Use of an arrangement for monitoring tools during machining of rotationally symmetrical workpieces

Abstract

Use of a multi-ring antenna (1) in electrode cap milling devices for monitoring milling tools (3) when using an RFID system, characterized in that a multi-ring antenna (1) is arranged on a tool carrier (2) in the vicinity of a rotationally symmetrical milling tool (3) in such a way that the multi-ring antenna (1) encloses the rotationally symmetrical milling tool (3), and this rotationally symmetrical milling tool (3) carries an RFID transponder (4), wherein this RFID transponder (4) is arranged in its position on the rotationally symmetrical milling tool (3) in such a way that it is located in the electromagnetic ring field of the multi-ring antenna (1), and the multi-ring antenna (1) is arranged on the tool carrier (2) in such a way that the RFID transponder (4) on the rotationally symmetrical milling tool (3) can be interrogated in any position, both in motion and at a standstill.

Description

[0001] The invention relates to the use of a multi-ring antenna in devices for metalworking, especially in the processing of rotationally symmetrical workpieces.

[0002] Such metalworking fixtures are used primarily for reworking electrode caps in resistance welding, but their application is not limited to this. The following discussion focuses on this area of ​​application.

[0003] Electrodes for resistance welding, which are guided in robotic or manual tongs, must be reworked depending on the wear on the caps to ensure the strength and reproducibility of the weld points. Due to its integration into automated processes, this machining operation must be minimal in time. It should largely restore the cap's original shape and, at the same time, ensure a long service life for the cap by minimizing material removal. Devices containing a cutting insert in a driven milling cutter holder are commonly used for this purpose (DE 201 00 102 U1).

[0004] One effect of such devices is that material is removed with each machining operation, resulting in a loss of volume and a reduction in the service life of the cap. Furthermore, the resulting chips must be reliably removed to the outside, requiring a special design of the cutter holder and an additional chip removal device.

[0005] DE 19930485 C1 describes a device for reforming welding electrode caps, in which the welding electrode caps are shaped in pairs with opposing working surfaces in a welding gun. The shaping surface consists of several surface sections arranged around the tool axis.

[0006] Devices for milling workpieces with surfaces of revolution, preferably electrode caps for resistance welding technology, are known, consisting of a pneumatically or electrically driven milling cutter holder, which consists of a detachably connected upper part and lower part and in whose milling cutter holder two cutting plates (3, 4) are fastened, one of which is designed as a flank cutter (4), the other as an end face cutter (3), and that cutouts (5) for the discharge of the chips are arranged between them.

[0007] Solutions are also known according to which the device for machining rotationally symmetrical metallic workpieces, in particular for reworking electrode caps, is equipped with a pneumatically or electrically driven machining head with a cutting plate mounted in a recess in the machining head, in other designs additionally with at least one forming roller with a bearing integrated in the machining head, wherein the contours of the cutting plate and, in other designs, also of the forming rollers in their working area correspond to the desired workpiece geometry.

[0008] An incorrect selection of the milling tool can be problematic when using the electrode cap milling cutters described above.

[0009] The shape of the electrode cap is ultimately determined by the selection of the milling tool with a cutting insert with defined contours. In the area of ​​highly automated processes, which is expected when using welding robots and automated cap milling machines, incorrect milling tool selection must be prevented.

[0010] The disadvantage, however, is that manual selection of the milling tool can lead to incorrect selection and thus cause high follow-up costs.

[0011] It is known to use ring-shaped antennas or multi-layer antennas, so-called multi-ring antennas, in electronic methods for monitoring rotationally symmetrical metallic workpieces.

[0012] US 2009 / 0295659 A1 claims an RFID antenna arrangement, a magnetic field generating device and a magnetic field focusing arrangement.

[0013] Therein, an RFID antenna arrangement is claimed which is configured to be excited with a carrier signal, wherein the RFID antenna arrangement comprises an inductive component with a loop antenna arrangement, wherein the circumference of the loop antenna arrangement is not more than 25% of the wavelength of the carrier signal and at least one capacitive component which is coupled to the inductive component.

[0014] This device has, according to claim 2, a second slot arrangement adjacent to the first slot arrangement.

[0015] Furthermore, a special feature of the RFID antenna arrangement is claimed, which includes a multi-segment loop antenna arrangement, wherein the multi-segment loop antenna arrangement comprises: at least one first antenna segment having at least one first phase-shifting element configured to reduce the phase shift of the carrier signal within the at least one first antenna segment, and wherein at least one second antenna segment comprises at least one second phase-shifting element configured to reduce the phase shift of the carrier signal within the at least one second antenna segment, at least one far-field antenna arrangement; wherein the length of each antenna segment is no more than 25% of the wavelength of the carrier signal; and at least one matching component configured to adjust the impedance of the multi-segment loop antenna arrangement.

[0016] WO 2009 / 049191 A2 (PCT / US 2008 / 079555) claims a patch antenna and a method for its production.

[0017] This patch antenna has a plurality of radiating layers (10), each radiating layer comprising: a first sheet-like dielectric substrate (14); a radiating element (12) on a first side of the dielectric substrate (14); a trench (16) in the dielectric substrate (14) around a periphery of the radiating element (12) and forming a continuous inner peripheral sidewall (18) and a continuous outer peripheral sidewall (20); a plurality of strips (28) extending between the inner peripheral sidewall (18) and the outer peripheral sidewall (20), the plurality of strips (28) functioning to maintain an inner substrate portion (24) in a fixed physical relationship to an outer substrate portion (26) of the dielectric substrate (14); a conductive coating disposed on the inner peripheral sidewall (18) and / or the outer peripheral sidewall (20);and a second sheet-like dielectric substrate (36) having a third side and an opposite fourth side, the second dielectric substrate (36) comprising a microstrip feed line (32) disposed on the third side; and a ground plane (38) disposed on the fourth side, the ground plane (38) having a hole (40) between the radiating element (12) and the microstrip feed line (32).

[0018] CN 203883119 U claims a multilayer microstrip antenna with a spacer ring, having the features that it comprises a base plate (4) and a plurality of microstrip antennas arranged on a base plate (4), each of the microstrip antennas being arranged in the order of radiation, and a dielectric substrate provided with a coaxial feed for feeding the cooler under the cooler and the coaxial feedthrough through the dielectric substrate through the base plate (4) (5) being arranged on the dielectric substrate of the microstrip antenna in the lower layer of each adjacent two-layer microstrip antenna. The feed area formed by the coaxial feed line of the upper microstrip antenna is distributed over the metallized vias.

[0019] In a further embodiment, this solution claims a multi-layer structure of the multi-layer microstrip antenna, deviating from the two-layer structure described in the first claim.

[0020] Also known is US 2008 / 0304929 A1, which describes an RFID system and refers to the arranged sensor elements. CA 2 607 599 A1 refers extensively to the structure of the RFID transponder and the tag antenna, but does not propose a solution for a transmitting and receiving antenna of the evaluation unit.

[0021] EP 1 746 530 A1 discloses a device for identifying machining tools or machining units held in a tool holder. This device comprises at least one tool holder rotatable about a longitudinal axis, at least one RFID transponder connected to the tool holder, each consisting of a memory chip and an antenna array, and at least one read / write device communicating with the transponder, in which at least one antenna array of at least one memory chip is arranged along the outer circumference of the tool holder. While this solution can generally identify a tool (matching the tool holder), it does not allow for unambiguous identification of the tool (e.g., based on the serial number / type number).

[0022] The object of the invention is to propose a solution with which an electronic control of the selection of milling tools can be realized.

[0023] According to the invention, this object is achieved by the use of a multi-layer annular antenna in electrode cap milling devices according to claim 1 and an arrangement for monitoring milling tools according to claim 3. Hereinafter, said antenna is referred to as a multi-ring antenna, consisting of at least two electrically conductive layers separated by an insulating layer.

[0024] The antenna used also has one or more insulation layers above and below the antenna structure and thus on any contact surfaces.

[0025] In the following, the solution according to the invention will be explained using the example of an electrode cap cutter and the Fig. be explained in more detail.

[0026] Fig.shows the arrangement of the multi-ring antenna 1 used according to the invention in a device for metal processing, especially when processing rotationally symmetrical metallic workpieces, here using the example of an electrode cap milling device.

[0027] A multi-ring antenna 1 is arranged on a tool carrier 2 in the vicinity of a rotationally symmetrical tool 3, here for example an electrode cap milling tool, such that the multi-ring antenna 1 encloses the rotationally symmetrical tool 3.

[0028] The multi-ring antenna 1 is connected to the process monitoring and control technology via an antenna connection 5

[0029] The rotationally symmetrical tool 3 carries an RFID transponder 4.

[0030] RFID is a technology for transmitter-receiver systems that are used for the automatic and contactless authentication and localization of objects and living beings using radio waves.

[0031] An RFID system consists of an RFID transponder, which is located on or in the object or living being and contains an identifying code, as well as a reader for reading this identification.

[0032] The RFID transponder 4 is positioned on the rotationally symmetrical tool 3 such that it is located in the electromagnetic ring field of the multi-ring antenna 1.

[0033] The multi-ring antenna 1 is arranged on the tool carrier 2 in such a way that the RFID transponder 4 on the rotationally symmetrical component can be interrogated in any position, both in motion and at a standstill.

[0034] To monitor the rotationally symmetrical tool 3, the RFID transponder 4 can be written to and read from this multi-ring antenna 1. This makes it possible not only to detect the presence of the rotationally symmetrical tool 3, but also to write and read specific information onto the RFID transponder 4 of the rotationally symmetrical tool 3, and thus to monitor it.

[0035] It is therefore possible and advantageous, particularly for process monitoring, to be able to read out information such as tool type, serial number of the tool, usage times, downtimes as well as, for example, tool type of the previously used tool, serial number of the previously used tool, usage times of the previously used tool, downtimes of the previously used tool.

[0036] This information to be monitored and retrieved enables direct process monitoring and control of the current tool as well as data that is advantageous for process monitoring for the statistical recording and evaluation of process-relevant data and information.

Claims

[1] Use of a multi-ring antenna (1) in electrode cap milling devices for monitoring milling tools (3) when using an RFID system, characterized by , that a multi-ring antenna (1) is arranged on a tool carrier (2) in the vicinity of a rotationally symmetric milling tool (3) such that the multi-ring antenna (1) surrounds the rotationally symmetric milling tool (3), and this rotationally symmetric milling tool (3) carries an RFID transponder (4), wherein this RFID transponder (4) is positioned on the rotationally symmetric milling tool (3) such that it is located in the electromagnetic ring field of the multi-ring antenna (1), and on the tool carrier (2) the multi-ring antenna (1) is arranged such that the querying of the RFID transponder (4) on the rotationally symmetric milling tool (3) can be realized in any position, whether moving or stationary. [2] Use of a multi-ring antenna (1) according to claim 1, characterized by, that the RFID transponder (4) of the rotationally symmetrical milling tool (3) can be written to and read from with this multi-ring antenna (1), which allows electronic control of the selection of the milling tool and the evaluation of targeted information such as milling tool type, serial number of the milling tool, operating times, and tool life. [3] Arrangement for monitoring milling tools (3) in electrode cap milling devices during the machining of rotationally symmetrical workpieces, characterized by, that a multi-layered, ring-shaped multi-ring antenna (1) for monitoring milling tools (3) during the machining of rotationally symmetrical workpieces is arranged such that it can write to and read an RFID transponder (4), and the multi-ring antenna (1) is arranged on a tool carrier (2), in the vicinity of a rotationally symmetrical milling tool (3) such that the multi-ring antenna (1) surrounds the rotationally symmetrical milling tool (3), and this rotationally symmetrical milling tool (3) carries the RFID transponder (4), wherein this RFID transponder (4) is arranged in its position on the rotationally symmetrical milling tool (3) such that it is located in the electromagnetic ring field of the multi-ring antenna (1), and on the tool carrier (2) the multi-ring antenna (1) is arranged such that the querying of the RFID transponder (4) on the rotationally symmetrical milling tool (3) is realized in every position in motion and at rest.

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