JPH05105385A - Magnetic device for sling-up transportation - Google Patents

Abstract

PURPOSE:To provide a magnetic device for sling-up transportation that can save energy by reducing electric power loss and solving the problem of internal temperature rise. CONSTITUTION:The proposed device is equipped with an iron core 1, an exciting coil 2 wound around the iron core 1, a permanent magnet 5 having a magnetic attraction force in a ratio of 1:1 relative to the magnetic attraction force of a magnet installed covering the end face of the magnetic pole portion of the iron core 1, and a control device 6 which can switch the exciting current of the exciting coil in normal/reverse direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic device for hoisting and carrying.

[0002]

2. Description of the Related Art As a device for hoisting and carrying a magnetic member such as steel, a hoisting electromagnet having an electromagnetic coil is generally used.

FIG. 3 shows an electromagnet of this type.
Is an iron core, 2 is an exciting coil wound around the iron core, 3 is a protective plate, and when hoisting a carrier W such as a steel material,
The electromagnet is lowered onto the conveyed object 4 and an exciting current (DC current) is caused to flow from the excitation power source 4 to the exciting coil 2 to generate a magnetic flux flowing from the magnetic pole portion 1N → the conveyed object 4 → the magnetic pole portion 1S to adsorb the conveyed object 4 , Lift the electromagnet with a crane and transport it to the designated place. When the paper is conveyed to a predetermined place, the supply of the exciting current is cut off to demagnetize and the electromagnetic attraction force disappears.

[0004]

As described above, the hoisting electromagnet can hold and release the article W by a simple operation of turning the power on and off. However, while the article W is being conveyed, the exciting current is supplied. Since it must be continuously supplied, the I ² R loss is large, and there is a problem in terms of energy saving, and the temperature rise inside the electromagnet is also a problem.

The present invention has been made to solve this problem, and provides a hoisting and transporting magnetic device capable of reducing power loss, saving energy, and solving the problem of internal temperature rise. The purpose is to do.

[0006]

In order to achieve the above object, the present invention provides a permanent magnet attached to an iron core, an exciting coil wound around the iron core, and an end surface of a magnetic pole portion of the iron core. A configuration is provided that includes a magnet and a control device that controls the exciting current of the exciting coil.

According to another aspect of the present invention, the control device includes an exciting power source,
A polarity switching circuit that switches the output polarity of this excitation power supply,
A magnetic flux sensor for detecting the amount of magnetic flux flowing through the iron core, and an exciting current control circuit for giving an exciting current command corresponding to the deviation between the magnetic flux amount and the magnetic flux command value to the exciting power supply are provided.

In the third aspect, the magnetic flux command has a magnitude that makes the magnetic attraction force component of the permanent magnet and the magnetic attraction force component of the electromagnet 1: 1, and the polarities are reversed between when the conveyed object is attracted and when it is released. It is configured to be.

[0009]

In the present invention, the attraction force for the conveyed product is the sum of the attraction force by the electromagnet and the attraction force by the permanent magnet. Further, by reversing the polarity of the magnetic flux command, it is possible to release the conveyed product by reducing the attraction force to the conveyed product to zero.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 12 shows the main body of the apparatus. Reference numeral 5 denotes a permanent magnet. The N-pole permanent magnet and the S-pole permanent magnet are fixed to cover the end faces of the magnetic pole portions 1N and 1S of the yoke 1 of the electromagnet 11, respectively.

The control device 6 for controlling the exciting current I _F comprises an exciting current control circuit 7, a polarity switching circuit 8, an error amplifier 9 and a magnetic flux sensor 10. The exciting current control circuit 7 detects the amount of magnetic flux detected by the magnetic flux sensor 10 (flows through the iron core 1) Φ.
And enter the deviation between the flux command [Phi ^* value when the polarity of the magnetic flux command [Phi ^* is inverted with providing the excitation current command I _F ^* excitation power 4 corresponding to the value of the flux command [Phi ^*, excitation direction switching instruction The signal S is given to the polarity switching circuit 8.

