Quick clamping device

Abstract

A quick clamping device for arranging at least one application tool on a power tool, in particular on an angle grinder, includes at least one output unit for moving the application tool about an output axis of the output unit, and at least one fixing unit having at least one movably mounted fixing element that is mounted, in particular in a non-removable manner, on the output unit, at least for axially fixing the application tool to the output unit. The quick clamping device has at least one securing unit, which has at least one, in particular movably mounted, securing element that is intended to secure the fixing element, which is mounted so as to be movable relative to the output unit at least about the output axis, so as to prevent the fixing element from moving about the output axis.

Claims

1. A quick-change clamping device for arranging at least one insert tool on a power tool, comprising: at least one output unit configured to rotate the insert tool about an output axis of the output unit, the at least one output unit having a hollow portion; at least one fixing unit having at least one fixing element configured to axially fix the insert tool on the output unit, the at least one fixing element being mounted on the output unit partially inside the hollow portion and rotatable relative to the output unit about the output axis in at least one first operating state of the quick-change clamping device; and at least one securing unit having at least one securing element that is movable relative to the fixing element and is configured, in at least one second operating state of the quick-change clamping device, to secure the fixing element against rotation relative to the output unit about the output axis.

2. The quick-change clamping device as claimed in claim 1, wherein the securing element has at least one contact surface configured to bear against the fixing element.

3. The quick-change clamping device as claimed in claim 1, wherein the securing element is movably mounted on and axially movable relative to at least one output element of the output unit, the output element having the hollow portion.

4. The quick-change clamping device as claimed in claim 1, wherein the securing unit has at least one securing spring, which biases the securing element with a spring force in a direction of a securing position of the securing element at which the fixing element is secured against rotation relative to the output unit.

5. The quick-change clamping device as claimed in claim 1, wherein the fixing unit has at least one clamping spring configured, in the at least one second operating state, to generate a clamping force that, by transmission via the fixing element, produces a rotational pressing force upon the securing element.

6. The quick-change clamping device as claimed in claim 1, wherein a maximum possible axial displacement of the fixing element out of a position that can be fixed by the securing element is at most 10 mm.

7. The quick-change clamping device as claimed in claim 1, further comprising: a cam mechanism configured to move the fixing element back and forth at least between two end positions, wherein one of the two end positions is one of the at least one second operating positions at which the fixing element is fixed by the securing unit.

8. The quick-change clamping device as claimed in claim 7, wherein the at least one cam mechanism includes a cam mechanism element defined by a recess in the output element.

9. The quick-change clamping device as claimed in claim 7, wherein the at least one cam mechanism that has at least one cam mechanism element arranged at least partially in a movable manner within the fixing element.

10. The quick-change clamping device as claimed in claim 1, wherein the output unit has at least one torque transmission element having an outer contour that is at least substantially congruent with an outer contour of a locking part of the fixing element in at least one position of the fixing element, the locking part configured to produce a form closure that holds the insert tool between the output element and the locking part.

11. The quick-change clamping device as claimed in claim 1, wherein the fixing element has at least one external thread configured as one of a trapezoidal thread and a buttress thread, the at least one external thread interacting with at least one internal thread of the output unit.

12. A power tool, comprising: at least one quick-change clamping device configured to arrange at least one insert tool on the power tool, the at least one quick-change clamping device comprising: at least one output unit configured to rotate the insert tool about an output axis of the output unit, the at least one output unit having a hollow portion; at least one fixing unit having at least one fixing element configured to axially fix the insert tool on the output unit, the at least one fixing element being mounted on the output unit partially inside the hollow portion and rotatable relative to the output unit about the output axis in at least one first operating state of the quick-change clamping device; and at least one securing unit having at least one securing element that is movable relative to the fixing element and is configured, in at least one second operating state of the quick-change clamping device, to secure the fixing element against rotation relative to the output unit about the output axis.

13. The power tool as claimed in claim 12, further comprising: the at least one insert tool, the at least one insert tool having at least one connection mechanism that corresponds, at least substantially, to a contour of the fixing element of the quick-change clamping device.

