Shock-absorbing cylinder for rotary drilling rig

Abstract

The present invention relates to a shock-absorbing oil cylinder for a rotary drilling rig, comprising a main oil cylinder and a sub-oil cylinder; an oil-gas shock-absorbing cylinder is arranged between the main cylinder base of the main oil cylinder and the cylinder base of the sub-oil cylinder; the oil-gas shock-absorbing cylinder comprises an oil storage cylinder barrel and an air storage cylinder barrel, an outer piston is arranged in the oil storage cylinder barrel, and an oil-passing gap is arranged on the outer piston; a cylinder hole is arranged on the cylinder head block, one end of the air storage cylinder barrel passes through the cylinder hole of the cylinder head block and is fixedly connected with the outer piston, and an inner piston is arranged in the air storage cylinder barrel; an air cavity is formed between the inner piston and the sub-cylinder base of the sub-oil cylinder, an oil-passing hole is arranged on the outer piston, and an oil storage cavity is formed between the inner piston and the main cylinder base of the main oil cylinder through the oil-passing hole of the outer piston. Two types of oil cylinders, the main and sub-oil cylinders, are configured to support the drill rod and the fuselage respectively, so that a stable support can be provided to the drill rod when operating on the drilling rig to achieve stability of the drill rod.

Description

Technical Field

[0001] The invention relates to the field of hydraulics, and in particular to a shock-absorbing oil cylinder for a rotary drilling rig. Background Art

[0002] At present, the oil cylinders used in rotary drilling rigs are all ordinary single-acting oil cylinders with a relatively simple structure. The oil cylinder is installed at a high position on the drilling rig. When the drill rod is just propped up, the drill rod is subjected to external forces, such as wind resistance. The force of the drill rod is transmitted to the machine body through the oil cylinder, causing the whole machine body to shake. Therefore, the oil cylinder needs to provide stable supporting force. The current oil cylinder has low shock absorption performance. The vibration of the drill rod is easily transmitted to the frame through the oil cylinder, causing the entire drilling rig structure to be unstable.

[0003] Secondly, the front end of the cylinder rod of the rotary drilling rig was connected to the drill bit on the drilling rig. The drill bit was generally large, and the oil cylinder and cylinder rod used in the rotary drilling rig did not have a locking mechanism. When the drill bit moved, the cylinder rod would be pulled out of the cylinder body, which could easily cause damage to the cylinder rod. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a shock-absorbing oil cylinder for a rotary drilling rig to solve the problem that the force exerted on the drill rod is directly transmitted to the machine body and causes the machine body to shake due to the poor shock-absorbing performance of the previous oil cylinder.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a shock-absorbing oil cylinder for a rotary drilling rig, comprising a main oil cylinder and a sub-oil cylinder; an oil-gas shock-absorbing cylinder is arranged between the main cylinder base of the main oil cylinder and the cylinder base of the sub-oil cylinder;

[0006] The oil-gas shock-absorbing cylinder comprises an oil storage cylinder and an air storage cylinder, one end of the oil storage cylinder is sealed and fixedly connected to the main cylinder base, the other end of the oil storage cylinder is sealed and provided with a cylinder head block, an outer piston is provided in the oil storage cylinder, an oil-passing gap is provided on the outer piston, and the oil-passing gap is suitable for connecting the rod cavity and the rodless cavity in the oil storage cylinder;

[0007] The cylinder head block is provided with a cylinder hole, one end of the gas storage cylinder passes through the cylinder hole of the cylinder head block and is fixedly connected to the outer piston, the other end of the gas storage cylinder is connected to the auxiliary cylinder base of the auxiliary oil cylinder and is sealed and fixedly connected, and an inner piston is arranged in the gas storage cylinder;

[0008] An air cavity is formed between the inner piston and the auxiliary cylinder base of the auxiliary oil cylinder, an oil through hole is provided on the outer piston, and an oil storage cavity is formed between the inner piston and the main cylinder base of the main oil cylinder through the oil through hole of the outer piston.

[0009] Furthermore, the connection structure between the cylinder head block and the oil storage cylinder barrel is as follows: a first step hole and a second step hole are formed in the oil storage cylinder barrel, the second step hole is close to the outside, and an internal thread is formed in the second step hole;

[0010] The cylinder head block is formed with a first step column and a second step column, an outer wall of the second step column is formed with an external thread, a first sealing ring is arranged on the outer wall of the first step column, a second sealing ring is arranged between the second step column and the cylinder head block, and an inclined sealing surface for cooperating with the second sealing ring is formed at the opening of the second step hole;

[0011] The first step column of the cylinder head block is inserted into the first step hole, the first sealing ring is sealed with the first step hole, the second step column is threadedly connected and fixed with the second step hole, and the inclined sealing surface of the second step hole is sealed with the second sealing ring.

[0012] Furthermore, the movable sealing structure between the inner piston and the gas storage cylinder is:

[0013] The outer wall of the inner piston is provided with a first guide ring and a second guide ring, and a step seal and an oil-gas seal are provided between the first guide ring and the second guide ring.

[0014] Furthermore, an air inlet nozzle is arranged on the auxiliary cylinder base, and the air inlet nozzle is connected with the air cavity of the air storage cylinder barrel, and is suitable for inputting nitrogen into the air cavity;

[0015] A first oil inlet nozzle is arranged on the master cylinder base, and a second oil inlet nozzle is arranged on the oil storage cylinder barrel.

[0016] Furthermore, the master oil cylinder comprises a master cylinder barrel and a master cylinder rod, a master cylinder head is fixedly arranged at the front end of the master cylinder barrel, a front end of the master cylinder rod extends out from the master cylinder head, and a connecting head is fixedly arranged at the front end of the master cylinder rod;

[0017] A first radial convex ring is formed on the connecting head, and a second radial convex ring is formed on the main cylinder head;

[0018] When the master cylinder rod is retracted into the master cylinder, the first radial convex ring and the second radial convex ring fit together, a pair of clamping blocks are arranged outside the first radial convex ring and the second radial convex ring, a pair of bayonet holes are formed inside the clamping blocks, the outer ends of the first radial convex ring and the second radial convex ring are arranged in the bayonet holes, and the outer ends of the two clamping blocks are connected with locking rings, and the locking rings are suitable for limiting the radial separation movement of the two clamping blocks, so that the first radial convex ring and the second radial convex ring are locked in the bayonet holes of the two clamping blocks;

[0019] The outer diameter of the master cylinder head is smaller than the inner diameter of the lock ring, so that when unlocking, the lock ring is moved to the master cylinder head, so that the two clamping blocks can be unlocked for radial separation and unlocking.

[0020] Furthermore, the clamping block is a semicircular ring structure, and two clamping blocks are spliced ​​to form a circular ring and clamped on the outside of the first radial convex ring and the second radial convex ring.

[0021] Furthermore, the two blocks have one side away from the master cylinder head that radially protrudes outward to form a third radial protruding ring. When the locking ring is sleeved on the outside of the two blocks, the two third radial protruding rings are suitable for limiting the locking ring from axially moving out of the blocks.

[0022] Furthermore, semicircular first sealing grooves are respectively opened on the outer walls of the two blocks, and the two first sealing grooves form a circular first sealing groove. A first sealing ring is arranged in the circular first sealing groove, and the first sealing ring contacts and cooperates with the inner hole of the locking ring to increase the friction force of the axial movement of the locking ring.

[0023] Furthermore, a second sealing groove is provided on the outer wall of the master cylinder head, a second sealing ring is arranged in the second sealing groove, and the second sealing ring is in contact with and cooperates with the inner hole of the locking ring to increase the friction force of the axial movement of the locking ring.

[0024] Furthermore, the connection structure between the master cylinder head and the master cylinder barrel is:

[0025] The front end of the main cylinder is welded to an extension tube, and the wall thickness of the extension tube is greater than the wall thickness of the main cylinder;

[0026] A fourth radial convex ring is formed on the master cylinder head, and the fourth radial convex ring abuts against the front end of the extension tube. A plurality of locking screws axially pass through the fourth radial convex ring and are threadedly connected to the extension tube to axially fix the master cylinder head to the front end of the extension tube.

[0027] The beneficial effects of the present invention are:

[0028] Provided is a shock-absorbing cylinder for a rotary drilling rig, which is equipped with two types of cylinders, a main cylinder and a secondary cylinder, which support the drill rod and the machine body respectively, and can provide a stable support for the drill rod when working on the drilling rig to achieve stability of the drill rod;

[0029] In addition, an oil-gas shock-absorbing cylinder is added to cushion the impact force exerted on the two oil cylinders through oil pressure and oil gas, so that the oil cylinder of the invention can cushion the impact force exerted on the drill rod on the body of the rotary drilling rig while providing stable support.

