Hand-held power tool and method for operating a hand-held power tool

Abstract

The invention relates to a handheld power tool, in particular a woodworking tool, comprising: a housing, a handle for positioning the power tool relative to a workpiece, a displacement unit for receiving a tool for creating a recess, in particular a hole and / or a groove, in the workpiece, a drive unit for driving the displacement unit, and a pressurized fluid dispensing device for dispensing gaseous pressurized fluid for flushing the recess created in the workpiece in order to effect and / or assist the transport of workpiece particles from the created recess.

Description

[0001] The invention relates to a handheld power tool, in particular a woodworking tool, comprising: a housing, a handle for positioning the power tool relative to a workpiece, a travel unit for receiving a tool for machining a workpiece and a drive unit arranged in the housing for driving the travel unit.

[0002] Handheld power tools are known from the prior art. For example, there are handheld power tools in the form of a hand-held milling machine for milling a recess in the form of a slotted hole into a workpiece, as disclosed in DE 10 2011 103 014 A1.

[0003] When machining a workpiece, for example, when creating a recess in a panel-shaped workpiece made of wood and / or composite material, workpiece particles, in particular dust and chips, are regularly generated. These can sometimes contribute to contamination of the recess, a work area, or the surrounding area, which can also impair the functionality and usability of the power tool. Extraction devices designed to extract the workpiece particles generated during machining have a limited penetration depth up to which the workpiece particles generated or present in the recess are captured by a suction flow. Consequently, material particles remain in areas not captured by the suction flow, particularly in the recess.Such workpiece particles can negatively impact the machining result by inhibiting the movement of the tool and compromising the dimensional accuracy of the recess. Inhibiting the movement of the tool also poses the risk of transmitting a driving force from the drive unit to a power tool user, causing injury to the user and / or slowing down the power tool's movement relative to the workpiece, thus unnecessarily extending the machining time.

[0004] Another problem is that the workpiece particles remaining in the recess continue to be chipped by the tool, thus leading to increased tool wear. The remaining material particles can also cause injury if a person tries to clean the machined workpiece of the workpiece particles.

[0005] Proceeding from this, the present invention is based on the object of creating an improved hand-held power tool of the type mentioned at the outset, which in particular overcomes at least one of the problems identified above.

[0006] According to the invention, this object is achieved by a handheld power tool having the features specified in claim 1. Preferred and advantageous embodiments of a power tool according to the invention are specified in the subclaims.

[0007] The power tool according to the invention comprises a pressurized fluid dispensing device having an outlet region for dispensing gaseous pressurized fluid into a working area of the tool during machining of the workpiece with the tool in order to flush the working area with the gaseous pressurized fluid.

[0008] The working area is understood to mean, in particular, the area in which the tool executes the movement intended for machining the workpiece, the space between the housing of the power tool and the workpiece during machining, and / or the space between the housing of the power tool and a guide unit of the power tool. Flushing with gaseous pressurized fluid removes workpiece particles from at least a portion of the working area, preventing any impairment of the functionality of the power tool.

[0009] In this context, an outlet region is understood to mean in particular at least one outlet opening through which pressure fluid can escape, wherein the outlet opening preferably has an outlet cross-sectional area.

[0010] The pressure fluid can be dispensed continuously or intermittently during machining of the workpiece, whereby the start or stop of the dispensing of pressure fluid can be initiated by the user, for example by actuating a corresponding switch or opening / closing a valve, and / or by a control provided in the power tool.

[0011] The pressure fluid dispensing device can be integrated into the power tool or designed as a modular, retrofittable system that can be connected to a power tool, for example by the pressure fluid dispensing device having a frame construction that can be connected to the housing of the power tool.

[0012] In particular, at least one electric motor is provided as the drive unit, which is supplied by a voltage source in the form of a mains connection or a rechargeable battery, preferably arranged on or in the housing. It is also possible for the drive unit to have a first electric motor, which can also be referred to as a drive motor, and at least one second electric motor, which can also be referred to as a servo motor.

[0013] The handheld power tool preferably further comprises the tool, wherein the tool serves to produce a depression, in particular a hole and / or a groove, in the workpiece, and the pressure fluid dispensing device serves to dispense the gaseous pressure fluid into the resulting depression during the production of the depression in order to effect and / or assist the transport of workpiece particles from the resulting depression. For this purpose, the outlet region is arranged in particular such that the outlet opening is oriented in the direction of the workpiece and / or the resulting depression. The orientation of the outlet opening is understood in particular to mean the direction of the normal vector of the outlet cross-sectional area directed in the outlet direction of the pressure fluid.The resulting depression has a base surface that is oriented essentially parallel or at an angle to a surface of the workpiece and is connected to the surface of the workpiece via a side surface, which can also be formed from multiple surfaces. By discharging the pressurized fluid into the resulting depression, workpiece particles located within the resulting depression can be completely transported out of it or at least removed from the area of the depression in which the tool performs the machining of the workpiece. This reduces the amount of material particles that remain in the depression or removes the material particles almost completely from the depression. The tool is preferably a milling cutter, in particular a wood milling cutter.

[0014] In a further preferred embodiment, the power tool comprises a suction device for sucking workpiece particles out of the work area. The suction device preferably comprises at least one suction nozzle which is designed for connection to a suction device, in particular in the form of a vacuum cleaner, and a suction opening. The suction opening is preferably oriented towards the work area in order to suck workpiece particles located in the work area out of it. The suction opening is particularly preferably arranged opposite the outlet area so that the tool and / or the travel unit is located between the suction opening and the outlet area. By means of the suction, the workpiece particles rinsed out of the work area or transported out of the resulting depression can be transported further so that the amount of workpiece particles in the work area orin the recess and the amount of workpiece particles that enter the environment can be further reduced.

[0015] The power tool preferably further comprises a guide unit with a stop surface for contact with the workpiece, wherein the pressurized fluid dispensing device is preferably arranged on and / or in the guide unit. The guide unit is preferably connected to the housing via a linear guide, which enables displacement of the housing relative to the guide unit. In this way, when the stop surface is in contact with the surface of the workpiece, the position of the tool relative to the workpiece surface can be adjusted. Alternatively, the linear guide can be fixedly connected to the housing. In this case, the position of the tool relative to the workpiece surface can be adjusted via a displacement unit provided for this purpose, in particular in the form of a CNC displacement unit. The displacement unit can be formed separately or integrated into the displacement unit or connected to it.Furthermore, the displacement unit enables linear displacement of the tool in any spatial direction relative to the workpiece surface. In this context, it can also be referred to as a 3-axis milling machine, especially a handheld one. The stop surface is preferably designed in several parts and comprises at least a first section and a second section, wherein the second section is connected to the guide unit by an angle adjustment device in order to adjust an angle between the first section and the second section. The stop surface can also be designed in the shape of a table or plate.

[0016] The stop surface preferably has a recess through which the tool for machining the workpiece extends, wherein the outlet region of the pressure fluid dispensing device is arranged in the region of the recess. The recess has an inlet edge directed towards the travel unit and an outlet edge connected to the inlet edge via a lateral surface and directed towards the workpiece, wherein the outlet region is preferably arranged in the region of the inlet edge, i.e. between the housing and the stop surface. The outlet region is thus protected from damage by the stop surface or the guide unit. For effective dispensing of pressure fluid into the resulting depression, the outlet opening or the outlet cross-sectional area can be oriented towards the outlet edge and / or the resulting depression and, for example, dispense the pressure fluid tangentially, in particular to the side wall of the depression, into the resulting depression.In other words, the outlet region of the pressure fluid dispensing device is designed such that pressure fluid is dispensed parallel to a central axis of the tool and / or to a central axis of the holder.

[0017] In a preferred embodiment of the power tool, the outlet area of the pressurized fluid dispensing device is arranged in a fixed position relative to, in, or on the guide unit. This means, in particular, that the outlet area remains fixed even during machining of the workpiece, and the distance between the outlet area and the tool remains constant. The fixed arrangement enables a simple design of the pressurized fluid dispensing device.

[0018] Preferably, the outlet area of the pressurized fluid dispensing device is arranged so as to be movable relative to, in, or on the guide unit. A movable arrangement makes it possible to adjust the position of the outlet area to the tool to be used and / or to the geometry of the recess. For example, it is conceivable that the distance between the outlet area and the tool is set larger for a recess in the form of a groove than for a recess in the form of a bore. The distance of the outlet area in the perpendicular direction of the stop surface can also be adjusted so that the outlet area is positioned closer to or further away from the workpiece surface during machining.

[0019] The drive unit is preferably designed to set the displacement unit in a displacement movement in order to move the tool relative to the workpiece. In this case, displacement movement is understood to mean, in particular, a movement relative to the workpiece or to the workpiece surface, wherein the movement to the workpiece surface comprises parallel and / or perpendicular components. For example, the displacement unit has a spindle that executes a rotational movement and the displacement unit. The tool is accommodated in the spindle and, in order to machine the workpiece, is set in a rotational movement, wherein the spindle is connected to the displacement unit in order to be displaced relative to the workpiece. The drive motor is provided to drive the spindle and the servomotor is provided to drive the displacement unit. A rotational movement is understood to mean a rotation of the tool around the central axis of the tool.

[0020] Advantageously, the outlet area is at least temporarily motion-coupled to the travel unit, so that the travel movement or part of the travel movement causes the outlet area to move relative to the guide unit in an outlet area motion. The motion coupling between the outlet area and the tool makes it possible to minimize the distance between the outlet area and the tool in order to achieve the most effective discharge of pressurized fluid into the resulting depression without restricting the travel movement of the travel unit, in particular the component parallel to the workpiece surface.

[0021] Particularly preferably, the displacement unit comprises a spindle holder which carries out the displacement movement and the spindle which carries out the rotational movement, wherein the spindle is arranged at least in sections within the spindle holder.

[0022] Further preferably, the pressure fluid dispensing device is motion-coupled to the spindle receptacle via a coupling unit, in particular a cam disk coupling. The spindle receptacle is in contact with a correspondingly designed cam section of the coupling unit during the travel movement or part of the travel movement, wherein the cam section, which is connected at least to the outlet region, can be spring-loaded in order to cause the outlet region to move back to an initial position. The initial position can be any position of the outlet region in the region of the recess, which enables pressure fluid to be dispensed, in particular through the recess of the stop surface. Preferably, the dispensing of pressure fluid is interrupted when the outlet region is temporarily located outside the region of the recess due to the outlet region movement.The coupling unit also enables motion coupling for travel movements that have a complex path geometry, for example a back-and-forth oscillating movement on a circular path section.

[0023] In a further embodiment of the power tool, the outlet region has an outlet opening that opens out of the tool. The outlet opening is preferably arranged on the end face or circumferential side of the tool and is oriented parallel and / or perpendicular to a channel formed in the tool and extending in the longitudinal direction of the tool, and is fluidically connected to the latter. Further preferably, the outlet opening can be arranged in a tool tip section and / or in a region different from the tool tip section, in particular a region adjacent to the tool tip section and / or on the circumferential side of the tool, in particular in a chip space of the tool, wherein the tool tip section is advantageously made of a material different from a base material of the tool, in particular of a hard metal.Due to the arrangement of the outlet opening in the tool, the gaseous pressure fluid can be discharged directly into the resulting depression.

[0024] The power tool preferably further comprises a pressurized fluid source that is fluidly connected to the pressurized fluid dispensing device and serves to provide the pressurized fluid to the pressurized fluid dispensing device. For example, the pressurized fluid source can be formed by a first element of a coupling, in particular a quick-connect coupling, that can be connected to a second element of the coupling arranged on a pressurized fluid line in order to provide a volume flow of pressurized fluid from the pressurized fluid line to the pressurized fluid dispensing device. For example, the pressurized fluid source can comprise an external supply unit that has a compressor or a pressurized fluid container and is fluidly connected to the pressurized fluid dispensing device, for example via a pressurized fluid line. The pressurized fluid dispensing device preferably has a quick-connect element for this purpose.The supply unit can also include a suction device that is fluidically connected to the suction device. It is advantageous to provide a volume flow of pressurized fluid of at least 20 l / s, preferably at least 35 l / s, to ensure adequate flushing of the work area and to effect and / or assist the transport of material particles from the resulting depression or the work area when the gaseous pressurized fluid is discharged.

[0025] In an advantageous embodiment of the power tool, the pressurized fluid source is arranged, particularly in a stationary manner, in or on the housing or the guide unit. One of these arrangement options improves the mobility of the power tool, and machining of the workpiece can be performed independently of an external supply unit. This can also be referred to as autonomous machining.

[0026] The pressurized fluid source preferably comprises a fluid reservoir. The fluid reservoir serves as a pressurized fluid reservoir and enables, for example, the provision of pressurized fluid when the power tool is not supplied via a pressurized fluid line, for example due to a temporary failure of the pressurized fluid line or when the power tool is to be used at a location remote from the pressurized fluid line. The fluid reservoir can already be filled with pressurized fluid or can be filled during operation by directing part of the volume flow of the pressurized fluid into the fluid reservoir. The fluid reservoir can also have a valve unit, in particular in the form of a shut-off valve and / or a pressure relief valve, in order to prevent the pressurized fluid from escaping from the fluid reservoir after it has been completely filled or to prevent further filling with pressurized fluid.It is also possible to release the pressure if the pressure of the pressure fluid exceeds a permissible value, for example as a result of a malfunction or excessive heating of the power tool or the fluid reservoir.

[0027] In a further embodiment of the power tool, the fluid reservoir is designed as a replaceable cartridge. Using the replaceable cartridge, which is filled with pressurized fluid, the power tool can be used for extended periods of time independently of a pressurized fluid line by replacing the cartridge with a new one after it has been emptied. The replaceable cartridge also enables the use of various gases as the gaseous pressurized fluid. For example, a shielding gas such as nitrogen or argon can also be used if the workpiece material or the environment in which the workpiece is being processed requires it.

[0028] Advantageously, the pressurized fluid source comprises a compressor. The compressor, which can be arranged in or on the housing or in or on the guide unit, enables autonomous processing of the workpiece over an extended period of time. The compressor can be designed as a separate unit with its own drive, in particular an electric motor, and its own power source. It can also be designed as an integrated unit, which is also powered by the drive unit of the power tool.

[0029] Furthermore, the power tool can comprise a blocking device designed to dispense gaseous pressurized fluid to provide a blocking fluid flow. The blocking device comprises a dispensing opening having a dispensing cross-sectional area, which is arranged such that a main flow direction of the blocking fluid flow runs substantially parallel to the workpiece surface. The blocking fluid flow can assist the transport of workpiece particles in the work area and thus prevent workpiece particles from leaving the work area in an uncontrolled manner. Uncontrolled is understood in particular to mean leaving the work area in the direction of the housing or in the direction of a user wielding the power tool. The dispensing opening is preferably oriented in the direction of the suction opening in order to further improve the transport of the workpiece particles from the work area.

[0030] The above-mentioned object is also achieved by a method for operating a handheld power tool according to the invention. The method comprises the steps of: machining the workpiece with the tool in the work area, discharging the gaseous pressurized fluid into the work area of the tool while machining the workpiece with the tool in order to flush the work area with the gaseous pressurized fluid.

[0031] Furthermore, the above-mentioned object is also achieved by a woodworking tool, in particular a wood milling cutter, comprising a channel extending along a central axis and an outlet opening fluidically connected to the channel for discharging gaseous pressurized fluid into a work area. The woodworking tool comprises, in particular, a first tool section, a second tool section with a tool tip section, and a pressurized fluid inlet chamber connected to the outlet opening via the channel.

[0032] The tool tip section forms the end section of the second tool section opposite the first tool section. The second tool section is designed, at least in part, for machining a wooden workpiece. In particular, the second tool section has cutting edges arranged circumferentially and extending in the longitudinal direction of the central axis. The tool tip section is designed for machining a wooden workpiece and extends from an end face of the woodworking tool along the central axis of the woodworking tool. The tool tip section can have end-face cutting edges extending in the radial direction on its end face.

[0033] The longitudinally extending cutting edge preferably extends spirally, with an angle resulting from the spiral course of the cutting edge, which can also be referred to as the spiral angle, between the cutting edge and the central axis of the woodworking tool preferably being 10° to 15°, particularly preferably 11° to 12°. The spiral angle in the region of the tool tip section can be larger, in particular by 0.5° to 1°, than the spiral angle in the remaining region of the second tool section. A correspondingly designed woodworking tool can also be referred to as a spiral milling cutter.

[0034] Advantageously, the tool tip section is made of a material different from a base material of the woodworking tool, in particular of a hard metal. The woodworking tool preferably has two, and more preferably three, cutting edges distributed at a uniform angular spacing around the circumference of the woodworking tool. The end face can be formed by a surface oriented substantially perpendicular to the central axis of the woodworking tool and / or by a plurality of cutting edges, wherein all or some of the plurality of cutting edges may not be oriented perpendicular to the central axis of the woodworking tool.

[0035] The outlet opening is arranged on the front and / or circumferential side of the woodworking tool and is oriented parallel and / or perpendicular to the channel formed in the woodworking tool.

[0036] Preferably, the outlet opening is arranged in a region of the second tool section different from the tool tip section, wherein the tool tip section is made of a material different from a base material of the woodworking tool, in particular of a hard metal. By arranging the outlet opening in the woodworking tool, the gaseous pressurized fluid can be discharged directly into the resulting depression. Furthermore, the channel can be introduced into an easily machined region of the woodworking tool during manufacture, while the areas of the cutting edges that are subject to high stress are made of a resistant material in the region of the tool tip section.

[0037] Alternatively, the channel may be arranged in a hard metal portion of the woodworking tool. In particular, the woodworking tool may be made entirely of hard metal.

[0038] In the following, preferred embodiments of the invention are explained in more detail with reference to the accompanying drawings. Fig. 1 a first embodiment of a hand-held power tool according to the invention in a perspective view from behind, Fig. 2 a first embodiment of a hand-held power tool according to the invention in a perspective view from the front, Fig. 3 a traversing unit of the power tool with a tool, a suction device and a first embodiment of a pressure fluid dispensing device in a side view in a sectional view, Fig. 4 the movement unit, the suction device and a second embodiment of a pressure fluid dispensing device in a side view in a sectional view, Fig. 5a shows an alternative travel unit of a second embodiment of the hand-held power tool in a first position, the suction device and a third embodiment of a pressure fluid dispensing device in a side view in a sectional view, Fig. 5b the travel unit Fig. 5a in a second position, the suction device and the design of the pressure fluid dispensing device from Fig. 5a in a side view in a sectional view, Fig. 5c the travel unit Fig. 5a in a third position, the suction device and the design of the pressure fluid dispensing device from Fig. 5a in a side view in a sectional view, Fig. 6a the pressure fluid dispensing device Fig. 5a in a side view, Fig. 6b the pressure fluid dispensing device Fig. 6a in a side view in a sectional view, Fig. 7 shows a section of a third embodiment of the hand-held power tool with a fourth embodiment of a pressure fluid dispensing device in a side view in a sectional view, Fig. 8a shows a first embodiment of a woodworking tool with an outlet area in a side view in a sectional view, Fig. 8b a second embodiment of a tool for woodworking with an outlet area in a side view in a sectional view, Fig. 8c a third embodiment of a tool for woodworking with an outlet area in a side view in a sectional view, Fig. 9a a fourth embodiment of a tool for woodworking with an outlet area in a side view and Fig. 9b Sectional view along the section plane AA of the embodiment of the tool from Fig. 9a in a top view.

[0039] In the Fig. 1 and Fig. Figure 2 shows a first embodiment of a handheld power tool 1 according to the invention. The power tool 1 comprises a housing 3, a guide handle 4 and a handle 5 for positioning the power tool 1 relative to a workpiece (not shown), a drive unit 7 arranged in the housing 3, and a guide unit 9.

[0040] In the area of the handle 5, an activation button 6 is arranged on an upper side of the housing 3, with which the power tool 1 can be switched on and off.

[0041] Furthermore, an adjustment element 8 is arranged on the top of the housing 3 in the area between the activation button 6 and the guide unit 9. The guide unit 9 has a stop surface 11 with which the guide unit 9 can be brought into contact with a surface of the workpiece to be machined.

[0042] The stop surface 11 of the illustrated guide unit 9 is constructed in several parts and comprises a first section 15 and a second section 17, wherein the second section 17 is connected to the guide unit 9 via an angle adjustment device 19 in order to be able to set an angle between the first section 15 and the second section 17. The guide handle 4 is arranged at an end of the second section 17 facing away from the first section 15. A setting is shown in which the angle between the first section 15 and the second section 17 is 180°. The angle can preferably be set in a range from 90° to 180°. To fix the set angle, the angle adjustment device 19 has a first locking element 20. At a lower edge 16 of the first section 15, ieAdjacent to the edge of the first section 15 facing away from the second section 17 is a floor stop surface 12 which is oriented substantially perpendicular to the first section 15 of the stop surface 11. A distance between an edge 18 of the second section 17 facing the first section 15 in a direction perpendicular to the floor stop surface 12, which can also be referred to as a vertical direction, is possible via a vertical guide device 22. This is particularly advantageous when the angle between the first section 15 and the second section 17 is 90° and the second section 17 is brought into contact with a surface of a workpiece to be machined, for example to machine an end face of the workpiece. A second locking element 24 is provided to determine the set distance between the edge 18 and the floor stop surface 12.

[0043] The guide unit 9 is connected to the housing 3 via a linear guide 13, which enables a displacement of the housing 3 relative to the guide unit 9. Such a displacement can also be referred to as a displacement in the longitudinal direction.

[0044] A tool 21 used to create a recess in the workpiece extends through a recess 23 formed in the first section 15 of the stop surface 11. A distance between the workpiece-side end of the tool 21, which can also be referred to as a milling cutter tip, and the first section 15 of the stop surface 11 can be varied, at least during machining of the workpiece, by moving the tool 21 in a direction perpendicular to the first section 15 when the stop surface 11 is at least partially in contact with the workpiece. For example, for this purpose, the housing 3 is displaced along the linear guide 13 of the guide unit 9 in the direction of the stop surface 11 or in the opposite direction.The maximum distance between the workpiece-side end of the tool 21 and the first section 15 of the stop surface 11 can be specified by a depth adjustment device 14, which limits the maximum displacement along the linear guide 13.

[0045] Furthermore, a pressure fluid dispensing device 25 and a suction device 27 are arranged on the guide unit 9. The pressure fluid dispensing device 25 with an outlet area 29 is designed to dispense gaseous pressure fluid into a working area of the tool 21 in order to flush the working area with the gaseous pressure fluid during machining of the workpiece or to dispense pressure fluid into the resulting depression. At the end of the pressure fluid dispensing device 25 facing away from the outlet area 29, as particularly shown in Fig. 1, a pressurized fluid source 41 is arranged, which is fluidically connected to the pressurized fluid dispensing device 25 and is designed, for example, in the form of a cylindrical cartridge. A working area is understood to be the area in which the tool 21 executes the movement intended for machining a workpiece, the space located between the housing 3 of the power tool 1 and the workpiece during machining, and the space between the housing 3 of the power tool 1 and a guide unit 9. By flushing with gaseous pressurized fluid, workpiece particles are transported out of at least a portion of the working area, preventing the functionality of the power tool 1 from being impaired.The workpiece particles are transported further by the suction device 27, wherein the suction device 27 has a suction nozzle 43 for connecting the suction device 27 to a suction device (not shown) and a suction opening 45, which in this case is arranged opposite the outlet area 29. The suction nozzle 43, arranged at an end of the suction device 27 opposite the suction opening 45, has locking elements 44 arranged on its circumference for connection to the suction device (not shown). Thus, for example, a connecting nozzle of the suction device can be locked to the suction nozzle 43.

[0046] The first embodiment of the pressure fluid dispensing device 25, a tool 21 and the suction device 27 are shown in Fig. 3. The outlet region 29 of the suction device 27 is arranged in a stationary manner on the guide unit 9 in the region of an inlet edge 33 of the recess 23, wherein an outlet opening 35 of the outlet region 29 is oriented in the direction of an outlet edge 39 of the recess 23, which is connected to the inlet edge 33 via a lateral surface 37. For the fluidic connection of the pressure fluid dispensing device 25 to the pressure fluid source 41, the pressure fluid dispensing device 25 has an inlet region 30 at its end opposite the outlet region 29. The inlet region 30 is fluidic connected to the outlet region 29 via a pressure fluid channel 32. For the removal or further transport of the fluid captured or conveyed by a pressure fluid flow.To remove the swirled-up workpiece particles, the suction opening 45 of the suction device 27 is oriented in the direction of the working area and is thus oriented, for example, perpendicular to a central axis 26 of the tool 21, wherein an orientation is understood to mean the direction of a normal vector of a suction opening cross-sectional area delimited by the suction opening 45.

[0047] The tool 21 is accommodated in a traversing unit 31, which is driven, at least rotationally, by the drive unit 7. To supply an electric motor of the drive unit 7 with voltage, a mains connection 47 is provided at the rear end of the housing 3, i.e., at the end opposite the guide unit 9, see Fig. 1, arranged.

[0048] The Fig. The embodiment of the pressurized fluid dispensing device 25 shown in Figure 4, whose outlet region 29 is oriented as described above, further comprises a blocking device 49. The blocking device 49 is designed to dispense gaseous pressurized fluid to provide a blocking fluid flow and comprises a dispensing opening 51 oriented in the direction of the suction opening 45, wherein an orientation is understood to mean the direction of a normal vector of a dispensing opening cross-sectional area delimited by the dispensing opening 51. In the illustrated embodiment, the blocking device 49 is connected via a further inlet region 50 to the pressurized fluid source 41 for supplying the blocking device 49 with pressurized fluid, wherein the dispensing opening 51 and the further inlet region are fluidically connected via a blocking fluid channel 52.By way of example, the blocking device 49 is integrated in the pressure fluid dispensing device 25, wherein the inlet region 30 and the further inlet region 50 open out at a common outer surface 28 of the pressure fluid dispensing device 25 and the pressure fluid channel 32 and the blocking fluid channel 52 run substantially parallel to one another.

[0049] The Fig. 5a, Fig. 5b and Fig. 5c show an alternative displacement unit 31 and a third embodiment of the pressure fluid dispensing device 25 of a second embodiment of the power tool 1, wherein the third embodiment of the pressure fluid dispensing device 25 is isolated in the Fig. 6a and Fig. 6b. The pressure fluid dispensing device 25 has the outlet region 29 and the inlet region 30, which are fluidically connected via the pressure fluid channel 32. In this embodiment, the inlet region 30 is designed as a plug-in connector that can be connected to a pressure fluid hose (not shown) in order to connect the pressure fluid dispensing device 25 to an external pressure fluid source (not shown), for example in the form of a compressor, for supplying the pressure fluid dispensing device 25 with pressure fluid. The suction device 27 is designed as previously described.

[0050] In this embodiment of the power tool 1, the drive unit 7 is designed to set the displacement unit 31 in a displacement movement in order to move the tool 21 relative to the workpiece. The displacement unit 31 comprises a spindle holder 53 which executes the displacement movement and a spindle 55 which is accommodated in sections in the spindle holder 53 and executes a rotational movement. In the present embodiment, the displacement movement takes place periodically between the Fig. 5a shown first position of the traversing unit 31 and the one in the Fig. 5c shown third position of the traversing unit 31, wherein the Fig. 5b, the second position of the traversing unit 31 is passed through during the traversing movement. A traversing movement is understood to mean a movement relative to the workpiece or the workpiece surface, wherein the movement comprises components parallel and / or perpendicular to the workpiece surface, wherein a movement amplitude parallel to the workpiece surface can be varied by means of the adjustment element 8.

[0051] In order to minimize a distance oriented parallel to the workpiece surface between the outlet area 29 and the tool 21 and to ensure the most effective discharge of pressure fluid into the resulting depression, the outlet area 29 is motion-coupled to the travel unit 31, so that the outlet area 29 is displaced into an outlet area movement relative to the guide unit 9 by the travel movement.

[0052] For the movement coupling between the outlet region 29 and the displacement unit 31, the pressure fluid dispensing device 25 has a coupling unit 57 having a curved section 59, wherein the spindle receptacle 53 is in contact with the curved section 59 of the coupling unit 57. By way of example, the curved section 59 is flat, but can have further profiles tailored to the displacement movement of the displacement unit 31.

[0053] The illustrated coupling unit 57 is designed in several parts and comprises a bearing element 61, which is arranged in a stationary manner in or on the guide unit 9, and a displacement element 63, which is connected to the bearing element 61 via guide rails 65, which enable a displacement of the displacement element 63 relative to the bearing element 61. The guide rails 65 are mounted in bearing sleeves 66 in the displacement element 63. In order to set the outlet area 29 into an outlet area movement relative to the guide unit 9 by the displacement movement, the outlet area 29 is firmly connected to the displacement element 63. Springs 67 are arranged between the bearing element 61 and the displacement element 63, which enable a return of the displacement element 63 to an initial position. If the spindle holder 53 performs a displacement movement directed in the direction of the bearing element 61 up to the first, in Fig. 5a, the displacement element 63 is displaced along the guide rails 65 in the direction of the bearing element 61. If the spindle holder 53, after reaching the first position, performs the opposite movement in the direction of the second ( Fig. 5b) or third ( Fig. 5c) position, the displacement element 63 is displaced away from the bearing element 61 along the guide rails 65 by the springs 67.

[0054] The coupling unit 57 contains limit switches (not shown) which are signal-linked to a control (not shown) provided in the power tool 1. Upon reaching the first position ( Fig. 5a), i.e., when the limit switches are triggered, the control system can stop the discharge of pressure fluid. Pressure fluid discharge will restart when the spindle holder 53 leaves the first position, so that the limit switches are no longer triggered.

[0055] In a third, sectionally in Fig. In the embodiment of the power tool 1 shown in Figure 7, the outlet region 29 has an outlet opening 35 leading out of the tool 21, so that pressurized fluid can be discharged from the tool 21 directly into the resulting recess in the workpiece to be machined. For fluidically connecting the outlet opening 35 to the pressurized fluid source 41 or to a pressurized fluid line 69 connected to the pressurized fluid source 41, a channel 71, 73 is formed in each of the spindle 55 and the tool 21, wherein the channels 71, 73 extend along the axial extent of the spindle 55 and the tool 21, respectively.

[0056] In the Fig. 8a, Fig. 8b and Fig. 8c are various embodiments of a tool 21 designed as a woodworking tool, more precisely as a wood milling cutter, for use with the tool shown in the Fig. 7 is shown in section. The illustrated embodiments of the woodworking tool each have two cutting edges 70 with corresponding chip spaces 79, wherein in the Fig. 8a, Fig. 8b and Fig. 8c only one cutting edge 70 is visible.

[0057] The Fig. The tool 21 shown in Figure 8a has a first tool section 74, which is essentially cylindrical, and a second tool section 75 with a smaller diameter, which adjoins the first tool section 74 and is, for example, partially cylindrical. A tool tip section 76 is formed on the region of the second tool section 75 opposite the first tool section 74 and extends to an end face 77 of the tool 21. The channel 73 of the tool 21 connects a pressure fluid inlet chamber 78 of the tool 21 to the outlet opening 35. To connect the tool 21 to the spindle 55, the pressure fluid inlet chamber 78 has, for example, an internal thread on its inside, wherein the spindle 55 has an external thread corresponding to this internal thread.

[0058] In the Fig. In the embodiment shown in Figure 8a, the outlet opening 35 is arranged in the end face 77 of the tool 21. The channel 73 thus extends in a straight line from the pressure fluid inlet chamber 78 to the outlet opening 35.

[0059] In the Fig. In the embodiment of the tool 21 shown in Fig. 8b, the outlet opening 35 opens out of the tool 21 on the circumference. The channel 73 has a first channel section 80 arranged parallel to a central axis 26 of the tool 21 and a second channel section 81 oriented perpendicular to the first channel section 80, which second channel section 81 fluidically connects the first channel section 80 to outlet openings 35. In this embodiment, the pressurized fluid is discharged perpendicular to the central axis 26 of the tool 21 into chip spaces 79 of the tool 21. In the present embodiment, an outlet opening 35 is arranged in each chip space 79.

[0060] In Fig. 8c shows a further embodiment of the tool 21, wherein the tool 21 has outlet openings 35 arranged in chip spaces 79 of the tool 21. In the present exemplary embodiment, an outlet opening 35 opens into each chip space 79, wherein the outlet openings 35 are connected to one another and to a first channel section 80 via channel sections 82. The outlet openings 35 are oriented such that the respective normal vector of an outlet opening cross-sectional area delimited by the respective outlet opening 35 has a component perpendicular to the central axis 26 of the tool 21 and a component parallel to the central axis 26 of the tool 21.

[0061] In the Fig. 9a and Fig. 9b is another embodiment of the tool 21 for use with the Fig.7. In this embodiment, two cutting edges 70 are formed, which extend over a substantial region of the second tool section 75. In this embodiment, the first tool section 74 and the second tool section 75 are made of a metallic base material, and the tool tip section 76 is made of hard metal. Outlet openings 35, which are formed in a region of the second tool section 75 consisting of the base material, each open into one of the chip spaces 79. A spiral angle α formed between the cutting edge 70 and the central axis 26 is constant over the entire extent of the cutting edges 70 in the embodiment of the tool 21 shown and is, for example, 11.5°. The chip spaces 79 are formed on the second tool section 75 to correspond to the cutting edges 70 and enable efficient chip removal from the workpiece to be machined. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2011 103 014 A1

[0002]

Claims

[1] Hand-held power tool (1), in particular a woodworking tool, comprising: - a housing (3), - a handle (5) for positioning the power tool relative to a workpiece, - a moving unit (31) for receiving a tool (21) for machining a workpiece, - a drive unit (7) arranged in the housing (3) for driving the travel unit (31), and - a pressure fluid dispensing device (25) having an outlet region (29) for dispensing gaseous pressure fluid into a working area of the tool (21) during machining of the workpiece with the tool (21) in order to flush the working area with the gaseous pressure fluid. [2] Hand-held power tool according to claim 1, further comprising the tool (21), wherein the tool (21) serves to produce a recess, in particular a hole and / or a groove, in the workpiece and the pressurized fluid dispensing device (25) serves to dispense the gaseous pressurized fluid into the resulting recess during the production of the recess in order to effect and / or assist the transport of workpiece particles from the resulting recess. [3] Power tool according to claim 1 or 2, further comprising a suction device (27) for sucking workpiece particles from the work area. [4] Power tool according to claim 1 or 2, further comprising a guide unit (9) with a stop surface (11) for contact with the workpiece, wherein the pressure fluid dispensing device (25) is arranged on and / or in the guide unit (9). [5] Power tool according to claim 4, wherein the stop surface (11) has a recess (23) through which the tool (21) extends for machining the workpiece, wherein the outlet region (29) of the pressure fluid dispensing device (25) is arranged in the region of the recess (23). [6] Power tool according to claim 5, wherein the outlet region (29) of the pressure fluid dispensing device (25) is arranged stationary relative to, in or on the guide unit (9). [7] Power tool according to claim 5, wherein the outlet region (29) of the pressure fluid dispensing device (25) is arranged to be movable relative to, in or on the guide unit (9). [8] Power tool according to claim 7, wherein the drive unit (7) is designed to set the displacement unit (31) into a displacement movement in order to move the tool (21) relative to the workpiece. [9] Power tool according to claim 7 or 8, wherein the outlet region (29) is at least temporarily coupled in movement to the displacement unit (31), so that the outlet region (29) is displaced into an outlet region movement relative to the guide unit by the displacement movement. [10] Power tool according to one of the preceding claims, wherein the displacement unit (31) comprises a spindle holder (53) performing the displacement movement and a spindle (55) performing a rotational movement, wherein the spindle (55) is arranged at least in sections within the spindle holder (53). [11] Power tool according to one of claims 7 to 10, wherein the pressure fluid dispensing device (25) is coupled in terms of movement to the spindle holder (53) via a coupling unit (57), in particular a cam coupling. [12] Power tool according to one of claims 1 to 3, wherein the outlet region (29) has an outlet opening (35) which opens out of the tool (21), in particular out of a tool tip section (76). [13] Power tool according to claim 12, wherein the tool (21) is a woodworking tool, in particular a wood milling cutter. [14] Power tool according to any preceding claim, further comprising a pressurized fluid source (41) fluidly connected to the pressurized fluid dispensing device (25) and serving to provide the pressurized fluid to the pressurized fluid dispensing device. [15] Power tool according to claim 14, wherein the pressure fluid source (41) is arranged, in particular stationary, in or on the housing (3) or the guide unit (9). [16] Power tool according to claim 14 or 15, wherein the pressurized fluid source (41) comprises a fluid reservoir. [17] Power tool according to claim 16, wherein the fluid reservoir is designed as a replaceable cartridge. [18] Power tool according to one of claims 14 to 17, wherein the pressurized fluid source (41) comprises a compressor. [19] Method for operating a hand-held power tool (1) according to one of the preceding claims, comprising the steps: - machining the workpiece with the tool (21) in the working area, - Dispensing the gaseous pressure fluid into the working area during machining of the workpiece with the tool (21) in order to flush the working area with the gaseous pressure fluid. [20] Tool (21) for woodworking, in particular wood milling cutter, with a channel (73) extending along a central axis (26) and an outlet opening (35) fluidically connected to the channel (73) for discharging gaseous pressurized fluid into a working area.

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