JP2012086949A - Bridge crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for suppressing a tension bar for hanging and supporting a boom of a bridge crane from being swung in a travelling direction.SOLUTION: The bridge crane 1 includes: a supporter 21; the long boom 22 provided to protrude from the supporter 21; the tension bar 23 that is provided by connecting an end of the boom 22 to the supporter 21 to be tilted to the boom 22 and hangs and supports the boom 22; and an attenuating means 3 attenuating vibration to the axial tension side of the tension bar 23.

Description

  The present invention relates to a bridge-type crane that suspends and supports a distal end portion of a long boom protruding from a support with a tension bar.

  Conventionally, a container crane (also referred to as a gantry crane) that travels in a container yard parallel to a quay and loads or unloads containers on a container ship anchored on the quay has been widely used. As a kind of container crane, a bridge-shaped crane in the shape of a bridge is known. This bridge crane has a long horizontal girder called a boom protruding from a support that runs on wheels, and the boom is suspended by connecting the tip of the boom and the support diagonally. A supporting tension bar is provided.

  With regard to this bridge crane, a damping device and damping control for suppressing vibration in the transverse direction of the crane, that is, the direction orthogonal to the traveling direction along the quay have been proposed in the past (for example, patents) Reference 1 and Patent Reference 2).

JP 2009-244202 A Japanese Patent No. 3565294

  However, in the conventional bridge crane, there is a problem in that when the elongated tension bar vibrates greatly in the traveling direction during traveling, a large load is generated at a portion where the tension bar is attached to the boom or the support body. More specifically, when the tension bar starts to vibrate in the traveling direction when the bridge crane is traveling, the boom starts to vibrate up and down at a frequency twice that of the natural frequency of the tension bar. This is because the boom is raised at a position where the tension bar vibrates and the tension is increased, and the boom is lowered at a position where the tension is weakened. When the boom starts to vibrate up and down in this way, the vibration in the traveling direction of the tension bar gradually increases due to the influence.

  Therefore, in order to prevent such a problem, it is necessary to suppress the vibration of the tension bar in the traveling direction. However, the vibration damping device and vibration damping control described in Patent Literature 1 and Patent Literature 2 can suppress vibration in the traverse direction of the entire bridge crane, but cannot suppress vibration in the traveling direction of the tension bar. There wasn't.

  The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide means for suppressing the tension bar that suspends and supports the boom of the bridge crane from vibrating in the traveling direction. is there.

  In order to achieve the above object, the present invention employs the following means. That is, the bridge crane according to the present invention includes a support, a long boom that projects from the support, and a tip of the boom and the support so as to be inclined with respect to the boom. And a tension bar for suspending and supporting the boom, and a damping means for attenuating vibration of the tension bar toward the tension side in the axial direction.

  According to such a configuration, the vibration of the tension bar in the traveling direction of the tension bar is suppressed by the vibration of the tension bar in the axial direction being attenuated by the damping means.

  Moreover, the bridge crane according to the present invention is characterized in that the damping means attenuates the vibration of the tension bar in the axial direction by attenuating the vibration in the vertical direction of the boom.

  According to such a configuration, the vibration of the tension bar toward the axial tension side is easily and reliably damped by the damping means.

  In the bridge crane according to the present invention, the damping means dampens vibration in a direction substantially orthogonal to the direction in which the boom is extended, thereby vibrating the tension bar toward the axial tension side. It is characterized by attenuating.

  According to such a configuration, the vibration of the tension bar toward the axial tension side is easily and reliably damped by the damping means.

  The bridge crane according to the present invention is characterized in that the damping means attenuates vibrations having a frequency twice as high as the natural frequency of the tension bar among the vibrations of the boom.

  According to such a configuration, the vibration component that amplifies the vibration in the traveling direction of the tension bar among the vibrations of the boom is attenuated by the damping means, so that the vibration to the tension bar in the axial direction is easy and reliable. Is attenuated.

  Moreover, the bridge crane according to the present invention is characterized in that the damping means is provided at a tip portion of the boom.

  According to such a configuration, the damping means is provided at the tip of the boom where the amplitude of vibration generated in the boom is maximized, so that the greatest damping effect by the damping means can be obtained.

  The bridge crane according to the present invention is characterized in that the damping means is provided on the tension bar.

  According to such a configuration, the vibration of the tension bar itself in the axial direction is directly damped by the damping means provided on the tension bar. Therefore, the vibration of the tension bar is provided by the damping means provided at a place other than the tension bar. As compared with the case of indirectly attenuating, a high attenuation effect by the attenuation means can be obtained.

