Automatic clamping and locking hydraulic cylinder for oil well

Abstract

This utility model provides an automatic clamping and locking hydraulic cylinder for oil wells. A piston is installed inside the cylinder, and a guide rod passes through the middle of the cylinder bottom. A locking nut is located inside the nut mounting cylinder. A threaded seat is provided at the bottom of the cylinder, and the locking nut is threadedly connected to the threaded seat. One end of the guide rod is connected to the piston, and the other end can contact the locking nut. A hydraulic motor is located at the tail end of the mounting cylinder, and an intermediate drive shaft is located at the output end of the hydraulic motor. The end of the intermediate drive shaft is keyed to the locking nut. The cylinder has a first oil passage acting on the first surface of the piston, and a second oil passage is provided at the bottom of the cylinder, acting on the second surface of the piston. A control valve block is installed in the nut mounting cylinder, and the control valve block is connected to the first oil passage, the second oil passage, and the hydraulic motor through pipelines. An electrical control system is installed inside the control valve block. This utility model provides higher mechanical locking reliability and solves the problem of unstable locking caused by hydraulic leakage.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic cylinders, and in particular relates to an automatic clamping and locking hydraulic cylinder for oil wells. Background Technology

[0002] As the cornerstone of my country's industry, the hydraulic manufacturing sector urgently needs to fully realize automated production under Industry 4.0. Hydraulic cylinders, the most common hydraulic products in the industry, are often used as mechanical force output components. Under certain working conditions, while outputting force, they also require prolonged locking. Due to hydraulic leakage, relying solely on hydraulic cylinders for prolonged locking has low reliability. Therefore, a combination of mechanical and hydraulic systems is needed. To meet automation requirements, electricity is also required, resulting in a mechatronic-hydraulic integrated hydraulic cylinder. Utility Model Content

[0003] In view of this, the present invention aims to propose an automatic clamping and locking hydraulic cylinder for oil wells, which has higher mechanical locking reliability and solves the problem of unstable locking caused by hydraulic leakage.

[0004] To achieve the above objectives, the technical solution of this utility model is implemented as follows: An automatic clamping and locking hydraulic cylinder for oil wells includes a cylinder, cylinder bottom, nut mounting sleeve, piston, guide column, locking nut, hydraulic motor, and control valve block; The cylinder, cylinder bottom, and nut mounting cylinder are connected end to end to form the hydraulic cylinder as a whole; The cylinder is equipped with a piston that can move inside the cylinder, and the piston rod of the piston extends out of the cylinder. The guide rod passes through the middle of the cylinder bottom; the locking nut is located inside the nut mounting sleeve. A threaded seat is provided on the side of the cylinder bottom away from the cylinder, and the locking nut is threadedly connected to the threaded seat; One end of the guide rod is connected to the piston, and the other end can contact the lock nut; The tail end of the mounting cylinder is equipped with a hydraulic motor, the output end of the hydraulic motor is equipped with an intermediate drive shaft, the end of the intermediate drive shaft is keyed to a locking nut, and the locking nut can move axially relative to the intermediate drive shaft. The cylinder is provided with a first oil passage that acts on the first side of the piston, and the bottom of the cylinder is provided with a second oil passage that acts on the second side of the piston. The control valve block is installed on the outside of the nut mounting cylinder, and the control valve block is connected to the first oil passage, the second oil passage and the hydraulic motor through pipelines.

[0005] Furthermore, the piston has a T-shaped structure, including a piston body and a piston rod. Both the piston rod and the piston body are provided with seals between themselves and the cylinder. The piston body is located in the inner cavity of the cylinder, and its two sides are respectively connected to the first oil passage and the second oil passage. The length of the piston body is less than the length of the inner cavity of the cylinder.

[0006] Furthermore, the cylinder is equipped with two proximity switches, which correspond to the extreme positions of the piston body at both ends, and are used to detect the position of the piston body; the two proximity switches are connected to the control valve block.

[0007] Furthermore, the side of the cylinder bottom that mates with the cylinder has a stepped structure, and the stepped structure is connected to the inner wall of the cylinder, with a sealing element between them.

[0008] Furthermore, the locking nut is movable within the inner cavity of the nut mounting sleeve, and when the locking nut is at its extreme position far from the intermediate drive shaft, the locking nut is not separated from the intermediate drive shaft.

[0009] Furthermore, the nut mounting sleeve is equipped with two proximity switches, which correspond to the extreme positions of the two ends of the locking nut, respectively, and are used to detect the position of the locking nut; the two proximity switches are connected to the control valve block.

[0010] Furthermore, the piston rod, the guide post, and the intermediate drive shaft are coaxially arranged.

[0011] Furthermore, the control valve block includes an SX1 sequence valve, an SX2 sequence valve, a DX hydraulic lock, a P1 oil inlet, and a P2 oil inlet; the inlet of the first oil circuit is port A1, and the inlet of the second oil circuit is port B1. The pipeline where the P2 oil inlet is located is divided into branch line 1 and branch line 2; branch line 1 is connected to port A1, and branch line 2 is connected to the hydraulic motor; branch line 1 is equipped with a DX hydraulic lock; branch line 2 is equipped with an SX2 sequence valve. The pipeline where the P1 oil inlet is located is divided into branch line 3 and branch line 4; branch line 3 is connected to port B1, and branch line 4 is connected to the hydraulic motor. Branch line 3 is equipped with SX1 sequence valve.

[0012] Furthermore, the opening pressure of the SX2 sequence valve is set to be greater than the pressure at the P2 inlet. The opening pressure of the SX1 sequence valve is set to be greater than the pressure at the P1 inlet.

[0013] Compared with the prior art, the automatic clamping and locking hydraulic cylinder for oil wells described in this utility model has the following advantages: (1) The automatic clamping and locking hydraulic cylinder for oil wells described in this utility model has higher mechanical locking reliability and solves the problem of unstable locking caused by hydraulic leakage.

[0014] (2) The automatic clamping and locking hydraulic cylinder for oil wells described in this utility model has a higher degree of automation, which solves the problem of inconvenience of manual operation; the proximity switch set on the cylinder can monitor the position of the cylinder in real time, which solves the problem of the cylinder not locking properly; this solution simplifies the overall mechanism, further reduces the manufacturing cost, and makes subsequent maintenance more convenient. Attached Figure Description

[0015] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings: Figure 1 This is a three-dimensional schematic diagram of the automatic clamping and locking hydraulic cylinder for oil wells as described in an embodiment of the present invention; Figure 2 This is a cross-sectional view of the automatic clamping and locking hydraulic cylinder for oil wells described in an embodiment of this utility model; Figure 3 This is a top view of the automatic clamping and locking hydraulic cylinder for oil wells described in an embodiment of this utility model; Figure 4 This is a schematic diagram of the hydraulic principle of the control valve block described in an embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures: 1. Cylinder; 11. No. 1 oil circuit; 12. No. 2 oil circuit; 2. Cylinder bottom; 3. Nut mounting sleeve; 4. Piston; 41. Piston body; 42. Piston rod; 5. Guide column; 6. Locking nut; 7. Hydraulic motor; 71. Intermediate drive shaft; 8. Control valve block; 81. SX1 sequence valve; 82. SX2 sequence valve; 83. DX hydraulic lock; 84. P1 oil inlet; 85. P2 oil inlet; 9. Proximity switch. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] Automatic clamping and locking hydraulic cylinders for oil wells, such as Figures 1-3 As shown, it includes a cylinder 1, a cylinder bottom 2, a nut mounting cylinder 3, a piston 4, a guide post 5, a locking nut 6, a hydraulic motor 7, and a control valve block 8; the cylinder 1, the cylinder bottom 2, and the nut mounting cylinder 3 are connected end to end to form an integral oil cylinder; The cylinder 1 is equipped with a piston 4, which can move inside the cylinder 1, and the piston rod 42 of the piston 4 extends out from the cylinder 1. The guide rod passes through the middle of the cylinder bottom 2; the locking nut 6 is disposed in the inner cavity of the nut mounting sleeve 3; The bottom of the cylinder 2 is provided with a threaded seat on the side away from the cylinder 1, and the locking nut 6 is threadedly connected to the threaded seat; one end of the guide rod is connected to the piston 4, and the other end can be set to contact the locking nut 6; The tail end of the mounting cylinder is equipped with a hydraulic motor 7, and the output end of the hydraulic motor 7 is equipped with an intermediate transmission shaft 71. The end of the intermediate transmission shaft 71 is keyed to a locking nut 6, and the locking nut 6 can move axially relative to the intermediate transmission shaft 71 without restricting the axial degree of freedom. This configuration allows the intermediate drive shaft 71 to drive the locking nut 6 to rotate, but the rotation process does not affect the axial movement of the locking nut 6. The cylinder 1 is provided with a first oil passage 11, which acts on the first surface of the piston 4. The cylinder bottom 2 is provided with a second oil passage 12, which acts on the second surface of the piston 4. The control valve block 8 is installed on the outside of the nut mounting cylinder 3. The control valve block 8 is connected to the first oil passage 11, the second oil passage 12 and the hydraulic motor 7 through pipelines. The control valve block 8 is equipped with an electrical control system.

