JP7312395B2 - running gear - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a traveling device, and more particularly to a traveling device that travels on the surface of an inspection object for non-destructive inspection of the inspection object.

2. Description of the Related Art Non-destructive inspection is widely known for detecting defects such as scratches and corrosion on at least one of the surface and inside of structures such as pipes, bridges, furnace walls, and chimneys made of steel without destroying the structure. In this non-destructive inspection, a traveling device is caused to travel on the surface of the object to be inspected, and defects are detected by an inspection unit mounted on the traveling device.

As a traveling device, a self-propelled traveling device in which wheels provided on a vehicle body are driven by a motor is known. It is also known to provide the traveling device with a magnet in order to attract the traveling device to the inspection object (see, for example, Patent Document 1).

JP-A-59-35139

In the case of a travel device having such a magnet, if the magnet comes into contact with the object to be inspected during travel, the surface of the object to be inspected may be damaged by the drag of the magnet, the running resistance may increase more than necessary, or, in the worst case, the magnet may stick to the object to be inspected, resulting in an impossibility of travel. In this respect, the structure of Patent Literature 1, in which the magnet is in contact with the inspection object, is disadvantageous, and it is preferable to provide an appropriately sized interval or gap between the inspection object and the magnet.

On the other hand, if the test object changes and its shape changes, the spacing between the test object and the magnet may change. In this case, the attracting force of the magnet to press the traveling device against the object to be inspected changes. If the attracting force is insufficient, the wheels may slip or the traveling device may come off.

Therefore, the present disclosure was created in view of such circumstances, and its object is to provide a travel device that can maintain the adsorption force of the travel device at an optimum level even if the shape of the inspection object changes.

According to one aspect of the present disclosure,
A traveling device that travels on the surface of the inspection object for non-destructive inspection of the inspection object,
a vehicle body;
an inspection unit mounted on the vehicle body;
wheels rotatably provided on the vehicle body;
a motor that drives the wheel;
a magnet unit disposed on the bottom surface of the vehicle body with a gap from the inspection object and including a magnet;
with
The traveling device is characterized in that the magnet unit can be exchanged for a different size according to the inspection object.

Preferably, the traveling device further includes a fluid pressure cylinder fixed to the vehicle body and detachably connected to the magnet unit, for raising the magnet unit away from the inspection object when pressurized fluid is supplied.

Preferably, the fluid pressure cylinder is arranged with the piston rod protruding from the cylinder body facing downward,
The magnet unit is coaxially and detachably connected to the piston rod.

Preferably, the magnet unit is connected to the piston rod by a screw coaxial with the piston rod.

Preferably, the wheels are interchangeable with different sizes depending on the inspection object.

Preferably, the wheel has a tapered tread on its outer side.

Preferably, the wheels are provided in front and rear of the vehicle body,
The traveling device includes a timing belt that connects front wheels and rear wheels.

Preferably, the traveling device includes a support member that supports the lower portion of the timing belt from above.

Preferably, the timing belt has inner and outer peripheral teeth.

According to the present disclosure, even if the shape of the object to be inspected changes, the adsorption force of the travel device can be maintained at an optimum magnitude.

It is a schematic diagram showing the whole inspection device. It is a perspective view which shows a traveling apparatus. It is a bottom view which shows a traveling apparatus. It is a front view which shows a traveling apparatus. It is a front view which shows the traveling apparatus in a minimum diameter pipe. It is a left vertical side view of a traveling device, and shows the state at the time of non-supply of the pressure fluid. It is a left vertical side view of a traveling apparatus, and shows the state at the time of supply of the pressure fluid. Fig. 3 is a left side view showing an enlarged timing pulley for the left front wheel and a left timing belt; It is a partial longitudinal front view of a traveling device. It is a front view which shows the traveling apparatus in intermediate diameter piping. It is a front view which shows the traveling apparatus in a maximum diameter pipe. It is a left vertical side view which shows the magnet unit adapted for intermediate diameter piping. It is a left vertical side view which shows the magnet unit adapted for maximum diameter piping. FIG. 5 is a schematic left side view of a traveling device according to a comparative example traveling on an inner corner portion of an elbow; FIG. 4 is a schematic left side view of the running device according to the present embodiment when running on the inside corner portion of the elbow;

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. Note that the present disclosure is not limited to the following embodiments.

FIG. 1 is a schematic diagram showing the entire inspection apparatus for non-destructive inspection of an object to be inspected. The object to be inspected is a magnetic steel structure, specifically a pipe P. The pipe P in the illustrated example is bent into a crank shape. The pipe P has a horizontally arranged straight pipe P1 having one end P11 open to the outside, an elbow P2 as a curved pipe connected to the other end P12 of the straight pipe P1 and bending upward at right angles, a straight pipe P3 connected to the upper end of the elbow P2 and extending upward, an elbow P4 connected to the upper end of the straight pipe P3 and bending at right angles, and a straight pipe P5 connected to the elbow P4 and extending in the horizontal direction. Each pipe and elbow are connected by flanges F and bolts and nuts (not shown).

On the inner surface 5 of the pipe P, iron as a raw material is exposed in a bare state. In addition, the inner surface 5 of the pipe P may be coated with a coating material such as a rust-preventing resin as necessary.

The inspection device includes: a traveling device 1 that travels on the surface of the pipe P; a control device 2 that receives data from an inspection unit mounted on the traveling device 1 and outputs electric power and control signals to the traveling device 1; a display 3 that displays an image based on the data sent to the control device 2; The pressure fluid in this embodiment is compressed air, and the fluid pressure supply device is configured as an air pressure supply device. Note that the pressure fluid can be changed as necessary, and for example, a pressurized liquid such as pressure oil may be used.

