JPH0672317A - Inside travel device - Google Patents

Abstract

PURPOSE:To facilitate directional change of a device main body in a pipe of small bore diameter and to reduce travel frictional force by judging a junction of the pipe by a control part in accordance with a detection signal of a sensor to detect the inwall of the pipe and by extending and contracting an arm along the inwall of the pipe accordingly. CONSTITUTION:In the case when a device main body 2 is, directionally changed for example to the right side at a T junction on a pipe inside face 1, in accordance with detection signals by a plural number of sensors 7-9 using infrared rays of the device main body 2, the T junction is judged by a control part 12. Thereafter, arm rotary part 5 is rotated, by driving a motor 6 by the control part 12 so that an arm 3 is directed to the right side. Simultaneously, by electrifying a shape memory alloy of an arm extension and contraction means 4 and heating and extending it, the arm 3 is extended to the inside of a conduit run on the right side. When the device main body 2 is farther advanced, a slide part 31 of the top end of the arm 3 makes contact with the inwall of the right side conduit run. Consequently, the arm 3 receives reaction force and is deformed, and simultaneously, the device main body 2 receives torque in the direction orthogonal to a central axis A and changes its direction along the pipe inside face 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-pipe traveling device for traveling in a pipe having a small diameter, and more particularly to a steering mechanism at a branch point.

[0002]

2. Description of the Related Art There is a conventional in-pipe traveling device having a structure as shown in FIG. 2A is a partial cross-sectional view showing the entire structure, and FIG. 2B is a partial side cross-sectional view showing the link mechanism. This is a link mechanism 17 in which a guide wheel 15 and a link arm 16 are connected to the front and rear portions of the main body drive 11.
Is used (Japanese Patent Laid-Open No. 61-278475). 1
8 is a servo motor, 19 is a worm gear 20 is a gear. To drive the in-pipe traveling device having such a configuration,
The servo motor 18 is rotated and the torque thereof is transmitted to the gear 20 through the worm gear 19, and the link mechanism 17 is steered in the bending direction. The link mechanism 17 can bend a branch pipe such as a T-shaped pipe or an L-shaped pipe along the inner surface of the pipe.

[0003]

However, according to the prior art, since the traveling link device has a large size because the steering link mechanism is provided at the front and rear portions of the main body drive unit, the steering device is required to be compatible with a small diameter pipe. Since the mechanism is complicated, there is a problem that the size becomes large. In addition, since this link mechanism always generates a frictional force between the mounted wheels and the inner surface of the pipe even when traveling straight, it is necessary to take a large driving force of the traveling device. It was difficult. Therefore, the present invention has been made to solve the above-mentioned problems, and it is easy to change the direction in a small-diameter pipe,
The object is to provide a small in-pipe traveling device.

[0004]

In order to solve the above problems, the present invention provides at least one front surface of the main body of the in-pipe traveling device.
A control unit having at least two sensors for detecting the inner wall of the pipe, which are provided on the outer peripheral portion of the front portion of the main body, and a determination unit for determining the branch point by measuring the distance to the inner wall of the pipe by the signal of the sensor. An arm having a sliding portion whose tip shape is a curved surface and an arm portion having a spring property, the arm being attached so as not to be parallel to the central axis in the longitudinal direction of the main body, and the sensor attached behind the arm. And a rotation means for rotating the arm in the circumferential direction of the traveling device in response to a signal from the sensor.

[0005]

