CN87209084U - Control push botton for self-protection - Google Patents

Abstract

The utility model relates to a control bottom of the electric motor, in particular to a control bottom for self-protection. The bottom is characterized in that a lever bridge and a microswitch are provided under a starting button; a minityped under voltage relay is arranged on the bottom of a stopping button. The utility model has the advantages of compact structure, strong versatility and convenient operation, and can implement the automatic protection to the malfunctions of the open phase, the overload, the under voltage, the short circuit and the looseness of a wiring pile generated in the operation of the electric motor.

Description

Control push botton for self-protection

The utility model relates to the control button of motor, particularly has the control button of automatic protection functions, abbreviates the self-insurance button again as.

The various faults of aging life-span cause that often do not reach it owing to motor are burnt, and cause unnecessary loss, for solving this difficult problem, many kinds occurred and have protected electrical equipment automatically.This class is protected automatically most typically in the electrical equipment to be had: three-phase structure is installed on main circuit and is had the thermal relay of open phase protection, this mode is more general, effect is also fine, and just cost is higher, versatility is poor, open phase protection is also reacted rapidly sensitive inadequately because of the thermo-lag of bimetal leaf; Another kind of mode is that thrermostatic bimetal-plate or temperature-sensitive element are embedded in the end coil of motor windings, directly monitors the actual temperature rise of motor windings, and this can protect motor reliably, is installing conveniently inadequately unfortunately, therefore uses less; Also have some custom-designed phase failure protectors, its function only is the protection open phase fault, and can not protect overload.For this reason, task of the present utility model is exactly the automatic protection problem that will solve motor, make out that cost is low, highly versatile, sensitivity and purpose that practical automatic protection control apparatus is exactly an invention self-insurance button.

The scheme that addresses this problem is: appoint in the three-phase fuse of main circuit and get two-phase and load onto starting fuse (select by the starting current value at this place fixed), and another phase (as the monitoring phase) is loaded onto operation fuse (selecting calmly by the load current value of this machine), a lever electric bridge and a sensitive switch are installed below starting button again, a miniature under voltage relay is installed below stop button.The contact of this lever electric bridge is to go up mutually and operation fuse shunt circuit in parallel in order to cut-off monitoring, and sensitive switch is coil (the exchanging 380V) electric current in order to cut-off miniature under voltage relay, cut-offs the sucking coil electric current of contactor again with the contact of this under voltage relay.Sensitive switch action bottom could getting excited after the contact that must make the lever electric bridge on the architectural feature when pressing starting button earlier closely contacts disconnects the contact of lever electric bridge again and sensitive switch is resetted.In addition, the under voltage relay coil must be with guarding and another power supply mutually, and the contactor sucking coil must be with guarding phase two-phase power supply in addition in addition, make the phase failure or under-voltage can both the monitoring and trigger action of arbitrary phase power supply in the three phase mains like this, thereby cut off principal current rapidly delicately; Produce as for interior circuit (main line) and to get loose or during disconnection fault from contactor to the motor pile extension; (because unclamp starting button be that end stake from the motor pile extension fetches and enters the under voltage relay coil again through stop button from the Control current of guarding phase afterwards); will cause that monitoring moves fuse failure mutually or makes the under voltage relay coil cut off Control current automatically because of holding voltage is not enough, the reliable open phase protection thereby internal, outer circuit all has sensitivity.Since three phase mains can not produce under-voltage or open-phase running, the three-phase current of motor should be that balance equates so, so just only needs wherein can guard reliably once the operation fuse of going up mutually the overlond running of motor.Fuse itself is very sensitive to the automatic protection of short trouble, and contactor and relay all have under-voltage protection function.In sum, the self-insurance button can reach and carry out sensitive and protection automatically reliably to faults such as overload, the phase failure (inside and outside circuit), under-voltage, short circuit and wiring pile get loose.

The self-insurance button only is to have reequiped a lever electric bridge in button inside and increased a sensitive switch and a miniature under voltage relay; these three parts are all very small and cost is very low; operation is also with the same easy originally; only be to select with corresponding operation fuse owing to installing and using at the motor of different capabilities; so the versatility of this device is very strong, energy centering, miniature motor are realized protection operation automatically.

Concrete structure principle of the present utility model and automatic protection functions are provided by following examples and accompanying drawing, will describe in further detail this utility model in conjunction with the accompanying drawings below:

Fig. 1 is the installation circuit theory diagrams of self-insurance button;

Fig. 2 is the structure principle chart of self-insurance button.

In Fig. 1, dress is thicker starting fuse in the fuse RD of A, B phase, and loads onto thinner operation fuse (blow-out current value of operation fuse is equal to or slightly less than the load current value of motor) in C phase (as the monitoring phase) fuse.When pressing starting button QA earlier will with shunt circuit in parallel (thick black line) conducting of operation fuse, press again beneath control circuit conducting, so under voltage relay QJ is because of experiencing the alternate line voltage adhesive action of B, C, produce its contact QJ closure, thus conducting contactor coil A that C links, the B control circuit between mutually, contactor produces the adhesive action and makes main contacts C closure, makes motor D begin starting.After motor enters normal operation, unclamp starting button QA, the control circuit under making earlier disconnects, and shunt circuit is disconnected, at this moment on the QJ coil required C phase power supply but from monitoring and motor pile extension D ₃Bottom foundation pile (directly being connected with the motor lead-out wire) attracts, and through stop button TA, enters the QJ coil again, so QJ still keeps attracting state, the monitoring motor D is normally moved.If press stop button TA, cut off the C phase power supply of QJ, make its release, its contact QJ disconnects like this, and the control circuit that has just cut off contactor C is so contactor main contacts C discharges and shuts down.Though after TA unclamps, reclosed the control circuit of QJ, because of contactor has disconnected main circuit, D ₃Therefore do not have power supply in the stake,, have only and press starting button QA and just can reset so can not start.

This circuit theory makes three phase mains all enter control circuit, so the outer circuit phase failure of any phase can both make under voltage relay or contactor release movement, thus autostop; And for interior circuit, if D ₃Pile extension gets loose or breaks, and at this moment the getable voltage of its foundation pile can only obtain the 220V alternating voltage on the QJ coil near 0 current potential so, and under voltage relay is because of incessantly discharging automatically from the 380V bust to 220V with regard to sticking; If D ₁Or D ₂Pile extension gets loose or the phase failure, and consequent single phasing must make the C phase current raise about 1.73 times, and this inevitable very fast fusing operation fuse so also equally makes contactor discharge and shuts down with regard to as above open phase protection.

In Fig. 2, bakelite shell (9) forms the space of four parts, upper left side space mounting starting button, and JLXK is installed in the below ₁-11 type sensitive switches (8); Stop button is installed in the upper right side, and under voltage relay is installed in the below.Holddown spring (3) is housed below starting button (1), and it tightly suppresses an end of lever electric bridge (4), and the purpose of using lever is for the contact that makes an end produces bigger specific contact pressure, can pass through powerful starting current.The lead of starting current is thicker, is connected on wiring copper coin (2) and (6) after introducing from the outside, welds up as for being connected also two ends with multiply annealed copper wire (5) between wiring copper coin (6) and the lever electric bridge (4).Be back-moving spring (7) below the lever electric bridge, it guarantees can reset very soon after unclamping starting button (1).Installing, the push rod top of sensitive switch (8) under the axial line of starting button is aimed at, and between button spindle and the push rod certain distance is arranged, touch the push rod of sensitive switch (8) again after button is pressed the lever electric bridge, and push rod can also be pressed down to and make its inside touch bridge to beat.The coil of under voltage relay (10) wants ability to exchange 380 volts of voltages, generally should be able to discharge to 90% situation under-voltage, and its contact drop-out current ability should have 5 amperes, and is to link with filament annealed copper wire (11) between its movable contact bridge and the link stake.On the top of stop button (15) is back-moving spring (14), and the bottom is holddown spring (12), and it is that the contact that tightly suppresses on the electric bridge (13) fits tightly, reliable conducting.Connection lead (not drawing among the figure) as for inside can weld by Fig. 1, forms the integral body of a combination, has the control button of automatic protection functions exactly.

The structural principle of self-insurance button only has been described below, and can be designed to rotating control button, block push button etc. by this principle that this carries out automatically protection control for using on the middle-size and small-size motor that can carry out across-the-line starting.

Claims (2)

1, the control button of motor particularly has the control button of automatic protection functions, it is characterized in that being equipped with below starting button lever electric bridge and a sensitive switch, and a miniature under voltage relay is installed below stop button.

2,, it is characterized in that the push rod top of the axial line aligning sensitive switch of starting button, and between button spindle and the push rod certain distance is arranged according to the device of claim 1 regulation.

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