CN219012530U

CN219012530U - Anti-drop pin of oil pipe elevator

Info

Publication number: CN219012530U
Application number: CN202222192269.7U
Authority: CN
Inventors: 马成云; 张春贵; 赵杰; 王红杰; 纪红军; 杨菊
Original assignee: China Petroleum and Chemical Corp; Oil and Gas Production Engineering Service Center of Sinopec Henan Oilfield Branch Co
Current assignee: China Petroleum and Chemical Corp; Oil and Gas Production Engineering Service Center of Sinopec Henan Oilfield Branch Co
Priority date: 2022-08-19
Filing date: 2022-08-19
Publication date: 2023-05-12
Anticipated expiration: 2032-08-19

Abstract

The utility model relates to the technical field of oil pipe suspension devices, in particular to an oil pipe elevator anti-drop pin, which comprises an outer cylinder and an inner rod, wherein the inner rod is movably inserted into a central hole of the outer cylinder up and down; the inner rod pushes the bearing part to withdraw from the central hole of the outer barrel when moving downwards so as to enable the locking block to rotate to a locking position, and the bearing part is moved away when moving upwards so as to enable the locking block to rotate to an unlocking position, the locking part stretches out of the side opening to form blocking fit with the side wall of the hanging groove on the oil pipe elevator in the upward direction when the locking block is in the locking position, the locking part retracts into the side opening when the locking block is in the unlocking position, and an elastic piece is arranged between the inner rod and the outer barrel and is used for applying downward elastic acting force to the inner rod; can realize stable locking and is reliable in use.

Description

Anti-drop pin of oil pipe elevator

Technical Field

The utility model relates to the technical field of oil pipe suspension devices, in particular to an oil pipe elevator anti-drop pin.

Background

In the development process of the oil-gas field, when the oil-gas well is subjected to daily maintenance or measure operation, an oil pipe in the well is required to be lifted, an oil pipe elevator is a common tool for lifting the oil pipe, a hanging groove for hanging a hanging ring is formed in the oil pipe elevator, the hanging groove is formed by two lugs which are opposite up and down, the notch of the hanging groove faces to one horizontal side, and the upper lug and the lower lug form the upper side wall and the lower side wall of the hanging groove. When the oil pipe elevator is used, after the oil pipe elevator is sleeved on the oil pipe, the oil pipe is hoisted by hanging a hoisting ring in the hoisting groove. In order to prevent the lifting ring from falling out of the lifting groove, a pin is usually arranged on the upper side wall and the lower side wall of the lifting groove, the pin is arranged in the pin hole in a penetrating mode, the lifting ring is hung on the inner side of the pin, the pin can prevent the lifting ring from falling out, and the lifting ring is prevented from falling out of the lifting groove outwards.

However, in the field operation process, due to factors such as vibration of the pipe column or non-insertion of the elevator pin, the pin can drop, so that the hoisting ring is separated from the elevator, a so-called single hoisting ring phenomenon occurs, the pipe column is deformed or the elevator is damaged, and serious safety accidents can occur.

Aiming at the safety problem in the operation process, the prior art adopts a magnetic elevator pin, and when the pin is used, after the pin is inserted into a pin hole on the elevator, the pin is magnetic, so that the pin is adsorbed in the pin hole and plays a role in preventing falling by means of magnetic attraction force.

However, when in field operation, dirty oil is often stained on the oil pipe elevator, the magnetic property of the pin can be influenced by the dirty oil on the oil pipe elevator, the magnetic property of the pin can be weakened after long-term use, the anti-falling capability is reduced, the anti-falling effect is not ideal, and the safety risk is high and the use is unreliable.

Disclosure of Invention

The utility model aims to provide an anti-drop pin of an oil pipe elevator, which solves the problem that the existing magnetic anti-drop pin is unreliable to use.

