Miniature wheeled pipe robot

Abstract

The present application relates to the technical field of pipeline robot, disclose a kind of miniature wheeled pipeline robot, including bending assembly, bending assembly both ends are connected with walking unit, walking unit includes two wheel train assemblies, wheel train assembly includes walking mechanism and variable diameter mechanism, walking mechanism includes stator coil, rotor, rotating disc and several elastic legs, stator coil and rotor are mutually adapted, rotating disc is coaxially fixed with rotor, elastic leg includes elastic sheet and walking wheel, walking wheel rotatably set in the one end of elastic sheet, the other end of elastic sheet is fixedly connected with rotating disc, the one end of elastic sheet setting walking wheel opens outward, the axis of walking wheel rotation and rotating disc is inclined, several elastic legs are circumferentially distributed, two wheel train assemblies are connected and symmetrically arranged;Variable diameter mechanism can make several elastic sheets the end far from rotating disc synchronously inwardly converge, bending assembly can make two walking units bend;The miniature wheeled pipeline robot is suitable for use in small pipe diameter multi-pass pipe network.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline robots, in particular to a miniature wheeled pipeline robot. BACKGROUND

[0002] In the industrial application fields of metallurgy, petroleum, biochemistry, etc., pipelines are often used for material conveying. With long-time operation, corrosion inevitably occurs on the inner wall of the pipeline. In order to prevent pipeline leakage and ensure production safety, the pipeline needs to be detected and maintained regularly. A pipeline robot is a device that can automatically walk along the inside of the pipeline, which can carry various sensors to detect the inner wall of the pipeline.

[0003] The existing pipeline robots usually have two structures of peristaltic type and wheeled type. The wheeled pipeline robot structure can be seen from a pipeline detection robot (application number: CN201921190328.9) of Chinese patent, which includes a base body and two wheel train assemblies, the two wheel train assemblies are coaxially arranged on the base body and are symmetrical to each other, the wheel train assembly includes a driving wheel and a plurality of driven sub-wheels, each driven sub-wheel is connected to the driving wheel through a corresponding telescopic rod and is uniformly distributed around the driving wheel, and the rotation axis of the driven sub-wheel is inclined to the axis of the driving wheel. In use, the pipeline detection robot is arranged inside the pipeline, each driven sub-wheel is pressed against the inner wall of the pipeline, and the pipeline detection robot can be driven to walk in the pipeline by driving the two driving wheels to rotate on the base body. Although the pipeline detection robot can be used for walking in a single-line pipeline, it is often involved in multi-branch pipeline situations such as three-way and four-way pipelines in actual pipe networks, and it is difficult for the pipeline detection robot to pass through the multi-branch joint position and cannot automatically turn. In addition, the above-mentioned pipeline detection robot has the following defects: first, the two driving wheels of the pipeline detection robot are driven by the structure of motor combined with gear set, which occupies a large space and is not conducive to simple design, and cannot be used in small-diameter pipelines; second, the telescopic rod of the pipeline detection robot is used to adjust the wheel train assembly to be adapted to the diameter of the pipeline to be detected before use, and it does not have the function of active adjustment after entering the pipeline, and it is difficult to pass through in some special situations such as the existence of bosses inside the variable-diameter pipeline.

