A dual liquid fuel high-pressure direct injection system

Abstract

The invention discloses a dual-liquid fuel high-pressure direct injection system, which relates to the technical field of engine fuel supply. The dual-liquid fuel high-pressure direct injection system includes a diesel supply system, a methanol supply system and a control valve. The diesel supply system includes a diesel common rail pipe and a diesel tank, wherein the diesel common rail pipe is connected to the diesel tank and an injector. The methanol supply system includes a methanol common rail pipe and a methanol tank, wherein the methanol common rail pipe is connected to the methanol tank and the injector. The control valve is connected to the diesel common rail pipe, the methanol common rail pipe and the methanol tank, and is configured to: when the pressure of the diesel common rail pipe is lower than that of the methanol common rail pipe, most of the methanol in the methanol common rail pipe is refluxed to the methanol tank, thereby reducing the pressure in the methanol common rail pipe, avoiding abnormal opening of the injector, and avoiding methanol from entering the diesel tank through the injector, thereby improving vehicle driving safety.

Description

Technical Field

[0001] The present invention relates to the technical field of engine fuel supply, and in particular to a dual liquid fuel high-pressure direct injection system. Background Art

[0002] The dual-fuel high-pressure direct injection system is an engine direct injection system that uses natural gas as the main fuel. When working, a small amount of diesel is first injected into the engine combustion chamber to ignite the engine, and then high-pressure natural gas is injected for main combustion. When methanol fuel is used in a compression-ignition engine, two fuel supply systems are required, namely the diesel supply system and the methanol supply system. The two fuels are injected by the same injector, and the pressure difference between the two fuels will affect the overall performance of the engine and the stability of its operation.

[0003] Existing methanol fuel supply systems utilize direct injection into the cylinder, ignited by a small amount of diesel fuel. However, when the methanol fuel pressure exceeds the diesel fuel pressure, this supply method can cause the methanol needle valve to abnormally open the injector, overcoming the diesel pressure and spring preload. This can also cause methanol to enter the diesel tank through the injector, compromising vehicle safety. Summary of the Invention

[0004] An embodiment of the present invention provides a dual-liquid fuel high-pressure direct injection system to solve the technical problem in the existing direct injection supply method in the related art that when the methanol fuel pressure is greater than the diesel fuel pressure, the methanol needle valve will abnormally open the injector by overcoming the diesel pressure and the spring preload force, and methanol will also enter the diesel tank through the injector, affecting the driving safety of the vehicle.

[0005] An embodiment of the present invention provides a dual liquid fuel high-pressure direct injection system, comprising:

[0006] A diesel supply system, comprising a diesel common rail pipe and a diesel tank, wherein the diesel common rail pipe is connected to the diesel tank and the injector;

[0007] A methanol supply system, comprising a methanol common rail and a methanol tank, wherein the methanol common rail is connected to the methanol tank and the injector;

[0008] A control valve is connected to the diesel common rail, the methanol common rail, and the methanol tank, and is configured to:

[0009] When the pressure of the diesel common rail pipe is lower than that of the methanol common rail pipe, most of the methanol in the methanol common rail pipe is refluxed to the methanol tank.

[0010] In some embodiments, the control valve comprises:

[0011] Valve body;

[0012] An interface component, comprising a diesel interface, a methanol outlet, and a methanol inlet. The diesel interface is located at the front end of the valve body and connected to the diesel common rail pipe. The methanol outlet is located at the rear end of the valve body and connected to the methanol tank. The methanol inlet is located at the lower end of the valve body and connected to the methanol common rail pipe.

[0013] A control component is arranged in the valve body, one end of the control component is connected to the diesel interface, and the other end is located at the front end of the methanol outlet. It is used to make the methanol outlet conductive when the pressure of the diesel common rail pipe is lower than that of the methanol common rail pipe, so that most of the methanol in the methanol common rail pipe flows back to the methanol tank through the methanol inlet and the methanol outlet.

[0014] In some embodiments, the control component includes:

[0015] a return spring, the return spring being arranged in the valve body along a horizontal direction;

[0016] A plunger, the plunger passes through the return spring and can slide along the length direction of the return spring, the front end of the plunger is the diesel interface, and the rear end of the plunger is the methanol outlet;

[0017] A sealing seat is provided at the rear end of the plunger and fixed in the valve body, and the sealing seat cooperates with the plunger to control the opening and closing of the methanol outlet.

