Air pressure constant power automatic buffering closing structure

Abstract

The application provides an air pressure constant power automatic buffering closing structure, which solves the problem of not locking in the prior art when doors and windows are closed. The structure comprises a steel pipe, a static positioning convex shaft fixedly installed in the inner cavity of the steel pipe and tightly matched with the inner wall of the steel pipe, a guide groove being formed in the lower part of the static positioning convex shaft, a damping convex shaft located below the static positioning convex shaft, a damping oil hole and a one-way stop valve being formed in the damping convex shaft, an adjusting fixed tail piece fixed to the bottom end of the steel pipe and forming an oil chamber with the damping convex shaft, an adjusting valve needle fixed to the adjusting fixed tail piece and penetrating into the damping oil hole, a gap being formed between the adjusting valve needle and the damping oil hole, and a waist line-shaped groove being formed in the upper end of the adjusting valve needle. The air pressure constant power automatic buffering closing structure is convenient to use, can effectively realize the function of automatically locking when closing the door, and has good practicability.

Description

Technical Field

[0001] This invention relates to the technical field of rotary positioning devices for doors and windows, and in particular to a pneumatic constant power automatic buffer closing structure that is simple in structure and easy to use. Background Technology

[0002] Floor springs and door closers are commonly used automatic return door closing devices in the current market. In existing pneumatic floor springs, the rotor and shaft are separate structures. During use, the rotation of the door or window compresses the internal sealed air chamber, and the pressure is released when the door or window returns to its original position. Chinese invention patent CN113047719A discloses a pneumatic automatic return device that uses the relative movement between an upper and lower convex shaft to compress the sealed air chamber, creating a higher internal air pressure. When the door or window returns to its original position, the pressure inside the sealed air chamber is released. The device can be adjusted according to the different weights of doors installed on the upper convex shaft to achieve different return speeds for different doors, thus meeting various needs. However, this automatic return device also has certain drawbacks in use: First, the contact surface between the upper and lower convex shafts in this structure is a spiral symmetrical structure, and there is no forced positioning mechanism between the upper and lower convex shafts, which causes the upper convex shaft to rotate within a 360° range. This makes the rotation of the door uncertain and poses certain safety hazards. Second, during the process of the door opening and closing, the pressure in the air chamber gradually decreases. The torque on the door is minimal when the door is about to close, which makes it very easy for the door to fail to engage (i.e., the door cannot engage with the lock due to the low torque). This is also not conducive to people's daily use. Therefore, at present, there is an urgent need for a structure that can solve the above problems. Summary of the Invention

[0003] This invention proposes an automatic buffer closing structure with constant pneumatic power, which solves the problem of doors and windows failing to lock when closed in the prior art.

[0004] The technical solution of this invention is implemented as follows: a constant pressure dynamic automatic buffer closing structure, comprising:

[0005] The steel pipe is installed vertically and closed at both ends;

[0006] A stationary positioning cam is fixedly installed in the inner cavity of the steel pipe and fits tightly with the inner wall of the steel pipe. A guide groove is opened at the lower part of the stationary positioning cam.

[0007] A damping cam shaft is located below the stationary positioning cam shaft. The damping cam shaft is provided with a damping helical surface. The damping helical surface reciprocates linearly in the guide groove. The damping cam shaft is also provided with a damping oil passage hole that runs vertically through the shaft and a one-way shut-off valve.

[0008] Adjustable fixed tail piece, which is fixed to the bottom end of the steel pipe, forms an oil chamber filled with oil between the adjustable fixed tail piece and the damping cam shaft, and the oil flows through the damping oil passage and the one-way shut-off valve.

[0009] An adjusting valve needle is fixed to the adjusting and fixing tail piece and passes through the damping oil passage. A gap is left between the adjusting valve needle and the damping oil passage. The upper end of the adjusting valve needle is provided with a waist-shaped groove.

[0010] A return spring is sleeved on the regulating valve needle and rests against the damping cam and the adjusting and fixing tail piece.

[0011] In a preferred embodiment, the adjusting and fixing tail piece has a valve needle threaded hole at the middle position, and the adjusting valve needle is provided with a valve needle thread that engages with the valve needle threaded hole.

[0012] The lower part of the regulating valve needle is provided with a first sealing ring, and an adjusting tool hole for adjusting its position is also opened on the lower end face.

