A petroleum pipeline sealing detection device

Abstract

The invention discloses a petroleum pipeline sealing detection device, which relates to the technical field of petroleum pipeline detection, and has the following beneficial effects compared with the prior art: the air pressure detection unit can be driven by a driving disk, and the oil pipeline can be detected section by section by forming a closed space through the expansion of a sealing body, so that the location of the leakage point can be determined more easily, and the oil pipeline laid underground after use can be detected by connecting a long-distance air pipe between the air source and the detection unit, thereby improving the application range; the device comprises: an air source; a detection unit, comprising two sealing bodies arranged at intervals, a connecting rod connecting the two sealing bodies and a driving disk slidably arranged on the connecting rod; an air pressure detection unit, which is arranged on one of the sealing bodies; an air inlet is arranged on the sealing body, the air source is connected to the air inlet, and the driving disk is configured to drive the connecting rod to move in an axial direction when reciprocating on the connecting rod.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum pipeline detection, and in particular to a petroleum pipeline sealing detection device. Background Art

[0002] Oil pipelines are pipelines for transporting oil and oil products. During the production, processing and use of oil pipelines, due to corrosion and aging of the raw materials of the oil pipelines and during use, leakage defects may occur on the side walls of the oil pipelines. In order to ensure the safety of oil transportation, the oil pipelines will be tested for sealing.

[0003] At present, the methods for testing the tightness of oil pipelines include traditional artificial water immersion method, ultrasonic detection and air pressure detection method, among which artificial bubble method and air pressure detection method are widely used due to their low detection cost and simple detection means. The current air pressure detection method achieves the effect of detecting tightness by blocking both ends of the pipeline, then passing gas of predetermined pressure into the pipeline, and then monitoring the air pressure changes inside the pipeline, but this method still has some disadvantages.

[0004] First, since it uses a monitoring method that blocks both ends of the pipeline, the detection structure can only obtain whether there is a leak in the pipeline. However, the entire oil pipeline is long, and the specific point of the leak needs to be confirmed again.

[0005] Second, it can only be applied to oil pipeline products after production and processing, and cannot be applied to oil pipelines that have already been laid and used, and has certain limitations in use. Summary of the invention

[0006] The object of the present invention is to solve at least one of the above problems and provide a petroleum pipeline sealing detection device.

[0007] To achieve the above object, the technical solution of the present invention is: a petroleum pipeline sealing detection device, comprising:

[0008] Gas source;

[0009] The detection unit comprises two sealing bodies arranged at intervals, a connecting rod connecting the two sealing bodies, and a driving disk slidably arranged on the connecting rod;

[0010] An air pressure detection unit is arranged on one of the sealing bodies;

[0011] The sealing body is provided with an air inlet, the air source is communicated with the air inlet, and the driving disk is configured to drive the connecting rod to move in an axial direction when reciprocating on the connecting rod.

[0012] Furthermore, at least three friction wheels are arranged on the outer circumferential surface of the driving disk, and the at least three friction wheels are evenly spaced around the axis of the driving disk. A one-way limiter that allows the friction wheel to rotate in one direction is arranged between the friction wheel and the driving disk.

[0013] Furthermore, the sealing body includes a circular support disc seat and an annular air bag arranged on the outer peripheral surface of the support disc seat, the support disc seat is connected to the connecting rod, and the air bag is connected to the air inlet.

[0014] Furthermore, it also includes at least one power telescopic rod, one end of which is connected to the driving disk, and the other end of which is connected to the supporting disk seat.

[0015] Furthermore, the air inlet includes a first air inlet provided on the support plate seat and a second air inlet provided at the end of the connecting rod, and the air bag is connected to the second air inlet.

[0016] Furthermore, a through hole is coaxially arranged on the support plate seat, and the connecting rod includes a rod body, a step shaft arranged at both ends of the rod body and guiding and cooperating with the through hole, and a second connecting air channel connected to the second air inlet and two sealing rings located on both sides of the second connecting air channel are arranged on the outer peripheral surface of the step shaft.

[0017] Furthermore, it also includes a spring arranged between the connecting rod and the driving disk, and the spring can provide an axial elastic force to the connecting rod, and the elastic forces provided by the spring to the driving disk and the connecting rod are in opposite directions.

[0018] Furthermore, it also includes a balance rod arranged around the connecting rod, the two ends of the balance rod are connected to the two supporting disc seats, the driving disc is in sliding cooperation with the guide of the balance rod, and the spring is sleeved on the outer periphery of the balance rod.

[0019] Furthermore, a plurality of the power telescopic rods are provided and are evenly spaced around the connecting rod.