The technical scheme of the anti-drop pin of the oil pipe elevator is as follows:

an anti-drop pin of an oil pipe elevator is used for being inserted into a pin hole on the side wall of an upper hanging groove of the oil pipe elevator, and comprises an outer cylinder and an inner rod, wherein the inner rod is movably inserted into a central hole of the outer cylinder up and down; the inner rod is used for pushing the bearing part to rotate and withdraw from a central hole of the outer cylinder when moving downwards so as to enable the locking piece to rotate to a locking position, the inner rod is also used for yielding the rotating bearing part to enter the central hole of the outer cylinder when moving upwards so as to enable the locking piece to rotate to an unlocking position, the locking part stretches out of the side opening when the locking piece is in the locking position so as to form blocking fit with the side wall of the hanging groove in the upward direction, the locking part retracts into the side opening when the locking piece is in the unlocking position, and an elastic piece is arranged between the inner rod and the outer cylinder and is used for applying downward elastic force to the inner rod.

The beneficial effects are that: the sleeve structure of the inner rod and the outer cylinder is arranged, so that the lock block can be switched between the locking position and the unlocking position by utilizing the up-and-down movement of the inner rod in the central hole of the outer cylinder; when the inner rod moves downwards in the central hole of the outer cylinder, the bearing part pushing the locking piece withdraws from the central hole of the outer cylinder and withdraws into the side hole, correspondingly, the bearing part is pushed to enable the locking part to extend out of the side hole, at the moment, the locking piece rotates to a locking position, the locking part protruding out of the outer cylinder can form blocking fit with the side wall of the hanging groove on the oil pipe hanging clamp, meanwhile, the elastic piece provides downward acting force for the inner rod to keep the position of the inner rod, and the locking piece is kept at the locking position, so that unlocking caused by unexpected falling of the inner rod due to vibration and the like is avoided; when the elastic force of the elastic piece is overcome to enable the inner rod to move upwards, the inner rod gives way to the bearing part of the unlocking block, the bearing part can enter the central hole of the outer cylinder, correspondingly, the locking part is retracted into the side hole, and the locking block is enabled to rotate to an unlocking position at the moment, so that the pin can be pulled out of the pin hole upwards or inserted into the pin hole downwards; after the anti-falling pin of the oil pipe elevator is inserted into the corresponding pin hole, the oil pipe elevator can enter a locking state under the action of the elastic piece, so that mechanical locking is formed, the locking state can be kept, and the reliability of the use process is ensured.

Further, the locking piece is triangular, and comprises a first corner, a second corner and a third corner, wherein the first corner is rotatably arranged in the side opening, one of the second corner and the third corner forms a bearing part, and the other one forms a locking part.

The beneficial effects are that: one corner of the triangular block is used as a rotation center, so that after the inner rod lets the bearing part open, the locking block can return to the unlocking position under the action of dead weight, and the unlocking mechanism is simple in structure and convenient to use.

Further, the elastic piece is a holding spring, the holding spring is sleeved on the inner rod, and the upper end and the lower end of the holding spring are respectively supported on the inner rod and the outer cylinder.

The beneficial effects are that: the holding spring sleeved on the inner rod applies force to the inner rod, so that the occupied space of the elastic piece is reduced.

Further, an upward supporting surface is arranged on the inner rod, the lower end of the retaining spring is propped against the upward supporting surface, and the upper end of the retaining spring is supported at the orifice of the central hole of the outer cylinder.

The beneficial effects are that: the retaining spring is pressed between the upward supporting surface of the inner rod and the orifice of the central hole of the outer cylinder, so that the retaining spring is positioned in the central hole of the outer cylinder, the spring can be protected, and the use is reliable.

Further, a stop ring table is arranged on the inner rod and provided with an upper side surface and a lower side surface, and the upper side surface of the stop ring table forms an upward supporting surface; an upward blocking surface is arranged in the central hole of the outer cylinder and is used for being blocked and matched with the lower side surface of the blocking ring table.

The beneficial effects are that: the retaining ring table can be pressed against the upward retaining surface of the central hole of the outer cylinder under the action of the elastic force of the retaining spring, so that the inner rod is prevented from shaking in the outer cylinder.

Further, the urceolus includes the upper baffle ring of main barrel and main barrel upper end, and the internal diameter of upper baffle ring is less than the internal diameter of main barrel, and the external diameter of upper baffle ring is greater than the external diameter of main barrel, keeps the upper end roof pressure of spring on the downside of upper baffle ring.

