Methanol-diesel composite injector with temperature adjustment and variable spray holes

Abstract

The invention discloses a methanol-diesel composite injector with temperature adjustment and variable spray hole, including a methanol injection unit, a diesel injection unit, a methanol preheating unit, a methanol switching unit and a spray hole cover, wherein the methanol injection unit includes a methanol needle valve body, a methanol electromagnetic coil, a methanol needle valve return spring, a methanol needle valve armature and a methanol needle valve, and the diesel injection unit includes a diesel needle valve body, a diesel electromagnetic coil, a diesel needle valve return spring, a diesel needle valve armature and a diesel needle valve. The methanol preheating unit is located at the top of the methanol-diesel composite injector, including a methanol fuel preheater upper end cover, a methanol fuel preheater housing and a methanol fuel preheating resistance wire. The methanol switching unit is located between the methanol preheating unit and the methanol injection unit, including a switching unit body, a switching unit upper cover, a switching unit turntable and a switching mechanism. The invention is convenient for switching between methanol and diesel, and methanol burns fully, which significantly improves the atomization characteristics of methanol fuel in the invention.

Description

Technical Field

[0001] The invention relates to a methanol-diesel composite fuel injector for a marine dual-fuel engine, in particular to a methanol-diesel composite fuel injector capable of making methanol fuel burn more completely and improving the atomization characteristics of methanol fuel, belonging to the technical field of dual-fuel engines. Background Art

[0002] Marine dual-fuel engines use petroleum products such as diesel and heavy oil as fuel, and their high NOx, SOx and PM emissions have led to the continuous deterioration of the environment in ports and coastal cities. The research results show that the use of dual-fuel direct injection technology can not only reduce the dependence of diesel engines on petroleum energy, but also greatly reduce pollutant emissions, effectively responding to more stringent emission regulations.

[0003] At present, the fuels for dual-fuel diesel engines are mainly LNG and alcohol-based fuels, among which alcohol-based fuels are mainly methanol fuel. Compared with LNG fuel, methanol fuel has the advantages of easy storage, low emissions and high energy efficiency, so it has received much attention. The fuels for marine dual-fuel engines are mainly alcohol-based fuels, mainly methanol fuel. Methanol fuel has the advantages of easy storage, low emissions and high energy efficiency, but when methanol fuel is directly injected into the cylinder, the vaporization heat absorption will lead to starting difficulties, incomplete combustion will produce formaldehyde and unburned methanol emissions. Therefore, how to solve the problems of starting difficulties caused by vaporization heat absorption caused by direct injection in the cylinder, and the production of formaldehyde and unburned methanol caused by incomplete combustion has become a technical difficulty for methanol-diesel dual-fuel composite injectors. Summary of the invention

[0004] The purpose of the present invention is to provide a methanol-diesel composite injector with temperature adjustment and variable spray holes, change the atomization characteristics of methanol fuel, achieve full combustion of methanol fuel in a methanol-diesel dual-fuel engine, improve starting difficulties, change the atomization characteristics of methanol fuel, and thus achieve full combustion of methanol fuel in a methanol-diesel dual-fuel engine.

[0005] The present invention is achieved through the following technical solutions:

[0006] A methanol-diesel composite injector with temperature adjustment and variable spray hole, comprising a methanol injection unit, a diesel injection unit, a methanol preheating unit, a methanol switching unit and a spray hole cover, wherein the methanol injection unit comprises a methanol needle valve body, a methanol electromagnetic coil, a methanol needle valve return spring, a methanol needle valve armature and a methanol needle valve, and the diesel injection unit comprises a diesel needle valve body, a diesel electromagnetic coil, a diesel needle valve return spring, a diesel needle valve armature and a diesel needle valve, wherein the methanol needle valve body and the diesel needle valve body are fixedly connected up and down and are embedded with a high-pressure alcohol-resistant sealing gasket; the methanol needle valve armature is fixed on the top of the methanol needle valve and is located in the lower part of the top chamber of the methanol needle valve body; the methanol electromagnetic coil is located in the methanol In the top chamber of the needle valve body, the methanol needle valve return spring sleeve is arranged outside the upper part of the methanol needle valve body; the diesel needle valve armature is fixed on the top of the diesel needle valve and is located in the lower part of the top chamber of the diesel needle valve body, and the inner hole of the diesel needle valve armature and the inner hole of the diesel needle valve are respectively matched with the clearance of the lower sleeve of the methanol needle valve body; the top chamber of the diesel needle valve body is located at the lower side of the top chamber of the methanol needle valve body, the diesel needle valve return spring and the diesel needle valve armature are respectively located in the top chamber of the diesel needle valve body, and the diesel needle valve return spring sleeve is arranged outside the lower sleeve of the methanol needle valve body; the diesel needle valve is embedded between the inner hole of the diesel needle valve body and the lower sleeve of the methanol needle valve body, and the diesel needle valve and the lower sleeve of the methanol needle valve body are matched with clearance.