In the case of this embodiment, the inspection device is configured for visual inspection, and the inspection unit includes a front camera and a rear camera for capturing the front and rear views of the running gear 1 respectively. These cameras are composed of CCD cameras. Data of images or videos taken by these cameras are sent to the control device 2 , and the control device 2 displays the images taken by one or both cameras on the display 3 . The operator S visually inspects the condition of the surface of the pipe P while viewing this image, and operates the controller 4 to cause the traveling device 1 to travel along the longitudinal direction of the pipe P.

In the illustrated example, the traveling device 1 is inserted into the pipe P from one end P11 of the straight pipe P1 and is caused to travel leftward in the figure toward the straight pipe P5 side. An image of the inner surface 5 of the pipe P is displayed on the display 3, and the inner surface 5 of the pipe P is inspected.

Although the details will be described later, the traveling device 1 is self-propelled and travels by driving the wheels thereof with a motor. Further, the travel device 1 is attracted to the surface of the pipe P, specifically, the inner surface 5 by a magnet. The running gear 1 can thus climb along the curved inner surfaces 5 of the elbows P2, P4 and also along the vertical inner surface 5 of the straight pipe P3. If necessary, it can also run upside down along the inner surface 5, which is the ceiling surface of the horizontal straight pipes P1 and P5.

Alternatively, the inspection device may be configured to perform other types of tests, such as well-known ultrasonic testing and eddy current testing. The inspection unit may also be changed to one suitable for other types of tests, such as an ultrasonic transmitter suitable for ultrasonic testing or a flaw detection coil suitable for eddy current testing. The inspection is not limited to the inner surface 5 of the pipe P, and the outer surface 6 may be inspected.

Next, the configuration of the travel device 1 will be described.

As shown in FIGS. 2 to 4, the traveling device 1 includes a vehicle body 11, an inspection unit 12 mounted on the vehicle body 11, wheels 13 rotatably provided on the vehicle body 11, a motor 14 for driving the wheels 13, and a magnet unit 15 including a magnet for attracting the traveling device 1 to the surface of the inspection object (specifically, the inner surface 5 of the pipe P). For the sake of convenience, the surface of the object to be inspected on which the traveling device 1 travels is also referred to as a traveling surface or a road surface. Also, the surface of the wheel 13 that comes into contact with the running surface is called a ground contact surface. The front, back, left, right, up and down directions of the traveling device 1 are as shown.

The vehicle body 11 has a monocoque structure made of resin so as to be as small and light as possible. The vehicle body 11 is configured by assembling a plurality of resin plates. However, the vehicle body 11 may be made of metal or may have a frame structure.

The inspection unit 12 includes a front camera 18 and a rear camera (not shown) that capture the front and rear views of the traveling device 1, respectively. These cameras are composed of CCD cameras. These cameras are rotatable around a horizontal axis of rotation (see Cc in FIG. 6), and can change their vertical angles based on control signals from the controller 4 .

The wheels 13 are provided on the front, rear, left, and right of the vehicle body 11 . That is, as the wheels 13, a total of four wheels of the same size, namely, a front left wheel FL, a front right wheel FR, a rear left wheel RL and a rear right wheel RR are provided. However, the number of wheels may be increased or decreased as required.

At least the contact surfaces of the wheels 13 are made of rubber. In the case of this embodiment, the wheel 13 is a substantially disc-shaped member made entirely of rubber. However, as is well known, a wheel may be constructed by mounting a rubber tire on a metal or resin wheel. Forming the ground contact surface with rubber in this manner suppresses the running surface from being damaged, and even if the running surface is wet or dirty, the wheels 13 can be well gripped on the running surface.

The wheel 13 has a reference ground plane 16 on its outer periphery parallel to the front axle Cf and the rear axle Cr. On the other hand, the wheel 13 has a tapered ground contact surface, ie, a tapered ground contact surface 17 on its outer side surface portion (side surface portion on the outer side in the vehicle width direction). The tapered ground contact surface 17 is provided adjacent to the reference ground contact surface 16 on the outer peripheral side of the outer side surface of the wheel 13 . The tapered ground contact surface 17 is tapered such that the outer diameter becomes smaller toward the outside in the vehicle width direction, and is inclined such that the angle θ with respect to the reference ground contact surface 16 is preferably 45° or more and less than 90°, more preferably 60° or more and less than 90° (approximately 70° in the illustrated example).

When the tapered contact surface 17 is provided in this way, as shown in FIG. 5, even when the inner diameter d of the pipe P is relatively small and it is difficult for the reference contact surface 16 to contact the contact surface, the tapered contact surface 17 can be brought into contact with the inner surface 5 of the pipe P and the vehicle can travel reliably.

The motor 14 is formed by an electric motor such as a DC motor, and is arranged inside the vehicle body 11 . In the case of this embodiment, the two motors 14, ie, the right wheel motor MR and the left wheel motor ML, are horizontally placed and arranged side by side in the front-rear direction. The right wheel motor MR is directly connected to the right front wheel FR, and the left wheel motor ML is directly connected to the left rear wheel RL. With such a layout, the two motors 14 can be arranged compactly in the small vehicle body 11 .

