A bidirectional composite motion stepping pigging device for rescuing pigs stuck in pipelines.

Abstract

This invention belongs to the field of pipeline pig rescue technology, solving the problem of effectively unblocking pipeline pigs. This invention relates to a bidirectional composite motion stepping pig rescue device for unblocking pipeline pigs, comprising a steel frame, a stepping device, a guiding and sealing device, and a buffer structure. The steel frame includes a front steel frame and a rear steel frame. The stepping device consists of a support frame and two sets of stepping actuators capable of generating radial and axial composite motion. The output ends of the two sets of stepping actuators are equipped with brake components that can press tightly against the pipeline wall. The support frame is connected between the front and rear steel frames. The guiding and sealing device includes a front guiding and sealing component and a rear guiding and sealing component, which are respectively fitted onto the front and rear steel frames and form a sealed contact with the pipeline wall. The buffer structure is fixed to the front end of the front steel frame and serves as the impact component that contacts the rear end of the pipeline pig. This invention achieves effective unblocking of pipeline pigs through the stepping impact of the pig.

Description

Technical Field

[0001] This invention belongs to the field of pipeline pig rescue technology, specifically relating to a bidirectional composite motion stepping pig cleaning device for rescuing pigs stuck in pipelines. Background Technology

[0002] Currently, pipeline pigs are commonly used for defect detection in oil and gas pipelines, traveling along with the pipeline medium. During the inspection process, when encountering partially open ball valves or welds, the pipeline pig can easily become stuck inside the pipeline, causing blockages and hindering medium flow. Currently, a pig is typically inserted into the pipeline to push out the stuck pig. Existing pigs mainly consist of a steel frame, a front guide cup fixed to the steel frame, a front sealing cup, and a rear sealing cup. The medium inside the pipeline exerts a thrust on the pig during operation, impacting the rear end of the pig to dislodge the blockage. However, when the pig's blocking force is large, the impact force provided by the pig is insufficient to push it out of the blockage point, resulting in a low success rate. Furthermore, the direct rigid impact between the pig and the rear end of the pig can easily cause significant damage. If the pig cannot be dislodged, manual excavation is required, consuming substantial manpower and resources.

[0003] Current methods for rescuing pigs stuck in pipes have not yet achieved both minimizing damage to the pigs and increasing the success rate of rescue. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a bidirectional compound motion stepping pig cleaning device for rescuing pigs stuck in pipelines, which can reduce damage to pigs in pipelines and significantly improve the success rate of rescue.

[0005] The above-mentioned objective of this invention is achieved through the following technical solution:

[0006] A bidirectional composite motion stepping pig cleaning device for rescuing pigs stuck in pipelines, characterized in that it includes a steel frame, a stepping device, a guiding sealing device, and a buffer structure;

[0007] The steel frame comprises a front steel frame and a rear steel frame arranged coaxially. The stepping device consists of a support frame and two sets of stepping actuators mounted on the support frame, capable of generating radial and axial composite motion. The output ends of the two sets of stepping actuators are equipped with brake components that can press against the pipe wall. The support frame is connected between the front steel frame and the rear steel frame. The guide sealing device includes a front guide sealing component and a rear guide sealing component, which are respectively fitted and fixed on the front steel frame and the rear steel frame, and both form a sealed contact with the pipe wall. The buffer structure is fixedly installed at the front end of the front steel frame and is an impact component that contacts the rear end of the pipe. The buffer device includes a buffer pad, and a pressure sensor is embedded in the buffer pad.

[0008] Moreover, both the front-end steel frame and the rear-end steel frame adopt a structure in which flanges are welded onto round steel.

[0009] Furthermore, the front-end guide sealing assembly consists of a guide cup, a first front-end sealing cup, a front-end spacer sleeve, and a second front-end sealing cup arranged sequentially from front to back. The first and second front-end sealing cups have a tapered sleeve structure with a smaller front end and a larger rear end, wherein the diameter of the larger end is larger than the inner diameter of the pipe. The diameter of the guide cup is less than or equal to the diameter of the smaller end of the first front-end sealing cup. A front-end flange is provided on the front steel frame at the front of the guide cup. The guide cup, the first front-end sealing cup, the front-end spacer sleeve, and the second front-end sealing cup are tightly pressed onto the flange on the front steel frame along the axial direction through the front-end flange and fixedly connected by bolts.

