JPH11314877A - Magnetic floating type hoist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To convey a load of a magnetic body by supporting (hanging down) it in a non-contact condition. SOLUTION: A wire rope 23 is wound and delivered from a hoist main body 22. To a pulley 25 provided at the upper part of a support block 24, the wire rope 23 is wound. At the lower part of the support block 24, an electromagnet 26 to attract a load 40 of a magnetic body is provided. The excitation of the electromagnet 26 is controlled to provide the gap between the electromagnet 26 and the load 40 in a specific distance. Consequently, the baggage 40 can be supported (hung down) in a non-contact condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic levitation type hoist, in which a load made of a magnetic material can be supported (suspended) and transferred without contact.

[0002]

2. Description of the Related Art A conventional hoist will be described with reference to FIG. As shown in FIG. 1, a drum 2 is provided in the hoist body 1, and a wire rope 3 is wound and fed from the drum 2. The pulley 5 of the hook block 4 is wound around the wire rope 3, and the hook 6 of the hook block 4 is hung by a wire 8 hung on a load 7.

The hoist body 1 is further provided with a drive wheel 9, a driven wheel 10, and a control box 11. The drive wheel 9 and the driven wheel 10 are mounted on a rail (not shown), and can be traversed (traveled) along the rail by rotating the drive wheel 9 by driving a drive motor (not shown).

In such a conventional hoist, a wire 8 is hung on a load 7 and the wire 8 is hung on a hook 6 to carry the load 7.

[0005]

As described above, in the conventional hoist, the load 7 is transported by hanging the wire 8 on the load 7 and hanging the wire 8 on the hook 6. Challenges.

Since the wire 7 is hung on the load 7, the load 7
Of the parts (points) where the wire 8 contacts,
Could be scratched.

A special technique (sling technique) was required to hang the wire 8 on the load 7.

[0008] A certain distance is required between the hook 6 and the load 7, and it is sometimes difficult to suspend a tall load in a place where the ceiling is low.

In view of the above prior art, an object of the present invention is to provide a magnetic levitation hoist which does not require a slinging technique and can be supported (suspended) without damaging a load.

[0010]

According to the present invention, there is provided a hoist body for winding and feeding a wire rope, and a pulley on which the wire rope is wound is provided at an upper portion and an electromagnet is provided at a lower portion. A support block, a gap sensor that detects a gap between the electromagnet and a load made of a magnetic material, and a control mechanism that controls excitation of the electromagnet such that the gap detected by the gap sensor is a fixed distance. It is characterized by having. Further, a plurality of the electromagnets are provided.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic levitation hoist according to an embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a magnetic levitation hoist according to a first embodiment. As shown in the figure, in the magnetic levitation hoist according to the present embodiment, both ends of the traversing rail 20 are supported by saddle units 21 and 21. The saddle units 21 and 21 travel in the direction of arrow A along travel rails (not shown). Hoist body 22
Travels in the direction of arrow B along the traversing rail 20.

From the hoist body 22, the wire rope 2
The wire rope 23 has a pulley 2 provided on an upper portion of a support block 24.
5 is wound. An electromagnet 26 is provided below the support block 24.

When the electromagnet 26 is excited, it can suck (support / suspend) the magnetic material 40 while maintaining a fixed distance. Further, the support block 24 is provided with a gap sensor 27 (not shown in FIG. 1 but hidden) for detecting a gap between the electromagnet 26 and the load (magnetic material) 30.

The excitation of the electromagnet 26 is controlled by a control mechanism described later. This control mechanism is mounted on the hoist main body 22 or is arranged at a position different from the hoist main body 22.

Control mechanisms for controlling the excitation of the electromagnet 26 include a type shown in FIG. 2 and a type shown in FIG.
As described later, regardless of the control mechanism, the electromagnet 2
The load 40 is sucked (supported / suspended) by the electromagnet 26 while keeping the distance between the load 6 and the load 40 constant, and the electromagnet 26 is controlled so as not to contact the load 40. In this state, the load 40 is moved by traversing the hoist body 22 or running the saddle unit 21.
Is carried out.

First, in the control mechanism shown in FIG. 2, a gap between the electromagnet 26 and the load 40 is detected by the gap sensor 27, and the detected gap value is input to the controller 28. In the controller 28, the difference between the gap command value and the detected gap value is calculated by the subtractor 28a, and the PID controller 28b outputs a voltage command value that makes the detected gap value equal to the gap command value. DC-DC converter 2
9 applies a voltage corresponding to the voltage command value to the electromagnet 26. As a result, while the load 40 is being transported (transported), the electromagnet 2
The distance between 6 and the load 40 is kept constant.

Next, in the control mechanism of FIG. 3, a gap between the electromagnet 26 and the load 40 is detected by the gap sensor 27, and the detected gap value is input to the controller 28. In the controller 28, the difference between the gap command value and the detected gap value is calculated by the subtractor 28a, and the PID controller 28b outputs a command value that makes the detected gap value equal to the gap command value. This command value is supplied to the current controller 30
To obtain the current command value. DC-DC converter 29A
Supplies a current corresponding to the current command value output from the current controller 30 to the electromagnet 26. Thereby, the distance between the electromagnet 26 and the load 40 is kept constant while the load 40 is being transported (transported).

The control mechanism shown in FIG. 3 is such that the DC-DC converter (power converter) 29A is of a current type.
Unlike the control mechanism shown in FIG. 2 (voltage type in FIG. 2), if the response of the current control system is sufficiently fast, adjustment of the control system becomes easier than in the voltage type of FIG. However, it becomes complicated in terms of hardware.

In the magnetic levitation hoist of this embodiment, the load 40 can be sucked (supported / suspended) while the electromagnet 26 keeps a fixed distance (gap) without contacting the load 40. Therefore, there is no need to wire the load 40. For this reason, the load 40 is not damaged, and the slinging operation is not required, so that the tact time is improved. Further, the gap between the electromagnet 26 and the load 40 can be reduced, and the load 40 can be hung even at a low ceiling.

Next, a magnetic levitation hoist according to a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, two electromagnets 26 and 26A are horizontally arranged below the support block 24. The excitation of these two electromagnets 26 and 26A is controlled so that the gap between the two electromagnets 26 and 26A is constant.

The structure of the other parts is the same as that of the first embodiment shown in FIG.

In the second embodiment, two electromagnets 2
With the 6, 26A, the load 40 can be sucked while maintaining a certain distance (gap), and can be stably supported (suspended) while the load 40 is kept horizontal.

[0024]

As described above in detail with the embodiments, according to the present invention, the load can be sucked (supported / suspended) by the electromagnet while keeping the gap between the electromagnet and the load at a constant distance. Therefore, slinging work is not required, and the tact time is improved. Further, since the load can be supported and suspended without contact, the load is not damaged.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a magnetic levitation hoist according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a control mechanism for controlling excitation of an electromagnet.

FIG. 3 is a block diagram showing a control mechanism for controlling excitation of an electromagnet.

FIG. 4 is a perspective view showing a magnetic levitation hoist according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a conventional hoist.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hoist main body 2 Drum 3 Wire rope 4 Hook block 5 Pulley 6 Hook 7 Load 8 Wire 9 Drive wheel 10 Follower wheel 11 Control box 20 Traversing rail 21 Saddle unit 22 Hoist main body 23 Wire rope 24 Support block 25 Pulley 26, 26A Electromagnet 27 Gap sensor 28 Controller 29, 29A DC-DC converter 30 Current controller 40 Load

Claims (2)

[Claims] 1. A hoist body for winding and unwinding a wire rope, a support block having an upper portion provided with a pulley around which the wire rope is wound and an electromagnet at a lower portion; A magnetic levitation hoist comprising: a gap sensor that detects a gap; and a control mechanism that controls excitation of the electromagnet so that the gap detected by the gap sensor is a fixed distance. 2. The magnetic levitation hoist according to claim 1, wherein a plurality of said electromagnets are provided.