Auxiliary device for setting and unsetting test of mechanical compression packer

Abstract

The utility model discloses a mechanical compression type packer setting and unsetting test auxiliary device which comprises a packer connecting and locking assembly, a power hydraulic cylinder and a packer locking and unlocking mechanism. The power hydraulic cylinder comprises a cylinder barrel, a piston is arranged in the cylinder barrel in a sleeved mode, a piston rod is connected in the piston, and the piston rod is connected with a packer connecting locking assembly. The power hydraulic cylinder is provided with a setting pressurizing opening above the piston, and the power hydraulic cylinder is provided with an unsetting pressurizing opening below the piston; the lower end of the power hydraulic cylinder and the piston rod are sealed in a long-acting mode, and the upper end of the power hydraulic cylinder and the piston rod are sealed through a packer locking and unlocking mechanism. When the portable pressure test pump is used for testing a tested packer, the requirements of quickly setting and unsetting the packer can be met by adopting an electric or manual pressure test pump, and the portable performance is better.

Description

TECHNICAL FIELD

[0001] The utility model relates to packer detection equipment technical field, and specifically is mechanical compression type packer setting and unsetting test auxiliary device. BACKGROUND

[0002] Packer is a kind of downhole tool widely used in oil and gas well downhole operation, is widely used in separate layer oil production, separate layer fracturing, separate layer water injection and other downhole operations, plays the purpose of isolating production layer, controlling fluid, protecting casing.With the deepening of oil and gas field development, the formation condition is more and more complex, and the failure of packer occurs occasionally, and the complex process puts forward higher requirements for the pressure resistance and other working performances of packer.Therefore, packer needs to be detected comprehensively in laboratory before entering well, to avoid downhole accidents caused by tool quality as much as possible, and to ensure the safety production of oil and gas well.

[0003] At present, for the performance test of Y221 and other mechanical compression setting type packers, test tooling or downhole experimental well is generally used, and special equipment is needed to provide setting force and unsetting force, especially after setting, pressure resistance and other tests are carried out by using existing test tooling, unsetting operation cannot be carried out directly by using test tooling, and special equipment such as tension test frame needs to be used for unsetting operation.The operation process is relatively complex, the labor intensity of test personnel is high, quick unsetting cannot be realized, for a large number of packer test and detection tasks, the working cycle is relatively long, and the working efficiency is low.

[0004] Publication No.: CN103630349B discloses a compression type packer test device, which comprises an ultrahigh pressure cylinder, a lower sealing structure and an upper sealing structure arranged at the lower and upper ends of the ultrahigh pressure cylinder, a test auxiliary component arranged in the ultrahigh pressure cylinder, and a heating jacket arranged on the outer wall of the ultrahigh pressure cylinder.The above-mentioned invention effectively realizes high temperature and high pressure test of compression type and expansion type packer assemblies of various sizes in the same container.

[0005] When the mechanical compression type packer setting and unsetting is carried out by using the prior art, tension and pressure equipment is used to provide power, and the portability is poor.

[0006] Publication No.: CN109799081B discloses a packer test device and use method, which comprises a central pipe, a limiting screw sleeve, a connecting screw sleeve, a sealing ring, a shell, an injection head, a push cylinder and a packer, the packer comprises a fixed screw sleeve, a rubber cylinder, a spacer ring, a pressure ring, a male expansion ring, a female expansion ring and a sliding sleeve, the fixed screw sleeve is fixedly arranged at the middle part of the central pipe, and the sliding sleeve is fixed at the lower end of the central pipe through a shear pin;The limiting screw sleeve is arranged at the upper part of the central pipe, the sealing ring is located between the limiting screw sleeve and the fixed screw sleeve, the upper end of the shell is fixedly connected with the sealing ring, the lower end of the shell is connected with the push cylinder, the injection head is located on the shell, the injection head is communicated with the gap between the sealing ring and the fixed screw sleeve, and the connecting screw sleeve is located in the limiting screw sleeve.

[0007] The prior art uses a tension and compression device to provide power when the mechanical compression packer is set and released, and has poor portability.

