Clamping connection device for electric machine tool and electric machine tool

Abstract

The utility model discloses a clamping connecting device for an electric machine tool, which is connected with an output shaft (1) of the electric machine tool, the output shaft (1) is provided with a waist-shaped groove (11) extending along the axial direction, the clamping connecting device (300) comprises a limiting piece (301), the limiting piece (301) is arranged in the waist-shaped groove, the limiting piece is used for being matched with a tool head (200) of the electric machine tool, and the limiting piece (301) is used for limiting the tool head (200) of the electric machine tool. The limiting piece can synchronously move in the kidney-shaped groove along with movement of the tool head (200) in the axial direction relative to the output shaft. The first elastic element (302) is arranged between the axial end face (12) of the output shaft (1) and the limiting piece (301) and applies elastic force to the limiting piece in the axial direction; when the limiting piece (301) moves to the terminal position along with the tool head in the axial direction in the direction towards the output shaft, the limiting piece (301) does not make contact with the axial end face of the output shaft.

Description

Technical Field

[0001] The utility model relates to a connection clamping device, in particular to a connection clamp for an electric tool machine. Background Art

[0002] Current electric machine tools often adopt the form of an electric machine tool body matched with a detachable and replaceable tool head.

[0003] For example, for a screwdriver or an electric wrench, a detachable and replaceable bit is connected to the output shaft of the screwdriver or the electric wrench.

[0004] For the currently common screwdrivers or electric wrenches, the types of bits used include double-ended bits with both ends in the axial direction being working ends and single-ended bits with one end in the axial direction being the working end. In terms of the specifications of the bits, there are long bits and short bits. Among them, the non-working end of the short bit close to the screwdriver or electric wrench is shorter than the non-working end of the long bit. This causes the limiting steel balls on the short bit to bear a larger load when the short bit is in the working state and bears the load, thereby being squeezed with the tool head of the screwdriver or electric wrench, such as the bit, for a long time, causing the limiting steel balls or the tool head to be deformed or damaged, and making it impossible to remove the bit from the screwdriver or electric wrench. Utility Model Content

[0005] One of the purposes of the utility model is to provide a clamping connection device for an electric machine tool, which can, on the basis of achieving the clamping effect on a detachable tool head, further ensure that the tool head will not transfer the load to a limiting element used to clamp the tool head when it is under load, thereby avoiding damage to the limiting element and / or the tool head and jamming of the tool head.

[0006] In order to achieve the above-mentioned object, the utility model proposes a clamping connection device for an electric tool machine, which is connected to the output shaft of the electric tool machine, wherein the output shaft is provided with a waist-shaped groove extending in the axial direction, and the clamping connection device comprises:

[0007] A limiting member is arranged in the waist-shaped groove, the limiting member is used to cooperate with the tool head of the electric tool machine, and the limiting member can move synchronously in the waist-shaped groove as the tool head moves in the axial direction relative to the output shaft;

[0008] a first elastic element, which is disposed between the axial step surface of the output shaft and the stopper and applies an elastic force along the axial direction to the stopper;

[0009] When the limiting member moves along with the tool head in the axial direction toward the output shaft to the terminal position, the limiting member does not contact the axial end surface of the output shaft.

[0010] Furthermore, in the clamping connection device described in the utility model, the first elastic element includes a first coil spring, and the first coil spring is sleeved on the output shaft.

[0011] Furthermore, in the clamping connection device described in the present utility model, the limiting member is constructed as a spherical member, and the lower part of the limiting member is adaptively arranged in an annular groove arranged on the outer circumferential wall outside the tool head.

[0012] Furthermore, the clamping connection device described in the utility model includes a sleeve, which is sleeved on the periphery of the output shaft, and the sleeve can move between a first position and a second position relative to the output shaft in an axial direction; wherein in the first position, the sleeve locks the limit member in a radial direction to prevent the limit member from escaping from the annular groove; wherein in the second position, the sleeve releases the limit member in a radial manner to allow the limit member to escaping from the annular groove.