[0018] In some embodiments, the plunger comprises:

[0019] a first valve core, wherein a front end of the first valve core is connected to the diesel port, a rear end of the first valve core is provided with a movable pin, and the first valve core drives the movable pin to move;

[0020] The second valve core is sleeved on the outside of the first valve core, a sliding groove is provided in the middle of the second valve core and is connected to the movable pin, and the movable pin moves in the sliding groove and pushes the second valve core.

[0021] In some embodiments, the control component further includes:

[0022] A limit spring is provided at the rear end of the first valve core and is located inside the second valve core.

[0023] In some embodiments, the diesel supply system further comprises:

[0024] a first filter, wherein a first end of the first filter is connected to the diesel tank;

[0025] A high-pressure oil pump, wherein a first end of the high-pressure oil pump is connected to the second end of the first filter, a second end of the high-pressure oil pump is connected to the diesel common rail pipe, and a third end of the high-pressure oil pump is connected to the diesel tank.

[0026] In some embodiments, the diesel supply system further comprises:

[0027] A first one-way valve, wherein a first end of the first one-way valve is connected to the diesel common rail pipe, and a second end of the first one-way valve is connected to the diesel tank.

[0028] In some embodiments, the methanol supply system further comprises:

[0029] a second filter, wherein a first end of the second filter is connected to the methanol tank;

[0030] A high-pressure methanol pump, wherein a first end of the high-pressure methanol pump is connected to the second end of the second filter, a second end of the high-pressure methanol pump is connected to the methanol common rail pipe, and a third end of the high-pressure methanol pump is connected to the methanol tank.

[0031] In some embodiments, the methanol supply system further comprises:

[0032] A second one-way valve, wherein a first end of the second one-way valve is connected to the methanol common rail pipe, and a second end of the second one-way valve is connected to the methanol tank.

[0033] In some embodiments, the dual liquid fuel high pressure direct injection system further comprises:

[0034] A control unit is connected to the high-pressure oil pump, the high-pressure methanol pump and the injector respectively, and is used to control the actions of the high-pressure oil pump, the high-pressure methanol pump and the injector.

[0035] The beneficial effects brought about by the technical solution provided by the present invention include:

[0036] An embodiment of the present invention provides a dual-liquid fuel high-pressure direct injection system, comprising a diesel supply system, a methanol supply system, and a control valve. The diesel supply system includes a diesel common rail and a diesel tank, the diesel common rail being connected to the diesel tank and the injectors. The methanol supply system includes a methanol common rail and a methanol tank, the methanol common rail being connected to the methanol tank and the injectors. The control valve is connected to the diesel common rail, the methanol common rail, and the methanol tank, and is configured to reflux most of the methanol in the methanol common rail to the methanol tank when the pressure in the diesel common rail is lower than that in the methanol common rail. The dual-liquid fuel high-pressure direct injection system of the present invention, through the control valve disposed between the diesel common rail and the methanol common rail, refluxes most of the methanol in the methanol common rail to the methanol tank when the pressure in the diesel common rail is lower than that in the methanol common rail. This reduces the pressure in the methanol common rail, prevents the injectors from opening abnormally, and prevents methanol from entering the diesel tank through the injectors, thereby improving vehicle driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A schematic structural diagram of a dual liquid fuel high-pressure direct injection system provided by an embodiment of the present invention;

[0039] Figure 2 A schematic structural diagram of a control valve provided in an embodiment of the present invention;

[0040] Reference numerals:

[0041] 1. Diesel common rail pipe;

[0042] 2. Diesel tank;

[0043] 3. Fuel injector;

[0044] 4. Methanol common rail pipe;

[0045] 5. Methanol tank;

[0046] 6. Control valve; 61. Valve body; 62. Interface assembly; 621. Diesel interface; 622. Methanol outlet; 623. Methanol inlet; 63. Control assembly; 631. Return spring; 632. Plunger; 6321. First valve core; 63211. Moving pin; 6322. Second valve core; 63221. Slideway; 633. Sealing seat; 634. Limit spring; 635. Sealing ring;

[0047] 7. First filter;

[0048] 8. High-pressure oil pump;

[0049] 9. First one-way valve;

[0050] 10. Second filter;

[0051] 11. High-pressure methanol pump;

[0052] 12. Second one-way valve. DETAILED DESCRIPTION

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0054] An embodiment of the present invention provides a dual-liquid fuel high-pressure direct injection system, which can solve the technical problem in the existing direct injection supply method in the related art that when the methanol fuel pressure is greater than the diesel fuel pressure, the methanol needle valve will abnormally open the injector by overcoming the diesel pressure and the spring preload force, and methanol will also enter the diesel tank through the injector, affecting driving safety.

