Air supply device at air inlet end of diesel engine

Abstract

The invention relates to an air supplementing device at the air inlet end of a diesel engine and relates to the technical field of diesel engines. The device comprises a blowdown pipe, a butt joint pipe and a supporting shaft, one end of the blowdown pipe is communicated with an air source, and the other end is communicated with the butting pipe; the butt joint pipe is sleeved outside the supporting shaft, and the supporting shaft is inserted in the diesel engine air inlet pipe. An air channel is formed in the inner wall of the butt joint pipe, and a vent hole communicated with the air channel is formed in the side wall of the supporting shaft; a piston plate is arranged in the butt joint pipe and located on the side, away from the diesel engine air inlet pipe, of the supporting shaft, the piston plate used for driving the piston plate to slide in the direction close to or away from the supporting shaft is arranged in the butt joint pipe, the piston plate, the supporting shaft and the inner wall of the butt joint pipe jointly define a first air cavity, and the first air cavity communicates with the air channel. The switching assembly is used for controlling whether the air channel is communicated with the vent hole or not; the diesel engine has the effects that the conveying amount of external air at the air inlet pipe of the diesel engine is effectively increased, and the combustion sufficiency in a combustion chamber of the diesel engine is optimized.

Description

Technical Field

[0001] The present application relates to the technical field of diesel engines, and in particular to an air supply device at the intake end of a diesel engine. Background Art

[0002] The automobile engine is a device that provides power for the car. It is the heart of the car and determines the car's power, economy, stability and environmental protection. Depending on the power source, automobile engines can be divided into diesel engines, gasoline engines, electric car motors and hybrid power.

[0003] Common gasoline engines and diesel engines are both reciprocating piston internal combustion engines. When a diesel engine is working, the diesel in the fuel tank is transported to the engine's cylinder for combustion. The chemical energy therein is released through combustion and converted into mechanical energy of the piston movement, thereby outputting power to the outside. In this process, whether the diesel combustion is sufficient determines the fuel consumption performance and environmental performance of the vehicle. Whether the combustion is sufficient is subject to whether the intake volume of the diesel engine intake pipe is sufficient. If the intake volume of the diesel engine intake pipe is insufficient, it is easy to cause the fuel in the diesel engine to not be fully burned, and then eventually lead to the emission of "black smoke" that pollutes the environment and endangers health. Therefore, it is urgent to design a structure that can effectively increase the delivery volume of external air at the diesel engine intake pipe to improve the combustion completeness in the diesel engine combustion chamber. Summary of the invention

[0004] In order to increase the amount of air delivered to an intake pipe of a diesel engine, the present application provides an air replenishing device at the intake end of a diesel engine.

[0005] The present application provides an air supply device for the intake end of a diesel engine, comprising an air supply pipe, a docking pipe, and a support shaft; one end of the air supply pipe is connected to an air source, and the other end is connected to the docking pipe; the docking pipe is sleeved on the outside of the support shaft, and the support shaft is inserted into the intake pipe of the diesel engine; an air duct is provided on the inner wall of the docking pipe, and an air vent for communicating with the air duct is provided on the side wall of the support shaft; a piston plate is provided inside the docking pipe and on the side of the support shaft away from the intake pipe of the diesel engine, and a piston plate for driving the piston plate to slide toward or away from the support shaft is provided in the docking pipe, and the piston plate, the support shaft and the inner wall of the docking pipe together enclose a first air cavity, and the first air cavity is connected to the air duct; a switching component is also included, and the switching component is used to control whether the air duct and the air vent are connected.

[0006] By adopting the above technical solution, the air source transmits the air to the first air cavity through the air supply pipe, and then drives the piston plate to move in the direction close to the support shaft, so as to accelerate the air in the first air cavity to be pushed into the air passage. Since the air passage is connected with the air vent, the air will enter the intake pipe of the diesel engine through the air vent to accelerate the supply of air to the intake pipe of the diesel engine. When the piston plate moves in the direction away from the support shaft to reset, the air passage and the air vent can be controlled to close by the switching component, so as to reduce the situation where the air in the intake pipe of the diesel engine flows back into the first air cavity.

