Force-adjustable heavy ultrathin door closer with double-cylinder structure and production process thereof

Abstract

The invention belongs to the technical field of door closers, and provides a force-adjustable heavy ultrathin door closer with a double-cylinder structure and a production process thereof.The door closer comprises a shell, two parallel channels are formed in the shell, a first cover plate and a second cover plate are arranged at the two ends of each channel respectively, and an oil injection pipe is arranged on each second cover plate; and a piston column is slidably installed in the channel, a through groove is formed in the piston column, a first rack is fixedly installed on the side wall in the through groove, and a rotating shaft is rotatably installed in the channel. Compared with the prior art, the door opening device has the following beneficial effects that the threaded rod rotates in different directions by opening and closing the door, the moving plate moves in different directions, the distance from the moving plate to the initial position of the piston column is changed, the subsequent compression amount of the first elastic piece is different, and then the door opening resistance force is changed; and the use requirements of different places can be met.

Description

Technical Field

[0001] The invention belongs to the technical field of door closers, and in particular relates to a heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force and a production process thereof. Background Art

[0002] The door closer is a spring-like hydraulic device on the door head. When the door is opened, it can be compressed and then released to automatically close the door. It acts like a spring door and can ensure that the door is closed to its initial position accurately and promptly after being opened.

[0003] When the door is opened, the door body drives the connecting rod to move and rotate the transmission gear, driving the rack plunger to move to the right. In the process of the plunger moving to the right, the spring is compressed, and the hydraulic oil in the right chamber is also pressurized. The one-way valve ball on the left side of the plunger opens under the action of oil pressure, and the hydraulic oil in the right chamber flows to the left chamber through the one-way valve. When the door opening process is completed, since the spring is compressed during the opening process, the accumulated elastic potential energy is released, pushing the plunger to the left, driving the transmission gear and the door closer connecting rod to rotate, thereby closing the door. The installation position of the spring of the existing door closer is mostly fixed when in use, that is, the deformation amount of the spring compression is the same each time the door is opened, and the elastic potential energy accumulated by the spring compression remains unchanged, so that the resistance force when opening the door is constant, it is difficult to adjust the resistance force when opening the door, and it cannot adapt to different usage scenarios. Summary of the invention

[0004] The purpose of the present invention is to provide a heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force and its production process, aiming to solve the technical problem in the prior art that the resistance force when opening the door is constant and cannot adapt to different usage scenarios.

[0005] The present invention is implemented as follows: a heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force comprises a housing, wherein two sets of parallel channels are opened in the housing, a first cover plate and a second cover plate are respectively arranged at both ends of the channel, and an oil injection pipe is arranged on the second cover plate; A piston column is slidably installed in the channel, a through slot is provided on the piston column, a first rack is fixedly installed on the side wall of the through slot, a rotating shaft is rotatably installed in the channel, one end of the rotating shaft extends out of the housing and a first gear meshing with the first rack is fixedly installed on the rotating shaft, and the ends of the two sets of rotating shafts are connected; A threaded rod distributed along the length direction of the channel is rotatably installed on the first cover plate, a movable plate is threadedly installed on the threaded rod, the movable plate is slidably connected to the channel, a telescopic rod is fixedly installed on the side of the movable plate close to the piston column, a push plate is fixedly installed on the end of the telescopic rod away from the movable plate, a first elastic member is fixedly installed on the movable plate, and the end of the first elastic member away from the movable plate is fixedly connected to the push plate, a power assembly for driving the threaded rod to rotate is arranged in the channel, and an oil delivery pipe connecting the two ends of the channel located at the lower side of the channel is opened in the shell.

[0006] Further technical solution: A through hole connecting the two groups of channels is opened in the shell, a connecting column is rotatably installed in the through hole, both side surfaces of the connecting column are opened with connecting grooves of non-circular structure, and a connecting block extending into the connecting groove is fixedly installed at the end of the rotating shaft.

