Variable-diameter tire structure of wall-climbing robot

Abstract

The invention relates to a variable-diameter tire structure of a wall-climbing robot, the variable-diameter tire structure comprises a support ring, a tire body is fixedly arranged on the support ring, and the tire body comprises an inner container and a tire tread; the tire body, the tire tread and the liner are all of flexible structures; a filler is arranged in the inner container, and the filler is of a particle structure; one end of the connecting ring is provided with a connecting port, the connecting ring is fixedly connected with the first end face of the tire body, the other end of the connecting ring is provided with a telescopic rod which is connected with the connecting ring in a matched mode, the telescopic rod is fixedly connected with the second end face, away from one end of the connecting port, of the tire body, and the position of the end face of the tire body can be changed along with stretching of the telescopic rod. The invention aims to solve the technical problem that when the wall-climbing robot faces wall surfaces with different curvatures, the tires are difficult to stably fit with the wall surfaces and reliably walk through flexible adjustment of the diameters.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of machine engineering, and relates to a variable-diameter tire structure of a wall-climbing robot. BACKGROUND

[0002] As an automatic device capable of performing detection, maintenance and other operations on vertical or inclined wall surfaces, the wall-climbing robot has important application value in the fields of building outer wall detection, large tank inspection, bridge maintenance and the like. One of the core performances thereof is the ability to adapt to wall surfaces of different curvatures and roughnesses, and high-efficiency operation is realized through stable adsorption and walking. The tire of the traditional wall-climbing robot is designed with a fixed diameter, and is attached to the wall surface by means of negative pressure adsorption, permanent magnet adsorption and the like, but the contact state of the tire and the wall surface directly affects the walking stability and obstacle-crossing ability of the robot, and therefore the adaptability of the tire structure becomes a key factor restricting the operation range thereof.

[0003] In actual application, the main problem faced by the wall-climbing robot is the contact adaptation difficulty brought by wall surfaces of different curvatures: when the curvature of the wall surface is small, such as a plane or a gentle curved surface, the fixed-diameter tire is prone to skidding due to insufficient contact area; when the curvature of the wall surface is large, such as a pipeline or an arc-shaped tank, the attachment of the tire to the wall surface decreases, and local stress concentration may occur, affecting the adsorption stability; and on rough or uneven wall surfaces such as concrete outer walls and rusted metal surfaces, the obstacle-crossing ability of the fixed-diameter tire is limited, and the robot is prone to scratching due to insufficient chassis height, resulting in interruption of operation. In addition, in some scenarios, the curvature of the wall surface may continuously change, such as a variable-diameter pipeline, and the traditional tire is difficult to dynamically adjust the contact state, further limiting the application range of the robot.

[0004] In view of the above problems, a variety of variable-diameter tire solutions have appeared in the prior art: patent CN202111511191.4, entitled "Variable-diameter wheel with elastic spokes", proposes to realize diameter change through the combination of a spring plate and a rubber wheel foot, and to adapt to soft road surfaces by using the elastic deformation of the spring plate, the advantages of which lie in that no complex driving mechanism is required, the weight is light, and shock absorption function is also possessed, but it relies on passive deformation, the diameter adjustment range is limited, and it is difficult to actively adapt to the dynamic needs of wall surfaces of different curvatures.

[0005] Patent CN202210148434.0, entitled "Firefighting robot based on variable-diameter wheel and control method thereof", adopts the cooperation of a motor-driven involute disc and a straight disc through a connecting rod mechanism to change the radial position of a T-shaped tire body, thereby realizing active diameter change, the advantages of which lie in that the diameter adjustment range is large and can be actively controlled, but the structure is complex, relies on rigid connecting rod transmission, and the flexible attachment ability of the tire to the wall surface is insufficient when operating on a vertical wall surface.

