DEVICE AND METHOD FOR GRINDING AND / OR POLISHING PLANNER SURFACES OF WORKPIECES

Description

Field of the invention

[0001] The invention relates to a device for grinding and / or polishing flat surfaces according to the preamble of claim 1. The invention further relates to a method for grinding and / or polishing flat surfaces using the device according to the invention. Background of the invention

[0002] The basic structures of classical optics include well-known structures such as lenses, prisms, polarizers, filters, phase plates, mirrors, apertures, and gratings. Development and production focus primarily on prisms, prism and mirror groups, lenses and lens arrays (spherical and aspherical, cylindrical, one-dimensional lines and two-dimensional arrays) with refractive or diffractive effects, as well as grating structures. The spectrum of materials used to manufacture optical structures is extremely broad and is currently being expanded. The most important materials for applications are glasses, including quartz glass, polymers, and silicon, as well as some crystals such as LiNbO3, GaAs, and GaP (the latter, as a high-index material, is suitable for wavelengths above 500 nm). For polymers, the low costs are a key driver for mass production.Silicon is a material of choice for mirrors and for the infrared spectral range, as its high refractive index provides optical advantages.

[0003] The optical function is realized by shaping the homogeneous optical medium or by changing the refractive index of an optical substrate that remains unchanged in its shape (gradient index devices, GRIN) or by a combination of both methods.

[0004] Individual optical components and lenses made of glass (especially prisms) with at least one flat surface are manufactured conventionally using classic manufacturing methods (grinding, polishing) or using complex CNC machines. The raw material is also ground to create, for example, the shape of a prism or an initial radius of both lens surfaces. Grinding involves a rough grinding and fine grinding step. The optics are then polished, again using very complex CNC machines or classic lever polishing machines. Grinding and polishing by hand is also still a common method for special optics. The polishing process takes from a few minutes to several hours, depending on the size, shape, and material of the optics. In industrial optics production, robots have been used successfully for some time, sporadically for the polishing of spherical and aspherical lenses.However, these types of optics differ greatly in their manufacturing processes. The existing robotic processes for lens processing are still not applicable to flat surfaces because they do not achieve sufficient quality for the required surface flatness. The polishing movements and directions of classic lever machines cannot be freely configured because the basic movement sequence is fixed by the principle of the lever machine. Cycles with completely different movement patterns cannot be implemented, which would be necessary for some types of optics to achieve the required surface quality. Polishing tools for lenses, such as those known from DE 60202804 T2, have a toric polishing surface and are therefore only suitable for polishing concave or convex surfaces, but not for polishing flat surfaces.

[0005] Conventional automated systems for polishing flat surfaces that require high precision, such as the flat surfaces of optical components, are therefore either very complex and expensive or fail to meet the desired quality requirements. While devices for polishing flat surfaces are known in related technical fields, they are not suitable for polishing flat surfaces that require high precision, such as the flat surfaces of optical components.

[0006] DE 60221502 T2, for example, relates to a polishing device for restoring optical discs or disks, e.g., CD, DVD, VD, and LD, comprising a disk rotation device for rotating an optical disc, and a polishing mechanism for polishing the surface of the optical disc. The polishing mechanism has an elastic mechanism for elastically holding a polishing pad, and the polishing pad has a polishing blade. The elastic mechanism is structurally designed such that the polishing blade comes into contact with the surface of the optical disc with a pressure required for polishing. However, the structural design of the elastic mechanism cannot be transferred to the polishing of plano optics.

[0007] DE 102014002844 A1 relates to a chemical-mechanical polishing pad comprising a polishing layer with a polishing surface and a broad-spectrum endpoint detection window block having a thickness along an axis perpendicular to a plane of the polishing surface. The broad-spectrum endpoint detection window block comprises a cyclic olefin addition polymer, the broad-spectrum endpoint detection window block having a uniform chemical composition throughout its thickness, the broad-spectrum endpoint detection window block having a spectrum loss of ≤ 40%, and the polishing surface being adapted for polishing a substrate selected from a magnetic substrate, an optical substrate, and a semiconductor substrate. This is a tool that must be used in conjunction with a conventional polishing machine and the associated disadvantages described above.

[0008] JP 2017 144531 A describes a device according to the preamble of claim 1 and relates to a polishing tool in which three support elements are arranged on a polishing plate. Each support element is positioned on the polishing plate by an arm with guide rollers, the arms being movable and driven by a drive mechanism. Description of the invention

[0009] The object of the invention was therefore to provide a device which is especially suitable for grinding and / or polishing flat surfaces which require high precision, such as flat surfaces of optical components, and with which the disadvantages of conventional grinding and / or polishing machines for optical structures can be overcome.

[0010] The object of the invention is achieved by a device for grinding and / or polishing plano optics according to claim 1.

[0011] The frame has an opening which contains the workpiece holder with at least one workpiece. The device according to the invention is designed such that a loose bearing is formed between the workpiece holder and the frame. The polishing tool and / or the grinding tool is arranged in a fixed position, in contrast to conventional polishing machines or grinding machines for optical structures; and also in contrast to conventional polishing or grinding machines for optical structures, the workpiece to be machined is not fixed, but is moved via the polishing tool. The workpiece holder with at least one workpiece is preferably guided in a plane which is predetermined by the resting surfaces of the at least one workpiece on the grinding and / or polishing tool. A horizontal movement of the workpiece holder with the at least one workpiece is particularly preferred.

[0012] The workpiece does not necessarily have to be contained in a workpiece holder, but can, if of appropriate size, also be contained directly in the frame and moved with it by the means for moving the frame.

[0013] The flat surfaces to be machined are preferably flat surfaces of optical components, more preferably flat optics and particularly preferably precision flat optics or micro-flat optics and are selected, for example, from optical prisms, wedges, rods, plates, etc. The device according to the invention is, however, fundamentally also suitable for polishing or grinding any type of flat surface where a high surface quality is important, such as optical disks or discs, e.g. CD, DVD, VD and LD, or wafers from the semiconductor industry. The device according to the invention is particularly well suited for polishing and / or grinding flat micro-optics. The device according to the invention can also be used for grinding and / or polishing any type of flat surface, even in other technical fields outside of optics and the semiconductor industry. Since the selection of the polishing orSince the grinding tool can be freely selected, the device according to the invention can also be used to grind or polish any type of material that is accessible to mechanical surface treatment.

[0014] As a means for moving the frame containing the workpiece holder with the at least one workpiece, in principle any means is suitable which is capable of guiding the workpiece holder with at least one workpiece in a plane which is predetermined by the resting surfaces of the workpiece on the polishing and / or grinding tool.

[0015] The means for moving the frame containing the workpiece holder with the at least one workpiece can, for example, be a conventional lever machine. However, the type and direction of movement of the frame and thus of the workpiece holder with the at least one workpiece are fixedly predetermined by the lever machine and are therefore limited. The means for moving the frame containing the workpiece holder with the at least one workpiece is therefore preferably free with regard to the design of the polishing and / or grinding movements and enables the implementation of movement cycles with very different movement patterns in one plane, which is not possible with conventional lever machines. Furthermore, the quality of the achievable surface, the polishing time and thus the efficiency can be positively influenced by designing the movement patterns that take place in one plane.

[0016] The "plane" in which these movements are carried out refers to the plane in which the at least one workpiece is guided over the polishing and / or grinding tool. In a particularly preferred embodiment of the invention, the at least one workpiece is guided horizontally over the polishing and / or grinding tool, i.e., the surface of a plano optic to be machined is guided with high precision parallel to the surface of the polishing and / or grinding tool. These desired movement cycles are implemented, for example, by a device with automatically moving axes (CNC machine) or a robot having a robot arm that serves as a means for moving the frame with the workpiece or workpiece holder movably arranged therein.According to the invention, the means for moving the frame, in which the workpiece or the workpiece holder with the at least one workpiece is movably arranged, is therefore a CNC machine or a robot with a robot arm or another device with automatically moving axes. A robot with a robot arm is particularly preferred in this context. The desired movement cycles and sequences are controlled by a control program executed in the control unit of the means for moving the frame. Control programs for controlling CNC machines, industrial robots, and other suitable devices for moving the frame of the device according to the invention are known to those skilled in the art.

[0017] The workpiece holder can be configured to accommodate a single workpiece for grinding and / or polishing. Depending on the size of the workpieces to be machined, it has proven useful to equip the workpiece holder with a support body suitable for accommodating multiple workpieces. This is advantageous because it allows several—and in the case of micro-planar optics, even a very large number—to be machined simultaneously.

[0018] In a particularly preferred embodiment, the invention therefore provides a device for polishing flat surfaces, in particular precision flat optics, comprising a CNC machine or a robot with a robot arm, a polishing and / or grinding tool, a frame connected to the CNC machine or the robot arm of a robot, and a workpiece or a holder for at least one workpiece, characterized in that the frame loosely contains the workpiece or the workpiece holder with at least one workpiece, thereby forming a loose bearing between the frame and the workpiece or the workpiece holder with workpiece, and the CNC machine or the robot with the robot arm is configured such that the workpiece or the workpiece holder with a workpiece or a support body with several workpieces is guided in a plane that is predetermined by the resting surfaces of the workpiece or the workpieces on the polishing and / or grinding tool.

[0019] In conjunction with the movement of the workpiece on the polishing and / or grinding tool, the device according to the invention can also be used to specifically generate motion sequences that depict purely linear or very slightly curved movements. In particular, rotation of the workpiece (either mechanically forced or enforced) can thus be avoided. The movements induced by the CNC machine or robot can therefore be used with the device according to the invention to create highly flexible paths and motion sequences in which the forces act only in the desired preferred directions. Furthermore, the speeds can be varied at different stages of the movement.

[0020] The "floating bearing" within the meaning of the invention is not a component per se, but is defined by the frame, which is connected to the means for moving the frame, and the workpiece holder. The frame has an opening of any geometric shape. The workpiece holder is movably arranged within this opening. The workpiece holder is therefore not rigidly connected to the frame. The workpiece holder is guided by the movements of the frame, i.e., the frame transmits the movements of the means for moving the frame (lever machine, CNC machine, robot) to the workpiece holder. This ensures that the workpiece holder can perform movements in one or two of the three spatial directions. This design preferably allows all types of movements (linear, curved, and rotary movements) of the workpiece holder with at least one workpiece or with a support body with multiple workpieces in a single plane.This arrangement is particularly advantageous because it prevents any rotation of the workpiece holder and thus of at least one workpiece from the horizontal plane (i.e., lateral tilting of the workpiece holder and the workpieces) or only allows it to be deliberately prevented by pre-set paths. Instead of the workpiece holder, it is also possible to loosely insert a workpiece directly into the frame, which is then guided therein for processing.

[0021] The previously described embodiments of the device according to the invention have the advantage that the polishing or grinding of the flat surface of the workpiece is carried out with the highest precision, and even the slightest vertical deflections of the robot arm and disruptive forces are not transmitted to the workpiece holder and workpiece. Thus, unwanted pressure and deflection of the workpiece or the workpiece holder and workpiece from the horizontal plane are effectively prevented. This achieves surface qualities that meet the requirements for flat optics. Furthermore, gentle processing is achieved, which can also be used to process micro-optics and other sensitive components.

[0022] The problem with conventional polishing machines is that even the smallest deflections of the polishing tool in all three spatial directions cannot be completely prevented because with conventional polishing machines it is not just the workpiece that is moved, but the polishing tool itself. Only horizontal deflection in two spatial directions in one plane is desirable. Likewise, it is not possible to completely prevent the moving means, in this case the polishing machine, from exerting a direct force of varying intensity on the workpiece from the polishing tool, in particular vertical pressure. The force or pressure cannot be fully controlled and in particular cannot be set to constant values. These disadvantages of the prior art are also overcome with the device according to the invention. The vertical application of force or pressure to the workpiece can be achieved through appropriate programming orConfiguration of the robot can be prevented.

[0023] In a further embodiment, the device according to the invention is therefore characterized in that the robot is configured such that no vertical force or pressure can be exerted on the workpiece by the robot arm. Pressure, within the meaning of the invention, is understood as the result of a force F acting vertically or obliquely from above on a surface A, where surface A refers to the flat surface of the workpiece to be polished.

[0024] According to the invention, the transmission of undesired deflections of the robot arm to the workpiece is prevented by the fact that the workpiece holder is not rigidly connected to the movement means, but is movably contained within the frame and guided by it. For more precise transmission of the frame's movements to the workpiece holder, it has proven advantageous for the frame to include means for guiding the workpiece holder.

[0025] In a further embodiment, the device according to the invention is therefore characterized in that the workpiece or the workpiece carrier is arranged loosely, i.e. movably, in the frame and the frame has lateral supports for guiding the workpiece. The lateral supports for guiding the workpiece holder are preferably made of an elastic and / or shock-absorbing material, which particularly preferably produces no or only minimal abrasion. A suitable material is felt, for example. Any other materials, including hard materials, which enable vertically directed sliding of the workpiece or the workpiece holder in the frame and thus ensure a loose fit, preferably in the horizontal direction, are also suitable. It is additionally advantageous if the frame is configured such that the workpiece or the workpiece holder is secured against twisting with at least one workpiece in the frame.

[0026] Alternatively, the lateral systems for guiding the workpiece holder can also be attached to the workpiece holder itself.

[0027] According to the invention, one or more workpieces can be contained in the workpiece holder or a support body, for example 1 to 10 or, in the case of smaller parts such as micro-optics, up to several hundred workpieces.

[0028] As already described, the opening of the frame in which the workpiece or workpiece holder is movably contained can have any geometric shape suitable for preventing the workpiece holder from twisting out of the horizontal plane, i.e., preventing the workpiece holder from tilting. In a particularly preferred embodiment of the invention, the frame therefore has a rectangular, trapezoidal, polygonal, elliptical, or any other shape.This makes it possible to implement movement cycles with very different movement forms of the workpiece holder with at least one workpiece in one plane, and to cleverly design the movement forms (linear, curved and rotary movements) that are to take place in one plane, without incorrect movements of the frame in an undesirable plane (such as twisting out of the horizontal plane), which are caused by incorrect movements of the means for moving the frame, being transferred to the workpiece holder and thus to the at least one workpiece.

[0029] In order to achieve the specified surface quality of a surface to be ground or polished, especially a flat optical element, it may be necessary to precisely control the movement of the workpiece holder with the workpiece. In a further embodiment of the invention, the device according to the invention is therefore configured to execute the movement of the workpiece holder with the workpiece in precisely predefined paths via the frame.

[0030] As mentioned above, the application of varying levels of pressure to the workpiece leads to undesirable deterioration in the quality of the workpiece's flat surface. This problem can be solved by controlling the pressure acting on the workpiece and / or the workpiece holder, preferably keeping it constant. This is achieved very simply with the device according to the invention by using the weight of the workpiece or of the workpiece with the workpiece holder and, if applicable, a support body for multiple workpieces to generate the required pressure, or by additionally applying a weight with a desired mass to the workpiece holder containing the workpiece and moving it together with the workpiece holder and the workpiece.In a further embodiment of the invention, the device is therefore configured such that the pressure required to carry out the polishing process is exerted by the workpiece weight itself, directly by the workpiece holder, and optionally, a weight applied to the workpiece and / or workpiece holder.

[0031] The surface quality of the planar optics can also be adversely affected if the workpiece begins to rotate due to the movements during grinding or polishing. In a further embodiment of the invention, the device is therefore configured to prevent forced rotation of the workpiece. This is achieved, for example, by the aforementioned geometric shape of the frame opening (rectangular, trapezoidal, polygonal, or elliptical) and a corresponding geometric shape of the part of the workpiece holder that is movably arranged in the frame.

[0032] "Loosely or movably contained" in the sense of the invention means that, on the one hand, the workpiece holder is not firmly connected to the frame, and the geometric shape of the frame opening essentially matches the geometric shape of the part of the workpiece holder arranged in the frame opening. Preferably, the distance between the frame opening and the outer edges of the part of the workpiece holder arranged in the frame opening is minimal and just large enough to prevent the workpiece holder from becoming jammed in the frame. The distance (circumferential) between the frame opening or the guides for the workpiece holder mounted there and the outer edges of the part of the workpiece holder contained in the frame opening can, for example, be between 0.01 and 10 mm, preferably between 0.1 and 5 mm, particularly preferably between 0.1 and 2 mm, or between 0.1 and 1 mm.

[0033] As already described, the device according to the invention comprises a grinding tool and / or a polishing tool.

[0034] In principle, any type of grinding tool suitable for grinding flat surfaces of optical structures can be used in the device according to the invention. The grinding tool is preferably a grinding wheel. Suitable grinding tools, in particular grinding wheels, are known to those skilled in the art. In principle, any type of polishing tool suitable for polishing flat surfaces of optical structures can be used in the device according to the invention. The polishing tool is preferably a polishing wheel. Suitable polishing tools, in particular polishing wheels, are known to those skilled in the art.

[0035] The polishing and grinding tools can also be identical. The desired surface quality of the workpiece can then be achieved, for example, by selecting suitable grinding and polishing agents that are familiar to the skilled person.

[0036] The invention further relates to a method according to claim 9.

[0037] The preferred embodiments and advantages of the device according to the invention apply equally to the method according to the invention, so that reference is made to the above. The method according to the invention is particularly characterized in that the pressure required to carry out the grinding and / or polishing process is exerted by the workpiece weight itself, directly by the workpiece holder, and optionally by a weight applied to the workpiece and / or workpiece holder, possibly with a support body for multiple workpieces, wherein this applied weight does not come into contact with the frame. This embodiment additionally supports the mobility of the workpiece holder in the frame and prevents the transmission of undesired movements of the frame to the workpiece holder.

[0038] In a further embodiment of the invention, the method is characterized in that the movement of the workpiece or the workpiece holder with the workpiece is carried out in precisely predefined paths via the frame of the device according to the invention. A further advantage of the invention is that both the device according to the invention and the method according to the invention are suitable for grinding and / or polishing a wide variety of materials from which optical structures are typically made, such as glasses, including quartz glass, polymers and silicon, as well as some crystals such as LiNbO 3 as well as GaAs and GaP. The method according to the invention is fundamentally suitable for grinding and / or polishing any type of material that is amenable to mechanical surface treatment.

[0039] Mechanical and / or chemical polishing agents are typically used for grinding and / or polishing optical structures. Such polishing agents are known to those skilled in the art and are not the subject of the present invention. In principle, all abrasives and polishing agents suitable for grinding or polishing optical structures can be used with the device and method according to the invention.

[0040] The device and method according to the invention preferably provide micro-plane optics and plane optics, as well as plane surfaces on other types of optics and parts (e.g., also on lenses or technical metal or ceramic parts), whose surface quality achieves a new, previously unknown quality. Therefore, in a further embodiment, the invention relates to plane optics, lenses with a plane surface, wafers, and any other type of glass, metal, plastic, or ceramic parts with at least one plane surface, which have been produced using the device and method according to the invention.

[0041] The invention provides an advantageous device and method for grinding and / or polishing flat surfaces requiring high precision. The device is based on a unique design for the workpiece connection via a frame and a special workpiece holder, as well as specific movement sequences. Using the method and device according to the invention, very sensitive flat optics and those with high quality can be ground and polished with very high efficiency. The method according to the invention, in conjunction with the developed frame and the connection of the workpiece holder by forming a floating bearing, is suitable for the industrial production of precision flat optics, which are used in a wide range of different applications.According to the current state of the art, these optics are ground or polished in the industrial sector either with conventional machines (lever polishing machines) or with very complex CNC machines. The disadvantage is that undesirable movements of the conventional machines are transferred directly to the grinding or polishing tools, which means that the quality of the ground or polished flat optics cannot meet the highest standards. Therefore, very delicate flat optics are often still polished at least partially by hand. The newly developed process can preferably be carried out with a collaborative robot in the current price range of approximately €30,000. The investment is thus significantly lower than with the currently common CNC technology, where a machine investment often reaches >€150,000.In addition, programming the robot's movement sequence is easier thanks to the more convenient control system and can be done after a relatively clear introduction and training period. A trained CNC specialist is not required to operate the robot according to the invention, which is very advantageous given the current shortage of skilled workers in these professions. Compared to grinding and / or polishing with classic lever machines, a very significant difference lies in the type of movement and thus in the mechanical stress on the workpieces. With the innovative use of the robot, one has complete freedom in designing the grinding and / or polishing movements, and cycles with very different movement forms can be implemented, something that is not possible with classic lever machines. With these, one has very few options because the basic movement sequence is fixed by the principle of the lever machine.Surprisingly, however, it has been shown that the quality of the achievable surface, the processing time, and thus the efficiency can be significantly influenced by skillfully designing the movements with which the workpiece is guided over the grinding and / or polishing tool. In this regard, the developed robotic process offers an additional spectrum of possibilities for improving quality and efficiency. Furthermore, the grinding and / or polishing process on lever machines is unsuitable for certain types and dimensions of flat optics because the mechanical forces acting on the workpieces due to the movements specified on these machines are too high, leading to damage. The robotic polishing process preferred according to the invention opens up the possibility of grinding and / or polishing these more sensitive parts mechanically and even automatically.Since the investment costs for a classic lever machine are close to the price of the robot, the advantages of the new robot process clearly outweigh the disadvantages.

[0042] In industrial optics manufacturing, robots have been used successfully for some time in another area, the polishing of spherical and aspherical lenses. However, these types of optics have very different manufacturing processes. Until now, existing robotic processes for lens processing have not been applicable to flat optics because they do not achieve sufficient quality for the achievable surface flatness. With the device according to the invention, and in particular with the frame and the connection of the workpiece holder to the robot via the frame, this problem has now been solved. With the device according to the invention and the method according to the invention, flat optics can now also be ground and polished automatically with industrial robots with the required quality and efficiency.

[0043] The floating bearing formed between the workpiece holder or the workpiece itself and the frame attached to the robot arm decouples the undesirable influences from the robot or any other means of moving the frame. This applies in particular to pressure (completely loose, essentially in the vertical axis => only "loose" lateral guidance without a firm grip and without pressure). The robot only guides the workpiece on the grinding and / or polishing tool in a plane predetermined by the surfaces of the workpiece resting on the grinding and / or polishing tool (guidance by lateral supports on the frame, loose, i.e., sitting movably within the frame of the fixture => but secured against rotation), without exerting any pressure itself. The workpiece or workpieces with their support sit loosely or tightly in the workpiece holder, which in turn is determined by the geometric shape of the opening of the enclosing frame (shape of the frame opening, e.g.The frame is secured against rotation by a workpiece holder (e.g., rectangular, trapezoidal, polygonal, elliptical, etc.). The frame is attached to the robot, and the frame guides the workpiece holder and the workpieces it contains along the desired path. The required pressure is generated by the workpiece weight itself, directly by the workpiece holder, and / or an optionally attached weight, which exerts uniform pressure on the workpiece. This achieves the required high level of flatness, which is crucial for planar optics and other flat surfaces, without the robot "crushing" them or pressing them unevenly, which would otherwise occur due to errors in the axes, the relative alignment, and the robot's movement patterns. Furthermore, motion sequences can be generated that follow precisely defined paths and avoid "forced rotation" of the workpiece.Such "forced rotation" occurs in classic lever machines, which is sometimes desirable, albeit for other applications. However, for parts with certain shapes or higher sensitivity, such as micro-planar optics, such "forced rotation" often results in excessive mechanical stress, which can lead to parts becoming detached from the assembly and thus destroying the overall assembly. The robot's movements can be used to precisely specify paths and motion sequences in which forces act only in the desired preferred directions and in which speeds can be individually optimized.

[0044] The invention is explained in more detail below with reference to six figures. They show: Figure 1: a schematic representation of the device according to the invention; Figure 2: an embodiment of the device according to the invention with a robot; Figure 3: an embodiment of the frame with a square opening; Figure 4: an embodiment of the frame with a rectangular opening; Figure 5: an embodiment of the frame with a triangular opening; Figure 6: an embodiment of the frame with a hexagonal opening; Figure 7: an embodiment of the frame with an elliptical opening; Figure 8: a schematic representation of a further embodiment of the device according to the invention; and Figure 9: a further schematic representation of a further embodiment of the device according to the invention.

[0045] Figure 1 shows schematically an embodiment of the device 100 according to the invention in side view ( Fig. 1A ) and in front view ( Figure 1B), comprising a frame 40 and a workpiece holder 30 with a workpiece 32 to be ground or polished or a plurality of workpieces 32 on a tool carrier or support body 31 and a grinding and / or polishing tool 20. The workpiece holder 30 forms a loose bearing with the frame 40, i.e. the workpiece holder 30 has an upper part 30' which is arranged in the frame 40. The upper part 30' of the workpiece holder is not fixedly connected to the frame 40, but projects into the opening of the frame 40 and is arranged to be movable in the opening of the frame 40. The frame 40 is connected to a means 10 for moving the frame 40. The movements of the frame 40 are transmitted to the workpiece holder 30, the support body 31 connected to it and the workpieces 32 via the upper part 30' of the workpiece holder 30. In the embodiment shown here, the means 10 for moving the workpiece holder 30 is the arm of a robot.Instead of a robot, however, a CNC machine or a conventional lever machine could also be used. The workpieces 32 are arranged on the support body 31. The support body 31 or an individual workpiece 32 can be arranged loosely, but preferably firmly, in the workpiece holder 30. To exert the necessary pressure on the workpieces 32 during the grinding and / or polishing process, the device 100 can optionally contain a weight 50 which is attached to the upper part 30' of the workpiece holder in such a way that contact with the frame 40 is avoided. This configuration of the device 100 advantageously prevents undesired twisting (indicated by the curved double arrow) of the workpiece holder 30 with support body 31 and workpieces 32 out of the horizontal plane (i.e., tilting of the workpiece holder 30) during the grinding and / or polishing process.

[0046] Figure 2shows an embodiment of the device 100 according to the invention as in Figure 1. In the embodiment shown here, the means 10 for moving the frame 40 is the arm of a robot. The frame 40 has a square opening in which the upper part 30' of the workpiece holder 30 with at least one workpiece is arranged. The frame 40 comprises lateral supports 41 for guiding the workpiece holder 30 or its upper part 30°. The upper part 30' has a geometric shape that is essentially identical to the shape of the opening of the frame 40, i.e., square in the case shown here. The distance between the opening of the frame 40 and the outer edges of the upper part 30' of the workpiece holder 30 is minimal and just large enough to allow the upper part 30' of the workpiece holder 30 to move freely in the opening of the frame 40, preventing the upper part 30' from becoming jammed in the frame 40.In the embodiment shown here, guides 41 made of a shock-absorbing material are attached to the opening of the frame 40 for the upper part 30' of the workpiece holder 30. The distance (circumferential) between the opening of the frame 40 or the guides 41 attached there and the outer edges of the upper part 30' of the workpiece holder 30 is approximately 1 mm in this case.

[0047] The square opening of the frame 40 ensures that a rotation of the workpiece holder 30 and thus of the workpieces 42 caused by the movement process is avoided. The robot arm 10 is configured such that the workpiece holder 30 with one or more workpieces is guided horizontally in a plane that is predetermined by the contact surfaces of the workpieces on the grinding and / or polishing tool 20. Within this plane, different movements in different directions can be carried out. Corresponding movement cycles can be programmed in the control unit of the robot 10. The grinding and / or polishing tool 20 is designed as a disk in the present embodiment. The pressure required to press the workpieces against the grinding and / or polishing tool 20 is Figure 1In the embodiment shown, the pressure is applied by a steel weight 50 arranged on the workpiece holder 30. Accordingly, a uniform application of constant pressure took place.

[0048] The Figures 3 to 7 show designs of the frame 40 with differently designed shapes of the opening for receiving the workpiece holder 30, 30', the workpiece carrier 31 or a workpiece 32. In principle, the opening of the frame 40 can have any geometric shape that is suitable for preventing rotation of the workpiece holder 30 and its upper part 30' in the frame 40 and tilting of the workpiece holder out of the horizontal plane. The Figures 3 to 7 The eight smaller holes shown serve to attach the frame to the means for moving 10, preferably to a robot arm 10.

[0049] Figure 8 shows a schematic representation of the device 100 according to the invention as in Figure 1, but in an embodiment in which the workpiece carrier 31 with several workpieces (32) is loosely contained directly in the frame 40 without an additional workpiece holder 30 and is moved together with the latter.

[0050] Figure 9 shows a schematic representation of the device 100 according to the invention as in Figure 1 , but in an embodiment in which a workpiece 32 is loosely contained directly in the frame 40 without an additional workpiece holder 30 or without an additional workpiece carrier 31 and is moved together with the latter. List of reference symbols

[0051] 10Means for moving the workpiece holder, robot with robot arm 20Grinding and / or polishing tool 30Workpiece holder 30Upper part of the workpiece holder 31Workpiece carrier, support body 32Workpiece 40Frame 41Lateral systems for guiding the workpiece holder 50Weight 100Device

Claims

1. Device (100) for the grinding and / or polishing of planar surfaces, comprising • a grinding and / or polishing tool (20), • a frame (40), • a workpiece (32) or a holder (30) for at least one workpiece (32), and • a means (10) for moving the frame (40) with the workpiece (32) or the workpiece holder (30) with the at least one workpiece (32), characterized in that the device (100) is set up in such a way that a loose bearing is formed between the workpiece (32) or the workpiece holder (30) with the at least one workpiece (32) and the frame (40) by the frame loosely containing the workpiece or the workpiece holder with at least one workpiece, and the means (10) for moving the frame (40) and the workpiece (32) or the workpiece holder (30, 30') with the at least one workpiece (32) is configured in such a way that the workpiece (32) or the workpiece holder (30) with the at least one workpiece (32) is guided in a plane which is predetermined by the surfaces of the at least one workpiece (32) resting on the grinding and / or polishing tool (20); in that the loose bearing is formed by the frame (40) having an opening in which the workpiece (32) or an upper part (30') of the workpiece holder (30) is arranged, in that the workpiece (32) or the upper part (30') of the workpiece holder (30) is movably arranged in the opening of the frame (40) and the workpiece (32) or the upper part (30') of the workpiece holder (30) is not fixedly connected to the frame (40); in that the means (10) for moving the frame (40) is selected from a robot with a robot arm, a CNC machine and some other device with automated axes; and in that the polishing tool is arranged as stationary.

2. Device (100) according to Claim 1, characterized in that the means (10) for moving the frame (40) is configured in such a way that no vertical exertion of pressure on the workpiece (32) can take place.

3. Device (100) according to one of the preceding claims, characterized in that the frame (40) has lateral abutments (41) for guiding the workpiece (32) or the workpiece holder (30', 30) .

4. Device (100) according to one of the preceding claims, the frame (40) and the upper part (30') of the workpiece holder (30) being configured in such a way that rotation of the workpiece holder (30) with the at least one workpiece (32) in the frame (40) that is enforced in the grinding and / or polishing operation is prevented, characterized in that the opening of the frame (40) and the upper part (30') of the workpiece holder (30) have a substantially identical geometrical form.

5. Device (100) according to Claim 4, characterized in that the opening of the frame (40) has a rectangular, trapezoidal, polygonal or elliptical or any other form that prevents twisting of the workpiece holder (30, 30') in the opening of the frame.

6. Device (100) according to Claim 4 or 5, characterized in that the distance between the opening of the frame (40) and the outer edges of the part of the upper part (30') of the workpiece holder (30) is minimal and made just large enough that jamming of the workpiece holder (30', 30) in the frame is avoided.

7. Device (100) according to one of the preceding claims, characterized in that the workpiece holder (30) contains a number of workpieces (32), which are arranged in a carrying body (31).

8. Device (100) according to one of the preceding claims, characterized in that the grinding and / or polishing tool (20) is a grinding and / or polishing wheel.

9. Method for the polishing of planar surfaces by using a device (100) according to one of the preceding claims, the method comprising the steps of: • introducing a workpiece (32) or a workpiece holder (30) with at least one workpiece (32) or a carrying body (31) into a frame (40), which is connected to means (10) for moving the frame (40), which optionally has lateral abutments (41) for guiding the workpiece holder; • moving the frame (40) with the workpiece (32) or the workpiece holder (30), which contains at least one workpiece (32) or a carrying body (31) with a number of workpieces (32), by the means (10) for moving the frame (40) in one plane, which is predetermined by the surfaces of the at least one workpiece (32) resting on a grinding and / or polishing tool (20); and • producing a ground and / or polished planar surface of the workpiece (32); the workpiece (32) or the workpiece holder (30) forming a loose bearing with the frame (40), the workpiece (32) or the workpiece holder (30, 30') being movably connected in the opening of the frame (40) and twists of the workpiece (32) or of the workpiece holder (30) with the at least one workpiece (32), in particular out of the horizontal resting plane of the workpieces (32), being avoided.

10. Method according to Claim 9, characterized in that the pressure required for performing the grinding and / or polishing operation is exerted by the weight of the workpiece (32) itself, directly by the workpiece holder (30) and if applicable by the carrying body (31), and optionally a weight (50) applied to the workpiece (32) and / or the workpiece holder (30).

11. Method according to Claim 9 or 10, characterized in that the movement of the workpiece (32) or the workpiece holder (30) with the at least one workpiece (32) is performed in precisely predefined paths by way of the frame (40).