Methanol fuel injector assembly

Abstract

The invention belongs to the technical field of injectors, and particularly discloses a methanol fuel injector assembly which comprises an injector body provided with an inner cavity. The methanol-resistant sealing ring is clamped in the inner cavity; the sealing gasket is clamped in the inner cavity and is arranged above the methanol-resistant sealing ring; one end of the control valve seat sequentially penetrates through the sealing gasket and the methanol-resistant sealing ring to reach the pressure chamber and is matched with the inner cavity, and the other end of the control valve seat is connected with the fixing nut valve assembly. According to the structure, methanol cannot leak from a gap between the control valve seat and the pressure chamber and a gap between the control valve seat and the inner cavity, so that the control valve seat is prevented from being corroded by methanol, and the service life of the ejector is prolonged. Engine oil is used as control liquid, so that an oil film is formed between the armature shaft and the inner wall of the armature seat, an oil film is formed between the needle valve and the inner wall of the control valve seat, the lubricity and durability of all sliding parts are improved, abrasion of all the sliding parts is reduced, and the service life of the ejector is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of injectors, and in particular relates to an injector assembly for methanol fuel. Background Art

[0002] Greenhouse gas emission reduction regulations are strongly promoting the green and low-carbon transformation of many fields such as ship power, automobile power, and construction machinery. This trend has become irreversible. Against this backdrop, renewable green and clean energy, as an ideal substitute for traditional fossil fuels, is widely regarded as an effective and practical way to achieve greenhouse gas emission reduction goals. As a potential power fuel, renewable low-carbon energy such as methanol, ammonia, and hydrogen have been widely used and practiced in many fields.

[0003] Methanol, because of its physical and chemical properties are quite similar to fossil fuels, especially its high energy density and the property of remaining liquid at room temperature, makes methanol fuel highly compatible with fossil fuels in all aspects such as storage, transportation, filling and use. This unique property greatly enhances the feasibility and attractiveness of methanol as a future mainstream fuel on the road to achieving carbon neutrality goals.

[0004] However, under current technical conditions, methanol fuel injectors generally use low-pressure intake duct injection, which often leads to poor atomization, thus affecting combustion efficiency and emission performance. To improve this situation, a common strategy is to increase the injection pressure to enhance the atomization effect. However, as a volatile and corrosive liquid, methanol's volatility and corrosiveness will be significantly enhanced under extreme conditions of high pressure and high temperature, which brings considerable challenges to the design and use of injectors.

[0005] In particular, the control valve seat of the injector is directly exposed to the high temperature and high pressure environment of the engine combustion chamber, and is frequently subjected to high-frequency mechanical impact. Under such extremely harsh working conditions, the control valve seat is prone to corrosion and wear. Once these problems occur, they will directly lead to the failure of the sealing performance of the control valve seat of the injector, which will seriously affect the stability and reliability of the injector. Summary of the invention

[0006] The purpose of the present invention is to provide an injector assembly for methanol fuel, which controls the valve seat to avoid sealing failure caused by methanol corrosion and prolongs the service life of the injector.

[0007] The objective of the present invention is achieved through such a technical solution, which specifically provides an injector assembly for methanol fuel, comprising:

[0008] The ejector body is provided with an inner cavity;

[0009] Methanol-resistant sealing ring, stuck in the inner cavity;

[0010] A sealing gasket is clamped in the inner cavity and arranged above the methanol-resistant sealing ring;

[0011] The control valve seat is arranged in the inner cavity, one end of which passes through the sealing gasket and the methanol-resistant sealing ring in sequence to the top of the pressure chamber, and the other end is connected to the fixing nut valve assembly.

[0012] Preferably, the methanol-resistant sealing ring material is resistant to methanol corrosion and swelling.

[0013] Preferably, the injector body also includes a solenoid valve assembly, and the fixed nut valve assembly includes a fixing nut, an armature over-stroke adjustment pad, an armature shaft, an armature seat and a switch ceramic ball. The fixing nut is provided with a step through hole running through its axial direction, the armature over-stroke adjustment pad is arranged on the step surface of the step through hole, the armature seat is arranged in the step through hole, one end of the armature seat is in contact with the solenoid valve assembly, and the other end of the armature seat is in contact with the armature over-stroke adjustment pad; the armature seat is provided with a sliding hole coaxial with the step through hole, the armature shaft is slidably arranged in the step through hole and the sliding hole, a spherical groove for matching with the switch ceramic ball is provided on one end surface of the armature shaft, and the other end is connected to the solenoid valve assembly, and the control valve seat is provided with a conical hole for matching with the switch ceramic ball.

[0014] Preferably, the control valve seat is provided with a control chamber, and the control chamber is communicated with the return oil metering hole and the inlet oil metering hole respectively.

[0015] Preferably, the diameter of the oil inlet metering hole is smaller than the diameter of the oil return metering hole.

[0016] Preferably, a first oil inlet passage is provided between the oil inlet metering hole and the control chamber, and an oil inlet filter is provided in the first oil inlet passage.

[0017] Preferably, an outer surface of the first oil inlet passage is provided with an external thread, and the injector body is provided with an internal thread matching the external thread.

[0018] Preferably, the control liquid in the control chamber is engine oil, and the inlet pressure of the engine oil is greater than the pressure of methanol entering the injector body.

[0019] Preferably, it also includes a needle valve assembly, which includes a needle valve, an injector pressure-regulating spring, a pressure-adjusting pad, a spring seat and an open gasket; the upper end of the needle valve is slidably arranged in the control valve seat, the outer surface of the needle valve is provided with a groove, and the open gasket is installed in the groove; the spring seat is sleeved into the needle valve and contacts with the upper end surface of the open gasket; the injector pressure-regulating spring is sleeved into the needle valve, one end contacts with the upper end surface of the spring seat, and the other end abuts against the inner wall of the control valve seat.

[0020] Preferably, a second annular groove is provided on the inner surface of the control valve seat, and the second annular groove is communicated with the oil inlet metering hole.

[0021] Preferably, a plurality of first annular grooves are arranged at intervals on the inner surface of the control valve seat.

[0022] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0023] The injector assembly of methanol fuel of the present invention is provided with a methanol-resistant sealing ring and a sealing gasket on the outer surface of the control valve seat, so that methanol cannot leak from the gap between the control valve seat and the pressure chamber and the gap between the control valve seat and the inner cavity. The control valve seat is prevented from being corroded by methanol and the control valve seat seal fails, thereby extending the life of the injector. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation of the present invention, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0025] Figure 1 It is a structural schematic diagram of a methanol fuel injector assembly of the present invention;

[0026] Figure 2 is a structural schematic diagram of a needle valve assembly;

[0027] Figure 3 This is an enlarged schematic diagram of point A;

[0028] Figure 4 This is an enlarged schematic diagram of point B;

[0029] Figure 5 Schematic diagram of the control valve seat.

[0030] Reference numerals:

[0031] 1- injector body, 11- inner cavity, 12- methanol inlet hole, 13- pressure chamber,

[0032] 2-Methanol resistant sealing ring, 3-Sealing gasket,

[0033] 4-control valve seat, 41-control chamber, 42-return oil metering hole, 43-inlet oil metering hole, 44-conical hole, 45-first oil inlet passage, 451-inlet oil filter, 46-first cavity, 47-first annular groove, 48-second oil inlet passage, 49-second annular groove,

[0034] 5-fixing nut valve assembly, 51-fixing nut, 511-step through hole, 512-step surface, 52-armature over-travel adjustment pad, 53-armature shaft, 531-spherical groove, 54-armature seat, 541-sliding hole, 55-switch ceramic ball, 56-armature shaft spring,

[0035] 6-solenoid valve assembly, 61-solenoid valve body, 611-second cavity, 62-solenoid valve pressure adjustment pad, 63-solenoid valve spring,

[0036] 7-needle valve assembly, 71-needle valve, 711-groove, 72-injector pressure regulating spring, 73-pressure adjusting pad, 74-spring seat, 75-opening gasket. DETAILED DESCRIPTION

[0037] See also Figure 1 and Figure 2 A methanol fuel injector assembly includes: an injector body 1, a methanol-resistant sealing ring 2, a sealing gasket 3 and a control valve seat 4.