As shown in FIG. 5, the magnet unit 15 is arranged on the bottom surface of the vehicle body 11 with a space or gap from the surface of the object to be inspected (the inner surface 5 of the pipe P). In particular, the magnet unit 15 can be exchanged for a different size depending on the object to be inspected.

FIG. 6 is a left vertical cross-sectional view of the travel device 1. FIG. The travel device 1 includes an air cylinder 19 as a fluid pressure cylinder fixed to the vehicle body 11 . The air cylinder 19, which will be described in detail later, is for forcibly separating the travel device 1 from the road surface. The magnet unit 15 is directly and detachably connected to the air cylinder 19 .

The magnet unit 15 includes a horizontal disc-shaped magnet 20 , a holder 21 that holds the magnet 20 , and a case 22 that houses the magnet 20 and the holder 21 . The magnet 20, holder 21 and case 22 are arranged coaxially with a vertical reference axis C1 extending in the vertical direction.

The holder 21 has a cylindrical holding container 23 with an open lower end and a closed upper end, an extension shaft portion 24 provided at the center of the upper surface of the holding container 23 and extending upward, and a male screw shaft 25 provided at the tip (upper end) of the extension shaft portion 24. The holding container 23 is fitted over the magnet 20 and fixed to the magnet 20 with an adhesive or the like. Although the holder 21 is made of metal, it may be made of another material.

The case 22 is a cylindrical container with an open upper end and a closed lower end, and is made of a relatively soft material, plastic in this embodiment, so as not to damage the surface of the object to be inspected even if it hits it. Case 22 is fitted to holding container 23 and magnet 20 from below to cover them. The case 22 has a flat lower end surface 22A. A snap ring 26 is attached to a ring groove provided on the inner peripheral surface of case 22 , and case 22 is detachably attached to holding container 23 and magnet 20 . This case 22 can prevent the hard magnet 20 from contacting and damaging the surface of the object to be inspected.

The air cylinder 19 has a cylindrical cylinder body 30 closed at both ends, a piston 31 reciprocally arranged in the cylinder body 30, and a piston rod 32 having one end connected to the piston 31 and the other end protruding from the cylinder body 30. The air cylinder 19 is arranged downward with a protrusion (referred to as a rod protrusion) 33 of the piston rod 32 protruding from the cylinder body 30 facing downward. The air cylinder 19 is arranged coaxially with the vertical reference axis C1.

The magnet unit 15 is coaxially and detachably connected to the lower end of the rod projecting portion 33 . Specifically, the magnet unit 15 is connected to the piston rod 32 by a screw coaxial with the piston rod 32 .

More specifically, a female screw hole 34 is coaxially provided in the lower end surface of the rod projecting portion 33 . By tightening the male screw shaft 25 of the magnet unit 15 into the female screw hole 34 , the magnet unit 15 is coaxially and detachably connected directly to the piston rod 32 .

When the magnet unit 15 is attached to the air cylinder 19 in this manner, the magnet unit 15 passes through a circular unit hole 36 provided in the bottom surface portion 35 of the vehicle body 11 with a minimum clearance and protrudes downward. In the illustrated example, the magnet unit 15 protrudes below the wheel 13 in accordance with the pipe P having a small diameter. The magnet unit 15 can move up and down according to the operating state of the air cylinder 19 .

As shown in FIG. 6, a seal ring 37 such as an O-ring is attached to the outer peripheral surface of the piston 31 and is in sliding contact with the inner peripheral surface of the cylinder body 30. The internal space of the cylinder body 30 is partitioned by the seal ring 37 into a space on the side of the piston rod 32, i.e., a rod side chamber 38, and a space on the opposite side, i.e., a non-rod side chamber 39. The anti-rod side chamber 39 is open to the atmosphere through an open port (not shown), while one end of an air pipe 40 is connected to the rod side chamber 38 . The other end of this air pipe 40 is connected to the aforementioned air pressure supply device. Therefore, it is possible to selectively supply compressed air from the air pressure supply device to the rod side chamber 38 .

FIG. 6 shows a state in which the air pressure supply device is not in operation and compressed air is not supplied to the rod side chamber 38, that is, the air cylinder 19. As shown in FIG. At this time, the piston 31 is basically free to move up and down, but in the illustrated example, the magnet unit 15 is attracted to the pipe P, so that the piston 31 is pulled downward and is positioned at the lowest lowered position. The magnet unit 15 is also positioned at a lowered position corresponding to the lowered position of the piston 31 .

On the other hand, FIG. 7 shows a state when the compressed air is supplied to the rod-side chamber 38, that is, the air cylinder 19, when the air pressure supply device is in operation. At this time, the compressed air supplied to the rod-side chamber 38 raises the piston 31 to the highest raised position, thereby raising the magnet unit 15 to a raised position corresponding to the raised position of the piston 31 . Then, the magnet unit 15 is forcibly separated from the inner surface 5 of the pipe P.

As shown in FIGS. 2 to 4, the traveling device 1 includes a timing belt 100 that connects the front wheel 13 and the rear wheel 13. Specifically, it includes a right timing belt BR that connects the right front and rear wheels FR and RR, and a left timing belt BL that connects the left front and rear wheels FL and RL. The wheel 13 can be exchanged for a different size according to the object to be inspected. The wheels 13 and the timing belt 100 are provided outside the vehicle body 11 in the vehicle width direction so as to be exposed to the outside.

A timing pulley 41 is detachably attached to the inner side surface of each wheel 13 in the vehicle width direction, that is, the inner side surface. An annular right timing belt BR is wound between timing pulleys 41 attached to the right front and rear wheels FR and RR. The right timing belt BR is made of rubber. The driving force applied from the right wheel motor MR to the right front wheel FR is also transmitted to the right rear wheel RR through the right timing belt BR. Thus, one right wheel motor MR can simultaneously drive two right wheels FR and RR.

A similar structure is adopted for the left side. That is, an annular left timing belt BL is wound between timing pulleys 41 attached to the left front and rear wheels FL, RL. The left timing belt BL is the same as the right timing belt BR. The driving force applied to the left rear wheel RL from the left wheel motor ML is also transmitted to the left front wheel FL through the left timing belt BL. Thus, one left wheel motor ML can simultaneously drive two left wheels FL and RL. The travel device 1 is configured as a four-wheel drive vehicle.

FIG. 8 is an enlarged view showing the timing pulley 41 for the left front wheel FL and the left timing belt BL. A plurality of teeth 42 are provided on the outer peripheral surface of the timing pulley 41, and these teeth 42 are engaged with a plurality of inner peripheral teeth 43 provided on the inner peripheral surface of the left timing belt BL. On the other hand, a plurality of outer peripheral teeth 44 are also provided on the outer peripheral surface of the left timing belt BL. In other words, the left timing belt BL is a belt having teeth on both sides. As will be described in detail later, the outer peripheral teeth 44 are useful when the left timing belt BL is used to drive the vehicle. The timing pulley 41 of the other wheel 13 and the right timing belt BR are similarly constructed.

FIG. 9 is a longitudinal front view at the position of the front axle Cf, showing the structure near the left and right front wheels. First, on the right side, a timing pulley 41 is detachably and coaxially fixed to a rotating shaft 45 of a right wheel motor MR fixed inside the vehicle body 11 . A right front wheel FR is detachably and coaxially fixed to the timing pulley 41 . The timing pulley 41 is made of resin, and the right front wheel FR is coaxially positioned by fitting a circular protrusion 46 formed on the outer surface of the timing pulley 41 . The right front wheel FR is shared with other wheels 13 . A plurality (four in this embodiment) of bolt holes 47 are provided in the right front wheel FR so as to penetrate in the axial direction at regular intervals in the circumferential direction. A plurality of female screw holes 49 corresponding to these bolt holes 47 are provided through the timing pulley 41 in the axial direction. The right front wheel FR is detachably and coaxially fixed to the timing pulley 41 by inserting a bolt 48 made of, for example, a hexagon socket bolt from the outside in the vehicle width direction into the bolt hole 47 and tightening it into the female screw hole 49 . A vehicle width direction outer end 50 of the bolt hole 47 is enlarged in diameter so as to completely accommodate the head 51 of the bolt 48 .

On the other hand, on the left side, a timing pulley 41 is detachably, coaxially and rotatably attached to a bearing boss 52 fixed to the vehicle body 11 via a ball bearing 53 as a bearing. The timing pulley 41 is prevented from slipping off from the bearing boss 52 by appropriate means. The left front wheel FL is detachably and coaxially fixed to the timing pulley 41 in the same manner as the right side.

While the right front wheel FR is a driving wheel directly driven by the right wheel motor MR, the left front wheel FL is a driven wheel indirectly driven by the driving force of the left wheel motor ML transmitted through the left timing belt BL.

The outer diameter Dp of the timing pulley 41 (meaning the outer diameter of the teeth 42) is set to a predetermined outer diameter slightly smaller than the outer diameter Dw of the wheel 13, and the outer diameter is set so that the timing belts BR and BL wound around the timing pulley 41 do not protrude outside the wheel 13 in the radial direction.

Although the left and right sides are reversed, the same structure as shown in FIG. 9 is adopted on the rear wheel side as well.

In this embodiment, the suspension is omitted, and the structure is such that the wheels 13 are rotated at a fixed position with respect to the vehicle body 11. Alternatively, the suspension may be provided.

As shown in FIG. 2, the timing belt 100 has an upper portion 54 connecting the upper ends of the front and rear timing pulleys 41 together and a lower portion 55 connecting the lower ends thereof. Tensioners 56 that push up the upper portion 54 and apply tension to the timing belt 100 are provided on the left and right side portions of the vehicle body 11 . The tensioner 56 is fixed to the vehicle body 11 by a pair of front and rear bolts 57 fixed to the vehicle body 11 and nuts 58 attached to the bolts 57 so as to be vertically adjustable.

Further, as shown in FIG. 3, the bottom portion 35 of the vehicle body 11 is provided with a support member 60 that supports the lower portion 55 of the timing belt 100 from above. Specifically, a right support member SR that supports the lower portion 55 of the right timing belt BR from above and a left support member SL that supports the lower portion 55 of the left timing belt BL from above are provided.

The right support member SR and the left support member SL are integrally provided on a common support plate 61 and are plate-like members. The support plate 61 has a ring portion 62 positioned around the aforementioned unit hole 36 , and the ring portion 62 is fixed to the bottom portion 35 with a plurality of screws 63 . A right support member SR and a left support member SL are integrally provided so as to protrude from the right end and left end of the ring portion 62 . The right support member SR and the left support member SL have a front-rear length L approximately equal to the distance between the rear end of the front wheel and the front end of the rear wheel, and have an outer edge 64 extending linearly in the front-rear direction at approximately the same position as the outer edge of the lower portion 55 in the vehicle width direction.

In addition to the above, the traveling device 1 is provided with a pair of left and right front lights 65 for illuminating the front, a pair of left and right backlights 66 for illuminating the rear, and an electric cable 67 for transmitting power and control signals to the traveling device 1, as shown in FIG.

