Linkage pressing type tong head reversing mechanism and power tongs

Abstract

The invention belongs to the technical field of oil field wellhead operation equipment, and particularly relates to a linkage pressing type tong head reversing mechanism and a pair of power tongs. The pressing rod intermittently abuts against a pressing plate located at the end of the power piece, the guide piston slides in an inner cavity of the shell, the plug pin alternately slides in an arc groove of the tong head, and a linkage mechanism is formed by a connecting rod, the guide piston and the pressing rod, and the connecting rod is hinged to the lower end of the shell and slides on the outer side of the guide piston in a hinged mode. The problem of inaccuracy or instability of bolt transposition is solved, the number of quick-wear parts is reduced, operation is more convenient, the failure rate and the maintenance cost caused by a complex structure are reduced, manual operation of the bolt or a reset knob is not needed, and therefore the operation time and the labor cost are remarkably reduced, and the working efficiency is improved. The production efficiency of oil field wellhead operation is improved, and the actual requirement for diversification of the oil field wellhead operation is met.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield wellhead operation equipment, and specifically relates to a linkage pressing type clamp head reversing mechanism and a power clamp, which are suitable for threaded connection make-up and make-out operations of tubular equipment such as oil pipes, casings, drill pipes, etc. Background Art

[0002] In oilfield wellhead operations, power tongs are commonly used threaded connection tools for tubular equipment. They can easily realize the make-up and make-out operations of tubular equipment such as oil pipes, casings, and drill pipes. In order to realize multi-directional operation, improve work efficiency, and enhance mechanical adaptability, a tongs head reversing mechanism is usually used to change the movement direction of the tongs head. At present, the power tongs tongs head reversing mechanism can realize the change of make-up and make-out directions by turning the reset knob assembly, but this structure has high manufacturing costs, many vulnerable parts, and is prone to failure when the torque increases, causing the power tongs to be unable to be used normally; the second is to use a pin-type reversing mechanism to change the position of the replacement pin to realize the change of make-up and make-out directions, but this structure requires manual insertion and removal of the pin, which is time-consuming and labor-intensive, has low production efficiency, and cannot meet the needs in remote or automatic operation environments.

[0003] There are studies on the problems of the current tongs reversing mechanism in the prior art, such as patent application CN101358511A-a power tongs lever-type tongs steering mechanism, which realizes the tongs steering mechanism through the lever principle. Although the structure is relatively simple, it still has problems of inconvenient operation and low reversing efficiency in practical applications. For example, patent application CN103993844A-a seesaw hydraulically controlled latch reversing reset device for power tongs and CN215672086U-a power tongs main tongs reversing mechanism, both of which realize remote reversing control through hydraulically controlled latch reversing reset devices, but in practical applications, the seesaw latch is very susceptible to factors such as slope friction and latch deadweight when climbing on the hydraulic ramp, resulting in inaccurate or unstable latch repositioning, while the guide rail movable hydraulically controlled stop pin reset device has the problems of the reset gear shaft extending out of the main tongs body, complex structure, and easy damage. Therefore, a new technical solution is needed to solve the above technical problems. Summary of the invention

[0004] The purpose of the present invention is to provide a linked pressing type clamp head reversing mechanism and a power clamp to solve the problems raised in the above background technology that the current clamp head steering mechanism has a complex structure, cumbersome operation, poor reversing stability, and is difficult to meet the actual needs of oil field wellhead operations.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a linkage pressing type pliers head reversing mechanism, comprising a shell and a power part, a group of latch assemblies are respectively provided at the left and right ends of the shell, the latch assembly slides in the shell through the power part, the upper part of the latch assembly is provided with a pressure rod passing through the top of the shell, the top end of the pressure rod is intermittently abutted against a pressure plate located at the end of the power part, the middle part of the latch assembly is provided with a guide piston sliding in the inner chamber of the shell, the guide piston and the connecting rod and pressure rod hinged to the lower end of the shell and simultaneously hingedly sliding on the outside of the guide piston form a linkage mechanism, the lower part of the latch assembly is provided with a latch passing through the bottom of the shell, the lower ends of the two latches drive the pressure plate through the power part and drive the linkage mechanism to press down or lift up, and the spring sleeved on the upper end of the latch slides alternately in the arc groove of the pliers head.

