Releasing packer

Abstract

The utility model belongs to the technical field of oil casing underground layering tools, and particularly relates to a releasing packer which comprises an upper releasing connector fixedly connected with an oil pipe and further comprises a releasing core pipe, a setting front sleeve, a setting rear sleeve and a central pipe. A self-adjusting connecting mechanism is arranged between the fishing head and the setting front sleeve, the self-adjusting connecting mechanism comprises a connecting pin in a right triangle shape, the connecting pin extends out of the inner surface of the setting front sleeve and then is inserted into the surface of the fishing head, and then the setting front sleeve is connected with the fishing head. The releasing packer is driven by an oil pipe to a designated position underground and then is pressed and set, then the oil pipe and the packer are separated, a casing pipe is not damaged, the sealing performance is good, releasing and unsealing are reliable, the tool is provided with two sets of releasing modes of hydraulic pressure and forward rotation, releasing of the tool under special conditions is guaranteed, and other tools can be hung to be used in a matched mode.

Description

Technical Field

[0001] The utility model relates to the technical field of downhole layering tools for petroleum casings, in particular to a hands-free packer. Background Art

[0002] During the oil extraction process, it is usually necessary to seal the oil, gas and water layers at the wellhead to achieve operations such as stratified oil production, stratified water injection, stratified testing, stratified research, stratified management, and stratified transformation.

[0003] The Chinese patent with the authorization announcement number CN2528926Y discloses a release packer, and the utility model discloses a release packer, which includes a force mechanism, a locking and unsealing mechanism, a sealing mechanism and an anchoring mechanism; it also includes a release and emergency release mechanism, which mainly includes a locking claw inner sleeve, a sliding sleeve, a locking claw, a release shear pin, a support ring and a nut. One end of the mechanism is clamped on one end face of the central tube through the step of the locking claw, and the other end is connected to the inner central tube, and is organically connected to other mechanisms. When the conventional release fails, the right-hand oil pipe string can be released.

[0004] ‌However,‌ traditional packers cannot meet the needs of side drilling, casing conversion wells, and small-diameter oil wells, and have problems such as easy failure, sliding, low bearing capacity, low construction success rate, and difficulty in unsealing. In addition, during the release or unsealing stage, the spear must be extended or pulled out by rotation to achieve a specific action, but the torque generated will increase the load on the equipment and cause the placement of the packer on the inner wall of the wellbore to be unstable. Therefore, the utility model proposes a release packer to solve the shortcomings of the above-mentioned technical problems. Utility Model Content

[0005] Based on the above existing technical problems, the utility model proposes a hands-free packer.

[0006] The utility model provides a hand-release packer, comprising a hand-release upper joint fixedly connected to the oil pipe, and also comprising a hand-release core tube, a front sleeve for setting, a rear sleeve for setting, and a center tube, wherein the front sleeve for setting is tightly connected to the bottom of the hand-release joint and moves downward after being pressurized, and the rear sleeve for setting is located below the front sleeve for setting and bears the pressure from the front sleeve for setting, the hand-release core tube passes through the front sleeve for setting and the rear sleeve for setting and is coaxially connected to the center tube, a fishing head is provided at the bottom of the front sleeve for setting, a self-adjusting connecting mechanism is provided between the fishing head and the front sleeve for setting, and the self-adjusting connecting mechanism comprises a connecting pin in the shape of a right triangle, and the connecting pin extends out from the inner surface of the front sleeve for setting and then is inserted into the surface of the fishing head, thereby connecting the front sleeve for setting and the fishing head.

[0007] Preferably, a releasing pawl is fixedly connected to the outer surface of the releasing mandrel, a ball seat is fixedly connected to the bottom of the releasing mandrel, and a steel ball is arranged inside the ball seat.

[0008] Through the above technical solution, the releasing pawl realizes the releasing function during the releasing operation through the interaction with the locking block. The locking block is usually installed outside the releasing mandrel. When the releasing operation is performed, the locking block will be released under a certain pressure or displacement, so that the releasing pawl participates in the releasing mechanism. This design ensures the safety and reliability of the releasing device. The steel ball is accommodated inside the ball seat and is used to block the internal flow channel of the packer.

