JPS6225509Y2 - - Google Patents

Description

[Detailed description of the idea] This idea concerns the improvement of the earthquake-resistant structure of cranes.

1 to 3 show the running mechanism of a conventional polar crane for nuclear reactors, in which running wheels 4 attached to both sides of a girder 3 rotate on circular rails 2 laid on the building ceiling 1. The trolley 6 is configured so that its traversing wheels 7 move on a traversing rail 5 laid on the girder 3 in its longitudinal direction.

In order to restrict the relative positional deviation between the traveling rail 2 and the traveling wheels 4 of the girder 3, a movement restricting member 8 that can be bent with an elastic body is attached to the girder 3.
Further, in order to restrict relative positional deviation between the running rail 2 and the running wheels 4, a collar 9 is provided on the running wheel 4 to partially inhibit movement of the wheel in a direction perpendicular to the rail.

When a crane configured as described above is subjected to a horizontal seismic force, since the wheels 4 and the rail 2 are usually clamped, the seismic force applied to the rail 2 via the building ceiling 1 is directly applied to the crane. However, if the structure allows slippage between the rail 2 and the wheels 4, a force greater than the frictional force will be applied to the girder 3.
Since the stress is not applied to the girder 3, the stress on the girder 3 is relaxed.

However, if slippage is allowed as described above, a relative displacement will occur between the rail 2 wheels 4, so
If a relative displacement of more than a certain level occurs, there is a possibility of the wheel coming off, and some kind of position holding mechanism is required. As this position holding mechanism, the above-mentioned wheel flange or a position holding mechanism constructed from a movement regulating member made of an elastic body can be considered, but the conventional mechanism has the following drawbacks.

When the girder 3 receives an external force in a direction perpendicular to the running rail 2, if the spring constant of the movement regulating member 8 that constitutes the position holding mechanism is too large, the running rail 2
If there is a gap between the traveling rail 2 and the movement restricting member 8 and they collide directly with the collar, the impact force at that time will be excessive. On the other hand, if the spring constant is low, the reaction force acting on the rail 2 will be small, making it safer in terms of strength, but
The position holding function deteriorates and there is a danger that it may lead to accidents such as wheels falling off.

When the girder 3 receives an external force in the tangential direction of the circular running rail 2, if the spring constant of the movement regulating member 8 is large, the girder 3 will be forced in the tangential direction of the rail.
The reaction force from the rail 2 against the rigidity displacement increases, equivalently increasing the frictional force in the running direction, increasing the stress within the girder 3, and reducing the degree of relaxation of stress due to slipping. Moreover, if the spring constant is small, the position holding function of the wheel 4 of the girder 3 will be reduced, and there is a possibility that the wheel will come off.

Therefore, the high frequency component (small displacement) of ground motion during an earthquake
, the spring is weakened to reduce the reaction force acting on the rail 2 and the stress generated on the girder 3,
It is necessary to prevent the wheels from coming off due to low frequency components (large displacement).

This proposal was proposed in view of the above circumstances.In a traveling crane having a girder with wheels rolling on a rail at the bottom of both ends, the crane faces the side of the rail at a predetermined distance, and An elastic movement regulating member having a lower horizontal piece extending toward the side surface of the rail is vertically disposed on the girder, and a support frame is vertically disposed on the girder adjacent to the back surface of the movement regulating member. A curved shape in which the gap between the support frame and the movement restriction member gradually increases as the surface facing the movement restriction member moves downward, and the point of contact with the movement restriction member shifts downward as the movement restriction member deforms. The purpose of this structure is to prevent the crane from slipping in the direction perpendicular to the rail and in the direction of the rail when the crane is subjected to horizontal force during an earthquake. In this case, the force acting between the rail and the wheel is suppressed to reduce the stress within the girder, and the amount of relative positional deviation between the rail and the wheel is within a predetermined range, so that problems such as derailment accidents do not occur. , to provide an improved crane earthquake-resistant structure.

In this case, as described above, the girder of a traveling crane is equipped with wheels that roll on a rail at the bottom of both ends, and is opposed to the side surface of the rail with a predetermined distance therebetween, and is directed toward the side surface of the rail. The gap between the elastic movement regulating member having a lower horizontal piece extending from the elastic movement regulating member and the member gradually increases as the surface that is adjacent to the back surface of the movement regulating member and facing the member moves downward, causing deformation of the member. As a result, the girder was vertically installed with a support frame formed in a curved shape so that the point of contact with the same member shifted downward, which caused the girder to receive horizontal loads from the earthquake and cause displacement in the direction perpendicular to the rail and in the direction of the rail. Then, the lower horizontal piece of the elastic movement regulating member is bent by being pressed against the rail.
At the start of this bending, the length of the elastic movement regulating member vertically disposed from the girder as a cantilever beam whose base end is the attachment portion to the girder is large, and the spring constant is small.

Therefore, when the relative positional deviation between the wheels of the girder and the rail is small, the spring constant of the elastic movement regulating member is small, so that the reaction force acting on the rail and the girder against the high frequency component (small displacement) of ground motion during an earthquake is small. The resulting stress can be reduced.

