JPS62156531A - Sensor for controlling process or machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention relates to a sensor used to control a process or machine, and in particular to turn a process or machine on or off.

(Prior Art) A switch is a device used to complete/break an electric circuit. The conventional technology has many mechanical arrangements, such as lever switches, knife switches, rotary switches, pushbutton switches, and microswitches with movement. Other switches include electromagnetic switches and power switches.

Prior art devices generally involve moving parts and are not simple.

SUMMARY OF THE INVENTION The present invention seeks to provide a sensor that has no moving parts, is simple, and can be used to control a process or machine.

Accordingly, the present invention provides a transducer adapted to provide an electrical output signal that is dependent on the degree of acoustic emission activity, and a transducer adapted to provide an electrical output signal that is dependent on the level of acoustic emission activity. a level detector configured to compare the level of acoustic inquiry activity to a set level of acoustic inquiry activity, the mechanism of acoustic inquiry activity being a comparator that generates a signal by detecting a change from a level smaller or larger than the set level of state query activity to a level larger or smaller than the set level of acoustic query activity, respectively; The present invention provides a sensor having the following features.

The comparator generates a digital signal level change or signal to change the state of the relay contact.

The comparator generates an on/off signal, ie, a signal indicating that the level of acoustic emission activity has changed.

A transducer is acoustically coupled to the body of the device and detects rail changes in acoustic emission activity in the housing.

A sensor is mounted within the broom and acoustically coupled to the housing to detect changes in the level of acoustic emission activity in the housing to generate signals to control the device. The sensor is hermetically sealed in a robust metal housing or other suitable material.

The level detector measures the root mean square or peak level of acoustic emission activity detected by the transducer.

the keyboard is adapted to receive a plurality of keypads;
each keypad is acoustically coupled to a respective sensor, each sensor having an enclosure that provides an increased attenuation path for acoustic query activity, and each sensor having an enclosure that provides an increased attenuation path for acoustic query activity at the respective keypad. a transducer adapted to provide an electrical output signal dependent on the degree of

The level of acoustic emission activity is determined by comparing the level of acoustic emission activity with a set level of acoustic emission activity using a sensor that measures the level of acoustic emission activity. a comparator that detects that the signal changes from a level smaller or larger than the set level of acoustic emission activity to a level larger or smaller than the set level of acoustic emission activity, respectively, and generates a signal; Become.

A method for controlling a process or machine includes detecting the level of acoustic emission activity from a relevant position in the process or machine, and detecting the acoustic emission activity level from the process or machine at the relevant position. The level of acoustic inquiry activity from the location of the process or machine is lower than or greater than the set level of acoustic inquiry activity. Detecting a change to a level higher or lower than the set level, respectively,
The change consists in generating a signal to control the process or machine.

A method for controlling a process or machine includes the steps of: detecting a level of acoustic emission activity from a position of a first process or a first machine; comparing the level of acoustic inquiry activity of the first process or the first machine with the set level of acoustic inquiry activity; detecting a change in mission activity to a level greater than or equal to or less than the predetermined level, respectively, and said change generating a signal for controlling a second process or a second machine. .

The signals for controlling the process or machine are on, off signals.

(Embodiments of the invention) The attached No. 1 (2) schematically shows a sensor according to the invention.
) The present invention will be described more fully by reference to the following.

The sensor 10 shown in FIG. 1 includes a converter 14, an amplifier 16,
It has a level detector 18 and a comparator 20.

The transducer is acoustically coupled to, for example, the machine 12, detects stress waves, also known as acoustic emission or secondary acoustic emission, and converts the acoustic emission into an electrical signal. Convert.

The electrical signal generated by converter 14 is then passed through amplifier 1
6 and supplied to the sensor 18. The level detector analyzes the amplified signal to detect or measure the level of acoustic emission activity detected by transducer 16. This level detector may be either a root mean square rail detector or a peak level detector.

The comparator 20 then compares the level of acoustic inquiry activity detected by the level detector 18 to the acoustic emission activity setting scheme and determines whether the level of acoustic emission activity is a smaller value or A change from a large value to a value larger or smaller than the set level, respectively, is detected and a signal is sent to the control device 22 of the machine 12.

The detected acoustic stress activity is not of the type caused by crack growth or plastic deformation, but of the type caused by impact, friction, and disturbance, and is in fact a process that produces broadband stress wave transients. .

The invention is further explained by reference to the following examples of possible uses of multiple sensors.

An impact between two bodies produces a broadband stress wave transient whose frequency content and amplitude are governed by the physical properties of the bodies. These stress waves can be detected in many different types of structures.

Example 1 The impact of two members coming into contact can be detected by the stress waves generated. The sensor can be used to generate a signal to confirm that the mechanism has been retained or fully retracted, and can also be used to determine the coordinates of the object by recording the impact of the probe. Examine.

EXAMPLE 2 Plasting processes used to clean articles, such as Sainte Plasting, Grid Plasting, Bead Plasting, and Steam Plasting, consist of a rapid series of violent impacts. Since these impacts are intentional, the sensor is effective in detecting the absence of the plasticizing medium or the absence of the workpiece and sends out a signal accordingly.

Example 3 Debris often creates impact under the influence of gravity.

For example, deposits may fall from machinery or structures. The sensor indicates that an accessory has fallen from the machine and can be used to switch off the machine.

Example 4 Debris from engines and machinery often becomes suspended in fluids. Examples include debris from bearings in oil systems and lubrication systems. Debris impact on the oil system housing generates stress waves. The sensor may indicate bearing wear or.

It can be used to switch off the machine when excessive stress wave levels are detected.

Perturbations in the fluid will generate broadband stress waves that propagate through the fluid and into the containment vessel. This broadband stress wave is generated by using transducers in the fluid.

Alternatively, even longer sections can be detected by using a transducer mounted on the wet surface of the container.

Example 5 Disturbances commonly occur within a fluid flow, resulting in stress waves. The stress wave activity level depends on the particular configuration. Sensors can be used to detect excessive turbulence, ie, stress wave activity, caused by excessive flow due to downstream leaks or failure of the valve to close, and shut down the system. Similarly, sensors can be used in coolant or lubricant systems to detect and shut down insufficient flow metering caused by loss of coolant or lubricant. this is,
It is useful for IC engines, turbines, etc.

Example 6 Transient stress waves are generated by the collapse of fluid bubbles, whether caused by cavitation, boiling, or bubbling, and the level of acoustic stress activity depends on the specific situation. . The sensor is used to generate a signal when bubbles are formed due to the above process or when their formation stops. This is applicable to pumps and chemical and food processing processes where cavitation occurs.

In addition to the generation of heat during the friction period, broadband stress waves are also generated as part of the energy loss. Sliding contact between two solid surfaces, whether macroscopic or microscopic, is a slip-stick process.
es), each of which acts as a source of stress wave transients.

Example 7 The natural slippage of a body that is fastened, wedged, tied, suspended, or bolted is
with broadband stress wave activity. The sensor can be used as a robot hand slip detector.

Example 8 The lubrication system aims to minimize scratches and friction losses. The efficiency of lubrication controls the stress wave activity generated. Sensors can be used in all types of machines and engines to detect transient stress wave activity due to loss of lubrication and shut down the machine or engine.

Example 9 Many stationary objects have low levels of stress wave activity except when physically disturbed. For example, unoccupied office buildings or household items are likely to have very low to low background stress wave activity.

Sensors can be used to detect attempts to pry open doors, desks, storage rooms for valuables, etc., and set off alarms.

The sensor according to the invention can be used as a switch and the transducer can be attached to the housing of a domestic or industrial article or device. The entire housing of the article will therefore act as a switch; touching the housing will generate stress waves that will be detected by the sensor if the level of stress wave activity changes at a set level. Ru. Thus, the housing is used to turn on or off a household or industrial item, or to detect a touch on the item.

The manually operated sensor can be mounted in a highly durable housing that resists breaking or breaking. The sensor can also be hermetically sealed, for example in a rigid metal object, if desired. Such a switch would have a moving part, so that the device could be switched on simply by being touched or impacted. It would also be possible to form a keyboard array with multiple keypads, each connected to a respective sensor. The keypad can be mounted in a durable housing within which increased damping is provided between the keypads. In other words, an impedance mismatch or damping material is used to reduce the transmission of stress waves between the keypads.

When the keypad is touched or impacted, stress waves are transmitted to the respective sensors. Although the false stress waves are at a level sufficient to provide switching action, the stress waves transmitted through the housing to the adjacent keypad and cell are.

This is an insufficient level to cause switching action. Such devices can be used in typewriters or, for example, in bank cash machine keys.

The sensors are attached to and acoustically coupled to each keypad. The sensor can also be hermetically sealed to the keypad l-' of metal or other suitable material.

All mechanical means of metal removal, such as milling, drilling, lathing, grinding, broaching, and polishing, generate broadband stress wave activity. The sensor may be attached to the tool, the blank, or a fixture holding the tool or blank so that the blank or tool can be changed without acting on the sensor.

Example 1O As the metal removal process begins, stress wave activity increases rapidly. A sensor can be used to recognize this change and generate a signal confirming that the material is within start-up tolerances.

Example 11 The level of stress wave activity is related to the rate of metal removal, and excessive cutting demands result in abnormally high stress wave activity levels.

Sensors can be used to recognize this and generate a signal to stop the process and prevent damage to the machine, tools, and workpieces.

EXAMPLE 12 Excessive tool wear that results in binding and distinct audible signals also generates increased broadband stress wave activity. The sensor recognizes this condition and stops the machine.
It can be used to prevent further damage to the tool.

Example 13 Failure of a cutting edge is characterized by a very brittle crack associated with high amplitude stress wave transients. Sensors can be used to detect this event, or the progression of stress wave activity from pre-failure to post-failure, and shut down the machine.

Various industrial processes, industrial plants, machinery, and equipment generate acoustic emission activities in performing their functions. Sensor signals can be used to turn on or off a mechanical device or process to ensure that the machine or process operates within a desired operating range.

Also, when the acoustic emission activity of the first process or machine changes from a level less than or greater than the set level to a level greater than or less than the set acoustic emission activity, respectively, the second process or machine is activated. A sensor can be used to turn on.

The invention is not limited to the given example, but can be applied to any situation where there is a change in the level of acoustic inquiry activity.

The sensor is used to generate a signal when the comparator detects that the acoustic emission activity level changes from a level below or above a set level to a level above or below the set level, respectively. I can do it.

The signal from the sensor is used to turn a machine, device, process on or off, or otherwise control a machine or process, or to indicate that a particular point in a process or machining process has been reached. It can be used for

Broadband stress waves generated by the process are always present;
It is often a very sensitive indicator of process changes.

A single sensor according to the present invention provides real-time monitoring of considerable range and quantity. The mounting position of the sensor is not critical as the stress waves propagate from the source to the sensor. This makes sensor installation easier.

Often non-intrusive, for example, sensors are mounted externally to monitor the interior of a machine.

The orientation of the sensor is not important. Sensors are generally simple;
Does not require expensive parts.

If the stress wave is overshadowed by another, more dominant source of the stress wave, it may be necessary to place the sensor acoustically closer to the source of the stress wave. I mean,
The use of Accordance Mission as Senna,
This is because it will only work if the source in question is dominant. Another method is to differentially analyze the output of a sensor with the output of another sensor placed in close proximity to a competing source of stress waves.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a sensor for controlling a process or machine according to the present invention. 10: Sensor 12: Machine 14: Converter 16: Amplifier 18: Level detector 20: Comparator 22: Control device (5 people in addition) 22 IT chief!

Claims (1)

[Scope of Claims] 1. A transducer adapted to provide an electrical output signal dependent on the degree of acoustic emission activity, and a transducer adapted to provide an electrical output signal dependent on the level of acoustic emission activity; A level detector adapted to measure and compare the level of acoustic inquiry activity to a set level of acoustic inquiry activity to determine whether the level of acoustic inquiry activity is higher than the level of acoustic inquiry activity. a comparator for detecting a change in acoustic emission activity from a level below or above a set level to a level above or below the set level, respectively, and generating a signal. 2. The sensor of claim 1, wherein the comparator generates a change in digital signal level. 3. The sensor of claim 1, wherein the comparator generates a signal that changes the state of a relay contact. 4. The sensor according to any one of claims 1 to 3, wherein the comparator generates a signal that is an on or off signal. 5. Any one of claims 1 to 4, wherein the transducer is acoustically coupled to a housing of the device to detect changes in the level of acoustic emission activity in the housing. The sensor described in 6. A patent in which the sensor is attached to and acoustically coupled to a housing to detect changes in the level of acoustic emission activity in the housing to generate a signal for controlling the device. A sensor according to any one of claims 1 to 4. 7. The sensor of claim 6, wherein the sensor is hermetically sealed in a robust metal housing or other suitable material. 8. A sensor according to any one of claims 1 to 3, wherein the comparator generates a signal indicating that the level of acoustic emission activity has changed. 9. A sensor according to any one of claims 1 to 7, wherein the level detector measures the level of the root mean square of the acoustic emission activity detected by the transducer. 10. A sensor according to any one of claims 1 to 7, wherein the level detector measures the peak level of acoustic emission activity detected by the transducer. 11. A keyboard having a housing adapted to receive a plurality of keypads acoustically coupled to respective sensors to provide an increased weight loss path for acoustic query activity, the keyboard comprising: , a transducer adapted to provide an electrical output signal dependent on the degree of acoustic inquiry activity at each keypad, and a level detector adapted to measure the level of acoustic inquiry activity. The level of acoustic inquiry activity is compared with the set level of acoustic inquiry activity, and the level of acoustic inquiry activity is set from a level smaller than or larger than the set level of acoustic inquiry activity. a comparator adapted to detect a change in query activity to a level greater or less than said set level, respectively. 12. The keyboard of claim 11, wherein each sensor is mounted at and acoustically coupled to a respective keypad. 13. The keyboard of claim 12, wherein each sensor is hermetically sealed to a robust metal keypad or other suitable material. 14. Detecting the level of acoustic inquiry activity from the relevant position of the process or machine; and setting the level of acoustic inquiry activity from the relevant position of the process or machine; and comparing the level of acoustic inquiry activity from the location of the process or machine with the set level of acoustic inquiry activity from a level less than or greater than the set level of acoustic inquiry activity. A method of controlling a process or machine comprising detecting a change to a higher or lower level, respectively, and said change generating a signal for controlling the process or machine. 15. Detecting the level of acoustic inquiry activity from the first process or the first machine at the location; and the acoustic inquiry activity from the first process or the first machine at the location. comparing the level of acoustic emission activity to a set level of acoustic emission activity, and the level of acoustic emission activity from the first process or the first machine at detecting a change in acoustic emission activity from a level less than or greater than a set level to a level greater than or less than said set level, respectively, and said change controlling a second process or a second machine; a method for controlling a process or machine, the method comprising the steps of: generating a signal for controlling a process or machine; 16. The method for controlling a process or machine according to claim 14, wherein the signal for controlling the process or machine is an on/off signal.