[0007] Further technical solution: The power assembly includes a support plate, which is fixedly installed in the channel and has a worm rotatably installed on the support plate. The worm is meshed with a worm wheel fixedly installed on the end of the threaded rod. A second gear is provided at the end of the worm away from the side wall of the channel, and the second gear is meshed with a second rack fixedly installed on the end face of the piston column.

[0008] Further technical solution: the second gear is rotatably installed on the worm through a turntable, and a lifting rod is slidably installed on the worm, the cross-section of the lifting rod is non-circular, a friction plate is fixedly installed on the end of the lifting rod close to the second gear, a second elastic member is fixedly installed on the friction plate, the end of the second elastic member away from the friction plate is fixedly connected to the end face of the worm, a first magnet is fixedly installed on the end of the lifting rod away from the friction plate, the first magnet is used in conjunction with a second magnet arranged on the shell, and when the second elastic member is in its original length state, a gap is arranged between the friction plate and the second gear.

[0009] Further technical solution: the shell is provided with a mounting hole located on the extension line of the lifting rod, a lower pressure rod is threadedly installed in the mounting hole, the second magnet is fixedly installed on the end of the lower pressure rod, and the surface magnetic poles of the second magnet and the first magnet close to each other are the same.

[0010] Further technical solution: two sets of collecting pipes are fixedly installed at both ends of the shell, the collecting pipes are connected to the oil pipeline and pipe covers are threadedly installed at the ends of the collecting pipes.

[0011] Further technical solution: mounting blocks are fixedly installed at both ends of the horizontal section of the oil pipeline, sliding rods are slidably installed on the mounting blocks, and the sliding rods are distributed along the length direction of the horizontal section of the oil pipeline. A power plate is fixedly installed at the end of the sliding rod away from the collecting pipe, and the diameter of the power plate is smaller than the inner diameter of the oil pipeline. A filter plate is fixedly installed at the end of the sliding rod close to the collecting pipe, and the filter plate is in sliding contact with the inner wall of the oil pipeline.

[0012] Further technical solution: a filter cartridge is fixedly installed on the surface of the filter plate close to the collecting tube, a guide tube extending into the filter cartridge is provided on the side wall of the filter cartridge, a baffle is fixedly installed on the end of the guide tube, and a gap is provided between the baffle and the end of the guide tube.

[0013] The present invention also provides a door closer production process, which is applied to the above-mentioned heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force, and comprises the following steps: Step S1: Install the piston column into the channel, and then install the rotating shaft into the channel, so that the rotating shaft is located in the through groove of the piston column and the first rack is meshed with the first gear, and the installation position of the rotating shaft is sealed by a sealing member; Step S2: installing the first cover plate and the second cover plate to the closed channels on both sides of the housing by fixing screws, respectively, so that the power assembly is connected to the piston column; Step S3: After the installation is completed, a set volume of buffer oil is injected into the area on both sides of the piston rod through the oil injection pipe; Step S4: After the assembly is completed, testing and debugging are performed.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. When it is necessary to adjust the thrust of the first elastic member on the piston column, first adjust the state of the power assembly to make it linked with the movement of the piston column. At this time, opening or closing the door drives the piston column to move. The movement of the piston column drives the threaded rod to rotate through the power assembly, so that the movable plate moves in the channel. By opening and closing the door, the threaded rod rotates in different directions, so that the movable plate moves in different directions, and the distance from the movable plate to the initial position of the piston column is changed, so that the subsequent compression amount of the first elastic member is different, thereby changing the resistance force of opening the door. It can be suitable for use in different places, and the compression amount of the first elastic member in the two sets of channels can be freely adjusted, which improves the flexibility of device adjustment.

[0015] 2. When adjusting the force, the power assembly, movable plate, threaded rod and other structures are all in the channel, and there is no need to disassemble the device, which will not affect the sealing of the device, further improve the sealing of the device and the convenience of force adjustment, and avoid the occurrence of disassembly oil leakage problems.

