JP2591541B2 - Underwater piping connection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater pipe connecting apparatus incorporating a memory alloy joint for connecting pipes used for repairing pipes underwater.

[0003]

2. Description of the Related Art In general, when repairing a submerged pipe, it is difficult to drain the water, and the working space for the repair is narrow, and as a device for connecting a pipe in a state where repair by welding cannot be performed. It is known to use shape memory alloy joints. Shape memory alloy joints (hereinafter referred to as joints) are formed by inserting a pipe into the joint and then heating the joint to a temperature equal to or higher than the transformation point of the shape memory alloy so that the joint shrinks and a claw formed on the inner surface of the joint. Has a structure that cuts into the pipe and connects the pipes. Means for heating the joint include steam heating, high-frequency heating, electric heater heating, and the like, but an electric heater is most suitable as a device that is simple and easy to control.

[0004]

When a joint is heated in water, the conventional electric heater removes heat from the outer surface of the heater in contact with water due to heat conduction and convection, and uniformly maintains the joint at a high temperature. Is difficult. Therefore, it is necessary to provide a heat insulator outside the electric heater to keep the temperature warm.However, it is difficult to install the heat insulator, and if the space is secured, the electric heater itself becomes large, and it is necessary to repair piping in narrow places. Has difficulties.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and in the case of connecting pipes with a joint using a shape memory alloy in water, it is necessary to surely and uniformly heat the joint to a temperature above the transformation point. It is an object of the present invention to provide an underwater pipe connection device capable of repairing a pipe in a narrow place by reducing the size.

Another object of the present invention is to provide a submersible pipe connection device that can easily and quickly install and remove an electric heater in a submerged pipe repair operation. [Configuration of the Invention]

[0007]

SUMMARY OF THE INVENTION The present invention provides a joint made of a shape memory alloy for connecting pipes, a split cylindrical metal case for holding the joint on an inner surface thereof, and an electric heater incorporated in the metal case. It is characterized by comprising a heater and a side convection prevention plate provided with a gap on the outer surface of the metal case.

[0008]

[Action] A pipe to be connected is inserted into the joint. When a plurality of electric heaters are brought into close contact with the metal case and energized and heated, the inner surface of the metal case is uniformly heated. The gap between the metal case and the side convection prevention plate serves as a heat insulating layer, and the heat insulating layer does not dissipate heat to the outside. In addition, the convection preventing plate prevents cold water from entering by convection, and the joint can be efficiently and uniformly heated to a temperature equal to or higher than the transformation point of the shape memory alloy, so that the pipes can be reliably connected to each other. Furthermore, the heat insulation layer is made to be small by making it a gap, the metal case is divided and made detachable, and the installation and removal work of the electric heater in the repair work of pipes in a narrow place underwater becomes easy, and it can be done in a short time. be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an underwater pipe connection device according to the present invention will be described with reference to FIGS. FIG. 2 is a cross-sectional view taken in the direction of arrows AA in FIG. In the drawing, reference numeral 1 denotes a joint formed of a shape memory alloy having a plurality of claws 2 provided on the inner surface, and the joint 1 is held on the inner surface of a split cylindrical metal case 3 which is divided into two. .
In the axial direction of the thick part of the metal case 3, ten vertical holes 4 are formed.
Are formed. In addition, a concave portion 5 whose surface is cut is formed on the outer peripheral surface of the metal case 3. In the metal case 3, an upper convection prevention plate 6 is provided at an upper end portion, a lower convection prevention plate 7 is provided at a lower end portion, and a side convection prevention plate 8 serving as a cover is provided at a side portion so as to be detachable. A gap 9 is provided between the side convection prevention plate 8 and the recess 5. A rod-shaped electric heater 10 is detachably inserted into the hole 4. The upper portion of the electric heater 10 is electrically connected to a cable 12 via a terminal rod 11. The terminal rod 11 is provided on the upper surface of the upper convection prevention plate 6.
An insulating member 13 that insulates the connection case 14 is provided, and an upper portion of the insulating member 13 is connected to the connection case 14. The cable 12 is connected to a voltage regulator 15 and a power supply 16.

