Backing pad device

Abstract

The invention relates to a backing pad device, in particular for mounting on a hand-held power tool (12), in particular an angle grinder, comprising: a base support (14) which has a central fastening region (16), a boundary region (18) which is adjacent to the fastening region (16) radially outwardly and extends around the fastening region (16) as a ring, and at least one air conduction channel (20) which extends at least in the boundary region (18) at least partially radially outwardly and is provided in at least one operating state for cooling the base support (14); an interface unit (22) for connecting to an output shaft of the hand-held power tool (12), in particular the angle grinder; and a connection unit (24) for fastening an abrasive disc (26a; 26b) to the base support (14). It is proposed that the at least one air conduction channel (20) has, in a plane perpendicular to the rotational axis (28) of the base support (14), a more particularly curved profile (30), the radially outer output vector (a) of which has a main circumferential direction component (au) which extends parallel to a circumferential direction in a point of the output vector (a).

Description

[0001] Description

[0002] Support plate device

[0003] State of the art

[0004] A support plate device has already been proposed, in particular for mounting on a hand-held power tool, in particular an angle grinder, comprising a base support which has a central fastening region, an edge region which adjoins the fastening region radially outwards and extends as a ring around the fastening region, and at least one air guide channel which extends at least partially radially outwards at least in the edge region and is provided for cooling the base support in at least one operating state, with an interface unit for connection to an output shaft of the hand-held power tool, in particular of the angle grinder, and with a connecting unit for fastening a fiber grinding disc to the base support.

[0005] Disclosure of the invention

[0006] The invention is based on a support plate device, in particular for mounting on a hand-held power tool, in particular an angle grinder, with a base support which has a central fastening region, an edge region which adjoins the fastening region radially outwards and extends as a ring around the fastening region, and at least one air guide channel which extends at least partially radially outwards at least in the edge region and is provided in at least one operating state for cooling the base support, in particular the base support and a fiber grinding wheel, with an interface unit for connection to an output shaft of the hand-held power tool, in particular the angle grinder, and with a connecting unit for fastening a fiber grinding wheel to the base support.

[0007] It is proposed that the at least one air duct has a course, in particular a curved course, in a plane perpendicular to the axis of rotation of the base support, the radially outer output vector of which has a substantial circumferential direction component which runs parallel to a circumferential direction at a point of the output vector. The plane perpendicular to the axis of rotation of the base support is formed in particular by a main extension plane of the base support. The course of the air duct has, in particular, different course directions at different points. Preferably, the output vector has a radial direction component and a circumferential direction component. Preferably, a radially inner input vector of the course likewise has a radial direction component and a circumferential direction component. Preferably, the air duct runs substantially in the radial direction.The air duct is formed, in particular, by a groove in the base support, which is intended to guide air, in particular cooling air for the base support and the fiber grinding disc. The air duct preferably has a defined inlet and a defined outlet. The air duct is open, in particular, toward the fiber grinding disc, with the fiber grinding disc being designed to close the air duct on one side during operation.

[0008] A "backing plate device" should preferably be understood as at least a part of a backing plate, in particular for a grinding wheel, preferably for fiber grinding wheels and / or sandpaper, which is intended for direct arrangement on a handheld power tool, in particular an angle grinder. In particular, the backing plate device can also comprise the entire backing plate. The backing plate device is intended in particular for direct arrangement and fastening on a tool interface of the handheld power tool. The fact that an object is intended for a specific function should preferably be understood to mean that the object fulfills and / or performs this specific function in at least one application and / or operating state.An "operating state" should preferably be understood as a state in which the support plate device is ready for operation for a turning operation and / or is at least coupled to the motor and / or the handheld power tool and / or is in a turning operation. A "handheld power tool" should be understood as meaning in particular a machine for machining workpieces, but advantageously a drill, a hammer drill and / or percussion hammer, a saw, a planer, a screwdriver, a milling machine, a grinder, an angle grinder, a gardening tool and / or a multi-function tool.

[0009] The base support, in particular, forms a base body of the support plate device. The base support preferably forms a plate that serves to support a fiber grinding disc. The base support, in particular, has a plate shape. The base support preferably has a plurality of air ducts evenly distributed in the circumferential direction. Preferably, a wall is arranged between each of the air ducts, which serves as a cooling fin. The walls between the air ducts are, in particular, narrower than the air ducts.

[0010] In this context, an "interface unit" should be understood to mean, in particular, a unit that serves to connect the backing plate device to an output shaft of the handheld power tool. The interface unit serves, in particular, to provide a direct, detachable connection to a tool holder, in particular a tool chuck, of the handheld power tool. The interface unit is arranged, in particular, on a side of the backing plate device facing away from a workpiece. The interface unit is intended, in particular, to enable an operator to detachably fasten the backing plate device directly to a tool holder of a handheld power tool in a manner that is at least rotationally fixed. The interface unit can, for example, be formed by a conventional interface, in particular a flange nut, or a quick-action clamping interface, in particular an X-Lock interface.The interface unit is preferably compatible with the X-Lock system. Alternatively, it would be conceivable for the interface unit to be formed, for example, by a threaded interface, in particular an M14 threaded interface. The interface unit preferably has a recess into which a tool holder of the handheld power tool can engage and secure the support plate device. The interface unit has, in particular, an interface element, in particular a metal sheet, which is firmly connected to the base support and delimits the recess.

[0011] Furthermore, a “connecting unit” should be understood to mean, in particular, a unit different from the interface unit, which serves for a detachable fastening of a fiber grinding disc to the backing plate device, in particular to the base support of the backing plate device. The connecting unit preferably serves, in particular, for a tool-free detachable connection of a fiber grinding disc to the base support of the backing plate device. In a fixed state, the fiber grinding disc is preferably also aligned relative to the base support via the connecting unit. The fiber grinding disc is intended to be connected to the base support in a rotationally fixed manner by the connecting unit. Preferably, the connecting unit has at least one part that is fixedly connected to the base support and at least one part that can be detachably connected to the base support, wherein the at least two parts together form a connection interface that can be detachably removed without the need for tools.The connecting unit preferably has at least one connecting section arranged on the base support and a connecting plate that is detachably connectable to the base support, in particular detachably connectable to the connecting section, and is provided to hold the fiber grinding disc on the base support in a form-fitting and / or force-fitting manner. The fiber grinding disc is pressed, in particular, at least partially onto the base support via the connecting plate. The connecting plate serves, in particular, to fix and center the grinding disc. The connecting plate is provided, in particular, to enable force-fitting and / or form-fitting rotational engagement.

[0012] The course of the air duct forms, in particular, an averaged course of the air duct. The course runs, in particular, along a central fiber of the air duct. The output vector is, in particular, composed of at least two vector components. In particular, the output vector comprises at least one radial direction component and one circumferential direction component. The term "significant circumferential direction component" should be understood, in particular, to mean that the circumferential direction component accounts for at least 10%, preferably at least 20%, more preferably 30%, and particularly preferably 40% of the output vector. Preferably, the output vector also has a significant radial direction component. Particularly preferably, the radial direction component of the output vector is greater than the circumferential direction component.Preferably, a value, in particular a length, of the circumferential direction component is at least 50%, preferably at least 60% and particularly preferably at least 70% of a value, in particular a length, of the radial direction component of the output vector.

[0013] A "main extension plane" of a structural unit is understood to mean, in particular, a plane that is parallel to the largest side surface of the smallest imaginary cuboid that just completely encloses the structural unit, and in particular, runs through the center of the cuboid. "Intended" is understood to mean, in particular, specifically programmed, designed, and / or equipped. The fact that an object is intended for a specific function is understood to mean, in particular, that the object fulfills and / or performs this specific function in at least one application and / or operating state.

[0014] The inventive design of the backing pad device enables, in particular, advantageous cooling of the base support and a fiber grinding disc during operation. This, in turn, enables, in particular, advantageous heat dissipation from the fiber grinding disc. The continuous air flow cools both the backing pad and the fiber grinding disc. This makes the backing pad more stable, and the fiber grinding discs have a longer service life. This theory has been proven in practice through thorough tests. The new design achieves significantly lower fiber grinding disc temperatures. Furthermore, it has already been demonstrated in this application that the significantly lower fiber grinding disc temperatures extend the service life of the fiber grinding disc.

[0015] It is further proposed that the course of the at least one air duct has a radially inner input vector which has a radial direction component running parallel to a radial direction at a point of the input vector, which radial direction component is greater than a radial direction component of the output vector running parallel to a radial direction at a point of the output vector. Preferably, the radially inner input vector of the course is oriented more in the direction of a radial direction than the radially outer output vector of the course. Preferably, an angle between the radially inner input vector of the course and a radial direction at the point of the input vector is smaller than an angle between the radially outer output vector and a radial direction at the point of the output vector.Preferably, the radially outer output vector has a circumferential direction component running parallel to a circumferential direction at a point of the output vector, which is greater than a circumferential direction component of the input vector running parallel to a circumferential direction at a point of the input vector. This makes it possible, in particular, to provide an advantageous air duct. In particular, a course of the air duct that is advantageous for cooling can be provided.

[0016] Furthermore, it is proposed that the at least one air guide channel has a course in a plane perpendicular to the axis of rotation of the base support that is curved radially outwards, counter to the direction of rotation. The air guide channel preferably runs from radially inward to radially outward in a circumferential direction that is counter to the direction of rotation of the support plate device. In this context, the term “curved counter to the direction of rotation” should be understood in particular to mean that a circumferential direction component oriented counter to the direction of rotation becomes larger radially outwards at every point along the course. In this context, a “direction of rotation” of the support plate device should be understood in particular to mean an intended direction of rotation in which the support plate device is rotated by a hand-held power tool during operation.The direction of rotation is preferably clockwise when viewed from above the interface unit. The direction of rotation is preferably counterclockwise when viewed from above a support surface of the base support. This makes it possible, in particular, to provide an advantageous air duct. In particular, a course of the air duct that is advantageous for cooling can be provided. It is further proposed that the at least one air duct has an intake opening on an inner side adjacent to the fastening region, which is open towards a side of the edge region facing away from a support surface of the base support. The base support has, in particular on a side facing away from the interface unit, a support surface for supporting the fiber grinding wheel. The support surface extends in particular over an edge region and a fastening region of the base support.The base support preferably has a central, circular-cylindrical fastening region with a central recess and an edge region which adjoins the fastening region radially outwards and extends as a ring around the fastening region. The intake opening is arranged in particular in a region of the inlet vector of the course of the air duct. The intake opening forms in particular an opening in the air duct through which air can flow into the air duct during operation. During regular operation, a significant air flow from the air duct preferably flows into the air duct via the intake opening. The intake opening is in particular passive and has no active air intake mechanisms. This can enable, in particular, advantageous air guidance.In particular, it can be made possible for air to flow radially outward through the air duct. In particular, an advantageous air duct can be provided.

[0017] It is further proposed that the intake opening is arranged in a transition region from the fastening region to the edge region. The fastening region preferably has a significantly greater axial extent than the edge region. An axial thickness of the base support therefore decreases in particular from the fastening region to the edge region. An annular transition region is preferably arranged between the fastening region and the edge region, in which the axial thickness of the base support decreases from the fastening region to the edge region. The transition region in particular has at least partially a hyperbolic funnel shape. This can in particular enable advantageous air guidance. In particular, it can be made possible for air to flow in a radially outward direction through the air guidance duct. In particular, an advantageous air guidance duct can be provided.In particular, an advantageously long air guide channel can be provided which has an advantageously large axial height in an inlet area.

[0018] It is further proposed that the at least one air duct comprises precisely one sub-duct in a radially inner region and at least two sub-ducts in a radially outer region. The air duct preferably branches off from a radially inner region to a radially outer region into two sub-ducts. The two sub-ducts of the radially outer region preferably have a cross-section that is at least approximately the same size, in particular at the same point along their course. The air duct preferably branches off into precisely two sub-ducts in the radially outer region. However, it would also be conceivable for the air duct to have at least three sub-ducts in the radially outer region. The two sub-ducts of the radially outer region preferably follow, on average, a course of the air duct. The two sub-ducts of the radially outer region preferably run at least approximately parallel.Preferably, the two sub-channels of the radially outer region partially diverge from each other with increasing radial distance from a rotational axis of the base support. The air duct preferably has a curved V-shape. Preferably, a wall forming a cooling fin is arranged between the at least two sub-channels of the radially outer region. This allows, in particular, advantageous air flow through the air duct to be achieved. In particular, an advantageous air duct with advantageous flow properties can be achieved. Branching into two sub-channels enables, in particular, advantageous air guidance.

[0019] Furthermore, it is proposed that a height of the at least one air duct decreases radially outward, in particular parallel to a rotational axis of the air duct. Preferably, a height of the at least one air duct decreases radially outward in the axial direction. In particular, a height of the air duct decreases along the course of the air duct from radially inside to radially outside. Preferably, a height of the air duct decreases along the course of the air duct from radially inside to radially outside by at least 5%, preferably at least 10%, and particularly preferably at least 15%.The height of the air duct is limited in a direction axially pointing away from the interface unit, preferably by the fiber grinding wheel. Without a fastened fiber grinding wheel, the air duct is formed in particular by a groove, wherein the height of the air duct is formed by an axial depth of the groove. The height of the air duct is preferably at least 30%, preferably at least 40%, of a maximum material thickness of the base support at the same distance from the axis of rotation of the base support. The air duct is designed to be open in particular radially outwards. The cross section of the air duct preferably decreases radially outwards. This makes it possible in particular to have advantageous air guidance. In particular, it can be made possible for air to be accelerated radially outwards due to the decreasing cross section.

[0020] It is further proposed that the air duct is provided in at least one operating state to transport particles, in particular from a working area of ​​the fiber grinding wheel, away from the working area. Preferably, the air duct can transport particles entering the air duct radially outwards, for example through openings in the fiber grinding wheel. Preferably, there is at least a slight negative pressure in the air duct compared to the working area, so that the passage of particles from the working area into the air duct is promoted. Preferably, the particles are sucked from the working area into the air duct by the accelerated air flow in the air duct and transported away radially outwards. Preferably, recesses are arranged in the fiber grinding wheel, which open into the air duct and thus enable the particles to be transported away.This can, in particular, enable a particularly good grinding result. It can also ensure reliable removal of particles.

