Pilot type controlled electromagnetic valve system

• US 4,967,996 A
• Filed: 06/19/1989
• Issued: 11/06/1990
• Est. Priority Date: 06/28/1988
• Status: Expired due to Term

• Current Assignee: Masako Kiyohara
• Original Assignee: Masako Kiyohara
• Inventors: Tomita, Atsuo, Tsubomoto, Koichi, Ideta, Eiji, Nishino, Koji, Sonoda, Yoshiteru
• Primary Examiner(s): Chambers, A. Michael
• Application Number:
  US07/367,803
• Time in Patent Office: 505 Days
• Field of Search: 251/30.02, 251/45, 251/129.15
• US Class Current: 251/30.02
• CPC Class Codes: F16K 31/402 acting on a diaphragm
• CPC Class Codes: H01F 7/122 by permanent magnets H01F7/1615, H01F7/1646 take precedence
• CPC Class Codes: H01F 7/1615 Armatures or stationary parts of magnetic circuit having permanent magnet

Abstract

The pilot type controlled electromagnetic valve system in accordance with the present invention is opened and closed principally by means of automatic remote control.

The controlled valve system comprises a main valve F; a pilot valve G for opening and closing the main valve F by means of the fluid pressure on the primary side; a latching solenoid H for opening and closing the pilot valve G; and a solenoid drive control unit I for driving the solenoid H by supplying a discharge current from a capacitor to the solenoid. A pulse discharge current is supplied to the solenoid H from the capacitor C only when the pilot valve G is opened or closed, and no excitation current is supplied continuously through the coil of the solenoid. As a result, the power source battery can be reduced in size, and therefore virtually no accidents take place in the controlled valve system due to no heat generation in the coil.

Claims

1. A pilot type controlled electromagnetic valve system comprising:

a main valve;

a pilot valve for selectively controlling a fluid flow path extending from said main valve through said pilot valve to thereby control operation of said main valve, said pilot valve comprising;

plunger means movable between a first position whereat it blocks said fluid flow path and a second position whereat it does not block said fluid flow path,

spring means for biasing said plunger means toward said first position,

a permanent magnet for generating a flux retaining said plunger means at said second position, and

coil means for selectively generating magnetic fields to move said plunger means from one of said positions to the other; and

,

a drive control circuit for applying a first or a second excitation current pulse to said coil means,

said coil means being responsive to said first excitation current pulse for moving said plunger means from said first to said second position against the bias of said spring means, and responsive to said second excitation current pulse for generating a flux offsetting said retaining flux of said permanent magnet whereby said plunger means is moved to said first position by said spring means;

said drive control circuit comprising;

first and second capacitors,

a battery,

switch means connected to said battery and said first and second capacitors, said switch means including means responsive to a first signal for connecting said battery to said first capacitor to charge said first capacitor and means responsive to a second signal for connecting said battery to said second capacitor to charge said second capacitor,

first and second gating devices,

said first gating device being connected to said first capacitor and said coil means for gating the charge on said first capacitor into said coil means as said first excitation current pulse,

said second gating device being connected to said second capacitor and said coil means for gating the charge on said second capacitor into said coil means as said second excitation current pulse;

said first gating device having a control electrode responsive to a voltage on said first capacitor for gating the charge on said first capacitor into said coil for a first interval of time, and,

said second gating device having a control electrode responsive to a voltage on said second capacitor for gating the charge on said second capacitor into said coil means for a second interval of time.

2. An electromagnetic valve system as claimed in claim 1 wherein said first and second intervals of time are between 0.1 second and 0.2 second.

3. An electromagnetic valve system as claimed in claim 1 wherein said first and second gating devices are responsive to the voltages on said first and second capacitors, respectively, attained between 30 seconds and 120 second after said switch means connects said battery to said first capacitor, or said second capacitor.

4. An electromagnetic valve system as claimed in claim 1 wherein said first and second gating devices are first and second silicon controlled rectifiers.

5. An electromagnetic valve system as claimed in claim 1 wherein,

said main valve comprises a main valve body having a valve seat, a diaphragm valve disk cooperating with said valve seat to selectively control fluid flow through said main valve from a primary fluid path to a secondary fluid path, and a bonnet mounted on said main valve body and cooperating with said diaphragm valve disk to form a bonnet chamber;

said pilot valve having a pilot valve housing fixed to the main valve housing and having a pilot valve chamber therein, a pilot valve seat, and a pilot valve disk carried by said plunger means and cooperating with said pilot valve seat;

said fluid flow path comprising a first fluid passage extending from said secondary fluid path to said pilot valve chamber through said pilot valve seat, and a second fluid passage connecting said pilot valve chamber and said bonnet chamber;

and a further fluid path connecting said pilot valve chamber with said primary fluid path.