[0007] The methanol preheating unit is located at the top of the methanol-diesel composite injector, and includes a methanol fuel preheater upper end cover, a methanol fuel preheater shell and a methanol fuel preheating resistance wire; a vertically upward center sleeve is provided in the cylindrical methanol fuel preheater shell, and a spiral methanol fuel preheating resistance wire is sleeved on the center sleeve; the lower flange of the methanol fuel preheater upper end cover is embedded in the upper end of the methanol fuel preheater shell, and a high-pressure alcohol-resistant upper sealing gasket is embedded between the lower side of the methanol fuel preheater upper end cover and the upper side of the outer edge of the methanol fuel preheater shell, the methanol fuel preheater upper end cover is fixed on the top of the methanol fuel preheater shell, and the methanol fuel oil inlet hole passes through the center of the methanol fuel preheater upper end cover and the center sleeve from top to bottom; the diesel needle valve is embedded between the inner hole of the diesel needle valve body and the lower sleeve of the methanol needle valve body, and the diesel needle valve and the diesel needle valve body are clearance-matched.

[0008] The methanol switching unit is located between the methanol preheating unit and the methanol injection unit, and includes a switching unit body, a switching unit upper cover, a switching unit turntable and a switching mechanism. The upper end of the switching unit body is a cylinder, and a methanol delivery rod extends downward from the center of the lower end of the cylinder. The methanol delivery rod is evenly distributed with two groups of multiple methanol axial delivery holes. The lower end of the methanol needle valve armature and the methanol needle valve are nested between the lower shaft sleeve of the methanol needle valve body and the methanol delivery rod, and are respectively matched with the methanol needle valve body and the methanol delivery rod; the switching unit turntable is embedded in the cylinder and is matched with the cylinder; the switching unit upper cover is fixed between the bottom of the methanol fuel preheater shell and the top of the cylinder, the bottom of the cylinder and the top of the methanol needle valve body are fixedly connected, and the upper and lower sides of the switching unit upper cover are respectively embedded with high-pressure alcohol-resistant sealing gaskets.

[0009] The switching mechanism is arranged between the methanol fuel preheater housing, the switching unit upper cover and the switching unit turntable, and the spray hole cover is fixed on the bottom surface of the diesel needle valve body and the bottom surface of the methanol delivery rod; the switching unit upper cover and the spray hole cover are respectively provided with two groups of switching unit upper cover methanol delivery holes and two groups of spray hole cover methanol delivery holes corresponding to the axial methanol delivery hole positions of the methanol delivery rod, and the switching unit turntable is provided with a circle of several switching unit turntable methanol delivery holes; the spray hole cover is fixed on the diesel needle valve body and the lower end head of the methanol delivery rod.

[0010] The switching mechanism includes a two-position four-way electromagnetic reversing valve, a first hydraulic oil channel and a second hydraulic oil channel symmetrically arranged on both sides of the methanol fuel preheater shell, as well as an arc-shaped oil channel on the upper end face of the upper cover of the switching unit, an arc-shaped oil channel on the upper end face of the cylinder, arc-shaped notches on both radial sides of the switching unit turntable, and fan-shaped dividing blocks on both radial sides of the inner hole of the cylinder, wherein the fan-shaped dividing blocks are respectively embedded in the corresponding arc-shaped notches to divide the arc-shaped notches on both radial sides of the switching unit turntable into a first cavity and a second cavity, as well as a third cavity and a fourth cavity arranged clockwise.

[0011] The purpose of the present invention can be further achieved by the following technical measures.

[0012] Furthermore, the first hydraulic oil channel and the second hydraulic oil channel are symmetrical L-shaped, and the upper ends of the L-shaped channels respectively cross the outer peripheral surface of the methanol fuel preheater shell, the upper end of the first hydraulic oil channel is connected to the first port of the two-position four-way electromagnetic reversing valve through a connecting pipe, and the upper end of the second hydraulic oil channel is connected to the second port of the two-position four-way electromagnetic reversing valve through a connecting pipe, the third port of the two-position four-way electromagnetic reversing valve leads to the oil tank, and the fourth port leads to the hydraulic power source; the lower end of the first hydraulic oil channel passes through the bottom surface of the methanol fuel preheater shell, and is connected to the first cavity through the first through hole of the upper cover of the switching unit, and the first cavity is connected to the third cavity through the arc-shaped oil channel on the upper end surface of the cylinder; the lower end of the second hydraulic oil channel passes through the bottom surface of the methanol fuel preheater shell, and is connected to the second cavity through the second through hole of the upper cover of the switching unit, and the second cavity is connected to the fourth cavity through the arc-shaped oil channel on the upper cover of the switching unit.

