JPH08259173A - Damping device for crane - Google Patents

Abstract

PURPOSE: To provide a damping device for a crane which is easily applicable to the crane at low cost. CONSTITUTION: This device is provided with at a wire 3 furnished on a crane 1 to suspend a cargo 5 and a conductive non-magnetic material 6 having holes 8, 9 to insert the wire 3 suspended from the crane 1 and arranged so as to cross magnetic fields of permanent magnets 12, 13, and when deflection of the wire 3 moves the conductive non-magnetic material 6 through the holes 8, 9, the magnetic fields of the permanent magnets 12, 13 add force in a direction to prevent movement of the conductive non-magnetic material 6 and damp deflection of the wire 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for a crane, which is designed to stop the vibration of a load lifted by a crane.

[0002]

2. Description of the Related Art When a crane starts traveling while a load is lifted by a wire, stops traveling, or turns, the load swings due to inertia.

In order to prevent such a swing of the load, conventionally, fuzzy control has been applied to a traveling motor or a swing motor of a crane to stop the swing of the load.

[0004]

The method of applying the fuzzy control to the traveling motor or the swinging motor of the crane to stop the swinging of the load exerts sufficient damping effect when the traveling pattern of the crane is clear. However, there is a problem that a sufficient damping effect cannot be exerted when the running motor is started and stopped by manual operation.

Further, it is difficult to apply fuzzy control to a traveling motor for an existing crane, and there is a problem that the cost is high.

The present invention solves these conventional problems,
It is an object of the present invention to provide a vibration damping device for a crane that can be easily applied at low cost.

[0007]

SUMMARY OF THE INVENTION The present invention has a wire for suspending a load in preparation for a crane, a hole for suspending a load from the crane and passing through the wire, and arranged so as to cross a magnetic field of a permanent magnet. The present invention relates to a vibration damping device for a crane, characterized by comprising: a conductive non-magnetic material, and a wire that moves through a hole provided in the conductive non-magnetic material by winding and unwinding the wire with respect to a winding drum. It can be a long hole in the direction.

[0008]

When the wire that suspends the load swings, the conductive non-magnetic material that passes through the wire also swings. However, the movement of the conductive non-magnetic material is stopped by the magnetic field of the permanent magnet. It is stopped by the acting force, and the swing of the load is also damped.

By making the hole provided in the electrically conductive non-magnetic material a long hole in the direction in which the wire moves by winding and unwinding the wire with respect to the winding drum, movement of the wire other than when vibration damping is required is prevented. Do not restrain.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of an embodiment of the present invention, in which an overhead traveling crane 1 is equipped with a winding drum 2, and one end 3a side of a wire 3 is wound around the winding drum 2. ing.

The other end 3b of the wire 3 is fixed to the crane 1, and a load 5 is hung via a sheave 4 at an intermediate portion of the wire 3. The winding drum 2 is rotated by a motor (not shown) to wind up or wind down the one end 3a side of the wire 3 to raise or lower the load 5.

Immediately below the winding drum 2, a conductive non-magnetic material 6 made of a copper plate is suspended from the crane 1 so that it can be freely moved by a suspension wire 7 having a low rigidity. At this time, as the conductive non-magnetic material 6, an aluminum plate or the like can be used in addition to the copper plate.

The conductive non-magnetic material 6 includes the wire 3 described above.
The hole 8 through which the one end 3a side wound around the winding drum 2 is inserted, and the hole 9 through which the other end 3b side of the wire 3 fixed to the crane 1 is inserted.

As shown in the plan view of FIG. 2, the hole 8 through which the one end 3a of the wire 3 is inserted is a long hole. The length of the long hole depends on the winding drum 2 winding the wire 3 around. Taking area 10
The length of the long hole is parallel to the central axis of the winding drum 2.

A hole 9 for inserting the other end 3b of the wire 3 therethrough
Has a minimum small hole necessary for inserting the other end 3b side of the wire 3.