[0004] In order to enable the wheeled pipeline robot to autonomously turn in the multi-pass pipeline, the prior art also carries out corresponding research, for example, a flexible pipeline robot (application number: CN201910356697.9) of Chinese patent, which is provided with a walking motor, a rotating motor, a variable diameter motor and a turning motor, the walking motor drives the driving wheel to rotate to drive the robot to advance or retreat, the rotating motor rotates the driving wheel set to change the advancing direction of the driving wheel, the variable diameter motor adjusts the opening angle of the driving wheel set and the driven wheel set, and the turning motor realizes the active turning control. Although the flexible pipeline robot can also realize the active turning of the multi-pass pipeline and the passing of the variable diameter pipeline, the setting of the above motors makes the overall structure and control of the pipeline robot more complex, which is not conducive to the simple design, and cannot be applied in small diameter pipelines. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art and provide a miniature wheeled pipeline robot which has a simple structure and has the functions of active turning and variable diameter in addition to walking in the pipeline, especially suitable for use in small diameter multi-pass pipeline.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] A miniature wheeled pipeline robot, comprising a walking unit, the walking unit comprising a shell assembly and two wheel train assemblies; the shell assembly comprising a shell and a central shaft arranged coaxially, the central shaft penetrating through the shell and being fixedly connected with the shell; the wheel train assembly comprising a walking mechanism, the walking mechanism comprising a stator coil, a rotor, a rotating disc and a plurality of elastic wheel legs, the stator coil being fixedly installed in the shell, the rotor being rotatably sleeved on the central shaft, the stator coil and the rotor being mutually adapted, the rotating disc being coaxially fixedly connected with the rotor and being driven to rotate when the stator coil is energized; the elastic wheel leg comprising an elastic sheet and a walking wheel, one end of the elastic sheet being fixedly connected with the rotating disc, the other end of the elastic sheet being outwardly opened away from the axis of the central shaft, the walking wheel being rotatably connected with the other end of the elastic sheet away from the rotating disc, the rotation axis of the walking wheel being inclined to the axis of the central shaft, a plurality of the elastic wheel legs being circumferentially distributed, when the walking unit is placed in the pipeline, each walking wheel can be pressed against the inner wall of the pipeline by each elastic sheet, and the walking unit can be centered to the coaxial position of the pipeline; two wheel train assemblies are symmetrically arranged at both ends of the shell, when the two rotating discs are synchronously rotated in opposite directions, the walking unit can be driven to walk in the pipeline along the axial direction and the shell assembly can not be rotated; when the two rotating discs are synchronously rotated in the same direction, the shell assembly can be driven to rotate in place.

[0008] Further, the wheel train assembly further comprises a variable diameter mechanism, the variable diameter mechanism is used for synchronously converging a plurality of the elastic sheets to the axis direction of the central shaft from one end of the rotating disc, and the radial size of the position of each walking wheel is smaller in the converging state.

[0009] Specifically, the variable diameter mechanism comprises a first SMA spring, a pull disc, a pull ring, a wire ring and a plurality of pull ropes, the first SMA spring, the pull ring and the wire ring are coaxially arranged outside the central shaft in sequence, the pull disc is coaxially and rotatably connected with the pull ring, one end of the first SMA spring is fixedly connected with the central shaft, the other end of the first SMA spring is fixedly connected with the pull disc, the pull ring is slidably connected with the wire ring, the wire ring is fixedly connected with the rotating disc, the plurality of pull ropes are respectively matched with the plurality of elastic sheets, one end of the pull rope is fixedly connected with one end of the elastic sheet away from the rotating disc, the other end of the pull rope is fixedly connected with the pull ring after passing through the wire ring, the first SMA spring can drive the pull disc to slide, and then the pull ring and the pull rope pull each elastic sheet to the wire ring, so that the converging process is completed.

[0010] Specifically, a plurality of wire holes are formed in the wire ring, the wire holes comprise first wire holes and second wire holes, the first wire holes are arranged along the radial direction of the wire ring, the second wire holes are parallel to the central shaft, one end of the second wire hole is communicated with the first wire hole, the other end of the second wire hole is arranged towards the pull ring, and one end of the pull rope away from the elastic sheet passes through the first wire hole and the second wire hole in sequence and is fixedly connected with the pull ring.

[0011] Further, the central shaft is a hollow pipe structure, and the wires of the stator coils and the first SMA spring can be arranged in the inner space of the central shaft.

[0012] Further, the micro wheel type pipeline robot comprises two aforementioned walking units, and further comprises a bending assembly, the bending assembly comprises a central block and two swing mechanisms, the swing mechanism comprises a swing arm and a driving element, one end of the swing arm is rotatably connected with the central block, the driving element is used for driving the swing arm to swing around the central block, the two swing mechanisms are symmetrically arranged at two ends of the central block, and one end of each of the two swing arms away from the central block is fixedly connected with the end of the central shaft.

[0013] Specifically, the center block is provided with a limiting part, the limiting part is used for limiting the two swing arms when the two center shafts are coaxial, the driving element comprises a second SMA spring and a torsional spring, the torsional spring is used for providing elastic force for swinging the swing arms to the direction close to the limiting part, and two ends of the second SMA spring are connected with the center block and the swing arm respectively, and the second SMA spring can swing the swing arm to the direction away from the limiting part.

[0014] The present application has the following advantages:

[0015] A miniature wheeled pipeline robot comprises a bending assembly and two walking units.