[0022] Preferably, the piston 4 has a T-shaped structure, including a piston body 41 and a piston rod 42. Both the piston rod 42 and the piston body 41 are provided with a seal between them and the cylinder 1. The piston body 41 is located in the inner cavity of the cylinder 1, and its two sides are respectively engaged with the first oil passage 11 and the second oil passage 12. The length of the piston body 41 is less than the length of the inner cavity of the cylinder 1.

[0023] Preferably, the cylinder 1 is provided with two proximity switches 9, which correspond to the extreme positions of the piston body 41 at both ends, and are used to detect the position of the piston body 41; the two proximity switches 9 are connected to the control valve block 8.

[0024] Preferably, the side of the cylinder bottom 2 that mates with the cylinder 1 has a stepped structure, the stepped structure is connected to the inner wall of the cylinder 1, and a sealing element is provided between the two.

[0025] Preferably, the locking nut 6 is movable within the inner cavity of the nut mounting sleeve 3, and when the locking nut 6 is at its extreme position far from the intermediate drive shaft 71, the locking nut 6 is not separated from the intermediate drive shaft 71.

[0026] Preferably, the nut mounting cylinder 3 is provided with two proximity switches 9, which correspond to the extreme positions of the two ends of the locking nut 6 respectively, and are used to detect the position of the locking nut 6; the two proximity switches 9 are connected to the control valve block 8.

[0027] Preferably, the piston rod 42, the guide post 5, and the intermediate transmission shaft 71 are coaxially arranged.

[0028] Preferably, the control valve block 8 includes an SX1 sequence valve 81, an SX2 sequence valve 82, a DX hydraulic lock 83, a P1 oil inlet 84, and a P2 oil inlet 85; the inlet of the first oil circuit 11 is port A1, and the inlet of the second oil circuit 12 is port B1. The pipeline where the P2 oil inlet 85 is located is divided into branch line 1 and branch line 2; branch line 1 is connected to port A1, and branch line 2 is connected to hydraulic motor 7; branch line 1 is equipped with DX hydraulic lock 83; branch line 2 is equipped with SX2 sequence valve 82. The pipeline at P1 inlet 84 is divided into branch line 3 and branch line 4; branch line 3 is connected to port B1, and branch line 4 is connected to hydraulic motor 7. Branch line 3 is equipped with sequence valve SX1 81.

[0029] Preferably, the opening pressure of the SX2 sequence valve 82 is greater than the pressure of the P2 inlet 85; the opening pressure of the SX1 sequence valve 81 is greater than the pressure of the P1 inlet 84.

