CN201693155U

CN201693155U - PLC electromagnetic valve control panel of die casting machine

Info

Publication number: CN201693155U
Application number: CN201020184785XU
Authority: CN
Inventors: 袁忠伟
Original assignee: NINGBO DONGFANG DIE-CASTING MACHINE Co Ltd
Current assignee: NINGBO DONGFANG DIE-CASTING MACHINE Co Ltd
Priority date: 2010-05-07
Filing date: 2010-05-07
Publication date: 2011-01-05
Anticipated expiration: 2020-05-07

Abstract

A PLC (programmable logic controller) electromagnetic valve control panel of a die casting machine includes a direct-current power supply, a PLC signal port and a controlled electromagnetic valve input port; the electromagnetic valve control panel comprises a sampling circuit, a switch control circuit, an input overvoltage protection circuit and an output short-circuit protection circuit; an electronic switch control circuit is adopted to replace the common relay contact output; a high-power triode controls high-current switch signal output by low-current signal input; the overvoltage protection circuit is added for efficiently protecting the normal work of the control panel and an output actuator; the short-circuit protection circuit is added for efficiently preventing the high-power triode in the control panel from being burnt down in case of short-circuit of the output actuator; and when overvoltage or short-circuit happens, the protection circuit automatically switches off the high-power triode and lock, and doesn't return to the normal state until the power is cut off. The non-contacting switch and the protection circuit greatly prolong the service life of the electromagnetic valve control panel, the production cost and the maintenance cost are halved compared with those of employing a relay, moreover the structure is simple and the wiring and the maintenance are convenient.

Description

Control panel of electromagnetic valve for programmable controller of die casting machine

Technical field

The utility model relates to a kind of electronic switching circuit, particularly a kind of control board of electromagnetic valve that is exclusively used in the Programmable Logic Controller of die casting machine.

Background technology

In the existing die casting machine control system, adopt the internal relay of PLC self band directly to drive magnetic valve mostly, advantage is that wiring is simple, the relay output form is not afraid of load short circuits, shortcoming is that volume is big, to take electric cabinet space many, and can only drive the load less than 2A, the contact time of relay has been grown to burn and has glued extremely, keeps in repair pretty troublesome.Also have and adopt the internal relay of PLC self band to drive auxiliary reclay, and then drive magnetic valve with auxiliary reclay, advantage is to drive the above load of 2A, is not afraid of load short circuits.Shortcoming is that wiring complexity, volume are big, and it is many to take electric cabinet space, also the contact time of auxiliary reclay grown and also can burn stickingly dead, cost is also very high.

Summary of the invention

The utility model proposes a kind of control board of electromagnetic valve that can replace auxiliary reclay at the problem that exists in the above-mentioned control system, possesses load short circuits protection and over-voltage protecting function, reaches purpose such as simple in structure, that wiring is easy, cost is low, the life-span is long.

Control panel of electromagnetic valve for programmable controller of die casting machine, comprise dc source, Programmable Logic Controller signal port and controlled solenoid valve input port, it is characterized in that control board of electromagnetic valve is made of sample circuit, ON-OFF control circuit, overvoltage crowbar and short-circuit protection circuit; Sample circuit connects the dc source positive terminal; the sample circuit input connects the overvoltage crowbar input; the sample circuit output connects the input of ON-OFF control circuit and short-circuit protection circuit; the Programmable Logic Controller signal port connects the input of ON-OFF control circuit; the output of short-circuit protection circuit and overvoltage crowbar is connected the input of ON-OFF control circuit, and the output of ON-OFF control circuit connects the controlled solenoid valve input port.

The utility model adopts electronic switch control circuit to replace the output of common relay contact, the output of high power third-level Guan Yixiao current signal input control high-current switch signal, increase overvoltage crowbar, can effectively protect the operate as normal of control panel and output actuator; Increase short-circuit protection circuit, burn out the large power triode in the control panel in the time of can effectively preventing to export the actuator short circuit.When overvoltage or short-circuit conditions generation, holding circuit automatically shuts down large power triode and locking, must outage just can return to normal later.Noncontacting switch and holding circuit have prolonged control board of electromagnetic valve service life greatly, and production cost and maintenance cost reduce half than with relay, and simple in structure, wiring and easy to maintenance.

Description of drawings

Fig. 1 is the utility model circuit structure block diagram.

Fig. 2 is ON-OFF control circuit figure.

Fig. 3 is short-circuit protection circuit figure.

Fig. 4 is overvoltage crowbar figure.

Fig. 5 implements circuit diagram for Fig. 1.

The specific embodiment

Below in conjunction with figure the structure of the present utility model and the course of work are briefly explained.

Referring to shown in Figure 1; the control board of electromagnetic valve of programmable controller of die casting machine is formed a control module by sample circuit 1, ON-OFF control circuit 2, short-circuit protection circuit 3, overvoltage crowbar 4, PLC signal port 5 and controlled solenoid valve input port 6; a unit output connects magnetic valve work of control; this example is 24 unit, and the PLC signal port has 24 signal elements to be connected with each control module input respectively.

Sample circuit 1 adopt resistance R 2 the 24V dc supply by the time pressure drop that produces make input signal, simple in structure, reliable operation.Sample circuit 1 connects dc source 24 anodes, and sample circuit 1 is the input that sample resistance R2 input connects overvoltage crowbar 4, and the output of sample circuit 1 connects the input of ON-OFF control circuit 2 and short-circuit protection circuit 3.Short-circuit protection circuit 3 is connected the input of ON-OFF control circuit 2 with the output of overvoltage crowbar 4.

Referring to shown in Figure 2, ON-OFF control circuit 2 comprises large power triode Q1, is connected to voltage-stabiliser tube Z1, resistance R 1 and the light emitting diode L1 of triode Q1 base input end, is connected to resistance R 27, light emitting diode L18 and the diode D6 of triode Q1 collector output.When input IN1 was 24V, Q1 ended, and OUT1 is output as 0V, and L1, L18 light emitting diode go out.When input IN1 is 0V, the Q1 saturation conduction, the OUT1 output voltage approximates 24V, and L1, L18 light emitting diode are bright.Wherein Z1 plays the effect of voltage clamp position, guarantees short-circuit protection and overvoltage crowbar operate as normal.D6 is an inductive load inverse electromotive force absorption circuit, reduces the interference to circuit of inductive load switch moment.

Referring to shown in Figure 3, short-circuit protection circuit 3 comprises bidirectional triode thyristor T1, diode D3 and D4, resistance R 3 and R5, light emitting diode L2 and electric capacity E1.Bidirectional triode thyristor T1 and resistance R 5 and light emitting diode L2 are connected on the 24V dc source, the output of bidirectional triode thyristor T1 connect with resistance R 3 and diode D4 back and sampling resistor R2 and be connected in triode Q1 emitter terminal, the positive terminal of electric capacity E1 and sample resistance R2 and+the 24V input mutually and connect, the output of bidirectional triode thyristor T1 is connected with high power valve Q1 base input end with voltage-stabiliser tube Z1 polyphone back by diode D3, during operate as normal, triode Q1 emitter voltage is near supply voltage, diode D4 instead ends partially, the T1 gate voltage approximates 0V, T1 ends, and the L2 light emitting diode goes out.When the output short circuit; the voltage of Q1 emitter stage becomes 0V, the D4 conducting, and E1 begins quick charge; because of the electric capacity both end voltage can not be suddenlyd change; the T1 gate voltage was drawn high about 24V by moment, triggered controllable silicon T1 conducting, and the L2 light emitting diode is bright; the 24V supply voltage is added to the base stage of triode Q1 by controllable silicon T1, diode D3 and voltage-stabiliser tube Z1; because of the clamping action of Z1, Q1 is ended rapidly, thereby play the short-circuit protection effect.

Referring to shown in Figure 4; overvoltage crowbar 4 comprises bidirectional triode thyristor T2, light emitting diode L3, voltage-stabiliser tube Z2, diode D5 and resistance R 4 and R6; bidirectional triode thyristor T2 and resistance R 6 and light emitting diode L3 are connected on the 24V dc source; the output of bidirectional triode thyristor T2 is attempted by the input of sample circuit R2 by voltage-stabiliser tube Z2, and another output of bidirectional triode thyristor T2 is connected with high power valve Q1 base input end by diode D5 and voltage-stabiliser tube Z1 series connection back.During operate as normal, the 24V supply voltage can't puncture Z2, and Z2 is equivalent to open circuit, and the T2 gate voltage approximates 0V, and T2 ends, and the L3 light emitting diode goes out.When supply voltage is elevated to certain value; cause Z2 breakdown; the T2 gate voltage raises; when gate voltage reaches the triggering threshold voltage of T2, the T2 conducting, the L3 light emitting diode is bright; supply voltage is added to the base stage of Q1 by T2, D5 and Z1; because of the Z1 clamping action, Q1 is ended rapidly, thereby play the overvoltage protection effect.

Referring to Fig. 1 and shown in Figure 5, the control signal of PLC signal port 5 is input to the input of ON-OFF control circuit 2, and L1 is bright for the input signal indicator lamp.The signal of input drives large power triode Q1 conducting, and this moment, output indicator L18 was bright.Direct current 24V cathode power supply process large power triode Q1 colelctor electrode is received the terminals of controlled solenoid valve input port 6, and another wiring and the direct current 24V negative pole of controlled solenoid valve input join, and drive loaded work piece.

Above-mentioned only is a control module basic composition and the course of work, and the composition structure and the course of work of other unit are basic identical, and present embodiment is made of the control board of electromagnetic valve of a Programmable Logic Controller 24 control modules.

Claims

1. control panel of electromagnetic valve for programmable controller of die casting machine, comprise dc source, Programmable Logic Controller signal port and controlled solenoid valve input port, it is characterized in that control board of electromagnetic valve is made of sample circuit, ON-OFF control circuit, overvoltage crowbar and short-circuit protection circuit; Sample circuit connects the dc source positive terminal; the sample circuit input connects the overvoltage crowbar input; the sample circuit output connects the input of ON-OFF control circuit and short-circuit protection circuit; the Programmable Logic Controller signal port connects the input of ON-OFF control circuit; the output of short-circuit protection circuit and overvoltage crowbar is connected the input of ON-OFF control circuit, and the output of ON-OFF control circuit connects the controlled solenoid valve input port.

2. control panel of electromagnetic valve for programmable controller of die casting machine according to claim 1 is characterized in that forming a control module by sample circuit (1), ON-OFF control circuit (2), short-circuit protection circuit (3), overvoltage crowbar (4), PLC signal port (5) and controlled solenoid valve input port (6).

3. control panel of electromagnetic valve for programmable controller of die casting machine according to claim 1 and 2, it is characterized in that ON-OFF control circuit (2) comprises large power triode Q1, be connected to voltage-stabiliser tube Z1, resistance R 1 and the light emitting diode L1 of triode Q1 base input end, be connected to resistance R 27, light emitting diode L18 and the diode D6 of triode Q1 collector output.

4. control panel of electromagnetic valve for programmable controller of die casting machine according to claim 1 is characterized in that short-circuit protection circuit (3) comprises bidirectional triode thyristor T1, diode D3 and D4, resistance R 3 and R5, light emitting diode L2 and electric capacity E1; Bidirectional triode thyristor T1 and resistance R 5 and light emitting diode L2 are connected on the 24V dc source, the output of bidirectional triode thyristor T1 connect with resistance R 3 and diode D4 back and sampling resistor R2 and be connected in triode Q1 emitter terminal, the positive terminal of electric capacity E1 and sample resistance R2 and+the 24V input mutually and connect, the output of bidirectional triode thyristor T1 then is connected with high power valve Q1 base input end by diode D3 and voltage-stabiliser tube Z1 polyphone.

5. control panel of electromagnetic valve for programmable controller of die casting machine according to claim 1; it is characterized in that overvoltage crowbar (4) comprises bidirectional triode thyristor T2, light emitting diode L3, voltage-stabiliser tube Z2, diode D5 and resistance R 4 and R6; bidirectional triode thyristor T2 and resistance R 6 and light emitting diode L3 are connected on the 24V dc source; the output of bidirectional triode thyristor T2 is attempted by the input of sample circuit R2 by voltage-stabiliser tube Z2, and another output of bidirectional triode thyristor T2 is connected with high power valve Q1 base input end by diode D5 and voltage-stabiliser tube Z1 series connection back.