Magnetizing device for permanent magnet motor for electric vehicle

• US 4,039,853 A
• Filed: 09/29/1975
• Issued: 08/02/1977
• Est. Priority Date: 09/30/1974
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Naito, Shotaro, Koizumi, Osamu, Saito, Shigeki
• Primary Examiner(s): Smith, Jr., David
• Application Number:
  US05/617,731
• Time in Patent Office: 673 Days
• Field of Search: 318/139, 310/156, 335/284, 307/101, 317/157.5
• US Class Current: 307/101
• CPC Class Codes: H01F 13/003 Methods and devices for magnetising permanent magnets permanent magnets H01F7/02
• CPC Class Codes: H02K 15/03 having permanent magnets
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

A magnetizing device for a permanent magnet motor used for driving an electric vehicle in which a magnetizing coil is wound around the permanent magnet of the permanent magnet motor, and means are provided for detecting a specific step such as manipulation of the key switch in the electric vehicle in a series of predetermined steps required for the operation of the electric vehicle. In response to the detection of such specific manipulation, magnetizing current is supplied to the magnetizing coil from the battery of the electric vehicle so that the permanent magnet can be automatically magnetized.

Claims

1. In an electric vehicle equipped with a main dc power source, a permanent magnet motor, and a chopper controlling the current supplied from said main dc power source to said permanent magnet motor, a magnetizing device comprising a magnetizing coil wound around the permanent magnet of said permanent magnet motor, and means for supplying magnetizing current to said magnetizing coil in response to a specific step in a series of predetermined steps required for the operation of the electric vehicle.

2. A magnetizing device as claimed in Claim 1, wherein said magnetizing current is supplied to said magnetizing coil through said chopper, and the circuit supplying said magnetizing current to said magnetizing coil is opened when the output current of said chopper is nil.

3. In an electric vehicle equipped with a main dc power source, a permanent magnet motor, a chopper, an accelerator pedal, a key switch for turning on the power source circuit whens turned on, and a chopper controller operative in response to the depression of said accelerator pedal for controlling said chopper thereby controlling the current supplied from said main dc power source to said permanent magnet motor, a magnetizing device comprising a magnetizing coil wound around the permanent magnet of said permanent magnet motor, and means for supplying magnetizing current to said magnetizing coil for a predetermined period of time in response to the initial depression of said accelerator pedal after turning on said key switch.