JPS5948236B2 - seismic mitigation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seismic mitigation device for increasing the seismic resistance of a crane, and more particularly to a traveling crane whose legs are supported on a traveling platform movable on rails via wheels. The legs and the running platform are slidably coupled by a connecting member, and the coupling allows the legs and the running platform to mutually slide in a direction perpendicular to the extending direction of the rail on a horizontal plane, and further A buffer member is interposed on the legs and the running base near the connecting member to buffer the sliding movement of the running base against the legs, and the horizontal shaking of the rail that occurs during an earthquake is guided to the running base via the wheels. This invention relates to a vibration damping device that allows a traveling platform to slide while being cushioned against the legs, thereby alleviating the vibrations of a crane caused by an earthquake.

In recent years, the need to improve safety in the field of industrial machinery has been generally recognized, and research has begun to improve seismic resistance as part of this safety improvement effort.

Among industrial machines, cranes, which are often used outdoors, are thought to have a particularly large impact on people and property outside if they collapse, but in the past, little consideration has been given to the earthquake resistance of cranes. It was never done.

As a result, when an earthquake occurs and the frequency of the earthquake is the same as or close to the natural frequency of the crane, there is a serious problem that the crane is likely to collapse, significantly increasing the danger to the outside.

To solve the above problem, it would be possible to make the crane strong enough to withstand all conceivable earthquakes, but this would require increasing the crane's own weight, which would make the crane expensive. There were drawbacks.

Furthermore, when a crane is installed on a pier or structure, secondary vibrations will occur between the crane and the pier or structure after an earthquake, so in order to prevent this, the pier and structure must be reinforced in the same way as the crane. However, it had the drawbacks of being expensive and time-consuming.

The present invention has been made in view of the problem that cranes are prone to collapse due to earthquakes as described above, and is intended to effectively solve this problem.

An object of the present invention is to provide a mobile crane in which legs are supported on a traveling base movable on rails via wheels, the legs and the traveling base being slidably connected by a connecting member, The connection allows the legs and the running base to mutually slide in a direction perpendicular to the extending direction of the rail on a horizontal plane;
Furthermore, a buffer member is interposed on the legs and the running base near the connecting member to buffer the sliding movement of the running base against the legs, and the lateral shaking of the rail that occurs when an earthquake occurs is guided to the running base via the wheels. To provide a vibration damping device capable of alleviating the vibrations of a crane caused by an earthquake by allowing the traveling platform to slide while being cushioned against the legs.

Furthermore, it is an object of the present invention to reduce the vibrations of a crane by interposing a buffer member between the crane legs and the traveling platform, without providing the crane with any particular strength for earthquake resistance. To provide a relatively lightweight and inexpensive vibration damping device capable of preventing secondary system vibrations.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram showing a traveling crane using a vibration damping device according to the present invention, and FIG. 2 is a side view showing an embodiment of the vibration damping device according to the present invention.

3 is an enlarged sectional view taken along the line A-A in FIG. 2, FIG. 4 is a partially enlarged sectional view taken along the line B-B in FIG. 3, and FIG. FIG. 7 is a sectional view showing another embodiment.

As shown in FIG. 1, reference numeral 1 is a traveling tower-shaped swing lever crane (hereinafter simply referred to as a crane), and a tiered traveling platform 3 is attached to the legs 2 of this crane 1. This allows the crane 1 to move on a foundation or substructure 4 (hereinafter simply referred to as the base).

Specifically, as shown in FIG. 2, the traveling platform 3 has a plurality of wheels 6 supported and guided by rails 5 laid on a base 4, and one or more of these wheels 6 are rotatable. It consists of a plurality of wheel holding frames 7 to be held, and a support frame 10 which rotatably connects each bracket 8 fixed to the upper surface of these wheel holding frames 7 via a rotation shaft 9.

As shown in FIG. 3, a rod-shaped connecting member 11 is fixedly attached to the leg 2 of the crane 1 so as to extend in a direction perpendicular to the extending direction of the rail 5 on a horizontal plane.

A hole 10a slightly larger than the diameter of the connecting member 11 is formed in the support frame 10 of the traveling platform 3, and by passing the connecting member 11 through this hole 10a, the support frame 10 and the leg 2 are slidably connected. There is.

In this way, the legs 2 and the carriage 3 are configured to be able to slide relative to each other in a direction perpendicular to the extending direction of the rail 5 on a horizontal plane.

A buffer member 1 is installed on the legs 2 and the traveling platform 3 near the connecting member 11.
2 is interposed.

Specifically, as shown in FIGS. 2 to 4, the buffer member 12 is fixedly attached to the leg 2 above the connecting member 11 in parallel with the connecting member 11, and has a groove 13a formed on the lower surface. Hollow guide rail 13 and this guide rail 13
It consists of an elastic body 14 filled therein and a protrusion 15 fixed to the upper surface of the support frame 10 of the carriage 3 and large enough to engage with the groove 13a of the guide rail 13.

By inserting the protrusion 15 into the groove 13a and holding the protrusion 15 inside the elastic body 14, the movement of the carriage 3 relative to the leg 2 can be appropriately damped.

Next, the operation of the present invention will be described.

In FIGS. 1 and 2, when an earthquake occurs, a wheel brake mechanism (not shown) is activated to stop the movement of the traveling platform 3 on the rail 5, and a drive source (not shown) is activated. stop all.

In this state, if the earthquake is a so-called pitching shaking, it is possible to prevent the crane 1 from collapsing by appropriately installing a suspension device (not shown), and if the earthquake is accompanied by a weak horizontal shaking. Even so, the suspension system can sufficiently prevent collapse.