14. The quick-change clamping device as claimed in claim 1, wherein the power tool is a power angle grinder.

15. The quick-change clamping device as claimed in claim 1, wherein the at least one fixing element is mounted in a non-removable manner on the output unit such that the at least one fixing element is arranged in a captive manner on the output unit and/or is inseparable from the output unit when the quick-change clamping device is in an open state.

16. The power tool as claimed in claim 12, wherein the power tool is a power angle grinder.

17. The quick-change clamping device as claimed in claim 1, wherein the at least one second operating state includes an open state in which the quick-change clamping device is configured to receive or unmount the at least one insert tool.

18. The quick-change clamping device as claimed in claim 17, wherein the at least one first operating state includes a closed state in which the fixing element produces a force closure and/or form closure that retains the insert tool on the quick-change clamping device.

19. The quick-change clamping device as claimed in claim 1, wherein, in the at least one second operating state, the at least one securing element is engaged with both the output unit and the fixing unit so as to secure the fixing element against rotation relative to the output unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages are given by the following description of the drawing. The drawing shows an exemplary embodiment of the disclosure. The drawing, the description and the claims contain numerous features in combination. Persons skilled in the art will also expediently consider the features individually and combine them to create appropriate further combinations.

(2) There are shown:

(3) FIG. 1 a schematic view of a power tool system, comprising an insert tool, and comprising a power tool having a quick-change clamping device,

(4) FIG. 2 a schematic view of a section through the power tool and through the quick-change clamping device,

(5) FIG. 3 a schematic, perspective view of the quick-change clamping device, in an open state, and

(6) FIG. 4 a schematic bottom view of the quick-change clamping device, in a closed state, with the insert tool.

DETAILED DESCRIPTION

(7) FIG. 1 shows a power tool system, comprising a power tool 12 that comprises a housing 78 and an insert tool 10. The power tool 12 is realized as a power angle grinder. The insert tool 10 is realized as a grinding disk. The insert tool 10 has a connection means 46 (see FIG. 4). The connection means 46 is realized as a through-recess 50.

(8) The power tool 12 has a quick-change clamping device. The quick-change clamping device is designed for arranging at least one insert tool 10 on the power tool 12. The power tool 12 has an actuating means 52 for opening and closing the quick-change clamping device. The actuating means 52 is realized as a pull lever 54. The pull lever 54 has an eccentric 74. The actuating means 52 is designed, in particular by means of the eccentric 74, to move an unlocking pin 76 (see FIG. 2) of the quick-change clamping device in the axial direction. The unlocking pin 76 is designed to unlock the quick-change clamping device, upon movement of the unlocking pin 76 into the housing 78 of the power tool 12. In the case of locking of the quick-change clamping device, the unlocking pin 76 moves out of the housing 78 of the power tool 12. The actuating means 52 shown in FIG. 1 is in a closed state. The power tool 12 has a drive unit 56. The drive unit 56 is designed, at least, to provide a movement energy that is designed to move, in particular to rotate, an insert tool 10. The drive unit 56 is arranged in the housing 78.

(9) FIG. 2 shows a central section through the quick-change clamping device. The quick-change clamping device has an output unit 14. The output unit 14 is designed to move the insert tool 10 about an output axis 16 of the output unit 14. The output unit 14 has an output element 28. The output element 28 is realized as a cylindrical hollow shaft. The output element 28 is centered around the output axis 16.

(10) The power tool 12 has a power transmission element 58 for transmitting, in particular taking up, power generated by the drive unit 56. The power transmission element 58 is realized as a bevel gear 60. The bevel gear 60 is connected by force closure to the output element 28. The bevel gear 60 is connected to the drive unit 56 by means of methods commonly used by persons skilled in the art, for example drive pinion and drive shaft (not shown). The bevel gear 60 can be driven in rotation by the drive unit 56.