[0020] Furthermore, at least three centering support frames are arranged on the sides of the two sealing bodies that are away from each other, and the at least three centering support frames are arranged at even intervals around the axis.

[0021] Compared with the prior art, the oil pipeline sealing detection device disclosed in the present invention has the following beneficial effects: the oil pipeline can be detected section by section, so that the location of the leakage point can be determined more easily, and the oil pipeline laid underground after use can be detected by connecting a long-distance air pipe between the air source and the detection unit, thereby improving the application range; the device comprises: an air source; a detection unit, comprising two sealing bodies arranged at intervals, a connecting rod connecting the two sealing bodies and a driving disk slidably arranged on the connecting rod; an air pressure detection unit, which is arranged on one of the sealing bodies; an air inlet is arranged on the sealing body, the air source is connected to the air inlet, and the driving disk is configured to drive the connecting rod to move in an axial direction when reciprocating on the connecting rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a schematic diagram of the overall structure of a petroleum pipeline sealing detection device of the present invention.

[0023] Figure 2 The structure of the detection unit in the oil pipeline sealing detection device of the present invention is shown in FIG. Figure 1 .

[0024] Figure 3 The structure of the detection unit in the oil pipeline sealing detection device of the present invention is shown in FIG. Figure 2 .

[0025] Figure 4 The structure diagram of a petroleum pipeline sealing detection device of the present invention in which the detection unit hides the connecting rod and a sealing body Figure 1 .

[0026] Figure 5 The structure diagram of a petroleum pipeline sealing detection device of the present invention in which the detection unit hides the connecting rod and a sealing body Figure 2 .

[0027] Figure 6 The present invention is a schematic diagram of the three-dimensional structure of a driving disk in a petroleum pipeline sealing detection device.

[0028] Figure 7 The present invention is a schematic diagram of the cross-sectional structure of a driving disc in a petroleum pipeline sealing detection device.

[0029] Figure 8 The present invention is a schematic structural diagram of a connecting rod in a petroleum pipeline sealing detection device.

[0030] Fig. 9 The present invention is a schematic diagram of the cross-sectional structure of a connecting rod in a petroleum pipeline sealing detection device.

[0031] Fig.10 for Figure 8The diagram shows a partially enlarged structural diagram of point A in a petroleum pipeline sealing detection device of the present invention.

[0032] Fig.11 The present invention is a schematic structural diagram of a power telescopic rod in a petroleum pipeline sealing detection device.

[0033] Fig.12 The present invention is a schematic diagram of the cross-sectional structure of a power telescopic rod in a petroleum pipeline sealing detection device.

[0034] Fig.13 for Fig.12 A schematic diagram of the partially enlarged structure of position B in a petroleum pipeline sealing detection device of the present invention.

[0035] Fig.14 for Fig.12 A schematic diagram of the partially enlarged structure of position C in a petroleum pipeline sealing detection device of the present invention.

[0036] Fig.15 The present invention is a schematic diagram of the cross-sectional structure of a sealing body and a connecting rod in a petroleum pipeline sealing detection device.

[0037] In the figure: 1, air source; 11, first solenoid valve; 12, second solenoid valve; 13, third solenoid valve; 2, control device; 3, detection unit; 31, sealing body; 310, centering support frame; 312, support plate seat; 3120, through hole; 3121, first air inlet; 3122, third connecting airway; 311, airbag; 32, drive plate; 320, friction wheel; 3200, friction layer; 3201, wheel body; 3202, one-way limiter; 3203, roller; 321, first guide hole; 322, threaded hole; 323, guide sleeve; 33, power telescopic rod; 330, connecting flange; 331, rigid air pipe; 332, piston rod; 3321, threaded end; 333, rigid cylinder; 3330, first Two chambers; 3331, connecting air channel; 334, piston; 34, spring; 35, balance rod; 36, connecting rod; 360, rod body; 361, internal channel; 3610, second air inlet; 362, external thread; 363, stepped shaft; 3630, annular groove; 3631, second connecting air channel; 364, sealing ring; 365, locking bolt; 37, control valve; 370, columnar cavity; 371, valve stem; 372, second piston; 373, first discharge channel; 374, second discharge channel; 375, first connecting air channel; 376, limiting surface; 377, second valve channel; 38, threaded end cap; 381, channel; 382, ​​valve ball; 383, retaining spring; 384, limiting column; 4, air pressure detection unit. DETAILED DESCRIPTION

[0038] The present invention will now be described in further detail with reference to the accompanying drawings. The accompanying drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and thus only show the components related to the present invention.

