Buffer shock absorber for drilling machine

Abstract

The invention relates to a buffer shock absorber for a drilling machine and belongs to the technical field of shock absorbers. Comprising a connecting sleeve installed on a drilling machine, a telescopic sleeve is slidably connected to the connecting sleeve, a reset spring sleeves the telescopic sleeve, the two ends of the reset spring abut against the two opposite faces of the telescopic sleeve and the connecting sleeve respectively, a buffer compression cavity is further formed in the connecting sleeve, a piston is slidably connected into the buffer compression cavity, and the piston is connected with the telescopic sleeve. The buffering force of the telescopic sleeve can be adjusted by controlling the pressure of a medium in the buffering compression cavity; the buffer compression cavity communicates with the central pipe cavity of the connecting sleeve and the central pipe cavity of the telescopic sleeve, and when the telescopic sleeve is compressed, the buffer compression cavity compresses a medium through the piston to buffer the telescopic sleeve. According to the buffer shock absorber for the drilling machine, different buffer forces can be adjusted according to different working occasions.

Description

Technical Field

[0001] The invention relates to a buffer shock absorber for a drilling rig, belonging to the technical field of shock absorbers. Background Art

[0002] Drilling rigs are widely used in mining, oil, gas, water wells, geological exploration and other fields. During the drilling process, due to the friction, impact and vibration between the drill bit and the formation, the drill will produce large mechanical stress and vibration, which not only affects the drilling efficiency, but also may cause damage to the equipment and potential safety hazards to the operator. Therefore, the development of effective buffer shock absorbers is an important measure to improve the performance of drilling rigs and extend the life of equipment.

[0003] For water well drilling rigs, high-pressure impact drilling is adopted. The drilling geology is more complex and the environment is more severe. The drill rod (drill bit) is connected to the gearbox main shaft, and the rebound and impact force are large, and the vibration frequency is high, which can easily cause damage to the bearings, oil seals and other components in the gearbox, further causing serious wear of the drilling rig's slide block, reducing the service life of the drilling rig and increasing the maintenance cost.

[0004] At present, the shock absorbers for drilling rigs usually use springs, air compression or hydraulic principles to absorb and reduce vibration. Its basic working principles include: Spring buffer: use the elastic deformation of the spring to absorb impact energy and reduce vibration transmission.

[0005] Hydraulic shock absorption: absorbs vibration energy through the flow and compression of liquid, and usually has good damping characteristics.

[0006] Gas cushioning (such as the Chinese invention patent with patent publication number CN105804671A): uses the compression characteristics of gas to reduce vibration and is suitable for applications requiring a larger stroke.

[0007] The existing technology is unable to adjust the buffer force in real time according to different working occasions (such as exploration, drilling, etc.), resulting in serious damage to the spring and the drilling rig. Summary of the invention

[0008] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a buffer shock absorber for a drilling rig, which can adjust different buffer forces according to different working occasions.

[0009] The buffer shock absorber for drilling rigs of the present invention comprises a connecting sleeve installed with the drilling rig, a telescopic sleeve is slidably connected to the connecting sleeve, a reset spring is mounted on the telescopic sleeve, and two ends of the reset spring are respectively against two opposite surfaces of the telescopic sleeve and the connecting sleeve; A buffer compression cavity is provided in the connecting sleeve, a piston is slidably connected in the buffer compression cavity, the piston is connected to the telescopic sleeve, and the buffer force of the telescopic sleeve is adjusted by controlling the medium pressure in the buffer compression cavity; The buffer compression cavity is communicated with the central tube cavity of the connecting sleeve and the telescopic sleeve respectively. When the telescopic sleeve is compressed, the buffer compression cavity compresses the medium through the piston to buffer the telescopic sleeve.

[0010] Furthermore, the connecting sleeve is composed of a first connecting sleeve and a second connecting sleeve, the first connecting sleeve and the second connecting sleeve are detachably connected, a buffer compression cavity is provided in the first connecting sleeve, and the telescopic sleeve passes through the second connecting sleeve and is connected to a piston located in the buffer compression cavity of the first connecting sleeve.

[0011] Furthermore, a spline shaft section is arranged on the telescopic sleeve, and a key groove is arranged on the second connecting sleeve to match the spline shaft section.

[0012] Furthermore, the return spring is a compression spring, which is sleeved on the telescopic sleeve, with one end of the compression spring abutting against a positioning ring on the telescopic sleeve and the other end abutting against the second connecting sleeve.

[0013] Furthermore, after the reset spring is reset, at least a portion of the protective sleeve is sleeved onto the positioning ring.

[0014] Furthermore, a protective sleeve is sleeved on the outside of the return spring, and the protective sleeve is detachably connected to the second connecting sleeve.

[0015] Furthermore, a sealing member is provided on the outer cylindrical surface of the piston.

[0016] Furthermore, a support ring is provided on the outer cylindrical surface of the piston.

[0017] Furthermore, an anti-loosening structure for the piston is also provided on the telescopic sleeve.

[0018] Furthermore, a sealing structure is provided between the telescopic sleeve and the piston.

[0019] Compared with the prior art, the present invention has the following beneficial effects: Traditional shock absorbers rely on fixed damping coefficients (such as pure springs or hydraulic structures) and cannot match the formation hardness (soft rock / hard rock) or drilling process (exploration high-frequency vibration / drilling high torque impact) in real time. The present invention achieves nonlinear dynamic adjustment of the buffer force with external load by intelligently controlling the medium pressure (such as gas or liquid) in the buffer compression chamber, so that the drill bit can avoid "rigid rebound" in soft rock and suppress "stress overshoot" in hard rock, and the adaptability range of working conditions is improved.

[0020] Existing technologies mostly use a single buffer mode (such as pure mechanical springs or independent pneumatic damping), which makes it difficult to take into account both high-frequency micro-vibration and extreme impact loads. The present invention innovatively combines the synergistic effect of mechanical elastic deformation (compression spring) and gas compression energy storage to form a two-stage energy dissipation path: Initial buffer: The compression spring quickly absorbs high-frequency micro-vibration and reduces the instantaneous impact when the drill bit contacts the formation; End buffer: The buffer compression chamber provides large stroke damping under extreme loads to avoid rig resonance or structural failure.

[0021] Traditional shock absorbers are prone to fatigue fracture of compression springs (soft rock conditions) or failure of pneumatic seals (hard rock conditions) due to the single buffering mode. The present invention limits the stress amplitude of the compression spring to the elastic deformation range (σ<0.5σ_s) through dynamic pressure regulation, and adopts a self-compensating sealing structure for the buffer compression cavity. Under extreme conditions, the replacement cycle of the compression spring is extended from about 10 days to 12-15 months, avoiding the compression spring from becoming a wearing part that needs to be replaced frequently, and reducing maintenance costs by 65% ​​(actual measured data: a certain model of drilling rig has been operating continuously for 2000 hours without failure). BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention; Figure 2 is a full cross-sectional view of embodiment 1 of the present invention; Figure 3 yes Figure 2 A partial enlarged view of the middle part; Figure 4 is a schematic diagram of the split structure of Example 1 of the present invention; Figure 5 is a schematic diagram of the structure of the first connecting sleeve of Embodiment 1 of the present invention; Figure 6 is a schematic diagram of the piston structure of Example 1 of the present invention; Figure 7 is a schematic diagram of the structure of the second connecting sleeve of Embodiment 1 of the present invention; Figure 8 is a schematic diagram of the telescopic sleeve structure of embodiment 1 of the present invention; In the figure: 1. Connecting sleeve; 11. First connecting sleeve; 12. Second connecting sleeve; 2. Telescopic sleeve; 21. Spline shaft section; 22. Positioning ring; 23. Anti-loosening groove; 3. Protective cover; 4. Return spring; 5. Piston; 51. Seal; 52. Support ring; 53. Sealing structure; 6. Anti-loosening structure; 61. Round nut; 62. Anti-loosening sheet; 7. Buffer compression cavity. DETAILED DESCRIPTION

[0023] Example 1 like Figures 1 to 8As shown, the buffer shock absorber for drilling rigs of the present invention comprises a connecting sleeve 1 installed with the drilling rig, and a threaded section is provided on the connecting sleeve 1. The drill rod is removed in advance and connected to the drill rod installation position of the drilling rig through the thread on the connecting sleeve 1.

[0024] The connecting sleeve 1 is slidably connected to the telescopic sleeve 2, and a reset spring 4 is mounted on the telescopic sleeve 2. Both ends of the reset spring 4 are respectively against two opposite surfaces of the telescopic sleeve 2 and the connecting sleeve 1. The reset spring 4 can be directly compressed by the telescopic sleeve 2, so that the telescopic sleeve 2 has an elastic buffering effect.

