A synchronous lifting structure for the main back clamp of a sleeve power clamp

Abstract

This utility model relates to the field of oil drilling technology, specifically to a synchronous lifting structure for the main and back clamps of a casing power tong. It includes multiple double-piston rod hydraulic cylinders arranged side-by-side and connected in series, and a hydraulic circuit controlling the synchronous movement of these cylinders. The hydraulic circuit includes a three-position four-way directional valve, a hydraulically controlled check valve, a hydraulically controlled check valve, and an oil tank. The three-position four-way directional valve has a P port, a T port, an A port, and a B port. By controlling the switching of the three-position four-way directional valve, hydraulic oil can drive the two ends of the multiple double-piston rod hydraulic cylinders to move synchronously, thereby achieving synchronous lifting and lowering of the main clamp and back clamp. This utility model, through the design of the hydraulic circuit, achieves forced synchronization and reliable locking of the main and back clamp lifting. It has advantages such as simple structure, low cost, safety, reliability, and convenient maintenance, and has good engineering application prospects and promotional value.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling equipment technology, and in particular to a synchronous lifting structure for the main back clamp of a casing power tong. Background Technology

[0002] In oil drilling and workover operations, the casing power tongs are key equipment used for tightening and loosening casing or tubing. They mainly consist of a main tong, a back tong, a transfer mechanism, and a power system. The main tong and back tong must move synchronously vertically to accommodate different joint heights and ensure that the two tongs remain parallel during clamping to prevent damage to the jaws, casing slippage, or equipment jamming due to uneven loading.

[0003] Currently, most casing power pliers widely used in the field employ hydraulic cylinders as the lifting actuators for the main and back clamps. A common structure involves separate hydraulic cylinders on both sides of the main and back clamps, driven by a single directional valve.

[0004] However, the inability to achieve complete synchronization of multiple hydraulic cylinders during operation results in the main and back clamps not being parallel, i.e., the main clamp and back clamp are tilted, which disrupts their parallelism. This not only affects the clamping effect and reduces work efficiency, but may also cause abnormal wear of the equipment or even safety accidents. Utility Model Content

[0005] In view of this, the purpose of this utility model is to propose a synchronous lifting structure for the main and back clamps of a sleeve power clamp, so as to solve the problem that multiple hydraulic cylinders cannot move synchronously when the main clamp and back clamp are driven by multiple hydraulic cylinders.

[0006] Based on the above objectives, this utility model provides a synchronous lifting structure for the main back clamp of a casing power clamp, including multiple double piston rod hydraulic cylinders arranged side by side and connected in series, and a hydraulic circuit for controlling the synchronous action of the multiple double piston rod hydraulic cylinders. The hydraulic circuit includes a three-position four-way directional valve, a hydraulically controlled check valve one, a hydraulically controlled check valve two, and an oil tank. The three-position four-way directional valve has a P port, a T port, an A port, and a B port. The P port of the three-position four-way directional valve is connected to an external power source M, the T port is connected to the oil tank, the A port is connected to the oil inlet of the hydraulically controlled check valve two, and the B port is connected to the oil inlet of the hydraulically controlled check valve one. The oil outlet of the hydraulic control check valve one is connected to the leftmost double piston rod hydraulic cylinder, the oil outlet of the hydraulic control check valve two is connected to the rightmost double piston rod hydraulic cylinder, the control oil port of the hydraulic control check valve one is connected to the oil circuit where the oil inlet of the hydraulic control check valve two is located, and the control oil port of the hydraulic control check valve two is connected to the oil circuit where the oil inlet of the hydraulic control check valve one is located, forming a cross control oil circuit; In this system, by switching the working position of the three-position four-way directional valve, the pistons of each double-piston rod hydraulic cylinder can extend or retract synchronously, thereby driving the main clamp and the back clamp to rise and fall synchronously.

[0007] Preferably, the double piston rod hydraulic cylinder has a first oil port, a second oil port, a third oil port, and a fourth oil port. The oil outlet of the hydraulic control check valve one is connected to the first oil port of the leftmost double piston rod hydraulic cylinder, and the oil outlet of the hydraulic control check valve two is connected to the fourth oil port of the rightmost double piston rod hydraulic cylinder. Furthermore, the fourth oil ports on two adjacent double piston rod hydraulic cylinders are connected to the first oil ports, so that multiple double piston rod hydraulic cylinders are connected in series.