[0016] 3. When the buffer oil flows in the oil pipeline, the filter plate is located at the entrance of the horizontal section of the oil pipeline, and the guide pipe is located directly below the vertical section of the oil pipeline. The end of the filter cartridge exceeds the vertical section of the oil pipeline. Then the buffer oil enters the filter cartridge from the guide pipe and then flows through the filter plate. At this time, the impurities in the buffer oil will be filtered by the filter plate and isolated in the filter cartridge, thereby filtering the impurities in the buffer oil, reducing the wear of the piston column during movement, and improving the service life of the equipment. When the buffer oil flows in the reverse direction, the filter plate is reset. At this time, the filter cartridge and the filter plate are moved out of the horizontal section of the oil pipeline, so that the impurities in the filter cartridge are pushed into the collection pipe, and when the oil flows in the reverse direction, due to the effect of the baffle, the probability of impurities in the filter cartridge flowing back into the channel is reduced, so that the impurities are retained in the filter cartridge as much as possible, further reducing the impurity content in the buffer oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2It is a schematic diagram of the first plane cross-sectional structure of the present invention.

[0019] Figure 3 It is a schematic diagram of the second plane cross-sectional structure of the present invention.

[0020] Figure 4 for Figure 2 A magnified schematic diagram of the A1 region in the middle.

[0021] Figure 5 It is a structural schematic diagram of the piston column in the present invention.

[0022] Figure 6 for Figure 5 A magnified schematic diagram of the A2 region in the middle.

[0023] Figure 7 It is a schematic structural diagram of the lower pressure column in the present invention.

[0024] Figure 8 for Figure 3 A magnified schematic diagram of the A3 region in the middle.

[0025] Fig. 9 It is a schematic diagram of the structure of the filter cartridge in the present invention.

[0026] In the accompanying drawings: 1, housing; 2, channel; 3, first cover plate; 4, second cover plate; 5, piston column; 6, through groove; 7, first rack; 8, rotating shaft; 9, first gear; 10, through hole; 11, connecting column; 12, connecting groove; 13, connecting block; 14, oil filling pipe; 15, threaded rod; 16, moving plate; 17, telescopic rod; 18, first elastic member; 19, push plate; 20, second rack; 21, support plate; 22 , worm; 23, worm wheel; 24, lifting rod; 25, first magnet; 26, turntable; 27, second gear; 28, second elastic member; 29, friction plate; 30, mounting hole; 31, push-down rod; 32, second magnet; 33, oil pipeline; 34, collecting pipe; 35, mounting block; 36, sliding rod; 37, power plate; 38, filter plate; 39, filter cartridge; 40, guide tube; 41, baffle; 42, power assembly. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0029] like Figure 1-Figure 7As shown, a heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force provided by the present invention comprises a housing 1, two sets of parallel channels 2 are opened in the housing 1, a first cover plate 3 and a second cover plate 4 are respectively arranged at both ends of the channel 2, and an oil injection pipe 14 is arranged on the second cover plate 4; A piston column 5 is slidably installed in the channel 2, a through groove 6 is provided on the piston column 5, a first rack 7 is fixedly installed on the side wall in the through groove 6, a rotating shaft 8 is rotatably installed in the channel 2, one end of the rotating shaft 8 extends out of the housing 1 and a first gear 9 meshing with the first rack 7 is fixedly installed on the rotating shaft 8, the ends of the two groups of rotating shafts 8 are connected, a through hole 10 connecting the two groups of channels 2 is provided in the housing 1, a connecting column 11 is rotatably installed in the through hole 10, both side surfaces of the connecting column 11 are provided with a connecting groove 12 of a non-circular structure, and a connecting block 13 extending into the connecting groove 12 is fixedly installed at the end of the rotating shaft 8; A threaded rod 15 distributed along the length direction of the channel 2 is rotatably mounted on the first cover plate 3, a movable plate 16 is threadedly mounted on the threaded rod 15, the movable plate 16 is slidably connected to the channel 2, a telescopic rod 17 is fixedly mounted on the side of the movable plate 16 close to the piston column 5, a push plate 19 is fixedly mounted on the end of the telescopic rod 17 away from the movable plate 16, a first elastic member 18 is fixedly mounted on the movable plate 16, and the end of the first elastic member 18 away from the movable plate 16 is fixedly connected to the push plate 19, a power assembly 42 for driving the threaded rod 15 to rotate is arranged in the channel 2, and an oil delivery pipe 33 is provided in the shell 1 and is located at the lower side of the channel 2 and connects the two ends of the channel 2.

[0030] In actual application of this embodiment, the assembled device is installed at a set position, and a set volume of buffer oil is injected into the area on both sides of the piston column 5. When the door is opened, the rotating shaft 8 will be driven to rotate. When the rotating shaft 8 rotates, the piston column 5 is driven to move in the direction close to the first cover plate 3 through the meshing first gear 9 and the first rack 7. At this time, the piston column 5 compresses the first elastic member 18 through the push plate 19. At the same time, when the piston column 5 moves, it will push the buffer oil in front of its moving direction to move. Due to the movement of the piston column 5, the space in front of its moving direction is reduced, so that the door can be opened quickly in the initial stage. When the space in front of the moving direction of the piston column 5 is completely filled with buffer oil, the piston column 5 will be opened quickly. When the liquid is full, the door opening will encounter obvious resistance at this time, and the door will be slowly opened as the buffer oil moves to the other end of the channel 2 through the oil delivery pipe 33, realizing door opening buffering, avoiding collision and other problems caused by rapid door opening. When closing the door subsequently, the push plate 19 is exerted with a reset thrust under the action of the first elastic member 18, thereby pushing the piston column 5 to reset. At this time, the rotating shaft 8 rotates in the opposite direction to drive the door to close. Consistent with the above-mentioned door opening, the buffer oil is used to release the buffer, so that the front section of the door is closed quickly, and then it is closed slowly to avoid collision caused by rapid door closing. At the same time, the buffer oil will not enter the piston column 5, reducing the oil leakage caused by the damage to the seal caused by the frequent rotation of the rotating shaft 8. When it is necessary to adjust the thrust of the first elastic member 18 on the piston column 5, the state of the power assembly 42 is first adjusted to make it linked with the movement of the piston column 5. At this time, opening or closing the door drives the piston column 5 to move, and the movement of the piston column 5 drives the threaded rod 15 to rotate through the power assembly 42, so that the movable plate 16 moves in the channel 2. By opening and closing the door, the threaded rod 15 rotates in different directions, so that the movable plate 16 moves in different directions, and the distance from the movable plate 16 to the initial position of the piston column 5 is changed, so that the subsequent compression amount of the first elastic member 18 is different, thereby changing the resistance force of opening the door, which can be suitable for use in different places, and the compression amount of the first elastic member 18 in the two groups of channels 2 can be freely adjusted, which improves the flexibility of the device adjustment. At the same time, when adjusting the force, there is no need to disassemble the device, and the adjustment structure is located in the device, which will not affect the sealing of the device, further improving the sealing of the device and the convenience of force adjustment.

[0031] In an example of this embodiment, the first elastic member 18 is a first spring, and of course it can also be other elastic components such as an elastic ball, and the first spring is compressed to apply a force to close the door.

[0032] like Figure 2-Figure 7 As shown, a heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force is provided by the present invention. The power assembly 42 includes a support plate 21, which is fixedly installed in the channel 2 and a worm 22 is rotatably installed on the support plate 21. The worm 22 is meshed with a worm wheel 23 fixedly installed at the end of the threaded rod 15. A second gear 27 is provided at one end of the worm 22 away from the side wall of the channel 2, and the second gear 27 is meshed with a second rack 20 fixedly installed on the end face of the piston column 5.

[0033] Specifically, the second gear 27 is rotatably mounted on the worm 22 through a turntable 26, and a lifting rod 24 is slidably mounted on the worm 22. The cross-section of the lifting rod 24 is non-circular, and a friction plate 29 is fixedly mounted on the end of the lifting rod 24 close to the second gear 27, and a second elastic member 28 is fixedly mounted on the friction plate 29. The end of the second elastic member 28 away from the friction plate 29 is fixedly connected to the end face of the worm 22, and a first magnet 25 is fixedly mounted on the end of the lifting rod 24 away from the friction plate 29. The first magnet 25 is used in conjunction with a second magnet 32 ​​arranged on the housing 1. When the second elastic member 28 is in the original length state, a gap is arranged between the friction plate 29 and the second gear 27.

