Casing clamping device and full casing full rotary drilling rig

Abstract

The present invention discloses a casing clamping device and a full casing full rotary drilling rig, wherein the casing clamping device comprises a first oil supply port, a second oil supply port, an upper clamping oil cylinder, a lower clamping oil cylinder, a first oil circuit, a second oil circuit, a third oil circuit and a fourth oil circuit, wherein the first oil circuit connects the first oil supply port and the first cavity, the second oil circuit connects the second cavity and the third cavity, the third oil circuit connects the first oil circuit and the fourth cavity, the fourth oil circuit connects the second oil supply port and the second oil circuit, the second oil circuit and the third oil circuit are respectively provided with a first sequence valve and a second sequence valve, the second oil circuit is also provided with a first check valve connected in parallel with the first sequence valve, the third oil circuit is also provided with a second check valve connected in parallel with the second sequence valve, and the fourth oil circuit is connected between the first sequence valve of the second oil circuit and the third cavity. In the casing clamping device and the full casing full rotary drilling rig of the present invention, the sequential action of the upper clamping oil cylinder and the lower clamping oil cylinder can be realized, thereby improving the construction safety and reducing the labor intensity of the operators.

Description

Technical Field

[0001] The invention relates to the technical field of engineering machinery, in particular to a casing clamping device and a full-casing full-rotation drilling rig. Background Art

[0002] Powerful engineering machinery is the guarantee for the smooth progress of the country's infrastructure construction. Because my country has a vast territory and the construction environment is very complex, construction in various geological environments such as plateaus, mountains, hills, beaches, rivers, lakes and seashores often encounters underground quicksand, caves, rock formations and other geological conditions. Traditional excavators and construction methods are difficult to construct. As an emerging product in the engineering machinery industry, the full-casing full-rotation drilling rig has become the most ideal construction machinery for drilling operations in high-speed railways, elevated roads, and building foundation projects. The full-casing full-rotation machine has the characteristics of high efficiency, high quality, and adaptability to various geological environments. When the full-casing full-rotation drilling rig is performing normal pressing and pulling work, the main clamping cylinder and the auxiliary clamping cylinder need to alternately clamp and release to achieve vertical movement of the casing.

[0003] The existing upper and lower clamping oil cylinders are controlled separately, which can easily cause the upper and lower clamping oil cylinders to fail to hold the casing or forget to release the lower clamping oil cylinder due to operator error, thus seriously damaging the lower clamping mechanism when pulling out the casing.

[0004] Please refer to Figure 1 A casing clamping device includes a first hydraulically controlled reversing valve 91, a second hydraulically controlled reversing valve 93, a first pipeline 94, a second pipeline 95, a third pipeline 96, a fourth pipeline 97, a lower clamping cylinder 98 and an upper clamping cylinder 99, the main oil circuit is respectively connected to the first hydraulically controlled reversing valve 91 and the second hydraulically controlled reversing valve 93, the two working oil ports of the first hydraulically controlled reversing valve 91 are respectively connected to the first pipeline 94 and the second pipeline 95, the two working oil ports of the second hydraulically controlled reversing valve 93 are respectively connected to the third pipeline 96 and the fourth pipeline 97, the first pipeline 94 is connected to the rodless chamber of the upper clamping cylinder, the second pipeline 95 is connected to the rod chamber of the upper clamping cylinder 98, the third pipeline 96 is connected to the rodless chamber of the lower clamping cylinder 99, and the fourth pipeline 97 is connected to the rod chamber of the lower clamping cylinder 99. By supplying oil to different oil ports in S1, S2, S3, and S4, the first hydraulically controlled reversing valve 91 and the second hydraulically controlled reversing valve 93 can be switched, thereby supplying and demanding different pipelines of the first pipeline 94, the second pipeline 95, the third pipeline 96, and the fourth pipeline 97, and realizing the clamping or loosening action of the upper clamping cylinder 98 and the lower clamping cylinder 99. It can be seen that in this control mode, the operator needs to frequently reciprocate the control switches of the upper and lower clamping cylinders 98 and 99, which increases the labor intensity of the construction workers, and due to the mistakes of the operators, the upper and lower clamping cylinders 98 and 99 may loosen the casing at the same time or forget to loosen the lower clamping cylinder 99, which may seriously damage the lower clamping mechanism when pulling out the casing. Summary of the invention

[0005] The purpose of the present invention is to provide a casing clamping device and a full casing full rotary drilling rig which can sequentially control the clamping oil cylinder, provide construction safety and reduce labor intensity.