[0009] Preferably, an upper cone and a lower cone are respectively fixedly sleeved on the outer surfaces of the upper end and the lower end of the central tube. A rubber barrel assembly is slidably sleeved on the outer surface of the middle part of the central tube. A slip cage is installed below the rubber barrel of the rubber barrel assembly, and slips are slidably telescoped in an annular array on the outer surface of the slip cage.

[0010] Through the above technical solution, the upper cone, the lower cone and the central tube are linked, so that after the slip cage fixes the slips and maintains their positions, the central tube pushes the upper cone to move, so that the upper cone pushes the slips to expand in the slip cage, realizing the mechanical locking function of the setting action, ensuring that the packer will not be accidentally released during operation. At the same time, after the setting sleeve is moved after setting, the rubber barrel of the rubber barrel assembly is squeezed by the setting sleeve to form an expansion, forming an additional seal.

[0011] Preferably, a setting piston is arranged inside the pre-setting sleeve, and shear pins are arranged inside the post-setting sleeve.

[0012] Through the above technical solution, the setting piston is located inside the pre-setting sleeve and moves downward when pressurized to push the pre-setting sleeve to complete the sealing. The shear pins connect multiple components and break under a specific pressure to release other components, ensuring a smooth release.

[0013] Preferably, the self-adjusting connection mechanism further includes a connecting pipe fixedly communicated with the lower surface of the fishing head. A conical connector is fixedly connected to the lower surface of the connecting pipe, and the surface of the connector is slidably connected with the outer surface of the connecting pin.

[0014] Through the above technical solution, in order to lift the packer out of the wellbore, the fishing head can be inserted into the pre-setting sleeve to catch the pre-setting sleeve, and then directly lifting it can release the packer and lift it out of the wellbore. In order to ensure that the fishing head will not be separated from the pre-setting sleeve during the lifting process, when the fishing head is inserted into the pre-setting sleeve, it is not necessary to rotate the fishing head, and the connecting pin can extend out and be clamped with the surface of the connector, thereby avoiding the separation of the pre-setting sleeve.

[0015] Preferably, a movable head is slidably sleeved on the outer surface of the connecting pipe. A tapered docking groove is formed on the upper surface of the clamping joint. The lower outer surface of the movable head is slidably inserted into the inner wall of the docking groove. A first return spring is fixedly sleeved on the outer surface of the connecting pipe. The free end of the first return spring is fixedly connected to the inner side wall of the clamping joint.

[0016] Through the above technical solution, in order to realize the clamping connection between the fishing head and the connecting pin, a movable head is arranged on the outer surface of the connecting pipe, so that the connecting pin is clamped between the movable head and the clamping joint. During the releasing process, in order to realize the quick separation between the fishing head and the pre-setting sleeve, the fishing head continues to move downward for a certain distance. At this time, the movable head presses the inclined surface of the connecting pin, causing it to retract and disengage from the clamping of the clamping joint. The movable head and the connecting pin are mutually pressed. At this time, when the fishing head moves upward, the movable head can move downward on the outer surface of the connecting pipe until the lower surface of the movable head is inserted into the docking groove. Then the connecting pin slides over the tapered surface of the clamping joint, and under the action of the first return spring, the movable head is reset, thus realizing the releasing action.

[0017] Preferably, a connecting ring is fixedly sleeved on the outer surface of the pre-setting sleeve. T-shaped telescopic grooves are symmetrically formed inside the connecting ring and the pre-setting sleeve. The outer surface of the connecting pin is slidably connected to the inner wall of the telescopic groove. One side surface of the connecting pin is fixedly connected with a telescopic rod. A second return spring is fixedly sleeved on the outer surface of the telescopic rod. The free end of the second return spring is fixedly connected to the inner wall of the telescopic groove.

[0018] Through the above technical solution, in order to realize the telescoping of the connecting pin and thus complete the clamping connection with the fishing head, when the movable head presses the connecting pin, the connecting pin drives the telescopic rod to retract in the telescopic groove. After the fishing head is withdrawn, the connecting pin is reset under the action of the second return spring. When the fishing head extends, the clamping joint can press the connecting pin to retract. After the clamping joint passes by the connecting pin, the connecting pin is reset to realize the connecting function.