When the amount of relative positional deviation between the wheel and the rail increases, and the deflection of the elastic movement regulating member increases, the movement regulating member is moved by the curved portion formed on the opposing surface of the movement regulating member in the support frame. , the contact point between the elastic movement regulating member and the support frame moves downward, the length of the elastic movement regulating member as a cantilever beam decreases, and the spring constant increases.

Therefore, by having a large spring constant of the movement regulating member with respect to the low frequency component (large displacement) of the ground motion during an earthquake, the amount of relative positional deviation between the girder wheels and the rail will be within a predetermined range, and escape will be prevented. Wheel accidents are prevented.

The present invention will be described below with reference to illustrated embodiments. 1
1 is a circular rail 13 installed on the building ceiling 12
A girder of a crane that travels via traveling wheels 14 disposed on both sides of the top, and is made of an elastic body and has elastic movement that can be bent to restrict relative positional deviation between the girder 11 and the rail 13. Regulation member 1
5 is vertically installed, and the tip of the member 15 is connected to the rail 13.
is opposed to the side surface of with a predetermined distance therebetween. Further, a sufficiently rigid support frame 16 is provided vertically from the girder 11 adjacent to the movement regulating member 15, and a surface of the support frame 16 facing the member 15 has a support frame 16 that is connected to the member 16 as it moves downward. A curved support surface 16a is formed such that the distance between the two sides gradually increases, and the upper part of the support surface 16a is in contact with the upper part of the movement regulating member 15.
Further, the wheel 14 is provided with a collar 17.

Therefore, if a horizontal load due to an earthquake is received in the direction perpendicular to the rail (direction a in Figure 3), the girder 11 will derail in the direction perpendicular to the rail, and if received in the direction of the rail (direction b in Figure 3), it will derail in the tangential direction of the rail. They each try to move as they do.

When the girder 11 is displaced in the direction perpendicular to the rail and in the rail direction as described above, the elastic movement regulating member 15 is pressed by the rail 13 and bends. At the start of bending, the length of the elastic movement regulating member 15 as a cantilever is large and the spring constant is small, but the amount of relative positional deviation between the wheel 14 and the rail 13 becomes large.

Furthermore, when the deflection of the elastic movement regulating member 15 increases, the member is pressed against the curved support surface 16a of the support frame 16, the length of the member 15 as a cantilever becomes smaller, and the spring constant becomes larger. FIG. 9 is an explanatory diagram showing this state, in which the horizontal axis X shows the relative displacement between the rail and the wheel, and the vertical axis Y shows the reaction force acting on the rail.

In this way, the elastic movement regulating member 15 that regulates the relative positional deviation between the girder 11 and the rail 13 is arranged in the ninth position.
In the case of having the spring characteristics shown in the figure, when the positional deviation between the girder 11 and the rail 13 is small, the spring constant is small. It is possible to reduce the reaction force and the stress generated in the girder, and because the spring constant is large for low frequency components (large displacement), it is possible to prevent wheel derailment, and it has an excellent earthquake resistance effect.

Furthermore, even if the girder 11 is subjected to a horizontal earthquake load in the direction shown in Figure 3b and attempts to move in the direction C where the rails derail, the elastic movement-limiting member 15 made of an elastic body is deformed in a direction perpendicular to the rail due to the bending of the rail 13, and the member 15 and the support frame 16 exert an effect similar to that in the case where the girder 11 is subjected to an earthquake load in a direction perpendicular to the rail.

In the embodiment shown in FIG. 5, the elastic movement regulating member 15 and the support frame 16 are arranged inside the rail 13, but they may be arranged outside the rail 13 as shown in FIG. .

Further, the movement regulating member 15 and the support frame 16 may be arranged at two locations in the front and back on both sides of the girder 11 as shown in FIG. 7, and as shown in FIG.
They may be arranged at one location in the center on both sides of the girder 11.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a crane equipped with a conventional earthquake-resistant structure, Fig. 2 is a side view thereof, Fig. 3 is a plan view thereof, and Fig. 4 is a longitudinal sectional view showing details of the earthquake-resistant structure.
5 and 6 are longitudinal sectional views showing respective embodiments of the earthquake-resistant structure of the crane according to the present invention, FIGS. 7 and 8 are partial plan views of the crane equipped with the earthquake-resistant structure of the present invention, and FIG. The figure is a chart showing the spring characteristics of the earthquake-resistant structure related to this proposal. DESCRIPTION OF SYMBOLS 11... Girder, 13... Rail, 14... Wheel, 15... Elastic movement regulating member, 16... Support frame, 16a... Curved support surface.

Claims (1)

[Scope of utility model registration request] In a traveling crane having a girder equipped with wheels rolling on a rail at the bottom of both ends, an elastic crane having a lower horizontal piece facing the side surface of the rail at a predetermined distance and extending toward the side surface of the rail. A movement regulating member is vertically installed on the girder, and
A support frame is vertically disposed on the girder adjacent to the back surface of the movement restriction member, and as the surface of the support frame facing the movement restriction member moves downward, the gap between the movement restriction member and the movement restriction member gradually increases. An earthquake-resistant structure for a crane, characterized in that the contact point with the movement regulating member is formed in a curved shape that moves downward as the movement regulating member deforms.