Handheld machine tool with tool holder and locking unit

Abstract

A handheld machine tool having a housing in which a drive motor and a transmission are arranged for driving a tool holder (150), the tool holder (150) being provided with a receiving sleeve (299), and a locking unit (190) for locking and unlocking an insert tool (140) that can be placed in the receiving sleeve (299), wherein the locking unit (190) is associated with at least one locking element (245) biased by a spring element (246), and the receiving sleeve (299) has a spring receiving portion (243) for receiving the spring element (246), wherein the spring receiving portion (243) is arranged at least approximately parallel to a rotation axis (201) of the tool holder (150).

Description

[Technical Field]

[0001] The invention relates to a handheld machine tool having a housing in which a drive motor and a transmission are arranged for driving a tool holder, the tool holder being provided with a receiving sleeve, and a locking unit for locking and unlocking an insert tool that can be placed in the receiving sleeve, wherein the locking unit is associated with at least one locking element biased by a spring element, and the receiving sleeve has a spring receiving section for receiving the spring element.

[0002] A handheld machine tool with a locking unit is known from the prior art. The handheld machine tool has a housing in which a drive motor and a transmission are arranged for driving a tool holder. The tool holder is provided with a receiving sleeve. A locking unit is also provided for locking and unlocking a tool insert that can be arranged in the receiving sleeve. At least one locking element biased by a spring element is associated with the locking unit, and the receiving sleeve has a spring receiving portion for receiving the spring element. The spring receiving portion is arranged perpendicular to the rotation axis of the tool holder and presses the locking element into the receiving sleeve perpendicular to the tool holder.

[0003] Disclosure of the Invention The invention relates to a handheld machine tool having a housing in which a drive motor and a transmission for driving a tool holder are arranged, the tool holder being provided with a receiving sleeve, and a locking unit for locking and unlocking a tool insert that can be placed in the receiving sleeve, the locking unit being associated with at least one locking element biased by a spring element, the receiving sleeve having a spring receiving portion for receiving the spring element, the spring receiving portion being arranged at least approximately parallel to the rotation axis of the tool holder.

[0004] With this configuration, the invention makes it possible to provide a handheld machine tool with a compact locking unit, thanks to the spring receptacle being arranged at least approximately parallel to the axis of rotation of the tool holder.

[0005] Preferably, the spring receiving portion is arranged between the inner receiving portion of the receiving sleeve and at least one bearing element of the tool holder which is arranged on the outer periphery of the receiving sleeve.

[0006] With this configuration, it is possible to easily arrange the spring receiving portions in an appropriate manner to form a compact locking unit.

[0007] Preferably, the spring receiving portion is at least partially closed along the axis of rotation of the tool holder by at least one bearing element.

[0008] This arrangement makes it possible to provide a secure and reliable arrangement of the spring element which can be arranged in the spring receiving portion.

[0009] The spring receiving portion is preferably oriented at an angle to the axis of rotation of the tool holder.

[0010] With this arrangement, an at least approximately parallel arrangement of the spring receptacle relative to the axis of rotation of the tool holder can be easily and simply achieved.

[0011] Preferably, the spring receiving portion is arranged in the receiving sleeve substantially transversely to the receiving portion of the locking element.

[0012] This arrangement makes it possible in a simple manner to arrange the spring receiving portion in relation to the locking element in a suitable manner.

[0013] Preferably, the spring element is at least partially arranged within an inner periphery of the at least one bearing element.

[0014] This arrangement makes it possible to provide a compact arrangement of the spring elements.

[0015] The spring element is preferably arranged at least partially radially with respect to the axis of rotation of the tool holder between the inner receiving portion of the receiving sleeve and the at least one bearing element.

[0016] This arrangement allows for a simple and compact arrangement of the spring elements.

[0017] According to one embodiment, a recess is arranged on the outer periphery of the receiving sleeve for accommodating a ring element that corresponds to the spring element.

[0018] This arrangement makes it possible to ensure a secure and reliable arrangement of the ring element in the receiving sleeve.

[0019] Preferably, the ring element presses the spring element into the spring receiving portion.

[0020] This arrangement allows for a simple and robust arrangement of the spring element in the spring receiving portion.