[0016] The walking unit comprises a shell assembly and two wheel train assemblies, and each wheel train assembly comprises a walking mechanism, the walking mechanism comprises a stator coil, a rotor, a rotating disc and a plurality of elastic legs, and the plurality of elastic legs are circumferentially distributed; the elastic leg comprises an elastic sheet and a walking wheel, one end of the elastic sheet is fixedly connected with the rotating disc, the other end of the elastic sheet is outwardly opened, the walking wheel is rotatably connected with the end of the elastic sheet away from the rotating disc, and the rotating shaft of the walking wheel is inclined to the axis of the rotating disc. When the walking unit is placed in the pipeline, the elastic force of each elastic sheet can press each walking wheel against the inner wall of the pipeline and center the walking unit to the position of the axis of the pipeline. The rotating disc and the rotor are coaxially fixedly connected, the shell assembly comprises a shell and a center shaft which are coaxially arranged, the center shaft penetrates through the shell and is fixedly connected with the shell, the stator coil is fixedly installed on the shell, the rotor is rotatably sleeved on the center shaft, and the rotor can be driven to rotate when the stator coil is powered, thereby driving the rotating disc and each elastic leg to rotate. Since the axis of each walking wheel is inclined to the axes of the rotating disc and the pipeline, when the rotating disc rotates, each walking wheel is subjected to a reaction force in the axial direction of the walking wheel, and the reaction force can be decomposed into an axial component and a tangential component. The two wheel train assemblies are symmetrically arranged at two ends of the shell assembly, so that the two walking mechanisms are symmetrical to each other, and when the two rotating discs synchronously rotate in opposite directions, the walking unit can be driven to walk in the axial direction in the pipeline and keep the shell assembly from rotating; when the two rotating discs synchronously rotate in the same direction, the shell assembly can be driven to rotate in place. As can be seen, the walking unit can be used as a pipeline robot alone, and in use, each elastic sheet can press the walking wheel against the inner wall of the pipeline to ensure driving stability, and the walking unit can be centered to the position of the axis of the pipeline to keep the position accurate; in the driving structure, the frameless motor design concept is adopted, so that the overall structure of the walking unit is simpler, the radial and axial dimensions are smaller, and the walking unit is suitable for use in small-diameter pipelines.

[0017] The wheel train assembly further comprises a variable-diameter mechanism, which can synchronously inwardly converge the elastic pieces away from one end of the rotating disc. On one hand, when the walking unit encounters a large protruding obstacle in the pipeline, the variable-diameter mechanism can actively converge the elastic pieces to smoothly pass through; on the other hand, when the walking unit travels to the multi-way joint position of the multi-way pipeline, the variable-diameter mechanism can actively converge the elastic pieces to avoid interference, thereby improving the passing ability of the walking unit and being suitable for different types of pipelines.

[0018] The bending assembly comprises a center block and two swing mechanisms, the swing mechanism comprises a swing arm and a driving element, one end of the swing arm is rotatably connected with the center block, and the driving element is used for driving the swing arm to swing around the center block; the two swing mechanisms are symmetrically arranged at both ends of the center block, and the ends of the two swing arms away from the center block are fixedly connected with the ends of the two center shafts, and the two swing arms can swing to make the two center shafts coaxial. As the overall implementation structure of the micro wheeled pipeline robot, it comprises four wheel train assemblies, when the two center shafts are in the coaxial position, the four wheel train assemblies are sequentially arranged in a symmetrical structure between the two end wheel train assemblies, when the two wheel train assemblies in the middle are in the converged state, the micro wheeled pipeline robot is similar to the structure of a single walking unit, which can drive the micro wheeled pipeline robot to axially walk in the pipeline and rotate in place in the aforementioned manner; at the same time, when the two wheel train assemblies of one walking unit are in the converged state, the two wheel train assemblies of the other walking unit can be opened to keep the micro wheeled pipeline robot stable in the center support in the pipeline and drive the micro wheeled pipeline robot to axially walk in the pipeline and rotate in place; in addition, the driving element can drive the swing arm to swing, and the swing action cooperates with the convergence action of each wheel train assembly and the axial walking and rotating in place action of the micro wheeled pipeline robot in the pipeline, so that the micro wheeled pipeline robot can actively turn in the multi-way pipeline and smoothly pass through. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Figure 1 is a structural schematic diagram of a walking unit in a micro wheeled pipeline robot according to the present application;

[0020] Figure 2 Figure 2 is a structural schematic diagram of a wheel train assembly in the walking unit shown in Figure 1; Figure 1

[0021] Figure 3 Figure 3 is a disassembled structural schematic diagram of the wheel train assembly shown in Figure 2; Figure 2

[0022] Figure 4 Figure 4 is a structural schematic diagram of a shell assembly in the walking unit shown in Figure 1; Figure 1

[0023] Figure 5 ​​​This is a schematic diagram of the overall structure of a miniature wheeled pipeline robot according to the present invention;

[0024] Figure 6 This is a schematic diagram of the bending component in a miniature wheeled pipe robot according to the present invention;

[0025] In the diagram, 10-housing assembly, 11-housing shell, 12-central shaft, 20-wheel train assembly, 21-stator coil, 22-rotor, 23-rotating disk, 24-elastic sheet, 25-traveling wheel, 26-first SMA spring, 27-pull plate, 28-pull ring, 29-wire ring, 30-wire hole, 31-center block, 32-swing arm, 33-limiting part, 34-second SMA spring, 35-torsion spring. Detailed Implementation

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0027] A miniature wheeled pipeline robot includes Figure 1 The walking unit shown includes a housing assembly 10 and two wheel systems 20.

[0028] like Figure 4 As shown, the housing assembly 10 includes a housing 11 and a central shaft 12. The central shaft 12 is coaxial with the housing 11 and passes through the housing 11 and is fixedly connected to the housing 11. Mounting cavities are machined inward at both ends of the housing 11.

[0029] like Figure 2 , Figure 3 As shown, the wheel assembly 20 includes a traveling mechanism, which comprises a stator coil 21, a rotor 22, a rotating disk 23, and several elastic wheels. The stator coil 21 is fixedly installed in the mounting cavity of the housing 11. The rotor 22 is rotatably mounted on the central shaft 12 via bearings. The stator coil 21 and rotor 22 are mutually adapted. The rotating disk 23 is coaxially and fixedly connected to the rotor 22. A frameless motor structure design is adopted here. When the stator coil 21 is energized, the rotor 22 and the rotating disk 23 can be driven to rotate. The rotation speed of the rotor 22 can be adjusted by adjusting the magnitude of the energizing current, and the rotation direction of the rotor 22 can be changed by changing the energizing direction. The aforementioned elastic wheels include elastic plates 24 and traveling wheels 25. One end of the elastic plate 24 is fixedly connected to the outer peripheral side of the rotating disk 23, and the other end of the elastic plate 24 opens outward in a direction away from the axis of the central shaft 12. The traveling wheels 25 are rotatably connected to the end of the elastic plate 24 away from the rotating disk 23, and the rotation axis of the traveling wheels 25 is inclined to the axis of the central shaft 12. In this wheel assembly 20, several elastic wheel legs are evenly distributed around the axis of the central shaft 12.

[0030] like Figure 1As shown, in the walking unit, two wheel train assemblies 20 are symmetrically arranged at both ends of the shell 11, and as an embodiment, the walking unit can be used as a pipe robot. When the walking unit is placed in a pipe (the diameter of the pipe is less than the distance between the walking wheel 25 in the wheel train assembly 20 and the axis of the central shaft 12 in the natural outward opening state of the walking wheel 25), the walking wheel 25 can be pressed against the inner wall of the pipe due to the elasticity of the one end of the elastic sheet 24 where the walking wheel 25 is installed, and the position of the walking unit can be positioned due to the multiple elastic legs in the wheel train assembly 20 and the circumferential distribution of the elastic legs, which is similar to the principle of the pawl, so that the central shaft 12 is centered to be coaxial with the pipe. After the two stator coils 21 are energized, the two rotating discs 23 can be driven to rotate, and the walking unit can be driven to move axially or rotate in the pipe. Specifically, in one wheel train assembly 20, due to the inclination of the rotating shaft of the walking wheel 25 and the axis of the central shaft 12, when the rotating disc 23 drives the elastic leg connected thereto to rotate, the position of the walking wheel 25 will be subjected to a force along the direction of the rotating shaft (similar to the principle of the Mecanum wheel), which can be decomposed into an axial component and a tangential component, wherein the axial component is parallel to the axis of the pipe, and the tangential component is equivalent to a rotating torque. Since the two wheel train assemblies 20 are symmetrically arranged, the inclined directions of the walking wheels 25 in the two wheel train assemblies 20 are opposite, and when the two rotating discs 23 are synchronously rotated in opposite directions, the rotating torques of the two elastic legs are counteracted, and the axial components are superimposed, so that the walking unit can be driven to walk axially in the pipe and keep the posture of the shell assembly 10 (the shell assembly 10 will not rotate); when the two rotating discs 23 are synchronously rotated in the same direction, the rotating torques of the two elastic legs are superimposed, and the axial components are counteracted, so that the shell assembly 10 can be driven to rotate in place to adjust the posture; in addition, when the rotating speeds of the two rotating discs 23 are out of synchronization, the walking unit can walk axially in the pipe, and the shell assembly 10 will rotate during the walking process.