  According to the bridge crane according to the present invention, the vibration in the traveling direction of the tension bar is suppressed by the vibration of the tension bar in the axial pulling side being attenuated by the damping means. It can prevent beforehand that a big load arises in the attachment location to a support body.

It is a schematic front view which shows the external appearance of the bridge crane which concerns on 1st Embodiment of this invention. It is a schematic plan view which shows the external appearance of the bridge crane which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the structure of an attenuation | damping means. It is the elements on larger scale which expanded the joint part of the support body and tension bar which comprise a crane main body.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings. First, the structure of the bridge crane which concerns on 1st Embodiment of this invention is demonstrated. FIG.1 and FIG.2 is a figure which shows the external appearance of the bridge crane 1 which concerns on 1st Embodiment, FIG. 1 is a schematic front view, FIG. 2 is a schematic plan view. The bridge crane 1 includes a crane main body 2 disposed at a position facing the quay G and damping means 3 attached to a predetermined position of the crane main body.

  The crane body 2 includes a support body 21 having a plurality of wheels 211 that can travel along the quay G, a boom 22 that is supported by the support body 21 and extends in the horizontal direction, and a top portion of the support body 21. And a tension bar 23 provided obliquely connecting the front end of the boom 22, a trolley 241, a rope 242, a suspension 243 provided movably along the boom 22, and a rear end of the boom 22. And a machine room 25 provided in the machine.

  As shown in FIG. 1, the support body 21 includes a pair of leg portions 212 extending in the vertical direction at predetermined intervals, a connecting portion 213 connecting the pair of leg portions 212 extending in the horizontal direction and integrating them, and an oblique direction. And a plurality of wheels 211 respectively provided at the lower ends of the pair of leg portions 212. The support 21 can travel in the direction along the quay G, that is, in the direction indicated by the arrow in FIG.

  As shown in FIG. 1, the boom 22 is a long member extending in a substantially horizontal direction, and its longitudinal central portion is supported by a pair of leg portions 212, and its distal end portion is on the sea side from the quay G. It protrudes and extends to above the container ship S anchored at the quay G. Further, the boom 22 is provided with a pin structure 221 at an intermediate portion in the longitudinal direction, and can be folded as shown by a two-dot chain line in FIG. 1 by being bent at the position of the pin structure 221.

  The tension bar 23 is made of, for example, a long H-shaped steel. As shown in FIG. 1, one end of the tension bar 23 is fixed to the top of the sea-side leg 212, and the other end is fixed to the tip of the boom 22. As a result, both the boom 22 and the leg 212 are inclined. Although not shown in detail in the figure, a pin structure is also provided in the middle portion in the longitudinal direction of the tension bar 23. When the boom 22 is folded, the tension bar 23 is also bent at the position of the pin structure. Therefore, it can be folded.

  The trolley 241 is used to load or unload the container C on the container ship S anchored on the quay G. As shown in FIG. 1, the trolley 241 is provided so as to be movable along the longitudinal direction of the boom 22, and is attached to the other end of the rope 242 with a rope 242 having one end held so as to be wound up by the trolley 241. And a hanging tool 243 to which the container C can be attached and detached. In the present specification, the moving direction of the trolley 241, that is, the direction substantially orthogonal to the traveling direction of the support 21 is referred to as a “transverse direction”.

  The machine room 25 is for housing a motor for driving various devices including the trolley 241, a rope 242, and electrical components. As shown in FIG. 1, the machine room 25 is provided at a rear end portion of the boom 22, more specifically at a land side position than a position supported by a land side leg portion 212.

  The damping means 3 attenuates the vibration of the boom 22 in the vertical direction. Here, FIG. 3 is a schematic diagram showing the configuration of the attenuating means 3. The damping means 3 includes a weight 31 and a coil spring 32 and a hydraulic damper 33 that connect the weight 31 to the boom 22 in parallel. Then, by appropriately setting the mass of the weight 31 and the elastic coefficient of the coil spring 32, for example, the vibration having a frequency twice the natural frequency of the tension bar 23 is attenuated. As shown in FIG. 1, the damping means 3 configured as described above is installed at the front end of the boom 22 in the longitudinal direction.

  Next, the effect of the bridge crane 11 which concerns on 1st Embodiment is demonstrated. When the bridge crane 1 travels along the quay G, vibration in the traveling direction may occur in the tension bar 23 as shown by a one-dot chain line in FIG. 2 (in FIG. 2, the vibration of the boom 22 is not shown in the figure). (Omitted). In this case, the boom 22 connected to the tension bar 23 at the tip is maximum displaced upward when the tension bar 23 reaches maximum displacement before and after the traveling direction, and the displacement of the tension bar 23 in the traveling direction is 0. When it becomes, it vibrates up and down so that it becomes maximum displacement downward. That is, the tension bar 23 vibrates in one cycle in the traveling direction, whereas the boom 22 vibrates in two cycles in the vertical direction. Therefore, the boom 22 vibrates at a frequency twice the natural frequency of the tension bar 23. To do. Then, when pulled by the boom 22 that vibrates in the vertical direction, the tension bar 23 is vibrated in the axial direction, and the vibration of the tension bar 23 in the traveling direction gradually increases.

  However, in the present embodiment, the vibration in the vertical direction of the boom 22 is attenuated by the damping means 3, so even if the tension bar 23 generates vibration in the traveling direction when the bridge crane 1 is traveling, Since vibration in the vertical direction does not occur, the vibration in the traveling direction of the tension bar 23 is suppressed from gradually increasing. Thereby, it can prevent beforehand that a big load arises in the fixed location to the boom 22 or the support body 21 by the vibration to the running direction of the tension bar 23. FIG.

In the present embodiment, one attenuation means 3 is installed, but any number of attenuation means 3 can be installed.
Further, the installation position of the damping means 3 is not limited to the distal end portion of the boom 22, and can be an arbitrary position along the longitudinal direction of the boom 22. However, it is preferable to install the boom 22 at the tip end portion of the boom 22 where the vibration of the boom 22 is maximized as in the present embodiment, because the damping effect by the damping means 3 can be obtained.
Further, in the present embodiment, the vibration of the frequency twice the natural frequency of the tension bar 23 is damped by the damping means 3, but depending on the configuration of the boom 22 and the tension bar 23, the vibration of an arbitrary frequency is obtained by the damping means 3. So that the mass of the weight 31 and the elastic coefficient of the coil spring 32 may be set as appropriate.
Further, the configuration of the attenuating means 3 is not limited to the present embodiment, and the design can be changed as appropriate, and either the active damping method or the passive damping method may be adopted.

(Second Embodiment)
Next, the structure of the bridge crane 1 which concerns on 2nd Embodiment of this invention is demonstrated. The bridge crane 1 of this embodiment is provided with the crane main body 2 and the damping means 3 attached to this crane main body 2 similarly to the bridge crane 1 of 1st Embodiment shown in FIG. . However, the function of the attenuating means 3 is different from that of the first embodiment. In addition, the same code | symbol is used about the same structure as 1st Embodiment, and the description is abbreviate | omitted.

  As in the first embodiment shown in FIG. 3, the damping means 3 includes a weight 31, a coil spring 32, and a hydraulic damper 33, and is installed at the front end of the boom 22 in the longitudinal direction. However, the damping means 3 attenuates vibrations in the direction substantially orthogonal to the direction in which the boom 22 extends, that is, in the present embodiment, in the traveling direction. The role is different from that of the attenuating means 3 of the first embodiment.

  Next, the effect of the bridge crane 1 which concerns on 2nd Embodiment is demonstrated. When the bridge crane 1 travels along the quay G, the boom 22 may generate not only vibration in the vertical direction but also vibration in the traveling direction. Also in this case, the tension bar 23 is vibrated in the axial direction by being affected by the vibration of the boom 22 in the traveling direction, whereby the vibration of the tension bar 23 in the traveling direction gradually increases. . However, in the present embodiment, the vibration in the traveling direction of the boom 22 is damped by the damping means 3, so that the vibration of the tension bar 23 in the traveling direction is suppressed from gradually increasing. Thereby, it can prevent beforehand that a big load arises in the fixed location to the boom 22 or the support body 21 by the vibration to the running direction of the tension bar 23. FIG.

It should be noted that an arbitrary number of the damping means 3 can be installed, the installation position of the damping means 3 can be an arbitrary position along the longitudinal direction of the boom 22, and the configuration of the damping means 3 is appropriately selected. The point that the setting can be changed is the same as in the first embodiment.
Further, in this embodiment, only the damping means 3 capable of damping the vibration in the traveling direction of the boom 22 is installed, but together with this, the damping means 3 of the first embodiment, that is, the vibration of the boom 22 in the vertical direction can be damped. A simple damping means 3 may also be installed. Then, the vibration can be damped in both the traveling direction and the vertical direction of the boom 22, so that the vibration in the traveling direction of the tension bar 23 can be further suppressed from gradually increasing.

