EP3616841B1 - Endless abrasive belt for a grinding machine - Google Patents

Description

The invention relates to an endless grinding belt for a grinding machine and a corresponding grinding machine with the endless grinding belt.

Endless sanding belts are used for processing metallic workpieces in particular with sometimes high contact forces and for this purpose are generally stretched between a sanding roller and tensioning roller of a grinding machine. The workpieces can be transported past the sanding roller by means of a transport direction and processed with the sanding belt, in that the sanding roller presses the active side of the endless sanding belt against the workpiece and a desired sanding result is achieved through the defined belt speed and contact pressure of the sanding belt. The endless sanding belts are exposed to high forces and deformations; they are guided over the rollers, sometimes also sliding over a sanding shoe or some other pressing device, whereby they are consistently exposed to tensile stress on the one hand and to the pressing force on the workpiece on the other.

Here, the endless sanding belt can develop a certain amount of slippage on its rear side (passive side) with respect to the rollers; When using a sanding shoe, sliding friction occurs on its surface, so that not only the active side of the sanding belt with abrasive grains taken up in a binder, but also the back formed by the support structure, e.g. a fabric, high deformations and forces as well as a mechanical wear is exposed.

In order to coordinate industrial production, transponders are increasingly being attached not only to workpieces, but also to the processing equipment, such as abrasives. The DE 10 2016 211 937 A1 describes a handheld power tool designed as an angle grinder, which takes a grinding wheel as an insert tool. A code is attached to the grinding wheel, which code can in particular be designed as an RFID code, the machine tool having an identification unit for identifying the code.

It turns out, however, that the attachment of such a transponder to an endless grinding belt is not without problems. RFID structures are generally quickly destroyed by the considerable mechanical loads and deformations. The not inconsiderable slip on the back of the sanding belt also leads to mechanical wear and tear, which can damage an RFID transponder accordingly.

The DE 10 2016 214 568 A1 describes a processing device in which a determined pressure force is transmitted to a control device by means of wireless data transmission, in particular RFID technology.

The DE 10 2014 104 310 U1 describes a wide belt sander with a sanding belt, the position of the tensioning roller being adjustable by means of an actuator in such a way that the sanding belt assumes a predetermined position on the sanding roller. Here, an oscillating signal is input via a control in order to change the position of the endless grinding belt in the transverse direction.

The WO 1998/026453 A1 describes a chip module and a method for its production in which a contact metallization is countersunk and in addition a coil for forming a transponder can be provided.

The DE 10 2014 224 570 A1 describes a protective device for a machine tool, which can be designed as an RFID communication device. Here, a sensor unit is provided that a parameter such. B. can detect and record the temperature of a workpiece surface.

The DE 20 2014 104 310 U1 shows a wide belt sanding machine with regulation of the tension roller to generate a predetermined sanding pattern. The position of the tensioning roller can be adjusted by means of an actuator in such a way that the sanding belt assumes a predetermined position on the sanding roller, the position of an edge of the sanding belt being detected by a position detector that generates a continuous actual signal that is sent to a controller is supplied to control the actuator.

The DE 10 2006 058 923 A1 relates to a method and a device as well as a grinding tool for the production of rotationally symmetrical workpieces. To monitor the process of a machine tool equipped with at least one grinding tool, data from a transponder module provided on the grinding tool are read out with a read / write device provided on the machine tool, with grinding wheel-specific data of the grinding tool provided for the subsequent machining process being integrated into machining parameters of the subsequent machining process The subsequent machining process is only released after the grinding tool intended for the subsequent machining has been identified.

The invention is based on the object of creating an endless grinding belt for a machine tool and a machine tool of this type which enable safe operation and reliable detection of the endless grinding belt.

This object is achieved by an endless grinding belt according to claim 1. The subclaims describe preferred developments. A sanding machine with the endless sanding belt is also provided.

Thus a transponder device with a wireless transponder is provided on the endless grinding belt. The transponder device protrudes laterally from the grinding belt so that the transponder lies outside the grinding belt; thus the transponder is not pressed against or between the support structure and the roller, especially when the grinding belt is tensioned on the rollers.