[0034] Specifically, the shell 1 is provided with a mounting hole 30 located on the extension line of the lifting rod 24, a lower pressure rod 31 is installed with internal threads of the mounting hole 30, and the second magnet 32 ​​is fixedly installed at the end of the lower pressure rod 31, and the second magnet 32 ​​and the first magnet 25 have the same surface magnetic poles close to each other.

[0035] In actual application of this embodiment, after the first cover plate 3 is installed, the worm wheel 23 is meshed with the worm 22, and the second gear 27 is meshed with the second rack 20. When it is necessary to adjust the thrust of the first elastic member 18 on the piston column 5, the pressing rod 31 is rotated to drive the second magnet 32 ​​to move downward. Since the second magnet 32 ​​and the first magnet 25 have the same surface magnetic poles close to each other, the lifting rod 24 is pushed downward and the second elastic member 28 is stretched under the action of the magnetic force. At this time, the second gear 27 under the friction plate 29 is in conflict. In the subsequent door opening process, the piston column 5 moves to the side of the first cover plate 3, and the second gear 27 is driven by the second rack 20. The wheel 27 rotates, and due to the resistance of the second gear 27 under the friction plate 29, the worm 22 is synchronously driven to rotate under the action of friction force. The worm 22 can drive the threaded rod 15 to rotate through the meshing worm wheel 23. The rotation of the threaded rod 15 can drive the movable plate 16 to move in the channel 2. The rotation direction of the threaded rod 15 can be changed by changing the rotation direction of the worm 22, thereby realizing the two-way position adjustment of the movable plate 16. When no adjustment is needed, the second magnet 32 ​​is reset. At this time, the friction plate 29 is reset under the action of the second elastic member 28. When the piston column 5 moves subsequently, the second gear 27 can idle through the turntable 26.

[0036] In an example of the present invention, the second elastic member 28 is a second spring, and of course, it can also be other elastic members such as an elastic ball, and the second spring applies a restoring pulling force to the friction plate 29 .

[0037] like Figure 8 , Fig. 9 As shown, a heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force is provided by the present invention. Two sets of collecting pipes 34 are fixedly installed at both ends of the shell 1. The collecting pipes 34 are connected to the oil pipeline 33 and the ends of the collecting pipes 34 are threadedly installed with pipe covers.

[0038] Specifically, mounting blocks 35 are fixedly installed at both ends of the horizontal section of the oil pipeline 33, and sliding rods 36 are slidably installed on the mounting blocks 35. The sliding rods 36 are distributed along the length direction of the horizontal section of the oil pipeline 33. A power plate 37 is fixedly installed at one end of the sliding rod 36 away from the collecting pipe 34. The diameter of the power plate 37 is smaller than the inner diameter of the oil pipeline 33. A filter plate 38 is fixedly installed at one end of the sliding rod 36 close to the collecting pipe 34. The filter plate 38 is in sliding contact with the inner wall of the oil pipeline 33.

[0039] Specifically, a filter cartridge 39 is fixedly installed on the surface of the filter plate 38 close to the collecting tube 34, a guide tube 40 extending into the filter cartridge 39 is provided on the side wall of the filter cartridge 39, a baffle 41 is fixedly installed on the end of the guide tube 40, and a gap is provided between the baffle 41 and the end of the guide tube 40.

