JPS5823269B2 - Running wheel device for in-service trolleys - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a running wheel device for a bogie running in a pipe, and more particularly to a running wheel device for stably moving a bogie running in a steel pipe for various purposes.

For example, there are various types of carts that run inside steel pipes, such as internal clamping devices used when welding butts of pipes, machines for painting or cleaning the inner surface of pipes, X-ray inspection machines, and TV camera carts. It has a trolley structure and can be driven within the pipe by itself or pulled by a drive device outside the pipe.

Conventionally, this kind of in-pipe running bogie has been equipped with a number of free or driven wheels that rotate radially around the outer periphery of the bogie body and in contact with the inner wall of the pipe, or one with three or more running wheels on the bottom of the bogie body. Many structures with similar structures are used.

However, in the former type, in which the wheels are mounted radially from the main body of the trolley, in order to keep the wheels in constant contact with the inner surface of the tube, it is necessary to adjust the wheels in the radial direction of the tube in accordance with changes in the tube diameter. It is also disadvantageous in terms of space and equipment.

On the other hand, with the latter type with wheels installed at the bottom, it is difficult to balance the left and right weight when traveling inside the pipe, and the cart rotates in the circumferential direction of the pipe.
Stable running may not be possible, and there is a risk of damage to the inner surface of the pipe or equipment.

Moreover, when it is necessary to center the tube, the entire cart must be lifted parallel to the tube axis, which is a difficult task and also results in poor centering accuracy.

The present invention solves the problems of conventional trolleys that travel within pipes, and allows the main body of the trolley to run stably within the pipe without rotating.
To provide a wheel device for an in-pipe traveling truck that does not damage various equipment and the inner surface of a pipe, allows easy centering work, and has high accuracy.

The running bogie of the present invention has one running wheel at the rear upper part of the bogie body, and two front wheels at the front lower part of the bogie body at a position close to the center of gravity of the bogie body or at a position where a large downward load due to its own weight is applied. It is characterized by being installed at a slight inclination in the direction in which it opens with respect to the direction in which the trolley travels.

As a result, the trolley running inside the pipe can run stably, with its three wheels correctly contacting the inner surface of the pipe and rotating, and the amount of rotation of the main body of the trolley in the circumferential direction of the pipe being small, so that the position of the trolley within the pipe remains almost constant. Become.

The details of the present invention will be explained below based on embodiments shown in the drawings.

FIGS. 1 and 2 are examples of the traveling trolley of the present invention, and 1
2 is the tube on which the trolley runs, and 2 is the main body of the trolley that incorporates the desired equipment (clamping, painting, inspection, etc.).
A wire or rope is connected to a connecting metal fitting 6 provided on one end side, and it is pulled in the direction of the arrow by a winch or the like.

Reference numeral 3 denotes one support roller provided at the rear upper part of the main body on the side opposite to the direction of travel of the cart, 4 a pair of running rollers arranged at the lower part near the front of the main body on the side in the direction of travel of the cart, and 5 the hanging bracket of main body 2. It is.

The center of gravity W of the bogie body 2 is positioned in front of the pair of front side wheels 4 as shown in the figure, and when the bogie is located inside the pipe, the axis a of the bogie body 2 is aligned with the pipe as shown in FIG. The front part is tilted downward by an angle θ3 from the center line of 1, so that a small upward load is constantly applied to the support roller 3, and a large downward load due to its own weight is applied to the running roller 4,
It is strongly pressed against the inner wall of the pipe.

Further, as shown in FIG. 2, the pair of running rollers 4 are pivotally supported by the main body 2 so as to be symmetrical with respect to the vertical line at an angle θ1.

This angle θ1 is maintained within a range of approximately 30 to 45 degrees.

Further, the running roller 4 is attached to the main body 2 so as to be inclined at an angle θ2 in an open direction with respect to the running direction of the trolley.

That is, when viewing the running roller 4 from the direction in which the bogie runs,
As shown in Figure 3, the bottom surface of the roller is slightly visible.
In other words, the roller is mounted by being rotated counterclockwise by an angle θ2 from the state in which the rotational direction of the roller is normally parallel to the truck axis in FIG.

Giving the angle θ2 to the running roller 4 in this way means that
The function of this running roller and the preferred range of the angle θ2 will be described later, which is extremely important for stable running of the truck.