[0039] Please refer to Figure 1-5 The technical solution of the present invention is: a petroleum pipeline sealing detection device, as a specific implementation, the device comprises:

[0040] Gas source 1; specifically, the gas source can be any gas supply device capable of supplying compressed gas, such as a high-pressure gas storage tank and an air pump.

[0041] The detection unit 3 includes two sealing bodies 31 arranged at intervals, a connecting rod 36 connecting the two sealing bodies 31, and a driving plate 32 slidably arranged on the connecting rod 36;

[0042] An air pressure detection unit 4 is disposed on one of the sealing bodies 31;

[0043] The sealing body 31 is provided with an air inlet, and the air source 1 is connected to the air inlet. The driving disk 32 is configured to drive the connecting rod 36 to move in an axial direction when reciprocating on the connecting rod 36 .

[0044] Specifically, refer to Figure 1The detection device provided in the present application includes a detection unit 3, an air source 1 and a control device 2. A first solenoid valve 11 and a second solenoid valve 12 are arranged between the air source 1 and the detection unit 3. The first solenoid valve 11 and the second solenoid valve 12 are connected to the control device 2. The detection unit 3 includes two sealing bodies 31 and a connecting rod 36 connecting the two sealing bodies 31. A driving disk 32 is slidably arranged on the connecting rod 36. When the sealing performance of the oil pipeline is detected, the detection unit 3 is arranged inside the oil pipeline. The air source 1 is used to supply air to the sealing body 31 so that the sealing body 31 expands and seals with the inner wall of the pipeline, thereby forming a sealed space between the two sealing bodies 31 and the inner wall of the oil pipeline. Then, compressed gas is supplied to the sealed space, and the air supply is stopped after the air pressure reaches a predetermined value and maintained for a certain period of time. During the maintained period of time, The detection value of the air pressure detection unit 4 is obtained to obtain the air tightness of the side wall of the detected section of the oil pipeline. Specifically, after a predetermined period of time, if the air pressure drop value in the sealed space is too large, it is determined that there is a leak on the side wall of the detected section of the oil pipeline. If the air pressure drop value is within a predetermined range, it is determined that the air tightness of the oil pipeline meets the requirements. The air pressure detection unit 4 can use an air pressure detection sensor in the prior art. The air pressure detection sensor can detect the air pressure value in the sealed space. According to the detected air pressure value, the detection value at different time points in the sealed space can be obtained, thereby obtaining the change value of the air pressure in the sealed space within a predetermined period of time to achieve the air tightness detection effect. It should be noted that the detection method for determining the air tightness of the oil pipeline by obtaining the air pressure change is a prior art, which will not be repeated here one by one, and those skilled in the art should understand. A discharge branch is also provided between the gas source 1 and the detection unit 3, and a third solenoid valve 13 is provided on the discharge branch. After detection, the third solenoid valve 13 is opened to discharge the air pressure in the sealing body 31 to make the sealing body 31 contract. During the contraction process, the high-pressure gas in the sealed space will be discharged from the gap between the sealing body 31 and the side wall of the oil pipeline. During the discharge process, the airflow will blow and clean the outer peripheral surface of the sealing body 31. After the air pressure in the sealing body 31 is discharged, the driving disk 32 can reciprocate once along the axial direction of the connecting rod 36, driving the connecting rod 36 to move axially, thereby driving the two sealing bodies 31 to move. The third solenoid valve 13 is controlled to close, the first solenoid valve 11 is controlled to open, and air is supplied into the sealing body 31 to expand the sealing body 31, and a sealed space is formed with the side wall of the oil pipeline again. Then the second solenoid valve 12 is controlled to open, and high-pressure gas is supplied into the sealed space to detect the next section of the oil pipeline. Through this setting, the oil pipeline can be detected section by section, so that the location of the leakage point can be determined more easily, and by connecting a long-distance air pipe between the air source 1 and the detection unit 3, the oil pipeline laid underground after use can be detected, thereby increasing the scope of application.

