CN87208136U - Switch type safety box for electric appliance - Google Patents

Abstract

The utility model discloses a switch type safety box for an electric appliance and relates to the improvement of the fuse of an electric appliance. The switch type safety box for an electric appliance overcomes the insufficiency that the existing fuse needs to consume lots of low melting point alloy material, the use is disposable, the replacement is inconvenient, etc. The switch type safety box for an electric appliance also overcomes the insufficiency that the structure of an existing current limiting device, such as a thermal relay and an air automatic switch, is complicated, the price is higher, the power consumption is large, etc. The switch type safety box for an electric appliance makes use of a pair of mechanical press keys to be matched with an electric magnet and a bimetal release. The utility model has the advantages of simple structure, low cost, convenient operation and wide ranges of application. The material and the energy can be saved. The switch type safety box for an electric appliance is not provided with a fuse wire. The switch type safety box for an electric appliance can replace an existing fuse.

Description

Switch type safety box for electric appliance

The utility model belongs to the electrical equipment protective device of electrical engineering and electric apparatus class, relates in particular to the improvement to fuse (safety box).

Various forms of fusible links, sheet that existing fuse all adopts low melting point alloy to make, when the electric current of flow through this fusible link, sheet surpassed limit value, fusible link, sheet cut off circuit because of heating fusing, have played the security personnel's effect to electrical equipment, circuit.The fusible link of this fuse, sheet are generally only done disposable use, need expend a large amount of low melting point alloys; Insensitive to little excess overcurrent; Owing to make its operation principle with hot melt, so the anxiety of power consumption is arranged; And shortcoming such as the trouble of replacing arranged in using.Some occasion is also used thermal relay; devices such as air automatic switch; do the current-limiting protection of electrical equipment, circuit; wherein for example approaching: " the DZ05-10 one pole automatic switch " that Shanghai Switch Factory No.3 produces with the utility model technology; it has the switch of two pairs of polyphones; the wherein tongue piece of main switch and self-locking button interlock; paying switch is a bimetal leaf; separate strike plate, a unlock button and an electromagnet of it and self-locking button are formed a release trigger mechanism, and that electromagnet coil is serially connected in is main, pay between two switches.When electrical equipment, circuit overload, owing to pay the crooked deformation of Switching Two sheet metal, touched the strike plate of separating of self-locking button, the action of release trigger mechanism is threaded off main switch, has cut off circuit; When short circuit or instantaneous large-current come then, the electromagnet reaction, strike plate is separated in adhesive, and main switch is threaded off and is opened circuit.Make protector with such switch, defectives such as have complex structure, price is higher, and oneself power consumption is also big, and can't solve the contradiction of the deferred action setting value and the real work setting value of instantaneous large-current well, in fact be not suitable for generally making being used for replacing general fuse.

The utility model is a kind of improvement project of doing at the above-mentioned deficiency of prior art, a kind of fusible link, sheet that low melting point alloy need not be installed is provided, there is preferably anti-moment peak gush current capability and have an oneself power consumption little, price low (with the similar price of ordinary porcelain matter safety box), the alarm of opening circuit is arranged, easily check, repair the switching mode electrical equipment safety box of advantages such as long service life.

This device technique is simple, and is rational in infrastructure, and cost is low, and saving metal material and energy can replace existing all kinds of fuse, and the scope of application is very wide, and favorable economic benefit and application prospect are arranged.

Main technical schemes of the present utility model is as follows: two buttons are arranged, the key lever bottom is with a little spring, the middle part is a projection, top is the button that is exposed at the safety box outside, raised position place at these two button middle parts, laterally nestle up a metallic elastic tongue piece, one end of this tongue piece is a hard contact, it and a fixed contact are formed the main switch of a quiet mould assembly, the other end and the support of tongue piece are fixed, also fixed an electromagnet on the support, tongue piece be the moving contact of main switch be again electromagnet armature, the fixed contact of main switch links to each other with power line, the moving contact of main switch is connected with an end of electromagnet coil through tongue piece, quiet, also and connect a branch road of being contacted by resistance and light-emitting diode, the other end of electromagnet coil links to each other with the load circuit between moving two contacts, and the coil two ends also and connect a quiet mould assembly auxiliary switch of making moving contact with bimetal leaf.The projection at its key lever of aforesaid two buttons middle part is that two shapes are inverted each other in the side by the metallic elastic tongue piece tiltedly splits.Key lever is made with hard insulation such as plastics, bakelite, pottery etc.