(Third embodiment)
Next, the structure of the bridge crane 1 which concerns on 3rd Embodiment of this invention is demonstrated. The bridge crane 1 of this embodiment is provided with the crane main body 2 and the damping means 3 attached to this crane main body 2 similarly to the bridge crane 1 of 1st Embodiment. However, the attachment position of the damping means 3 in the crane body 2 is different from that in the first embodiment. In addition, the same code | symbol is used about the same structure as 1st Embodiment, and the description is abbreviate | omitted.

  FIG. 4 is a partially enlarged front view in which a joint portion between the support body 21 and the tension bar 23 constituting the crane body 2 is enlarged. The support body 21 and the tension bar 23 are coupled by, for example, pin coupling, and a link 231 provided at one end of the tension bar 23 is rotatably fitted to a pin 215 that protrudes from the support body 21. Yes. Attenuating means 4 is provided at a position near the link 231 of the tension bar 23 for attenuating vibration of the tension bar 23 toward the axial tension side. The damping means 4 includes a coil spring 42 and a hydraulic damper 43.

Next, the effect of the bridge crane 1 which concerns on 3rd Embodiment is demonstrated. When the bridge crane 1 travels along the quay G, the tension bar 23 may vibrate in the travel direction as described above. Then, by being affected by the vibration in the vertical direction or traveling direction generated in the boom 22, the tension bar 23 is vibrated toward the axial pulling side, whereby the tension bar 23 is gradually vibrated in the traveling direction. Become bigger.
However, in the present embodiment, the vibration of the tension bar 23 toward the axial pull side is attenuated by the damping means 4, so even if the boom 22 generates vibration in the vertical direction or the traveling direction, the tension is affected by the influence. It can suppress that the vibration to the running direction of the bar 23 becomes large gradually. Thereby, it can prevent beforehand that a big load arises in the fixed location to the boom 22 or the support body 21 by the vibration to the running direction of the tension bar 23. FIG.

The installation position of the attenuating means 4 is not limited to a position close to the link 231 and can be an arbitrary position along the longitudinal direction of the tension bar 23.
Further, it is the same as in the first embodiment that an arbitrary number of attenuation means 4 can be installed and that the configuration of the attenuation means 4 can be appropriately changed.
In this embodiment, only the damping means 4 capable of damping the vibration of the tension bar 23 in the axial direction is installed. However, the damping of the first embodiment capable of damping the vibration of the boom 22 in the vertical direction is also provided. The means 3 and the damping means 3 of the second embodiment capable of damping the vibration in the traveling direction of the boom 22 may be installed together. By doing so, vibration can be attenuated for both the tension bar 23 and the boom 22, so that the vibration in the traveling direction of the tension bar 23 can be further suppressed from gradually increasing.
Moreover, although this embodiment demonstrated the case where the damping means 4 was provided in the tension bar 23 provided diagonally connecting the top part of the support body 21 and the front-end | tip part of the boom 22, the top part of the support body 21 and a boom are demonstrated. The damping means 4 may be provided on a tension bar 23 provided obliquely connecting the rear end portion of 22.

  In each of the above embodiments, the case where the tension bar 23 is vibrated in the traveling direction when the bridge crane 1 is traveling has been described as an example. The present invention can also be applied to vibration in a direction.

  The various shapes, combinations, operation procedures, and the like of the constituent members shown in the above-described embodiments are merely examples, and various changes can be made based on design requirements and the like without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Bridge crane 2 Crane main body 21 Support body 211 Wheel 212 Leg part 213 Connection part 214 Reinforcement part 215 Pin 22 Boom 221 Pin structure 23 Tension bar 231 Link 24 Cargo handling unit 241 Trolley 242 Rope 243 Lifting tool 25 Machine room 3 Damping means 31 Weight 32 Coil spring 33 Hydraulic damper 4 Damping means 42 Coil spring 43 Hydraulic damper C Container ship G Quay S Container ship

Claims (6)

A support;
A long boom provided overhanging from the support;
A tension bar provided to connect the tip of the boom and the support so as to be inclined with respect to the boom, and to support the boom by hanging;
Damping means for damping the vibration to the tension side of the tension bar;
A bridge crane characterized by comprising:   2. The bridge crane according to claim 1, wherein the damping means attenuates vibration of the tension bar in the axial direction by attenuating vibration in the vertical direction of the boom.   2. The damping means attenuates the vibration of the tension bar toward the axial tension side by attenuating vibration in a direction substantially perpendicular to the direction in which the boom extends. The bridge crane described in 1.   The bridge crane according to claim 2 or 3, wherein the damping means attenuates vibrations having a frequency twice the natural frequency of the tension bar among vibrations of the boom.   The bridge crane according to any one of claims 2 to 4, wherein the damping means is provided at a tip of the boom.   The bridge crane according to claim 1, wherein the damping means is provided on the tension bar.

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