[0008] Publication No. CN205642812U discloses a packer setting and pressure resistance performance detection device, which comprises an outer cylinder, a sealing insert pipe, an upper joint, and a sealing device. The upper joint is connected to the upper end of the outer cylinder, the sealing insert pipe is inserted into the inner cavity of the outer cylinder from the upper joint, the sealing device is arranged between the inner wall of the upper joint and the sealing insert pipe, the upper joint is provided with a radial liquid inlet, the liquid inlet communicates the annular space between the outer cylinder and the sealing insert pipe, and the height of the liquid inlet is lower than that of the sealing device.

[0009] The prior art uses a tension and compression device to provide power when the mechanical compression packer is set and released, and has poor portability.

[0010] In summary, the technical solutions of the above disclosed technologies, the technical problems to be solved, and the beneficial effects produced are all different from those of the present utility model. The above disclosed technology documents do not have technical inspiration for more technical features, technical problems to be solved, and beneficial effects of the present utility model. Utility model content

[0011] In view of the above defects of the prior art, the purpose of the present utility model is to provide a mechanical compression packer setting and releasing test auxiliary device.

[0012] In order to achieve the above purpose, the present utility model adopts the following technical solutions:

[0013] The mechanical compression packer setting and releasing test auxiliary device comprises a packer connecting and locking assembly, a power hydraulic cylinder, and a packer locking and releasing mechanism. The power hydraulic cylinder comprises a cylinder barrel, a piston is sleeved in the cylinder barrel, a piston rod is connected to the piston, and the piston rod is connected to the packer connecting and locking assembly. The power hydraulic cylinder is provided with a setting and pressing port above the piston, and is provided with a releasing and pressing port below the piston. The lower end of the power hydraulic cylinder is in long-term sealing with the piston rod, and the upper end of the power hydraulic cylinder is sealed with the piston rod through the packer locking and releasing mechanism.

[0014] Further, the power hydraulic cylinder comprises an upper end cover, a cylinder barrel, and a lower end cover connected in sequence from top to bottom.

[0015] Specifically, the upper end cover is provided with a setting and pressing port, and the lower end cover is provided with a releasing and pressing port.

[0016] Specifically, the inner wall of the lower end cover is provided with a sealing convex ring, and the inner wall of the sealing convex ring is in contact with and sealed with the outer wall of the piston rod.

[0017] Further, the packer locking and releasing mechanism comprises a lock sleeve and a lock ring.

[0018] Specifically, the lock sleeve is sleeved on the piston rod, the lock sleeve is located above the piston, the inner wall of the upper end cover is provided with a locking convex ring, the locking ring is arranged in the inner wall of the locking convex ring, the inner wall of the locking ring is connected with the outer wall of the lock sleeve in one-way non-retraction, and the lock sleeve can only move downward along the locking ring;

[0019] Specifically, the sealing compression ring is sleeved on the piston rod, the sealing compression ring is sealed with the upper end cover, the sealing compression ring is sealed with the piston rod, and the sealing compression ring is connected with the upper end cover through the compression ring.

[0020] Further, the packer connecting locking assembly comprises a center pipe;

[0021] Specifically, the center pipe is inserted into the inner hole of the piston rod, the upper end of the center pipe is connected with the locking nut, the lower end of the center pipe is connected with the connecting joint, the lower end surface of the piston rod is in contact with the connecting joint, and the upper end surface of the piston rod is in contact with the locking nut.

[0022] Further, the lower end of the lower end cover is connected with a sealing joint, and the sealing joint is used for connecting a test casing.

[0023] Further, the inner wall of the upper end cover is provided with an upper inner convex ring, and the setting and pressing port radially penetrates through the upper inner convex ring; the inner wall of the lower end cover is provided with a lower inner convex ring, and the unsetting and pressing port radially penetrates through the lower inner convex ring.

[0024] Specifically, the lower end surface of the upper inner convex ring is in contact with the upper end surface of the cylinder barrel, and the upper end surface of the lower inner convex ring is in contact with the lower end surface of the cylinder barrel.

[0025] Further, the piston rod is provided with an upward first step, the piston is located on the first step, the piston rod is connected with a piston locking nut, and the piston locking nut presses the piston on the first step.

[0026] Further, the lower end surface of the lock sleeve is located on the upper end surface of the piston locking nut, the piston rod is connected with a lock sleeve locking nut, and the upper end surface of the lock sleeve is locked through the lock sleeve locking nut.

[0027] Further, the inner wall of the locking convex ring is provided with an upward second step, and the locking ring is located on the second step.

[0028] Specifically, the lower end outer wall of the sealing compression ring is provided with a lower limiting convex ring, the upper end inner wall of the sealing compression ring is provided with an upper limiting convex ring, the lower limiting convex ring is in contact with the upper end surface of the locking convex ring to position the upper end surface of the locking ring, and the upper limiting convex ring positions the upper end surface of the lock sleeve locking nut.

[0029] Specifically, the inner wall of the lower end of the compression ring is connected with the outer wall of the upper end of the upper end cover, the lower limiting convex ring of the compression ring is locked and sealed, the outer wall of the lower limiting convex ring is sealed with the inner wall of the upper end cover, and the inner wall of the upper limiting convex ring is sealed with the outer wall of the piston rod.

[0030] Further, the one-way non-retracting connection is a clasp, the lock ring is an open ring, the inner wall of the lock ring is provided with an inner clasp, the outer wall of the lock sleeve is provided with an outer clasp, the inner clasp is matched with the outer clasp, and the lock sleeve can only move downward.

[0031] Compared with the prior art, the utility model has the following beneficial effects:

[0032] 1. The utility model improves the locking and unlocking structure of the packer setting and releasing, the lock and release mechanism is externally detachable design, the setting and releasing operation of the measured packer is simple, convenient to disassemble and assemble, the test cost is lower, and the utility model has remarkable use effect and application value.

[0033] 2. In the utility model, the connecting joint is inserted with the lower outer surface of the piston rod, the locking central tube and the central tube locking nut are used to assist in locking the measured packer, and the installation is simple and fast.

[0034] 3. When the utility model is used for testing the measured packer, electric or manual pressure testing pump can realize the requirements of fast setting and releasing the packer, and the utility model has good portability; the utility model can also meet the requirements of the slip anchoring and pressure test of the measured packer. BRIEF DESCRIPTION OF DRAWINGS

[0035] Fig. 1 It is the structure diagram of the utility model mechanical compression type packer setting and releasing test auxiliary device;

[0036] Fig. 2 It is the working state schematic diagram when the measured packer is set and released;

[0037] Fig. 3 It is the working state schematic diagram when the measured packer is released.

[0038] In the drawing: central tube 1, locking nut 2, piston rod 3, sealing compression ring 4, compression ring 5, upper end cover 6, setting and pressing port 6-1, cylinder 7;Lower end cover 8, releasing and pressing port 8-1, sealing connector 9, upper sealing differential pressure pressing port 9-1, connecting joint 10, piston 11, piston locking nut 12, lock ring 13, lock sleeve 14, lock sleeve locking nut 15, test casing 16, mechanical compression type packer 17. DETAILED DESCRIPTION

[0039] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described, obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0040] Embodiment 1:

[0041] Please refer to Figs. 1 to 3 The embodiment provides a mechanical compression packer setting and unsetting test auxiliary device, which comprises a power liquid cylinder, a packer locking and unlocking mechanism, a packer connecting and locking assembly and a sealing joint 9.

[0042] Further, the power liquid cylinder comprises an upper end cover 6, a cylinder barrel 7 and a lower end cover 8 connected in sequence from top to bottom, the upper end cover 6 is provided with a setting and pressing port 6-1, the lower end cover 8 is provided with an unsetting and pressing port 8-1, the cylinder barrel 7 is provided with a piston 11, and the inner wall of the piston 11 is connected with a piston rod 3.

[0043] Specifically, the upper end cover 6, the cylinder barrel 7 and the lower end cover 8 are connected through threads and sealed through a sealing ring.