Accompanying drawing 1 is an electrical schematic diagram of the present utility model;

Accompanying drawing 2 is that structure of the present utility model is faced diagrammatic sketch;

Accompanying drawing 3 is three-dimensional diagrammatic sketch of the utility model partial structurtes.

Below in conjunction with explanation, principle of the present utility model and embodiment are described further accompanying drawing 1, Fig. 2, Fig. 3:

Main switch K ₁Be serially connected on the power circuit with electromagnet 7 because electromagnet 7 adopts the enamelled wire than the thick line footpath to turn to coil 1, the number of turn again seldom, so resistance value is very little, with it and the auxiliary switch K that connects ₂Resistance is also very little, and the total resistance value as a result of both parallel connections is littler, if with the resistance and the auxiliary switch K of electromagnet coil 1 ₂Resistive arrangement become certain ratio, the then electric current of flowing through coil 1 and the auxiliary switch K that flows through ₂Electric current also will be by this proportional diverting.If establishing both resistance ratios is 1:4, then the electric current I of flowing through coil 1 ₁With the auxiliary switch K that flows through ₂Electric current I K ₂Should be I ₁: IK ₂=1:4 is 2 if deliberately set up the operating current of electromagnet 7, auxiliary switch K ₂The separation electric current be 4 because both split ratio is 1:4, so the setting current of safety box still is 5.At this moment, when 5 following electric currents were flowed through safety box, safety box can not move; Be 5 or only greater than 5 o'clock at electric current, auxiliary switch K ₂At first separate, as long as separation trend one occurs, the parallel branch at electromagnet coil 1 two ends or equivalence open circuit or resistance value increase suddenly, have quickened the action of electromagnet 7, main switch K ₁Thread off immediately, cut off circuit, played protective effect; When short circuit current produced, at first action was electromagnet 7, equally the energy fast cut-off circuit; And when one when short circuit current produces greater than the instantaneous large-current of setting current, for example immediate current is 9 o'clock, can be calculated by aforesaid split ratio: I ₁=1.9, IK ₂=7.1, at this moment, electromagnet 7 still is failure to actuate, auxiliary switch K ₂Again because thermal inertia does not also reach reaction, so safety box is failure to actuate to this big electric current.Design mainly is to consider that the cold silk electric current of some electrical equipment and starting current are all big than normal electric current like this, even big several times.Above principle is a basic mentality of designing of the present utility model.

Two button J ₁, J ₂Key lever top be button 11, bottom 9 is with little spring 2, the projection at middle part 10 is two by metallic elastic tongue piece 5 one sides and invertedly each other tiltedly splits.Button J ₁Be a self-locking type button, middle part projection 10 is smooth bevels, during the safety box operate as normal, and button J ₁Take off, tongue piece 5 loads are at J ₁Button J has been pinned at the omoplate place that the top, slope one of key lever projection 10 is narrow ₁Button J ₂Be a no lock button, the projection 10 at its middle part is smooth being " a 7 " shape inclined-plane, and during the safety box operate as normal, tongue piece 5 is the bottoms, inclined-plane that abut against its projection 10.At this moment, the moving contact 4 and main switch K of tongue piece 5 front ends ₁Fixed contact 3 reliably contact, electric current is through main switch K ₁→ electromagnet coil 1 and auxiliary switch K ₂Flow to load, constitute path.

Served as live stream and come then, because coil 1 and auxiliary switch K ₂Split ratio determine that most of electric current is from main switch K ₁→ auxiliary switch K ₂→ load, and only the fraction electric current from main switch K ₁Also deficiency is so that electromagnet 7 action for → coil 1 → load, this fraction electric current, and this most electric current makes bimetal leaf 8 heating distortion, makes auxiliary switch K ₂The contact separation of former closure.This segregation phenomenon causes auxiliary switch K even be a trend ₂The contact is loosening, auxiliary switch K ₂Contact resistance just increase suddenly, destroyed original shunting proportionate relationship, cause most electric current to change its course and walk toward coil 1, electromagnet 7 moves immediately, adhesive tongue piece 5, and the suction-combining force does not also require very big, as long as can make elastic tongue piece 5 slightly activity once, tongue piece 5 will be from J ₁Landing on the narrow omoplate of key lever projection 10, again because the effect that the little spring 2 of key lever bottom 9 is upspring, the mechanical movement of this landing, make tongue piece 5 along the smooth bevel of key lever projection 10 reliable and main switch K ₁Fixed contact 3 break away from J ₁After key lever was upspring, tongue piece 5 was at J ₁The action that one time overcurrent cuts off has been finished in the convex position place locking of key lever projection 10.Main switch K ₁After the disconnection, by the alarm indicating circuit work of resistance R and LED polyphone, the luminous indication of LED.

When short circuit current comes, because short circuit current is very big, no matter coil 1 and auxiliary switch K ₂Split ratio how, the electric current of flowing through coil 1 is certain to greater than its current value of action of adjusting, electromagnet 7 actions, main switch K ₁Cut-out, alarm are finished in action as described above; If when one arrives much smaller than short circuit current and greater than the instantaneous large-current of safety box setting current, bimetal leaf 8 is because of its thermal inertia effect, generally more slow to the immediate current reaction, and being diverted to the operating current of adjusting of the also not enough electromagnet 7 of electric current of electromagnet coil 1 this moment, electromagnet 7 also is failure to actuate.Certainly, to consider the cold silk electric current of general electrical equipment and the proportionate relationship of starting current and running current to the setting of the operating current of adjusting of electromagnet 7, suitably selecting the setting value of electromagnet 7, is to solve the key point that the contradiction that electric current is failure to actuate is gushed in the action of safety box distinguish short-circuit electric current, normal peak.

Button J ₂Be manual release button, in the time of need cutting off the electricity supply maintenance electrical equipment, circuit, as long as take this key off, immediate tongue piece 5 has been released on " 7 " shape inclined-plane of this key key lever projection 10, makes it from button J ₁The omoplate of projection 10 on landing, J ₁Eject, pinned tongue piece 5, disconnected main switch K ₁

Claims (3)

1, a kind of switching mode electrical equipment safety box comprises an electromagnet and armature thereof, it is characterized in that having two button J ₁, J ₂Key lever bottom 9 is with a little spring 2, and there is a projection 10 at the middle part, and top is to be exposed at the outer button 11 of safety box housing, at these two button J ₁, J ₂Protruding 10 positions, middle part laterally nestle up a metallic elastic tongue piece 5, and these tongue piece 5 one ends are hard contacts 4, with fixing contact 3 compositions, one a quiet mould assembly main switch K ₁, the other end and support 6 is fixing, also fixes an electromagnet 7 on the support 6, tongue piece 5 K switch of both having decided ₁Moving contact, make the armature of electromagnet 7, main switch K again ₁Fixed contact 3 link to each other main switch K with power line ₁Moving contact 4 link to each other main switch K through tongue piece 5 with an end of electromagnet coil 1 ₁Between two contacts also and connect a branch road of being contacted by resistance R and LED, the other end of electromagnet coil 1 links to each other with load, and coil 1 two ends also and met the quiet mould assembly auxiliary switch K that a usefulness bimetal leaf 8 is made moving contact ₂

2,, it is characterized in that described two button J according to the described switching mode safety box of claim 1 ₁, J ₂, the projection 10 at its key lever middle part is tiltedly split being that two shapes are inverted each other by metallic elastic tongue piece 5 one sides.

3, according to claim 1 or 2 described switching mode electrical equipment safety boxs, it is characterized in that described two button J ₁, J ₂Its key lever is to make with hard insulation such as plastics, bakelite, pottery etc.

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