The beneficial effects are that: the outer ring part of the upper baffle ring can be stopped at the orifice of the pin hole after the pin is inserted into the pin hole, and the inner ring part can form a downward supporting surface for supporting the retaining spring, so that the retaining spring is reliably supported.

Further, an annular upper baffle table is arranged above the baffle ring table on the inner rod and is positioned above the upper baffle ring, and the annular upper baffle table is used for being covered at an upper orifice of the central hole of the outer cylinder.

The beneficial effects are that: therefore, after the pin is inserted into the pin hole of the oil pipe elevator, the annular upper baffle can cover the annular space between the outer cylinder and the inner rod, and dirt is prevented from entering the annular space to influence the use of the pin.

Further, the inner rod is provided with an insurance rope hole, and the insurance rope hole is used for threading the insurance rope.

The beneficial effects are that: through setting up the insurance rope hole and wearing dress insurance rope to avoid the pin to lose.

Further, a handle is arranged on the inner rod.

The beneficial effects are that: through setting up the handle, make things convenient for staff's application of force to carry the pull inner rod.

Further, the inner rod is L-shaped and comprises a transverse section and a vertical section, the vertical section extends along the up-down direction, the transverse section horizontally extends, the vertical section is movably inserted into the central hole of the outer cylinder up and down, and the transverse section forms a handle.

The beneficial effects are that: the handle is formed by the horizontal section which extends horizontally, the structure is simple, the manufacture is convenient, and meanwhile, the force application to the handle is convenient.

Drawings

FIG. 1 is a schematic diagram of an anti-drop pin for an oil pipe elevator according to embodiment 1 of the present utility model;

FIG. 2 is a schematic view of the structure of an oil pipe elevator with an anti-drop pin mounted on the oil pipe elevator and a locking block in a locked position;

FIG. 3 is a schematic view of the structure of the oil pipe elevator with the anti-drop pin mounted on the oil pipe elevator and the locking block in the unlocked position;

fig. 4 is a schematic view of the oil pipe elevator anti-drop pin in the oil pipe lifting process.

In the figure: 1. an inner rod; 11. a handle; 12. a safety rope hole; 13. an annular upper baffle table; 14. a stop ring table; 2. an outer cylinder; 21. an upper baffle ring; 3. a holding spring; 4. a mounting shaft; 5. a locking piece; 6. an oil pipe elevator; 7. coupling; 8. an oil pipe; 9. and (5) hanging rings.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the particular embodiments described herein are illustrative only and are not intended to limit the utility model, i.e., the embodiments described are merely some, but not all, of the embodiments of the utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present utility model.

It is noted that relational terms such as "first" and "second" and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, terms such as "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the possible occurrence of the phrase "comprising one … …" or the like does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

In the description of the present utility model, the terms "mounted," "connected," "coupled," and "connected," as may be used broadly, and may be connected, for example, fixedly, detachably, or integrally, unless otherwise specifically defined and limited; can be mechanically or electrically connected; either directly, indirectly through intermediaries, or in communication with the interior of the two elements. The specific meaning of the above terms in the present utility model can be understood by those skilled in the art in specific cases.

In the description of the present utility model, unless explicitly stated and limited otherwise, the term "provided" as may occur, for example, as an object of "provided" may be a part of a body, may be separately arranged from the body, and may be connected to the body, and may be detachably connected or may be non-detachably connected. The specific meaning of the above terms in the present utility model can be understood by those skilled in the art in specific cases.

The present utility model is described in further detail below with reference to examples.