Note that in the illustrated example, the upper support roller 3 and the running roller 4 are not driven, and the cart is moved using a separate winch or the like, but the present invention is not limited to this. It can also be self-propelled with one drive roller.

Next, the operation of the traveling trolley of the present invention will be explained.

While the trolley is running in the pipe, if for some reason the left and right balance in the circumferential direction of the pipe is lost and the trolley body 2 begins to rotate to one side, it will rotate clockwise (arrow A) as shown in Figure 6, for example.
, the right roller 4a moves to the lower position of the tube and the left roller 4b moves to the lateral position.

Therefore, the weight of the truck body 2 is mainly applied to the one roller 4a that has moved to the lower part.

In this state, no load or only a small load is applied to the other roller 4b.

Since the running roller 4 is given the inclination angle θ2 as described above, the load mainly acts on one roller 4a.
As the trolley advances, it moves in the opposite direction BK to the direction A in which it had been rotating along this angle θ2, and a force acts to return it to its original position, returning it to a state of left-right balance. .

In Fig. 4, the rotation of the trolley body is excessively increased in order to make it easier to understand the function of the traveling roller 4, but in reality, even if the balance between the left and right rollers is lost, there will be a difference in the loads on the left and right rollers, as described above. As a result, a return force acts in the opposite direction to the rotating direction of the truck body.

This running cart rotates in one direction, does not fall over, and runs stably.

The inclination angle θ2 of the running roller 4 needs to be maintained in the range of 1 to 8 degrees in order to perform the above-mentioned effect, and an angle of 3 to 4 degrees is particularly preferable to maximize the effect. It is.

If the angle is less than 1 degree, there will be no force to restore the trolley to its original position when it begins to rotate while running, and if it exceeds 8 degrees, running resistance will increase and unreasonable force will be applied to the running, making it unstable. So I don't like it.

If you still want to stop the cart at a predetermined position and center it, the first
In the figure, if a clamp arm is appropriately extended in the pipe radial direction from the front part of the roller 4 on the truck body 2, the truck body 2 can be centered simply by swinging at an angle corresponding to θ3, which makes this work easier. It is easy and has high centering accuracy.

The effects obtained by the present invention are as follows.

(1) With fewer wheels, the amount of rotation is small and no undue force is applied to the device, allowing for stable running.In addition to the running wheels, there is no need for auxiliary wheels to prevent falls or springs for pressing, which reduces costs. is cheap and extremely practical.

(2) Since each of the three wheels reliably runs in contact with the inner wall of the pipe, the position of the cart relative to the pipe remains constant, making positioning easy and accurate.

(3) Since the center of gravity of the bogie body is located in front of the front wheels, even if the center of gravity of the bogie body protrudes from the tube end, the bogie can be held by the inner wall of the tube (convenient for inspecting the equipment), and it is also easy to move in and out of the tube. The main body can be inserted while suspended at a single point at the center of gravity, eliminating the need for a cradle or the like.

(4) Since it does not rotate or fall inside the pipe, it can be used in equipment that requires horizontal maintenance, such as hydraulic equipment, and it can also be used without twisting ropes, cables, and hoses connected to the outside of the pipe.

(5) The inclination of the trolley body can be changed by adjusting the mounting height of the rear upper wheel, making it easier to center.

(6) There is little rotation of the device, there is no risk of damage to the device or tube body, and there is no need to correct the position, improving work efficiency.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of the running truck of the present invention, FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1, FIG. 3 is an enlarged view of the running roller in FIG. 2, and FIG. It is a schematic diagram without detailed explanation. 1... Steel pipe, 2... Bogie body, 3...
...Support roller, 4...Travel roller, 5.
...Hanging fittings, 6...Connecting fittings.

Claims (1)

[Claims] 1. In a wheel device for an in-pipe traveling truck that has floating or driven wheels in contact with the pipe inner wall and moves in the direction of the pipe axis,
Two wheels placed at the bottom of the truck on the side in the direction of travel and one wheel placed on the top of the truck on the rear side in the direction of travel are positioned so that the center of gravity of the truck body is further forward than the front lower wheel position. Also, a running wheel device for a running bogie in a pipe, characterized in that the front lower wheel is mounted with a slight inclination in an opening direction with respect to the moving direction of the bogie.