[0006] Furthermore, the power part includes a hydraulic cylinder or an air cylinder, the cylinder body end of the hydraulic cylinder or the air cylinder is fixed on the main structure of the pliers head, and the piston rod end of the hydraulic cylinder or the air cylinder is fixedly connected to the bottom of one end of the pressure plate; the bottom of the other end of the pressure plate is set to move up and down by the piston rod of the hydraulic cylinder or the air cylinder and at the same time intermittently abuts against the top of the pressure rod; the bottom end of the pressure rod passes from the outside of the top of the shell to the inner cavity of the shell and is fixed to the top of the guide piston at the same time.

[0007] Furthermore, the bottom end of the guide piston is fixedly connected to the top end of the latch and is also fixedly connected to a spring sleeved on the top end of the latch; the bottom end of the spring is fixed to the bottom end of the inner chamber of the shell; the inner chamber of the shell is elastically slidably connected to the guide piston via the spring; the bottom end of the latch passes from the inner chamber of the shell to the outside of the bottom end of the shell and slides in the arc groove of the pliers head.

[0008] Furthermore, a sliding groove is provided on the outer surface of the guide piston, a roller slides in the sliding groove, the end of the roller is fixed to the inner side of the upper end of the connecting rod, a pin is fixed to the inner side of the lower end of the connecting rod and is hinged to the lower end of the shell through the pin; the connecting rod slides cyclically on the outer side of the guide piston along the annular structure of the sliding groove through the roller; the upper part of the sliding groove is eccentrically provided with an upper concave point, and the lower part of the sliding groove is eccentrically provided with a lower concave point.

[0009] In addition to the above technical solutions, there is also a power tongs with the linked pressing type tongs head reversing mechanism.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention utilizes the linkage between the guide piston, the connecting rod and the pressure rod and the elastic effect of the spring, so that the latches arranged at the left and right ends of the housing slide alternately in the arc groove of the clamp head under the drive of the power piece, so that the clamp head has the function of reversing. Compared with the existing lever-type, latch-type or seesaw-type reversing mechanism, the stability of reversing is significantly improved, the problem of inaccuracy or instability of latch repositioning is effectively avoided, the number of wearing parts is reduced, the operation is more convenient, and the failure rate and maintenance cost caused by complex structure are reduced. The driving mode of the power piece is adopted, so that the clamp head reversing mechanism has the function of remote operation, and there is no need to manually operate the latch or reset knob, thereby significantly reducing the operation time and labor cost, improving the production efficiency of oilfield wellhead operations, and meeting the actual needs of diversified oilfield wellhead operations; 2. The present invention controls the pressure plate to move up and down by means of a hydraulic cylinder or an air cylinder, and intermittently abuts against the pressure rod, thereby ensuring the continuity and efficiency of power transmission, avoiding power loss and unstable factors in the transmission process, thereby making the maintenance of the entire clamp head reversing mechanism more convenient and reducing the maintenance cost. The spring sleeved on the upper end of the latch is arranged between the bottom end of the guide piston and the bottom end of the inner chamber of the shell, so that the latch can always maintain the pre-tightening force under the action of the spring, thereby improving the flexibility and accuracy of the reversing action, and at the same time realizing the buffering and stabilizing effect of the latch in the reversing process, thereby avoiding the problem of damage or error caused by impact, and further improving the service life of the entire mechanism; 3. The present invention adopts the sliding cooperation of the slide groove of the annular structure and the roller to realize the relative movement between the connecting rod and the guide piston. While ensuring the continuity and stability of the connecting rod during the reversing process, it also effectively avoids damage or error problems caused by excessive movement, and also reduces the friction resistance during the movement, making the movement of the entire mechanism smoother and more efficient. By utilizing the eccentric setting of the upper and lower concave points, the connecting rod can accurately control its movement direction through the change of the contact point between the roller and the slide groove when the hydraulic cylinder or the cylinder drives the pressure plate to drive the pressure rod and the guide piston to move up and down, thereby realizing the precise reversal of the pin in the circular arc groove of the clamp head, improving the production efficiency of oilfield wellhead operations, and meeting the actual needs of diversified oilfield wellhead operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 A schematic diagram of the connection structure between the middle housing and the latch assembly; Figure 3 for Figure 1 Schematic diagram of the structure of the single-group latch assembly (excluding the connecting rod); Figure 4 for Figure 1A schematic diagram of the structure of the middle shell; Figure 5 It is a top view schematic diagram of the connection between the reversing mechanism and the clamp head of the present invention; Figure 6 It is a schematic diagram of the flow of the reversing mechanism of the present invention.