[0006] In the prior art, the passive variable-diameter structure cannot meet the requirements of the wall-climbing robot on active adaptability, and the active variable-diameter structure is designed mainly for the ground moving scene and does not fully consider the adsorption stability and flexible contact requirements of the vertical wall surface. Therefore, a variable-diameter tire structure with active adjustment capability, flexible fitting characteristics and lightweight structure is needed to solve the problems of stable fitting and reliable walking of the wall-climbing robot on different curvature wall surfaces. The flexible inner liner and the active telescopic drive are combined to realize flexible adjustment of the tire diameter, and the plasticity of the granular filler is used to ensure close contact with the wall surface, so as to meet the dual requirements of active control and flexible adaptation. SUMMARY

[0007] The application provides a variable-diameter tire structure of a wall-climbing robot, which solves the technical problem that the tire of the wall-climbing robot cannot realize stable fitting and reliable walking on the wall surface through flexible adjustment of the diameter when facing different curvature wall surfaces.

[0008] In order to solve the above problems, the technical scheme adopted by the application is: A variable-diameter tire structure of a wall-climbing robot, comprising a support ring, a tire body is fixedly arranged on the support ring, the tire body comprises an inner liner and a tire surface; the tire body, the tire surface and the inner liner are provided in a flexible structure; the inner liner is provided with a filler, the filler is provided in a granular structure; one end of the connecting ring is provided with a connecting port, the connecting ring is fixedly connected to the first end surface of the tire body, the other end is provided with a telescopic rod which is connected to the connecting ring, the telescopic rod is fixedly connected to the second end surface of the tire body away from the connecting port, and the end surface of the tire body can change position with the telescopic rod.

[0009] The principle and benefits of the present application are as follows: The support ring provides a mounting base for the entire tire structure, the flexible tire body, the tire surface and the inner liner provide a structural basis for diameter change, and the granular filler inside can adaptively flow with the change of the tire shape to ensure that the tire can maintain stable structural support when the diameter changes. One end of the connecting ring is fixedly connected to the first end surface of the tire body, and the other end is connected to the second end surface of the tire body through the telescopic rod. When the telescopic rod is telescoped, the second end surface of the tire body is moved, so that the tire body is stretched or compressed in the axial direction, thereby changing the diameter of the tire. In this process, the granular filler will be redistributed in the flexible inner liner, cooperating with the flexible deformation of the tire surface, to ensure that the tire can always maintain good contact with the wall surface of different curvature, realizing stable fitting and reliable walking. Compared with the prior art, in the prior art, the tires of the wall climbing robot are mostly fixed diameter structures. When facing different curvature walls, either the diameter is too large to fit the small curvature wall, or the diameter is too small to have insufficient contact area on the large curvature wall, resulting in poor walking stability. The present scheme solves this problem by moving the tire end face with the telescopic rod to achieve flexible adjustment of the diameter. For example, when climbing walls with large differences in diameter, the existing fixed diameter tires need to be replaced with different size tires to complete the work. The present scheme only needs to adjust the tire diameter quickly by telescoping the telescopic rod, which can adapt to different pipe curvatures and greatly improve work efficiency. At the same time, the combination of granular filler and flexible structure enables the tire to maintain uniform support force and good sealing performance when the diameter changes. The air bag type diameter adjustment structure in the prior art is prone to local air leakage, resulting in unstable support. For rough surfaces, the friction is usually large and there are many obstacles. At this time, the contraction of the telescopic rod drives the tire body to shorten axially, increasing the tire diameter and reducing the thickness. This "fat diameter" adjustment can raise the chassis, allowing it to smoothly cross rough surfaces and avoid scratching or interruptions in work caused by insufficient chassis height. On the other hand, although the tire becomes thinner, it may theoretically reduce friction, but since the rough surface itself has a large friction, it compensates for the reduction in contact area, ensuring that the tire still provides sufficient grip.