[0013] Furthermore, the upper cover of the switching unit, the methanol delivery rod and the spray hole cover are respectively provided with two groups of methanol delivery holes of equal number, and the two groups of methanol delivery holes are evenly distributed on the same center circle, wherein the aperture of the first group of methanol delivery holes is larger than the aperture of the second group of methanol delivery holes, the center angle α of the first group of methanol delivery holes and the adjacent second group of methanol delivery holes is equal, and the rotation angle β of the arc notch is equal to the center angle α.

[0014] Furthermore, the spray hole cover is evenly distributed with two groups of first group methanol spray holes and second group methanol spray holes, which are equal in number and correspond to the two groups of methanol delivery holes on the upper cover of the switching unit and the methanol delivery rod, and several diesel spray holes corresponding to the corresponding holes of the lower shaft sleeve of the methanol needle valve body, and the central circle diameter Φ1 of the diesel spray hole distribution is greater than the central circle diameter Φ2 of the two groups of methanol spray holes distribution;

[0015] The directions of multiple methanol spray holes on the spray hole cover are inclined toward the outer edge of the spray hole cover, and the directions of several diesel spray holes are inclined toward the center of the spray hole cover; the lower end of the methanol delivery rod and the lower end of the methanol needle valve are provided with a methanol delivery on-off mechanism, and the lower end of the lower sleeve of the methanol valve body, the lower end of the diesel needle valve and the lower end of the diesel needle valve body are provided with a diesel injection on-off mechanism.

[0016] Furthermore, the methanol delivery on-off mechanism includes several radial holes evenly distributed at the lower end of the methanol delivery rod and several inverted L-shaped holes communicating with the end face of the lower end of the methanol delivery rod, the radial holes are respectively communicated with the corresponding axial methanol delivery holes; the horizontal holes at the upper end of the inverted L-shaped holes are respectively communicated with the outer peripheral surface of the methanol delivery rod, the horizontal holes are located at the lower side of the radial holes, and the vertical holes at the lower end of the inverted L-shaped holes are respectively communicated with the corresponding methanol spray holes on the spray hole cover; it also includes several C-shaped holes evenly distributed at the lower end of the inner side of the methanol needle valve, the upper and lower ends of the C-shaped holes correspond to the positions of the radial holes and the horizontal holes at the upper end of the inverted L-shaped holes, and the distance A1 between the center of the upper end of the C-shaped hole and the center of the radial hole is equal to the distance A2 between the center of the lower end of the C-shaped hole and the center of the horizontal hole at the upper end of the inverted L-shaped hole.

[0017] Furthermore, the diesel injection on-off mechanism includes a diesel needle valve body conical hole arranged at the bottom of the inner hole of the diesel needle valve body, a conical surface at the bottom of the diesel needle valve, and an inverted L-shaped hole at the bottom of the lower sleeve of the methanol valve body. The diesel needle valve body conical hole matches the conical surface at the bottom of the diesel needle valve, and the upper end of the bottom inverted L-shaped hole of the lower sleeve of the methanol valve body matches the bottom position of the diesel needle valve body conical hole.

[0018] The methanol fuel preheating unit of the present invention adopts a methanol fuel preheating resistor wire to preheat the methanol fuel, which reduces the heat absorption of methanol direct injection vaporization in the cylinder, making the methanol fuel burn more fully. The methanol switching unit adopts the switching of a two-position four-way electromagnetic reversing valve, and the hydraulic oil drives the switching unit turntable to rotate to achieve the switching of two groups of methanol delivery holes with different apertures, thereby achieving the change of the methanol delivery flow rate and improving the atomization characteristics of the methanol fuel. The methanol needle valve and the methanol fuel are isolated and arranged, which reduces the contact area between the needle valve and the methanol fuel and improves the corrosion resistance of the methanol needle valve. The present invention has a compact structure, fast startup, and convenient switching between methanol and diesel; the methanol burns fully, which significantly improves the atomization characteristics of the methanol fuel in the present invention.

[0019] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments thereof, which are given by way of example only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 yes Figure 1 AA section enlarged view;

[0022] Figure 3 It is a stereogram of the switching unit turntable;

[0023] Figure 4 is a stereoscopic view of the switching unit turntable installed in the upper end of the switching unit body;

[0024] Figure 5 yes Figure 1 A magnified view of part I;

[0025] Figure 6 yes Figure 1 The enlarged view of part II;

[0026] Figure 7 It is an enlarged front view of the nozzle cover. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0028] In the description of the present invention, terms indicating orientation or positional relationship such as "up", "down", "left", "right", "inside" and "outside" are based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the device referred to must have a specific orientation.