[0055] Figure 1 A dual liquid fuel high-pressure direct injection system provided by an embodiment of the present invention includes: a diesel supply system, a methanol supply system and a control valve 6. The diesel supply system includes a diesel common rail pipe 1 and a diesel tank 2, wherein the diesel common rail pipe 1 is connected to the diesel tank 2 and the injector 3. The methanol supply system includes a methanol common rail pipe 4 and a methanol tank 5, wherein the methanol common rail pipe 4 is connected to the methanol tank 5 and the injector 3. The control valve 6 is connected to the diesel common rail pipe 1, the methanol common rail pipe 4 and the methanol tank 5, and is configured to: when the pressure of the diesel common rail pipe 1 is lower than that of the methanol common rail pipe 4, most of the methanol in the methanol common rail pipe 4 is refluxed to the methanol tank 5.

[0056] The dual liquid fuel high-pressure direct injection system of the embodiment of the present invention is provided with a diesel supply system, a methanol supply system and a control valve. The diesel supply system includes a diesel common rail pipe and a diesel tank. The diesel common rail pipe is connected to the diesel tank and the injector for outputting diesel to the injector. The injector is also connected to the diesel tank for transporting the remaining diesel back to the diesel tank. The methanol supply system includes a methanol common rail pipe and a methanol tank. The methanol common rail pipe is connected to the methanol tank and the injector for outputting methanol to the injector. The control valve is connected to the diesel common rail pipe, the methanol common rail pipe and the methanol tank, and is configured to: when the pressure of the diesel common rail pipe is lower than that of the methanol common rail pipe, most of the methanol in the methanol common rail pipe is refluxed. To the methanol tank, when the pressure of the diesel common rail pipe is greater than that of the methanol common rail pipe, the diesel opens the injector and is injected into the load through the injector together with the methanol; when the pressure of the diesel common rail pipe is less than that of the methanol common rail pipe, the methanol needle valve overcomes the diesel pressure and the spring preload force and abnormally opens the injector, and also allows methanol to enter the diesel tank through the injector; through the control valve provided between the diesel common rail pipe and the methanol common rail pipe, when the pressure of the diesel common rail pipe is less than that of the methanol common rail pipe, most of the methanol in the methanol common rail pipe is refluxed to the methanol tank, thereby reducing the pressure in the methanol common rail pipe, avoiding abnormal opening of the injector, and avoiding methanol from entering the diesel tank through the injector, thereby improving vehicle driving safety.

[0057] As an optional embodiment, in one embodiment of the invention, see Figure 2As shown, the control valve 6 includes: a valve body 61, an interface component 62 and a control component 63, the interface component 62 is a diesel interface 621, a methanol outlet 622 and a methanol inlet 623, the diesel interface 621 is provided at the front end of the valve body 61 and is connected to the diesel common rail pipe 1, the methanol outlet 622 is provided at the rear end of the valve body 61 and is connected to the methanol tank 5, the methanol inlet 623 is provided at the lower end of the valve body 61 and is connected to the methanol common rail pipe 4, the control component 63 is provided in the valve body 61, one end of the control component 63 is connected to the diesel interface 621, and the other end is located at the front end of the methanol outlet 622, for when the pressure of the diesel common rail pipe 1 is lower than that of the methanol common rail pipe 4 , so that the methanol outlet 622 is conductive, most of the methanol in the methanol common rail pipe 4 flows back to the methanol tank 5 through the methanol inlet 623 and the methanol outlet 622. When the pressure of the diesel common rail pipe 1 is lower than that of the methanol common rail pipe 4, the control component 63 moves away from the methanol outlet 622, and the methanol inlet 623 and the methanol outlet 622 form a passage. Then, most of the methanol in the methanol common rail pipe 4 flows back to the methanol tank 5 through the methanol inlet 623 and the methanol outlet 622, and only a small part of the methanol flows to the injector 3. However, at this time, the pressure in the methanol common rail pipe 4 is low, making it difficult to open the injector 3, thereby avoiding the abnormal flow of methanol into the diesel tank 2.

[0058] As an optional embodiment, in one embodiment of the invention, see Figure 2As shown, the control assembly 63 includes: a return spring 631, a plunger 632 and a sealing seat 633. The return spring 631 is arranged in the valve body 61 along the horizontal direction. The plunger 632 passes through the return spring 631 and can slide along the length direction of the return spring 631. The front end of the plunger 632 is the diesel interface 621, and the rear end of the plunger 632 is the methanol outlet 622. The sealing seat 633 is arranged at the rear end of the plunger 632 and fixed in the valve body 61. The sealing seat 633 cooperates with the plunger 632 to control the opening and closing of the methanol outlet 622. When the pressure of the diesel common rail pipe 1 is greater than that of the methanol common rail pipe 4, the diesel in the diesel common rail pipe 1 enters the diesel interface 621, pushing the plunger 632 to move to the right along the length direction of the valve body 61 and compressing the return spring 631. The plunger 63 2 moves to the front of the methanol outlet 622 and is located in the middle of the sealing seat 633, then the methanol outlet 622 is blocked by the plunger 632, and the methanol in the methanol common rail pipe 4 flows directly to the injector 3; when the pressure of the diesel common rail pipe 1 is lower than that of the methanol common rail pipe 4, the pressure at the diesel interface 621 is low, and the return spring 631 drives the plunger 632 to move to the left along the length direction of the valve body 61 and return to its original position. The plunger 632 moves away from the methanol outlet 622, and the methanol outlet 622 is opened. The methanol in the methanol common rail pipe 4 enters the control valve 6 from the methanol inlet 623 and then flows back to the methanol tank 5 through the methanol outlet 622; when the pressure of the diesel common rail pipe 1 is the same as that of the methanol common rail pipe 4, the plunger 632 remains stationary and is located at the leftmost side of the valve body 61 under the action of the return spring 631.

[0059] As an optional embodiment, in one embodiment of the invention, see Figure 2As shown, the plunger 632 includes: a first valve core 6321 and a second valve core 6322, the front end of the first valve core 6321 is connected to the diesel interface 621, and the rear end of the first valve core 6321 is provided with a moving pin 63211, the first valve core 6321 drives the moving pin 63211 to move, the second valve core 6322 is sleeved on the outside of the first valve core 6321, the middle part of the second valve core 6322 is provided with a sliding groove 63221 and connected to the moving pin 63211, the moving pin 63211 moves in the sliding groove 63221 and pushes the second valve core 6322, when the pressure of the diesel common rail pipe 1 is greater than the pressure of the methanol common rail pipe 4, the diesel in the diesel common rail pipe 1 enters the diesel interface 621, pushing the first valve core 6321 to move to the right side of the valve body 61, and the moving pin 63211 also moves to the right side of the valve body 61 in the sliding groove 63221 until the moving pin 6321 1 moves to the right top end of the slide groove 63221, the moving pin 63211 of the first valve core 6321 further pushes the second valve core 6322 to move to the right to the front end of the methanol outlet 622, and the width of the second valve core 6322 matches the size of the opening in the middle of the sealing seat 633, then the second valve core 6322 moves to the middle of the sealing seat 633 and closes the methanol outlet 622 together with it; when the pressure of the diesel common rail pipe 1 is lower than the pressure of the methanol common rail pipe 4, the return spring 631 drives the first valve core 6321 and the second valve core 6322 to move to the left, then the moving pin 63211 also moves to the left side of the valve body 61 in the slide groove 63221 until the moving pin 63211 moves to the left top end of the slide groove 63221, and the moving pin 63211 further drives the second valve core 6322 away from the methanol outlet 622, and the methanol outlet 622 is opened.

[0060] As an optional embodiment, in one embodiment of the invention, see Figure 2 As shown, the control component 63 also includes: a limit spring 634, which is arranged at the rear end of the first valve core 6321 and located inside the second valve core 6322. Since the limit spring 634 is compressed and deformed under the action of an external force, only when the pressure of the diesel common rail pipe 1 is large, the first valve core 6321 moves to the right to compress the limit spring 634, and then the second valve core 6322 can be further pushed. The limit spring 634 is used to prevent erroneous opening and over-regulation caused by pressure fluctuations between the diesel common rail pipe 1 and the methanol common rail pipe 4.

[0061] As an optional embodiment, in one embodiment of the invention, see Figure 2As shown, the plunger 632 also includes: a sealing ring 635, which is arranged at the top of the first valve core 6321 along the circumferential direction and is located between the first valve core 6321 and the valve body 61. The sealing ring 635 is used to form an effective seal between the first valve core 6321 and the valve body 61 to prevent the diesel on the left side of the first valve core 6321 and the methanol on the right side from leaking, and can also prevent other external impurities from entering the valve body 61.

[0062] As an optional embodiment, in one embodiment of the invention, see Figure 2 As shown, the diesel supply system also includes: a first filter 7 and a high-pressure fuel pump 8, wherein the first end of the first filter 7 is connected to the diesel tank 2, the first end of the high-pressure fuel pump 8 is connected to the second end of the first filter 7, the second end of the high-pressure fuel pump 8 is connected to the diesel common rail pipe 1, and the third end of the high-pressure fuel pump 8 is connected to the diesel tank 2. The first filter 7 is used to filter out harmful impurities from the diesel, so as to extend the service life of the high-pressure fuel pump 8 and the injector 3 with clean diesel. The high-pressure fuel pump 8 is used to transport the diesel in the diesel tank 2 to the diesel common rail pipe 1, and also transport the remaining diesel back to the diesel tank 2.

[0063] As an optional embodiment, in one embodiment of the invention, see Figure 2 As shown, the diesel supply system further includes: a first one-way valve 9, a first end of which is connected to the diesel common rail pipe 1, and a second end of which is connected to the diesel tank 2. The first one-way valve 9 only allows the diesel in the diesel common rail pipe 1 to flow into the diesel tank 2, and prevents the diesel in the diesel tank 2 from flowing into the diesel common rail pipe 1. That is, the first one-way valve 9 is only opened when the pressure in the diesel common rail pipe 1 is high, and allows the remaining diesel in the diesel common rail pipe 1 to flow back to the diesel tank 2 through the first one-way valve 9.

[0064] As an optional embodiment, in one embodiment of the invention, see Figure 2 As shown, the methanol supply system also includes: a second filter 10 and a high-pressure methanol pump 11. The first end of the second filter 10 is connected to the methanol tank 5, the first end of the high-pressure methanol pump 11 is connected to the second end of the second filter 10, the second end of the high-pressure methanol pump 11 is connected to the methanol common rail pipe 4, and the third end of the high-pressure methanol pump 11 is connected to the methanol tank 5. The second filter 10 is used to filter out harmful impurities from methanol to extend the service life of the high-pressure methanol pump 11 and the injector 3 with clean methanol. The high-pressure methanol pump 11 is used to transport the methanol in the methanol tank 5 to the methanol common rail pipe 4, and also transport the remaining methanol back to the methanol tank 5.

[0065] As an optional embodiment, in one embodiment of the invention, see Figure 2 As shown, the methanol supply system further includes: a second one-way valve 12, a first end of the second one-way valve 12 is connected to the methanol common rail pipe 4, and a second end of the second one-way valve 12 is connected to the methanol tank 5. The second one-way valve 12 only allows the methanol in the methanol common rail pipe 4 to flow to the methanol tank 5, and prevents the methanol in the methanol tank 5 from flowing to the methanol common rail pipe 4. That is, the second one-way valve 12 is only opened when the pressure of the methanol common rail pipe 4 is high, and allows the remaining methanol in the methanol common rail pipe 4 to flow back to the methanol tank 5 through the second one-way valve 12.

[0066] As an optional embodiment, in one embodiment of the invention, see Figure 1 As shown, the dual liquid fuel high-pressure direct injection system also includes: a control unit, which is respectively connected to the high-pressure oil pump 8, the high-pressure methanol pump 11 and the injector 3, and is used to control the operation of the high-pressure oil pump 8, the high-pressure methanol pump 11 and the injector 3. When the load needs to be supplied with fuel, the control unit controls the high-pressure oil pump 8, the high-pressure methanol pump 11 and the injector 3 to start, and the high-pressure oil pump 8 and the high-pressure methanol pump 11 respectively deliver diesel and methanol to the injector 3, and inject them to the load through the injector 3.

[0067] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0068] It should be noted that, in the present invention, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0069] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is to be construed in the widest possible manner consistent with the principles and novel features of the present invention.