Here, the transponder device can in particular have a fastening area and a flag, the fastening area z. B. is attached to the back of the sanding belt and carries the flag that protrudes laterally over the sanding belt and picks up the transponder.

Thus, in the grinding operation or during workpiece machining, the grinding belt with its active layer is pressed against the workpiece in the usual way and guided along the workpiece by the grinding roller. The laterally protruding transponder received in the flag is, however, at least not directly loaded by the forces and deformations that occur.

The transponder can in particular be an RFID transponder and have an RFID chip with an antenna or antenna structure. Thus can the transponder can be read wirelessly by a detector of the machine tool, in particular the RFID technology also allows larger reading distances, so that z. B. a single detector is sufficient and, if necessary, after a short transport of the grinding belt, establishes data communication with the transponder and can read out the data stored in the transponder.

Data relevant to the machining processes can advantageously be stored in the transponder, in particular one or more of the following data: data on the series of the sanding belt, the grain size, a delivery date, and machining data such as the contact force or the contact pressure, transport speed, maximum usage times or machining times , as well as an individual identification number.

This enables the endless sanding belt to be clearly identified at a later date. If the sanding belt no longer allows optical identification due to abrasion on its rear side, and there also z. If, for example, the active layer in modern compact grains is no longer clearly identifiable by the grain size even by a person skilled in the art, the transponder still enables clear identification subsequently without being subjected to the direct stress during processing.

According to a further development, the transponder, in particular its transponder chip, can also be written, in particular with wear-dependent data, preferably with a running time and / or running distance and / or a wear-dependent evaluation number, which is e.g. is formed. If the endless belt is later used again in this or another corresponding machine tool, then these data can be read out again.

This enables an improved utilization of the permissible wear-dependent parameters. An exchange of an endless belt, e.g. also an interruption of a current processing, e.g. to resume processing with the first belt after the interim use of another belt, thus no longer leads to a loss of grinding capacity, whereby in particular errors or uncertainties in handling can be avoided.

According to a further embodiment, as an alternative or in addition to storing the wear-dependent data in the transponder, current storage can also take place in the machine tool, in particular a writable memory of the machine tool, in which case, for example, data records with individual identification numbers of the endless grinding belts can be created. In this way, various endless belts can be used, even for short processing times, and appropriately reused later in order to optimally utilize the endless belts.

According to a preferred embodiment, the transponder device is formed with a plastic strip which has an adhesive layer; thus a strip of adhesive film can in particular be provided here. The adhesive film can directly form the fastening area, which is glued to the back of the grinding belt or the back of the carrier structure of the grinding belt. Preferably, the adhesive strip or the adhesive film is folded over or folded in at its protruding end in which the transponder is attached, whereby the rigidity of the flag formed in this way is increased and the adhesive layer is covered in the protruding end. The fastening area with the adjoining, somewhat stiffer and no longer adhesive flag can thus be formed from an adhesive film or an adhesive strip with little effort in a surprisingly simple manner.

The transponder device can in particular be received on a roll as a pull-off strip. The user pulls off a peel-off strip, folds the front end with the transponder, for which purpose a predetermined kink or fold line is advantageously formed so that the user can fold the end in a defined manner and thereby form the stiffened, no longer adhesive flag. Subsequently, the user can thus glue the transponder device with the fastening area, which continues to have the adhesive layer, to the back of the endless sanding belt or its carrier structure, which already ensures secure fastening.

The transponder device is advantageously designed as an elongate strip, for example with a rectangular shape. In this case, the fastening area is advantageously applied to the endless sanding belt at an inclined angle, ie. H. in particular, it does not extend from the edge perpendicular to the center of the endless sanding belt, but at an oblique angle of z. B. 10 to 80 °. It is recognized here that the adhesive film of the fastening area can also represent a certain mechanical resistance of the sanding belt guided over the rollers and thus, when attached at an angle, the front and rear edges of the fastening area do not lead to excessive jerking, but successively on the rollers and if necessary a sanding shoe.

If the fastening area is made shorter, the angle of attachment is no longer so relevant, so that the grinding process is not affected to a relevant extent by this; thus a non-inclined attachment can be made.

Fig. 1

eine Schleifmaschine mit einem Endlos-Schleifband gemäß einer Ausführungsform der Erfindung bei der Bearbeitung eines Werkstücks;

Fig. 2

eine Aufsicht auf das Endlos-Schleifband im Bereich des Transponders, mit Detailvergrößerung;

Fig. 3

einen Schnitt durch das Endlos-Schleifband gemäß einer Ausführungsform;

Fig. 4

die Schritte a), b) der Ausbildung der Transpondereinrichtung bei Einsatz einer Klebefolie.

The invention is explained in more detail below with reference to the accompanying drawings of some embodiments. Show it:

Fig. 1

a grinding machine with an endless grinding belt according to an embodiment of the invention when machining a workpiece;

Fig. 2

a plan view of the endless grinding belt in the area of the transponder, with an enlarged detail;

Fig. 3

a section through the endless grinding belt according to an embodiment;

Fig. 4

the steps a), b) the formation of the transponder device when using an adhesive film.

Figure 1 shows a grinding machine 1 in the machining of a workpiece 2, which z. B. can be a metallic tube or metallic profile and is conveyed in the transport direction t. The grinding machine 1 has a grinding roller 3, a tension roller 4, a drive (motor) 5 for driving the grinding roller 3 at a belt speed v, furthermore a control device 6 and an input and output unit 7, e.g. B. with monitor and keyboard. Furthermore, an endless sanding belt 8 is stretched between the tensioning roller 4 and the sanding roller 3, to which a transponder device 9 is attached, which is detected by a detector 10 connected to the control device 6. To this end, the detector 10 sends out RFID interrogation signals R1, which the transponder device 9 picks up and uses them to form and output RFID response signals R2.

The grinding roller 3 is pressed onto the surface 2a of the workpiece 2 with a pressing force F or a pressing pressure, so that the endless grinding belt 8 accordingly processes the upper side 2a of the workpiece 2. The grinding machine 1 can in particular have further details, e.g. B. an oscillation adjustment of the endless grinding belt 8 in the transverse direction by a corresponding adjusting device, as well as an edge detection or edge control, as is not shown here. For example, the endless grinding belt 8 can also be guided over a shoe or some other pressing device.

How out Fig. 3 can be seen, the endless sanding belt 8 has a support structure 12 which, for. B. can be designed as a fabric, fleece or paper material. The active layer 14, which in particular can have abrasive grains 15 in a synthetic resin 16, is formed on the carrier structure 12. In addition, an adhesion promoting layer (not shown here) can be provided between the carrier structure 12 and the active layer 14. The abrasive grains 15 can, for. B. fully ceramic based on alumina, or based on zirconium corundum. In a manner not shown here, the endless grinding belt 8 - as usual as such - by z. B. a joint of the ends of a grinding belt or with an overlap to the endless grinding belt 8 is formed.

On a rear side 12a of the support structure 12, i. H. thus the rear side of the endless grinding belt 8, the transponder device 9 is attached. The transponder device 9 has an adhesive strip 18 which is designed as a plastic film or plastic strip 19 with an adhesive layer 20 on its underside 19a and a non-adhesive top side 19b. A transponder 21 as an RFID sticker with RFID chip 22 and antenna 23 is preferably stuck flat on the non-adhesive upper side 19b.

For the production of the transponder device 9 according to Figure 4 the plastic strip 19 with its adhesive layer 20 formed on the underside 19a reversibly onto a base, e.g. B. a carrier for adhesive strips, glued and the transponder 21 is glued as an RFID sticker on the top 19b. Thus z. B. a plurality of such transponder devices on a roll 9 provided. For attachment to the endless grinding belt 8, a transponder device 9 is pulled off the base and shown in FIG Figure 4a folded along a fold line (predetermined kink line) 25 in such a way that an upper part of the plastic strip 19 with the RFID sticker 21 is folded over, the adhesive layer 20 coming to rest on itself. Thus, according to Figure 4b subsequently the transponder device 9 is formed with a remaining fastening area 26, on the underside of which the adhesive layer 20 is also formed, and a flag 28 formed by folding the upper area in which the transponder 21 with the RFID chip 22 and the antenna 23 is received wherein the flag 28 is non-adhesive and made somewhat stiffer by being folded down.

The transponder device 9 embodied in this way is then attached with the fastening area 26 to the underside 12a of the carrier structure 12, i.e. H. the underside of the endless sanding belt 8, glued so that it is advantageously attached non-perpendicularly or at an attachment angle α to the edge line, where α ≠ 90 °, z. B. α = 10 ° to 80 °. The fastening area 26 thus runs obliquely with respect to the running direction or transport direction t of the endless sanding belt 8. The flag 28 is positioned outside the endless sanding belt 8, i.e. the flag 28 protrudes laterally.

During operation of the grinding machine 1, the endless grinding belt 8 is thus pressed by the tension roller 4 and the grinding roller 3 against the upper side 2a of the workpiece 2 to be processed, whereby the rear side 12a of the support structure 12 comes to rest against the rollers 3, 4. The fastening area 26 also comes to the rollers 3, 4, whereby it forms a relatively low resistance and in particular no jerk when grinding due to its inclined attachment to the rollers. The flag 28 with the transponder 21, ie the RFID chip 22 and the antenna 23, is to the side over and is therefore not braced. In particular, the transponder 21 is not mechanically stressed between the grinding roller 3 and the workpiece 2.

The detector 10 can be next to the endless grinding belt 8, i. H. one of the strands to be positioned. However, since the RFID technology here also allows greater detection distances, the detector 10 can also be positioned at a greater distance from the endless grinding belt 8. The detector 10 reads the RFID transponder 21 in a correspondingly contactless manner by outputting the RFID query signals R1 and receiving the RFID response signals R2, the RFID transponder 21 correspondingly functioning as a passive transponder. The detector 10 then sends a detection signal S1 to the control device 6, which in turn controls the drive 5 for the grinding roller 3 accordingly. The user can use the input and output device 7 to check the data stored on the RFID chip 22 at any time. Furthermore, the control device 6 can also output warning signals S2 to the input and output device 7 if the settings that are stored on the RFID chip 22 do not match the work parameters set via the control device 6, such as contact pressure F, belt speed v, etc. match, or, if necessary, a non-matching endless grinding belt 8 is used.

In a further development, the RFID chip 22 can also be written to via the detector 10, if a corresponding RFID chip 22 and an actively writing detector 10 are used. In particular, wear-dependent data, such as the running time and / or distance traveled, can be stored and / or an evaluation number, which is formed, for example, from the running time and a contact force and evaluates the previous wear.

Furthermore, the storage of the wear-dependent data, e.g. running time and / or running distance, is also possible together with an identification number of the endless grinding belt 8 in the machine tool 1, e.g. a memory 6a which is provided internally or externally to the control device 6, the memory 6a can also be combined with the input and output device 7.

List of reference symbols

1

Grinding machine

2

workpiece

3

Sanding roller

4th

Tension roller

5

drive

6th

Control device

6a

Memory, in particular writable and readable

7th

Input and output device

8th

Endless sanding belt

9

Transponder device

10

detector

12

Support structure, e.g. B. tissue

12a

Underside of the support structure 12

12b

Top of the support structure 12

14th

active layer of the endless sanding belt 8

15th

Abrasive grains

16

Binder, synthetic resin

18th

Adhesive tape

19th

Plastic strips

19a

bottom

19b

Top, non-adhesive

20th

Adhesive layer

21st

RFID sticker

22nd

RFID chip

23

antenna

25th

Intended buckling line

26th

Attachment area

28

banner

t

Transport direction

F.

Contact pressure

v

Belt speed

R1

RFID query signals

R2

RFID response signals

S1

Detection signal

S2

Warning sign

α

Mounting angle

Claims (15)

