CN2113481U

CN2113481U - Pressure detecting meter

Info

Publication number: CN2113481U
Application number: CN 91221801
Authority: CN
Inventors: 李兰香; 冯玉宪; 冯岳政
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-10-01
Filing date: 1991-10-01
Publication date: 1992-08-19

Abstract

The utility model relates to a pressure detecting meter for detecting gases and liquid pressure parameters and performance of vehicle braking elements, pipelines, etc. In order to solve the defects that the original mechanical pressure meter and the original electric pressure recorder can not directly reflect the relationship between multipath pressures and the relationship of pressure change and time, the utility model adopts the microcomputer technology to dynamically detect pressure through the electric lines, such as a pressure sensor, a keyboard, a displayer, a status indication, etc. The pressure detecting meter can directly and simply reflect the relationship of multipath pressure and the relationship of pressure and time. The pressure detecting meter can be suitable for detecting gases and liquid pressure parameters and performance of vehicle braking elements, pipelines and other engineering fields.

Description

Pressure detecting meter

The utility model relates to a kind of pressure detecting instrument that detects gas, fluid pressure parameter and performances such as vehicle braking system element, pipeline.

Car brakeing is that element and pipeline are the guarantees of traffic safety, and its pressure to gas or liquid is changed, distributed and transmits, and finally provides reliable brake power to clamping device.For each braking system element and pipeline, each output pressure is with having specific relation between the input pressure, and this also is the important process performance index of braking member.Moreover, its output pressure and input pressure also are the important performance indexes of braking member over time.Detection means in the past is that one of employing or many mechanical pointer tensimeters detect individually or simultaneously to braking member, relation between it and relation in time often can not directly reflect, more can't measure variation fast force value and time corresponding changing value, this debugging to its manufacturing and maintenance brings inconvenience.Although the electronic pressure register instrument of existing band pressure transducer can substitute the mechanical compression table, it still can't resolve the problems referred to above, and its volume is big, operates loaded down with trivial details.

The utility model call on provide a kind of computer self-timing or (with) level pressure is single, hyperchannel comprehensive pressure index detecting instrument, it has adopted central processing unit, large scale integrated circuit and computer software technologies such as semiconductor memory, realized simple to operation, automatically detect, function such as data accumulating and demonstration, secondly, " when level pressure is surveyed " is set on operation keyboard, " regularly pressure measurement ", button such as " manually " and " automatically " is controlled central processing unit and is measured by the program of setting, calculate, and with tested force value, pressure difference value and detect and show with the variation relation of time.

The utlity model has housing (1) and be installed on the interior feed circuit of housing (1), it also comprises:

The output terminal of a, one or many pressure transducers (2) is connected with the input end of voltage amplifier circuit in being installed on housing (1), the output terminal of one or more voltage amplifier circuit links to each other with each input end of analog switch respectively, the output of analog switch links to each other with the input end of analog signal of modulus converter A/D, and its digital output signal line can link to each other with the data bus dbus of central processor CPU;

The DBUS of b, CPU also should with the corresponding connection of data line end of random access memory ram, read only memory ROM, timer CTC, parallel IO interface PIO, the corresponding connection of address line end of its address bus ABUS and above-mentioned RAM, ROM device or the address line end by code translator and CTC, PIO device or sheet select to hold and are connected;

The I/O line of c, PIO can connect keyboard (6), display circuit, indicating circuit, powered-down circuit respectively.

Keyboard of the present utility model (6) is provided with when surveying " level pressure ", " regularly pressure measurement ", " manually " and buttons such as " automatically ", one end ground connection or connect power supply, the I/O line of another termination PIO by resistance.

Voltage amplifier circuit of the present utility model can adopt the differential amplifier circuit of secondary high input impedance, it is the in-phase input end of the negative output termination first order amplifier AV1 of pressure transducer (2), the output terminal of amplifier AV1 connects the inverting input of second level amplifier AV2 by resistance R 3, the in-phase input end of the positive output termination amplifier AV2 of pressure transducer (2), the two ends of feedback resistance R2 and R4 connect inverting input and the output terminal of AV1 and AV2 respectively, the inverting input of AV1 is through resistance R 1 ground connection, when selecting resistance value R1/R2=R4/R3, this ratio has determined the enlargement factor of this amplifying circuit simultaneously.

Analog switch of the present utility model and A/D can be the integrated circuit (IC)-components of body of uniting two into one, as ADCO808, ADCO809 etc.

CPU of the present utility model, RAM, ROM, PIO, CTC can be the one-chip computer integrated circuit (IC)-components that is integrated, the one-chip computer integrated circuit (IC)-components that can be integrated as MCS8749, MCS8751 etc. or CPU, RAM, PIO, CTC, A/D, as MCS8022 etc., or the one-chip computer integrated circuit (IC)-components of the external EPROM of need, as MCS8039, MCS8031 etc.

The indicating circuit of the utility model indication keyboard (6) duty can be by the I/O line of PIO by latch, code translator, the some light emitting diodes of driver control (8) or (with) hummer (9).

Display circuit of the present utility model can be light emitting diode indicator LED or the LCD LCD(10 that is passed through latch, code translator, driver control by the I/O line of PIO).

Powered-down circuit of the present utility model can be the high-power switch device of being controlled by code translator, latch by the I/O line of PIO that is serially connected with the power supply input circuit.

Data latches of the present utility model, code translator, driver can be the integrated circuit (IC)-components that is integrated, as CD4056, CD4054 etc.

Advantage of the present utility model is that its measurement, recognition are convenient, can reflect between the multichannel pressure and and the time between variation relation, can adapt to car brakeing is gas, the pressure and other parameters of liquid, performance detection such as element, pipeline.

Fig. 1 is an electric theory diagram of the present utility model;

Fig. 2 is the embodiment electrical schematic diagram that the utility model adopts the one-chip computer chip;

Fig. 3 is " subroutine when level pressure is surveyed " process flow diagram;

Fig. 4 is " regularly pressure measurement subroutine " process flow diagram;

Fig. 5 is the utility model structural representation, and this figure is as Figure of abstract.

Further specify below in conjunction with accompanying drawing:

Heart of the present utility model shown in Figure 1 is a central processor CPU, and the data line end of the read only memory ROM of its data line end and parallel input/output interface PIO, stored routine, data buffering random access memory ram, outside watchdog timer CTC, analog/digital signal conversion device A/D is connected to form BDB Bi-directional Data Bus DBUS.The address wire of CPU links to each other with the address wire of storer ROM and RAM and constitutes address bus ABUS, the code translator in addition that links to each other with address bus ABUS, and each chip beyond the CPU is controlled in its output respectively, as address line end or the sheet choosing end of PIO, CTC.The I/O line cap of PIO can connect keyboard (6), also can be to demonstration, indicating circuit data feed or control signal.

The voltage signal of pressure transducer (2) amplifies through voltage amplifier circuit earlier, again after analog switch gating one road voltage signal is delivered to A/D converter and quantized, is adopted to the RAM in order to handling by DBUS by CPU.CPU handles the data in the RAM in ROM and under the control of program curing, and result is delivered to display circuit by the I/O line of PIO shows.

CPU by CTC regularly and in conjunction with software program may command analog switch at the moment gating road signal that requires, carry out subsequent treatment, last video data is to realize the needs of " when level pressure is surveyed " and " timing pressure measurement ".

Digital indicator can use light emitting diode or LCD, be LED or LCD(10), its data terminal joins by the data bus dbus of data latches, code translator, driver and CPU or the I/O line cap of PIO, and the control end of data latches can join by the I/O line end of code translator and PIO.

The duty of keyboard (6) can indicate by the I/O line traffic control indicating circuit of PIO.Indicating circuit can adopt LED (8) to link to each other with PIO or CPU by driver, code translator, latch etc., can also adopt driving hummer (10) to indicate in addition.

The one-chip computer that the utility model shown in Figure 2 selects for use CPU, PIO, CTC, ROM and RAM to be integrated is finished functions such as computing, I/O interface, timing and storage, can select the one-chip computer of 8 positive 5 volts of power supplys of 8749H type of MCS48 series, this one-chip computer has 40 pins, the erasable read-only memory EPROM of 128 byte RAM and 2K byte.Have 1 timer, have 8 two-way I/O lines, also have the I/O line of 3 difference in functionalitys, as interrupt line INT, p-wire T0, T1 except that PIO interface has 16, DBUS.One-chip computer can be up to the frequency of operation work of 11MHZ on the one hand, and it does not have external address bus on the other hand, and data access and exchange are all carried out in inside, so its arithmetic speed can satisfy the needs that the utility model is measured in real time.Its I/O line can distribute use like this in the utility model: its 8 DBUS lines separately with select 8 data lines of the modulus converter A/D (ADC0809) of 1 analog switch to link to each other with 4, path as the cpu data input, 4 I/O lines of interface can be as the data line of demonstration or indicating circuit, keyboard (6) takies 6 I/O lines, analog switch can be distinguished gating 4 tunnel simulating signals with 2 I/O lines, and 4 I/O lines can be controlled the data latching end of the latch of display circuit, indicating circuit, powered-down circuit by 4-10 code translator (CD4028) respectively.

Input circuit of the present utility model is: the electric signal of one or more pressure transducer (2) amplifies the input end of delivering to multiway analog switch (ADC0809) again through one or more voltage amplifier circuit, analog switch is under the control of one-chip computer interface I/O line, a road required signal of gating enters A/D converter A/D(ADC0809), and under the control of other I/O line and interrupt line INT, finish mould/number conversion, data are appeared on the DBUS, select a good opportunity for CPU and select for use.CPU delivers to display circuit to operation result through the I/O of interface line and shows.

Wherein voltage amplifier circuit can adopt the differential amplifier circuit of secondary high input impedance, it is the in-phase input end of the negative output termination first order amplifier AV1 of pressure transducer (2), the output terminal of amplifier AV1 connects the inverting input of second level amplifier AV2 by resistance R 3, the in-phase input end of the positive output termination amplifier AV2 of pressure transducer (2), the two ends of feedback resistance R2 and R4 connect inverting input and the output terminal of AV1 and AV2 respectively, the inverting input of AV1 is through resistance R 1 ground connection, when selecting resistance value R1/R2=R4/R3, this ratio has determined the voltage amplification factor of this amplifying circuit simultaneously, and amplifier can be selected the LM358 dual operational amplifier for use;

The display of display circuit can be selected 3 half digital lcd (10), each is controlled its 38 font numerals by a slice CD4056, symbols such as its radix point are controlled by 2 CD4054, CD4054 and CD4056 are like this work: after data content to display appears at its data input pin by 4 I/O lines as the PIO of data line, other I/O line of PIO through 4-10 code translator (CD4028) conversion gating one road signal make certain-end that latchs of CD4054 or CD4056 is negative pulse and opens inner code translator or passage, and export pulse signal to display (10) through inner drive.The frequency of operation of display (10) is 32HZ, and the oscillator that is made of 3 not gates (CD4011) is produced; Selection to each path, working method, operational form, can indicate with some LEDs (8), at first will need luminous LED(8) coding appear on 4 I/O lines as the PIO of data line, and latch by 4-10 code translator control lock storage (CD4076) by other I/O line, with latched data again by another 4-10 code translator select one the tunnel and make LED(10 by driver (CD4009)) luminous;

Powered-down circuit of the present utility model can be to control the high-power switching circuit (TH8778) that is serially connected with the power supply input circuit by the I/O line of PIO by the 4-10 code translator with as the d type flip flop (CD4013) of latch, when the pulse of sending as PIO made the d type flip flop output switching activity, high-power switching circuit was by making the entire circuit outage.

Keyboard of the present utility model (6) is provided with " when level pressure is surveyed ", " regularly pressure measurement ", " manually " and " automatically " button etc., one end ground connection, the I/O line of another termination PIO, " keyboard scan and the identification key subroutine " of program can be on time read in CPU with the state of keyboard (6), and carry out software cancel key shake and judge identification whether have key press, be which key by inferior, and under the guiding of master routine, enter in the corresponding subroutine.

After pressing " when level pressure is surveyed " key, program enters " subroutine when level pressure is surveyed " (Fig. 3), at first deposit target pressure value in RAM by keyboard (6), then by " manually " key, program enters calendar subroutine, CPU carries out pressure detection when CTC works, and compare with desired value among the RAM, when institute's measured value conforms to desired value, CTC stops counting, and startup hummer (9) sounding informs that display shows that pressure reaches the instantaneous pressure value of required time of desired value and other passage and the pressure difference value between special modality simultaneously.Can't follow the tracks of survey soon during the time when being changed by measuring pressure, can be after inserting target pressure value, by " automatically " key, program at first enters " judging pressure valve unlatching subroutine ".Be the cycle detection force value, and mutually relatively, after fiducial value is greater than preset threshold, enter " calendar subroutine ".

