Wheels and work vehicles

Abstract

To provide wheels and a work vehicle that can prevent a magnet from decreasing in magnetic force owing to heating.SOLUTION: A wheel 1 comprises a wheel body 2 which rotates to travel on a travel surface 201, a magnet 4 which is installed on the vehicle body 2 to magnetically attract the wheel body 2 to the travel surface 201, and a temperature suppression part 5 which suppresses the magnet 4 from rising in a temperature. Then the temperature suppression part 5 is so configured to suppress the magnet 4 from rising in temperature through at least one of air cooling and liquid cooling.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a wheel and a work vehicle. [Background technology]

[0002] A vehicle (gondola) equipped with wheels with built-in magnets is known (see, for example, Patent Document 1). The vehicle described in Patent Document 1 can be attached to a wall surface by the magnetic force of the magnets, and can move along the wall surface as it is. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2639895 Summary of the Invention [Problem to be solved by the invention]

[0004] The vehicle described in Patent Document 1 can be used, for example, by mounting a welding device on the vehicle and moving it over a wall surface to weld the wall surface. However, in this case, the heat from the welding is transferred to the magnet, causing the magnet to heat up and weakening its magnetic force. This weakening of the magnetic force could lead to the vehicle falling off the wall. An object of the present invention is to provide a wheel and a work vehicle that can prevent the magnetic force of the magnet from decreasing due to heating. [Means for solving the problem]

[0005] One aspect of the wheel of the present invention includes a wheel body that runs on a running surface by rotation; a magnet that is installed on the wheel body and that attracts the wheel body and the running surface by magnetic force; and a temperature suppression unit that suppresses a temperature rise of the magnet. Furthermore, one aspect of the work vehicle of the present invention includes the above-described wheel. [Effects of the Invention]

[0006] According to the present invention, even if the wheel body is heated, the temperature suppression unit can prevent the magnetic force of the magnet from being reduced by the heat, thereby maintaining the magnetic force of the magnet and allowing the wheel body to be sufficiently attracted to the running surface. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 4 is a vertical cross-sectional view showing a second embodiment of the present invention. [Figure 5] FIG. 5 is a vertical longitudinal sectional view showing a third embodiment of the present invention. [Figure 6] FIG. 6 is an exploded perspective view of the wheel shown in FIG. [Figure 7] FIG. 7 is a side view showing a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] The wheel and work vehicle of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings. For convenience of explanation, the upper side in Figures 1 to 7 will be referred to as "upper" and the lower side will be referred to as "lower."

[0009] First Embodiment A first embodiment of a wheel and a work vehicle according to the present invention will be described with reference to FIGS. 1 is a welding robot that moves in the direction of arrow α on horizontally placed iron plate materials (steel plates) 20, welding the plates 20 together. After welding, the plates 20 are used, for example, as a floor. The work vehicle 10 includes a vehicle body 11, a welding device 12, four wheels 1, and a drive unit 16 that drives each wheel 1 to rotate.

[0010] The vehicle body 11 has a rotation support portion (support portion) 13 that rotatably supports each wheel 1 (wheel body). 2, the rotation support portion 13 has a pair of opposing protruding pieces 131. The wheel 1 can be rotatably supported between these protruding pieces 131.

[0011] Additionally, a drive unit 16 is fixed to one of the protruding pieces 131. The drive unit 16 is configured, for example, by a gear motor (geared motor), and is connected to the wheel 1. The wheel 1 can be rotated by operating the drive unit 16. This rotation allows the work vehicle 10 to travel using the front surface (upper surface) of the plate material 20 as the travel surface 201.

[0012] A welding device 12 is mounted on the vehicle body 11. The welding device 12 includes a welding torch 14 and a displacement mechanism 15 that supports the welding torch 14 so that the welding torch 14 can be displaced. The welding torch 14 is configured to perform arc welding by arc discharge, which allows the plate materials 20 to be welded together easily and firmly.

[0013] The displacement mechanism 15 includes a first movement mechanism 151, a second movement mechanism 152, a third movement mechanism 153, and a rotation mechanism (angle adjustment mechanism) 154. First moving mechanism 151 is a mechanism that moves welding torch 14 relative to vehicle body 11 in a direction parallel to the direction of arrow α.