[0008] Preferably, the second and third oil ports of the dual piston rod hydraulic cylinder are used for initial oil filling and venting, and are closed during operation.

[0009] Preferably, the three-position four-way directional valve is an electromagnetic directional valve or a manual directional valve.

[0010] Preferably, the system also includes a pressure gauge and an overflow valve, wherein the pressure gauge is located upstream of the P port of the three-position four-way directional valve and is used to monitor the system pressure.

[0011] Preferably, the overflow valve is connected between the P port of the three-position four-way directional valve and the oil tank to limit the maximum operating pressure of the system.

[0012] The beneficial effects of this utility model are as follows: When it is necessary to control the synchronous raising of the main clamp and the back clamp, the three-position four-way directional valve is switched to flow through port A. The hydraulic oil flows simultaneously to the control ports on both the pilot-operated check valve 2 and the pilot-operated check valve 1. When the hydraulic oil flows to the control port on the pilot-operated check valve 1, it opens the pilot-operated check valve 1. The hydraulic oil flowing into the pilot-operated check valve 2 enters the double piston rod cylinder, pushing the piston to move upward. The hydraulic oil flowing back into the double piston rod cylinder returns to the oil tank through the pilot-operated check valve 1 and port B of the three-position four-way directional valve, thus achieving the purpose of controlling the synchronous raising of the main clamp and the back clamp.

[0013] When it is necessary to control the synchronous descent of the main clamp and the back clamp, the three-position four-way directional valve is switched to flow through port B. Hydraulic oil flows simultaneously to the control ports on both the pilot-operated check valve 1 and the pilot-operated check valve 2. When the hydraulic oil flows to the control port on the pilot-operated check valve 2, it opens the pilot-operated check valve 2. The hydraulic oil flowing into the pilot-operated check valve 1 enters the double piston rod cylinder, pushing the piston downward. The hydraulic oil flowing back into the double piston rod cylinder returns to the oil tank through the pilot-operated check valve 2 and port A of the three-position four-way directional valve, thus achieving the purpose of controlling the synchronous descent of the main clamp and the back clamp. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram showing the distribution of the oil ports on the double piston rod hydraulic cylinder of this utility model.

[0016] In the diagram: 1. Pressure gauge; 2. Relief valve; 3. Three-position four-way directional valve; 4. Hydraulic check valve one; 5. Hydraulic check valve two; 6. Double piston rod hydraulic cylinder; 7. Oil tank; 8. First oil port; 9. Second oil port; 10. Third oil port; 11. Fourth oil port. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0018] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0019] like Figure 1 , Figure 2 As shown, a casing power clamp main and back clamp synchronous lifting structure includes multiple double piston rod hydraulic cylinders 6 arranged side by side and connected in series, and a hydraulic circuit for controlling the synchronous movement of multiple double piston rod hydraulic cylinders 6. The main clamp and back clamp of the power clamp can be respectively installed on the two output ends of the double piston rod hydraulic cylinders 6, so that when the piston of the double piston rod hydraulic cylinder 6 moves upward, it can synchronously drive the main clamp and back clamp to rise, and vice versa, it can synchronously drive the main clamp and back clamp to fall. The hydraulic circuit includes a three-position four-way directional valve 3, a pilot-operated check valve 4, a pilot-operated check valve 5, and an oil tank 7. The three-position four-way directional valve 3 is an electromagnetic or manual directional valve with a neutral-position closed or O-type function to keep the cylinder stationary in any position. The three-position four-way directional valve 3 has a P port, a T port, an A port, and a B port. The P port of the three-position four-way directional valve 3 is connected to an external power source M, the T port is connected to the oil tank 7, the A port is connected to the oil inlet of the pilot-operated check valve 5, and the B port is connected to the oil inlet of the pilot-operated check valve 4. The oil outlet of hydraulic check valve 4 is connected to the leftmost double piston rod cylinder 6, the oil outlet of hydraulic check valve 5 is connected to the rightmost double piston rod cylinder 6, the control oil port of hydraulic check valve 4 is connected to the oil circuit where the oil inlet of hydraulic check valve 5 is located, and the control oil port of hydraulic check valve 5 is connected to the oil circuit where the oil inlet of hydraulic check valve 4 is located, forming a cross control oil circuit. The two piston rods of the dual piston rod hydraulic cylinder 6 are used to connect and drive the main clamp and the back clamp to move up and down synchronously.

[0020] In this process, by switching the working position of the three-position four-way directional valve 3, the pistons of each double piston rod hydraulic cylinder 6 are extended or retracted synchronously, thereby driving the main clamp and the back clamp to rise and fall synchronously.

[0021] In a preferred embodiment of this utility model, the double piston rod hydraulic cylinder 6 has a first oil port 8, a second oil port 9, a third oil port 10, and a fourth oil port 11. The oil outlet of the hydraulic control check valve 4 is connected to the first oil port 8 of the leftmost double piston rod hydraulic cylinder 6, and the oil outlet of the hydraulic control check valve 5 is connected to the fourth oil port 11 of the rightmost double piston rod hydraulic cylinder 6. The fourth oil port 11 on two adjacent double piston rod hydraulic cylinders 6 is connected to the first oil port 8, so that multiple double piston rod hydraulic cylinders 6 are connected in series.

[0022] By connecting multiple double-piston rod hydraulic cylinders 6 in series, and each double-piston rod hydraulic cylinder 6 has an upper chamber and a lower chamber, when hydraulic oil enters the lower chamber of the rightmost double-piston rod hydraulic cylinder 6 from the hydraulic control check valve 2 5, the hydraulic oil will push the piston inside to move upward. At this time, the hydraulic oil in the upper chamber will enter the lower chamber of the adjacent double-piston rod hydraulic cylinder 6 through the oil passage, thereby pushing the piston inside to move upward. Finally, the returning hydraulic oil will return to the oil tank 7 through the hydraulic control check valve 4.

[0023] When hydraulic oil enters the upper chamber of the leftmost double piston rod cylinder 6 from the hydraulic control check valve 4, the hydraulic oil pushes the piston inside to move down. At this time, the hydraulic oil in the lower chamber will enter the upper chamber of the adjacent double piston rod cylinder 6 through the oil passage, thereby pushing the piston inside to move down. Finally, the returning hydraulic oil will return to the oil tank 7 through the hydraulic control check valve 5.

[0024] The second oil port 9 and the third oil port 10 of the double piston rod hydraulic cylinder 6 are used for initial oil filling and venting, and are closed in the working state.

[0025] In another preferred embodiment of this invention, a pressure gauge 1 and a relief valve 2 are also included. The pressure gauge 1 is located upstream of the P port of the three-position four-way directional valve 3 and is used to monitor the system pressure. The relief valve 2 is connected between the P port of the three-position four-way directional valve 3 and the oil tank 7 and is used to limit the maximum operating pressure of the system.

[0026] When it is necessary to control the synchronous rise of the main clamp and the back clamp, the upper position of the three-position four-way directional valve 3 is activated, so that port P is connected to port A and port T is connected to port B. The hydraulic oil enters port P of the three-position four-way directional valve 3 from the external power source M and flows out from port A. The hydraulic oil flowing out from port A flows to the inlet of the hydraulic control check valve 2 5 and the control port on the hydraulic control check valve 1 4. When the hydraulic oil flows to the control port on the hydraulic control check valve 1 4, it will open the hydraulic control check valve 1 4. The hydraulic oil flowing into the hydraulic control check valve 2 5 will enter the lower chamber of the rightmost double piston rod cylinder 6, pushing the piston to move upward. Since multiple double piston rod cylinders 6 are connected in series, the pistons in multiple double piston rod cylinders 6 all move upward. The hydraulic oil caused by the upward movement of the pistons in the double piston rod cylinders 6 will return to the oil tank 7 through the hydraulic control check valve 1 4, port B and port T of the three-position four-way directional valve 3, thereby achieving the purpose of controlling the synchronous rise of the main clamp and the back clamp.

[0027] When it is necessary to control the synchronous descent of the main clamp and the back clamp, the three-position four-way directional valve 3 is lowered, connecting port P to port B and port A to port T. Hydraulic oil enters port P of the three-position four-way directional valve 3 from the external power source M and flows out from port B. The hydraulic oil flowing out from port B flows simultaneously to the inlet of hydraulic control check valve 4 and the control port on hydraulic control check valve 5. When the hydraulic oil flows to the control port on hydraulic control check valve 5, it opens hydraulic control check valve 5. The hydraulic oil flowing into hydraulic control check valve 4 enters the upper chamber of the leftmost double piston rod cylinder 6, pushing the piston downward. Since multiple double piston rod cylinders 6 are connected in series, the pistons in multiple double piston rod cylinders 6 all move downward. The hydraulic oil caused by the downward movement of the pistons in the double piston rod cylinders 6 returns to the oil tank 7 through hydraulic control check valve 5, port A, and port T of the three-position four-way directional valve 3, thereby achieving the purpose of controlling the synchronous descent of the main clamp and the back clamp.

[0028] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention is limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in the details for the sake of brevity.

[0029] The embodiments of this utility model are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A synchronous lifting structure for the main back clamp of a sleeve power clamp, characterized in that, It includes multiple double piston rod hydraulic cylinders (6) arranged side by side and connected in series, and a hydraulic circuit for controlling the synchronous action of multiple double piston rod hydraulic cylinders (6); The hydraulic circuit includes a three-position four-way directional valve (3), a hydraulic control check valve one (4), a hydraulic control check valve two (5), and an oil tank (7). The three-position four-way directional valve (3) has a P port, a T port, an A port, and a B port. The P port of the three-position four-way directional valve (3) is connected to an external power source M, the T port is connected to the oil tank (7), the A port is connected to the oil inlet of the hydraulic control check valve two (5), and the B port is connected to the oil inlet of the hydraulic control check valve one (4). The oil outlet of the hydraulic control check valve 1 (4) is connected to the leftmost double piston rod cylinder (6), the oil outlet of the hydraulic control check valve 2 (5) is connected to the rightmost double piston rod cylinder (6), the control oil port of the hydraulic control check valve 1 (4) is connected to the oil circuit where the oil inlet of the hydraulic control check valve 2 (5) is located, and the control oil port of the hydraulic control check valve 2 (5) is connected to the oil circuit where the oil inlet of the hydraulic control check valve 1 (4) is located, forming a cross control oil circuit; The two piston rods of the double piston rod hydraulic cylinder (6) are used to connect and drive the main clamp and the back clamp to lift and lower synchronously. In this process, by switching the working position of the three-position four-way directional valve (3), the pistons of each double piston rod hydraulic cylinder (6) are extended or retracted synchronously, thereby driving the main clamp and the back clamp to rise and fall synchronously.

2. The synchronous lifting structure of the main back clamp of the sleeve power clamp according to claim 1, characterized in that, The double piston rod hydraulic cylinder (6) has a first oil port (8), a second oil port (9), a third oil port (10) and a fourth oil port (11). The oil outlet of the hydraulic control check valve one (4) is connected to the first oil port (8) of the leftmost double piston rod hydraulic cylinder (6), and the oil outlet of the hydraulic control check valve two (5) is connected to the fourth oil port (11) of the rightmost double piston rod hydraulic cylinder (6). The fourth oil port (11) on two adjacent double piston rod hydraulic cylinders (6) is connected to the first oil port (8), so that multiple double piston rod hydraulic cylinders (6) are connected in series.

3. The synchronous lifting structure of the main back clamp of the sleeve power clamp according to claim 2, characterized in that, The second oil port (9) and the third oil port (10) of the double piston rod hydraulic cylinder (6) are used for initial oil filling and venting, and are closed in the working state.

4. The synchronous lifting structure of the main back clamp of the sleeve power clamp according to claim 1, characterized in that, The three-position four-way directional valve (3) is either an electromagnetic directional valve or a manual directional valve.

5. The synchronous lifting structure of the main back clamp of the sleeve power clamp according to claim 1, characterized in that, It also includes a pressure gauge (1) and an overflow valve (2), wherein the pressure gauge (1) is located upstream of the P port of the three-position four-way directional valve (3) for monitoring system pressure.

6. The synchronous lifting structure of the main back clamp of the sleeve power clamp according to claim 5, characterized in that, The overflow valve (2) is connected between the P port of the three-position four-way directional valve (3) and the oil tank (7) to limit the maximum working pressure of the system.

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