CN214818328U - Electric tool - Google Patents

Abstract

The utility model provides an electric tool, which comprises a shell, a driving piece, a tool holding piece and a fastener, wherein the driving piece is arranged in the shell; the electric tool also comprises a screwing device, the screwing device comprises a limiting piece, a screwing piece and a fastening matching piece, the limiting piece is fixedly connected to the shell, and the fastening matching piece is installed on the screwing piece and sleeved with the tool retaining piece; the rotating part is sleeved with the limiting part, one of the rotating part and the limiting part is provided with a first groove, and the other one of the rotating part and the limiting part is provided with a first bulge which can be correspondingly clamped in the first groove; the screwing piece is provided with a first position which is connected with the limiting piece in a rotation stopping mode, and a second position which is connected with the fastening piece in a rotation stopping mode through the fastening matching piece. The utility model provides an electric tool revolves wrong device through setting up on the casing, efficiency when having improved the electric tool operation.

Description

Electric tool

Technical Field

The utility model relates to a hand tool technical field especially relates to an electric tool.

Background

The electric tool is a necessary tool for people to carry out screwing operation in daily life in the society at present. The existing electric tools generally include a plurality of working heads mounted on a driving shaft, the working heads can be detachably connected to the driving shaft through fasteners, and the working heads are commonly referred to as a drill, a cutting blade, a polishing rod, etc., wherein each working head has different specifications and sizes to correspond to different processing requirements, so that the working heads are generally required to be detached for replacement in a using process. The existing electric tool is mainly disassembled through tools such as a wrench, and the structural design not only causes encumbrance in carrying but also causes the complexity of procedures in disassembly, thereby causing the low working efficiency

SUMMERY OF THE UTILITY MODEL

The utility model provides a modified electric tool, this electric tool have relatively higher integrating, and it is all very convenient when carrying and dismantling, can improve work efficiency.

The utility model provides an electric tool, which comprises a shell, a driving piece, a tool holding piece and a fastener, wherein the driving piece is arranged in the shell, the first end of the tool holding piece is fixedly connected with a driving shaft of the driving piece, the second end of the tool holding piece is configured into a clamping part which can radially expand and contract, and the clamping part is sleeved with the fastener;

the electric tool further comprises a screwing device, the screwing device comprises a limiting piece, a screwing piece and a fastening matching piece, the limiting piece is fixedly connected to the shell, and the fastening matching piece is mounted on the screwing piece and sleeved with the tool holding piece; the screwing piece is sleeved with the limiting piece, one of the inner side surface of the screwing piece and the outer side surface of the limiting piece is provided with a first groove, and the other one of the inner side surface of the screwing piece and the outer side surface of the limiting piece is provided with a first bulge which can be correspondingly clamped in the first groove; the first groove and the first protrusion both extend in the axial direction of the tool holder;

the screwing piece is provided with a first position which is connected with the limiting piece in a rotation stopping mode, and a second position which is connected with the fastening piece in a rotation stopping mode through the fastening matching piece.

Furthermore, the outer side surface of the limiting piece is also provided with a limiting structure; when the screwing piece is at the first position, the limiting piece limits the screwing piece through the limiting structure.

Furthermore, the limiting structure is a first check ring which is convexly arranged on the outer side surface of the limiting part, and a second check ring is convexly arranged on the inner side surface of the screwing piece;

the limiting part limits the screwing part at the first position through the abutting of the first check ring to the second check ring.

Furthermore, one end of the limiting part, which is relatively close to the fastening part, is further provided with a plurality of first through holes penetrating through the end face, and the plurality of first through holes are arranged at intervals along the axial direction of the limiting part.

Furthermore, the first groove is formed in the outer side surface of the limiting member, and the first protrusion is arranged on the inner side surface of the screwing member; the screwing piece is connected to the limiting piece in a rotation stopping mode through the embedding of the first protrusion into the first groove.

Furthermore, a plurality of second protrusions which are arranged at intervals are convexly arranged on the outer side surface of the limiting piece, and a first groove is formed between every two adjacent second protrusions; the first protrusion and the second protrusion have the same height.

Furthermore, the screwing piece is respectively provided with second through holes at two sides of the first protrusion, and the part provided with the first protrusion is configured to be an elastic part.

Furthermore, the limiting structure is a third protrusion formed at one end of the first protrusion, which is relatively far away from the limiting part, in a protruding manner, and a step is formed between the bottom wall of the first groove and the outer side surface of the limiting part;

when the screwing piece is at the first position, the third bulge of the screwing piece is abutted against the step of the limiting piece.

Furthermore, a fourth protrusion is further convexly arranged at one end of the limiting member, which is relatively close to the fastening member, the fourth protrusion is arranged opposite to the first protrusion in the screwing member, and the fourth protrusion is used for abutting against the screwing member when the limiting member is located at the second position.

Furthermore, the electric tool also comprises a switch, a deflector rod, a locking block and an elastic piece; the switch is arranged on the outer side surface of the shell and connected to the shifting lever; one end of the shifting lever is in inclined plane fit with the locking block, and the other end of the shifting lever is connected with the driving piece and used for controlling the opening and closing of the driving piece; one end of the elastic piece acts on the inner side surface of the shell, and the other end of the elastic piece acts on the locking block; the locking block can lock a driving shaft of the driving piece;

when the switch is closed, the driving shaft of the driving piece is locked by the locking block under the control of the deflector rod, and when the switch is opened, the driving shaft is unlocked by the locking block under the control of the deflector rod.

The utility model provides an electric tool revolves wrong device through setting up on the casing, can twist through the condition of no external tool and revolve the change that revolves owner and independent carrying out the working head, has saved the requirement that needs carry appurtenance, and is also very convenient when dismantling, has improved the efficiency when electric tool operates.

Drawings

Fig. 1 is a schematic structural view of an electric tool according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the power tool of FIG. 1;

FIG. 3 is a disassembled schematic view of the power tool of FIG. 1;

FIG. 4 is a disassembled view of the turning device of the power tool shown in FIG. 1 from a first perspective;

FIG. 5 is a disassembled view of the screwing device shown in FIG. 4 from a second perspective;

FIG. 6 is a disassembled view of the screwing device shown in FIG. 4 from a third perspective;

FIG. 7 is an enlarged schematic view of the power tool of FIG. 2 at A;

fig. 8 is a schematic structural view of a screwing device according to a second embodiment of the present invention;

FIG. 9 is a cross-sectional view of the screwing device of FIG. 8;

FIG. 10 is a schematic view of a position-limiting member of the screwing device of FIG. 8;

FIG. 11 is a schematic view of the screw of the screwing device of FIG. 8;

fig. 12 is an enlarged schematic view of the power tool of fig. 2 at B.

Description of reference numerals:

100. an electric tool; 11. a housing; 12. a battery; 13. a drive member; 131. a drive shaft; 14. a tool holder; 141. a first end; 142. a second end; 15. a fastener; 16. a working head; 17. a switch; 20. a screwing device; 21. a limiting member; 211. a first groove; 212. a second protrusion; 213. a first retainer ring; 214. a first through hole; 215. a step; 216. a fourth protrusion; 22. a screwing member; 221. a first protrusion; 222. a second retainer ring; 223. a second through hole; 224. a third protrusion; 23. fastening a fitting piece; 231. a clamping hole; 31. a deflector rod; 32. a locking block; 33. an elastic member.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

It will be understood that when an element is referred to as being "mounted on" another element, it can be directly mounted on the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 3, fig. 1 is a schematic structural diagram of an electric tool 100 according to an embodiment of the present invention, fig. 2 is a schematic sectional structural diagram of the electric tool 100 shown in fig. 1, and fig. 3 is an exploded schematic view of the electric tool 100 shown in fig. 1.

The power tool 100 is used to perform a work such as screwing or grinding of an object. In the present embodiment, the electric tool 100 is used to screw a screw, that is, the target object is a screw, and the electric tool 100 is used as an electric screwdriver. It is understood that in other embodiments, the power tool 100 may be used as a power drill or other tool other than a power screwdriver.

Specifically, the electric power tool 100 includes a housing 11, a battery 12, a driving member 13, a tool holder 14, a fastening member 15, and a working head 16, wherein the battery 12 and the driving member 13 are mounted inside the housing 11, the battery 12 is electrically connected to the driving member 13, the tool holder 14 is mounted between the driving member 13 and the working head 16, and the fastening member 15 is sleeved on the tool holder 14.

The shell 11 is used for supporting a battery 12, a driving piece 13, a tool holder 14, a fastening piece 15 and a working head 16, the battery 12 is used for driving the driving piece 13 to rotate, the driving piece 13 is used for driving the working head 16 to rotate, and the tool holder 14 is used for clamping the working head 16; the fastener 15 is used for locking the working head 16 on the tool holder 14 or for unlocking the tool holder 14 from the working head 16; the working head 16 is used for achieving screwing operation on an object.

The driving part 13 outputs driving force in the form of rotation under the energy supply of the battery 12, the driving part 13 is fixedly connected with the tool holder 14, the tool holder 14 and the working head 16 can also be fixedly connected under the locking action of the fastener 15, so that the driving part 13 can drive the working head 16 to rotate through the tool holder 14, and the working head 16 is driven to perform operations such as drilling or screwing.

The end of the housing 11 is hollow for the tool holder 14 to protrude from the interior of the housing 11. In the present embodiment, the housing 11 has a substantially long shank shape. It is understood that in other embodiments, the housing 11 may be in a shape of a gun or the like for holding by a user.

In the present embodiment, the battery 12 is located at one end of the housing 11 relatively far from the working head 16, and the battery 12 may be a detachable non-rechargeable battery or a rechargeable battery; the driving member 13 is a motor, and the driving shaft 131 of the driving member 13 is a motor shaft of the motor. It is understood that in other embodiments, the position of the battery 12 inside the housing 11 can be adjusted according to different structural designs, and the driving member 13 can also be a power element such as a pneumatic cylinder or a hydraulic cylinder.

The tool holder 14 is substantially in the shape of a long rod, and the tool holder 14 has two ends, namely a first end 141 and a second end 142, which are opposite to each other and connected to each other. The first end 141 of the tool holder 14 is fixedly attached to the drive shaft 131 of the driver 13 and the second end 142 of the tool holder 14 is fixedly attached to the working head 16.

To achieve a stable grip of the working head 16, the second end 142 of the tool holder 14 is configured as a radially collapsible grip, the second end 142 of the tool holder 14 sheathing the working head 16.

In this embodiment, the radial expansion and contraction function of the clamping portion in the tool holder 14 is achieved by forming a plurality of through holes extending in the axial direction of the tool holder 14 on the second end 142, each through hole penetrating through the end surface of the second end 142, and the formation of the plurality of through holes enables the second end 142 to form an elastic petal-shaped structure, so that the second end 142 has the radial expansion and contraction function; the tool holder 14 further adjusts and limits the radial expansion and contraction degree of the tool holder through the fastener 15, so that the radial expansion and contraction of the tool holder is limited when the clamping part clamps the working head 16, and the fixed connection between the tool holder and the working head 16 is realized.

It is understood that in other embodiments, the radial expansion and contraction function of the clamping portion can be realized by other structures besides the above, and the present invention is not limited to the connection structure between the second end 142 of the tool holder 14 and the working head 16, as long as the second end 142 of the tool holder 14 can realize the adjustment of the radial expansion and contraction degree under the screwing action of the fastening member 15.

The fastener 15 is sleeved on the second end 142 (i.e., the clamping portion) of the tool holder 14, and the fastener 15 rotates around the tool holder 14 in the axial direction to adjust the radial expansion and contraction degree (i.e., the clamping force) of the clamping portion. Generally, a threaded connection is formed between the fastener 15 and the second end 142 of the tool holder 14 such that the process of rotating the fastener 15 may be translated into a radial compression process on the second end 142. Of course, the fastener 15 may take other forms to achieve fastening and adjustment of the clamp.

In the present embodiment, the working head 16 is a screwdriver bit. It is understood that in other embodiments. The working head 16 may also employ a drill, cutting blades, and a sanding bar, among others.

In order to control the on/off of the power supplied to the battery 12, the housing 11 is provided with a switch 17 electrically connected to the battery 12. In the present embodiment, the switch 17 is provided on the outer surface (outer peripheral surface) of the housing 11. It will be appreciated that the switch 17 may be located elsewhere on the housing 11; if the power tool 100 is directly driven by the commercial power, the battery 12 may be omitted; if the electric power tool 100 is a plug-and-play electric power tool, the switch 17 may be further omitted; if the electric power tool 100 is a hand tool, the driver 13 is rotated and supplied by a manual force.

Since the power tool 100 needs to be adapted to different working heads 16, each working head 16 often comprises different specifications and sizes to meet different machining requirements, the power tool 100 usually needs to be frequently disassembled to replace the working head 16 during use. However, the existing electric tool still needs an auxiliary tool such as a wrench to be adjusted, which is very cumbersome when being carried, cumbersome when being disassembled, and extremely low in working efficiency.

The utility model provides an electric tool 100 revolves wrong device 20 through setting up on casing 11, can be through the condition of no external instrument user revolve twist owner and independent change that carries out working head 16, has saved the requirement that needs carry appurtenance, and is also very convenient when dismantling, has improved the efficiency when electric tool 100 operates.

Referring to fig. 4 to 6, fig. 4 is a disassembled view of the screwing device 20 of the electric tool 100 shown in fig. 1 from a first viewing angle, fig. 5 is a disassembled view of the screwing device 20 shown in fig. 4 from a second viewing angle, and fig. 6 is a disassembled view of the screwing device 20 shown in fig. 4 from a third viewing angle.

The screwing device 20 comprises a limiting member 21, a screwing member 22 and a fastening fitting 23, wherein the limiting member 21 is fixedly installed at one end of the housing 11 and is used for limiting the rotation of the screwing member 22 or allowing the screwing member 22 to rotate; the fastening fitting 23 is arranged at the screw element 22, and the fastening fitting 23 can be clamped with the fastening element 15 and can drive the fastening element 15 to rotate along with the rotation of the screw element 22; the screwing piece 22 is sleeved on the limiting piece 21, and the screwing piece 22 is used for driving the fastening matching piece 23 to rotate.