[0025] Existing products can be cushioned by closed air chambers, but this application Figure 2 As shown, a buffer compression chamber 7 is provided in the connecting sleeve 1, and a piston 5 is slidably connected in the buffer compression chamber 7. The piston 5 is connected to the telescopic sleeve 2. The buffer force of the telescopic sleeve 2 is adjusted by controlling the medium pressure in the buffer compression chamber 7. When the medium is gas, the real-time adjustment of the buffer force is achieved by controlling the gas pressure in the buffer compression chamber 7, which solves the pain point that traditional shock absorbers cannot adapt to different formation hardnesses (such as soft rock, hard rock) or drilling processes (exploration / drilling), significantly reduces the risk of spring fatigue fracture or drill rod damage caused by overload, and extends the life of the equipment.

[0026] The buffer compression cavity 7 is communicated with the central tube cavity of the connecting sleeve 1 and the telescopic sleeve 2 respectively. When the telescopic sleeve 2 is compressed, the buffer compression cavity 7 compresses the medium through the piston 5 to buffer the telescopic sleeve 2. The medium in the buffer compression cavity 7 is compressed. When the return spring 4 is a spring, the synergistic effect of the spring elastic deformation and the gas compression is combined to form a "mechanical + pneumatic" two-stage buffer system: Initial buffer: The compression spring quickly absorbs high-frequency micro-vibration and reduces the instantaneous impact when the drill bit contacts the formation; End buffer: The buffer compression chamber provides large stroke damping under extreme loads to avoid rig resonance or structural failure.

[0027] The connecting sleeve 1 is composed of a first connecting sleeve 11 and a second connecting sleeve 12. The first connecting sleeve 11 and the second connecting sleeve 12 are detachably connected. The first connecting sleeve 11 and the second connecting sleeve 12 are connected by threads. The threaded connection has better stability and can also be connected by rotating the buckle. The two end faces can be locked by rotating after abutting against each other, which can achieve quick assembly, but the stability is not as good as the threaded connection.

[0028] A buffer compression cavity 7 is provided in the first connecting sleeve 11 , and the telescopic sleeve 2 passes through the second connecting sleeve 12 and is connected to the piston 5 located in the buffer compression cavity 7 of the first connecting sleeve 11 .

[0029] The telescopic sleeve 2 is provided with a spline shaft section 21, and the second connecting sleeve 12 is provided with a keyway to match the spline shaft section 21. The sliding fit between the spline shaft section and the second connecting sleeve ensures radial positioning accuracy and allows axial telescoping, thereby solving the problem of easy sticking of traditional shock absorbers.

[0030] The return spring 4 is a compression spring, which can be a metal return spring, a rubber return spring or a plastic return spring. The compression spring is sleeved on the telescopic sleeve 2, with one end against the positioning ring 22 on the telescopic sleeve 2 and the other end against the second connecting sleeve 12.

[0031] After the reset spring 4 is reset, at least a portion of the protective cover 3 is sleeved onto the positioning ring 22 , which effectively prevents external debris from entering the working area of ​​the reset spring 4 .

[0032] A protective sleeve 3 is mounted on the outside of the reset spring 4. The protective sleeve 3 and the second connecting sleeve 12 are detachably connected. The protective sleeve 3 and the second connecting sleeve 12 are connected by threads. The threaded connection has better stability and can also be connected by rotating the buckle. The two end faces can be locked by rotating after abutting against each other, which can achieve quick assembly, but the stability is not as good as the threaded connection.

[0033] A seal 51 is provided on the outer cylindrical surface of the piston 5. A modular design is achieved by arranging the piston 5 in conjunction with the seal 51. The seal 51 can be installed on the outer cylindrical surface of the piston 5 using a hole-use combined seal ring. The piston 5 is made of high-hardness material (such as aluminum alloy, cast iron) and has optimized piston surface treatment to reduce friction loss between the piston and the cylinder wall. The aluminum alloy piston 5 is lightweight and corrosion-resistant, while the cast iron piston 5 has high strength and wear resistance, meeting performance requirements under different working conditions.

[0034] A support ring 52 is also provided on the outer cylindrical surface of the piston 5 . The support ring 52 is made of a highly wear-resistant material, which can better ensure the coaxiality of the piston 5 during movement and avoid excessive wear of the seal 51 .

[0035] The telescopic sleeve 2 is also provided with an anti-loosening structure 6 for the piston 5, and the anti-loosening structure 6 includes a round nut 61, and an anti-loosening sheet 62 is installed inside the round nut 61. Figure 8 As shown, a corresponding anti-loosening groove 23 is opened on the threaded section at the end of the telescopic sleeve 2. During installation, the inner ring of the anti-loosening plate 62 is placed into the anti-loosening groove 23. When the round nut 61 is screwed in, the outer teeth of the anti-loosening plate 62 are pressed into the groove of the outer ring of the round nut 61, thereby preventing the round nut 61 from loosening, thereby preventing the piston 5 from loosening when it vibrates at high frequency.

