Title:
STROKE DETECTOR FOR CYLINDER TYPE ACTUATOR
Document Type and Number:
Japanese Patent JPS63277912
Kind Code:
A
Abstract:
PURPOSE:To easily correct variation in the sound speed in working oil in such a case the sound speed is varied by finding the stroke of a piston while removing the influence of the acoustic speed in the working oil. CONSTITUTION:A pulser 17 sends pulsating ultrasonic waves from ultrasonic sensors 12 and 13. The ultrasonic wave sent by the sensor 12 is propagated in the working oil 9 and reflected by the piston 5 and the ultrasonic wave sent by the sensor 13, on the other hand, is propagated in the working oil 9 in a through hole 11, and reflected by a reflecting plate 14, so that they are received by the sensors 12 and 13 respectively. Counters 21 and 22 count the times t1 and t2 from the transmission of the ultrasonic waves from the sensors 12 and 13 to the rereception of them after the reflection. Then a CPU 23 finds a distance l1 corresponding to the stroke of the piston 5 from equations I, II, and III because a distance l2 is already known from the setting position of the reflecting plate 14 when the acoustic wave in the working oil 9 is denoted as (c).
Inventors:
OMORI HIDEKI
EMA HIROAKI
EMA HIROAKI
Application Number:
JP11327687A
Publication Date:
November 15, 1988
Filing Date:
May 08, 1987
Export Citation:
Assignee:
KUBOTA LTD
International Classes:
G01B17/00; B60G17/019; (IPC1-7): G01B17/00
Attorney, Agent or Firm:
Yoshihiro Morimoto
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