Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M65/00—Testing fuel-injection apparatus, e.g. testing injection timing ; Cleaning of fuel-injection apparatus
  • F02M65/001—Measuring fuel delivery of a fuel injector

Definitions

• the present invention relates to a device for measuring a quantity of fluid injected by an injector.
• the present invention relates more particularly to a device for measuring a quantity of fluid injected intermittently or blow by blow by an injector.
• the measuring device finds particular application in fuel injection systems, used in combustion engines, in the form of a device for measuring a quantity of fuel injected.
• the present invention is not limited to such application in thermal engines, but may find applications in other areas of fluid quantity measurement, in liquid or gaseous form.
• a measuring device comprising a measuring chamber into which the fluid is injected, a device for injecting the fluid. in the measuring chamber, a pressure sensor and a temperature sensor arranged in the measuring chamber and adapted to respectively measure the pressure and the temperature prevailing in this measuring chamber.
• a closed measuring chamber in which the fluid is injected, and in which at least the pressure variation is measured and, in addition, the temperature.
• the present invention aims to improve the accuracy of the measurement of the pressure variation in the measuring chamber by attenuating the disturbing pressure waves.
• a device for measuring a quantity of fluid injected by an injector comprising a measurement chamber in which is injected the fluid, a device for injecting the fluid into said measuring chamber, at least one pressure sensor disposed in said measuring chamber and adapted to measure the pressure in said measuring chamber, said device being remarkable in that that the measuring chamber has a generally ellipsoidal shape, in particular of the ellipsoidal type of revolution, having a first and a second foci, in that the injection device comprises an injection orifice positioned on the first focus of said measuring chamber , and in that the pressure sensor is positioned on the second focus of said measuring chamber.
• the path length between the two foci after a single reflection on the envelope of the ellipsoid is constant regardless of the location of the reflection point on the envelope.
• the pressure wave paths between the starting point (injection orifice located at the first focus) and the measuring point (sensor pressure located on the second focus) all have the same length after a first reflection on the inner wall of the measuring chamber.
• the fluid is injected at the first focus of the ellipsoid and the pressure measurements are made at the second focus.
• the pressure waves will propagate between their source (injection orifice located at the first focus) and their arrival (pressure sensor located on the second focus) along paths of the same length and therefore with equivalent delays after a first reflection on the inner wall of the measuring chamber, thus limiting the harmful effect of the pressure waves and improving the accuracy of the measurement.
• the device further comprises a temperature sensor disposed in the measuring chamber and adapted to measure the temperature in said measuring chamber, and this temperature sensor is also positioned on the second focus of said measuring chamber, adjacent to the pressure sensor.
• the device further comprises a device for emptying the measuring chamber having a drain orifice also positioned on the second focus of said measuring chamber, adjacent the pressure sensor.
• a device for emptying the measuring chamber having a drain orifice also positioned on the second focus of said measuring chamber, adjacent the pressure sensor.
• a focus certainly constitutes a specific point location, and it is clear that the location of the injection port, the pressure sensor, the temperature sensor and / or the drain orifice on the home concerned means a location on the home even in the immediate vicinity of the punctual focus.
• the device further comprises first and second hollow supports sealingly traversing the measuring chamber and having free ends positioned respectively on the first and second foci of said measuring chamber and supporting respectively the orifice of injection and the pressure sensor.
• Such supports make it possible to hold the pressure sensor and the injection orifice in place on the respective foci, with the injection duct of the injection device extending at least partly inside the first support. and with the connections of the pressure sensor (for an electrical connection with a control and / or supply system) arranged at least partly within the second support.
• the second support also supports at its free end the temperature sensor and / or the drain orifice, thus making it possible to take advantage of the second support to position the pressure sensor with the temperature sensor on the second focus. / or the drain port, the second support for accommodating within it the links of the temperature sensor (for an electrical connection with a control system and / or supply) and / or the drain line.
• the device comprises seals interposed between the supports and the measuring chamber, preferably of the fluid seal type.
• fluid seals is particularly advantageous for reducing the vibrations that could transmit the supports, and in particular the first support which partially supports the injection device which, in the case a fuel injector, is a real shock generator; such vibrations being sources of disturbance for the measurement of the pressure by the pressure sensor, and therefore for the accuracy of the measurement.
• fluid seals can eliminate any rigid mechanical contact between the supports and the measuring chamber.
• the device further comprises a screen disposed inside the measuring chamber and interposed between the two homes on the virtual line directly connecting the two homes between them.
• this screen makes it possible to eliminate the pressure waves flowing directly between the two foci in order to favor only those that have made at least a first reflection on the internal walls of the measurement chamber.
• this screen is made of a material absorbing pressure waves, or is covered with a coating made of such a material, in order to cope with a rapid attenuation of these direct pressure waves.
• the screen is held suspended between the two homes with one or more links fixed on the measuring chamber and on the screen.
• the device furthermore comprises an external enclosure inside which the measurement chamber is kept suspended, without direct contact between the external enclosure and the measurement chamber, with one or more links fixed on the measuring chamber and on the outer enclosure, preferably flexible links, elastic or shock absorbers.
• the measuring chamber is thus decoupled from external influences and in particular from shocks and vibrations, and the design of the measuring chamber is simplified because it is the outer enclosure that will withstand the static pressure of the fluid, which pressure can typically rise up to 200 bar in applications with fuel injection systems for a heat engine.
• the aforementioned joints are of the solid seal type made from a tight and flexible material, it is preferable to provide a safety valve in the measuring chamber, to allow a safety discharge from the measuring chamber to the external enclosure in case of overpressure.
• the device further comprises a system for regulating the pressure inside the external enclosure.
• the device does not include this external enclosure and, in this case, the measurement chamber is in direct contact with the environment and with the fluid injection system which constitutes a source of shocks and of vibrations.
• the measuring chamber must be designed to withstand the static pressure of the fluid which, as a reminder, can rise up to 200 bar with the fuel injection systems. It is also preferable, in this simplified version, to provide a safety valve in the measuring chamber, to allow a safety discharge of the measuring chamber to the outside in case of overpressure.
• a Helmholtz resonator which opens on a wall of the measurement chamber to attenuate the waves. Note that the use of such a Helmholtz resonator in a measurement chamber could also be considered with measuring chambers having shapes other than the ellipsoidal shape.
• Helmholtz resonator is relatively effective for at least the resonance frequency of the resonator, so that a significant improvement of the attenuation of the waves can be obtained by employing several Helmholtz resonators which have frequencies of different resonance, so as to be able to attenuate the main disturbing frequencies within the measuring chamber.
• the Helmholtz resonator adapts itself to the inherent characteristics of the fluid.
• the invention also relates to a device according to the invention which constitutes a device for measuring a quantity of fuel injected by an injector used in a heat engine.
• the invention also relates to the use of such a device as a device for measuring a quantity of fuel injected by an injector used in a heat engine.
• FIG. 1 is a schematic view of a first measuring device according to the invention.
• FIG. 2 is a schematic view of a second measuring device according to the invention.
• FIG. 3 is a schematic view of a third measuring device according to the invention.
• FIGS. 1 to 3 respectively disclose a first, a second and a third embodiment of the invention and, unless explicitly or implicitly indicated, organs, parts, devices or structural or functional elements. identical or similar will be designated by identical references in Figures 1 to 3.
• a measuring device 1 designed for measuring a quantity of fluid injected by an injector, comprises: a measurement chamber 2 in which the fluid is injected, said measurement chamber 2 being delimited by a wall which internally defines a closed space;
• a device 3 for injecting the fluid into the measurement chamber 2 the injection device 3 being supported by a first support 30 and comprising an injection conduit 31 which terminates in an injection orifice 32 located at the inside the measuring chamber 2;
• a pressure sensor 4 disposed inside the measuring chamber 2 and supported by a second support 40;
• control system 7 of the measurement in particular of the electronic controller type.
• the measurement chamber 2 has a generally ellipsoidal shape, in other words its wall is in the form of a non-spherical ellipsoid, and it has first and second foci F1, F2.
• the measuring chamber 2 has a general shape of ellipsoid of revolution.
• This measuring chamber 2 has in its wall two so-called through holes, for example threaded holes, for the sealed passage of the supports 30, 40.
• the injection device 3 comprises:
• a regulating device 33 in particular of the actuator type, making it possible to regulate the flow rate and the pressure of the fluid entering via an inlet conduit 34 of the fluid;
• the regulation device 33 is controlled either by the control system 7 (as visible in FIGS. 1 and 2 with the link 71), or by an external control system.
• the emptying device 6 comprises: a regulating device 63, in particular of the actuator type, making it possible to regulate the flow rate and the pressure of the fluid leaving the drain conduit 61;
• the regulation device 63 is controlled either by the control system 7 (as visible in FIGS. 1 and 2 with the link 72), or by an external control system.
• the first support 30 consists of a hollow tube which passes through the wall of the measuring chamber 2 in a sealed manner, and inside which the injection duct 31 is arranged in part.
• This first support 30 has a free end 35 positioned on the first focus F1 of the measuring chamber 2.
