摘要:
An electrical heating element 35, 35' is located in a thin walled, closed metal tube or sleeve 37, 37' which is packed with a packing material 38, 38' of good heat conductive, insulating properties; the electrical heating element is a spirally wound resistance heater embedded in the insulating packing. A solid electrolyte body 11, 68 surrounds at least a portion of the thin walled metal sleeve and is positioned in heat exchange relation therewith. The solid electrolyte body may be a closed tube 11 or may be applied as a ring element 68 over the thin walled metal tube with an insulating material layer 66 interposed.
摘要:
An ignition chamber device is described which has an elongated, rotationally symmetrical form. The wall of the ignition chamber which protrudes into the main combustion chamber of the internal combustion engine has a coaxial overflow conduit embodied by a nozzle and radially extending discharge conduits which extend into the annular chamber which surrounds the nozzle. The ignition chamber is provided with an ignition device which has a central electrode that leads from the outside into the interior and by means of this central electrode the ignition voltage is carried via a conductor path, disposed in the wall, to a wall location opposite the nozzle, from where the ignition spark can leap the gap. A heat pipe is disposed in the nozzle and includes a portion arranged in close proximity to the cylinder wall, which prevents the ignition chamber from becoming overheated and on the other hand also enables the inflowing mixture to be heated up in optimal fashion on the way to the ignition location.
摘要:
To apply a measured quantity of air to the electrodes applied to a plate-like solid electrolyte body, which may be a chip on a carrier or may, itself, form the carrier, grooves, flutes, ducts, or depressions are formed in the carrier and/or a cover plate, the grooves terminating at an edge portion with access to the gas to be supplied, and having a size such that their clear height is preferably in the lower micron region, and a width, preferably under 1 mm, and particularly between 0.2 and 0.4 mm. The higher limits are applicable to apply, for example, air to a reference electrode, to apply ambient oxygen thereto; the lower limits are appropriate when operating the sensor as a polarographic sensor, in which the diffusion limited current, upon application of a bias voltage, is an analog measure of the oxygen concentration in the gas, and the gas supply to the electrode must be suitably controlled to prevent saturation conditions. The grooves may be formed, for example, by sandblasting or by applying insulating material in the form of posts, ridges, and the like, on the respective element, filling the space therebetween with a filler substance which, upon subsequent sintering, escapes, thus leaving the voids forming the grooves, depressions, and the like.
摘要:
To render output of a polarographic sensor essentially independent of aging of electrodes and temperature effects of the solid electrolyte body, within the operating ranges of the sensor to measure the oxygen composition of exhaust gases, the solid electrolyte plate of, for example, 50 mm length, 8 mm width and 1 mm thickness has a sensing electrode system including a cathode (2), and an anode (3) applied thereto, connected to a voltage source (7) of controllable output voltage. An oxygen molecule diffusion barrier (6) is applied to the cathode electrode. Additionally, a further electrode pair (5,4) is applied to the solid electrolyte body (1), serially connected in the current limiting circuit including the control voltage source. The voltage across one (2,3) of the electrode pairs is measured and compared with the voltage across the other electrode pair (4,5) voltage source, since the resistance of the zirconium solid electrolyte body drops with increasing temperature at roughly the same rate as the increase in limit current flow with increasing temperature. Both electrode pairs (2,3; 4,5) on the solid electrolyte body (1) are exposed to the gases, the oxygen content of which is to be analyzed.
摘要:
A sensor (10) optically coupled to the combustion chamber (10') of an internal combustion (IC) engine is kept free from contaminating or dirt deposits, or the like, by subjecting the sensor to mechanical shocks or vibration. The mechanical shocks or vibration are obtained by the engine itself by controlling the engine to operate for a predetermined time period as set by a monostable flip-flop (FF) (18) under controlled knocking conditions, the shock waves within the combustion chamber causing flaking off or dropping off of contaminating deposits. Controlled knocking can be obtained by advancing ignition timing by additional control of an ignition system (19) in a direction of excessive spark advance, or overriding a knocking inhibiting system already present on the engine. The degree of contamination of the sensor can be determined, for example, by integrating the light received over a predetermined angle of rotation of the engine crankshaft and comparing this rotation with the amount of fuel supplied to the engine for combustion, for example by comparison with timing of a fuel injection pulse, or the like.
摘要:
To detect detonations in the combustion chamber of an internal combustion engine, the sensor system is constructed as a unit that may be threadedly engaged with the combustion chamber wall, the unit including an antechamber in the region near the combustion chamber and a detector being disposed at the base of the antechamber. The sensor system further may be equipped with a heater for burning off contaminations. In a further embodiment, at least one filter disc is disposed in front of the detector, so that a selective processing of the received optical signals is possible.
摘要:
To permit a layer construction, which is inexpensive and lends itself to mass production manufacture, a solid electrolyte body, in plate-like construction, with electrodes at either thereof is positioned in a housing with a portion thereof extending in the region where it is exposed to gases to be sensed; a porous cover is applied on one of the electrodes, the porous cover having a predetermined diffusion resistance to oxygen molecules. A flat insulating plate of approximately the same dimension as the solid electrolyte plate is positioned flat thereagainst, and a flat layer-like electrical heating element is secured on the flat insulating plate or, in other embodiments, against another insulating covering on the other side of the heating element as well, close to the electrodes and adjacent the plane surfaces of the body. The heating element and the electrodes of the sensing element are carried out as conductive tracks for connection to respective sources of operating or biassing potential and, with respect to the sensing electrodes, to an evaluation circuit.
摘要:
A method and system for controlling the temperature of a heat measuring sensor such as an oxygen sensor located in the exhaust line of an internal combustion engine so that the oxygen sensor will operate within optimal operating temperature. To accomplish this, a heating system including a control mechanism is provided for the oxygen sensor which adjusts the temperature of the oxygen sensor by controlling the output of a heater during the operation of the internal combustion engine according to characteristic engine operating conditions which have an effect on the temperature of the oxygen sensor, the most significant of which is engine load status. These conditions are sensed as a quantity by probes located so as to measure such operating conditions and send a signal to the control mechanism and its sensor heater.
摘要:
An electro-chemical sensor to determine the oxygen content of exhaust gases, particularly from internal combustion engines. The sensor contains a tubular solid electrolyte closed at one end having a catalytically active layer on the outside to be exposed to the exhaust gas. The inside of said solid electrolyte tube is exposed to the ambient air and is provided with a contact portion arranged at the bottom of said solid electrolyte tube. The sensor contains an elongated axial center electrode which is pressured against the bottom (closed end) of the inside of the tubular solid electrolyte, preferably by means of a compression spring which may be mounted internal of said center electrode or external thereof. The central electrode comprises an insulating body having a heating element in the area which will be adjacent the portion of the solid electrolyte in contact with the exhaust gases. Additionally the central electrode also carries an electric lead to said contact portion. The contact portion may be attached to the central electrode.
摘要:
A method and apparatus is proposed for obtaining a control variable for the closed-loop control of the fuel-air ratio of the operating mixture of internal combustion engines, in which a threshold-current sensor of known structure is used. By means of varying the measurement voltage present at the threshold-current sensor by voltage amounts which correspond to a change in oxygen concentration to be expected in association with a change in operational state, the time behavior of the threshold-current sensor, which is essentially sluggish, is compensated for and it becomes possible to use it for rapidly-functioning closed-loop control systems in internal combustion engines.