hand tool

Abstract

A hand-held power tool (100) is disclosed, comprising a housing (110), a drive motor (114), an intermediate shaft (120), the intermediate shaft (120) being drivable by the drive motor (114), an impact mechanism (122) being drivable at least partially by the intermediate shaft (120), and a tool holder (150) for receiving an insert tool (140), the tool holder (150) being drivable by means of the impact mechanism (122). It is proposed that the hand-held power tool (100) has a sensor wheel arrangement (200) which can be driven at least partially by the tool holder (150).

Description

The present invention relates to a hand-held power tool according to the preamble of claim 1.Prior ArtDE 10 2017 200 988 A1 discloses a sensor wheel arrangement for determining an absolute angle position of an electric motor.Disclosure of the InventionThe present invention is based on a hand-held power tool having a housing, having a drive motor, having an intermediate shaft, the intermediate shaft being drivable by the drive motor, having a striking mechanism which is drivable at least partially by the intermediate shaft, and having a tool receptacle for receiving an insert tool, the tool receptacle being drivable by means of the striking mechanism. It is proposed that the hand-held power tool has a transmitter wheel arrangement which can be driven at least partially by the tool holder.The invention provides a hand-held power tool in which a rotation angle of the tool holder per stroke of the striking mechanism can be determined. This increases a screwing-in accuracy.The hand-held power tool can be designed as an electrically operated hand-held power tool. The electrically operated hand-held power tool can be designed as a mains-operated or as a battery-operated hand-held power tool. For example, the hand-held power tool can be designed as a rotary impact wrench.The housing of the hand-held power tool is designed to at least partially accommodate the tool holder, the drive motor, the intermediate shaft and the striking mechanism. The housing can be designed as a shell housing with two half shells.The drive motor can be designed as an electrically commutated drive motor, in particular as at least one electric motor. The drive motor is designed in such a way that it can be actuated via a manual switch. If the hand switch is operated by a user, the drive motor is switched on and the hand-held power tool is put into operation. If the manual switch is accordingly no longer actuated by the user, the drive motor is switched off. The drive motor is preferably electronically controllable and / or regulable in such a way that a reversing operation and a specification for a desired rotational speed can be realized. In the reversing mode, the drive motor can be switchable between a clockwise direction of rotation and a counterclockwise direction of rotation. To switch over the drive motor in the reversing mode, the hand-held power tool can have a rotation direction switching element, in particular a rotation direction switching device.The drive motor is designed to drive the intermediate shaft. For this purpose, the drive motor and the intermediate shaft are connected to one another. The intermediate shaft is arranged between the drive motor and the tool holder. The intermediate shaft can have a transmission unit. The transmission unit can be designed as at least one planetary gear, wherein it can be shifted, for example. The planetary gear can have at least one planetary stage. In a shiftable transmission, it is possible to switch between at least two gear stages by means of at least one gear switching element, in particular a gear change-over switch. The transmission unit can have a transmission cover. The transmission cover is designed to cover, in particular at least partially close, the transmission unit with respect to the drive motor. The transmission cover can be arranged between the planetary transmission, in particular the planetary stage, and the drive motor. The transmission unit, in particular the planetary transmission, can have a ring gear. Here, for example, the ring gear and the transmission cover can be integral.The striking mechanism is designed to be operated in a striking mode. During the percussion operation, the percussion mechanism generates high torque peaks in order to thereby release tightly seated connecting means or to fasten connecting means. The striking mechanism has a striking mechanism and a striking mechanism spring. The striking mechanism can be connected to the drive motor by means of the gear unit of the intermediate shaft. The striking mechanism can be designed, for example, as a rotary striking mechanism or a V-groove striking mechanism. The striking mechanism can be driven by the intermediate shaft. The striking mechanism can be arranged between the drive motor and the tool holder. The striking mechanism has a striking mechanism housing in which the striking mechanism and the striking mechanism spring are arranged. In addition, the striking mechanism has a striking mechanism cover. The striking mechanism cover can close the striking mechanism in the direction of the drive motor. The striking mechanism cover can be arranged between the drive motor and the tool holder, in particular the intermediate shaft, very particularly the transmission unit. It is possible for the striking mechanism cover and the transmission cover to be integral, so that the striking mechanism cover forms the ring gear.The striker and the striking mechanism spring can be arranged around the intermediate shaft in the circumferential direction. The striker can be mounted on the intermediate shaft by means of striking mechanism balls. In addition, the striking mechanism balls are designed to move the striking element at least partially, in particular axially, in the direction of the drive motor. The striker can be arranged in a position facing the tool holder or in a position facing the drive motor. In the position facing the tool holder, the striker can abut a rear end of the tool holder by means of at least one striking cam. Here, for example, two striking cams are provided, wherein more than two striking cams are also conceivable. In the position facing the drive motor, the striker can be arranged at a distance from the tool holder. The striking mechanism balls are designed to pull the striking mechanism open from a triggering torque, which can be applied to the tool holder, in that the striking mechanism balls move, in particular displace, the striking mechanism from the position facing the tool holder counter to a spring force of the striking mechanism spring into the position facing the drive motor. The performed spring force of the striking mechanism spring is stored as the performed clamping work. As soon as the striker reaches the position facing the drive motor, the striker can be guided back into the position facing the tool holder by means of the striking mechanism spring. In this case, the clamping work performed is released, as a result of which the club is guided into the position facing the tool holder. The club can perform a rotational movement and an axial movement.The drive motor has a drive shaft. The drive shaft is mounted in the housing by means of at least one drive shaft bearing. The drive motor can drive by means of the drive shaft, the intermediate shaft, the transmission unit, the striking mechanism and / or the tool holder. The drive shaft bearing can be designed, for example, as a ball bearing, a rolling bearing or a sliding bearing. The drive shaft bearing is arranged at an end of the drive motor facing the tool holder. The drive shaft can project into the intermediate shaft through the transmission unit. The drive shaft bearing can be arranged in the intermediate shaft, so that the drive shaft is mounted in the intermediate shaft by means of the drive shaft bearing. The drive shaft can have a further drive shaft bearing which is arranged on an end facing away from the drive motor. Thus, the drive shaft can then be rotatably mounted in the housing by means of the drive shaft bearing and the further drive shaft bearing. It is possible for the drive shaft to protrude into the transmission cover and / or to engage into the transmission cover. The hand-held power tool can have a tool axis. In this case, an axis of rotation of the drive shaft can form the tool axis. In particular, "axial" is to be understood to mean substantially parallel to the tool axis. Whereas, "radial" is to be understood to mean substantially perpendicular to the tool axis.The tool holder can be designed as an inner tool holder, such as a bit holder, for example, and / or as an outer tool holder, such as a nut holder, for example. It is also conceivable for the tool holder to be designed as a drill chuck. The tool holder can hold insert tools, such as, for example, helical bits or socket wrench, so that a user can produce screw connections from a fastening element to a fastening carrier.In addition, the hand-held power tool comprises an energy supply, wherein the energy supply is provided for battery operation by means of batteries, in particular hand-held power tool battery packs, and / or for grid operation. In a preferred embodiment, the energy supply is designed for battery operation. In the context of the present invention, a "hand-held power tool battery pack" is intended to mean a connection of at least one battery cell and one battery pack housing. The handheld power tool rechargeable battery pack is advantageously designed for supplying energy to commercially available battery-operated handheld power tools. The at least one battery cell can be designed, for example, as a Lilon battery cell having a rated voltage of 3.6 V. By way of example, the handheld power tool battery pack can comprise up to ten battery cells, wherein a different number of battery cells is also conceivable. An embodiment as a battery-operated hand-held power tool and also the operation as a mains-operated hand-held power tool are sufficiently known to the person skilled in the art, for which reason the details of the energy supply will not be discussed here.The hand-held power tool can have a control unit at least for controlling the drive motor. The control unit can be arranged in the housing, for example in a handle of the hand-held power tool or in a region of a power supply interface.The encoder wheel arrangement can be driven at least partially by the tool holder. When the tool holder rotates, the encoder wheel arrangement rotates at least partially. In this case, for example, a rotational angle of the encoder wheel arrangement, a rotational angle speed of the encoder wheel arrangement, a rotational angle acceleration of the encoder wheel arrangement and / or a multiple rotation of at least one component of the encoder wheel arrangement can be measured.In one embodiment of the hand-held power tool, the encoder wheel arrangement has at least one axis of rotation which is substantially parallel, in particular parallel, to an axis of rotation of the tool holder. The axis of rotation of the encoder wheel arrangement is offset substantially parallel to the axis of rotation of the tool axis. In addition, the axis of rotation of the encoder wheel arrangement is spaced radially from the tool axis from the axis of rotation of the tool holder.In one embodiment of the hand-held power tool, the encoder wheel arrangement has at least one encoder wheel which can be driven by the tool holder. The encoder wheel can be embodied, for example, in the manner of a disk, ring or gearwheel. The encoder wheel can be magnetic or magnetized. It is possible for a plurality of encoder wheels to be provided.In one embodiment of the hand-held power tool, the striking mechanism housing of the striking mechanism has a receptacle for the encoder wheel. The receptacle for the encoder wheel can be formed radially offset with respect to the tool receptacle. The encoder wheel can have a bearing bolt. The receptacle for the encoder wheel can be designed to receive the bearing bolt of the encoder wheel. In this case, the receptacle for the encoder wheel can receive the bearing bolt in such a way that the encoder wheel is rotatable. In this case, the encoder wheel or the bearing bolt can be rotatably mounted. The receptacle for the encoder wheel can be formed on the striking mechanism housing in the direction of the tool receptacle.In one embodiment of the hand-held power tool, the encoder wheel arrangement has at least one sensor element which is designed to detect at least one change in the encoder wheel. The sensor element can be designed as a sensor for measuring AMR, GMR, CMR, TMR, EMR or optical, inductive, capacitive or resistive angle measurement. The sensor element is designed to detect a change, such as a rotation or a magnetic field change. It is conceivable for the sensor element to be of modular design, such that it can also be separated from the hand-held power tool, for example as a type of adapter or attachment.In one embodiment of the hand-held power tool, the striking mechanism housing of the striking mechanism has a sensor receptacle which is designed to receive the sensor element. The striking mechanism housing can form the sensor receptacle, so that these are integral. The sensor element can be arranged substantially within the sensor receptacle. The sensor receptacle can be designed, for example, in the manner of a pot, a shell, a cap, a recess or a shaft.In one embodiment of the hand-held power tool, the sensor element is arranged axially, in particular in alignment with the axis of rotation of the encoder wheel arrangement, with the encoder wheel. The encoder wheel is arranged axially, in particular with respect to the axis of rotation of the encoder wheel arrangement, between the striking mechanism housing and the sensor element. The axis of rotation of the encoder wheel can be coaxial to the sensor element. Accordingly, the sensor receptacle can likewise be configured to be substantially axially aligned on the striking mechanism housing.In one embodiment of the hand-held power tool, the sensor element is arranged radially offset from the encoder wheel, in particular with respect to the axis of rotation of the encoder wheel arrangement. Accordingly, the sensor receptacle can be formed radially offset on the striking mechanism housing.In one embodiment of the hand-held power tool, the tool holder has a drive element which is designed to drive the encoder wheel. The drive element can be connected to the tool holder in a rotationally fixed manner, so that the drive element rotates when the tool holder rotates. The drive element can be connected to the tool holder in a form-fitting, force-fitting and / or materially integral manner. It is possible for the tool holder to form the drive element, so that these are one piece. The drive element can be formed in the circumferential direction around the tool holder. The drive element can be formed axially between anvil cams of the tool holder and a bearing of the tool holder. The drive element can have a toothing in the manner of a toothed wheel. Furthermore, the drive element can engage in the encoder wheel in a substantially form-fitting manner, such that the rotation of the tool holder can be transmitted to the drive element.In one embodiment of the hand-held power tool, the drive element and the encoder wheel are toothed with one another by means of spur gear teeth. Further couplings are conceivable, such as for example by means of a toothed belt, a friction gearing or a magnetic coupling.Brief Description of the DrawingsThe invention is explained below with reference to a preferred embodiment. The drawings show: FIG. 1 shows a schematic view of a hand-held power tool according to the invention; FIG. 2 shows a detail of a longitudinal section of the hand-held power tool;DESCRIPTION OF THE EMBODIMENTFIG. 1 shows a hand-held power tool 100 according to the invention, wherein it is designed here as an exemplary battery-operated rotary impact wrench. The hand-held power tool 100 comprises an output shaft 124, a tool holder 150 and a striking mechanism 122, for example a rotary or rotary striking mechanism. The hand-held power tool 100 has a housing 110 with a handle 126. The hand-held power tool 100 can be connected mechanically and electrically to a power supply for battery operation to form a power supply independent of the grid, so that the hand-held power tool 100 is designed as a battery-operated hand-held power tool 100. A handheld power tool rechargeable battery pack 130 is used here as the energy supply. However, the present invention is not limited to battery-operated hand-held power tools, but can also be used in grid-dependent, i.e. grid-operated, hand-held power tools.The housing 110 comprises a drive unit 111 and the striking mechanism 122, wherein the drive unit 111 and the striking mechanism 122 are arranged in the housing 110. The drive unit 111 comprises an electrically commutated drive motor 114, which is supplied with current by the handheld power tool rechargeable battery pack 130, and a transmission unit 118. The transmission unit 118 is designed as at least one planetary gear. The drive motor 114 is designed such that it can be actuated, for example, via a manual switch 128, with the result that the drive motor 114 can be switched on and off. The drive motor 114 can advantageously be controlled and / or regulated electronically, so that a reversing operation, as well as a desired rotational speed, can be realized. For the reversing operation, the hand-held power tool 100 has a rotation direction switching element 121, which is designed as a rotation direction switcher. The rotation direction switching member 121 is configured to switch the drive motor 114 between a clockwise rotation direction and a counterclockwise rotation direction. The structure and the mode of operation of a suitable drive motor are sufficiently known to the person skilled in the art, for which reason they will not be discussed in more detail here.The gear unit 118 is connected to the drive motor 114 via a drive shaft 116. The drive shaft 116 is mounted in the housing 110 by means of a motor-side bearing, not shown in detail. The transmission unit 118 is provided to convert a rotation of the drive shaft 116 into a rotation between the transmission unit 118 and the striking mechanism 122 via an intermediate shaft 120. Preferably, this conversion is such that the intermediate shaft 120 rotates relative to the input shaft 116 at an increased torque but at a decreased rotational speed. The intermediate shaft 120 drives the striking mechanism 122 at least partially. The transmission unit 118 includes a transmission case 119 disposed in the housing 110. The hand-held power tool 100 comprises a tool axis 102, wherein here an axis of rotation of the drive shaft 116 forms the tool axis 102.The striking mechanism 122 is connected to the intermediate shaft 120 and comprises a striking element 300 and a striking-element spring 350, wherein the striking mechanism 122 generates abrupt rotational pulses with high intensity during a striking