MACHINE TOOL WITH A TORQUE CLUTCH

Description

State of the art

[0001] The present invention relates to a hand-held power tool, in particular a screwdriver, with a housing in which at least one gearbox and a drive motor for the rotary drive of a tool holder are arranged, and with a torque coupling which has a torque setting unit associated with the gearbox, to which a transmission element acted upon by at least two spring elements is associated, wherein a torque level of the torque coupling can be adjusted via a user-operated control element, wherein the at least two spring elements are arranged between the transmission element and a spring retaining ring, and wherein the spring retaining ring is arranged on a side of the transmission element facing away from the gearbox and is connected to the control element for setting a torque level via a toothed connection.

[0002] A hand-held power tool of this type, designed as a screwdriver, is known from CN 103862419 A. The screwdriver has a torque coupling with a torque adjustment unit, which includes an adjusting sleeve for setting the torque level of the torque coupling. Spring elements are associated with the torque adjustment unit and are arranged between a transmission element and the adjusting sleeve.

[0003] US 2013 / 333907 A1 describes a hand-held power tool according to the preamble of claim 1, in particular a hand-held power tool for operation in impact drilling, drilling and screwing modes, which has a mode setting device with an actuating element and an adjusting element as well as a gearbox for driving an output shaft. Revised description page 1a - Final version

[0004] In DE 10 2017 222006 A1 a hand-held machine tool is described with a housing in which a drive motor and a gearbox driven by the drive motor are arranged to drive an output shaft.

[0005] From EP 3 028 815 A1 a hand-held machine tool is known with a gearbox arranged in a gearbox housing for driving an output spindle, and with a torque coupling assigned to the output spindle. Disclosure of the invention

[0006] The invention relates to a hand-held power tool, in particular a screwdriver, with a housing in which at least one gearbox and a drive motor for the rotary drive of a tool holder are arranged, and with a torque coupling that has a torque setting unit associated with the gearbox, to which a transmission element acted upon by at least two spring elements is associated, wherein a torque level of the torque coupling can be adjusted via a user-operated control element, wherein the at least two spring elements are arranged between the transmission element and a spring retainer ring, and wherein the spring retainer ring is arranged on a side of the transmission element facing away from the gearbox and is connected to the control element for adjusting a torque level via a toothed connection. The spring retainer ring has bearing points associated with the at least two spring elements.

[0007] The invention thus enables the provision of a hand-held power tool with a torque coupling and a torque adjustment unit, in which the spring retaining ring with the bearing points enables a safe and reliable arrangement of the at least two spring elements on the spring retaining ring.

[0008] Preferably, the bearing points are designed as ribs and / or receptacles.

[0009] This allows suitable storage locations to be provided in a simple way.

[0010] According to the invention, the bearing points have different lengths along a longitudinal extension of the housing.

[0011] This allows for the easy and straightforward use of different spring forces.

[0012] According to one embodiment, the bearing points have a length in the range of 7 mm to 11.5 mm.

[0013] This allows for the provision of safe and reliable storage facilities.

[0014] Preferably, a plurality of bearing points are provided, which are arranged in the circumferential direction of the spring retaining ring.

[0015] This allows for a stable and robust arrangement of the spring elements on the spring retaining ring.

[0016] Preferably, the bearing points are arranged with different lengths in the circumferential direction, alternating.

[0017] This allows for a simple and straightforward arrangement of the bearing points on the spring retaining ring.

[0018] The bearing points are preferably formed in one piece with the spring retaining ring.

[0019] This allows for the provision of a compact spring retaining ring.

[0020] According to one embodiment, the bearing points designed as receptacles are shaped like a half-shell or a cylinder.

[0021] This allows suitable mounting points for the at least two spring elements to be provided in a simple manner.

[0022] Preferably, the spring retaining ring has an inner recess with at least one recess for rotationally secure arrangement on a clutch housing associated with the torque coupling.

[0023] This allows for a safe and reliable arrangement of the spring retaining ring on the clutch housing.

[0024] Preferably, the spring retaining ring has at least one weight-reduction recess radially between its outer circumference and the bearing points.

[0025] This makes it easy and straightforward to provide a weight-optimized spring retainer ring.

[0026] The at least two spring elements preferably abut a side of the transmission element facing the spring retaining ring.

