Vacuum actuator

• US 4,669,361 A
• Filed: 01/30/1985
• Issued: 06/02/1987
• Est. Priority Date: 10/22/1980
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ito, Tosikazu, Komathuzaki, Kiyomi, Horibe, Kiyoshi, Chonan, Kenichi
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Neils, Paul F.
• Application Number:
  US06/696,479
• Time in Patent Office: 853 Days
• Field of Search: 91/433, 91/454, 91/457, 91/459, 91/469, 91/275, 91/361, 91/6, 91/32, 91/443, 91/418, 92/94, 92/99, 137/DIG. 8, 137/625.65, 137/907, 251/129
• US Class Current: 91/459
• CPC Class Codes: B60H 1/00485 Valves for air-conditioning devices, e.g. thermostatic valves valves per se F16K; thermostatic valves per se G05D23/02
• CPC Class Codes: F15B 15/10 the motor being of diaphragm type
• CPC Class Codes: Y10S 137/907 Vacuum-actuated valves

Abstract

A vacuum actuator having a vacuum chamber and an atmospheric chamber separated from each other by a diaphragm, and an actuator rod connected at one end to the diaphragm and extending across the atmospheric chamber to the outside of the actuator so as to be connected to an object to be actuated. At least one annular solenoid coil is mounted on the upper surface of the upper wall of the case defining the vacuum chamber, with the axis of the solenoid coil extending substantially at a right angle to the axis of the actuator rod. A plunger of the annular solenoid coil is adapted to be moved in one and the other directions along the axis of the annular solenoid coil. The end of the plunger is adapted to be moved into and out of a control pressure chamber of valve case. A port for introducing a vacuum from a vacuum passage into the control pressure chamber and a port for introducing the atmospheric pressure into the same are formed in the valve case coaxially with each other. A valve member disposed between these ports and displaceable by the plunger selectively opens and closes these ports. The pressurized fluid in the control pressure chamber is introduced into the vacuum chamber through a passage interconnecting the control pressure chamber and the vacuum chamber, to thereby produce a force which acts on the diaphragm.

Claims

1. A vacuum actuator comprising:

a diaphragm chamber defined between a diaphragm and an actuator case means for housing said diaphragm;

an actuator rod means for transferring a displacement of said diaphragm;

a valve member for controlling a communication of vacuum with said diaphragm chamber;

solenoid means for actuating said valve member, said solenoid means being mounted on an outer surface of said actuator case and including an annular solenoid coil, a plunger means for displacing said valve member under an electromagnetic force caused by said solenoid coil and a cylindrical case means made of magnetic material for receiving said solenoid coil;

a valve case means made of resin for forming a part of a vacuum passage and for housing said valve member secured to the solenoid means, said valve case means having a vacuum input nipple and an output nipple communicating with each other to form the passage;

means for securing said solenoid means to said actuator case means in such a manner that an outer cylindrical surface of said cylindrical case means of said solenoid means is in sideways contact with an outer surface of said actuator case means over a substantially full length of the cylindrical case means such that the centroid of said solenoid means is positioned as close as possible to the outer surface of said actuator case means and said valve case means is disposed on an outer surface so as to enable a completion of said vacuum passage, and

wherein the output nipple is disposed at substantially a right angle to an upper surface of the actuator case means.

2. A vacuum actuator as claimed in claim 1, wherein said means for securing comprises a flange formed integrally with said valve case, a threaded fastening means, a bore formed on said valve case, and a means formed on said actuator case means for receiving said threaded fastening means, said means for receiving being disposed such that when said threaded fastener means extends through said through bore and is received by said means for receiving, said solenoid means is secured in place.

3. A vacuum actuator as claimed in claim 1, wherein said valve case means is made of a resin, said solenoid means includes a portion made of a resin, and said valve case means is welded to said resin portion of the solenoid means.

4. A vacuum actuator as claimed in claim 1, wherein said solenoid means includes a pole yoke which is coaxially housed in said annular solenoid coil and has a conically shaped end, and said plunger means has a conically recessed end facing said conically shaped end of the pole yoke.

5. A vacuum actuator as claimed in claim 4, wherein said plunger means has an axial length shorter than an axial length of said pole yoke.

6. A vacuum actuator as claimed in claim 1, wherein said valve case means comprises a valve chamber for housing said valve member therein, a vacuum inlet port for introducing vacuum to said valve chamber, and a vacuum outlet nipple for introducing said vacuum from said valve chamber to said diaphragm chamber, said vacuum outlet nipple being so formed on said valve case means so as to project from said valve case means, said actuator case means is formed with a through hole and an annular protrusion surrounding the through hole to receive said vacuum outlet nipple for communicating with said diaphragm chamber, and seal means being interposed between the annular protrusion and the outlet nipple.

7. A vacuum actuator as claimed in claim 6, wherein said valve case means further comprises an atmosphere inlet port opening in an opposite side of said valve chamber from said vacuum inlet port for introducing the atmosphere to said valve chamber, and said valve member is disposed between said vacuum inlet port and said atmosphere inlet port and is adapted to selectively open and close both said vacuum inlet port and said atmosphere inlet port upon a displacement of said plunger through said atmosphere inlet port.

8. A vacuum actuator as claimed in claim 7, wherein first spring means are provided in said valve case means for biasing said valve member toward said atmosphere inlet port, and second spring means stronger than said first spring means are provided in the cylindrical case means of said solenoid means for biasing said valve member toward said vacuum inlet port through said plunger so that said valve member is biased so as to close said vacuum inlet port when said solenoid coil is deenergized.