JPH039088Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a physical quantity detection device that continuously detects the states of various physical quantities and sequentially holds the values of the physical quantities when the change in the physical quantity is within a predetermined range.

Conventional physical quantity measuring devices or detection devices indicate the physical quantity at the current moment or continuously record the physical quantity that changes sequentially, and check whether the physical quantity is within a predetermined range. There is no other way than to manually judge based on the instruction status or recording status, and if an abnormality occurs in the equipment, equipment, parts, etc. targeted for physical quantity detection, the occurrence of the abnormality can be detected in advance and automatically from changes in the physical quantity. This results in defects that cannot be detected.

The purpose of this invention is to eliminate such drawbacks of the conventional methods at once, and includes a signal generating means SS, SEL, ADC that sequentially converts physical quantities that change sequentially into electrical signals at a predetermined timing and outputs the electrical signals. Switching circuit SW that switches the electrical signal between the first output and the second output
a holding circuit MM that inputs an electrical signal output from the signal generating means to update and store the already stored contents when the switching circuit is switched to the first output; and a switching circuit. is switched to the second output, inputs the electrical signal output from the signal generating means, compares this current input electrical signal with the electrical signal held in the holding circuit, and calculates the current input electrical signal. Comparators CP1 and CP2 output an in-range signal when the difference between the signal and the electrical signal held in the holding circuit is within a predetermined range, and a second output is always output when the comparator outputs an in-range signal. It consists of a switching control means LAT2 that switches the switched switching circuit to the first output, and the device, equipment,
The present invention provides an extremely effective physical state detection device that detects a physical quantity immediately before a component or the like becomes abnormal.

Hereinafter, details of the present invention will be explained with reference to block diagrams showing embodiments.

In the figure, sensors SS such as microphones and strain gauges that convert physical quantities into electrical signals are shown.
The output of is given to a plurality of band wavers BPF ₁ to BPF _o , each having a different passing frequency band, and divided into components for each frequency band, and a selector that operates according to the timing pulse Pt from the pulse generator PG.
SEL sequentially and iteratively selects and converts the selected output to an analog-to-digital converter (hereinafter referred to as
ADC) After converting into a digital signal by A/D, it is applied to comparison inputs A of comparators CP ₁ to _{CP 3} via a switching circuit SW.

On the other hand, initial values are stored in each address of the memory MM as a holding circuit in correspondence with the bandpass filters BPF ₁ to BPF _o , and these are the timing pulses.
The latch circuit LAT is sequentially read out by the addressing signal Sa sent out from the pulse generator PG in synchronization with Pt, and is output by the latch circuit LAT according to the latch pulse Pl ₁ which is extracted by differentiating the leading edge of the timing pulse Pt by the differentiating circuit DF ₁ . ₁ , and the content of this is added by the bias circuit BAS ₁ for determining the upper limit value of a predetermined range, and a bias +a in the upper limit direction is added, and the bias circuit BAS 1 for determining the lower limit value of the predetermined range is added. A bias -a in the lower limit direction is added by the circuit BAS ₂ , and is applied to the reference input B of the comparators CP ₁ and CP ₂ .

For this reason, the ADC that converted the current physical quantity
The output of the A/D and the initial value to which biases +a and -a are added are compared by each comparator CP ₁ and CP ₂ , and in the comparator CP ₁ , under the condition of reference input B>comparison input A In the case of BA, the comparison output becomes, for example, "L" (low level), and in the case of BA, the comparison output becomes, for example, "H" (high level).In the comparator CP ₂ , under the condition of reference input B<comparison input A, the comparison output becomes "L" (low level). Since the comparison output is set to be, for example, "H" when is "L" and BA is "L", if the output of ADC/A/D is within a predetermined range with respect to the initial value, each comparison output will be The signal becomes "L", is inverted by NOR gate _G1 , becomes "H", and is sent to inhibit gate _G2 .

Also, in comparator CP ₃ , to comparison input A
The output of ADC/A/D is given, and each reference input C
and B includes a reference value circuit E ₁ that generates a signal corresponding to the absolute upper limit value of the physical quantity, and a reference value circuit E 1 that generates a signal corresponding to the absolute lower limit value of the physical quantity.
E ₂ is given, and reference input B < comparison input A
<Under the condition of reference input C, the comparison output is set to be, for example, “L”, and under the conditions of BA or CA, the comparison output is set to be, for example, “H”, so the output of ADC/A/D is an absolute value. If it is within the upper and lower _limits of
The output of _G1 is sent to the latch circuit _LAT2 via the inhibit gate _G2 .

The latch circuit LAT ₂ holds the output of the inhibit gate G ₂ according to the latch pulse Pl ₂ obtained by differentiating the trailing edge of the timing pulse Pt by the differentiating circuit DF ₂ , and in this example, the holding content is “H”. In order to drive the switching circuit SW at this time, the output of the ADC/A/D corresponding to the current physical quantity is given to the memory MM, and the contents are updated and stored at the address specified by the address designation signal Sa.

For this reason, in synchronization with the operation of selector SEL, it corresponds to the current physical quantity divided for each frequency band.
The outputs of the ADC/A/D are sequentially and repeatedly stored in the addresses corresponding to the bandpass filters BPF ₁ to BPF _o of the memory MM, and the stored values are given to the latch circuit LAT ₁ as the next reference value. This is the value obtained by converting the previous physical quantity, and is compared with the value obtained by converting the current physical quantity at the next point in time.
If the comparison result is within the specified range, the memory MM
and repeat these operations.

Regarding the above, if the output of ADC/A/D deviates from the predetermined range, the comparison output of comparator CP ₁ or CP ₂ changes to "H" and the output of NOR gate G ₁ becomes "L". If the output of the inhibit gate _G2 also becomes "L" or the output of the ADC/A/D deviates from the absolute upper and lower limit range, the output of the comparator _CP3 becomes "H" and the inhibit gate _G2 turns off, and in this case as well, the output of the same gate _G2 becomes "L", so the switching circuit SW is not driven, and the ADC/A/D that converted the current physical quantity
The output of each comparator CP ₁ to _{CP 3} is not stored in the memory MM, and the comparison output of each comparator CP 1 to CP 3 is sent out as the alarm signal AL via the OR gate G ₃ .
Since the pulse generator PG stops working depending on the
The value obtained by converting the immediately previous physical quantity is held in the memory MM.

Therefore, the contents of memory MM are transferred to the computer CPU.
When read out and processed by , the data immediately before the physical quantity becomes an abnormal value can be obtained for each frequency band, and by appropriately setting a predetermined range and absolute upper and lower limits, it is possible to prevent equipment, equipment, etc. from completely failing. Repairs to the target area can be made in advance.

However, the sensor SS is a microphone,
In addition to strain gauges, any device that converts a physical quantity into an electrical signal, such as a temperature sensor, pressure sensor, or flow rate sensor, can be used depending on the conditions.
The same applies to items that are selected sequentially and repeatedly using SEL, and are configured using analog circuits.
ADC/A/D may be omitted.

Further, instead of the memory MM, counters, accumulators, etc. may be used, and a number of these items corresponding to the number of inputs of the selector SEL may be provided, and each gate G ₁ to
The present invention can be modified in various ways, such as replacing _G3 with another gate circuit depending on conditions.

As is clear from the above explanation, according to the present invention, in order to continuously and automatically detect the physical state of devices, equipment, etc., and maintain the value immediately before the state change,
Labor savings can be realized in determining the lifespan, maintenance, and operation of equipment, equipment, parts, etc., and particularly when applied to large machine tools, dental grinders, etc., great effects can be obtained.

[Brief explanation of drawings]

The figure is a block diagram showing an embodiment of the present invention. SS...Sensor, BPF ₁ to BPF _o ...Bandwidth wave device,
SEL...selector, A/D...ADC (analog/
digital converter), SW...switching circuit, MM...
...Memory (holding circuit), CP ₁ to _{CP 3} ...Comparator,
BAS ₁ , BAS ₂ ...Bias circuit, _E1 , _E2 ...Reference value circuit.

Claims (1)

[Claims for Utility Model Registration] Signal generating means that sequentially converts physical quantities that change sequentially into electrical signals at predetermined timings and outputs them, and a switching circuit that switches the input electrical signals to a first output and a second output. and a holding circuit that inputs the electric signal output from the signal generating means when the switching circuit is switched to the first output and updates and stores the already stored contents; inputting the electrical signal output from the signal generating means when the switching circuit is switched to the second output, and comparing this current input electrical signal with the electrical signal held in the holding circuit; a comparator that outputs an in-range signal when the difference between the current input electrical signal and the electrical signal held in the holding circuit is within a predetermined range;
1. A physical state detection device comprising: switching control means for switching a switching circuit that has been switched to the first output to the first output.