Buffer and buffer device for moving door
By using damping tubes and damping fluid in the mobile door buffer, combined with the design of the main piston and piston rod, the problem of reducing the buffering effect of the existing buffer after long-term use is solved, achieving a more stable and durable buffering effect .
Patent Information
- Application Number
- CN202421235695.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-31
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-05-31
AI Technical Summary
After long-term use of existing buffers, the buffering effect is reduced and the door frame and door body cannot be effectively protected.
The movable door buffer is adopted, including a damping tube, a connector, a piston rod, a main piston and a first spring. The pressure of the damping liquid produces a buffering effect. The main piston and the piston rod move along the axial direction of the damping tube, and the channel design makes the damping. The liquid flows from the first cavity to the second cavity, and the pressure is adjusted to control the buffering effect.
It maintains a good cushioning effect, and it is not easy to reduce even after long-term use, and is more durable and stable than traditional spring structures.
Smart Images
Figure CN222501416U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of buffers for doors and windows, in particular to a buffer and a buffer device for a movable door. Background Art
[0002] At present, buffers are commonly used in various types of movable door systems. When the door is closed or opened, the buffer will buffer the door, so that the door slowly approaches the door frame to avoid a violent collision between the two, and protect the door frame and the door from damage. However, the existing buffers generally use tension springs for elastic buffering. After long-term use, the elastic force of the tension springs decreases, resulting in a decrease in the buffering effect of the buffer. Utility Model Content
[0003] The utility model provides a buffer and a buffer device for a movable door, which can solve the problem that the buffer effect of the existing buffer is reduced after long-term use.
[0004] In order to solve the above problems, the utility model adopts the following technical solutions:
[0005] According to the first aspect of the utility model, an embodiment of the utility model provides a buffer for a movable door, comprising a damping tube, a connecting head, a piston rod, a main piston and a first spring; the damping tube is sealed and filled with damping fluid; the main piston and the first spring are both arranged in the damping tube, one end of the piston rod extends into the damping tube and is connected to the main piston, and the other end is fixedly connected to the connecting head, and the main piston and the piston rod can both move along the axial direction of the damping tube; the main piston divides the inner cavity of the damping tube into a first cavity close to the connecting head and a second cavity away from the connecting head, the first spring is arranged in the second cavity, and the first spring abuts the main piston or is connected to the main piston; the main piston is provided with a channel for connecting the first cavity and the second cavity, and the channel is configured so that the flow velocity of the damping fluid in the second cavity flowing through the channel to the first cavity is greater than the flow velocity of the damping fluid in the first cavity flowing through the channel to the second cavity.
[0006] In some embodiments, the main piston includes a shaft body and a first sealing ring; the shaft body extends axially along the damping tube, and a first convex ring and a second convex ring are provided on the circumferential surface of the shaft body, the second convex ring is located on the side of the first convex ring close to the connecting head, the first sealing ring is sleeved on the shaft body and located between the first convex ring and the second convex ring, and the first sealing ring abuts against the inner wall of the damping tube; the channel includes a first channel formed between the first convex ring and the inner wall of the damping tube, a second channel penetrating the first convex ring along the axial direction of the damping tube, and a third channel penetrating the second convex ring along the axial direction of the damping tube, and the cross-sectional area of the first channel is greater than the cross-sectional area of the second channel; when the piston rod extends out of the damping tube, the first sealing ring abuts against the first convex ring and blocks the first channel, and when the piston rod contracts into the damping tube, the first sealing ring moves away from the first convex ring to release the blockage of the first channel.
[0007] In some embodiments, one second channel is provided and a plurality of third channels are provided.
[0008] In some embodiments, a partition is provided in the second cavity, the partition divides the second cavity into a first sub-cavity close to the first cavity and a second sub-cavity away from the first cavity, the partition is provided with a through hole connecting the first sub-cavity and the second sub-cavity, the first spring is provided in the first sub-cavity, and a protective device that can elastically expand and contract along the axial direction of the damping tube is provided in the second sub-cavity; when the pressure in the first sub-cavity is greater than the preset pressure, the protective device shrinks in the direction away from the first sub-cavity under the action of pressure.
[0009] In some embodiments, the protection device includes a second spring and a secondary piston, the secondary piston is located on a side of the second spring close to the first sub-chamber, and the second spring abuts against the secondary piston or is connected to the secondary piston.
[0010] In some embodiments, a sealing assembly is provided at one end of the damping tube close to the connector, and the sealing assembly is used to seal the end of the damping tube close to the connector; the piston rod passes through the sealing assembly and can move axially along the damping tube relative to the sealing assembly.
[0011] In some embodiments, the sealing assembly includes a front end cover, a second sealing ring and a gasket arranged sequentially along the direction of contraction of the piston rod into the damping tube. The front end cover is interference fit with the damping tube, and the second sealing ring abuts against the inner wall of the piston rod and the damping tube.
[0012] In some embodiments, the second sealing ring is provided with a central hole for the piston rod to pass through, and the diameter of the central hole gradually decreases in the direction in which the piston rod contracts into the damping tube.
[0013] In some embodiments, when the piston rod extends out of the damping tube, the first spring provides a thrust to the main piston.
[0014] According to the second aspect of the utility model, an embodiment of the utility model provides a buffer device, comprising a shell, a baffle and a buffer for a movable door as described in any one of the first aspects above, the shell is provided with a sliding groove, the damping tube is fixed in the sliding groove, the connecting head and the baffle are both arranged in the sliding groove, and the connecting head and the baffle are connected, and the baffle is connected to the sliding groove in an axial sliding manner along the damping tube.
[0015] The utility model has at least the following beneficial effects: when the door body is close to the door frame, the door body drives the piston rod to extend out of the damping tube, the main piston squeezes the first cavity, and the damping fluid in the first cavity flows to the second cavity through the channel. Since the flow rate of the damping fluid in the first cavity flowing to the second cavity through the channel is low, the pressure of the first cavity will not decrease rapidly, thereby generating a reverse thrust on the main piston, limiting the main piston from moving too fast, thereby reducing the movement speed of the door body and playing a buffering role for the door body; and when the door body is away from the door frame, the door body drives the piston rod to shrink into the damping tube, the main piston squeezes the second cavity, and the damping fluid in the second cavity flows to the first cavity through the channel. In this flow direction, the flow rate of the damping fluid is relatively greater, and the pressure of the second cavity decreases faster, making it easy for the main piston to move, and then making the door body able to smoothly move away from the door frame; therefore, the utility model mainly generates a buffering effect through the pressure of the damping fluid. Compared with the traditional tension spring structure, after long-term use, the buffer of the utility model can still maintain a good buffering effect, and its buffering effect is not easy to decrease. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic structural diagram of a buffer for a movable door according to an embodiment of the utility model;
[0017] Figure 2 A schematic cross-sectional view of a buffer for a movable door according to an embodiment of the utility model when the piston rod is retracted;
[0018] Figure 3 A schematic cross-sectional view of a buffer for a movable door according to an embodiment of the utility model when the piston rod is extended;
[0019] Figure 4 It is a cross-sectional schematic diagram of a main piston in one state according to an embodiment of the utility model;
[0020] Figure 5 It is a cross-sectional schematic diagram of a main piston of an embodiment of the utility model in another state;
[0021] Figure 6 A cross-sectional schematic diagram of a sealing assembly according to an embodiment of the utility model;
[0022] Figure 7This is a schematic diagram of the structure of a buffer device according to an embodiment of the utility model;
[0023] Figure 8 This is an exploded schematic diagram of a buffer device according to an embodiment of the utility model.
[0024] Wherein, the accompanying drawings are marked as follows:
[0025] Damping tube 100, first cavity 101, second cavity 102, first sub-cavity 103, second sub-cavity 104, partition 110;
[0026] Connecting head 200, piston rod 210;
[0027] The main piston 300, the shaft body 310, the first convex ring 320, the first channel 321, the second channel 322, the first sealing ring 330, the second convex ring 340, and the third channel 341;
[0028] A first spring 400;
[0029] Protective device 500, auxiliary piston 510, second spring 520;
[0030] Sealing assembly 600, front end cover 610, second sealing ring 620, center hole 621, gasket 630;
[0031] Housing 700 , sliding slot 701 , and stopper 710 . DETAILED DESCRIPTION
[0032] The utility model provides the following description with reference to the accompanying drawings to help fully understand the various embodiments of the utility model as defined by the claims and their equivalents. The description includes various specific details to help understanding, but these details should be regarded as exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of the utility model.
