US20210023675A1 - Abrasive Disk, Hand-Held Power Tool and Control Method - Google Patents
Abrasive Disk, Hand-Held Power Tool and Control Method Download PDFInfo
- Publication number
- US20210023675A1 US20210023675A1 US16/762,839 US201816762839A US2021023675A1 US 20210023675 A1 US20210023675 A1 US 20210023675A1 US 201816762839 A US201816762839 A US 201816762839A US 2021023675 A1 US2021023675 A1 US 2021023675A1
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- United States
- Prior art keywords
- abrasive disk
- conductor loop
- closed conductor
- sensor
- power tool
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 238000000034 method Methods 0.000 title claims description 5
- 239000004020 conductor Substances 0.000 claims abstract description 81
- 239000006061 abrasive grain Substances 0.000 claims abstract description 4
- 238000004891 communication Methods 0.000 claims description 9
- 230000004044 response Effects 0.000 claims description 3
- 238000001514 detection method Methods 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
- B24B49/10—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation involving electrical means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B47/00—Drives or gearings; Equipment therefor
- B24B47/10—Drives or gearings; Equipment therefor for rotating or reciprocating working-spindles carrying grinding wheels or workpieces
- B24B47/18—Drives or gearings; Equipment therefor for rotating or reciprocating working-spindles carrying grinding wheels or workpieces for rotating the spindle at a speed adaptable to wear of the grinding wheel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B51/00—Arrangements for automatic control of a series of individual steps in grinding a workpiece
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
- B24D5/02—Wheels in one piece
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B27/00—Other grinding machines or devices
- B24B27/06—Grinders for cutting-off
- B24B27/08—Grinders for cutting-off being portable
Definitions
- the present invention relates to a disk, a hand-held power tool for abrasive disks and a control method.
- Abrasive disks rotate at high speed. During use of the disk, abraded matter of the disk and of the machined material fly away from the disk at high speed. Furthermore, the disk is subject to high loads due to centrifugal force. For safety reasons, therefore, the regulatory authorities set an upper limit for the rotational speed.
- Abrasive disks are subject to wear.
- the wear leads to a reduced periphery and thus reduced rotational speed.
- the reduced rotational speed adversely affects the machining performance of the disks.
- An abrasive disk according to the invention has one or more layers, in which abrasive grains are embedded. Embedded in one layer is sensor for detecting an original periphery of the abrasive disk that has been altered by wear.
- the sensor has at least one closed conductor loop, which is arranged at a radial distance from the original periphery such that, when the original periphery is worn by more than the radial distance, the conductor loop is interrupted.
- a transponder emits a radio signal indicative of whether the conductor loop is closed or interrupted.
- the radio signals indicate the radial wear of the disk.
- a hand-held power tool can adjust the speed accordingly.
- a hand-held power tool for the abrasive disk has a holder for the abrasive disk, an electric motor for rotating the abrasive disk and a speed control for the electric motor.
- a communication device is set up to receive the radio signal emitted by the transponder of the abrasive disk.
- a device controller sets the speed for the speed control based on the radio signal received.
- FIG. 1 shows an electric angle grinder
- FIG. 2 shows an abrasive disk in cross section
- FIG. 3 shows the abrasive disk in a plan view
- FIG. 4 shows a detail of an abrasive disk
- FIG. 5 shows a detail of an abrasive disk.
- FIG. 1 shows an electric hand-held power tool 1 for abrasive disks 2 .
- the hand-held power tool 1 has a tool holder 3 for an abrasive disk. 2
- the tool holder 3 is coupled to an electric motor 4 , which rotatably drives the tool holder 3 about its axis.
- a speed control 5 controls the electric motor 4 .
- the speed control 5 limits the speed to a maximum speed in order to prevent damage to the abrasive disk 2 and possible injury to the user.
- a protective hood 6 annularly encloses more than half of the tool holder 3 , in order to protect the user from flying sparks and substance abrasively removed.
- the hand-held power tool 1 has a handle 7 with which the user can hold and guide the hand-held power tool 1 in operation. At or near the handle 7 , a button 8 for starting the electric motor 4 is arranged.
- the hand-held power tool 1 can be powered from the grid or by means of batteries 9 .
- the hand-held power tool 1 has a device controller 10 .
- the device controller 10 sets the target speed for the speed control 5 .
- the device controller 10 may access a memory 11 , in which a target speed is stored.
- the device controller 10 may also access a communication device 12 in order to communicate with an abrasive disk 2 .
- the communication device 12 has a transmitter 13 for transmitting radio-based signals and a receiver 14 for receiving a radio-based response of the abrasive disk 2 .
- a transmission power of the transmitter 13 is preferably sufficient to power a transponder, e.g., a radio-frequency identification (RFID) chip, without its own energy source via the transmission power.
- RFID radio-frequency identification
- the device controller 10 When the button 8 is actuated, the device controller 10 directs a request to the disk 2 to identify it.
- the disk 2 if equipped with a transponder 15 , reports an identification number or type number.
- the device controller 10 checks whether the type number differs from the disk 2 last used. If this is the case, the device controller 10 inquires what is a maximum permissible speed for the disk 2 .
- the device controller 10 stores the maximum permissible speed in the memory 11 .
- the disk 2 transmits a list of different maximum speeds to be used depending on a degree of wear of the disk 2 . The degree of wear is coded in radio signals which are transmitted in the list.
- the device controller 10 stores the list in the memory 11 .
- the device controller 10 sets the speed of the speed control 5 to the maximum permissible speed that corresponds to the current degree of wear.
- the device controller inquires at intervals via the communication device 12 what is the degree of wear of the disk 2 .
- the radio signal received as a response by the communication device 12 is compared with the stored list.
- the maximum permissible speed associated with the radio signal is transmitted to the speed control 5 .
- FIG. 2 schematically shows an embodiment of an abrasive disk 2 in cross section.
- the abrasive disk 2 shown is a multi-layer cutting disk with different grains.
- the abrasive disk 2 has a middle layer 16 with first grains.
- the middle layer 16 can be produced for example by an electrodeposited matrix in which the grains are distributed.
- the two outer layers 17 , 18 can also be produced with an electrodeposited matrix and scattered embedded grains.
- the grains of the middle layer 16 may be larger than the grains of the outer layers 17 , 18 .
- the grains given by way of example have a diameter of 4 ⁇ m to 10 ⁇ m and 10 ⁇ m to 20 ⁇ m, respectively.
- the production of the layers 18 is purely exemplary.
- Another method given by way of example is based on fabrics that are impregnated with resins mixed the grains. The resins are then cured.
- the number of different layers is also purely exemplary.
- Other disks have one, two or more different abrasive layers.
- the disks 2 are provided with a cover layer 19 , on which the disk type, manufacturer, etc. are indicated.
- the disks are produced with different diameters. Diameters given by way of example are 8.9 cm and 11.2 cm.
- FIG. 3 illustrates an instance of wear given by way of example.
- the as-new disk 2 has the original periphery 20 .
- the disks 2 become worn during use, which reduces the diameter and periphery. Examples of a periphery 21 of a worn disk 2 are shown by dashed lines.
- the original diameter, original radius or original periphery 20 designates the respective property of a new, unused abrasive disk 2 .
- a sensor 22 which detects wear and the degree of wear of the disk 2 .
- the sensor 22 is based on one or more closed conductor loops 23 , 24 .
- the conductor loops 23 , 24 run parallel to the abrasive layers 16 .
- the conductor loop 23 may be printed on a film of non-conductive plastic.
- the film is stacked as a further layer 25 with the other layers 16 .
- the film may be arranged as shown on the abrasive layers 16 or between the abrasive layers 18 .
- the conductor loops 23 , 24 have a low mechanical strength.
- the conductor loops 23 , 24 preferably have a height of less than 100 ⁇ m.
- the conductor loops 23 , 24 are preferably made of copper or graphite.
- the closed conductor loop 23 has a (detection) portion 26 which is closest to the periphery 20 and farthest from a center of the disk 2 .
- the detection portion 26 is at a radial distance 27 .
- the detection portion 26 given by way of example lies within the original periphery 20 and outside a worn periphery 21 .
- the radius of the worn periphery 20 corresponds to the original radius reduced by the distance 27 .
- the detection portion 26 is exposed by the distance 27 , i.e., up to the worn periphery 21 , and destroyed.
- the previously closed conductor loop 23 is then interrupted.
- a sensor 22 for example on in the layer 25 with the conductor loops.
- the sensor 22 may be realized for example as an RFID chip.
- the sensor 22 checks the closed or interrupted state of the conductor loop 23 .
- the sensor 22 determines the electrical properties of the conductor loop 24 , e.g., resistivity, inductance and electromagnetic resonant frequency.
- the sensor 22 is based for example on an ohmmeter for determining the electrical resistance value of the conductor loop 23 . If the resistance value exceeds a threshold value, e.g., 1 megohm, the conductor loop 24 is considered to be interrupted, otherwise the conductor loop 23 is considered to be closed.
- the conductor loop 23 is galvanically connected to the sensor 22 .
- the ohmmeter applies a voltage to the conductor loop 23 and measures the amplitude of the current flowing in the conductor loop 23 .
- Another configuration of the sensor 22 determines the inductance of the conductor loop 23 .
- a further configuration of the sensor 22 determines whether the resonant frequency of the conductor loop 23 changes.
- the conductor loop 23 may be part of an electrical oscillating circuit or be inductively coupled to an oscillating circuit of the sensor 22 . While the conductor loop 23 or the oscillating circuit can be excited at a predetermined resonant frequency with a closed conductor loop 23 , this is not possible with an interrupted conductor loop, or if it is at a different resonant frequency.
- the sensor 22 excites the oscillating circuit at the predetermined resonant frequency.
- the conductor loop 23 is considered to be closed, otherwise it is considered to be interrupted.
- the described configurations for determining the electrical properties of the conductor loop 23 are given by way of example.
- the sensor 22 may also be passively formed.
- An external transmission source excites the oscillating circuit 28 .
- the sensor 22 includes a transponder 15 .
- the transponder 15 may consist of a passive antenna.
- the transponder 15 transmits the state of the conductor loop, i.e., whether the conductor loop is interrupted or whether the conductor loop is closed.
- the senor 22 includes a memory 29 , in which characteristics of the abrasive disk 2 are stored. For example, a maximum permissible speed for the disk 2 when the conductor loop 23 is closed and a maximum permissible speed for the disk 2 when the conductor loop 23 is interrupted are stored in the memory 29 .
- the sensor 22 determines the currently permissible rotational speed based on the determined state of the conductor loop 23 .
- the permissible speed is output via the transponder 15 .
- the transponder 15 can transmit both values, i.e., for the closed conductor loop 23 and the interrupted conductor loop 23 , at one time to the communication device 12 of the hand-held power tool 1 . At the same time, the transponder 15 transmits the radio signals or their coding for the two states. An evaluation can thus be transmitted to the device controller 10 .
- the sensor 22 may have a. second conductor loop 24 or a number of conductor loops.
- the second conductor loop 24 is at a greater distance 30 from the original periphery 20 . Accordingly, the second conductor loop 24 is only severed when there is a greater degree of wear 31 .
- the second conductor loop 24 has a detection portion 32 in a way similar to the first conductor loop 23 . The detection portion 32 is destroyed when the abrasive disk 2 is worn by more than the distance 30 .
- the sensor 22 detects whether the second conductor loop 24 is closed or interrupted.
- the two conductor loops 23 , 24 can be galvanically isolated as shown.
- the sensor 22 can scan the conductor loops 23 , 24 one after the other.
- the transponder 15 transmits a radio signal in which the state of both conductor loops 23 , 24 is coded,
- the number of conductor loops 23 , 24 may be greater than two, e.g., up to ten conductor loops.
- the sensor 22 and the memory 29 need only be scaled accordingly.
- FIG. 4 and FIG. 5 show other configurations of the conductor loops, in which the conductor loops 33 , 34 are galvanically connected.
- a first conductor loop 33 is at the smallest distance 27 from the original periphery 20 .
- a second conductor loop 24 is at a greater distance 30 from the original periphery 20 .
- Their respective detection portions 35 , 36 are radially offset from one another, as in the first embodiment.
- the sensor 22 may for example determine the change in resistance of the connected conductor loops.
- the conductor loops 33 , 34 form an electrical parallel circuit. With each interrupted conductor loop 33 , the resistance value of the parallel circuit increases.
- the conductor loops 33 , 34 preferably each have a clearly measurable resistance 37 .
- the resistance 37 may for example be produced by using graphite instead of a metal for the conductor loops 33 , 34 .
- the sensor 22 may determine the inductance or resonant frequency of the parallel-connected conductor loops 33 , 34 .
- the inductance of the parallel circuit decreases with each severed conductor loop 33 .
- the resonant frequency increases with each separated conductor loop 33 .
- the parallel-connected conductor loops 33 , 34 may be part of an oscillating circuit 28 of the sensor 22 or be inductively excited via an oscillating circuit 28 of the sensor 22 .
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Polishing Bodies And Polishing Tools (AREA)
Abstract
Description
- This application is a National Stage of PCT International Application No. PCT/EP2018/079648, filed Oct. 30, 2018, which claims priority under 35 U.S.C. § 119 from European Patent Application No. 17201070.4, filed Nov. 10, 2017, the entire disclosures of which are herein expressly incorporated by reference.
- The present invention relates to a disk, a hand-held power tool for abrasive disks and a control method.
- Abrasive disks rotate at high speed. During use of the disk, abraded matter of the disk and of the machined material fly away from the disk at high speed. Furthermore, the disk is subject to high loads due to centrifugal force. For safety reasons, therefore, the regulatory authorities set an upper limit for the rotational speed.
- Abrasive disks are subject to wear. The wear leads to a reduced periphery and thus reduced rotational speed. The reduced rotational speed adversely affects the machining performance of the disks.
- An abrasive disk according to the invention has one or more layers, in which abrasive grains are embedded. Embedded in one layer is sensor for detecting an original periphery of the abrasive disk that has been altered by wear. The sensor has at least one closed conductor loop, which is arranged at a radial distance from the original periphery such that, when the original periphery is worn by more than the radial distance, the conductor loop is interrupted. A transponder emits a radio signal indicative of whether the conductor loop is closed or interrupted.
- The radio signals indicate the radial wear of the disk. A hand-held power tool can adjust the speed accordingly.
- A hand-held power tool for the abrasive disk has a holder for the abrasive disk, an electric motor for rotating the abrasive disk and a speed control for the electric motor. A communication device is set up to receive the radio signal emitted by the transponder of the abrasive disk. A device controller sets the speed for the speed control based on the radio signal received.
- The following description explains the invention on the basis of exemplary embodiments and Figures.
-
FIG. 1 shows an electric angle grinder; -
FIG. 2 shows an abrasive disk in cross section; -
FIG. 3 shows the abrasive disk in a plan view; -
FIG. 4 shows a detail of an abrasive disk; and -
FIG. 5 shows a detail of an abrasive disk. - identical or functionally identical elements are indicated by the same reference numerals in the Figures, unless stated otherwise.
-
FIG. 1 shows an electric hand-heldpower tool 1 forabrasive disks 2. The hand-heldpower tool 1 has atool holder 3 for an abrasive disk. 2 Thetool holder 3 is coupled to an electric motor 4, which rotatably drives thetool holder 3 about its axis. Aspeed control 5 controls the electric motor 4. Thespeed control 5 limits the speed to a maximum speed in order to prevent damage to theabrasive disk 2 and possible injury to the user. Aprotective hood 6 annularly encloses more than half of thetool holder 3, in order to protect the user from flying sparks and substance abrasively removed. The hand-heldpower tool 1 has ahandle 7 with which the user can hold and guide the hand-heldpower tool 1 in operation. At or near thehandle 7, abutton 8 for starting the electric motor 4 is arranged. The hand-heldpower tool 1 can be powered from the grid or by means ofbatteries 9. - The hand-held
power tool 1 has a device controller 10. Among other things, the device controller 10 sets the target speed for thespeed control 5. The device controller 10 may access amemory 11, in which a target speed is stored. The device controller 10 may also access acommunication device 12 in order to communicate with anabrasive disk 2. Thecommunication device 12 has atransmitter 13 for transmitting radio-based signals and areceiver 14 for receiving a radio-based response of theabrasive disk 2. A transmission power of thetransmitter 13 is preferably sufficient to power a transponder, e.g., a radio-frequency identification (RFID) chip, without its own energy source via the transmission power. - When the
button 8 is actuated, the device controller 10 directs a request to thedisk 2 to identify it. Thedisk 2, if equipped with atransponder 15, reports an identification number or type number. The device controller 10 checks whether the type number differs from thedisk 2 last used. If this is the case, the device controller 10 inquires what is a maximum permissible speed for thedisk 2. The device controller 10 stores the maximum permissible speed in thememory 11. Preferably, thedisk 2 transmits a list of different maximum speeds to be used depending on a degree of wear of thedisk 2. The degree of wear is coded in radio signals which are transmitted in the list. The device controller 10 stores the list in thememory 11. The device controller 10 sets the speed of thespeed control 5 to the maximum permissible speed that corresponds to the current degree of wear. The device controller inquires at intervals via thecommunication device 12 what is the degree of wear of thedisk 2. The radio signal received as a response by thecommunication device 12 is compared with the stored list. The maximum permissible speed associated with the radio signal is transmitted to thespeed control 5. -
FIG. 2 schematically shows an embodiment of anabrasive disk 2 in cross section. Theabrasive disk 2 shown is a multi-layer cutting disk with different grains. Theabrasive disk 2 has amiddle layer 16 with first grains. Themiddle layer 16 can be produced for example by an electrodeposited matrix in which the grains are distributed. The twoouter layers middle layer 16 may be larger than the grains of theouter layers layers 18 is purely exemplary. Another method given by way of example is based on fabrics that are impregnated with resins mixed the grains. The resins are then cured. The number of different layers is also purely exemplary. Other disks have one, two or more different abrasive layers. Typically, thedisks 2 are provided with acover layer 19, on which the disk type, manufacturer, etc. are indicated. - The disks are produced with different diameters. Diameters given by way of example are 8.9 cm and 11.2 cm.
FIG. 3 illustrates an instance of wear given by way of example. The as-new disk 2 has theoriginal periphery 20. Thedisks 2 become worn during use, which reduces the diameter and periphery. Examples of a periphery 21 of aworn disk 2 are shown by dashed lines. In the following, the original diameter, original radius ororiginal periphery 20 designates the respective property of a new, unusedabrasive disk 2. - Embedded in the
abrasive disk 2 is asensor 22, which detects wear and the degree of wear of thedisk 2. Thesensor 22 is based on one or moreclosed conductor loops 23, 24. Theconductor loops 23, 24 run parallel to the abrasive layers 16. For example, theconductor loop 23 may be printed on a film of non-conductive plastic. The film is stacked as afurther layer 25 with the other layers 16. The film may be arranged as shown on theabrasive layers 16 or between the abrasive layers 18. Theconductor loops 23, 24 have a low mechanical strength. Theconductor loops 23, 24 preferably have a height of less than 100 μm. Theconductor loops 23, 24 are preferably made of copper or graphite. - The
closed conductor loop 23 has a (detection)portion 26 which is closest to theperiphery 20 and farthest from a center of thedisk 2. Thedetection portion 26 is at aradial distance 27. Thedetection portion 26 given by way of example lies within theoriginal periphery 20 and outside a worn periphery 21. The radius of theworn periphery 20 corresponds to the original radius reduced by thedistance 27. As thedisk 2 becomes worn, thedetection portion 26 is exposed by thedistance 27, i.e., up to the worn periphery 21, and destroyed. The previously closedconductor loop 23 is then interrupted. - Preferably arranged on the
disk 2 is asensor 22, for example on in thelayer 25 with the conductor loops. Thesensor 22 may be realized for example as an RFID chip. Thesensor 22 checks the closed or interrupted state of theconductor loop 23. Thesensor 22 determines the electrical properties of the conductor loop 24, e.g., resistivity, inductance and electromagnetic resonant frequency. Thesensor 22 is based for example on an ohmmeter for determining the electrical resistance value of theconductor loop 23. If the resistance value exceeds a threshold value, e.g., 1 megohm, the conductor loop 24 is considered to be interrupted, otherwise theconductor loop 23 is considered to be closed. Theconductor loop 23 is galvanically connected to thesensor 22. The ohmmeter applies a voltage to theconductor loop 23 and measures the amplitude of the current flowing in theconductor loop 23. Another configuration of thesensor 22 determines the inductance of theconductor loop 23. A further configuration of thesensor 22 determines whether the resonant frequency of theconductor loop 23 changes. Theconductor loop 23 may be part of an electrical oscillating circuit or be inductively coupled to an oscillating circuit of thesensor 22. While theconductor loop 23 or the oscillating circuit can be excited at a predetermined resonant frequency with aclosed conductor loop 23, this is not possible with an interrupted conductor loop, or if it is at a different resonant frequency. Thesensor 22 excites the oscillating circuit at the predetermined resonant frequency. If the power consumption exceeds a threshold value due to the resonant excitation, theconductor loop 23 is considered to be closed, otherwise it is considered to be interrupted. The described configurations for determining the electrical properties of theconductor loop 23 are given by way of example. Thesensor 22 may also be passively formed. An external transmission source excites theoscillating circuit 28. - The
sensor 22 includes atransponder 15. Thetransponder 15 may consist of a passive antenna. Thetransponder 15 transmits the state of the conductor loop, i.e., whether the conductor loop is interrupted or whether the conductor loop is closed. - In one configuration, the
sensor 22 includes amemory 29, in which characteristics of theabrasive disk 2 are stored. For example, a maximum permissible speed for thedisk 2 when theconductor loop 23 is closed and a maximum permissible speed for thedisk 2 when theconductor loop 23 is interrupted are stored in thememory 29. Thesensor 22 determines the currently permissible rotational speed based on the determined state of theconductor loop 23. The permissible speed is output via thetransponder 15. In one configuration, thetransponder 15 can transmit both values, i.e., for theclosed conductor loop 23 and the interruptedconductor loop 23, at one time to thecommunication device 12 of the hand-heldpower tool 1. At the same time, thetransponder 15 transmits the radio signals or their coding for the two states. An evaluation can thus be transmitted to the device controller 10. - In addition to the
first conductor loop 23 described, thesensor 22 may have a. second conductor loop 24 or a number of conductor loops. The second conductor loop 24 is at agreater distance 30 from theoriginal periphery 20. Accordingly, the second conductor loop 24 is only severed when there is a greater degree ofwear 31. The second conductor loop 24 has adetection portion 32 in a way similar to thefirst conductor loop 23. Thedetection portion 32 is destroyed when theabrasive disk 2 is worn by more than thedistance 30. Thesensor 22 detects whether the second conductor loop 24 is closed or interrupted. The twoconductor loops 23, 24 can be galvanically isolated as shown. Thesensor 22 can scan theconductor loops 23, 24 one after the other. With the second conductor loop 24, three states of wear can be distinguished: low, medium, high. For each of the states of wear, a separate maximum speed can be defined, and for example stored in thememory 29. Thetransponder 15 transmits a radio signal in which the state of bothconductor loops 23, 24 is coded, The number ofconductor loops 23, 24 may be greater than two, e.g., up to ten conductor loops. Thesensor 22 and thememory 29 need only be scaled accordingly. -
FIG. 4 andFIG. 5 show other configurations of the conductor loops, in which theconductor loops first conductor loop 33 is at thesmallest distance 27 from theoriginal periphery 20. A second conductor loop 24 is at agreater distance 30 from theoriginal periphery 20. Theirrespective detection portions - The
sensor 22 may for example determine the change in resistance of the connected conductor loops. Theconductor loops conductor loop 33, the resistance value of the parallel circuit increases. Theconductor loops measurable resistance 37. Theresistance 37 may for example be produced by using graphite instead of a metal for theconductor loops - The
sensor 22 may determine the inductance or resonant frequency of the parallel-connectedconductor loops conductor loop 33. The resonant frequency increases with each separatedconductor loop 33. The parallel-connectedconductor loops oscillating circuit 28 of thesensor 22 or be inductively excited via anoscillating circuit 28 of thesensor 22.
Claims (17)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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EP17201070.4 | 2017-11-10 | ||
EP17201070.4A EP3482876A1 (en) | 2017-11-10 | 2017-11-10 | Abrasive disc, handheld machine tool and control method |
PCT/EP2018/079648 WO2019091823A1 (en) | 2017-11-10 | 2018-10-30 | Abrasive disk, hand-held power tool and control method |
Publications (1)
Publication Number | Publication Date |
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US20210023675A1 true US20210023675A1 (en) | 2021-01-28 |
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ID=60331418
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US16/762,839 Pending US20210023675A1 (en) | 2017-11-10 | 2018-10-30 | Abrasive Disk, Hand-Held Power Tool and Control Method |
Country Status (4)
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US (1) | US20210023675A1 (en) |
EP (2) | EP3482876A1 (en) |
CN (1) | CN111132801B (en) |
WO (1) | WO2019091823A1 (en) |
Cited By (7)
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US20190344400A1 (en) * | 2017-01-23 | 2019-11-14 | Voith Patent Gmbh | Grinding robot and method for grinding electrically conductive workpieces |
US20200039027A1 (en) * | 2018-08-02 | 2020-02-06 | Saint-Gobain Abrasives, Inc. | Abrasive article including a wear detection sensor |
CN112207714A (en) * | 2019-07-10 | 2021-01-12 | 鼎朋企业股份有限公司 | Grinding machine tool with random eccentric orbit motion speed detection |
US20210008688A1 (en) * | 2019-07-08 | 2021-01-14 | Milwaukee Electric Tool Corporation | Power tool with electronic control of multiple speeds |
CN113001352A (en) * | 2021-03-22 | 2021-06-22 | 吾尚良品环境服务(上海)有限公司 | A spooler for stone material is polished |
US20210308825A1 (en) * | 2018-08-27 | 2021-10-07 | 3M Innovative Properties Company | A system for monitoring one or more of an abrading tool, a consumable abrasive product and a workpiece |
US20220111490A1 (en) * | 2018-08-27 | 2022-04-14 | 3M Innovative Properties Company | Embedded electronic circuit in grinding wheels and methods of embedding |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102019207736A1 (en) * | 2019-05-27 | 2020-12-03 | Robel Bahnbaumaschinen Gmbh | Method and cut-off machine for cutting through a rail of a track |
TWI690385B (en) * | 2019-06-28 | 2020-04-11 | 鼎朋企業股份有限公司 | Grinding machine tool with random eccentric orbit motion speed detection |
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4646001A (en) * | 1983-11-21 | 1987-02-24 | Morganite Electrical Carbon Limited | Resistive wear sensors |
DE10105781A1 (en) * | 2000-02-07 | 2001-08-30 | Cornelius Gaiser | Device for detecting and evaluating geometrical changes in objects, e.g. in milling, polishing or braking systems where conducting loops and resistances are used to detect electrical changes that are then related to size changes |
US20030006898A1 (en) * | 2001-07-03 | 2003-01-09 | International Business Machines Corporation | Warning method and apparatus |
US6602109B1 (en) * | 1998-12-16 | 2003-08-05 | University Of Massachusetts | Grinding wheel system |
US7840305B2 (en) * | 2006-06-28 | 2010-11-23 | 3M Innovative Properties Company | Abrasive articles, CMP monitoring system and method |
US20120043980A1 (en) * | 2009-02-27 | 2012-02-23 | Brian Investments Pty Ltd | Wear sensor |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007031299B4 (en) * | 2007-07-05 | 2013-02-28 | Peter Wolters Gmbh | Double side processing machine for machining a workpiece |
CN202155778U (en) * | 2011-06-01 | 2012-03-07 | 张文锦 | Automatic grinding wheel abrasion detecting device |
DE102013113202B4 (en) * | 2013-11-28 | 2016-12-08 | Rhodius Schleifwerkzeuge Gmbh & Co. Kg | Arrangement with a hand-held machine tool and a grinding wheel; Method for controlling the rotational speed of a hand-held machine tool and use of this method and this arrangement |
KR20170093238A (en) * | 2014-12-16 | 2017-08-14 | 티알더블유 오토모티브 유.에스. 엘엘씨 | Tire fill assist method and apparatus |
CN204686664U (en) * | 2015-05-29 | 2015-10-07 | 青岛理工大学 | A kind of grinding-wheel grinder undermines the measurement mechanism of G ratio |
-
2017
- 2017-11-10 EP EP17201070.4A patent/EP3482876A1/en not_active Withdrawn
-
2018
- 2018-10-30 WO PCT/EP2018/079648 patent/WO2019091823A1/en unknown
- 2018-10-30 EP EP18792949.2A patent/EP3706955A1/en active Pending
- 2018-10-30 CN CN201880061212.7A patent/CN111132801B/en active Active
- 2018-10-30 US US16/762,839 patent/US20210023675A1/en active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4646001A (en) * | 1983-11-21 | 1987-02-24 | Morganite Electrical Carbon Limited | Resistive wear sensors |
US6602109B1 (en) * | 1998-12-16 | 2003-08-05 | University Of Massachusetts | Grinding wheel system |
DE10105781A1 (en) * | 2000-02-07 | 2001-08-30 | Cornelius Gaiser | Device for detecting and evaluating geometrical changes in objects, e.g. in milling, polishing or braking systems where conducting loops and resistances are used to detect electrical changes that are then related to size changes |
DE10105781B4 (en) * | 2000-02-07 | 2004-03-04 | Gaiser, Cornelius, Dipl.-Wirtsch.-Ing. | Device for recording and method for evaluating geometry changes on rotating objects |
US20030006898A1 (en) * | 2001-07-03 | 2003-01-09 | International Business Machines Corporation | Warning method and apparatus |
US7840305B2 (en) * | 2006-06-28 | 2010-11-23 | 3M Innovative Properties Company | Abrasive articles, CMP monitoring system and method |
US20120043980A1 (en) * | 2009-02-27 | 2012-02-23 | Brian Investments Pty Ltd | Wear sensor |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20190344400A1 (en) * | 2017-01-23 | 2019-11-14 | Voith Patent Gmbh | Grinding robot and method for grinding electrically conductive workpieces |
US11772233B2 (en) * | 2017-01-23 | 2023-10-03 | Voith Patent Gmbh | Grinding robot and method for grinding electrically conductive workpieces |
US20200039027A1 (en) * | 2018-08-02 | 2020-02-06 | Saint-Gobain Abrasives, Inc. | Abrasive article including a wear detection sensor |
US20210308825A1 (en) * | 2018-08-27 | 2021-10-07 | 3M Innovative Properties Company | A system for monitoring one or more of an abrading tool, a consumable abrasive product and a workpiece |
US20220111490A1 (en) * | 2018-08-27 | 2022-04-14 | 3M Innovative Properties Company | Embedded electronic circuit in grinding wheels and methods of embedding |
US11628541B2 (en) * | 2018-08-27 | 2023-04-18 | 3M Innovative Properties Company | Embedded electronic circuit in grinding wheels and methods of embedding |
US20210008688A1 (en) * | 2019-07-08 | 2021-01-14 | Milwaukee Electric Tool Corporation | Power tool with electronic control of multiple speeds |
CN112207714A (en) * | 2019-07-10 | 2021-01-12 | 鼎朋企业股份有限公司 | Grinding machine tool with random eccentric orbit motion speed detection |
CN113001352A (en) * | 2021-03-22 | 2021-06-22 | 吾尚良品环境服务(上海)有限公司 | A spooler for stone material is polished |
Also Published As
Publication number | Publication date |
---|---|
CN111132801A (en) | 2020-05-08 |
EP3706955A1 (en) | 2020-09-16 |
EP3482876A1 (en) | 2019-05-15 |
CN111132801B (en) | 2022-05-17 |
WO2019091823A1 (en) | 2019-05-16 |
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