[0045] Further, as a specific implementation method, refer to Figure 5-Figure 7At least three friction wheels 320 are arranged on the outer circumference of the driving disk 32. The at least three friction wheels 320 are evenly spaced around the axis of the driving disk 32. A one-way stopper 3202 is arranged between the friction wheel 320 and the driving disk 32 to allow the friction wheel 320 to rotate in one direction. Figure 6 A first guide hole 321 is provided in the middle area of ​​the driving disk 32 for guiding and slidingly cooperating with the connecting rod 36. Three friction wheels 320 are evenly spaced on the outer circumference. The axes of the three friction wheels 320 are perpendicular to the axis of the connecting rod 36. A supporting ear plate is provided on the driving disk 32. The friction wheel 320 includes a wheel body 3201, a friction layer 3200 and a roller shaft 3203 provided on the outer circumference of the wheel body 3201. The roller shaft 3203 is connected to the supporting ear plate. As a specific implementation method, the one-way limiter 3202 is a one-way bearing provided between the supporting ear plate and the roller shaft 3203. The provision of the one-way bearing can make the friction wheel 320 rotate in one direction. In the specific use process, the outer circumference of the three friction wheels 320 can contact the petroleum to be detected. The inner wall of the pipeline is in contact with friction fit. Through this setting, when in use, when the driving disc 32 moves along the axial direction of the connecting rod, the movement direction of the driving disc 32 is called the first direction, and the friction wheel 320 can be driven to rotate. After moving a certain distance, a thrust is applied between the driving disc 32 and the connecting rod 36 to make the two move away from each other. At this time, the driving disc 32 is subjected to a reaction force in the opposite direction to the first direction. At this time, due to the setting of the one-way bearing, the friction wheel 320 cannot rotate. The friction force between the friction wheel 320 and the side wall of the oil pipeline limits the movement of the driving disc 32. At this time, the force can push the connecting rod 36 to move in the first direction, thereby achieving the purpose of driving the connecting rod 36 to move. For specific methods of applying thrust, please refer to the following.

[0046] Further, as a specific implementation method, refer to Figure 4 , Figure 5 , Figure 8-Figure 10 The sealing body 31 includes a circular support disc seat 312 and an annular airbag 311 arranged on the outer peripheral surface of the support disc seat 312. The support disc seat 312 is connected to the connecting rod 36, and the airbag 311 is connected to the air inlet. The support disc seat 312 is a circular structure made of metal material. The outer peripheral surface of the support disc seat 312 is sleeved with a rubber airbag 311. The airbag 311 is an annular structure. The support disc seat 312 is connected to the connecting rod 36. The airbag 311 is connected to the air inlet. When gas is pumped into the airbag 311, the airbag 311 can be expanded, so that the outer peripheral surface of the airbag 311 fits the inner wall of the oil pipeline to form a sealing fit. When the airbag 311 is deflated, it shrinks under the action of its own elastic force, and the outer peripheral surface is separated from the inner wall of the oil pipeline. After separation, the air pressure in the sealed space is released.

[0047] Further, as a specific implementation, it also includes at least one power telescopic rod 33, one end of the power telescopic rod 33 is connected to the driving disk 32, and the other end is connected to the supporting disk seat 312. Figure 2-Figure 5 A power telescopic rod 33 is arranged between the driving disc 32 and a sealing body 31, wherein the telescopic direction of the power telescopic rod 33 is parallel to the axial direction of the connecting rod 36, wherein the power telescopic rod 33 can be any one of a pneumatic telescopic rod and an electric telescopic rod.

[0048] Further, as a specific implementation method, refer to Figure 1 , Figure 4 The air inlet includes a first air inlet 3121 disposed on the support plate 312 and a second air inlet 3610 disposed at the end of the connecting rod 36, and the air bag 311 is connected to the second air inlet 3610. Specifically, a vent is disposed through a support plate 312, and the first air inlet 3121 is disposed on the vent. Fig. 9 An internal channel 361 is arranged inside the connecting rod 36, and a second air inlet 3610 is arranged at the end of the internal channel 361. The internal channel 361 is communicated with the two air bags 311 on the two sealing bodies 31, and the first air inlet 3121 is communicated with the air source 1. A second solenoid valve 12 is arranged between the air source 1 and the first air inlet 3121, and a first solenoid valve 11 is arranged between the second air inlet 3610 and the air source 1. A discharge branch is arranged between the first solenoid valve 11 and the second air inlet 3610, and a third solenoid valve 13 is arranged on the discharge branch. The first solenoid valve 11, the second solenoid valve 12 and the third solenoid valve 13 are all connected to the control device 2, and the opening and closing of the three solenoid valves are controlled by the control device 2.