[0031] According to the above, the walking unit can move axially in the pipeline and can rotate in place, and after the corresponding sensor is carried on the shell assembly 10, it can be used for detecting the inner wall of the pipeline. In a specific application, taking pipe diameter measurement as an example, by measuring the diameter of each part in the pipeline, it can be identified whether there is wear, corrosion, scaling and the like on the inner wall of the pipeline, at this time, a distance measuring sensor can be carried on the shell assembly 10, the distance measuring sensor is arranged in the radial direction of the central shaft 12, and by driving the shell assembly 10 to rotate in place, circumferential distance scanning can be realized, and by driving the walking unit to move axially, the axial position of the scanning slice can be adjusted. Since the walking unit can be centered on the pipeline axis by the elastic force of each elastic sheet 24 as described above, the position between the distance measuring sensor and the pipeline axis can be determined, which is beneficial to ensure the accuracy of the measurement; at the same time, the arrangement of the elastic sheet 24 is also beneficial to keep each walking wheel 25 pressed on the inner wall of the pipeline to ensure reliable driving, and in addition, it also has higher obstacle crossing ability when there are rust, scaling and other protruding areas on the inner wall of the pipeline. In terms of driving, each wheel train assembly 20 only consists of a driving structure of the stator coil 21 and the rotor 22, and the aforementioned motion control can be completed by adjusting the current direction and size of the two stator coils 21, the whole control process is simple, and the frameless motor design concept is adopted to make the walking unit highly integrated in structure, and the shell assembly 10 can have smaller radial and axial dimensions, and can be applied to small-diameter pipelines.

[0032] Further, the wheel train assembly 20 described above further comprises a variable diameter mechanism, which is used to synchronously converge the one ends of the plurality of elastic sheets 24 away from the rotating disc 23 to the axial direction of the central shaft 12, so as to adjust the radial distance between each walking wheel 25 and the axis of the central shaft 12. In some special cases, for example, when there is a large boss in the variable-diameter pipeline, since each elastic sheet 24 presses the walking wheel 25 against the inner wall of the pipeline by elastic force, during the movement from the large-diameter part of the variable-diameter pipeline to the small-diameter part, the walking unit will have difficulty in crossing the large protruding obstacles, and the variable diameter mechanism can actively converge each elastic sheet 24 when encountering such a situation, so that it can smoothly pass through the small-diameter part; in addition, when used for active steering of the multi-pass pipeline (to be described later), the elastic sheet 24 can also be converged by the variable diameter mechanism to avoid interference of the wheel train assembly 20 at the multi-pass joint position. The variable diameter mechanism described above can be selected in various structural forms, for example, a convergence ring is arranged in the wheel train assembly 20, the convergence ring is coaxially arranged with the shell assembly 10 and is in sliding connection, so that each elastic sheet 24 of the wheel train assembly 20 passes through the convergence ring, and driving the convergence ring to slide towards the walking wheel 25 can complete the aforementioned variable diameter convergence process.