[0030] "Clamping" refers to the process where, after the piston rod 42 extends to the designated position, it mechanically locks against the object being fixed. To ensure a smooth tightening process for the locking nut 6 at the tail of the cylinder (i.e., the nut tightening process does not bear the axial force of the cylinder), the hydraulic principle is used... Figure 4 As shown, the locking action of the locking nut 6 must be performed after the cylinder extension action is completed. Therefore, the opening pressure set by the SX2 sequence valve 82 must be greater than the pressure of the P2 oil inlet 85. The hydraulic oil is input through the P2 inlet 85 of the control valve block 8, and is divided into two branches. Branch one enters the cylinder A1 port via the DX hydraulic lock 83, and branch two enters the hydraulic motor 7 via the SX2 sequence valve 82. Because the set opening pressure of the SX2 sequence valve 82 on branch two is greater than the pressure at the P2 inlet 85, branch two is not yet open. The hydraulic oil then enters port A1 via branch one until the cylinder piston rod 42 is fully extended (the proximity switch 9 here can monitor whether the piston rod 42 is fully extended). (Whether it extends to the correct position) Due to the continuous oil supply from the P2 oil inlet 85, the oil pressure rises until the opening pressure of the SX2 sequence valve 82 is reached. The SX2 sequence valve 82 opens, and the oil enters the hydraulic motor 7 through the second branch. The hydraulic motor 7 drives the locking nut 6 to rotate through the intermediate transmission shaft 71 until the spiral nut is tightened and presses against the guide post 5. Then, the proximity switch 97 set at this point (the end of the stroke of the locking nut 64) sends a signal to the electronic control system. The electronic control system controls the P2 oil inlet 85 to stop supplying oil, thus completing the locking and fixing. Because of the presence of the DX hydraulic lock 83, when the oil supply to the P2 inlet 85 stops, the high pressure of the cylinder will not be released, and the piston rod 42 will continue to maintain the output state of axial force, thus offsetting the axial force borne by the locking nut 6.

[0031] "Unlocking" refers to the process where the piston rod 42 of the hydraulic cylinder retracts to the designated position, releasing the fixed object. To ensure a smooth locking process for the locking nut 6 at the tail of the hydraulic cylinder (i.e., the nut 4 does not bear the axial force of the hydraulic cylinder during the unlocking process), the hydraulic principle is used... Figure 2 As shown, the unlocking action of the locking nut 64 must be performed before the cylinder retraction action is initiated. Therefore, the opening pressure set by the SX1 sequence valve 81 must be greater than the pressure of the P1 oil inlet 84. Then, hydraulic oil is input through the P1 inlet 84 of the control valve block 8. The hydraulic oil is divided into two branches: the third branch enters the B1 port of the cylinder via the SX1 sequence valve 81, and the fourth branch enters the hydraulic motor 7. Because the set opening pressure of the SX1 sequence valve 81 on the third branch is greater than the pressure of the P1 inlet 84, the third branch is not opened temporarily. The hydraulic oil enters the hydraulic motor 7 via the fourth branch. The hydraulic motor 7 drives the locking nut 6 to rotate and unlock via the intermediate drive shaft 71 until the locking nut 6 is completely retracted to the unlocking guide post 5. The proximity switch 97 set here (at the limit position of the lock nut 64's stroke) can monitor whether the lock nut 64 has returned to its original position; at this time, the continuous oil supply from the P2 oil inlet 85 causes the oil pressure to rise until it reaches the opening pressure of the SX1 sequence valve 81. The SX1 sequence valve 81 opens, and the oil enters the cylinder B1 port through the third branch. At the same time, another oil line opens the DX hydraulic lock 83, and the cylinder piston rod 42 retracts (the proximity switch 9 set here can monitor whether the piston rod 42 has retracted to its original position), completing the unlocking process.

[0032] The extension, retraction, locking and unlocking processes of the hydraulic cylinder and the locking nut 6 can all be automated. At the same time, the proximity switch 9 can monitor the movement of the hydraulic cylinder in real time, realizing integrated mechanical-electrical-hydraulic control.

