JP2804180B2 - Vacuum adsorption self-propelled trolley - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-propelled trolley that can be vacuum-adsorbed on an inner wall surface of a large-diameter pipe or the like and can move along the wall surface.

[0002]

2. Description of the Related Art As a device capable of adsorbing and moving on a vertical or inclined wall such as a hull or an oil storage tank,
For example, as disclosed in Japanese Utility Model Publication No. 57-56943, a pressure receiving body, a plurality of wheels installed on the pressure receiving body and in contact with a wall, and at least a free end mounted on the pressure receiving body and having a free end contacting the wall. There is known an apparatus comprising vacuum generating means for discharging air from a decompression region defined by a suction pad formed of a flexible material.

[0003] In such an apparatus, the fluid pressure acting on the pressure receiving body due to the pressure difference between the fluid inside and outside the depressurized region is transmitted to the wall surface via the wheel by the action of the vacuum generating means, or the pressure receiving body is The device is attracted to the wall by pulling it with a cylinder and pressing the wheel against the wall as a reaction force. The pressure receiving body is usually arranged at the center of the front and rear wheels. Further, the above-described device has a driving unit such as an electric motor, and the driving unit can drive the wheels while adsorbing the wall surface.

[0004]

However, the above-mentioned known devices have the following problems.

[0005] First, when ascending and traveling on a curved surface such as a 90-degree elbow having a bent portion (generally called a shrimp joint), since the pressure receiving body is disposed at the center of the front and rear wheels, the bent portion is formed. Before and after passing, the load directions acting on the front and rear wheels reverse (the upward load acts on the front wheels and the downward load acts on the rear wheels, respectively). If the frictional force of the bent portion is not increased, the bent portion cannot travel upward.

Second, when the suction pad is made of an inflexible material when passing over a convex portion (for example, a weld seam, that is, a weld bead) uniformly formed in the wall surface, The free end of the pad is not flexible enough to get over the protrusion, so it becomes an obstacle and cannot pass. Conversely, if the suction pad is made of a rather flexible material, the amount of fluid that rolls up and flows in from the outside of the decompression region when the free end of the suction pad goes over the protrusion. And the pressure in the decompression region rises, so that the device cannot be adsorbed on the wall surface.

Third, when passing straight (in a direction crossing at right angles) on a convex portion (weld bead, etc.) in the wall surface, the pressure in the depressurized region is maintained considerably low regardless of the material of the suction pad. In this case, the free end of the suction pad is pressed considerably strongly against the wall surface due to the pressure difference between the fluid inside and outside the pressure reduction region. For this reason, the frictional force between the free end portion of the suction pad and the wall surface increases, and the pad passes over the convex portion in such a state, so that it is difficult to get over the convex portion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to be able to smoothly climb up a curved surface such as a 90-degree elbow and to stably move on a uniform convex portion in the curved surface. It is an object of the present invention to provide a vacuum suction self-propelled trolley that can move smoothly while adsorbing with a reduced suction force.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a pair of frames to which a front wheel and a rear wheel are attached, respectively, are arranged on both sides of a bogie body, and one of the frames is fixed. The other frame is rotatably mounted via a bearing, and one or more pressure receivers are installed at a position near the front wheel in the moving direction of the bogie main body, and the pressure receiver is fixed on the bogie main body. It is configured to be connected to the rod end of the cylinder.

[0010]

In the vacuum suction self-propelled trolley having such a configuration, one of the pair of frames attached to the trolley body is fixed, and the other is rotatable via a bearing. The front wheel and the rear wheel attached to each frame can always move following the bending of the wall surface. Further, since the pressure receiving member is installed at a position closer to the front wheel side in the moving direction of the bogie, the pressing force acting on the front wheel is larger than that of the rear wheel. Therefore, when the vehicle runs vertically on a bent portion such as a 90-degree elbow, the force acting on the front wheel is larger even if the load direction acting on the front wheel and the rear wheel is reversed before and after passing through the bent portion. Therefore, the influence of the rear wheels can be reduced, and a smooth climbing can be performed.

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing an example of the configuration of a vacuum suction self-propelled truck according to the present invention, FIG. 2 is a plan view, and FIG. 3 is a side view. As shown in FIGS. 1 to 3, a pair of frames 2 a and 2 b are arranged on the left and right side surfaces of the bogie main body 1, and one of the frames 2 a is attached to two places of the bogie main body 1 by bolts 3 and the other frame 2 b Is rotatably mounted at one position on the carriage body 1 via a bearing 4. Wheels 5a and rear wheels 5b are provided at front and rear ends of the pair of frames 2a and 2b.
Motors 6 for driving these wheels are respectively mounted. An elliptical plate-shaped pressure receiving main body 7 made of a rigid or semi-rigid material such as a steel plate is provided at the front of the frames 2a and 2b. The pressure receiving body 7 has a suction pad 8 attached to the periphery thereof, and the rod ends of two large cylinders 9 fixed to the carriage body 1 and the tension plate 10.
Are connected via A flexible hose 12 is connected to the center of the pressure receiving main body 7 through an exhaust pipe 11, and penetrates through the bogie main body 1 and is connected to an exhaust device (not shown).