[0013] In a preferred embodiment, a second sealing ring that mates with the inner wall of the steel pipe is fitted on the damping cam shaft, and the damping oil passage is located in the middle of the damping cam shaft;

[0014] The one-way shut-off valve closes when the damping cam moves downward and opens when the damping cam moves upward.

[0015] In a preferred embodiment, a rotating sliding cam is provided above the stationary positioning cam and engages with its helical surface. The rotating sliding cam rotates synchronously and moves up and down along the helical surface.

[0016] The linear travel of the damping cam is less than that of the rotary sliding cam.

[0017] In a preferred embodiment, a guide slider is provided above the rotating sliding cam shaft, and a sealed air chamber with a high-pressure environment is located above the guide slider. When the guide slider moves linearly along the axial direction of the steel pipe, the size of the sealed air chamber changes accordingly.

[0018] The sealed air chamber is equipped with a drive shaft. The drive shaft extends upward from the upper end of the steel pipe and is connected to the rotation shaft of the door. The lower end passes through the guide slider and engages with the rotating sliding cam key.

[0019] In a preferred embodiment, the rotary sliding cam extends into the interior of the stationary positioning cam and engages with its helical surface;

[0020] The outer wall of the rotating sliding cam is provided with vertically extending outer limiting teeth, and the inner wall of the stationary positioning cam is provided with vertically extending inner limiting teeth. When the outer limiting teeth rotate with the rotating sliding cam, they are limited by the inner limiting teeth.

[0021] In a preferred embodiment, the rotating sliding cam can rotate in one direction or in two directions.

[0022] After adopting the above technical solution, the beneficial effects of the present invention are as follows: The automatic buffer closing structure of the present invention realizes the flow of oil in the oil chamber by adjusting the movement of the valve needle in the damping oil passage, and then cooperates with the damping cam shaft above to realize the opening and closing of the door. During the closing process, initially, since there is only a helical surface fit between the stationary positioning cam shaft and the rotating sliding cam shaft, the rotational speed and linear speed of the rotating sliding cam shaft are relatively fast under the action of the high pressure environment in the sealed air chamber, and the closing speed of the door is also relatively fast. When the rotating sliding cam shaft moves downward to contact the damping cam shaft, it is subjected to the force of the damping cam shaft and the oil. At this time, the oil will slowly flow through the gap between the adjusting valve needle and the damping oil passage, and the corresponding movement speed of the rotating sliding cam shaft and the closing speed of the door will also slow down rapidly. Until the waist-shaped groove of the adjusting valve needle moves into the damping oil passage, the oil flow increases rapidly, the downward speed of the damping cam shaft increases rapidly, the rotational speed of the rotating sliding cam shaft increases sharply, and the closing speed of the door also increases sharply, thereby realizing the locking function and ensuring that the door is completely closed. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the closed state of an embodiment of the present invention;

[0025] Figure 2 for Figure 1 The diagram shows the open state structure of the embodiment shown.

[0026] Figure 3 for Figure 1 An exploded view of the embodiment shown;

[0027] Figure 4 This is a schematic diagram of the structure of the regulating valve needle;

[0028] Figure 5 A front view schematic diagram of a stationary positioning cam shaft;

[0029] Figure 6 for Figure 5 A side view diagram;

[0030] Figure 7 for Figure 5 A diagram showing the view from below;

[0031] Figure 8 for Figure 5 A top-down view;

[0032] Figure 9 This is a front view schematic diagram of the rotating sliding cam shaft;

[0033] Figure 10 for Figure 9 A side view diagram;

[0034] Figure 11 for Figure 10 A top-down view;

[0035] Figure 12 for Figure 9 A top-down view;

[0036] Figure 13 This is a front view schematic diagram of the damping cam shaft;

[0037] Figure 14 for Figure 13 A side view diagram;

[0038] Figure 15 for Figure 13 A top-down view;

[0039] Figure 16 for Figure 13 A diagram showing the view from below;

[0040] Figure 17 Schematic diagram of another type of static positioning cam shaft and rotary sliding cam shaft structure;

[0041] Figure 18 for Figure 17 A side view diagram;