Example 1 of an oil pipe elevator anti-drop pin of the present utility model:

as shown in fig. 1, fig. 2, fig. 3 and fig. 4, the anti-falling pin of the oil pipe elevator comprises an outer cylinder 2 and an inner rod 1, the inner rod 1 is movably inserted into a central hole of the outer cylinder 2 up and down, a side hole is arranged on the cylinder wall of the outer cylinder 2 and is communicated with the central hole of the outer cylinder 2 left and right, a locking piece 5 is rotatably arranged in the side hole, a rotation axis of the locking piece 5 extends along the front-rear direction, the locking piece 5 is provided with a locking position and an unlocking position on a rotation stroke, the inner rod 1 is matched with the locking piece 5, when the inner rod 1 moves downwards, the inner rod 1 can push the locking piece 5 to rotate and enable the locking piece 5 to rotate to the locking position, when the locking piece 5 is in the locking position, the pin can be prevented from falling from a pin hole of the oil pipe elevator 6, and when the inner rod 1 moves upwards, the locking piece 5 can be prevented from rotating to the unlocking position, and when the locking piece 5 is in the unlocking position, the pin can be pulled out of the pin hole or inserted into the pin hole.

The central hole of the outer cylinder 2 is an upper through hole and a lower through hole, the outer cylinder 2 comprises a main cylinder body and an upper baffle ring 21 at the upper end of the main cylinder body, the inner diameter of the upper baffle ring 21 is smaller than that of the main cylinder body, the outer diameter of the upper baffle ring 21 is larger than that of the main cylinder body, and the inner hole of the main cylinder body and the inner hole of the upper baffle ring 21 jointly form the central hole of the outer cylinder 2. The inner hole of the main cylinder body is a step hole, and comprises a big hole section and a small hole section which are distributed up and down, an upward blocking surface is formed at the transition part between the big hole section and the small hole section, the upward blocking surface is opposite to the lower side surface of the upper blocking ring 21 up and down, and the aperture of the inner hole of the upper blocking ring 21 is the same as that of the small hole section of the main cylinder body. The upper baffle ring 21 is provided with an outer ring part positioned at the periphery of the main cylinder body and an inner ring part corresponding to the inner hole of the main cylinder body, and the outer ring part of the upper baffle ring 21 can be stopped at the orifice of the pin hole after the pin is inserted into the pin hole, so that the pin and the oil pipe elevator 6 form downward stop fit.

The inner rod 1 is L-shaped and comprises a transverse section and a vertical section, the vertical section extends along the up-down direction, the transverse section extends along the left-right direction, the transverse section is arranged at the upper end of the vertical section, the vertical section is movably inserted into a central hole of the outer cylinder 2 up and down, and the transverse section forms a handle 11 so as to facilitate the force application of a hand to the handle 11.

The vertical section of the inner rod 1 is provided with a stop ring table 14, the stop ring table 14 is vertically movably arranged in the large hole section of the main cylinder body, the inner rod 1 is sleeved with a retaining spring 3, the retaining spring 3 forms an elastic piece, the retaining spring 3 is positioned in the large hole section of the main cylinder body, and the upper end and the lower end of the retaining spring 3 respectively press against the stop ring table 14 and the upper stop ring 21. The stopper ring table 14 has an upper side surface and a lower side surface, and the upper side surface of the stopper ring table 14 constitutes an upward supporting surface against which the lower end of the holding spring 3 is pressed. The upper end of the holding spring 3 is pressed against the lower side surface of the upper baffle ring 21, and the inner ring part of the upper baffle ring 21 can form a downward supporting surface for supporting the holding spring 3, so that the upper end of the holding spring 3 is supported at the orifice of the central hole of the outer cylinder 2, and the holding spring 3 is positioned in the central hole of the outer cylinder 2, thereby protecting the spring and being beneficial to use reliability. The holding spring 3 sleeved on the inner rod 1 applies downward force to the inner rod 1, so that the occupied space of the elastic piece is reduced.

The lower side of the stop ring table 14 is used for being in stop fit with an upward stop surface in the central hole of the outer cylinder 2, and the stop ring table 14 can be propped against the upward stop surface in the central hole of the outer cylinder 2 under the action of the elastic force of the retaining spring 3, so that the inner rod 1 is prevented from shaking in the outer cylinder 2. When the inner rod 1 is not subjected to external force, the retaining ring table 14 can be pressed against the upward retaining surface of the outer cylinder 2 under the elastic force of the retaining spring 3, and the inner rod 1 can retain the locking piece 5 in the locking position. In order to facilitate the installation of the stop ring table 14 into the outer cylinder 2, the main cylinder body of the outer cylinder 2 and the upper stop ring 21 are separately arranged, and after the stop ring table 14 of the inner rod 1 extends into the main cylinder body, the upper stop ring 21 and the main cylinder body are welded and fixed.

