CN2075384U

CN2075384U - Fuse with microswitch

Info

Publication number: CN2075384U
Application number: CN 90206720
Authority: CN
Inventors: 李雁
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-05-20
Filing date: 1990-05-20
Publication date: 1991-04-17

Abstract

The utility model provides a fuse with a microswitch, being especially suitable for the open-phase protective circuit of a three-phase motor. A broken wire is connected in parallel at the two terminals of an existing fuse, and the actions of a microswitch can be controlled by the tension of the broken wire. The fuse with a microswitch can be connected in the open-phase protective circuit of a three-phase motor; when single-phase short circuit occurs, the microswitch can act to cut off each phase of electrical source of the entire motor, and the single-phase running of the motor can be avoided.

Description

Fuse with microswitch

The utility model relates to a kind of fuse with sensitive switch, when particularly being used in the single-phase winding of threephase motor and being short-circuited fault, when making the fuse opening of its phase, the sensitive switch action, cut off the power supply of whole motor circuit, make motor avoid single phasing.

Present fuse is used in each circuitry phase of motor, and single short circuit in winding makes the fuse opening of its phase, but motor still can continue operation, can not shut down, and accident is enlarged.

Task of the present utility model provides a kind of fuse that is suitable for use in the three phase electric machine open-phase protection circuit.

Task of the present utility model is finished as follows, and with the two ends of conventional fuse fuse and connect a fracture of wire, fracture of wire is tightened up fixing, is moved by fracture of wire Tension Control one sensitive switch.

When the fuse with three band sensitive switches is connected in the open-phase protection circuit of three phase electric machine; in a certain phase short circuit; make the fuse opening of its phase; the electric current fracture of wire of will flowing through then also makes fracture of wire blow, and fracture of wire loses tension force; the sensitive switch action; by the sensitive switch effect, can cut off each phase power supply of whole motor, can avoid the motor single phasing.

Concrete structure of the present utility model is provided by following two embodiment and accompanying drawing thereof.

Fig. 1 is the profile of the fuse of slotting formula band sensitive switch.

The fuse of Fig. 2 band sensitive switch, the winding diagram in the three phase electric machine circuit.

The fuse structure schematic diagram of the spiral band sensitive switch of Fig. 3.

The fuse blows state work sheet of the spiral band sensitive switch of Fig. 4.

Below in conjunction with Fig. 1, Fig. 2 first embodiment that provides according to the utility model is described, inserts the concrete structure and the working condition of the fuse of formula band sensitive switch.It is to be widened by common plug fuse, there is an insulating support 5 to support a bimetallic lever 7 in 6 last slotting the lid, one end of lever 7 is connected on the moving contact 3 by a flexible conductor 4, the other end of lever 7 is a fracture of wire 8, fracture of wire 8 is strained and fixed on another moving contact, promptly is that fuse and fracture of wire are attempted by slotting the lid in 6 on the safety box.

Insert when cover 6 insertion bases 1 last, two moving contacts 3 join with base 1 corresponding fixed contact 2 respectively, and make that lever 7 pushes down following sensitive switch K ram 9.When fuse, fracture of wire 8 blow, lever 7 perks, sensitive switch restores.

It is used in the open-phase protection circuit of threephase motor; the fuse RK of three band sensitive switches is connected on respectively in each circuitry phase; normally opened contact K with three sensitive switch K is serially connected in the start-up circuit again; when each fracture of wire 8 is connected; insert to insert on good each fuse and cover 6; go up to insert cover that 6 interior levers 7 push down sensitive switch ram 9; make its normally opened contact K closure, when pressing starting switch CA, KC is charged for contactor line bag; each normally opened contact KC closure of contactor; motor D is normally moved, and to compare resistance than fuse big because of fracture of wire, so its inserts fuse two ends; primary circuit there is not influence; when the three phase electric machine D fault that is short-circuited mutually wherein, with its fuse opening, then the fracture of wire 8 in parallel with fuse also blows immediately; lever 7 perks; sensitive switch K restores, and its normally open contact K disconnects, and makes contactor KC line bag dead electricity; with the motor D dump, avoid the motor single phasing.The installation of fracture of wire and fuse is very convenient; Also fuse and fracture of wire two parts can be separated, utilize the existing formula insurance of inserting, again and connect the lever segment by the fracture of wire tension of a control sensitive switch.

Second embodiment sees the fuse of the spiral band sensitive switch of Fig. 3, it is also the same with general screw type fuse, loam cake is arranged, base and fusion tube three parts are formed, second embodiment of the utility model increases by a sensitive switch K in base, sensitive switch K rams 26 under fusion tube 22 centers, fusion tube 22 is interior except that being fixed the fuse 24 by metal backup shoe 21 about it, also the fracture of wire 23 by the band metal hammer is pressed in a little spring 25 in the columniform sulculus of 22 times metal backup shoes 21 of fusion tube, and pass down the centre bore of metal backup shoe 21, through fusion tube, tension fracture of wire 23 is fixed by last metal backup shoe.Fracture of wire 23 is with fuse 24 up and down between the metal backup shoes of fusion tube that are fixed in parallel like this.Then the fusion tube 22 of this fuse 24, fracture of wire 23 parallel connections is packed in the base, screw on loam cake, it is the same with the work electricity principle of fuse that first embodiment inserts formula band sensitive switch, difference be sensitive switch be normally-closed contact, normally in service at motor, sensitive switch is failure to actuate, and utilizes normally closed interlock work, when fuse 24 blows, fracture of wire 23 also can blow, spring 25 ejects, and raming of sensitive switch 26 depressed, and its normally closed interlock is disconnected.

The utility model is simple in structure, and cost is low, installs easily, and is easy to use, is used in the three phase electric machine open-phase protection circuit, avoids the motor single phasing reliably.

Claims

1, a kind of fuse with sensitive switch; particularly be used in the fuse in the circuit of three phase electric machine open phase protection, it is made up of loam cake 6, base 1 and fuse, it is characterized by; one in parallel is tightened up fixing fracture of wire 8 at the fuse two ends, also has the sensitive switch K by the fracture of wire Tension Control.

2, fuse according to claim 1, it is characterized in that: fixing at the fracture of wire 8 of fuse two ends parallel connection, it is to have an insulating support 5 to support a bimetallic lever 7 in 6 last slotting the lid, one end of lever 7 is connected on the moving contact 3 by a flexible conductor 4, and the other end of lever 7 is a fracture of wire 8, and fracture of wire 8 is tightened up and is fixed on another moving contact, to go up to insert and cover 6 insertion bases 1, what lever 7 was pushed down following sensitive switch K rams 9, and fracture of wire blows, and lever perk sensitive switch restores.