[0044] Specifically, the inner wall of the upper end cover 6 is provided with an upper inner convex ring, the setting and pressing port 6-1 radially penetrates through the upper inner convex ring, the inner wall of the lower end cover 8 is provided with a lower inner convex ring, the unsetting and pressing port 8-1 radially penetrates through the lower inner convex ring, the lower end surface of the upper inner convex ring is in contact with the upper end surface of the cylinder barrel 7, and the upper end surface of the lower inner convex ring is in contact with the lower end surface of the cylinder barrel 7, so that the setting and pressing port 6-1 and the unsetting and pressing port 8-1 do not coincide with the piston 11, and the controllability of pressing is maintained.

[0045] Specifically, the inner wall of the lower end cover 8 is provided with a sealing convex ring, the inner wall of the sealing convex ring is in contact with the outer wall of the piston rod 3 and sealed through a sealing ring.

[0046] Specifically, the piston rod 3 is provided with an upward first step, the piston 11 is seated on the first step, the piston rod 3 is threadedly connected with a piston locking nut 12, and the piston locking nut 12 presses the piston 11 on the first step.

[0047] Specifically, the piston 11, the cylinder barrel 7 and the piston rod 3 are sealed through a sealing ring.

[0048] Further, the packer locking and unlocking mechanism comprises a locking sleeve 14 and a locking ring 13, the locking sleeve 14 is sleeved on the piston rod 3, the locking sleeve 14 is located above the piston 11, the inner wall of the upper end cover 6 is provided with a locking convex ring, the locking ring 13 is arranged in the inner wall of the locking convex ring, the inner wall of the locking ring 13 is connected with the outer wall of the locking sleeve 14 in one-way non-backoff mode, and the locking sleeve 14 can only move downward along the locking ring 13.

[0049] Specifically, the lower end surface of the locking sleeve 14 is positioned on the upper end surface of the piston locking nut 12, the piston rod 3 is threadedly connected with the locking sleeve locking nut 15, and the upper end surface of the locking sleeve 14 is locked by the locking sleeve locking nut 15.

[0050] Specifically, the inner wall of the locking convex ring is provided with an upward second step, the locking ring 13 is seated on the second step, the sealing compression ring 4 is sleeved on the piston rod 3, the lower end outer wall of the sealing compression ring 4 is provided with a lower limiting convex ring, the upper end inner wall of the sealing compression ring 4 is provided with an upper limiting convex ring, the lower limiting convex ring is in contact with the upper end surface of the locking convex ring to position the upper end surface of the locking ring 13, and the lower end surface of the upper limiting convex ring positions the upper end surface of the locking sleeve locking nut 15, the sealing compression ring 4 is externally sleeved with the compression ring 5, the lower end inner wall of the compression ring 5 is threadedly connected with the upper end outer wall of the upper end cover 6, and the compression ring 5 locks the lower limiting convex ring of the sealing compression ring 4.

[0051] Specifically, the outer wall of the lower limiting convex ring, the inner wall of the upper end cover 6 and the outer wall of the piston rod 3 are all sealed by sealing rings.

[0052] Specifically, the one-way non-backoff connection is a zigzag buckle, the inner wall of the locking ring 13 is provided with an inner zigzag buckle, the outer wall of the locking sleeve 14 is provided with an outer zigzag buckle, and the inner zigzag buckle and the outer zigzag buckle are matched to enable the locking sleeve 14 to only move downward.

[0053] Specifically, the locking ring 13 is an open ring, which facilitates the dismounting of the locking ring 13, and the opening of the locking ring 13 is a straight slot or an inclined slot which is longitudinally and through the locking ring 13.

[0054] Further, the packer connecting and locking assembly comprises a central pipe 1, the central pipe 1 is inserted into the inner hole of the piston rod 3, the upper end of the central pipe 1 is threadedly connected with the locking nut 2, the lower end of the central pipe 1 is threadedly connected with the connecting joint 10, the lower end surface of the piston rod 3 is in contact with the connecting joint 10, and the upper end surface of the piston rod 3 is in contact with the locking nut 2, so that the central pipe 1, the connecting joint 10 and the piston rod 3 are locked.

[0055] Specifically, the lower end of the connecting joint 10 is provided with a joint thread for connecting the mechanical compression packer 17.

