US3889711A

US3889711A - Low pressure operable, diaphragm type logical element

Info

Publication number: US3889711A
Application number: US346407A
Authority: US
Inventors: Toshiro Hirao
Original assignee: Meidensha Electric Manufacturing Co Ltd
Current assignee: Meidensha Electric Manufacturing Co Ltd
Priority date: 1972-04-01
Filing date: 1973-03-30
Publication date: 1975-06-17
Anticipated expiration: 1992-06-17
Also published as: JPS5440709B2; JPS48101867A

Abstract

A low pressure operable, diaphragm-type logical product AND element includes a plurality of parallel pressure relief passages each of which may be closed by an external signal-actuated diaphragm to increase the pressure of an outlet which may be connected to several pure fluidic logic elements when all of the relief passages are closed. The logical summation element further incorporates an impedance matcher.

Description

O Unlted States Patent 1191 [111 3, 1 Hirao [451 June 17, 1975 [54] Low PRESSURE ()PE AB DIAPHRAGM 3,698,413 10/1972 Sulich 137/842 TYPE LOGICAL ELEMENT 3,747,637 7/1973 Mollere.... 25l/61.l X 3,767,161 10/1973 Blatter 235/20] ME X Inventor: shir lllr Yokohama, p n 3,768,521 10/1973 Blychta et al 235/201 ME x Assignw {feldau ha Electric M g- FOREIGN PATENTS OR APPLICATIONS QkYQ Japan 111,405 1964 Czechoslovakia 235/201 ME [22] Filed: Mar 30, 1973 21 A N 34 a 407 Primary Examiner-William R. Cline 1 pp 0 Attorney, Agent, or Firm-Lane, Aitken, Dunner &

Ziems [30 Foreign Application Priority Data Apr. 1, 1972 Japan 47032148 [57] ABSTRACT 52 U.S. Cl. 137/599; 251/61.l' 235/201 ME A Pressure Perab1e diaphragm'type kgical [5l 1 Int. CL n F1 5 c 3/04 uct AND element includes a plurality of parallel pres- [58] Field of 596 sure relief passages each of which may be closed by an ""235/201 M 5 6 external signal-actuated diaphragm t0 i fi the pressure of an outlet which may be connected to sev- [56 References Cited era] pure fluidic logic elements when all of the relief passages are closed. The logical summation element UNITED STATES PATENTS further incorporates an impedance matcher; 3,636,964 11/1969 Colamussi et a1 137/842 8/1972 Helinski 235/201 ME x 5 Claims, 7 Drawing Figures PATENTEDJUN 17 ms FIG. 6

FIG.?

1 LOW PRESSURE OPERABLE, DIAPHRAGM TYPE LOGICAL ELEMENT BACKGROUND OF THE INVENTION This invention relates to a low pressure operable, diaphragm-type logical product element and, more particularly, to a diaphragm-type logical element having logical product AND capability using low pressure air.

Logical elements using air as an operating medium can be classified into two general types: a moving type and a pure fluidic type. Most moving type elements, which use air at pressures as high as 0.5 to 5.0 kg/cm suffer from various shortcomings arising from the high pressure piping material which must be used, pressure resistance, pressure leakage and other manufacturing requirements imposed by high pressure operation. In addition, a moving type logic element used to drive several pure fluidic elements, is often susceptible to energy losses and load variations in the feeding fluid flow which effects signal transmission, thus limiting the number of pure fluid elements which may be supplied by the output of the moving element. Further, certain logic operations involve the use of complicated logic elements (OR, NOR, etc.) to attain the desired logic functions, instead of using a single internally complicated element, resulting in a complex piping arrangement which impairs the reliability of the operational logic element and raises the manufacturing cost.

The pure fluidic element is desirable because it has no moving parts, exhibits improved reliability and service life, and is adaptable to the combination of fundamental logic elements described earlier. However, expensive control is necessary to maintain the quality of air used requiring costly filtration and other support equipment. Further, the amplification ratio, the ratio of an input signal pressure to an output pressure, is approximately 3 to 5, thus making it necessary to increase the number of elements if the desired logic functions require an amplifier.

Among the objects of the present invention are, therefore: the provision of a low pressure operable, diaphragm-type logical product element which incorporates an impedance matcher; the provision of a diaphragm-type logical product element which can drive several pure fluidic elements by means of a single AND element; the provision of a diaphragm-type logical product which may be employed in a hybrid arrangement including moving and pure fluidic elements; the provision of a diaphragm-type logical product element which reduces signal transmission losses and sensitivity to varying load; the provision of a diaphragm-type logical product element which permits easy control of air used; and the provision of a diaphragm-type logical product element which presents a moderate responsing capability to an input signal.

