CN85100193B

CN85100193B - Self-closing electromagnetic contactor

Info

Publication number: CN85100193B
Application number: CN85100193A
Authority: CN
Inventors: 郭行干
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-04-01
Filing date: 1985-04-01
Publication date: 1987-11-18
Also published as: CN85100193A

Abstract

The present invention relates to a self-holding electromagnetic contactor which is characterized in that an iron core of the contactor is made of semi-hard magnetic material, the contactor is attracted by DC pulse current, and the attracting state is kept by residual magnetism. After the magnetism is removed by inverse-direction DC pulse current with proper size, the contactor can be released. Martensite magnetic steel is used by the semi-hard magnetic material. Because the current for keeping attraction is saved, the self-holding electromagnetic contactor has the advantages of energy saving, no burnout of excitation coils, no noise, reduction of manufacturing cost and improvement of functional reliability.

Description

Self-closing electromagnetic contactor

The invention is a kind of electric power switch unit, particularly a kind of general purpose big-and-middle-sized self-closing electromagnetic contactor.

General purpose big-and-middle-sized electromagnetic contactor is being kept make position, must supply with constantly exciting current to the electromagnet of operation usefulness, so that contactor keeps attracting state.Consumed like this electric energy, the heat that gives out burns magnet exciting coil easily, has reduced dependability, and produces electromagnetic vibration noise easily.People have made extensive efforts in order to overcome these shortcomings.

A scheme that comparatively extensively adopts is, contactor kept the excitation AC stream that adhesive uses become direct current with diode rectification, reduced like this eddy current and the magnetic hysteresis loss in the iron core, and saves energy reduces heating, avoids noise.But the control circuit more complicated has affected the further raising of reliability.

In Japan clear 56-900 patent of invention is arranged.This patent is to insert a permanent magnet in magnetic excitation circuit, when stopping to supply with exciting current with dc pulse current after with the armature adhesive, the magnetic flux that relies on permanent magnet to produce is kept adhesive, when magnet exciting coil is supplied with suitable big or small reciprocal dc pulse current, the magnetic flux of permanent magnet is cancelled, contactor is just by disjunction, although this scheme has overcome the shortcoming that general contactor exists.But needing increases a permanent magnet, has strengthened overall dimension, and manufacturing cost improves, and is unfavorable for producing in enormous quantities.

On the 30th～68 page of " motor engineering handbook " the 5th volume (power transmission and transforming equipment) that China China Machine Press publishes nineteen eighty-two, list contactor and derived from kind table (table 30.5-2), at length introduce various contactor kinds, wherein also introduced the remanent magnetism contactor.It is to make iron core with the ferromagnetic material of high-coercive force, and magnet exciting coil namely cuts off the power supply after the energising adhesive, and contactor utilizes left magnetic effect to keep adhesive, not power consumption during work, dependable performance, noiselessness.But because the high-coercive force ferromagnetic material is expensive, this contactor can only be made low capacity, uses in automatic control system, and in general purpose big-and-middle-sized contactor, does not also have so far this remanent magnetism contactor.

Task of the present invention provides a kind of general purpose big-and-middle-sized electromagnet contactor, and it can overcome general electromagnetic contactor power consumption, heating, noisy shortcoming, and easy, reliable, cheap.

The invention is achieved in that the soft magnetic material (being generally silicon steel sheet) that operation electromagnet in the general purpose big-and-middle-sized electromagnetic contactor is used, and changes to adopt half retentive material.Its control mode is to make the contactor closure with dc pulse current, remanent magnetism by semi-hard magnetic material after switching current disappears maintains closure state with contactor, when passing into the opposite direction pulse current of suitable size, after the semi-hard magnetic material demagnetization, contactor can discharge.

Semi-hard magnetic material can be done diversified selection, the invention select to be rich in martensitic in or high-carbon steel.Carbon steel produces martensite through Quenching Treatment, and it has the Hard Magnetic characteristic.Medium carbon steel (phosphorus content is 0.25～0.6%) and high-carbon steel (phosphorus content is more than .6%) are along with the increase of phosphorus content, residual magnetic flux density (Br) is down to about 6000 Gausses by 11000 Gausses, and coercive force (Hc) is risen to about 70 oersteds by 20 oersteds.Take No. 45 carbon steels as example, Br is roughly 10500 Gausses, and Hc is 30 oersteds.Because its Hc is smaller, can not use in a lot of occasions, therefore often ignored by people.But this material is used in the invention and is well suited for.In this device, magnetic circuit very long (about about 20～40 centimetres), and air gap very little (about 0.1 millimeter), the remanent magnetism that this coercive force produces has enough used.On the contrary, if the coercive force of magnet is excessive, make to discharge difficulty.The high remanent induction intensity that this material has can make under certain magnetic circuit cross section and produce bigger the suction-combining force.A shortcoming of this material is the growth along with age, and magnetic has certain decay, and this also is the reason that people ignore it.As long as this decay is left enough stockages is can not cause adverse consequences, easy to process, the price of magnet steel cheap is a very outstanding advantage, uses it that this installation cost is descended greatly, is fit to a large amount of production in this device.

Below in conjunction with drawings and Examples the invention is further described.

Figure one is the contactor schematic diagram.(1), (2) are the contacts that control power circuit break-make is used among the figure, (3) be the spring that returns armature (4) usefulness, (6) be fixed core, (5) be magnet exciting coil, (7) be often to open auxiliary contact, (10) be normally closed auxiliary contact, it obtains delay breaking characteristics about 0.02 second by spring (8) and weight (9).

Figure two is one of ac contactor control circuits.QA is push button among the figure, and B1, B2, B3 are diodes, and R1, R2 are current-limiting resistances, and JLC-1, JLC-2 are auxiliary contact (among the figure one (7), (10)), and LQ is magnet exciting coil (among the figure one (5)).

Figure three is two of ac contactor control circuits.This circuit is identical with figure two circuit, but increases R3 current-limiting resistance, C1 capacitor, B4 diode, under voltage relay coil JQ and its contact J-1.

Figure four is contactor armature and the magnetic hysteresis loop of iron core ((4), (6) among the figure one) when make position.A, b, c, o are each working points among the figure.

When utilizing figure two to make control circuit, press push button QA, circuit consists of path by QA → B1 → R1 → JLC-1 → LQ, and LQ magnet exciting coil (5) flows through big switching current makes armature (4) by adhesive, and contact (1), (2) closure are finished the connection task.The B3 diode is that LQ consists of a path when the power-half cycle, has had it can strengthen the suction-combining force, crosses when strong at the suction-combining force that it can omit.The magnetic state in the iron core is a point (figure four) before the outage after adhesive.Adhesive postponed by 0.02 second, and after iron core was fully magnetized, auxiliary contact JLC-1 was with circuitry cuts, and attract current disappears, and relies on carbon steel remanent magnetism to keep the attracted position, and magnetic state unshakable in one's determination this moment moves to b point (figure four).When pressing disjunction button TA, circuit consists of path by TA → B2 → R2 → JLC → 2 → LQ, flow through the branch brake current by the right quantity of R2 control among the LQ, at this moment C point (figure four) is shifted in magnetic state, the magnetic flux trend disappears, suction weakens greatly, effect lower armature at spring (3) separates with fixed core, in case occur separating air gap, magnetic flux more reduces, strengthened centrifugation, contact (1), (2) are left under armature drives, and finish the disjunction task, follow by JLC-2 circuitry cuts, separating brake current vanishes, magnetic state move to 0 point (figure four).

Figure three is another control circuit of A.C. contactor.It duplicates in figure two, but has increased a under voltage release portion.A.C. contactor is normally in service, capacitor C ₁On be filled with high voltage, the enough energy of contain, when supply voltage disappears, C ₁On the voltage rapid decrease, electric current reduces among the coil JQ of under voltage relay, relay is released, J-1 closure, C ₁To the LQ discharge, demagnetized in contactor iron core (4), (6), and armature discharges immediately.In some circuit, according to technological requirement, when electric current suddenly disappears and should cut off circuit, can adopt this control circuit.

By front as can be known described, new contactor is to rely on remanent magnetism to keep closure state, need not exciting current, thereby have energy-conservation, advantages such as heating burnout coil, noiseless not.

The overall dimension of this new contactor can be identical with the overall dimension of original contactor, and this is more convenient than Japanese clear 56-900 patent of invention in the standardization that realizes design, makes, uses.Owing to saved a permanent magnet, it is unshakable in one's determination to have selected magnet steel to do, and greatly reduces manufacturing cost, is applicable to general purpose big-and-middle-sized contactor.

In people life and producing, when interrupting once in a while, power supply wishes sometimes that mains switch do not want automatic disjunction, in order to can in time recover electricity consumption when sending a telegram here subsequently, reduce operation.In this occasion, original contactor is automatically disjunction owing to lose exciting current, uses inconvenient.In this occasion, change and use the new contactor of making by figure two control circuits just greatly convenient.

Automatic switch does not generally adopt operation electriomagnet power, because inconvenience is used in its automatic disjunction of meeting when instantaneous power-off, and the manual or electric motor operated power of its general employing.Automatic switch can select the invention to operate power now, and such electrical equipment not only can have contactor function but also can have auto-switch function, has realized a New Combined Switchgear.

Claims

1, a kind of general purpose big-and-middle-sized contactor, its iron core and armature are made of half-hard magnetic material, utilize the remanent magnetism of this material to keep closure and form self-closing electromagnetic contactor, it is characterized in that: A, iron core and armature adopt be rich in martensitic in or high-carbon steel make; The control mode of the control winding of B, this contactor is: make the contactor closure by DC pulse, only behind the reverse impulse that passes into suitable size, contactor is discharged.

2, according to the described general purpose big-and-middle-sized contactor of claim 1, it is characterized in that the circuit design that satisfies the control mode of said control winding is: push button (QA) and diode (B ₁), current-limiting resistance (R ₁), can postpone auxiliary normally closed contact (JLC-1), magnet exciting coil (LQ) series connection of left and right sides disjunction in 0.02 second, with the diode (B in parallel with JLC-1, LQ ₃) form the combined floodgate circuit, by disjunction button (TA) and diode (B ₂), resistance (R ₂), auxiliary normal opened contact (JLC-2), magnet exciting coil (LQ) be composed in series opening circuit, and select B ₁, B ₃, and B ₂Polarity make switching current and separating brake opposite current.

3, according to the described general purpose big-and-middle-sized contactor of claim 2, it is characterized in that the auxiliary normally closed contact that has to obtain postponing about 0.02 second disjunction by spring and weight.