[0033] In the description of the present invention, descriptions of orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0034] It will be understood that when one element (eg, a first element) is “connected” to another element (eg, a second element), the element may be directly connected to the other element or an intervening element (eg, a third element) may be present between the element and the other element.
[0035] The embodiment of the utility model provides a buffer for a movable door, such as Figure 1-3 As shown, it includes a damping tube 100, a connector 200, a piston rod 210, a main piston 300 and a first spring 400. The damping tube 100 is airtight and filled with a damping liquid. The damping liquid can be oil or other liquid that can provide damping force. The damping tube 100 is set to a closed structure to avoid leakage of the damping liquid. The main piston 300 and the first spring 400 are both arranged in the damping tube 100. One end of the piston rod 210 extends into the damping tube 100 and is connected to the main piston 300. The other end of the piston rod 210 is fixedly connected to the connector 200. Both the main piston 300 and the piston rod 210 can move along the axial direction of the damping tube 100. Since the connector 200, the piston rod 210 and the main piston 300 are linked, the connector 200 can also move along the axial direction of the damping tube 100 accordingly. The connector 200 is used to be connected to an external stopper. When the door body touches the stopper, the connector 200 is driven to move along the axial direction of the damping tube 100 accordingly.
[0036] The main piston 300 divides the inner cavity of the damping tube 100 into a first cavity 101 close to the connector 200 and a second cavity 102 far from the connector 200, and both the first cavity 101 and the second cavity 102 are filled with damping fluid. The first spring 400 is arranged in the second cavity 102, and one end of the first spring 400 abuts against the main piston 300 or is connected to the main piston 300, and the other end of the first spring 400 can abut against the end wall of the tail end of the damping tube 100, the partition arranged in the damping tube 100, or be fixedly connected to the damping tube 100. When the main piston 300 moves along the axial direction of the damping tube 100, the first spring 400 will be elastically expanded and contracted. The main piston 300 is provided with a channel for connecting the first cavity 101 and the second cavity 102, and the damping fluid in the first cavity 101 and the damping fluid in the second cavity 102 can flow through the channel. The channel is configured so that a flow velocity of the damping fluid in the second cavity 102 flowing through the channel toward the first cavity 101 is greater than a flow velocity of the damping fluid in the first cavity 101 flowing through the channel toward the second cavity 102 .
[0037] When the door body approaches the door frame, the state of the buffer of this embodiment will be changed from Figure 2 Towards Figure 3 The door body drives the piston rod 210 to extend out of the damping tube 100, and the main piston 300 squeezes the first cavity 101. The damping fluid in the first cavity 101 flows to the second cavity 102 through the channel. Since the flow rate of the damping fluid in the first cavity 101 to the second cavity 102 through the channel is low, the pressure in the first cavity 101 will not decrease rapidly, thereby generating a reverse thrust on the main piston 300, limiting the main piston 300 from moving too fast, thereby reducing the movement speed of the door body and having a buffering effect on the door body.
[0038] When the door body is away from the door frame, the state of the buffer of this embodiment will be changed from Figure 3 Towards Figure 2 The door body drives the piston rod 210 to contract into the damping tube 100, and the main piston 300 squeezes the second cavity 102. The damping fluid in the second cavity 102 flows to the first cavity 101 through the channel. In this flow direction, the flow speed of the damping fluid is relatively greater, and the pressure in the second cavity 102 decreases faster, making it easy for the main piston 300 to move, and thus allowing the door body to smoothly move away from the door frame.
[0039] Therefore, the buffering effect is mainly generated by the pressure of the damping fluid in this embodiment. Compared with the traditional tension spring structure, after long-term use, the buffer of this embodiment can still maintain a good buffering effect, and its buffering effect is not easy to reduce. Since there is no external tension spring, its overall structure is compact, thereby reducing the manufacturing cost, and the spring is arranged in the damping tube, which reduces the contact with the air and prevents rust, thereby increasing its service life. The noise generated by the expansion and contraction of the spring will also be effectively silenced by the damping tube. Therefore, the buffer of this embodiment is relatively quiet when used.