(11) The quick-change clamping device has a fixing unit 20. The fixing unit 20 is designed to axially fix the insert tool 10 on the output unit 14. The fixing unit 20 has a fixing element 18. The fixing element 18 is arranged in a captive manner on the output unit 14, in particular the output element 28, and/or is mounted in a non-removable manner on the output unit 14, in particular the output element 28. The fixing element 18 has a locking part 66. The locking part 66 is integral with the fixing element 18. The locking part 66, as viewed along the output axis 16, is arranged on a lower side that faces away from the output unit 14. The locking part 66 has a contour 48 in the shape of an angled cross. The locking part 66 is designed to produce a form closure for holding an insert tool 10 between the output element 28 and the locking part 66.

(12) The fixing unit 20, in particular the fixing element 18, has a thread 44. The thread 44 of the fixing unit 20 is realized as a trapezoidal thread or as a buttress thread. The thread 44 of the fixing unit 20 is integral with the fixing element 18. The thread 44 of the fixing unit 20 is realized as an external thread. The output unit 14 has a further thread 92. The further thread 92 is integral with the output element 28. The further thread 92 is realized as an internal thread. The further thread 92 is realized as a trapezoidal thread or as a buttress thread. The thread 44 of the fixing unit 20 corresponds to the further thread 92.

(13) The fixing element 18 is movably mounted. The fixing element 18 is mounted so as to be movable, relative to the output unit 14, about the output axis 16. The fixing element 18 is mounted so as to be movable, relative to the output unit 14, in the direction of the output axis 16. The quick-change clamping device has a securing unit 22. The securing unit 22 has two securing elements 24. A maximum possible axial displacement of the fixing element 18 from a position that can be fixed by the securing element 24 is at most 10 mm. The maximum possible axial displacement of the fixing element 18 is defined by a pitch of the thread 44 and/or a pitch of the further thread 92. The securing element 24 is movably mounted. The securing element 24 is designed to secure the fixing element 18 against movement of the fixing element 18 about the output axis 16. When the fixation element 18 is secured by the securing element 24, the securing element 24 prevents rotation of the fixing element 18 by means of a form closure.

(14) The securing element 24 has a contact surface 26. The contact surface 26 is designed to bear against the fixing element 18. The securing element 24 has an axial extension 70. The contact surface 26 is arranged on the axial extension 70. The securing element 24 has a further contact surface 96. The further contact surface 96 is designed, in at least one operating state, to bear against an insert tool 10.

(15) The securing element 24 is movably mounted on the output element 28 of the output unit 14. The securing element 24 is mounted in a sleeve 72 delimited by the output element 28. The securing element 24 is mounted such that it can be moved into the sleeve 72 and moved out of the sleeve 72. The sleeve 72 is integral with the output element 28. The securing unit 22 has at least one securing spring 30. Each securing element 24 of the securing unit 22 has a securing spring 30. The securing spring 30 biases the securing element 24 with a spring force in the direction of a securing position of the securing element 24. The securing spring 30 shown in FIG. 2 is in a loaded state. In the absence of blocking by the fixing element 18, the securing element 24 moves out of the sleeve 72 by means of the securing spring 30.

(16) The fixing unit 20 has a clamping spring 32. The fixing unit 20, in particular the fixing element 18, encompasses the clamping spring 32. The clamping spring 32 is arranged within the fixing unit 20, in particular within the fixing element 18. The clamping spring 32 is realized as a compression spring. FIG. 2 shows the clamping spring 32 in a non-loaded state. The clamping spring 32, in at least one operating state (see FIG. 3), generates a clamping force that, by means of transmission via the fixing element 18, produces a pressing force upon the contact surface 26 of the securing element 24. The securing element 24, in at least one operating state, prevents unloading of the clamping spring 32, in that it prevents the fixing element 18 from rotating.

(17) The quick-change clamping device has a cam mechanism 34. The cam mechanism 34 is designed to move the fixing element 18 back and forth at least between two end positions, one of the end positions being a position that can be fixed by the securing unit 22. The cam mechanism 34 has a plurality of cam mechanism elements 38, 40, 82.

(18) The output unit 14 has a cam mechanism element 38. The cam mechanism element 38 of the output unit 14 is realized as a recess 36 in the output element 28. The cam mechanism element 38 of the output unit 14 realizes a path 80 having a course angled in relation to the output axis 16. The fixing unit 20 has a cam mechanism element 82. The cam mechanism element 82 of the fixing unit 20 is realized as a recess 84 in the fixing element 18. The cam mechanism element 82 of the fixing unit 20 realizes a path 86 having a course parallel to the output axis 16. The cam mechanism element 40 of the cam mechanism 34 that differs from the cam mechanism elements 38, 82 of the output unit 14 and of the fixing unit 20 is realized as a movable cam mechanism element 88. The cam mechanism element 40 of the cam mechanism 34, in particular the movable cam mechanism element 88, is arranged, at least partially, within the fixing element 18. The cam mechanism element 40 of the cam mechanism 34, in particular the movable cam mechanism element 88, is arranged in an axially movable manner. The cam mechanism element 40 of the cam mechanism 34, in particular the movable cam mechanism element 88, is arranged in a rotationally movable manner. The cam mechanism element 40 of the cam mechanism 34, in particular the movable cam mechanism element 88, engages, at least partially, in the cam mechanism element 38 of the output unit 14 and/or in the cam mechanism element 82 of the fixing unit 20. The cam mechanism element 40 of the cam mechanism 34, in particular the movable cam mechanism element 88, has a contact surface 90 that is designed to bear against the unlocking pin 76, in at least one operating state.

(19) Pressing the unlocking pin 76 into the housing 78 of the power tool 12 causes an axial displacement of the cam mechanism element 40 of the cam mechanism 34, in particular of the movable cam mechanism element 88. As a result of the movable cam mechanism element 88 engaging with contact in the cam mechanism element 38 of the output unit 14, the movable cam mechanism element 88 follows the angled path 80 of the cam mechanism element 38 of the output unit 14, causing a rotational movement of the movable cam mechanism element 88. The rotational movement of the movable cam mechanism element 88 engaging in the cam mechanism element 82 of the fixing unit 20 forces the fixing element 18, arranged between the movable cam mechanism element 88 and the output unit 14, to rotate.

(20) The output unit 14 has at least one torque transmission element 42. The torque transmission element 42 is designed to transmit a torque from the output unit 14 to an insert tool 10. The torque transmission element 42 is integral with the output element 28. The torque transmission element 42 has an outer contour 68 in the shape of an angled cross (see FIG. 3). The torque transmission element 42 is designed to form a form closure with an insert tool 10, in the mounted state, by means of the outer contour 68.

(21) The outer contour 68 of the torque transmission element 42 is realized so as to be congruent with the fixing element 18, in particular the locking part 66 of the fixing element 18, in at least one position of the fixing element 18 (see FIG. 3). The outer contour 68 of the torque transmission element 42 is realized so as to be congruent with the connection means 46 of the insert tool 10, in at least one position of the insert tool 10. The connection means 46, in particular an inner contour 94 of the connection means 46, is realized so as to correspond to a contour 48 of the fixing element, in particular of the locking part 18 of the quick-change clamping device.

(22) A movement of the movable cam mechanism element 88, in particular in the case of clamping of the clamping spring 32, by a distance of X, results in a rotation of the fixing element 18 by an angle α. This rotation causes, in particular by means of the thread 44 and/or the further thread 92, an axial displacement that depends on a pitch S of the thread 44 and/or of the further thread 92. The axial displacement is thus α/360°*S. A transmission ratio of a clamping force of the clamping spring 32 to a clamping force of the fixing element 18 is U=X*360°*S/α. The clamping force of the fixing element 18 is consequently U times greater than the clamping force of the clamping spring 32.

(23) In the exemplary embodiment shown, in the case of a maximum displacement of the movable cam mechanism element 88 of X=11 cm, α=36° and S=3 mm. In the exemplary embodiment shown, the transmission ratio assumes the value U=37.