[0021] According to one embodiment, the locking unit has an operating sleeve for unlocking an insert tool that can be placed in the tool holder, the operating sleeve being provided for releasing a locking element biased by a spring element.

[0022] With this configuration, unlocking can be easily performed.

[0023] Preferably, the operating sleeve is movable along a direction away from the handheld machine tool to unlock a tool insert disposed in the tool holder.

[0024] With this configuration, a relatively small movement distance of the operating sleeve can enable a secure and reliable unlocking.

[0025] Preferably, the locking element is at least partially arranged in at least one state within an inner periphery of the at least one bearing element.

[0026] This configuration allows for a stable arrangement of the locking element.

[0027] The locking element is preferably arranged in at least one position radially relative to the axis of rotation of the tool holder between the inner receiving portion of the receiving sleeve and the at least one bearing element.

[0028] This arrangement allows for a simple and robust arrangement of the locking element.

[0029] According to one embodiment, the locking unit is arranged at least partially radially with respect to the rotation axis of the tool holder between the inner receiving part of the receiving sleeve and the at least one bearing element.

[0030] With this configuration, it is possible to easily achieve a compact configuration for the lock unit.

[0031] Preferably, the spring receiving portion is formed in such a way that an inner periphery of the at least one bearing element facing the tool holder and a spring element arranged in the spring receiving portion are in partial contact with each other.

[0032] In this way, the support of the spring element can be easily and simply achieved.

[0033] The invention will be explained in more detail in the following description with reference to an embodiment shown in the drawing. [Brief explanation of the drawings]

[0034] [Figure 1] 1 shows a schematic diagram of a handheld machine tool with a tool holder and a locking unit; FIG. [Figure 2] 2 is a longitudinal sectional view showing the tool holder and lock unit shown in FIG. 1 in an unlocked position, and a plan view showing the insertion tool. [Figure 3] 3 is a vertical cross-sectional view showing the tool holder and the lock unit shown in FIG. 2 when the insertion tool shown in FIG. 2 is being pushed into the tool holder. FIG. [Figure 4] 4 is a longitudinal cross-sectional view of part of the tool holder and locking unit shown in FIGS. 2 and 3 when the insertion tool shown in FIG. 2 is further pushed into the tool holder; FIG. [Figure 5] 5 is a vertical cross-sectional view showing a part of the tool holder and the lock unit shown in FIGS. 2 to 4 in a locked position. FIG. [Figure 6] 6 is a vertical cross-sectional view showing the tool holder and the lock unit shown in FIGS. 2 to 5 when a load is applied to the insertion tool from the tool holder outward in the locked position. FIG. [Figure 7] 7 is a vertical cross-sectional view showing a part of the tool holder and the lock unit shown in FIGS. 2 to 6 when unlocked. FIG.

[0035] Description of Examples In the drawings, elements having the same or comparable function are given the same reference numerals and will be described in more detail only once.

[0036] 1 shows a handheld machine tool 100 provided with a tool holder 150, the handheld machine tool 100 having a housing 110 with a grip 126. According to one embodiment, the handheld machine tool 100 is mechanically and electrically connectable to a battery pack 130 for grid-independent power supply.

[0037] Arranged within the housing 110 are an electric drive motor 114 and a transmission 118, which in the illustrated embodiment is supplied with current from a battery pack 130. The drive motor 114 can be operated, i.e., connected and disconnected, for example, via a hand switch 128 and can be of any motor type, such as an electronically commutated motor or a DC motor. Preferably, the drive motor 114 is electronically controllable or adjustable so that reverse operation and setting of the desired rotation speed are possible. The function and design of suitable drive motors are sufficiently known from the prior art and will not be described in detail here for the sake of brevity.

[0038] The drive motor 114 is connected via the associated motor shaft 116 to a transmission 118, which converts the rotation of the motor shaft 116 into the rotation of the driven shaft 124. This conversion preferably takes place in such a way that the driven shaft 124 rotates with increased torque relative to the motor shaft 116 but at a reduced rotational speed. In the illustrated embodiment, the drive motor 114 is arranged in a motor housing 115. The transmission 118 is arranged in a transmission housing 119. The transmission housing 119 and the motor housing 115 are arranged, for example, in the housing 110.

[0039] According to one embodiment, a mechanical striking mechanism 122 is provided. The drive motor 114 is connected via an associated motor shaft 116 to a transmission 118 in such a way that the rotation of the motor shaft 116 is converted into the rotation of an intermediate shaft 120 arranged between the transmission 118 and the striking mechanism 122. In the illustrated embodiment, the mechanical striking mechanism 122 and / or the transmission 118 are arranged in a common transmission housing 119. Alternatively, the mechanical striking mechanism 122 may be arranged in a separate striking mechanism housing.

[0040] The mechanical striking mechanism 122 coupled to the intermediate shaft 120 is, for example, a rotary striking mechanism, which generates a high-intensity rotary striking pulse and transmits it to the driven shaft 124, for example, a driven spindle. Hereinafter, the mechanical striking mechanism will be referred to as the "mechanical rotary striking mechanism 122." In particular, the mechanical rotary striking mechanism 122 is provided to strike and drive the tool holder 150. The mechanical rotary striking mechanism 122 has a spring-loaded striking body (205 in FIG. 2), which is connected to the intermediate shaft 120 and supported by the intermediate shaft 120 so as to be movable in the axial direction 102 of the transmission 118.

[0041] The driven shaft 124 is provided with a tool holder 150, which is preferably configured to receive a tool insert and can be coupled to a tool insert 140, preferably having an external polygonal connection. The tool insert 140 is configured, for example, as a screwdriver bit with an external polygonal connection, an octagonal connection in the illustrated embodiment. Such screwdriver bits are sufficiently known in the prior art and will not be described in detail here for the sake of brevity. Furthermore, in the illustrated embodiment, a locking unit 190 is provided for locking and unlocking the tool insert 140 placed in the tool holder 150.

[0042] 2 shows the tool holder 150 and locking unit 190 from FIG. 1, with the locking unit 190 shown in the unlocked position 200 and, by way of example, with a tool insert 140 arranged outside the tool holder 150. In the illustrated embodiment, the tool holder 150 has a receiving sleeve 299 in which the tool insert 140 arranged therein can be locked. For this purpose, the locking unit 190 is assigned at least one locking element 245 biased by a spring element 246.

[0043] Preferably, the receiving sleeve 299 has a spring receiving portion 243 for receiving the spring element 246. According to one embodiment, the spring receiving portion 243 is configured as an elongated hole. Preferably, the spring receiving portion 243 is milled.

[0044] Preferably, at least one spring element 246 is arranged in the at least one spring receiving section 243. Preferably, there are two spring receiving sections 243 located diametrically opposite each other, each with one spring element 246. However, any number of spring receiving sections 243 arranged in the circumferential direction of the receiving sleeve 299 may be provided. According to one embodiment, the at least one, or in the illustrated embodiment, two, spring elements 246 are configured as compression springs with an inner diameter 248. Preferably, the inner diameter 248 is smaller than the diameter 249 of the locking element 245. According to one embodiment, the spring element 246 comprises a plastic with spring properties.

[0045] According to one embodiment, the locking elements 245, which are respectively assigned to one spring element 246, are formed as rotationally symmetrical elements, for example as balls, or alternatively as pins.

[0046] According to the invention, the spring receiving portion 243 is arranged approximately parallel to the rotation axis 201 of the tool holder 150. In particular, the spring receiving portion 243 is oriented at an angle 209 relative to the rotation axis 201 of the tool holder 150. The angle 209 is preferably between 0° and 80°, in particular between 5° and 20°. Preferably, the angle 209 is 12°.

[0047] Preferably, the spring receiving portion 243 is arranged radially between the inner receiving portion 241 of the receiving sleeve 299 and at least one bearing element 231, 232 of the tool holder 150, which is arranged on an outer periphery 247 of the receiving sleeve 299. The spring receiving portion 243 is at least partially closed along the rotation axis 201 of the tool holder 150 by the at least one bearing element 231, 232, with the inner periphery facing the receiving sleeve 299 covering the spring receiving portion 243. Preferably, the inner periphery facing the tool holder 150 of the at least one bearing element 232 and the spring element 246 arranged in the spring receiving portion 243 are in partial contact with each other. Preferably, the locking unit 190 is at least partially arranged radially with respect to the rotation axis 201 of the tool holder 150 between the inner receiving portion 241 of the receiving sleeve 299 and the at least one bearing element 231 , 232 .