[0012] Among them: 1. Shell; 101. Inner chamber; 2. Hydraulic cylinder or air cylinder; 201. Piston rod; 3. Latch assembly; 301. Pressure rod; 302. Guide piston; 303. Latch; 4. Pressure plate; 5. Spring; 6. Clamp head; 601. Arc groove; 7. Connecting rod; 8. Slide groove; 801. Upper concave point; 802. Lower concave point; 9. Roller; 10. Pin shaft. DETAILED DESCRIPTION

[0013] The following examples are used to further illustrate the content of the present invention, but do not limit the application of the present invention. Embodiment 1:

[0014] See also Figure 1-Figure 6 The present embodiment provides a linkage pressing type clamp head reversing mechanism, including a housing 1 and a hydraulic cylinder or an air cylinder 2 for providing a power source, the cylinder end of the hydraulic cylinder or the air cylinder 2 is fixed to the main structure of the clamp head 6 (the functions and structures of conventional equipment such as the main structure of the clamp head are well known in the art, and the connection settings are also common knowledge, so no further explanation is given here, and it is not shown in the drawings), and a group of latch assemblies 3 for controlling the reversal of the clamp head are respectively provided at the left and right ends of the housing 1, and the latch assemblies 3 slide in the housing 1 through the hydraulic cylinder or the air cylinder 2, so that the bottom ends of the two groups of latch assemblies 3 can alternately slide in the arc groove 601 of the clamp head 6, thereby realizing the reversal of the clamp head 6; The latch assembly 3 includes a pressure rod 301 arranged at the upper part and passing through the top of the shell 1, a guide piston 302 arranged at the middle part and sliding in the inner chamber 101 of the shell 1, and a latch 303 arranged at the lower part and passing through the bottom of the shell 1, wherein the top end of the pressure rod 301 is intermittently abutted against the pressure plate 4 located at the end of the hydraulic cylinder or the air cylinder 2, the bottom end of the pressure rod 301 passes from the outside of the top end of the shell 1 to the inner chamber 101 of the shell 1 and is fixed to the top end of the guide piston 302 at the same time, the bottom end of the guide piston 302 is fixedly connected to the upper end of the latch 303 and is also fixedly connected to the spring 5 sleeved on the upper end of the latch 303, the lower end of the spring 5 is fixed to the bottom end of the inner chamber 101 of the shell 1, the inner chamber of the shell 1 is elastically slidably connected to the guide piston 302 through the spring 5, the lower end of the latch 303 passes from the inner chamber 101 of the shell 1 to the outside of the bottom end of the shell 1 and slides in the arc groove 601 of the clamp head 6; The bottom of one end of the pressing plate 4 is fixed to the piston rod end of the hydraulic cylinder or the air cylinder 2, and the bottom of the other end of the pressing plate 4 is moved up and down by the piston rod 201 of the hydraulic cylinder or the air cylinder 2 and intermittently contacts the top of the pressing rod 301; The guide piston 302 forms a linkage mechanism with the connecting rod 7 and the pressure rod 301 which are hinged to the lower end of the housing 1 and hingedly slide on the outside of the guide piston 302; A slide groove 8 for the connecting rod 7 to slide is provided on the outer surface of the guide piston 302, a roller 9 for driving the connecting rod 7 to move slides in the slide groove 8, the end of the roller 9 is fixed to the inner side of the upper end of the connecting rod 7, a pin 10 for hinge is fixed to the inner side of the lower end of the connecting rod 7 and is hinged to the lower end of the housing 1 through the pin 10; The connecting rod 7 slides cyclically on the outer side of the guide piston 302 along the annular structure of the slide groove 8 through the roller 9, and the upper part of the slide groove 8 is eccentrically provided with an upper concave point 801 for the connecting rod 7 to slide to the upper end limit of the slide groove 8, and the lower part of the slide groove 8 is eccentrically provided with a lower concave point 802 for the connecting rod 7 to slide to the lower end limit of the slide groove 8; The above arrangement enables the lower ends of the two groups of latches 303 arranged at the lower part of the latch assembly 3 to alternately slide in the arc groove 601 of the pliers head 6 by means of the hydraulic cylinder or the air cylinder 2 driving the pressure plate 4 and driving the linkage mechanism to press down or lift up, and utilizing the elastic restoring effect of the spring, thereby realizing the reversing operation of the pliers head 6.