[0038] The injector body 1 is provided with an inner cavity 11, and the methanol-resistant sealing ring 2 is clamped in the inner cavity 11; the sealing gasket 3 is clamped in the inner cavity 11 and is arranged above the methanol-resistant sealing ring 2; the control valve seat 4 is arranged in the inner cavity 11, one end of which passes through the sealing gasket 3 and the methanol-resistant sealing ring 2 in sequence to the top of the pressure chamber 13, and the other end is connected to the fixed nut valve assembly 5. Specifically, the methanol-resistant sealing ring 2 is put in from the upper end of the injector body 1 and is clamped in the inner cavity 11 of the injector body 1; the sealing gasket 3 is put in from the upper end of the injector body 1, and the bottom surface contacts the methanol-resistant sealing ring 2 and is clamped in the inner cavity 11 of the injector body 1; the control valve seat 4 is put in from the upper end surface of the injector body 1, and the lower end of the control valve seat 4 passes through the sealing gasket 3 and the methanol-resistant sealing ring 2 in sequence, and cooperates with the contact surface of the injector body 1. The fixed nut valve assembly 5 is screwed into the injector body 1, contacts and presses the upper surface of the control valve seat 4. A methanol inlet hole 12 is provided at the lower end of the injector body 1, and a pressure chamber 13 connected to the methanol inlet hole 12 is provided in the injector body 1. High-pressure methanol enters the pressure chamber 13 through the methanol inlet hole 12, and the control valve seat 4 extends into the upper end of the pressure chamber 13. The material of the methanol-resistant sealing ring 2 has methanol corrosion resistance and swelling properties. Preferably, the methanol-resistant sealing ring 2 is butyl rubber, and the material of the sealing pad 3 is fluororubber.

[0039] In the injector assembly of methanol fuel of the present invention, high-pressure methanol enters into the pressure chamber 13 through the methanol liquid inlet hole 12, and the methanol-resistant sealing ring 2 and the sealing gasket 3 are utilized to effectively control the leakage of methanol into the gap between the control valve seat 4 and the pressure chamber 13 and the gap between the control valve seat 4 and the inner cavity 11, thereby preventing the control valve seat 4 from being corroded by methanol and causing the sealing failure of the control valve seat 4, thereby extending the service life of the injector.

[0040] See also Figures 1 to 4Further, the injector body 1 also includes a solenoid valve assembly 6, the fixed nut valve assembly 5 includes a fixed nut 51, an armature over-stroke adjustment pad 52, an armature shaft 53, an armature seat 54 and a switch ceramic ball 55, the fixed nut 51 is provided with a step through hole 511 running through its axial direction, the armature over-stroke adjustment pad 52 is arranged on the step surface 512 of the step through hole 511, the armature seat 54 is arranged in the step through hole 511, one end of which contacts with the solenoid valve assembly 6, and the other end of which contacts with the armature over-stroke adjustment pad 52; the armature seat 54 is provided with a sliding hole 541 coaxial with the step through hole 511, the armature shaft 53 is slidably arranged in the step through hole 511 and the sliding hole 541, a spherical groove 531 matching the switch ceramic ball 55 is provided on one end surface of the armature shaft 53, and the other end is connected to the solenoid valve assembly 6, and the control valve seat 4 is provided with a tapered hole 44 matching the switch ceramic ball 55. Specifically, the armature shaft 53 passes through the armature over-travel adjustment pad 52 and the step through hole 511, and the spherical groove 531 contacts the switch ceramic ball 55. An armature shaft spring 56 is provided between the inner wall of the control valve seat 4 and the outer side of the armature seat 54. The armature shaft spring 56 has a buffering effect when the solenoid valve assembly 6 applies pressure to the armature seat 54, and also has energy storage when compressed. When the armature seat 54 is forced to move upward, the armature shaft spring 56 has the function of accelerating the movement of the armature seat 54. The required electromagnetic force is small, and the electromagnetic force is positively correlated with the size of the solenoid valve assembly. It plays an important role in the miniaturization of the solenoid valve and facilitates the miniaturization of the injector. The over-travel adjustment pad 52 is provided to limit the armature seat 54 to the extreme position of the downward movement, ensuring that the armature seat 54 can quickly realize the function of opening or closing. The armature shaft 53 is clearance-matched with the armature seat 54 and the fixing nut 51. The solenoid valve assembly 6 includes a solenoid valve body 61, a solenoid valve pressure adjustment pad 62 and a solenoid valve spring 63. The solenoid valve body 61 is screwed into the injector body 1 and is provided with a second cavity 611. The solenoid valve spring 63 and the solenoid valve pressure adjustment pad 62 are arranged in the second cavity 611. One end of the solenoid valve spring 6 abuts against the surface of the solenoid valve pressure adjustment pad 62, and the other end abuts against the upper end of the armature shaft 53. By adjusting the solenoid valve pressure adjustment pad 62 of different thicknesses, the preload force of the solenoid valve spring 63 can be adjusted.