[0027] This allows for a simple arrangement of at least two spring elements on the transmission element.

[0028] According to one embodiment, the torque setting unit has at least one detent element which is arranged along the longitudinal extent of the housing on an end face of the gearbox facing the transmission element, wherein the at least one detent element is designed as a pin and / or ball.

[0029] This allows a detent element for the torque setting unit to be provided easily and without complications.

[0030] Preferably, the end face of the gearbox faces a ring gear associated with the gearbox, and the at least one detent element is arranged on an end face of the ring gear.

[0031] This allows for a secure and robust arrangement of at least one locking element.

[0032] The clutch housing has first and second receptacles arranged facing the spring retaining ring, the first receptacle being designed to receive the at least one detent element and the second receptacles being designed to receive the at least two spring elements.

[0033] This allows for a simple arrangement of at least two spring elements on the clutch housing.

[0034] Preferably, the transmission element has internal recesses for placement on the coupling housing.

[0035] This allows the transmission element to be easily and simply arranged on the coupling housing. Brief description of the drawings

[0036] The invention is explained in more detail below with reference to exemplary embodiments illustrated in the drawings. The drawings show: Fig. 1 a side view of a hand-held power tool according to the invention with an exemplary torque setting unit, Fig. 2 an exploded view of the torque setting unit of Fig. 1 , Fig. 3 a longitudinal section through the torque setting unit of Fig. 1 and Fig. 2 , Fig. 4 a perspective top view of one of the torque setting units of Figs. 1 to 3 associated spring retaining ring, and Fig. 5 a sectional view of the spring retaining ring of Fig. 4 . Description of the exemplary implementations

[0037] In the figures, elements with the same or comparable function are given identical reference symbols and described in detail only once.

[0038] Fig. 1Figure 1 shows an exemplary hand-held power tool 100, which for illustrative purposes has an elongated housing 110. The elongated housing 110 gives the hand-held power tool 100 an exemplary "rod-shaped" design. Preferably, the hand-held power tool 100 is designed as a screwdriver, in particular as a rod screwdriver. According to one embodiment, the hand-held power tool 100 can be mechanically and electrically connected to a power supply unit for independent power supply. Preferably, the power supply unit is designed as a battery or battery pack 150.

[0039] In the illustrative elongated housing 110, at least one drive motor 140 for driving a tool holder 120 is preferably arranged. The tool holder 120 preferably has a base body 122 that is at least partially tubular or sleeve-shaped. The base body 122, which is at least partially tubular, preferably has an internal recess 125 for receiving an insert tool. Preferably, the internal recess 125 is a hexagonal socket for a screwdriver bit or bit insert tools in general.

[0040] The elongated housing 110 preferably has a cylindrical, at least partially sleeve-shaped base body with a first axial end 101 and an opposing second axial end 102, wherein the tool holder 120 is arranged in the region of the first axial end 101 by way of example. For illustrative purposes, a longitudinal direction 105 of the elongated housing 110 is formed between the first and second axial ends 101, 102.

[0041] At the in Fig. 1In the hand-held power tool 100 shown, the tool holder 120, the drive motor 140, and the housing 110 are arranged along a common longitudinal axis, which is preferably congruent with a rotational axis 103 of the tool holder 120. Preferably, all elements of the hand-held power tool 100 are arranged in the elongated housing 110. Thus, in the hand-held power tool 100, the battery 150 is also preferably arranged in the housing 110, in contrast to a hand-held power tool with a pistol-shaped housing in which the battery is arranged perpendicular to the drive motor, which is well known from the prior art.

[0042] According to one embodiment, a gearbox 145 is associated with the drive motor 140. Preferably, the gearbox 145 is designed as a planetary gearbox. Furthermore, a slide switch 170 is preferably provided, which is arranged on the housing 110 to activate a reversing operation of the drive motor 140.

[0043] Likewise, the housing 110 preferably has a torque coupling 135 at its axial end 101. The torque coupling 135 has a torque setting unit 139 associated with the gearbox 145. A desired torque limit or torque level of the torque coupling 135, e.g., job-specific, can be set via a user-operated control element 130. The control element 130 is preferably designed as a rotatable control sleeve. Furthermore, for illustrative purposes, an operating mode indicator unit 190 is arranged axially between the control element 130 and the elongated housing 110, which preferably displays a set operating mode and a torque level. Preferably, the torque coupling 135 is mounted on the gearbox 145, in particular in a coupling housing (220 in Fig. 2 and Fig. 3 ). The torque setting unit 139, on the other hand, is preferably arranged radially within the control element 130.