[0049] Further, as a specific implementation method, refer to Figure 4 , Figure 8-Figure 10 , Fig.15A through hole 3120 is coaxially arranged on the support plate seat 312, and the connecting rod 36 includes a rod body 360, a step shaft 363 arranged at both ends of the rod body and guiding and cooperating with the through hole 3120, and a second connecting air channel 3631 connected to the second air inlet 3610 and two sealing rings 364 located on both sides of the second connecting air channel 3631 are arranged on the outer peripheral surface of the step shaft 363. Specifically, a through hole 3120 is coaxially arranged in the central area of ​​the support disc seat 312, and the connecting rod 36 includes a rod body 360 and a stepped shaft 363 arranged at both ends of the rod body 360. The outer circumference of the stepped shaft 363 is guided and slidably matched with the inner circumference of the through hole 3120. A second stepped shaft is locked at the end of the stepped shaft 363. An external thread 362 is arranged on the outer circumference of the second stepped shaft, so that the stepped shaft 363 can be extended into the through hole 3120, and then a locking bolt 365 is screwed on the external thread 362 for fixing. Two annular grooves 363 are arranged at intervals on the outer circumference of the stepped shaft 363. 30. A sealing ring 364 is arranged in the annular groove 3630. After the step shaft 363 is inserted into the through hole 3120, the step shaft 363 and the through hole 3120 are sealed by the sealing ring 364. A second connecting air passage 3631 connecting to the internal channel 361 is drilled on the outer peripheral surface of the step shaft 363 between the two annular grooves 3630, and a third connecting air passage 3122 is drilled on the inner side wall of the through hole 3120. One end of the third connecting air passage 3122 is located between the two sealing rings 364, and the other end is connected to the airbag 311, thereby achieving the effect of connecting to the airbag 311.

[0050] Further, as a preferred embodiment, there are multiple power telescopic rods 33, which are evenly spaced around the connecting rod 36. Figure 1-Figure 4 The power telescopic rods 33 include three evenly spaced ones. By evenly spaced ones around the connecting rod 36, the three power telescopic rods 33 can synchronously apply driving force to the driving disk to ensure uniformity of force application, thereby ensuring that the driving disk 32 can move smoothly on the connecting rod 36.

[0051] Further, as a preferred embodiment, refer to Figure 1-Figure 4At least three centering support frames 310 are arranged on the side away from each other of the two sealing bodies 31, and at least three centering support frames 310 are evenly spaced around the axis. Specifically, the centering support frame 310 includes three, one end of the centering support frame 310 is hingedly connected to an ear plate through a pin shaft, and the other end is rotatably connected to a roller, the axis of the roller is parallel to the axis of the pin shaft and is perpendicular to the axis of the connecting rod 36, the ear plate is arranged on the support disc seat 312, and a torsion spring (not shown in the figure) is arranged between the support disc seat 312 and the centering support frame 310. Under the elastic force of the torsion spring, the end of the centering support frame 310 provided with the roller can expand outward. When it is arranged inside the oil pipeline for work, under the elastic force of the torsion spring, the three rollers at the ends of the three centering support frames 310 can be connected to the centering support frame 310. The inner wall of the oil pipeline is in contact with the support, and the axis of the connecting rod 36 coincides with the axis of the oil pipeline to be detected during centering positioning. Through this arrangement, when the airbag of the sealing body 31 shrinks, the sealing body 31 can be supported in a centering manner by the centering support frame. On the one hand, the resistance encountered by the detection unit 3 when moving in the oil pipe can be reduced, and the driving disk 32 can ensure that the connecting rod 36 drives the movement; on the other hand, during the contraction and expansion of the airbag 311, the sealing body 31 can be coaxial with the oil pipeline, which is more conducive to the uniform expansion of the airbag 311, and can make the airbag 311 better fit and seal with the side wall of the oil pipeline to ensure the sealing effect.

[0052] Specifically, in this embodiment, the detection method of the detection device includes the following steps:

[0053] Step 1: connect the detection unit 3 to the air source 1 through the air pipe, connect the air pressure detection unit 4 to the control device 2 through the wiring harness, and then control the first solenoid valve 11, the second solenoid valve 12 and the third solenoid valve 13 to remain in an open state;

[0054] Step 2: Place the detection unit 3 at the initial end of the oil pipeline to be detected and inside the pipeline, and place the sealing body 31 provided with the air inlet on one side of the initial end, use the centering support frame 310 for centering support, keep the power telescopic rod 33 in the initial state of extension, and place the driving disk 32 on the side close to the initial end;

[0055] Step 3: Control the second solenoid valve 12 and the third solenoid valve 13 to close, and the first solenoid valve 11 to open, and supply air to the second air inlet 3610, so that the airbag 311 expands and contacts and seals with the inner wall of the oil pipeline to form a sealed space. Then, control the first solenoid valve 11 to close, and the second solenoid valve 12 to open, and supply air to the sealed space. At this time, the control device 2 obtains the detection value of the air pressure detection unit 4, and controls the second solenoid valve 12 to close when the air pressure reaches a predetermined value.

[0056] Step 4: Keep the first solenoid valve 11 and the second solenoid valve 12 closed for a predetermined time, obtain the detection value of the air pressure detection unit 4, so as to determine the sealing performance of the oil pipeline. During this process, the power telescopic rod 33 contracts a certain distance, driving the driving disc 32 to move, and the friction wheel 320 can rotate freely.

