JPH0227078B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a device for working on the inner surface of a tube, and more particularly to a device that travels on the inner surface of a tube to perform work.

It has been difficult to work inside small-diameter pipes, and the situation has been almost impossible. This is because it is difficult to enter the limited narrow space inside the pipe, the installation conditions such as the inclination of the pipe are not constant, the ability of the pipe running device to adapt to the pipe diameter and bending is poor, and the work is necessary. This is caused by the difficulty of holding stable equipment and tools. Although various efforts have been made to solve these problems, there are few examples of vehicles that can adaptively travel within pipes to perform work.

This will be explained below using an example of pipe welding work. Pipe welding work generally involves beveling,
These include groove alignment, tacking, first layer welding, and subsequent welding of the required number of layers.

Incidentally, it is important that the weld metal and the base metal have as smooth a shape as possible in order to reduce stress concentration. However, in the case of pipes, there are problems with the pipe diameter, the distance from the pipe end to the groove, and maintaining the center, and it is often impossible to weld from the inside of the pipe. It is necessary to obtain a smooth bead with no defects on not only the outer surface of the tube but also the inner surface of the tube by welding from the welding process.
For this reason, attempts are being made to solve the above problem by producing a Uranami using the Uranami welding method for the inner bead, but at present, it is technically difficult to weld from the outer surface of the tube to produce a uniform Uranami. It is difficult and requires a great deal of dedication. Furthermore, polishing, cleaning, and other operations cannot be performed from the outside of the pipe, making it extremely difficult to obtain a welded pipe of good quality.

[Object of the Invention] In view of the above-mentioned problems, an object of the present invention is to provide a pipe inner surface working device that enables work inside a pipe.

[Summary of the Invention] In the present invention, the characteristics of a triangle are as follows: (1) A line (median line) connecting the midpoints of two sides (hypotenuses) is always parallel to the other side (base), and 1/2 The above objective is achieved by utilizing the following facts: (2) If the hypotenuse is a constant length, the height increases as the angle between them becomes smaller.

That is, in the present invention, rolling elements are arranged at the portions corresponding to the vertices of the triangle, and the portions corresponding to the bases are made expandable and retractable, and between the link frames forming the portions corresponding to the hypotenuses, By installing a clamping force generation mechanism that applies a biasing force in the direction of narrowing the clamping angle formed by these link frames, a running body that can respond to changes in pipe diameter is realized. By holding the working equipment between the midpoints, the working equipment is always maintained at the center of the pipe, thereby keeping the distance between the working tool and the inner surface of the pipe constant, thereby ensuring stable work.

[Embodiments of the Invention] The present invention will be described below with reference to embodiments shown in the drawings. The present invention is disclosed in Japanese Patent Application Laid-Open No. 59-109456.
This method utilizes the mechanism of the intraductal moving device disclosed in No. 59-109470 and No. 59-109470.

1 and 2 show a side view and a front view of a tube inner surface working device 1 according to the present invention, and FIG. 3 is a diagram showing the mechanism of the device 1. FIG.

The machine frame 2 of this pipe inner surface working device 1 has four link frames 2a, 2b, 2c, 2d connected to pins 3a,
It has a so-called pantograph structure in which it is rotatably connected to each other by 3b, 3c, and 3d. Ball-shaped rolling elements 4a and 4b are disposed at one end of each of the link frames 2a and 2b, and a roll-shaped rolling element 4c is disposed on a pin 3c that is a pair of the link frames 2c and 2d. is supported. Further, in this machine frame 2, a tension spring 5 is interposed between link frames 2c and 2d, and a housing 6 of a working device (a welder in the embodiment) is installed in the link frames 2a and 2b. It is located in the middle of the height H of the frame 2.

This housing 6 has a rotating shaft 7,
A torch 8 and a sensor 9 are arranged on the head 7a at the tip thereof in a direction perpendicular to the axis. The torch 8 and sensor 9 are moved to the head 7a via a moving mechanism consisting of, for example, a pinion and a rack.
is maintained.

The operation of the pipe inner surface working device 1 will be explained below.
The configuration will also be explained in more detail.

In this device 1, the machine frame 2 has a pantograph structure, and a spring 5 is arranged between the link frames 2c and 2d, so that the rolling elements 4a, 4b, 4c are always urged outward in FIG. has been done. Therefore, the rolling elements 4a, 4b, 4c are always in contact with the inner surface of the tube A, and the machine frame 2 is maintained in the diametrical direction of the tube A.