[0044] It should be noted at this point that the present invention is not limited to hand-held power tools designed as stick screwdrivers, but can be applied to all hand-held power tools with a torque coupling 135 and a torque setting unit 139. In other words, the present invention is not limited to hand-held power tools with elongated housings, but can be implemented regardless of the specific housing type.

[0045] According to one embodiment, a control element 175 is provided for activating the drive motor 140. The drive motor 140 is preferably activated by a user operating the control element 175. The control element 175 is preferably arranged on a grip area 115 of the elongated housing 110.

[0046] Preferably, a locking device 180 is provided for the releasable locking of an insert tool that can be arranged in the inner receptacle 125. The locking device 180 preferably has a locking sleeve 127.

[0047] The tool holder 120 is shown to have an axial longitudinal extent 109 for illustrative purposes. It should be noted that, in the context of the present invention, the term "axial" refers to a direction along the longitudinal extent 109 of the tool holder 120. Furthermore, the term "radial" refers to a direction approximately perpendicular to the longitudinal extent 109 of the tool holder 120. Thus, a radial direction 108 is arranged approximately perpendicular to the longitudinal direction 105 of the elongated housing 110, or perpendicular to the longitudinal extent 109 of the tool holder 120. Furthermore, the axial direction is arranged substantially parallel or congruent to the longitudinal extent 109 of the tool holder 120, or parallel or congruent to the axis of rotation 103 of the tool holder 120.

[0048] Fig. 2 shows the torque coupling 135 with the torque adjusting unit 139 from Fig. 1 This clarifies Fig. 2 a gearbox 145 from Fig. 1 The associated ring gear 210 has a hollow cylindrical or sleeve-shaped base body with internal teeth 212 on its inner circumference. On an end face 213 (illustratively right-hand), facing the torque setting unit 139 or the tool holder 120, the ring gear 210 preferably has at least one axial actuation element 214, 216. For illustrative purposes, six actuation elements 214, 216 are arranged along one circumference of the ring gear 210 on the end face 213. Preferably, the actuation elements 214, 216 are arranged at regular intervals from one another. The ring gear 210 is preferably arranged such that the end face 213 of the ring gear 210 is located on an end face 299 associated with the transmission 145.

[0049] The ring gear 210 is preferably arranged section by section in an internal recess of a clutch housing 220 associated with the torque coupling 135. The clutch housing 220 has, for illustrative purposes, a left-hand hollow cylindrical or annular receiving section 229 for at least sectionally receiving the ring gear 210 of the transmission 145. Axially adjoining this section in the direction of the torque coupling 135, the clutch housing 220 preferably has axial webs 223 arranged circumferentially within the hollow cylindrical receiving section 229. A recess 222 is preferably formed between each pair of adjacent webs 223. The recess 222 is, for illustrative purposes, designed as a half-shell. Preferably, each recess 222 is associated with a recess 221. The recess 221 is preferably designed as an internal recess within the hollow cylindrical receiving section 229. In one embodiment, the recess 221 is designed as a cylinder.In the axial direction 109, the two recordings 221, 222 are connected to each other or merge into each other.

[0050] Furthermore, a transmission element 250 is preferably associated with the torque coupling 135. The transmission element 250 is preferably disc-shaped and has an internal recess 252. The internal recess 252 is designed for mounting on the coupling housing 220, in particular on the webs 223. For this purpose, the internal recess 252 has alternating recesses 251 and contact surfaces 254 in the circumferential direction. The recesses 251 preferably have a larger inner diameter than the contact surfaces 254.

[0051] Furthermore, a spring retaining ring 270 is preferably associated with the torque coupling 135. The spring retaining ring 270 preferably has a hollow cylindrical or annular base body with a toothed section 271 arranged on its outer circumference and with at least one recess 272 arranged on its inner circumference. Preferably, the at least one recess 272 is designed to prevent rotation on the coupling housing 220. For illustrative purposes, the spring retaining ring 270 is also connected via the toothed section 271 to the operating element 130 for setting a torque level.

[0052] Alternatively, an end stop element 280 is assigned to the torque coupling 135, which is designed to form an axial stop of the spring retaining ring 270 towards the tool holder 120.

[0053] Preferably, at least two, and for illustrative purposes six, spring elements 260 are associated with the transmission element 250. Preferably, the spring elements 260 are identical and, in particular, designed as coil springs. However, different spring elements can also be used. All spring elements 260 can be of the same length or have different lengths. Preferably, the spring elements 260 are arranged axially between the transmission element 250 and the spring retaining ring 270. Here, the spring elements 260 abut a side 253 of the transmission element 250 facing the spring retaining ring 270. The spring retaining ring 270, in turn, is preferably arranged on a side of the transmission element 250 facing away from the gearbox 145, or the tool holder 120.

[0054] Preferably, the torque adjusting unit 139 has at least one detent element 230, 240, which is arranged along the longitudinal extent 103 of the housing 110 or in the axial direction 109 on the end face 299 of the transmission element 145 facing the transmission element 250. The at least one detent element 230, 240 is preferably designed as a pin and / or ball. For illustrative purposes, the detent elements 240 are designed as pins and the detent elements 230 are designed as balls. In this case, the detent elements 230 are arranged facing the ring gear 210 and the detent elements 240 are arranged facing the transmission element 250. In particular, the detent elements 240 bear against the transmission element 250. Preferably, the detent elements 230, 240 are arranged on an end face 213 of the ring gear 210. The transmission element 250 is preferably arranged axially between the locking elements 240 designed as pins and the spring elements 260.

[0055] Furthermore, the receptacles 221 of the clutch housing 220 are preferably designed to receive the detent elements 230, 240. In addition, the receptacles 222 are preferably designed to receive the spring elements 260.

[0056] Fig. 3 shows the torque coupling 135 with the torque adjusting unit 139 from Fig. 1 and Fig. 2 This clarifies Fig. 3 the arrangement of the detent elements 230, 240 on the end face 213 of the ring gear 210 and on the end face 299 of the transmission 145, respectively. Furthermore, in Fig. 3 The radial arrangement of the ring gear 210 in the clutch housing 220 is visualized. Furthermore, it shows Fig. 3 the arrangement of the locking elements 230, 240 radially within the coupling housing 220 or within the preferably cylindrical receptacles 221 of the coupling housing 220.

[0057] Fig. 3The arrangement of the transmission element 250 on the webs 223 of the coupling housing 220 is also illustrated, wherein the transmission element 250 abuts axially against an end face 399 of the hollow cylindrical receiving section 229 of the coupling housing 220 facing the tool holder 120. Furthermore, the transmission element 250 is arranged axially between the detent elements 230, 240 and the spring elements 260.

[0058] Preferably, the operating element 130 has a toothed section 320 on its inner surface facing the spring retaining ring 270. The toothed section 320 is preferably designed as an internal thread, and the toothed section 271 of the spring retaining ring 270 is designed as an external thread, with the two toothed sections 320 and 271 facing each other to adjust a torque level. When setting a desired torque level, the axial position of the spring retaining ring 270 can be changed by displacement. Different spring forces of the spring elements 260 can be set by adjusting the different axial positions of the spring retaining ring 270. If the set spring forces are exceeded, the torque clutch 135 is released, and the tool holder 120 enters a neutral position in which no torque is transmitted.

[0059] Furthermore, it shows Fig. 3The arrangement of the spring elements 260 in the receptacles 222 of the clutch housing 220. Preferably, the spring retaining ring 270 has bearing points 331, 333 associated with the spring elements 260. The bearing points 331, 333 are preferably designed as webs and / or receptacles. For illustrative purposes, the bearing points 331, 333 are designed as axial webs, on the outer circumference of which an associated inner circumference of each spring element 260 is arranged section by section.

[0060] According to the invention, the bearing points 331, 333 along the longitudinal extent 103 of the housing 110 have Fig. 1The bearings 331 and 332 have different lengths 332 and 334 in the axial direction 109. Preferably, the bearing 331 has a length 332 and the bearing 333 has a length 334. According to one embodiment, the bearings 331 and 332 have axial lengths 332 and 334 in the range of 7 mm to 11.5 mm. Preferably, the lengths 332 and 334 are 7 mm to 9 mm. More preferably, the lengths 332 and 334 are 9.5 mm to 11.5 mm.