SUMMARY OF THE INVENTION According to the present invention, a diaphragmtype logical product AND element includes a supply portion and a common output port connected to a plurality of fluid passages in communication with a plurality of pressure relief passages each containing a diaphragm which may be displaced by an external signal pressure to close a nozzle in the pressure relief passage to increase the pressure at the output portion when all of the relief passages are closed to produce a logic signal which may be transmitted to pure fluidic elements. The logical product element permits the generation of a pressure at the output port only when external signal pressures are exerted upon all of the diaphragms. According to another aspect of the present invention, an impedance matcher provided in the supply portion for reducing energy losses and susceptibility to varying loads has a nozzle, an enlarged diameter portion, and relief ports which discharge or suck in air depending on load conditions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view showing an outline of the logical product element of the present invention;

FIG. 2 is a longitudinal cross-sectional view of one embodiment of the logical product element of the invention; I

FIG. 3 is a plan view of the logical product element of the invention of FIG. 2;

FIG. 4 is a schematic longitudinal cross-sectional view of an impedance matcher used with the logical product element of the invention;

FIG. 5 is a schematic view showing the logical product element of the invention which drives several pure fluidic elements;

FIG. 6 is a schematic longitudinal cross-sectional view of an orifice or nozzle of a simple construction; and

FIG. 7 is a longitudinal cross-sectional view of one modification of the logical product element of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1-4 of the drawing, a supply portion 1 supplies a compressible fluid, for example, air, to an impedance matcher 25 and a diaphragm-type logic element 29. The air fed through the supply portion 1 passes through a nozzle 2 or fluid inlet passage of cylindrical shape in the impedance matcher 25 where the flow rate is restricted. The exit of the nozzle 2 is in communication with an enlarged diameter portion 23, to the base of which relief ports 3 extend at right angles. The cylindrically shaped fluid outlet passage 23 being of a diameter greater than the diameter of the fluid inlet passage 2 and being coaxial with the inlet passage 2 serves to define a radial interface establishing a stepped junction 48 between the inlet and outlet passages. The relief ports or the discharge-suction passages 3 intersect the outlet passage 23 at this stepped junction. The air which has passed through the nozzle 2 will be discharge through relief ports 3 if the load resistance is great, thus preventing pressure of the load from reaching the pressure of the air supplied. If the load resistance is small, however, a low pressure vortex region will be created in part of the enlarged diameter portion 23, such that the air will be sucked through relief ports 3 from the atmosphere causing no appreciable reduction in the pressure of the load. In this manner, the relief ports 3 in the impedance matcher 25 act to suck or discharge air from the atmosphere, depending on the magnitude of the load resistance, thus maintaining the output pressure of the impedance matcher 25 constant despite fluctuation in the load, regardless of whether the expansion number (or factor) of the logical element 29 is changed by varying the number of fluid discharge passages or fluid elements in the circuit supplied by the impedance matcher 25.

The constant pressure supply air from the impedance matcher 25 is fed past

parallel supply ports

4, 5 and 6 into a plurality of identical parallel pressure relief passages within unit chambers A, B and C. Chamber C, for example, includes supply port 4 which opens into a chamber 4a including an output port 16 spaced from the supply port 4 and an intermediate nozzle 10 which communicates with a pressure relief passage through discharge port 20. A signal port 26 communicates with the space above a diaphragm 13 which may be displaced downwardly to block the nozzle 10 when a pressure signal is exerted at the port 26. The remaining unit chambers A and B include

supply ports

5 and 6 which open to identical chambers and pressure relief passages. The

outlet ports

16, 17 and 18 are interconnected at a common outlet 19.

In operation, when there is no signal pressure exerted at either one of the

signal ports

26, 27 or 28, the air will be discharged through nozzles 10, 11 and 12 and

discharge ports

20, 21 and 22, respectively, to the atmosphere, thus restricting the pressure at the output port 19 which will be in an OFF condition. If there are pressure signals exerted at less than all of the

signal ports

26, 27 and 28, the air will be discharged through the relief passages remaining open to

discharge ports

20, 21 or 22, and the output port 19 will remain in an OFF condition. But when signal pressures are exerted to all of the

signal ports

26, 27 and 28, then all the

diaphragms

13, 14 and 15 will be displaced downwardly away from their home positions to block the nozzles 10, 11 and 12, and disable the pressure relief function of the logical element 26 is of a logical product AND nature. Signal transmission from the output port 19 to an external element, for example a pure fluid element, is effected by movement ofa diaphragm over a very small stroke, instead of by feeding fluid flow, thus reducing energy losses and improving response capability. By reducing energy losses, it is possible to increase the expansion number (or factor) of the logical element by combining several unit chambers while meeting the demands of any external elements.