[0033] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An automatic clamping locking hydraulic cylinder for oil wells, characterized in that: It includes a cylinder, a cylinder bottom, a nut mounting sleeve, a piston, a guide column, a locking nut, a hydraulic motor, and a control valve block; the cylinder, cylinder bottom, and nut mounting sleeve are connected end to end to form a complete hydraulic cylinder. The cylinder is equipped with a piston that can move inside the cylinder, and the piston rod of the piston extends out of the cylinder. The guide post extends through the middle of the cylinder bottom; the locking nut is located inside the nut mounting sleeve. A threaded seat is provided on the side of the cylinder bottom away from the cylinder, and the locking nut is threadedly connected to the threaded seat; one end of the guide post is connected to the piston, and the other end is set to contact the locking nut; The tail end of the mounting cylinder is equipped with a hydraulic motor, the output end of the hydraulic motor is equipped with an intermediate drive shaft, the end of the intermediate drive shaft is keyed to a locking nut, and the locking nut can move axially relative to the intermediate drive shaft. The cylinder is provided with a first oil passage that acts on the first side of the piston, and the bottom of the cylinder is provided with a second oil passage that acts on the second side of the piston. The control valve block is installed on the outside of the nut mounting cylinder. The control valve block is connected to the first oil passage, the second oil passage and the hydraulic motor through pipelines. The control valve block is equipped with an electrical control system.

2. The automatic pinch and lock hydraulic cylinder for oil wells according to claim 1, characterized in that: The piston has a T-shaped structure, including a piston body and a piston rod. Both the piston rod and the piston body are provided with seals between themselves and the cylinder. The piston body is located in the inner cavity of the cylinder, and its two sides are respectively connected to the first oil passage and the second oil passage. The length of the piston body is less than the length of the inner cavity of the cylinder.

3. The automatic pinch and lock hydraulic cylinder for oil wells according to claim 2, characterized in that: The cylinder is equipped with two proximity switches, which correspond to the extreme positions of the piston body at both ends, and are used to detect the position of the piston body; the two proximity switches are connected to the control valve block.

4. The automatic clamping and locking hydraulic cylinder for oil wells according to claim 1, characterized in that: The bottom of the cylinder and the side that mates with the cylinder have a stepped structure. The stepped structure is connected to the inner wall of the cylinder, and a sealing element is provided between the two.

5. The automatic clamping and locking hydraulic cylinder for oil wells according to claim 1, characterized in that: The locking nut is movable within the cavity of the nut mounting sleeve, and when the locking nut is at its extreme position far from the intermediate drive shaft, the locking nut is not separated from the intermediate drive shaft.

6. The automatic clamping and locking hydraulic cylinder for oil wells according to claim 5, characterized in that: The nut mounting sleeve is equipped with two proximity switches, which correspond to the extreme positions of the two ends of the locking nut and are used to detect the position of the locking nut; the two proximity switches are connected to the control valve block.

7. The automatic clamping and locking hydraulic cylinder for oil wells according to claim 2, characterized in that: The piston rod, the guide post, and the intermediate transmission shaft are coaxially arranged.

8. The automatic clamping and locking hydraulic cylinder for oil wells according to claim 1, characterized in that: The control valve block includes an SX1 sequence valve, an SX2 sequence valve, a DX hydraulic lock, a P1 oil inlet, and a P2 oil inlet; the inlet of the first oil circuit is port A1, and the inlet of the second oil circuit is port B1. The pipeline where the P2 oil inlet is located is divided into branch line 1 and branch line 2; branch line 1 is connected to port A1, and branch line 2 is connected to the hydraulic motor; branch line 1 is equipped with a DX hydraulic lock; branch line 2 is equipped with an SX2 sequence valve. The pipeline where the P1 oil inlet is located is divided into branch line 3 and branch line 4; branch line 3 is connected to port B1, and branch line 4 is connected to the hydraulic motor. Branch line 3 is equipped with SX1 sequence valve.

9. The automatic clamping and locking hydraulic cylinder for oil wells according to claim 8, characterized in that: The opening pressure of the SX2 sequence valve is set to be greater than the pressure at the P2 inlet; the opening pressure of the SX1 sequence valve is set to be greater than the pressure at the P1 inlet.

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