[0056] Specifically, the connecting joint 10 is provided with a cover ring at the upper end, the lower end of the piston rod 3 is inserted into the cover ring and positioned in contact with the transition step, and the inner wall of the cover ring is sealed with the outer wall of the piston rod 3 through a sealing ring.

[0057] Further, the lower end of the lower end cover 8 is threadedly connected to a sealing joint 9, which is sealed through a sealing ring, and the sealing joint 9 is provided with an upper sealing differential pressure pressing port 9-1, and the sealing joint 9 is used to connect a test sleeve 16.

[0058] Embodiment 2:

[0059] Based on the embodiment 1, the embodiment provides a use method of the mechanical compression packer setting and unsetting test auxiliary device, including the following steps:

[0060] Before the packer is set:

[0061] The sealing joint 9 is connected to the lower end cover 8 of the power liquid cylinder and the test sleeve 16, respectively, the mechanical compression packer 17 is connected to the connecting joint 10, the connecting joint 10 is connected to the central tube 1 and is inserted into the inner hole of the piston rod 3 as a whole, and the piston rod 3 is locked with the central tube locking nut 2.

[0062] As shown in the figure, when the packer is set: Fig. 2

[0063] The setting and pressing port 6-1 of the upper end cover 6 is connected to the pressing pipeline and the pressure test pump, the cavity between the upper end cover 6, the sealing ring 4 and the piston 11 is pressed by the pressure test pump, the pressure acts on the upper end surface of the piston 11 and forms a downward thrust, which pushes the piston rod 3 downward and transmits the thrust to the connecting and locking assembly of the mechanical compression packer 17 to compress the packer to set; at the same time, the downward thrust also drives the lock sleeve 14 fixed on the piston rod 3 to move downward, so that the lock ring 13 and the lock sleeve 14 slide relatively, and the connecting and locking assembly and other components of the mechanical compression packer 17 are locked through the cooperation of the ratchet-shaped threads between the lock ring 13 and the lock sleeve 14, so as to prevent back-off and maintain the setting force.

[0064] In the setting state of the mechanical compression packer 17, the pressing pipeline is connected to the upper sealing differential pressure pressing port 9-1 of the sealing joint 9, so as to test the upper pressure difference resistance of the rubber cylinder of the mechanical compression packer 17.

[0065] As shown in the figure, when the packer is unset: Fig. 3

[0066] ​​Remove the compression ring 5, take out the sealing compression ring 4, connect the pressure pipeline with the unsealing pressure port 8-1 of the lower end cover 8, the cavity between the lower end cover 8 and the piston 11 can be pressurized by the pressure test pump, the pressure acts on the lower end surface of the piston 11 and forms an upward thrust, drives the piston rod 3 and the connecting locking assembly of the mechanical compression packer 17 to go up, and pulls the packer unsealing.

[0067] In the present application, the parts not discussed in detail, the connection mode of each part in the present application belongs to the known technology in the technical field. Direct application can be used, and will not be described again.

[0068] In the present application, the term "a plurality of" refers to two or more, unless otherwise explicitly limited. The terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, "connecting" can be fixed connection, or detachable connection, or integrally connected; "connected" can be directly connected, or indirectly connected through an intermediate medium. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0069] In the description of the present application, it should be understood that the terms "up", "down", "left", "right", "front", "back" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or unit referred to must have a particular direction, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the present application.

[0070] In the description of the present application, the terms "one embodiment", "some embodiments", "specific embodiments" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0071] The above is only the preferred embodiment of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A mechanical compression packer setting and unsetting test auxiliary device, comprising a packer connecting and locking assembly, characterized in that, Also include power liquid cylinder, packer lock mechanism; The power liquid cylinder includes a cylinder barrel, a piston is sleeved in the cylinder barrel, a piston rod is connected in the piston, and the piston rod is connected with a packer connecting and locking assembly; The power liquid cylinder is provided with a setting and pressing port above the piston, and is provided with an unsetting and pressing port below the piston; The lower end of the power liquid cylinder is long-term sealed with the piston rod, and the upper end of the power liquid cylinder is sealed with the piston rod through the packer lock mechanism.