[0019] The beneficial effects of the present utility model are as follows:

[0020] 1. Due to the adoption of the double-directional slip design, the hanging load is large, and various types of screen pipes can be hung for sand control, simplifying the sand control process, saving construction costs, and being applicable to sidetracking wells, casing deformation wells, and small-diameter oil wells.

[0021] 2. By setting up a self-adjusting connection mechanism, the pre-setting sleeve can be quickly connected to and disengaged from the fishing head. During the adjustment process, when the fishing head extends, the clamping joint can squeeze the connecting pin to retract. After the clamping joint passes the connecting pin, the connecting pin resets to achieve the connection function. When disengaging, the fishing head continues to move downward for a certain distance. At this time, the movable head squeezes the inclined surface of the connecting pin, causing it to retract and disengage from the clamping of the clamping joint. The movable head and the connecting pin squeeze each other. At this time, when the fishing head moves upward, the movable head can move downward on the outer surface of the connecting pipe until the lower surface of the movable head is inserted into the docking groove. Then the connecting pin slides over the conical surface of the clamping joint, and under the action of the first return spring, the movable head resets, thus realizing the releasing action.

[0022] 3. A releasing packer involved in the present utility model is brought to a designated position underground by a tubing string and then pressure-set. Then the tubing string and the packer are separated without damaging the casing. It has good sealing performance, reliable releasing and unsealing. This tool is designed with two releasing methods, hydraulic pressure and forward rotation, to ensure that the tool can be released under special circumstances and can also be used in cooperation with other tools by hanging. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of a releasing packer proposed by the present utility model;

[0024] Figure 2 is a releasing packer proposed by the present utility model Figure 1 and is an enlarged view of the structure at A in

[0025] Figure 3 is a releasing packer proposed by the present utility model Figure 1 and is an enlarged view of the structure at B in

[0026] Figure 4 is a cross-sectional view of the lower vertebral body structure of a releasing packer proposed by the present utility model;

[0027] Figure 5 is a releasing packer proposed by the present utility model Figure 4 and is an enlarged view of the structure at C in

[0028] Figure 6 is a releasing packer proposed by the present utility model Figure 4 and is an enlarged view of the structure at D in

[0029] Figure 7 is a cross-sectional view of the rubber barrel assembly structure of a releasing packer proposed by the present utility model;

[0030] Figure 8 is a releasing packer proposed by the present utility model Figure 7 and is an enlarged view of the structure at E in

[0031] Figure 9 Front view of the pre-setting sleeve structure of a releasing packer proposed by the present utility model;

[0032] Figure 10 Stereogram of the connecting ring structure of a releasing packer proposed by the present utility model;

[0033] Figure 11 Stereogram of the connecting pin structure of a releasing packer proposed by the present utility model;

[0034] Figure 12 Stereogram of the card joint structure of a releasing packer proposed by the present utility model;

[0035] Figure 13 Stereogram of the movable head structure of a releasing packer proposed by the present utility model.

[0036] In the figure: 1, releasing upper joint; 2, pre-setting sleeve; 3, post-setting sleeve; 4, releasing core tube; 5, releasing pawl; 6, ball seat; 7, central tube; 8, upper vertebral body; 9, lower vertebral body; 10, rubber barrel assembly; 11, slip cage; 12, slips; 13, setting piston; 14, steel ball; 15, fishing head; 16, shear pin; 17, connecting pin; 18, connecting pipe; 19, card joint; 20, movable head; 21, docking groove; 22, first return spring; 23, connecting ring; 24, telescopic groove; 25, telescopic rod; 26, second return spring. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0038] Referring to Figures 1 - 13 , a releasing packer includes a releasing upper joint 1 fixedly connected to the oil pipe, and further includes a releasing core tube 4, a pre-setting sleeve 2, a post-setting sleeve 3, and a central tube 7. The pre-setting sleeve 2 is tightly connected below the releasing upper joint 1 and moves downward under pressure. The post-setting sleeve 3 is located below the pre-setting sleeve 2 and bears the pressure from the pre-setting sleeve 2. The releasing core tube 4 passes through the pre-setting sleeve 2 and the post-setting sleeve 3 and is coaxially connected to the central tube 7. A fishing head 15 is provided at the bottom of the pre-setting sleeve 2, and a self-adjusting connection mechanism is provided between the fishing head 15 and the pre-setting sleeve 2. The self-adjusting connection mechanism includes a connecting pin 17 in the shape of a right triangle. After the connecting pin 17 extends out of the inner surface of the pre-setting sleeve 2, it is inserted into the surface of the fishing head 15, thereby connecting the pre-setting sleeve 2 and the fishing head 15.