[0041] See also Figure 1 and Figure 5 Furthermore, the control valve seat 4 is provided with a control chamber 41, and the control chamber 41 is communicated with the return oil metering hole 42 and the inlet oil metering hole 43 respectively.

[0042] Furthermore, the diameter of the oil inlet metering hole 43 is smaller than the diameter of the oil return metering hole 42 .

[0043] See also Figure 3Furthermore, the control liquid of the control chamber 41 is engine oil, and the entry pressure of the engine oil is greater than the pressure of methanol entering the injector body 1. Engine oil is used as the control liquid, which is different from the prior art that uses fuel as the control liquid and engine oil as the lubricating oil for the internal parts of the injector. Only one type of engine oil is used, and the user does not need to add multiple oils, and there is no need to worry about the control liquid contaminating other oils due to penetration. The engine oil enters from the high-pressure oil channel, a small amount of engine oil will penetrate out, and when the injector is working, part of the engine oil will enter the gap between the armature shaft 53 and the armature seat 54 when returning the oil, so that an oil film is formed between the inner walls of the armature shaft 53 and the armature seat 54, thereby increasing the durability of the armature shaft 53 and the armature seat 54. Avoiding the prior art of using a dedicated lubrication channel to lubricate the armature shaft 53 and the armature seat 54 makes the injector structure simpler.

[0044] See also Figure 2 Furthermore, a first oil inlet passage 45 is provided between the oil inlet metering hole 43 and the control chamber 41, and the first oil inlet passage 45 is provided with an oil inlet filter 451. The oil inlet filter 451 is provided to filter the oil entering the first oil inlet passage 45, so that the oil entering the control chamber 41 does not contain large particles of impurities, thereby extending the service life of the injector.

[0045] Furthermore, the outer surface of the first oil inlet passage 45 is provided with an external thread, and the injector body 1 is provided with an internal thread matched with the external thread. Through the thread matching, the first oil inlet passage 45 is convenient to disassemble, thereby facilitating the replacement or maintenance of the oil inlet filter element 451.

[0046] See also Figure 1 , Figure 3 and Figure 5 , further, it also includes a needle valve assembly 7, which includes a needle valve 71, an injector pressure regulating spring 72, a pressure regulating pad 73, a spring seat 74 and an opening gasket 75; the upper end of the needle valve 71 is slidably arranged in the control valve seat 4, the outer surface of the needle valve 71 is provided with a groove 711, and the opening gasket 75 is installed in the groove 711; the spring seat 74 is inserted into the needle valve 71 and contacts the upper end surface of the opening gasket 75; the injector pressure regulating spring 72 is inserted into the needle valve 71, one end of which contacts the upper end surface of the spring seat 74, and abuts against the inner wall of the control valve seat 4. Specifically, the control valve seat 4 is provided with a first cavity 46, and the needle valve 71 is slidably arranged in the first cavity 46.

[0047] See also Figure 3Furthermore, a plurality of first annular grooves 47 are provided at intervals on the inner surface of the control valve seat 4. The pressure of the engine oil is greater than the pressure of methanol, and a small amount of engine oil will penetrate, so that an oil film is formed between the inner wall of the needle valve 71 and the control valve seat 4, thereby increasing the durability of the needle valve 71 and the control valve seat 4. In front of the pressure chamber 13, a plurality of first annular grooves 47 are provided on the inner surface of the control valve seat 4, and the engine oil will be stored in the first annular grooves 47, which can effectively prevent the engine oil from entering the pressure chamber 13 from the matching position of the needle valve 71 and the control valve seat 4. Preferably, two first annular grooves 47 are provided along the axial direction of the inner side of the control valve seat 4.