The upper part of the vertical section of the inner rod 1 above the stop ring table 14 is also provided with an annular upper stop table 13, the annular upper stop table 13 is positioned above the upper stop ring 21, the outer diameter of the annular upper stop table 13 is larger than the bore diameter of the upper stop ring 21, after the inner rod 1 is inserted into the central hole of the outer cylinder 2, the annular upper stop table 13 is covered at the upper orifice of the central hole of the outer cylinder 2, so that the annular upper stop table 13 can cover the annular space between the outer cylinder 2 and the vertical section of the inner rod 1, and the use of pins is prevented from being influenced by dirt entering the annular space.

The safety rope hole 12 is arranged at the junction of the vertical section and the transverse section on the inner rod 1, and the safety rope hole 12 is used for threading the safety rope, so that the safety rope is conveniently tied at a proper position to avoid the loss of a pin.

The locking piece 5 is triangular, and comprises a first corner, a second corner and a third corner, wherein the first corner is rotatably arranged in a side opening, the side opening is arranged below an upward blocking surface of the outer cylinder 2, an outer side orifice of the side opening is positioned on the outer peripheral surface of the outer cylinder 2, and an inner side orifice is positioned on the inner peripheral surface of the small hole section. The side trompil is the slot hole that extends from top to bottom, and the side trompil has the relative both sides pore wall in front and back, is fixed with installation axle 4 on this relative both sides pore wall in front and back, and installation axle 4 extends along the fore-and-aft direction, and the first bight rotation of locking piece 5 is installed on installation axle 4 to can the horizontal hunting, the rotation stroke needs of locking piece 5 can be satisfied to the size of side trompil. The second corner is closer to the central hole of the outer cylinder 2 than the third corner, the second corner forms a bearing part, the third corner forms a locking part, when the locking piece enters the locking position from the unlocking position, the bearing part and the locking part form a driving end and an output end of the lever mechanism based on the rotation axis of the locking piece, and the bearing part rotates along with the locking piece and corresponds to the unlocking position of the locking piece to enter the central hole of the outer cylinder and corresponds to the locking position of the locking piece to exit the central hole of the outer cylinder.

When the inner rod 1 moves downwards in the central hole of the outer cylinder 2, the bearing part of the pushing locking piece 5 withdraws from the central hole of the outer cylinder 2 and retracts into the side hole, so that the locking part extends out of the side hole, at the moment, the locking piece 5 rotates to a locking position, the locking part protruding out of the outer cylinder 2 can form a blocking fit with the side wall of the hanging groove on the oil pipe hanging clamp 6 in the upward direction, meanwhile, the retaining spring 3 provides a downward acting force for the inner rod 1 to keep the position of the inner rod 1, and the locking piece 5 is kept in the locking position, so that the inner rod 1 is prevented from being accidentally separated due to vibration and the like to unlock; when the elastic force of the elastic piece is overcome to enable the inner rod 1 to move upwards, the inner rod 1 gives way to the bearing part of the unlocking block 5, the bearing part can enter the center hole of the outer cylinder 2, the locking part is retracted into the side hole, at the moment, the locking block 5 is enabled to rotate to an unlocking position, and therefore the pin can be pulled out of the pin hole upwards or inserted into the pin hole downwards.

One corner of the triangular block is used as a rotation center, so that after the inner rod 1 lets the bearing part open, the locking block 5 can restore to the unlocking position under the action of dead weight, and the locking mechanism is simple in structure and convenient to operate.