[0042] In the diagram: 1-Steel pipe; 2-Static positioning cam shaft; 3-Guide groove; 4-Damping cam shaft; 5-Damping helical surface; 6-Damping oil passage; 7-One-way shut-off valve; 8-Adjusting and fixing tail piece; 9-Oil chamber; 10-Adjusting valve needle; 11-Waist-shaped groove; 12-Reset spring; 13-Valve needle threaded hole; 14-Valve needle thread; 15-First sealing ring; 16-Adjusting tool hole; 17-Second sealing ring; 18-Rotary sliding cam shaft; 19-Guide slider; 20-Sealed air chamber; 21-Drive shaft; 22-Outer limiting tooth; 23-Inner limiting tooth; 24-Pressure bearing; 25-Front seal; 26-Bottom seal; 27-First helical surface; 28-Second helical surface; 29-Inner sliding tooth; 30-Outer sliding tooth. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1:

[0045] like Figure 1 , Figure 2 The image shown is an embodiment of the pneumatic constant-force automatic buffer closure structure of the present invention. Figure 1 This is a schematic diagram of the door in the closed state. Figure 2 This is a schematic diagram of the door in the open state. To better illustrate the internal structure, the door is not shown in any of the attached diagrams. Figure 1 and Figure 2 These are diagrams from different angles. Figure 3 This is an exploded view diagram of this embodiment. Figure 4 This is a partial structural diagram of the lower part of steel pipe 1. Figure 5 , Figure 6 , Figure 7 and Figure 8 This is a schematic diagram showing different angles of the stationary positioning cam 2 in this embodiment. Figure 9 , Figure 10 , Figure 11 and Figure 12 This is a schematic diagram showing different angles of the rotating sliding cam 18 in this embodiment. Figure 13 , Figure 14 , Figure 15 and Figure 16 This is a schematic diagram showing different angles of the damping cam shaft in this embodiment. The structure of this embodiment will be described in detail below.

[0046] This embodiment first includes a vertical steel pipe 1. During installation, the steel pipe 1 should generally be coaxial with the door's rotating shaft and can be installed in different locations on the door as needed, such as the floor or at the hinge. Inside the steel pipe 1, from bottom to top, several components are installed sequentially: an adjusting and fixing tail piece 8, an adjusting valve needle 10, a damping cam 4, a stationary positioning cam 2, a rotating sliding cam 18, a guide slider 19, a bottom seal 26, a front seal 25, and a pressure bearing 24. The lower end of the steel pipe 1 is tapered, and the adjusting and fixing tail piece 8 is fixed to the steel pipe 1 by groove or welding. After fixing, the seal between the tail piece and the steel pipe 1 must be ensured. A valve needle threaded hole 13 is opened in the middle of the adjusting and fixing tail piece 8. The purpose is to install the regulating valve needle 10. For this purpose, a valve needle thread 14 is provided on the regulating valve needle 10. The regulating valve needle 10 can be fixed on the regulating fixing tail piece 8 through the threaded engagement between the valve needle thread 14 and the valve needle thread hole 13. In order to further ensure the sealing, a first sealing ring 15 is also provided at the lower part of the regulating valve needle 10. At the same time, an adjustment tool hole 16 is opened on the bottom surface of the regulating valve needle 10. The operator can adjust the position of the regulating valve needle 10 accordingly through the adjustment tool hole 16.

[0047] The main function of the regulating valve needle 10 is to control the amount of oil passing through, especially to achieve the door locking function at the moment the door is about to close. This is achieved by setting a waist-shaped groove 11 at the upper end of the regulating valve needle 10. The operating principle of this technical feature will be described later.