By the way, in the travel device 1 of the present embodiment, the magnet unit 15 can be replaced with one having a different size depending on the inspection object. Also, the wheel 13 can be exchanged for a different size depending on the object to be inspected. These points will be described below.

In the case of this embodiment, three types of pipes P having different inner diameters d are used as inspection objects. Three types of magnet units 15 of different sizes and two types of wheels 13 are prepared corresponding to these pipes P. Note that the number of these types can be arbitrarily increased or decreased, and only one example of them is described in this embodiment.

A pipe P shown in FIG. 5 is a pipe having the smallest inner diameter d (d=d1). In contrast, the pipe P shown in FIG. 10 has a larger intermediate inner diameter d (d=d2>d1), and the pipe P shown in FIG. 11 has an even larger maximum inner diameter d (d=d3>d2). Hereinafter, the pipe P in FIG. 5 is called the minimum diameter pipe P01, the pipe P in FIG. 10 is called the intermediate diameter pipe P02, and the pipe P in FIG. 11 is called the maximum diameter pipe P03.

The magnet unit 15 of the travel device 1 described above with reference to FIGS. 2 to 9 is adapted to the minimum diameter pipe P01, and is sized such that the amount of downward protrusion Z from the bottom surface portion 35 is the largest Z1. This magnet unit 15 is denoted by U1. As shown in FIG. 6, the amount of protrusion Z is defined as the amount of protrusion when the magnet unit 15 is positioned at the lowered position when compressed air is not supplied.

On the other hand, as shown in FIG. 10, the magnet unit 15 (represented by symbol U2) adapted to the intermediate diameter pipe P02 is sized such that the protrusion amount Z from the bottom surface portion 35 is an intermediate size Z2. Furthermore, as shown in FIG. 11, the magnet unit 15 (represented by symbol U3) adapted to the maximum diameter pipe P03 is sized such that the amount of protrusion Z from the bottom surface portion 35 is the smallest size Z3.

6, 12 and 13 show magnet units U1, U2 and U3 adapted to the minimum diameter pipe P01, intermediate diameter pipe P02 and maximum diameter pipe P03, respectively. As can be understood from these figures, the magnet units U1, U2 and U3 differ in at least one dimension of the magnet 20, the holder 21 and the case 22. FIG.

Comparing the magnet units U1 and U2 with reference to FIGS. 6 and 12, the magnets 20 have the same size, that is, the thickness t in the vertical direction of the magnets 20 is the same. However, the shape and height dimension of the holder 21 are different. As a result, the vertical height dimension H from the position of the holder 21 contacting the lower end surface of the rod projecting portion 33 to the lower end surface of the magnet unit U2 (i.e., the lower end surface 22A of the case 22) is smaller than that of the magnet unit U1, and as a result, the protrusion amount Z is smaller than that of the magnet unit U1. Further, the height dimension h of the case 22 is also reduced in accordance with the reduction in the height dimension of the holder 21 .

The outer diameter D of the magnet 20, the inner and outer diameters of the holding container 23, and the inner and outer diameters of the case 22 with respect to the vertical reference axis C1 are the same for all units. Also, the thickness of the case 22 is the same for all units. Therefore, the protrusion amount of the magnet unit may alternatively be defined as the vertical distance obtained by subtracting the thickness of the case 22 from the protrusion amount Z, that is, the vertical distance from the vehicle body bottom portion 35 to the lower end of the magnet 20.

Next, comparing the magnet units U2 and U3 with reference to FIGS. 12 and 13, the magnet 20 of the magnet unit U3 has a smaller thickness t than the magnet 20 of the magnet unit U2. Along with this thinning of the magnet 20, the height dimension of the holding container 23 of the holder 21 of the magnet unit U3 and the height dimension h of the case 22 are also made smaller than those of the magnet unit U2. Also in the holder 21 of the magnet unit U3, the extension shaft portion 24 is omitted and the male screw shaft 25 is directly provided in the holding container 23, similarly to the magnet unit U2.

As a result, the vertical height dimension H from the position of the holder 21 in contact with the lower end surface of the rod projecting portion 33 to the lower end surface of the magnet unit U3 is smaller than in the case of the magnet unit U2, and as a result, the amount of protrusion Z is smaller than in the case of the magnet unit U2.

Next, the difference in size of the wheels 13 will be described. As can be seen by comparing FIGS. 5, 10 and 11, wheels 13 having the same outer diameter Dw and Dw1 are used for the minimum diameter pipe P01 and the medium diameter pipe P02. However, in the case of the maximum diameter pipe P03, wheels 13 with a larger outer diameter Dw2 are used.

Next, the operation of this embodiment will be described.

As shown in FIG. 1, the traveling device 1 is inserted into the pipe P when performing a visual inspection of the inner surface 5 of the pipe P. As shown in FIG. Then, the operator S operates the controller 4 to steer the traveling device 1, and causes the traveling device 1 to travel along the longitudinal direction of the pipe P toward the end point on the left side in the drawing. At the same time, the worker S looks at the image displayed on the display 3 and visually inspects the state of the inner surface 5 .

As shown in FIGS. 2 and 3, in the traveling device 1, the right wheels FR, RR and the left wheels FL, RL can be individually driven by the right wheel motor MR and the left wheel motor ML, respectively. By individually controlling the rotation speeds of the right wheels FR, RR and the left wheels FL, RL, the traveling device 1 can be moved forward, backward, straight, and turned right and left.