[0029] like Figure 1 to Figure 7 As shown, this embodiment includes a methanol injection unit 1, a diesel injection unit 2, a methanol preheating unit 3, a methanol switching unit 4 and a spray hole cover 5. The methanol injection unit 1 includes a methanol needle valve body 11, a methanol electromagnetic coil 12, a methanol needle valve return spring 13, a methanol needle valve armature 14 and a methanol needle valve 15. The diesel injection unit 2 includes a diesel needle valve body 21, a diesel electromagnetic coil 22, a diesel needle valve return spring 23, a diesel needle valve armature 24 and a diesel needle valve 25. The methanol needle valve body 11 and the diesel needle valve body 21 are fixedly connected by threads at the top and bottom. The methanol needle valve armature 14 is fixed on the top of the methanol needle valve 15 and is located in the lower part of the top chamber 111 of the methanol needle valve body. The methanol electromagnetic coil 12 is located in the top chamber 111 of the methanol needle valve body, and the methanol needle valve return spring 13 is sleeved outside the upper part of the methanol needle valve body 11. The lower end of the methanol needle valve armature 14 and the methanol needle valve 15 are nested between the lower shaft sleeve 112 of the methanol needle valve body and the methanol delivery rod 412, and are clearance-matched with the methanol needle valve body 11 and the methanol delivery rod 412 respectively.

[0030] The diesel needle valve armature 24 is fixed on the top of the diesel needle valve 25 and is located in the lower part of the top chamber 211 of the diesel needle valve body. The inner hole of the diesel needle valve armature 24 and the inner hole of the diesel needle valve 25 are respectively matched with the lower shaft sleeve 112 of the methanol needle valve body. The top chamber 211 of the diesel needle valve body is located at the lower side of the top chamber 111 of the methanol needle valve body. The diesel needle valve return spring 23 and the diesel needle valve armature 24 are respectively located in the top chamber 211 of the diesel needle valve body. The diesel needle valve return spring 25 is sleeved outside the lower shaft sleeve 112 of the methanol needle valve body. The diesel needle valve 25 is embedded between the inner hole of the diesel needle valve body 21 and the lower shaft sleeve 112 of the methanol needle valve body. The diesel needle valve 25 is matched with the lower shaft sleeve 112 of the methanol needle valve body.

[0031] The methanol preheating unit 3 is located at the top of the present embodiment, and includes a methanol fuel preheater upper end cover 31, a methanol fuel preheater shell 32 and a methanol fuel preheating resistance wire 33. A vertically upward central sleeve 321 is provided in the cylindrical methanol fuel preheater shell 32, and the spiral methanol fuel preheating resistance wire 33 is sleeved on the central sleeve 321. The lower flange of the methanol fuel preheater upper end cover 31 is embedded in the upper end of the methanol fuel preheater shell 32, and a high-pressure alcohol-resistant upper sealing gasket 34 is embedded between the lower side of the methanol fuel preheater upper end cover 31 and the upper side of the outer edge of the methanol fuel preheater shell 32. The methanol fuel preheater upper end cover 31 is fixed to the top of the methanol fuel preheater shell 32 by 6 screws 311, and the methanol fuel oil inlet hole 312 runs through the center of the methanol fuel preheater upper end cover 31 and the central sleeve 321 from top to bottom.

[0032] The methanol switching unit 4 is located between the methanol preheating unit 3 and the methanol injection unit 1, and includes a switching unit body 41, a switching unit upper cover 42, a switching unit turntable 43 and a switching mechanism 44. The upper end of the switching unit body 41 is a cylindrical body 411, and a methanol delivery rod 412 extends downward from the lower end center of the cylindrical body 411. The methanol delivery rod 412 is evenly distributed with two groups of multiple methanol axial delivery holes. The switching unit turntable 43 is embedded in the cylindrical body 411 and has a clearance fit with the cylindrical body 411. The switching unit upper cover 42 is fixed between the bottom of the methanol fuel preheater housing 32 and the top of the cylindrical body 411 by 6 upper screws 45. The bottom of the cylindrical body 411 and the top of the methanol needle valve body 11 are fixedly connected by 6 lower screws 46. The upper and lower sides of the switching unit upper cover 42 are respectively embedded with medium and high pressure alcohol resistant sealing gaskets 47.