[0048] The upper part of the regulating valve needle 10 is the damping cam 4. The damping cam 4 and the adjusting fixed tail piece 8 form an oil chamber 9 for containing liquid oil. The regulating valve needle 10 is immersed in the oil. At the same time, a return spring 12 is also sleeved on the regulating valve needle 10. The return spring 12 abuts against the damping cam 4 and the adjusting fixed tail piece 8 to reset the damping cam 4. In order to ensure that the oil flows along the set path, this embodiment provides a second sealing ring 17 on the outer ring of the damping cam 4. The second sealing ring 17 is in sealing contact with the inner wall of the steel pipe 1 to prevent the oil from flowing from the outer ring of the damping cam 4. A damping oil passage 6, extending vertically through the middle of the damping cam 4, is provided. The upper end of the adjusting valve needle 10 passes through this damping oil passage 6, with a suitable gap between them. When the door opens or closes, the damping cam 4 undergoes a certain displacement in the axial direction of the steel pipe 1, thereby changing the size of the oil chamber 9. The oil in the oil chamber 9 flows through this gap. Because the gap is small, the oil flows slowly, and correspondingly, the vertical movement speed of the damping cam 4 is also slow. However, once the waist-shaped groove 11 enters the damping oil passage 6, the gap between the adjusting valve needle 10 and the damping oil passage 6 suddenly increases, the oil flow rate increases sharply, and the linear movement speed of the damping cam 4 also increases, causing the door to close sharply and achieving the locking function. How the movement of the damping cam 4 is transmitted to the door will be described in detail later.

[0049] A one-way shut-off valve 7 is also provided on the damping cam shaft 4, located on one side of the damping oil passage 6. This one-way shut-off valve 7 is also vertically connected, and its function is to allow the oil to pass through in one direction. Specifically, when the valve... Figure 1 The closed state moves to Figure 2 When the door is in the open state, the damping cam 4 moves upward. At this time, the oil above the damping cam 4 can flow into the oil chamber 9 through the gap between the one-way shut-off valve 7, the regulating valve needle 10, and the damping oil passage 6. When the door is open... Figure 2 The indicated open state moves to Figure 1 When in the closed state shown, the one-way shut-off valve 7 automatically closes, preventing the oil in the oil chamber 9 from passing through the one-way shut-off valve 7. The oil can only flow through the gap between the regulating valve needle 10 and the damping oil passage 6. As for the specific structure of the one-way shut-off valve 7, its one-way shut-off function can be achieved by using a valve ball and having an upper opening smaller than the valve ball and a lower opening larger than the valve ball. The structure of the one-way shut-off valve 7 is quite common in existing technology and will not be described in detail here.

[0050] Above the damping cam 4 are a stationary positioning cam 2 and a rotary sliding cam 18. The stationary positioning cam 2 is fixedly mounted on the inner wall of the steel pipe 1 and fits tightly therewith, creating two isolated spaces above and below the stationary positioning cam 2. Two symmetrical guide grooves 3 are formed at the lower part of the stationary positioning cam 2. The main function of the guide grooves 3 is to provide corresponding sliding space for the movement of the damping cam 4, while ensuring that the damping cam 4 only reciprocates linearly in the vertical direction. Therefore, in this embodiment, a damping helical surface 5 corresponding to the guide groove 3 is provided on the damping cam 4. The damping helical surface 5 only moves up and down within the guide groove 3.

[0051] The stationary positioning cam 2 and the rotary sliding cam 18 are engaged by a helical surface. During engagement, the rotary sliding cam 18 is inserted into the stationary positioning cam 2. Specifically, a first helical surface 27 is provided inside the stationary positioning cam 2, and a corresponding second helical surface 28 is provided on the rotary sliding cam 18. Through the engagement of the first helical surface 27 and the second helical surface 28, the rotary sliding cam 18 can achieve synchronous rotational and linear motion within the stationary positioning cam 2. In this embodiment, the rotary sliding cam 18 can only rotate in one direction. This type of helical surface structure has been disclosed in the prior art, for example, as shown in publication number CN214943445U, and will not be described again here.

[0052] exist Figure 1 When the door is closed, the rotating sliding cam 18 is in its lowest position, and its lower end face is in contact with the upper end face of the damping cam 4, which is also in its lowest position. When the door is opened to... Figure 2 In the state shown, the rotating sliding cam 18 rotates to the highest position along the first helical surface 27 and the second helical surface 28. At this time, the damping helical surface 5 on the damping cam 4 is completely embedded in the guide groove 3. Therefore, the up and down movement stroke of the damping cam 4 is less than the movement stroke of the rotating sliding cam 18, and the top surface of the guide groove 3 is the limit position of the damping cam 4.