[0048] In the illustrated embodiment, two bearing elements 231, 232 are provided, which are arranged in a bearing receptacle 230 of the housing 110. Preferably, the bearing receptacle 230 is arranged in the transmission housing 119 or in the striking mechanism housing of the additional rotary mechanical striking mechanism 122. The two bearing elements 231, 232 are preferably in contact with each other along the longitudinal extension 203 of the tool holder 150. Preferably, the two bearing elements 231, 232 are configured as rolling bearings, in particular as ball bearings. Additionally, only one bearing element 231, 232 may be provided.

[0049] Preferably, the spring receiving portion 243 is arranged in the receiving sleeve 299 substantially transversely to the receiving portion 242 of the locking element 245. Furthermore, the spring element 246 is preferably arranged at least partially within the inner periphery 298 of the at least one bearing element 231, 232. Likewise, the spring element 246 is preferably arranged at least partially radially with respect to the rotation axis 201 of the tool holder 150 between the inner receiving portion 241 of the receiving sleeve 299 and the at least one bearing element 231, 232.

[0050] Furthermore, in the illustrated embodiment, the locking unit 190 comprises an operating sleeve 250 for unlocking the tool insert 140 which can be placed in the tool holder 150, the operating sleeve 250 being provided for releasing the locking element 245 biased by the spring element 246. The operating sleeve 250 preferably has a pressing section 252 on its inner periphery facing the inner receiving portion 241.

[0051] In the unlocked position 200 shown in FIG. 2, the locking element 245 is partially in contact with the pressure section 252. Furthermore, the operating sleeve 250 is fixed to the outer periphery 247 of the receiving sleeve 299 via a disk-shaped fastening element 254. A fastening ring 253 is preferably associated with the disk-shaped fastening element 254. The fastening ring 253 is arranged in a circumferential groove formed in the outer periphery 247 of the receiving sleeve 299. A spring element 251 is preferably arranged axially between the pressure section 252 and the disk-shaped fastening element 254. The spring element 251 is designed to press the operating sleeve 250 against the at least one bearing element 231, 232 along the longitudinal extension 203 of the tool holder 150.

[0052] Furthermore, a recess 262 is preferably arranged on the outer periphery 247 of the receiving sleeve 299 for accommodating a ring element 260 corresponding to the spring element 246. Preferably, the ring element 260 presses the spring element 246 into the spring receiving portion 243. In this way, the ring element 260 prevents the spring element 246 from being pushed out radially towards the operating sleeve 250 when the spring element 246 is compressed.

[0053] Furthermore, the ring element 260 is preferably configured as an axial stop for the operating sleeve 250 or for the pressure element 252 of the operating sleeve 250. Furthermore, the ring element 260 is preferably configured as a blind and dirt-proof cover, which prevents dirt from reaching the inside of the locking unit 190. According to one embodiment, the ring element 260 is configured as an O-ring or an expansion ring.

[0054] Preferably, the spring receptacle 243 and / or the receptacle 242 of the locking element 245 are formed in the form of a cylinder or a truncated cone. Preferably, the tool holder 150 has at least one spring element 246 associated with the locking element 245 and at least one spring element 251 associated with the operating sleeve 250.

[0055] It should be noted that the term "radial direction" in the context of the present invention means a direction that is approximately perpendicular to the longitudinal extension 203 of the tool holder 150. Furthermore, the term "axial direction" means a direction along or parallel to the longitudinal extension 203 of the tool holder 150. The radial direction 202 is therefore oriented approximately perpendicular to the axial direction 102 of the transmission 118 or to a direction along the longitudinal extension 203 of the tool holder 150. Furthermore, the axial direction 102 is oriented substantially parallel to the longitudinal extension 203 of the tool holder 150 or to the rotation axis 201 of the tool holder 150.

[0056] In one embodiment of the handheld machine tool 100 equipped with the mechanical rotary impact mechanism 122 shown in FIG. 1 , the mechanical rotary impact mechanism 122 includes an impact body 205 and an anvil 220 that can be loaded by the impact body 205. Preferably, the anvil 220 is associated with the tool holder 150. In particular, the anvil 220 is preferably formed integrally with the tool holder 150. The mechanical rotary impact mechanism 122 generates a high-intensity rotary impact pulse and transmits this rotary pulse to the driven shaft 124 or, via the anvil 220, to the receiving sleeve 299. The spring-loaded impact body 205 is supported movably in the axial direction 102 of the transmission 118. Such mechanical rotary impact mechanisms 122 are well known in the art and will not be described in detail here for the sake of brevity.

[0057] 2 further shows an insertion tool 140, which in the illustrated embodiment is configured as a bit tool. The insertion tool 140 has a locking region 210. As described in FIG. 1, the locking region 210 has an outer polygonal shape. For locking by at least one locking element 245, the locking region 210 has a locking groove 211 on its outer periphery.

[0058] 3 shows the tool holder 150 and locking unit 190 shown in FIGS. 1 and 2 when the tool insert 140 has been pushed along arrow 301 into the inner receiving portion 241 of the tool holder 150. In the illustrated embodiment, the locking region 210 is partially arranged in the inner receiving portion 241 of the receiving sleeve 299. The locking elements 245, which are arranged diametrically opposite each other, are not yet loaded in FIG. 3.

[0059] During such pushing, the insertion tool 140 is simply pushed into the inner receiving portion 241. At this time, the operating sleeve 250 does not need to be operated in a predetermined direction by the operator of the handheld machine tool 100 shown in FIG.

[0060] Figure 4 shows the tool holder 150 and locking unit 190 of Figures 2 and 3 in position 499, after the tool insert 140 has been pushed further into the inner receiving portion 241 of the tool holder 150 in the direction of arrow 301 compared to Figure 2. In this situation, the locking region 210 of the tool insert 140, or an edge 410 of the tool insert 140 that corresponds to the end face of the locking region 210, presses the diametrically arranged locking element 245 from the inner receiving portion 241 of the receiving sleeve 299 towards the outer periphery 247. The locking element 245 presses against the spring element 246 against the spring force of the spring element 246. The operating sleeve 250 remains substantially stationary.

[0061] 4, the illustrated locking element 245 is arranged on an inner periphery of the ring element 260, which is directed towards the locking element 245. Furthermore, the locking element 245 is arranged at least partially inside the inner periphery 298 of the at least one bearing element 231, 232. Furthermore, the locking element 245 is then preferably arranged radially with respect to the rotation axis 201 of the tool holder 150 between the inner receiving portion 241 of the receiving sleeve 299 and the at least one bearing element 231, 232.

[0062] 5 shows the tool holder 150 and the locking unit 190 shown in FIGS. 2 to 4 in the locked position 500. In the locked position 500, the tool insert 140 has been moved into the inner receiving space 241 in the direction of the arrow 301 compared to FIGS. 2 to 4, whereby the locking section 210 is located in the inner receiving space 241. The locking element 245 then locks the tool insert 140 in the locking groove 211 in the inner receiving space 241 of the tool holder 150. The locking element 245 is pressed against its receiving space 242 by the spring element 246. At the same time, the pressing section 252 of the operating sleeve 250 presses the locking element 245 into the locking groove 210 of the tool insert 140. The locking element 245 is then located radially between the tool insert 140 and the pressing section 252. The locking element 245 is also preferably arranged axially beside at least one of the bearing elements 231,232.

[0063] 6 shows the tool holder 150 and locking unit 190 of FIGS. 2 to 5 in the locked position 500, in which an axial force 601 is exerting on the tool insert 140 in a direction that pushes it out of the inner receiving portion 241. The axial force 601 represents, for example, a pulling force on the tool insert 140. The pressing section 252 then presses the locking element 245 towards the locking groove 211 of the tool insert 140, thereby locking the tool insert 140 in the inner receiving portion 241.