[0033] The switching mechanism 44 is arranged between the methanol fuel preheater housing 32, the switching unit upper cover 42 and the switching unit turntable 43. The spray hole cover 5 is fixed to the bottom surface of the diesel needle valve body 21 and the bottom surface of the methanol delivery rod 412 by 7 lower screws 51, and is embedded with a high-pressure alcohol-resistant lower sealing gasket 45. The switching unit upper cover 42 and the spray hole cover 5 are respectively provided with two groups of 6 switching unit upper cover methanol delivery holes 421 and two groups of 6 spray hole cover methanol delivery holes 52 corresponding to the position of the axial methanol delivery hole 4121 of the methanol delivery rod 412, and the switching unit turntable 43 is provided with a circle of 6 switching unit turntable methanol delivery holes 431.

[0034] The switching mechanism 44 includes a two-position four-way electromagnetic reversing valve 441, a first hydraulic oil channel 442 and a second hydraulic oil channel 443 symmetrically arranged on both sides of the methanol fuel preheater shell 32, as well as an arc-shaped oil channel 444 on the upper end face of the upper cover of the switching unit, an arc-shaped oil channel 445 on the upper end face of the cylinder, concave arc-shaped notches 432 respectively provided on both radial sides of the switching unit turntable 43, and fan-shaped dividing blocks 413 respectively provided on both radial sides of the inner hole of the cylinder 411, the fan-shaped dividing blocks 413 are respectively embedded in the corresponding arc-shaped notches 432, dividing the arc-shaped notches 432 on both radial sides of the switching unit turntable 43 into a first cavity 4321 and a second cavity 4322, as well as a third cavity 4323 and a fourth cavity 4324 arranged clockwise.

[0035] The upper cover 42 of the switching unit, the methanol delivery rod 412 and the spray hole cover 5 are respectively provided with two groups of 6 methanol delivery holes, and the two groups of methanol delivery holes are evenly distributed on the same center circle, wherein the aperture of the first group of methanol delivery holes 421 is larger than the aperture of the second group of methanol delivery holes 422, the center angle α of the first group of methanol delivery holes 421 and the adjacent second group of methanol delivery holes 422 is equal, and the rotation angle β of the arc notch 432 is equal to the center angle α, such a structure ensures that when the switching unit turntable 43 rotates by an angle β, the switching of the two groups of methanol delivery holes with different apertures can be completed, thereby realizing the adjustment of the methanol injection flow rate.

[0036] The first hydraulic oil passage 442 and the second hydraulic oil passage 443 are symmetrical L-shaped, and the upper ends of the L-shaped ... The lower end of the second hydraulic oil passage 443 passes through the bottom surface of the methanol fuel preheater shell 32 and communicates with the second cavity 4322 through the second through hole 47 of the upper cover of the switching unit. The second cavity 4322 communicates with the fourth cavity 4324 through the arc oil passage 444 of the upper cover of the switching unit.

[0037] The spray hole cover 5 is evenly distributed with two groups of six first groups of methanol spray holes 52 and six second groups of methanol spray holes 53 corresponding to the two groups of methanol delivery holes of the switching unit upper cover 42 and the methanol delivery rod 412, and six diesel spray holes 54 corresponding to the corresponding holes of the lower sleeve 112 of the methanol needle valve body. The center circle diameter Φ1 of the diesel spray hole distribution is larger than the center circle diameter Φ2 of the two groups of methanol delivery holes.

[0038] The six first group methanol spray holes 52 and the six second group methanol spray holes 53 on the spray hole cover 5 are inclined toward the outer edge of the spray hole cover 5, and the six diesel spray holes 54 are inclined toward the center of the spray hole cover 5. The lower end of the methanol delivery rod 412 and the lower end of the methanol needle valve 15 are provided with a methanol delivery on-off mechanism 55, and the lower end of the lower shaft sleeve 112 of the methanol valve body, the lower end of the diesel needle valve 25 and the lower end of the diesel needle valve body 21 are provided with a diesel spray hole on-off mechanism 56.

[0039] The methanol delivery on-off mechanism 55 includes a plurality of radial holes 551 evenly distributed at the lower end of the methanol delivery rod 412 and a plurality of inverted L-shaped holes 552 communicating with the end surface of the lower end of the methanol delivery rod. The radial holes 551 are respectively communicated with the corresponding axial methanol delivery holes 4121. The horizontal holes 5521 at the upper ends of the inverted L-shaped holes 552 are respectively communicated with the outer peripheral surface of the methanol delivery rod 412. The horizontal holes 5521 are located at the lower side of the radial holes 551. The vertical holes 5522 at the lower ends of the inverted L-shaped holes 552 are respectively communicated with the corresponding methanol spray holes 52 on the spray hole cover 5. It also includes several C-shaped holes 251 evenly distributed at the lower end of the inner side of the methanol needle valve 25, the upper and lower ends of the C-shaped hole 251 correspond to the radial hole 551 and the horizontal hole 5521 at the upper end of the inverted L-shaped hole 552, and the distance A1 between the center of the upper end of the C-shaped hole 251 and the center of the radial hole 551 is equal to the distance A2 between the center of the lower end of the C-shaped hole 251 and the horizontal hole 5521 at the upper end of the inverted L-shaped hole 552. Such a structure facilitates the opening and closing of the methanol delivery on-off mechanism 55.