[0057] Step 5: After the detection is completed, the third solenoid valve 13 is opened to release the air pressure in the airbag 311, the airbag 311 is separated from the side wall of the oil pipeline, and the power telescopic rod 33 is extended to the initial state. At this time, the friction wheel 320 cannot rotate, and the power telescopic rod 33 can push the connecting rod 36 to drive the sealing body 31 to move a certain distance into the oil pipeline;

[0058] Step 6: Repeat steps 3 to 5 to perform segmented inspection on the oil pipeline.

[0059] Embodiment 2

[0060] The present application provides a petroleum pipeline sealing detection device, which is different from the first embodiment in that Figure 4 , Figure 5 , Figure 11-Figure 14 , further comprising a spring 34 disposed between the connecting rod 36 and the driving disk, wherein the spring 34 can provide an axial elastic force to the connecting rod 36 , and the elastic forces provided by the spring 34 to the driving disk 32 and the connecting rod 36 are in opposite directions.

[0061] Furthermore, it also includes a balance rod 35 arranged around the connecting rod 36 , the two ends of the balance rod 35 are connected to the two supporting disc seats 312 , the driving disc 32 is guided and slidably matched with the balance rod 35 , and the spring 34 is sleeved on the outer periphery of the balance rod 35 .

[0062] Specifically, the balance rod 35 includes three evenly spaced ones around the connecting rod 36, the end of the balance rod 35 is threadedly fixedly connected to the support disc seat 312, the driving disc 32 is provided with a guide sleeve 323 that slides with the balance rod 35, the spring 34 includes three springs sleeved on the three balance rods 35, the two ends of the spring 34 are respectively against the driving disc 32 and the support disc seat 312, the power telescopic rod 33 includes a rigid cylinder 333, the end of the rigid cylinder 333 is provided with a connecting flange 330, the connecting flange 330 is connected to a support disc seat 312, and the end surface of the support disc seat 312 is in contact with the end surface of the support disc seat 312. The surfaces are sealed together, and a vent hole connected to the end of the rigid cylinder 333 is provided on the support disc seat 312; a piston rod 332 is coaxially guided at the other end of the rigid cylinder 333, and a threaded end 3321 is provided at the end of the piston rod 332, and a threaded hole 322 threadedly connected to the threaded end 3321 is provided on the drive disc 32, and a piston 334 is provided in the rigid cylinder 333, and the piston 334 is fixedly connected to the piston rod 332, and the piston 334 divides the rigid cylinder 333 into a second chamber 3330 and a first chamber connected to the vent hole on the support disc seat 312, and the end of the rigid cylinder 333 is provided with a second chamber 3330 connected to the first chamber The connecting air passage 3331 of 3330 is arranged in this way. The initial state of the detection unit 3 is: the elastic force of the spring 34 can push the driving disc 32 to move, and the driving disc 32 pulls the piston rod 332 to drive the piston 334 to move until the piston 334 abuts against the end of the rigid cylinder 333. After a sealed space is formed between the inner wall of the oil pipeline and the two sealing bodies 31, high-pressure gas is introduced into the sealed space. At this time, the air pressure in the closed space is higher than the external atmospheric pressure. The connecting air passage 3331 can connect the sealed space with the second chamber 3330, so that an air pressure difference is formed on both sides of the piston 334. The piston 334 is pushed downward to move, and the piston rod 332 is driven to pull the drive disk 32 to resist the elastic force of the spring 34, compressing the spring 34 until the piston 334 abuts against the support disk seat 312 connected to the connecting flange 330 and stops moving. During this process, since the airbag 311 expands and contacts the side wall of the oil pipeline, the sealing body 31 and the connecting rod 36 do not move. Therefore, the power telescopic rod 33 will pull the drive disk 32 to move when it shrinks. By controlling the limiting direction of the one-way limiting member 3202, the friction wheel 320 can roll freely during the movement of the driving disk 32, and rolling friction occurs with the side wall of the oil pipeline.

[0063] After the detection is completed, the air bag 311 and the sealed space are deflated. After the air is deflated, the second chamber 3330 is connected to the atmosphere. At this time, the air pressure difference on both sides of the piston 334 gradually becomes zero. At this time, the elastic force of the spring 34 is greater than the air pressure difference on the piston 334. Under the action of the elastic force of the spring 34, there is a tendency to push the drive disk 32 to move in the opposite direction. However, due to the setting of the one-way limiter 3202, the friction wheel 320 cannot rotate at this time. The friction force between the friction wheel 320 and the side wall of the oil pipeline prevents the drive disk 32 from moving. Therefore, under the action of the elastic force of the spring 34, the support disk seat 312 can be driven to move, thereby achieving the purpose of driving the detection unit 3 to move.