[0007] Preferably, an annular cavity is formed between the end wall of the docking tube and the support shaft, and the air duct and the air vent are respectively connected to the annular cavity; the switching assembly is used to drive the docking tube to move in a direction parallel to the axial direction of the support shaft, and when the docking tube moves to fit with the support shaft, the air duct and the diesel engine intake pipe are not connected to each other.

[0008] By adopting the above technical solution, when the docking tube moves close to the support shaft and fits with the support shaft, the annular cavity space is almost 0. At this time, the air duct and the diesel engine intake pipe are not connected to each other. At this time, when the piston plate moves away from the support shaft and resets, the air that has entered the diesel engine intake pipe will not flow back into the first air cavity.

[0009] Preferably, the switching assembly includes a positioning member and a first opening and closing member; the positioning member is used to drive the butt joint tube to slide relative to the axial direction of the support shaft and fix the sliding position, and when the end wall of the butt joint tube and the support shaft are not in contact with each other, there is an air vent hole coaxially arranged with the air duct; the first opening and closing member is used to open and close the connection position between the air duct and the diesel engine intake pipe, and when the end wall of the butt joint tube and the support shaft are in contact with each other, the air duct and the diesel engine intake pipe are not connected to each other.

[0010] By adopting the above technical solution, when it is necessary to supply air to the diesel engine intake pipe, and the piston plate moves toward the direction close to the support shaft and pushes the gas to flow to the diesel engine intake pipe through the air duct, there is an air vent coaxially arranged in the air duct to reduce the impact force of the airflow on the inner wall of the annular cavity, so that most of the air can flow smoothly and directly into the diesel engine intake pipe through the air duct; and when the piston plate approaches the direction away from the support shaft, the connecting position between the air duct and the diesel engine intake pipe is closed by the first opening and closing member, so that the air duct and the diesel engine intake pipe are not connected to each other, thereby preventing the air in the diesel engine intake pipe from flowing back into the first air cavity.

[0011] Preferably, the support shaft is provided with a sliding member for driving the piston plate to slide back and forth in a direction approaching or away from the support shaft; the positioning member includes two groups of docking blocks and two groups of positioning blocks, and each positioning block is also provided with a corresponding positioning spring; the docking blocks are arranged on the inner wall of the docking tube, and one group of docking blocks is located in the sliding direction when the piston plate slides toward the support shaft, and the other group of docking blocks is located on the sliding path when the piston plate slides away from the support shaft; the positioning blocks are arranged on the outer wall of the docking tube, the positioning springs are connected between the corresponding positioning blocks and the outer wall of the docking tube, and the positioning blocks are slidingly connected to the outer wall of the docking tube through the corresponding positioning springs; the side wall of the support shaft is provided with a positioning groove, and when the positioning groove is located in the sliding direction of the positioning block, the positioning block can be inserted into the positioning groove under the elastic force of the positioning spring.

[0012] By adopting the above technical solution, the piston plate can slide toward or away from the support shaft under the drive of the sliding member, and when the piston plate is not in contact with any set of docking blocks, the sliding of the piston plate is relative to the docking tube. When the piston plate further slides after contacting any docking block, the piston plate will drive the docking tube to slide relative to the support shaft, and during the sliding process, the positioning spring, the positioning block and the positioning groove cooperate with each other to achieve the positioning of the docking tube relative to the support shaft, such as fixing the end wall of the docking tube to fit the side wall of the support shaft.

[0013] Preferably, the first opening and closing member includes a rotating shaft, a baffle, a docking torsion spring and a docking rod, the docking torsion spring is sleeved on the rotating shaft, and the rotating shaft is rotatably connected to the support shaft through the docking torsion spring, the baffle is arranged on the side wall of the rotating shaft and fits against the side surface of the support shaft facing the diesel engine intake pipe, the docking rod is arranged on the end wall of the docking tube, and the end of the docking rod away from the docking tube is inserted into the support shaft; when the docking torsion spring is not deformed, the baffle is located on the moving path of the docking rod when it moves with the docking tube toward the support shaft, and the baffle is used to make a circular motion with the rotating shaft as the center when it is resisted by the docking rod, the vent is located on the moving path of the baffle making a circular motion, and when the end wall of the docking tube fits against the side wall of the support shaft, the baffle covers the surface of the vent.