1. Endless grinding belt (8) for a grinding machine (1), wherein the endless grinding belt (8) has:

   a flexible carrier structure (12),

   at an upper side (12b) of the carrier structure (12) an active layer (14) having a binder (16) and abrasive grains (15) which are received in the binder (16),

   characterised in that

   a transponder device (9) is secured at a lower side (12a) of the carrier structure (12) and/or the endless grinding belt (8),

   wherein the transponder device (9) has a securing region (26) and a lug (28),

   the securing region (26) is adhesively bonded to the lower side (12a) with an adhesive layer (20),

   the lug (28) is retained by the securing region (26) and protrudes in a lateral direction from the endless grinding belt (8) and a transponder (21) with a transponder chip (22) and an antenna (23) for a wireless data connection to the grinding machine (1) is arranged in the lug (28).
2. Endless grinding belt (8) according to claim 1, characterised in that the lug (28) is retained directly by the securing region (26).
3. Endless grinding belt (8) according to either of the preceding claims, characterised in that the securing region (26) has an elongate extent, preferably of rectangular form, wherein the securing region (26) with respect to a side edge (8c) of the endless grinding belt (8) has a mounting angle (α) not equal to 90°, for example, from 10° to 80°, in order to form an oblique path of the securing region (26) at the lower side with respect to a transport direction (t).
4. Endless grinding belt (8) according to any one of the preceding claims, characterised in that the transponder chip (22) is constructed as an RFID chip (22) which the antenna (23) adjoins as a planar structure.
5. Endless grinding belt (8) according to any one of the preceding claims, characterised in that the transponder device (9) has a plastics material strip (19) having an adhesive layer (20) which is formed at the lower side (19a) thereof,
   wherein the plastics material strip (19) is adhesively bonded to the endless grinding belt (8) in such a manner that it forms the securing region (26) on the endless grinding belt (8), and
   the lug (28) is formed by a projecting region of the plastics material strip (19).
6. Endless grinding belt (8) according to claim 5, characterised in that the plastics material strip (19) in order to form the lug (28) is turned over or folded up in such a manner that the adhesive layer (20) moves into abutment with itself.
7. Endless grinding belt (8) according to claim 6, characterised in that the plastics material strip (19) is turned over in the region of a desired folding line (25), for example, with a perforation or weakened portion.
8. Endless grinding belt (8) according to any one of claims 5 to 7, characterised in that the transponder (21) is adhesively bonded to the plastics material strip (19) as a transponder label (21), preferably to a non-adhesive upper side (19b) of the plastics material strip (19).
9. Endless grinding belt (8) according to any one of the preceding claims, characterised in that on the transponder chip (22) one or more of the following data are stored and can be read by the detector (10):
   grain size of the endless grinding belt (8), delivery date, series, pressing pressure, pressing force (F), running time, running path, running speed of the endless grinding belt (8).
10. Endless grinding belt (8) according to claim 9, characterised in that the transponder chip (22) can also be written by the detector (10), in particular with wear-dependent data, preferably with a running time and/or running path and/or a wear-dependent evaluation number, for example, depending on the running time and the pressing force during the running time.
11. Endless grinding belt (8) according to any one of the preceding claims, characterised in that the carrier structure (12) is formed from textile material, for example, woven fabric or nonwoven fabric, or paper material.
12. Endless grinding belt (8) according to any one of the preceding claims, characterised in that the transponder (21) is located completely laterally outside the carrier structure (12) and the active layer (14), preferably with a parallel orientation relative to the carrier structure (12).
13. Grinding machine (1) which has:

    a grinding roller (3),

    a tensioning roller (4),

    a control device (6),

    an input and output unit (7),

    an endless grinding belt (8) according to any one of the preceding claims which is tensioned between the tensioning roller (4) and the grinding roller (3),

    a drive (5) for driving the grinding roller (3) and/or the endless grinding belt (8),
    and

    a detector (10) which transmits wireless interrogation signals, in particular RFID interrogation signals (R1) to the transponder device (9) of the endless grinding belt (8) and which receives wireless response signals (R2) which are transmitted by the transponder device (9) and which depending on the response signals (R2) transmits identification signals (S1) to the control device (6).
14. Grinding machine (1) according to claim 13, characterised in that the control device derives from the identification signals (S1) stored process parameters of the transponder device (9) and using the process parameters checks the drive (5), in particular a pressing force (F) and/or a belt speed (v), and depending on the check transmits a notification signal or an error signal (S2) to the input and output device (7), for the information of the user.
15. Grinding machine (1) according to claim 13 or 14, characterised in that it has a writable and readable memory (6a) for storing wear-dependent data of one or more endless grinding belts (8), in particular with data sets which contain a clear identification number of the endless grinding belt (8).

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