RU2511638C2 - Piston flow metre - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to control and measurement means for accounting of fuel consumption by internal combustion engines and may be used in a system of control and monitoring of operation of mobile and stationary energy facilities, including agricultural equipment. A piston flow metre comprising a rectangular body with process and fastening holes, closed at two sides by covers with sensors of piston position, four electromagnetic valves, a piston, and a metering cylinder, and also supply and discharge nozzles. The piston is made with an optimal gap for fuel systems of internal combustion engines, having, as is known, pulsating nature of fuel movement in pipelines, and there is no seal between the metering cylinder and the piston. At the same time it becomes possible to avoid leaks of fuel via a gap in the "cylinder-piston" coupling from one metering chamber into another, since the piston has the same specific weight as the volume of liquid it displaces, at the same time the gravity force of the piston is balanced with buoyancy force. The piston in this flow metre is a mark for an electronic unit of control and monitoring, which freely moves with the fuel flow along the metering cylinder. Each of two capacitance sensors of piston position has one metal lining of a capacitor, and the second lining of such sensors is an end part of the piston.

EFFECT: higher accuracy of measurement of fuel flow in all modes of operation of an internal combustion engine due to reduction of a dynamic component of measurement error; increased functional possibilities that consist in higher universality of using a flow metre both for accounting of fuel flow and other liquid media that are not aggressive to materials of a measurement system, due to reduced requirements to quality and purity of accounted liquid.

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Description

The invention relates to control and measuring means for accounting for fuel consumption by internal combustion engines and can be used in a system for monitoring and controlling the operation of mobile and stationary energy facilities, including agricultural machinery.

The literature describes the design of piston flow meters [3], [4], [5]. The disadvantages of these piston flow meters are the increased resistance to movement of the piston along the cylinder due to the sealing of the cylinder-piston interface, the wedging of the piston in the cylinder with insufficient fuel cleaning quality, which increases the dynamic error in measuring fuel consumption; insufficiently reliable piston positioning system at the extreme points of the measuring system, as well as the fuel flow control valve drive system.

Known universal volumetric fuel flow meter [6]. The measuring chambers of the flowmeter are separated by a membrane, which made it possible to reduce the dynamic component of the error of the device. But at the same time, during the “aging” of the separation membrane, its rigidity changes and, as a result, uneven deflection during operation. As a result, the unit volumes of the measuring chambers change and the measurement error increases.

Closest to the claimed piston flow meter is a fuel flow meter, including solenoid valve controls, control elements of the measuring signal in the form of a piston primary measuring transducer, which is a cylinder, inside of which there is a piston system equipped with a bar with an optical raster deposited on it. In the wall of the cylindrical inner cavity of the primary measuring transducer, the photocells of the measuring signal receiving device with two branches, which are an electric bulb and a photoresistor, are rigidly mounted. Solenoid valves and photocells are connected to the electronic unit [1].

The disadvantages of the known device are: with the relative error achieved, only the total fuel consumption can be measured, and when measuring current fuel consumption values, the error increases depending on the operating mode of the internal combustion engine, because the pulsating primary measuring transducer is affected by the pulsating nature of the movement of fuel in the pipelines [2]; the flow meter has limited use, as its design does not allow to measure the flow rate of opaque and opaque liquids; production and setup of this device is also difficult, because some of its parts require high precision machining.

The technical result consists in increasing the accuracy of measuring fuel consumption in all operating modes of an internal combustion engine by reducing the dynamic component of the measurement error; increasing the functionality, which consists in increasing the versatility of using a flow meter both for accounting for fuel consumption and other liquid media that are non-aggressive to the materials of the measuring system, by reducing the requirements for the quality and purity of the considered fluid.

The technical result is achieved by the fact that in the proposed piston flow meter containing a rectangular housing with technological and mounting holes, covers closed on both sides with piston position sensors, four solenoid valves, a piston and a measuring cylinder, as well as inlet and outlet fittings.

The piston is manufactured with an optimal clearance for ICE fuel systems, which, as you know, have a pulsating nature of the fuel movement in the pipelines, and there is no seal between the measuring cylinder and the piston.

In this case, fuel leaks through the gap in the cylinder-piston interface from one measuring chamber to another can be avoided due to the fact that the piston has the same specific gravity as the volume of liquid displaced by it. In this case, the gravity of the piston is balanced by the Archimedean force. The piston in this flow meter is a mark for the electronic control and control unit, which moves freely with the fuel flow along the measuring cylinder.

In this flowmeter, the piston is positioned using capacitive position sensors, the signal from which is sensed by the electronic control unit. Each of the two capacitive piston position sensors has one metal plate of the capacitor, and the end of the piston serves as the second plate of such sensors. When the piston approaches the capacitive sensor, an abrupt increase in capacity is observed, which is perceived by the electronic valve control system.

The drive of the fuel flow control valves is carried out by means of electromagnets, powered by the on-board network of the energy facility through the electronic control unit. The proposed flowmeter uses four electromagnetic valves operating according to the "diagonal" scheme, distributing fluid flows between the measuring cavities of the measuring cylinder.

The drawing shows a structural diagram of the proposed device, consisting of a rectangular casing - 1, four solenoid valves - 2, 3, 4, 5. In the casing there are inlet - 6 and outlet - 7 lines, in the central part of the casing a measuring cylinder is pressed in, 8 which moves the piston - 9, dividing the cylinder along the length into two measuring chambers "A" and "B". On both sides, the cylinder is closed with caps - 12, 13 with capacitive piston position sensors - 10, 11.

The flow meter, for example, is installed in the fuel system of the engine between the fuel pre-filter and the fuel priming pump.

Solenoid valves, an electronic control unit are connected to the on-board network.

The fuel flow meter operates as follows. When the engine is running, the fuel priming pump moves fuel through the closed fuel system of the engine, while the electronic control unit supplies voltage to two solenoid valves (for example, 2 and 5) connected in a diagonal pattern. Fuel from the supply line - 6 through an open solenoid valve - 2 enters the measuring chamber "A", causing the piston - 9 to move in the direction of the measuring chamber "B". Fuel from the measuring chamber "B" through an open solenoid valve - 5 enters the discharge line - 7 and then to the fuel priming pump. When the piston reaches the capacitive sensor, it changes the total sensor capacity, which is perceived by the electronic control and control unit as a signal for reversing the direction of the fuel flow and ending the unit measuring cycle. The solenoid valves - 2 and 5 are turned off and, under the action of the return spring, they lock the fuel holes. Power is supplied to the solenoid valves - 3 and 4. Fuel begins to flow into the measuring chamber “B”, and the measuring chamber “A” starts to empty. The piston starts moving towards the measuring chamber "A" and the working cycle of the piston flow meter is repeated. The control unit summarizes the number of individual strokes of the piston. Knowing the unit volume of the measuring chamber, fuel consumption can be displayed in any form convenient for further calculation, including taking into account the correction for the temperature component.

Compared with the known solutions, the proposed piston fuel flow meter can improve the accuracy of measuring fuel consumption at all operating modes of the internal combustion engine by reducing the dynamic component of the measurement error when measuring the total and current values of fuel consumption, as well as expand its functionality and increase versatility the use of a flow meter both for metering fuel consumption and other liquid media non-aggressive to the materials of the measuring system, due to t reducing the requirements for quality and purity accounted liquid.

Used sources

1. Kremlin P.P. Flow meters and quantity counters. Directory. Ed. 4. L .: Mechanical engineering, 1989, pp. 614-616, fig. 362.

2. "Tractors and agricultural machinery", 2005, No. 6. The accuracy of measuring the fuel consumption of internal combustion engines using piston flow meters. C 37 - 38.

3. Copyright certificate of the USSR N 1185093, cl. G01F 9/00, 1985.

4. Copyright certificate of the USSR N 1435944, cl. G01F 3/16, 1988.

5. Patent No. 2084833, cl. G01F 03/3.

6. Thesis for the degree of Doctor of Technical Sciences Glotov Sergey Viktorovich "Improving the functioning of machine-tractor units by improving the control of operational parameters of tractors." 2004 year

Claims (1)

A piston flowmeter, comprising a rectangular housing with technological and mounting holes, closed on both sides with caps with piston position sensors, four solenoid valves, a piston and a measuring cylinder, as well as supply and outlet fittings, characterized in that there is no between the measuring cylinder and the piston the seal, while the piston has the same specific gravity as the volume of the measured fluid displaced by it, and each of the two capacitive piston position sensors has one metal conde nsator, and the second lining of such sensors is the end of the piston.

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