[0014] By adopting the above technical solution, when the docking tube slides toward the direction close to the support shaft, the docking rod penetrates the support shaft and contacts the baffle, so that the baffle rotates around the rotating shaft after being contacted by the docking rod, and when the wall of the docking tube fits against the side wall of the support shaft, the baffle rotates to a position covering the surface of the vent hole.

[0015] Preferably, the piston plate comprises a mesh plate, a cover plate and a second opening and closing member, wherein the second opening and closing member is used to drive the cover plate to move so that the cover plate opens or closes the mesh holes on the mesh plate during movement.

[0016] By adopting the above technical solution, when the piston plate moves toward the direction approaching the support shaft, the second opening and closing member drives the cover plate to move and cover the mesh holes of the mesh plate, so that the air in the first air cavity can be fully pushed into the airway; and when the piston plate moves toward the direction away from the support shaft, the second opening and closing member drives the cover plate to move and open the mesh holes of the mesh plate, so that the air in the space on the side of the piston plate away from the first air cavity can flow into the first air cavity through the mesh holes.

[0017] Preferably, the cover plate is rotatably connected to one side of the mesh plate, and the cover plate rotates relative to the mesh plate to cover or open the mesh holes of the mesh plate.

[0018] By adopting the above technical solution, when the piston plate slides along the length direction of the docking tube, the slider slides in the slide groove, and the opening and closing of the mesh holes of the mesh plate are realized by controlling the cover plate to rotate relative to the mesh plate. When the piston plate moves toward the direction close to the support shaft, the cover plate will rotate and close the mesh holes of the mesh plate. When the piston plate moves toward the direction away from the support shaft, the cover plate will rotate and open the mesh holes of the mesh plate.

[0019] Preferably, the air supply pipe is provided with a filter and a cleaning member for clearing the mesh of the filter.

[0020] By adopting the above technical solution, the filter can filter the air entering the connecting pipe through the air supply pipe, and the cleaning component can clean and clear the filter, ensuring the filtering effect of the filter on the air in the air supply pipe.

[0021] Preferably, the filter is rotatably connected to the air supply pipe, and the peripheral wall of the filter passes through the air supply pipe and is located outside the air supply pipe, and the cleaning part includes a scraper rod, a docking ring and a rack; the scraper rod is arranged on the inner wall of the air supply pipe, and the scraper rod is attached to the side wall of one side of the filter, the docking ring is sleeved with the peripheral wall of the filter, and the peripheral wall of the docking ring is provided with a tooth groove for engaging with the rack, and the end of the rack is connected to the side wall of the support shaft.

[0022] By adopting the above technical solution, since the air supply pipe is connected to one side of the docking pipe, when the docking pipe slides relative to the support shaft, the air supply pipe will move together with the docking pipe, so that under the meshing action of the docking ring tooth groove and the rack, the docking ring and the filter screen rotate relative to the air supply pipe, that is, the filter screen rotates relative to the scraper rod, and then the scraper rod is used to scrape the surface of the filter screen to achieve unblocking of the filter screen.

[0023] Preferably, a sealing strip is provided between the filter screen and the wall of the air supply pipe.

[0024] By adopting the above technical solution, the provision of the sealing strip can be used to improve the sealing performance of the connection position between the filter screen and the air supply pipe, so that the air entering the air supply pipe can fully flow into the docking pipe.

[0025] In summary, this application includes the following beneficial technical effects: The reciprocating movement of the piston plate accelerates the air entering the docking tube and pushes it into the diesel engine intake pipe, thereby realizing the air replenishment operation of the diesel engine intake pipe; thereby effectively increasing the delivery volume of external air at the diesel engine intake pipe and improving the combustion completeness in the diesel engine combustion chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an air replenishing device at the intake end of a diesel engine disclosed in an embodiment of the present application.

