US3762445A

US3762445A - Fluidic device

Info

Publication number: US3762445A
Application number: US00202772A
Authority: US
Inventors: T Orita; Y Hara
Original assignee: Agency of Industrial Science and Technology
Current assignee: National Institute of Advanced Industrial Science and Technology AIST
Priority date: 1971-11-29
Filing date: 1971-11-29
Publication date: 1973-10-02
Anticipated expiration: 1990-10-02

Abstract

A fluidic element having a jet nozzle in a side wall of a central chamber provided in the element and outlets in the opposite side wall of the central chamber is disposed within a container and, by supplying a liquid to the container, a gasliquid boundary face is formed in the central chamber. The boundary face is adjusted in accordance with the amount of the liquid supplied and the direction of a jet from the jet nozzle is controlled by said boundary face.

Description

United States Patent 1 1 Orita et al. 1 Oct. 2, 1973 1 FLUIDIC DEVICE 3,561,465 2/1971 DeGraef 137/815 3, 6 ,462 21971 B 137 81.5 X [75] Inventors: Toyok|0r1ta;Yosh1ak1Hara, both of 3 g 336 9119 fi h I 37/815 Tokyo, Japan 3,620,050 11/1971 Glasgow 137/815 x [73] Assignee: Agency of Industrial Science &

Technology, Tokyo, Japan Primary Examiner-Samuel Scott Filed: o 1971 AttorneyKurt Kelman [21] Appl. No.: 202,772 ABSTRACT A fluidic element having a jet nozzle in a side wall of [52] U.S. Cl. 137/806, 137/836 a central chamber provided in the element and Outlets [51] Int. Cl. FlSc 1/04 1n the opposite s1de wall of the central chamber 15 d1s- [58] Fleld of Search 137/815 posed w1th1n a contamer and, by supplylng a l1qu1d to the container, a gas-liquid boundary face is formed in [56] References cued the central chamber. The boundary face is adjusted in UNITED STATES PATENTS accordance with the amount of the liquid supplied and 3,595,259 7/1971 Adams 137/815 the direction of a jet from the jet nozzle is controlled 2,247,301 6/1941 LBSS6I..... 137/815 UX said boundary face. 3,191,860 6/1965 Wadey.... 137/815 X 3,395,720 Brooks 137/815 4 Claims, 3 Drawing Figures FLUIDIC DEVICE The present invention relates to a fluidic device.

It has heretofore been thought that the Coanda effect occurs in a fluidic element due to the fact that the jet of fluid issuing from the nozzle entrains and incorporates a part of the fluid existing in the region between the jet nozzle of fluid and the solid wall provided in the direction of the jet along the direction thereof so that the pressure in the region is reduced and that consequently the Coanda effect cannot occur in the absence of such a solid wall.

A main object of the present invention is to provide a fluidic device capable of providing an effect similar to the Coanda effect without providing a solid wall as is necessary in the conventional fluidic elements.

Other objects and features of the present invention will become apparent from the following description of the present invention with reference to the attached drawings, in which:

FIG. I is a sectional view of one embodiment of the fluidic device of the present invention;

FIG. 2 is a sectional view of another embodiment of the fluidic device of the present invention; and

FIG. 3 is a sectional view of still another embodiment of the fluidic device of the present invention.

Referring to FIG. 1, a fluidic element 2 having a central chamber extending vertically through the element and opening to the exterior of the element at the top and the bottom surfaces thereof is flxed in a container 1 equipped with appropriate means (not shown) for supplying and discharging liquid. The central chamber 5 communicates through a fluid jet nozzle 4 provided in one side wall of the chamber 5 with a fluid supplying portion 3. At a corresponding position of the opposite side wall of the central chamber 5 to the nozzle 4, an opening is provided from which a pair of

output passages

6 and 7, separated by a wall portion 8 disposed at a center of the opening, extend to the outside of the element.

When a fluid such as water is supplied to the fluid supplying portion 3 by a suitable means (not shown), the fluid is discharged as a jet from the jet nozzle 4 toward the wall 8 and separated thereby into the

output passages

6 and 7 without causing the Coanda effect because no solid wall effect is provided.

When a suitable liquid such as water is supplied to the container 1 the liquid enters the chamber from the bottom of the chamber 5, thereby forming an air-liquid boundary face. When the level of the boundary face level is above the jet nozzle 4 the liquid jetted from the fluid supplying portion 3 incorporates a part of the liquid existing between the boundary face and the jet stream. An effect similar to the Coanda effect is thus produced and the jet stream is deflected toward the output passage 7 and derived as an output signal. On the other hand, when the boundary face level is set at a level below the jet nozzle 4 by regulating the amount of the water supplied to the container 1, the jet stream produces an effect similar to the Coanda effect and incorporates the air existing between the boundary face and the jet stream with the result that the jet stream is deflected toward the output passage 6 and derived from the passage 6 as an output. In this case, however, when the distance between the boundary face and the jet stream is very close or very large, the above mentioned effect will not be obtained. Therefore, the distance should be regulated suitably depending upon the size of the fluidic element, the kind of the fluid and the velocity of the jet stream etc. Since the liquid present in the chamber is discharged out of the fluidic device together with the jet stream, it is necessary to maintain the level of the boundary face suitably by replenishing the container with liquid by an appropriate means.

