Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H39/00—Switching devices actuated by an explosion produced within the device and initiated by an electric current
  • H01H39/006—Opening by severing a conductor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N11/00—Starting of engines by means of electric motors
  • F02N11/10—Safety devices

Definitions

• the invention relates to an electrical conductor with an ignition device which is in thermal contact with the conductor and is provided in order to ignite when a limit temperature of the conductor is exceeded and to destroy the conductor.
• a conductor is known from DE 1 96 20 204 AI.
• This known conductor is provided for connecting a pole of a motor vehicle battery to the electrical system of the motor vehicle and is intended to self-destruct if, for example, a short circuit occurs in the electrical system as a result of an accident, which could otherwise lead to a vehicle fire. It contains an electrical plug connection in a housing, in which the socket of the plug connection contains a squib, which heats up when a short-circuit current flows through the conductor and, through its explosion, pushes the pin of the plug connection out of the socket and thus the short-circuited circuit separates. Due to the contact resistance of the connector, the connector heats up even with moderate currents.
• the extent of the heating depends on the quality of the contact between the pin and the socket of the plug connection and is therefore variable for different copies of the same plug connection. Although this is not critical in the protection of short-circuit currents, it makes the known conductor unsuitable for protecting consumers against electrical overload where reproducible ignition behavior of the conductor is important. Even if it were possible to protect a consumer designed for high currents against overcurrents with the aid of the known conductor, it would be necessary to use a very large-format plug-in connection in order to heat it up in the currents required for the operation of the consumer To keep limits at which the ignition device certainly does not ignite. This would make the use of the known conductor for protecting high-current consumers expensive and, if there is not enough space for the attachment of the connector, sometimes even impossible.
• a conductor of the type mentioned at the beginning comprises one or more cores which extend continuously between the ends of the conductor, and that the ignition device is arranged on the conductor in order to split these cores in the event of ignition.
• this enables a more compact and considerably simplified construction of the conductor with the ignition device, since a conventional, continuous cable is simply and simply an option, and on the other hand, a substantial voltage drop within the conductor is avoided by dispensing with the plug connection, which is particularly desirable when supplying consumers with high currents.
• the ignition device comprises an ignition material arranged in a ring around the cable.
• This ignition material does not necessarily have a great explosive effect, as is indispensable for the separation of the known conductor, it may be sufficient if it releases a strong heat which, together with the heating of the conductor caused by the current flow, leads to the fact that this in Melted area of the ignition device and so the flow of electricity to the consumer is interrupted.
• the ignition material can be surrounded by a capsule or housing that is resistant to ignition.
• this housing has the effect of protecting the surroundings of the conductor from separated, red-hot conductor material, on the other hand it can cause the separated sections of the conductor to be pressed out of different openings of the capsule by the pressure of the hot material contained therein and so the two sections are separated from one another in a particularly reliable manner.
• the ignition device is surrounded by the conductors of the conductor.
• the ignition device when the ignition device is ignited, at least some of these wires are torn by the resulting explosion pressure, as a result of which the line cross section of the conductor is significantly reduced and those wires which may not yet be torn melt through in the shortest possible time.
• the ignition device is preferably arranged approximately halfway along the conductor.
• the conductor is preferably a flexible strand made up of a large number of cores.
• An important application of the conductor according to the invention is in motor vehicle technology, in particular as a connection between a starter relay and a starter motor of a motor vehicle.
• the reason for this is that modern motor vehicles use ever lighter starter motors which, because of their low mass, also have a low heat capacity and can therefore easily overheat and be damaged if they are exposed to the starter current for too long.
• the heat that such an overloaded starter motor and / or its supply lines develop creates the risk of motor fires.
• Such overload situations can occur, in particular, if a vehicle driven by the starter motor alone has to travel longer distances and, in particular, drive up ramps, which is an inadmissible abuse in itself, but nevertheless when loading vehicles, for example onto rail or road transporters or onto Ships, common.
• a conductor according to the invention as a connection between the starter relay and starter motor ensures effective protection of the latter and also enables the owner of the vehicle, who is often not the one who misuses the starter in the manner described, to prove the misuse.
• FIGS. 1, 2 and 2a show exemplary embodiments of a conductor
• Figure 3 shows a conventional conductor
• FIG. 3 shows a conventional arrangement of a conductor 1 in the form of a strand and a brush 2 of a starter motor, as is currently used in motor vehicles.
• a motor vehicle usually has two or four such arrangements.
• the conductor 1 consists of a large number of flexible, braided or stranded single wires, one end of which has been pressed or soldered in the brush 2 with high pressure and a correspondingly low contact resistance.
• the second end 3 freely shown in the figure can be crimped, for example, with a cable lug.
• FIG. 1 shows a first embodiment of the conductor according to the invention.
• the hose-like braided outer sheath of the strand is cut open in an area 4 and gives a view of an ignition device 5.
• the ignition device 5 consists of an explosive material compressed into a hard pill or, better yet, embedded in a capsule, which is at a temperature ignites which is reached by the surrounding stranded wire when the vehicle is driven by the starter motor with increased power or for longer distances. How high this temperature is depends on the suitable dimensioning of the wire cross section depending on the performance characteristics of the starter motor can be set within wide limits, for example a useful value is in the range from 400 to 500 ° C.
• the igniter 5 ignites and the strand is torn at least over a substantial part of its circumference.
• the drive current of the starter motor which concentrates on a smaller cable cross-section, leads within a fraction of a second to heating the remaining wires of the stranded wire to white heat and to their evaporation.
• the strand - optionally together with the starter relay and the starter motor - can be enclosed in a separate housing which catches the glowing parts in the event of an explosion .
• FIG. 2 shows a second preferred embodiment of the conductor according to the invention.
• the ignition device 5 is not housed inside the conductor as in FIG. 1, but surrounds it in a ring.
• a section through the ignition device is shown in FIG. 2a.
• the ignition device 5 has a fixed outer housing 6 which is clamped to the conductor 1 via two sleeves 7 on opposite sides of the housing. Inside defines the housing 6 together with the Head 1 is a toroidal chamber which is filled with an ignition material 8.
• the ignition material 8 can be an explosive material, that is to say a material whose combustion generates high pressures, but it can also be a material whose combustion releases extreme heat, such as for example that known under the name Thermit Geraische or other mixtures which contain in particular oxygen releasers and fine metal powders such as magnesium or aluminum.
• the material can also be a mixture of explosive material and heat-forming material.
• the temperature of the conductor 1 exceeds the ignition temperature of the material 8, it burns under different degrees of heat and pressure development depending on the composition.
• the heat heats the conductor to the melting point of its wires or at least in the vicinity of the melting point; the pressure has the effect that at least one of the sections of the conductor on both sides of the ignition material is pressed out of its sleeve 7 and the sections are thus separated from one another.
• the material of the conductor 1 which melts when ignited essentially remains in the housing 6. catch, the material and wall thickness depending on the ignition material 8 are chosen so that it survives the ignition substantially intact. In this way it is avoided that molten material is distributed in the vicinity of the conductor 1 and leads to further damage there.

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• Fuses (AREA)
• Air Bags (AREA)
• Ignition Installations For Internal Combustion Engines (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7894815

Family Applications (1)

Country Status (6)

Families Citing this family (7)

Family Cites Families (11)

• 1999
  • 1999-01-20 DE DE19902073A patent/DE19902073A1/de not_active Ceased
  • 1999-12-23 EP EP99967898A patent/EP1064665A1/de not_active Withdrawn
  • 1999-12-23 BR BR9908903-3A patent/BR9908903A/pt not_active IP Right Cessation
  • 1999-12-23 JP JP2000595361A patent/JP2002535814A/ja active Pending
  • 1999-12-23 WO PCT/DE1999/004083 patent/WO2000044019A1/de not_active Application Discontinuation
  • 1999-12-23 US US09/646,627 patent/US6552890B1/en not_active Expired - Fee Related

Non-Patent Citations (1)

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