[0015] The working principle and use process of this embodiment are as follows: Figure 1-Figure 6 As shown in the figure, after the assembly of the linkage pressing type clamp head reversing mechanism is completed, the operator installs the clamp head reversing mechanism as a whole on the power clamp (the functions and structures of conventional equipment such as power clamps are well known in the art, and the connection settings are also common knowledge, so no further explanation is given here, and it is not shown in the drawings). The purpose is to make the latches 303 arranged at the left and right ends of the housing 1 slide alternately in the arc groove 601 of the clamp head 6 under the drive of the hydraulic cylinder or the air cylinder 2, so that the clamp head 6 has the function of reversing, solves the problem of inaccuracy or instability of the latch position change, reduces the number of wearing parts, makes the operation more convenient, reduces the failure rate and maintenance cost caused by the complex structure, and does not need to manually operate the latch or reset knob, thereby significantly reducing the operation time and labor cost, improving the production efficiency of oilfield wellhead operations, and meeting the actual needs of diversified oilfield wellhead operations; Since the left side of the slide groove 8 is a channel for the connecting rod 7 to slide upward, and the right side is a channel for the connecting rod 7 to slide downward, the upper end of the connecting rod 7 first slides from the lower concave point 802 along the upward sliding channel to the upper concave point 801 through the roller 9, and then slides from the upper concave point 801 along the downward sliding channel to the lower concave point 802. When the pliers head of the power tongs needs to be reversed, the operator first installs the two sets of latch assemblies 3 on the left and right ends of the housing 1 respectively, and then slides the connecting rod 7 on the outside of the guide piston 302 in the latch assembly 3 at the left end of the housing 1 along the upward sliding channel to the upper concave point 801 through the roller 9 (the guide piston 302 is located at the lower part of the inner chamber 101, and the pressure rod 301 is in a low position), and the connecting rod 7 on the outside of the guide piston 302 in the latch assembly 3 at the right end of the housing 1 slides along the downward sliding channel to the lower concave point 802 through the roller 9 (the guide piston 302 is located at the upper part of the inner chamber 101, and the pressure rod 301 is in a high position). At this time, the lower end of the latch 303 in the latch assembly 3 at the left end of the housing 1 slides in the arc groove 601 of the pliers head 6, and at the same time, the lower end of the latch 303 in the latch assembly 3 at the right end of the housing 1 is in a retracted state (such as Figure 6 As shown in the first figure from top to bottom, it is the initial state of the reversing mechanism). Since the hydraulic cylinder or air cylinder 2 is controlled by a control box or controller (the functions and structures of conventional equipment such as a control box or controller are well known in the art, and the connection settings are also common knowledge, so no further explanation is given here and it is not shown in the accompanying drawings), when the reversing mechanism is reversed, the operator remotely controls the piston rod 201 of the hydraulic cylinder or air cylinder 2 to retract (the initial state of the piston rod 201 is extended) through the control box or controller, and the pressure plate 4 will move downward under the retraction of the piston rod 201, so that it first contacts the pressure rod 301 in the high position and drives the pressure rod 301 to compress the spring 5 downward until the pressure rod 301 in the high position is pressed down to the same position as the pressure rod 301. The pressure rod 301 at the lower position is at the same height, and the piston rod 201 stops retracting, so that the guide piston 302 located at the upper part of the inner chamber 101 slides from the upper part of the inner chamber 101 to the lower part of the inner chamber 101 under the downward pressure of the pressure rod 301, and the guide piston 302 located at the lower part of the inner chamber 101 remains motionless under the downward pressure of the pressure rod 301. At the same time, the connecting rod 7 at the left end of the shell 1 will remain motionless at the upper concave point 801 or slide slightly to the right side of the upper concave point 801, and the connecting rod 7 at the right end of the shell 1 will slide to the upper concave point 801 along the upward sliding channel through the roller 9. At this time, the bottom ends of the latch pin 303 at the left end of the shell 1 and the latch pin 303 at the right end of the shell 1 are on the same horizontal plane (such as Figure 6As shown in the second figure from top to bottom in the figure), the piston rod 201 of the hydraulic cylinder or the air cylinder 2 is remotely controlled to extend through the control box or the controller, so that the pressure plate 4 is lifted upward under the extension of the piston rod 201, so that the connecting rod 7 at the left end of the shell 1 will slide from the upper concave point 801 along the downward sliding channel to the lower concave point 802 under the combined action of its own weight and the elastic return of the spring 5. At this time, the guide piston 302 and the pressure rod 301 at the left end of the shell 1 will be lifted upward at the same time under the linkage of the connecting rod 7, forcing the latch 303 at the left end of the shell 1 to enter the retracted state, while the connecting rod 7 at the right end of the shell 1 will remain stationary at the upper concave point 801. At this time, the guide piston 302 and the pressure rod 301 at the right end of the shell 1 will also remain stationary, forcing the lower end of the latch 303 at the right end of the shell 1 to slide in the arc groove 601 of the clamp head 6 (as shown in the figure). Figure 6 As shown in the third figure from top to bottom in the figure), the reversing operation of the clamp head 6 is completed, and the control of the buckle-up and buckle-down directions is realized. Embodiment 2:

[0016] See also Figure 1-Figure 6 As another object of the present invention, a power tongs is provided, in which the above-mentioned linked pressing type tongs head reversing mechanism is provided. Therefore, the power tongs can obtain any beneficial effect of the linked pressing type tongs head reversing mechanism described above, which will not be repeated here.

Claims

1. A linkage pressing type clamp head reversing mechanism, comprising a housing and a power part, characterized in that: A group of latch assemblies are respectively provided at the left and right ends of the shell, and the latch assemblies slide in the shell through a power piece. The upper part of the latch assembly is provided with a pressure rod passing through the top of the shell, and the top end of the pressure rod is intermittently abutted against a pressure plate located at the end of the power piece. The middle part of the latch assembly is provided with a guide piston sliding in the inner chamber of the shell, and the guide piston forms a linkage mechanism with a connecting rod and a pressure rod hinged to the lower end of the shell and hingedly sliding on the outside of the guide piston. The lower part of the latch assembly is provided with a latch passing through the bottom of the shell, and the lower ends of the two latches drive the pressure plate through the power piece and drive the linkage mechanism to press down or lift up, and the spring sleeved on the upper end of the latch slides alternately in the arc groove of the pliers head.

2. A linkage pressing type clamp head reversing mechanism according to claim 1, characterized in that: The power part comprises a hydraulic cylinder or an air cylinder, the cylinder body end of the hydraulic cylinder or the air cylinder is fixed on the main structure of the clamp head, and the piston rod end of the hydraulic cylinder or the air cylinder is fixedly connected to the bottom of one end of the pressure plate.

3. The linkage pressing type clamp head reversing mechanism according to claim 2, characterized in that: The bottom of the other end of the pressing plate is arranged to move up and down through a piston rod of a hydraulic cylinder or a gas cylinder and at the same time intermittently abuts against the top of the pressing rod.

4. The linkage pressing type clamp head reversing mechanism according to claim 3, characterized in that: The bottom end of the pressure rod passes from the outside of the top end of the shell to the inner chamber of the shell and is fixed to the top end of the guide piston at the same time.

5. The linkage pressing type clamp head reversing mechanism according to claim 4, characterized in that: The bottom end of the guide piston is fixedly connected to the upper end of the latch and to the spring at the same time. The bottom end of the spring is fixed to the bottom end of the inner chamber of the shell. The inner chamber of the shell is elastically slidably connected to the guide piston through the spring.

6. The linkage pressing type clamp head reversing mechanism according to claim 5, characterized in that: The lower end of the latch passes from the inner chamber of the shell to the outside of the bottom end of the shell and slides in the arc groove of the clamp head.

7. The linkage pressing type clamp head reversing mechanism according to claim 1, characterized in that: A slide groove is provided on the outer surface of the guide piston, a roller slides in the slide groove, the end of the roller is fixed to the inner side of the upper end of the connecting rod, and a pin is fixed to the inner side of the lower end of the connecting rod and is hinged to the lower end of the shell through the pin.

8. The linkage pressing type clamp head reversing mechanism according to claim 7, characterized in that: The connecting rod slides cyclically on the outer side of the guide piston along the annular structure of the sliding groove through the roller.

9. The linkage pressing type clamp head reversing mechanism according to claim 8, characterized in that: An upper concave point is eccentrically arranged at the upper part of the slide groove, and a lower concave point is eccentrically arranged at the lower part of the slide groove.

10. A power tongs, characterized in that: It comprises a linked pressing type clamp head reversing mechanism as described in any one of claims 1 to 9.

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