EP0756302B1 - Thermostat of modular construction - Google Patents

Abstract

The switch has a bimetallic snap-action disc Ä34Ü that inverts its shape when a set temperature is reached and this is mounted with a metal spring backing disc. The assembly is supported at the edges on a conducting ring Ä23Ü. Located above the assembly is an electrical resistance heating element Ä17Ü and underneath is a bias resistance element Ä43Ü. The bias resistor is connected in series with the switch contacts Ä32,33Ü with the heating resistor in parallel. The circuit is coupled to the input output wires Ä37,39Ü

Description

The present invention relates to a temperature monitor one to protect a consumer in the event of overtemperature Bimetal rear derailleur, one assigned to the bimetal rear derailleur first electrical component, at least when open Bimetal rear derailleur in series between connectors of the Temperature monitor is located, and an associated with the bimetal switchgear second electrical component, at least when closed Bimetal rear derailleur in series with this between the connections of the temperature monitor.

Such a temperature monitor is known from EP-A1-226 663.

Such temperature monitors are used to protect electrical consumers used for which they are connected in series with the consumer be so that its operating current through the Temperature monitor flows. The temperature monitor is close thermal contact with the consumer to be monitored, so that this transfers its temperature to the bimetal switchgear. If the temperature of the consumer rises inadmissibly, so the bimetal switchgear opens, and the current flow to it Consumer is interrupted.

Such temperature monitors are known in practice.

It is also known to additionally use this temperature monitor a self-holding function and / or an overcurrent sensitivity equip.

Such a temperature monitor is from DE-OS-41 42 716 known.

The known temperature monitor includes an overtemperature or overcurrent opening bimetal switchgear, to which a first Heating resistor in parallel and with a second heating resistor is connected in series.

Another temperature monitor known from DE-OS-43 36 564 includes one with conductive and insulating coatings Provided ceramic carrier plate, on which an encapsulated bimetal rear derailleur is arranged, next to which a PTC thermistor module sits, which is electrically parallel to the bimetal rear derailleur is switched and acts as the first heating resistor. On the Ceramic carrier plate is also a thick film resistor arranged, which leads under the bimetal rear derailleur and with this is connected in series. The series resistor is used here however, not for overcurrent protection, but for adjustment of the switching point.

The task of these known temperature monitors is to control the current flow interrupted by the electrical consumer if this Consumer has too high a temperature, or possibly also then when the current through the consumer is too high values having. For this purpose, the well-known temperature monitor connected in series to the consumer, so that the temperature monitor flowed through by the current flowing through the consumer the bimetal rear derailleur at temperatures below the response temperature and / or for currents below of the response current is closed.

The operating current of the consumer flows in series switched second heating resistor of a few ohms as well the closed contacts of the bimetallic rear derailleur that the bridges the first heating resistor. Exceeds the temperature of the consumer now a predetermined limit value, so opens the bimetal switchgear in thermal contact with the consumer suddenly his contacts by a bimetallic snap disc jumps around inside the bimetal rear derailleur. The current now flows through the series resistor as well as the second heating resistor, the one has such a large resistance that the current is much lower is than the original operating current, so the consumer is quasi switched off. Due to the PTC characteristic the second heating resistor at the temperature monitor from the DE-OS-43 36 564 the current goes with heating this Heating resistor further back. By heat radiation and / or The bimetallic snap disk becomes the line from this heating resistor further heated up so that they hold themselves in their Position with open contacts remains. In this way is prevented that when the due to Automatic shutdown of excess temperature Reconnection takes place, resulting in a so-called contact flutter with periodic switching on and off again could and is usually undesirable.

Reaches not the temperature but the current through the consumer and thus through the bimetal switchgear predetermined limit value, then the series connected heats up Heating resistor according to the description of DE-OS-41 42 716 so far that the switchgear will eventually reach its response temperature reached and opens. In this case, self-retention takes place in the same way as described above.

Although the temperature monitor known from DE-OS-43 36 564 functionally meets many requirements, it is disadvantageous that it has a relatively bulky and large design, the is due in particular to the ceramic carrier plate. For reasons of accommodation and heat capacity Such temperature monitors are usually very small executed, for example. They have a diameter of 10 mm and a height of 5 mm, which places extreme demands on manufacturing accuracy represents and at the same time the need simple and at the same time functionally reliable constructions.

From the generic DE-OS 41 42 716 is in such Miniature version of a temperature monitor with self-holding heating resistor connected in parallel and in the smallest space integrated heating resistor connected in series, which ensures current monitoring. The series resistor is as Etched or stamped part or as printed with a resistor Foil in the immediate vicinity as well as in thermal and electrical Such contact with the spring washer of the bimetal rear derailleur arranged to lie down in the bottom part of the housing comes.

In addition to the complex assembly of the well-known temperature monitor Another disadvantage is that here as heating resistors used etched or stamped parts with regard to Resistance value not too accurate and only for a small one Resistance range can be manufactured. It is an additional one Insulating component between the housing bottom and the heating resistor and mostly for reasons of resistance adjustment an additional, high-resistance resistor placed on the outside required in series with the series resistor mentioned, what overall the manufacturing effort and also the external dimensions increased.

All of these known temperature monitors are different Constructions known to the particular area of application as well as the special switching behavior. However, this leads to that for different temperature monitors Various components are required, so that Manufacturers overall have a large inventory of various Parts is required.

The inventors of the present application have now recognized that this problem in particular results from the fact that for the different How the temperature monitors work new such temperature monitors have been constructed.

The temperature monitor known from the aforementioned EP-A1-226 663 has two contact strips provided with contact flags on, which are kept apart by two pins are. At one of the contact strips is an end of a bimetal tongue attached to their other, freely movable end carries a contact head. If the ambient temperature is below a limit temperature, the contact head touches one fixed mating contact on the opposite contact strip, so that the thermal monitor is closed. If the The temperature limit deforms the bimetal tongue, causing the contact head lifts off the fixed counter contact and the Circuit is interrupted. One or both pens that the Keep the two contact strips at a distance as PTC resistors executed. When the switch is open, these are Resistors thus with the terminal lugs in series, making a Self-holding function due to that generated by the resistors Heat is reached.

Against this background, it is an object of the present invention to create a temperature monitor that does the above Does not have disadvantages. It is also an object of the invention an improved manufacturing process for a temperature monitor to accomplish.

According to the invention, this task with regard to the temperature monitor solved in that the first component at comparable mechanical construction as a heating resistor or as an insulator and / or the second component with a comparable mechanical Structure designed as a series resistor or as a short-circuit part is, so that with the same mechanical structure according to the modular principle built-up temperature monitor with pure overtemperature protection, with overtemperature protection and self-holding function, with overtemperature protection and current sensitivity or with Over-temperature protection, self-holding function and current sensitivity are provided, one being the bimetal rear derailleur Receiving housing is provided, which is a pot-like, electrical conductive lower part and a closing, has electrically conductive cover part, which with the lower part is connected via insulation, the first component between Cover part and lower part is switched, under the bimetal rear derailleur the second component is arranged at the bottom of the lower part is that between the lower part and a contact surface is switched, and the bimetal rear derailleur in the closed State the cover part connects to the contact surface.

a) Bereitstellen eines Temperaturwächters mit einem zum Schutz eines Verbrauchers bei Übertemperatur schaltenden Bimetall-Schaltwerk, in den nach dem Baukastenprinzip:

i) ein dem Bimetall-Schaltwerk zugeordnetes erstes elektrisches Bauteil, das zumindest bei geöffnetem Bimetall-Schaltwerk in Reihe zwischen Anschlüssen des Temperaturwächters liegt, und

ii) ein dem Bimetall-Schaltwerk zugeordnetes zweites elektrisches Bauteil, das zumindest bei geschlossenem Bimetall-Schaltwerk in Reihe mit diesem zwischen den Anschlüssen des Temperaturwächters liegt,

eingebaut werden kann,

b) Auswahl eines bestimmten ersten elektrischen Bauteils aus mehreren ersten elektrischen Bauteilen mit vergleichbarem mechanischem Aufbau, die teilweise als Heizwiderstand und teilweise als Isolator ausgebildet sind,

c) Auswahl eines bestimmten zweiten elektrischen Bauteils aus mehreren zweiten elektrischen Bauteilen mit vergleichbarem mechanischem Aufbau, die teilweise als Vorwiderstand (R_v) und teilweise als Kurzschlußteil ausgebildet sind,

d) Einbau des bestimmten ersten elektrischen Bauteils und des bestimmten zweiten elektrischen Bauteils in den Temperaturwächter, so daß je nach getroffener Auswahl ein Temperaturwächter mit reinem Übertemperaturschutz, mit Übertemperaturschutz und Selbsthaltefunktion, mit Übertemperaturschutz und Stromempfindlichkeit oder mit Übertemperaturschutz, Selbsthaltefunktion und Stromempfindlichkeit bereitgestellt wird.