For a better understanding of the logic element structure, reference is made to FIGS. 2 and 3 in which parts corresponding to the outlined portions of FIG. I bear the same reference numerals. Another embodiment of the present invention is illustrated in FIG. 7, in which the unit chambers A, B and C are arranged side by I side.

formed therein openings for the supply port, the common outlet port, and the signal ports. Each of the

chamber defining plates

36, 38 and 40 is formed with

identical inlet ports

4, 5, and 6 connected in parallel to the main supply port 1. Identical discharge ports 16, l7, and 18 are formed in each of the plates spaced from the supply ports and connected in parallel to a common discharge port 19.

Diaphragms

13 and 14 are disposed between adjacent

chamber defining plates

36 and 38 and 38 and 40, respectively. These

diaphragms

13 and 14 face the intermediate nozzles 10 and 11 and have a home position permitting communication between the

supply ports

4 and 5 and

relief discharge ports

20 and 21 through the nozzles 10 and 11. As shown, gaskets 42 and 44 are placed above the

diaphragms

13 and 14 and in conjunction with these diaphragms define signal receiving chambers. A diaphragm 15 is placed on the uppermost chamber defining plate 40 and faces the nozzles 12 of this plate. A cover plate 34 is superimposed on the diaphragm l5 and in conjunction therewith defines a signal receiving chamber for the uppermost plate 40. As shown, each of the plates or

chamber defining units

36, 38, and 40 are formed with identical relief passageways, intake ports, and outlet ports. Further the lowermost unit 36 is formed with a cylindrical signal port 26 opening into the signal receiving chamber defined by diaphragm 13 and adjacent plates 38 as well as having formed therein passageways aligned with the

signal ports

27 and 28 of plates 38 and 40. Likewise plate 38 is formed with two passageways with one passageway aligned with the signal port 27 which opens up into the signal receiving chamber defined by diaphragm 14 and adjacent plate 40 and a passageway aligned with the signal port 28 formed in plate 40. The logic element 29 shown in FIG. 2 is therefore formed by sandwiching stacked, separately formed, modular

chamber defining plates

36, 38 and 40 between a base plate 32 and a cover plate 34 with the supply ports and the outlet ports connected in parallel. The diaphragm-type logical product AND element produces a signal at the common outlet 19 when pressure signals are applied to all of the signal ports moving the diaphragms to close the nozzles 10, 11, and 12.

The element 29 of the present invention may be connected with and used to drive several pure fluidic elements 30, as shown in FIG. 5, or used by itself. When pressure recovery rate is desired, a pure orifice 31 may be used in the input portion, as shown in FIG. I

6, in place of the impedance matcher 25 in an attempt to attain the same function as the impedance matcher 25. The term pressure recovery rate" is defined as follows:

(Output pressure Pressure supplied) X 100%.

As is apparent from the foregoing, the logical product element of the present invention avoids extreme A susceptibility to a load because of the use of the impedance matcher 25. In addition, the element may be used in ahybrid arrangement combining a pure fluidic element adapted to applications where a specific response is required or where a pure fluidic element is provided as part of complicated logic functions. The element of the present invention, therefore, is adapted to the applications other than those of a pure fluidic element alone. By placing unit chambers such as A, B and C one on top of the other as shown in FIGS. 1 and 2, it is possible to obtain an unlimitedly increased expansion number (or factor) because the signal transmission is effected by using pressure diaphragms rather than feeding fluidflows, thus resulting in little energy loss. Supply air quality control is much easier than with pure fluidic elements because the passages having greater cross sectional areas and the wall attachment phenomenon experienced with pure fluidic elements is dispensed with. The short stroke of the diaphragm, 0.5 to 1 mm., allows improved responsing capability for a signal of a frequency in the order of 100 (HZ) and operation at low pressures of from 0.05 to 0.5 kg/cm which present no likelihood of piping pressure leakage. Since the amplification ratio is from 8 to 10, the element also can be used as an amplifier.

While the present invention has been described herein with reference to certain embodiments thereof, it should be understood that .various changes, modifications, and alternations may be effected without departing the spirit and the scope of the present invention, as defined in the appended claims.