[0053] The upper part of the rotating sliding cam 18 consists of a guide slider 19, a bottom seal 26, a front seal 25, and a pressure bearing 24. The bottom seal 26 and the front seal 25 form a high-pressure sealed air chamber 20, the size of which can change with the opening and closing of the door. The rotating sliding cam 18 and the guide slider 19 continuously abut against each other and move synchronously. A drive shaft 21, aligned with the axial direction of the steel pipe 1, is also provided in the sealed air chamber 20. This drive shaft 21 passes downwards through the bottom seal 26 and the guide slider 19 and extends into the rotating sliding cam 18. The upper end of the drive shaft 21 passes through the front seal 25 and the pressure bearing 24 and extends to the outside of the steel pipe 1. The pressure bearing 24 reduces friction and resistance during the rotation of the drive shaft 21. The upper end of the drive shaft 21 is connected to the rotation shaft of the door. Therefore, when people push the door to open or close, the rotation shaft of the door will drive the drive shaft 21 to rotate accordingly. Since the drive shaft 21 only rotates in the circumferential direction of the steel pipe 1 and does not move in the vertical direction, an outer sliding tooth 30 is provided at the lower end of the drive shaft 21 in this embodiment, and an inner sliding tooth 29 is provided in the inner cavity of the rotating sliding cam 18. The outer sliding tooth 30 and the inner sliding tooth 29 cooperate to enable the drive shaft 21 and the rotating sliding cam 18 to rotate synchronously, and the rotating sliding cam 18 can also move up and down. Of course, the drive shaft 21 and the rotating sliding cam 18 can also be connected by a key or other means to achieve synchronous rotation, and can ensure that the rotating sliding cam 18 can move in the vertical direction.

[0054] like Figures 9-12 As shown, a vertically extending outer limiting tooth 22 is provided on the outer wall of the rotating sliding cam 18, such as... Figures 5-8 As shown, vertically extending inner limiting teeth 23 are also provided on the inner wall of the stationary positioning convex shaft 2, in conjunction with... Figure 1 , Figure 2 and Figure 3 Since the rotating sliding cam 18 is inserted into the stationary positioning cam 2, there is not only a mating relationship between the two with the first helical surface 27 and the second helical surface 28, but also, when the rotating sliding cam 18 rotates within the stationary positioning cam 2, the outer limiting tooth 22 is limited by the inner limiting tooth 23. That is, when the rotating sliding cam 18 rotates to the position where the outer limiting tooth 22 contacts the inner limiting tooth 23, the rotating sliding cam 18 will be unable to continue rotating in the same direction and can only rotate in the opposite direction. This embodiment can achieve the forced positioning effect of the rotating sliding cam 18 through this structure. The forced positioning effect of the rotating sliding cam 18 is equivalent to the forced positioning effect of the drive shaft 21 and the door. Therefore, during production, the maximum opening angle of the door can be changed by changing the central angle of the outer limiting tooth 22 and the inner limiting tooth 23 to adapt to different usage scenarios.

[0055] The following is a detailed description of the process of opening and closing in this embodiment.

[0056] like Figure 1 The diagram shows the state of this embodiment when the door is closed. At this time, the damping cam 4 and the rotating sliding cam 18 are both at the lower limit position. The rotating sliding cam 18 and the stationary positioning cam 2 are fully engaged through the first helical surface 27 and the second helical surface 28. The damping helical surface 5 of the damping cam 4 is partially embedded in the guide groove 3 and abuts against the lower end surface of the rotating sliding cam 18.

[0057] When a person pushes the door open, the door's rotating shaft rotates, causing the drive shaft 21 to rotate. Since the lower end of the drive shaft 21 engages with the rotating sliding cam 18 via the outer sliding teeth 30 and inner sliding teeth 29, the drive shaft 21 further drives the rotating sliding cam 18 to rotate. With the cooperation of the first helical surface 27 and the second helical surface 28, the rotating sliding cam 18 rotates and moves upwards simultaneously. At this time, the return spring 12 presses against the damping cam 4, causing the rotating sliding cam 18 to move upwards. Under the elastic force of the return spring 12, and with the cooperation of the first helical surface 27 and the second helical surface 28, the rotating sliding cam 18 rotates and moves upwards, pressing against the guide slider 19 and the bottom seal 26, compressing the sealed air chamber 20, further increasing the high pressure inside the sealed air chamber 20 and storing potential energy. At the same time, due to the upward movement of the damping cam 4, the regulating valve needle 10 will move in the damping oil passage 6, the volume of the oil chamber 9 will increase, and the oil above the damping cam 4 can flow into the oil chamber 9 through the gap between the one-way shut-off valve 7, the regulating valve needle 10 and the damping oil passage 6.