For example, when the traveling device 1 is to be driven forward and straight, the right wheels FR, RR and the left wheels FL, RL are driven forward at the same speed. Further, when the traveling device 1 is to be driven forward and turned to the right, the left wheels FL, RL are driven forward at a higher speed than the right wheels FR, RR.

In this embodiment, as the controller 4, a stick controller having two sticks for individually controlling the right wheel motor MR and the left wheel motor ML is used. However, the present invention is not limited to this, and for example, a wheeler-type controller having a gun grip and a steering wheel may be used.

As shown in FIG. 5, when the pipe P is the minimum diameter pipe P01, the magnet unit 15 (U1) having the maximum projection amount Z (Z1) and the wheel 13 having the small diameter (Dw1) are attached to the travel device 1. Also, during running, the front light 65 and the back light 66 are turned on so that a clear image can be displayed on the display 3 even in the dark pipe P.

Since compressed air is not supplied to the travel device 1, the magnet unit 15 is positioned at the lowered position closest to the inner surface 5 of the pipe, as shown in FIG. Then, the magnet unit 15 attracts the inner surface 5 of the pipe facing thereto, and the traveling device 1 is pressed against the inner surface 5 of the pipe by the reaction force thereof, thereby attracting the inner surface 5 of the pipe.

Since the size of the magnet unit 15 (such as the size of the magnet 20) and the amount of protrusion Z are adapted to the minimum diameter pipe P01, the space between the magnet unit 15 (more specifically, the magnet 20) and the inner surface 5 of the pipe is optimal. Therefore, the attraction force (or down force) that presses the travel device 1 against the inner surface 5 of the pipe can be optimized. It is possible to suppress slippage of the wheels 13 and dropout of the traveling device 1 (for example, when the straight pipe P3 rises) due to insufficient attractive force, and increase in running resistance (or drag) and impossibility of running due to excessive attractive force.

The inner surface 5 of the pipe, which is the surface to be inspected, is a concave surface having an arcuate cross-section that separates from the magnet unit 15 as it approaches the vertical reference axis C1 in the vehicle width direction. Therefore, the gap between the magnet unit 15 and the inner surface 5 of the pipe varies depending on the position in the vehicle width direction.

As shown in FIG. 5, the inner diameter d1 of the minimum-diameter pipe P01 is large enough to allow the travel device 1 to just barely fit therein. Therefore, although the reference ground surface 16 of the wheel 13 is difficult to ground on the inner surface 5 of the pipe, the outer tapered ground surface 17 can be sufficiently grounded, so that the necessary traction can be reliably obtained.

As shown in FIG. 1, the traveling device 1 basically causes all the four wheels 13 to be grounded while adhering to the inner surface 5 of the pipe, and travels forward by obtaining propulsive force from all the wheels. After traveling along the inner bottom surface of the straight pipe P1, it travels along the outer corner portion of the elbow P2, and then travels upward along the straight pipe P3. After that, it travels along the inner corner portion of the elbow P4, and then travels toward the end point in the straight pipe P5.

At this time, especially when traveling on the inside corner of the elbow P4 (indicated by the phantom line in the figure), it may be difficult to bring all four wheels to the ground due to the sharp bend. However, in this embodiment, even in such a case, the driving force can be obtained by grounding the timing belt 100, and it is possible to reliably continue running.

Moreover, in this embodiment, since the support member 60 that supports the lower portion 55 of the timing belt 100 from above is provided, it is possible to suppress the bending of the timing belt 100 when it touches the ground, and to reliably obtain the propulsive force of the timing belt 100.

FIG. 14 shows a case where the traveling device according to the comparative example travels on the inner corner portion of the elbow P4 when the support member 60 is not provided. FIG. 15 shows the case where the traveling device 1 of the present embodiment with the support member 60 travels on the inside corner portion of the elbow P4.

In both figures, line a indicates the pipe inner surface 5 at the position of the wheel 13 in the vehicle width direction. A line b indicates the pipe inner surface 5 at the position of the vertical reference axis C1 in the vehicle width direction. O4 is the center of bend of elbow P4. Lines a and b are represented by arcs centered on O4. Since the pipe inner surface 5 is concave, the line b is located radially inside the line a.

In the comparative example shown in FIG. 14, front and rear wheels 13 (only left front wheel FL and rear wheel RL are shown) are in contact with line a. The lower portion 55 of timing belt 100 (only the left timing belt BL is shown) contacts line a and is flexed along line a. Therefore, as far as these points are concerned, not only the front and rear wheels 13 but also the timing belt 100 can be used to kick the inner surface 5 of the pipe and obtain a forward driving force.

However, in this case, the magnet unit 15 bites radially inward from the line b. This means that the magnet unit 15 comes into contact with the pipe inner surface 5 and is completely attracted to it, and the travel device cannot be moved forward. The state shown in the figure is impossible, and the magnet unit 15 touches the ground before both the front and rear wheels touch the ground, so one or both of the front and rear wheels are lifted off the road surface.

As described above, in the comparative example, the lower portion 55 of the timing belt 100 is freely bent along the line a, so that the magnet unit 15 hits the inner surface 5 of the pipe, resulting in a so-called tortoise state, which makes it impossible to run.