After pressing " regularly pressure measurement " key, program enters " regularly pressure measurement subroutine " (Fig. 4), at first insert time value by keyboard (6), then by " manually " key, program enters " subroutine when subtracting ", CPU carries out dynamic pressure measurement and the dynamic pressure value can be shown on the display when the work of CTC counting, after the CTC gate time arrives, and each passage instantaneous pressure value that display can arrive the demonstration time and the pressure difference value between special modality.As fixing time weak point, can be by " automatically " key, program enters " judge pressure valve open subroutine ", and then enters " subroutine when subtracting ".

Feed circuit of the present utility model can be battery (5) power supplies, also can be the direct supplys through voltage stabilizing.

Circuit part of the present utility model (4) can place in the housing (1), and pressure transducer (2) links to each other with circuit part (4) in the housing (1) through socket (3), and keyboard (6) is installed on the panel (7) of housing (1).

The utility model simultaneously can also timing, has the clocking capability of electronic watch.

The utility model also can be used for parameter, performance detection such as the gas, fluid pressure in other engineering field.

Claims

1, a kind of pressure detecting instrument that detects vehicle braking system element pressure parameter and performance has housing (1) and is installed on the interior feed circuit of housing (1), it is characterized in that it:

The input end of the voltage amplifier circuit of installing in the output terminal of a, or many pressure transducers (2) and the housing (1) is connected, the output terminal of one or more voltage amplifier circuit links to each other with each input end of analog switch respectively, the output of analog switch links to each other with the input end of analog signal of modulus converter A/D, and its digital output signal line can link to each other with the data bus dbus of central processor CPU;

2, pressure detecting instrument according to claim 1 is characterized in that keyboard (6) is provided with when surveying " level pressure ", " regularly pressure measurement ", " manually " and " automatically " button, one end ground connection or connect power supply, the I/O line of another termination PIO by resistance.

3, pressure detecting instrument according to claim 1, it is characterized in that voltage amplifier circuit can adopt the differential amplifier circuit of secondary high input impedance, it is the in-phase input end of the negative output termination first order amplifier AV1 of pressure transducer (2), the output terminal of amplifier AV1 connects the inverting input of second level amplifier AV2 by resistance R 3, the in-phase input end of the positive output termination amplifier AV2 of pressure transducer (2), the two ends of feedback resistance R2 and R4 connect inverting input and the output terminal of AV1 and AV2 respectively, and the inverting input of AV1 is through resistance R 1 ground connection.

4, pressure detecting instrument according to claim 1 is characterized in that analog switch and A/D can be the integrated circuit (IC)-components that is integrated, as ADCO808, ADCO809.

5, pressure detecting instrument according to claim 1, it is characterized in that CPU, RAM, ROM, PIO, CTC can be the one-chip computer integrated circuit (IC)-components that is integrated, as MCS8749, MCS8751, or CPU, RAM, PIO, CTC, the A/D one-chip computer integrated circuit (IC)-components that can be integrated, as MCS8022, or the one-chip computer integrated circuit (IC)-components of the external EPROM of need, as MCS8039, MCS8031.

6, pressure detecting instrument according to claim 1, the indicating circuit that it is characterized in that indicating keyboard (6) duty can be by the I/O line of PIO by latch, code translator, driver control some light emitting diodes (8) or (with) hummer (9).

7, pressure detecting instrument according to claim 1 is characterized in that its display circuit can be light emitting diode indicator LED or the LCD LCD(10 that is passed through latch, code translator, driver control by the I/O line of PIO).

8, pressure detecting instrument according to claim 1 is characterized in that its powered-down circuit can be by the I/O of the PIO high-power switch device that is serially connected with the power supply input circuit by code translator, latch control.

9,, it is characterized in that data latches, code translator, driver can be the integrated circuit (IC)-components that is integrated, as CD4056, CD4054 according to claim 1 or 6 or 7 described pressure detecting instruments.