Abstract:
PROBLEM TO BE SOLVED: To guarantee reliable pump operation capable of continuously making concrete flow. SOLUTION: In order to guarantee certain operation even in the case wherein a switching sensor or pressure sensors 20, 22 and 24 are failed, the estimated stroke time of pistons 8 and 8' inside of driving cylinders 5 and 5' is measured and recorded in calibration of a concrete pump and/or in operation of the pump, and the stroke time is monitored during each conveying stroke, and is compared with the estimated stroke time. In the case wherein the stroke time exceeds the estimated stroke time by a predetermined amount, a reversible hydraulic pump 6 is turned to reverse the flow, and/or a pipe slide 56 is controlled to reverse. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
The present invention discloses a piston and cylinder combination driven by linear motor with cylinder position recognition system, comprising a support structure (4) forming an air gap (12); a motor winding (6) generating a variable magnetic flow at least along part of the air gap (12); a cylinder (2) having a head at one of its ends; a piston (1) connected to a magnet (5), the magnet being driven by the magnetic flow of the motor winding (6) to move inside a displacement path including at least partially the air gap (12); the displacement of the magnet making the piston (1) reciprocatingly move inside the cylinder (2); and an inductive sensor (8) disposed at a point of the displacement path of the magnet (5), such that when the piston (1) reaches a position of closest approach to the cylinder head, the inductive sensor detects a variation in the magnetic field resulting from the corresponding position of the magnet, and generates a voltage signal arising from this magnetic field variation. The invention also discloses a linear motor compressor, which comprises a piston and cylinder combination of the kind of the present invention, and is capable of recognizing the position of the cylinder.
Abstract:
PROBLEM TO BE SOLVED: To certainly detect mixing of gas into the pump chamber of a chemical pump, and as a result to suitably deliver and supply chemical liquid by the chemical pump. SOLUTION: In the chemical pump 10, a bellows type partition member 12 as a capacity variable member is stored in a pump housing 11, and the pump chamber 13 and a pressure acting chamber 14 are separately formed by the bellows type partition member 12. An electropneumatic regulator 28 is connected to the pressure acting chamber 14. A rod 33 is connected to the bellows type partition member 12, and the displacement of the rod 33 is detected by a position detector 36. With the inside of the pump chamber 13 tightly closed, a controller 40 outputs an operational command signal to the electropneumatic regulator 28 and also determines the presence or absence of gas in the pump chamber 13 on a basis of a result detected by the position detector 36 at that time. COPYRIGHT: (C)2007,JPO&INPIT