Neutral point voltage adjuster of torque sensor

• US 6,467,329 B1
• Filed: 02/14/2000
• Issued: 10/22/2002
• Est. Priority Date: 02/15/1999
• Status: Expired due to Fees

• Current Assignee: Showa Corporation (Hitachi, Ltd.)
• Original Assignee: Showa Corporation (Hitachi, Ltd.)
• Inventors: Senda, Shunya, Ueno, Takayuki
• Primary Examiner(s): Noland, Thomas P.
• Application Number:
  US09/503,637
• Time in Patent Office: 981 Days
• Field of Search: 73/11.1, 73/10.9, 73/18.8, 702/87, 702/104
• US Class Current: 73/1.11
• CPC Class Codes: G01L 25/003 for measuring torque

Abstract

The present invention provides a neutral point voltage adjuster of a torque sensor which comprises: a pair of coils having inductances changing mutually in a reverse direction in accordance with a torque; and a differential amplifier means inputting first and second sub-voltages based on each inductance change of both coils, and amplifying a difference between the first and second sub-voltages so as to output it as a main voltage, and which uses a neutral point where no torque is inputted as a boundary between right and left directions, and detects each torsional torque in the right and left direction, comprising: a neutral point voltage setter for displacing a main voltage of an output from the differential amplifier on the basis of an adjusting signal so as to set a neutral point voltage; a memory for storing a neutral point voltage setting state by the neutral point voltage setter; and a neutral point voltage adjuster for storing a neutral point voltage used as a reference of a main voltage, and inputting the main voltage, and further, outputting the adjusting signal to the neutral point voltage setter so that a difference between the neutral paint voltage read from the main voltage and the reference neutral point voltage is reduced.

Claims

1. A neutral point voltage adjuster of a torque sensor which comprises:

a pair of coils having inductances changing mutually in a reverse direction in accordance with a torque; and

a differential amplifier means inputting first and second sub-voltages based on each inductance change of both coils, and amplifying a difference between the first and second sub-voltages so as to output it as a main voltage, and which uses a neutral point where no torque is inputted as a boundary between right and left directions, and detects each torsional torque in the right and left direction, comprising;

a neutral point voltage setting means for displacing the main voltage of the output from the differential amplifier means on the basis of an adjusting signal so as to set a neutral point voltage;

a storing means for storing a neutral point voltage setting state by the neutral point voltage setting means; and

a neutral point voltage adjusting means for storing a neutral point voltage used as a reference of the main voltage, and inputting the main voltage, and further, outputting the adjusting signal to the neutral point voltage setting means so that a difference between the neutral point voltage read from the main voltage and the reference neutral point voltage is reduced.

2. The neutral point voltage adjuster of a torque sensor according to claim 1, wherein the neutral point voltage adjusting means repeatedly outputs the adjusting signal until a difference between the neutral point voltage and the reference neutral point voltage falls within a predetermined value.

3. The neutral point voltage adjuster of a torque sensor according to claim 2, further computing a rewrite means for rewriting a stored content of the storing means into the neutral point voltage setting state after adjustment by the neutral point voltage adjusting means.

4. The neutral point voltage adjuster of a torque sensor according to claim 3, further comprising an operating switch means for instructing a neutral point voltage adjustment by the neutral point voltage adjusting means.

5. The neutral point voltage adjuster of a torque sensor according to claim 2, further comprising an operating switch means for instructing a neutral point voltage adjustment by the neutral point voltage adjusting means.

6. The neutral point voltage adjuster of a torque sensor according to claim 1, further comprising an operating switch means for instructing a neutral point voltage adjustment by the neutral point voltage adjusting means.