DE2657604A1 - DEVICE FOR REGULATING A FLOWABLE MEDIUM - Google Patents

Description

W 185 laser grade (Ireland)

Password: "Carburetor Control" Limited, Dublin / IRELAND

Device for regulating a flowable

Medium

The invention relates to a control system for controlling a flowable Medium «whereby a state of this medium, such as its pressure or its throughput, can be regulated automatically, to maintain a predetermined relationship to a variable demand signal.

Such control systems essentially comprise a sensor for detecting the relationship between an existing state of the Medium and a demand signal, furthermore a control device which is controlled by the output from said sensor and which regulates the state of the medium, if it deviates from a specified ratio to the demand signal, by the specified one Restore relationship.

The control system according to the invention is intended to apply in particular, but not exclusively, to the supply of vaporized material Hydrogen fuel (especially liquefied petroleum gas), e.g. Propane, in internal combustion engines. In these applications, the demand signal can be designed in such a way that ^ s maps itself continuously as fluid pressure, which is related to the running conditions of the engine and the throttle setting, for example by using a venturi nozzle in the inlet of the engine above the throttle valve.

The main object of the invention is an electro-fluidic To create a control system that is capable of controlling the supply of

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To regulate liquefied gas to an internal combustion engine.

According to the invention, the sensor of the control system is provided with means equipped to create a regulating pressure of the medium which is an indication of the relationship between an existing one Condition of the medium and a demand signal, furthermore is a Control chamber provided, in which the said control pressure of the medium against a bias pressure on a movable control member works. The locking element is part of a transducer, with an electrical output that is the instantaneous Position of said control element is reflected, is constantly generated by the sensor. This is also the control device mentioned regulated by the electrical output signal, the existing Condition of the medium is regulated in such a way that said regulating pressure of the medium is essentially constant Value is held.

Said regulating member preferably comprises a flexible membrane, whose elasticity is essentially constant, so that its deflection from a rest position is proportional to that acting transversely to it Djfferential pressure is. The membrane carries an organ whose location is from is detected by the sensor.

Said control element can be part of an impedance device, e.g. an inductance or capacitance, which produces an alternating current oscillation depending on the position of the mentioned control element modulated to produce said electrical output signal. A detector circuit can then convert the modulated oscillation into convert an analogous statement. Alternatively, said transducer can have an electro-optical device, which works with direct current and generates an analog signal directly. Such an analog signal can then be used again to act on a magnet. This is a solenoid valve assigned, namely a proportional flow controller, which represents said control device.

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If the control system according to the invention is applied to a gasification plant an internal combustion engine that uses liquefied petroleum gas For example, to regulate the volume flow of liquid gas, said regulating pressure of the medium can be derived in that one negative pressure, which comes from an above a carburetor throttle valve is tapped, in relation to an overpressure in the supply line of the liquid gas * This can be done by that one in the venturi nozzle and in the supply line contained pressures recorded directly. Alternatively, the supply line be interconnected with the gasifier in such a way that the required control pressure of the medium is automatically in the supply line is set.

As will be seen from the following description, can Gasoline gasification systems through a simple redesign for the Converting operation of liquefied gas * whereby the inventive Hegel system can be used, and one is still able to work alternatively with gasoline as fuel.

The invention is explained in more detail with reference to the drawing.

Fig. 1 shows a schematic representation of a fluid control system according to the invention, applied to a conventional gasifier operating on liquefied petroleum gas.

Fig. 2 shows again in the scheme «like that shown in FIG System looks like. When applied to a composite gasoline carburetor that runs on liquefied petroleum gas is operated.

Flg. 3 shows a diagram of a liquid control system according to the invention * applied to a liquefied petroleum gas carburetor.

4 shows a diagram of another according to the invention Fluid control system.

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Fig. 5 shows a block diagram of the electronic part of the control system which corresponds to the control systems of FIGS. X to 4.

Flg. 6 is an exploded view of the control system in its structural design.

Fig. 7 shows the sensor in cross section and as a construction drawing dar *

As can be seen from Fig. 1, a delivery line 81 is used to bring liquefied gas from a storage container (not shown) to a first pressure regulator 2. The liquefied gas flows from the first pressure regulator 2 through a proportional flow solenoid valve 3. It arrives at a delivery pipe I ₉ the has an injector nozzle 4 at its outlet. This is arranged at the normal air inlet of a gasoline carburetor 50, namely above the venturi nozzle 5 of the carburetor.

The magnet 3a of the solenoid valve 3 1st is connected to the Output of an electronic control device 6. This in turn is controlled by a pressure measuring device 7 (see also Fig. 7). The pressure measuring device 7 has a control chamber 8, and also one low silicone rubber membrane 9 * in the chamber 8 below lighter tension is mounted, and a sensing coil 10, the distance between itself and a mounted in the center of the membrane 9 Bolt detected "By using a rubber content with a low silicone content, a constant elasticity is created, thus a · membrane of constant characteristics.

The membrane 9 divides the chamber into two caaars 8a and 8b. Zwlsohenkaosier 8a is connected to the atmosphere and creates «Omit a reference drusk« which acts on the one «side of the membrane 9 * Zwlsohenkammer 8b is connected to the pipeline 11, d1 has an attenuation nozzle 49 * Si «opens into two lines 11a and Hb «in which nozzles 52 and 53 have. The latter

709828/0603 5

'j-

can be of different sizes · The line 11a leads through a small hole into the constriction area of the carburetor venturi nozzle 5 # while the line lib to a gas supply line

I leads. In this way, a negative pressure is created in the pipe 11a created that is related to that in the constriction zone the vacuum present in the venturi nozzle 5; An overpressure is created in the line lib which corresponds to that in the supply line 1 is related to the prevailing pressures. The negative pressure prevailing in line 11a represents a measure of the engine consumption, since it depends on the operating conditions of the engine and on the setting of a throttle valve 54 and thus a consumption benchmark gives · The overpressure in line 11b adjusts Measure for the volume flow depending on the value for the demand. The negative and positive pressures are mutually exclusive at point A. superimposed and the resulting pressure is fed via a line 11 of the intermediate cararaer 3b. Here it acts on the membrane in relation to the reference pressure prevailing in intermediate chamber 8a.

The leverage system shown in Fig. 2, which is an adaptation to the composite carburetor reproduced in Fig. 1, has a throttle valve 56. This will be fully opened before the Throttle valve 57 is opened »In this case, the line

II an additional branch lic on which has a narrow bore into the constriction area of a second Venturi nozzle 58 which has a nozzle 59. Otherwise, the system shown in FIG. Is similar to that in FIG. 1 shown.

The system shown in Fig. 3 represents a carburetor system which is intended exclusively for use on Flüa & ggas 1st * In this system, the supply line 1 leads to the containment area the carburetor venturi nozzle 6l. It has a main mixing screw 62, which together with the pressure prevailing in line 1 determines the idle solution. The line 11 is Although not branched, it leads directly to the supply line 1. In this way, a pressure is generated in line 11 which is related to to the pressure prevailing in line 1 and therefore as

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Display means for the existing relationship between the demand signal (determined by the pressure prevailing in "Venturi nozzle 61) and the feed rate in line 1 is. Otherwise this system is similar to that in Pig. I illustrated.

FIG. 4 shows a modification of that shown in FIG Systems. Here, the demand signal is in the air inlet opening of the carburetor measured, und.zwar in the flow direction above an air filter 63 by means of a separate Venturi nozzle 64. Im Otherwise, the system shown here is similar to that shown in FIG .

In Fig. 5 is the block diagram of the control system 6 and the associated Sensor 7 is shown against the magnet Yes, valve 3 is shown.

The probe coil 10 constitutes part of a high-frequency oscillator 70 (RF-Os zi Hat or), the output of which depends on the distance of the bolt 51 is modulated by the coil 10. If the bolt 51 consists of certain metals, this results in amplitude modulation evoked. If it consists of ferrite, this leads to frequency modulation, since the inductance of the coil IO is changed, but not their amount of charge. The output from the high-frequency oscillator is fed to the detector 71, which modulates the Output from the oscillator 70 is converted into an analog value. The output of the detector 71 is fed to an integrator 72 whose The purpose is to integrate an analog signal as required to create and thus to keep the electro-fluid circuit, of which it forms part, stable. The output of the integrator is fed to an amplifier 73 in order to be applied of the solenoid valve 3a required energy available. the Bias control 55 is in turn controlled by a temperature control unit 74 regulated so that your applied, the oscillator 70 input Value also depends on the temperature. This is during a cold start beneficial for the engine.

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The control system thus has an electro-fluidic control circuit, at which the difference between the pressures in the intermediate chambers 8a and 8b are related to the preselection of a pilot control 55 and the idling gain of the electro-fluidic control circuit.

The not shown energy circuit of the control system 6 consists e.g. from the engine battery · A wire? 6 leads from an interrupter contact 75 aes motor distributor to an amplifier circuit 77, the output of which is fed to the integrator 72. Circle 77 sends a short pulse to the integrator right after it begins the impulses from the motor distributor. The long lasting impulses influence in turn the output of the integrator to the effect that it briefly increases the energy to be supplied to the solenoid valve Yes and thus the gas supply via the supply line 1 in the form of a Gas surge at nozzle 4 increases. This is very beneficial when starting the engine.

The line 76 from contact 75 also leads to a shutdown circuit , so that the application of the solenoid valve is switched off in the absence of pulses from the motor distributor and thus a reliable shut-off of the liquid gas supply is guaranteed.