[0010] For smooth walls, the friction is small, which can easily cause slipping. By lengthening the telescopic rod, the tire body is axially lengthened, reducing the tire diameter and increasing the thickness. The increased thickness of the tire significantly increases the contact area with the smooth wall, thereby increasing the friction and effectively preventing slipping.

[0011] Further, the filler is a circular rubber particle filler, and a lubricating layer is arranged on the surface of the filler. From the perspective of the interaction between the particles, the circular structure itself can reduce mechanical jamming when the particles come into contact, and the lubricating layer can further reduce the friction coefficient between the particles, making it easier for the particles to slide relative to each other during the deformation of the tire body, ensuring uniform distribution of the filler when the tire diameter changes, and avoiding sudden changes in tire stiffness caused by local accumulation. From the perspective of energy loss, the lubricating layer can reduce the heat energy loss caused by particle collisions, improving the energy utilization efficiency of the tire diameter change process, especially when the telescopic rod is adjusted at a high frequency, which can significantly reduce the temperature rise caused by particle friction, ensuring the mechanical property stability of the flexible material of the tire body. From the perspective of service life, the lubricating layer can effectively reduce the wear between the particles and the inner wall of the liner, as well as the mutual grinding of the particles themselves, slowing down the aging and damage speed of the rubber particles, prolonging the replacement cycle of the filler, and thus improving the durability of the entire tire structure.

[0012] Further, the tire surface is provided with a plurality of anti-skid grooves, which are arranged in an inclined annular manner on the tire surface, and the inclined angle can form an oblique engagement with the wall surface when the tire is rolling, compared with straight grooves, which can generate radial and circumferential friction force components at the same time, and improve the anti-slip ability when climbing the wall, especially when moving on the vertical or inclined wall, which can effectively offset the tendency of sliding down caused by the gravity of the robot; from the effect of removing obstacles, the annular arrangement forms a continuous spiral channel with the tire rotating, which can timely remove the air, water vapor or dust and other sundries between the tire and the wall, avoid the decrease of the friction coefficient caused by the interface medium, and guide the sundries to concentrate and separate from the contact area along the groove discharge direction, reducing the interference of the sundries on the adhesion force; from the structural adaptability, the inclined annular design can cooperate with the change of the tire diameter, and when the telescopic rod adjusts the tire diameter, the inclined angle of the anti-skid groove can keep a relatively stable stress state with the stretching or contraction of the tire surface, avoiding the cracking problem caused by the local stress concentration of the straight groove in the diameter change process, so as to balance the anti-skid function and the variable diameter characteristics of the tire structure.

[0013] Further, the telescopic rod is telescopic along the vertical first end surface of the tire body and the second tire surface of the tire body, from the structural stability, the telescopic direction can ensure that the force is always perpendicular to the tire end surface, so that the tire body is uniformly stressed during the diameter change, avoiding the distortion caused by the eccentric load, ensuring the flatness of the tire surface and the wall contact, and further maintaining the stable adhesion force; from the adjustment efficiency, the vertical telescopic direction can directly convert into the change amount of the tire diameter, reducing the decomposition loss of force, forming a linear corresponding relationship between the telescopic amount of the telescopic rod and the diameter change amount of the tire, facilitating the accurate control of the tire diameter, especially when the wall climbing robot needs to quickly adjust to different curvature walls, the response speed can be improved; from the structural synergy, the vertical telescopic direction is adapted to the annular structure of the tire body, which can make the connection ring and the telescopic rod cooperate more closely, reduce the mechanical wear caused by the angle deviation, and at the same time ensure that the tire end surface is always perpendicular to the tire axis during movement, avoiding the interference to the uniformity of the filler distribution, and ensuring the stability of the overall performance during the tire diameter change.

[0014] Further, the end of the telescopic rod away from the first end surface of the tire body is provided with a protrusion, and the protrusion is provided with a connecting bearing, which is connected with the protrusion, the protrusion can enhance the connection strength between the telescopic rod and the bearing, avoid the loosening or falling of the bearing under the action of high frequency telescopic and radial force, and at the same time, the interference fit between the inner ring of the bearing and the protrusion can ensure the stability of power transmission, so that the telescopic amount of the telescopic rod is accurately converted into the change of the tire diameter, and the reliability of the variable diameter is ensured.