I claim:

1. A low pressure operable, diaphragm-type logical element comprising:

a base having formed therein a main supply port, a

base outlet port, and a plurality of base signal ports;

a plurality of superimposed, modular chamber defining plates vertically stacked on said base, each of said plates having formed therein a supply port to receive fluid from said main supply port, an intermediate nozzle, a relief discharge port intercommunicating with said supply port through said intermediate nozzle and a chamber signal port communicating with one of said base signal ports, at least one of said superimposed, modular chamber defining plates having formed therein an outlet port spaced from said supply port and communicating with said base outlet port;

a plurality of diaphragms disposed between adjacent chamber defining plates, each of said diaphragms facing one of said intermediate nozzles and each having a home position permitting communicating between said relief discharge ports and said supply ports through said nozzles and each of said diaphragms in conjunction with said adjacent chamber defining plates forming a plurality of signal receiving chambers into which one of said signal ports opens thereby forming a low pressure operable, diaphragm-type logical element capable of producing a signal at said base outlet when said signal receiving chambers receive a pressure signal and said diaphragms move to a position closing said nozzles, whereby the number of signal receiving chambers may be altered merely by stacking an appropriate number of pre-formed modular chamber defining plates one on top of the other.

2. The diaphragm-type logical element defined by claim 1 further including a diaphragm placed on the uppermost modular chamber defining plate of said plates vertically stacked on said base and facing said intermediate nozzle of said uppermost plate; and a cover plate placed on said diaphragm and defining in conjunction with said diaphragm a signal receiving chamber into which said signal port of said uppermost chamber defining plate opens.

3. The diaphragm-type logical element defined by claim 2 wherein said main supply port, said common outlet port, said signal ports, and said signal receiving chambers are of circular crosssection.

4. The diaphragm-type logical element defined by claim 3 wherein said main supply port contains an impedance matcher comprising: a body having a fluid inlet passage of cylindrical shape formed therein; said body also having formed therein a cylindrically shaped fluid outlet passage of a diameter greater than the diameter of said inlet passage, said outlet passage being coaxially aligned with said inlet passage and defining with said inlet passage a radial interface, thereby to establish a stepped junction between said inlet and said outlet passage; and said body further having at least one fluid discharge suction passage of cylindrical shape formed therein and extending at a right angle with respect to a plane parallel to the longitudinal axis of said outlet passage and intersecting said outlet passage at said stepped junction thereby communicating said stepped junction with the atmosphere.

5. The diaphragm-type logical element defined by claim 1 wherein said element is a product AND element in which each of said supply ports are connected in parallel with said main supply port and wherein each of said superimposed, modular chamber defining plates has formed therein an outlet port spaced from said supply port, said outlet ports of each of said chamber de-' fining plates being connected in parallel and communicating with said common outlet port.

Claims

1. A low pressure operable, diaphragm-type logical element comprising: a base having formed therein a main supply port, a base outlet port, and a plurality of base signal ports; a plurality of superimposed, modular chamber defining plates vertically stacked on said base, each of said plates having formed therein a supply port to receive fluid from said main supply port, an intermediate nozzle, a relief discharge port intercommunicating with said supply port through said intermediate nozzle and a chamber signal port communicating with one of said base signal ports, at least one of said superimposed, modular chamber defining plates having formed therein an outlet port spaced from said supply port and communicating with said base outlet port; a plurality of diaphragms disposed between adjacent chamber defining plates, each of said diaphragms facing one of said intermediate nozzles and each having a home position permitting communicating between said relief discharge ports and said supply ports through said nozzles and each of said diaphragms in conjunction with said adjacent chamber defining plates forming a plurality of signal receiving chambers into which one of said signal ports opens thereby forming a low pressure operable, diaphragm-type logical element capable of producing a signal at said base outlet when said signal receiving chambers receive a pressure signal and said diaphragms move to a position closing said nozzles, whereby the number of signal receiving chambers may be altered merely by stacking an appropriate number of pre-formed modular chamber defining plates one on top of the other.

3. The diaphragm-type logical element defined by claim 2 wherein said main supply port, said common outlet port, said signal ports, and said signal receiving chambers are of circular cross-section.

5. The diaphragm-type logical element defined by claim 1 wherein said element is a product AND element in which each of said supply ports are connected in parallel with said main supply port and wherein each of said superimposed, modular chamber defining plates has formed therein an outlet port spaced from said supply port, said outlet ports of each of said chamber defining plates being connected in parallel and communicating with said common outlet port.