Reference numerals 17 and 18 denote submerged pipes, which are inserted into the joint 1, and 19 denotes a connection point.
The upper convection prevention plate 6 and the lower convection prevention plate 7 are for preventing cold water from flowing from the outside between the joint 1 and the metal case 3, and the side convection prevention plate 8 is made of a divided metal. This is for preventing cold water from flowing through a gap generated between the cases 3 before heating.

The connection of the pipes 17 and 18 by the joint 1 in a narrow place in the water by the underwater pipe connection device having the above-described configuration is performed, for example, as follows. First, the pipes 17 and 18 are inserted into the joint 1, and the power is supplied from the power supply 16 to the electric heater 10 to heat the metal case 3. Since the metal case 3 is in close contact with the outer surface of the joint 1, the joint 1 is uniformly heated by the heat transfer effect. Since the gap 9 is provided between the metal case 3 and the side convection preventing plate 8 to form a heat insulating layer, heat is prevented from being dissipated to the outside. When heating is started by the electric heater 10, convection of water occurs due to a temperature difference around the underwater pipe connection device, and cold water flows through the gap between the joint 1 and the metal case 3. Due to cooling, the temperature may not rise to the transformation point temperature of the shape memory alloy. However, the upper and lower convection prevention plates 6 and 7 prevent cold water from entering.

Further, since the joint 1 contracts in the radial direction, the metal case 3 is pushed following the contraction, and the gap between the joint 1 and the metal case 3 is reduced as much as possible. Therefore, before heating, a joint 1 is provided between the metal cases 3 divided as shown in FIG.
A gap is provided for the shrinkage allowance. A side convection prevention plate 8 is provided outside the gap to prevent cold water from entering. After the electric heater 10 is connected in the connection case 14, it is subjected to a water sealing process and connected to the cable 12, the voltage regulator 15, and the power supply 16 to adjust the output of the heater 10.

When the electric heater 10 is adjusted to a predetermined output by the voltage regulator 15 in the above-described state, the metal case 3
The amount of heat taken out to the outside by the heat insulating effect of the gap 9 on the outside is small, the intrusion of cold water is prevented by the convection prevention plates 6, 7, and 8, the temperature of the inner surface of the metal case 3 becomes uniform, and the joint 1 becomes Heats to a temperature above the transformation point and shrinks. When the joint 1 contracts, the claw 2 in the joint 1 is connected to the pipe.
Bites 17 and 18 are connected, and pipes 17 and 18 are securely connected.

[0014]

According to the present invention, the temperature of the inner surface of the metal case is made uniform by arranging the electric heaters in the metal case in a circumferential shape, and the outer side of the metal case and the side convection preventing plate are provided. By providing a gap between them, a heat insulating effect and miniaturization can be achieved.

Even if convection occurs between the metal case and the joint 1, cold water can be prevented from flowing by the convection preventing plate, and the shape memory alloy of the joint can be heated to the transformation point or higher. It is possible to repair pipes in narrow places underwater.

Furthermore, since the apparatus is simple and the metal case can be divided, it can be easily attached to and detached from the pipe connection part, and the pipe connection work can be performed in a short time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of an underwater pipe connection device according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Joint, 2 ... Claw, 3 ... Metal case, 4 ... Hole, 5 ... Depression, 6 ... Upper convection prevention plate, 7 ... Lower convection prevention plate, 8 ... Side convection prevention plate, 9 ... Gap, 10 ... Electric heater, 11 terminal strip, 12 cable, 13 insulating member, 14 connection case,
15 ... voltage regulator, 16 ... power supply, 17, 18 ... piping, 19 ... connection points.

Claims (1)

(57) [Claims] 1. A joint made of a shape memory alloy for connecting a pipe, a split cylindrical metal case for holding the joint on the inner surface, an electric heater incorporated in the metal case, and the metal case. And a side convection prevention plate provided with a gap on the outer surface of the underwater pipe connection device.