[0039] The outer surface of the release core tube 4 is fixedly connected with a release pawl 5, the bottom of the release core tube 4 is fixedly connected with a ball seat 6, and a steel ball 14 is arranged inside the ball seat 6. The release pawl 5 realizes the release function during the release operation through interaction with the locking block. The locking block is usually installed on the outside of the release core tube 4. When the release operation is performed, the locking block will be released under a certain pressure or displacement, so that the release pawl 5 participates in the release mechanism. This design ensures the safety and reliability of the release device. The steel ball 14 is accommodated inside the ball seat 6 to block the internal flow channel of the packer.

[0040] The upper and lower outer surfaces of the center tube 7 are fixedly sleeved with an upper vertebra 8 and a lower vertebra 9 respectively, and the middle outer surface of the center tube 7 is slidably sleeved with a rubber cylinder assembly 10. A slip cage 11 is installed under the rubber cylinder of the rubber cylinder assembly 10. The outer surface of the slip cage 11 is distributed with slips 12 in a circular array for sliding and retracting. The upper vertebra 8, the lower vertebra 9 and the center tube 7 are linked to each other, so that after the slip cage 11 fixes the slip 12 and maintains its position, the center tube 7 pushes the upper vertebra 8 to move, so that it pushes the slip 12 to expand in the slip cage 11, thereby realizing the mechanical locking function of the sealing action, ensuring that the packer is not accidentally released during operation, and at the same time, after the sealing rear sleeve 3 is moved, the rubber cylinder of the rubber cylinder assembly 10 is squeezed by the sealing rear sleeve 3 to expand, forming an additional seal.

[0041] Due to the bidirectional slip 12 design, the suspension load is large and various screens can be suspended for sand control, which simplifies the sand control process and saves construction costs. It is suitable for side drilling wells, casing change wells, and small diameter oil wells.

[0042] A sealing piston 13 is provided inside the front sealing sleeve 2, and a shear pin 16 is provided inside the rear sealing sleeve 3. The sealing piston 13 is located in the front sealing sleeve 2, and moves downward when pressurized to push the front sealing sleeve 2 to complete the seal. The shear pins 16 connect multiple components and break under a specific pressure to release other components, ensuring smooth release.

[0043] In order to lift the packer out of the wellbore, the fishing head 15 can be extended into the front setting sleeve 2 to catch the front setting sleeve 2, and the packer can be lifted up directly to release the seal and lift it out of the wellbore. In order to ensure that the fishing head 15 will not be separated from the front setting sleeve 2 during the lifting process, the self-adjusting connection mechanism also includes a connecting pipe 18 fixedly connected to the lower surface of the fishing head 15, and a conical clamping joint 19 is fixedly connected to the lower surface of the connecting pipe 18. The surface of the clamping joint 19 is slidably connected to the outer surface of the connecting pin 17. When the fishing head 15 is extended into the front setting sleeve 2, the connecting pin 17 can be extended and clamped with the surface of the clamping joint 19 without rotating the fishing head 15, thereby preventing the front setting sleeve 2 from being separated.

[0044] In order to achieve the clamping connection between the fishing head 15 and the connecting pin 17, a movable head 20 is slidably sleeved on the outer surface of the connecting pipe 18. By arranging the movable head 20 on the outer surface of the connecting pipe 18, it, together with the clamping joint 19, clamps the connecting pin 17 between them. During the releasing process, in order to achieve the quick detachment between the fishing head 15 and the pre-setting sleeve 2 before setting, a conical docking groove 21 is formed on the upper surface of the clamping joint 19. The lower outer surface of the movable head 20 is slidably inserted into the inner wall of the docking groove 21. A first return spring 22 is fixedly sleeved on the outer surface of the connecting pipe 18, and the free end of the first return spring 22 is fixedly connected to the inner side wall of the clamping joint 19. The fishing head 15 continues to move downward for a certain distance. At this time, the movable head 20 presses the inclined surface of the connecting pin 17, causing it to retract and disengage from the clamping of the clamping joint 19. The movable head 20 and the connecting pin 17 are mutually pressed. At this time, when the fishing head 15 moves upward, the movable head 20 can move downward on the outer surface of the connecting pipe 18 until the lower surface of the movable head 20 is inserted into the docking groove 21. Then the connecting pin 17 slides over the conical surface of the clamping joint 19, and at the same time, under the action of the first return spring 22, the movable head 20 resets, thus realizing the releasing action.