As above mentioned, since in the fluidic device according to the present invention the jet stream can easily be controlled by setting the level of the boundary face in the chamber 5 either above or below the jet nozzle 4 upon the regulation of the amount of liquid supplied to the container 1, the present fluidic device can be applied to many fields to which application has not hitherto been possible such as the detection of the liquid level and the control thereof etc.

FIG. 2 shows another embodiment of the present fluidic device. In FIG. 2, a wall 9 for causing the Coanda effect is provided below the jet nozzle 4 in the chamber 5 of the fluidic element 2 and a liquid is supplied to the chamber 5 through a small hole 5|, for example, until the boundary face of the liquid and air reaches a level at which the Coanda effect resulting from the wall 9 is overcome. Under these conditions, when a jet stream of fluidis discharged from the nozzle 4, it is directed to the oppositely disposed opening and then passes through the passage 7. On the contrary, when the level of the boundary face is changed and thus the Coanda effect due to the wall 9 appears, the jet stream is deflected toward the passage 6. Since, by changing the level of the boundary face in the chamber 5 in the above described manner, the direction of the jet stream can easily be controlled, this embodiment is suitable for use in detecting and controlling the liquid level.

FIG. 3 shows another embodiment which differs in construction from the embodiment shown in FIG. I in the point that a control nozzle 10 is provided for controlling the jet stream from the jet nozzle 4. When a liquid is supplied to the container 1 so that an air-liquid boundary face is formed at a predetermined level in the chamber 5, and then ajet stream is discharged from the jet nozzle 4 as the main jet, the main jet is deflected to the passage 7 due to the Coanda-like effect caused by the boundary face. Under these conditions, when a suitable control signal such as a gas stream is supplied through the control nozzle 10 to the chamber 5, the main jet is deflected to the passage 6. Since in this case, the amount of liquid passing through both output passages can be regulated by varying the intensity of the control signal, this embodiment can be used as an element for intensifying the control signal.

As above mentioned, a fluidic device in accordance with the present invention is very simple in construction and is capable of providing an effect similar to the Coanda effect without using the solid wall which is required for the conventional element. The present fluidic device makes possible the easy regulation of the gas-liquid boundary face level, it can be utilized for many previously impossible applications such as the detection of liquid level and the control thereof etc.

Furthermore, as mentioned above, by providing a control nozzle such as nozzle 10, the present fluidic device can be used as an amplifier for a control signal.

What is claimed is:

l. A fluidic device which comprises in combination, a fluidic element having a central chamber in the central portion thereof to which liquid is supplied and discharged, said central chamber being vertically disposed through the fluidic clement, ajet nozzle in one side wall of the central chamber and disposed in a relative perpendicular position thereto, a pair of outlet passages in the opposite side wall of said central chamber disposed substantially opposite the position of said jet nozzle and in fluid communication therewith, and a container adapted to house said fluidic element and to prevent said liquid supplied to said container from flowing out, one of said pair of outlet passages disposed through an upper'wall of the container and the other disposed through a lower wall thereof, said liquid supplied to said chamber forming a gas-liquid boundary face in UNITED STATES PATENT OFFICE CERTIFECATE 0F CORRECTION Patent No. 3, 762 ,445 Deted Oct. 2 l973 Invent0r(s) Toyoki Orita et 31.

It is certified that error appears in the above-identified patent and that said Letters Patent are 1" 1 r e by" corrected as shown below:

On the front page, after "12y" insert:--

1597 Foreign Application Priority Data 7 Nev, 27, 1970 Japan .......5.,104659/70 Signed and sealed this 12th day of March 1974.

(SEAL) Attest:

EDWARD M.FLETCHERI,JR.' Y C. MARSHALL DANN Attesting Officer Commissioner 'of Patents FORM po'wso 1 USCOMM-DC 60376-P69 I U. 5. GOVERNMENT PRINTING OFFICE l9. O-IiGi-SSl.

Claims

1. A fluidic device which comprises in combination, a fluidic element having a central chamber in the central portion thereof to which liquid is supplied and discharged, said central chamber being vertically disposed through the fluidic element, a jet nozzle in one side wall of the central chamber and disposed in a relative perpendicular position thereto, a pair of outlet passages in the opposite side wall of said central chamber disposed substantially opposite the position of said jet nozzle and in fluid communication therewith, and a container adapted to house said fluidic element and to prevent said liquid supplied to said container from flowing out, one of said pair of outlet passages disposed through an upper wall of the container and the other disposed through a lower wall thereof, said liquid supplied to said chamber forming a gas-liquid boundary face in said central chamber which boundary face causes an effect similar to the Coanda effect to control flow of fluid from the jet nozzle relative said pair of outlet passages.

2. A fluidic device as set forth in claim 1, further having a Coanda effect wall provided below said jet nozzle.

3. A fluidic device as set forth in claim 1, further having a control means for supplying a control signal to said chamber.

4. A fluidic device as set forth in claim 1 wherein the liquid is water.