[0040] In some embodiments, Figure 3-5 As shown, the main piston 300 includes a shaft body 310 and a first sealing ring 330. The shaft body 310 extends along the axial direction of the damping tube 100, and the circumferential surface of the shaft body 310 is provided with a first convex ring 320 and a second convex ring 340, the second convex ring 340 is located on the side of the first convex ring 320 close to the connector 200, and the first sealing ring 330 is sleeved on the shaft body 310 and located between the first convex ring 320 and the second convex ring 340. The first sealing ring 330 abuts against the inner wall of the damping tube 100 to seal the outer periphery. Under the friction between the first sealing ring 330 and the inner wall of the damping tube 100, the moving direction of the main piston 300 relative to the damping tube 100 is opposite to the moving direction of the first sealing ring 330 relative to the shaft body 310.
[0041] The channel includes a first channel 321 formed between the first protruding ring 320 and the inner wall of the damping tube 100, a second channel 322 penetrating the first protruding ring 320 axially along the damping tube 100, and a third channel 341 penetrating the second protruding ring 340 axially along the damping tube 100. The cross-sectional area of the first channel 321 is greater than the cross-sectional area of the second channel 322. Therefore, the speed at which the damping fluid flows along the first channel 321 is greater than the speed at which it flows along the second channel 322.
[0042] like Figure 4 As shown in FIG. 1 , when the piston rod 210 extends out of the damping tube 100, Figure 4For example, the piston rod 210 moves to the right side in the figure, and the first sealing ring 330 moves toward the direction close to the first convex ring 320. The first sealing ring 330 will abut against the first convex ring 320 and block the first channel 321. The damping fluid in the first cavity 101 cannot pass through the first channel 321, but Figure 4 As shown by the middle arrow, the damping fluid first passes through the third channel 341, then passes through the central through hole of the first sealing ring 330, and then flows to the second cavity 102 via the second channel 322. Since the cross-sectional area of the second channel 322 is small, the damping fluid in the first cavity 101 can only pass slowly, so that the pressure of the first cavity 101 will not decrease rapidly, thereby generating a reverse thrust on the main piston.
[0043] like Figure 5 As shown in FIG. 1 , when the piston rod contracts into the damping tube 100, Figure 5 For example, the piston rod 210 moves to the left in the figure, and the first sealing ring 330 moves away from the first convex ring 320, thereby releasing the blockage of the first channel 321, and the damping fluid in the second cavity 102 can pass through the first channel 321. Figure 5 As shown by the middle arrow, the damping fluid in the second cavity 102 first passes through the first channel 321, then passes through the central through hole of the first sealing ring 330, and then flows to the first cavity 101 via the third channel 341. Since the cross-sectional area of the first channel 321 is large, the flow speed of the damping fluid is relatively larger, and the pressure of the second cavity 102 decreases faster, making it easier for the main piston to move.
[0044] Furthermore, there is one second channel 322, and the number of second channels 322 is smaller, so that the damping fluid flows through the second channel 322 at a lower speed, which can generate a greater reverse thrust on the main piston and achieve a better buffering effect. A plurality of third channels 341 are provided so that the damping fluid can pass quickly.
[0045] In some embodiments, Figure 2 and Figure 3As shown, a partition 110 is disposed in the second cavity 102, and the partition 110 divides the second cavity 102 into a first sub-cavity 103 close to the first cavity 101 and a second sub-cavity 104 far from the first cavity 101. The partition 110 is provided with a through hole connecting the first sub-cavity 103 and the second sub-cavity 104, so that the damping fluid in the first sub-cavity 103 and the second sub-cavity 104 can flow mutually. The first spring 400 is disposed in the first sub-cavity 103, and one end of the first spring 400 far from the main piston 300 can abut against the partition 110 or be connected to the partition. The second sub-chamber 104 is provided with a protective device 500 which can elastically expand and contract along the axial direction of the damping tube 100. When the pressure in the first sub-chamber 103 is greater than a preset pressure (the preset pressure is adjusted by a person skilled in the art according to actual conditions), the protective device 500 contracts in a direction away from the first sub-chamber 103 under the action of pressure. Since the first sub-chamber 103 and the second sub-chamber 104 are connected through the perforations on the partition 110, this is equivalent to increasing the space of the first sub-chamber 103, thereby releasing the pressure in the first sub-chamber 103, avoiding problems such as bursting of the damping tube 100 due to excessive hydraulic pressure, and can increase the service life of the entire buffer.