[0015] Further, the maximum stroke length of the telescopic rod is equal to the diameter of the end face of the tire body when the telescopic stroke of the telescopic rod is equal to the diameter of the tire body, and when the stroke reaches this value, the adjustment range of the tire diameter can be maximized and more reasonable, which can both shrink the tire to the minimum diameter to adapt to narrow space and fully stretch to the maximum diameter to increase the contact area with the wall surface to meet the needs of different wall climbing scenes; at the same time, such stroke setting can make the tire body more balanced in force during telescopic process, avoid insufficient adjustment due to too short stroke or excessive stretching damage of the tire due to too long stroke, ensure the structural stability and service life of the tire during diameter change, and form a good match with the driving ability of the telescopic rod, improve the efficiency and reliability of the diameter adjustment of the whole tire structure.

[0016] Further, the inner liner of the tire body is made of polyimide film with a thickness of 0.1-0.2mm, and the outer wall of the inner liner is compounded with a carbon fiber braid layer with a braid angle of Interleaved braid, braid density is 80-100 , the ultra-thin thickness of the polyimide film can not only ensure the flexible deformation ability of the inner liner to adapt to the diameter change of the tire, but also has excellent high and low temperature resistance and chemical stability, which can resist the long-term friction of the particle filler; and The interleaved carbon fiber braid layer can form a two-way force skeleton, which allows stretching or shrinking in the radial direction when the diameter of the tire changes, and limits excessive deformation through the axial strength of the fiber, and cooperates with the high-density braid of 80-100 , which can uniformly disperse the wall reaction force transmitted by the tire surface to avoid damage to the inner liner caused by local stress concentration; in terms of structural synergy, the composite structure of the film and the braid layer realizes the balance of flexible substrate + rigid reinforcement, which not only retains the variable diameter characteristics of the tire body adjusted by the telescopic rod, but also improves the tear resistance of the inner liner through the high strength of the carbon fiber, solving the problem of easy damage of pure flexible material under high pressure adhesion, and the high-density braid can also reduce the local flow of particle filler to ensure uniform stiffness distribution during diameter change of the tire.

[0017] Further, the tire tread and the inner container are provided with a honeycomb support framework, the framework is made of 3D printed polyether ether ketone material, the honeycomb unit is a regular hexagonal structure, the unit side length is 2-5 mm, the wall thickness is 0.3-0.5 mm, the regular hexagonal honeycomb unit has optimal mechanical stability, can provide uniform support force for the tire tread while being lightweight, the unit side length of 2-5 mm can balance the flexible deformation requirement and structural rigidity of the tire, avoid the collapse of the tire tread caused by insufficient support or the hindrance of radial deformation caused by excessive rigidity; in terms of material compatibility, the polyether ether ketone material has high temperature resistance, wear resistance and excellent mechanical strength, and can accurately form a complex honeycomb structure through a 3D printing process, the wall thickness of 0.3-0.5 mm can not only ensure the bearing capacity of the framework itself, but also reduce the amount of material to reduce the overall weight, which meets the requirement of lightweight of the wall climbing robot; from the perspective of functional synergy, the framework can uniformly transmit the wall reaction force borne by the tire tread to the inner container, avoid local stress concentration damage to the flexible inner container, the air cavity formed by the honeycomb structure can buffer the vibration impact in the wall climbing process, improve the shock absorption performance of the tire, and the symmetry of the regular hexagonal unit can ensure that the framework is uniformly stressed when the tire is radially stretched, and will not be jammed due to structural deformation, thereby meeting the multiple requirements of support, shock absorption and variable diameter. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present application. DETAILED DESCRIPTION

