WO1996020066A1

WO1996020066A1 - A detection system, concerning the function control of material manipulating tools of machines

Info

Publication number: WO1996020066A1
Application number: PCT/BE1995/000122
Authority: WO
Inventors: Simonne De Rijck
Original assignee: Simonne De Rijck
Priority date: 1994-12-27
Filing date: 1995-12-22
Publication date: 1996-07-04
Also published as: BE1009011A5

Abstract

The invention foresees a break control of material-manipulating tools at machines or installations. The detection installation consists in principal one or more vibration sensitive detectors (1), which, during the material manipulation function in the material to be manipulated (6), detect the vibrations, vibrations created by the friction, tearing or deforming function of one or more used material manipulating tools (2), and the friction vibrations or other vibrations caused by the drive mechanism (3 and 13), whereby by unsufficient vibration receipt of the mentioned vibration sources, they can be increased by the extra foreseen artificially created vibration (rubbing) sources (4), whereby by fracture of a manipulation tool (2), the mentioned vibrations, which reach by normal function the fracture detector (1) via the manipulation tool (2), are interrupted, so that this fracture can be signalised through the steering-unit (5), whereby the lowest limits of the manipulation signals during the manipulation procedure are controlled, as well as the highest limits, under influence of the increased or extra vibration signals, can be controlled, whereby by passing these adjusted limits a signal will be sent to the machine or installation.

Description

A detecti on system, concern i ng the function control of materi al mani pul ati ng tool s of machi nes

The invention consists in a detection system for the fracture detection of tools for the manipulation of material with machinery, apparatus or installations, computerised or not, such as drills, fraises, chisels, wire-cutting tools, cutting stamps, grindstones, cutting scissors, or other material-manipulating tools, which have a cutting, material tearing, deforming or rubbing function on the manipulating material during the manipulation, by which in combination with the fracture detection system, the wastage of the used manipulation tools, either or not can be detected, aswell as the control of the increased or extra manipulating fibrations due to the process of the manipulation of the material, influenced by for example an unsufficient greasing or cooling of the manipulation tools during the manipulation procedure, aswell as a control of the proceeding by the cutting or manipulation tools in the material to be manipulated.

In the technical position, there exist systems whereby by means of for example a laserbeam or photo-electrical eel the breaking of the drills of drilling machines are controlled. A laserbeam or infra-red light beam is aimed at the drilling tools, whereby after the breaking of the drill, the light-beam gets a free passage and so it can reach a light-receiver or a detection control, whereby the lightbeam is reflected on the manipulating tool to a foreseen receiver by the presence of a tool. This fracture control is in principal used in therefore foreseen places between certain manipulations.

The disadvantage of the present optical detection systems is, that they are, or sensitive to dust, chips or liquide dirt, or they are difficult to be installed on the desired detection place. Moreover, it is impossible to detect during the manipulation, as the tool is at that moment completely or partly in the material out of the reach of the optical system. Aswell, it is impossible to control the wastage of the tools or other manipulation controls during the manipulation procedure.

As far as known, for the breaking control of cutting or other material manipulation tools of machines, there doesn't exist any detection system, whereby the rubbing, tearing or deforming working of the tools in the material, either in combination with the possible rubbing or vibrations caused by the driving mechanism of the tool or the material to be manipulated, can be detected, whereby these fibrations can be suppor- ted by extra artificial fibration (friction) sources, at the moment that the fibration sign has decreased till a certain secure detectable level, for example when decreasing th turning of the cutting tool during certain manipulations. For the detection contro vibration receivers are used which are put into contact with the manipulation tool through the materials which are standing in connection with the manipulation tool durin the functions, whereby in case of fracture of the manipulation tool, the vibrations whic go through the tools during the normal working of the concerned material, are interrupte and so detected. Aswell there exsists the possibility, beside this fraction detection, t make a control on unwanted extra manipulation vibrations, caused by the wastage of th tools, or by the badly tightening of the tools, by local thinning or hardening in th material to be manipulated, by badly chosen manipulation adjustements, by the lack o reduction of the used cooling or greasing products, etc... aswell as a control of the wa made by this tool, whereby the full manipulation control can be made.

The new detection system contains one or more vibration sensitive sensors which ar installed in contact with the material to be manipulated, preferably in the near surroun ding of the place where the tool is working in the material to be manipulated, so that th largest possible detection signal can be received. To obtain the largest possible vibration contact of the used vibration receivers in accor dance with the area to be detected, the one or more vibration receivers are installed o pressed against the mass, for example the metal of the chosen detection place, either o not foreseen of a special vibration passing fabric betweenthe detector part and the surface to be detected, so that the vibrations receive a minimum of resistance to reach th detection element. According to the material to be manipulated itself and the differen materials which exist between the vibrations to be detected and the detector element, an the detector element, and depending of the physical qualities of these fabrics between, th vibration signal will receive less or more resistance to reach the detector element and s will be weakened more or less. In case that the detection area to be detected is too large it can be advisable to place several detectors, divided over the working area to be control led, so to be able to receive in each place of the expected detection surface sufficien detection signals, according to the expected manipulation dimensions. Another possibili ty consists in foreseeing a detector that is put into contact with the detection place, b means of for example a liniair moving installation, or a friction installment, whereby th detector in accordance with the manipulation tool guards always the same distance an so will receive the same foreseen signal dimensions. As next point, it is important t choose on which side in accordance with the manipulation tool, the one or more fraction detectors have to be installed. It can be considered that there are two possible areas of installment, whereby the rubbing or cutting side of the manipulation tool makes the division between the two possible installment areas. The first possible installment area is the side of the manipulation unity, as for example a milling or drill unity, including the manipulation tool, for example a fraise or drill. The second possible installment area can be described as the material that is manipulated by the working tool, installed between the machine vice or the workbench or machine table, or a clutch, or another material- clamping installation. The choise for the placement of the one or more applied fraction detectors in the one or other installment area, is made by the fact that the used fraction- detectors always have to be installed on the place where a maximum of difference of signal can be created, between the breaking or not of a manipulating tool. At for example, a drilling-machine, the fraction detectors will be placed for example at the side of the material to be manipulated, as the cutting tool, in this case a dril, is driven by a motor through a suspension and conduction which, during the working creates rubbing vibrations and other working vibrations due to the used bearings or other parts, whereby the detectors during the manipulation of the material will detect not only the rubbing vibrations and working vibrations of the manipulating tool, but aswell the vibrations caused by the drive mechanism of the concerning tool, in this case a drill. In case of a possible fracture of the drill, not only the vibration signal of the drill will disappear, but aswell the extra vibrations caused by the driving mechanism of the drill itself, which pass during a normal working through the drill, will be broken. Only a minimum of the remaining vibration signal of the concerning drill-drive mechanism can reach the detector part through the surrounding air or via the suspension or construction of the machine that stands in connection with the drill-table, aswell depending from the construction of the machine or used materials. By placing vibration-demping materials, it can be avoided that in certain cases too large a vibration signal of the drive-mechanism via the mass or basis of the machine could be send to the detector. By, on the contrary, for example, a traditional centre lathe, computerised or not, the detection system for the fracture control of for example a manipulating chisel, will be normally placed at the side of the chisel, as in this example the material to be manipulated is driven and so will contain extra vibrations, this in comparing to the less moving chisel-holder that will contain only a small amount of vibrations. When the fraction detector is placed on the most vibration-free installment are, after the tool's fraction, not only the vibrations caused by the manipulation tool itself but aswell the vibrations caused by the driving machanism of the tool will be broken. Hereby, it made that when the vibration signal level is received, a maximum difference is create between the broken or not broken tool. In case of a low circumference-speed of f example the drill-function, it is not excluded that the vibration signals, activated by t rubbing or cutting working of the drill, aswell depending of the kind of the material to b manipulated and the contact surface of the drill with the material, will in many cases b smaller than the vibration signal, caused by the drill-driving mechanism, that via the dri in contact with the manipulating material will reach the fraction detector, whereby i some cases the importance of these secundary vibrations for the reliable working of t fraction detection system can increase even more. If the total vibration signal of the dri manipulation and the drill-driving mechanism is too small, the detection signal can b supported by adding extra artificially created rubbing vibrations which are sent throug the material to be manipulated to the fraction detector. Therefore, a rotating or rubbin part can be installed at the side of the driving mechanism that stands in acustic conta with the driving mechanism, or the other vibration(rubbing) creating source, as a reson tor or an ultra-sonic vibration source, that imitate electronically the mechanical create rubbing vibrations, whereby making attention, that the activated vibrations stand outsid the resonation-field of the drill, so that this drill cannot break or cause damage due t these vibrations. Aswell the signal size of this extra vibration creator or source is adapte in function to the kind of the drill manipulation and stopped by heavy manipulation seen that at the moment the material manipulation vibrations are sufficiently high t proceed with a reliable detection, whereby damages to the material surfaces or quicke usages of the manipulating tools can be avoided. In the case that two or more drill funtions or other functions are effected in the sam material to be manipulated with a small distance between the one and the other, it mig be advisable to make a larger detectable difference between these similar functions, so t make possible a reliable detection. When we take for example a drill funtion, whereb two or more drills at the same time effect a drill funtion in the material to be manipulated it is possible that without any additional foresights, for example the central place fraction detector at the side of the material to be manipulated will detect a lower signa when one of the drills brakes, and so will detect and signal this. In case that the detectio difference is considered to be too low and so unsufficiently reliable, and if the two driv mechanismes of the rotating drill-holder are sufficiently acustically divided the one fro the other, by for example to foresee one of both drill units of an artificial vibration(ru bing) source. The meaning of this extra vibration source is, that by fracture of the dril the extra vibration signal is broken via the tool, whereby a larger detectable difference is created between the breaking or not of a certain drill. When both separate drill units are foreseen with an extra artificially created vibration(rubbing) source, whereby the signals of both sources are coded in amplitude and/or frequency(s), (for example by interrupting step by step the added artificially reacted vibration(rubbing) signal, whereby the pulsating recognisable character of this signal per drill is obtained, or for example, by step by step deceasing or increasing of the signal potention, this to mention only a few examples), it is possible via electronical and/or pfysical way, when one of the signals coming from the said vibration(rubbing) sources deceases importantly, by the breaking of the drill concer- ned, to signalise through the drive unit which drill exactly is broken. If it is found, that certain vibration sources outside of the detection field, that reach the detectors via the manipulation tool or not, eventually coming from the other machines, are so strong, that they are creating a disturbing influence on the reliability of the detection, specially if the frequencies received are corresponding with the expected breaking detection signal, vibration receivers can be installed, possible on the foot or the connection points of the machine, if the disturbing signals are sent via the floor, so that the received signals can be detected electronically and so can be recognised, so that they can be filtered in accordan¬ ce with the foreseen detection signals. As described, the new descovered detection system is foreseen step by step of extra equipments if necessary, whereby in principal the cheepest way is chosen so to find the most economical solution. Moreover, extra vibration(rubbing) courses, extra vibration receivers or break detectors ask for a supple¬ mentary cost price and are only used, if the reliability of the detection function requests so. Thus, the step by step construction of the invented detection system can also be seen as a capacity of the invention itself. As to the break detectors themselves, they are foreseen of a vibration sensitive element, normally a piezo-element or another vibration senitive element that has the capacity to transfer mechanical vibrations in an electrical signal that is sent to a direction unity for its further reading, if it is chosen to distinguish certain signals from the unwanted signals by electronical filtration, one make attention that the resonant area of the detection element stays out of the reach of the signals to be detected, so to receive a vibration spectrum as complete and undeformed as possible that can be used for further filtration and investigation. The resonation frequenty whereby the detection element can start to resonate, is for example dependant of the chosen dimensions and composition of the piezo-element. By the physical characteristics of for example the dimensions of the piezo-element, it is possible to calculated by wich frequency and amplitude the concerning fibration receiver w resonate, so whereby this resonation can be avoided. Aswell there exists the possibility t effect one or several detection tests authomatical or not for each material manipulatio by the normal function of the manipulation tool, so to adjust authomatically a detecti level by the direction unity, whereby by each change of manipulation procedure, f example a slow turning drilling against a very fast manipulation, the most appropia adjustment level can be put. Seen that the manipulation tool mostly doasn't effect contineous procedure during the full function cycle, it is necessary to effect the contr only then, when the manipulation tool is effectivily working of a minimum of time perio and detectability. Herefore, there exists the possibility to foresee a system whereby f example, in case of a drill manipulation, a sensor or switch controls when the cutting go into the manipulation material, for example by placing a switch on the shaft of t drilling spindle that is activated when this is deplaced till a certain depth, that in norm circumstances gives the position of the drill in the manipulation material. At CN computer guided machines, the control periods for the control of the break detectio aswell as the switch level of the expected manipulation signals, can be foreseen in th computer programm. Aswell there exists the possibility to make a taking of a fully norm work cycle in function to the time and/or the way made of this cycle, after which autom tically or manually the switch level can be adjusted or programmed by means of th driving unit during the complete time period of the manipulation cycle or on certai chosen moments, so that the correlative identical work cycles can be controlled accordin to these adjusted values.

Apart from the specific break control of the manipulating tools, it is aswell possible wit the same detectors, in combination or not with other therefore foreseen vibration sensitiv detectors, to effect a control on increased and/or extra manipulation vibrations of th manipulation functions, as for example the control of the usage of the manipulation too the way made by the tool and/or the increased or extra vibrations caused by the badl stretching of the tool or material or under influence of the hardenings in the material to b manipulated, the whole or partly missing of the possible used cooling and/or greasin products, etc... Seen that the detection signals can be detected during the normal workin cycle, the maximum signal sizes or values can aswell be adjusted in function to thes signals, in which the manipulation signals need to be working with anormal function of certain manipulation. By exceeding the upper values, it is possible that these unwante vibrations cause a negative influence on the quality of the manipulation, whereby fo example, irregularities in the worked surface can exist, such as inequalities or undulati ties or undulations, size differences, etc... which can be detected and signaled by this additional detection adjustment, so that certain feeding speeds or cutting speeds during for example a certain time can be adjusted automatically, in function to the received detection signals, or that the irregularities for example can be signaled by the operator of the machine or installation or similar.

The received detection can increase under influence of for example the wearing off of the tool, seen that by wastage of the cutting surface of the manipulating tool higher forces are needed, and/or a signal increase is caused, by the partly or total absence of the cooling and/or greasing products, whereby higher frictions and vibrations exist in the material or by other material manipulation irregularities. As there exists aswell the possibility to control the manipulation time whereby the tool stands in contact with the material to be manipulated, whereby during this contact a remaining fibration signal is received, it is possible to control if the period of a certain manipulation according to the before adjusted time limits are not exceeded, whereby there exists the possibility to control that for example a frease or drill cannot work any longer so for example deeper in the material than needed. If wanted, in function to the time period that the manipulation tool creates vibrations in the material with a known feeding speed, it can be determined when for example the manipulation has to be stopped or modified. Moreover, the time period of the created manipulation vibrations in function to the known feeding speed, makes it possible to calculate the way made by the manipulation material in the material to be manipulated. In case that the detectors need to be placed on a moving or rotating part of for example a machine, there exists aswell the possibility to proceed the detection system wireless. The received signals can for example, by means of ultrasonical signals, inductive or other means, be sent to the foreseen receiver, whereby otherwise the necessary electrical connections which are subject to multiple mechanical movements, are avoided, which otherwise could badly influate the reliability of the foreseen detection system. For the contactless electrical feeding of the detectors, loadable or non-loadable batteries and/or condensors can be used, whereby these loadable batteries and/or condensors are loaded on certain periods through an electrical contact or even through an contactless inductive transmission of energy transmission supply. Aswell, in combination or not of those batteries and/or condensors, light receiving cells can be applied for the electrical loading of the before named elements, ar an application whereby the inductive (or electro¬ magnetic) transmission of the electrical energy or the energy got via cells during the detection control, is immediately used for the feeding of the detectors, or a system whereby sliding contacts or temporal contact bridges provide for the energy supply of th detection system.

The advantage of the new detection system is, that under all circumstances a reliabl control of the full execution of the material manipulations can be made. Oil, used coolin liquides, fabrics, chips, or other, cannot effect the reliability of the detection system, see the closed character of the used detectors. As the detection system can be built step b step, for each application the most suitable and reliable and the most rendable solutio can be chosen for all types of manipulations, starting from the detection control of th very slow turning manipulations till controls whereby more tools are manipulating withi a very restricted area and need to be controlled separately. By possible adding extr artifically created vibration(rubbing) sources by low vibrating(rubbing) manipulations, a to the fracture detections, it is avoided that by larger manipulations these extra vibration can cause surface damage in the material and/or quicker usage of the manipulation tool Beside, there exists the advantage that to the breaking detection system more function can be added, such as a wearing control of the manipulating tool, the authomatica adjustment of the cutting and/or feeding speeds in function to the received vibration o friction signal of the used tool, to control the possible use of the cooling and/or greasin products and to control the time period of the manipulations. Another advantage of th detection system is, that during the complete course of time that the manipulation too stands in contact with the material to be manipulated, a continuous control is possible Comparing to the optical systems, the detectors do not need to be aimed to the manipula tion tool itself, which can simplify the installment. Seen the universal character of th detection systems, there exists the possibility to apply this system in each domain of th industry whereby friction, tearing or deforming functions need to be controlled, such a by drill functions, press functions, cutting machines, metal, wood or artificial product manipulating machines, milling machines, centre lathes, cutter machines, draw machine or draught machines, grinding machines, etc...

The invention is not restricted to the given form. As illustration, an application i connection to the drill function is chosen, whereby extra vibration sources are uses (4) wich provide that by very light drill manipulations, whereby only few vibrations are mad by the drill manipulation itself, they are supported during the drill detection function b these extra artificially created vibration(rubbing) sources (4), whereby a sufficient reliabl vibration difference can be detected during the detection function by the applied vibration receivers or breaking detectors (1).

By the indicated picture, the detectors (1) stand in contact with the bench- or machine vices (10), which themselves stand in contact with the tensed manipulation material (6). By a normal function of the tool (2), as indicated during the drill manipulation by the right drill unit, the vibrations by the procedure of the drill manipulation, created by the rubbing, cutting or tearing function of the drills (2) in the material to be manipulated (6), aswell as the vibrations, created by the rotating, possible rubbing function of the drill drive (3 and 13), aswell as the artificially created vibrations coming from the vibration sources (4), flow or transmit through the contact surface of the drills (2) to the material to be manipulated (6) and the detectors (1), as indicated by the stip-lines on the right drill unit. By fraction of the drill (2), as indicated on the left drill head (3) on the picture, the mentioned vibrations will break, which at a normal drill function fload or transmit through the drill tool (2) to the material to be manipulated (6), whereby this signal interruption will be signaled by the detector (1) via the drive unit (5). To prevent that too many leaking vibrations, coming from the drill manipulation, via the feet (8) and the drill table or basis (9), would stream to the detectors (1), vibration demping fabrics (7) are installed between the machine scews (10) and the drill table or basis (9). The remaining vibrations, which are still received by the detectors (1) through the environment air and the vibration demping fabrics (7), can be eliminated by adjusting a minimal distribution level, whereby only by surpassing this level a wrong signal is created via the drive unit (5). For the determination of the detection moment, end-course switches are used (11) which are activated by a certain position of the drill holder (12), and that indicate that the drill tool (2) in the material to be manipulated (6) at a normal function, is effecting a drill manipulation, and so the control has to be effected on this indicated moment.

Beside the control of drill fractions, it is aswell possible, in function to the chosen drill manipulations, to effect a control as to the drill usage and/or the possible receiving of cool and/or greaing products, whereby it is controlled that the vibration signals stay within a certain maximal adjusted limit value, according to the kind of drill manipulation, so that by passing these limits, adjusted via the driving unit (5), a wrong signal is created.

Claims

CLAIMS:

1. Detection installment for the function control of material manipulation tools machines that are computerised or not, apparatus or installations, such as drills, fraise chisels, wire-cutting tools, grindstones, cutting stamps, or other material manipulatin tools, which have a cutting, material tearing, grinding, deforming or rubbing manipulatio on the material during the manipulation procedure, whereby it is characteri s e d, that one or more vibration sensitive detection elements are used, that detect th vibrations and transform that in an electrical usable signal, vibrations, caused by th rubbing, tearing, cutting of the material deforming manipulation of the one or more use tools, aswell as the vibrations caused by the function of the driving mechanism(es whereby by fracture detection of the material manipulating tool, the named vibratio which by normal material manipulations are transmitted through the manipulation too are interrupted, whereby so the one or more foreseen vibration receivers, which stand i contact with the manipulation tool, will detect this signal changement, whereby b reaching the one or more values previously adjusted of the received detection signal, a indication of the fault will be given automatically by the foreseen detection system.

2. Installment according to conclusion 1, whereby it is characterised, tha in case that the material manipulation vibrations, caused by the working of the tool(s) an the drive mechanism(es), are decreased till a certain reliable detectable level, thes vibration signals are boosted by adding artificially created vibration (rubbing) source that will simulate the material manipulation vibrations.

3. Installment according to conclusion 2, whereby it is characterised, tha by adding artificially created vibration (rubbing) sources, which are sent through th manipulation tool during the funtion, in case that several manipulation tools are workin at the same moment in the same manipulation material or work part, these adde vibration source(s) will be coded according to the frequency and/or amplitude, for th distinguishing of a fracture detection by one of the manipulation tools.

4. Installment according to conclusion 1 till 3, whereby it is characterised that unwanted detection influencing vibrations, coming from other machines or vibratio causing sources, can be completely or partly eliminated or filtrated via electronical way supported or not by separately placed vibration sensitive receivers, that can detect thes disturbing signals, so that via the drive unit it can be determined wich signals have to b filtrated.

5. Installment according to conclusions 1 till 4, whereby it is charaterised that the used detectors for the detection tool fractures, can aswell detect and signal the increased or extra rubbing or tearing vibrations or other vibrations, that are caused by the usage or damage of the cutting or manipulation surfaces of the used material manipulati¬ on tools during the manipulation.

6. Installment according to conclusions 1 till 5, whereby it is characterised, that the used detectors for the detection of the tool fractures, aswell can control the adding or not of the cooling and/or greasing products by the material manipulation.

7. Installment according to conclusions 1 till 6, whereby it is characterised, that the used detectors or the detection of the tool fractures, aswell can control the time period of the material manipulations.

8. Installment according to conclusions 5 till 7, whereby it is characterised, that the several control functions of the used detectors, can be divided or parted over more therefore foreseen vibration sensitive detectors with a specific control function(s).

9. Installment according to conclusions 1 till 8, whereby it is characterised, that the used detectors can be provided contactless, as to the transmitting of the detecta¬ ble signals to the drive unit, aswell the electrical feeding of the used detectors.

10. Installment according to conclusions 1 till 9, whereby it is characterised, that the detection signals by the normal manipulation cycle of the machine can be registered by a therefore foreseen registration installation, whereby the received vibration signals can be used as basis for the manuel or authomatical adjustmant of the upper or lower limit values of the accepted vibration signals, being filtrated or not of onwanted side vibrations as to the amplitude and/or frequencies, whereby aswell the timings of the control functions of the proceeding manipulation cycles can be programmed, whereby by reaching these adjusted values, a signal is sent to the machine or installation, so to stop the machine or to adapt or not the manipulation speeds or other interventions that can be made, or to activate the light or sound signal.