[0040] The diesel injection on-off mechanism 56 includes a diesel needle valve body conical hole 211 arranged at the bottom of the inner hole of the diesel needle valve body 21, a conical surface 252 at the bottom of the diesel needle valve, and an inverted L-shaped hole 1121 of the methanol needle valve at the bottom of the lower sleeve 112 of the methanol valve body. The diesel needle valve body conical hole 211 matches the bottom conical surface of the diesel needle 25, and the upper end of the inverted L-shaped hole 1121 of the methanol needle valve matches the bottom position of the diesel needle valve body conical hole 211. Such a structure facilitates the opening and closing of the diesel injection hole on-off mechanism 56.

[0041] The working process of the switching mechanism 44 is as follows:

[0042] When the hydraulic control unit (HCU) receives the signal from the dual-fuel engine electronic control unit (ECU) that the methanol injection is switched to the second group of methanol injection holes 53, the methanol injection unit 1 stops working, the electromagnet of the two-position four-way solenoid reversing valve 441 is energized, the valve core moves from the left to the right position, and the oil inlet path of the pressure oil output by the hydraulic power source 446 is as follows: pressure oil output by the hydraulic power source 446 - the fourth port 4414 of the two-position four-way solenoid reversing valve 441 - the connecting pipe 447 - the first hydraulic oil channel 442 - the first through hole 46 on the upper cover of the switching unit - the first radial cavity 4321 of the switching unit turntable 43 - the arc-shaped oil channel 445 on the upper end surface of the cylinder - the third radial cavity 4323 of the switching unit turntable 43 - push the switching unit turntable 43 to rotate clockwise.

[0043] The oil return path is as follows: the fourth radial cavity 4324 of the switching unit turntable 43 - the arc-shaped oil passage 444 on the upper end face of the switching unit upper cover - the second radial cavity 4322 of the switching unit turntable 43 - the second through hole 47 of the switching unit upper cover - the second hydraulic oil passage 443 - the connecting pipe 447 - the fourth port 4414 of the two-position four-way solenoid reversing valve 441 - the oil return tank 445, thereby pushing the switching unit turntable 43 to rotate clockwise by an angle β until one side of the arc-shaped notch 432 abuts against one side of the fan-shaped dividing block 413. At this time, the second group of methanol delivery holes 422 rotate to the position of the previous first group of methanol delivery holes 421, respectively, completing the switching of the two groups of methanol delivery holes with different apertures, thereby realizing the adjustment of the methanol injection flow rate.

[0044] The working processes of the methanol delivery on-off mechanism 55 and the diesel injection on-off mechanism 56 are respectively as follows:

[0045] When the dual-fuel engine electronic control unit (ECU) commands to switch to the methanol injection mode, the diesel injection unit 2 stops working and the methanol injection unit 1 is ready to start working. The methanol delivery on-off mechanism 55 is started, and the electromagnetic force generated by the methanol electromagnetic coil 12 is energized to make the methanol needle valve armature 14 overcome the elastic force of the methanol needle valve return spring 13 to drive the methanol needle valve 15 to move up a distance A1, so that the several radial holes 551 at the lower end of the methanol delivery rod 412 are connected to the inverted L-shaped hole 552 and the six first group of methanol injection holes 52 or the six second group of methanol injection holes 53 on the injection hole cover 5 through the several C-shaped holes 251 in sequence, so that the injection of methanol can be realized.

[0046] When the dual-fuel engine electronic control unit (ECU) commands to switch to the diesel injection mode, the methanol injection unit 1 stops working and the diesel injection unit 2 is ready to start working. The electromagnetic force generated by the diesel electromagnetic coil 22 makes the diesel needle valve armature 24 overcome the elastic force of the diesel needle valve return spring 23 to drive the diesel needle valve 25 to move upward, and the bottom cone surface 252 of the diesel needle valve is separated from the cone hole 211 of the diesel needle valve body. The cone hole 211 of the diesel needle valve body is connected with the six diesel injection holes 54 on the injection hole cover 5 through the inverted L-shaped hole 1121 of the methanol needle valve, so that the injection of diesel can be realized.

[0047] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A methanol-diesel composite injector with temperature adjustment and variable spray hole, comprising a methanol injection unit and a diesel injection unit, wherein the methanol injection unit comprises a methanol needle valve body, a methanol electromagnetic coil, a methanol needle valve return spring, a methanol needle valve armature and a methanol needle valve, and the diesel injection unit comprises a diesel needle valve body, a diesel electromagnetic coil, a diesel needle valve return spring, a diesel needle valve armature and a diesel needle valve, wherein the methanol needle valve body and the diesel needle valve body are fixedly connected up and down; the methanol needle valve armature is fixed on the top of the methanol needle valve and is located in the lower part of the top chamber of the methanol needle valve body; the methanol electromagnetic coil is located at the top of the methanol needle valve body The diesel needle valve armature is fixed on the top of the diesel needle valve and is located in the lower part of the top chamber of the diesel needle valve body. The inner hole of the diesel needle valve armature and the inner hole of the diesel needle valve are respectively matched with the clearance of the lower shaft sleeve of the methanol needle valve body; the top chamber of the diesel needle valve body is located at the lower side of the top chamber of the methanol needle valve body, the diesel needle valve return spring and the diesel needle valve armature are respectively located in the top chamber of the diesel needle valve body, and the diesel needle valve return spring sleeve is arranged outside the lower shaft sleeve of the methanol needle valve body; the diesel needle valve is embedded between the inner hole of the diesel needle valve body and the lower shaft sleeve of the methanol needle valve body, and the diesel needle valve and the lower shaft sleeve of the methanol needle valve body are matched with clearance; It is characterized in that It also includes a methanol preheating unit, a methanol switching unit and a spray hole cover. The methanol preheating unit is located at the top of the methanol-diesel composite injector, including a methanol fuel preheater upper cover, a methanol fuel preheater shell and a methanol fuel preheating resistance wire; a vertically upward center sleeve is provided in the cylindrical methanol fuel preheater shell, and a spiral methanol fuel preheating resistance wire is sleeved on the center sleeve; the lower flange of the methanol fuel preheater upper cover is embedded in the upper end of the methanol fuel preheater shell, and a high-pressure alcohol-resistant upper sealing gasket is embedded between the lower side of the methanol fuel preheater upper cover and the upper side of the outer edge of the methanol fuel preheater shell. The methanol fuel preheater upper cover is fixed on the top of the methanol fuel preheater shell, and the methanol fuel oil inlet hole runs through the center of the methanol fuel preheater upper cover and the center sleeve from top to bottom; methanol The switching unit is located between the methanol preheating unit and the methanol injection unit, and includes a switching unit body, a switching unit upper cover, a switching unit turntable and a switching mechanism. The upper end of the switching unit body is a cylinder, and a methanol delivery rod extends downward from the center of the lower end of the cylinder. The methanol delivery rod is evenly distributed with two groups of multiple methanol axial delivery holes. The lower end of the methanol needle valve armature and the methanol needle valve are nested between the lower shaft sleeve of the methanol needle valve body and the methanol delivery rod, and are respectively matched with the methanol needle valve body and the methanol delivery rod; the switching unit turntable is embedded in the cylinder and is matched with the cylinder; the switching unit upper cover is fixed between the bottom of the methanol fuel preheater shell and the top of the cylinder, the bottom of the cylinder and the top of the methanol needle valve body are fixedly connected, and the upper and lower sides of the switching unit upper cover are respectively embedded with high-pressure alcohol-resistant sealing gaskets; The switching mechanism is arranged between the housing of the methanol fuel preheater, the upper cover of the switching unit and the switch unit turntable. The spray hole cover is fixed on the bottom surface of the diesel needle valve body and the bottom surface of the methanol delivery rod. A high-pressure alcohol-resistant lower sealing gasket is embedded on the upper side of the spray hole cover. The upper cover of the switching unit and the spray hole cover are respectively provided with two groups of methanol delivery holes of the upper cover of the switching unit and two groups of methanol delivery holes of the spray hole cover corresponding to the axial methanol delivery hole position of the methanol delivery rod. The switch unit turntable is provided with a circle of several methanol delivery holes of the switch unit turntable. The switching mechanism includes a two-position four-way electromagnetic reversing valve, a first hydraulic oil channel and a second hydraulic oil channel symmetrically arranged on both sides of the methanol fuel preheater shell, an arc-shaped oil channel on the upper end face of the upper cover of the switching unit, an arc-shaped oil channel on the upper end face of the cylinder, arc-shaped notches concave on both sides of the radial direction of the switching unit turntable, and fan-shaped dividing blocks located on both sides of the radial direction of the hole in the cylinder, the fan-shaped dividing blocks are respectively embedded in the corresponding arc-shaped notches, and the arc-shaped notches on both sides of the radial direction of the switching unit turntable are divided into a first cavity and a second cavity, as well as a third cavity and a fourth cavity arranged clockwise.