[0033] In the embodiment, as shown in Figures 1 to 3As shown, the variable diameter mechanism includes a first SMA spring 26, a pull plate 27, a pull ring 28, a wire ring 29 and a plurality of pull ropes (not shown in the figure). The first SMA spring 26, the pull ring 28 and the wire ring 29 are coaxially arranged outside the central shaft 12 in sequence, the pull plate 27 is coaxially and rotatably connected with the pull ring 28, one end of the first SMA spring 26 is fixedly connected with the central shaft 12, the other end of the first SMA spring 26 is fixedly connected with the pull plate 27, the pull ring 28 is slidably connected with the wire ring 29, and the wire ring 29 is fixedly connected with the rotating disc 23 through a plurality of connecting plates. The plurality of pull ropes are respectively correspondingly matched with the plurality of elastic sheets 24, one end of the pull rope is fixedly connected with the end of the elastic sheet 24 away from the rotating disc 23, and the other end of the pull rope is fixedly connected with the pull ring 28 after passing through the wire ring 29. The wire ring 29 is used for limiting and guiding the pull rope, and a plurality of wire holes 30 are formed in the wire ring 29 in specific implementation, the wire hole 30 includes a first guide hole and a second guide hole, the first guide hole is arranged along the radial direction of the wire ring 29, the second guide hole is parallel to the central shaft 12, one end of the second guide hole is communicated with the first guide hole, and the other end of the second guide hole is arranged towards the pull ring 28. The end of the pull rope away from the elastic sheet 24 passes through the first guide hole and the second guide hole in sequence and is fixedly connected with the pull ring 28. The first SMA spring 26 is made of shape memory alloy material and can be deformed and contracted under the effect of heat after being powered, thereby pulling the pull plate 27 to slide towards the shell 11, and further pulling the end of each elastic sheet 24 away from the rotating disc 23 towards the wire ring 29 through each pull rope, so that the above-mentioned variable diameter and collection process can be completed; because each elastic sheet 24 has an outward elastic force, the first SMA spring 26 can be quickly restored after being powered off in the collection state. The variable diameter mechanism adopts the above design, the overall structure thereof surrounds the central shaft 12, which is beneficial to reducing the radial size and is suitable for use in small-diameter pipelines; when in use, the pull ring 28 and the wire ring 29 can rotate with the rotating disc 23, the pull rope can be prevented from being wound, and the reliability of the variable diameter and collection process can be ensured.

[0034] Specifically, the central shaft 12 is a hollow pipe structure, and in the above structure, the central shaft 12 is relatively fixed with the stator coil 21 and the first SMA spring 26, and the wires of the stator coil 21 and the first SMA spring 26 can directly pass out of the hollow inner cavity of the central shaft 12 and be connected with the power supply and control equipment outside the pipeline, without the need to set an unwinding structure for the wires, which is convenient for wiring, and the wires stored in the central shaft 12 also make the overall structure of the traveling unit compact and clean.

[0035] Further, as shown in the figure, Figure 5 As a whole implementation form, the micro wheeled pipeline robot includes two above-mentioned traveling units, and a bending assembly is further arranged between the two traveling units. As shown in the figure, Figure 6As shown, the bending assembly includes a center block 31 and two swing mechanisms, each of which includes a swing arm 32 rotatably connected to the center block 31 at one end and a driving element for driving the swing arm 32 to swing about the center block 31. The two swing mechanisms are symmetrically arranged at the two ends of the center block 31, and the ends of the two swing arms 32 away from the center block 31 are fixedly connected to the ends of the two center shafts 12, respectively. The two swing arms 32 can be swung to make the two center shafts 12 coaxial. The miniature wheeled pipeline robot includes four wheel train assemblies 20, which are named as No. 1 wheel train, No. 2 wheel train, No. 3 wheel train and No. 4 wheel train from left to right for convenience of description. Since the two swing mechanisms are symmetrically arranged at the two ends of the center block 31, the two walking units are symmetrical to each other when the two center shafts 12 are coaxial. At this time, the No. 1 wheel train and the No. 2 wheel train, the No. 1 wheel train and the No. 4 wheel train, and the No. 3 wheel train and the No. 4 wheel train are in a symmetrical relationship. Figure 5 As shown, the bending assembly includes a center block 31 and two swing mechanisms, each of which includes a swing arm 32 rotatably connected to the center block 31 at one end and a driving element for driving the swing arm 32 to swing about the center block 31. The two swing mechanisms are symmetrically arranged at the two ends of the center block 31, and the ends of the two swing arms 32 away from the center block 31 are fixedly connected to the ends of the two center shafts 12, respectively. The two swing arms 32 can be swung to make the two center shafts 12 coaxial. The miniature wheeled pipeline robot includes four wheel train assemblies 20, which are named as No. 1 wheel train, No. 2 wheel train, No. 3 wheel train and No. 4 wheel train from left to right for convenience of description. Since the two swing mechanisms are symmetrically arranged at the two ends of the center block 31, the two walking units are symmetrical to each other when the two center shafts 12 are coaxial. At this time, the No. 1 wheel train and the No. 2 wheel train, the No. 1 wheel train and the No. 4 wheel train, and the No. 3 wheel train and the No. 4 wheel train are in a symmetrical relationship.

