CN203238304U

CN203238304U - Novel track frame resistance furnace control system

Info

Publication number: CN203238304U
Application number: CN 201320076598
Authority: CN
Inventors: 罗伟; 黄�俊
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-02-01
Filing date: 2013-02-01
Publication date: 2013-10-16
Anticipated expiration: 2023-02-01

Abstract

The utility model discloses a novel track frame resistance furnace control system. The novel track frame resistance furnace control system adopts an STC89C58RD+ singlechip as a core, and consists of two paths of temperature acquisition circuit, a temperature setting circuit, a real-time clock circuit, a voltage/current conversion circuit, a digital to analog (D/A) conversion circuit, a liquid crystal display (LCD) circuit, a driving isolating circuit and a recommended standard (RS) 232 interface circuit. Two paths of temperature sensor are used for measuring the internal temperature of a resistance furnace and the external environment temperature respectively. The internal temperature of the resistance furnace is measured through a thermocouple and a specified digital converter MAX6675; the environment temperature is acquired through a DS18B20 single-line integrated temperature sensor without an A/D conversion circuit. An analog quantity is output by using an 8-bit serial input D/A converter MAX517 to send a control signal into an electric actuator. Additionally, the openness of an air inlet valve and the openness of an air outlet valve are controlled through photoelectric drive. The system is also provided with 16 thin film switches which are used for setting a target temperature curve, a 2*16-character liquid crystal display which is used for displaying the working state of the system, and a buzzer which is used for realizing an abnormity warning function.

Description

Novel steering framework frame resistance furnace Controlling System

Technical field

The utility model relate to a kind of easy to operate, control accuracy is high, long-lived novel railway rolling stock bogie framework resistance furnace Controlling System.

Background technology

Along with improving constantly of China railways passenger and freight train running speed and transportcapacity, more and more higher to the performance requriements of bogie.Bogie frame (hereinafter to be referred as framework) is the important load bearing component of bogie, is the installation basis of other each component of bogie, and framework is the full electrically-welded structure that is welded by curb girder, crossbeam, sleeper beam and end carriage.Its complex structure, rigidity is large, be in operation and bear serious vibration and impact, thereby welding technique is had relatively high expectations.And one of main source of welding deficiency is stress and the distortion that welding process produces, heat treating process is a kind of traditional technology of eliminating welding residual stress, annealing is that the welding interior stress that internal structure after the framework welding produces is carried out anneal by heating, insulation, cooling, eliminate or the minimizing welding residual stress, the test of static strength load that makes rolling stock bogie framework fatigue strength meet the UIC515-4 of International Union of Railways or TB/T2368 regulation is implemented requirement.On whole bogie production line, the framework resistance furnace is eliminated or the minimizing welding stress for guaranteeing the intensity of bogie frame, prevents that welding distortion from playing an important role.At present, the most of locomotives of China, vehicle manufacturing concern adopt the traditional technology heat treating process to eliminate welding residual stress, generally framework are taked integrally annealed technique.

Early stage framework resistance furnace automatic control system is comparatively simple, to use some unit aggregated instruments to form position formula control device mostly, because exist in the framework course of processing non-linear and the time stickiness, this simple control mode is difficult to reach the control accuracy of expection, even causes error.

Summary of the invention

Traditional control method (comprising classical control and modern control) when being applied to the controlled plant of non-linear or out of true characteristic, is difficult to obtain promising result.And the whole ag(e)ing resistance stove of framework course of processing temperature controlling system is non-linear, Large-lag System, and larger pure hysteresis can cause that system is unstable.The utility model Controlling System is take the temperature difference and rate of temperature change as input, take the state of each valve and heating power as work output.

Referring to accompanying drawing 1, the control requirement according to system has designed corresponding hardware circuit, and the hardware design of system takes into full account the practical situation of technical requirements and factory, has adopted upper and lower machine structure, and upper computer adopts industrial control computer; The lower computer system hardware circuit mainly is made of STC89C58RD+ micro-chip and peripheral components, can be divided into five parts such as power source circuit, pilot circuit, temperature measuring circuit, holding circuit, operator-machine-interface circuit by functional structure.

Then micro-chip collecting temperature signal sends to upper computer by serial ports, and PC receives data, through after certain control algolithm, the manipulated variable signal is issued lower computer, after micro-chip receives data, control working order and the heating power of each valve by output circuit.Industrial control computer has preferably man-machine interface, is convenient to algorithm and revises, and after algorithm was determined, only need to revise a little program just portable had shortened the development time in micro-chip.

Referring to accompanying drawing 2, novel steering framework frame resistance furnace Controlling System two-way the temperature sensor respectively interior temperature of measuring resistance stove and ambient temperature.Temperature in the resistance furnace records by thermopair and its special-purpose quanxtizer MAX6675, and MAX6675 is the digital conversion chip of the thermocouple amplifier of integrated thermocouple amplifier, cold junction compensation, A/D converter and a SPI serial ports.Temperature collection adopts DS18B20 single line integrated temperature sensor, do not need the A/D change-over circuit, include temperature sensor, thermometric speed is fast, and precision is high, and interchangeability is good, link to each other with 1 I/O line of micro-chip, saved greatly the I/O mouth line of micro-chip, and communication is convenient, long transmission distance and freedom from jamming are good.Because the design of forward path has been simplified in the application of MAX6675 and DS1820 greatly, so that this system has a circuit structure is simple, debug easily characteristics.

Referring to accompanying drawing 3, the output of analog quantity uses a slice 8 bit serial input D/A converter MAX517 that control signal is sent into YE.MAX517 finishes 2 road D/A conversion, and the voltage signal after the D/A conversion is transformed to current signal through V/I, can realize long-distance transmissions, is used for control heating power size.In addition, drive the aperture of control blast inlet valve and exhaust outlet valve by photoelectricity.

Referring to accompanying drawing 4, system has also designed 16 thin film switches, is used for liquid crystal to the arranging of target temperature curve, a slice 2*16 character to be used for the working order of indicating system, and hummer is with the function that realizes abnormal alarm.

Description of drawings

Fig. 1 is novel steering framework frame resistance furnace Controlling System structural principle block diagram

Fig. 2 is novel steering framework frame resistance furnace Controlling System hardware circuit principle figure

Fig. 3 is RS232 interface circuit, temperature measuring circuit, D/A change-over circuit, V/I translation circuit schematic diagram

Fig. 4 is clock circuit and keyboard interface and display circuit schematic diagram

Embodiment

1, pilot circuit: pilot circuit is made of principal controller and system clock, and principal controller is adopted the STC89C58RD+ micro-chip, inner integrated MAX810 Special reset circuit and watchdog circuit.Because the resistance furnace heat-processed cycle is longer, thus do not adopt the micro-chip timer internal as system clock, but adopt special-purpose clock chip DS12887.

2, forward path configuration and interface:

(1) thermopair interface MAX6675 namely is integrated thermocouple amplifier and a quanxtizer of thermocouple amplifier, cold junction compensation, A/D converter and SPI serial ports.Need not external any peripheral components during its work, for reducing the Electric source coupling noise, before its power pins and ground terminal, accessed the electric capacity that capacity is 0.1 μ F here.Because STC89C58RD+ do not possess the spi bus interface, therefore adopt the method for SPI-bus analogue to realize interface with MAX6675 here.Wherein P1.0 simulates the data input pin (MISO) of SPI, the serial clock output terminal SCK of P1.1 simulation SPI, the slave selecting side SSB of P1.2 simulation SPI.

(2) temperature survey DS18B20 digital temperature sensor.Employing is in board-like measuring technology, and with whole sensing members, change-over circuit is integrated on the chip piece with the interface circuit of controller, output be numerary signal, thereby the peripheral components that needs is few, circuit layout is simple, cost is low, good reliability.。

3, backward channel configuration and interface

(1) D/A change-over circuit: MAX518 serial D/A transmodulator.The output of MAX518 digital to analog converter aanalogvoltage is through the follower (playing the internally buffered effect) of a precision, and the Slew Rate of follower is 1V/us, and namely output voltage range can be from 0V-VDD; And have two-way D/A output, just in time satisfy native system control requirement.

(2) voltage amplifier circuit: system adopts the AD694 chip to do the V/I conversion, and the input voltage that this chip needs is 0-10V, therefore before the V/I conversion, first the voltage signal of 0-5V is enlarged into the voltage signal of 0-10V.Another benefit that voltage signal is amplified is the stepping spacing that can improve between each manipulated variable of output, thereby improves output accuracy.

(3) V/I translation circuit: in industrial control system, usually with the current mode transmission signal, because electric current is suitable for long Distance Transmission, the transmission signal decay is few, and immunity from interference is strong.And general scm application system analog signal output is voltage signal, and it is treatable generally also to be voltage signal, therefore in some occasion that needs electric current output or only provide current signal, need to carry out the voltage/current conversion.The AD694 chip that adopts AD company to produce is realized the V/I conversion, and it can convert voltage signal to the current signal of 4-20mA.

(4) switching value output driving circuit: adopt photoelectrical coupler and bidirectional thyristor as the driving of each switch-valve in the native system.MOC3041 is the zero cross fired type photoelectric coupled device of commonly using.The withstand voltage 400V of output optical controlled bidirectional thyrister of this device, rated current 100mA, 360 Ω resistance play the input metering function, the break-make of 3041 output control bidirectional thyristor KS.

4, man-machine channel arrangement and interface

(1) keyboard interface: keyboard portion is provided with numerical key and function key.Native system adopts 4 * 4 membrane keyboard, the line of its each function button, and prefabricated finishing in the lump when making " switch " all, circuit can avoid welding the mistake of generation.Adopted keyboard Special Interface Chip HD7279.HD7279A is the special intelligent control chip of a kind of supervisory keyboard and light-emitting diode display, it can manage and drive 8 common cathode light-emitting diode displays or 64 LED luminotrons, simultaneously the button situation of 8 * 8 keyboard matrix is nearly monitored, have the function of automatic cancel key shake and key range code, thereby can improve the efficient of CPU work.

(2) display interface: in the native system, consider that the information of demonstration is more, therefore select liquid-crystal display SMC1602.This liquid-crystal display and interface microcontroller are simple, can show two row, and 16 characters of every row can satisfy the requirement of native system.

(3) serial communication interface: because PC output is the RS-232C level of standard, and micro-chip output is Transistor-Transistor Logic level, therefore must adopt the MAX232 chip that Transistor-Transistor Logic level and RS-232C level are changed.MAX232 is line driver/receptor, uses single 5V Power supply, connects 41 μ F chemical capacitors, can finish the conversion between RS-232C level and the Transistor-Transistor Logic level.

Claims

1. novel bogie frame resistance furnace Controlling System, it is characterized in that take the STC89C58RD+ micro-chip as core, by the two-way temperature collection circuit, temperature setting circuit, real time clock circuit, the voltage/current translation circuit, the D/A change-over circuit, the LCD display circuit, driving isolation circuit and RS232 interface circuit form, system two-way the temperature sensor respectively interior temperature of measuring resistance stove and ambient temperature, temperature in the resistance furnace records by thermopair and its special-purpose quanxtizer MAX6675, temperature collection adopts DS18B20 single line integrated temperature sensor, do not need the A/D change-over circuit, the output of analog quantity uses a slice 8 bit serial input D/A converter MAX517 that control signal is sent into YE, MAX517 finishes 2 road D/A conversion, voltage signal after the D/A conversion is transformed to current signal through V/I, can realize long-distance transmissions, be used for control heating power size, in addition, drive the aperture of control blast inlet valve and exhaust outlet valve by photoelectricity, system has also designed 16 thin film switches, be used for arranging the target temperature curve, the liquid crystal of a slice 2*16 character is used for the working order of indicating system, and hummer is with the function that realizes abnormal alarm.