That is, in this device 1, a pantograph structure is adopted for the machine frame 2, and in the pantograph structure, as shown in FIG. 3, the link frame 2b is parallel to the extension line 2a' of the link frame 2d. , and the link frame 2a is parallel to the extension line 2b' of the link frame 2c. Furthermore, since the link frames 2a' and 2b' have the same length as 2a and 2b, the machine frame 2 is substantially equal to an isosceles triangle with hypotenuses of 2d and 2a' and 2c and 2b', respectively.

Further, the housing 6 of the working equipment installed in the machine frame 2 is always maintained at the center of the pipe A because it is arranged along the median line m of the isosceles triangle shown in FIG.

Furthermore, in this device 1, the sensor 9 and the torch 8
and move on the same plane, the position of the sensor 9 in the tube axis direction corresponds to the position of the torch 8, and the amount of protrusion of the sensor 9 in the radial direction of the tube A corresponds to the amount of protrusion of the torch 8. Therefore, the sensor 9 detects the groove 11.
Welding work can be performed by rotating the torch 8 along the groove 11 while or immediately after the detection.

In the above embodiment, the sensor 9 and the torch 8 are arranged on the same straight line, but the sensor 9 and the torch 8 may be arranged in a certain relationship, for example, offset by a certain distance, or the torch 8 may be arranged on the same straight line. It may be arranged so that it rotates independently.

Further, although the machine frame 2 in the above embodiment has a pantograph structure, it is of course possible to adopt a triangular structure as shown by the two-dot chain line in FIG.

Further, in the above embodiments, a welding device is shown as the tube inner surface working device, but it goes without saying that the present invention can be applied to other working devices such as a tube inner surface cleaning device, a tube inner surface polishing device, and the like. Furthermore, the structure shown in FIGS. 4 and 5 can be adopted as the working device depending on the shape and size of the attachment. Both have bodies 12, 13 and car frames 14, 15 added to the structure shown in FIG. 1, and link frames 2a, 2b are of equal length and rotate in opposite directions via a gear 16. Similarly, the link frames 2c and 2d have the same length and rotate in opposite directions via the gear 16. Therefore, the bodies 12 and 13 always move on the same straight line. In other words, the pantograph composed of the link frames 2a, 2b, 2c, and 2d moves the bodies 12 and 13 on the same axis by deforming itself, so the height of the traveling device can be easily adjusted, and the pipe diameter It is suitable for realizing a device that can adapt to a wide range of changes. In FIG. 4, one end of the body 12 is fixed at a right angle to the center of the vehicle frame 14, and even if the pantograph is deformed, the triangle connecting the three wheels remains an isosceles triangle, similar to the structure in FIG. 1. m in the figure is 1/ of the height of the traveling device.
This is the line indicating the location of point 2, and the positioning sensor is placed on this line.
If a rotatable torch is loaded, these are automatically held in the center of the tube.

In FIG. 5, the vehicle frames 14 and 15 are connected to the body 12,
If the wheels are not fixed at 13, but are supported so that the magnitudes of the intersection angles θu and θd can vary freely, and the wheels are controlled so that θu = θd, all four wheels will be pressed against the pipe wall surface, and m will be within the pipe. Matches the line connecting the centers. According to this structure, devices necessary for the work can be held at the center of the pipe even in the reducer section and the bending part of the pipe, so that stable work can be achieved.

[Effects of the Invention] As described above, the pipe inner surface working device according to the present invention always comes into contact with the inner surface of the pipe regardless of the shape of the pipe, and the working equipment is always positioned at the center of the pipe, so stable work can be achieved. It can be performed.

[Brief explanation of drawings]

Fig. 1 is a side view showing a pipe inner surface working device according to the present invention, Fig. 2 is a front view of the device, Fig. 3 is a mechanical diagram of the device, and Figs. 4 and 5 show other parts of the working device. This is a structural example. 1... Pipe inner surface working device, 2... Machine frame, 2a, 2
b, 2c, 2d... link frame, 3a, 3
b, 3c, 3d...pin, 4a, 4b, 4c, 4
d...Rolling element, 5...Spring (pinching force generation mechanism), 6...Equipment housing, 7...Shaft, 7a...
...Head, 8...Torch, 9...Sensor, 10...
...Movement mechanism, 11...Bevel.

Claims (1)

[Claims] 1 A pair of link frames whose one end is connected to a common rotation fulcrum and the other end is a free end, and a biasing force is applied to the pair of link frames in a direction that pinches the angle formed by the link frames. a clamping force generation mechanism, a first rolling element disposed at the rotational fulcrum of the pair of link frames, and second and third rolling elements disposed at each of the free ends of the pair of link frames; A working device, wherein a housing is mounted on the pair of link frames located between the first rolling element and the second and third rolling elements, and the housing has a rotational drive shaft for a working tool at the center of the housing. A pipe inner surface working device characterized by comprising: