Handheld tool device
10960526 ยท 2021-03-30
Assignee
Inventors
Cpc classification
B25D17/06
PERFORMING OPERATIONS; TRANSPORTING
B25D16/00
PERFORMING OPERATIONS; TRANSPORTING
B25D2211/006
PERFORMING OPERATIONS; TRANSPORTING
International classification
B25D11/00
PERFORMING OPERATIONS; TRANSPORTING
B25D17/06
PERFORMING OPERATIONS; TRANSPORTING
B25D16/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A handheld tool device includes a hammer mechanism that has at least a striker and a cam guide that drives the striker at least in a hammer-drilling mode. The striker has at least a portion of the cam guide.
Claims
1. A handheld tool device, comprising: a hammer mechanism which includes a striker and at least one cam guide which drives the striker at least in a hammer-drilling mode, wherein the striker has at least a portion of the cam guide, wherein the cam guide has an impact free-running region, wherein the cam guide has an impact pull-up region, wherein the impact free-running region has an impact flank and an impact free-running flank, wherein the impact flank and the impact free-running flank extend away from each other in a first section of the impact free-running region.
2. The handheld tool device as recited in claim 1, wherein the cam guide has a mounting aperture.
3. The handheld tool device as recited in claim 1, wherein the hammer mechanism includes a hammer mechanism spindle which has at least a portion of the cam guide.
4. The handheld tool device as recited in claim 3, wherein the hammer mechanism spindle has a guide cam of the cam guide.
5. The handheld tool device as recited in claim 3, wherein the striker at least substantially surrounds the hammer mechanism spindle on at least one plane.
6. The handheld tool device as recited in claim 3, wherein the hammer mechanism has a connecting element which in at least one operating state transmits a motion to the striker.
7. The handheld tool device as recited in claim 6, wherein the connecting element is embodied as a ball.
8. The handheld tool device as recited in claim 6, wherein the guiding flank is configured to guide the connecting element through the impact pull-up region.
9. The handheld tool device as recited in claim 3, further comprising: a tool spindle, wherein the striker at least substantially surrounds the tool spindle on at least one plane.
10. The handheld tool device as recited in claim 9, wherein the tool spindle is disposed at least substantially coaxially with the hammer mechanism spindle.
11. The handheld tool device as recited in claim 3, wherein the hammer mechanism includes a first cam guide and a second cam guide.
12. The handheld tool device as recited in claim 11, wherein the first cam guide and the second cam guide are disposed offset by 180 degrees about the rotation axis.
13. The handheld tool device as recited in claim 11, wherein the first cam guide and the second cam guide are disposed one behind the other in the axial impact direction.
14. The handheld tool device as recited in claim 1, wherein the hammer mechanism has a striker guide which supports the striker in a rotationally rigid manner.
15. The handheld tool device as recited in claim 1, further comprising: a handheld tool housing, wherein the hammer mechanism has a hammer mechanism spring which is supported on the striker and on the handheld tool housing.
16. The handheld tool device as recited in claim 1, wherein the impact flank, starting from an end of the impact pull-up region, runs approximately parallel to an impact direction.
17. The handheld tool device as recited in claim 1, wherein the impact flank and the impact free-running flank extend towards each other in a second section of the impact free-running region.
18. The handheld tool device as recited in claim 1, wherein the impact free-running flank is configured to limit the impact free-running region relative to an impact direction.
19. The handheld tool device as recited in claim 1, wherein the impact pull-up region comprises a guiding flank and a supporting flank, wherein the guiding flank and the supporting flank are approximately parallel to each other.
20. The handheld tool device as recited in claim 19, wherein the impact free-running flank is connected to the supporting flank and the impact flank is connected to the guiding flank in a connecting region of the impact free-running region and the impact pull-up region.
21. The handheld tool device as recited in claim 19, wherein the guiding flank is configured to guide the connecting element through the impact pull-up region.
22. A handheld tool device, comprising: a hammer mechanism which includes a striker and at least one cam guide which drives the striker at least in a hammer-drilling mode, wherein the striker has at least a portion of the cam guide, wherein the cam guide has an impact free-running region, wherein the cam guide has an impact pull-up region, wherein the impact pull-up region is of a helical configuration and extends through 180 degrees about a rotation axis of the hammer mechanism spindle.
23. The handheld tool device as recited in claim 22, wherein the impact free-running region connects two ends of the helical impact pull-up region and extends through 180 degrees about the rotation axis of the hammer mechanism spindle, wherein the cam guide has an impact free-running region, wherein the cam guide has an impact pull-up region, wherein the impact free-running region has an impact flank and an impact free-running flank, wherein the impact flank and the impact free-running flank extend away from each other in a first section of the impact free-running region.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
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(21) Tool guiding unit 20a includes a tool chuck 36a and a tool spindle 38a. During a work operation, tool chuck 36a fastens an application tool, not shown here, for example a drill bit or a driver bit. Tool chuck 36a fastens the application tool non-positively. Tool chuck 36a has three clamping jaws which are movably fastened by an operator and which fasten the application tool in a work operation. In addition, tool chuck 36a fastens the application tool in such a way that it is axially immobile relative to tool chuck 36a and especially tool spindle 38a in a work operation. A portion of tool chuck 36a and tool spindle 38a are connected to each other in such a way as to be immobile relative to each other. In this case, tool chuck 36a and tool spindle 38a are screwed to each other. Handheld tool device 12a has a bearing element 40a which supports tool spindle 38a on a side toward tool chuck 36a. Bearing element 40a supports tool spindle 38a in an axially displaceable manner. Bearing element 40a is connected to tool spindle 38a in an axially fixed manner. Bearing element 40a is supported to be axially movable in handheld tool housing 14a. Handheld tool device 12a has a further bearing element 41a which supports tool spindle 38a on a side toward planetary gear 28a. Bearing element 41a is in the form of a rolling bearing, in this case a needle bearing, whereby low-backlash support is possible. Bearing element 41a supports tool spindle 38a in an axially displaceable manner. A hammer mechanism spindle 46a surrounds bearing element 41a. Bearing element 41a is operatively disposed between tool spindle 38a and hammer mechanism spindle 46a.
(22) Tool spindle 38a includes an impact face 42a on which a striker 44a of hammer mechanism 22a strikes in a hammer-drilling mode. Striker 44a has a mass that is at most two thirds as great as a mass of tool guiding unit 20a. In this case, the mass of striker 44a is less than half as great as the mass of tool guiding unit 20a. The mass of striker 44a is approximately 45% of the mass of tool guiding unit 20a.
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(25) Hammer mechanism spring 48a accelerates striker 44a in impact direction 54a prior to an impact. For that purpose, handheld tool housing 14a supports hammer mechanism spring 48a on a side remote from striker 44a. Hammer mechanism spring 48a presses directly against striker 44a. Striker 44a has a spring fastening 60a. Spring fastening 60a is in the form of an annular depression.
(26) Hammer mechanism spindle 46a is in the form of a hollow shaft. Planetary gear 28a drives hammer mechanism spindle 46a. For that purpose, hammer mechanism spindle 46a has toothing 76a on a side remote from tool chuck 36a. Guide cams 66a, 68a each have an impact free-running region 78a, 80a, an impact pull-up region 82a, 84a and a mounting aperture 86a, 88a. In a mounting operation, connecting elements 70a, 72a are introduced into fastening recesses 74a of striker 44a through mounting apertures 86a, 88a. Hammer mechanism spindle 46a rotates in the hammer-drilling mode in the clockwise direction as viewed in impact direction 54a. Impact pull-up regions 82a, 84a are of a helical configuration. They extend through 180 degrees about a rotation axis 90a of hammer mechanism spindle 46a. Impact pull-up regions 82a, 84a move connecting elements 70a, 72a and hence striker 44a counter to impact direction 54a in the hammer-drilling mode. Accordingly, hammer mechanism 22a includes connecting elements 70a, 72a which, in at least one operating state, transmit a motion from hammer mechanism spindle 46a to striker 44a.