When an earthquake causes so-called lateral shaking, it can be roughly divided into cases where the lateral shaking is in the extending direction of the rails 5 and cases where the lateral shaking is perpendicular to the extending direction of the rails 5 on the horizontal plane.

First, if the horizontal shaking due to an earthquake is in the extending direction of the rail 5, the locked wheels 6 will slip on the rail 5 on the base 4, and the crane 1 will be moved to the rail via the traveling platform 3 and the legs 2. Move over 5.

At this time, since the frictional force between the wheels 6 and the rails 5 appropriately restricts the movement of the crane 1 on the rails 5, the vibration of the crane 1 due to the earthquake is reduced.

Next, if the horizontal shaking due to an earthquake is perpendicular to the extending direction of the rail 5 on the horizontal plane, the rail 5 on the base 4 will cause horizontal shaking, and this rolling of the rail 5 will be caused by the wheels 6 and the wheel support. It is transmitted to the support frame 10 via the frame 7, bracket 8, and rotation shaft 9.

However, as shown in FIGS. 3 and 4, the support frame 10 is slidably connected to the leg 2 via the connecting member 11, and the protrusion 15 of the support frame 10 is elastically connected to the guide rail 12 of the leg 2. Since the support frame 10 slides while being buffered via the body 14, the horizontal vibration of the support frame 10 exceeding a predetermined strength is not directly transmitted to the legs 2, and the support frame 10 side slides with respect to the legs 2 while being buffered. That will happen.

In other words, only the traveling platform 3 is moved while being cushioned, and the legs 2 are
It acts to reduce the horizontal vibration of the

Thereby, the vibration of the crane 1 can be reduced.

Note that the horizontal shaking of the support frame 10 exceeding a predetermined strength refers to horizontal shaking that may cause the crane 1 to collapse if the buffer member 12 and the connecting member 11 are not provided.

In this way, the crane
can prevent collapse.

In the above embodiment, the case where the connecting member 11 is fixedly attached to the leg 2 and the support frame 10 is made slidable with respect to the connecting member 11 has been described, but in the present invention, the connecting member 11 is attached to the support frame 10. It may be fixedly attached and the connecting member 11 may be slidable relative to the leg 2.

Moreover, the groove 13a of the guide rail 13 in the embodiment
A stopper 16 may be formed in the support frame 10 to appropriately restrict the sliding range of the protrusion 15 and prevent the support frame 10 from colliding with the leg 2.

In the above embodiment, the buffer member 12 using the elastic body 14 was explained, but in the present invention, as shown in FIG. The shock absorbing member 12 may be made up of a fluid cylinder 19 fixedly attached to the leg 2 by attaching the tip of the shock absorbing member 12, or any material that can be used as a base may be used.

Incidentally, in the above embodiment, the case where the buffer member 12 is provided between the leg 2 and the support frame 10 has been described, but in the present invention, the buffer member 12 is provided between the support frame 10 and the wheel holding frame 8, respectively. Good too.

Furthermore, although the tower-type swing lever crane 1 has been described in the above embodiment, the present invention is not limited to this, and any mobile crane may be used as long as it is a traveling crane, and furthermore, any industrial machine similar to a crane may be used. good.

As explained above, according to the present invention, in a traveling crane whose legs are supported on a traveling platform movable on rails via wheels, the legs and the traveling platform are slidably connected by a connecting member. The combination allows the legs and the running platform to slide against each other in a direction perpendicular to the extending direction of the rail and on a horizontal plane, and furthermore, by interposing a buffer member on the legs and running platform near the connecting member. , the sliding motion of the traveling platform against the legs is buffered, and the rolling motion of the rail that occurs during an earthquake can be guided to the traveling platform via the wheels, and the traveling platform can be made to slide while being buffered against the legs. This is something that can reduce the vibrations of cranes caused by earthquakes.

Further, according to the present invention, by interposing a buffer member between the crane legs and the traveling platform, the vibration of the crane can be relaxed without providing the crane with any special strength for earthquake resistance. This also reduces vibrations in the secondary system, thereby preventing the crane from collapsing due to an earthquake.

Furthermore, according to the present invention, by using the above-mentioned mechanism, it is possible to reduce the vibration of the crane due to an earthquake without increasing the weight of the crane, and the earthquake resistance of the crane can be increased at a relatively low cost. Furthermore, it has excellent effects such as making it possible to easily make existing cranes earthquake resistant by simply modifying the connecting part between the legs and the traveling platform.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a traveling crane using a vibration damping device according to the present invention, FIG. 2 is a side view showing an embodiment of the vibration damping device according to the present invention, and FIG. 3 is an A of FIG. - A enlarged cross-sectional view taken along the arrow A; FIG. 4 is an enlarged partial cross-sectional view taken along the line B-B of FIG. 3;
The figure is a sectional view showing another embodiment of the seismic mitigation device according to the present invention. In the figure, 1 is a crane, 2 is a leg, 3 is a running base, 5 is a rail, 6 is a wheel, 11 is a connecting member, and 12 is a buffer member.

Claims (1)

[Claims] 1. In a traveling crane whose legs are supported by a traveling platform that can be moved on rails via wheels, the legs and the traveling platform are slidably connected by a connecting member, and the connection between the legs and the traveling platform is made possible. can slide on each other in a direction perpendicular to the extending direction of the rails on a horizontal plane, and furthermore, a buffer member is interposed on the legs and the running base near the connecting member to buffer the sliding movement of the running base on the legs. In this way, the horizontal shaking of the rails that occurs when an earthquake occurs is guided to the running platform via the wheels, and the running platform slides against the legs while being cushioned, thereby reducing the vibration of the crane caused by the earthquake. A seismic mitigation device characterized by: