CN202433146U

CN202433146U - Digital cylinder pressure detector based on singlechip

Info

Publication number: CN202433146U
Application number: CN2011204936262U
Authority: CN
Inventors: 张文广; 杜春臣; 王坤
Original assignee: Changan University
Current assignee: Changan University
Priority date: 2011-12-01
Filing date: 2011-12-01
Publication date: 2012-09-12
Anticipated expiration: 2021-12-01

Abstract

The utility model discloses a digital cylinder pressure detector based on a singlechip. A circuit part comprises a pressure sensor, a signal conditioning circuit, an A/D conversion circuit, a singlechip, a display module, a communication module and a host computer; the pressure sensor and the signal conditioning circuit are connected; the signal conditioning circuit is connected with the singlechip through an A/D conversion circuit; the display module and the communication module are arranged on the singlechip; and wireless communication is carried out between the communication interface and the host computer. The digital cylinder pressure detector based on a singlechip realizes the functions for real-time acquisition, analysis, processing and displaying of the cylinder pressure of a combustion motor, and uses the common chip, thus being low in price and stable in performance, and effectively solving the problem of accurate measurement of the cylinder pressure.

Description

A kind of SCM Based digital cylinder pressure detector

Technical field

The utility model relates to a kind of detector, particularly a kind of SCM Based digital cylinder pressure detector.

Background technology

Internal combustion engine is the heart of various diesel locomotives, is the motive power of drive wheels motion.Cylinder of internal-combustion engine is the source of realizing working cycle, producing power.Piston is to-and-fro movement in cylinder, forms volume and does the seal cavity that rule changes, and fuel is in this space internal combustion, and the gas power of generation promotes piston motion.It is thus clear that; Cylinder pressure is the important parameter that internal combustion engine runs well, through the test of cylinder pressure, and some most common failures of the internal combustion engine that can accurately form a prompt judgement out; Therefore, measure the method that cylinder pressure is the disgnosizing internal combustion engine fault of a kind of not only simple but also science.

Traditional common pointer pressure precision is low, spoilage is high; And Cylinder Pressure of Internal Combustion Engine changes rapidly especially; On graduation apparatus, show as pointer and acutely swing, the operation maintainer can't accurately judge force value, can only be according to amplitude of fluctuation and working experience estimated pressure scope of living in; Therefore produce so inevitably than mistake, design that a kind of accuracy of detection is high, cylinder pressure detector easy to use is very necessary.

Summary of the invention

To defective or deficiency that above-mentioned prior art exists, the purpose of the utility model is, a kind of SCM Based digital cylinder pressure detector is provided, and this detector has accuracy of detection height, easy to use, characteristics that versatility is good.

In order to realize above-mentioned task, the utility model adopts following technical solution to be achieved:

A kind of SCM Based digital cylinder pressure detector; It is characterized in that circuit part includes pressure transducer, signal conditioning circuit, A/D change-over circuit, single-chip microcomputer, display module, communication module and host computer; Pressure transducer is connected with signal conditioning circuit; Signal conditioning circuit links to each other with single-chip microcomputer through the A/D change-over circuit, on single-chip microcomputer, also is connected with display module and communication module, and communication interface and host computer carry out wireless telecommunications.

Other characteristics of the utility model are:

Described single-chip microcomputer adopts the AT89C52 single-chip microcomputer.

Described pressure transducer adopts the AK-3d pressure unit,

Described display module adopts the keyboard control chip ZLG7289A with SPI serial line interface function.

Described communication interface adopts the RS232 interface.

Also connect supervisory circuit on the described single-chip microcomputer, supervisory circuit adopts the X25045 chip.

The SCM Based digital cylinder pressure detector of the utility model; Realized the function such as real-time collection, analysis, processing, demonstration of Cylinder Pressure of Internal Combustion Engine; Because of adopting conventional chip, have low, the steady performance of price, efficiently solve the accurate problems of measurement of cylinder pressure.

Description of drawings

Fig. 1 is the SCM Based digital cylinder pressure detector hardware block diagram of the utility model;

Fig. 2 is the dimensional drawing of AK-3d pressure unit.

Fig. 3 is an AK-3d pressure unit picture in kind.

Fig. 4 is the hardware connection layout of A/D change-over circuit TLC0838 and single-chip microcomputer.

Fig. 5 is supervisory circuit X25045 and single-chip microcomputer hardware connection layout.

Fig. 6 is the hardware connection layout of communication interface.

Below in conjunction with accompanying drawing and embodiment the utility model is done further explain.

Embodiment

With reference to Fig. 1; Present embodiment provides a kind of circuit hardware structure of SCM Based digital cylinder pressure detector, includes pressure transducer, signal conditioning circuit, A/D change-over circuit, single-chip microcomputer, display module, communication module and host computer; Pressure transducer is connected with signal conditioning circuit; Signal conditioning circuit links to each other with single-chip microcomputer through the A/D change-over circuit, on single-chip microcomputer, also is connected with display module and communication interface, and communication interface and host computer carry out wireless telecommunications.

The pressure signal of pressure transducer collection at first is transformed into electric signal, and signal conditioning circuit is done amplification, filtering, isolation and protection processing to signal then.Signal after the processing is delivered to analysis and processing that single-chip microcomputer carries out signal after the A/D conversion, under the control of keyboard, single-chip microcomputer shows gaging pressure through I/O mouth output signal at the LED display circuit, and communication module and host computer carry out wireless telecommunications.

In the actual detection process, for preventing program fleet, also adopted supervisory circuit on the single-chip microcomputer, supervisory circuit adopts the X25045 chip of U.S. Xicor company.

Simultaneously, upper PC is arranged between tool car, is used for showing the parameter value of cylinder pressure information and other each several parts of internal combustion engine, comprehensively judge the internal combustion engine failure cause.

The single-chip microcomputer of present embodiment adopts the AT89C52 single-chip microcomputer of atmel corp, and volume is little, price is low, precision is high.

Pressure transducer adopts AK-3d pressure unit (referring to Fig. 2 and Fig. 3), its measurement range selection 0～10MPa, the corresponding 0～5V of output voltage.

The A/D change-over circuit adopts the TLC0838A/D converter.

Fig. 4 is an A/D change-over circuit inner structure; Consider that the pressure in the cylinder is uneven, two place's pressure signals in the cylinder are gathered, gather the inner pressure of air cylinder signal by the AK-3d pressure unit; By CH0 and CH1 input; Select suitable I/V conversion regime, make conversion output voltage range later can satisfy the input range of TLC0838, convert digital signal input single-chip microcomputer then into and carry out analyzing and processing.

With reference to Fig. 5, in the microcontroller that single-chip microcomputer constitutes, because the working site situation is complicated, regular meeting receives various electromagnetic interference (EMI), causes the race of program to fly, and makes program get into endless loop, can cause The whole calculations machine system cisco unity malfunction.For this reason; The X25045 chip (house dog) that has added the monitoring facilities operation; Reset circuit of SCM and X25045 reset circuit are integrated and are linked together;

SO, SCK, SI end link to each other with 4 I/O mouths of microprocessor respectively, make that the circuit reaction velocity is fast, antijamming capability is strong.

Display circuit is selected the keyboard control chip ZLG7289A with SPI serial line interface function for use, and ZLG7289A can drive 8 common cathode charactrons simultaneously, can connect the nearly keyboard matrix of 64 keys simultaneously, and monolithic can be accomplished the repertoire of LED demonstration, keyboard interface.

Fig. 6 is the communication module circuit, and a upper PC is arranged between the tool car of diesel locomotive, is used for showing the parameter value of cylinder pressure information and other each several parts of internal combustion engine, thereby comprehensively judges the internal combustion engine failure cause.Because this device is to do on-the-spot the detection; Transmission range is short, adopt the RS232 interface to carry out serial transmission and be sufficient for sb.'s need, and hardware circuit is simple; Strong interference immunity also can be directly and the PC interface; Need not add protocol conversion circuitry, communicate by letter with PC, need between the interface of single-chip microcomputer PC, increase the level shifting circuit that constitutes with MAX232 for making the monolithic function.

In sum, the SCM Based digital cylinder pressure detector of the utility model is a core with the AT89C52 single-chip microcomputer, and numeral shows that inner pressure of air cylinder changes, and is easy to use, precision is high, has solved the accurate problems of measurement of cylinder pressure effectively.

Claims

1. SCM Based digital cylinder pressure detector; It is characterized in that circuit part includes pressure transducer, signal conditioning circuit, A/D change-over circuit, single-chip microcomputer, display module, communication module and host computer; Pressure transducer is connected with signal conditioning circuit; Signal conditioning circuit links to each other with single-chip microcomputer through the A/D change-over circuit, on single-chip microcomputer, also is connected with display module and communication interface, and communication interface and host computer carry out wireless telecommunications.

2. SCM Based digital cylinder pressure detector as claimed in claim 1 is characterized in that, described single-chip microcomputer adopts the AT89C52 single-chip microcomputer.

3. SCM Based digital cylinder pressure detector as claimed in claim 1 is characterized in that, described pressure transducer adopts the AK-3d pressure unit.

4. SCM Based digital cylinder pressure detector as claimed in claim 1 is characterized in that, described change-over circuit adopts the TLC0838A/D converter.

5. SCM Based digital cylinder pressure detector as claimed in claim 1 is characterized in that, described display module adopts the keyboard control chip ZLG7289A with SPI serial line interface function.

6. SCM Based digital cylinder pressure detector as claimed in claim 1 is characterized in that, described communication interface adopts the RS232 interface.

7. SCM Based digital cylinder pressure detector as claimed in claim 1 is characterized in that, also connects supervisory circuit on the described single-chip microcomputer.

8. SCM Based digital cylinder pressure detector as claimed in claim 7 is characterized in that, described supervisory circuit adopts the X25045 chip.