DE2018205A1 - Gas stove with piezoelectric ignition - Google Patents

Description

Gas stove with piezoelectric ignition The piezoelectric ignition from gas stoves and gas hotplates is in direct competition with that from the Mains powered electrical spark ignition.

The advantage of piezoelectric ignition is its independence of the connection to a socket and the relief made possible by it Connection or relocation of a stove or a gas hob.

Piezoelectric ignitions can also be used in camping stoves Use where a normal type of electric ignition could hardly be used.

However, there is a disadvantage in the designs that have become known up to now of gas stoves or gas hobs with piezoelectric ignition is the relative high effort that is driven and of course the resulting price.

The previously known versions of gas stoves and gas stoves with piezoelectric ignition use, for example, a piezoelectric voltage generator, the energy of which is supplied to the individual ignition points by one from the respective tap Switch is supplied.

Each lighting point therefore needs a switch, i. H.

with four hotplates and a grill, as well as an oven six switches are required.

However, these switches must at least withstand the ignition voltages that occur So at least about 4-8 kilovolts have grown. In addition, these switches should of course even the rough operation in the kitchen without too many failures be grown. There are also wires from the central ignition element to each switch and from the switches to the spark plugs or ignition points.

In another known embodiment, for each ignition point or focal point separate piezoelectric voltage generators are used.

This means that the effort for the generator is roughly: Multiply the piezo element, bracket, actuation mechanism by the number of lighting points *; The invention described below now reduces this effort considerably and, in its various embodiments, results in simple and operationally reliable Ignition systems.

After a series of deliberations and attempts, it has been shown that that it is possible, as the invention suggests, two or more ignition spark gaps to connect electrically in series without therefore reducing the output voltage of the ignition element to have to increase significantly.

Fig. 1 shows the circuit diagram of an embodiment with, for example spark gaps connected in series.

The process for a Ignition described. The generator (1) with the from the piezo elements and the im Generator created by mechanical construction capacity (2) is carried out as usual a mechanical pressure a tension at point (3) of the spark gap (3 and 4) produce. As long as there is no flashover, point (4) remains on the spark gap (3 and 4) on the ground potential (13), since the lead to be thought of as ground Switching capacity (5) due to the high resistance, but must be taken into account Insulation resistance (6) is discharged. So there is a potential between point (3) and point (4) until there is a flashover, i.e. a spark. Since the capacitance (5) is now very small, the spark occurs shortly after the start of the spark the generator voltage at point (4) and thus at point (7) of the spark gap (7 to 8) reduced by the Amount of the during the duration of the spark at the Spark gap existing voltage drop. In relation to the on the generator (1) possible open circuit voltages of approx. 10-16 kilovolts, this drop is almost completely to neglect.

In the same way, an increase in voltage now occurs, slightly shifted in time between electrodes (7) and (8) until a spark current begins to flow, then the switching capacitance (9) is charged and the voltage begins between the points (11) and (12) of the last spark gap to rise until a rollover here too arises and the charge stored in the capacity (2) by the generator (1) has flown off is.

Another embodiment of the invention relates to insulation the burners, which are otherwise often made of metal, or the manufacture of these burners made of electrically insulating material, otherwise a shunt due to the flame ionization according to mass by the burning points upstream of the last ignition point as soon as they are up and running.

Another embodiment of the invention relates to the general usual thermostatic ignition fuses, which are used here as well are insulated buses or with a heat-resistant, electrically insulating material, be coated at least in the places where they are exposed to the flame have to.

The ignition spark gaps are also advantageously provided with a touch guard surrounded so that accidentally touching a spark plug does not cause a startle reaction can be triggered. Of course, it must be a logical consequence of the idea of the invention both electrodes can be protected, for example by using Xeraaik.

Another and very interesting embodiment of the invention results the use of a generator whose two poles are not connected to the hearth ground and in this case the double-pole insulated ignition electrodes, as the flame ionization can no longer cause a short circuit here, the measures for isolation are unnecessary of burners and thermocouples.

Claims (1)

S C H U T Z A N P R Ü C H E Claim 1. Gas stove or gas hob with piezoelectric ignition the individual hotplates, as well as the grill and oven ignition points that may be present characterized in that two or more ignition points or their ignition sparks are plugged be connected electrically in series and a piezoelectric voltage generator two or more of these are supplied with spark gaps. Claim 2: gas stove or gas hob with piezoelectric ignition the individual hotplates, as well as the oval. existing grill and oven ignition points according to claim 1, characterized in that the burners of this stove are made of material with electrically insulating properties, or of general wetness to which the ground pole of the piezoelectric generator (s) is connected, be electrically isolated. Claim 3: gas stove or gas hob with piezoelectric ignition the individual hotplates, as well as the grill and oven ignition points that may be present according to claims 1 and 2, characterized in that the known thermoelectric Elements for ignition protection and their supply lines are electrically isolated from the general Wet or in areas exposed to the flame with a heat-resistant electrically insulating material are coated. Claim 4: gas stove or gas hob with piezoelectric ignition the individual hotplates, as well as the grill and oven ignition points that may be present according to claims 1, 2, 3 and 4, characterized in that the ignition spark gaps be installed as contact protection sonin electrically insulating material that a flashover in the air to the outer surfaces to be touched with a finger at the highest occurring voltage from both electrodes under normal conditions does not occur. Claim 5: gas stove or hot plate with piezoelectric ignition the individual hotplates, as well as the grill and oven ignition points that may be present according to claim 1 or claims 1 and 4, characterized in that both poles of the or the piezoelectric voltage generators opposite the metal parts of the cooker All connections of the two or in pipes are kept insulated as well several spark gaps.