With the above-mentioned means, the branch point can be recognized, and a single arm having a spring property can be directed in the bending direction to easily change the direction along the inner surface of the pipe. When moving straight, since the arm is in a contracted state, it can be moved with a small driving force without friction with the inner surface. Therefore, since the traveling device can be downsized, it can be applied in a pipe having a small diameter.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the figure, 1 is an inner surface of a pipe, 2 is a main body of a traveling device having a substantially cylindrical shape, 3 is a metal arm having a roller-shaped sliding portion 31 and an arm portion 32 having a spring property at a tip thereof. It is provided in a curved shape so as not to be parallel to the central axis A. Reference numeral 4 denotes an arm expanding / contracting means manufactured by repeatedly bending a shape memory alloy strip, 5 an arm rotating portion for rotating the arm 3 and the arm expanding / contracting means 4 in the circumferential direction via a bearing 11, and 6 an arm rotating portion 5. It is a driving motor. 7-
Reference numeral 9 is a sensor using infrared rays for measuring the distance to the inner wall of the tube, 7 is a front sensor provided on the front surface of the main body 2,
Reference numerals 8 and 9 denote lateral sensors provided on the outer periphery of the front portion of the main body 2. Wheels 10 are provided on the inner surface 1 of the pipe via springs (not shown), and are independently driven by the wheel driving unit 13 to move the main body 2 forward or backward. The number of wheels 5 is eight, but may be four depending on the mounting position. Reference numeral 12 denotes arm expansion / contraction means 4 based on information from the sensor.
And a control unit that controls the arm rotation unit 5 and the wheel drive unit 13. The operation in the case of turning rightward in the state of FIG. 1 will be described. Now, based on the signals from the sensors 7 to 9, the control unit 12 recognizes that there are pipe passages in the forward and rightward directions, that is, a T-junction.
Next, when the motor 6 is driven, the arm rotating part 5 rotates, and the arm 3 is turned to the right. When an electric current is applied to the shape memory alloy of the arm expansion / contraction means 4 through a lead wire (not shown) to heat it, the entire length becomes longer, and the arm 3 is placed in the right conduit.
Extends. When the main body 2 is advanced, the sliding portion 31 at the tip of the arm 3 comes into contact with the inner wall of the right pipeline. Further, when the main body 2 is moved forward, the arm 3 is subjected to a reaction force while being in contact with the arm 3 to be bent and deformed. The main body 2 receives a rotational force in a direction perpendicular to the central axis A and changes its direction along the inner surface of the tube. When the energization of the shape memory alloy is stopped after the direction is changed, the temperature drops and the arm 3 moves toward the main body 2 and separates from the inner surface of the tube. In this embodiment, one arm is rotated in the circumferential direction of the traveling device by using the arm rotation part according to the signal of the sensor depending on the bending direction, but the arm rotation part is omitted and the two arms are moved to the left and right. The configuration provided in the above may be used. Next, even if the arm extending / contracting means 4 is configured to use an exciting coil, a solenoid composed of an iron core and a magnet (not shown), the arm 3 can be extended / contracted, so that the direction can be similarly changed. In this case, the expansion and contraction operation of the arm 3 can be performed quickly, which is suitable when a fast operation is required. In addition to the above, the expansion / contraction means 4 may use a piezo actuator or a gear such as a rack and a pinion.

[0007]

As described above, according to the present invention, since the small arm having the spring property is used, it is possible to easily change the direction in the pipe having the small diameter and to reduce the friction during running. Since the force can be reduced, there is an effect that a small in-pipe traveling device can be provided.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an in-pipe traveling device of the present invention.

FIG. 2 is a partial cross-sectional view showing a conventional pipe running device.

[Explanation of symbols]

1 Pipe Inner Surface 12 Control Unit 2 Main Body 13 Wheel Drive Unit 3 Arm 14 Main Body Drive Unit 4 Arm Expansion / Expansion Means 15 Guide Wheel 5 Arm Rotating Unit 16 Link Arm 6 Motor 17 Link Mechanism 7 Front Sensor 18 Servo Motor 8, 9 Lateral Direction Sensor 19 Worm gear 10 Wheel 20 Gear 11 Bearing A Center axis of main body

Continuation of the front page (72) Inventor Takenori Harada No. 2 Kurosaki Shiroishi, Hachimannishi-ku, Kitakyushu, Fukuoka Prefecture Yasukawa Electric Co., Ltd.

Claims (4)

[Claims] 1. An in-pipe traveling device comprising a sensor for detecting an inner wall of a pipe, a drive unit for traveling, and an arm for changing direction at a branch point or a bending point of the pipe, at least one in front of the main body. A controller having at least two sensors for detecting the inner wall of the pipe provided on the outer periphery of the front part of the main body, and a determination means for determining the branch point by measuring the distance to the inner wall of the pipe by the signal of the sensor; An arm which is composed of a sliding portion having a curved surface and an arm portion having a spring property and which is attached so as not to be parallel to the central axis in the longitudinal direction of the main body, and a signal of the sensor which is attached behind the arm. And an arm expanding / contracting means for expanding / contracting the arm according to the above. 2. The in-pipe traveling device according to claim 1, wherein the arm expanding and contracting means is made of a shape memory alloy or a solenoid. 3. The in-pipe traveling device according to claim 1, wherein the sliding portion of the arm has a roller shape and the arm portion has a curved shape. 4. The in-pipe traveling device according to claim 1, wherein the sensor uses infrared rays or light.