[0010] Furthermore, the rear-end guide sealing assembly consists of a rear-end first sealing cup, a rear-end spacer sleeve, and a rear-end second sealing cup arranged sequentially. A rear-end flange is provided on the rear-end steel frame at the rear of the rear-end second sealing cup. The rear-end first sealing cup, the rear-end spacer sleeve, and the rear-end second sealing cup are tightly pressed onto the flange on the rear-end steel frame through the rear-end flange and fixedly connected by bolts. The rear-end first sealing cup and the rear-end second sealing cup adopt a tapered sleeve structure with a smaller front and a larger rear outer surface, wherein the diameter of the larger end is larger than the inner diameter of the pipe.

[0011] Furthermore, the buffer structure includes the buffer pad and the buffer pad connecting screw; the buffer pad is fixedly installed at the front end of the front steel frame by the buffer pad connecting screw.

[0012] Furthermore, the two sets of stepper actuators share a single dual-axis motor. Each set of stepper actuators adopts a slider-linkage structure, including a first link, a second link, a third link, a first hinge, a second hinge, and a sliding groove block. One end of the first link is fixedly connected to the output shaft of the dual-axis motor. One end of the second link is hinged to the other end of the first link via the first hinge. The inner end of the third link is hinged to the other end of the second link via the second hinge. The outer side of the sliding groove block is radially slidably connected to the third link, and the inner side of the sliding groove block is axially slidably engaged with the corresponding sidewall of the support frame. The outer end of the third link constitutes the output end of the stepper actuator.

[0013] Furthermore, the stepper actuator also includes a stabilizing slide block, the outside of which is slidably engaged with the second link, and the inside of which is rotatably connected to the corresponding side wall of the support frame.

[0014] Furthermore, each brake assembly includes a brake plate and a high-friction coefficient plate; the inner center of the brake plate is vertically fixed to the outer end of the third link; both the brake plate and the high-friction coefficient plate are arc-shaped plates, the brake plate is a rigid plate, and the high-friction coefficient plate is a flexible plate. An installation groove is provided on the outer side of the brake plate, and the high-friction coefficient plate is embedded and fixed in the installation groove by means of adhesive bonding or other methods, and the outer side of the high-friction coefficient plate is higher than the outer side of the brake plate.

[0015] The advantages and positive effects of this invention are as follows:

[0016] 1. This invention achieves the formation of a pressure difference between the front and rear ends of the pipeline through the front sealing component and the rear sealing component. The medium in the pipeline pushes the device to move to the rear end of the pipeline pig and impacts the pipeline pig.

[0017] 2. The present invention sets a buffer structure at the front end of the pipeline pig. The buffer structure contacts the rear of the pipeline pig, avoiding rigid impact on the pipeline pig, thus reducing damage to the pipeline pig.

[0018] 3. This device has a stepping device installed between the front and rear steel frames. The stepping device generates axial and radial movements. The radial movement achieves the pressing contact between the outer side of the brake assembly and the pipe wall, while the axial movement achieves the hammering effect on the rear end of the pipe blockage. After one or more hammerings, the blockage of the pipe blockage can be released, thus improving the success rate of rescuing stuck pipe blockages. Attached Figure Description

[0019] Figure 1 This is an isometric view of the entire invention;

[0020] Figure 2 This is an overall side view of the invention;

[0021] Figure 3This is a schematic diagram showing the connection of the steel frame, support frame, and buffer structure of the present invention;

[0022] Figure 4 This is an isometric view of the stepping device of the present invention;

[0023] Figure 5 This is a front view of the stepping device of the present invention;

[0024] Figure 6 This is a schematic diagram of the first stage of the position change of the stepping device of the present invention;

[0025] Figure 7 This is a schematic diagram of the second stage of the position change of the stepping device of the present invention;

[0026] Figure 8 This is a schematic diagram of the third stage of the position change of the stepping device of the present invention. Detailed Implementation

[0027] The structure of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that these embodiments are descriptive and not limiting.

[0028] like Figures 1 to 8 As shown, a bidirectional composite motion stepping pig cleaning device for rescuing pigs stuck in pipelines is invented by including a steel frame 3, a stepping device 4, a guiding and sealing device 2, and a buffer structure 1.