[0019] The reference signs in the drawings of the specification include: tire tread 1, inner container 2, anti-skid groove 3, filler 4, support ring 5, connecting hole, adjusting rod 6, protrusion 7, connecting bearing 8, tire body 9, tire body first end face 10, tire body second end face 11, framework 12, connecting hole 13 Example 1, as Figure 1 shown, a variable diameter tire structure of a wall climbing robot, comprising a support ring 5, the support ring 5 is a ring-shaped plate structure made of metal material, the support ring is provided with a connecting hole near one end of the driving shaft, the connecting hole is matched with the driving shaft of the wall climbing robot, and the tire is fixed through the connecting hole.

[0020] The end of the support ring 5 near the connecting hole is fixedly connected with the tire body 9 through an adhesive, the tire body 9 is made of flexible rubber material and has a whole ring-shaped columnar structure, the tire body comprises an inner layer inner container 2 and an outer layer tire tread 1. The inner container 2 is made of polyimide film with a film thickness of 0.15 mm, and the outer wall is compounded with a carbon fiber woven layer with a weaving angle of interlaced weaving, and the weaving density is 90 roots , which not only ensures the flexible deformation capacity of the inner container 2, but also enhances the structural strength.

[0021] The inner container 2 is filled with round rubber particles as filler 4, the particle diameter is 2-3 mm, the surface is sprayed with a polytetrafluoroethylene lubricating layer, which can reduce the frictional resistance between the particles, so that the particles can flow smoothly when the tire deforms. A honeycomb support framework 12 is provided between the inner container 2 and the tire tread 1, which is made of 3D printed polyether ether ketone material, the honeycomb unit is a regular hexagonal structure, the unit side length is 3 mm, and the wall thickness is 0.4 mm, which can provide uniform support for the tire tread 1 and adaptively adjust with the tire deformation.

[0022] The tire tread 1 is made of wear-resistant rubber material, and a plurality of anti-skid grooves 3 are provided on the surface, the anti-skid grooves 3 are arranged in an inclined annular shape, the inclination angle is 30°, the groove depth is 2 mm, the groove width is 1.5 mm, and the spacing between adjacent anti-skid grooves 3 is 5 mm, forming a continuous spiral channel, which can discharge air, water vapor and dust and other impurities on the contact surface when the tire rolls.

[0023] The tire body 9 is provided with opposite tire body first end face 10 and tire body second end face 11 along the axial direction, the tire body first end face 10 is welded and fixed with the outer side wall of the support ring 5, and the center position of the tire body second end face 11 is fixedly connected with one end of the adjusting rod 6, the adjusting rod 6 is a cylindrical rod body made of metal material, which is arranged in a direction perpendicular to the tire body first end face 10 and the tire body second end face 11, and the other end is provided with a cylindrical protrusion 7, the outer diameter of the protrusion 7 is in interference fit with the inner ring of the connecting bearing 8, the outer ring of the connecting bearing 8 is connected with the driving sliding block of the wall climbing robot, ensuring the stability of the adjusting rod 6 when it is stretched or contracted.

[0024] The maximum extension stroke of the adjusting rod 6 is equal to the diameter of the tire body 9 end face, when the adjusting rod 6 is stretched or contracted, it will drive the tire body second end face 11 to move along the axial direction, so that the tire body 9 is stretched or compressed in the axial direction, thereby changing the diameter of the tire. For example, when the adjusting rod 6 is contracted, the axial length of the tire body 9 is shortened, and the diameter is increased, which can reduce the contact area with the wall surface of large curvature; when the adjusting rod 6 is elongated, the axial length of the tire body 9 is increased, and the diameter is reduced, which can increase the contact area of the wall surface of small curvature or narrow space, and also can adjust the height, which has good adaptability.