operation, see also FIG. 2. These abrupt rotational pulses are transmitted via the striking element 300 to the output shaft 124, for example a work spindle. The striking mechanism 122 comprises a striking mechanism housing 123, wherein the striking mechanism 122 can also be arranged in another suitable housing, such as the transmission housing 119. The striking mechanism 122 is designed to drive the output shaft 124. A tool holder 150 is provided on the output shaft 124. The tool holder 150 is preferably formed and / or formed on the output shaft 124. The tool holder 150 is preferably arranged in an axial direction 132 facing away from the drive unit 111. The tool holder 150 is designed here as an internal hexagonal holder, in the manner of a bit holder, which is provided to receive an insert tool 140. The insert tool is shaped in the manner of a screwdriver bit with a polygonal outer coupling 142. The type of screwdriver bit, for example of the HEX type, is sufficiently known to the person skilled in the art. However, the present invention is not limited to the use of HEX screwdriver bits, but other tool holders that appear expedient to the skilled person can also be used, such as HEX drills, SDS quick inserts, nuts or round shank drill chucks. In addition, the structure and the mode of operation of a suitable bit holder are sufficiently known to the person skilled in the art.The hand-held power tool 100 has a control unit 170 at least for controlling the drive unit 111, in particular the drive motor 114. The housing 110 at least partially receives the control unit 170. The control unit 170 has a microprocessor, not shown in detail. In addition, the housing 110 includes a power supply holder 160. The energy supply holding device 160 accommodates the handheld power tool battery pack 130 and forms a stand 162 with a standing surface. The handheld power tool rechargeable battery pack 130 can be detached from the energy supply holding device 160 without tools. Further, the housing 110 includes the handle 126 and the power supply holder 160. The handle 126 may be grasped by the user. In one embodiment, the power supply holder 160 is disposed on the handle 126. The hand-held power tool 100 can be set down by means of the stand 162.The hand-held power tool 100 comprises a transmitter wheel arrangement 200. The encoder wheel arrangement 200 can be driven at least partially by the tool holder 150. The encoder wheel arrangement 200 is designed to detect a rotation angle of the tool holder 150.FIG. 2 shows a detail 500 of a longitudinal section of the hand-held power tool 100. The drive shaft 116 is not shown here, wherein this is mounted in the intermediate shaft 120 by means of a drive shaft bearing 117. The drive shaft bearing 117 is formed here as a needle bearing, for example. The striking mechanism 122 is formed here as a V-groove striking mechanism. A striker 300 and a striking mechanism spring 350 are arranged in the striking mechanism housing 123. The striker 300 is mounted on the intermediate shaft 120 by means of striking mechanism balls 310. The striking mechanism balls 310 are provided to move the striking mechanism 300 at least partially in the direction of the drive motor 114. The striking mechanism spring 350 is arranged around the intermediate shaft 120 in the circumferential direction and encloses the latter accordingly in the circumferential direction with respect to the tool axis 102. The club 300 includes striking cams 312. The impact cams 312 are designed to abut on the output shaft 124 and drive it.The encoder wheel assembly 200 includes a rotational axis 202. The axis of rotation 202 of the encoder wheel arrangement is substantially parallel to an axis of rotation 103 of the tool holder 150. Here, the axis of rotation 103 of the tool holder 150 is the tool axis 102 by way of example. The axis of rotation 202 of the encoder wheel arrangement 200 is offset substantially parallel to the axis of rotation 103 of the tool axis 150. The axis of rotation 202 of the encoder wheel arrangement 200 is spaced apart from the axis of rotation 103 of the tool holder 150 radially with respect to the tool axis 102. The encoder wheel assembly 200 includes an encoder wheel 220. The encoder wheel 220 can be driven by the tool holder 150. For example, the encoder wheel 220 is shaped in the manner of a magnetized gearwheel.The encoder wheel 220 comprises a bearing bolt 222. The striking mechanism housing 123 comprises a receptacle 260 for the encoder wheel 220, in particular for the bearing bolt 222. The receptacle 260 for the encoder wheel 220 is shaped to receive the bearing bolt 222 of the encoder wheel 220 and to rotatably mount it. The receptacle 260 for the encoder wheel 220 is formed radially offset with respect to the tool receptacle 