[0006] A casing clamping device comprises a first oil supply port, a second oil supply port, an upper clamping oil cylinder, a lower clamping oil cylinder, a first oil circuit, a second oil circuit, a third oil circuit and a fourth oil circuit, wherein the first oil circuit connects the first oil supply port and the first cavity of the upper clamping oil cylinder, the second oil circuit connects the second cavity of the upper clamping oil cylinder and the third cavity of the lower clamping oil cylinder, the third oil circuit connects the first oil circuit and the fourth cavity of the lower clamping oil cylinder, the fourth oil circuit connects the second oil supply port and the second oil circuit, a first sequence valve and a second sequence valve are respectively provided on the second oil circuit and the third oil circuit, a first check valve connected in parallel with the first sequence valve is also provided on the second oil circuit, a second check valve connected in parallel with the second sequence valve is also provided on the third oil circuit, and the fourth oil circuit is connected between the first sequence valve and the third cavity of the second oil circuit.

[0007] In one embodiment, the control port of the first sequence valve is connected to one end of the second oil circuit communicating with the third chamber, and the control port of the second sequence valve is connected to one end of the third oil circuit communicating with the first chamber.

[0008] In one embodiment, the first one-way valve only allows oil to flow into from one side of the second chamber, and the second one-way valve only allows oil to flow into from one side of the fourth chamber.

[0009] In one embodiment, a first hydraulically controlled switching valve is provided on the first oil circuit, and a second hydraulically controlled switching valve is provided on the second oil circuit. The control port of the first hydraulically controlled switching valve is connected to the second oil circuit, and the control port of the second hydraulically controlled switching valve is connected to the first oil circuit. The first hydraulically controlled switching valve can be opened by the pressure oil on the first oil circuit, and the second hydraulically controlled switching valve can be opened by the pressure oil on the second oil circuit.

[0010] In one embodiment, a third hydraulically controlled switching valve is further provided on the second oil circuit, and a fourth hydraulically controlled switching valve is provided on the third oil circuit. The control port of the third hydraulically controlled switching valve is connected to the third oil circuit, and the control port of the fourth hydraulically controlled switching valve is connected to the second oil circuit. The third hydraulically controlled switching valve is provided between the third chamber and the second hydraulically controlled switching valve. The third hydraulically controlled switching valve can be opened by the pressure oil on the second oil circuit, and the fourth hydraulically controlled switching valve can be opened by the pressure oil on the third oil circuit.

[0011] In one embodiment, the first hydraulically controlled on-off valve, the second hydraulically controlled on-off valve, the third hydraulically controlled on-off valve and the fourth hydraulically controlled on-off valve are all hydraulically controlled one-way valves.

[0012] In one embodiment, the casing clamping device further includes a third oil supply port and a fifth oil circuit, wherein the fifth oil circuit is used to connect the third oil supply port and the second oil circuit; a switch valve is also provided on the second oil circuit to control the on-off of the second oil circuit.

[0013] In one embodiment, one end of the fifth oil circuit is connected between the second hydraulically controlled on / off valve and the first sequence valve of the second oil circuit.

[0014] In one embodiment, the casing clamping device also includes a power station, an oil pipe and a joint, the two ends of the two oil pipes are respectively connected to the power station and the joint, the joint includes a first interface and a second interface, the first interface is connected to the first oil supply port, and the second interface is connected to the second oil supply port or the third oil supply port.

[0015] The present invention also provides a full-casing and full-rotation drilling rig, which comprises the above-mentioned casing clamping device.

[0016] In the casing clamping device and the full-casing full-rotation drilling rig of the present invention, the sequential action of the upper clamping cylinder and the lower clamping cylinder can be realized. When switching between the clamping of the upper clamping cylinder and the clamping of the lower clamping cylinder, it is ensured that the upper and lower cylinders are clamped at the same time and then one of them is released, thereby preventing the upper and lower cylinders from being loosened at the same time, effectively preventing the casing from falling when the casing is pulled out after the hole is formed, thereby improving the construction safety. At the same time, there is no need for the operator to frequently reciprocate the control switches of the upper and lower clamping cylinders, thereby reducing the labor intensity of the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a schematic diagram of the structure of a casing clamping device.

[0018] Figure 2 It is a schematic structural diagram of a casing clamping device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to further explain the technical methods and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and embodiments.

[0020] like Figure 2As shown, the casing clamping device of one embodiment of the present invention comprises a first oil supply port 11, a second oil supply port 13, an upper clamping oil cylinder 15, a lower clamping oil cylinder 17, a first oil circuit 19, a second oil circuit 21, a third oil circuit 23 and a fourth oil circuit 25. The first oil circuit 19 connects the first oil supply port 11 and the first cavity 152 of the upper clamping oil cylinder 15, the second oil circuit 21 connects the second cavity 154 of the upper clamping oil cylinder 15 and the third cavity 172 of the lower clamping oil cylinder 17, the third oil circuit 23 connects the first oil circuit 19 and the fourth cavity 174 of the lower clamping oil cylinder 17, and the fourth oil circuit 25 connects the second oil supply port 13 and the second oil circuit 21. The second oil circuit 21 and the third oil circuit 23 are provided with a first sequence valve 212 and a second sequence valve 214, respectively. The second oil circuit 21 is also provided with a first check valve 216 connected in parallel with the first sequence valve 212. The third oil circuit 23 is also provided with a second check valve 218 connected in parallel with the second sequence valve 214. The fourth oil circuit 25 is connected between the first sequence valve 212 of the second oil circuit 21 and the third chamber 172. Specifically, the first check valve 216 only allows oil to flow in from the second chamber 154 side, and the second check valve 218 only allows oil to flow in from the fourth chamber 174 side.

[0021] In this embodiment, the control port of the first sequence valve 212 is connected to one end of the second oil circuit 21 communicating with the third chamber 172 , and the control port of the second sequence valve 214 is connected to one end of the third oil circuit 23 communicating with the first chamber 152 .

[0022] In this embodiment, a first hydraulically controlled one-way valve 192 is provided on the first oil circuit 19, and a second hydraulically controlled one-way valve 219 is provided on the second oil circuit 21. The control port of the first hydraulically controlled one-way valve 192 is connected to the second oil circuit 21, and the control port of the second hydraulically controlled one-way valve 219 is connected to the first oil circuit 19. In this way, when the first oil circuit 19 passes through high-pressure oil, the second hydraulically controlled one-way valve 219 is opened, and when the second oil circuit 21 passes through high-pressure oil, the first hydraulically controlled one-way valve 192 is opened. It can be understood that the first hydraulically controlled one-way valve 192 and the second hydraulically controlled one-way valve 219 can also be replaced by other hydraulically controlled switch valves such as hydraulically controlled stop valves, hydraulically controlled reversing valves, etc., as long as the hydraulically controlled switch valve on the first oil circuit 19 can be opened by the pressure oil on the first oil circuit 19 and can be opened by the pressure oil on the second oil circuit 21, and the hydraulically controlled switch valve on the second oil circuit 21 can be opened by the pressure oil on the second oil circuit 21 and can be opened by the pressure oil on the first oil circuit 19. For example, the first hydraulically controlled one-way valve 192 and the second hydraulically controlled one-way valve 219 can be replaced by a two-position, two-way hydraulically controlled reversing valve, where one position of the hydraulically controlled reversing valve is connected and the other position is blocked.

[0023] In this embodiment, a third hydraulically controlled one-way valve 221 is further provided on the second oil circuit 21, a fourth hydraulically controlled one-way valve 232 is provided on the third oil circuit 23, a control port of the third hydraulically controlled one-way valve 221 is connected to the third oil circuit 23, a control port of the fourth hydraulically controlled one-way valve 232 is connected to the second oil circuit 21, and the third hydraulically controlled one-way valve 221 is provided between the third chamber 172 and the second hydraulically controlled one-way valve 219. Thus, when the second oil circuit 21 is connected to high-pressure oil, the fourth hydraulically controlled one-way valve 232 is opened, and when the third oil circuit 23 is connected to high-pressure oil, the third hydraulically controlled one-way valve 221 is opened. It can be understood that the third hydraulically controlled one-way valve 221 and the fourth hydraulically controlled one-way valve 232 can also be replaced by other hydraulically controlled switch valves such as hydraulically controlled stop valves and hydraulically controlled reversing valves, as long as the hydraulically controlled switch valve on the second oil circuit 21 can be opened by the pressure oil on the second oil circuit 21 and can be opened by the pressure oil on the third oil circuit 23, and the hydraulically controlled switch valve on the third oil circuit 23 can be opened by the pressure oil on the third oil circuit 23 and can be opened by the pressure oil on the second oil circuit 21. For example, the third hydraulically controlled one-way valve 221 and the fourth hydraulically controlled one-way valve 232 can be replaced by two-position two-way hydraulically controlled reversing valves, where one position of the hydraulically controlled reversing valve is connected and the other position is blocked.