The crane 1 is provided with a yoke 11, to which permanent magnets 12 and 13 are attached so that their magnetism is opposite. Then, one side of the above-mentioned conductive non-magnetic material 6 is inserted between the permanent magnets 12 and 13, and is arranged so as to cross the magnetic field generated by the permanent magnets 12 and 13.

Next, the operation of the above-mentioned device will be described.

When the winding drum 2 is rotated by a motor (not shown) to wind up or wind back the one end 3a side of the wire 3, the wire 3 raises or lowers the load 5 via the sheave 4.

At this time, the one end 3a side of the wire 3 wound around the winding drum 2 is wound around the winding drum 2 and rises, or is rewound from the winding drum 2 and is lowered, while being in the hanging position. Also moves within the winding area 10 of the winding drum 2. Therefore, even at the position of the long hole 8 as shown in FIG. 2, the wire 3 moves in the length direction of the hole 8 while moving up and down, and the hole 8 of the conductive non-magnetic material 6 is moved.
Does not hinder the winding and unwinding of the wire 3.

On the other hand, the other end 3b side of the wire 3 is fixed to the crane 1 and is not wound or unwound. Therefore, the wire 9 is kept almost stationary inside the small hole 9. .

When the load 5 shakes together with the wire 3 due to the start or stop of the traveling of the crane 1 or the like, the wire 3 also shakes at the places where the holes 8 and 9 of the wire 3 are inserted, and the wire 3 is made of a conductive nonmagnetic material. 6 will be moved. If the deflection direction of the wire 3 at this time is parallel to the central axis of the winding drum 2, one end 3a side of the wire 3 has a hole 8a.
Does not contribute to the movement of the conductive non-magnetic material 6 because it moves in the length direction of the wire 3, but the other end 3b side of the wire 3 moves the conductive non-magnetic material 6 through the hole 9 and the deflection direction of the wire 3 Is in the other direction, one end 3a of the wire 3 is
Both the side and the other end 3b side move the conductive non-magnetic material 6 through the holes 8 and 9.

As described above, when the load 5 swings together with the wire 3 and the conductive non-magnetic material 6 moves by the wire 3, one side of the conductive non-magnetic material 6 that crosses the magnetic field between the permanent magnets 12 and 13. An eddy current is generated in the portion, and a force in a direction to prevent the movement acts on the conductive nonmagnetic material 6.

Therefore, the conductive non-magnetic material 6 applies a force to the wire 3 through the holes 8 and 9 in a direction to stop the vibration, and the vibration of the wire 3 and the load 5 is rapidly attenuated.

FIG. 3 shows another embodiment of the present invention, in which an undulating wire 15 wound around an undulating drum 14 is used.
Winding reel 17 is attached to the tip of jib 16 which is undulated by
There is shown a jib type crane 19 in which the wire 3 wound around the take-up drum 18 hoists and lowers the load 5 via the hoisting reel 17, and swivels by the swivel base T. The conductive non-magnetic material 6 is provided directly below the winding reel 17 at the tip of the jib 16.
It is hung so as to be freely movable with respect to a fixing member 20 provided on the jib 16 via a short suspension wire 7 having low rigidity.

The conductive non-magnetic material 6 is provided with a hole 21 through which the wire 3 suspended from the winding reel 17 is inserted. Since the wire 3 suspended from the winding reel 17 does not move in position even when the load 5 is wound down, the wire 3 is inserted into the hole 21 formed in the conductive non-magnetic material 6. It has the minimum required small holes.

The jib 16 is provided with a yoke 11,
Permanent magnets 12 and 13 are attached to the yoke 11 so as to have opposite magnetism. Then, one side of the above-mentioned conductive non-magnetic material 6 is inserted between the permanent magnets 12 and 13, and is arranged so as to cross the magnetic field generated by the permanent magnets 12 and 13.

