EP3591684A1 - Relay with impact-compensated contact bridge - Google Patents

Abstract

The relay (1) according to the invention for closing or interrupting the circuit between two relay contacts (2 ₁, 2 ₂) comprises: a switch that can be moved between two relay positions in the relay housing (4), electrically conductive contact bridge (5), which is in one, closed relay position on the two relay contacts (2 ₁, 2 ₂) and in the other, open relay position of the two Relay contacts (2 ₁, 2 ₂) is lifted, a magnetic drive (7) with a magnetic coil (8) and one parallel or almost parallel to the direction of displacement (6) of the contact bridge ( 5) displaceably guided armature (9), which can be displaced by reversing the polarity of the magnet coil (8), and a double-armed lever (12) mounted in the relay housing (4) rotatable about an axis (13) running at right angles to the direction of displacement (6), on the lever the arm (9) is articulated to a lever arm (12a) and to its other lever arm (12b) are.

Description

The present invention relates to a relay for closing or interrupting the circuit between two relay contacts.

Such relays are well known and are used, for example, as disconnectors in the vehicle sector for 48V applications or in a battery management system for Li-ion batteries. In situations in which the battery cells can no longer be balanced, such as in critical thermal states of the battery or in dangerous situations (crash), the relay disconnects the vehicle electrical system (+ pole) from vehicle consumers. This protects the cells and the vehicle from critical situations. The requirements in a vehicle make it necessary to withstand extreme shock situations, for example in the event of a crash: the relay has opened and must remain in this state even after the crash; Here acceleration values of approx. 150 g occur for 10 ms. In decentralized battery storage systems such as solar energy stores, these relays are also integrated as disconnectors in battery management systems up to 50VDC. The relay must also be able to switch off overcurrent situations, ie avoid short circuits in the battery.

It is therefore the object of the present invention to ensure, in the case of a relay, that the relay, once opened, is not fired again by a crash.

• eine zwischen zwei Relaispositionen verschiebbare, elektrisch leitende Kontaktbrücke, die in der einen, geschlossenen Relaisposition an den beiden Relaiskontakten anliegt und in der anderen, geöffneten Relaisposition von den beiden Relais kontakten abgehoben ist,
• einen Magnetantrieb mit einer Magnetspule und einem parallel oder nahezu parallel zur Verschieberichtung der Kontaktbrücke verschiebbar geführten Anker, der durch Umpolen der Magnetspule verschiebbar ist, und
• einen im Relaisgehäuse drehbar um eine rechtwinklig zur Verschieberichtung verlaufende Achse gelagerten, doppelarmigen Hebel, an dessen einem Hebelarm die Kontaktbrücke und an dessen anderem Hebelarm der Anker angelenkt sind.

This object is achieved according to the invention by a relay for closing or interrupting the circuit between two relay contacts, comprising:

• an electrically conductive contact bridge which can be moved between two relay positions and which is in one closed relay position against the two relay contacts and in the other open relay position is lifted off the two relay contacts,
• a magnet drive with a magnet coil and an armature displaceably guided parallel or almost parallel to the direction of displacement of the contact bridge, which armature can be displaced by reversing the polarity of the magnet coil, and
• one in the relay housing rotatable about an axis running at right angles to the direction of displacement, double-armed lever, on one lever arm the contact bridge and on the other lever arm the armature.

According to the invention, the signs of acceleration acting on the armature and on the contact bridge are reversed in the event of a shock, so that the total torque acting on the armature and on the contact bridge is mutually reduced by the lever deflection and the relay therefore remains in its previous state despite the shock. The relay can be implemented in a monostable version as normaly open or in a bistable version.

For the mass M1 and the lever length L1 of the contact bridge and for the mass M2 and the lever length L2 of the armature, the following preferably applies: 0.5 <(M1 * L1) / (M2 * L2) <2, particularly preferably: 0.95 <( M1 * L1) / (M2 * L2) <1.05. The more the torques acting on the armature and on the contact bridge are compensated for, the smaller the resulting total torque, and the relay remains in its previous state despite the shock. Ideally, the torques acting on the armature and the contact bridge in the event of an impact are completely compensated, i.e. the following applies: M1 * L1 = M2 * L2. If additional parts are attached to the contact bridge, via which the contract bridge is articulated on one lever arm, the mass M1 is defined by the total mass of all moving parts on the contact bridge side and the lever arm L1 by the articulation point on the double-armed lever.

For a compact design of the relay, it is advantageous if the contact bridge and the armature are arranged on the same side of the double-armed lever. Alternatively, the contact bridge and the armature can also be arranged on different sides of the double-armed lever.

The contact bridge is preferably resiliently mounted in the displacement direction in a bridge cage which is displaceably guided in the relay housing in the displacement direction and on which a lever arm is articulated. With this spring suspension bridge suspension, the mass M1 is given by the total mass of the contact bridge and bridge cage. The contact bridge is advantageously biased in the bridge cage in the direction of the relay contacts, which on the one hand specifies the contact pressure with which the contact bridge is in contact with the relay contacts in the closed relay position, and on the other hand causes the relay to close with less bounce.

The contact bridge can be formed by a single wide bridge or, which is preferred, by a plurality of parallel, narrow individual bridges, each with two contact heads.

The two electrical relay contacts are preferably arranged on the free ends of two mutually facing, U-shaped relay connection contacts.

This reduces the dynamic lifting of the contact bridge at high short-circuit currents, since the magnetic field, which is generated by the current flowing through the U-shaped relay connection contacts, additionally pushes the contact bridge in the contact closing direction.

Further advantages and advantageous configurations of the subject matter of the invention can be found in the description, the drawing and the claims. Likewise, the features mentioned above and those listed further can be used individually or in combination in any combination. The embodiment shown and described is not to be understood as an exhaustive list, but rather has an exemplary character for the description of the invention.

Fig. 1

das erfindungsgemäße Relais mit einer verschiebbaren Kontaktbrücke und mit einem Magnetantrieb;

Fign. 2a-2c

eine Hebelumlenkung zwischen dem Magnetantrieb und der Kontaktbrücke in einer Seitenansicht (Fig. 2a), in einer perspektivischen Ansicht (Fig. 2b) und in einer Ansicht von unten (Fig. 2c); und

Fign. 3a, 3b

eine gefederte Lagerung der Kontaktbrücke in einem Brückenkäfig in einer perspektivischen Ansicht schräg von oben (Fig. 3a) und in einer perspektivischen Ansicht von unten (Fig. 3b).

Show it:

Fig. 1

the relay according to the invention with a sliding contact bridge and with a magnetic drive;

FIGS. 2a-2c

a lever deflection between the magnetic drive and the contact bridge in a side view ( Fig. 2a ), in a perspective view ( Fig. 2b ) and in a view from below ( Fig. 2c ); and

FIGS. 3a, 3b

a spring-loaded mounting of the contact bridge in a bridge cage in a perspective view obliquely from above ( Fig. 3a ) and in a perspective view from below ( Fig. 3b ).

This in FIGS. 1 and 2 Relay (disconnector) 1 shown is used to close or interrupt the circuit between two electrical relay contacts 2 ₁ , 2 ₂ , which are arranged as contact heads at the free ends of two mutually facing, U-shaped relay connection contacts 3 ₁ , 3 ₂ . As in Fig. 2b shown, each relay contact 2 ₁ , 2 _{2 is formed} by a series of three contact heads.

In the space between the two U-shaped relay connection contacts 3 ₁ , 3 ₂ , an electrically conductive contact bridge 5 (for example made of copper) is guided in the relay housing 4 in the direction of the double arrow 6 between two relay positions. In the one, closed relay position, the contact bridge 5 is in each case with three contact buttons 5 ₁ and 5 ₂ on the two relay contacts 2 ₁ , 2 ₂ and is in the other, open relay position, which in the FIGS. 1 and 2 is shown, lifted from the two relay contacts 2 ₁ , 2 ₂ .

To move the contact bridge 5, the relay 1 has a magnetic drive 7 with a magnet coil 8 and an armature 9 which is displaceable parallel to the direction of displacement 6 of the contact bridge 5 and which moves from its one end position by reversing the polarity of the magnet coil 8 against the restoring force of a compression spring 10 into its other End position is displaceable. In the relay housing 4, a double-armed lever 12 is also rotatably mounted about an axis 13 extending at right angles to the direction of displacement 6, on one lever arm 12a of which the armature 9 at 14a and on the other arm 12b of which the contact bridge 5 at 14b are articulated. In the exemplary embodiment shown, the magnetic drive 7 is designed as a monostable lifting magnet and the armature 9 as a plunger core (plunger) which is guided in the magnetic coil 8 in a linear manner.

As in FIGS. 3a, 3b shown, the contact bridge 5 can be resiliently mounted in a bridge cage 15 (for example made of steel) which carries the axis 14b and is in turn guided in the relay housing 4 in the direction of displacement 6 between the two two relay positions. The contact bridge 5 consists of several (here three by way of example) parallel single bridges 5a, 5b, 5c , each with two contact heads 5 ₁ , 5 ₂ , which are displaceably guided independently of one another in the bridge cage 15 in the direction of displacement 6. In Fig. 3a the left single bridge 5a is omitted for reasons of clarity.

The individual bridges 5a, 5b, 5c are each prestressed by a compression spring 17 supported on the cage ceiling 16 in contact with an intermediate floor 18 of the bridge cage 15. The intermediate floor 18 is designed as a separate steel sheet and has a plurality of bent guide fingers 19 in order to separate the individual bridges 5a, 5b, 5b from one another and to guide them against tilting in the direction of displacement 6. The bridge cage 15 carries a guide cap 20 which overlaps the cage cover 16 and by means of which the bridge cage 15 is displaceably guided in a plastic holder 21 of the relay housing 4. Point for minimal contact with the plastic holder 21 the guided side walls of the bridge cage 15 each have only one punctiform guide projection 22 and the guided sides of the guide cap 20 have a plurality of guide ribs 23 , so that in operation, despite hot individual bridges 5a, 5b, 5b, the bridge cage 15 and the guide cap 20 preferably do not come into contact with the plastic holder 21 come and can melt on it or the individual bridges 5a, 5b, 5b, if possible, cannot shift or block against each other.

To switch relay 1, the magnetic field of magnet coil 8 is switched on or off. The anchor 9 is, as in the FIGS. 1 and 2 shown, pressed down by the compression spring 10 when the magnetic field is switched off and thereby also pushes the bridge cage 15 together with the individual bridges 5a, 5b, 5b up via the lever 10, until in the open relay position the single bridges 5a, 5b, 5b from the relay contacts 2 ₁ , 2 _{2 are} lifted off. When the magnetic field is switched on, the armature 9 is drawn upward into the magnet coil 8 against the action of the compression spring 10 and, as a result, the bridge cage 15 together with individual bridges 5a, 5b, 5c is also pulled down via the lever 10 until the individual bridges 5a, 5b, 5b on the relay contacts 2 ₁ , 2 ₂ . The contact pressure of the contact buttons 5 ₁ , 5 ₂ on the two relay contacts 2 ₁ , 2 ₂ is given by the compressive force of the compressed compression spring 17. In the closed relay position, the compression springs 17 also counteract the deflection of the individual bridges 5a, 5b, 5b in the opening direction of the relay 1, which leads to a reduced-bounce closing of the relay 1.

The mutually facing, U-shaped relay connection contacts 3 ₁ , 3 ₂ also reduces dynamic lifting at high short-circuit currents, since the magnetic field which is generated by the current flowing through the U-shaped relay connection contacts 3 ₁ , 3 ₂ , the individual bridges 5a , 5b, 5b additionally presses in the contact closing direction.

In order to keep the relay 1 in the desired state even in the event of an impact, the movable parts of the magnetic drive 7, that is to say the magnet armature 9, and the contact bridge 5 (including the bridge cage 15) are designed such that for the mass M1 (including the bridge cage 15 ) and the lever length L1 of the contact bridge 5 as well as for the mass M2 and the lever length L2 of the armature 9 applies: M1 * L1 ∼ M2 * L2. In this In the event of an impact, the torques acting on the armature 9 and on the contact bridge 5 cancel each other out, which is achieved by the lever deflection. The signs of acceleration and torque are therefore inverse.

Claims (9)

Relay (1) for closing or interrupting the circuit between two relay contacts (2 ₁ , 2 ₂ ), comprising
an electrically conductive contact bridge (5) that can be moved between two relay positions in the relay housing (4), which is in one closed relay position against the two relay contacts (2 ₁ , 2 ₂ ) and in the other, open relay position of the two relay contacts (2 ₁ , 2 ₂ ) is lifted off,
a magnet drive (7) with a magnet coil (8) and an armature (9) which is displaceably guided parallel or almost parallel to the direction of displacement (6) of the contact bridge (5) and which can be displaced by reversing the polarity of the magnet coil (8), and
one in the relay housing (4) rotatable about an axis (13) extending at right angles to the direction of displacement (6), double-armed lever (12), on one lever arm (12a) the contact bridge (5) and on the other lever arm (12b) the armature (9) are articulated. Relay according to Claim 1, characterized in that the following applies to the mass M1 and the lever length L1 of the contact bridge (5) and the mass M2 and the lever length L2 of the armature (9): $$\mathrm{0}.\mathrm{5}<\left(\mathrm{M}\mathrm{1}*\mathrm{L}\mathrm{1}\right)/\left(\mathrm{M}\mathrm{2}*\mathrm{L}\mathrm{2}\right)<\mathrm{Second}$$

Relay according to Claim 2, characterized in that the following applies to the mass M1 and the lever length L1 of the contact bridge (5) and the mass M2 and the lever length L2 of the armature (9): $$\mathrm{0}.\mathrm{95}<\left(\mathrm{M}\mathrm{1}*\mathrm{L}\mathrm{1}\right)/\left(\mathrm{M}\mathrm{2}*\mathrm{L}\mathrm{2}\right)<1.05.$$

in particular: $$\mathrm{M}\mathrm{1}*\mathrm{L}\mathrm{1}=\mathrm{M}\mathrm{2}*\mathrm{L}\mathrm{Second}$$

Relay according to one of the preceding claims, characterized in that the contact bridge (5) and the armature (9) are arranged on the same side of the double-armed lever (12). Relay according to one of the preceding claims, characterized in that the relay contacts (2 ₁ , 2 ₂ ) are each formed by at least one contact button, in particular by a number of several contact heads. Relay according to one of the preceding claims, characterized in that the contact bridge (5) is guided in a bridge cage (15) which is displaceably guided in the relay housing (4) in the displacement direction (6) and on which a lever arm (12b) is articulated the direction of displacement (6) is resilient. Relay according to claim 6, characterized in that the contact bridge (5) in the bridge cage (15) is biased towards the relay contacts (2 ₁ , 2 ₂ ). Relay according to one of the preceding claims, characterized in that the contact bridge (5) is formed by at least two parallel individual bridges (5a, 5b, 5c), each with two contact heads (5 ₁ , 5 ₂ ). Relay according to one of the preceding claims, characterized in that the two electrical relay contacts (2 ₁ , 2 ₂ ) are arranged at the free ends of two mutually facing, U-shaped relay connection contacts (3 ₁ , 3 ₂ ).

Images