[0013] Furthermore, in the clamping connection device described in the utility model, the inner wall of the sleeve has a protrusion extending radially inward; wherein in the first working position, the protrusion abuts against the top end of the limiting member.

[0014] Furthermore, the clamping connection device described in the utility model also includes a limiting ring, which is sleeved on the output shaft and abuts against the axial outer end surface of the sleeve in the first working position.

[0015] Furthermore, the clamping connection device described in the present invention also includes a second elastic element, which is arranged between the output shaft and the sleeve in the axial direction to apply an elastic force to the sleeve to reset it to the first position.

[0016] Furthermore, in the clamping connection device described in the present invention, the second elastic element includes a second coil spring.

[0017] Another object of the present invention is to provide an electric tool, wherein during use, a detachable tool head will not get stuck and cannot be removed.

[0018] Based on the above purpose, the utility model further provides an electric machine tool, which includes the clamping connection device as described above, and the clamping connection device is connected between the output shaft and the tool head of the electric machine tool.

[0019] Furthermore, in the electric tool machine described in the utility model, the tool head includes a long bit, whose tail end abuts against the axial inner end face of the output shaft under load working state; or the tool head includes a short bit, whose tail end abuts against the axial inner end face of the coupling under load working state.

[0020] The clamping and connecting device for an electric machine tool described in the utility model, on the basis of ensuring the clamping of a detachable tool head, further realizes that when the tool head is in a loaded working state, the load will not be transferred to a limiting element used to clamp the tool head. That is, whether in a loaded working state or in a free state, the limiting element will not bear the working load, thereby effectively avoiding damage to the limiting element and further avoiding the situation where the tool head is stuck and cannot be removed from the electric machine tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 An electric machine tool is shown schematically.

[0022] Figure 2 A schematic structural diagram of a clamping connection device according to the utility model in one embodiment is shown.

[0023] Figure 3 The waist-shaped groove on the output shaft of the clamping connection device described in the utility model in one embodiment is shown.

[0024] Figure 4 The figure shows the state of a short screwdriver bit clamped by the clamping connection device described in the utility model in a free state in one embodiment.

[0025] Figure 5 The figure shows the state of a short screwdriver bit clamped by the clamping connection device described in the utility model under a load working state in one embodiment.

[0026] Figure 6 Partially shows an electric machine tool equipped with the clamping connection device of the utility model.

[0027] Figure 7 The figure shows the state of a long screwdriver bit clamped by the clamping connection device described in the utility model under a load working state in one embodiment. DETAILED DESCRIPTION

[0028] The clamping connection device for an electric tool machine described in the present invention will be further explained and illustrated below in conjunction with the drawings and specific embodiments of the specification. However, such explanation and illustration do not constitute an improper limitation on the technical solution of the present invention.

[0029] Figure 1 An electric machine tool is shown schematically.

[0030] like Figure 1As shown, the current electric tool 100, such as a screwdriver or an electric wrench, often uses a clamping connection device 300 to achieve the connection between the output shaft and the tool head 200, such as a bit. When the tool head 200 needs to be replaced, the tool head 200 can be removed from the electric tool.

[0031] The problem existing in the prior art is that when a screwdriver bit, especially a short screwdriver bit, is subjected to load in a working state, the steel balls for clamping and limiting the short screwdriver bit will be squeezed against the screwdriver bit due to the limitation of the output shaft accommodation space and will be subjected to a large load for a long time. As a result, after the electric tool has been used for a period of time, the limiting steel balls and / or the tool head will be damaged or deformed, making it impossible to remove the screwdriver bit from the electric tool.

[0032] In view of the above technical problems, the utility model provides a clamping connection device in one embodiment.

[0033] Figure 2 A schematic structural diagram of a clamping connection device according to the utility model in one embodiment is shown.

[0034] like Figure 2 As shown, the clamping connection device is connected to the output shaft 1 of the electric tool, as shown in FIG. Figure 3 As shown, the output shaft 1 is provided with a waist-shaped groove 11 extending in the axial direction.

[0035] Continue reading Figure 2 The clamping connection device includes: a limit member 301 matching the tool head of the electric tool machine, which is arranged in the waist-shaped groove 11. When the tool head (not shown in the figure) moves in the axial direction relative to the output shaft 1, the limit member 301 can move synchronously in the waist-shaped groove 11 as the tool head moves in the axial direction relative to the output shaft.

[0036] In some more preferred embodiments, the stopper 301 is constructed as a spherical member, such as a steel ball. Compared with stoppers of other shapes or structures, when the tool head needs to be removed from the electric tool machine, the spherical member is easier to escape from the groove of the tool head adapted thereto, thereby making the removal of the tool head more convenient and labor-saving. Of course, in some other optional embodiments, the stopper may also be an element with a partial curved surface.

[0037] Continue reading Figure 2 The clamping connection device also includes a first elastic element 302, which is arranged between the axial end face 12 of the output shaft and the limiting member 301, and applies an elastic force along the axial direction to the limiting member 301.

[0038] In some embodiments, the first elastic element 302 may be Figure 2The first coil spring shown is sleeved on the output shaft 1 .

[0039] Of course, in some other embodiments, the first elastic element 302 may also be a leaf spring, a tension spring, or other elastic elements such as these, which are arranged between the axial end surface 12 of the output shaft and the limiting member 301 .

[0040] Continue reading Figure 2 In some embodiments, the clamping connection device further includes a sleeve 303, which is sleeved on the periphery of the output shaft 1, and the sleeve 303 can move between a first position and a second position relative to the output shaft 1 along the axial direction. In the first position, the sleeve 303 locks the limiter 301 in the radial direction; in the second position, the sleeve 303 releases the limiter 301 in a radial manner.

[0041] Figure 4 The figure shows the state of a short screwdriver bit clamped by the clamping connection device described in the utility model in a free state in one embodiment.

[0042] like Figure 4 As shown, in the normal state where the clamping connection device clamps the tool head, such as the short screw bit 201, the sleeve 303 is located in the first working position. At this time, the sleeve 303 locks the limit member 301 in the radial direction, so that the limit member 301 cannot escape from the annular groove 203 of the output shaft 1, thereby achieving a stable connection between the short screw bit 201 and the output shaft 1.

[0043] In some more specific embodiments, the sleeve 303 abuts against the top of the limiting member 301 through a protrusion 3031 extending radially inward on the inner wall of the sleeve 303, so as to lock the limiting member 301 in the radial direction at the first working position.

[0044] according to Figure 4 In the direction shown, when external force is applied to cause the sleeve 303 to move to the right along the axial direction relative to the output shaft 1, the protrusion 3031 originally resting on the top of the limit member 301 will leave the limit member, that is, the sleeve 303 switches from the first position to the second position, thereby releasing the limit member 301 in a radial manner, so that the limit member 301 can be disengaged from the annular groove 203 of the output shaft 1. In this way, the tool head, such as the short bit 201, can be removed from the electric tool.

[0045] In some preferred embodiments, a second elastic element 304 may be provided between the output shaft 1, for example, an axial step surface 13 of the output shaft and the sleeve 303, and the second elastic element 304 applies an elastic force in the axial direction to the sleeve 303 to reset it to the first position. In this way, when the external force applied to the sleeve is removed, the sleeve 303 is reset to the first position under the elastic force of the second elastic element 304. When the tool head needs to be installed on the electric tool machine, an external force in the axial direction is first applied to the sleeve to make it leave the first position, and then the tool head to be installed is inserted into the center hole of the output shaft, and then the external force is removed, so that the sleeve is reset to the first position, and the tool head is clamped again.

[0046] In some more specific embodiments, the second elastic element 304 may include a second coil spring.

[0047] Of course, in some other embodiments, the second elastic element 304 may also be a leaf spring, a tension spring, or other elastic elements of the same type disposed between the axial step surface of the output shaft and the sleeve.

[0048] Continue reading Figure 4 , which shows the free state of the short screwdriver bit 201 when it is not in working state. It can be seen that in this free state, the left end 2011 (non-working end) of the short screwdriver bit 201 is still a distance away from the axial inner end face 14 of the output shaft 1, and the stopper 301 is located at a relatively right position in the waist-shaped groove 11, and it is of course not in contact with the axial end face 12 of the output shaft 1. Therefore, in this free state, the stopper 301 is not subjected to force. At the same time, the first elastic element 302 is also in a free state, and it does not apply elastic force to the stopper 301.

[0049] Figure 5 The figure shows the state of a short screwdriver bit clamped by the clamping connection device described in the utility model under a load working state in one embodiment.

[0050] like Figure 5 As shown, when the electric tool is working, the tool head, such as the short bit 201, will bear the working load, so it will move in the axial direction toward the output shaft (such as Figure 5 The tool head 201 moves in the axial direction toward the output shaft 1 (in the left direction) until the left end 2011 (non-working end) of the short screwdriver bit 201 abuts against the axial inner end face 14 of the output shaft 1. In this process, based on the setting of the waist-shaped groove 11, the limiter 301 moves along with the tool head in the axial direction toward the output shaft 1 until the terminal position. At this time, the first elastic element 302 applies an axial rightward elastic force to the limiter 301, so that the limiter 301 does not contact the axial end face 12 of the output shaft 1 at the terminal position, thereby preventing the limiter from bearing load.

[0051] It should be noted that, in the present invention, the “terminal position” refers to the extreme position to which the limiting member moves along with the tool head when the tool head is carrying a workload.

[0052] It can be seen that when the clamping connection device described in the utility model is used to clamp a short screw bit, the limit member will not contact the axial end face of the output shaft whether in a free state or in a working load state, so it will not bear the load and will not be damaged, thereby preventing the tool head from getting stuck and unable to be disassembled.

[0053] In some embodiments, Figure 4 and Figure 5 As shown, the clamping connection device may further include a limiting ring 305 which is sleeved on the output shaft 1 and abuts against the axial outer end surface of the sleeve 303 when the sleeve 303 is located at the first position, thereby limiting the axial position of the sleeve 303 .

[0054] Another embodiment of the present invention further provides an electric machine tool having the clamping connection device as described above.

[0055] like Figure 6 As shown, the clamping connection device 300 is mounted on the power tool 100 (partially shown) and connected between the output shaft and the tool head (not shown in the figure).

[0056] As described above, the clamping connection device is suitable for the short screwdriver bit 201. When the short screwdriver bit 201 is under load working condition, the tail end or non-working end 2011 (i.e. Figure 4 and Figure 5 The left end of the short screwdriver bit 201 abuts against the axial inner end face 14 of the output shaft, that is, the working load borne by the short screwdriver bit 201 is borne by the axial inner end face 14, and the limiting member 301 does not bear any working load and thus will not be damaged.

[0057] Likewise, if Figure 7 As shown, the clamping connection device is also applicable to the long screwdriver bit 202. The clamping and releasing process of the clamping connection device for the long screwdriver bit 202 is the same as that for the short screwdriver bit, so it will not be repeated here.

[0058] like Figure 7 As shown, when the electric tool is working, the long screwdriver bit 202 will bear the working load, so it will move in the axial direction toward the output shaft (such as Figure 7The tool head 202 moves in the axial direction toward the output shaft 1 until the left end 2021 (non-working end, or tail end) of the long screwdriver bit 202 abuts against the axial inner end face 14 of the output shaft 1. In this process, based on the setting of the waist-shaped groove 11, the limiter 301 will also move along with the tool head in the axial direction toward the output shaft 1 until the terminal position. At this time, the first elastic element 302 will also apply an axial rightward elastic force to the limiter 301. The limiter 301 does not contact the axial end face 12 of the output shaft 1 at the terminal position, and thus does not bear any load.

[0059] It should also be noted that, in the present invention, a short screwdriver bit means that its non-working end is relatively short, so that when the first elastic element is not provided, under the working load, the limiter will first contact with the axial step surface of the output shaft and bear the load. A long screwdriver bit means that its non-working end is relatively long, so that under the working load, the non-working end of the long screwdriver bit (i.e., the left end or the tail end in the figure) will first contact with the axial end face of the output shaft and bear the load.