In contrast, in the case of the present embodiment shown in FIG. 15, such a situation can be prevented or suppressed. That is, even if the lower portion 55 of the timing belt 100 hits the line a and tries to bend, the support member 60 (only the left support member SL is shown) prevents or suppresses the bending. Accordingly, the lower portion 55 of the timing belt 100 is maintained substantially straight. As a result, the front wheel 13 and the lower portion 55 of the timing belt 100 are in contact with the line a, and the rear wheel 13 is lifted from the line a. As a result of setting the traveling device 1 in a rearward rising posture, the magnet unit 15 is prevented from biting inward in the radial direction from the line b, and the magnet unit 15 is separated radially outward from the line b to prevent the magnet unit 15 from being completely attracted to the inner surface 5 of the pipe. Therefore, the front wheel 13 and the lower portion 55 of the timing belt 100 kick the road surface, and the traveling apparatus 1 can be reliably propelled forward.

Moreover, since the timing belt 100 has the outer peripheral teeth 44, the jagged outer peripheral surface of the timing belt 100 is brought into contact with the road surface, and the outer peripheral teeth 44 positively kick the road surface, thereby increasing the driving force.

Further, even if there is a projection (including a step) on the road surface, by placing the lower part 55 of the timing belt 100 on the projection and preventing the deflection by the support member 60, the complete attraction of the magnet unit 15 to the projection can be suppressed or prevented, and the passage of the projection can be facilitated.

Further, even if the magnet unit 15 comes into contact with the road surface and is completely attracted to the road surface and becomes unable to travel, the magnet unit 15 can be separated from the road surface by operating the air cylinder 19, and the traveling device 1 can be forcibly separated from the road surface.

That is, as shown in FIG. 7, when the air pressure supply device is operated, compressed air is supplied to the rod side chamber 38 of the air cylinder 19, and the piston 31 is raised to the raised position. As a result, the magnet unit 15 is also lifted to the raised position, and the magnet unit 15 is forcibly separated from the pipe inner surface 5 and drawn toward the vehicle body 11 side. Then, the attraction force of the traveling device 1 to the road surface is significantly reduced, so that the traveling device 1 can be easily peeled off from the road surface. Thus, even if the traveling device 1 suddenly becomes unable to travel, the traveling device 1 can be immediately and easily recovered.

By the way, in this embodiment, when the type of pipe P to be inspected changes, the magnet unit 15 is replaced and, if necessary, the wheel 13 is also replaced in order to maintain the attractive force of the traveling device 1 optimally.

For example, when the pipe P is changed from the minimum diameter pipe P01 to the intermediate diameter pipe P02 as shown in FIG. 10, the magnet unit 15 is also changed from the minimum diameter pipe magnet unit U1 to the intermediate diameter pipe magnet unit U2. At this time, the magnet unit U1 can be easily removed only by gripping the portion of the case 22 of the magnet unit U1 protruding from the vehicle body bottom surface 35 and rotating the magnet unit U1 in the direction of loosening the male screw shaft 25.例文帳に追加After that, the magnet unit U2 can be easily attached by simply holding the case 22 of the magnet unit U2 and rotating the magnet unit U2 so as to tighten the male screw shaft 25 into the female screw hole .

Since the magnet unit 15 is connected to the piston rod 32 by the screws 25 and 34 coaxial with the piston rod 32 in this way, the magnet unit 15 can be replaced easily and quickly.

When attaching the magnet unit U2, one or more washers may be fitted around the male screw shaft 25, and then the male screw shaft 25 may be tightened into the female screw hole 34, and the washer may be interposed between the holder 21 and the piston rod 32. In this way, the protrusion amount Z of the magnet unit U2, the distance between the magnet unit U2 and the pipe inner surface 5, and the attractive force of the travel device 1 can be finely adjusted.

Similarly, when the pipe P is changed from the minimum diameter pipe P01 to the maximum diameter pipe P03 as shown in FIG. 11, the magnet unit 15 is replaced from the minimum diameter pipe magnet unit U1 to the maximum diameter pipe magnet unit U3. Also at this time, the magnet unit 15 can be replaced very easily as described above.

At this time, the wheel 13 is also replaced from the wheel 13 with a small diameter (Dw1) to the wheel 13 with a large diameter (Dw2). At this time, as shown in FIG. 9 , the bolt 48 fixing the small-diameter wheel 13 is removed, and the small-diameter wheel 13 is removed from the timing pulley 41 . After that, the large-diameter wheel 13 is attached to the timing pulley 41 using the bolt 48 . Thus, the replacement work of the wheel 13 is also very easy.

In addition, the mounting method of the wheel 13 is not restricted to the above. For example, a center lock system or the like may be adopted in order to perform wheel replacement work more quickly.

As described above, in the traveling device 1 of the present embodiment, the magnet unit 15 can be replaced with one having a different size according to the type of the pipe P. Therefore, even if the pipe P to be inspected is changed and its shape is changed, the distance between the magnet unit 15 and the inner surface 5 of the pipe can be maintained at an optimum size as shown in FIGS.

In addition, in the traveling device 1 of the present embodiment, the wheels 13 can also be replaced with those of different sizes according to the type of the pipe P, so coupled with the replacement of the magnet unit 15, the interval between the magnet unit 15 and the inner surface 5 of the pipe can be kept at an optimum size. Then, the attraction force of the travel device 1 can be maintained at an optimum level.

Incidentally, in this embodiment, as shown in FIGS. 5, 10, and 11, as the inner diameter d of the pipe P increases, the curvature of the inner surface 5 of the pipe between the left and right wheels 13, that is, the concave surface becomes looser, and the concave surface tends to approach the magnet unit 15. Therefore, in accordance with this tendency, the projecting amount Z of the magnet unit 15 is decreased as the inner diameter d of the pipe P is increased.