[0040] In actual application of this embodiment, when the buffer oil flows in the oil pipeline 33, the horizontal flow of the buffer oil through the oil pipeline 33 will push the power plate 37 to drive the filter plate 38 to move until the filter plate 38 contacts the mounting block 35. At this time, the filter plate 38 is located at the entrance of the horizontal section of the oil pipeline 33, and the guide pipe 40 is located directly below the vertical section of the oil pipeline 33. The end of the filter cartridge 39 exceeds the vertical section of the oil pipeline 33. After that, the buffer oil enters the filter cartridge 39 from the guide pipe 40, and then flows through the filter plate 38. At this time, the impurities in the buffer oil will be filtered by the filter plate 38 and isolated in the filter cartridge 39, thereby achieving the filtration of impurities in the buffer oil. , reducing the wear of the piston column 5 when it moves, and improving the service life of the equipment. When the buffer oil flows in the reverse direction, the buffer oil pushes the power plate 37 to move in the reverse direction. When the power plate 37 contacts the mounting block 35, the filter plate 38 is reset. At this time, the filter cartridge 39 and the filter plate 38 move out of the horizontal section of the oil pipe 33, so that the impurities in the filter cartridge 39 are pushed into the collecting pipe 34. When the oil flows in the reverse direction, due to the action of the baffle 41, the probability of the impurities in the filter cartridge 39 flowing back into the channel 2 is reduced, so that the impurities are retained in the filter cartridge 39 as much as possible, further reducing the impurity content in the buffer oil. The impurities can be released by directly opening the pipe cover of the collecting pipe 34.

[0041] like Figure 1-Figure 6 As shown, a door closer production process provided by the present invention is applied to the above-mentioned heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force, and comprises the following steps: Step S1: Install the piston column 5 into the channel 2, and then install the shaft 8 into the channel 2, so that the shaft 8 is located in the through groove 6 of the piston column 5 and the first rack 7 is meshed with the first gear 9, and the installation position of the shaft 8 is sealed by a seal; Step S2: The first cover plate 3 and the second cover plate 4 are respectively mounted to the closed channels 2 on both sides of the housing 1 by fixing screws, so that the power assembly 42 is connected to the piston column 5; Step S3: After the installation is completed, a set volume of buffer oil is injected into the area on both sides of the piston rod 5 through the oil injection pipe 14; Step S4: After the assembly is completed, testing and debugging are performed.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0043] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force, comprising a housing (1), characterized in that: Two sets of parallel channels (2) are provided in the housing (1); a first cover plate (3) and a second cover plate (4) are provided at both ends of the channels (2); and an oil injection pipe (14) is provided on the second cover plate (4); A piston column (5) is slidably mounted in the channel (2), a through groove (6) is formed on the piston column (5), a first rack (7) is fixedly mounted on the side wall of the through groove (6), a rotating shaft (8) is rotatably mounted in the channel (2), one end of the rotating shaft (8) extends out of the housing (1) and a first gear (9) meshing with the first rack (7) is fixedly mounted on the rotating shaft (8), and the ends of the two sets of rotating shafts (8) are connected; A threaded rod (15) distributed along the length direction of the channel (2) is rotatably mounted on the first cover plate (3), a movable plate (16) is threadably mounted on the threaded rod (15), the movable plate (16) is slidably connected to the channel (2), a telescopic rod (17) is fixedly mounted on the side of the movable plate (16) close to the piston column (5), a push plate (19) is fixedly mounted on the end of the telescopic rod (17) away from the movable plate (16), a first elastic member (18) is fixedly mounted on the movable plate (16), and the end of the first elastic member (18) away from the movable plate (16) is fixedly connected to the push plate (19), a power assembly (42) for driving the threaded rod (15) to rotate is arranged in the channel (2), and an oil delivery pipe (33) is provided in the housing (1) and is located at the lower side of the channel (2) and connects the two ends of the channel (2).

2. A heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force according to claim 1, characterized in that: The housing (1) is provided with a through hole (10) for connecting the two groups of channels (2), a connecting column (11) is rotatably mounted in the through hole (10), both side surfaces of the connecting column (11) are provided with connecting grooves (12) of non-circular structure, and a connecting block (13) extending into the connecting groove (12) is fixedly mounted at the end of the rotating shaft (8).

