An angle grinder (200), which includes a gear neck (210) for connecting a dust hood (100, 100′) equipped with a flange (90), the angle grinder (200) including a sensor unit (20), with the aid of which it is possible to detect which type of dust hood (100, 100′) is connected to the angle grinder (200), the angle grinder (200) also including rotational direction control electronics (230), which are connected by signals to the sensor unit (20) in such a way that the rotational direction (GGD, GLD) of a cutting wheel (220) of the angle grinder (200) is predefined as a function of the dust hood type detected by the sensor unit (20).

In an automatic wet sanding apparatus including a paper peeling unit that has a clamping shaft and a clamping hook, an inclination angle of a leading end surface of the clamping hook is equal to an inclination angle of an outer circumferential surface of a cushion pad at the start of a paper peeling step. Thus, the leading end surface of the clamping hook comes into contact with an outer circumferential end of a disc at the same time as coming into contact with the outer circumferential surface of the cushion pad, so that the cushion pad is less likely to get caught due to deformation of the outer circumferential surface and its peripheral part of the cushion pad. It is therefore possible to appropriately remove the sandpaper from the cushion pad and stably perform the task of removing the sandpaper.

In an automatic wet sanding apparatus including a paper peeling unit that has a clamping shaft and a clamping hook, an inclination angle of a leading end surface of the clamping hook is equal to an inclination angle of an outer circumferential surface of a cushion pad at the start of a paper peeling step. Thus, the leading end surface of the clamping hook comes into contact with an outer circumferential end of a disc at the same time as coming into contact with the outer circumferential surface of the cushion pad, so that the cushion pad is less likely to get caught due to deformation of the outer circumferential surface and its peripheral part of the cushion pad. It is therefore possible to appropriately remove the sandpaper from the cushion pad and stably perform the task of removing the sandpaper.

A method for cylindrical grinding of cylindrical workpieces on a grinding machine, in which an axes of rotation of a grinding disc and of the workpiece are aligned in parallel to one another and the grinding disc is moved relative to the workpiece in a longitudinal-axial direction of the workpiece during the grinding process. A first grinding disc is followed by a second grinding disc at a continuously constant distance. The distance is determined by the width of the first grinding disc and the remaining grinding parameters, such as the rotational speeds of the first grinding disc and of the workpiece and the feed rate in the longitudinal-axial direction, such that the second grinding disc grinds the helical error lines generated by the first grinding disc during the grind process. A control device adjusts the distance between the first and second grinding discs.

A method for cylindrical grinding of cylindrical workpieces on a grinding machine, in which an axes of rotation of a grinding disc and of the workpiece are aligned in parallel to one another and the grinding disc is moved relative to the workpiece in a longitudinal-axial direction of the workpiece during the grinding process. A first grinding disc is followed by a second grinding disc at a continuously constant distance. The distance is determined by the width of the first grinding disc and the remaining grinding parameters, such as the rotational speeds of the first grinding disc and of the workpiece and the feed rate in the longitudinal-axial direction, such that the second grinding disc grinds the helical error lines generated by the first grinding disc during the grind process. A control device adjusts the distance between the first and second grinding discs.

A sanding automation system for removing a surface defect of an exterior component includes a first robot for generating an inspection mark of a certain pattern on an exterior component with uniform pressure through an inspection mark tool to secure visibility of a surface defect, a vision system for analyzing an image of the exterior component photographed through at least one vision sensor and recognizing a surface defect marking position and a surface defect depth level displayed on the exterior component on which the inspection mark is generated, and a second robot for removing the surface defect by sequentially moving a sanding tool to at least one of the surface defect marking positions and performing a sanding operation with the set amount of sanding according to a corresponding surface defect depth level.

A machine tool of high-frequency vibration is provided. A main shaft structure of the machine tool comprises a rotating shaft, the end of which is provided with a tool holder chuck for fixing a tool holder; the upper portion of which is provided with a rotating coil portion; the main shaft structure is correspondingly provided with a stationary coil portion; and the tool holder is provided with a high-frequency vibration module. By non-contact coils, an external electric power/signal can be transmitted into the high-frequency vibration module to avoid a wear phenomenon in a contact-rotating electrode. Because the inductive coil is arranged outside of the tool holder, the manufacturing cost of the tool holder is reduced, and the convenience of changing the tool holder is increased. Moreover, the machining stability and efficiency of the tool holder are improved by a control method of sensing/feedback signals with wireless transmission.

A machine tool of high-frequency vibration is provided. A main shaft structure of the machine tool comprises a rotating shaft, the end of which is provided with a tool holder chuck for fixing a tool holder; the upper portion of which is provided with a rotating coil portion; the main shaft structure is correspondingly provided with a stationary coil portion; and the tool holder is provided with a high-frequency vibration module. By non-contact coils, an external electric power/signal can be transmitted into the high-frequency vibration module to avoid a wear phenomenon in a contact-rotating electrode. Because the inductive coil is arranged outside of the tool holder, the manufacturing cost of the tool holder is reduced, and the convenience of changing the tool holder is increased. Moreover, the machining stability and efficiency of the tool holder are improved by a control method of sensing/feedback signals with wireless transmission.

A method for controlling the polishing of a gemstone includes: obtaining a three-dimensional model of the gemstone; fixing the gemstone in a dop, wherein an initial facet to be polished is aligned; obtaining at least one image of the initial facet; based on the obtained at least one image and the obtained three-dimensional model, determining at least first setting parameters for a first planned facet positioned between the initial facet and a desired final polished facet; setting the dop for obtaining a polished gemstone having a polished facet approaching the first planned facet; obtaining at least one image of the polished facet; based on the obtained at least one image of the polished facet and the three-dimensional model, determining at least further setting parameters for a further planned facet; setting the dop for obtaining a polished gemstone having a polished facet approaching the further planned facet.

A method for controlling the polishing of a gemstone includes: obtaining a three-dimensional model of the gemstone; fixing the gemstone in a dop, wherein an initial facet to be polished is aligned; obtaining at least one image of the initial facet; based on the obtained at least one image and the obtained three-dimensional model, determining at least first setting parameters for a first planned facet positioned between the initial facet and a desired final polished facet; setting the dop for obtaining a polished gemstone having a polished facet approaching the first planned facet; obtaining at least one image of the polished facet; based on the obtained at least one image of the polished facet and the three-dimensional model, determining at least further setting parameters for a further planned facet; setting the dop for obtaining a polished gemstone having a polished facet approaching the further planned facet.