Title:
STROKE DETECTOR OF PISTON
Document Type and Number:
Japanese Patent JPH055603
Kind Code:
A
Abstract:
PURPOSE:To obtain a stroke detector for a piston which allows accurate detection of the behavior of the piston in an engine in which the piston reciprocates within a cylinder under severe application conditions, for example, rock drill. CONSTITUTION:As a piston 28 reciprocates, magnetism from a disc-shaped magnet 32 provided on the base end face thereof is detected with a plurality of magnetic sensors 34 arranged on the inner circumference 24a of a cylinder at an equal interval in the direction of the axis line thereof. Based on a detection signal, the position of the piston 28 in the direction of stroke and the speed thereof are calculated with a stroke computing circuit 36. The use of the magnet 32 allows the formation of an intense magnetic field not available with a mere magnetic recording layer or the like thereby enables magnetic detection at a level high sufficiently even though the interval may be widened to a certain extent between the magnetic sensor 34 and the piston 28.
Inventors:
TSUJI YORIICHI
HIRANO SHINICHI
EKUSA KENICHIRO
HIGAKI TAKASHI
HIRANO SHINICHI
EKUSA KENICHIRO
HIGAKI TAKASHI
Application Number:
JP15634291A
Publication Date:
January 14, 1993
Filing Date:
June 27, 1991
Export Citation:
Assignee:
MAZDA MOTOR
MATSUDA ASTEC KK
MATSUDA ASTEC KK
International Classes:
B25D17/00; E21B1/00; E21B1/26; F15B15/28; G01B7/00; (IPC1-7): B25D17/00; E21C3/20; F15B15/28; G01B7/00
Attorney, Agent or Firm:
Seiji Yanagida (1 person outside)
Next Patent: ELECTRIC TIMER CIRCUIT