Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23Q—IGNITION; EXTINGUISHING-DEVICES
  • F23Q7/00—Incandescent ignition; Igniters using electrically-produced heat, e.g. lighters for cigarettes; Electrically-heated glowing plugs
  • F23Q7/001—Glowing plugs for internal-combustion engines
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
  • G01L23/08—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid operated electrically
  • G01L23/10—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid operated electrically by pressure-sensitive members of the piezoelectric type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P19/00—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition
  • F02P19/02—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs
  • F02P19/028—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs the glow plug being combined with or used as a sensor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23Q—IGNITION; EXTINGUISHING-DEVICES
  • F23Q7/00—Incandescent ignition; Igniters using electrically-produced heat, e.g. lighters for cigarettes; Electrically-heated glowing plugs
  • F23Q7/001—Glowing plugs for internal-combustion engines
  • F23Q2007/002—Glowing plugs for internal-combustion engines with sensing means

Definitions

• the invention relates to an apparatus for detecting the pressure in a combustion chamber of an internal combustion engine.
• an apparatus comprising: - a functional member useful for operating the engine, the functional member passing through the wall of a cylinder head, inside an orifice having an axis and formed in this wall, the functional member communicating through this orifice with a combustion chamber of the engine and being intended to be mechanically linked to the cylinder head, with a capacity for a part of this functional member to move axially relative to the rest of the functional member secured to the cylinder head under the pressure prevailing in the combustion chamber,
• a combustion pressure sensor in said chamber, the sensor being axially pressurized against a part linked to the functional member, via a fixed bearing surface in position relative to the cylinder head, independently pressure in the combustion chamber, so that the sensor detects the movement of said part of the functional member during variations in the combustion pressure in the combustion chamber.
• this functional member comprises an inner core capable of moving axially with respect to an outer body screwed into the orifice of the cylinder head, under the effect of the combustion pressure, the sensor being interposed between two local areas of the soul and body, the relevant surface of the latter then defining the "bearing surface" presented above.
• a functional member comprises an inner core capable of moving axially with respect to an outer body screwed into the orifice of the cylinder head, under the effect of the combustion pressure, the sensor being interposed between two local areas of the soul and body, the relevant surface of the latter then defining the "bearing surface" presented above.
• Such a design also imposes mounting characteristics which, for example, oblige the manufacturer of the cylinder head to tap the latter at the location of the spark plug mounting hole and to use the sensor body as a surface for fixed reference for pressure reading.
• the object of the invention is: - to dispense with having to pierce the cylinder head in order to place a detection device there, - ensuring more practical conditions for fixing the functional member to the cylinder head,
• this additional means exerts pressure on the sensor by defining said fixed bearing surface in position relative to the cylinder head when the functional member which is mounted on the cylinder head is in an operational state ready to be subjected to pressure in the combustion chamber.
• An additional problem concerns the way of connecting the functional member to the cylinder head, without necessarily fixing the first directly to the second, so as to favor the use of the aforementioned displacement sensor, including with the “monoblock” functional members devoid of moving part, such as spark plugs or injectors.
• the additional means comprises a flange fixedly connected to the cylinder head and a nut screwed to a thread of the flange, the nut putting the sensor and a shoulder of the functional member axially under pressure between it and a shoulder of the flange,
• the additional means comprises a flange structurally independent of the cylinder head, the flange having a first mechanical fixing zone intended to penetrate inside the orifice and comprising first fixing means adapted to engage second means of fixing provided in the wall of the cylinder head orifice, in order to fix the flange to this cylinder head, in the orifice, and a second fixing zone located away from the orifice and having third fixing means for a mechanical connection between the functional member and the flange,
• the additional means also comprises a pressure and fixing member comprising fourth fixing means adapted to engage the third fixing means, so as to exert an axial pressure on the sensor independently of the combustion pressure and to mechanically link the functional member at the flange, part of the outer periphery of this functional member intended to come immediately opposite the wall of the orifice of the cylinder head being mounted freely inside this orifice, being devoid of fixing means engaging the wall of this orifice.
• the external periphery of the functional member has locally a shoulder defining said part linked to the functional member against which the sensor is pressurized by means of the bearing surface
• the flange comprises a hollow cylindrical part having a first part having a first diameter to be placed inside the orifice and a second part of second diameter located outside of the orifice, at l axial opposite of the combustion chamber, this second diameter being greater than the first diameter, the second part thus having an internal volume adapted to receive a shoulder of the functional member as well as the sensor which has an annular shape locally surrounding an external surface of the functional organ.
• the additional means include a flange fixed to the cylinder head outside the orifice, the flange locally defining said fixed bearing surface in position relative to the cylinder head,
• FIG. 1 shows a spark plug mounted axially floating in the orifice of a cylinder head to act on a pressure or displacement sensor
• FIG. 2 shows a fuel injector mounted slightly differently in an orifice of the cylinder head
• FIG. 3 shows a glow plug mounted on the cylinder head
• Figure 4 shows, in enlarged view, the mounting on a cylinder head, of a fuel injector.
• FIG. 1 we see a spark plug 1 electrically powered at 2 and mounted towards its base in a threaded orifice 3 of the cylinder head 5 of an internal combustion engine block 7 comprising a combustion chamber 9.
• the head 1a of the spark plug 1 passes through the orifice and comprises an end with electrodes which communicates with the combustion chamber 9 and which is therefore subjected to the pressure which prevails there.
• the pressure reading in the chamber 9 is carried out by means of a piezoelectric sensor 13.
• the flange is presented as a hollow cylindrical part having a first threaded part 15a, engaged in the thread 3a of the orifice 3 and a second part 15b of larger diameter located outside the orifice, opposite the axial of the combustion chamber.
• the parts 15a and 15b are connected by a shoulder 15c which comes to rest on the cylinder head 5.
• the second part 15b thus defines an interior volume adapted to receive a shoulder 1b of the spark plug and the sensor 13, which is in an annular shape locally surrounding an exterior surface of the spark plug.
• the nut (or threaded ring) 17 is screwed into a thread 16 of the second part 15b.
• the displacement sensor (or pressure sensor) comprises a sensitive element 19 of piezoelectric material (ceramic) interposed between two conductive, contact rings, 21a, 21b, and electrically isolated from the shoulder 1b and the nut 17 by means of insulating rings 23a, 23b.
• the conductive rings of the sensor can be connected to an electronic computer 25 controlling the operation of an injector 27.
• the computer can thus measure the voltage difference between the conductive rings, and deduce from it the quantity of fuel to be injected into the combustion chamber and the moments of injection.
• the pressure in the combustion chamber 9 increases and the spark plug 1 is subjected to it. Since the spark plug is not screwed into the orifice 3, this pressure tends to make it move substantially along the axis 11, towards the outside of the chamber 9, thereby compressing the sensor 13 between the shoulder 1 b and the nut 17.
• the modification of the pressure exerted on the piezoelectric element 19 generates a potential difference between the contact rings 21a, 21b.
• This information is processed by the computer 25 which determines the injection conditions, in particular by reference to an operating model entered in memory, which can make it possible to take account of the state of the engine whatever its operating history.
• FIG. 2 there is a fuel injector 1 'mounted freely, along the axis 11, in the orifice 3 of the cylinder head 5 of an automobile engine, by means of a flange 15 screwed in 15a in the thread 3a of the orifice 3, the pressure and fixing means 17 engaged on the enlarged rear part of the flange 15 pressurizes the displacement sensor 13.
• the displacement sensor 13 is interposed between a radial shoulder, perimeter 25 of the injector 1 'and a shoulder 15c of the flange 15.
• the shoulder 15c of the flange is radial to the mounting axis 11, once all the elements of the device are mounted on the cylinder head and is located between the parts 15a, 15b of the flange.
