Magnet Unit, Elevator Guiding Apparatus and Weighing Apparatus

• US 20080257655A1
• Filed: 05/10/2005
• Published: 10/23/2008
• Est. Priority Date: 05/11/2004
• Status: Active Grant

• Current Assignee: Toshiba Elevator Kabushiki Kaisha
• Original Assignee: Toshiba Elevator Kabushiki Kaisha
• Inventors: Ito, Hiroaki, Morishita, Mimpei, Tonami, Yosuke
• Granted Patent: US 7,924,128 B2
• Time in Patent Office: Days
• US Class Current: 187/406
• CPC Class Codes: B66B 1/3476 Load weighing or car passenger counting devices B66B5/14 takes precedence
• CPC Class Codes: B66B 7/044 with magnetic or electromagnetic means
• CPC Class Codes: G01G 19/18 having electrical weight-sensitive devices
• CPC Class Codes: G01G 7/02 by electromagnetic action

Abstract

A magnet unit includes a first magnetic pole (7a), a second magnetic pole (7b) and a third magnetic pole (7c) at a center between the first magnetic pole (7a) and the second magnetic pole (7b), providing an E-shaped configuration. In the magnet unit, a first magnet is defined between the first magnetic pole (7a) and the third magnetic pole (7c) by connecting two electromagnets (71aa, 73aa) with each other through a permanent magnet (72a), while a second magnet is defined between the second magnetic pole (7b) and the third magnetic pole (7c) by connecting two electromagnets (71ba, 73ba) with each other through a permanent magnet (72b). With this configuration, it is possible to reduce a deviation in the length of respective magnetic paths from the permanent magnets (72a, 72b) up to their respective magnetic poles. By controlling exciting currents to the respective magnetic poles. By controlling exciting currents to the respective electromagnets (71aa, 73aa, 71ba, 73ba), it is also possible to adjust fluxes (or flux density) in respective directions x, y individually.

Claims

1. A magnet unit having an E-shaped configuration, comprising:

first and second magnetic poles opposed to each other, having same polarity;

a third magnetic pole arranged at a center between the first magnetic pole and the second magnetic pole, having a different polarity from that of the first and second magnetic poles;

a first magnet defined between the first magnetic pole and the third magnetic pole, the first magnet having two electromagnets connected with each other through the intermediary of a permanent magnet; and

a second magnet defined between the second magnetic pole and the third magnetic pole, the second magnet having two electromagnets connected with each other through the intermediary of another permanent magnet.

2. The magnet unit of claim 1, wherein

the first, second and third magnetic poles are arranged so as to oppose a guide member of magnetic material through respective gaps,

the magnet unit further comprises

sensors adapted to detect respective conditions of magnetic circuits in the magnet unit.

3. An elevator guiding apparatus comprising:

a magnet unit having an E-shaped configuration, including

first and second magnetic poles opposed to each other, having same polarity,

a third magnetic pole arranged at a center between the first magnetic pole and the second magnetic pole, having a different polarity from that of the first and second magnetic poles,

a first magnet defined between the first magnetic pole and the third magnetic pole, the first magnet having two electromagnets connected with each other through the intermediary of a permanent magnet, and

a second magnet defined between the second magnetic pole and the third magnetic pole, the second magnet having two electromagnets connected with each other through the intermediary of another permanent magnet, wherein that the first, second and third magnetic poles are arranged so as to oppose a guide member made of magnetic material through respective gaps;

a plurality of sensors for detecting respective conditions of magnetic circuits in the magnet unit; and

a control unit for controlling exciting currents supplied to the electromagnets of the magnet unit based on output signals from the sensors.

4. The elevator guiding apparatus of claim 3, wherein

the control unit controls the exciting currents so that the magnetic circuits are stabilized while the exciting currents to the electromagnet are zero.

5. A weighing apparatus comprising:

a movable body for mounting an object to be measured, the movable body having a plurality of magnet units attached to sidewalls of the movable body on exterior sides, the magnet unit having an E-shaped configuration, the magnet unit including

first and second magnetic poles opposed to each other, having same polarity,

a third magnetic pole arranged at a center between the first magnetic pole and the second magnetic pole, having a different polarity from that of the first and second magnetic poles,

a first magnet defined between the first magnetic pole and the third magnetic pole, the first magnet having two electromagnets connected with each other through the intermediary of a permanent magnet, and

a second magnet defined between the second magnetic pole and the third magnetic pole, the second magnet having two electromagnets connected with each other through the intermediary of another permanent magnet;

a frame for supporting the movable body movable in a vertical direction and provided with a plurality of guide members made of magnetic material corresponding to the magnet units, respectively;

a plurality of sensors for detecting respective conditions of magnetic circuits in the magnet units at respective gaps each between the magnetic poles of the magnet units and the guide member; and

a control unit for controlling exciting currents to electromagnets of the magnet units based on output signals from the sensors.

6. The weighing apparatus of claim 5, wherein

the control unit controls the exciting currents so that the magnetic circuits are stabilized while the exciting currents to the electromagnet are zero.

7. A weighing apparatus comprising:

a movable body for mounting an object to be measured, the movable body having a plurality of guide member made of magnetic material attached to sidewalls of the movable body on exterior sides;

a frame for supporting the movable body movable in a vertical direction and provided with a plurality of magnet units corresponding to the guide members, the magnet unit having an E-shaped configuration, the magnet unit including

first and second magnetic poles opposed to each other, having same polarity,

a third magnetic pole arranged at a center between the first magnetic pole and the second magnetic pole, having different polarity from that of the first and second magnetic poles,

a first magnet defined between the first magnetic pole and the third magnetic pole, the first magnet having two electromagnets connected with each other through the intermediary of a permanent magnet, and

a second magnet defined between the second magnetic pole and the third magnetic pole, the second magnet having two electromagnets connected with each other through the intermediary of another permanent magnet;

a plurality of sensors for detecting respective conditions of magnetic circuits in the magnet units at respective gaps each between the magnetic poles of the magnet unit and the guide member; and

a control unit for controlling exciting currents to electromagnets of the magnet units based on output signals from the sensors.

8. The weighing apparatus of claim 7, wherein

the control unit controls the exciting currents so that the magnetic circuits are stabilized while the exciting currents to the electromagnet are zero.