US 12,281,952 B2
Torque measuring device and manufacturing method thereof
Masahiro Kobayashi, Fukuroi (JP); Kota Fukuda, Fukuroi (JP); Hisayoshi Fukui, Fukuroi (JP); Takahiro Odera, Fukuroi (JP); Haruhiko Tanno, Fukuroi (JP); Yoshinori Kubo, Tokyo (JP); Naoki Futakuchi, Tokyo (JP); Ken Okuyama, Tokyo (JP); and Teruyuki Nakamura, Tokyo (JP)
Assigned to NSK LTD., Tokyo (JP); and PROTERIAL, LTD., Tokyo (JP)
Filed by NSK LTD., Tokyo (JP); and PROTERIAL, LTD., Tokyo (JP)
Filed on Feb. 28, 2023, as Appl. No. 18/176,098.
Claims priority of application No. 2022-031028 (JP), filed on Mar. 1, 2022.
Prior Publication US 2023/0280223 A1, Sep. 7, 2023
Int. Cl. G01L 3/10 (2006.01)
CPC G01L 3/102 (2013.01) [G01L 3/108 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A manufacturing method of a torque measuring device, the torque measuring device comprising:
a sensor portion having a bridge circuit in which four detection coils arranged around a magnetostrictive effect section of a rotating shaft are arranged on four sides;
an oscillator configured to apply an input voltage to two end points of the bridge circuit;
a voltage measuring portion configured to measure an output voltage that is a voltage between two midpoints of the bridge circuit; and
a torque calculating portion configured to calculate torque applied to the rotating shaft using the output voltage measured by the voltage measuring portion;
the torque calculating portion having a temperature measurement function that measures a temperature of the sensor portion; a function of performing temperature correction of the output voltage measured by the voltage measuring portion using the temperature of the sensor portion measured by the temperature measurement function, and a temperature change rate VT of the output voltage, which is a correction parameter stored in advance in the torque calculating portion; and a function of calculating torque applied to the rotating shaft based on an output voltage after the temperature correction; and
the manufacturing method of the torque measuring device comprising:
a first step of performing testing of a plurality of test samples having the same configuration as the torque measuring device to be manufactured to find a coil balance Cb that is a ratio (R1×R3)/(R2×R4) of a product R1×R3 of resistance values R1 and R3 of two opposite sides forming one pair of opposite sides of the four sides, and a product R2×R4 of resistance values R2 and R4 of two opposite sides forming another pair of opposite sides of the four sides, and the temperature change rate VT, and acquiring a relationship X between the coil balance Cb and the temperature change rate VT from the test results; and
a second step of measuring the resistance values R1, R2, R3, and R4 of each of the four sides to find the coil balance Cb for the torque measuring device to be manufactured, and using the found coil balance Cb to find the temperature change rate VT therefor from the relationship X acquired in the first step.