[0046] Furthermore, the protection device 500 includes a second spring 520 and a secondary piston 510, the secondary piston 510 is located on a side of the second spring 520 close to the first sub-chamber 103, one end of the second spring 520 abuts against the secondary piston 510 or is connected to the secondary piston 510, and the other end of the second spring 520 can abut against the rear end wall of the damping tube 100 or be connected to the damping tube 100. When the pressure in the first sub-chamber 103 is greater than the preset pressure, the hydraulic pressure will push the secondary piston 510 to move away from the first sub-chamber 103, and the second spring 520 will contract, which is equivalent to increasing the space of the first sub-chamber 103, so that the pressure in the first sub-chamber 103 can be released.
[0047] In some embodiments, Figure 2 and Figure 3 As shown, a sealing assembly 600 is provided at one end of the damping tube 100 close to the connector 200, and the sealing assembly 600 is used to seal the end of the damping tube 100 close to the connector 200 to prevent leakage of the damping fluid. At the same time, the piston rod 210 passes through the sealing assembly 600 and can move relative to the sealing assembly 600 along the axial direction of the damping tube 100 without affecting the movement of the piston rod 210.
[0048] Further, such as Figure 2 and Figure 6As shown, the sealing assembly 600 includes a front end cover 610, a second sealing ring 620 and a gasket 630 which are sequentially arranged along the direction in which the piston rod 210 contracts into the damping tube 100. The front end cover 610 is interference fit with the damping tube 100 to be clamped and fixed in the damping tube 100. The second sealing ring 620 abuts against the inner wall of the piston rod 210 and the damping tube 100 to improve the sealing performance and reduce the leakage of the damping fluid. The gasket 630 can provide protection for the second sealing ring 620. The main piston 300 will not be directly pressed on the second sealing ring 620, but will be pressed on the gasket 630, so that the impact on the sealing effect of the second sealing ring 620 can be reduced.
[0049] Furthermore, the second sealing ring 620 is provided with a center hole 621 for the piston rod 210 to pass through. In the direction in which the piston rod 210 contracts into the damping tube 100, the aperture of the center hole 621 gradually decreases. This structure makes it easier for the piston rod 210 to pass through the center hole 621, and the thickness of the part of the second sealing ring 620 close to the piston rod 210 is smaller and easier to deform, so that it can fit tightly against the piston rod 210 to improve the sealing effect.
[0050] In some embodiments, Figure 2 and Figure 3 As shown, when the door body is close to the door frame, the door body drives the piston rod 210 to extend out of the damping tube 100. Since the hydraulic pressure in the first cavity 101 is relatively large, if only relying on the driving force of the door body, there may be a problem that the piston rod 210 cannot be pushed to extend out of the damping tube 100. For this reason, the first spring 400 of this embodiment provides a thrust to the main piston 300, so that the original driving force of the door body and the thrust of the first spring 400 act on the main piston 300 together, ensuring that the piston rod 210 can smoothly extend out of the damping tube 100.
[0051] The embodiment of the utility model provides a buffer device, such as Figure 7 and Figure 8 As shown, the movable door buffer comprises a housing 700, a stopper 710 and any of the above-mentioned embodiments. The specific description of the movable door buffer can refer to the above-mentioned embodiments and will not be repeated here. The housing 700 is provided with a sliding groove 701, the damping tube 100 is fixed in the sliding groove 701, the connector 200 and the stopper 710 are both provided in the sliding groove 701, and the connector 200 and the stopper 710 are connected so that the main piston, the piston rod, the connector 200 and the stopper 710 are linked in the axial direction of the damping tube 100. The stopper 710 is slidably connected with the sliding groove 701 along the axial direction of the damping tube 100.
[0052] When the door body is closed, the contact piece on the door body will touch the stopper 710, thereby driving the stopper 710 to move to the side away from the damping tube 100. Correspondingly, the piston rod extends out of the damping tube 100. Due to the internal structure of the buffer, the stopper 710 can be limited from moving too fast, thereby reducing the movement speed of the door body and playing a buffering role on the door body.
[0053] When the door body is opened, the contact member on the door body will drive the stopper 710 to move toward the side close to the damping tube 100, and accordingly, the piston rod retracts into the damping tube 100 so as not to affect the opening of the door body.
[0054] The terms and words used in the above description and claims are not limited to the literal meanings, but are only used by the applicant to enable a clear and consistent understanding of the utility model. Therefore, it should be clear to those skilled in the art that the above description of various embodiments of the utility model is provided only for illustration, and not for limiting the utility model as defined by the attached claims and their equivalents.