[0058] The above actions are performed simultaneously until the damping spiral surface 5 of the damping cam 4 is fully embedded in the guide groove 3. At this time, the upper end surface of the damping spiral surface 5 abuts against the top surface of the guide groove 3, and the damping cam 4 can no longer move upward. The damping cam 4 reaches its upper limit position, and the volume of the oil chamber 9 also reaches its maximum state. People continue to push the door to rotate. At this time, although the rotating sliding cam 18 has disengaged from the damping cam 4 and is no longer subject to the force of the return spring 12 and the damping cam 4, the force of people pushing the door will still continue to drive the rotating sliding cam 18 to rotate and move upward while cooperating with the first spiral surface 27 and the second spiral surface 28. Until the rotating sliding cam 18 rotates to the point where the outer limit tooth 22 contacts the inner limit tooth 23, the rotating sliding cam 18 will no longer be able to rotate in the same direction, and people will no longer be able to push the door to continue rotating, thus achieving the forced positioning state of this embodiment (e.g., Figure 2 (As shown). Of course, as explained above, the positions and central angles of the outer limit tooth 22 and the inner limit tooth 23 can be customized as needed, which is equivalent to controlling the maximum opening angle of the door.

[0059] The following is a detailed description of the opening and closing process of this embodiment.

[0060] like Figure 2 The diagram shown illustrates the state of the door after it is opened in this embodiment. It should be noted beforehand that this is for ease of description and understanding. Figure 2 and Figure 1 This is not a schematic diagram taken at the same angle as in this embodiment. In this state, both the damping cam 4 and the rotary sliding cam 18 are at their upper limit positions, the upper end face of the damping helical surface 5 of the damping cam 4 rests against the top surface of the guide groove 3, the return spring 12 is in its longest state, and the volume of the oil chamber 9 is in its maximum state.

[0061] When a person pushes the door to close, the door's rotating shaft rotates, causing the drive shaft 21 to rotate. Since the lower end of the drive shaft 21 engages with the rotating sliding cam 18 via external sliding teeth 30 and internal sliding teeth 29, the drive shaft 21 further drives the rotating sliding cam 18 to rotate. Under the engagement of the first helical surface 27 and the second helical surface 28, and under the force of the high-pressure environment within the sealed air chamber 20, the rotating sliding cam 18 rotates while simultaneously moving downwards. The high pressure within the sealed air chamber 20 continuously pushes the bottom seal 26 and the guide slider 19 downwards.

[0062] The above actions are performed simultaneously until the lower end face of the rotating sliding cam 18 contacts the upper end face of the damping spiral surface 5. At this time, under the high pressure in the sealed air chamber 20 and with the cooperation of the first spiral surface 27 and the second spiral surface 28, the rotating sliding cam 18 will continue to push the damping cam 4 downward, so that the damping cam 4 slowly moves out of the guide groove 3 and reduces the volume of the oil chamber 9. However, at this time, due to the closure of the one-way shut-off valve 7, the oil in the oil chamber 9 cannot pass through the one-way shut-off valve 7. The oil can only slowly flow into the upper part of the damping cam 4 through the gap between the regulating valve needle 10 and the damping oil passage 6. This makes the downward movement speed of the damping cam 4 very slow, the downward movement speed and rotation speed of the rotating sliding cam 18 are also very slow, and the rotation speed of the drive shaft 21 and the door are also very slow. When the damping oil passage 6 reaches the waist-shaped groove 11 of the adjusting valve needle 10, the gap between the adjusting valve needle 10 and the damping oil passage 6 increases sharply, and the oil flow increases sharply. This indirectly drives the damping cam 4, the rotating sliding cam 18, the drive shaft 21, and the door to move / rotate at a sharp speed, thereby achieving the locking effect when the door is closed. At this point, this embodiment has achieved... Figure 1 The state shown.