In this structure, assuming that the attractive force (generated magnetic flux amount) required to safely attract and hold the conveyed article W is 1, the permanent magnet 6 shares 0.5 of this attractive force, and the electromagnet 11 has this attractive force. It is assumed that the value of the magnetic flux command Φ ^* is set so as to share 0.5 of the above. When hoisting the conveyed product W such as steel material, the device 12 is lowered onto the conveyed product W to give the magnetic flux command Φ ^* . Given a flux command [Phi ^* (positive flux command), the excitation current control circuit 7 supplies the excitation current command I _F ^* of a size corresponding to the excitation power supply 4 to the flux command [Phi ^*, exciting the electromagnetic coil 3 A current I _F flows and the magnetic pole portion 1N →
A magnetic flux Φ1 flowing from the conveyed product 4 to the magnetic pole portion 1S is generated. On the other hand, since the generated magnetic flux Φ2 (= Φ1) of the permanent magnet 5 also flows in the same direction, the attraction force for the conveyed article W is the sum of the attraction force by the electromagnet 11 and the attraction force by the permanent magnet 5.

In this way, the article W is adsorbed and the apparatus 1
2 is lifted by a crane and transported to a specified place
Ends, the magnetic flux command Φ^*Reverse the polarity of. Magnetic flux finger
Order Φ ^*Is reversed, the exciting current control circuit 7
Since the switching command S is given to the polarity switching circuit 8, the electromagnetic coil
Excitation current I flowing in 3_FOf the electromagnet 11 is reversed.
The generated magnetic flux is a magnetic flux that cancels the generated magnetic flux Φ2 of the permanent magnet 5.
(-Φ), and the conveyed product W is released.

[0015] In this embodiment, since the half of the required attraction force the permanent magnet 5 share the exciting current I _F is requires only half as compared with the case of the configuration in FIG. 3, I ² R loss Will be reduced to 1/4, and the temperature rise can be suppressed by that much as compared with the conventional case.

Further, since the exciting current I _F flowing for releasing the conveyed object W is only at the end of the conveying, I ² due to this is generated.
R loss is extremely small, and during non-conveyance (during empty conveyance),
Since the state away from the conveyed object, (although it is preferred that the safety cancels) necessary to cancel the attractive force of the permanent magnet 5 is not, since it is not necessary to energize the electromagnet 11, generated I ² R loss In effect, the transported article W is transported.

In the above embodiment, the permanent magnet 5 shares the attraction force (generated magnetic flux amount), for example, 0.8 required for the safe attraction and holding of the conveyed product W, and the electromagnet 11 shares the remaining 0.2. However, the required power supply capacity may be lower when the permanent magnet 5 shares 0.5 and the electromagnet 11 shares the remaining 0.5 as in the present embodiment.

[0018]

As described above, according to the present invention, since the permanent magnet and the electromagnet are combined, it is possible to reduce power loss, save energy, and solve the problem of internal temperature rise.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a block diagram of a control device of the above embodiment.

FIG. 3 is a sectional view of a conventional lifting electromagnet.

[Explanation of symbols]

 1 Iron Core 2 Excitation Coil 4 Excitation Power Supply 5 Permanent Magnet 6 Controller 7 Excitation Current Control Circuit 8 Polarity Switching Circuit 9 Error Amplifier 10 Magnetic Flux Sensor 11 Electromagnet W Transported Object

Claims (3)

[Claims] 1. A magnetic material for hoisting and transporting, comprising an iron core, an exciting coil wound around the iron core, a permanent magnet attached to cover an end surface of a magnetic pole portion of the iron core, and a controller for controlling an exciting current of the exciting coil. apparatus. 2. The control device responds to an excitation power source, a polarity switching circuit that switches the output polarity of the excitation power source, a magnetic flux sensor that detects the amount of magnetic flux flowing in the iron core, and a deviation between the magnetic flux amount and the magnetic flux command value. The magnetic apparatus for lifting and transporting according to claim 1, further comprising an exciting current control circuit for giving the exciting current command to the exciting power source. 3. The magnetic flux command is of a magnitude that makes the magnetic attraction force component of the permanent magnet and the magnetic attraction force component of the electromagnet 1: 1 and the polarity is reversed between when the conveyed object is attracted and when it is released. The magnetic device for lifting and transporting according to claim 1, wherein: