DE102014008410A1 - microswitch - Google Patents

Abstract

The invention relates to a microswitch with at least two contacts (4, 9). According to the invention, at least one additional circuit contact (2) is provided.

Description

The invention relates to a micro-switch with at least two contacts. The microswitch is preferably a switch in the manner of a pushbutton or a pressure switch.

Microswitches are being used in increasingly complex technical machines and in increasingly complex technical applications. One of many possible examples is the use of microswitches in modern passenger cars. The microswitches generate or control electrical signals. Typically, microswitches know only the two simple switching states "on" and "off". These switching states can be read out as signals from the microswitch, for example by means of an electronic control device connected to the microswitch. For better control and control of the functional processes in the complex technical applications, more different signals are needed.

Possible solutions are those in which resistors, diodes or other electronic components are housed within the microswitch. However, such solutions are disadvantageous in terms of the flexibility of the circuit, the power (and thus the size of the resistors) and the complexity (for example, the arrangement of three or more resistors).

Another possibility is the external wiring of resistors in a wiring harness, which is connected to a microswitch and can thus serve for function detection. However, the effort is high. The measure is therefore very expensive. In addition, there is a higher space requirement and the risk of electrical short circuits.

Object of the present invention is to provide a flexible, diagnosable microswitch. In particular, the microswitch should be flexible with regard to the concrete circuit. Complex arrangements should be possible, as well as high or different performances. The function of the microswitch should be better monitored.

To solve the problem, the micro-switch according to the invention has the features of claim 1. The microswitch is provided with at least one additional circuit contact. As contacts are typically understood the led out of a housing of the microswitch electrical conductor. Outside the housing lying free ends of the contacts are referred to as terminals. The additional circuit contact enables the arrangement of additional electronic components between the two existing contacts and the additional circuit contact. The components are designed so that more different signals can be tapped off at least two of the now present total of three contacts (including the Beschaltungskontakts) and in connection with two states of the microswitch (on or off) than a microswitch with only two contacts in total.

According to a further aspect of the invention, the external circuit contact assumes the function of one of the two contacts and has a connection for this purpose. The microswitch is therefore connected via the connection of the circuit contact on the one hand and the connection of one of the two contacts with leading to the microswitches electrical connections, such as by soldering or terminals.

According to a further aspect of the invention, the circuit contact and at least one of the two contacts in a circuit region of the switch are interconnected by at least one electrical or electronic component, wherein the component in particular at least one resistor, a diode, an integrated circuit (IC) or an operational amplifier includes. Preferably, both contacts are connected via one or more electrical or electronic components with the Beschaltungskontakt.

According to a further aspect of the invention, the components are connected by soldering, welding, insulation displacement technology or crimping with the Beschaltungskontakt and with the two contacts. Other possibilities for connection can be provided. Important is a good and permanent electrical connection.

According to a further aspect of the invention, the circuit contact is connected to one of the two contacts by a component, while the circuit contact is also connected to the other of the two contacts by a component. This allows the largest number of different, evaluable signals at the terminals of the microswitch.

According to a further aspect of the invention, the switch has a normally open function, wherein one of the two contacts is in particular a bottom contact. Upon actuation of the microswitch, for example by pressing a button, the microswitch closes the electrical connection from an armature contact to the bottom contact. Preferably, the lower contact has no connection to the outside. D. h., The wiring contact replaced to the outside of the bottom contact. The other externally accessible contact is preferably the armature contact.

According to a further aspect of the invention, the microswitch has an opener function, wherein one of the two contacts is in particular a top contact. Thus, an electrical circuit is opened or interrupted an electrical line upon actuation of the microswitch. Preferably, the upper contact is formed without connection to the outside. That is, the circuit contact replaced outwardly the top contact.

According to a further aspect of the invention, a sealing frame is provided on the microswitch or around the microswitch, in particular for the formation of an electrically insulated functional unit with a protected against contamination or moisture Beschaltungsbereich. In the protected wiring area, the electrical or electronic components are preferably arranged.

According to a further aspect of the invention, only one connection of the wiring contact and one connection of one of the two contacts protrude from the wiring region, while a connection of the other contact is in particular concealed and does not protrude from the wiring region. The wiring area is preferably protected by the sealing frame.

According to a further aspect of the invention, the circuit contact is connected via a first resistor to one of the two contacts. In addition, the circuit contact is connected via a second resistor to the other of the two contacts, wherein the first resistor is lower impedance than the second resistor. Preferably, the first (low resistance) resistor is connected to the top contact or bottom contact, while the second (higher resistance) resistor is connected to the armature contact.

The microswitch has a housing, in which preferably an armature is movably and resiliently held. The individual contacts protrude into the housing, preferably also an actuating element, such as a push button. Openings in the housing for the contacts and the actuating element are preferably sealed. The wiring area is outside the housing. Said sealing frame can be attached to the housing and thus cover the wiring area with a part of the housing and seal.

The microswitch according to the invention has integrated resistors, diodes or other electronic components which function as fixed components of the microswitch. The resistors, diodes or other components are electrically and mechanically connected to the microswitch at its terminals, so that a total of a new functional unit results. The microswitch allows the diagnosis of the switching state. That is, various signals can be diagnosed upon application of a corresponding voltage to the microswitch. For example, the microswitch is connected with its terminals to a control unit, which detects the voltage drops at the terminals. This can be distinguished from the control unit, whether the micro-switch is present, is in the open state, is in the closed state or a short circuit exists. When using diodes, additional information can be detected, for example the polarity.

Further features of the invention will become apparent from the description, moreover, and from the claims. Advantageous embodiments of the invention are explained below with reference to drawings. Show it:

1 a microswitch with normally open function,

2 a microswitch with NC function,

3 a microswitch with sealing frame,

4 a circuit diagram of the microswitch according to 1 .

5 a circuit diagram of the microswitch according to 2 .

6 a modification of the micro-switch according to 1 , as a functional unit with diode and resistor,

7 a circuit diagram of the microswitch according to 6 ,

Shown is a microswitch 1 with integrated resistors 3 . 5 . 15 . 16 , This affects the microswitch 1 as a new functional unit 22 . 24 , So together with the resistor circuit in a variety of versions with respect to type of electrical function, eg. B. NC / NO with or without upstream resistor 5 , with different resistance values of the individual resistors 3 . 5 , with different performances of the individual resistances. Also possible are different versions with respect to parallel or series connection of the resistors 3 . 5 or mixed circuits, eg. A resistor and a diode, see 6 ,

The resistors 3 . 5 cause a modification and extension of the function of the microswitch 1 , A circuit contact is planned 2 that in the switch 1 firmly attached. A special feature is also the way of execution of the Beschaltungskontakts 2 , which is mounted like a switch contact, but now the connection of the resistors 3 . 5 with a switch connection 2 represents.

It is important that due to the electrical function, the Beschaltungskontakt 2 no electrical contact with a switching system 13 inside a housing of the microswitch 1 has because of the microswitch 1 as in 1 represented, the closing function must meet. Therefore the circuit contact is 2 electrically isolated from the switching system 13 positions and only fulfills the wiring and connection function.

The same applies to a wiring contact 18 during the execution of a diagnosable switch 21 with normally closed function according to 2 ,

• a) Falls ein Kurzschluss auftritt, ist zwischen Anschlusspunkten 11 und 12 Null Ohm.
• b) Im elektrisch geöffneten Zustand (in 1 gezeigt) des Mikroschalters 1 ist nur der Widerstand 5 in Funktion und der Spannungsabfall kann entsprechend des Widerstandswertes erkannt werden.
• c) Im geschalteten Zustand des Mikroschalters 1 (elektrisch geschlossen, in 1 nicht gezeigt), sind die Widerstände 3 und 5 parallel geschaltet und damit kann der so eingestellte Widerstandswert über den sich damit ergebenen Spannungsabfall erkannt werden.
• d) Falls die Funktionseinheit 22 an beiden Anschlüssen 11, 12 nicht angeschlossen ist oder ein Anschluss keine Verbindung mehr hat, weist die Funktionseinheit einen sehr hohen (unendlichen) Widerstandswert auf, d. h. es steht die volle Spannung an der Steuereinheit an.

The following states can be used with the in 1 shown functional unit 22 be recognized:

• a) If a short circuit occurs, is between connection points 11 and 12 Zero ohms.
• b) In the electrically opened state (in 1 shown) of the microswitch 1 is only the resistance 5 in function and the voltage drop can be detected according to the resistance value.
• c) In the switched state of the microswitch 1 (electrically closed, in 1 not shown), are the resistors 3 and 5 connected in parallel and thus the resistance value set in this way can be detected via the resulting voltage drop.
• d) If the functional unit 22 at both connections 11 . 12 is not connected or a connection has no connection, the functional unit has a very high (infinite) resistance value, ie it is the full voltage to the control unit.

The execution of the functional unit 22 loud 1 is electrically loud with the wiring diagram 5 shown. For this version, the contacts must 2 . 4 . 9 have different lengths, so that the electrical insulation is given and the space for the resistance 3 is available. Due to the arrangement of the resistors shown 3 . 5 results in a compact and electrically safe (because no risk of short circuit) execution of a diagnostic microswitch. The resistance 3 for example, has about 520 ohms and the resistance 5 has about 3900 ohms. The high-resistance resistor is preferably between the terminals 11 . 12 respectively. 19 . 20 , while the relatively low resistance between the Beschaltungskontakt 2 . 18 and the switching system 13 . 14 lies.

Further versions of a switch capable of diagnosis are in 2 and 6 shown. In 2 is the microswitch 21 shown as a normally closed version. The wiring with the resistors 15 . 16 is also designed as a parallel connection, but now the wiring contact 18 in the middle of the microswitch 21 is positioned. Again, the resistors can be attached to the switch with a different function, so that the resistors 15 . 16 z. B. can also be connected in series.

The versions of the different circuits are in the circuit diagrams 4 and 5 shown. By this type of structure of the diagnostic microswitch can be realized in relation to the respective requirement in the technical applications, a variety of circuit diagrams.

Another of the complexities is the introduction of one or more diodes 25 instead of z. B. two resistors 3 and 5 , This embodiment is not known as a functional unit, see 6 , "Diagnosable switch with diodes". In 7 the circuit diagram of a diagnosable switch with diode and resistor is shown. By introducing diodes, the safety and functionality can be extended far, z. B. is thus the polarity of signals recognizable.

Likewise, other semiconductor devices can be integrated to realize yet another diagnostic options, z. As ICs, operational amplifiers, etc. Preferred is the use of relatively small components that fit into the Beschaltungsbereich, ie between the contacts outside the microswitch.

Another feature results from the encapsulation by means of a sealing frame 23 , which is available for receiving and protecting the resistors, diodes, etc., see 3 , One from the sealing frame 23 Covered wiring area is filled with sealant and thus electrically and mechanically protected against external influences. This results in a new functional unit 22 , z. B. consisting of microswitch 1 , Resistors 3 . 5 , Wiring contact 2 and sealing frame 23 with sealant, whereby the integrated additional function "diagnosable", compared to a simple micro-switch, is realized.

LIST OF REFERENCE NUMBERS

1

microswitch

2

Wiring contact NC version

3

Resistance I

4

Anchor contact microswitch 1

5

Resistance II

6

Connection resistance 5 with wiring contact 2

7

Connection resistance 5 with anchor contact 4

8th

Connection resistance 3 with sub contact 9

9

under contact

10

Anchor contact microswitch 21

11

Connection of the circuit contact 2

12

Connection anchor contact 4

13

Switching system microswitch 1

14

Switching system microswitch 21

15

Resistance III

16

Resistance IV

17

top Contact

18

Wiring contact normally open version

19

Connection of the circuit contact 18

20

Connection anchor 10

21

microswitch

22

Functional unit "diagnosable microswitch"

23

sealing frame

24

Functional unit "diagnosable microswitch" with diode and resistor

25

diode

Claims (10)

Microswitch ( 1 . 21 ) with at least two contacts ( 4 . 9 or 10 . 17 ), characterized by at least one additional circuit contact ( 2 . 18 ). Microswitch according to claim 1, characterized in that the wiring contact ( 2 . 18 ) outwardly the function of one of the two contacts ( 4 . 9 ; 10 . 17 ) and takes a connection ( 11 . 19 ) having. Microswitch according to claim 1 or 2, characterized in that the wiring contact ( 2 . 18 ) and at least one of the two contacts ( 4 . 9 ; 10 . 17 ) are connected together in a circuit region of the switch by an electrical or electronic component, wherein the component in particular comprises at least one resistor, a diode, an integrated circuit (IC) or an operational amplifier. Microswitch according to claim 3, characterized in that the components by soldering, welding, insulation displacement or crimping with the Beschaltungskontakt ( 2 . 18 ) and with the two contacts ( 4 . 9 ; 10 . 17 ) are connected. Microswitch according to claim 3 or 4, characterized in that the wiring contact ( 2 . 18 ) with one of the two contacts ( 4 . 9 ; 10 . 17 ) is connected by a component, and that the wiring contact ( 2 . 18 ) is also connected to the other of the two contacts by a component. Microswitch according to Claim 1 or one of the further claims, characterized by a normally open function, one of the two contacts ( 4 . 9 ; 10 . 17 ), in particular a subcontact ( 9 ). Microswitch according to Claim 1 or one of the further claims, characterized by an opening function, one of the two contacts ( 4 . 9 ; 10 . 17 ), in particular a top contact ( 17 ). Microswitch according to Claim 1 or one of the further claims, characterized by a sealing frame ( 23 ) on the microswitch or around the microswitch, in particular to form an electrically isolated functional unit ( 22 . 24 ) with a protected against dirt or humidity wiring area. Microswitch according to claim 1 or one of the further claims, characterized in that from the wiring area only one connection ( 11 . 19 ) of the wiring contact ( 2 . 18 ) and a connection ( 12 . 20 ) one of the two contacts ( 4 . 9 ; 10 . 17 protrude), while a connection of the other contact is particularly hidden and does not stick out of the wiring area. Microswitch according to Claim 1 or one of the further claims, characterized in that the wiring contact ( 2 . 18 ) via a first resistor ( 3 . 16 ) with one of the two contacts ( 9 . 17 ), the circuit contact ( 2 . 18 ) via a second resistor ( 5 . 15 ) with the other of the two contacts ( 4 . 10 ), and that the first resistor ( 3 . 16 ) is lower impedance than the second resistance ( 5 . 15 ).

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