[0064] 7 shows the tool holder 150 and locking unit 190 of FIGS. 2-5 when unlocking the tool insert 140. To unlock, the operating sleeve 250 is actively moved axially in the direction of arrow 701 away from the handheld machine tool 100 of FIG. 1 by a user of the handheld machine tool 100 of FIG. 1, and the tool insert 140 is also moved out of the tool holder 150 in the direction of arrow 701. The spring element 251 of the operating sleeve 250 is then compressed, causing the pressure section 252 to release the locking element 245. This causes the locking element 245 to move along its receiving portion 242, preferably approximately radially outward from the inner receiving portion 241, until the locking element 245 is finally positioned axially next to the pressure section 252. In particular, the locking element 245 is partially disposed between the ring element 260 and the pressure section 252 in the axial direction 102.

Claims

1. A handheld machine tool (100) comprising: a housing (110) in which a drive motor (114) and a transmission (118) are arranged for driving a tool holder (150), the tool holder (150) being provided with a receiving sleeve (299); and a locking unit (190) for locking and unlocking an insert tool (140) that can be placed in the receiving sleeve (299), wherein the locking unit (190) is associated with at least one locking element (245) biased by a spring element (246), and the receiving sleeve (299) has a spring receiving portion (243) for receiving the spring element (246). The spring receiving portion (243) is arranged at least approximately parallel to the rotation axis (201) of the tool holder (150). A handheld machine tool characterized by:

2. 2. The handheld machine tool according to claim 1, wherein the spring receiving portion (243) is arranged between the inner receiving portion (241) of the receiving sleeve (299) and at least one bearing element (231, 232) of the tool holder (150) arranged on the outer periphery (247) of the receiving sleeve (299).

3. 3. The handheld machine tool according to claim 2, wherein the spring receiving portion (243) is at least partially closed along the rotation axis (201) of the tool holder (150) by the at least one bearing element (231, 232).

4. 4. The handheld machine tool according to claim 1, wherein the spring receiving portion (243) is oriented at an angle (209) to the axis of rotation (201) of the tool holder (150).

5. 5. The handheld machine tool according to claim 1, wherein the spring receiving portion (243) is arranged in the receiving sleeve (299) substantially transversely to the receiving portion (242) of the locking element (245).

6. 6. A handheld machine tool according to claim 1, wherein the spring element (246) is at least partially arranged within an inner periphery (298) of the at least one bearing element (231, 232).

7. 7. The handheld machine tool according to claim 1, wherein the spring element (246) is arranged at least partially radially with respect to the rotation axis (201) of the tool holder (150) between the inner receiving portion (241) of the receiving sleeve (299) and the at least one bearing element (231, 232).

8. 8. A handheld machine tool according to claim 1, wherein a recess (262) is arranged on the outer periphery (247) of the receiving sleeve (299) for arranging a ring element (260) corresponding to the spring element (246).

9. The handheld machine tool of claim 8, wherein the ring element (260) presses the spring element (246) into the spring receiving portion (243).

10. 10. The handheld machine tool according to claim 1, wherein the locking unit (190) has an operating sleeve (250) for unlocking the tool insert (140) that can be placed in the tool holder (150), the operating sleeve (250) being provided for releasing the locking element (245) biased by the spring element (246).

11. 10. The handheld machine tool of claim 9, wherein the operating sleeve is movable along a direction away from the handheld machine tool to unlock a tool insert disposed in the tool holder.

12. 12. The handheld machine tool according to claim 2, wherein the locking element (245) is arranged at least partially within an inner periphery (298) of the at least one bearing element (231, 232) in at least one state (499).

13. 13. The handheld machine tool according to claim 2, wherein the locking element (245) is arranged in at least one position (499) radially relative to the rotation axis (201) of the tool holder (150) between the inner receiving portion (241) of the receiving sleeve (299) and the at least one bearing element (231, 232).

14. 14. The handheld machine tool according to claim 2, wherein the locking unit (190) is arranged at least partially radially with respect to the rotation axis (201) of the tool holder (150) between the inner receiving portion (241) of the receiving sleeve (299) and the at least one bearing element (231, 232).

15. 15. The handheld machine tool according to claim 2, wherein the spring receiving portion (243) is formed such that an inner circumferential portion of the at least one bearing element (232) facing the tool holder (150) and the spring element (246) arranged in the spring receiving portion (243) are in partial contact with each other.

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