JPS63170180A - Pipe traveling device - Google Patents

Abstract

PURPOSE:To prevent any rotation of a device itself from occurring, by installing at least three crawlers set up radially and also both first and second trucks having three pieces of wheels likewise, and transmitting power of the motor mounted on the second truck to these crawlers, thereby making them travel. CONSTITUTION:This pipe traveling device consists of a first truck 1 as a crawler part installing three crawlers 3 at equi-angular intervals and as second truck 2 as a motor mounting part installing three wheels 18 at equi-angular intervals likewise, and both these trucks 1 and 2 are coupled together by a shaft 13 and a spline 14. A toe-in angle is put on two wheels among these three wheels 18, whereby rectilinearity is improved and, what is more, a device itself is prevented from rotating. And, with rotation of the motor 17 mounted on the truck 2, a sprocket 11 is rotated by a worm 8, a worm wheel 7 installed in the shaft 13 and a sprocket 9 being set up on the same shaft via a chain 10, thereby driving each of these crawlers 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an in-pipe traveling device that travels within a conduit in a pipeline or the like.

[Conventional technology]

BACKGROUND ART In conduits such as pipelines, it is necessary to run a working trolley or tow them by other traveling devices for internal measurement inspection, repair, painting, etc. For this reason, covered carts and the like have been used conventionally.

However, when a conventional trolley runs inside a pipe, it rotates in the circumferential direction (
Particularly when passing through a bent pipe section (a section where the pipe curves in the horizontal direction), the trolley may ride up on the inner wall of the pipe, and the subsequent inclination becomes even greater, causing the trolley to overturn. There was a problem that made it impossible to drive.

The simplest means to prevent this overturning is to lower the center of gravity of the trolley so that even if it tilts, the wheels etc. will slide and it will return to the horizontal position naturally.

However, depending on the coefficient of friction between the pipe surface and the wheels and the curvature of the pipe, there is still a risk of the pipe falling over.

The steering mechanism is effective in preventing tilting, and patents using this mechanism include JP-A No. 6G-5828s and JP-A-80-1.
No. 76862 is known. In the former example, since the traveling device consists of four wheels, steering is performed using either the front wheels or the rear wheels, which is quite common. In the latter example, the traveling device is composed of crawlers arranged in a V-shape, and steering is performed by turning on and off the operation of the left and right crawlers.

The causes of rotation (tilting) in the circumferential direction of the traveling device include (1) running over a bent pipe, (1) unbalanced weight of the device itself, and (II) effects of kinks in connected cables. is possible.

Therefore, rotation (tilting) occurs not only in the bent pipe section but also in the straight pipe section.

In the case of the structure in which the above-mentioned steering mechanism prevents rotation, there is a disadvantage that if the grip force with the tube wall is weak (il) *(the influence of the stile becomes large and the amount of steering operation becomes large).

[Summary of the invention]

The present invention has been made in order to improve the above-mentioned prior art, and includes a first truck having at least three crawlers that are grounded radially on the inner wall of the tube centering on the tube axis direction, and a second truck rotatably connected in the circumferential direction and equipped with a motor for driving the crawler; and at least three wheels attached to the second truck and grounded radially on the inner wall of the pipe centering on the pipe axis direction. The basic feature is that at least two of the wheels are provided with a toe-in angle to prevent rotation of the second truck.

According to the present invention, first, in order to avoid overturning and the resulting inability to travel, the portion that contacts the inner wall of the tube is structured radially around the tube axis. However, if the traveling device has a radial structure, it will not fall over and become unable to travel, but the device will still rotate while traveling a long distance. In this case, twisting of the cable that sends power, control signals, etc. from outside the pipe becomes a problem. Slip rings or the like can be used to connect the cable to the traveling equipment, but in that case they are likely to be affected by the conditions inside the pipe. This is particularly undesirable from the point of view of explosion-proofing when it is desired to perform molding work automatically within a pipe.

Therefore, in the present invention, the truck is divided into a first truck and a second truck,
These are rotatably connected, a motor is mounted on the second truck, and the second truck is constructed so as not to rotate, thereby solving the problem of cable twisting.