[0024] In this embodiment, the casing clamping device further includes a third oil supply port 27 and a fifth oil circuit 29, and the fifth oil circuit 29 is used to connect the third oil supply port 27 and the second oil circuit 21. Specifically, one end of the fifth oil circuit 29 is connected between the second hydraulically controlled one-way valve 219 and the first sequence valve 212 of the second oil circuit 21. By providing the third oil supply port 27, the upper clamping cylinder 15 can be loosened.

[0025] In this embodiment, a switch valve 223 is further provided on the second oil circuit 21 to control the on-off of the second oil circuit 21. Specifically, the switch valve 223 can be a ball valve, and of course the switch valve 223 can also be a reversing valve, as long as the on-off of the oil circuit can be achieved. Specifically, the switch valve 223 is arranged between the third hydraulically controlled one-way valve 221 and the first sequence valve 212. When the oil pipe is connected to the first oil supply port 11 and the third oil supply port 27, the switch valve 223 can be closed to control the loosening of the upper clamping oil cylinder 15, and the lower clamping oil cylinder 17 does not move; when the oil pipe is connected to the first oil supply port 11 and the second oil supply port 13, the switch valve 223 can be opened to control the sequential action of the upper clamping oil cylinder 15 and the lower clamping oil cylinder 17.

[0026] In this embodiment, the casing clamping device further includes a power station, an oil pipe and a joint, the two ends of the two oil pipes are respectively connected to the power station and the joint, the joint includes a first interface and a second interface, the first interface is connected to the first oil supply port 11, and the second interface is connected to the second oil supply port 13 or the third oil supply port 27. In this embodiment, only two oil pipes are required to be connected to the power station, which saves costs.

[0027] In this embodiment, the casing clamping device also includes a reversing valve, which is connected between the power station and the oil pipe. By reversing the reversing valve, it can be controlled whether the pressure oil is supplied to the first oil supply port 11 or the second oil supply port 13, or whether the pressure oil is supplied to the first oil supply port 11 or the third oil supply port 27.

[0028] In this embodiment, the sleeve clamping device also includes a transition slider 31, and a plurality of oil ports are provided on the transition slider 31. The first oil supply port 11, the second oil supply port 13, the third oil supply port 27, the first chamber 152, the second chamber 154 of the upper clamping oil cylinder 15, the third chamber 172, the fourth chamber 174 of the lower clamping oil cylinder 17, and the fourth oil circuit 25 are respectively connected to different oil ports on the transition slider 31, and the oil circuit is connected in conjunction with the oil passage inside the transition slider 31, so that the oil circuit connection is more convenient. It can be understood that the transition valve block 31 can also be omitted, and the oil circuit can be directly connected.

[0029] In this embodiment, the casing clamping device further includes a sequence valve block 33, and the first sequence valve 212, the second sequence valve 214, the first check valve 216 and the second check valve 218 are all integrated on the sequence valve block 33, which can also make the oil circuit connection more convenient. It can be understood that the sequence valve block 33 can also be omitted, and the oil circuit can be directly connected.

[0030] In this embodiment, the first hydraulically controlled one-way valve 192 and the second hydraulically controlled one-way valve 219 may also be integrated on the same valve block. The third hydraulically controlled one-way valve 221 and the fourth hydraulically controlled one-way valve 232 may also be integrated on the same valve block.

[0031] The working process of the casing clamping device is described in detail below.

[0032] When the joint is connected to the first oil supply port 11 and the third oil supply port 27, the switch valve 223 is closed to shield the lower clamping oil cylinder 17. When the pressure oil is supplied to the first oil supply port 11, the pressure oil reaches the first chamber 152 of the upper clamping oil cylinder 15 through the first oil circuit 19, the piston rod moves left until the sleeve is clamped, the second hydraulically controlled one-way valve 219 is opened by the pressure oil of the first oil circuit 19, and the return oil in the second chamber 154 reaches the third oil supply port 27 through the second hydraulically controlled one-way valve 219 for return oil, and the sleeve is clamped by the upper clamping oil cylinder 15. When the third oil supply port 27 is supplied with pressure oil, the pressure oil reaches the second chamber 154 of the upper clamping oil cylinder 15 through the fifth oil circuit 29 and the second oil circuit 21, the piston rod moves rightward to release the sleeve, the first hydraulically controlled one-way valve 192 is opened by the pressure oil of the second oil circuit 21, and the return oil of the first chamber 152 reaches the first oil supply port 11 through the first hydraulically controlled one-way valve 192 for return oil, and the sleeve is released by the upper clamping oil cylinder 15. Among them, whether the pressure oil is supplied to the first oil supply port 11 or the third oil supply port 27 is controlled by the reversing valve.