Claims
1. A buffer for a sliding door, characterized in that: The invention comprises a damping tube, a connector, a piston rod, a main piston and a first spring; the damping tube is airtight and filled with damping fluid; the main piston and the first spring are both arranged in the damping tube, one end of the piston rod extends into the damping tube and is connected to the main piston, and the other end is fixedly connected to the connector, and both the main piston and the piston rod can move along the axial direction of the damping tube; the main piston divides the inner cavity of the damping tube into a first cavity close to the connector and a second cavity away from the connector, the first spring is arranged in the second cavity, and the first spring abuts against the main piston or is connected to the main piston; the main piston is provided with a channel for connecting the first cavity and the second cavity, and the channel is configured so that the flow velocity of the damping fluid in the second cavity flowing through the channel to the first cavity is greater than the flow velocity of the damping fluid in the first cavity flowing through the channel to the second cavity.
2. The buffer for a sliding door according to claim 1, characterized in that: The main piston includes a shaft body and a first sealing ring; the shaft body extends along the axial direction of the damping tube, and the circumferential surface of the shaft body is provided with a first convex ring and a second convex ring, the second convex ring is located on the side of the first convex ring close to the connecting head, the first sealing ring is sleeved on the shaft body and located between the first convex ring and the second convex ring, and the first sealing ring abuts against the inner wall of the damping tube; the channel includes a first channel formed between the first convex ring and the inner wall of the damping tube, a second channel penetrating the first convex ring along the axial direction of the damping tube, and a third channel penetrating the second convex ring along the axial direction of the damping tube, and the cross-sectional area of the first channel is greater than the cross-sectional area of the second channel; when the piston rod extends out of the damping tube, the first sealing ring abuts against the first convex ring and blocks the first channel, and when the piston rod contracts into the damping tube, the first sealing ring moves away from the first convex ring to release the blockage of the first channel.
3. The buffer for a sliding door according to claim 2, characterized in that: One second channel is provided, and a plurality of third channels are provided.
4. The buffer for a sliding door according to any one of claims 1 to 3, characterized in that: A partition is arranged in the second cavity, and the partition divides the second cavity into a first sub-cavity close to the first cavity and a second sub-cavity away from the first cavity. The partition is provided with a through hole connecting the first sub-cavity and the second sub-cavity. The first spring is arranged in the first sub-cavity. A protective device that can elastically expand and contract along the axial direction of the damping tube is arranged in the second sub-cavity; when the pressure in the first sub-cavity is greater than the preset pressure, the protective device shrinks in the direction away from the first sub-cavity under the action of pressure.
5. The buffer for a sliding door according to claim 4, characterized in that: The protection device comprises a second spring and a secondary piston. The secondary piston is located on a side of the second spring close to the first sub-chamber. The second spring abuts against the secondary piston or is connected to the secondary piston.
6. The buffer for a sliding door according to any one of claims 1 to 3, characterized in that: A sealing assembly is provided at one end of the damping tube close to the connector, and the sealing assembly is used to seal the end of the damping tube close to the connector; the piston rod passes through the sealing assembly and can move relative to the sealing assembly along the axial direction of the damping tube.
7. The buffer for a sliding door according to claim 6, characterized in that: The sealing assembly includes a front end cover, a second sealing ring and a gasket which are arranged in sequence along the direction in which the piston rod contracts into the damping tube. The front end cover is interference fit with the damping tube, and the second sealing ring abuts against the inner wall of the piston rod and the damping tube.
8. The buffer for a sliding door according to claim 7, characterized in that: The second sealing ring is provided with a central hole for the piston rod to pass through, and the aperture of the central hole gradually decreases in the direction in which the piston rod contracts into the damping tube.
9. The buffer for a sliding door according to any one of claims 1 to 3, characterized in that: When the piston rod extends out of the damping tube, the first spring provides thrust to the main piston.
10. A buffer device, characterized in that: It comprises a shell, a baffle and a buffer for a movable door as described in any one of claims 1 to 9, wherein the shell is provided with a sliding groove, the damping tube is fixed in the sliding groove, the connecting head and the baffle are both arranged in the sliding groove, and the connecting head and the baffle are connected, and the baffle is connected to the sliding groove in an axial sliding manner along the damping tube.