[0027] Figure 2 It is a top view of an air replenishing device at the intake end of a diesel engine disclosed in an embodiment of the present application.

[0028] Figure 3 yes Figure 2 Sectional view along AA direction.

[0029] Explanation of the accompanying drawings: 1. air supply pipe; 11. one-way valve; 12. filter; 13. sealing strip; 14. cleaning part; 141. scraper rod; 142. docking ring; 1421. tooth groove; 143. rack; 2. docking pipe; 21. piston plate; 211. mesh plate; 212. cover plate; 22. first air cavity; 23. second opening and closing part; 24. air duct; 3. support shaft; 31. annular cavity; 32. vent hole; 33. sliding part; 34. positioning groove; 35. motor; 4. diesel engine intake pipe; 5. switching assembly; 51. positioning part; 511. docking block; 512. positioning block; 513. positioning spring; 52. first opening and closing part; 521. rotating shaft; 522. baffle; 523. docking torsion spring; 524. docking rod. DETAILED DESCRIPTION

[0030] The following is combined with Figure 1-3 This application is described in further detail.

[0031] The embodiment of the present application discloses a gas replenishing device at the intake end of a diesel engine. Figure 1 , Figure 2 and Figure 3The air supply device at the intake end of the diesel engine includes an air supply pipe 1, a butt joint pipe 2 and a support shaft 3; the end of the support shaft 3 is fixedly inserted into the end of the diesel engine intake pipe 4, the butt joint pipe 2 is sleeved on one end of the support shaft 3 away from the diesel engine intake pipe 4, and the butt joint pipe 2 and the end of the support shaft 3 close to each other enclose an annular cavity 31; the other end of the butt joint pipe 2 is closed. The air supply pipe 1 is inserted through the side wall of the butt joint pipe 2 and is connected to the butt joint pipe 2. The end of the air supply pipe 1 away from the butt joint pipe 2 is connected to an air source, which is used to supply air to the air supply pipe 1. A one-way valve 11 is also provided on the air supply pipe 1 to limit the air to only enter the butt joint pipe 2 through the air supply pipe 1 through the one-way valve 11. An air passage 24 communicating with the annular cavity 31 is provided on the inner wall of the butt-joint tube 2 along its length direction, and an air vent 32 communicating with the annular cavity 31 is provided on the end wall of the support shaft 3. Air is transported into the butt-joint tube 2 through the air supply pipe 1, and then the air is allowed to enter the diesel engine intake pipe 4 with the help of the air passage 24, the annular cavity 31 and the air vent 32 to achieve air supply.

[0032] Reference Figure 2 and Figure 3 A piston plate 21 is also provided inside the butt-joint tube 2. The piston plate 21, the peripheral wall of the butt-joint tube 2 and the end wall of the support shaft 3 together enclose a first air cavity 22. A sliding member 33 is provided inside the support shaft 3. The sliding member 33 is used to drive the piston rod to slide back and forth in a direction parallel to the length direction of the butt-joint tube 2. In the embodiment of the present application, the sliding member 33 can specifically be a mini cylinder.

[0033] Reference Figure 2 and Figure 3 The piston plate 21 includes a mesh plate 211 and a cover plate 212 disposed on one side of the mesh plate 211. The mesh plate 211 and the cover plate 212 are coaxially disposed, and a motor 35 is embedded in the center of the mesh plate 211. The driving end of the motor 35 is connected to the center of the cover plate 212, so that the cover plate 212 can rotate relative to the mesh plate 211, and a preset through hole is opened through the side wall of the cover plate 212, and the preset through hole is used to communicate with the mesh plate 211 when the cover plate 212 rotates.