[0064] Under the elastic force of the spring 34, the spring 34 stretches, causing the piston 334 to rest against the end of the rigid cylinder 333 again, and then high-pressure gas is repeatedly introduced into the airbag 311 to expand the airbag 311 to form a sealed space, and then high-pressure gas is introduced into the sealed space, so that the power telescopic rod 33 repeats the above-mentioned action, driving the detection unit 3 to move, and detecting the oil pipeline section by section.

[0065] Furthermore, it is understandable that, during the deflation of the airbag 311, after the air pressure in the airbag 311 decreases and the outer peripheral surface of the airbag 311 is not completely separated from the side wall of the oil pipeline, the sealing effect decreases due to the decrease in air pressure. At this time, the air pressure in the sealing space will be released, and the elastic force of the spring 34 will be greater than the air pressure difference on both sides of the piston 334. At this time, the spring 34 has a tendency to stretch, but at this time, the outer peripheral surface of the airbag 311 and the side wall of the oil pipeline still have friction. At this time, the extension of the spring 34 may push the drive disk 32 to cause the friction wheel 320 to slide and move with the side wall of the pipeline, thereby affecting the driving displacement of the detection unit 3. In order to avoid the above phenomenon, refer to Figure 4 , Figure 11-Figure 14A blind hole is provided at the end of the rigid cylinder 333, and a communicating air passage 3331 is provided at the bottom of the blind hole. A threaded end cap 38 is threadedly connected to the end of the blind hole. A flow passage 381 coaxial with the blind hole is provided in the threaded end cap 38, and a valve ball 382 is provided in the flow passage 381. A retaining spring 383 is provided between the valve ball 382 and the bottom of the blind hole. A limiting column 384 is provided at the bottom of the blind hole. Under the elastic force of the retaining spring 383, the valve ball 382 can be pressed against the bottom wall of the flow passage 381 to form a sealing fit, so that the air flow can enter the blind hole from the outside in one direction; a control valve 37 is also provided on the side wall of the rigid cylinder 333, and the control valve 37 includes a valve body, which is provided with a first discharge flow passage 373 communicating with the second chamber 3330, and a valve body having a plurality of holes 374 connected to the valve body. The first discharge channel 373 is connected to the second valve channel 377 and the columnar cavity 370 is coaxially arranged with the second valve channel 377. A valve cover is arranged at the other end of the columnar cavity 370, and a rigid air pipe 331 is connected to the valve cover. The other end of the rigid air pipe 331 is connected to the airbag 311; a valve stem 371 is inserted into the second valve channel 377, a second piston 372 is arranged in the columnar cavity 370, and the second piston is connected to the valve stem 371. A first connecting air channel 375 connected to the atmosphere is arranged at one end of the columnar cavity 370 close to the second valve channel 377, and a second discharge channel 374 connected to the atmosphere is arranged on the side wall of the second valve channel 377. The cross section of the columnar cavity 370 is larger than the cross section of the second valve channel 377, and a limited position surface 376 is arranged on the valve cover.

[0066] Specifically, through the above arrangement, when air is ventilated into the airbag 311 to expand the airbag 311, the air pressure in the columnar cavity 370 increases, thereby pushing the second piston 372 to move so that the end of the valve stem 371 abuts against the bottom of the second valve channel 377. At this time, the state of the control valve 37 is as follows: Fig.14In the closed state shown in the figure, the valve stem 371 blocks the second discharge flow channel 374 at this time, and after the airbag 311 expands to form a sealed space between the sealing body 31 and the inner wall of the oil pipeline, high-pressure gas is introduced into the sealed space. At this time, the air pressure in the sealed space increases. As the air pressure increases, the airflow can push the valve ball 382 to move through the flow channel 381 and the connecting air channel 3331 into the second chamber 3330, so that the air pressure in the second chamber 3330 increases, pushing the piston 334 to move and squeeze the spring 34. In this process, the control valve 37 remains in the closed state. After the air tightness test is completed, the air pressure in the airbag 311 is released, the air tightness between the airbag 311 and the side wall of the oil pipeline is reduced, and the air pressure in the sealed space is released. At this time, there is still a certain air pressure in the airbag 311. Under the action of this air pressure, the control valve 37 remains in the closed state. The air pressure in the airbag 311 continues to decrease until the gas pressure reaches a predetermined air pressure P1. At this time, the outer circumferential radius of the airbag 311 is R1, and the inner circumferential radius of the oil pipeline is r, R1=r+c, and the value range of c is 2-3 mm. At this time, the air pressure difference on both sides of the second piston 372 is equal to the air pressure difference received by the valve stem 371. As the air pressure in the airbag 311 continues to be discharged, the air pressure difference received by the valve stem 371 is greater than the air pressure difference received by the second piston 372. At this time, the valve stem 371 pushes the second piston 372 to move until the first discharge channel 373 and the second discharge channel 374 are connected, and the air pressure in the second chamber 3330 is discharged. At this time, the spring 34 gradually extends, pushing the sealing body 31 and the connecting rod 36 to move. In this way, it can be ensured that the spring 34 will not extend until the airbag 311 is completely separated from the side wall of the oil pipeline. Furthermore, by providing the first discharge channel 373 and the second discharge channel 374 , the gas in the second chamber 3330 is released at a uniform speed, thereby preventing the spring 34 from extending too quickly due to the excessive release of the gas flow.

