US 11,335,491 B2Granted

Fluid servo valve and fluid servo apparatus

AssigneeTokkyokiki Corporation

InventorsTeruo Maruyama, Kozo Okamoto, Takumi Okada, Satoki Yamaguchi, Masataka Nakashima

Life of this patent

Estimating the term…

Loading patent…

Abstract

The present invention controls the pressure and flow rate of fluid, in order to obtain uniform performance, configure a closed loop magnetic circuit so as to include an electromagnet, a flapper, and a yoke material, and elastically deform the flapper itself by Maxwell attractive force generated between a magnetic pole of the electromagnet and the flapper to make the separation distance between the nozzle and the flapper variable. As opposed to a rigid flapper structure that swingably moves around a supporting point, like a conventional servo valve, the electromagnet, the magnetic pole, the nozzle, the flapper, and the like are arranged such that a change in magnetic gap directly leads to a change in air gap.

Claims11

Dependent claims

A fluid servo valve comprising:

a forward nozzle that is connected to a fluid supply source and supplies a fluid;
a reverse nozzle that is provided so as to face the forward nozzle, and exhaust the fluid;
a supporting shaft that has an inner flow channel that is connected to the forward nozzle or the reverse nozzle;
a disc that is formed as a thin plate and is provided between a tip part of the forward nozzle and a tip part of the reverse nozzle;
a disc supporting member that fixes a peripheral region of the disc;
an electromagnet that has a magnetic pole provided so as to face the disc, generates an attractive force to deform the disc to a thickness direction of the disc, and has a coil wound around the supporting shaft;
a closed loop magnetic circuit that a magnetic flux generated by applying voltage to the electromagnet flows at least inside of the disc;
and
a ring-shaped magnetic path that is defined as an magnetic path area based on a thickness h and a radius r1, the thickness h being a thickness of a part of the disc that faces to the magnetic pole of the electromagnet and the radius r1 being a radius of the supporting shaft, wherein
a magnetic characteristic curve of the disc has a linear region and a magnetic saturation region, the linear region being a region where a magnetic flux density increases proportionally with respect to a magnetizing force and the magnetic saturation region being a region where a gradient of the magnetic flux density with respect to the magnetizing force decreases as compared with a gradient in the linear region,
in the closed loop magnetic circuit, the magnetic density is configured to enter the magnetic saturation region when the magnetic flux that flows radially inside of the disc passes through the ring-shaped magnetic path, and
without a permanent magnet, the disc is configured to be positioned at any position between the forward nozzle and the reverse nozzle by the attractive force generated corresponding to a current applied to the electromagnet.

9 more elements

A fluid servo valve comprising:

a housing that has a fluid intake port and a fluid ejection part;
a flow rate regulation valve adapted to regulate an opening level of a flow path connecting between the intake port and the ejection port;
and
a microactuator part that drives the flow rate regulation valve, wherein
the microactuator part comprises:
an electromagnet;
a disc that is formed as a thin plate;
a ring-shaped magnetic path that is defined as a magnetic path area based on a thickness h and a radius r1, the thickness h is a thickness of a part of the disc that faces to the magnetic pole of the electromagnet and the radius r1 is an internal radius of the electromagnet;
a disc supporting member that fixes a peripheral region of the disc;
and
an output shaft that is fixed to the disc and drives the flow regulation valve,
the output shaft forms a closed loop magnetic circuit with the electromagnet, the disc, and a yoke material, and the output shaft is configured to be moved by Maxwell attractive stress generated between the electromagnet and the disc,
a magnetic characteristic curve of the disc has a linear region and a magnetic saturation region, the linear region being a region where a magnetic flux density increases proportionally with respect to a magnetizing force and the magnetic saturation region being a region where a gradient of the magnetic flux density with respect to the magnetizing force decreases as compared with a gradient in the linear region,
in the closed loop magnetic circuit, the magnetic density is configured to enter the magnetic saturation region when the magnetic flux that flows radially inside of the disc passes through the ring-shaped magnetic path, and
without a permanent magnet, the disc is configured to be positioned by the attractive force generated corresponding to a current applied to the electromagnet.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/583,065Filed 25 Sep 2019 · continuation
Priority: 9 Feb 2016
Published: US 2020/0018418 A116 Jan 2020
Granted: 17 May 2022
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

H01F 7/1805
Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for…:…
F15B 13/02
Details of servomotor systems ; Valves for servomotor systems: fluid distribution or supply devices characterised by their adaptation to the…
F16K 31/0606
Multiple-way valves: fluid passing through the solenoid coil
F16K 31/0641
Multiple-way valves: the valve member being a diaphragm

Family

Application15/019,898Parent of this continuation · filed 9 Feb 2016
US 2020/0018418 A1Pre-grant publication · published 16 Jan 2020
US 10,465,816 B2Parent of this continuation
US 2016/0228889 A1Published application
US 11,335,491 B2This patent

From the US filing history. Foreign family members aren’t listed.