At the front and rear ends of the suction pad 8 of the pressure receiving main body 7, a plurality of small cylinders 13 are installed via push plates 14, respectively.
Are connected to the free end of the で by a string 15 or the like. The casters 16 are fixed to the rod ends of the small cylinders 13.

Next, the operation of the vacuum suction self-propelled truck constructed as described above will be described.

Here, the operation when the vehicle travels vertically up a bent portion such as a 90-degree elbow will be described with reference to FIG.
Are located at the center of the frames 2a and 2b and on the front wheel side, respectively. FIGS. 4 (a) to 4 (c) are vertical rising traveling diagrams when the pressure receiving main body 7 is located at the center of the frames 2a and 2b, and FIGS.
FIG. 2B shows a vertical ascending traveling diagram when the vehicle is on the front wheel side of FIG. In order for the vacuum suction self-propelled truck to travel on the wall surface of the bent portion, the vertical position of the pressure receiving main body 7 and the suction pad 8 is adjusted so that the large cylinder 9 can follow the wall surface 17.

First, when the pressure receiving body 7 is located at the center of the frames 2a and 2b, the front wheel 5a and the rear wheel 5b are respectively used as the reaction force of the tensile force Fc of the large cylinder 9 in FIG.
7 is pressed vertically by the forces of Fa and Fb. in this case,
Since the forces of Fa and Fb are set at the center of the frames 2a and 2b as fulcrums, the front wheels 5a and the rear wheels 5b act on the walls as equal loads. When the pressure receiving main body 7 comes to the center of the bent portion as shown in FIG. 4B, the pressing force Fa of the front wheel 5a is divided into a force Fa1 perpendicular to the wall surface 17 and a force 2Fa parallel to the wall surface and upward. . On the other hand, rear wheel 5
The pressing force Fb of b is also divided into Fb1 and Fb2. At this time, the driving force of the front wheel 5a is Fa1 × μ + Fa2,
The driving force of b can be expressed as Fb1 × μ−Fb2. Here, μ is the friction coefficient of the wheel. Therefore, the front wheel 5
The sum of a and the driving force of the rear wheel 5b, that is, the total driving force F (b) of the device can be expressed as F (b) = (Fa1 × μ + Fa2 ) + (Fb1 × μ− Fb2 ). At this time, Fa2 = Fb2. Similarly, the total driving force F (c) of the device when the pressure receiving main body 7 passes through the center of the bent portion as shown in FIG. 4 (c) is also F (c) = (Fa1 × μ + Fa2 ) + ( Fb1 × μ− Fb2 ). In this case, since the fulcrum position and the ground contact position of the front wheel 5a are on the same inclined surface, the downward force acting on the rear wheel 5b is lower than the upward force acting on the front wheel 5a. The power is greater. That is, since Fa2 <Fb2, the driving force and
If you do not increase the frictional force between the wheel and the wall,
You cannot run uphill.

On the other hand, the pressure receiving main body 7 has the frame 2a,
If it is on the front wheel side of 2b, that position is used as a fulcrum.
Therefore, as shown in FIGS. 4 (d), (e) and (f), the front wheels
The force Fa is always applied to the rear wheel 5 so that 5a presses the wall surface 17 vertically.
b is greater than the force Fb for vertically pressing the wall 17
You. Accordingly, after the pressure receiving body 7 has passed through the bent portion, FIG.
(E) and (f), the upward force acting on the front wheel 5a
Is greater than the downward force acting on the rear wheel 5b, and the vehicle can smoothly travel vertically upward at a bent portion.

A plurality of small cylinders 13 installed at the front and rear ends of the suction pad 8 fixed around the pressure receiving body 7
Always presses down the free end of the suction pad 8 via the pressing plate 14, so that when the suction pad 8 passes over the welding bead 18, the free end does not roll up to the outside, and It can move following irregularities. In addition, since the casters 16 are provided at the rod ends of the plurality of small cylinders 13, the frictional force between the free end of the suction pad 8 and the wall surface is reduced, and the stable running without damaging the wall surface 17 is achieved. It is possible to move by force.