[0033] When the joint is connected to the first oil supply port 11 and the second oil supply port 13, the switch valve 223 is opened. When the pressure oil is supplied to the first oil supply port 11, the pressure oil first passes through the first hydraulically controlled one-way valve 192 and the first oil circuit 19 to enter the first chamber 152 of the upper clamping oil cylinder 15, and the piston rod moves left until the sleeve is clamped, while the return oil of the second chamber 154 of the upper clamping oil cylinder 15 passes through the second hydraulically controlled one-way valve 219, the second oil circuit 21, the first one-way valve 216, and the fourth oil circuit 25 to reach the second oil supply port 13, and then flows back to the power station for oil return; the upper clamping oil cylinder 15 holds the sleeve. After the casing is inserted, the pressure in the first oil supply port 11 soars instantly, and the high-pressure oil flows to the fourth chamber of the lower clamping cylinder 17 through the first oil circuit 19, the third oil circuit 23, the second sequence valve 214, and the fourth hydraulically controlled one-way valve 232. The piston rod of the lower clamping cylinder 17 moves right to loosen the casing, and the oil in the third chamber 172 reaches the second oil supply port 13 through the second oil circuit 21, the third hydraulically controlled one-way valve 221, the switch valve 223, and the fourth oil circuit 25, and then flows back to the power station for oil return. When pressure oil is supplied to the second oil supply port 13, the pressure oil first enters the third chamber 172 of the lower clamping cylinder 17 through the fifth oil circuit 25, the first oil circuit 21, and the third hydraulically controlled one-way valve 221, and the piston rod of the lower clamping cylinder 17 moves leftward until the sleeve is clamped, and the return oil of the fourth chamber 174 of the lower clamping cylinder passes through the third oil circuit 23, the fourth hydraulically controlled one-way valve 232, and the second one-way valve 218 to reach the first oil supply port 11, and then flows back to the power station for oil return; After the clamping cylinder 17 holds the casing, the pressure at the second oil supply port 13 soars instantly, and the high-pressure oil flows to the second chamber of the upper clamping cylinder 15 through the fourth oil circuit 25, the first sequence valve 212, the second oil circuit 21, and the second hydraulically controlled one-way valve 219. The piston rod of the upper clamping cylinder 15 moves to the right to loosen the casing, and the oil in the first chamber 152 reaches the first oil supply port 11 through the first hydraulically controlled one-way valve 192 and the first oil circuit 19, and then flows back to the power station for oil return.

[0034] When the joint is connected to the first oil supply port 11 and the second oil supply port 13, the casing clamping device can realize the sequential action of the upper clamping cylinder 15 and the lower clamping cylinder 17. When switching between the clamping of the upper clamping cylinder 15 and the clamping of the lower clamping cylinder 17, it is ensured that the upper and lower parts are clamped at the same time and then one of them is loosened, thus realizing the state of clamping the upper part and loosening the lower part, clamping the lower part and loosening the upper part, and clamping the upper and lower parts at the same time, thus preventing the situation of loosening the upper and lower parts at the same time, and effectively preventing the casing from falling off when pulling out the casing after hole formation.

[0035] In the casing clamping device of the present invention, the sequential action of the upper clamping cylinder 15 and the lower clamping cylinder 17 can be realized. When switching between the clamping of the upper clamping cylinder 15 and the clamping of the lower clamping cylinder 17, it is ensured that the upper and lower cylinders are clamped at the same time and then one of them is released, thereby preventing the upper and lower cylinders from being loosened at the same time. This effectively prevents the casing from falling when the casing is pulled out after drilling, thereby improving construction safety. At the same time, there is no need for the operator to frequently reciprocate to operate the control switch of the upper and lower clamping cylinders, thereby reducing the labor intensity of the operator.

[0036] The present invention also provides a full-casing and full-rotation drilling rig, which comprises the above-mentioned casing clamping device.

[0037] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above in preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A casing clamping device, characterized in that: The invention comprises a first oil supply port (11), a second oil supply port (13), an upper clamping oil cylinder (15), a lower clamping oil cylinder (17), a first oil circuit (19), a second oil circuit (21), a third oil circuit (23) and a fourth oil circuit (25), wherein the first oil circuit (19) connects the first oil supply port (11) and a first cavity (152) of the upper clamping oil cylinder (15), and the second oil circuit (21) connects the second cavity (154) of the upper clamping oil cylinder (15) and the third cavity (172) of the lower clamping oil cylinder (17). The third oil circuit (23) is connected to the first oil circuit (19) and the fourth chamber (174) of the lower clamping oil cylinder (17); the fourth oil circuit (25) is connected to the second oil supply port (13) and the second oil circuit (21); the second oil circuit (21) and the third oil circuit (23) are respectively provided with a first sequence valve (212) and a second sequence valve (214); the second oil circuit (21) is also provided with a first check valve (216) connected in parallel with the first sequence valve (212); the third oil circuit ( The fourth oil circuit (25) is connected between the first sequence valve (212) and the third chamber (172) of the second oil circuit (21); the control port of the first sequence valve (212) is connected to one end of the second oil circuit (21) communicating with the third chamber (172); the control port of the second sequence valve (214) is connected to one end of the third oil circuit (23) communicating with the first chamber (152); and the control port of the second sequence valve (214) is connected to one end of the third oil circuit (23) communicating with the first chamber (152). end, so that the pressure oil provided by the first oil supply port (11) first enters the first chamber (152) of the upper clamping cylinder (15), and then enters the fourth chamber (174) of the lower clamping cylinder (17) after the second sequence valve (214) is opened, and the pressure oil provided by the second oil supply port (13) first enters the third chamber (172) of the lower clamping cylinder (17), and then enters the second chamber (154) of the upper clamping cylinder (15) after the first sequence valve (212) is opened.

2. The casing clamping device according to claim 1, characterized in that: The first one-way valve (216) only allows oil to flow in from one side of the second chamber (154), and the second one-way valve (218) only allows oil to flow in from one side of the fourth chamber (174).

3. The casing clamping device according to claim 1, characterized in that: A first hydraulically controlled on-off valve is provided on the first oil circuit (19), and a second hydraulically controlled on-off valve is provided on the second oil circuit (21). The control port of the first hydraulically controlled on-off valve is connected to the second oil circuit (21), and the control port of the second hydraulically controlled on-off valve is connected to the first oil circuit (19). The first hydraulically controlled on-off valve can be opened by the pressure oil on the first oil circuit (19), and the second hydraulically controlled on-off valve can be opened by the pressure oil on the second oil circuit (21).

4. The casing clamping device according to claim 3, characterized in that: A third hydraulically controlled on-off valve is also provided on the second oil circuit (21), and a fourth hydraulically controlled on-off valve is provided on the third oil circuit (23). The control port of the third hydraulically controlled on-off valve is connected to the third oil circuit (23), and the control port of the fourth hydraulically controlled on-off valve is connected to the second oil circuit (21). The third hydraulically controlled on-off valve is provided between the third chamber (172) and the second hydraulically controlled on-off valve. The third hydraulically controlled on-off valve can be opened by the pressure oil on the second oil circuit (21), and the fourth hydraulically controlled on-off valve can be opened by the pressure oil on the third oil circuit (23).

5. The casing clamping device according to claim 4, characterized in that: The first hydraulically controlled on-off valve, the second hydraulically controlled on-off valve, the third hydraulically controlled on-off valve and the fourth hydraulically controlled on-off valve are all hydraulically controlled one-way valves.

6. The casing clamping device according to claim 4, characterized in that: The casing clamping device further comprises a third oil supply port (27) and a fifth oil circuit (29), wherein the fifth oil circuit (29) is used to connect the third oil supply port (27) and the second oil circuit (21); a switch valve (223) is also provided on the second oil circuit (21) to control the on and off of the second oil circuit (21).

7. The casing clamping device according to claim 6, characterized in that: One end of the fifth oil circuit (29) is connected between the second hydraulically controlled on / off valve and the first sequence valve (212) of the second oil circuit (21).

8. The casing clamping device according to claim 6, characterized in that: The casing clamping device also includes a power station, an oil pipe and a joint, the two ends of the two oil pipes are respectively connected to the power station and the joint, the joint includes a first interface and a second interface, the first interface is connected to the first oil supply port (11), and the second interface is connected to the second oil supply port (13) or the third oil supply port (27).

9. A full casing full rotary drilling rig, characterized in that: The invention comprises a casing clamping device as claimed in any one of claims 1 to 8.

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