[0063] Example 2:

[0064] like Figure 17 and Figure 18The diagram shows a structural schematic of a static positioning cam 2 and a rotating sliding cam 18 in another structural form. The difference between this embodiment and the first embodiment is that the rotating sliding cam 18 in the first embodiment can only rotate in one direction, that is, the door can only open in one direction. However, the rotating sliding cam 18 in this embodiment can rotate in both directions, that is, the door can open in two directions. This is mainly achieved by the structure of the first helical surface 27 and the second helical surface 28. In this embodiment, the first helical surface 27 and the second helical surface 28 are set as symmetrical structures to achieve the function of bidirectional rotation. This has been applied in the prior art and will not be described in detail here.

[0065] The remaining structures in this embodiment are the same as in Embodiment 1, and will not be described again here.

[0066] In summary, the pneumatic constant power automatic buffer closing structure of this invention is easy to use and can effectively achieve the function of automatic locking when the door is closed, thus having great practicality.

[0067] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pneumatic constant-force automatic buffer closing structure, characterized in that, include: Steel pipe (1), which is set vertically and closed at both ends; A stationary positioning cam shaft (2) is fixedly installed in the inner cavity of the steel pipe (1) and tightly fitted with the inner wall of the steel pipe (1). A guide groove (3) is opened at the lower part of the stationary positioning cam shaft (2). Damping cam shaft (4) is located below the stationary positioning cam shaft (2). The damping cam shaft (4) is provided with a damping helical surface (5). The damping helical surface (5) moves back and forth in the guide groove (3). The damping cam shaft (4) is also provided with a damping oil passage (6) that runs vertically through the shaft and a one-way shut-off valve (7). Adjust the fixed tail piece (8), which is fixed to the bottom end of the steel pipe (1). The adjustment fixed tail piece (8) and the damping cam (4) form an oil chamber (9) filled with oil. The oil flows in the damping oil passage (6) and the one-way shut-off valve (7). The regulating valve needle (10) is fixed on the regulating fixed tail piece (8) and passes through the damping oil passage (6). There is a gap between the regulating valve needle (10) and the damping oil passage (6). The upper end of the regulating valve needle (10) is provided with a waist-shaped groove (11). The return spring (12) is sleeved on the regulating valve needle (10) and abuts against the damping cam (4) and the adjusting and fixing tail piece (8); Above the stationary positioning cam (2) is a rotating sliding cam (18) that engages with its helical surface. The rotating sliding cam (18) rotates synchronously and moves up and down along the helical surface. The linear travel of the damping cam (4) is less than the linear travel of the rotary sliding cam (18); The adjusting and fixing tail piece (8) has a valve needle thread hole (13) in the middle position, and the adjusting valve needle (10) is provided with a valve needle thread (14) that is threaded to the valve needle thread hole (13). The lower part of the regulating valve needle (10) is provided with a first sealing ring (15), and an adjusting tool hole (16) for adjusting its position is also opened on the lower end face.

2. The pneumatic constant force automatic buffer closing structure as described in claim 1, characterized in that: The damping cam (4) is fitted with a second sealing ring (17) that fits with the inner wall of the steel pipe (1), and the damping oil passage (6) is located in the middle of the damping cam (4). The one-way shut-off valve (7) closes when the damping cam (4) moves downward and opens when the damping cam (4) moves upward.

3. The pneumatic constant force automatic buffer closing structure as described in claim 1, characterized in that: A guide slider (19) is provided above the rotating sliding cam (18). Above the guide slider (19) is a sealed air chamber (20) in a high-pressure environment. When the guide slider (19) moves linearly along the axial direction of the steel pipe (1), the size of the sealed air chamber (20) changes accordingly. The sealed air chamber (20) is provided with a drive shaft (21). The drive shaft (21) extends upward from the upper end of the steel pipe (1) and is connected to the rotating shaft of the door. The lower end passes through the guide slider (19) and is keyed to the rotating sliding cam (18).

4. The pneumatic constant force automatic buffer closing structure as described in claim 1, characterized in that: The rotating sliding cam (18) extends into the interior of the stationary positioning cam (2) and engages with its helical surface; The outer wall of the rotating sliding cam (18) is provided with a vertically extending outer limiting tooth (22), and the inner wall of the stationary positioning cam (2) is provided with a vertically extending inner limiting tooth (23). When the outer limiting tooth (22) rotates with the rotating sliding cam (18), it is limited by the inner limiting tooth (23).

5. The pneumatic constant force automatic buffer closing structure as described in claim 1, characterized in that: The rotating sliding cam (18) can rotate in one direction or in two directions.

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