DE7817351U1 - PROBE FOR SIGNALING LIQUID LEVEL - Google Patents

Description

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VDO 6 FRAHKFÜRT / MAIN 90

ADOLF SCHINDLING AG GRÄFSTRASSE 103

Probe for signaling a liquid level

The innovation relates to a probe for signaling a liquid level, which is particularly in an oil dipstick hole of a motor vehicle engine can be plugged in, with a Housing that has an externally heated resistor as Comprises level sensor, a ground connector and a resistor connector isolated from it.

Such known probes are provided because of their small dimensions in an oil dipstick bore of a motor vehicle engine to be used. To do this, the probe can be attached to an oil dipstick. With the Resistance element is used to measure the oil level or, in other applications, other liquids in measured in such a way that a constant current is passed through the resistance wire of high temperature coefficient and that an organ for measuring the voltage on its terminals and a device for comparing them Voltage with a comparison voltage are provided. The measuring and alarm circuit connected to the reference junction serves to signal the undershot of a certain liquid level, in a suitable one Embodiment of the electrical circuit arrangements too several specified liquid levels.

Particularly in connection with monitoring the motor οίε but it is ir Freq not only desired, the oil level zx \ control, but to also know the oil temperature. For the latter purpose, it is also part of the state of the art to accommodate a thermistor pill in the oil v; anne in order to draw conclusions about the dip oil temperature from the voltage drop across the heating conductor.

7817351 08/21/78

The present innovation is based on the task of a probe for signaling a liquid level so that it can also be used to measure the liquid temperature with the simplest design of the probe is possible. The probe should therefore be particularly easy to manufacture and, in particular, also in the usual way Insert it into an oil dipstick hole. Furthermore should the probe is characterized by its safe operation.

This object is renewal achieved, according to a probe of the _{(above-mentioned} type in that a * at the lower portion of the housing arranged metal cap, a thermistor umschlosser is, which is clamped by a spring between the lower portion of the housing and the cap, that a ground line is led from the cap in a housing wall inside the probe to the ground connection and that from the lower section of the housing on which the spring rests, a second line on the housing wall also inside the probe

is led up to another connector. _; ,

S In this v / Eiteren formation of the probe so the thermistor is placed to the fluid temperature measurement below the hot conductor for liquid level control, and this is isolated. The hot conductor for temperature measurement is easily accessible, in that the sleeve attached to the lower section of the probe can be easily pulled off by removing the spring ring. The metallic sleeve ensures a good heat transfer from the medium to be measured to the heat conductor. In addition, the metallic sleeve is used to make contact with an end of the heat conductor, with the power being supplied via the sleeve and the spring ring via the ground line to the ground connection. The second supply line to the hot

7817351 09/21/78

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Like the ground line, the conductor is arranged on a wall inside the housing and is thus protected housed, it was an unproblematic use this probe into an oil dipstick hole is possible. Overall, this probe is characterized by a relatively simple addition to the known probe, which does not require the manufacturing effort of the usual probe significantly increased, but allows a larger area of application of this probe.

A particularly useful embodiment of the probe is therefore, as already indicated above, characterized in that the metallic cap is provided with a spring ring is held on the lower section of the housing and that the ground line via the spring washer to the ground connection is led. - This means that the heat conductor is easily accessible for any exchange the heat conductor cartridge, as well as a good current transfer to the line that connects to the third connector connected, enables.

In a variant of the probe, in which a convenient exchangeability of the hot conductor is less important, this can be designed so that the metallic cap is glued to the lower portion of the housing. - In In this case, the manufacturing outlay is particularly low.

The utility model is shown below using a drawing explained, in which the probe is shown enlarged in a longitudinal section.

In a housing 1 made of plastic, a chamber 3 is provided on a lower section 2, in which a resistance element 4 exists of spirally wound wire, is arranged. From the resistance element 4 lead im

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Inside the housing two mutually insulated lines 5 and 6 to an upper section 7 of the housing. By doing Upper section 7 is a ground connection piece 8 and a resistor connection piece which is isolated from it embedded.

Furthermore, a third connection piece is embedded in the upper section of the housing, which is used for power supply serves to a heat conductor 11 in the lower portion of the housing. For this purpose, a line 12 is on the inside of a wall of the housing to a contact piece 14 on which a compression spring 15 is seated.

The heat conductor 11 is housed inside a metallic cap 16 which extends over the lower section 2 of the Housing is pushed and can snap into an annular recess 17. The metallic cap is in this recess is held by a spring ring 18.

The heat conductor is contacted on one side by the compression spring 15, while the other side d ° s Heat conductor is contacted by the metallic cap. For this purpose, a lower end of a ground line 19 can be used the cap can be connected by the spring ring. The ground line 19 is in turn inside the housing on the wall 13 raised to the ground connection piece 8 and connected to this at connection point 20.

The hot conductor 11 is connected to a measuring and alarm circuit (not shown) that is integrated in one Instrument can be housed in the cockpit, in such a way that the ground connection 6 and the third connector can be connected to this circuit arrangement in order to measure the temperature of the liquid which is in the housing 1 with the metallic cap 16 flows around it. The level

7817351 21.es.78

measurement or signaling takes place by connecting the electrical circuit arrangement to the ground connection piece 8 and the resistor connector 9.

7817351 21.99.78

Claims (2)

I ϊ · III * »» 1 3 * »> I: III! TI 3 J 3 O ■ * ¥ 3333 333 VDO 6 FRANKFURT / MAIN 90 ADOLF SCHINDLING AG GRÄFSTRASSE 103 claims for protection 1. Probe for signaling a liquid state, which can in particular be inserted into an oil dipstick bore of a motor vehicle engine, with a housing which comprises an externally heated resistance element as a level sensor, a ground connector and an isolated from it Vi 'resistor connector, characterized in that one at the bottom Section (2) of the housing (1) arranged metallic cap (16) a circuit conductor (11) is enclosed, which is clamped by a spring (15) between the lower section of the housing and the cap that of the cap (16) a Ground line (19) in a housing wall (13) inside the probe to the ground connection (8) and that from the lower section (2) of the housing, on which the spring (15) rests, a second line (12) ier housing wall (13) is also led up inside the probe to a further connection piece (10). 2. Probe according to protection claim 1, characterized in that the metallic cap (16) is held by a spring ring (18) on the lower section (2) of the housing (1) and that the Messel ^ itunr (19) via the spring ring ( 18) to the box connector (r). J. Probe according to protection claim 1, characterized in that the metallic cap (16) is glued to the lower section (2) of the housing (1). 7817351 09/21/78