• the injection orifice 32 opens sealingly on this free end 35: this free end 35 is closed to prevent a return of fluid within the first hollow support.
• the injection port 32 is positioned on this first focus F1.
• the second support 40 consists of a hollow tube which passes sealingly through the wall of the measuring chamber 2, and inside which the drain duct 61 is partly arranged.
• This second support 40 has a free end 45 positioned on the second focus F2 of the measuring chamber 2.
• the emptying orifice 62 opens sealingly on this free end 45: this free end 45 is closed to prevent a return of fluid inside the second hollow support 40.
• the emptying orifice 62 is positioned on this second focus F2.
• the pressure sensors 4 and temperature 5 are also mounted on this free end 45, so that these two sensors 4, 5 are also positioned on the second focus F2.
• the sensors 4, 5 are connected to the control system 7, via respective links 74, 75, to ensure both the supply of the sensors 4, 5 and the transmission of the measurement data to the control system 7 .
• the device 1 further comprises seals 37, 47 interposed between the supports 30, 40 and the wall of the measuring chamber 2, at the through holes for these supports 30, 40.
• These seals 37, 47 can be of the fluid seal type, made in particular by applying a fluid joint paste, in particular in the case where the through holes are threaded with the supports 30, 40 which are screwed into these through holes.
• these seals are of the solid seal type, that is to say made of a tight and flexible material.
• the device 1 further comprises a screen 8 disposed inside the measuring chamber 2 and interposed between the two foci F1, F2, on the virtual line directly connecting the two foci F1, F2 between them.
• This screen has the function of eliminating the pressure waves from the first focus F1 and going directly to the second focus F2 without reflecting on the wall of the measurement chamber 2, to favor the waves that perform at least one first reflection on this wall.
• This screen 8 may be made entirely or with a coating of material absorbing the pressure waves, and it is held suspended between the two foci F1, F2 with at least one link 80 fixed on the wall of the measuring chamber 2 and on the screen 8.
• This or these links 80 may be rigid link type, for example steel, or flexible link type, elastic or shock absorber.
• the screen 8 has limited dimensions so as not to disturb the pressure waves which carry out at least one reflection in the measuring chamber 2, with for example dimensions less than 40%, or even 30%, of the spacing between the two outbreaks F1, F2. In general, this screen 8 does not come into direct contact with the wall of the measuring chamber 2.
• the measuring device 1 further comprises an outer enclosure 9 inside which is held suspended measurement chamber 2, without direct contact between the outer enclosure 9 and the measuring chamber 2, with several links 90 fixed on the measuring chamber 2 and on the outer enclosure 9.
• this external enclosure 9 The main purpose of this external enclosure 9 is to isolate the measurement chamber 2 from external influences and in particular shocks and vibrations.
• these links 90 are preferably flexible links, elastic or dampers, which are configured to damp the vibrations and shocks received by the outer enclosure 9 while preventing the measuring chamber 2 from bumping against the outer enclosure 9 .
• the device 1 further comprises a regulation system 91 of the pressure inside the outer enclosure 9, which integrates: a regulating device 92, in particular of the actuator type, making it possible to regulate the fluid pressure in the outer enclosure 9 via a control duct 93 which opens inside the outer enclosure 9;
• the control device 92 is controlled either by the control system 7 (as visible in FIGS. 1 and 2 with the link 73), or by an external control system.
• This regulation system 91 further comprises a pressure sensor 96 and, optionally, a temperature sensor 97 disposed in the outer enclosure 9 and adapted to respectively measure the pressure and the temperature prevailing in this outer enclosure 9; these sensors 96, 97 being in connection with the control system 7, via respective links 76, 77, to ensure both the supply of the sensors 96, 97 and the transmission of measurement data to the control system 7 .
• the supports 30, 40 also pass in a sealed manner to the external enclosure 9.
• the or each Helmholtz resonator 100 comprises a closed cavity 101 of volume V which communicates with the inside of the measuring chamber 2 via a tube 102 of length L and of section S, otherwise called the neck of the resonator. where the aforementioned dimensions are small in front of the wavelength of the pressure waves that it is desired to dampen.
• control system 7 makes it possible to carry out the measurement and to control and control the measurement conditions, it is connected with the outside, such as for example an operator or a control system. or automation at a higher level.
• the control system 7 thus receives instructions, it optionally controls the regulating devices 33, 63, 92, receives the measurement data from the sensors 4, 5 and possibly 96, 97, and calculates measurement results (quantity of fluid injected) and supplies them externally.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Measuring Fluid Pressure (AREA)
• Measuring Volume Flow (AREA)

Applications Claiming Priority (2)

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• 2012
  • 2012-09-19 FR FR1258770A patent/FR2995640B1/fr not_active Expired - Fee Related
• 2013
  • 2013-09-18 EP EP13779621.5A patent/EP2898213A1/de not_active Withdrawn
  • 2013-09-18 WO PCT/FR2013/052144 patent/WO2014044967A1/fr active Application Filing
  • 2013-09-18 CN CN201380048795.7A patent/CN104641103A/zh active Pending
  • 2013-09-18 JP JP2015531632A patent/JP2015529777A/ja active Pending

Non-Patent Citations (1)

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