JPS632748B2 - - Google Patents

Description

[Detailed Description of the Invention] Conventionally, the work of tightening and loosening the bolts that fasten the primary side manhole cover of the steam generator of a nuclear power plant has been performed using a single-tightening hydraulic torque wrench, a spanner, and a hammer. However, these tools were held and operated manually, which resulted in long hours of work, risk of radiation exposure, and inability to ensure bolt tightening accuracy.

In order to solve the above problems, the present invention provides a rotary joint that is removably attached to a telescopic rod such as a manhole cover handling device, a holder that is removably attached to a cushion cylinder of the rotary joint, and a holder that is removably attached to a cushion cylinder of the rotary joint. A bolt fastening device characterized by comprising a pair of diagonally supported sockets and a hydraulic rotary torque wrench for rotating the sockets, the purpose of which is to tighten bolts. The aim is to save labor in work and loosening work, reduce manual labor, and improve bolt tightening accuracy, while also reducing radiation exposure and contributing to safety.

Hereinafter, the present invention will be specifically described with reference to an embodiment shown in the drawings.

1 is a primary side manhole cover of the steam generator, 2 is a bolt that fastens the manhole cover 1, 10 is a torque wrench body, 20 is a manhole cover handling device for holding and transporting the manhole cover 1, and 30 is a hydraulic pressure The pump unit is shown. The torque wrench body 10 is a cushion cylinder 1 of a rotary joint 11.
2, a pair of sockets 5 pivotally supported by a pin 4 on the diagonal of the holder 3, a lever 7 whose base end is fixed to the pin 4, and a tip of the lever 7. It consists of a hydraulic rotary torque wrench 8 interposed between the holder 3 and the holder 3.

This torque wrench body 10 is connected to a rod 22 that extends and contracts from a cylinder 21 of a manhole cover handling device 20.
It can be attached by removing a cover holder (not shown) provided on the holder and fixing the rotary joint 11 in its place. The rotary joint 11 can rotate 360 degrees around the axis 15 by supplying and discharging pressure oil from pressure oil pipes 18 and 18.
Further, the rotary joint 11 is connected to a hydraulic pump unit 30 via pressure oil piping 13, 13, and is also connected to a hydraulic rotary torque wrench 8 and a pressure oil piping 1.
4 and 14. The cushion cylinder 12 can be raised and lowered by about 40 mm along the axis 15, and can be tilted by 0 to 2 degrees with respect to the axis 15, making it easy to fit the socket 5 and the bolt 2 together.

In order to tighten the bolts, the manhole cover handling device 20 is first operated to align the axis 15 with the center of the manhole cover 1. Next, the cushion box 12 is pushed down against the spring 16 therein by holding the knob 17 and pulling it as shown by the broken line, and the rotary joint 11 is pushed down against the spring 16 therein.
After aligning the socket 5 and the bolt 2 by rotating the socket 5 about the axis 15, when the knob 17 is released, the socket 5 moves forward due to the expansion of the spring 16 and is fitted onto the bolt 2.

Thereafter, the hydraulic pressure adjustment lever of the hydraulic pump unit 30 is adjusted to a predetermined pressure while monitoring the torque meter, and by operating the drive operation lever, the pressure oil is transferred to the pressure oil piping 13, the rotary joint 11, The hydraulic rotary torque wrench 8 is supplied and discharged via pressure oil piping 14, 14, and two
Tighten the two bolts 2 at once. Next, knob 1
7 and pull down the cushion box 12 against the spring 16 to separate the socket 5 from the bolt 2, rotate the rotary joint 11 slightly around the axis 15, and move the socket 5 adjacent to the fastened bolt 2. Align it with bolt 2, and then repeat the above operation.

When loosening the fastened bolt 2, the socket 5 can be rotated in the opposite direction by replacing the ratchet 19. Thus, by using the above-mentioned device, two bolts can be tightened or loosened at once with high accuracy without manual intervention. In addition, since the torque wrench body 10 can be attached to and detached from the cushion cylinder 12 of the rotary joint 11, it is lightweight and
It is small and convenient for attaching and detaching and carrying.

Therefore, by using the device of the present invention, the work that was conventionally done by five workers can now be done by two people, reducing the work time to about 1/4, and reducing radiation exposure to about 1/2. It is now possible to reduce it to 10,
Bolt tightening accuracy also improves.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, FIG. 1 is a schematic plan view of the torque wrench main body,
FIG. 2 is a schematic front view showing the overall configuration. Manhole cover handling device...20, rod...22,
Rotary joint...11, cushion cylinder...12, holder...3, socket...5, hydraulic rotary torque wrench...8.

Claims (1)

[Claims] 1. A rotary joint that is removably attached to a telescopic rod of a manhole cover handling device, etc., a holder that is removably attached to a cushion cylinder of the rotary joint, and a pair of rotary joints that are pivoted diagonally on the holder. A bolt fastening device comprising: a socket; and a hydraulic rotary torque wrench for rotating the socket.