[0061] Preferably, a plurality of bearing points 331, 332 are provided, arranged circumferentially around the spring retaining ring 270. The bearing points 331, 332, with their different lengths 332, 334, are preferably arranged alternately circumferentially. However, it should be noted that the bearing points 331, 332 can also be arranged circumferentially in predetermined patterns, e.g., two bearing points 331 of length 332 next to each other and then, for example, three bearing points 332 of length 334 next to each other.

[0062] According to one embodiment, the bearing points 331, 332 are formed integrally with the spring retaining ring 270. Preferably, the bearing points 331, 332, which are designed as receptacles, are shaped like a half-shell or a cylinder.

[0063] For illustrative purposes, the torque adjusting unit 139 is arranged radially between the operating element 130 and the coupling housing 220 or the webs 223. The torque adjusting unit 139 includes, by way of example, the operating element 130, the spring retaining ring 270, the spring elements 260, and the transmission element 250. The torque coupling 135, on the other hand, is preferably arranged radially between the coupling housing 220 and a coupling part of the tool holder 120. For illustrative purposes, the torque coupling 135 is arranged axially between the ring gear 210 and the torque adjusting unit 139. The ring gear 210, in particular the axial actuation elements 214, 216 of the ring gear 210, and the detent elements 230, 240 are associated with the torque coupling 135 by way of example. Preferably the detent elements 230 are arranged on the ring gear 210 and the detent elements 240 are arranged between the detent elements 230 and the transmission element 250.In this case, the detent elements 240 preferably lie on a side of the transmission element 250 facing away from the spring retaining ring 270.

[0064] Within the gearbox 145, a support torque is generated by the torque and speed conversion. This torque is transmitted by planetary gears of a front, illustrative left-hand planetary stage to the ring gear 210. The torque clutch 135 engages when the support torque exceeds the applied holding torque, ultimately causing the ring gear 210 to slip or spin freely. In this case, the transmission between the gearbox 145 and the tool holder 120 is interrupted or deactivated, or at least limited. The respective holding torque acting on the ring gear 210 depends on the axial position of the spring retaining ring 270 and thus on the rotational position of the operating element 130.

[0065] Fig. 4shows the spring retaining ring 270 of the torque coupling 135 or the torque adjusting unit 139 of Figs. 1 to 3with the toothing 271 arranged on its outer circumference and the recess 272, as well as the illustrative six bearing points 331, 333. Preferably, the recess 272 is associated with protrusions 410, 430, 440. The protrusions 410, 430, 440 are preferably arranged circumferentially between the bearing points 331, 333. Preferably, a protrusion 410, 430, 440 is arranged between each pair of bearing points 331, 333 adjacent circumferentially to the spring retaining ring 270. For illustrative purposes, two protrusions 410, 430, 440 are arranged diametrically opposite each other. Preferably, the protrusion 410 forms an approximately cup-shaped recess section of the recess 272, and the protrusion 440 forms an approximately semicircular recess section. The bulge 430 illustrates a recessed section in the form of a circular segment.The bulge 410 preferably has a diameter 411, the bulge 440 a diameter 421, and the bulge 430 a diameter 431. Similarly, two bearing points 331, 333 are arranged diametrically opposite each other and have a diameter 401. The diameters 411, 421 are preferably larger than the diameters 401, 431. According to one embodiment, the diameters 401, 431 are the same.

[0066] Furthermore, it visualizes Fig. 4 The bearing points 331, 333, each illustratively showing a receptacle 451 in the form of a half-shell and a central web 452. Thus, the spring element 260 can be Fig. 2 and Fig. 3 The spring element 260 is mounted section by section on its outer circumference at the receptacle 451 and on its inner circumference at the web 452. Furthermore, a base surface 453 is preferably assigned to a bearing point 331, 333, on which the spring element 260 is mounted. Fig. 2 and Fig. 3with its tool holder 120 of Figs. 1 to 3 The axial end is located at the facing end. Lengths 332, 334 are preferably formed between the base surface 453 and an axial end face associated with the spring retaining ring 270. Each axial position of the base surface 453 thus forms one of the lengths 331, 333. It should be noted that the bearing points 331, 333, as described above, can also each be designed simply as a receptacle 451 or cylindrical recess, or simply as a web 452.

[0067] According to one embodiment, the spring retaining ring 270 has at least one weight-reducing recess 420 radially between its outer circumference and the bearing points 331, 333. For illustrative purposes, the weight-reducing recess(s) 420 are each designed as a recess, but can also be designed as a through-opening.

[0068] Fig. 5shows the spring retaining ring 270 from Figs. 2 to 4 with the bearing points 331, 333, which have different lengths 332, 334. Furthermore, it illustrates Fig. 5 the arrangement of the weight reduction recesses 420, which are arranged radially between the outer circumference of the spring retaining ring 270, or the toothing 271, and the bearing points 331, 333 for illustrative purposes.

Claims

1. Hand-held power tool (100), in particular screwdriver, having a housing (110) in which at least a gearbox (145) and a drive motor (140) for driving a tool receptacle (120) in rotation are arranged, and having a torque clutch (135) which has a torque adjusting unit (139) which is associated with the gearbox (145) and with which a transmission element (250) which is acted on by at least two spring elements (260) is associated, wherein a torque level of the torque clutch (135) can be adjusted via a user-operable operator control element (130), wherein the at least two spring elements (260) are arranged between the transmission element (250) and a spring retaining ring (270), and wherein the spring retaining ring (270) is arranged on a side of the transmission element (250) facing away from the gearbox (145) and is connected via a toothing (271) to the operator control element (130) for adjusting a torque level, wherein the spring retaining ring (270) has bearing points (331, 333) assigned to the at least two spring elements (260), characterized in that the bearing points (331, 333) have different lengths (332, 334) along a longitudinal extent (103) of the housing (110).

2. Hand-held power tool according to Claim 1, characterized in that the bearing points (331, 333) are in the form of webs and / or receptacles.

3. Hand-held power tool according to Claim 1 or 2, characterized in that the bearing points (331, 332) have a length (332, 334) in the range of 7 mm to 11.5 mm.

4. Hand-held power tool according to any of the preceding claims, characterized in that a plurality of bearing points (331, 332) are provided, which are arranged in the circumferential direction of the spring retaining ring (270).

5. Hand-held power tool according to Claims 1 and 4, characterized in that bearing points (331, 332) with different lengths (332, 334) are arranged alternately in the circumferential direction.

6. Hand-held power tool according to any of the preceding claims, characterized in that the bearing points (331, 332) are formed in one piece with the spring retaining ring (270).

7. Hand-held power tool according to any of Claims 2 to 6, characterized in that the bearing points (331, 332) in the form of a receptacle are formed in the manner of a half-shell or a cylinder.

8. Hand-held power tool according to any of the preceding claims, characterized in that the spring retaining ring (270) has an internal recess with at least one recess (272) for rotationally fixed arrangement on a clutch housing (220) associated with the torque clutch (135).

9. Hand-held power tool according to any of the preceding claims, characterized in that the spring retaining ring (270) has at least one weight-reducing recess (420) radially between its outer circumference and the bearing points (331, 333).

10. Hand-held power tool according to any of the preceding claims, characterized in that the at least two spring elements (260) are present on a side (253) of the transmission element (250) facing the spring retaining ring (270).

11. Hand-held power tool according to any of the preceding claims, characterized in that the torque adjusting unit (139) has at least one latching body (230, 240) which is arranged on an end side (299) of the gearbox (145) arranged facing the transmission element (250) along the longitudinal extent (103) of the housing (110), wherein the at least one latching body (230, 240) is in the form of a pin and / or ball.

12. Hand-held power tool according to Claim 11, characterized in that the end side (299) of the gearbox (145) faces a ring gear (210) associated with the gearbox (145), and the at least one latching body (230, 240) is arranged on an end side (213) of the ring gear (210).

13. Hand-held power tool according to Claims 8 and 11 or 12, characterized in that the clutch housing (220) has first and second receptacles (221, 222) arranged facing the spring retaining ring (270), wherein the first receptacle (221) is designed for receiving the at least one latching body (230, 240) and the second receptacles (222) are designed for receiving the at least two spring elements (260).

14. Hand-held power tool according to Claim 8, characterized in that the transmission element (250) has internal recesses (252) for arrangement on the clutch housing (220).