[0014] A second moving mechanism 152 is connected to the first moving mechanism 151. The second moving mechanism 152 is a mechanism that moves the welding torch 14 relative to the vehicle body 11 in a direction perpendicular to the direction of the arrow α. A third movement mechanism 153 is connected to the second movement mechanism 152. The third movement mechanism 153 is a mechanism that moves the welding torch 14 relative to the vehicle body 11 in the vertical direction.

[0015] A rotation mechanism 154 is connected to the third movement mechanism 153. The rotation mechanism 154 is a mechanism that rotates the welding torch 14 relative to the vehicle body 11 around a horizontal axis. The displacement mechanism 15 configured in this way makes it possible to appropriately change the position and posture of the welding torch 14 relative to the joint between the plate materials 20, thereby facilitating welding.

[0016] As described above, the work vehicle 10 is equipped with four wheels 1. The four wheels 1 have the same configuration except for their locations, so the following description will be given representatively of one wheel 1. Note that, although the number of wheels 1 arranged is four in this embodiment, it is not limited to this.

[0017] As shown in FIGS. 2 and 3, the wheel 1 includes a wheel body 2, a rotation shaft (axis) 3, and a magnet 4. The wheel body 2 is made up of a rotating body, and the rotation shaft 3 passes through and is fixed to the center of the wheel body 2. This allows the wheel body 2 to rotate together with the rotation shaft 3 around the rotation shaft 3.

[0018] 2, in this embodiment, the outer peripheral surface 21 of the wheel body 2 is configured as a curved surface that curves outward in an arc shape, but is not limited to this. Also, in the wheel body 2, each side surface 22 located on both sides in the longitudinal direction of the rotation shaft 3 is configured as a flat surface, but is not limited to this.

[0019] In this embodiment, the wheel body 2 is made of a non-magnetic material. There are no particular limitations on the non-magnetic material, and aluminum, austenitic stainless steel, etc., can be used, for example. The wheel body 2 may also be made of a heat-resistant resin material. The rotating shaft 3 is connected to the drive unit 16. In addition, both ends of the rotating shaft 3 are supported by bearings 132. This allows the wheel body 2 to rotate stably and smoothly together with the rotating shaft 3 when the drive unit 16 is activated.

[0020] As shown in Fig. 3, multiple magnets 4 (eight in the illustrated configuration) are installed on the wheel body 2. These magnets 4 are embedded (buried) in the wheel body 2 and are arranged at regular intervals around the center of rotation of the wheel body 2, i.e., the rotation axis 3. The direction of the magnetic force of these magnets 4 is, for example, radial, with the rotation axis 3 as the center.

[0021] The magnetic force of each magnet 4 can attract the wheel body 2 and the running surface 201 (plate material 20). Then, when the wheel body 2 rotates, the work vehicle 10 can run stably on the running surface 201 without spinning, i.e., without slipping. This allows the work vehicle 10 to perform rapid welding with the welding device 12 while moving. Furthermore, since multiple magnets 4 are arranged at regular intervals around the rotation axis 3, even when the wheel body 2 rotates, the wheel body 2 and the running surface 201 can be attracted to each other with just the right amount, regardless of the rotation angle. This contributes to the stable running of the work vehicle 10.

[0022] 1, the plate material 20 is installed horizontally, but is not limited to this, and may be installed, for example, at an angle to the horizontal direction, or may be installed upright vertically. Regardless of the installation state of the plate material 20, i.e., the posture, the work vehicle 10 can travel stably on the plate material 20 due to the magnetic force of each magnet 4.

[0023] The magnet 4 is a permanent magnet, which maintains a constant magnetic force and allows the wheel body 2 to attract the running surface 201 just right. For example, a neodymium magnet or a samarium-cobalt magnet is used as the permanent magnet. The number of magnets 4 to be arranged is not limited to eight, as long as it is plural.

[0024] As described above, the plate materials 20 are welded together by arc welding. In this case, the plate materials 20 are heated to a high temperature, and the heat is transferred to the wheel body 2. Then, inside the wheel body 2, the magnets 4 are also heated to a high temperature. The high temperature of the magnets 4 reduces the magnetic force, which may make it difficult for the work vehicle 10 to travel stably on the plate materials 20. If the magnet 4 is a neodymium magnet, its heat resistance temperature is approximately 200 degrees Celsius at most, and if the magnet 4 is a samarium-cobalt magnet, its heat resistance temperature is approximately 350 degrees Celsius at most.