[0036] The above-mentioned miniature wheeled pipeline robot can be used in a multi-pass pipeline. When in use, the miniature wheeled pipeline robot is first adjusted to the state that the two center shafts 12 are coaxial and placed in one of the pipelines in the multi-pass pipeline. The corresponding variable-diameter mechanisms are used to make the elastic sheets 24 of the No. 2 wheel train and the No. 3 wheel train change in diameter and be gathered, so that the walking wheels 25 of the No. 2 wheel train and the No. 3 wheel train are away from the inner wall of the pipeline. At this time, the miniature wheeled pipeline robot is supported by the No. 1 wheel train and the No. 4 wheel train, and its overall structure and the structure of a single walking unit are similar to those described above. The miniature wheeled pipeline robot can move axially in the pipeline and rotate in place in the pipeline in the manner described above. The direction of the No. 1 wheel train is the front direction of axial movement. When the front end approaches the position of the multi-pass joint, the following steps can be taken to actively turn:

[0037] S1, the variable-diameter mechanism of the No. 3 wheel train is used to release the gathered state, so that the walking wheels 25 of the No. 3 wheel train are extended and abut against the inner wall of the pipeline;

[0038] S2, the variable-diameter mechanism of the No. 1 wheel train is used to make the elastic sheets 24 of the No. 1 wheel train change in diameter and be gathered. At this time, the walking wheels 25 of the No. 1 wheel train and the No. 2 wheel train are gathered away from the inner wall of the pipeline. The miniature wheeled pipeline robot is supported by the No. 3 wheel train and the No. 4 wheel train;

[0039] S3, the No. 3 wheel train and the No. 4 wheel train are used to drive the center shaft 12 to rotate, thereby driving the bending assembly to rotate to adapt to the direction to be turned;

[0040] S4, the swing arm 32 is driven to swing by the driving element, so that the walking unit in front (the walking unit to which the No. 1 wheel train and the No. 2 wheel train belong) is gradually bent to the direction to be turned. At the same time, the No. 3 wheel train and the No. 4 wheel train are used to drive the pipeline robot to move axially while keeping the bending assembly from rotating. The bending action and the axial movement action are cooperatively controlled until the walking unit in front extends into another pipeline to be turned.

[0041] S5, the diameter changing mechanism of the first wheel system and the second wheel system is released from the bunched state, and the walking wheels 25 of the first wheel system and the second wheel system are expanded to abut against the inner wall of the pipeline into which the pipeline robot turns;

[0042] S6, the diameter changing mechanism of the third wheel system and the fourth wheel system performs the diameter changing and bunching action, so that the walking wheels 25 of the third wheel system and the fourth wheel system are away from the inner wall of the pipeline, and at this time the miniature wheel type pipeline robot is supported by the first wheel system and the second wheel system;

[0043] S7, the swing arm 32 is driven to swing by the driving element, so that the rear walking unit (the walking unit to which the third wheel system and the fourth wheel system belong) is gradually reset, and at the same time the pipeline robot is driven to move axially forward by the first wheel system and the second wheel system in the state that the bending assembly is not rotated, the reset action and the axial movement action are cooperatively controlled until the rear walking unit turns into the pipeline to be turned;

[0044] S8, the diameter changing mechanism of the fourth wheel system is released from the bunched state, and then the diameter changing mechanism of the second wheel system performs the diameter changing and bunching action, so that the miniature wheel type pipeline robot returns to the state of being supported by the first wheel system and the fourth wheel system.

[0045] According to the above working process, the miniature wheel type pipeline robot can walk along the pipeline axially and can turn in place in the pipeline, and can also actively turn in each direction at the multi-way joint position, meeting the use requirements in the multi-way pipeline. In the specific structural design, each walking unit can effectively reduce the radial and axial dimensions in the bunched state through compact design, which is also conducive to smooth turning in the small-diameter multi-way pipeline network.

[0046] The above driving element can be selected in various structural forms, for example, a rudder can be selected in the application scene of a larger pipeline diameter, the rudder is fixedly connected with the center block 31, the output shaft of the rudder is connected with the swing arm 32 as the rotation shaft of the swing arm 32 relative to the center block 31, that is, the swing arm 32 can be driven to swing by the rudder. In the specific implementation, as shown in the embodiment, a limiting part 33 is arranged on the center block 31, the limiting part 33 is used for limiting and blocking the two swing arms 32 when the two center shafts 12 are coaxial. Figure 6 The foregoing driving element includes a second SMA spring 34 and a torsional spring 35, the torsional spring 35 is used for providing the elastic force for swinging the swing arm 32 to the direction close to the limiting part 33, in the natural state, the elastic force of the torsional spring 35 makes the swing arm 32 abut against the limiting part 33, at this time the two center shafts 12 are coaxial, and the state can be maintained with the necessary stiffness under the action of the elastic force of the torsional spring 35, the coaxial state of the two center shafts 12 is always maintained in the foregoing step S3; the two ends of the second SMA spring 34 are connected with the center block 31 and the swing arm 32 respectively, the second SMA spring 34 is compressed by being electrified, and the swing arm 32 can be driven to swing to the direction away from the limiting part 33. It should be noted that,Figure 6 The structure shown is only a structural diagram of the bending assembly. Since the bending action or the resetting action in the aforementioned steps S4 and S7 needs to be controlled in coordination with the axial movement action, in actual application, the second SMA spring 34 is composed of multiple segments of memory alloy springs in series, and each segment of memory alloy spring can be controlled separately so as to be coordinated with the axial movement action described in steps S4 and S7.