[0030] When the master cylinder rod is reset and retracted into the master cylinder barrel, the connecting head and the master cylinder head can be locked, limiting the axial movement of the two and preventing the master cylinder rod from moving out of the master cylinder barrel, thereby providing good protection for the master cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is further described below in conjunction with the accompanying drawings.

[0032] Figure 1 is a schematic diagram of a shock absorbing oil cylinder of the present invention;

[0033] Figure 2 It is a schematic diagram of the oil and gas shock cylinder;

[0034] Figure 3 It is a structural diagram of the oil storage cylinder, the main steel base, the outer piston, the gas storage cylinder and the inner piston;

[0035] Figure 4 It is a partial diagram of the inner piston;

[0036] Figure 5 Schematic diagram of the mechanical lock structure of the cylinder rod for rotary drilling rig;

[0037] Figure 6 It is a schematic diagram of two card blocks;

[0038] Among them, 2. main oil cylinder, 21. main cylinder base, 22. main cylinder barrel, 3. auxiliary oil cylinder, 31. auxiliary cylinder base, 4. oil and gas shock absorber cylinder, 41. gas storage cylinder barrel, 42. oil storage cylinder barrel, 43. cylinder head block, 43A. first step column, 43B. second step column, 44. outer piston, 45. inner piston, 45A. first guide ring, 45B. second guide ring, 45C. step seal, 45D. oil and gas seal; 51. main cylinder rod, 52. connecting head, 521. first radial convex ring, 6. clamping block, 61. third radial convex ring, 7. extension cylinder, 8. main cylinder head, 81. second radial convex ring, 82. fourth radial convex ring, 9. locking ring. DETAILED DESCRIPTION

[0039] The present invention will now be further described in conjunction with the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0040] Embodiment 1

[0041] like Figure 1 As shown, a shock-absorbing cylinder for a rotary drilling rig comprises a main cylinder 2 and a subsidiary cylinder 3; an oil-gas shock-absorbing cylinder 4 is arranged between a main cylinder base 21 of the main cylinder 2 and a cylinder base of the subsidiary cylinder 3.

[0042] like Figure 2 As shown, the oil-gas shock absorber cylinder 4 includes an oil storage cylinder barrel 42 and an air storage cylinder barrel 41. One end of the oil storage cylinder barrel 42 is sealed and fixedly connected to the master cylinder base 21, and the other end of the oil storage cylinder barrel 42 is sealed with a cylinder head block 43. An outer piston 44 is arranged in the oil storage cylinder barrel 42, and an oil passing gap is arranged on the outer piston 44. The oil passing gap is suitable for connecting the rod cavity and the rodless cavity in the oil storage cylinder barrel 42.

[0043] The cylinder head block 43 is provided with a barrel hole, one end of the gas storage cylinder 41 passes through the barrel hole of the cylinder head block 43 and is fixedly connected to the outer piston 44, the other end of the gas storage cylinder 41 is connected to the auxiliary cylinder base 31 of the auxiliary oil cylinder 3 and is sealed and fixedly connected, an inner piston 45 is arranged in the gas storage cylinder 41; an air cavity is formed between the inner piston 45 and the auxiliary cylinder base 31 of the auxiliary oil cylinder 3, an oil hole is provided on the outer piston 44, and an oil storage cavity is formed between the inner piston 45 and the main cylinder base 21 of the main oil cylinder 2 through the oil hole of the outer piston 44.

[0044] An air inlet nozzle is arranged on the auxiliary cylinder base 31, and the air inlet nozzle is connected to the air cavity of the air storage cylinder barrel 41, and is suitable for inputting nitrogen into the air cavity. The air inlet nozzle adopts a one-way air inlet nozzle; a first oil inlet nozzle is arranged on the main cylinder base 21, and a second oil inlet nozzle is arranged on the oil storage cylinder barrel 42. The two oil inlet nozzles are suitable for inputting hydraulic oil into the oil storage cylinder barrel 42.

[0045] like Figure 3 As shown, the connection structure between the cylinder head block 43 and the oil storage cylinder barrel 42 is as follows: a first step hole and a second step hole are formed in the oil storage cylinder barrel 42, the second step hole is close to the outside, and an internal thread is formed in the second step hole;

[0046] The cylinder head block 43 is formed with a first step column 43A and a second step column 43B, the outer wall of the second step column 43B is formed with an external thread, a first sealing ring is arranged on the outer wall of the first step column 43A, a second sealing ring is arranged between the second step column 43B and the cylinder head block 43, and an inclined sealing surface for cooperating with the second sealing ring is formed at the opening of the second step hole;

[0047] The first step column 43A of the cylinder head block 43 is inserted into the first step hole, the first sealing ring is sealed with the first step hole, the second step column 43B is threadedly connected and fixed with the second step hole, and the inclined sealing surface of the second step hole is sealed with the second sealing ring.

[0048] By means of the above connection structure, the cylinder head block 43 is stably connected to the end of the oil storage cylinder barrel 42, and the connection has high sealing performance and is not easy to leak.

[0049] A plurality of sealing rings are arranged in the bore of the cylinder head block 43 , which are suitable for improving the sealing performance between the cylinder head block 43 and the outer wall of the gas storage cylinder 41 .

[0050] like Figure 4 As shown, the movable sealing structure between the inner piston 45 and the gas storage cylinder 41 is as follows: a first guide ring 45A and a second guide ring 45B are provided on the outer wall of the inner piston 45, and a step seal 45C and an oil-gas seal 45D are provided between the first guide ring 45A and the second guide ring 45B.

[0051] By virtue of the sealing structure, hydraulic oil is not easy to enter the air cavity, thereby improving the sealing performance of the inner piston 45 .

[0052] During operation, the shock-absorbing cylinder in this embodiment is installed on the rotary drilling rig, the main cylinder 2 is connected to the drill rod, and the auxiliary cylinder 3 is connected to the fuselage. When the drill rod is lifted, the main cylinder 2 supports the drill rod, and the auxiliary cylinder 3 supports the fuselage. The two-way support improves the stability of the drill rod support; when the drill rod is subjected to wind force, the force received by the main cylinder 2 is transmitted to the oil-gas shock-absorbing cylinder 4, the air storage cylinder 41 and the outer piston 44 move relative to the oil storage cylinder 42, and the hydraulic oil in the rodless cavity pushes the inner piston 45 to squeeze the air cavity, and the wind force is buffered by the compressed gas. At the same time, some hydraulic oil will enter the rod cavity through the oil gap of the outer piston 44 to buffer the pressure of the hydraulic oil in the rodless cavity. After passing through the oil-gas shock-absorbing cylinder 4, the vibration received by the auxiliary cylinder 3 is smaller, and the vibration transmitted to the fuselage of the drilling rig is also smaller, and the stability of the whole machine is higher.

[0053] Embodiment 2

[0054] On the basis of the first embodiment, Figure 5 Figure 6 As shown, the master cylinder 2 in this embodiment includes a master cylinder barrel 22 and a master cylinder rod 51, a master cylinder head 8 is fixedly arranged at the front end of the master cylinder barrel 22, the front end of the master cylinder rod 51 extends out from the master cylinder head 8, and a connecting head 52 is fixedly arranged at the front end of the master cylinder rod 51; a first radial convex ring 521 is formed on the connecting head 52, and a second radial convex ring 81 is formed on the master cylinder head 8; when the master cylinder rod 51 is retracted into the master cylinder barrel 22, the first radial convex ring 521 and the second radial convex ring 81 fit together, a pair of clamping blocks 6 are arranged outside the first radial convex ring 521 and the second radial convex ring 81, a pair of bayonet holes are formed inside the clamping blocks 6, the outer ends of the first radial convex ring 521 and the second radial convex ring 81 are arranged in the bayonet holes, and the outer ends of the two clamping blocks 6 are connected with locking rings 9, and the locking rings 9 are suitable for limiting the radial separation movement of the two clamping blocks 6, so that the first radial convex ring 521 and the second radial convex ring 81 are locked in the bayonet holes of the two clamping blocks 6;

[0055] The outer diameter of the master cylinder head 8 is smaller than the inner diameter of the lock ring 9, so that when unlocking, the lock ring 9 is moved to the master cylinder head 8, so that the two clamping blocks 6 can be unlocked for radial separation and unlocking.

[0056] Specifically, the clamping block 6 is a semicircular ring structure. Two clamping blocks 6 are spliced ​​to form a circular ring and clamped on the outside of the first radial convex ring 521 and the second radial convex ring 81.

[0057] Specifically, the two blocks 6 have one side away from the master cylinder head 8 that radially protrudes outward to form a third radial protrusion ring 61 . When the locking ring 9 is sleeved on the outside of the two blocks 6 , the two third radial protrusion rings 61 are suitable for limiting the locking ring 9 from axially moving out of the blocks 6 .

[0058] Specifically, semicircular first sealing grooves are respectively opened on the outer walls of the two clamping blocks 6, and the two first sealing grooves form a circular first sealing groove. A first sealing ring is arranged in the circular first sealing groove, and the first sealing ring contacts and cooperates with the inner hole of the locking ring 9 to increase the friction force of the axial movement of the locking ring 9.

[0059] Specifically, a second sealing groove is provided on the outer wall of the master cylinder head 8 , a second sealing ring is arranged in the second sealing groove, and the second sealing ring contacts and cooperates with the inner hole of the locking ring 9 to increase the friction force of the axial movement of the locking ring 9 .

[0060] Specifically, the connection structure between the master cylinder head 8 and the master cylinder barrel 22 is as follows: the front end of the master cylinder barrel 22 is welded to the extension tube 7, and the wall thickness of the extension tube 7 is greater than the wall thickness of the master cylinder barrel 22; a fourth radial convex ring 82 is formed on the master cylinder head 8, and the fourth radial convex ring 82 is abutted and fit with the front end of the extension tube 7, and a plurality of locking screws axially pass through the fourth radial convex ring 82 and are threadedly connected to the extension tube 7, so that the master cylinder head 8 is axially fixed to the front end of the extension tube 7.

[0061] When it is necessary to lock the position of the master cylinder rod 51, the master cylinder rod 51 retracts into the master cylinder 22, the first radial convex ring 521 and the second radial convex ring 81 fit together, and the two semicircular blocks 6 are clamped outside the first radial convex ring 521 and the second radial convex ring 81. The first radial convex ring 521 and the second radial convex ring 81 are located in the bayonet formed by the two blocks 6, thereby limiting the movement of the connecting head 52 relative to the master cylinder head 8, and then a first sealing ring is arranged in the circular first sealing groove, and then the locking ring 9 outside the master cylinder head 8 is moved to the outside of the two blocks 6 to limit the radial separation of the two blocks 6, and the first sealing ring increases the friction force of the axial movement of the locking ring 9.

[0062] When unlocking is required, the locking ring 9 is moved from the outside of the two blocks 6 to the outside of the master cylinder head 8, and cooperates with the second sealing ring on the outside of the master cylinder head 8. The second sealing ring increases the friction of the axial movement of the locking ring 9, and limits the locking ring 9 to the outside of the master cylinder head 8. Then the first sealing ring is removed, and the two blocks 6 are radially separated, so that the connection block and the master cylinder head 8 are unlocked, and the master cylinder rod 51 can move relative to the master cylinder barrel 22.

[0063] The mechanical lock structure of the oil cylinder rod for the rotary drilling rig of the present invention can lock the connecting head 52 and the main cylinder head 8 when the main cylinder rod 51 is reset and retracted into the main cylinder barrel 22, thereby limiting the axial movement of the two and preventing the main cylinder rod 51 from moving out of the main cylinder barrel 22, thereby providing good protection for the oil cylinder.

[0064] In summary, after the shock-absorbing cylinder of the present invention is used in a rotary drilling rig, the support for the drill rod is improved, the buffering of the drill rod is effectively buffered, and the stability of the entire operation is improved.

[0065] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A shock-absorbing cylinder for a rotary drilling rig, characterized in that: It includes a main oil cylinder and a sub-oil cylinder; an oil-gas shock-absorbing cylinder is arranged between the main cylinder base of the main oil cylinder and the cylinder base of the sub-oil cylinder; The oil-gas shock-absorbing cylinder comprises an oil storage cylinder and an air storage cylinder, one end of the oil storage cylinder is sealed and fixedly connected to the main cylinder base, the other end of the oil storage cylinder is sealed and provided with a cylinder head block, an outer piston is provided in the oil storage cylinder, an oil-passing gap is provided on the outer piston, and the oil-passing gap is suitable for connecting the rod cavity and the rodless cavity in the oil storage cylinder; The cylinder head block is provided with a cylinder hole, one end of the gas storage cylinder passes through the cylinder hole of the cylinder head block and is fixedly connected to the outer piston, the other end of the gas storage cylinder is connected to the auxiliary cylinder base of the auxiliary oil cylinder and is sealed and fixedly connected, and an inner piston is arranged in the gas storage cylinder; An air cavity is formed between the inner piston and the auxiliary cylinder base of the auxiliary oil cylinder, an oil through hole is provided on the outer piston, and an oil storage cavity is formed between the inner piston and the main cylinder base of the main oil cylinder through the oil through hole of the outer piston; An air inlet nozzle is arranged on the auxiliary cylinder base, and the air inlet nozzle is communicated with the air cavity of the air storage cylinder barrel, and is suitable for inputting nitrogen into the air cavity; A first oil inlet nozzle is arranged on the master cylinder base, and a second oil inlet nozzle is arranged on the oil storage cylinder barrel; The master oil cylinder comprises a master cylinder barrel and a master cylinder rod, a master cylinder head is fixedly arranged at the front end of the master cylinder barrel, the front end of the master cylinder rod extends from the master cylinder head, and a connecting head is fixedly arranged at the front end of the master cylinder rod; A first radial convex ring is formed on the connecting head, and a second radial convex ring is formed on the main cylinder head; When the master cylinder rod is retracted into the master cylinder, the first radial convex ring and the second radial convex ring fit together, a pair of clamping blocks are arranged outside the first radial convex ring and the second radial convex ring, a pair of bayonet holes are formed inside the clamping blocks, the outer ends of the first radial convex ring and the second radial convex ring are arranged in the bayonet holes, and the outer ends of the two clamping blocks are connected with locking rings, and the locking rings are suitable for limiting the radial separation movement of the two clamping blocks, so that the first radial convex ring and the second radial convex ring are locked in the bayonet holes of the two clamping blocks; The outer diameter of the master cylinder head is smaller than the inner diameter of the lock ring, so that when unlocking, the lock ring is moved to the master cylinder head, so that the two clamping blocks can be unlocked for radial separation and unlocking.

2. The shock-absorbing cylinder for a rotary drilling rig according to claim 1 is characterized in that: The connection structure between the cylinder head block and the oil storage cylinder barrel is as follows: a first step hole and a second step hole are formed in the oil storage cylinder barrel, the second step hole is close to the outside, and an internal thread is formed in the second step hole; The cylinder head block is formed with a first step column and a second step column, an outer wall of the second step column is formed with an external thread, a first sealing ring is arranged on the outer wall of the first step column, a second sealing ring is arranged between the second step column and the cylinder head block, and an inclined sealing surface for cooperating with the second sealing ring is formed at the opening of the second step hole; The first step column of the cylinder head block is inserted into the first step hole, the first sealing ring is sealed with the first step hole, the second step column is threadedly connected and fixed with the second step hole, and the inclined sealing surface of the second step hole is sealed with the second sealing ring.

3. The shock absorbing cylinder for rotary drilling rig according to claim 1 is characterized in that: The movable sealing structure between the inner piston and the gas storage cylinder is: A first guide ring and a second guide ring are arranged on the outer wall of the inner piston, and a step seal and an oil-gas seal are arranged between the first guide ring and the second guide ring.

4. The shock-absorbing oil cylinder for a rotary drilling rig according to claim 1 is characterized in that: The clamping block is a semicircular ring structure, and two clamping blocks are spliced ​​to form a circular ring and clamped on the outside of the first radial convex ring and the second radial convex ring.

5. The shock absorbing cylinder for rotary drilling rig according to claim 4 is characterized in that: The two clamping blocks are radially protruded outwards on one side away from the master cylinder head to form a third radial protruding ring. When the locking ring is sleeved on the outside of the two clamping blocks, the two third radial protruding rings are suitable for limiting the locking ring from axially moving out of the clamping blocks.

6. The shock-absorbing cylinder for a rotary drilling rig according to claim 4 is characterized in that: Semicircular first sealing grooves are respectively provided on the outer walls of the two clamping blocks, and the two first sealing grooves form a circular first sealing groove. A first sealing ring is arranged in the circular first sealing groove, and the first sealing ring contacts and cooperates with the inner hole of the locking ring to increase the friction force of the axial movement of the locking ring.

7. The shock-absorbing oil cylinder for a rotary drilling rig according to claim 4 is characterized in that: The outer wall of the master cylinder head is provided with a second sealing groove, a second sealing ring is arranged in the second sealing groove, and the second sealing ring is in contact with the inner hole of the locking ring to increase the friction force of the axial movement of the locking ring.

8. The shock absorbing cylinder for rotary drilling rig according to claim 1, characterized in that: The connection structure between the master cylinder head and the master cylinder barrel is as follows: The front end of the main cylinder is welded and connected to the extension tube, and the wall thickness of the extension tube is greater than that of the main cylinder; a fourth radial convex ring is formed on the main cylinder head, and the fourth radial convex ring abuts and fits against the front end of the extension tube, and a plurality of locking screws axially pass through the fourth radial convex ring and are threadedly connected to the extension tube to axially fix the main cylinder head to the front end of the extension tube.

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