With regard to the method for producing a temperature monitor, the task is solved by a method with the following steps:

a) Provision of a temperature monitor with a bimetal switchgear to protect a consumer in the event of overtemperature, in which according to the modular principle:

i) a first electrical component assigned to the bimetal switching mechanism, which is at least in series between connections of the temperature monitor when the bimetal switching mechanism is open, and

ii) a second electrical component assigned to the bimetallic switching mechanism, which at least when the bimetallic switching mechanism is closed lies in series with the latter between the connections of the temperature monitor,

can be installed

b) selection of a specific first electrical component from a plurality of first electrical components with a comparable mechanical structure, some of which are designed as heating resistors and some as insulators,

c) selection of a specific second electrical component from a plurality of second electrical components with a comparable mechanical structure, some of which are designed as a series resistor (R _v ) and some of which are designed as a short-circuit part,

d) Installation of the specific first electrical component and the specific second electrical component in the temperature monitor so that, depending on the selection made, a temperature monitor with pure overtemperature protection, with overtemperature protection and self-holding function, with overtemperature protection and current sensitivity or with overtemperature protection, self-holding function and current sensitivity is provided.

The object on which the invention is based is achieved in this way completely solved. The inventors have found that it Surprisingly, with an appropriate arrangement of the individual Parts are possible, either as a resistance element or as a short circuit part / insulator so that two alternatives are available for each component have to be a total of four different temperature monitors to be able to assemble. The state of the art Known warehousing of various parts is avoided.

This measure is also from a design point of view an advantage, because it is made of an extremely pressure-resistant housing electrically conductive lower part and lid part formed that completely encapsulates the bimetal rear derailleur, so that this protected from external influences in a manner known per se becomes. Another advantage is that the assembly of the new Temperature monitor designed very simple, in the lower part you only have to do the second component one after the other, then the bimetal rear derailleur, then the first component and finally the cover part with the interposition of insulation be introduced, while still being inserted for the to ensure electrical connections between the individual parts is.

It is then preferred if the second component is a Bottom of the base covering plate is between the Contact surface and the lower part is switched, the plate either has an insulating carrier material on which a series resistor is arranged, which with the contact surface and is connected to the lower part, or even a short circuit represents between the contact surface and the lower part. The The contact surface is preferably electrical conductive ring formed between the plate and the bimetal rear derailleur is arranged.

These measures are also constructive and when assembling Advantage, because only by inserting the plate into the lower part and by placing the electrically conductive ring either a series resistor or a short circuit between the contact surface and the lower part, others Connection measures are not necessary.

It is also preferred if the first component is a ring part is on which the cover part rests and through its ring opening through the bimetal rear derailleur in connection with the cover part arrives, the ring member preferably on an electrical conductive ring washer, which is conductive with the lower part connected is. The ring part is either made of resistance material, preferably made of PTC material, or else an isolator.

This measure is also constructive and when assembling Advantage, because after inserting the bimetal rear derailleur only the electrically conductive washer first and then the ring part itself can be inserted into the lower part, whereupon the cover part is placed on the ring part. The electrical The connection between the individual parts is the only one already by the support and by closing the lower part by means of the cover part.

Overall, it is preferred if the bimetal rear derailleur has one carried by the cover part fixed switching contact and one associated movable switching contact comprises of a spring washer movable by a bimetallic snap disc worn and electrically connected to it, whereby the spring washer is preferably supported on the contact surface and the movable switch contact against the fixed switch contact presses when the bimetal rear derailleur is in its closed Condition.

This measure is also constructive and when assembling Advantage, because after inserting the plate and the electrical conductive ring is first the spring washer on this ring with movable switching contact carried by it. Then the bimetallic snap disc is put over the contact part, whereupon the electrically conductive washer is inserted, on which then the ring part and on this then the cover part comes to rest.

In a further development, it is then preferred if in the Lower part of a tubular insulating part is provided on the the electrically conductive washer is supported.

The advantage here is that there is first electrical insulation between the lower part on the one hand and the plate on the other, the spring washer and the bimetallic snap washer is, this isolation at the same time as a support for the serves as an electrically conductive washer over which the ring part comes into contact with the lower part.

Further advantages result from the description and the attached drawing.

It is understood that the above and those below Features still to be explained not only in the respective specified combinations, but also in other combinations or can be used alone, without the scope of to leave the present invention.

Fig. 1

einen Axialschnitt durch den neuen Temperaturwächter; und

Fig. 2

ein elektrisches Ersatzschaltbild des Temperaturwächters aus Fig. 1.