[0029] The steel frame consists of two parts: a front steel frame 3.1 and a rear steel frame 3.2. Both the front and rear steel frames adopt a structure of welded flanges on round steel, namely the front flange 3.1.1 and the rear flange 3.2.1, respectively. Bolt holes are provided on both the front and rear flanges along the circumferential direction. The front and rear steel frames are coaxially fixedly connected by the support frame of the stepping device.

[0030] The guiding sealing device includes a front-end guiding sealing assembly and a rear-end guiding sealing assembly. The front-end guiding sealing assembly is fitted and fixed to the front-end steel frame, and the rear-end guiding sealing device is fitted and fixed to the rear-end steel frame. The front-end seal and rear-end seal are formed by interference fit between the largest outer diameter surface and the pipe wall. The front-end guiding sealing assembly consists of a guide cup 2.2, a first front-end sealing cup 2.3, a front-end spacer sleeve 2.4, and a second front-end sealing cup 2.5 arranged sequentially. The first and second front-end sealing cups have a tapered sleeve structure with a smaller front end and a larger rear end, where the diameter of the larger end is larger than the inner diameter of the pipe. The diameter of the guide cup is less than or equal to the diameter of the smaller end of the first front-end sealing cup. A front flange 2.1 is fixed to the front end of the guide cup on the front-end steel frame. The guide cup, the first front-end sealing cup, the front-end spacer sleeve, and the second front-end sealing cup are axially and tightly press-fitted onto the flange on the front-end steel frame via the front flange. The rear-end guide sealing assembly consists of a rear-end first sealing cup 2.6, a rear-end spacer sleeve 2.7, and a rear-end second sealing cup 2.8 arranged sequentially. A rear-end flange 2.9 is located on the rear steel frame behind the rear-end second sealing cup. The rear-end first sealing cup, rear-end spacer sleeve, and rear-end second sealing cup are tightly press-fitted onto the flange on the rear steel frame via the rear-end flange and fixedly connected by bolts. Both the rear-end first and rear-end second sealing cups adopt a tapered sleeve structure with a smaller front and larger rear end, where the diameter of the larger end is larger than the inner diameter of the pipe.

[0031] The buffer structure includes a buffer pad 1.1 and a buffer pad connecting screw 1.2. The buffer pad is a circular pad, and the size of the circular pad must match the size of the rear end of the pipe pig. The buffer pad is fixedly connected to the front end of the front steel frame by the buffer pad connecting screw, so as to achieve direct contact with the rear end of the pipe pig.

[0032] The stepping device is a key mechanism of this pipeline pig, generating bidirectional compound stepping motion along the axial and radial directions. It mainly includes a support frame 4.2, a dual-axis motor 4.10, a slider linkage assembly, and a braking assembly. The support frame is a four-sided hollowed-out vertical frame, with a motor support plate fixed inside. One stepping device can be installed, or multiple devices can be connected sequentially along the pipeline axis. The front and rear side walls of the support frame are connected to the rear end of the front steel frame and the front end of the rear steel frame, respectively, using screws or other connection methods. The dual-axis motor is fixedly mounted above the motor support plate. The slider linkage assembly consists of two sets, left and right, connected to the left and right output shafts of the dual-axis motor, respectively. The two braking assemblies are connected to the end pieces of the slider linkage assembly, achieving tight compression contact with the inside of the pipeline at a certain stage during the stepping process, thereby enabling the entire pipeline pig to move forward.

[0033] Each slider-link assembly includes a first link 4.7, a second link 4.4, a third link 4.8, a first hinge 4.6, a second hinge 4.3, a stabilizing slide block 4.5, and a sliding slide block 4.9. One end of the first link is fixedly connected to the output shaft of the dual-axis motor. One end of the second link is hinged to the other end of the first link via the first hinge. The stabilizing slide block is externally slidably engaged with the second link, and its interior is rotatably connected to the corresponding side wall of the support frame. The inner end of the third link is connected to the other end of the second link via the second hinge. The sliding slide block is externally slidably connected to the third link radially, and its interior is axially slidably engaged with the corresponding side wall of the support frame.