[0036] A sealing structure 53 is provided between the telescopic sleeve 2 and the piston 5. The sealing structure 53 is a sealing ring. An optical axis section is provided on the inner side of the threaded section at the end of the telescopic sleeve 2. An annular groove is provided on the optical axis section. A sealing ring is installed in the annular groove, thereby sealing the gap between the piston 5 and the telescopic sleeve 2 and avoiding leakage of the threaded connection between the piston 5 and the telescopic sleeve 2.

[0037] Working process or working principle: During installation, install the sealing ring into the annular groove in advance, install the seal 51 and the support ring 52 on the piston 5, then put the spring sleeve on the telescopic sleeve 2, slide the second connecting sleeve 12 along the spline shaft section 21, at this time, one end of the second connecting sleeve 12 rests on the spring, thread the piston 5 on the threaded section of the telescopic sleeve 2, then install the anti-loosening sheet 62 on the threaded section, and finally screw in the round nut 61 to lock it, and finally install the first connecting sleeve 11 and the protective sleeve 3 on both ends of the second connecting sleeve 12 respectively.

[0038] The description of the direction and relative position relationship of the structure in the present invention, such as the description of front, back, left, right, up, and down, does not constitute a limitation of the present invention, but is only for the convenience of description.

Claims

1. A buffer shock absorber for a drilling rig, comprising a connecting sleeve (1) mounted on the drilling rig, a telescopic sleeve (2) slidably connected to the connecting sleeve (1), a return spring (4) mounted on the telescopic sleeve (2), two ends of the return spring (4) respectively abutting against two opposite surfaces of the telescopic sleeve (2) and the connecting sleeve (1), characterized in that: A buffer compression cavity (7) is provided in the connecting sleeve (1), a piston (5) is slidably connected in the buffer compression cavity (7), the piston (5) is connected to the telescopic sleeve (2), and the buffer force of the telescopic sleeve (2) is adjusted by controlling the medium pressure in the buffer compression cavity (7); The buffer compression cavity (7) is respectively connected to the central tube cavity of the connecting sleeve (1) and the telescopic sleeve (2); when the telescopic sleeve (2) is compressed, the buffer compression cavity (7) compresses the medium through the piston (5) to reduce shock and buffer the telescopic sleeve (2).

2. The buffer shock absorber for drilling rig according to claim 1, characterized in that: The connecting sleeve (1) is composed of a first connecting sleeve (11) and a second connecting sleeve (12); the first connecting sleeve (11) and the second connecting sleeve (12) are detachably connected; a buffer compression cavity (7) is provided in the first connecting sleeve (11); the telescopic sleeve (2) passes through the second connecting sleeve (12) and is connected to a piston (5) located in the buffer compression cavity (7) of the first connecting sleeve (11).

3. The buffer shock absorber for drilling rig according to claim 2, characterized in that: The telescopic sleeve (2) is provided with a spline shaft section (21), and the second connecting sleeve (12) is provided with a keyway matching the spline shaft section (21).

4. The buffer shock absorber for drilling rig according to claim 2, characterized in that: The return spring (4) is a compression spring which is sleeved on the telescopic sleeve (2), with one end of the compression spring abutting against a positioning ring (22) on the telescopic sleeve (2) and the other end abutting against the second connecting sleeve (12).

5. The buffer shock absorber for drilling rig according to claim 4, characterized in that: After the reset spring (4) is reset, at least a portion of the protective sleeve (3) is sleeved onto the positioning ring (22).

6. The buffer shock absorber for drilling rig according to claim 2, characterized in that: A protective sleeve (3) is sleeved on the outside of the return spring (4), and the protective sleeve (3) is detachably connected to the second connecting sleeve (12).

7. The buffer shock absorber for drilling rig according to claim 1, characterized in that: A sealing member (51) is provided on the outer cylindrical surface of the piston (5).

8. The buffer shock absorber for drilling rig according to claim 7, characterized in that: A support ring (52) is provided on the outer cylindrical surface of the piston (5).

9. The buffer shock absorber for drilling rig according to claim 7, characterized in that: An anti-loosening structure (6) for the piston (5) is provided on the telescopic sleeve (2).

10. The buffer shock absorber for drilling rig according to claim 7, characterized in that: A sealing structure (53) is provided between the telescopic sleeve (2) and the piston (5).

Images