Patent Application
20240293909
The invention relates to a grinding device for creating surface structures with at least one endless grinding belt guided over deflection elements in at least one direction of circulation and with a press-on arrangement which is configured and arranged such that it exerts a force from the inside on the grinding belt in a press-on area. The press-on arrangement has a base body and at least one press-on element arranged on the side of the base body facing the inside of the grinding belt. Further, the invention relates to a belt grinding machine with such a grinding device for grinding a flat workpiece and with at least one transport unit for transporting the workpiece in the direction of travel past the machining area of the grinding device.
Document DE 10 2004 037 148 C5 discloses a grinding station for a belt grinding machine with at least one endless grinding belt guided over deflection rollers and a pressure lamella belt circulating within it for pressing the grinding belt against a workpiece. In such a belt grinding machine, the circulating endless grinding belt oscillates transversely to its direction of circulation. The pressure lamella belt causes an effective grinding operation only in those areas in which the pressure lamellae exert a press-on force on the grinding belt in the direction of the workpiece to be machined. As a result, short cuts are created in the surface of the workpiece to be machined along the pressure lamellae of the pressure lamella belt by the abrasive particles of the grinding belt, by which short cuts a uniform grinding pattern is achieved given the continuous drive of the pressure lamella belt over the entire working width of the grinding station, in which grinding pattern the effects of the oscillating movement of the grinding belt are not visible.
Document EP 1 530 509 B1 discloses a grinding machine for grinding the surface of a workpiece, comprising oscillating drive means for imparting an oscillating grinding motion to abrasive means. Further, the grinding machine comprises an activation device having a plurality of activation areas controllable in such a manner that alternately different areas of the abrasive can be activated independently of the oscillating grinding motion. The provision and control of the activation areas is relatively complex. The aim is to obtain a surface without directional grinding marks. The oscillating grinding principle creates a circular motion, and the alternating press-on areas are intended to interrupt this circular cutting motion in an irregular manner. Created grinding marks cannot laterally be moved further than the circular diameter of the circular motion.
Document EP 3 326 750 A1 discloses a grinding machine for grinding the surface of a workpiece, the grinding machine having at least one circulating grinding belt and at least one pressure beam for exerting pressure on the grinding belt. A plate is arranged between the grinding belt and the pressure beam, which plate is movably mounted in a plane arranged perpendicular to the direction of the exertable pressure. The plate is provided with elevations, the arrangement of which is irregular. Due to this irregular arrangement, the grinding forces are also transmitted irregularly and create an irregular deep structure.
However, for different applications it is desirable to use press-on elements with differently structured surfaces in order to incorporate desired grinding results, in particular desired structures in the surface of a workpiece to be machined. In this way, surface structures deviating from a flat surface of the workpiece can be created. In the prior art, the press-on belts or press-on beams must be replaced by press-on belts or press-on beams with a different surface structure.
It is the object of the invention to specify a grinding device which can easily create desired surface structures. Further, a belt grinding machine with such a grinding device as well as a press-on belt or a press-on beam for such a grinding device are specified.
This object is solved by a grinding device with the features of claim 1. Advantageous embodiments are specified in the dependent claims.
In particular, by the fact that the at least one press-on element is connected to the base body by means of a Velcro or adhesive connection, it is achieved that the press-on element can be connected to the base body at any point thereof, so that a suitable press-on element pattern can be created, especially when using several press-on elements. The press-on element can also be exchanged for another press-on element, in particular for a press-on element with a different shape, different hardness, different size or different thickness. By providing a Velcro or adhesive connection, the press-on elements can be detached from the base body without tools. In particular, the number and arrangement of the press-on elements can be freely selected. If a press-on element wears out, it can be easily replaced. Thus, the density of the press-on elements and/or the structure of the arrangement of the press-on elements as well as the type and shape of the press-on elements that are connected to the base body can be freely configured.
The Velcro or adhesive connection is configured such that press-on elements can be detached from the base element and reconnected to it without being destroyed.
Velcro or adhesive connections exist over the entire contact surface between the outer side facing the grinding belt, in particular the lateral surface in the case of a press-on belt, and the inner side of the press-on element facing away from the grinding belt.
Preferably, there is a full-surface adhesive or Velcro connection between the base body and the press-on element.
The press-on element preferably comprises first Velcro or adhesive elements and the base element comprises second Velcro or adhesive elements complementary to the first Velcro or adhesive elements.
The structure of the press-on device in the press-on area, in which the at least one press-on element exerts a force on the inside of the grinding belt, is preferably as follows in the direction of the grinding belt:
The Velcro or adhesive elements or part of the Velcro or adhesive elements can also be integrated into the base body. In particular, the surface of the base body facing the press-on element and/or the surface of the press-on element facing the base body may comprise Velcro elements, which are produced in particular in a casting process together with the base body or with the press-on element. Further, the base body may be made of a ferromagnetic material so that the base body itself is an adhesive element, at least if the press-on element comprises or consists of a magnetic material.
When using a press-on belt, the entire lateral surface of the base body of the press-on belt can have a first Velcro layer and the side of the press-on element facing the base body can have a second Velcro layer complementary to the first Velcro layer.
When using a press-on beam, the entire surface of the base body of the press-on beam facing the inside of the grinding belt can have a first Velcro layer and the side of the press-on element facing the base body can have a second Velcro layer complementary to the first Velcro layer. It is particularly advantageous if the press-on elements cover an area on the side of the base body facing the inside of the grinding belt in the range from 1% to 95%, in particular in the range between 5% and 75%.
Further, it is advantageous if the base area of a press-on element, with which it is connected to the base body of the press-on arrangement via a Velcro or adhesive connection, is in the range of 0.01% and 5%, in particular 0.1% and 0.5%, of the area of the base body facing the grinding belt. Further, the base area of a press-on element with which it is connected to the base body of the press-on arrangement via a Velcro or adhesive connection can have a value in the range of 1 cm2 and 100 cm2. This allows the press-on element to be arranged relatively freely so that desired press-on patterns can be easily created. The press-on elements are then also moved with the aid of the press-on arrangement during the grinding process, i.e. when the grinding belt moves, preferably in the direction of movement of the grinding belt, against the direction of movement of the grinding belt, transversely to the direction of movement of the grinding belt or in an oscillating movement.
In a further embodiment of the grinding device, the press-on arrangement comprises an endless press-on belt configured and arranged such that it exerts a force from the inside on the grinding belt in a press-on area, wherein the endless press-on belt comprises an endless base body and at least one press-on element arranged on the lateral surface of the base body. Hereby, a continuous grinding operation can be easily carried out, in which a desired grinding pattern is created on the workpiece to be machined. Here, the press-on belt can be driven continuously in one direction or moved back and forth according to a preset drive pattern, in which case different areas of the endless press-on belt with different press-on element arrangements can be placed in the press-on area, so that different grinding patterns can then be created in an easy manner with a single press-on belt.
In another embodiment of the grinding device, the press-on arrangement comprises a press-on beam which is configured and arranged such that it exerts a force from the inside on the grinding belt in a press-on area, the press-on beam comprising a base body and at least one press-on element arranged on the side of the base body facing the inside of the grinding belt. Hereby, the grinding device can be constructed in a simple manner. The press-on beam can be moved back and forth or in an oscillating motion during the grinding operation, so that desired non-uniform grinding patterns can be created.
It is particularly advantageous if, in the grinding device according to claim 1 or in an embodiment, the base body comprises a base layer and a first Velcro adhesive layer and if the at least one press-on element has a second Velcro adhesive layer on the side facing the base body. This enables a simple design of the base body and the press-on element, which enables a Velcro connection between the press-on element and the base body.
The first and/or second Velcro adhesive layer may comprise, in particular, a Velcro non-woven layer, a Velcro velour layer, a fleece tape Velcro layer, a Velcro hook layer or a mushroom head Velcro layer. Here, the Velcro adhesive layer can preferably be a metallic Velcro adhesive layer or a plastic Velcro adhesive layer. Combinations of the following Velcro layers are particularly advantageous: hook Velcro tape-fleece Velcro tape; mushroom head Velcro tape-velour Velcro tape; mushroom head Velcro tape-velour tape and mushroom head Velcro tape-mushroom head Velcro tape. The Velcro adhesive layers are firmly bonded to the base body or firmly bonded to the press-on element, in particular firmly glued, or directly formed in the material of the base body or in the material of the press-on element.
The base layer of the press-on belt can be a fiber-reinforced plastic layer or a metal strip. This structure of the base layer is particularly suitable, especially sufficiently robust, for achieving long service lives of the press-on belt.
The base layer of the press-on beam can comprise a metal, a wood or a plastic profile. The metal or plastic profile can be designed in particular as an extruded profile. It is particularly advantageous if the metal, wood or plastic profile is torsionally rigid. This enables a simple and robust design of the press-on beam.
Further, the base body may comprise a ferromagnetic material. The at least one press-on element can then comprise a magnet. The magnet can in particular be a permanent magnet, a neodymium magnet or a Heusler magnet. This enables a simple, tool-free connection between the base body and the press-on element, which can be easily disconnected again without tools in a non-destructive manner, so that the press-on elements can be interchanged and desired press-on element patterns can be created on the base body.
The endless press-on belt can be driven by a drive unit. The press-on beam can also be movable in a press-on plane with the aid of a drive unit so that, in conjunction with the press-on elements arranged on the base body, desired grinding patterns can be created when machining the workpiece.
At least two of the used and/or usable press-on elements can differ in shape, size and/or strength. This makes it easy to create areas of the press-on arrangement with different press-on properties.
It is also advantageous if the press-on belt is guided over at least two deflection elements, preferably around at least three deflection rollers. A drive unit can drive at least one deflection roller for driving the press-on belt. This provides a simple means of moving the press-on belt. The direction of circulation of the press-on belt runs transversely to the direction of circulation of the grinding belt, at least in the press-on area. Alternatively, the direction of circulation of the press-on belt can run along and opposite to the direction of circulation of the grinding belt, at least in the press-on area. This allows simple arrangements of grinding belt and press-on belt.
It is particularly advantageous if the deflection elements are deflection rollers, wherein the endless grinding belt is preferably guided over at least three deflection rollers. This enables a simple and robust design of the grinding device.
At least for a direction of movement of the press-on belt in the press-on area transverse to the movement of the grinding belt, a sliding layer can be arranged between the press-on belt and the endless grinding belt. This prevents heavy abrasion and thus heavy wear of the press-on elements and the inside of the grinding belt.
A second aspect of the invention relates to a belt grinding machine for grinding a flat workpiece, wherein the workpiece passes through the belt grinding machine in a predetermined direction of travel. The belt grinding machine comprises at least one grinding device according to claim 1 or to an embodiment of such grinding device disclosed in the dependent claims or further above. By means of such a belt grinding machine, a safe and simple machining of a flat workpiece with a high-quality grinding result, in particular with a desired surface structure, is possible.
It is particularly advantageous if the belt grinding machine has at least one transport unit for transporting the workpiece in the direction of travel past the machining area of the grinding device. The grinding device and the transport unit are configured and arranged such that the workpiece passing the grinding device is contacted by the machining area of the grinding belt. This enables easy and reliable machining of the workpiece.
Further, it is advantageous if the grinding device is configured as a belt grinding station with a wide grinding belt circulating parallel to the direction of travel of the workpiece, the width of which extends essentially over the working width of the belt grinding machine and is guided over deflection elements directed transversely to the direction of travel of the workpiece. This allows a simple design of the entire belt grinding machine.
It is particularly advantageous if the belt grinding machine has several grinding stations, with one grinding device each.
A third aspect of the invention relates to a press-on belt or a press-on beam for exerting a force in a press-on area from the inside on a grinding belt of a grinding device. The press-on belt or press-on beam has a base body and at least one press-on element disposed on the base body. The at least one press-on element is connected to the base body by a Velcro or adhesive connection. This makes it easy to flexibly arrange suitable press-on elements on the base body. Further, the press-on element pattern created by the press-on elements can be easily changed at any time. Alternatively or additionally, the press-on characteristics of the press-on element pattern can be changed by replacing individual press-on elements. The press-on elements can differ in particular in shape, size and strength or hardness.
Further features and advantages result from the following description, which explains embodiments in more detail in connection with the attached figures.