[0034] Reference Figure 3 , and also includes a switching component 5, the switching component 5 includes a positioning member 51 and a first opening and closing member 52, the positioning member 51 includes two groups of docking blocks 511 and two groups of positioning blocks 512, the two groups of docking blocks 511 are respectively fixedly connected to the inner walls of the docking tube 2, and one group of docking blocks 511 is located on the sliding path when the piston plate 21 slides toward the support shaft 3, and the other group of docking blocks 511 is located on the sliding path when the piston plate 21 slides away from the support shaft 3. When the piston plate 21 contacts the docking blocks 511 and continues to slide, the piston plate 21 will drive the docking tube 2 to slide relative to the support shaft 3.

[0035] Reference Figure 2The positioning block 512 is arranged on the outer wall of the butt joint tube 2, and each positioning block 512 corresponds to a positioning spring 513, the positioning spring 513 is connected between the outer wall of the butt joint tube 2 and the corresponding positioning block 512, the positioning spring 513 is always in a deformed state, and the side wall of the support shaft 3 is provided with a positioning groove 34 for inserting the positioning block 512. When the butt joint tube 2 slides down and fits against the side wall of the support shaft 3 driven by the piston plate 21, the positioning block 512 is inserted into one of the positioning grooves 34 to fix the position of the butt joint tube 2 relative to the support shaft 3.

[0036] Reference Figure 2 and Figure 3 The first opening and closing member 52 includes a rotating shaft 521, a baffle 522, a docking torsion spring 523 and a docking rod 524. The rotating shaft 521 is rotatably connected to the end wall of the support shaft 3 facing the diesel engine intake pipe 4. The docking torsion spring 523 is sleeved on the outside of the rotating shaft 521 and connected between the rotating shaft 521 and the end wall of the support shaft 3. The baffle 522 is connected to the rotating shaft 521, and the docking rod 524 is arranged on the end wall of the docking pipe 2, and one end of the docking rod 524 away from the docking pipe 2 is inserted into the support shaft 3. When the docking torsion spring 523 is not deformed, the baffle 522 is located on the path of the docking rod 524 as the docking rod 524 moves toward the support shaft 3. When the baffle 522 is resisted by the docking rod 524 and rotates around the rotating shaft 521, the vent 32 is located on the rotation path of the baffle 522. When the docking tube 2 moves to the point where the end wall is in contact with the side wall of the support shaft 3, the baffle 522 rotates to a position covering the vent 32, so that the air duct 24 and the diesel engine intake pipe 4 are not connected to each other.

[0037] Reference Figure 1 and Figure 3 , a filter screen 12 is also provided on the air supply pipe 1, and the filter screen 12 is located on the side of the one-way valve 11 away from the docking pipe 2. The filter screen 12 is rotatably connected to the air supply pipe 1, and the peripheral wall of the filter screen 12 penetrates the air supply pipe 1 and is located outside the air supply pipe 1. A sealing strip 13 made of rubber material is provided between the filter screen 12 and the outer wall of the air supply pipe 1. It also includes a cleaning member 14, and the cleaning member 14 includes a scraper rod 141, a docking ring 142 and a rack 143. The docking ring 142 is connected to the outer peripheral wall of the filter screen 12 through a support frame, and a tooth groove 1421 is provided on the peripheral wall of the docking ring 142. The rack 143 is fixedly connected to the support shaft 3, and the rack 143 is meshedly connected to the docking ring 142 through the tooth groove 1421.

[0038] The implementation principle of the air supply device at the intake end of a diesel engine in the embodiment of the present application is as follows: the one-way valve 11 is opened to allow the air delivered by the air source to enter the intake pipe through the air supply pipe 1, and the piston plate 21 is driven by the sliding member 33 to move toward the direction close to the support shaft 3, so that the air in the first air cavity 22 flows through the air passage 24, the annular cavity 31 and the vent hole 32 in sequence and then flows into the diesel engine intake pipe 4. Before the movement, the cover plate 212 is driven to rotate by the motor 35, and the preset through holes on the cover plate 212 are not connected to the mesh holes on the mesh plate 211.