[0045] In order to achieve the telescopic movement of the connecting pin 17 and thus complete the clamping connection with the fishing head 15, a connecting ring 23 is fixedly sleeved on the outer surface of the pre-setting sleeve 2 before setting. T-shaped telescopic grooves 24 are symmetrically arranged inside the connecting ring 23 and the pre-setting sleeve 2 before setting. The outer surface of the connecting pin 17 is slidably connected to the inner wall of the telescopic groove 24. A telescopic rod 25 is fixedly connected to one side surface of the connecting pin 17. A second return spring 26 is fixedly connected to the outer surface of the telescopic rod 25, and the free end of the second return spring 26 is fixedly connected to the inner wall of the telescopic groove 24. When the movable head 20 presses the connecting pin 17, the connecting pin 17 drives the telescopic rod 25 to retract in the telescopic groove 24. After the fishing head 15 withdraws, the connecting pin 17 resets under the action of the second return spring 26. When the fishing head 15 extends, the clamping joint 19 can press the connecting pin 17 to retract. After the clamping joint 19 passes by the connecting pin 17, the connecting pin 17 resets to realize the connecting function.

[0046] By providing a self-adjusting connection mechanism, the front sleeve 2 for setting can be quickly connected and disconnected with the fishing head 15. During the adjustment process, when the fishing head 15 is extended, the clamping joint 19 can squeeze the connecting pin 17 to retract. After the clamping joint 19 passes the connecting pin 17, the connecting pin 17 is reset to achieve the connection. When disengaging, the fishing head 15 continues to move downward for a distance. At this time, the movable head 20 squeezes the inclined surface of the connecting pin 17 to retract it and disengage from the clamping connection with the clamping joint 19. The movable head 20 and the connecting pin 17 squeeze each other. At this time, the fishing head 15 moves upward, which can make the movable head 20 move downward on the outer surface of the connecting pipe 18 until the lower surface of the movable head 20 is inserted into the docking groove 21. Then the connecting pin 17 slides over the conical surface of the clamping joint 19. At the same time, the movable head 20 is reset under the action of the first reset spring 22, thereby achieving the action of releasing the hands.

[0047] The utility model relates to a release packer, which is brought to a designated position underground by an oil pipe, and then a seat seal is pressed, and then the oil pipe and the packer are separated without damaging the casing, with good sealing performance, and reliable release and unsealing. The tool is designed with two sets of release modes, hydraulic and forward, to ensure that the tool can be released under special circumstances, and can also be suspended for use with other tools.

[0048] Working principle: In a specific embodiment, the utility model is composed of the following actions:

[0049] Sealing: Figures 4 - 6 As shown, the hand-free packer is lowered into the well together with the oil pipe to a predetermined position, hydraulic pressure is added from the oil pipe to a specified pressure, and the liquid enters the setting working chamber, pushing the setting piston 13, pushing the setting front sleeve 2 to move downward, pushing the fishing head 15, cutting the shear pins 16, pushing the setting rear sleeve 3 to squeeze the rubber cylinder assembly 10 and simultaneously pushing the upper cone to move, and the slip 12 is opened to complete the setting;

[0050] Throwing hands: Figures 7 - 8 As shown, after the packing is set, the pressure is continued to be applied to push the steel ball 14 downward, and the steel ball 14 pushes the ball seat 6 to move, shearing the shear nail 16, and the release pawl 5 and the central pipe 7 release the lock block, and the release lower joint and the packer remain in the well, thus achieving release;

[0051] Unblock: Figure 9 As shown, a special spear is used to catch the front sleeve 2 of the setting seal, and the seal can be released by directly lifting it up to lift the packer out of the wellbore;

