injector body; a methanol fuel accumulator cavity is formed between the needle valve and the injector body; characterized in that: A methanol inlet / outlet port is provided on one side of the injector body, and the methanol inlet / outlet port is connected to the methanol inlet oil passage. A sealing assembly, which is a piston, is provided on the needle valve stem at the bottom of the needle valve spring; a sealing structure is formed between the sealing assembly and the inner wall of the injector body. The piston includes a piston body and piston rings, the piston rings being fitted onto the outside of the piston body; By introducing methanol inlet and outlet ports, control oil can lubricate the solenoid valve through the control oil inlet port, significantly increasing the durability of the methanol fuel injector. Simultaneously, by introducing a piston body, the control oil in the control oil accumulator cavity is isolated from the methanol in the methanol inlet circuit cavity. Through pressure control, a small amount of control oil in the control oil accumulator cavity seeps out through the piston body, forming an oil film between the piston body and the inner wall of the injector body. Methanol in the methanol inlet circuit cavity will not flow into the cavitation solenoid valve at the top of the injector, preventing rapid damage to the injector. Methanol fuel and control oil are independent of each other, and the sealing components prevent methanol from leaking into the control oil. The needle valve stem and the sealing assembly are separate components.

2. The methanol fuel injector for an engine according to claim 1, characterized in that: The solenoid valve is a ball valve.

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