[0039] When the piston plate 21 moves to contact with a set of docking blocks 511 above, the piston plate 21 continues to move toward the direction close to the support shaft 3. At this time, the docking tube 2 will move toward the direction close to the support shaft 3 under the drive of the piston plate 21, so that the space of the annular cavity 31 is gradually reduced, and the air in the annular cavity 31 is forced into the diesel engine intake pipe 4. At this time, the side wall of the docking tube 2 close to the inlet position of the air passage 24 moves and fits against the side wall of the support shaft 3, so as to close the lower end of the air passage 24 with the help of the support shaft 3; At the same time, the docking rod 524 moves toward the direction close to the baffle 522, and causes the baffle 522 to rotate relative to the surface of the support shaft 3. In addition, during this period, the docking ring 142 will drive the filter 12 to rotate relative to the scraper rod 141, so that the scraper rod 141 scrapes the surface of the filter 12. When the docking tube 2 moves up to fit the side wall of the support shaft 3, the baffle 522 just rotates to the position covering the vent hole 32. Then, the piston plate 21 is driven downward by the sliding member 33, and the cover plate 212 is driven to rotate relative to the mesh plate 211 by the motor 35, so that the preset through holes on the cover plate 212 are connected with the mesh holes on the mesh plate 211, so that during the downward movement of the piston plate 21, the air on the side of the piston plate 21 away from the first air cavity 22 can enter the first air cavity 22. When the piston plate 21 moves to contact the docking block 511 away from the support shaft 3, the piston plate 21 continues to move downward and drives the docking tube 2 to move in the direction away from the support shaft 3 to reopen the annular cavity 31.

[0040] The reciprocating movement of the piston plate 21 accelerates the air entering the docking pipe 2 and pushes it into the diesel engine intake pipe 4 , thereby realizing the air replenishment operation for the diesel engine intake pipe 4 .

[0041] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An air supply device at the intake end of a diesel engine, characterized in that: The invention comprises an air supply pipe (1), a butt joint pipe (2), and a support shaft (3); one end of the air supply pipe (1) is connected to an air source, and the other end is connected to the butt joint pipe (2); the butt joint pipe (2) is sleeved on the outside of the support shaft (3), and the support shaft (3) is inserted into an intake pipe (4) of a diesel engine; an air passage (24) is provided on the inner wall of the butt joint pipe (2), and a vent hole (32) for communicating with the air passage (24) is provided on the side wall of the support shaft (3); a vent hole (32) is provided inside the butt joint pipe (2) and located away from the support shaft (3) and away from the diesel engine. A piston plate (21) is provided at one side of the oil engine air inlet pipe (4); a piston plate (21) is provided in the butt joint pipe (2) for driving the piston plate (21) to slide in a direction close to or away from the support shaft (3); the piston plate (21), the support shaft (3) and the inner wall of the butt joint pipe (2) together enclose a first air cavity (22); the first air cavity (22) is connected to the air passage (24); and a switching component (5) is also included, the switching component (5) being used to control whether the air passage (24) is connected to the air vent (32).

2. The air supply device at the intake end of a diesel engine according to claim 1, characterized in that: An annular cavity (31) is formed between the end wall of the butt-joint tube (2) and the support shaft (3), and the air passage (24) and the air vent (32) are respectively connected to the annular cavity (31); the switching assembly (5) is used to drive the butt-joint tube (2) to move in a direction parallel to the axial direction of the support shaft (3), and when the butt-joint tube (2) moves to fit the support shaft (3), the air passage (24) and the diesel engine intake pipe (4) are not connected to each other.

3. The air supply device at the intake end of a diesel engine according to claim 2, characterized in that: The switching assembly (5) comprises a positioning member (51) and a first opening and closing member (52); the positioning member (51) is used to drive the butt joint tube (2) to slide relative to the axial direction of the support shaft (3) and fix the sliding position, and when the end wall of the butt joint tube (2) and the support shaft (3) are not in contact with each other, there is an air vent (32) coaxially arranged with the air duct (24); the first opening and closing member (52) is used to open and close the communication position between the air duct (24) and the diesel engine intake pipe (4), and when the end wall of the butt joint tube (2) and the support shaft (3) are in contact with each other, the air duct (24) and the diesel engine intake pipe (4) are not in contact with each other.