Also, if the small-diameter wheels 13 are used in the maximum-diameter pipe P03 as shown in FIG. 11, even if the maximum-diameter pipe magnet unit U3 is used, the magnet unit U3 may come too close to the concave surface. A large diameter wheel 13 is therefore used to keep the magnet unit U3 away from the concave surface. Thus, the outer diameter Dw of the wheel 13 tends to increase as the inner diameter d of the pipe P increases.

Although not shown, the travel device 1 may be used to inspect the outer surface 6 of the pipe P (see FIG. 1). In this case, the shape of the pipe outer surface 6 between the left and right wheels 13 becomes a convex surface opposite to the above, and the tendency is opposite to the above. As the outer diameter of the pipe P increases, the protrusion amount Z of the magnet unit 15 tends to increase and the outer diameter Dw of the wheel 13 tends to decrease.

Although the embodiments of the present disclosure have been described in detail above, various other embodiments and modifications of the present disclosure are conceivable.

(1) For example, the magnet unit 15 may be indirectly connected to the air cylinder 19 via a link mechanism or the like. By doing so, the degree of freedom in layout of the air cylinder 19 can be increased.

(2) The threads connecting the magnet unit 15 and the piston rod 32 may be reversed. For example, the magnet unit 15 may be provided with a female thread and the piston rod 32 may be provided with a male thread.

(3) The magnet unit 15 and the piston rod 32 may be connected by a method other than screw connection. For example, a shaft provided on one side may be slide-inserted into a hole provided on the other side, and the shaft may be fixed in the hole by a stopper screw.

(4) If possible, only the right front and rear wheels FR and RR may be connected by the timing belt 100, or only the left front and rear wheels FL and RL may be connected by the timing belt 100. The support member 60 can also be provided only on one side where the timing belt 100 is located. In addition to the left and right front and rear wheels described above, separate front and rear wheels may be provided, and the separate front and rear wheels may be connected by a timing belt. A supporting member corresponding to this timing belt may be provided.

(5) In the above embodiment, the inner and outer teeth 43 and 44 of the timing belt 100 have the same number of teeth.

(6) By the way, according to the present disclosure, it is possible to comprehend a traveling device that does not require the exchangeability of the magnet unit 15 as an essential component. Therefore, according to another aspect of the present disclosure, for example, the following traveling device is provided.

(i) A traveling device that travels on the surface of the object to be inspected for non-destructive inspection of the object to be inspected, comprising: a vehicle body; an inspection unit mounted on the vehicle body; wheels rotatably provided on the vehicle body; a motor that drives the wheels; A traveling device comprising:

(ii) A traveling device for traveling on the surface of the object to be inspected for non-destructive inspection of the object to be inspected, the traveling device comprising: a vehicle body; an inspection unit mounted on the vehicle body; wheels rotatably provided on the vehicle body; a motor for driving the wheels;

(iii) A traveling device for traveling on the surface of the object to be inspected for non-destructive inspection of the object to be inspected, comprising: a vehicle body; an inspection unit mounted on the vehicle body; wheels rotatably provided on the vehicle body; a motor for driving the wheels; A traveling device characterized by:

Embodiments of the present disclosure are not limited to the above-described embodiments, and include all modifications, applications, and equivalents included in the concept of the present disclosure defined by the claims. Accordingly, the present disclosure should not be construed in a limited manner, and can be applied to any other technology that falls within the spirit of the present disclosure.

1 traveling device 5 inner surface 6 outer surface 11 vehicle body 12 inspection unit 13 wheel 14 motor 15 magnet unit 17 tapered contact surface 20 magnet 25 male screw shaft 30 cylinder body 32 piston rod 34 female screw hole 35 bottom portion 43 inner peripheral tooth 44 outer peripheral tooth 60 support member 100 timing belt P pipe BR right timing belt BL left timing belt SR right support member SL left support member

Claims (9)

A traveling device that travels on the surface of an object to be inspected for non-destructive inspection of the object to be inspected made of a magnetic material ,
a vehicle body;
an inspection unit mounted on the vehicle body;
wheels rotatably provided on the vehicle body;
a motor that drives the wheel;
a magnet unit disposed on the bottom surface of the vehicle body with a gap from the inspection object and including a magnet;
with
The traveling device, wherein the magnet unit can be exchanged for a different size depending on the shape of the inspection object. 2. The traveling apparatus according to claim 1, further comprising a fluid pressure cylinder fixed to the vehicle body and detachably connected to the magnet unit, for raising the magnet unit away from the inspection object when pressure fluid is supplied. The fluid pressure cylinder is arranged with the piston rod protruding from the cylinder body facing downward,
The traveling device according to claim 2, wherein the magnet unit is coaxially and detachably connected to the piston rod. The travel device according to claim 3, wherein the magnet unit is connected to the piston rod by a screw coaxial with the piston rod. The traveling device according to any one of claims 1 to 4, wherein the wheels can be exchanged for different sizes according to the inspection object. The traveling device according to any one of claims 1 to 5, wherein the wheel has a tapered contact surface on its outer side surface. The wheels are provided in front and rear of the vehicle body,
The traveling device according to any one of claims 1 to 6, wherein the traveling device includes a timing belt that connects a front wheel and a rear wheel. 8. The travel device according to claim 7, further comprising a support member that supports the lower portion of the timing belt from above. The traveling device according to claim 7 or 8, wherein the timing belt has inner peripheral teeth and outer peripheral teeth.

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