[0021] Furthermore, the invention is based on a grinding wheel system with the backing plate device and with a fiber grinding wheel, which can be connected directly to the backing plate device via the connecting unit. It is proposed that the fiber grinding wheel has at least two dust passage openings, which are provided during operation to guide particles from a working area of ​​the fiber grinding wheel into the at least one air guide channel. The dust passage openings preferably open into the at least one air guide channel of the backing plate device. The dust passage openings can in particular be arranged randomly distributed or adapted to the air guide channel. The dust passage openings are in particular arranged in a working area of ​​the fiber grinding wheel. The dust passage openings are in particular designed differently from a central recess.The fiber grinding disc preferably has a plurality of dust passage openings distributed over a working area of ​​the fiber grinding disc. The dust passage openings are formed, in particular, by through-holes. The dust passage openings are preferably formed by circular through-holes. The dust passage openings are arranged, in particular, on at least two, preferably at least three imaginary rings, each of which has a defined distance from a rotational axis. Preferably, the number of dust passage openings per ring is identical, with the dust passage openings being arranged evenly distributed in the circumferential direction on the respective imaginary ring. The fiber grinding disc comprises, in particular, a support layer and an abrasive cover layer.The fiber grinding disc preferably has a central fastening area and a working area extending annularly around the fastening area. The working area is particularly intended to be brought into contact with a workpiece during operation. This can, in particular, enable an advantageously good grinding result. In particular, it can enable reliable removal of particles.

[0022] It is further proposed that the fiber grinding disc has at least one central connecting recess, wherein the connecting unit of the support plate device has at least one connecting section arranged on the base support and a connecting plate which can be detachably connected to the base support and which is intended to hold the fiber grinding disc on the base support via the connecting recess in a form-fitting and / or force-fitting manner. The connecting recess is arranged in particular in the fastening region. Preferably, the connecting unit serves in particular to connect a fiber grinding disc to the base support of the grinding disc device in a way that can be detached without the use of tools. Preferably, the fiber grinding disc is also aligned relative to the base support via the connecting unit in a fixed state. The fiber grinding disc is intended to be connected to the base support in a rotationally fixed manner by the connecting unit.The connecting unit preferably has at least one connecting section arranged on the base support and a connecting plate which can be detachably connected to the base support, in particular detachably connected to the connecting section, and which is intended to hold the fiber grinding wheel on the base support in a form-fitting and / or force-fitting manner. The fiber grinding wheel is pressed, in particular, at least partially onto the base support via the connecting plate. The connecting plate serves, in particular, to fix and center the fiber grinding wheel. The connecting unit can, in particular, enable an advantageously reliable fixation of a grinding wheel. In particular, relative rotation of the grinding wheel can also be avoided. Furthermore, the grinding wheel can, in particular, be changed regardless of whether the base support is mounted on a handheld power tool or not.The grinding wheel can either be pre-assembled on the base carrier and then mounted on the hand tool or the base carrier can be changed on the hand tool.

[0023] Furthermore, the invention is based on a hand-held power tool system with a hand-held power tool, in particular an angle grinder, and with the support plate device, in particular with the grinding wheel system.

[0024] The support plate device according to the invention is not intended to be limited to the application and embodiment described above. In particular, the support plate device according to the invention may have a number of individual elements, components, and units that differs from the number stated herein to fulfill a function described herein. Furthermore, in the value ranges specified in this disclosure, values ​​within the stated limits are also to be considered disclosed and can be used arbitrarily. Drawing

[0025] Further advantages will become apparent from the following description of the drawings. The drawings illustrate two exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0026] They show:

[0027] Fig. 1 shows a hand-held power tool system with a hand-held power tool, with a support plate device according to the invention and with a fiber grinding wheel in a schematic representation,

[0028] Fig. 2 shows the support plate device according to the invention with a base support, with an interface unit and with a connecting unit in a schematic 3D representation from below, Fig. 3 shows the support plate device according to the invention with the base support, with the interface unit and with the connecting unit in a schematic 3D side view,

[0029] Fig. 4 the support plate device according to the invention with the base support, with the interface unit and with the connecting unit in a schematic view from below,

[0030] Fig. 5 shows the support plate device according to the invention with the base support, with the interface unit and with the connecting unit in a schematic side view,

[0031] Fig. 6 shows the support plate device according to the invention with the base support in a schematic sectional view in a sectional plane perpendicular to a rotation axis of the base support,

[0032] Fig. 7 shows the support plate device according to the invention with the base support in a schematic sectional view in a sectional plane parallel to a rotation axis of the base support,

[0033] Fig. 8 shows a partial section of the support plate device according to the invention with the base support, with the interface unit and with the connecting unit in a schematic view from below,

[0034] Fig. 9 shows the fiber grinding disc in a schematic plan view and Fig. 10 shows an alternative fiber grinding disc in a schematic plan view.

[0035] Description of the embodiments

[0036] Fig. 1 shows a handheld power tool system 58 with a handheld power tool 12, which has a housing 60, with a backing plate device 10, and with an insert tool in the form of a fiber grinding wheel 26a. The handheld power tool 12 is designed as an angle grinder. However, another design that would appear appropriate to a person skilled in the art would also be conceivable. The fiber grinding wheel 26a has a connection device 62a (cf. Fig. 8). The connection device 62a comprises a continuous central connecting recess 52a, which is adjacent to several, in particular eight, narrow recesses 64a extending radially outward. The handheld power tool 12 has a drive unit 66. The drive unit 66 is provided at least to provide kinetic energy, which is provided to move, in particular to rotate, the backing plate device 10 and, via the backing plate device 10, the fiber grinding wheel 26a.The drive unit 66 is arranged in the housing 60. The handheld power tool 12 further comprises a gear unit 68, in particular an angular gear unit, and an output shaft. The drive unit 66 is provided to drive the output shaft in rotation via the gear unit 68. Furthermore, the handheld power tool 12 comprises, for example, a clamping device. The clamping device is provided to arrange the support plate device 10 or other insert tools on the handheld power tool 12. The clamping device is arranged on the output shaft. The handheld power tool 12 comprises an actuating means 70 for locking the drive shaft. Furthermore, the clamping device comprises a flange nut (not further visible).

[0037] Alternatively, it would also be conceivable that the clamping device could be

[0038] Quick-release clamping device is formed. In the case of a quick-release clamping device, in particular an actuating means would be provided which is intended for opening and closing the quick-release clamping device. The actuating means would in this case be designed in particular as a pull lever. The pull lever has an eccentric. The actuating means is provided, in particular by means of the eccentric, to move an unlocking bolt of the quick-release clamping device in the axial direction. The unlocking bolt is provided to unlock the quick-release clamping device when the unlocking bolt moves into the housing 60 of the hand-held power tool 12. The quick-release clamping device is formed, for example, by an X-Lock quick-release clamping device. However, other clamping devices which appear appropriate to a person skilled in the art, in particular quick-release clamping devices, are also conceivable.

[0039] The backing plate device 10 is intended for mounting on the handheld power tool 12. The backing plate device 10 has a base support 14. The base support 14 forms a base body of the backing plate device 10. The base support 14 forms a plate which serves to support a fiber grinding disc 26a. The base support 14 has a plate shape, in particular a circular one. However, other shapes for the base support 14 that would appear appropriate to a person skilled in the art are also conceivable. The base support 14 has a central, circular-cylindrical fastening area 16 with a central recess. Furthermore, the base support 14 has an edge area 18 which adjoins the fastening area 16 radially outwards and extends as a ring around the fastening area 16. The edge area 18 has, in particular, a thinner material thickness than the fastening area 16.The axial thickness of the base support 14 therefore decreases from the fastening region 16 to the edge region 18. An annular transition region 38 is arranged between the fastening region 16 and the edge region 18, in which the axial thickness of the base support 14 decreases from the fastening region 16 to the edge region 18. The transition region 38 has at least partially a hyperbolic funnel shape. The base support 14 has, on a side facing away from the handheld power tool 12, a support surface 36 for supporting the fiber grinding wheel 26a. The support surface 36 extends over the edge region 18 and the fastening region 16. The base support 14 is made of a plastic and / or preferably of an elastomer. The base support 14 is flexible. Furthermore, the support plate device 10 has an interface unit 22 for connection to the output shaft of the handheld power tool 12.The interface unit 22 provides a direct, detachable connection to the quick-clamping device of the handheld power tool 12. The interface unit 22 is arranged on a side of the base support 14 of the support plate device 10 facing away from the support surface 36. The interface unit 22 has an interface element 74 which is firmly connected to the base support 14 and has a central recess. The interface element 74 is directly connected, in particular screwed, to the fastening area 16 of the base support 14. The interface element 74 is formed from a metal sheet. The interface unit 22 is intended to fasten the support plate device 10 directly to the clamping device of the handheld power tool 12 in a way that is detachable by an operator and at least rotationally fixed, and thus to connect the support plate device 10 rotationally fixed to the output shaft. The interface unit 22 is formed, for example, by a conventional interface.Alternatively, the interface unit 22 can be formed, for example, by an X-Lock interface. Preferably, the interface unit 22 can be compatible with the X-Lock system. For this purpose, the interface unit 22 has a recess in the interface element 74, into which the clamping jaws of the quick-action clamping device of the handheld power tool 12 can engage and secure the support plate device 10.