〔Example〕

An embodiment of the present invention will be described below based on the drawings. 1st
The figure shows the front entrance, and FIG. 2 is a sectional view taken along the line A-A in FIG. 1.

In the figure, (1) is a first truck, which is a crawler section. (2) is the second truck, which is the motor mounting section. In this embodiment, the crawler part (1) and the motor mounting part (
2) are connected by shaft 0 and spline a4. For simplicity, Figure 1 shows three crawlers (3),
Although one wheel a8 is shown as a representative, the crawler (3) and the wheels α are mounted radially around the tube axis direction at an angle of 120°.

The rotation of the motor aD is transmitted to the worm (8) connected to the shaft (13) via the spline a4.The worm wheel (7) and the sprocket (9) arranged on the same axis are connected to the sprocket using a chain member. a
Rotate υ. This sprocket is configured to drive a crawler (timing belt) by a coaxial timing pulley α■.

The spline I is attached to the motor mounting portion (2) via a self-aligning roller bearing a9, thereby making it rotatable. This bearing a9 also has the role of absorbing bending of the crawler section (1) and the motor mounting section (2). If the curvature is larger, use a flexible joint, universal joint, etc. on the shaft.

The crawler (3) is pressed against the tube wall by the link (4). This is due to the restoring force of the pressing spring (6), and the pressing force can be adjusted using the set bolt (5). The wheel α barrel is also pressed against the pipe wall by a pressing spring U. Note that in the figure (le is a free bearing, and ■ is a coupler, to which a measuring device, a work cart such as a paint machine, etc. is connected).

In this embodiment, three wheels are provided, two of which have a toe-in angle to improve straightness and prevent rotation. Further, the remaining one wheel may be provided with a steering mechanism so that the direction can be changed freely.

Motor a again? ) must be received by the wheel frame, but in order to do so the following conditions need to be met. When the tractive force of the crawler section (1) is F and the radius of the timing pulley α is r, the torque is Fr. If the reduction ratio of the transmission path from the timing pulley (13) to the worm (8) is n, the torque acting on the worm (8) is Frn
, and therefore the shaft αj also receives the same torque. If the coefficient of friction of the wheels is μ, the length from the center of the device to the inner wall of the tube (radius of the tube) is R9, and the pressing force per wheel is N, then the rotational reaction force is 3 μRN. Therefore, F r
It is sufficient if n<3μRN, which is a sufficiently practicable condition.

According to the traveling device configured as described above, the crawler portion (1) rotates freely, but this does not make the device unable to travel, and the motor mounting portion (2) does not rotate due to the toe-in angle and steering mechanism. This prevents the cable from getting twisted and disconnected. Furthermore, since it is divided into two parts, a mechanism that generates sufficient pressing force can be attached to the crawler part, making it possible to increase the traction force. In addition, since the cable is not twisted, it is not subject to the resistance force caused by untwisting, so it is very advantageous in terms of long-distance running compared to conventional traveling machines. By roughly dividing the motor mounting section, it is possible to use a motor with a diameter approximately equal to the pipe diameter, and in the case of small diameter pipes, it is possible to increase the output compared to conventional traveling machines.

〔Effect of the invention〕

As explained above, the running device of the present invention can completely eliminate the inability to run due to rotation, etc., and can also run smoothly without twisting of the cable.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the traveling device of the present invention, and FIG. 2 is a sectional view taken along the line A--A. (1)...Crawler part, (2)...Motor mounting part,
(3)...Crawler, (17)...Motor, (l
I--Wheel.

Claims (1)

[Claims] A first truck having at least three crawlers that are grounded on the inner wall of the pipe radially around the tube axis direction, and a motor that is rotatably connected to the first truck in the circumferential direction and drives the crawlers. It has a second truck, and at least three wheels that are attached to the second truck and are in contact with the inner wall of the tube in a radial direction centered on the tube axis, and at least two of the wheels have a toe-in angle. An in-pipe traveling device characterized in that rotation of the second cart is prevented.