[0052] The connection between the fishing head 15 and the front casing 2 is as follows: Figures 10 - 13As shown, when the fishing head 15 extends in, the clamping joint 19 can squeeze the connecting pin 17 to retract. After the clamping joint 19 passes by the connecting pin 17, the connecting pin 17 resets to achieve the connection function. When disengaging, the fishing head 15 continues to move downward for a certain distance. At this time, the movable head 20 squeezes the inclined surface of the connecting pin 17, and the connecting pin 17 drives the telescopic rod 25 to retract in the telescopic groove 24. After retracting, the clamping of the clamping joint 19 is released. The movable head 20 and the connecting pin 17 squeeze each other. At this time, when the fishing head 15 moves upward, the movable head 20 can move downward on the outer surface of the connecting pipe 18 until the lower surface of the movable head 20 is inserted into the docking groove 21. Then the connecting pin 17 slides over the conical surface of the clamping joint 19, and under the action of the first return spring 22, the movable head 20 resets, thus realizing the releasing action.

[0053] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A releasing packer, comprising a releasing upper sub (1) fixedly connected to a tubing string, and further comprising a releasing core tube (4), a pre-setting sleeve (2), a post-setting sleeve (3), and a central tube (7), characterized in that: The pre-setting front sleeve (2) is tightly connected below the releasing upper joint (1) and moves downward under pressure. The pre-setting rear sleeve (3) is located below the pre-setting front sleeve (2) and bears the pressure from the pre-setting front sleeve (2). The releasing core tube (4) penetrates through the pre-setting front sleeve (2) and the pre-setting rear sleeve (3) and is coaxially connected to the central tube (7). A fishing head (15) is provided at the bottom of the pre-setting front sleeve (2). A self-adjusting connecting mechanism is arranged between the fishing head (15) and the pre-setting front sleeve (2). The self-adjusting connecting mechanism includes a connecting pin (17) in the shape of a right triangle. After the connecting pin (17) extends out of the inner surface of the pre-setting front sleeve (2), it is inserted into the surface of the fishing head (15), thereby connecting the pre-setting front sleeve (2) and the fishing head (15).

2. The releasing packer according to claim 1, wherein: A releasing ratchet (5) is fixedly connected to the outer surface of the releasing core tube (4). A ball seat (6) is fixedly connected to the bottom of the releasing core tube (4). A steel ball (14) is arranged inside the ball seat (6).

3. A releasing packer according to claim 2, characterized in that: Upper cones (8) and lower cones (9) are respectively fixedly sleeved on the outer surfaces of the upper end and the lower end of the central tube (7). A rubber cylinder assembly (10) is slidably sleeved on the outer surface of the middle part of the central tube (7). A slip cage (11) is installed below the rubber cylinder of the rubber cylinder assembly (10). Sliding and telescoping slips (12) are annularly and arrayedly distributed on the outer surface of the slip cage (11).

4. A releasing packer according to claim 3, wherein: A setting piston (13) is arranged inside the pre-setting front sleeve (2). A shear pin (16) is arranged inside the pre-setting rear sleeve (3).

5. The releasing packer according to claim 1, wherein: The self-adjusting connecting mechanism further includes a connecting pipe (18) fixedly communicated with the lower surface of the fishing head (15). A conical connector (19) is fixedly connected to the lower surface of the connecting pipe (18). The surface of the connector (19) is slidably connected to the outer surface of the connecting pin (17).

6. The releasing packer according to claim 5, wherein: A movable head (20) is slidably sleeved on the outer surface of the connecting pipe (18). A conical docking groove (21) is formed on the upper surface of the connector (19). The lower outer surface of the movable head (20) is slidably inserted into the inner wall of the docking groove (21). A first return spring (22) is fixedly sleeved on the outer surface of the connecting pipe (18). The free end of the first return spring (22) is fixedly connected to the inner side wall of the connector (19).

7. The releasing packer according to claim 6, characterized in that: A connecting ring (23) is fixedly sleeved on the outer surface of the pre-setting front sleeve (2). T-shaped telescopic grooves (24) are symmetrically formed between the connecting ring (23) and the inside of the pre-setting front sleeve (2). The outer surface of the connecting pin (17) is slidably connected to the inner wall of the telescopic groove (24). A telescopic rod (25) is fixedly connected to one side surface of the connecting pin (17). A second return spring (26) is fixedly connected to the outer surface of the telescopic rod (25). The free end of the second return spring (26) is fixedly connected to the inner wall of the telescopic groove (24).

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