When the control system is operating, the idle gain is very high, for example the change in the output from the amplifier is relatively very large with a very small deflection of the diaphragm. From this it follows that, for any given demand signal, the membrane is set to a position of equilibrium which, for practical purposes, is always the same, so that the pressure at point A remains constant.

When assembling the Begelsysteoies, the greetings of the injector nozzle 4 selected in such a way that they achieve the desired ratio to the cross-sectional area of the constriction area of the Venturi nozzle 5 has. The sizes of the nozzles 52 and 5? are chosen in such a way that these have a predetermined relationship to one another

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as well as the size of the injector nozzle 4, the main gas-air mixture define. The preselection device 55 is set when the engine is idling in such a way that an air-gas ratio of Idle mixture is achieved, which produces the desired CO content of the exhaust gases from the engine. As you can see, this becomes the Pressure at point A set to a certain value.

If the demand signal varies, e.g. by adjusting the throttle valve, this causes a change in the pressure at point A. emerged. This in turn causes a change in the differential pressure caused between the Zwisohenkaramern 8a and 8b, so that the membrane 9 executes a movement as a function of this change. Since the movement is damped by the damping nozzle 49 the amount of movement is determined by the change in pressure. Generate the movement of the membrane and thus of the bolt 51 a change in the modulation of the high frequency output of the oscillator 70, which in turn causes the integrator 72 to do so will change its state of charge and thus that of the magnet 3a supplied energy flow. This causes the gas flow in that sense changed so that the pressure at point A is returned to its original value. When this original pressure is reached, the The membrane is almost returned to its original position and the integrator is now held at its new load value for as long as than the demand signal remains the same.

Figures 6 and 7 show the structural design of the solenoid control valve and the associated sensor and the control device. The first pressure regulator 2 and the proportional flow solenoid valve 3 are mounted on a base plate 12. The key coil 10 of the sensor 7 and the electronic control system 6 with the exception of the power amplifier 72 together form the element 41. The base plate 12 necessarily comprises a part of the gas supply line 1 and the line 11.

The primary pressure regulator 2 is essentially conventional Construction. It comprises a ball valve 13 »a plunger 14, a spring 15 and a retaining cap 16. Plunger 14, however, is not of conventional construction. It has a seat for an O-ring 17

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fitted. This is not rectangular in the usual way Structure, but it is undercut at its rear end in such a way that that the O-ring can move a little in the groove. This reduces the wear on the O-ring as well as the mechanical The hysteresis of the plunger 14 is reduced.

The proportional flux Magnetvenfcil 3 includes a fitting 18 (so the actual valve part), which is biased by a spring 19 with a cap 20. The valve 18 is located inside a coil 21 wound on a core 22. The entire element is supported by a base plate 23, an outer magnet housing 24 and the magnet upper part 25 held in place. the The fitting is provided with a recess at its upper end in which a disc-like rubber seal 26 is received

The solenoid valve base 23 is provided with a pair of threaded bores 27 into which screws, not shown, can be screwed. These go through bores 28 in the base plate 12. A chamber 29 is provided in the base plate 12 and has an inlet Ji . The outlet opening of the inlet Jl is surrounded by a valve seat 30. The chamber 29 is provided with an outlet 32. The chamber 29 is supplied with liquid gas from the main gas supply line S1 (FIG. 1), which flows through the primary pressure regulator 2 and through the inlet 31 into the chamber 29. The gas flows into the supply line 1 through the outlet 32. An adjusting screw (not shown) is arranged in the threaded bore 35 in the upper part of the magnet and engages in the cap 20 for the purpose of adjusting the preload spring 19.

The sensor 7 has a cover 36 (see Fig. 7), which the membrane braced at its periphery against the base plate 12, so that said Intermediate chamber 8b is formed. The membrane 9 is curved Shape and equipped with an inner part in which a metal ring is embedded, which the said plug 51 forms. The membrane 9 is stretched in its position when it is clamped so that it is forced into a central location. The sensing coil 10, which is of conventional construction is in a housing 39 in the lid 36 mounted.

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10

The proportional flow solenoid valve 3 works as follows: The valve is pressed in the non-acted state of the magnet by the bias spring 19 down, so that the seal 2.6 rests against the seat JQ and blocks the passage Jl. If the magnet is acted upon by the control device 6, it lifts the armature 18 against the pressure of the pretensioning spring 19. As soon as the fitting 18 goes up, gas flows in the fitting 18 through its passage Ji and into the chamber 29.

The amount of gas depends on the distance that forms the valve to the passage Jl, which in turn depends on the magnet of the MaS the Snergiebeaufschlagung.

An electrical heating device 19 is arranged on the base plate 12, in order to heat the liquefied gas and thus convert it from its liquid state into vapor form.

Heidenheim, December 16, 1976
DrW / Srö

709828/0603

Claims (20)

W 185 Laser-Grade (Ireland) Password: "Carburetor Control" Limited, Dublin / IRELAND Claims 1. Control system for regulating a flowable medium (liquid, Gas) with a sensor for detecting the relationship between an existing state of the flowable medium and a Demand signal, characterized by the combination of the following features a) A control device is provided, which is controlled by the output of the sensor for the purpose of Regeins the state of the flowable Medium is controlled when it deviates from a predetermined ratio to the demand signal to the predetermined ratio restore; b) the sensor is equipped with means for a control pressure derive, which serves as an indicator for the relationship that exists between an existing state of the flowable Medium and a demand signal prevails! c) a control chamber is provided in which said control pressure of the flowable medium acts against a reference pressure, namely on a movable control element! d) said control element is part of a transducer, in which an electrical output, which the instantaneous Reproduces position of said control member, is constantly generated in that said sensor and said control device can be regulated by appropriate design and / or arrangement of said electrical output, and that the existing state of the flowable medium is regulated in such a way that the control pressure of the flowable medium is kept essentially at a constant value " ORIGINAL INSPECTED 7 09828/0603 2. Control system for regulating a flowable medium according to claim 1, characterized in that said regulating device is a Froportionalfluß-Regelorgan that of. one Magnet is operated (solenoid valve), the electrical application of which is regulated by the aforementioned electrical output will. 3. Control system for a flowable medium according to claim 1 or 2, characterized in that said reference pressure assumes a substantially constant value. 4. Control system for a flowable medium according to claim j5 # thereby characterized in that the reference pressure is atmospheric pressure. 5. Control system according to one of claims 1 to 4, characterized in that that said control member has a flexible membrane, the elasticity of which is substantially constant and which has a device, the position of which is represented by said electrical output. 6. Control system according to one of claims 1 to 5 *, characterized in that that said control element is part of an impedance device which is designed in such a way that it receives an alternating current modulated as a function of the position of said control element in order to generate said electrical output. 7. Control system according to one of claims 1 to 6, characterized in that that said impedance device has an inductance, the characteristic of which depends on the distance (or near) to modulate the sinusoidal waveform of a high frequency oscillator. 8. Control system according to one of claims β or 7 *, characterized in that the modulated sinusoidal current oscillation is fed to a detector in order to create an analog output that serves as an indicator for the position of said control element. 709828/0603 9 «control system naoh claim 8, characterized in that the Output from said detector is fed to an integrator. 10. Control system according to claim 9 *, characterized in that the Output from said integrator regulates the output level of an amplifier, the output of which is applied to the control device . 11. Control system according to one of claims 6 to 10, characterized in that that a pretensioning device is provided, by which the modulation level of said sinusoidal current oscillation for a given position of said control element can be adjusted. 12. Control system according to one of claims 1 to 5, characterized in that that said transducer has an electro-optical device. 13 * control system according to one of the preceding claims * thereby characterized in that it is used in connection with the gasification system of an internal combustion engine running on liquefied petroleum gas is operated that the control device is arranged and / or designed so that it controls the volume flow of the Liquid gas in a line regulates the liquid gas to the gasifier system, and that the control pressure of the flowable Medium is obtained by one on a Venturi valve tapped negative pressure with one in the supply line relates the prevailing overpressure 14. Control system naoh claim 15 * characterized in that the Carburetor system has a carburetor, which is also suitable for processing gasoline, and that the supply line for Liquid gas flows into a nozzle in the air inlet of the carburetor. 709828/0603 15. Control system for a flowable medium according to claim 14, characterized in that the control pressure for the medium is generated by the pressures in the supply line and separately recorded and added in a venturi. 16. Liquid control system according to claim I5, characterized in that that in the venturi nozzle of the carburetor a hole for detecting the prevailing in the venturi nozzle Unterdruokes is provided. 17. Control system according to claim I5 * characterized in that the called negative pressure in a supply air line above an air filter is arranged, which is assigned to the carburetor, and that the supply line for liquid gas in a provided in the air filter Nozzle opens. 18. Control system according to claim 13, characterized in that the Feed line for liquid gas opens into a Venturi nozzle, and that said regulating pressure of the medium is derived from the pressure which prevails at a certain point in said supply line. 19 * Hegel system according to one of claims 13 to IS ₂ , characterized in that the engine works with spark ignition, which is controlled by a distributor, and an amplifier circuit is provided which modifies the said electrical output signal for a short time when the distributor pulse is ignited , «If a liquid gas surge was fed into the carburetor system, 20. Control system according to one of the claims 13 to 19 «characterized» in that the said motor works by means of spark ignition, which is controlled by a distributor, and that a cut-off circuit is provided which is designed in such a way that it includes the said control device In the absence of distributor pulses. 709828/0603
Heldenheim, December 16, 1976
DrW / Srö