WO2009080088A1

WO2009080088A1 - Device for the sparkless disconnection of a solenoid

Info

Publication number: WO2009080088A1
Application number: PCT/EP2007/011413
Authority: WO
Inventors: Ralf Höhn; Heiko Kühbauch
Original assignee: Festo Ag & Co. Kg
Priority date: 2007-12-22
Filing date: 2007-12-22
Publication date: 2009-07-02
Also published as: EP2208261A1; EP2208261B1

Abstract

The invention relates to a device for the sparkless disconnection of a solenoid that can be connected to two direct current voltage contacts (19, 20) by means of two electric plug-in elements (12, 13). The first and the second of said plug-in elements (12, 13), when plugged in, are electrically connected to the first or second direct current voltage contacts (19, 20) by means of a first and a second spring arrangement (21, 24), at least one diode (25) with a pole in the blocking direction interconnecting the two spring arrangements (21, 24). At least the first spring arrangement (21) consists of two sub-areas (22, 23), the first sub-area (22) of which is continuously connected to the diode (25) and lies elastically against the first plug-in element (12) when said element is plugged in and the second sub-area (23) of which electrically connects said plug-in element (12) to the first direct current voltage contact (19). The second sub-area (23) is designed to separate said electrical connection during disconnection before the first sub-area (22) is released from its position against the first plug-in element and before the second spring arrangement (24) is released from its position against the second plug-in element (13).

Description

Device for spark-free disconnection of a magnetic coil

The invention relates to a device for spark-free unplugging a via two electrical connector elements of a connector assembly with two DC voltage contacts electrically connectable solenoid.

In the separation of live magnetic coils, such as valve solenoid coils of their electrical connections due to the induction voltage sparks, which must not occur in explosion-proof environment. This problem also occurs, for example, in explosion protection in categories 2 and 3. In order to avoid such sparks, it is known to connect a protective diode in parallel with the magnetic coil. About this diode when unplugging the polarity of the terminals oppositely directed induction voltage is reduced or short-circuited, so that no energy for sparking remains. The disadvantage of this known arrangement is that the Schuztdiode is firmly connected to the solenoid or integrated in the magnetic coil containing device, for example in a solenoid valve. Since it usually does not know, especially in mass production, in which environment the device should work later, considerable costs and a considerable effort would be required to prophylactically integrate a protective diode in all devices. Since only very few devices will be used later in an explosion-proof environment, such would be one Expenditure also not to represent. On the other hand, it also means no small effort to produce small series of devices especially for explosion-proof environments. Another problem is that when replacing a device in an explosion-proof environment, it is sometimes impossible to determine with certainty whether the new device also contains a protective diode.

In the case of magnetic coils provided with a protective diode, it must also be ensured that the connection polarity is correct, otherwise the protective diode would be destroyed.

An object of the present invention is to provide a device of the type mentioned, by the use of not provided with protective diodes magnetic coils or devices provided with magnetic coils is also possible in explosion-proof environment and it is ensured that when unplugging yet no sparking arises.

This object is achieved by a device having the features of claim 1.

Advantageously, the protective diode is not arranged on the magnetic coil or on the device provided with the magnetic coil but in the plug-in receptacle for the connector elements of the magnetic coil. In this case, it is ensured that the separation of the connection of one of the Steckverbindungselemen- te with the associated DC voltage contact the protective diode still connects the two connector elements of the solenoid, so that the negative voltage pulse is short-circuited by induction, without a sparking can occur. The diode also acts as an overvoltage limit during the regular shutdown process. Magnetic be inserted with and without protection diode so that appropriate considerations, which solenoid can be used, are not required. Simple and inexpensive magnet coils or devices provided with magnet coils without protective circuit, ie standard magnet coils, can be used, in particular also in environments in which explosion protection is required or prescribed.

The measures listed in the dependent claims advantageous refinements and improvements of the claim 1 device are possible.

In an advantageous first embodiment, the second portion of the first spring assembly is electrically fixed to the first DC voltage contact and lies in the Aussteckrichtung behind the second portion elastically on the first connector element. The two subregions of the first spring arrangement are expediently designed as spring tongues, which also applies in particular to the second spring arrangement. Here, simple and inexpensive spring arrangements can be used.

In an advantageous second embodiment variant, the first spring arrangement is formed as a two-stage, compressible by the first connector element when inserting pressure spring assembly, wherein the first portion rests as a first stage on the first connector element and the second portion as a second stage for electrical connection to the first portion and the first DC voltage contact is formed from a predetermined spring pressure. By optimizing the spring properties, it is possible to determine how long the diode has time for the short-circuiting of the negative voltage pulse, for which only a few μsec is needed. The first portion is suitably designed as a helical spring and the second portion as a leaf or plate spring. In principle, it is also possible to design both partial regions as a helical spring or both partial regions as leaf or plate springs.

The second spring arrangement is expediently designed in the second embodiment as compressible by the second connector element when inserting pressure spring assembly and has spring properties that ensure release of the system on the second connector element upon removal after releasing the electrical connection of the first spring assembly from the first DC voltage contact.

The two plug-in connection elements are expediently arranged on the housing of a magnetic valve in which the magnetic coil is located. In principle, a cable connection is possible.

A plug-in receptacle of the plug connection arrangement for receiving the plug connection elements can be arranged on a housing or on an electrical, connectable with a cable coupling element.

Two embodiments of the invention are illustrated in the drawing and explained in more detail in the following description. Show it:

FIG. 1 shows a device provided with a magnet coil, whose plug connection elements are plugged into a plug receptacle of a plug connection arrangement as the first exemplary embodiment of the invention, FIG. 2 shows the same arrangement during the removal operation in which the connection to the negative pole of a supply voltage source is already interrupted;

Figure 3 shows the same arrangement in the unplugged state and

Figure 4 shows a similar arrangement in the inserted state as a second embodiment of the invention.

In the first embodiment shown in Figures 1 to 3, a solenoid valve 10 shown schematically includes a magnetic coil 11, the electrical connections lo are connected to two connector elements 12, 13 of a connector assembly 14. The two plug connection elements 12, 13 can be arranged either on the housing of the solenoid valve 10 or on a plug which is connected via lines to the solenoid valve 10. Instead of a solenoid valve 10, the solenoid coil 11 can also be arranged or integrated in another electrical device, for example in an electromagnet, a relay or the like.

The plug-in connection elements 12, 13 together with a 20 electrical plug-in receptacle 15, the connector assembly 14. The receptacle 15 may be arranged on or in an electrical device or be designed as an electrical counter-coupling element or mating connector, which is mounted on an electrical cable 16. In the case of the arrangement 25 on or in an electrical device, the electrical cable 16 extends within the same and is in any case connected to a not shown electrical Gleichspannungsversorgungs- source. Opposite the two insertion openings 17, 18 for receiving the two plug connection elements 12, 13, two DC voltage contacts 19, 20 are arranged in the plug receptacle 15, wherein the DC voltage contact 19 is connected to the negative pole and s the DC voltage contact 20 to the positive pole of the DC voltage source. Above the negative DC voltage contact 19, a two-stage compression spring arrangement 21 is arranged, whose first partial region 22 is designed as a first step as a helical spring and the first Einstecklo opening 17 faces, while the second portion 23 is formed as a second stage as a leaf or plate spring and the negative DC voltage contact 19 bridged.

At the positive DC voltage contact 20, a second, designed as a helical spring compression spring assembly 24 is net angeord- 15, which faces the second insertion opening 18.

The first two-stage compression spring assembly 21 and its second portion 23 is connected via a protective diode serving as diode 25 to the positive DC voltage contact 20 and poled so that it locks when applying the DC voltage 20. Instead of a diode 25, a plurality of diodes may also be connected in parallel and / or series connection.

FIG. 1 shows a state in which the plug connection elements 12, 13 are inserted into the plug receptacle 15. In this case, the first compression spring arrangement 21 is so through

25 compresses the first connector element 12 that its second portion 23 comes into contact with the negative DC voltage contact 19, which mechanically bridges in the unloaded state, that is not electrically connected to the second portion 23 of the first compression spring assembly 21

30 is. The installation of the two plug-in connection elements 12, 13 on the two compression spring arrangements 21, 24 thus leads to that the magnetic coil 11 is acted upon by the DC voltage.

FIG. 2 shows a state in which the plug-in connection elements 12, 13 have already been partly pulled out, that is to assume a position during the removal operation. In this state, the two compression spring assemblies 21, 24 are still at the two connector elements 12, 13, but the spring force has already been reduced so that the second portion 23 of the first compression spring assembly 21 has lifted from the first DC voltage contact 19 and no longer connected to this consists. However, the diode 25 continues to connect the two connector elements 12, 13 via the two compression spring assemblies 21, 24. By the separation from the circuit an oppositely directed induction voltage in the magnetic coil 11 is formed, which can now be degraded via the diode 25, so that no shutdown sparks occur and so operation in explosion-proof environment is possible.

FIG. 3 shows the completely unplugged state in which the two plug connection elements 12, 13 no longer have any contact with the compression spring arrangements 21, 24.

The spring force, in particular of the first compression spring arrangement 21, must be adjusted such that the first partial region 23 of the first compression spring arrangement 21 designed as a leaf or partial spring is pressed down in such a way that it comes into contact with the negative DC voltage contact 19. If the first subregion 22 of the compression spring arrangement 21 has a harder spring characteristic than the second subregion 23, a relatively early contact takes place when the plug connection elements 12, 13 are plugged in, and a relatively late detachment occurs during disengagement From the first DC voltage contact 19, while this is the case in reverse properties in the reverse manner, ie at a first portion 22 with softer spring characteristic over the second portion 23 is a relatively late contact during insertion and a relatively early contact separation during unplugging.

In a modification of the illustrated embodiment, instead of a combined two-stage compression spring arrangement 21, one can also be used in which the two partial areas are formed by two coil springs or by two sheet or plate springs in a stepped arrangement, ie in a row arrangement. The second compression spring assembly 24 is then each formed with appropriate dimensioning and spring characteristics, that is, in the illustrated embodiment, the second compression spring assembly 24 has the same or similar spring characteristics as the first portion 22 of the first compression spring assembly 21.

Of course, the first compression spring arrangement 21 and the second compression spring arrangement 24 can also be arranged reversed with respect to the two poles, wherein two-stage compression spring arrangements can in principle also be provided at both poles. The essential thing is merely that when unplugging the connector elements 12, 13 is still a contact with the two terminals of the diode 25 after the connection with one of the DC voltage contacts 19, 20 has been disconnected.

In the second embodiment shown in Figure 4 the same or equivalent components or assemblies are provided with the same reference numerals and not described again. Instead of pressure or coil springs occur in the second embodiment, spring tongues 26 to 28, which in inserted state of the two connector elements 12, 13 abut resiliently laterally thereto and thereby establish the electrical connection with the two DC voltage contacts 19, 20 and the diode 25.

The two spring tongues 26, 27 form a first spring arrangement 29, wherein the spring tongue 26 as a first portion of the first spring assembly 29 with a terminal of the diode 25 and the spring tongue 27 as a second portion of the first spring assembly 29 with the negative DC voltage contact 19 is connected. These two spring tongues 26, 27 are in the insertion direction one behind the other laterally on the first connector element 12, wherein the system of the spring tongue 26 is further removed from the negative DC voltage contact 19, as the system of the second spring tongue 27th

The spring tongue 28 forms the second spring arrangement 30, which rests in the inserted state of the connector elements 12, 13 on the second connector element 13 in height corresponding to the spring tongue 26.

As a result of this step-like succession arrangement of the spring tongues 26, 27 on the first connector element 12 loses when unplugged first connected to the negative DC voltage contact 19 spring tongue 27 makes contact with the connector element 12, so that the circuit is separated to the solenoid 11. About the then still in contact with the two connector elements 12, 13 located spring tongues 26 and 28 which are connected to the diode 25, this diode 25 bridges the two terminals of the solenoid 11 and closes the induction voltage spark-free short. Only then is the release of the remaining spring tongues 26, 28 from the plug connection elements 12, 13 carried out. For the distance of the system of the spring tongue 28 on the second connector element 13, it is essential that this system still exists when the spring tongue 27 detaches from the connector element 12.

In the second Ausführuήgsbeispiel shown in Figure 4 instead of the connector assembly 14 of the first embodiment, a modified connector assembly 14 'and instead of the plug-in receptacle 15 of the first embodiment, a modified socket 15'.

Claims

claims

1. A device for spark-free unplugging a via two electrical connector elements (12, 13) of a connector assembly (14, 14 ') with two DC voltage contacts (19, 20) electrically connectable magnetic coil (11), 5 characterized in that the first and the second of these plug connection elements (12, 13) in the inserted state via a first and a second spring arrangement (21, 24, 29, 30) with the first and the second DC voltage contact (19, 20) is electrically connected and at least one poled in lo reverse direction diode (25) connects the two spring arrangements (21, 24, 29, 30) to each other, and that at least the first spring arrangement (21, 29) consists of two partial areas (22, 23, 26, 27), of which the first partial area (22 26) is permanently connected to the diode (25) and resiliently abuts the first connector element (12) in the inserted state thereof, and of which the second section (23; 27) of this connector element ent (12) electrically connected in the inserted state with the first DC voltage contact (19), wherein the second portion (23; 27) for the

20 of this electrical connection before loosening the system of the first portion (22, 26) of this spring arrangement (21, 29) on the first plug connection element (12) and before releasing the contact of the second spring arrangement (24, 30) on the second plug connection element (13 ) is formed when unplugging.

2. Device according to claim 1, characterized in that the second portion (27) of the first spring arrangement (29) is electrically fixedly connected to the first DC voltage contact (19) and in the Aussteckrichtung behind the second

5 portion (27) elastically abuts the first connector element (12).

3. Apparatus according to claim 2, characterized in that the two partial regions (26, 27) of the first spring arrangement (29) are designed as spring tongues.

4. The device according to claim 2 or 3, characterized in that the second spring arrangement (30) is designed as a spring tongue (28).

5. The device according to claim 1, characterized in that the first spring arrangement (21) is formed as a two-stage by the first i5 plug connection element (12) compressible compression spring assembly, wherein the first portion (22) as a first stage on the first connector element (12). is present and the second portion (23) as a second stage for electrical connection between the first Teilbe-

20 rich (22) and the first DC voltage contact (19) is formed from a predetermined spring pressure.

6. Apparatus according to claim 5, characterized in that the first portion (22) is designed as a helical spring and the second portion (23) as a leaf or plate spring.

25 7. The device according to claim 5, characterized in that both partial regions are formed as helical springs.

8. The device according to claim 5, characterized in that both portions are formed as leaf or disc springs.

9. Device according to one of claims 5 to 8, characterized 5 indicates that the second spring arrangement (24) as by the second connector element (14) compressible compression spring assembly is formed and has spring properties, a release of the system on the second connector element (14 ) when unplugging after loosening the electrical see connection of the first spring assembly (21) from the first DC voltage contact (19) guaranteed.

10. Device according to one of the preceding claims, characterized in that the magnetic coil (11) is designed as a magnetic coil of a solenoid valve (10).

11. The device according to claim 10, characterized in that the two plug connection elements (14) on the housing of the solenoid valve (10) are arranged.

12. Device according to one of the preceding claims, characterized in that a plug-in receptacle (15, 15 ') of the 20 plug connection arrangement (14, 14') is arranged on a housing or on an electrical, connected to a cable or connectable coupling element.