[0067] As a specific implementation, the radius of the second discharge channel 374 is 0.3 mm-0.5 mm.

[0068] Specifically, by setting the limiting surface 376 , the second piston 372 can be limited. When the second piston 372 contacts the limiting surface 376 , the valve stem 371 is still inserted into the second valve channel 377 , and at this time the valve stem 371 does not block the second discharge channel 374 .

[0069] Furthermore, there are multiple power telescopic rods 33 , which are evenly spaced around the connecting rod 36 .

[0070] Furthermore, at least three centering support frames 310 are disposed on the sides of the two sealing bodies 31 that are away from each other, and the at least three centering support frames 310 are evenly spaced around the axis.

[0071] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A petroleum pipeline sealing detection device, characterized in that: include: Gas source (1); The detection unit (3) comprises two sealing bodies (31) arranged at an interval, a connecting rod (36) connecting the two sealing bodies (31), and a driving disk (32) slidably arranged on the connecting rod (36); An air pressure detection unit (4) is arranged on one of the sealing bodies (31); The sealing body (31) is provided with an air inlet, the air source (1) is in communication with the air inlet, and the driving disk (32) is configured to drive the connecting rod (36) to move in an axial direction when reciprocating on the connecting rod (36); At least three friction wheels (320) are arranged on the outer circumferential surface of the driving disk (32), the at least three friction wheels (320) are arranged at even intervals around the axis of the driving disk (32), and a one-way limiting member (3202) is arranged between the friction wheel (320) and the driving disk to allow the friction wheel (320) to rotate in one direction; The sealing body (31) comprises a circular support disc seat (312) and an annular air bag (311) arranged on the outer peripheral surface of the support disc seat, the support disc seat (312) is connected to the connecting rod (36), and the air bag (311) is connected to the air inlet; It also comprises at least one power telescopic rod (33), one end of the power telescopic rod (33) being connected to the driving disk (32), and the other end of the power telescopic rod (33) being connected to the supporting disk seat (312); It also includes a spring (34) disposed between the connecting rod (36) and the driving disk (32), wherein the spring (34) can provide an axial elastic force to the connecting rod (36), and the elastic forces provided by the spring (34) to the driving disk (32) and the connecting rod (36) are in opposite directions.

2. A petroleum pipeline sealing detection device according to claim 1, characterized in that: The air inlet comprises a first air inlet (3121) arranged on the support disc seat (312) and a second air inlet (3610) arranged at the end of the connecting rod (36). The air bag (311) is in communication with the second air inlet (3610).

3. A petroleum pipeline sealing detection device according to claim 2, characterized in that: A through hole (3120) is coaxially arranged on the support disc seat (312); the connecting rod (36) comprises a rod body (360), a stepped shaft (363) arranged at both ends of the rod body (360) and guidingly matched with the through hole (3120); a second communicating air channel (3631) communicating with the second air receiving port (3610) and two sealing rings (364) located on both sides of the second communicating air channel (3631) are arranged on the outer peripheral surface of the stepped shaft (363).

4. The oil pipeline sealing detection device according to claim 1, characterized in that: It also includes a balancing rod (35) arranged around the connecting rod (36), the two ends of the balancing rod (35) are connected to two supporting disc seats (312), the driving disc (32) and the balancing rod (35) are guided and slidably matched, and the spring (34) is sleeved on the outer periphery of the balancing rod (35).

5. The oil pipeline sealing detection device according to claim 1, characterized in that: There are a plurality of power telescopic rods (33), which are evenly spaced around the connecting rod (36).

6. The oil pipeline sealing detection device according to claim 1, characterized in that: At least three centering support frames (310) are arranged on the sides of the two sealing bodies (31) that are away from each other, and the at least three centering support frames (310) are arranged at even intervals around the axis.

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