[0047] The above description is only the preferred embodiment of the present application, and it should be understood that the present application is not limited to the form disclosed herein, and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein, by the above teaching or related technical or knowledge. Any modification and change made by the person skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the claims of the present application.

Claims

1. A miniature wheeled pipe robot, characterized by The walking unit comprises a shell assembly and two wheel train assemblies; The shell assembly comprises a housing and a central shaft coaxially arranged, the central shaft penetrates through the housing and is fixedly connected with the housing; The wheel train assembly comprises a walking mechanism, the walking mechanism comprises a stator coil, a rotor, a rotating disc and a plurality of elastic legs, the stator coil is fixedly installed in the housing, the rotor is rotatably sleeved on the central shaft, the stator coil and the rotor are matched with each other, the rotating disc is coaxially and fixedly connected with the rotor, The elastic leg comprises an elastic sheet and a walking wheel, one end of the elastic sheet is fixedly connected with the rotating disc, the other end of the elastic sheet is outwardly opened away from the axis direction of the central shaft, the walking wheel is rotatably connected with the other end of the elastic sheet away from the rotating disc, the rotation axis of the walking wheel is inclined to the axis of the central shaft, and a plurality of elastic legs are circumferentially distributed; The two wheel train assemblies are symmetrically arranged at two ends of the housing; The wheel train assembly further comprises a variable-diameter mechanism, the variable-diameter mechanism is used for synchronously converging a plurality of elastic sheets away from the rotating disc to the axis direction of the central shaft; The walking unit has two, and a bending assembly is further arranged, the bending assembly comprises a central block and two swing mechanisms, The swing mechanism comprises a swing arm and a driving element, one end of the swing arm is rotatably connected with the central block, and the driving element is used for driving the swing arm to swing around the central block, The two swing mechanisms are symmetrically arranged at two ends of the central block, one end of each of the two swing arms away from the central block is fixedly connected with the end of the central shaft, and the two swing arms can swing to make the two central shafts coaxial; The variable-diameter mechanism comprises a first SMA spring, a pull plate, a pull ring, a wire ring and a plurality of pull ropes, The first SMA spring, the pull ring and the wire ring are coaxially arranged outside the central shaft in sequence, the pull plate is coaxially and rotatably connected with the pull ring, one end of the first SMA spring is fixedly connected with the central shaft, the other end of the first SMA spring is fixedly connected with the pull plate, the pull ring is slidably connected with the wire ring, and the wire ring is fixedly connected with the rotating disc, The one end of each of the plurality of pull ropes is fixedly connected with the end of the elastic sheet away from the rotating disc, and the other end of the pull rope is fixedly connected with the pull ring after passing through the wire ring.

2. The miniature wheeled pipe robot according to claim 1, wherein A plurality of wire holes are formed in the wire ring, the wire holes comprise first wire holes and second wire holes, the first wire holes are arranged along the radial direction of the wire ring, the second wire holes are parallel to the central shaft, one end of the second wire hole is communicated with the first wire hole, the other end of the second wire hole is arranged towards the pull ring, and the one end of the pull rope away from the elastic sheet passes through the first wire hole and the second wire hole in sequence and is fixedly connected with the pull ring.

3. The miniature wheeled pipe robot of claim 2, wherein, The central shaft is a hollow pipe structure.

4. The miniature wheeled pipe robot of claim 1, wherein, A limiting portion is arranged on the central block, the limiting portion is used for limiting the two swing arms when the two central shafts are coaxial, The driving element comprises a second SMA spring and a torsion spring, the torsion spring is used to provide elastic force for swinging the swing arm towards the limiting part, two ends of the second SMA spring are connected with the center block and the swing arm respectively, and the second SMA spring can swing the swing arm away from the limiting part.

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