Claims

1. A dual liquid fuel high pressure direct injection system, characterized in that: include: A diesel supply system, comprising a diesel common rail pipe (1) and a diesel tank (2), wherein the diesel common rail pipe (1) is connected to the diesel tank (2) and a fuel injector (3); A methanol supply system, comprising a methanol common rail pipe (4) and a methanol tank (5), wherein the methanol common rail pipe (4) is connected to the methanol tank (5) and the injector (3); A control valve (6) is connected to the diesel common rail pipe (1), the methanol common rail pipe (4) and the methanol tank (5), and is configured as follows: When the pressure of the diesel common rail pipe (1) is lower than that of the methanol common rail pipe (4), most of the methanol in the methanol common rail pipe (4) is refluxed to the methanol tank (5); The control valve (6) comprises: Valve body (61); An interface component (62), the interface component (62) comprising a diesel interface (621), a methanol outlet (622), and a methanol inlet (623), the diesel interface (621) being located at the front end of the valve body (61) and connected to the diesel common rail pipe (1), the methanol outlet (622) being located at the rear end of the valve body (61) and connected to the methanol tank (5), and the methanol inlet (623) being located at the lower end of the valve body (61) and connected to the methanol common rail pipe (4); a control assembly (63), the control assembly (63) being arranged in the valve body (61), one end of the control assembly (63) being connected to the diesel interface (621), and the other end being located at the front end of the methanol outlet (622), for allowing the methanol outlet (622) to be opened when the pressure of the diesel common rail pipe (1) is lower than that of the methanol common rail pipe (4), so that most of the methanol in the methanol common rail pipe (4) flows back to the methanol tank (5) through the methanol inlet (623) and the methanol outlet (622); The control component (63) includes: a return spring (631), the return spring (631) being arranged in the valve body (61) along a horizontal direction; a plunger (632), the plunger (632) passing through the return spring (631), and the plunger (632) being slidable along the length direction of the return spring (631), the front end of the plunger (632) being the diesel interface (621), and the rear end of the plunger (632) being the methanol outlet (622); A sealing seat (633) is provided at the rear end of the plunger (632) and fixed in the valve body (61); the sealing seat (633) cooperates with the plunger (632) to control the opening and closing of the methanol outlet (622).

2. The dual liquid fuel high pressure direct injection system according to claim 1, characterized in that: The plunger (632) comprises: A first valve core (6321), wherein the front end of the first valve core (6321) is connected to the diesel interface (621), and a movable pin (63211) is provided at the rear end of the first valve core (6321), and the first valve core (6321) drives the movable pin (63211) to move; The second valve core (6322) is sleeved on the outside of the first valve core (6321), and a sliding groove (63221) is provided in the middle of the second valve core (6322) and is connected to the movable pin (63211). The movable pin (63211) moves in the sliding groove (63221) and pushes the second valve core (6322).

3. The dual liquid fuel high pressure direct injection system according to claim 2, characterized in that: The control component (63) further includes: A limit spring (634), the limit spring (634) is arranged at the rear end of the first valve core (6321) and is located inside the second valve core (6322).

4. The dual liquid fuel high pressure direct injection system according to claim 1, characterized in that: The diesel supply system further comprises: a first filter (7), wherein a first end of the first filter (7) is connected to the diesel tank (2); A high-pressure oil pump (8), wherein a first end of the high-pressure oil pump (8) is connected to a second end of the first filter (7), a second end of the high-pressure oil pump (8) is connected to the diesel common rail pipe (1), and a third end of the high-pressure oil pump (8) is connected to the diesel tank (2).

5. The dual liquid fuel high pressure direct injection system according to claim 4, characterized in that: The diesel supply system further comprises: A first one-way valve (9), wherein a first end of the first one-way valve (9) is connected to the diesel common rail pipe (1), and a second end of the first one-way valve (9) is connected to the diesel tank (2).

6. The dual liquid fuel high pressure direct injection system according to claim 5, characterized in that: The methanol supply system further comprises: a second filter (10), wherein a first end of the second filter (10) is connected to the methanol tank (5); A high-pressure methanol pump (11), wherein a first end of the high-pressure methanol pump (11) is connected to a second end of the second filter (10), a second end of the high-pressure methanol pump (11) is connected to the methanol common rail pipe (4), and a third end of the high-pressure methanol pump (11) is connected to the methanol tank (5).

7. The dual liquid fuel high pressure direct injection system according to claim 6, characterized in that: The methanol supply system further comprises: A second one-way valve (12), wherein a first end of the second one-way valve (12) is connected to the methanol common rail pipe (4), and a second end of the second one-way valve (12) is connected to the methanol tank (5).

8. The dual liquid fuel high pressure direct injection system according to claim 7, characterized in that: Also includes: A control unit is connected to the high-pressure oil pump (8), the high-pressure methanol pump (11) and the injector (3) respectively, and is used to control the operation of the high-pressure oil pump (8), the high-pressure methanol pump (11) and the injector (3).

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