Torque limiting device for motors in electically driven vehicles and electrically driven vehicle incorporation the torque limiting device

• US 5,971,090 A
• Filed: 08/19/1997
• Issued: 10/26/1999
• Est. Priority Date: 08/20/1996
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Matsumoto, Toshihiro, Maeda, Yoshihiko, Sagara, Hiroaki, Tanaka, Tatsuaki, Suhara, Toshihiro
• Primary Examiner(s): Mai, Lanna
• Assistant Examiner(s): CUFF, MICHAEL A
• Application Number:
  US08/918,591
• Time in Patent Office: 798 Days
• Field of Search: 180/205, 180/206, 180/207, 180/220
• US Class Current: 180/206.2
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 50/53 in combination with an external power supply, e.g. from overhead contact lines
• CPC Class Codes: B62M 6/45 Control or actuating devices therefor
• CPC Class Codes: B62M 6/50 characterised by detectors or sensors, or arrangement thereof
• CPC Class Codes: B62M 6/60 power-driven at axle parts
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A torque limiting device for motors in electrically driven vehicles includes a control device for controlling an electric driving power supplied to a motor in an electrically driven vehicle; a detecting section for detecting a driven state of the motor and outputting an output signal of the motor; and an upper electric driving power limit setting device in which a plurality of restricting values corresponding to the output signal from the detecting section are previously set, wherein the upper electric driving power limit setting device gives a command to the control device to restrict an upper limit of the driving power on the basis of one of the plurality of restricting values when the output signal is outputted, thereby limiting a torque of the motor.

Claims

1. A torque limiting device for a motor in an electrically driven vehicle, comprising:

a control device for controlling an electric driving power supplied to the motor;

a detecting section for detecting a driven state of the motor and outputting an output signal thereof;

an upper electric driving power limit setting device in which a restricting value corresponding to the output signal from the detecting section is previously set; and

a motor torque setting device in which a motor torque to be limited by the upper electric driving power limit setting device is previously set;

wherein the control device is operated on the basis of the output from the motor torque setting device, the output signal is a signal determined on the basis of the torque of the motor to be limited by the upper electric driving power limit setting device, and

the upper electric driving power limit setting device gives a command to the control device to restrict an upper limit of the driving power on the basis of the restricting value when the output signal is outputted, thereby limiting the motor torque.

2. A torque limiting device according to claim 1, wherein the control device is a pulse width modulation control device.

3. A torque limiting device according to claim 1, wherein the upper electric driving power limit setting device is an upper duty limit setting device, whereby the electric driving power controlled by the control device is restricted on the basis of upper duty ratio limits which are the restricting values.

4. A torque limiting device according to claim 1, further comprising a power supply voltage designation means for designating a voltage of a power source of the electric driving power and the upper electric driving power limit setting device determines the upper limit of the electric driving power by means of the output signal and a designation signal from the power supply voltage designation means.

5. A torque limiting device according to claim 1, further comprising a motor characteristics designation means for designating characteristics of the motor and the upper electric driving power limit setting device determines the upper limit of the electric driving power by means of the output signal and a designation signal from the motor characteristics designation means.

6. A torque limiting device according to claim 1, wherein the upper electric driving power limit setting device determines the upper limit of the electric driving power in accordance with a size of a driving wheel of the electrically driven vehicle.

7. A torque limiting device according to claim 1, wherein the motor for the electrically driven vehicle is a motor of an electrically assisted bicycle in which a human driving power is assisted with a motor driving power.

8. A torque limiting device according to claim 7, wherein the upper electrical driving power limit setting device determines the upper limit of the electric driving power so that the assist ratio which is a ratio of the motor driving power to the human driving power lies within a restricted range.