4. The air supply device at the intake end of a diesel engine according to claim 3, characterized in that: The support shaft (3) is provided with a sliding member (33) for driving the piston plate (21) to slide back and forth in a direction approaching or away from the support shaft (3); the positioning member (51) comprises two groups of docking blocks (511) and two groups of positioning blocks (512), and each positioning block (512) is also provided with a corresponding positioning spring (513); the docking blocks (511) are arranged on the inner wall of the docking tube (2), and one group of the docking blocks (511) is located in the sliding direction when the piston plate (21) slides toward the support shaft (3), and the other group of the docking blocks (511) is located on the sliding path when the piston plate (21) slides away from the support shaft (3); The positioning block (512) is arranged on the outer wall of the butt joint tube (2); the positioning spring (513) is connected between the corresponding positioning block (512) and the outer wall of the butt joint tube (2); the positioning block (512) is slidably connected to the outer wall of the butt joint tube (2) via the corresponding positioning spring (513); a positioning groove (34) is arranged on the side wall of the support shaft (3); when the positioning groove (34) is located in the sliding direction of the positioning block (512), the positioning block (512) can be inserted into the positioning groove (34) under the elastic force of the positioning spring (513).

5. The air supply device at the intake end of a diesel engine according to claim 3, characterized in that: The first opening and closing member (52) comprises a rotating shaft (521), a baffle (522), a docking torsion spring (523) and a docking rod (524); the docking torsion spring (523) is sleeved on the rotating shaft (521); the rotating shaft (521) is rotatably connected to the support shaft (3) via the docking torsion spring (523); the baffle (522) is arranged on a side wall of the rotating shaft (521) and is attached to a side surface of the support shaft (3) facing the diesel engine intake pipe (4); the docking rod (524) is arranged on an end wall of the docking pipe (2); and one end of the docking rod (524) away from the docking pipe (2) is inserted into the support shaft (3); When the docking torsion spring (523) is not deformed, the baffle (522) is located on the moving path of the docking rod (524) when it moves along with the docking tube (2) toward the support shaft (3), and the baffle (522) is used to make a circular motion around the rotating shaft (521) when it is resisted by the docking rod (524). The vent (32) is located on the moving path of the baffle (522) making a circular motion, and when the end wall of the docking tube (2) is in contact with the side wall of the support shaft (3), the baffle (522) covers the surface of the vent (32).

6. The air supply device at the intake end of a diesel engine according to claim 1, characterized in that: The piston plate (21) comprises a mesh plate (211), a cover plate (212) and a second opening and closing member (23), wherein the second opening and closing member (23) is used to drive the cover plate (212) to move, so that the cover plate (212) opens or closes the mesh holes on the mesh plate (211) during the movement.

7. The air supply device at the intake end of a diesel engine according to claim 6, characterized in that: The cover plate (212) is rotatably connected to one side of the mesh plate (211); the cover plate (212) rotates relative to the mesh plate (211) and covers or opens the mesh holes of the mesh plate (211).

8. The air supply device at the intake end of a diesel engine according to claim 1, characterized in that: The air supply pipe (1) is provided with a filter screen (12) and a cleaning member (14) for clearing the mesh of the filter screen (12).

9. The air supply device at the intake end of a diesel engine according to claim 8, characterized in that: The filter screen (12) is rotatably connected to the air supply pipe (1), and the peripheral wall of the filter screen (12) penetrates the air supply pipe (1) and is located outside the air supply pipe (1). The cleaning member (14) comprises a scraper rod (141), a docking ring (142) and a rack (143); the scraper rod (141) is arranged on the inner wall of the air supply pipe (1), and the scraper rod (141) is attached to a side wall of the filter screen (12); the docking ring (142) is sleeved on the peripheral wall of the filter screen (12); the peripheral wall of the docking ring (142) is provided with a tooth groove (1421) for meshing with the rack (143); and the end of the rack (143) is connected to the side wall of the support shaft (3).

10. The air supply device at the intake end of a diesel engine according to claim 9, characterized in that: A sealing strip (13) is provided between the filter screen (12) and the wall of the air supply pipe (1).

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