[0048] See also Figure 5 , further, the inner surface of the control valve seat 4 is provided with a second annular groove 49, and the second annular groove 49 is connected to the oil inlet metering hole 43. Specifically, the second annular groove 49 is arranged between the first annular grooves 47, and the oil inlet metering hole 43 is connected to the second annular groove 49 through the second oil inlet passage 48 in the injector body 1. High-pressure engine oil enters from the oil inlet metering hole 43, and a high-pressure engine oil ring belt is formed in the second annular groove 49. When the armature seat 54 is sucked up, the control chamber 41 returns oil, and its pressure drops. The engine oil pressure of the high-pressure sealing ring belt is always greater than the methanol pressure of the pressure chamber 13, thereby avoiding the leakage of methanol into the control valve seat 4 due to the pressure drop of the control chamber 41, and has an auxiliary effect in extending the life of the injector. Because the pressure of the methanol in the pressure chamber 13 does not change much after injection, and the engine oil is relatively viscous, a small amount of engine oil penetrates during injection, and even if it penetrates, it will be stored in the first annular groove 47.

[0049] The working principle of the injector assembly of methanol fuel of the present invention is as follows:

[0050] In the initial state, the control liquid enters the control chamber 41 from the oil inlet metering hole 43. Since the switch ceramic ball 55 is closed under the action of the preload spring force of the solenoid valve spring 63, a stable oil pressure is formed in the control chamber 41; methanol enters the pressure chamber 13 through the methanol inlet hole 12 of the injector body 1. Since the needle valve 71 is closed under the dual action of the preload spring force of the injector pressure regulating spring 72 and the force formed by the upper and lower pressure surfaces of the needle valve 71, a stable hydraulic pressure is formed in the pressure chamber 13.

[0051] When the injection is in the open state, the solenoid valve assembly 6 is acted upon by the opening control electrical signal, generating an electromagnetic force to overcome the preload spring force of the solenoid valve spring 63 to lift the armature seat 54, and the armature shaft 53 is acted upon by the armature seat 54 to move up to the top dead center, and the engine oil pushes open the switch ceramic ball 55 through the return oil metering hole 42 to relieve the pressure, and the decompressed engine oil flows back to the engine oil tank through the oil return oil metering hole 42, and since the aperture of the oil inlet metering hole 43 is smaller than the aperture of the return oil metering hole 43, the pressure in the control chamber 41 continues to decrease; when the upward force formed by the pressure surfaces at the upper and lower ends of the needle valve 71 overcomes the preload spring force of the injector pressure regulating spring 72, the needle valve 71 opens, and methanol is sprayed out from the spray hole of the injector body 1 in atomized form.

[0052] When the injection is closed, the solenoid valve assembly 6 is de-energized by the closing control electrical signal, and the solenoid valve assembly 6 does not generate electromagnetic force. The armature seat 54 slowly moves down to the initial position under the action of gravity and the spring force of the armature shaft spring 56. The spring force of the solenoid valve spring 6 presses the armature 21 downward, so that the switch ceramic ball 55 is closed, and the engine oil continuously flows into the control chamber 41 through the oil inlet metering hole 43, so that the upward force formed by the upper and lower pressure surfaces of the needle valve 71 is less than the spring force of the injector pressure regulating spring 72, so that the needle valve 71 continuously moves down until it is closed, and the injector body 1 stops spraying oil; the control chamber 41 is continuously filled with engine oil until a stable oil pressure is formed, and methanol flows into the pressure chamber 13 through the methanol inlet hole 12 until a stable hydraulic pressure is formed.

[0053] The injector assembly of methanol fuel of the present invention is provided with a methanol-resistant sealing ring 2 and a sealing gasket 3 on the outer surface of the control valve seat 4, so that the leakage of methanol to the control valve seat 4 and the pressure chamber 13, and the control valve seat 4 and the inner cavity 11 can be effectively controlled, so as to avoid the problems of corrosion and wear of the injector by methanol, and extend the life of the injector. The control liquid is engine oil, and the inlet pressure of the engine oil is greater than the pressure of the methanol entering the injector body, so that an oil film is formed between the armature shaft and the inner wall of the armature seat, and an oil film is formed between the needle valve and the inner wall of the control valve seat, so as to increase the durability of each sliding part and reduce the wear of each sliding part. The side surface of the needle valve 71 is provided with a plurality of first annular grooves 712, and the engine oil will be stored in the first annular grooves 712, which can effectively prevent the engine oil from entering the pressure chamber 13 from the matching position of the needle valve 471 and the control valve seat 4. An oil inlet filter element 451 is provided, so that the engine oil entering the control chamber 41 does not contain large particles of impurities, and the service life of the injector is extended. A high-pressure oil ring belt is formed in the second annular groove 49 to prevent methanol from leaking into the control valve seat 4 due to a pressure drop in the control chamber 41 , thereby helping to extend the life of the injector.