150 and with respect to the tool axis 102. The receptacle 260 for the encoder wheel 220 is shaped on the striking mechanism housing 123 in the direction of the tool receptacle 150. The encoder wheel arrangement 200 comprises a sensor element 230. Sensor element 230 is designed to detect at least one change in encoder wheel 220. By way of example, the sensor element 230 is formed as a sensor for measuring AMR, GMR, CMR, TMR, EMR or optical, inductive, capacitive or resistive angle measurement. Sensor element 230 detects a change in encoder wheel 220. The striking mechanism housing 123 comprises a sensor receptacle 210. The sensor receptacle 210 is shaped to receive the sensor element 230. The striking mechanism housing 123 shapes the sensor receptacle 210 and the sensor element 230 is arranged substantially within the sensor receptacle 210. By way of example, the sensor receptacle 210 is shaped in the manner of a cap. Sensor element 230 is situated axially, in particular flush with encoder wheel 220, in particular with axis of rotation 202 of encoder wheel arrangement 200. Furthermore, the encoder wheel 220 is arranged axially, in particular with respect to the axis of rotation 202 of the encoder wheel arrangement 200, between the striking mechanism housing 123 and the sensor element 230.The tool holder 150 comprises a drive element 270. The drive element 270 is designed to drive the encoder wheel 220. The drive element 270 is connected to the tool holder 150 in a rotationally fixed manner, wherein they are in one piece here. Upon a rotation of the tool holder 150, the drive element 270 rotates along. The drive element 270 is formed in the circumferential direction around the tool holder 150. The output shaft 124 includes anvil cams, not shown. The impact cams 312 abut on the anvil cam for driving the output shaft 124, which is not illustrated. The drive element 270 is formed axially between anvil cams of the tool holder 150 and a bearing 158 of the tool holder 150. The bearing 158 here comprises two ball bearings by way of example. The drive element 270 comprises a toothing in the manner of a toothed wheel on its circumference, so that the drive element 270 engages in the encoder wheel 230 in a substantially positive-locking manner. The drive element 270 and the encoder wheel 230 form a toothing by means of a spur gear toothing.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2017 200 988 A1

[0002]

Claims

Hand-held power tool (100) having a housing (110), having a drive motor (114), having an intermediate shaft (120), the intermediate shaft (120) being drivable by the drive motor (114), having a striking mechanism (122) which is drivable at least partially by the intermediate shaft (120), and having a tool receptacle (150) for receiving an insert tool (140), the tool receptacle (150) being drivable by means of the striking mechanism (122), characterized bya master wheel arrangement (200) which is drivable at least partially by the tool receptacle (150).Hand-held power tool (100) according to Claim 1, characterized in that the encoder wheel arrangement (200) has at least one axis of rotation (202) which is substantially parallel to an axis of rotation (103) of the tool holder (150).Hand-held power tool (100) according to Claim 1 or 2, characterized in that the encoder wheel arrangement (200) has at least one encoder wheel (220) which can be driven by the tool holder (150).Hand-held power tool (100) according to Claim 3, characterized in that a striking-mechanism housing (123) of the striking mechanism (122) has a receptacle (260) for the encoder wheel (220).Hand-held power tool (100) according to Claim 3 or 4, characterized in that the encoder wheel arrangement (200) has at least one sensor element (230) which is designed to detect at least one change in the encoder wheel (220).Hand-held power tool (100) according to Claim 5, characterized in that a striking-mechanism housing (123) of the striking mechanism (122) has a sensor receptacle (270) which is designed to receive the sensor element (230).Hand-held power tool (100) according to Claim 5 or 6, characterized in that the sensor element (230) is arranged axially flush with the encoder wheel (220).Hand-held power tool (100) according to Claim 5 or 6, characterized in that the sensor element (230) is arranged radially offset with respect to the encoder wheel (220).Hand-held power tool (100) according to one of Claims 3 to 8, characterized in that the tool holder (150) has a drive element (270) which is designed to drive the encoder wheel (220).Hand-held power tool (100) according to Claim 9, characterized in that the drive element (270) and the encoder wheel (220) are toothed with one another by means of spur gear teeth.

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