[0034] Each brake assembly 4.1 includes a brake plate 4.4.1 and a high-friction coefficient plate 4.1.2. The high-friction coefficient plate is made of silicone rubber or has its surface roughened on ordinary rubber material to increase the friction coefficient. The inner center of the brake plate is vertically fixed to the outer end of the third connecting rod. Both the brake plate and the high-friction coefficient plate are arc-shaped plates; the brake plate is a rigid plate, and the high-friction coefficient plate is a flexible plate. A mounting groove is provided on the outer side of the brake plate, and the high-friction coefficient plate is embedded and fixed in the mounting groove by means of adhesive bonding or other methods. The outer surface of the high-friction coefficient plate is higher than the outer surface of the brake plate. When the slider-connecting rod assembly runs to the outer working position with the largest radial dimension, a firm surface contact is formed between the outer surface of the high-friction coefficient plate and the inner wall of the pipe.

[0035] The aforementioned stabilizing slide block includes a stabilizing slide on the outer side and a mounting rod on the inner side. The stabilizing slide is passed through by a second connecting rod, and the mounting rod is mounted on the corresponding side wall of the support frame. The stabilizing slide block can rotate with the mounting rod.

[0036] The aforementioned sliding block includes a sliding groove (in the radial direction) on the outer side and a T-shaped guide rail (in the axial direction) on the inner side. The sliding groove is passed through by a third connecting rod, and the T-shaped guide rail is connected to the support frame through a T-shaped groove on the side of the bracket. The sliding block can move along the T-shaped groove of the support frame.

[0037] The aforementioned buffer pad has an embedded pressure sensor (not shown in the attached figure). When the buffer pad hits the tail of the pipe pig, the pressure sensor senses the impact pressure and starts the motor through the control device.

[0038] In addition, this pig also includes an electrical control device. An inner cavity can be set inside the front steel frame, and the electrical control device can be installed in the inner cavity. The electrical control device includes a control unit and a power supply unit. The power supply unit uses a battery to provide electrical energy to the motor. The control unit is used to control the start and stop of the motor according to the detection signal of the pressure sensor.

[0039] The working principle of this bidirectional composite motion stepping pig cleaning tool for unblocking pigs in pipelines is as follows:

[0040] During operation, the pig moves through the pipeline under the influence of the medium inside the pipeline until the buffer pad hits the stuck pig. If the stuck pig is knocked out of the blockage point, the pig moves out of the pipeline together with the stuck pig. If the stuck pig is not knocked out of the blockage point, the stepping device starts to work.

[0041] When the pig fails to move the stuck pig out of the blockage point, the output shaft of the dual-shaft motor rotates, driving the first connecting rod to rotate, which in turn drives the second connecting rod, which in turn drives the third connecting rod. This gives the braking assembly the ability to move relative to the pig in the axial and radial directions. The braking assembly is initially in position A. As the output shaft of the dual-shaft motor rotates, the braking assembly moves to position B. Subsequently, as the output shaft of the dual-shaft motor rotates, the braking assembly remains stationary against the pipe wall, while the steel frame moves forward relative to the braking assembly, thus pushing the stuck pig forward until the braking assembly reaches position C. The output shaft of the dual-shaft motor continues to rotate, and the braking assembly gradually returns to position C, completing one cycle. This cycle is repeated until the stuck pig is moved out of the blockage point.