An embodiment of the invention is shown in the drawing and is explained in more detail in the following description. Show it:

Fig. 1

an axial section through the new temperature monitor; and

Fig. 2

an electrical equivalent circuit diagram of the temperature monitor from FIG. 1.

In Fig. 1, 10 denotes a temperature monitor, the one Housing 12 includes an electrically conductive material manufactured lower part 13 and also made of electrical Conductive material manufactured cover part 14, by that the lower part 13 is closed. For this purpose an insulating sleeve between the lower part 13 and the cover part 14 15 provided that the cover part 14 laterally and partially overlaps above. Via the insulating sleeve 15 there is an edge 16 of the lower part 13 which is crimped over, to close the housing 12.

The cover part 14 is supported with its underside a first electrical component 17, which is in the form of a ring part 18 is trained. The ring part 18 in turn lies on one electrically conductive washer 19 on its edges is conductively connected to the lower part 13.

The washer 19 is on its way away from the ring member 18 Underside provided with an insulating layer 20, over which they rests on a tubular insulating part 21. The insulating part 21 in turn is supported electrically with a shoulder 22 conductive ring 23, on the top of a contact surface 24 is provided.

The ring 23 in turn lies on a second electrical component 25 in the form of a plate 26 which in the lower part 13 on the Floor 27 is arranged. The plate 26 has a via 28 on that a conductive connection between the Lower part 13 and the top 29 of the plate 26 produces.

A convex spring washer 31 sits on the contact surface 24, which carries a movable switch contact 32, which by the Ring part 18 cooperates with a fixed switching contact 33, which is arranged on the cover part 14. On the movable switch contact 32 is a bimetallic snap disk 34 put over, in the switching state shown in Fig. 1 Has temperature below their switching temperature.

Spring washer 31, movable switch contact 32, fixed switch contact 33 and bimetallic snap disk 34 together form one Bimetal switching mechanism 35, which in the state shown in FIG. 1 an electrically conductive connection between the cover part 14 and the contact surface 24. If the temperature the bimetallic snap disk 34 beyond the switching temperature increases, the bimetallic snap disc suddenly snaps off of the convex shown into a concave shape, whereupon they now with its outer edge on the insulating layer 20 supports and the movable switch contact against the force of Spring washer 31 lifts off the fixed switch contact 33, so that the electrical connection just discussed between the Cover part 14 and the contact surface 24 is opened.

It should also be noted that on the cover part 14 as the first connection 37 a strand 38 is provided, while on the edge 16 of the Lower part 13 as a second connection 39, another strand 40 is welded on.

Due to the construction chosen, the first is electrical Component 17 between the cover part 14 and the lower part 13 switched, parallel to this first electrical component a series connection of the bimetal switchgear 35 and the second electrical component 25 is arranged as shown in the electrical equivalent circuit diagram of FIG. 2 is indicated.

The temperature monitor 10 described so far is based on the modular principle in that both the first electrical component 17 and the second electrical component 25 can be constructed on the one hand as heating resistors and on the other hand as an insulator / short-circuit part. The ring part 18 can be, for example, an insulating part 41 or a PTC resistor 42. In the same way, the plate 26 can either be an electrical short-circuit part 43 or else a carrier part 44 on which an electrical series resistor R _{v is} arranged. This series resistor R _v can, for example, run as a thick-film resistor on the upper side 29 and can be connected between the electrically conductive ring 23 and the plated-through hole 28.

Depending on the selection of the properties of the components 17, 25, temperature monitors 10 which are completely identical in terms of their mechanical properties, but which differ in their electrical properties, can thus be produced in a modular manner. If, for example, the component 17 is an insulating part 41 and the component 25 is a short-circuit part 43, the temperature monitor 10 fulfills a pure temperature monitoring function. If, on the other hand, the component 25 is equipped with a series resistor R _V , the temperature monitor is current sensitive, the flowing current generates heat in the series resistor R _V , which ensures that the bimetallic switching mechanism 35 opens when the current flow is too high.

If the component 17 is designed as a holding resistor R _H , the current flowing through this component 17 when the bimetallic switching mechanism 35 is open ensures that sufficient heat is generated to keep the bimetallic switching mechanism 35 open. When the bimetallic switching mechanism 35 is closed, the resistance of the series circuit comprising the bimetallic switching mechanism 35 and the component 25 is very much lower than the resistance of the component 17, so that virtually no current flows through this component 17.