[0025] Therefore, the wheel 1 is configured to be able to prevent such problems. The configuration and operation of this configuration will be described below. As shown in Fig. 2, the wheel 1 is equipped with a temperature suppression unit (temperature rise suppression unit) 5 that suppresses a rise in temperature of the magnet 4. The temperature suppression units 5 are respectively arranged on each side surface 22 of the wheel body 2. Since each temperature suppression unit 5 has the same configuration except for the location where they are arranged, one of the temperature suppression units 5 will be representatively described below.

[0026] The temperature suppression unit 5 has a heat dissipation unit 6 capable of dissipating heat and a cooling unit 7 capable of cooling. The heat dissipation section 6 is a heat sink having a plurality of fins 61 formed in a protruding plate shape. The heat dissipation part 6 is a disk-shaped part that is concentrically arranged and fixed (installed) on the side surface 22 of the wheel body 2. This makes it possible to ensure that the contact area of ​​the heat dissipation part 6 with the wheel body 2 is as large as possible.

[0027] The material of the heat dissipation section 6 is not particularly limited, and may be, for example, a metal material such as aluminum or copper, which has excellent thermal conductivity. The heat dissipation section 6 configured as described above can dissipate as much heat as possible when heat is transferred from the plate material 20 to the wheel body 2. This can prevent the magnet 4 from being heated.

[0028] The cooling unit 7 has a built-in motor (not shown) and a fan 71 that is rotated by this motor. The cooling unit 7 is mounted on a protruding piece 131 of the rotation support unit 13 that rotatably supports the wheel body 2, and faces the heat dissipation unit 6. This allows the cooling unit 7 to blow air towards the heat dissipation unit 6. When the air from the cooling unit 7 hits the heat dissipation unit 6, heat dissipation in the heat dissipation unit 6 is promoted.

[0029] The temperature suppression unit 5 configured as described above can quickly suppress the temperature rise of the magnets 4 along with the wheel body 2 through the synergistic effect of heat dissipation by the heat dissipation unit 6 and cooling (air cooling) by the cooling unit 7. This prevents a decrease in the magnetic force of each magnet 4 due to heating, and allows the wheel body 2 and the running surface 201 to be attracted to each other via the magnets 4. This attraction allows the work vehicle 10 to run stably on the plate material 20.

[0030] The fan 71 may be constantly rotating during welding work, or may alternately rotate and stop under the following conditions. For example, the temperature of the heat dissipation unit 6 may be detected, and when the detected temperature is equal to or higher than a threshold, the fan 71 may rotate, and when the detected temperature falls below the threshold, the fan 71 may stop rotating. This reduces the power consumption for rotating the fan 71 by the amount that the fan 71 is stopped from rotating.

[0031] Furthermore, the rotation speed of the fan 71 may be variable in proportion to the detected temperature of the heat dissipation unit 6. For example, when the detected temperature of the heat dissipation unit 6 is on the rise, the rotation speed of the fan 71 may also be increased. Furthermore, in this embodiment, the temperature suppression unit 5 includes both the heat dissipation unit 6 and the cooling unit 7, but is not limited to this, and one of the heat dissipation unit 6 and the cooling unit 7 may be omitted.

[0032] Second Embodiment A second embodiment of the wheel and working vehicle of the present invention will be described below with reference to FIG. 4, but differences from the previously described embodiment will be mainly described, and explanations of similar points will be omitted. 4, the magnet 4 is ring-shaped (annular) and is arranged concentrically with the center of rotation (rotation axis 3) of the wheel body 2. Such a magnet 4 also allows the wheel body 2 and the running surface 201 to be attracted to each other just enough, regardless of the rotation angle of the wheel body 2, allowing the work vehicle 10 to run stably.