[0042] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A bi-directional composite motion pig step-out pipe pig for freeing a stuck pipe, characterized in that: The device comprises a steel skeleton, a stepping device, a guiding sealing device and a buffer structure. The steel skeleton comprises a front-end steel skeleton and a rear-end steel skeleton arranged coaxially; the stepping device comprises a support frame and two groups of stepping execution mechanisms arranged on the support frame to generate radial and axial compound motion, and the output ends of the two groups of stepping execution mechanisms are provided with brake assemblies capable of being in close contact with the pipe wall; the support frame is connected between the front-end steel skeleton and the rear-end steel skeleton; the guiding sealing device comprises a front-end guiding sealing assembly and a rear-end guiding sealing assembly, and the front-end guiding sealing assembly and the rear-end guiding sealing assembly are respectively fixed on the front-end steel skeleton and the rear-end steel skeleton and are in sealing contact with the pipe wall; the buffer structure is fixedly installed at the front end of the front-end steel skeleton and is an impact member for contacting the pipe pig; the buffer structure comprises a buffer pad, and a pressure sensor is embedded in the buffer pad. The two groups of stepping execution mechanisms share a double-shaft motor; each group of stepping execution mechanisms adopts a slider-linkage group structure, comprising a first linkage, a second linkage, a third linkage, a first hinge, a second hinge and a sliding chute block; one end of the first linkage is fixedly connected to the output shaft of the double-shaft motor, one end of the second linkage is hingedly connected to the other end of the first linkage through the first hinge, the inner end of the third linkage is hingedly connected to the other end of the second linkage through the second hinge, the outer part of the sliding chute block is slidably connected to the third linkage in the radial direction, and the inner part of the sliding chute block is slidably connected to the corresponding side wall of the support frame in the axial direction; and the outer end of the third linkage constitutes the output end of the stepping execution mechanism. The stepping execution mechanism further comprises a stable sliding chute block, the outer part of the stable sliding chute block is slidably connected to the second linkage, and the inner part of the stable sliding chute block is relatively rotatably connected to the corresponding side wall of the support frame. During the operation of the device, the pig moves in the pipe under the pushing of the medium in the pipe until the buffer pad hits the blocked pipe pig; if the blocked pipe pig is knocked out of the blocking point, the blocked pipe pig moves out of the pipe together with the pig; if the blocked pipe pig cannot be knocked out of the blocking point, the stepping device starts to work; the output shaft of the double-shaft motor rotates to drive the first linkage to rotate, the first linkage drives the second linkage to move, the second linkage drives the third linkage to move, so that the brake assembly has the ability to move in the axial direction and the radial direction relative to the pig; the brake assembly first moves to a first position, then moves forward relative to the brake assembly when the brake assembly is in close contact with the pipe wall and does not move, then the brake assembly returns to the first position to complete a periodic action, and the periodic action is repeated until the blocked pipe pig is moved out of the blocking point.

2. The bidirectional composite motion pig step-out pipe pig for freeing up a pigging pipeline according to claim 1, characterized in that: The front-end steel skeleton and the rear-end steel skeleton both adopt the structure of welding a flange plate on a round steel.

3. The bidirectional composite motion pig step-out pipe pig for freeing up a pigging pipeline according to claim 2, characterized in that: The front-end guide sealing assembly is composed of a guide leather cup, a front-end first sealing leather cup, a front-end spacer sleeve and a front-end second sealing leather cup arranged in sequence from front to back; the front-end first sealing leather cup and the front-end second sealing leather cup are conical sleeve structures with the outer side being smaller in front and larger in back, and the diameter of the larger end is larger than the inner diameter of the pipeline; the diameter of the guide leather cup is equal to or smaller than the small end diameter of the front-end first sealing leather cup; a front-end flange is arranged on the front end of the guide leather cup on the front-end steel framework, the guide leather cup, the front-end first sealing leather cup, the front-end spacer sleeve and the front-end second sealing leather cup are tightly pressed on the flange plate on the front-end steel framework in the axial direction through the front-end flange, and are fixedly connected through bolts.

4. The bidirectional composite motion pig step-out pipe pig for freeing up a pigging pipeline according to claim 2, characterized in that: The rear-end guide sealing assembly is composed of a rear-end first sealing leather cup, a rear-end spacer sleeve and a rear-end second sealing leather cup arranged in sequence from front to back; a rear-end flange is arranged on the rear end of the rear-end second sealing leather cup on the rear-end steel framework, the rear-end first sealing leather cup, the rear-end spacer sleeve and the rear-end second sealing leather cup are tightly pressed on the flange plate on the rear-end steel framework through the rear-end flange, and are fixedly connected through bolts; the rear-end first sealing leather cup and the rear-end second sealing leather cup are conical sleeve structures with the outer side being smaller in front and larger in back, and the diameter of the larger end is larger than the inner diameter of the pipeline.

5. The bidirectional composite motion pig step-out pipe freeing pig of claim 1, wherein: The buffer structure includes a buffer pad and a buffer pad connecting screw; the buffer pad is fixedly installed on the front end of the front-end steel framework through the buffer pad connecting screw.

6. The bidirectional composite motion pig step-out pipe pig of claim 1, wherein: Each brake assembly includes a brake plate and a high-friction coefficient plate; the inner side middle part of the brake plate is fixedly connected with the outer end of the third connecting rod perpendicularly; the brake plate and the high-friction coefficient plate are both arc-shaped plates, the brake plate is a rigid plate, the high-friction coefficient plate is a flexible plate, a mounting groove is arranged on the outer side of the brake plate, the high-friction coefficient plate is fixedly embedded in the mounting groove through adhesion, and the outer side of the high-friction coefficient plate is higher than the outer side of the brake plate.

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