When the oil pipe elevator 6 is sleeved on the oil pipe 8 and after the coupling 7 at the upper end of the oil pipe 8 is supported on the oil pipe elevator 6, the hanging ring 9 is hung in a hanging groove on the oil pipe elevator 6, the hanging groove is formed by two lugs which are opposite up and down, and the two lugs are provided with pin holes which are corresponding up and down; inserting an oil pipe elevator anti-drop pin into the pin hole and penetrating through the hanging groove, wherein the hanging ring 9 is blocked on the inner side; when the pin is inserted, the inner rod 1 is lifted up relative to the outer cylinder 2 through the handle 11, the elasticity of the retaining spring 3 is overcome, the inner rod 1 moves upwards until the unlocking block 5 is released, the locking block 5 rotates under the action of dead weight, the bearing part enters the central hole of the outer cylinder, the locking part is retracted into the side opening, the locking block 5 enters the unlocking position, the pin can be inserted into the pin hole at the moment, the pin is released when the upper baffle ring 21 of the outer cylinder 2 is blocked on the oil pipe elevator 6, the inner rod 1 moves downwards under the action of the retaining spring 3 and pushes the locking block 5 to enter the locking position, the inner rod abuts against the bearing part, the locking part protrudes outwards beyond the outer cylinder 2, and when the pin moves upwards, the locking part can be blocked and matched with the upper side wall of the hanging groove, so that the pin is prevented from falling.

Through the suit structure that sets up interior pole 1 and urceolus 2 like this to can utilize interior pole 1 to realize the switching between locking position and unblock position at the downthehole upper and lower activity of urceolus 2 centre, prevent falling the pin at the oil pipe elevator and insert corresponding pinhole after, can get into the locking state under the effect of elastic component, form mechanical locking and can keep the locking state, guaranteed the reliability of use.

Example 2 of the drop-preventing pin of the oil pipe elevator of the present utility model:

the difference between this embodiment and embodiment 1 is that in embodiment 1, the lock block is triangular and includes a first corner, a second corner, and a third corner, where the first corner is rotatably installed in the side hole, one of the second corner and the third corner forms a bearing portion, and the other forms a locking portion. In this embodiment, the locking piece is L-shaped and includes a first extension section and a second extension section that are perpendicular to each other, the junction of the first extension section and the second extension section is rotatably mounted in the side opening, one of the first extension section and the second extension section forms the bearing portion, and the other one forms the locking portion.

Example 3 of the anti-drop pin of the oil pipe elevator of the present utility model:

the present embodiment is different from embodiment 1 in that in embodiment 1, the elastic member is a holding spring. In this embodiment, the elastic member is an elastic band, and two ends of the elastic band are respectively connected with the inner rod and the outer cylinder.

Example 4 of the drop-preventing pin of the oil pipe elevator of the present utility model:

the difference between this embodiment and embodiment 1 is that in embodiment 1, a stop ring table is provided on the inner rod, the stop ring table has an upper side and a lower side, the upper side of the stop ring table forms an upward supporting surface, and the inner hole of the main cylinder body of the outer cylinder is a stepped hole to form an upward stop surface that is in stop fit with the stop ring table. In this embodiment, the lower part of the inner rod, which is located at the annular upper baffle table, is a step shaft part, the step shaft part comprises a small-diameter section and a large-diameter section which are distributed up and down, an upward supporting surface is formed at the joint of the small-diameter section and the large-diameter section, the inner hole of the main cylinder body of the outer cylinder is an equal-diameter hole, and the inner diameter of the equal-diameter hole is adapted to the outer diameter of the large-diameter section so as to enable the inner rod to move up and down.

Example 5 of the anti-drop pin for an oil pipe elevator of the present utility model:

this embodiment differs from embodiment 1 in that in embodiment 1 the inner rod is L-shaped, comprising a transverse section and a vertical section, the transverse section constituting the handle. In this embodiment, the upper end of the inner rod is provided with a ball head, and the ball head forms a handle.