Claims (13)

1. A temperature controller (10) comprising a bimetallic switching device (35) that switches at excess temperature to protect a load, a first electrical component (17) assigned to the bimetallic switching device (35) and connected in series between terminals (37, 39) of the temperature controller (10) at least when the bimetallic switching device (35) is open, and a second electrical component (25) assigned to the bimetallic switching device (35) and connected in series with the latter between the terminals (37, 39) of the temperature controller (10) at least when the bimetallic switching device (35) is closed,
   characterized in that
   the first component (17) is designed with a comparable mechanical construction as a heating resistor (42) or as an insulator (41), and/or that the second component (25) is designed with a comparable mechanical construction as a series resistor (R_v) or as a short-circuit part (43), such that with the same mechanical construction and according to the principle of a modular system temperature controllers can be provided with purely overheating protection, with overheating protection and self-holding function, with overheating protection and current sensitivity, and with overheating protection, self-holding function and current sensitivity, respectively, and whereby a housing (12) is provided to accommodate the bimetallic switching device (35), said housing having a pot-shaped electrically conductive base part (13) and an electrically conductive cover part (14) to close the base part, the cover part being connected to the base part via an insulation (15), whereby the first component (17) is connected between the cover part (14) and the base part (13), the second component (15) is arranged beneath the bimetallic switching device (35) on the bottom (27) of the base part (13), the second component being connected between the base part (13) and a contact surface (24), the bimetallic switching device (35) connecting the cover part (14) to the contact surface (24) when closed.
2. The temperature controller of claim 1 characterized in that the second component (25) is a plate (26) covering the bottom (27) of the base part (13) and connected between the contact surface (24) and the base part (13).
3. The temperature controller of claim 1 or 2, characterized in that the first component (17) is a ring part (18) on which the cover part (14) rests and through whose ring opening the bimetallic switching device (35) makes contact to the cover part (14).
4. The temperature controller of claim 3, characterized in that the ring part (18) rests on an electrically conductive ring disk (17) which is conductively connected with the base part 13.
5. The temperature controller of any of claims 1 or 4, characterized in that the bimetallic switching device (35) comprises a fixed switching contact (33) borne by the cover part (14) and a corresponding movable switching contact (35) borne by and electrically connected to a spring disk (31) which is moved by a bimetallic snap disk (34).
6. The temperature controller of claims 1 and 5, characterized in that the spring disk (31) rests on the contact surface (24) and presses the movable switching contact (32) against the fixed switching contact (33) when the bimetallic switching device (35) is in its closed state.
7. The temperature controller of claim 2 and any of claims 3-6, characterized in that the plate (26) has an insulating carrier part (44) on which a series resistor (R_V) is arranged that is connected with the contact surface (24) and the base part (13).
8. The temperature controller of claim 2 and any of claims 3-6, characterized in that the plate (26) itself provides a short-circuit between the contact surface (24) and the base part (13).
9. The temperature controller of claim 3 and any of claims 4-8, characterized in that the ring part (18) is made from resistor material, preferably from PTC-material (42).
10. The temperature controller of claim 3 and any of claims 4-8, characterized in that the ring part (18) is an insulating part (41).
11. The temperature controller of claim 1 and any of claims 2-10, characterized in that the contact surface (24) is provided at an electrically conductive ring (23) which is arranged between the bimetallic switching device (35) and the plate (26).
12. The temperature controller of claim 4 and any of claims 5-11, characterized in that in the base part (13) a tube-shaped insulating part (21) is provided on which the electrically conductive ring disk (19) rests.
13. A method for producing a temperature controller (12) according to claims 1-12, comprising the steps:

    a) providing a temperature controller (10) having a bimetallic switching device (35) that switches at excess temperature to protect a load, into which according to the principles of a modular system can be mounted:

    i) a first electrical component (17) assigned to the bimetallic switching device (35) and connected in series between terminals (37, 39) of the temperature controller (10) at least when the bimetallic switching device (35) is open, and

    ii) a second electrical component (25) assigned to the bimetallic switching device (35) and connected in series with the latter between the terminals (37, 39) of the temperature controller (10) at least when the bimetallic switching device (35) is closed,

    b) choosing a certain first electrical component (17) out of several first electrical components with comparable mechanical construction, some of which are designed as heating resistors and some of which as insulator,

    c) choosing a certain second electrical component (25) out of several second electrical components with comparable mechanical construction, some of which are designed as series resistor (R_V) and some of which as short circuit part (43),

    d) mounting the certain first electrical component and the certain second electrical component into the temperature controller so that according to the respective choice a temperature controller is provided with purely overheating protection, with overheating protection and self-holding function, with overheating protection and current sensitivity, or with overheating protection, self-holding function and current sensitivity, respectively.

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