3. A heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force according to claim 1, characterized in that: The power assembly (42) comprises a support plate (21), the support plate (21) being fixedly mounted in the channel (2) and having a worm (22) rotatably mounted on the support plate (21), the worm (22) meshing with a worm wheel (23) fixedly mounted on the end of the threaded rod (15), a second gear (27) being provided at one end of the worm (22) away from the side wall of the channel (2), the second gear (27) meshing with a second rack (20) fixedly mounted on the end surface of the piston rod (5).

4. A heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force according to claim 3, characterized in that: The second gear (27) is rotatably mounted on the worm (22) via a rotating disk (26); a lifting rod (24) is slidably mounted on the worm (22); the lifting rod (24) has a non-circular cross section; a friction plate (29) is fixedly mounted on one end of the lifting rod (24) close to the second gear (27); a second elastic member (28) is fixedly mounted on the friction plate (29); an end of the second elastic member (28) away from the friction plate (29) is fixedly connected to an end surface of the worm (22); a first magnet (25) is fixedly mounted on one end of the lifting rod (24) away from the friction plate (29); the first magnet (25) is used in conjunction with a second magnet (32) arranged on the housing (1); when the second elastic member (28) is in an original length state, a gap is arranged between the friction plate (29) and the second gear (27).

5. The heavy-duty ultra-thin door closer with double-cylinder structure and adjustable force according to claim 4, characterized in that: The housing (1) is provided with a mounting hole (30) located on the extension line of the lifting rod (24), a lower pressing rod (31) is installed with an internal thread of the mounting hole (30), a second magnet (32) is fixedly mounted on the end of the lower pressing rod (31), and the second magnet (32) and the first magnet (25) have the same surface magnetic poles when they are close to each other.

6. The heavy-duty ultra-thin door closer with double-cylinder structure and adjustable force according to claim 1, characterized in that: Two sets of collecting pipes (34) are fixedly mounted on both ends of the shell (1); the collecting pipes (34) are connected to the oil delivery pipe (33) and pipe caps are threadedly mounted on the ends of the collecting pipes (34).

7. A heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force according to claim 6, characterized in that: Both ends of the horizontal section of the oil pipeline (33) are fixedly mounted with mounting blocks (35), and sliding rods (36) are slidably mounted on the mounting blocks (35). The sliding rods (36) are distributed along the length direction of the horizontal section of the oil pipeline (33). A power plate (37) is fixedly mounted on one end of the sliding rod (36) away from the collecting pipe (34), and the diameter of the power plate (37) is smaller than the inner diameter of the oil pipeline (33). A filter plate (38) is fixedly mounted on one end of the sliding rod (36) close to the collecting pipe (34), and the filter plate (38) is in sliding contact with the inner wall of the oil pipeline (33).

8. The heavy-duty ultra-thin door closer with double-cylinder structure and adjustable force according to claim 7, characterized in that: A filter cartridge (39) is fixedly mounted on the surface of the filter plate (38) close to the collecting tube (34); a guide tube (40) extending into the filter cartridge (39) is provided on the side wall of the filter cartridge (39); a baffle plate (41) is fixedly mounted on the end of the guide tube (40); a gap is provided between the baffle plate (41) and the end of the guide tube (40).

9. A door closer production process, characterized in that: A heavy-duty ultra-thin door closer with a double-cylinder structure and adjustable force as claimed in any one of claims 1 to 5, comprising the following steps: Step S1: installing the piston column (5) into the channel (2), and then installing the rotating shaft (8) into the channel (2), so that the rotating shaft (8) is located in the through groove (6) of the piston column (5) and the first rack (7) is meshed with the first gear (9), and the installation position of the rotating shaft (8) is sealed by a sealing member; Step S2: The first cover plate (3) and the second cover plate (4) are respectively mounted on the closed channels (2) on both sides of the housing (1) by means of fixing screws, so that the power assembly (42) is connected to the piston column (5); Step S3: After the installation is completed, a set volume of buffer oil is injected into the area on both sides of the piston rod (5) through the oil injection pipe (14); Step S4: After the assembly is completed, testing and debugging are performed.

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