[0025] In use, the tire structure is fixed on the driving shaft of the wall climbing robot through the connecting hole 13 of the support ring 5, and the connecting bearing 8 is connected with the adjusting driving mechanism of the robot. When the wall climbing robot encounters wall surfaces of different curvatures, the driving mechanism drives the adjusting rod 6 to stretch or contract, and the tire body 9 is axially deformed accordingly, the filler 4 in the inner container 2 flows uniformly under the action of the lubricating layer, and cooperates with the deformation of the honeycomb support framework 12, so that the tire tread 1 always maintains good contact with the wall surface. At the same time, the anti-skid grooves 3 on the tire tread 1 are designed in an inclined annular shape, which can provide sufficient friction while avoiding stress concentration and cracking caused by diameter change, ensuring that the robot can walk stably on wall surfaces of different curvatures.

[0026] The above is only an embodiment of the present application, and the common knowledge of specific structures and characteristics in the scheme is not described in detail here. The ordinary skilled person in the art knows all the ordinary technical knowledge in the field of the present application before the application date or the priority date, can know all the prior art in the field, and has the ability to apply conventional experimental means before that date. The ordinary skilled person in the art can perfect and implement the present scheme based on the disclosure given in the present application and in combination with their own ability. Some typical known structures or known methods should not be an obstacle for the ordinary skilled person in the art to implement the present application. It should be noted that, for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, and these will not affect the implementation effect and practicality of the patent. The protection scope claimed in the present application should be subject to the content of its claims, and the specific implementation mode in the specification can be used to explain the content of the claims.

Claims

1. A variable-diameter tire structure for a wall-climbing robot, characterized by: It includes a support ring, on which a tire body is fixedly arranged, and the tire body includes an inner liner and a tire surface; the tire body, tire surface and inner liner are all flexible structures; a filler is arranged inside the inner liner, and the filler is a granular structure; one end of the connecting ring is provided with a connecting port, and the connecting ring is fixedly connected to the first end face of the tire body, and the other end is provided with a telescopic rod that is matched with the connecting ring, and the telescopic rod is fixedly connected to the second end face of the tire body away from the connecting port, and the end face of the tire body can change position as the telescopic rod is extended or retracted.

2. The variable diameter tire structure of a wall-climbing robot according to claim 1, characterized in that: The filler is a round rubber particle filler, and a lubricating layer is provided on the surface of the filler.

3. The variable diameter tire structure of a wall-climbing robot according to claim 1, characterized in that: A plurality of anti-skid grooves are arranged on the tire surface, and the anti-skid grooves are arranged in an oblique annular pattern on the tire surface.

4. The variable diameter tire structure of a wall-climbing robot according to claim 1, characterized in that: The telescopic rod is telescopic along the vertical first end surface of the tire body and the second end surface of the tire body.

5. The variable diameter tire structure of a wall-climbing robot according to claim 1, characterized in that: A protrusion is provided at one end of the telescopic rod away from the first end face of the tire base, and a connecting bearing is provided on the protrusion, and the connecting bearing is cooperatively connected with the protrusion.

6. The variable diameter tire structure of a wall-climbing robot according to claim 1, characterized in that: The maximum stroke length of the telescopic rod is equal to the diameter of the end surface of the tire body perpendicular to the telescopic rod when the telescopic stroke of the telescopic rod is equal to the diameter of the end surface of the tire body perpendicular to the telescopic rod.

7. The variable diameter tire structure of a wall-climbing robot according to claim 1, characterized in that: The inner shell of the tire body is made of polyimide film with a thickness of 0.1 to 0.2 mm, and the outer wall of the inner shell is composited with a carbon fiber braided layer with a braiding angle of Interlaced weaving, weaving density is 80 to 100 strands .

8. The variable diameter tire structure of a wall-climbing robot according to claim 1, characterized in that: A honeycomb support frame is provided between the tire surface and the inner liner. The tire body is made of 3D-printed polyetheretherketone material. The honeycomb unit is a regular hexagonal structure with a unit side length of 2 to 5 mm and a wall thickness of 0.3 to 0.5 mm.

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