A press-on belt 220 guided over deflection rollers 222, 224 is arranged inside the endless grinding belt 210, press-on elements 232, 242 being formed on the circumferential surface of the press-on belt 220, the press-on elements 232, 242 having a first size in a first section 230 and being arranged in a first arrangement and having a second size in a second section 240 and being arranged in a second arrangement. In other embodiments, the press-on elements 232, 242 are arranged in a uniform, continuous press-on element pattern on the circumferential surface of the press-on belt 220.
To drive the press-on belt 220, in the present embodiment the deflection roller 224 is drivable by means of a first drive unit. In other embodiments, the other deflection roller 222, another deflection roller or both deflection rollers 222, 224 may also be drivable. With the aid of the first drive unit, the press-on belt 220 can be driven either in the direction of circulation P2 or in the opposite direction to the direction of circulation P2, depending on the control of the first drive unit. This also makes it possible to move the press-on belt 220 back and forth to create different or uniform surface structures. Of course, a continuous, in particular uniform, drive in the direction of circulation P2 or in the opposite direction to the direction of circulation P2 is also possible.
A sliding layer 250 is arranged between the press-on belt 220 and the inner side 211 of the endless grinding belt 210, which prevents direct friction between the press-on belt 220 and the grinding belt 210. In particular, this reduces abrasion on the inner side of the grinding belt 210 and the associated wear of the grinding belt 210. The press-on elements 232, 242 of the press-on belt 220 press against the inner side 211 of the grinding belt 210 in a press-on area 229, wherein the sliding layer 250 can be arranged between the press-on elements 232, 242 and the inner side 211 of the grinding belt 210. In other embodiments, no sliding layer 250 is provided.
The press-on area 229 comprises the entire possible surface of the press-on belt 220 opposite the inner side 211 of the grinding belt 220. The corner points of the press-on area 229 or the surface are designated in
Depending on the structure, shape and size of the press-on elements 232, 242 of the different sections 230, 240 and by a drive of the press-on belt 220, different surface structures can be created during grinding of the workpiece 10.
The grinding station 200 comprises a second drive unit for driving the endless grinding belt 210 in a direction of circulation P3 and/or in the opposite direction to the direction of circulation P3. Preferably, this second drive unit is used to drive the deflection roller 212, 214 and/or 216.
The grinding station 200 according to the first embodiment is in particular a longitudinal structuring device or longitudinal grinding device, in which the direction of circulation P3 of the grinding belt 210 in the press-on area 229 of the press-on belt 220 runs parallel to the transport direction P1 of the workpiece 10, i.e. the direction of circulation P3 of the grinding belt 210 in the press-on area 229 of the press-on belt 220 is in or opposite to the transport direction P1 of the workpiece 10.
The endless press-on belt 220 is guided around three deflection rollers 322, 324, 326. In other embodiments, only two deflection rollers or more than three deflection rollers may be provided. Alternatively, other deflection elements, such as deflection plates, may be provided instead of the deflection rollers 322, 324, 326.
At least one of the deflection rollers 322, 324, 326, in particular the deflection roller 322, is driven by a first drive unit for driving the press-on belt 220. The deflection roller 322 also serves as a tensioning roller for tensioning the press-on belt 220. With the aid of the first drive unit, the press-on belt 220 can be driven either in the direction of circulation P2 or in the opposite direction to the direction of circulation P2, depending on the control of the first drive unit. This enables both a continuous drive of the press-on belt 220 and a back-and-forth movement of the press-on belt 220 to create different surface structures.
The endless grinding belt 310 is guided around three deflection rollers 312, 314, 316. In other embodiments, only two deflection rollers or more than three deflection rollers may be provided. Alternatively, other deflection elements, such as deflection plates, may be provided instead of the deflection rollers 312, 314, 316. At least one of the deflection rollers 312, 314, 316, in particular the deflection roller 312, is driven by a second drive unit for driving the grinding belt 310. The deflection roller 312 also serves as a tensioning roller for tensioning the grinding belt 310. With the aid of a second drive unit, the grinding belt 310 can be driven either in the direction of circulation P3 or in the opposite direction to the direction of circulation P3, depending on the control of the second drive unit. It is also possible to move the grinding belt 320 back and forth to create different surface structures.
The press-on belts 220 of the first and second embodiments are the same.
Preferably, the deflection rollers 314, 316 are arranged outside the press-on area 229 of the press-on belt 220, in particular laterally next to the deflection rollers 322, 324, for deflecting the press-on belt 220.
In both the first and second embodiments, the press-on elements 232, 242 are connected to a base body 264 of the press-on belt 220 via a Velcro connection. In other embodiments, the press-on elements 232, 242 may be connected to the base body 264 of the press-on belt 220 via an adhesive connection, in particular with the aid of a magnet.
During the grinding operation, the grinding belt 210 is driven in the direction of the arrow P3 and the press-on beam 710 is moved back and forth in the direction of the arrow P4. The base body 712 of the press-on beam 710 is designed to be torsionally rigid and comprises a wooden profile, a metal profile or a plastic profile. In particular, the metal profile or plastic profile may be a continuously cast profile. The press-on elements 232, 242, 262 can be freely positioned on the side of the base body 712 facing the grinding belt 210 via the Velcro adhesive connection, so that any suitable press-on element patterns in the same way as described in connection with the press-on belts 220, can be created. In this way, desired grinding patterns and structures can be created when grinding the surface of the workpiece 10.
In alternative embodiments, instead of reciprocating, the press-on beam 710 may be driven to perform an oscillating motion.
By connecting the press-on elements 232, 242 via a rod-shaped element 233, 243 to the press-on belt 220, the respective press-on element 232, 242 can be pivoted when force is applied by elastic deformation of the rod-shaped element 233, 243 and can adapt to the contours of the workpiece 10 to be machined.
The press-on elements 232, 242 shown in
Additionally or alternatively, the properties of the press-on element patterns can be easily changed by replacing the press-on elements 232, 242 with press-on elements 232, 242 having different properties, such as shape, size, hardness, without having to replace the press-on belt 220, 260 itself. Again, this does not require a tool, nor does it damage the press-on elements 232, 242 or the base body 264. Rather, the press-on elements 232, 242 are non-destructively connected to the base body 264 and non-destructively disconnected from the base body 264.
In the same way as on the lateral surface of the press-on belt 220, 260, a Velcro adhesive layer 280 is provided on the side of the base body 712 of the press-on beam 710 facing the inner side 211 of the grinding belt 210, so that the press-on elements 232, 242, 262 can be freely positioned there in the same way as on the base body 264 of the press-on belt 220, 260.
Preferably, the base body 264 of the press-on belt 220, 260 comprises or consists of an endless metal belt, in particular an endless steel belt. Alternatively, the press-on belt may comprise or be a textile belt or a fiber-reinforced plastic belt.
The first and/or second Velcro adhesive layer 280, 282 may in particular comprise a Velcro non-woven layer, a Velcro velour layer, a fleece tape Velcro layer, a Velcro hook layer or a mushroom head Velcro layer. Here, the Velcro adhesive layer can preferably be a metallic Velcro adhesive layer or a plastic Velcro adhesive layer. Combinations of the following Velcro layers are particularly advantageous: hook Velcro tape-fleece Velcro tape; mushroom head Velcro tape-velour Velcro tape; mushroom head Velcro tape-velour tape and mushroom head Velcro tape-mushroom head Velcro tape. The Velcro adhesive layers 280, 282 are firmly connected to the base body 264 or firmly bonded to the press-on element 232, 242, in particular firmly glued, or directly formed in the material of the base body 264 or in the material of the press-on element 232, 242.
Alternatively, the press-on elements 232, 242, 262 can also be connected to the base body 264 via an adhesive connection. For this purpose, the respective press-on element 232, 242, 262 may each comprise at least one magnet and the base body 264, 712 may comprise a ferromagnetic material. Alternatively, the respective base body 264, 712 may comprise a magnetic layer, such as a magnetic foil, or several individual magnets that are preferably arranged in a grid.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 103 966.5 | Feb 2021 | DE | national |
This application is a National Phase of International Application No. PCT/EP2022/053811, filed Feb. 16, 2022, which claims the benefit of German Application 10 2021 103 966.5, filed Feb. 19, 2021, both of which are incorporated herein in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/053811 | 2/16/2022 | WO |