According to the embodiment shown in FIG. 3, the wire 3 is moved by starting and stopping the work such as undulation and turning of the jib 16.
At the same time, when the load 5 shakes, the load 3 also shakes at a position where the wire 21 is inserted through the hole 21, and the wire 3 moves the conductive non-magnetic material 6. When the conductive non-magnetic material 6 is moved by the wire 3, an eddy current is generated in a part of the conductive non-magnetic material 6 that crosses the magnetic field between the permanent magnets 12 and 13, and the conductive non-magnetic material 6 is generated. Exerts a force in the direction of blocking its movement.

Therefore, the conductive non-magnetic material 6 applies a force to the wire 3 through the hole 21 in the direction to stop the vibration, and the vibration of the wire 3 and the load 5 is rapidly attenuated.

FIG. 4 shows another embodiment of the present invention, in which a gate frame 24 running on rails 23 by wheels 22 is provided with a winding drum 25, and a wire 3 is used for hoisting and lowering a load 5. The above-mentioned portal crane 26 is shown, in which the conductive non-magnetic material 6 is provided immediately below the winding drum 25 with a short suspension wire 7 having low rigidity with respect to the support member 27 of the winding drum 25. It is suspended so that it can move freely through.

The conductive non-magnetic material 6 includes the winding drum 2
A hole 28 through which the wire 3 unwound from 5 is inserted is formed. The hole 28 through which the wire 3 is inserted is provided when the winding drum 25 winds and unwinds the wire 3.
Has a long hole in the moving direction (axial direction of the winding drum) so as not to restrain the movement of the wire 3 when the wire 3 is wound and unwound.

A yoke 11 is provided on the gate-shaped frame 24, and permanent magnets 12 and 13 are attached to the yoke 11 so as to have opposite magnetism. Then, one side of the above-mentioned conductive non-magnetic material 6 is inserted between the permanent magnets 12 and 13, and is arranged so as to cross the magnetic field generated by the permanent magnets 12 and 13.

According to the embodiment shown in FIG. 4, when the load 5 swings together with the wire 3 due to the start or stop of traveling of the gate-type crane 26, the swinging also occurs at the position where the hole 28 of the wire 3 is inserted. Occurs, and the wire 3 moves the conductive non-magnetic material 6. When the conductive non-magnetic material 6 is moved by the wire 3, an eddy current is generated in a part of the conductive non-magnetic material 6 that crosses the magnetic field between the permanent magnets 12 and 13.
A force is applied to the electrically conductive non-magnetic material 6 in a direction to prevent its movement.

Therefore, the conductive non-magnetic material 6 applies a force to the wire 3 through the hole 28 in a direction to stop the vibration, and the vibration of the wire 3 and the load 5 is rapidly attenuated.

[0035]

According to the first aspect of the present invention, since the conductive non-magnetic material traversing the magnetic field of the permanent magnet attenuates the deflection of the wire and the load through the hole, it is not necessary to perform any operation.
With a simple device, the swinging of the load can be stopped, and it is possible to equip an existing crane at low cost.

The invention of claim 2 has an effect that the swing of the wire and the load can be damped without the hole of the conductive non-magnetic material hindering the winding and unwinding of the wire.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention applied to an overhead traveling crane.

FIG. 2 is a plan view of an example of a conductive non-magnetic material used in the present invention.

FIG. 3 is a side view showing an embodiment of the present invention applied to a jib type crane.

FIG. 4 is a front view showing an embodiment of the present invention applied to a gate type crane.

[Explanation of symbols]

 1 Crane 2 Winding Drum 3 Wire 6 Conductive Non-Magnetic Material 8 Hole 9 Hole 12 Permanent Magnet 13 Permanent Magnet 19 Crane 21 Hole 25 Winding Drum 28 Hole

Claims (2)

[Claims] 1. A wire for suspending a load in preparation for a crane, and a conductive non-magnetic material having a hole which is hung from the crane and through which the wire is inserted and which is arranged so as to cross the magnetic field of a permanent magnet. A vibration damping device for a crane, characterized by being equipped with. 2. The vibration damper for a crane according to claim 1, wherein the hole provided in the electrically conductive non-magnetic material is an elongated hole in a direction in which the wire is moved by winding and unwinding the wire with respect to the winding drum. apparatus.