• the internal volume of larger diameter of the part 15b of the flange situated outside the orifice 3 is sufficient to receive the part of the body of the injector having the shoulder 25, thus that the annular sensor 13 then located around this body.
• the sensor 13 is interposed between the shoulders 15 and 25, these two members being subjected to the axial pressure of the pressure and fixing means 17, which again consists of a nut engaging the tapping 16 of the external part 15b of the flange.
• the spark plug 10 can be a glow plug of a diesel engine, extending in the direction of elongation 11.
• the spark plug comprises an outer body 27, a central core 29 extending inside the body, and a insulating ring 31 disposed between the body and the core, generally constituted by a seal made of elastomeric material.
• the core comprises an electrical resistance 33 protected by a sheath 35 extending as far as the combustion chamber 9, and a rod 29 integral with the sheath 35 and connecting the resistance 33 to a current adductor (not shown) on which comes connect the electrical supply to the resistor.
• the external body 27 of the spark plug 10 has a radially projecting shoulder 41.
• a flange or flange 43 is fixedly connected to the cylinder head 5 for mounting and operating a displacement sensor 45 (annular, identical to sensor 13), in connection with the spark plug and its shoulder 41, under the pressure and the support provided by the rear pressure and fixing means 47, which once again consists of a nut engaged in the rear thread 53 of the part of the flange 43 located outside of the orifice 3, opposite the combustion chamber 9.
• EP-A-1 096 141 Unlike what is provided in EP-A-1 096 141, it is however not the slight axial displacement which can occur between the core 29 and the body 27 during the operation of the engine which is here used to vary the pressure exerted on the sensor 45, but the displacement (typically of a few microns) of the assembly of the spark plug 10, as a function of the pressure prevailing in the combustion chamber.
• FIG. 1 the assembly of FIG. 1, with the computer 25 and the injector 27, can be reproduced in FIG. 3 or in FIG. 2, since the sensor concerned can be made up with the same annular parts as the sensor 13.
• Figure 4 we see the application of the invention to an injector 30, (otherwise called "fuel injection means").
• the injection nozzle 30a opens into the combustion chamber 9 and that the injector is mounted inside the orifice 3 of the cylinder head 5 without being directly attached to it, that is to say that, as in the versions of FIGS. 1, 2 and 3, the part of the external periphery of the functional member coming immediately opposite the wall of the orifice 3 is freely mounted inside this orifice, being devoid of fixing means engaging the wall of this orifice.
• the supply of the injector 30, at the rear, opposite the combustion chamber 9, has not been shown.
• the injector has a shoulder 71 radial to the mounting axis 11 (which is always the axis of the orifice 3). Still on the same side, a flange 73 extending perpendicular to the axis 11 is fixed to the cylinder head 5 by screws 75 and 77.
• the rear end 32 of the injector 30 can pass through an opening provided for this purpose in the flange 73, which will allow to axially pressurize the pressure / displacement sensor 79 interposed between the flange 73 and the shoulder 71 , while the injector 30 is pressed axially against a shoulder 3a of the orifice 3, by means of a spacer 81, at the place where the injector 30 has a shoulder 83.
• the injector 30 tends to be pushed back in the direction of the arrow 85, which exerts additional pressure on the sensor 79, which transmits this information from the already indicated with reference to Figure 1, the computer 25 can if necessary act back on the injector 30 to adapt its operation, depending on the response transmitted by the sensor.
• the pressure / displacement sensor 79 is here annular, being arranged around a part of the body of the injector 30. If necessary, in the different versions, the sensor can be screwed around the part of the functional organ selected.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Measuring Fluid Pressure (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Ignition Installations For Internal Combustion Engines (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=32406297

Family Applications (1)

Country Status (6)

Families Citing this family (14)

Family Cites Families (27)

• 2002
  • 2002-12-20 FR FR0216372A patent/FR2849192B1/fr not_active Expired - Fee Related
• 2003
  • 2003-12-12 KR KR1020057011389A patent/KR20060014022A/ko not_active Ceased
  • 2003-12-12 JP JP2004561278A patent/JP2006510888A/ja active Pending
  • 2003-12-12 EP EP03785799A patent/EP1573291A2/de not_active Withdrawn
  • 2003-12-12 WO PCT/EP2003/014103 patent/WO2004057293A2/fr not_active Ceased
  • 2003-12-12 US US10/538,748 patent/US20060123887A1/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events