DE2361358A1 - Liq. gas regulator for carburettor feed - has diaphragm chambers, one connected to press. duct and other contg. spring - Google Patents

Abstract

Regulator for a liq. gas plant to supply a carburettor attached to the intake channel of an i.c. engine has gas inlet and outlet channels, a valve body and seal between the channels, and an adjuster for the body with 2 chambers sepd. by a diaphragm. One diaphragm chamber is connected to an actual gas press. duct. A spring in the other chamber exerts a force corresp. to a given reference press. on the first diaphragm. The spring is connected with a second adjuster which alters the force of the spring during idling. Use of a smaller diaphragm surface permits a direct change of operating state from idling to partial or full load with change of the throttle flap setting.

Description

Keyword: Membrane Relief II
Inventor: Dolderer, KoIb, Neun

Control device, especially for a liquefied gas system

for internal combustion engines

The invention relates to a control device, in particular for a liquid gas system for supplying a mixing device connected to an intake duct of an internal combustion engine, preferably a carburetor, with a gas inlet duct, a gas outlet duct, a valve body with an associated valve seat between the inlet and outlet duct and an adjusting device for the valve body.

This generic term refers to the state of the art referred to as it is known from DOS 2 108 183, for example, in the case of liquid gas systems.

With liquid gas systems it is necessary that

a) When the system is at a standstill, no liquid gas can flow into the intake duct, the engine and the atmosphere.

b) when starting and idling the engine, a relatively small one, with a view to low pollutant emissions (CO, NO, CH etc.) as constant as possible Amount of liquid gas supplied to the engine via the intake duct

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c) in the event of a change in the operating state from idling to partial or full load, the one supplied to the engine for the Idle sufficient amount of liquid gas in a very short time Time is increased to an amount necessary to achieve and maintaining the new operating state is required.

The transition from one operating state to another should therefore be feasible in a short time and therefore the Response time of the liquid gas system must be short.

In order to meet these requirements, the liquefied gas system with the carburetor of the internal combustion engine mentioned at the beginning connected to a control valve, which has two chambers separated by a membrane. The one The diaphragm chamber is connected to the suction channel via a control pressure line, while the other diaphragm chamber represents the back pressure space of the control valve. The membrane is connected to the valve body.

When the liquid gas system comes to a standstill, a closed valve located in the gas inlet channel of the control valve is activated Solenoid valve prevents LPG from flowing into the control valve and engine.

When starting the engine is due to the valve body exerted liquid gas pressure of the valve body pressed onto the valve seat and at the same time via a valve body and valve seat bridging by-pass line a predetermined amount of idle liquid gas into the back pressure chamber and fed from there to the engine. When the engine accelerates from idling to partial load, what can be achieved by opening the engine throttle. is due to after opening the throttle increasing absolute pressure in the control pressure line and thus in one diaphragm chamber on one side of the diaphragm acting control pressure greater than the liquid gas pressure acting on the other side of the membrane and the valve body lifted off the valve seat due to this pressure difference.

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Depending on the membrane surface area for the same Regelventildurohmesser is a more or less large pressure differential required (gr membrane (about 200 mm 0) -.. Kl "pressure differential] kl membrane (OEF less than 100 mm.) - gr pressure difference) to the Ventilkörper- from Lift off the valve seat.

However, this has the disadvantage that when using a small membrane, which is in terms of compact and space-saving formation of the liquid gas quantity is desirable, due to the greater pressure difference then required A certain time elapses from the opening of the throttle valve to the lifting of the valve body.

The result is that immediately after opening the throttle valve the pressure in the downstream pressure chamber drops and only rises again after the valve body has been lifted.

Thus, at the moment of the desired transition from idling to partial load, a pressure drop occurs - in technical jargon referred to as the "hole in the controller", which adversely affects the acceleration behavior.

The object of the invention is to provide a device of the initially called type to create that despite using a.small Diaphragm area a change in operating state from idling to partial or full load immediately with a change in the throttle valve setting enables.

To solve this problem it is proposed according to the invention in a device of the type mentioned that one diaphragm chamber is connected to a gas actual value pressure line and in the other diaphragm chamber one, a predetermined one Setpoint pressure value corresponding force on the membrane exerting device, preferably a spring, is provided is, and that furthermore the spring with a second changing the force of the spring when the engine is idling Actuating device is connected.

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The invention advantageously ensures that the size of the spring which determines the nominal pressure force is determined by the idle dependent controlled actuator relaxes and the valve body by the gas pressure is pressed sealingly onto the valve seat. At the same time, a predetermined amount of gas is necessary for an optimal Idling is required via a bypassing the valve body and the valve seat to the carburetor and thus fed to the engine.

In this context it should be noted that it It is of course also possible to use the second adjusting device to only close the set compression spring so far relax so that the valve body is lifted by a certain amount from the valve seat to the passage the amount of idle liquid gas, however, this solution requires an exact manufacture of the valve seat and valve body and the adjusting device, so an amount of about $ 5 or less - the idle amount - the maximum of Regulator deliverable liquid gas amount is kept constant.

If the operating status changes from idling to partial load, with the idle quantity being supplied via the bypass, the setpoint pressure spring force is set by the adjusting device increased to a value that allows a sudden, predeterminable lifting of the valve body from the valve seat causes. As soon as the operating state change is initiated (opening the throttle valve), a compared to the idle amount, the larger amount of liquid gas for Motor, In the invention, the lifting of the valve body is thus controlled by a controllable change in the target compression spring force achieved. A "hole" when accelerating from idling to partial or full load no longer occurs and it is possible to use a very small membrane area for the first membrane (0 about 80-100 mm). this has the advantage that the controller is space-saving can be.

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Only after the nominal compression spring force has been increased so that the valve body lifts up does the actual control process occur in force and the amount of gas is dependent on the pressure difference between the actual gas pressure in the gas outlet channel and the target compression spring force changed.

In an advantageous development of the invention, the second adjusting device has a magnet - in its Exciter circuit, a contact that can be actuated as a function of the position of the engine throttle valve is provided. Through the magnet, which is preferably designed as a lifting magnet in a pulling or pushing design, a simple adjusting device that can be used advantageously for all types of motor is achieved. In addition, the contact, which can be actuated as a function of the engine throttle valve, is achieved immediately and almost instantly when accelerating from idling to partial load - engine throttle and then further opened and the contact actuated - the target pressure spring in a preferably adjustable stop Pressed predetermined position, at the same time the target pressure spring is tensioned and then connected with the actual value pressure of the valve body from the valve seat is lifted.

The invention is explained in more detail below with the aid of a drawing and with reference to further advantageous features. -.

The liquid gas system 10 is used to supply a gasifier 12 connected to an intake duct 11 of an internal combustion engine (not shown) with liquid gas / The liquid gas system 10 has a gas supply device 13 which can be constructed as a single or multi-stage pressure regulator Gas inlet duct Ik connected to a liquid gas tank 15 and via a gas outlet duct 16 to the carburetor 12 »-

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Between the inlet and outlet channels 14 and 16 is a Valve body 17 with associated valve seat 18 is provided. The valve body 17 is provided by means of a membrane device 19 moves, which has two chambers 21 and 22 separated by a first membrane 20 According to the invention, one membrane chamber 21 is connected to a gas discharge pressure line 23, which is preferred to the cavity 24 (narrowest point of the Venturi nozzle 25) of a Venturi nozzle arranged in the gas outlet channel 16 connected. By means of the Venturi nozzle 25 it is advantageously achieved that the sensed actual gas value pressure is lower is than the actual value pressure actually present in the gas outlet channel, with the difference between the actual and sensed actual value pressure from the flow velocity in the Venturi nozzle 25 is dependent (Kl. flow velocity results in small pressure deviation; gr. flow velocity results in a large pressure deviation).

Furthermore, the membrane chamber 21 is via a second, one Line 27 having adjustable throttle 26 is connected to the gas outlet channel 16. Through venturi nozzle 25 and throttle 26, a pressure regulator is obtained in which, with increasing quantity, the output pressure is also obtained at the same time with increases. Any setting of the regulator characteristic (gas pressure via gas volume) possible.

In the other diaphragm chamber 22 of the diaphragm device is a spring. 28 provided, which are used to generate a, A force acting on the first membrane 20 proportional to a predetermined target gas pressure is used. Also has the membrane chamber 22 has a vent hole 29. The spring 28 stands with one when the engine is idling Force of the spring 28 changing the second adjusting device in connection.

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The adjusting device 30 consists essentially of a magnet 31, in the excitation circuit 32 of which is a function from the position of the throttle valve 33 actuatable contact 34 is provided. Contact 34 is preferred through the throttle valve 33 on the one hand and through the throttle valve stop screw 33a (ground pole) is formed. But it is also advantageously possible to use a contact 34 through to use the gas pendulum operated switch, etc. It is essential that the contact 34 when opening the throttle valve ' is operated.

The magnet 31 is preferably designed as a lifting magnet with a magnetic plunger 35, which is mechanically connected to the nominal pressure spring 28 via a spring plate 36. If the magnet 31 is designed in a pulling design, a further compression spring 37 is provided between the spring plate 36 and the magnet housing, in which case the force F proportional to the generation of a predetermined target gas pressure from the addition of the force F, the spring 28 and the force F _{2 of} the spring 37 results when the magnet is not energized,

If, on the other hand, a magnet 31 is provided in a pushing design, then the force F is equal to the force F _{1 of} the spring 28 when the magnet is energized; the spring 37 can advantageously be omitted. A commercially available magnet is preferably used as the magnet ".

The magnet 31 is fastened in a housing 38. The housing 38 is in the Mernbrankamnier 22 via a thread 39 attached. By turning the housing 41 to the left or right, the set compression spring 28 can be set in the simplest way are biased "that in the position illustrated in the drawing, the valve body 17 by a certain Amount is lifted from the valve seat 18.

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Furthermore, the gas inlet and gas outlet channels are 14 ozvj. 16 connected by a bypass 40 bridging the valve body 17 and the valve seat 18, in the course of which an adjustable throttle is provided for adjusting the amount of idle liquid gas. Furthermore, a shut-off valve 42, preferably a solenoid valve, is arranged in the gas inlet channel 14.

The operation of the device according to the invention is the following:

When starting the internal combustion engine, for example The solenoid valve 42 is opened via the ignition lock and the starter of the engine is actuated at the same time. At the same time, the excitation circuit 32 is also closed. The contact 34 is due to the Throttle valve 33 abutting stop screw 33a closed. This is when illustrated in the drawing pulling solenoid version of the magnet 31 is excited and the plunger is pulled in the direction of arrow 43, whereby the spring 28 is relieved.

As a result, the first diaphragm 20, the target compression spring 28 and the spring 37 from that illustrated in the drawing Position moved in the direction of arrow 43. In connection with the pressure of the liquid gas acting on the valve body 17, the valve body 17 is on the valve seat pressed.

At the same time, however, a predetermined rate flows through the bypass 40 Amount of liquid gas for idling in the gas outlet channel 16 and thus in the carburetor 12 and the internal combustion engine.

If the throttle valve 33 is now opened when the operating state changes from idling to partial load, so the connection between the throttle valve 33 and the stop screw 33a is opened and the magnet 31 is de-energized.

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Thus the force of the spring 37 becomes effective and the spring stretched (direction of arrow 44). At the same time, due to the tension of the spring 28, the first membrane 20 and the Valve body 17 pressed into the position illustrated in the drawing (target position), the valve body is lifted from the valve seat by a predetermined amount.

If, according to a further exemplary embodiment, the magnet is designed in a pushing design, then the magnet is not energized during exhaust and idle. For this purpose, a changeover relay 45 is provided in the exciter circuit 32, which interrupts the excitation circuit 32 when the contact 34 closes, or when the contact 34 opens the excitation circuit 32 closes. (The changeover relay is only provided in this version in the excitation circuit 32 and therefore drawn in dotted lines). Due to the non-excited magnet 31, the plunger 35 is in the upper end position and the spring 28 relaxed in the direction of arrow 43. The spring 37 is not required in this example. When the operating state changes from idling to partial load, the magnet 31 is excited and presses the spring 28 in debit position.

Thus, in both exemplary embodiments, the change in operating state occurs immediately when the operating state is initiated a larger amount of liquid gas to the carburetor 12 compared to the idle amount. The invention provides a closing pressure compensated Pressure regulator created, which despite its small design (total volume approx. 750 cm) no "Hole" when there is a change in the operating state, in particular from idling to partial load.

Instead of the exemplary embodiments described, there are of course a large number of possibilities for the actuating device.

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It is essential that achieved by the adjusting device is that the valve body when the engine is idling on the The valve seat rests in a sealing manner.

The individual components of the liquid gas system according to the invention can with regard to their structural design can be trained in any way. The liquid gas system is also advantageous in so-called two-fuel systems, in which the carburetor can either be gasoline with commercially available vehicle equipment or liquefied petroleum gas can be supplied to the liquid gas system. Of course, the invention can also be used in injection engines

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Claims (1)

December 4, 1973 Be / ne Expectations Control device, especially for a liquid gas system for supplying a mixing device connected to an intake duct of an internal combustion engine, preferably a carburetor, with a gas int rittskanal. a .gas outlet duct, a Valve body, with the associated valve seat between the inlet and outlet channels and an adjusting device for the valve body, the membrane device containing two chambers separated by a first membrane , characterized in that the one merabran chamber (21) with a gas actual value pressure line (23) and in the other diaphragm chamber (22) a force on the first diaphragm corresponding to a predetermined target pressure value (20) exercising device, preferably a spring (28) is provided, and that also the spring (28) with a second adjusting device which changes the force of the spring (28) when the engine is idling (30) is connected. Device according to claim 1, characterized in that the second adjusting device (30) has a magnet (31), in whose exciter circuit (32) a contact (3 ² O) is provided, which can preferably be actuated depending on the position of the motorized throttle valve (33) Device according to claim 1 or 2, characterized in that the gas inlet channel (14) and the gas outlet channel (l6) bridging the valve body (17) and the valve seat (18) <At-Passport (40) are connected. " ² ~ 509825/0466 4. Device according to one of claims 1 to 3, characterized in that in the gas inlet channel (14) a shut-off valve (42), preferably a solenoid valve, is provided. 50982 5/0466