Applicant claims priority under 35 U.S.C. § 119 of German Application No. 10 2018 121 139.2 filed on Aug. 29, 2018, the disclosure of which is incorporated by reference.
The invention relates to an endless abrasive belt for a sanding machine as well as a corresponding sanding machine including such endless abrasive belt.
Endless abrasive belts are used to process, in particular, metal work pieces sometimes using high contact forces for which purpose there are usually clamped between a grinding cylinder and a tension roller of a sanding machine. The work pieces can be transported past the grinding cylinder by means of a transport direction processed by means of the abrasive belt in that the grinding cylinder presses the active side of the endless abrasive belt against the work piece in a defined manner and the defined belt velocity and contact force of the grinding belt create a desired sanding result. Hereby, the endless abrasive belts are subjected to strong forces and deformations; they are guided across the cylinders, sometimes even sliding in addition, across a grinding shoe or another pressing device, whereby they are constantly subject to a tension force and also the pressure force against the work piece.
Hereby, the endless abrasive belt may develop a certain slippage in relation to the cylinders at its back side (passive side); when utilizing a grinding shoe, correspondingly, there will be some sliding friction on its surface so that not only the active side of the abrasive belt with abrasive grains held inside a binder but also the back side formed by the support structure, e.g. a fabric, is exposed to a high degree of deformation and forces as well as mechanical wear.
For the purpose of coordinating industrial manufacturing processes transponders are increasingly applied not only to work pieces but also to the processing mean including abrasives. The document DE 10 2016 211 937 A1 describes a hand-operated machine tool designed as an angle grinder holding a grinding disk as replacement tool. A code is applied on the grinding disk which can be designed, in particular, as an RFID code, with the machine tool comprising an identification unit for identifying the code.
It is apparent, however, that the attachment of such a transponder on an endless abrasive belt is not without problems. Owing to the considerable mechanical load and deformation, RFID structures are destroyed quickly in general. The considerable slippage on the back side of the abrasive belt, too, leads to mechanical wear that may correspondingly damage an RFID transponder.
The citation DE 10 2016 214 568 A1 describes a processing means in which a determined pressure force is transmitted by means of wireless data transmission, in particular, RFID technology, to a controller device.
The document DE 20 2014 104 310 U1 describes a broad belt grinder with an abrasive belt, whereby the position of the tension roller is adjustable by means of an actuator in such a way that the abrasive belt assumes a predetermined position on the grinding cylinder. Hereby, an oscillating signal is input via a control so as to change the position of the endless abrasive belt in a perpendicular direction.
The citation WO 1998/026453 A1 describes a chip module as well as a method for manufacturing the same in which a contact metallization is recessed and, in addition, a coil for realizing a transponder may be provided.
The document DE 10 2014 224 570 A1 describes a protector device for a machine tool which may be designed as an RFID communication device. Hereby, a sensor unit is provided which can detect and capture a characteristic such as e.g. the temperature of the surface of a work piece.
The invention is based on the object of creating an endless abrasive belt for a machine tool and a machine tool of this type allowing for a secure operation and a secure detection of the endless abrasive belt.
This task is solved by an endless abrasive belt according to claim 1. The sub-claims describe preferred further developments. In addition, a sanding machine including said endless abrasive belt is provided.
Thus, a transponder device having a wireless transponder is provided on the endless abrasive belt. Hereby, the transponder device projects laterally away from the abrasive belt so that the transponder lies outside the abrasive belt; thus, the transponder is not pressed on or in-between the rollers and the support structure including, in particular, when clamping the abrasive belt to the rollers.
Hereby, the transponder device may comprise, in particular, an attachment region and a flag, with the attachment region being attached e.g. on the back side of the abrasive belt and carrying the flag which laterally projects beyond the abrasive belt and hosts the transponder.
Thus, in grinding operation or, respectively, when processing the work piece, the active layer of the abrasive belt is pressed against the work piece in the usual manner and guided along the work piece by the grinding cylinder. Owing to the hereby occurring forces and deformations, the transponder housed in the flag and protruding laterally is not affected, at least, not directly.
The transponder may be, in particular, an RFID transponder sein and comprise an RFID chip including an aerial or antenna structure respectively. Thus, the Transponder can be read out wirelessly by a detector of the machine tool, whereby, in particular, the RFID technology also allows for greater distances in reading so that e.g. a single detector is sufficient and established, maybe following a short transport of the abrasive belt, a data communication with the transponder and can read out the data stored in the transponder.
Advantageously, data relevant to the processing procedures can be stored in the transponder, in particular, one or more of the following data: data relating to the series of the abrasive belt, the grain size, a shipment date, as well as processing data such as the pressure force, transport velocity, maximum operating times or processing time respectively, as well as an individual identification number.
Thus, it is possible, even retrospectively, to enable an unambiguous identification of the endless abrasive belt. Therefore, if the abrasive belt should no longer allow for an identification due to abrasion on its back side, and since even e.g. the active layer in the case of modern compact grains can no longer be unambiguously identified by means of the grain size even by an expert, the transponder will still subsequently allow for an unambiguous identification without being exposed to the direct load during processing.
According to a further development, in particular, data related to wear, preferably time of operation and/or distance of operation and/or an evaluation index depending upon wear, formed e.g. as a function of the previous time of operation and the pressure force during such time of operation, may also be written into the transponder, in particular, its transponder chip. In the event that the endless belt will be reused later again in this or another similar machine tool, this data can be read out again.
This allows for an improved utilization of the permissible wear-dependent parameters. Thus, replacement of an endless belt, e.g. even an interruption of a current processing operation in order to e.g. continue operation with the first belt following an intermediate use of another belt, no longer leads to a loss of sanding capacities, whereby, in particular, even errors or insecurities in handling can be avoided.
In accordance with a further embodiment, in the alternative or in addition to storing the wear-dependent data in the transponder, current data storage may also happen in the machine tool—in particular, a writable memory of the machine tool, whereby, in this case, e.g. data sets with individual identification numbers of the endless abrasive belts can be created. Thus, it is possible to insert different endless belts, even for short times of operation, and reused later appropriately so as to utilize the endless belt in an optimum manner.
According to a preferred embodiment, the transponder device is designed to include a plastics strip comprising an adhesive layer; thus, here, in particular, a strip of an adhesive sheet may be provided. The adhesive sheet may directly constitute the attachment region which is glued onto the backside of the abrasive belt or, respectively, the backside of the support structure of the abrasive belt. Preferably, the adhesive strip or the adhesive sheet respectively is flipped over or folded inwards respectively at its protruding end where the Transponder is housed, thereby increasing the stiffness of the so designed flag and covering the adhesive layer in the protruding end. Thus, an adhesive sheet or, respectively, an adhesive strip can be used, with little effort and in s surprisingly simple manner, to create the attachment region including the joining flag which is a little stiffer and no longer adhesive.
The transponder device may, in particular, be housed on a roller as a strip-away strip. Thus, the user will strip off a strip-away strip and flip over the front part including the transponder, for which purpose, advantageously, a desired predetermined bending line or folding line respectively is formed so that the user can flip over the end in a defined manner thereby creating the more rigid and no longer adhesive flag. Then, subsequently, the user may thus glue the transponder device using the attachment region still having the adhesive layer onto the backside of the endless abrasive belt or, respectively, its support structure, already establishing the secure attachment.
Advantageously, the transponder device is designed as an elongated strip, e.g. having a rectangular shape. Hereby, advantageously, the attachment region is applied to the endless abrasive belt at an inclined mounting angle, i.e. it runs, in particular, not perpendicular from the edge to the center of the endless abrasive belt but, rather, at an inclined angle of e.g. between 10 and 80°. Hereby, it is recognized that the adhesive sheet of the attachment region, too, can represent a certain mechanical resistance of the abrasive belt guided across the cylinders and, therefore, when applied at an inclined angle, the front and back edge of the attachment region will not create strong jerking action but, rather, come into contact with the cylinders and perhaps a contact shoe always gradually.
If the attachment region is designed to be shorter, the mounting angle is of less relevance so that the sanding process is not impaired thereby by any relevant degree; thus, it is possible to make the application at a non-inclined angle.
The invention is further illustrated in the following by means of a few embodiment examples by means of the attached drawings. These show in:
The grinding cylinder 3 is pressed against the surface 2a of the work piece 2 at a pressure force F or, respectively, a contact pressure, such that the endless abrasive belt 8 acts on the upper side 2a of the work piece 2 appropriately. The sanding machine 1 may comprise, in particular, further details, e.g. an oscillation adjustment of the endless abrasive belt 8 in the perpendicular direction by means of a corresponding actuator device, as well as an edge recognition or edge control respectively, but such is not shown here in detail. Also, e.g. the endless abrasive belt 8 may be guided sliding across a shoe or another pressing device.
As can be seen in
The transponder device 9 is affixed on a back side 12a of the support structure 12, i.e., thus, the back side of the endless abrasive belt 8. The transponder device 9 comprises an adhesive strip 18 auf, designed as a plastics sheet or, respectively, plastics strip 19 including an adhesive layer 20 at its underside 19a and a non-adhesive upper side 19b. Preferably, a transponder 21 as an RFID sticker including an RFID chip 22 and aerial 23 is glued flatly onto the non-adhesive upper side 19b.
In accordance with
Then, the attachment region 26 of the so formed transponder device 9 is glued onto the underside 12a of the support structure 12, i.e. the underside of the endless abrasive belt 8, in such a way that it, advantageously, is mounted not perpendicular or, respectively, at a mounting angle α in relation to the edge line, whereby α≠90°, e.g. α=10° to 80°. Thus the attachment region 26 runs at an angle in relation to the running direction or, respectively, transport direction t of the endless abrasive belt 8. The flag 28 is positioned outside of the endless abrasive belt 8, i.e. the flag 28 protrudes laterally.
Thus, in operation of the sanding machine 1, the endless abrasive belt 8 is pressed by the tension roller 4 and the grinding cylinder 3 against the upper side 2a of the work piece 2 to be processed, whereby, correspondingly, the back side 12a the support structure 12 comes into contact with the cylinders 3, 4. Thus, the attachment region 26, too, comes into contact with the cylinders 3, 4, whereby, owing to its angular attachment on the cylinders, provides relatively low resistance and, in particular, no jerking action during sanding. Die flag 28 including the transponder 21, i.e. the RFID chip 22 and the aerial 23, protrudes laterally and is, therefore, not clamped. In particular, the transponder 21 is not mechanically stressed between the grinding cylinder 3 and the work piece 2.
The detector 10 may be positioned next to the endless abrasive belt 8, i. h. one of the strands. However, because the RFID technology, also allows for larger detection distances here, the detector 10 may be positioned also at a larger distance from the endless abrasive belt 8. The detector 10 correspondingly reads out the RFID transponder 21 contactless by putting out the RFID query signals R1 and receiving the RFID response signals R2, whereby the RFID-Transponder 21 correspondingly functions as a passive transponder. Subsequently, the detector 10 puts out a detection signal S1 to the controller device 6, which in turn correspondingly triggers the drive 5 for the grinding cylinder 3. The user can check the data stored on the RFID chip 22 at any time via the input and output device 7. Moreover, the controller device 6 can also put out warning signals S2 to the input and output device 7 if the settings stored on the RFID chip 22 do not match the working parameters set via the controller device 6 such as pressure force F, belt velocity v etc., or if, generally, a non-matching endless abrasive belt 8 is in use.
In a further development it is possible via the detector 10 to write onto the RFID chip 22, using an appropriate RFID chip 22 and an active writing detector 10. Hereby, it is possible, in particular, to store data relating to wear, e.g. the time of operation and/or distance of operation, and/or an evaluation index created e.g. from the time of operation and a pressure force and evaluating the previous wear.
Furthermore, it is also possible to store data relating to wear, e.g. the time of operation and/or distance of operation, together with an identification number of the endless abrasive belt 8, in the machine tool 1, e.g. a memory 6a, provided internally or externally of the controller device 6, whereby the memory 6a may also be combined with the input and output device 7.
Number | Date | Country | Kind |
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10 2018 121 139.2 | Aug 2018 | DE | national |
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