2. The methanol-diesel composite fuel injector with temperature adjustment and variable spray holes as claimed in claim 1, It is characterized in that The first hydraulic oil channel and the second hydraulic oil channel are symmetrical L-shaped, and the upper ends of the L-shaped channels respectively cross the outer peripheral surface of the methanol fuel preheater shell. The upper end of the first hydraulic oil channel is connected to the first port of the two-position four-way electromagnetic reversing valve through a connecting pipe, and the upper end of the second hydraulic oil channel is connected to the second port of the two-position four-way electromagnetic reversing valve through a connecting pipe. The third port of the two-position four-way electromagnetic reversing valve leads to the oil tank, and the fourth port leads to the hydraulic power source; the lower end of the first hydraulic oil channel passes through the bottom surface of the methanol fuel preheater shell, and is connected to the first cavity through the first through hole of the upper cover of the switching unit, and the first cavity is connected to the third cavity through the arc-shaped oil channel on the upper end surface of the cylinder; the lower end of the second hydraulic oil channel passes through the bottom surface of the methanol fuel preheater shell, and is connected to the second cavity through the second through hole of the upper cover of the switching unit, and the second cavity is connected to the fourth cavity through the arc-shaped oil channel on the upper cover of the switching unit.

3. The methanol-diesel composite injector with temperature adjustment and variable spray holes as claimed in claim 1, It is characterized in that The upper cover of the switching unit, the methanol delivery rod and the spray hole cover are respectively provided with two groups of methanol delivery holes of equal number, and the two groups of methanol delivery holes are evenly distributed on the same center circle, wherein the aperture of the first group of methanol delivery holes is larger than the aperture of the second group of methanol delivery holes, the center angle α of the first group of methanol delivery holes and the adjacent second group of methanol delivery holes is equal, and the rotation angle β of the arc notch is equal to the center angle α.

4. The methanol-diesel composite fuel injector with temperature adjustment and variable spray holes as claimed in claim 3, It is characterized in that The spray hole cover is evenly distributed with two groups of first group methanol spray holes and second group methanol spray holes, which are equal in number and correspond to the two groups of methanol delivery holes on the upper cover of the switching unit and the methanol delivery rod, and several diesel spray holes corresponding to the corresponding holes of the lower shaft sleeve of the methanol needle valve body, and the central circle diameter Φ1 of the diesel spray hole distribution is greater than the central circle diameter Φ2 of the two groups of methanol spray holes distribution; The directions of multiple methanol spray holes on the spray hole cover are inclined toward the outer edge of the spray hole cover, and the directions of several diesel spray holes are inclined toward the center of the spray hole cover; the lower end of the methanol delivery rod and the lower end of the methanol needle valve are provided with a methanol delivery on-off mechanism, and the lower end of the lower sleeve of the methanol needle valve body, the lower end of the diesel needle valve and the lower end of the diesel needle valve body are provided with a diesel injection on-off mechanism.

5. The methanol-diesel composite injector with temperature adjustment and variable spray holes as claimed in claim 4, It is characterized in that The methanol delivery on-off mechanism includes several radial holes evenly distributed at the lower end of the methanol delivery rod and several inverted L-shaped holes communicating with the end face of the lower end of the methanol delivery rod, the radial holes are respectively communicated with the corresponding axial methanol delivery holes; the horizontal holes at the upper end of the inverted L-shaped holes are respectively communicated with the outer peripheral surface of the methanol delivery rod, the horizontal holes are located at the lower side of the radial holes, and the vertical holes at the lower end of the inverted L-shaped holes are respectively communicated with the corresponding methanol spray holes on the spray hole cover; it also includes several C-shaped holes evenly distributed at the lower end of the inner side of the methanol needle valve, the upper and lower ends of the C-shaped holes correspond to the positions of the radial holes and the horizontal holes at the upper end of the inverted L-shaped holes, and the distance A1 between the center of the upper end of the C-shaped hole and the center of the radial hole is equal to the distance A2 between the center of the lower end of the C-shaped hole and the center of the horizontal hole at the upper end of the inverted L-shaped hole.

6. The methanol-diesel composite fuel injector with temperature adjustment and variable spray holes as claimed in claim 4, It is characterized in that The diesel injection on-off mechanism includes a diesel needle valve body conical hole arranged at the bottom of the inner hole of the diesel needle valve body, a conical surface at the bottom of the diesel needle valve, and an inverted L-shaped hole arranged at the bottom of the lower sleeve of the methanol needle valve body. The diesel needle valve body conical hole matches the conical surface at the bottom of the diesel needle valve, and the upper end of the inverted L-shaped hole matches the bottom position of the diesel needle valve body conical hole.

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