WO2023036828A1 - Verfahren zur bestimmung eines verschleisszustandes eines werkzeugs und vorrichtung hierfür - Google Patents
Verfahren zur bestimmung eines verschleisszustandes eines werkzeugs und vorrichtung hierfür Download PDFInfo
- Publication number
- WO2023036828A1 WO2023036828A1 PCT/EP2022/074878 EP2022074878W WO2023036828A1 WO 2023036828 A1 WO2023036828 A1 WO 2023036828A1 EP 2022074878 W EP2022074878 W EP 2022074878W WO 2023036828 A1 WO2023036828 A1 WO 2023036828A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- wear
- tool
- sacrificial
- test
- workpiece
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 48
- 238000005520 cutting process Methods 0.000 claims abstract description 154
- 238000012360 testing method Methods 0.000 claims abstract description 106
- 238000003754 machining Methods 0.000 claims abstract description 73
- 238000005259 measurement Methods 0.000 claims abstract description 73
- 239000000463 material Substances 0.000 claims description 63
- 238000003801 milling Methods 0.000 claims description 30
- 238000012545 processing Methods 0.000 claims description 28
- 230000015572 biosynthetic process Effects 0.000 claims description 16
- 230000005540 biological transmission Effects 0.000 claims description 9
- 238000012544 monitoring process Methods 0.000 claims description 9
- 238000003860 storage Methods 0.000 abstract description 2
- 229910052751 metal Inorganic materials 0.000 description 9
- 239000002184 metal Substances 0.000 description 9
- 229910000831 Steel Inorganic materials 0.000 description 8
- 238000000418 atomic force spectrum Methods 0.000 description 8
- 230000008901 benefit Effects 0.000 description 8
- 239000010959 steel Substances 0.000 description 8
- 230000006870 function Effects 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 238000011156 evaluation Methods 0.000 description 5
- 230000006399 behavior Effects 0.000 description 4
- 238000005336 cracking Methods 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 239000002826 coolant Substances 0.000 description 3
- 239000003082 abrasive agent Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000009795 derivation Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005242 forging Methods 0.000 description 2
- 238000012804 iterative process Methods 0.000 description 2
- 230000036316 preload Effects 0.000 description 2
- 230000002028 premature Effects 0.000 description 2
- 239000007779 soft material Substances 0.000 description 2
- 238000004901 spalling Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000002068 genetic effect Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 239000011859 microparticle Substances 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000003252 repetitive effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/58—Investigating machinability by cutting tools; Investigating the cutting ability of tools
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/56—Investigating resistance to wear or abrasion
Definitions
- the invention relates to a method for determining the state of wear of a tool, in particular a tool based on hard metal, and a device for this.
- the tool has a cutting edge whose state of wear is determined using the method. If the tool is a multi-edged tool, the state of wear of at least one cutting edge or multiple cutting edges is determined, which is currently in a ready-to-use setting or position.
- Milling processes with hard metal-based tools are used, among other things, for machining workpieces.
- the workpiece is machined with a defined cutting edge of the tool based on hard metal in a metal-cutting process.
- a geometrically defined chip is generated when the workpiece is machined.
- the tools used and the workpieces to be machined can be made of very different materials. Accordingly, a pair of materials is created that can vary greatly depending on the material of the tool and the material of the workpiece. This results in various physical variables, such as variables relevant to tool wear, among other things.
- the economic and technical service life, also known as the service life, of tools made of a cutting material is determined by the degree of wear of the cutting material.
- optical monitoring methods are known in the prior art, in which the cutting edge of the tool is observed by means of a camera.
- the contour of the cutting edge is compared with specified patterns or dimensions in order to identify a maximum state of wear. If it is detected that the maximum state of wear has been reached, the tool is changed by the output of a corresponding signal or relevant information. If the tool is a multi-edged tool, the cutting edge is changed. It is also known to measure the temperature at the cutting edge in order to draw conclusions about the degree of wear on the cutting edge. It is also known that force or torque measurements take place.
- One exemplary embodiment of the invention relates to a method for determining the state of wear of a tool and/or at least one cutting edge, in particular of a tool which is used for machining a workpiece, with the tool or the at least one cutting edge being in a new condition or in a used condition a test measurement with test machining is carried out on at least one sacrificial workpiece, the test machining being monitored by means of at least one measuring device with at least one sensor and measured values of the test measurement being storable in a memory, wherein after a defined machining of workpieces by means of the tool or by means of the at least one Cut at least one further test measurement with test machining on the sacrificial workpiece, which is also monitored by the measuring device with the at least one sensor and measured values of the test measurement can be stored, with the result measured values indicate a wear condition of the tool and/or the at least one cutting edge is determined, the test machining being machining of the sacrificial workpiece, the tool being moved in a predefined feed direction
- a wear condition of the tool can thus be determined from a comparison of stored measured values from the new condition or from a used condition with measured values from a current condition after workpieces have been machined.
- the use of a force at the predefined angle, in particular at an angle of 90° to the feed direction, causes the influence of the cutting edge or the tool on the sacrificial workpiece to be sensed, in particular as free as possible from disruptive influences.
- any tool can be used as the starting point for determining the state of wear, regardless of whether it is a tool that is new or a tool that is in a used condition and is intended to continue to be used.
- the angle, in particular 90° to the feed direction is measured in a plane in which the test machining is carried out, the angle to the feed direction being determined.
- test machining is a milling machining of a sacrificial workpiece using a tool as a milling tool, in particular with a cutting edge or with a plurality of cutting edges. This allows standardized processing to be carried out, which can be reproduced again and again in the same way in order to be able to determine the influence of wear and the state of wear.
- the tool is moved in a straight line in the predefined feed direction at the predefined feed rate relative to the sacrificial workpiece during the test machining. Because of the rectilinear course, a disruptive influence due to changes in direction is reduced or avoided.
- the angle is aligned in the range from 60° to 120°, in particular approximately 90°, to the feed direction. With such an angle, the disturbing influence of inappropriate influences is reduced, in particular with an angle of 90°.
- the senor is a force or pressure sensor which is arranged in such a way that only a force or pressure acts on it which is at an angle in the range from 60° to 120°, in particular about 90°, to the Feed direction is aligned.
- a force can thus be determined and evaluated in a reproducible direction, which facilitates the reproducibility of the measurement results and their measurement conditions.
- the measurement of the force is recorded with high resolution, so that at least one force value or a force curve with several force values can be assigned to each cutting edge of the tool.
- at least one force profile, in particular with a maximum is therefore measured for each cutting edge provided.
- Out of a maximum force value can then be assigned to the respective cutting edge to the value of the maximum of the force curve. From these force values or from the maximum force values, a mean value can be determined over one or more revolutions of the tool, which can be used to determine the state of wear.
- the state of wear is differentiated according to at least one state of wear of the following types of wear/failure: flank wear, crater wear, built-up edge, crack formation and/or broken edge. Accordingly, the state of wear is specifically assigned to the most probable types of wear/failure, so that the further course of wear can be better estimated as the tool is used further.
- the state of wear is determined from a respective state of wear consisting of at least flank wear, crater wear, built-up edge, crack formation and/or a broken edge.
- a respective state of wear consisting of at least flank wear, crater wear, built-up edge, crack formation and/or a broken edge.
- an individual state of wear according to the specified types of wear or types of failure is brought together in order to determine a general state of wear, which takes into account the considered types of wear and failure as a whole.
- test measurement is carried out separately with the test machining for each type of wear/failure under consideration or that a test measurement is carried out with one test machining or several test measurements are carried out with one test machining each and a wear/failure type is determined from this.
- individual or different test measurements with test processing are carried out on sacrificial materials or on different sacrificial materials with different processing parameters.
- processing parameters adapted to the type of wear/failure to be detected for the respective test processing. In this way, specific consideration can be given to the behavior of the respective type of wear/failure.
- test measurement is carried out with the test processing for one or for several or for each considered type of wear/failure on a sacrificial workpiece provided for this purpose.
- specific consideration can be given to the behavior of the respective type of wear/failure.
- test measurement is carried out with the test machining for one or for several or for each type of wear/failure under consideration with machining parameters provided for this purpose. In this way, specific consideration can be given to the behavior of the respective type of wear/failure.
- the state of wear is determined by comparing stored measured values and/or stored processed measured values from test measurements on at least one sacrificial workpiece or on a plurality of sacrificial workpieces. This allows the state of wear to be reliably determined.
- processed measured values have or are first derivatives and/or second derivatives of measured value curves over time. In this way, even small deviations can be better recognized.
- a recommendation for further use or replacement of the tool and/or the cutting edge and/or cutting edges is made from the determined state of wear or from the determined states of wear.
- the recommendation can be that the processing is carried out unchanged, that processing with other parameters is being carried out or that processing will be terminated. Machining with modified parameters can be machining with a reduced feed rate, for example.
- An exemplary embodiment of the invention relates to a device for determining the wear status of a tool and/or at least one cutting edge, in particular a tool which is used for machining a workpiece, with a tool having at least one cutting edge for machining a workpiece, with a measuring device at least one sensor for monitoring a test measurement with test processing and with at least one sacrificial workpiece for carrying out the test measurement with test processing on the sacrificial workpiece, in particular for carrying out a method according to the invention.
- a first receptacle is provided for the sacrificial workpiece and a second receptacle is provided for the sensor, the sacrificial workpiece being coupled to the sensor in such a way that during test processing of the sacrificial workpiece, a force is exerted by the sacrificial workpiece the sensor can be transmitted.
- a base body which forms the second receptacle for the sensor, with a carrier being provided which is guided so that it can be displaced in one direction relative to the base body wherein the carrier forms the first receptacle and the sensor is arranged between the second receptacle and the carrier and is subjected to a force. This ensures that the force acts on the sensor in the direction in which the carrier can be displaced relative to the base body, which is also sufficient for the reproducibility of exact conditions.
- an energy accumulator is provided, which pretensions the carrier towards the sensor. This avoids that undefined states can be avoided and the sensor experiences at least a minimum force due to the preload. It is also advantageous if the preload can be adjusted, in particular by means of an adjusting screw or the like.
- a transmission element is arranged between the carrier and the sensor, in particular a spherical element as the transmission element. As a result, the force is once again concentrated in one direction on the sensor, so that interference can be largely ruled out.
- a sacrificial workpiece is provided, which is arranged on the carrier, or if a predefined number of sacrificial workpieces is provided, with the sacrificial workpieces being arranged on the carrier.
- the machining of the at least one sacrificial workpiece can be arranged on the carrier, so that the force to be observed can be recorded by the sensor during the machining process of the test machining.
- the at least one sacrificial workpiece is provided and can be processed in order to determine at least one state of wear or several states of wear, or that the individual sacrificial workpieces are each used to determine one Wear condition are provided and editable according to a specific wear Zfailure type. This enables the tool or the at least one cutting edge to be monitored easily, in particular also with regard to individual states of wear.
- sacrificial workpieces in particular two or three sacrificial workpieces, made of different sacrificial materials are provided for determining a state of wear according to flank wear, crater wear, built-up edge, crack formation and/or a broken edge.
- a combined sacrificial workpiece can also be provided, which has several sacrificial materials.
- Fig. 1 is a schematic representation of an inventive
- Fig. 2 is a schematic sectional view of a
- Fig. 3 is a schematic representation to explain the
- Figure 1 shows a schematic representation of a device 1 with a tool 2 with at least one cutting edge 3, in particular with several cutting edges 3, which is used for machining a workpiece 4, in particular for milling the workpiece 4.
- At least one first drive 5 is provided in order to rotate the tool 2 with its at least one cutting edge 3 or with its several cutting edges 3 in order to be able to provide the speed of the tool 2 required for the milling process.
- the speed of the tool 2 can be controlled by means of the first drive 5, in particular between zero and a maximum speed nMaxl.
- At least one first actuator 6 is provided in order to be able to displace the tool 2 with its at least one cutting edge 3 or with its multiple cutting edges 3 relative to the workpiece 4 . It makes sense here if the tool 2 can be pivoted and/or moved in particular about at least three axes.
- the pivoting speed and/or the traversing speed can be controlled by means of the at least one first actuator 6, in particular between zero and a maximum pivoting speed and/or a maximum traversing speed or also called cutting speed or feed rate.
- the tool 2 is held interchangeably in a tool holder, which can be driven in rotation and/or pivoted by means of the at least one first drive 5 and/or the at least one first actuator 6 and/or can be moved, so that the tool 2 can be rotated, pivoted and/or moved accordingly.
- the workpiece 4 is held in a workpiece holder 7 .
- the workpiece 4 and/or the workpiece holder 7 with the workpiece 4 can optionally be driven in rotation by means of a second drive 8 and/or pivoted and/or moved by means of at least one second actuator 9 .
- at least one second drive 8 can optionally be provided in order to be able to set the workpiece 4 in rotation.
- the speed of the workpiece 4 can be controlled by means of the second drive 8, in particular between zero and a maximum speed nMax2.
- At least one second actuator 9 can also optionally be provided in order to be able to displace the workpiece 4 relative to the tool 2 . It makes sense here if the workpiece 4 can be pivoted and/or moved about at least three axes.
- the swiveling speed and/or the movement speed can be controlled by means of the at least one second actuator 8, in particular between zero and a maximum swiveling speed and/or movement speed.
- a holding device 10 is provided, by means of which a sacrificial workpiece 11 can be held.
- the purpose of the sacrificial workpiece 11 is for the tool 2 to machine the sacrificial workpiece 11 with the at least one cutting edge 3 in order to monitor this test machining using sensors 12 .
- the data from sensors 12 relating to the test machining is stored, for example, in a memory 13 of a control unit 14 that takes over the control and compared with other test measurements in order to determine a wear condition of the tool 2 and/or the at least one cutting edge 3 or the cutting edges 3.
- the state of wear of a tool 2 or a cutting edge 3 or the cutting edges 3 is determined, for example, in direct comparison to the new condition of the tool 2, the cutting edge 3 or the cutting edges 3 .
- the state of wear can be determined in relation to the specific type of wear and failure.
- test machining steps are carried out as test millings on the sacrificial workpiece 11 .
- the measured values of physical variables of this new condition determined by means of the sensor(s) 12 are stored as a reference pattern for the new condition.
- a test measurement or test measurements which is or will be carried out on the sacrificial workpiece 11, is or will be carried out again at a later point in time after the machining of workpieces.
- measured values are again recorded by the sensor 12 or the sensors 12 in order to compare them with the measured values of the new condition.
- the measured values not only the absolute values of the measured values are explicitly taken into account during the evaluation, but the course of the measured values over time can also be taken into account.
- both the absolute value of measured values and/or the chronological progression of measured values can be used for the evaluation. For example, a development and/or an imminent probability of failure can be determined or inferred therefrom.
- test measurements In the case of repeated test measurements on the sacrificial workpiece 11, correspondingly repeated measured values are taken, which are assigned to the respective test measurement.
- Such test measurements can be carried out at regular and/or irregular intervals and/or be recorded depending on the event in order to determine the respective state of wear of the tool 2 and/or the cutting edge 3 and/or the cutting edges 3 at the time of the test measurement.
- a comparison is made between the measured values of the corresponding test measurement and the measured values of the test measurement in new condition. In this way, a state of wear can be determined. A chronological development of wear states can also be determined if data from different test measurements are evaluated. Advantageously, a comparison between different test measurements can optionally also be carried out in order to identify a development of wear states.
- a test measurement can be carried out in the new state with test measurements for a current state of wear, these test measurements being carried out accordingly with a tool which is currently being used when machining workpieces 4 .
- the course of the values as a function of the period of use of the tool is also advantageous in order to be able to derive a qualified statement about the state of wear of the tool 2, the cutting edge 3 and/or the cutting edges 3.
- Specific materials and/or specific process parameters and/or specific milling methods are used to determine the state of wear with regard to the individual types of wear and tear that are considered, in which the measured values are recorded on the sacrificial workpiece 11 .
- the specific milling processes can be used at a defined cutting speed, rotational speed, feed rate, with up-cut milling and/or up/down-cut milling in order to determine the respective specific state of wear. It turns out that the materials used as the sacrificial workpiece 11 and the process parameters and/or milling methods used in the test measurements for the optimal determination of the respective state of wear with regard to the wear/failure type considered can be different, so that it is advantageous if depending on the wear considered -ZFailure type, a different or adapted sacrificial workpiece 11 is used and different or adapted process parameters and/or milling methods are used.
- a method for determining a state of wear is optionally defined for the method according to the invention, in which, when using a new tool 2 as a cutting tool, a corresponding measurement is carried out as a reference section for each type of wear failure considered. If, for example, three types of wear/failure are considered, then three test measurements are carried out in new condition as reference cuts, one reference cut each for each possible type of failure considered, each with specific parameters and/or specific milling methods on a specific sacrificial workpiece 11 in each case.
- measured values are recorded by means of at least one sensor 12, with a time profile of the measured value being recorded during the test measurement, and the absolute values of the measured values thus being determined.
- the change in the course of the measured value over time, the first derivation can be determined as a function of time and/or the second derivation of the measured value can also be determined as a function of time.
- test measurements can be carried out during processing, such as milling, on the individual available sacrificial materials with the framework conditions specified in each case, such as in the first test measurement when new, recorded, compared and the course or courses of the measured values determined or updated in the sense of a history.
- test measurements also referred to as reference cuts, are carried out on specific sacrificial materials depending on the types of wear/failure considered.
- the sacrificial materials used can be arranged on the same measuring device with the sensors 12 provided, provided that comparable signals/physical quantities are used to determine the specific state of wear. If several different signals/physical quantities are required, several measuring devices with corresponding sensors 12 can also be used.
- a multifunctional measuring device with different sensors 12 for determining different signals/physical variables, which are used to determine the state of wear, would also be advantageous.
- an evaluation unit 15 which can be embodied, for example, as the control unit 14 or which can also be provided as a separate evaluation unit 15, it is possible, on the basis of the measured values determined and their time profiles, to calculate first derivatives and/or second derivatives as values and/or or their time courses to recognize the respective tool condition or wear condition depending on the specific type of wear and failure and/or the specific probability of failure.
- Probability of failure can be recognized by defined algorithms. For this the different measured values and/or wear states per type of wear Z-failure are processed together and depending on the overall result of this processing, a recommendation for the remaining use and/or further use of the tool, the cutting edge 3 and/or the Cutting 3 are issued.
- a recommendation can be given according to which the cutting speed should be reduced, the feed increased or an immediate tool change or cutting edge change should be carried out.
- the measuring device provided with the at least one sensor 12 with the clamped sacrificial materials is designed individually for each type of wear or failure.
- the measuring devices can also form a technical unit.
- the measuring device with the arranged or clamped sacrificial materials can also be designed as a multifunctional element and form a technical unit.
- the measuring device with the arranged or clamped sacrificial material or with the arranged or clamped sacrificial materials as an independent, in particular preassemblable, unit in a processing space of a device for processing workpieces, such as a machine tool , can be arranged.
- the measuring device can be arranged on a machine table of the device for machining workpieces or can be integrated into the machine table.
- the sensors for the function of measuring the signals and/or physical quantities during the test processing of the sacrificial workpiece 11 made of the sacrificial material i.e. the measuring device
- the clamping of the sacrificial workpiece 11 or the sacrificial workpieces 11 made of the sacrificial material or are housed from the sacrificial materials in one array or in two separate arrays or units.
- the measuring device can be arranged, for example, between the tool and a drive unit, such as a drive spindle.
- a tool 2 with at least one cutting edge 3 can be identified by using at least one sensor 12 and the state of wear or states of wear can be stored individually for each type of wear, which is particularly advantageous for tools 2 that are only used temporarily.
- the senor 12 could also be arranged in the drive train, in particular between the drive 5 and the actuator 6.
- the tool 2 according to the invention is in particular a multi-edged milling tool, the cutting edges 3 being based on a hard metal.
- the tool and/or the cutting edges are exchangeable.
- the tools are highly positive tools.
- the use of highly positive tools means the use of tools with a decreasing rake angle or with a reduced rake angle compared to conventional tools with the usual rake angles.
- the development of highly positive tools, i.e. with a decreasing rake angle means that different advantages can be exploited when machining using highly positive tools. This The main advantages are significantly reduced cutting forces. Due to the lower cutting resistance as a result of the reduced angle, a lower energy conversion is also generated during cutting, which results in significantly reduced heat absorption on the workpiece to be machined and also on the tool. As a result, the thermal expansion is lower and the accuracy of the method increases. In roughing processes, a significantly higher machining volume per unit of time can therefore be expected with comparable heat absorption on the workpiece. Likewise, less drive energy is advantageously required.
- the method according to the invention for determining the state of wear of a tool therefore offers the possibility of better monitoring the use, in particular also of highly positive tools, and of predicting or estimating their wear or failure before damage occurs to the workpiece. This has the advantage that the market penetration of highly positive tools can be accelerated with the advantages mentioned.
- a cutting edge fracture occurs when the tool is subjected to excessive mechanical stress. This type of wear can also occur as a result of other types of wear. Crater wear, built-up edges, high flank wear and/or other process-influencing elements, such as vibrations or incorrectly selected cutting parameters, can lead to a broken edge. In addition, an inhomogeneity of the hard metal can lead to local spalling. For example, in the case of abrasive materials, if the Co content in the hard metal is too low, breakouts can occur on the cutting edge of the cutting edge.
- a tool such as an indexable insert, with a defined cutting geometry cannot be used equally well for all materials.
- the cutting edge fracture is the result of a cutting edge that is subjected to too much stress and can be seen as the final instance in all of the following types of wear.
- Cutting edge breakage is to be avoided in all machining operations.
- the cutting parameters are decisive for this. These should be adjusted in good time when wear begins.
- a brittle material with good transmission of structure-borne noise is suitable for carrying out the test measurement on a sacrificial material as a sacrificial workpiece.
- Climb milling can be carried out, for example, which generates a pronounced signal peak when the cutter blade enters the workpiece. Normal feed rates and cutting speeds specific to the sacrificial material can be used.
- a structure-borne noise measurement ie a vibration measurement and/or a structure-borne noise measurement in combination with a force measurement and/or also in combination with a Optical monitoring, for example by means of a camera system, can be carried out.
- Flank wear is one of the most common types of wear in machining. This type of wear usually occurs when the actual clearance angle is too small, with abrasive materials or when the selected cutting speed is too high. Flank wear is very common in finishing because the cutting speed is high and the feed rate is low during finishing. Due to the high cutting speed, the temperature increases and as a result, microparticles of the hard metal are dissolved in the cutting material. In addition, the friction between the cutting edge and the material increases because the tool is engaged for a longer time due to the low feed rate.
- the solution and example is to reduce the cutting speed.
- the cutting speed is reduced, for example.
- the cutting speed can be reduced from 240 m/min to 210 m/min. This optimization can increase the service life by 25%.
- a ductile/soft material can be considered as the sacrificial material, possibly also a plastic composite material.
- a counter-rotation method can be used, for example with a gentle entry with an increase in the chip thickness and the cutting forces. With increasing flank wear, the material tends to "smear". The limit can be detected much better with soft material.
- Very low feed rates can be used here.
- a low cutting speed and possibly also running through a speed scale can be used.
- a force measurement can be carried out.
- Crater wear is thermal diffusion that occurs on the rake face due to mechanical abrasion between the workpiece and the tool. This type of wear is an indication that the cutting speed selected is too high for an unfavorable cutting material and/or insufficient cooling and lubrication during the machining process.
- Crater wear can usually be reduced or avoided by optimizing the tool cooling and reducing the cutting speed. Machining a flange made of steel 1 .4301 at a selected cutting speed of 180 m/min causes premature crater wear. The addition of coolant and reducing the cutting speed to 120 m/min eliminated crater wear and increased tool life by 30%.
- a tough material can be used as the sacrificial material.
- a reverse flow method can be used, for example with a gentle entry with increasing chip thickness and cutting forces. Normal feed values can be used here. Specific cutting speeds can be used depending on the sacrificial material.
- a force measurement or optionally a force measurement in combination with optical monitoring can be used. This can be checked, for example, on a sacrificial workpiece made from a sacrificial material with steel 1.4301 or 1.2738.
- a cutting speed that is too low or a tooth feed that is too low can lead to a built-up edge. This results in material sticking to the cutting face of the tool. Edge build-up can occur, especially with tough materials such as stainless steel, aluminum and steel with a low carbon content.
- the built-up edge can be counteracted by increasing the cutting speed and more precise coolant supply.
- Roughing a forging die made of 1.2738 steel revealed the following problem.
- a cutting speed of 180 m/min after a short period of use, there was a significant amount of material sticking to the cutting surface of the tool, i.e. an indexable insert. This led to an unforeseeable breaking of the cutting edge after a service life of approx. 66 m per cutting edge.
- Increasing the cutting speed to 210 m/min resulted in a 15% longer tool life. This can be checked, for example, on a sacrificial workpiece made from a sacrificial material with steel 1.4301 or 1.2738.
- a tough material can be used as a sacrificial material in the opposite direction or in the synchronous direction. Normal feed rates may be used, such as normal cutting speeds specific to the sacrificial material. A force measurement or optionally a force measurement in combination with optical monitoring can be used. cracking:
- a crack in a tool tends to propagate on the flank face. After the crack has grown, neither the cutting edge nor the contact surface is functional. Built-up edge is one of the most common causes of cracking during the machining process.
- the chips stuck to the cutting edge absorb the cutting forces and at the same time store the high heat. Accordingly, they cause the spalling on the cutting edge.
- the chips penetrate into the crack gaps and generate indefinite stresses, which further influence the course of the crack formation. Severe temperature changes and the constant cutting in and out during milling result in so-called comb crack formation on the cutting edge.
- the following measures can be taken to counteract the formation of cracks and comb cracks: If cracks form due to high mechanical loads, the tooth feed should be reduced so that the fatigue strength of the cutting material is maintained. If cracks form due to built-up edges, the countermeasures for avoiding built-up edges must be applied, see above under the topic of built-up edges. Measures can be taken against temperature fluctuations if comb cracks form. dry machining or Sufficient coolant supply and a reduction in the cutting speed can remedy the situation.
- a brittle material with good transmission of structure-borne noise can be used as the sacrificial material. Up-cut milling can be used. In particular, low feed rates specific to the sacrificial material chosen can be employed.
- a structure-borne noise measurement, such as a vibration measurement, can be carried out.
- the method according to the invention provides in particular that the test machining is machining of the sacrificial workpiece, the tool being moved in a predefined feed direction at a predefined feed rate relative to the sacrificial workpiece, the sensor exerting a force exerted by the tool on the sacrificial workpiece Absorbs force, the direction of the absorbed force being aligned at a predefined angle to the feed direction.
- FIG. 2 shows a schematic sectional illustration of an exemplary embodiment of a device according to the invention for carrying out test processing and test measurement.
- Milling of a sacrificial workpiece can be performed as a test machining using a tool as a milling tool, in particular with one cutting edge or with a plurality of cutting edges.
- Figure 2 shows a device 1 for determining the state of wear of a tool 2 and/or at least one cutting edge 3, in particular a tool 2 according to Figure 1, a holding device 10 being provided with a first receptacle 20 for at least one sacrificial workpiece 21
- FIG. 2 shows various sacrificial workpieces 21 which are arranged in a stepped manner one on top of the other. A different arrangement can also be provided, for example just one sacrificial workpiece 21 .
- a second receptacle 22 is provided for the sensor 12, on which the sensor 12 is arranged.
- the at least one sacrificial workpiece 21 is coupled to the sensor 12 in such a way that at a Test processing of the sacrificial workpiece 21, a force from the sacrificial workpiece 21 to the sensor 12 can be transmitted.
- the holding device 10 has a base body 23 which is arranged, for example, on a machine table 24 of the processing machine, such as the milling machine.
- the base body 23 forms the second receptacle 22 for the sensor 12 .
- a carrier 25 is provided, which is guided to be displaceable in one direction relative to the base body 23 .
- the carrier 25 forms the first receptacle 20 for the sacrificial workpiece 21 .
- the sensor 12 is arranged between the second receptacle 22 and the carrier 25 and is subjected to a force by the carrier 25 .
- the force accumulator 26 is advantageously supported on the base body 23 on a contact surface of an adjusting screw 27, so that the prestressing of the force accumulator 26 can be adjusted.
- a transmission element 28 is arranged between the carrier 25 and the sensor 12 in order to be able to align and/or define the direction in which the force is introduced onto the sensor.
- the advantage here is that it can be achieved that with a point contact, for example, due to the spherical transmission element 28, only compressive forces can be transmitted in the normal direction, so that interference can be reduced.
- the carrier 25 is guided by a guide 29 in the base body 23 such that the carrier 25 relative to the base body 23 in a defined Direction is stored displaceable.
- the base body 23 has at least one guide column 30 which is guided through a guide bushing 31 so that the carrier 25 can only be displaced in the longitudinal direction of the guide column 30 .
- At least one sacrificial workpiece 21 is provided on the carrier 25 and is arranged fastened on the carrier 25 .
- a predefined number of sacrificial workpieces 21 is provided.
- a sacrificial workpiece 21 is provided or two or three sacrificial workpieces 21 made of different sacrificial materials are provided for determining a state of wear according to flank wear, crater wear, built-up edge, crack formation and/or a broken edge.
- the tool 2 is moved in a straight line in the predefined feed direction 33 at the predefined feed rate relative to the sacrificial workpiece 21 during the test machining.
- the force is measured in a force direction 34, which the sensor 12 detects, at a defined angle a to the feed direction 32. It is advantageous if the angle a is aligned in the range from 60° to 120°, in particular approximately 90°, such as 90°, to the feed direction 32, see Figure 2.
- the sensor 12 is a force or pressure sensor, which is arranged in such a way that only one force acts on it, the force direction 34 of which is aligned at an angle a in the range of 60° to 120°, in particular approximately 90°, to the feed direction 32.
- the sacrificial workpiece 21 is milled along the feed direction 32 of the tool 2 at the feed rate of the tool 2 by means of the tool 2, in particular in a rectilinear direction.
- the force direction 34 of the detected force is essentially perpendicular to the feed direction 32 . This can reduce interference.
- a specific "tool/sacrificial material reference curve" can be generated for the different tools 2, such as different types of milling cutters, see Figure 4.
- This reference curve according to Figure 4 can be generated in that with a new tool 2 the forces Fy are measured on the defined sacrificial workpiece 21. Both the course of the force as a function of time and the peak values of the forces that occur per cutting edge 3 are determined, see FIG. 5.
- FIG. 5 shows an example course of the force Fy as a function of time during test machining.
- the tool 2 After the test measurement with this new tool 2 on a sacrificial workpiece 21, the tool 2 is used on a workpiece to be machined in the further course of the use of the tool 2 on conventional workpieces and is thus worn out.
- the reference curve of FIG. 4 can be determined as a function of the degree of wear of the cutting edges 3 or the tool 2.
- the degree of wear and the permissible limits of wear of the tool or the cutting edges 3 are defined visually.
- the force value that is present at the just permissible wear is stored as a limit value and can later be stored as the "switch-off intermediate point".
- the course of the cutting force according to FIG. 5 can also be determined and recorded.
- This course corresponds to a “so “genetic” fingerprint of the tool used 2, such as a milling tool, and of each individual cutting edge 3.
- the time course of the force of each Tool 2 or each cutting edge 3 compared with the original force curve of the new tool or the new milling cutter. This comparison shows whether, in addition to the "normal" wear, there is a special event such as a broken edge or crater wear.
- the advantage here is that to assess the current wear situation of the tool 2 or the cutting edges 3, only the force profile of one revolution of the milling cutter is required. It can thus be assumed that the sacrificial material is used to a minimum.
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Machine Tool Sensing Apparatuses (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE112022004346.6T DE112022004346A5 (de) | 2021-09-10 | 2022-09-07 | Verfahren zur Bestimmung eines Verschleißzustandes eines Werkzeugs und Vorrichtung hierfür |
EP22782468.7A EP4399502A1 (de) | 2021-09-10 | 2022-09-07 | Verfahren zur bestimmung eines verschleisszustandes eines werkzeugs und vorrichtung hierfür |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102021210051 | 2021-09-10 | ||
DE102021210051.1 | 2021-09-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2023036828A1 true WO2023036828A1 (de) | 2023-03-16 |
Family
ID=83505883
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2022/074878 WO2023036828A1 (de) | 2021-09-10 | 2022-09-07 | Verfahren zur bestimmung eines verschleisszustandes eines werkzeugs und vorrichtung hierfür |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP4399502A1 (de) |
DE (2) | DE102022209160A1 (de) |
WO (1) | WO2023036828A1 (de) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007005221A1 (de) * | 2006-02-03 | 2007-08-23 | Ceramtec Ag Innovative Ceramic Engineering | Einsatz von piezokeramischen Wandlern zur Regelung der spanabhebenden Werkstückbearbeitung |
-
2022
- 2022-09-02 DE DE102022209160.4A patent/DE102022209160A1/de active Pending
- 2022-09-07 DE DE112022004346.6T patent/DE112022004346A5/de active Pending
- 2022-09-07 EP EP22782468.7A patent/EP4399502A1/de active Pending
- 2022-09-07 WO PCT/EP2022/074878 patent/WO2023036828A1/de active Application Filing
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007005221A1 (de) * | 2006-02-03 | 2007-08-23 | Ceramtec Ag Innovative Ceramic Engineering | Einsatz von piezokeramischen Wandlern zur Regelung der spanabhebenden Werkstückbearbeitung |
Non-Patent Citations (1)
Title |
---|
WANG C Y ET AL: "Wear and breakage of TiAlN- and TiSiN-coated carbide tools during high-speed milling of hardened steel", WEAR, vol. 336, 4 May 2015 (2015-05-04), pages 29 - 42, XP029232890, ISSN: 0043-1648, DOI: 10.1016/J.WEAR.2015.04.018 * |
Also Published As
Publication number | Publication date |
---|---|
DE102022209160A1 (de) | 2023-03-16 |
EP4399502A1 (de) | 2024-07-17 |
DE112022004346A5 (de) | 2024-06-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2924526B9 (de) | Verfahren zur einrichtung und/oder überwachung von betriebsparametern einer werkstückbearbeitungsmaschine | |
EP0051771B1 (de) | Verfahren und Vorrichtung zur Überwachung der Schneidplatten in Werkzeugmaschinen | |
DE3903133A1 (de) | Werkstueckbearbeitbarkeitsdetektionsverfahren und verfahren zum spanabhebenden bearbeiten eines werkstuecks mit hilfe einer spanabhebenden bearbeitungsmaschine unter anwendung dieses verfahrens | |
DE19716888B4 (de) | Werkzeugmaschine mit einer Abnutzungs-Erfassungsfunktion für das Werkzeug und Verfahren zur Erfassung der Abnutzung eines Werkzeugs einer Werkzeugmaschine | |
EP0705156B1 (de) | Verfahren zur vermeidung von überbeanspruchungen eines werkstückes beim schleifen | |
EP3389890B1 (de) | Verfahren und vorrichtung zum trennen eines werkstückes | |
DE102012106139A1 (de) | Verfahren und Vorrichtung zur Ermittlung eines Werkzeugverschleißes in einer Werkzeugmaschine zur geometrisch bestimmten Zerspanung | |
EP3792712A1 (de) | Verfahren zur korrektur von werkzeugparametern einer werkzeugmaschine zur bearbeitung von werkstücken | |
EP2156921A1 (de) | Vorrichtung zur Verminderung von Schwingungen einer Werkzeugspindel | |
WO2017009414A1 (de) | Werkzeugmaschineneinheit mit einer werkzeug-spannvorrichtung | |
EP3636373B1 (de) | Verfahren und vorrichtung zur kontrolle einer stabmessereinspannung und/oder eines messerschachts eines stabmesserkopfs zur kegelradherstellung | |
WO2021185820A1 (de) | Verfahren zur bestimmung eines verschleisszustandes eines werkzeuges und vorrichtung hierfür | |
EP0268622A1 (de) | Verfahren, messgerät, feinverstellbare werkzeughalterung mit kompensationseinrichtung für prozessintegrierte qualitätssicherung in spanenden nc-werkzeugmaschinen | |
WO2023036828A1 (de) | Verfahren zur bestimmung eines verschleisszustandes eines werkzeugs und vorrichtung hierfür | |
CH705388B1 (de) | Werkzeug. | |
DE102008055977A1 (de) | Verfahren und Vorrichtung zur Bestimmung der Verformung eines rotierenden spanenden Werkzeugs | |
EP2347844B1 (de) | Verfahren zum Nachbearbeiten einer Zentrierbohrung | |
DE3902840C2 (de) | ||
DE29722951U1 (de) | Werkzeugpositionsdetektor für eine Drehbank | |
CH676341A5 (de) | ||
DE102020110343B4 (de) | Verfahren zur adaptiven Vorschubregelung an einer CNC-gesteuerten Drehmaschine | |
DE102018002444B9 (de) | Verfahren und Einrichtung zum Zuführen von Kühlmittel an einer Schleifmaschine | |
EP0163035B1 (de) | Verfahren zum Reprofilieren von Profilen von Radsätzen | |
DE19722937A1 (de) | Regelsystem und Verfahren zur Regelung von Bearbeitungsgeschwindigkeiten bei der Holzbearbeitung | |
DE102020205088A1 (de) | Verfahren und Auswertesystem zur Überwachung eines Werkzeugverschleißes von Werkzeugkomponenten bei zerspanenden Fertigungsanlagen |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22782468 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2022782468 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2022782468 Country of ref document: EP Effective date: 20240410 |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: R225 Ref document number: 112022004346 Country of ref document: DE |