[0033] <Third embodiment> A third embodiment of the wheel and work vehicle of the present invention will be described below with reference to Figs. 5 and 6, but differences from the previously described embodiment will be mainly described, and explanations of similar points will be omitted. 5 and 6, the wheel 1 includes a cover 8 attached to each side surface 22 of the wheel body 2. The cover 8 has a disk-shaped portion 81 and a tubular portion 82 formed to protrude in a tubular shape from the center of the disk-shaped portion 81.

[0034] The disk-shaped portion 81 is arranged concentrically on the side surface 22 of the wheel body 2. A plurality of through holes 811, through which the bolts 17 are inserted, are formed near the edge of the disk-shaped portion 81. The bolts 17 inserted through the through holes 811 can then be threaded into the internal threads 23 of the wheel body 2. This allows the cover 8 to be fixed to the wheel body 2.

[0035] The inside of the tubular portion 82 functions as a flow path 90 through which a refrigerant Q passes. The refrigerant Q is supplied from a temperature suppression unit 5, which will be described later. The refrigerant Q is not particularly limited, and examples thereof include liquids such as oil, water, and ethanol.

[0036] Each side surface 22 of the wheel body 2 is formed with grooves 24 and communication holes 25 that connect the grooves 24 to each other. Each groove 24 is formed, for example, in a spiral shape from the center of the side surface 22 outward. Furthermore, each groove 24 has an inner end 241 located at the center of the side surface 22 that communicates with the tubular portion 82 of the lid 8. Meanwhile, the inner end 241 and the outer end 242 opposite to the inner end 241 of each groove 24 communicate with each other via a communication hole 25.

[0037] The grooves 24 and the communication holes 25 function together with the tubular portion 82 as a flow path 90 through which the refrigerant Q passes. Additionally, a ring-shaped groove 26 is formed on each side surface 22 of the wheel body 2 so as to surround the groove 24. A ring-shaped packing (O-ring) 27 can be placed in the groove 26. This makes it possible to prevent the refrigerant Q from leaking out from between the wheel body 2 and the lid body 8. In addition, a strip-shaped elastic body 28 is wound around the outer peripheral surface 21 of the wheel body 2. The elastic body 28 is made of, for example, a heat-resistant rubber material.

[0038] The drive unit 16 has a gear motor (geared motor) 161 installed on the rotation support unit 13, a pulley 162 connected to the geared motor 161, a pulley 163 connected to the tubular portion 82 of one of the two lid bodies 8 (the right side in Figure 5), and a timing belt 164 looped around the pulley 162 and the pulley 163. In the drive unit 16 configured as above, when the gear motor 161 is operated, the pulley 162 rotates, and the rotational force is transmitted to the pulley 163 via the timing belt 164. This causes the wheel 1 to rotate.

[0039] The temperature suppression unit 5 has a cooling unit 9. As shown in Fig. 5, the cooling unit 9 has a cooling mechanism 91, a delivery pipe 92 that delivers the refrigerant Q from the cooling mechanism 91, and a return pipe 93 that returns the refrigerant Q to the cooling mechanism 91. The cooling mechanism 91 is mounted on, for example, the vehicle body 11. The cooling mechanism 91 has a storage unit 911 that temporarily stores the refrigerant Q, a pump 912 connected to the upstream side of the storage unit 911, and a cooler 913 connected to the downstream side of the storage unit 911. Note that the order in which the storage unit 911, the pump 912, and the cooler 913 are connected is not limited to the order shown in FIG.

[0040] In the cooling mechanism 91 configured as above, when the pump 912 is operated, the refrigerant Q stored in the storage portion 911 can be pushed out toward the cooler 913. The refrigerant Q is sufficiently cooled by the cooler 913 and then sent out. The downstream side of the cooling mechanism 91 (cooler 913) and the tubular portion 82 of one of the lid bodies 8 are connected via a delivery pipe 92. Furthermore, the upstream side of the cooling mechanism 91 (pump 912) and the tubular portion 82 of the other lid body 8 are connected via a return pipe 93. As a result, the refrigerant Q from the cooling mechanism 91 passes through the delivery pipe 92, the flow path 90, and the return pipe 93 in this order, and returns to the cooling mechanism 91.

[0041] The refrigerant Q can cool each magnet 4 by removing (absorbing) heat from each magnet 4 while passing through the flow path 90. In this manner, in this embodiment, the temperature suppression unit 5 is configured to suppress a temperature rise of the magnet 4 by liquid cooling. This makes it possible to prevent a decrease in the magnetic force of each magnet 4 due to heating.

[0042] <Fourth embodiment> A fourth embodiment of the wheel and working vehicle of the present invention will be described below with reference to FIG. 7, but differences from the previously described embodiment will be mainly described, and explanations of similar points will be omitted. As shown in Fig. 7, the temperature suppression unit 5 is disposed above each wheel 1. Each temperature suppression unit 5 is configured to spray refrigerant Q toward the wheel 1. This cools the magnet 4 together with the wheel body 2, making it possible to suppress a temperature rise of the magnet 4. The refrigerant Q may be, in addition to the liquid mentioned above, nitrogen gas obtained by vaporizing liquid nitrogen, for example.

[0043] While the wheel and work vehicle of the present invention have been described above in relation to the illustrated embodiments, the present invention is not limited to these, and each part of the wheel and work vehicle may be replaced with any other part that can perform the same function. Also, any other component may be added. Furthermore, the wheel and work vehicle of the present invention may be a combination of any two or more of the configurations (features) of the above-described embodiments.

[0044] Furthermore, the work vehicle is not limited to traveling on floor surfaces, but can also travel on walls, ceilings, etc. Magnetic force also allows the work vehicle to travel stably on curved surfaces such as the inside and outside of pipes. Furthermore, although the work vehicle 10 is applied to a welding robot, the invention is not limited to this and can also be applied to, for example, a welding (cutting) robot, a painting robot, and the like. Furthermore, the magnet 4 is not limited to a permanent magnet, but may be, for example, an electromagnet. Furthermore, the temperature suppression unit 5 may be configured to suppress the temperature rise of the magnet 4 by both air cooling and liquid cooling. [Explanation of symbols]

[0045] 1 wheel 2 Wheel body 21 Outer surface 22 Side 23 Internal thread 24 groove 241 Inner end 242 Outer edge 25 Communication hole 26 Groove 27 Packing (O-ring) 28 Elastic Body 3 Rotation axis (axis) 4. Magnets 5 Temperature suppression section (temperature rise suppression section) 6 Heat radiation part 61 Finn 7 Cooling section 71 fans 8 Lid 81 Disc-shaped part 82 Tubular part 9 Cooling section 90 Flow Channel 91 Cooling mechanism 92 Delivery pipe 93 Return pipe 10 Work vehicles 11 Body 12 Welding equipment 13 Rotation support part (support part) 131 Projecting piece 132 Bearings 14 Welding torch 15 Displacement mechanism 151 1st movement mechanism 152 Second movement mechanism 153 Third movement mechanism 154 Rotation mechanism (angle adjustment mechanism) 16 Drive unit 161 Gear motor (geared motor) 162 Pulley 163 Pulley 164 Timing belt 17 volts 20 Plate material (steel plate) 201 Running surface Q Refrigerant α arrow

Claims

1. a wheel body that rotates to travel on a travel surface; a rotation shaft that penetrates the wheel body and rotates the wheel body when a drive unit provided separately from the wheel is activated; a magnet that is installed on the wheel body and that attracts the wheel body and the running surface by magnetic force; a temperature suppression unit that suppresses a temperature rise of the magnet; Equipped with the temperature suppression unit has a heat dissipation unit capable of dissipating heat and a cooling unit that cools the heat dissipation unit, The wheel body has a side surface on a longitudinal direction side of the rotation shaft, the heat dissipation portion is disposed on the side surface and has fins formed on an outer surface thereof to protrude therefrom; the cooling unit is installed on a rotation support unit that rotatably supports the rotation shaft, thereby suppressing a temperature rise of the magnet. A wheel characterized by:

2. The wheel according to claim 1 , wherein the heat dissipation portion is a disk-shaped portion concentrically disposed on the side surface.

3. The wheel according to any one of claims 1 to 2, wherein the cooling section is installed so as to be able to blow air toward the heat dissipation section so as to be able to cool the heat dissipation section.

4. A wheel as described in Claim 3, wherein the cooling section is installed facing the heat dissipation section.

5. A work vehicle comprising the wheel according to any one of claims 1 to 4.

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