Further, as shown in FIG. 5 (b), in order for these casters 16 to get over the welding bead 18 well, the traveling direction of the bogie is changed obliquely by Θ with respect to the welding bead 18. Thus, the vehicle can smoothly travel on the convex portion. Here, FIG. 5 is a traveling diagram showing the direction in which the pressure receiving body 7 moves forward with respect to the welding bead 18, and FIG. The case where the forward direction is a right angle is shown. In this case, since the free end of the tip of the suction pad 8 of the pressure receiving body 7 crosses the welding bead 18 at a right angle,
Receive great resistance. On the other hand, as shown in FIG. 5B, the pressure receiving body 7 is changed by changing the left and right rotation speeds of the front and rear wheels 5a, 5b.
When the bogie main body 1 is curved and advanced so that the main body 1 is inclined by an angle of Θ, the free end of the tip of the suction pad 8 can pass over the welding bead 18 with a small resistance. As shown in FIG. 5, when the pressure receiving main body 7 is mounted on the bogie main body 1, the pressure receiving main body 7 is attached at an angle of Θ degrees with respect to a direction orthogonal to the traveling direction of the bogie main body 1, and the bogie main body 1 is advanced. As described above, the free end of the tip of the suction pad 8 can cross the welding bead 18 with a small resistance.

As described above, in this embodiment, one of the pair of frames 2a and 2b is fixed to the side surface of the bogie main body 1 at two places, and the other is rotatably mounted via the bearing. The front wheel 5a and the rear wheel 5b on the side of the frame 2b which are mounted via the inner wall can always move following the bending of the wall surface 17, so that three wheels out of the four are always mounted on the wall surface 17.
Ground, and stable running is possible. In addition, since the pressure receiving main body 7 is provided on the front end side of the frames 2a and 2b, the pressing force acting on the front wheel 5a is larger than that of the rear wheel 5b.

Therefore, when the vehicle travels vertically up a bent portion such as a 90-degree elbow, the front wheel 5 is moved before and after the passage.
Even if the load direction acting on the rear wheel 5b is reversed, the force acting on the front wheel side is larger, so that the influence of the rear wheel 5b can be reduced, and a smooth climbing run is possible.

Also, a plurality of small cylinders 13 installed around the pressure receiving body 7 and at the front and rear ends of the suction pad 8 always press the free end of the suction pad 8 downward through the pressing plate 14. Therefore, even if the suction pad 8 is formed of a material having considerable flexibility, the suction pad 8 does not turn up, and follows the unevenness of the wall surface 17 while adsorbing on the welding bead 18 in the wall surface with a stable suction force. It is possible to move. In addition, by changing the pressure of these small cylinders 13, the pressing pressure can be adjusted.

Since the casters 16 are provided at the rod ends of the plurality of small cylinders 13, the frictional force between the free end of the suction pad 8 and the wall surface is reduced, and the wall surface is stable without being damaged. The wall surface 17 can be moved while maintaining the running force. Further, in order for these casters 16 to get over the projections of the welding beads 18, the traveling direction of the bogie body 1 is changed to the welding beads 1.
By changing the convex portion 8 in the oblique direction by Δ, the vehicle can smoothly travel on the convex portion.

[0024]

As described above, according to the present invention, 90
Vacuum suction self-propelled bogie that can smoothly run up even on curved surfaces such as elbows and can move smoothly while adsorbing on a stable convexity on a curved surface with a stable suction force Can be provided.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a plan view of the embodiment.

FIG. 3 is a side view of the embodiment.

FIG. 4 is an explanatory diagram of a traveling process in which the bogie moves vertically up a bent portion in the embodiment.

FIG. 5 is a traveling diagram showing the direction in which the pressure receiving body advances with respect to the welding bead in the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bogie main body, 2a, 2b ... Frame, 3 ... Bolt, 4
... bearings, 5a, 5b ... front and rear wheels, 6 ... motor, 7 ... pressure receiving body, 8 ... suction pad, 9 ... large cylinder, 10 ... tension plate, 11 ... exhaust pipe, 12 ... flexible hose, 13 ...
Small cylinder, 14 ... push plate, 15 ... string, 16 ... caster.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Urakami 4-17-17 Konandai, Konan-ku, Yokohama-shi, Kanagawa Prefecture Inside the Research Laboratory of Urakami Co., Ltd. (72) Hiroshi Nagashima 4--17 Konandai, Konan-ku, Yokohama, Kanagawa Prefecture No. 24 Inside the Urakami Technical Research Institute Co., Ltd. (56) References JP-A-50-59138 (JP, A) JP-A-52-75758 (JP, A) JP-A-59-184071 (JP, A) 2-85080 (JP, A) JP-A-2-95989 (JP, A) JP-A-61-183786 (JP, U) JP-A-57-56943 (JP, Y2) (58) Fields investigated (Int. Cl. ⁶ , DB name) B62D 57/024

Claims (1)

(57) [Claims] 1. A pair of frames each having a front wheel and a rear wheel mounted thereon are arranged on both side surfaces of a bogie main body, one of the frames is fixed, and the other frame is rotatably mounted via a bearing. Installing one or more pressure receivers at a position near the front wheel in the direction of movement of the bogie body,
A vacuum suction self-propelled trolley, wherein the pressure receiving body is connected to a rod end of a cylinder fixed on the trolley body.