(27) Impact free-running regions 78a, 80a each connect two ends 92a, 94a, 96a, 98a of impact pull-up regions 82a, 84a. Impact free-running regions 78a, 80a extend through 180 degrees about a rotation axis 90a of hammer mechanism spindle 46a. Impact free-running regions 78a, 80a each have an impact flank 100a, 102a which, starting from an end 94a, 96a of impact pull-up region 82a toward planetary gear 28a, runs approximately parallel to impact direction 54a. Once connecting elements 70a, 72a penetrate into impact free-running regions 78a, 80a, hammer mechanism spring 48a accelerates striker 44a and connecting elements 70a, 72a in impact direction 54a. In the process, connecting elements 70a, 72a move through impact free-running regions 78a, 80a, without experiencing an axial force, until striker 44a meets impact face 42a. Cam guides 62a, 64a are disposed offset by 180 degrees about rotation axis 90a. Cam guides 62a, 64a are disposed one behind the other in the axial direction.
(28) Planetary gear 28a has first planetary gear stage 104a, a second planetary gear stage 106a, a third planetary gear stage 108a and a fourth planetary gear stage 110a.
(29) First impact deactivation device 24a fixes ring gear 116a of first planetary gear stage 104a immovably relative to handheld tool housing 14a in a hammer-drilling mode. First impact deactivation device 24a is intended to switch on striker driving device 50a in a first, clockwise drilling rotational direction and to automatically switch off striker driving device 50a in a second, anticlockwise drilling rotational direction. First impact deactivation device 24a acts on ring gear 116a of first planetary gear stage 104a. First impact deactivation device 24a locks ring gear 116a of first planetary gear stage 104a in the first, clockwise drilling rotational direction. First impact deactivation device 24a releases ring gear 116a of first planetary gear stage 104a in the second, anticlockwise drilling rotational direction, so that it is able to rotate. For that purpose, first impact deactivation device 24a has three clamping mechanisms 122a. Clamping mechanisms 122a each include a blocking element 124a, a first clamping face 126a, a second clamping face 128a, and free-running faces 130a. Blocking element 124a is in the form of a roller. First clamping face 126a forms an external region of a surface of ring gear 116a of first planetary gear stage 104a. Second clamping face 128a is disposed immovably relative to handheld tool housing 14a. Upon operation in the first, clockwise drilling rotational direction, blocking elements 124a become jammed between first clamping faces 126a and second clamping face 128a. Upon operation in the second, anticlockwise drilling rotational direction, free-running faces 130a guide blocking elements 124a and prevent jamming.
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(32) Second impact deactivation device 26a has an impact deactivation coupling 142a. Impact deactivation coupling 142a is formed partially in one piece with planetary gear 28a. Impact deactivation coupling 142a is disposed between first planetary gear stage 104a and second planetary gear stage 106a. Impact deactivation coupling 142a has a first coupling element 144a which is connected to a planet carrier 114a of first planetary gear stage 104a in a rotationally rigid manner. Impact deactivation coupling 142a has a second coupling element 146a which is connected to a planet carrier 120a of second planetary gear stage 106a in a rotationally rigid manner. In the screwing mode illustrated and in the drilling mode, impact deactivation coupling 142a is open. In a hammer-drilling operation, tool spindle 38a transmits an axial coupling force to impact deactivation coupling 142a when the operator presses an application tool against a workpiece. The coupling force closes impact deactivation coupling 142a. In
(33) Planet carrier 120a of second planetary gear stage 106a is constructed in two parts. A first part 150a of planet carrier 120a of second planetary gear stage 106a is connected to tool spindle 38a in a rotationally rigid manner. First part 150a of planet carrier 120a is connected to tool spindle 38a in an axially displaceable manner, whereby planet carrier 120a remains rotationally coupled to tool spindle 38a also during an impact. Accordingly, first part 150a is permanently connected to tool spindle 38a. First part 150a of planet carrier 120a is supported to be axially displaceable toward impact switch spring 148a. A second part 152a of planet carrier 120a of second planetary gear stage 106a is connected to first part 150a of planet carrier 120a in a rotationally rigid manner. First part 150a and second part 152a of planet carrier 120a are connected in such a manner as to be axially displaceable relative to each other. First part 150a and second part 152a of planet carrier 120a are connected in a permanently rotationally rigid manner.
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(36) Control element 134a of handheld tool device 12a has support elements 190a which prevent axial movement of stop element 182a at least in a drilling mode. For that purpose, support elements 190a support stop element 182a in the axial direction. Stop element 182a has screw apertures 192a which stop elements 182a enter when the maximum tool torque is reached in a screwing mode illustrated especially in
(37) Alternatively, stop elements could also be so disposed in a hammer-drilling mode that they are able to enter screw apertures. In that manner, a torque limiting unit would be active in the hammer-drilling mode.
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(41) Ring gear 204a of third planetary gear stage 108a is supported to be displaceable in the axial direction, as shown in
(42) Operating device 32a has a first operating element 218a and a second operating element 220a. First operating element 218a is disposed on a side of handheld tool housing 14a remote from hand grip 18a. It is supported to be movable parallel to the axial direction of planetary gear 28a. First operating element 218a is connected to ring gear 204a of third planetary gear stage 108a in the axial direction via an adjusting element 222a of operating device 32a. Ring gear 204a of third planetary gear stage 108a has a keyway 224a with which adjusting element 222a engages. Accordingly, ring gear 204a of third planetary gear stage 108a is connected to adjusting element 222a in the axial direction in such a manner as to be axially rotatable relative to adjusting element 222a. Adjusting element 222a is constructed to be resilient, whereby the gear ratio may be adjusted independently of a rotational position of ring gear 204 of third planetary gear stage 108a. When first operating element 218a is pushed in the direction of tool chuck 36a, the first gear ratio is set. When second operating element 220a is pushed away from tool chuck 36a, the second gear ratio is set.
(43) Second operating element 220a is disposed on a side of handheld tool housing 14a remote from hand grip 18a. Second operating element 220a is disposed so as to be displaceable about an axis oriented parallel to the axial direction of planetary gear 28a. Second operating element 220a is connected to control element 134a of handheld tool device 12a in a rotationally rigid manner. With second operating element 220a, the screwing mode, the drilling mode and the hammer-drilling mode may be set. When second operating element 220a is pushed to the left as viewed in impact direction 54a, the hammer-drilling mode is set. When second operating element 220a is pushed to the right as viewed in impact direction 54a, the screwing mode is set. When second operating element 220a is situated centrally as viewed in impact direction 54a, the drilling mode is set.
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(45) Drive unit 30a is in the form of an electric motor. Drive unit 30a has a maximum torque which causes a maximum tool torque of more than 15 Nm in the first gear ratio and of less than 15 Nm in the second gear ratio. The maximum tool torque in the first gear ratio is 30 Nm. The maximum tool torque in the second gear ratio is 10 Nm. The tool torque is to be specified in this case in accordance with the DIN EN 60745 standard.
(46) In a hammer-drilling mode, impact switch spring 148a of handheld tool device 12a opens impact deactivation coupling 142a when the operator removes the application tool from the workpiece. Impact switch spring 148a is disposed coaxially with planetary gear stages 104a, 106a, 108a, 110a of planetary gear 28a. Second planetary gear stage 106a and third planetary gear stage 108a each surround impact switch spring 148a on at least one plane that is oriented perpendicularly to the axial direction of planetary gear 28a. Second planetary gear stage 106a and third planetary gear stage 108a are each operatively disposed between at least two further planetary gear stages 104a, 106a, 108a, 110a of planetary gear 28a. Planet carrier 120a of second planetary gear stage 106a supports impact switch spring 148a on a side remote from tool chuck 36a.
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(52) Safety device 226e has a free-running region 248e delimited by first operating element 218e. Safety device 226e has a free-running region 250e delimited by second operating element 220e. Free-running region 248e of first operating element 218e makes it possible to set the screwing mode, the drilling mode and the hammer-drilling mode when a second gear ratio is set. Free-running region 250e of second operating element 220e makes it possible to set the screwing mode and the drilling mode when a first gear ratio is set. In the hammer-drilling mode, safety device 226e prevents setting of the first gear ratio. When first gear ratio is set, safety device 226e prevents setting of the hammer-drilling mode.