[0054] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A methanol fuel injector assembly, characterized in that: include: The injector body (1) is provided with an inner cavity (11); A methanol-resistant sealing ring (2) is clamped in the inner cavity (11); A sealing gasket (3) is clamped in the inner cavity (11) and arranged above the methanol-resistant sealing ring (2); as well as The control valve seat (4) is arranged in the inner cavity (11), one end of which passes through the sealing gasket (3) and the methanol-resistant sealing ring (2) in sequence to the top of the pressure chamber (13), and the other end of which is connected to the fixing nut valve assembly (5).

2. The injector assembly for methanol fuel according to claim 1, characterized in that: The material of the methanol-resistant sealing ring (2) is resistant to methanol corrosion and swelling.

3. The injector assembly of methanol fuel according to claim 1 or 2, characterized in that: The injector body (1) also includes a solenoid valve assembly (6). The fixed nut valve assembly (5) includes a fixed nut (51), an armature over-travel adjustment pad (52), an armature shaft (53), an armature seat (54) and a switch ceramic ball (55). The fixed nut (51) is provided with a step through hole (511) running through the axial direction thereof. The armature over-travel adjustment pad (52) is arranged on a step surface (512) of the step through hole (511). The armature seat (54) is arranged in the step through hole (511) and one end is connected to the solenoid valve assembly (6). The control valve seat (54) is provided with a sliding hole (541) coaxial with the step through hole (511), and the armature shaft (53) is slidably arranged in the step through hole (511) and the sliding hole (541). A spherical groove (531) matched with a switch ceramic ball (55) is provided on one end surface of the armature shaft (53), and the other end is connected to the solenoid valve assembly (6). The control valve seat (4) is provided with a tapered hole (44) matched with the switch ceramic ball (55).

4. The injector assembly for methanol fuel according to claim 1 or 2, characterized in that: The control valve seat (4) is provided with a control chamber (41), and the control chamber (41) is communicated with the oil return metering hole (42) and the oil inlet metering hole (43) respectively.

5. The injector assembly of methanol fuel according to claim 4, characterized in that: The diameter of the oil inlet metering hole (43) is smaller than the diameter of the oil return metering hole (42).

6. The injector assembly of methanol fuel according to claim 4, characterized in that: A first oil inlet passage (45) is provided between the oil inlet metering hole (43) and the control chamber (41), and the first oil inlet passage (45) is provided with an oil inlet filter element (451).

7. The injector assembly for methanol fuel according to claim 5 or 6, characterized in that: The control liquid in the control chamber (41) is engine oil, and the inlet pressure of the engine oil is greater than the pressure of methanol entering the injector body (1).

8. The injector assembly for methanol fuel according to claim 1, 2, 5 or 6, characterized in that: The invention also comprises a needle valve assembly (7), the needle valve assembly (7) comprising a needle valve (71), an injector pressure regulating spring (72), a pressure regulating pad (73), a spring seat (74) and an opening gasket (75); the upper end of the needle valve (71) is slidably arranged in the control valve seat (4), the outer surface of the needle valve (71) is provided with a groove (711), and the opening gasket (75) is installed in the groove (711); the spring seat (74) is inserted into the needle valve (71) and contacts the upper end surface of the opening gasket (75); the injector pressure regulating spring (72) is inserted into the needle valve (71), one end of the spring seat (74) contacts the upper end surface of the spring seat (74), and the other end abuts against the inner wall of the control valve seat (4).

9. The injector assembly for methanol fuel according to claim 1, 2, 5 or 6, characterized in that: A plurality of first annular grooves (47) are arranged at intervals on the inner surface of the control valve seat (4).

10. The injector assembly of methanol fuel according to claim 5 or 6, characterized in that: The inner surface of the control valve seat (4) is provided with a second annular groove (49), and the second annular groove (49) is communicated with the oil inlet metering hole (43).

Images