JPS6414343A - Wefting fluid pressure control apparatus of jet loom - Google Patents

Abstract

PURPOSE: To provide the subject controller capable of carrying out the changeover to another pressure fluid system in the direction to eliminate a fluctuation with a pressure regulating circuit when flying characteristics of a weft yarn are outside an allowable dead zone width of the reference timing and further performing even the microadjustment of a small fluctuation within the allowable dead zone width and carrying out stable picking. CONSTITUTION: When the arrival timing of a weft yarn at the side opposite to yarn feed is within an allowable dead zone width of about the reference timing, a system under the intermediate pressure in three pressure fluid systems different in set pressure is used to carry out picking. If flying characteristics of a weft yarn are fluctuated for some reasons and outside the allowable dead zone width, the system under the intermediate pressure is changed over to either one of the systems under a high and a low set pressures in the direction to compensate the fluctuation in the weft yarn flying characteristics by operations of a pressure correcting circuit. The microadjustment of the set pressure for the fluctuation within the allowable dead zone width can be carried out to perform stable picking with good responsiveness to a sudden change in the flying characteristics of the weft yarn and the optimal pressure.