[0040] In a further alternative embodiment, it would be conceivable for the interface unit 22 to have an internal thread, in particular an M14 internal thread, and to be designed to be mounted on a handheld power tool 12, in particular an angle grinder, with an M14 spindle. Instead of the X-Lock interface, an M14 thread is integrated into the base support 14.

[0041] Furthermore, the backing plate device 10 has a connecting unit 24 for attaching the fiber grinding disc 26a to the base support 14. The connecting unit 24 is separate from the interface unit 22 and designed independently of it. The connecting unit 24 serves to connect the fiber grinding disc 26a to the base support 14 of the backing plate device 10 in a tool-free, detachable manner. In a fixed state, the fiber grinding disc 26a is also aligned and centered relative to the base support 14 via the connecting unit 24. However, it would also be conceivable for the connecting unit 24 to be designed together with the interface unit 22.The connecting unit 24 of the support plate device 10 has a connecting section 54 arranged on the base support 14 and a connecting plate 56 which can be detachably connected to the base support 14 and which is intended to hold the fiber grinding wheel 26a positively and / or non-positively on the base support 14 via the connecting recess 52a.

[0042] Furthermore, the base support 14 has at least one air duct 20. The base support 14 has a plurality of air ducts 20. By way of example, the base support 14 has fifteen air ducts 20. The air ducts 20 are arranged evenly distributed in the circumferential direction over the base support 14. The air ducts 20 are each formed by grooves in the base support 14. The air ducts 20 extend at least partially radially outward, at least in the edge region 18. The air ducts 20 are arranged in the support surface 36. The air ducts 20 each have a defined inlet and a defined outlet. The air ducts 20 are open towards the fiber grinding wheel 26a, wherein the fiber grinding wheel 26a is provided to close the air duct 20 on one side during operation.Furthermore, the air guide channels 20 are provided for cooling the base support 14 in at least one operating state. The air guide channels 20 are provided for guiding air, in particular cooling air, in the base support 14.

[0043] A wall 78 is arranged between each of the air ducts 20, which serves as a cooling fin and as a support surface for the fiber grinding wheel 26. The walls 78 between the air ducts 20 are narrower than the air ducts 20.

[0044] The air ducts 20 are identically designed and are each merely rotated relative to one another about a rotational axis 28 of the base support 14. Therefore, essentially only one of the air ducts 20 will be described in detail below, whereby the description of the air duct 20 is fundamentally applicable to all of the air ducts 20. The air duct 20 has a curved profile 30 in a plane perpendicular to the rotational axis 28 of the base support 14, the radially outer initial vector a of which has a significant circumferential direction component a u which runs parallel to a circumferential direction at a point of the initial vector a. The course 30 of the air duct 20 has different course directions at different points. The initial vector a has a radial direction component a r and a circumferential component a u Particularly preferably, the radial direction component a rof the output vector a is greater than the circumferential direction component a u . Preferably, a value, in particular a length, of the circumferential direction component a u at least 50%, preferably at least 60% and particularly preferably at least 70% of a value, in particular a length, of the radial direction component a r of the output vector a. Furthermore, the curve 30 has a radially inner input vector e, which also has a radial direction component e r and a circumferential component e u Particularly preferably, the radial direction component e r of the input vector e is significantly larger than the circumferential component e u. The air duct 20 extends substantially in the radial direction. The course 30 of the at least one air duct 20 has the radially inner input vector e, which represents the radial direction component e running parallel to a radial direction at a point of the input vector e. r which is greater than a radial direction component a running parallel to a radial direction at a point of the initial vector a rof the output vector a. The radially inner input vector e of the curve 30 is oriented more in the direction of a radial direction than the radially outer output vector a of the curve 30. An angle between the radially inner input vector e of the curve 30 and a radial direction at the point of the input vector e is smaller than an angle between the radially outer output vector a and a radial direction at the point of the output vector a. The radially outer output vector a has the circumferential direction component a running parallel to a circumferential direction at a point of the output vector a. u which is larger than the circumferential direction component e running parallel to a circumferential direction at a point of the input vector e uof the input vector e. The air duct 20 has, in a plane perpendicular to the axis of rotation 28 of the base support 14, a curved profile 30 in a radially outward direction, counter to a direction of rotation 32. The air duct 20 runs from radially inward to radially outward in a circumferential direction which is opposite to the direction of rotation 32 of the support plate device 10.

[0045] The air duct 20 has an intake opening 34 on an inner side adjacent to the fastening area 16, which is open towards a side of the edge area 18 facing away from a support surface 36 of the base support 14. The intake opening 34 is arranged in a region of the inlet vector e of the profile 30 of the air duct 20. The intake opening 34 forms an opening in the air duct 20 through which air can flow into the air duct 20 during operation. During regular operation, a substantial air flow from the air duct 20 preferably flows into the air duct 20 via the intake opening 34. The intake opening 34 is passive and has no active air intake mechanisms. The intake opening 34 is arranged in the transition area 38 from the fastening area 16 to the edge area 18. The suction opening 34 is introduced into the base support 14 essentially parallel to the axis of rotation 28 of the base support 14.

[0046] The air duct 20 comprises precisely one sub-duct 40 in a radially inner region and at least two sub-ducts 42, 44 in a radially outer region. The air duct 20 has precisely two sub-ducts 42, 44 in the radially outer region. However, it would also be conceivable for the air duct 20 to have at least three sub-ducts 42, 44 in the radially outer region. The two sub-ducts 42, 44 of the radially outer region have a cross-section that is at least approximately the same size, in particular at the same point along their course. The two sub-ducts 42, 44 of the radially outer region follow, on average, the course 30 of the air duct 20. The two sub-ducts 42, 44 of the radially outer region run at least approximately parallel. The two sub-ducts 42, 44 of the radially outer region move away from one another with increasing radial distance from a rotation axis 28 of the base support 14. The air duct 20 has a curved V-shape.Between the two sub-channels 42, 44 of the radially outer region, a wall 76 is arranged, which forms a cooling fin and serves as a support surface for the fiber grinding wheel 26. The wall 76 has at least an approximately triangular shape.

[0047] A height hi, h2 of the air duct 20 parallel to a rotation axis 28 of the air duct 20 decreases radially outwards. The height hi, h2 of the air duct 20 decreases along the course 30 of the air duct 20 from radially inside to radially outside. The height hi, h2 of the air duct 20 decreases along the course 30 of the air duct 20 from radially inside to radially outside by at least 5%, preferably at least 10%, and particularly preferably at least 15%. The height hi, h2 of the air duct 20 is limited in a direction axially pointing away from the interface unit 22 by the fiber grinding wheel 26a. Without a fastened fiber grinding wheel 26a, the air duct 20 is formed by a groove, wherein the height hi, h2 of the air duct 20 is formed by an axial depth of the groove.The height hi, h2 of the air duct 20 is at least 30%, preferably at least 40% of a maximum material thickness of the base support 14 at the same distance from the rotation axis 28 of the base support 14.

[0048] The air guide channels 20 are provided, in an operating state, to transport particles 46 from a working area 48 of the fiber grinding disc 26a out of the working area 48. The fiber grinding disc 26a has at least two dust passage openings 50a, which, in operation, are provided to guide particles 46 from the working area 48 of the fiber grinding disc 26a into the air guide channels 20. The dust passage openings 50a open into the air guide channels 20 of the support plate device 10. The dust passage openings 50a are arranged in a processing area 80a of the fiber grinding disc 26a. The dust passage openings 50a are designed differently from the central connecting recess 52a. The fiber grinding disc 26a has a plurality of dust passage openings 50a, which are arranged distributed over the processing area 80a of the fiber grinding disc 26a. The fiber grinding wheel 26a has, for example, 24 dust passage openings 50a.The dust passage openings 50a are formed by through-holes. The dust passage openings 50a are formed by circular through-holes. The dust passage openings 50a are arranged, for example, on three imaginary rings, each of which has a defined distance from a rotation axis 28. The number of dust passage openings 50a per ring is identical, with the dust passage openings 50a being evenly distributed in the circumferential direction on the respective imaginary ring. The dust passage openings 50a of adjacent rings are, in particular, offset from one another in the circumferential direction. Eight dust passage openings 50a are arranged per ring. The fiber grinding disc 26a comprises a support layer and an abrasive cover layer. Furthermore, the fiber grinding disc 26a has a central fastening region and the processing region 80a extending annularly around the fastening region.

[0049] Figure 10 shows a further embodiment of the fiber grinding wheel of the invention. The following descriptions and the drawings are essentially limited to the differences between the embodiments, in particular between the fiber grinding wheels, whereby with regard to components with the same designation, in particular with regard to components with the same reference numerals, reference can in principle also be made to the drawings and / or the description of the other embodiments, in particular Figures 1 to 9. To distinguish the fiber grinding wheels of the embodiments, the letter a follows the reference numerals of the fiber grinding wheel of the first embodiment in Figures 1 to 9. In the embodiment of Figure 10, the letter a is replaced by the letter b.

[0050] Figure 10 shows a fiber grinding disc 26b. The fiber grinding disc 26b has a connecting device 62b. The connecting device 62b comprises a continuous central connecting recess 52b, which is adjacent to several, in particular eight, narrow recesses 64b extending radially outward.