2. The mechanical compression packer setting and unsetting test auxiliary device according to claim 1, characterized in that, The power liquid cylinder includes an upper end cover, a cylinder barrel and a lower end cover connected in sequence from top to bottom; The upper end cover is provided with a setting and pressing port, and the lower end cover is provided with an unsetting and pressing port; The inner wall of the lower end cover is provided with a sealing convex ring, and the inner wall of the sealing convex ring is in contact with and sealed with the outer wall of the piston rod.

3. The mechanical compression packer setting and unsetting test auxiliary device according to claim 2, characterized in that, The packer lock mechanism includes a lock sleeve and a lock ring; The lock sleeve is sleeved on the piston rod, the lock sleeve is located above the piston, the inner wall of the upper end cover is provided with a locking convex ring, the lock ring is arranged on the inner wall of the locking convex ring, the inner wall of the lock ring is in one-way non-back connection with the outer wall of the lock sleeve, and the lock sleeve can only move downward along the lock ring; The piston rod is sleeved with a sealing compression ring, the sealing compression ring is sealed with the upper end cover, the sealing compression ring is sealed with the piston rod, and the sealing compression ring is connected with the upper end cover through a compression ring.

4. The setting and unsetting test auxiliary device for mechanical compression packer according to claim 1, characterized in that, The packer connecting and locking assembly includes a central tube; The central tube is inserted into the inner hole of the piston rod, the upper end of the central tube is connected with a locking nut, the lower end of the central tube is connected with a connecting joint, the lower end surface of the piston rod is in contact with the connecting joint, and the upper end surface of the piston rod is in contact with the locking nut.

5. The setting and unsetting test auxiliary device for mechanical compression packer according to claim 2, characterized in that, The lower end of the lower end cover is connected with a sealing joint, and the sealing joint is used for connecting a test casing.

6. The setting and unsetting test auxiliary device for mechanical compression packer according to claim 2, characterized in that, The inner wall of the upper end cover is provided with an upper inner convex ring, and the setting and pressing port radially penetrates through the upper inner convex ring; the inner wall of the lower end cover is provided with a lower inner convex ring, and the unsetting and pressing port radially penetrates through the lower inner convex ring; The lower end surface of the upper inner convex ring is in contact with the upper end surface of the cylinder barrel, and the upper end surface of the lower inner convex ring is in contact with the lower end surface of the cylinder barrel.

7. The setting and unsetting test auxiliary device for mechanical compression packer according to claim 3, characterized in that, The piston rod is provided with an upward first step, the piston is seated on the first step, the piston rod is connected with a piston locking nut, and the piston locking nut presses the piston on the first step.

8. The mechanical compression packer setting and unsetting test auxiliary device according to claim 7, characterized in that, The lower end surface of the lock sleeve is positioned on the upper end surface of the piston locking nut, the piston rod is connected with a lock sleeve locking nut, and the upper end surface of the lock sleeve is locked through the lock sleeve locking nut.

9. The mechanical compression packer setting and unsetting test auxiliary device according to claim 8, characterized in that, The inner wall of the locking convex ring is provided with an upward second step, and the lock ring is seated on the second step; The lower end outer wall of the sealing compression ring is provided with a lower limiting convex ring, and the upper end inner wall of the sealing compression ring is provided with an upper limiting convex ring; the lower limiting convex ring is in contact with the upper end surface of the locking convex ring to position the upper end surface of the lock ring, and the upper limiting convex ring positions the upper end surface of the lock sleeve locking nut; The lower end inner wall of the compression ring is connected with the upper end outer wall of the upper end cover, the lower limiting convex ring of the compression ring is locked by the compression ring, the outer wall of the lower limiting convex ring is sealed with the inner wall of the upper end cover, and the inner wall of the upper limiting convex ring is sealed with the outer wall of the piston rod.

10. The setting and unsetting test auxiliary device for mechanical compression packer according to claim 3, characterized in that, The one-way non-back connection is a zigzag buckle, the lock ring is an open ring, the inner wall of the lock ring is provided with an inner zigzag buckle, the outer wall of the lock sleeve is provided with an outer zigzag buckle, the inner zigzag buckle cooperates with the outer zigzag buckle to enable the lock sleeve to only move downward.

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