It should be noted that the above-mentioned embodiments are merely preferred embodiments of the present utility model, and the present utility model is not limited to the above-mentioned embodiments, but may be modified without inventive effort or equivalent substitution of some of the technical features thereof by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. An anti-drop pin of an oil pipe elevator is used for being inserted into a pin hole on the side wall of an upper hanging groove of the oil pipe elevator (6), and is characterized by comprising an outer cylinder (2) and an inner rod (1), wherein the inner rod (1) is movably inserted into a central hole of the outer cylinder (2) up and down, a side opening is arranged on the cylinder wall of the outer cylinder (2), the side opening is communicated with the central hole of the outer cylinder (2) left and right, a locking piece (5) is rotatably arranged in the side opening, the rotation axis of the locking piece (5) extends along the front and back direction and is provided with a locking position and an unlocking position on the rotation stroke, the locking piece (5) comprises a bearing part and a locking part, the bearing part and the locking part form a driving end and an output end of a lever mechanism based on the rotation axis of the locking piece (5), and the bearing part rotates along with the locking piece (5) and corresponds to the unlocking position of the locking piece (5) to enter the central hole of the outer cylinder (2) and corresponds to the locking position of the locking piece (5) to exit the central hole of the outer cylinder (2); the inner rod (1) is used for pushing the bearing part to rotate when moving downwards and withdrawing from the central hole of the outer cylinder (2) so as to enable the locking piece (5) to rotate to a locking position, the inner rod (1) is also used for yielding the rotating bearing part to enter the central hole of the outer cylinder (2) when moving upwards so as to enable the locking piece (5) to rotate to an unlocking position, the locking part stretches out of the side opening to be used for forming blocking fit with the side wall of the hanging groove in the upward direction when the locking piece (5) is in the locking position, the locking part retracts into the side opening when the locking piece (5) is in the unlocking position, and an elastic piece is arranged between the inner rod (1) and the outer cylinder (2) and is used for applying downward elastic acting force to the inner rod (1).

2. The drop-preventing pin of an oil pipe elevator according to claim 1, wherein the locking piece (5) is triangular and comprises a first corner, a second corner and a third corner, the first corner is rotatably arranged in the side opening, one of the second corner and the third corner forms a bearing part, and the other forms a locking part.

3. The drop-preventing pin for the oil pipe elevator according to claim 1 or 2, wherein the elastic member is a retaining spring (3), the retaining spring (3) is sleeved on the inner rod (1), and the upper end and the lower end of the retaining spring (3) are respectively supported on the inner rod (1) and the outer cylinder (2).

4. An oil pipe elevator drop prevention pin according to claim 3, characterized in that the inner rod (1) is provided with an upward supporting surface, the lower end of the holding spring (3) is pressed against the upward supporting surface, and the upper end of the holding spring (3) is supported at the orifice of the central hole of the outer cylinder (2).

5. The drop preventing pin for the oil pipe elevator according to claim 4, wherein the inner rod (1) is provided with a stop ring table (14), the stop ring table (14) is provided with an upper side surface and a lower side surface, and the upper side surface of the stop ring table (14) forms an upward supporting surface; an upward blocking surface is arranged in the central hole of the outer cylinder (2) and is used for being blocked and matched with the lower side surface of the blocking ring table (14).

6. The drop preventing pin for an oil pipe elevator according to claim 5, wherein the outer cylinder (2) comprises a main cylinder body and an upper baffle ring (21) at the upper end of the main cylinder body, the inner diameter of the upper baffle ring (21) is smaller than that of the main cylinder body, the outer diameter of the upper baffle ring (21) is larger than that of the main cylinder body, and the upper end of the retaining spring (3) is propped against the lower side surface of the upper baffle ring (21).

7. The drop preventing pin for the oil pipe elevator according to claim 6, wherein an annular upper baffle table (13) is arranged above the baffle ring table (14) on the inner rod (1), the annular upper baffle table (13) is positioned above the upper baffle ring (21), and the annular upper baffle table (13) is used for being covered at an upper orifice of the central hole of the outer cylinder (2).

8. The oil pipe elevator anti-drop pin according to claim 1 or 2, characterized in that the inner rod (1) is provided with a safety rope hole (12), and the safety rope hole (12) is used for threading a safety rope.

9. An oil pipe elevator drop prevention pin according to claim 1 or 2, characterized in that the inner rod (1) is provided with a handle (11).

10. The drop-preventing pin for the oil pipe elevator according to claim 9, wherein the inner rod (1) is L-shaped and comprises a transverse section and a vertical section, the vertical section extends in the up-down direction, the transverse section horizontally extends, the vertical section is movably inserted into a central hole of the outer cylinder (2) up and down, and the transverse section forms a handle (11).