[0060] In some more specific embodiments, the electric tool may be an electric screwdriver or an electric wrench, or other electric tools equipped with a tool head.

[0061] It should be noted that the terms “upper”, “lower”, “left” and “right” described in this article are for ease of understanding and are based on Figures 1 to 7 This is an exemplary description of the arrangement mode and direction of the clamping connection device, which is not intended to limit the present invention.

[0062] It should be noted that the prior art part in the protection scope of the utility model is not limited to the embodiments given in the application documents. All prior art that does not contradict the scheme of the utility model, including but not limited to prior patent documents, prior public publications, prior public uses, etc., can be included in the protection scope of the utility model.

[0063] In addition, the combination of the various technical features in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments. All technical features recorded in this case can be freely combined or combined in any way unless there is a contradiction between them.

[0064] It should also be noted that the above-listed embodiments are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made therewith are directly derived or easily associated with the contents disclosed by those skilled in the art from the present invention, and should all fall within the protection scope of the present invention.

Claims

1. A clamping connection device for an electric machine tool, connected to an output shaft (1) of the electric machine tool, characterized in that: The output shaft (1) is provided with a waist-shaped groove (11) extending in the axial direction, and the clamping connection device (300) comprises: A limiting member (301) is arranged in the waist-shaped groove (11), the limiting member is used to cooperate with a tool head (200) of the electric tool machine, and the limiting member (301) can move synchronously in the waist-shaped groove (11) as the tool head (200) moves in the axial direction relative to the output shaft (1); A first elastic element (302), which is disposed between the axial end surface (12) of the output shaft (1) and the limiting member (301), and applies an elastic force along the axial direction to the limiting member (301); When the limiting member (301) moves along with the tool head (200) in the axial direction toward the output shaft to a terminal position, the limiting member (301) does not contact the axial end surface of the output shaft.

2. The clamping connection device according to claim 1, characterized in that: The first elastic element (302) comprises a first coil spring, and the first coil spring is sleeved on the output shaft (1).

3. The clamping connection device according to claim 1, characterized in that: The limiting member (301) is constructed as a spherical member, and the lower portion of the limiting member is adaptively arranged in an annular groove (203) arranged on the outer circumferential wall outside the tool head.

4. The clamping connection device according to claim 3, characterized in that: Also includes: A sleeve (303) is sleeved on the periphery of the output shaft (1), and the sleeve (303) is movable between a first position and a second position relative to the output shaft in an axial direction; wherein at the first position, the sleeve (303) locks the limit member (301) in a radial direction to prevent the limit member (301) from escaping from the annular groove (203); wherein at the second position, the sleeve (303) releases the limit member (301) in a radial manner to allow the limit member (301) to escaping from the annular groove (203).

5. The clamping connection device according to claim 4, characterized in that: The inner wall of the sleeve (303) has a protrusion (3031) extending radially inward; wherein in the first working position, the protrusion (3031) abuts against the top end of the limiting member (301).

6. The clamping connection device according to claim 4, characterized in that: Also includes: A limiting ring (305) is sleeved on the output shaft (1) and abuts against the axial outer end surface of the sleeve (303) in the first working position.

7. The clamping connection device according to claim 4, characterized in that: Also includes: A second elastic element (304) is arranged between the output shaft (1) and the sleeve (303) in the axial direction to apply an elastic force to the sleeve to reset it to the first position.

8. The clamping connection device according to claim 7, characterized in that: The second elastic element (304) includes a second coil spring.

9. An electric machine tool (100), characterized in that: It comprises a clamping connection device (300) as claimed in any one of claims 1 to 8, wherein the clamping connection device (300) is connected between an output shaft (1) of an electric machine tool and a tool head (200).

10. The electric machine tool according to claim 9, characterized in that: The tool head comprises a short bit (201), whose tail end abuts against the axial inner end surface (14) of the coupling under load working condition; or the tool head comprises a long bit (202), whose tail end abuts against the axial inner end surface (14) of the output shaft under load working condition.

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