JP2000281179A - Opening/closing device for manhole lid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manbole lid opening/closing device which eliminates any work using a heavy tool in the opening/closing work of a manhole lid of a closed tank, contributes to reduction of a working space, and is unnecessary for any special technology. SOLUTION: In the opening/closing device for a manhole lid 1 in which the manhole lid 1 is fitted to a manhole 3 of a metal closed tank 2 in which a high-pressure gas is sealed, and the manhole lid 1 is opened/closed, a traveling rail 8 extending in the horizontal direction is provided in the vicinity of the manhole 3, a truck 7 is placed on the traveling rail 8, a stud 6 for jack-up extending upward is fixed to the truck 7, a nut 5 for jack-up is screwed to the stud 6 for jack-up, and the nut 5 for jack-up is rotatably fitted to the manhole lid 1 through a bearing 4, and locked to its lower end manhole lid 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for opening and closing a manhole cover of a closed tank made of metal.

[0002]

2. Description of the Related Art A manhole cover of a metal hermetically sealed tank filled with high-pressure gas used for a gas insulated switchgear, etc.
In a normal use state, it is in a closed state. However, at the time of work inside the closed tank and at the time of inspection, it is necessary to open and close the manhole cover. Since the manhole cover is made of a plate thickness that can withstand the pressure of high-pressure gas, the larger the diameter of the manhole, the larger the weight, and it is difficult for the manhole to move up and down and open and close. Heavy equipment such as cranes were used.

FIG. 4 shows an example of a conventional manhole cover opening / closing device. The manhole cover 1 is disposed above a manhole 3 formed in a metal closed tank 2, and the manhole cover 1 has hanging ears 11 at two symmetrical positions on the side surface.

At the time of opening / closing the manhole cover 1, the hanging ear 11 and the crane 9 are connected using the wire 10, and the manhole cover 1 is lifted by the crane 9, and the crane 9 travels on the crane traveling rail 12. , Can be opened and closed.

[0005]

However, in this conventional apparatus, since the wire 10 and the crane 9 are used to lift the manhole cover 1, the support of the crane 9 and the crane traveling rail 12 are attached to the manhole cover 1. It needs to be installed around, and requires a larger space than the manhole cover 1. Therefore, the place where the manhole cover 1 is installed is subject to space restrictions.

[0006] Each time work is performed in the closed tank 2 at the time of inspection or the like, the crane 9 and the crane traveling rail 12 are moved.
As a result, the problem of an increase in working time occurs. Even if the crane 9 and the crane traveling rail 12 are always installed for each manhole 3, a problem of equipment cost occurs. Furthermore, slinging and crane operations require specialized skills, and training of workers is also required.

Accordingly, an object of the present invention is to provide a manhole cover opening / closing device which reduces the space required for opening / closing the manhole cover as close as possible to the size of the manhole cover itself, and which does not require specialized skills. And

[0008]

According to the present invention, a manhole cover is attached to a manhole of a tank, and a manhole cover opening and closing device for opening and closing the manhole cover is provided with a traveling rail extending in the horizontal direction near the manhole. A truck is placed on the traveling rail, a jack-up stud extending upward is fixed to the truck, a jack-up nut is screwed to the jack-up stud, and the jack-up nut is attached to the truck. The manhole cover is rotatably attached to the manhole cover via a bearing, and a lower end portion of the manhole cover is locked to the manhole cover.

[0009]

1 to 3 show an embodiment of a manhole cover opening / closing device according to the present invention.
2 and 3 show a normal use state (closed state), a jack-up state, and an open state of the manhole cover, respectively. The manhole cover 1 of the manhole 3 is provided with seats 1a at four corners in which bearings 4 having balls 4c are fitted.
The jack-up nut 5 and the bearing 4 are fitted and connected by the inner ring 4b of the bearing 4, so that the frictional force when the jack-up nut 5 rotates is not directly applied to the seat 1a. The jack-up nut 5 is screwed into the external thread 6a of the jack-up stud 6 at its female thread 5a. The jack-up stud 6 is integrated with a truck 7, and the truck 7 is installed on a traveling rail 8.

In the manhole cover opening / closing apparatus, when the manhole cover 1 shown in FIG. 1 is opened from the closed state, the jack-up nut 5 is rotated counterclockwise. The female thread 5a and the external thread 6a of the jack-up stud 6 are screwed together to move upward along the jack-up stud 6. At this time, the jack-up nut 5 pushes up the inner ring 4b of the bearing 4, and the pushing force is transmitted to the outer ring 4a of the bearing 4 via the ball 4c of the bearing 4, and further transmitted to the seat 1a, and the manhole cover 1
Moves upward. This state is shown in FIG.

The manhole cover 1 having been jacked up is moved laterally on a running rail 8 by a bogie 7 through a seat 1a, a bearing 4, a jackup nut 5 and a jackup stud 6, and the manhole cover 1 is moved. Can be opened. This state is shown in FIG. Note that the operation of closing the manhole cover 1 may be performed in a completely opposite manner to the above-described opening operation, and a description thereof will be omitted.

[0012]

According to the manhole cover opening / closing device of the present invention, no heavy equipment is required for opening / closing the manhole cover, and the work space only requires a jack-up allowance for the manhole cover. In addition, the cost for installing heavy equipment can be reduced and the work space can be reduced. Also, since the work content does not require specialized skills, training of specialized skills is not required.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of a manhole cover opening / closing device according to the present invention, and is a view showing a normal use state (closed state).

FIG. 2 is a diagram showing the jack-up state.

FIG. 3 is a view showing the open state.

FIG. 4 is a diagram showing an example of a conventional manhole cover opening / closing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Manhole cover 1a Seat 2 Sealed tank 3 Manhole 4 Bearing 4a Outer ring 4b Inner ring 4c Ball 5 Jack-up nut 5a Female thread 6 Jack-up stud 6a Male thread 7 Truck 8 Traveling rail

Claims (1)

[Claims] 1. A manhole cover opening / closing device for attaching a manhole cover to a manhole of a tank and opening and closing the manhole cover, comprising: a traveling rail extending horizontally in the vicinity of the manhole; A jack-up stud extending upward is fixed to the carriage, a jack-up nut is screwed to the jack-up stud, and the jack-up nut is rotated on the manhole cover via a bearing. A manhole cover opening and closing device, wherein the manhole cover is attached as possible and a lower end portion thereof is locked to the manhole cover.