CN2093449U - Three-phase multifunctional electric protector for machine tool - Google Patents

Abstract

The utility model relates to a three-phase multifunctional electric protector for a machine tool, comprising a casing, a controller for controlling on-off state of the power source, a power amplifier circuit, and a rectification circuit. The utility model is characterized in a three phase sample and hold circuit, a voltage comparator, a strobe circuit for signals, and a standard voltage generation circuit. The utility model has the advantages of accurate sampling, strong anti-interference ability, multiple protection function, small size, and low energy consumption. The three-phase multifunctional electric protector for a machine tool can realize the reliable protection for various fault states of the three phase power supply such as overvoltage, undervoltage, phase interruption, short circuit, etc. The overall error is within 1%. The utility model can meet the requirement of the exported machine tool for the protector.

Description

Three-phase multifunctional electric protector for machine tool

The utility model belongs to electric equipment, relates to the improvement to the Machine Tools Electric protective device.

Homemade lathe in use often burns out the accident of Machine Tools Electric equipment owing to be not with the phase failure, overvoltage, under-voltage, short-circuit protection.In recent years, the lathe of China's outlet, outer commercial city requires to install the electic protection device.Function singleness, poor reliability such as domestic original protector such as DY-20 type electromagnetism one-phase relay, BY-10 type three-phase transistor low-voltage variation device.Chinese patent application CN85104228A provides a kind of multifunctional automatic contactor, only carries out single-phase sampling, can not adapt to the many requirements of three phase mains fault assembled state.

The purpose of this utility model provide a kind of can overcome three phase mains fault assembled state many, disturb big difficult point, have the multi-function protector of overvoltage, under-voltage, the phase failure, short-circuit alarming and defencive function.

The utility model comprise controller, the driving governor action of a housing, control lathe on/off power amplifier, lower pressure rectifier circuit, it is characterized in that,

The first, a three-phase voltage sampling hold circuit is arranged, by resistance R ₁～R ₆, diode D ₁～D ₃, capacitor C ₁～C ₃, potentiometer W ₁～W ₃Form resistance R ₁, R ₂, R ₃Respectively with R ₄, R ₅, R ₆Be composed in series three electric resistance partial pressure branch roads, an end of branch road connects three phase mains respectively, and the other end is interconnected to constitute the protector ground wire, diode D ₁, D ₂, D ₃Positive pole be connected with the dividing point of dividing potential drop branch road respectively, negative pole respectively with capacitor C ₁, C ₂, C ₃Positive pole connect potentiometer W ₁, W ₂, W ₃Stiff end respectively with capacitor C ₁, C ₂, C ₃Parallel connection, sliding end are the sampled signal output, resistance R ₁=R ₂=R ₃, R ₄=R ₅=R ₆, capacitor C ₁=C ₂=C ₃, potentiometer W ₁=W ₂=W ₃,

The second, by 4 integrated operational amplifier IC ₁～IC ₄Form 4 road voltage comparators, IC ₁And IC ₂Output be connected IC with the power amplifier input ₃And IC ₄Output be connected with the warning luminous tube,

Three, have by D between three-phase voltage sampling hold circuit and the voltage comparator ₄～D ₉The diode selection door of forming and by diode D ₁₀～D ₁₂, resistance R ₀The codan that is composed in series, diode D ₅, D ₇, D ₉Form under-voltage signal gating door, their negative pole respectively with potentiometer W ₁, W ₂, W ₃Sliding end connect positive pole and IC ₁And IC ₄Signal input part connect D ₄, D ₆, D ₈Form overvoltage signal gating door, their positive pole respectively with W ₁, W ₂, W ₃Sliding end connect the input (D of negative pole and codan ₁₀Negative pole) connect the output (D of codan ₁₁Positive pole and D ₁₂The tie point of negative pole) and IC ₂And IC ₃Signal input part connect,

Four, there is one to provide the standard voltage generation circuit through the two-stage voltage stabilizing of normal voltage, potentiometer W to voltage comparator ₄～W ₇With second level voltage-stabiliser tube WY ₂Parallel connection, its sliding end connects voltage comparator ic respectively ₁～IC ₄The normal voltage input.

The course of work of the present utility model is, when overvoltage (or under-voltage) appearred in a certain phase voltage, after its numerical value reached predetermined alarming value, sampled signal was sent into voltage comparator ic through the diode selection door ₂And IC ₃(under-voltage signal is sent into IC ₁And IC ₄) compare with the normal voltage signal, make IC ₃(or IC ₄) upset output high level lights luminous tube D ₁₉Report to the police, when sampled signal further reaches the protection value of regulation, IC ₂(or IC ₁) upset drives power amplifier that controller action is cut off the electricity supply, and lights protection indication luminous tube D simultaneously ₁₈

The utility model has the advantages that: adopt the three-phase sampling hold circuit, sampling is accurate, and antijamming capability is strong; Defencive function is many, is applicable to the protection under tens kinds of unusual combined situation of arbitrary phase, two-phase or three-phase; It is reliable to be active in one's movements, and composition error is in 1%; Energy consumption is little, working stability; Volume is little, and overall dimension is 75 * 95 * 110 millimeters, satisfies the requirement of outlet Machine-Tool Control box to the protector size restrictions.

Fig. 1 is the utility model theory diagram.Fig. 2 is the circuit diagram of a kind of embodiment of the utility model.In Fig. 1; (1) be the three-phase voltage sampling hold circuit, A, B, C connect three phase mains, and D is the ground of protector; (2) be the diode selection door; (3) be codan, (4) are voltage comparator circuits, and (5) are power amplifiers; (6) be controller; (7) be standard voltage generation circuit, (8) are the secondary voltage stabilizing circuits, and (9) are the lower pressure rectifier circuit.The embodiment that provides below in conjunction with Fig. 2 further specifies this suitable novel CONSTRUCTED SPECIFICATION.

Lathe general technical specifications GB5226-87 regulation: agree generally not allow to set up center line without the user.In order to guarantee not establish center line to the accurate sampling of fault-signal, R in the sample circuit ₁～R ₆Answer Select Error 0.5% with interior precision resistance, its span is R ₁=R ₂=R ₃=140K Ω～170K Ω, R ₄=R ₅=R ₆=20K Ω～24K Ω.Capacitor C ₁=C ₂=C ₃=220 μ f～470 μ f, W ₁=W ₂=W ₃=10K Ω～18K Ω.Three diode D that are connected in series in the same way ₁₀, D ₁₁, D ₁₂And R ₀The series arm of forming is with D ₄, D ₆, D ₈Input voltage comparator IC after the overvoltage signal dividing potential drop of storbing gate output ₂And IC ₃, guarantee its input end in high-impedance state, suppress interference signal and make it be lower than the sampled signal level.Should select precision height, drift is little, bias current is little, drive current is little, input offset current is little integrated circuit as four operational amplifiers of voltage comparator, LM324 for example is at voltage comparator ic ₁Output and the overvoltage storbing gate between have one by diode D ₁₇With resistance R ₇The series arm of forming, diode D ₁₇Negative pole and D ₄, D ₆, D ₈Negative pole connect diode D ₁₇Positive pole through resistance R ₇With voltage comparator ic ₁Input connect.Its effect is when occurring under-voltage and reaching the protection value, IC ₁The output high level is through R ₇, D ₁₇After make IC ₂Input actual detected to an overvoltage protection signal cause IC ₂Also upset output high level is realized the reliable protection action.Supply with IC ₁～IC ₄Normal voltage through voltage-stabiliser tube WY ₁And WY ₂Obtain W after the two-stage voltage stabilizing ₄～W ₇Be 10K Ω potentiometer and voltage-stabiliser tube WY ₂In parallel.Regulate W as requested ₄～W ₇, can make the threshold value of reporting to the police and protecting satisfy the requirement of different user.For example adjust W ₄～W ₇Sliding end and the resistance value ratio between the ground be 4.2:4.5:6.0:6.3, the index of protector is: 10% or the under-voltage numerical value that overvoltage numerical value reaches rated value reaches 15% o'clock of rated value and reports to the police luminous tube D ₁₉Light; When 15% or the under-voltage numerical value that overvoltage numerical value reaches rated value reaches the rated value 25% and the phase failure, delay time and realized the protection operation in 1 second, protect indicator tube D simultaneously ₁₈Light.Controller is a relay J, and its normally closed contact K is connected in the lathe contactor solenoid loop, when transistor BG is driven conducting, and the J action, K disconnects and makes the lathe outage.Rectified current routing transformer BY, rectifying tube D ₁₃～D ₁₆, capacitor C ₄With voltage-stabiliser tube WY ₁Form, for protector provides direct voltage.This protector is used for three-phase protective, also can be used for single phasing protection.

Claims (3)

1, a kind of three-phase multifunctional Machine Tools Electric protector comprises the controller of a housing, control lathe on/off, power amplifier, the lower pressure rectifier circuit of driving governor action, it is characterized in that,

(1), a three-phase voltage sampling hold circuit is arranged, by resistance R ₁～R ₆, diode D ₁～D ₃, capacitor C ₁～C ₃, potentiometer W ₁～W ₃Form resistance R ₁, R ₂, R ₃Respectively with R ₄, R ₅, R ₆Be composed in series three electric resistance partial pressure branch roads, an end of branch road connects three phase mains respectively, and the other end is interconnected to constitute the protector ground wire, diode D ₁, D ₂, D ₃Positive pole be connected with the dividing point of dividing potential drop branch road respectively, negative pole respectively with capacitor C ₁, C ₂, C ₃Positive pole connect potentiometer W ₁, W ₂, W ₃Stiff end respectively with capacitor C ₁, C ₂, C ₃Parallel connection, sliding end are the sampled signal output, resistance R ₁=R ₂=R ₃, R ₄=R ₅=R ₆, capacitor C ₁=C ₂=C ₃, potentiometer W ₁=W ₂=W ₃,

(2), by 4 integrated operational amplifier IC ₁～IC ₄Form 4 road voltage comparators, IC ₁And IC ₂Output be connected IC with the power amplifier input ₃And IC ₄Output be connected with the warning luminous tube,

(3), have by D between three-phase voltage sampling hold circuit and the voltage comparator ₄～D ₉The diode selection door of forming and by diode D ₁₀～D ₁₂, resistance R ₀The codan that is composed in series, diode D ₅, D ₇, D ₉Form under-voltage signal gating door, their negative pole respectively with potentiometer W ₁, W ₂, W ₃Sliding end connect positive pole and IC ₁And IC ₄Signal input part connect D ₄, D ₆, D ₈Form overvoltage signal gating door, their positive pole respectively with W ₁, W ₂, W ₃Sliding end connect the input (D of negative pole and codan ₁₀Negative pole) connect the output (D of codan ₁₁Positive pole and D ₁₂The tie point of negative pole) and IC ₂And IC ₃Signal input part connect,

(4), there is one to provide the standard voltage generation circuit through the two-stage voltage stabilizing of normal voltage, potentiometer W to voltage comparator ₄～W ₇With second level voltage-stabiliser tube WY ₂Parallel connection, its sliding end connects voltage comparator ic respectively ₁～IC ₄The normal voltage input.

2, protector according to claim 1 is characterized in that R ₁～R ₆For error 0.5% with interior precision resistance, its span is R ₁～R ₃: 140K Ω～170K Ω, R ₄～R ₆: 20K Ω～24K Ω.

3, according to claim 1 or 2 described protectors, it is characterized in that diode D ₁₇Negative pole and D ₄, D ₆, D ₈Negative pole connect diode D ₁₇Positive pole through resistance R ₇With voltage comparator ic ₁Output connect.

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