[0051] The fiber grinding disc 26b has at least two dust passage openings 50b, which, during operation, are provided to guide particles 46 from a working area 48 of the fiber grinding disc 26b into the air guide channels 20. The dust passage openings 50b open into the air guide channels 20 of the support plate device 10. The dust passage openings 50b are arranged in a processing area 80b of the fiber grinding disc 26b. The dust passage openings 50b are designed differently from the central connecting recess 52b. The fiber grinding disc 26b has a plurality of dust passage openings 50b, which are distributed over the processing area 80b of the fiber grinding disc 26b. The fiber grinding disc 26b has, for example, 24 dust passage openings 50b. The dust passage openings 50b are formed by through-holes. The dust passage openings 50b are formed by circular through recesses.The dust passage openings 50b are arranged, for example, on four imaginary rings, each of which has a defined distance from a rotational axis 28b. The number of dust passage openings 50b per ring is identical, with the dust passage openings 50b being evenly distributed in the circumferential direction on the respective imaginary ring. The dust passage openings 50b of adjacent rings are, in particular, offset from one another in the circumferential direction. Eight dust passage openings 50b are arranged per ring. The fiber grinding disc 26b comprises a base layer and an abrasive cover layer. Furthermore, the fiber grinding disc 26b has a central fastening region and the processing region 80b extending in a ring around the fastening region.

Claims

Claims 1. A support plate device, in particular for mounting on a hand-held power tool (12), in particular an angle grinder, comprising a base support (14) which has a central fastening region (16), an edge region (18) which adjoins the fastening region (16) radially outwards and extends as a ring around the fastening region (16), and at least one air duct (20) which extends at least partially radially outwards at least in the edge region (18) and is provided for cooling the base support (14) in at least one operating state, comprising an interface unit (22) for connection to an output shaft of the hand-held power tool (12), in particular of the angle grinder, and comprising a connecting unit (24) for fastening a fiber grinding disc (26a;26b) on the base support (14), characterized in that the at least one air guide channel (20) has a, in particular curved, course (30) in a plane perpendicular to the axis of rotation (28) of the base support (14), the radially outer output vector (a) of which has a substantial circumferential direction component (a; u ) which runs parallel to a circumferential direction at a point of the initial vector (a).

2. Support plate device according to claim 1, characterized in that the course (30) of the at least one air guide channel (20) has a radially inner input vector (e) which has a radial direction component (e) running parallel to a radial direction at a point of the input vector (e r ) which is greater than a radial direction component (a r ) of the output vector (a).

3. Support plate device according to one of the preceding claims, characterized in that the at least one air guide channel (20) has a curved course (30) in a plane perpendicular to the axis of rotation (28) of the base support (14) in a radially outward direction, counter to a direction of rotation (32).

4. Support plate device at least according to claim 1, characterized in that the at least one air guide channel (20) has an intake opening (34) on an inner side adjacent to the fastening area (16), which is open towards a side of the edge area (18) facing away from a support surface (36) of the base support (14).

5. Support plate device at least according to claim 2, characterized in that the suction opening (34) is arranged in a transition region (38) from the fastening region (16) to the edge region (18).

6. Support plate device according to one of the preceding claims, characterized in that the at least one air guide channel (20) comprises exactly one partial channel (40) in a radially inner region and comprises at least two partial channels (42, 44) in a radially outer region.

7. Support plate device according to one of the preceding claims, characterized in that a height (hi, h2) of the at least one air guide channel (20), in particular parallel to a rotation axis (28) of the air guide channel (20), decreases radially outwards.

8. Support plate device according to the preamble of claim 1, in particular according to one of the preceding claims, characterized in that the air guide channel (20) is provided in at least one operating state to transport particles (46), in particular from a working area (48) of the fiber grinding wheel (26a; 26b), from a working area (48).

9. Grinding wheel system with a support plate device (10) according to one of the preceding claims and with a fiber grinding wheel (26a; 26b) which can be connected directly to the support plate device (10) via the connecting unit (24) 10. Grinding wheel system according to claim 9, characterized in that the fiber grinding wheel (26a; 26b) has at least two dust passage openings (50a; 50b) which, during operation, are provided to guide particles (46) from a working area (48) of the fiber grinding wheel (26a; 26b) into the at least one air guide channel (20).

11. Grinding wheel system according to one of claims 9 or 10, characterized in that the fiber grinding wheel (26a; 26b) has at least one central connecting recess (52a; 52b), wherein the connecting unit (24) of the support plate device (10) has at least one connecting section (54) arranged on the base support (14) and a connecting plate (56) which can be detachably connected to the base support (14) and which is intended to hold the fiber grinding wheel (26a; 26b) positively and / or non-positively on the base support (14) via the connecting recess (52a; 52b).

12. Hand tool system with a hand tool (12), in particular an angle grinder, and with a support plate device (10) according to one of claims 1 to 8, in particular with a grinding wheel system according to one of claims 9 to 11.

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