The stopper 21 is substantially hollow cylindrical, and the stopper 21 is fitted to the housing 11. In this embodiment, the limiting member 21 is in threaded connection with the housing 11, an external thread is formed at one end of the housing 11, an internal thread is formed on an inner side surface of the limiting member 21, and the limiting member 21 and the housing 11 are fixed to each other through the threaded connection between the external thread and the internal thread.

The fastening fitting piece 23 is substantially sheet-shaped, the inside of the fastening fitting piece 23 is hollow and forms a clamping hole 231; the shape of the clamping hole 231 is matched with that of the fastener 15, and the fastening matching piece 23 can be sleeved with the fastener 15 through the clamping hole 231 to realize rotation stopping connection between the clamping hole 231 and the fastener 15.

In the present embodiment, the cross section of the fastener 15 is substantially in the shape of a rounded rectangle; in order to adapt to the cross-sectional shape of the fastener 15, the clamping hole 231 of the fastening fitting piece 23 is also approximately in a round rectangle shape, i.e. the clamping hole 231 is a kidney-shaped hole. It can be understood that when the shape of the fastening member 15 is changed, the shape of the snap hole 231 of the fastening fitting member 23 is also adapted, as long as the irregular fit between the fastening member 15 and the fastening fitting member 23 can be formed; of course, the rotation stopping connection between the fastener 15 and the fastening fitting 23 may be formed by a lateral buckle or the like, and the present invention is not limited to a specific implementation manner.

It should be additionally noted that the term "rotation-stop connection" as used herein means that there is no mutual rotation between the two objects (but other forms of mutual movement, such as axial sliding, are allowed).

The screw 22 is a hollow cylinder, the end of the screw 22 opposite to the housing 11 is provided with the fastening fitting 23, and the end of the screw 22 opposite to the housing 11 is sleeved with the limiting member 21.

In the present embodiment, the screwing element 22 is provided with a plurality of protrusions (not numbered), the fastening fitting 23 is provided with a plurality of grooves (not numbered) corresponding to the protrusions, the protrusions and the grooves are respectively formed on the screwing element 22 or the fastening fitting 23 by an integral injection molding method, and the screwing element 22 realizes the limit of the fastening fitting 23 by the embedding of the protrusions in the corresponding grooves.

It will be appreciated that the projections and recesses described above may be manufactured by way of secondary operations.

One of the inner side surface of the screw 22 and the outer side surface of the limiting member 21 is provided with a first groove 211, and the other one is provided with a first protrusion 221; the first projection 221 and the first recess 211 both extend in the axial direction of the housing 11 (i.e., the axial direction of the tool holder 14); the first protrusion 221 can be clamped into the first groove 211, so that rotation stopping connection between the screw 22 and the limiting member 21 is realized; if the first protrusion 221 is not clamped in the first groove 211, the screw 22 can rotate relative to the limiting member 21.

At this time, the screw 22 has two positions relative to the limiting member 21, namely a first position where the screw 22 is connected to the limiting member 21 in a rotation-stopping manner, and a second position where the screw is connected to the fastening member 15 in a rotation-stopping manner through the fastening fitting member 23.

It should be additionally noted that the outer side surface of the limiting member 21 is not limited to the circumferential side surface around it, but may be a bottom surface. The first position of the screw 22 is relatively close to the housing 11, and the second position of the screw 22 is relatively far away from the housing 11; the screw 22 is relatively far away from the housing 11 in the axial direction of the tool holder 14, so that the first protrusion 221 can be disengaged from the first groove 211 to release the rotation-stopping connection between the screw 22 and the limiting member 21; at this time, the screwing member 22 is angularly adjusted to smoothly clamp the fastening member 15 through the clamping hole 231 of the fastening fitting member 23, thereby realizing the switching process from the first position to the second position. The switching process from the second position to the first position is the reverse of the above process, and is not described herein again.

Furthermore, the outer side surface of the limiting member 21 is provided with a limiting structure (not numbered); when the screwing piece 22 is at the first position, the limiting piece 21 limits the screwing piece 22 through the limiting structure, so that the screwing piece 22 is prevented from being separated from the limiting piece 21 at the first position, the clamping connection of the first protrusion 221 to the first groove 211 is ensured, and the connection stability of the rotation stopping connection of the first protrusion and the first groove is ensured.

As for the realization form of the limiting structure itself, any limiting fit in the mechanical connection structure may be selected, for example, an embedding fit between the protrusion and the groove, or a clamping fit between the protrusion and the protrusion. The projections and recesses may be arranged in any manner, as far as the limitation of the screw element 22 in the first position is achieved.

Referring to fig. 7, fig. 7 is an enlarged schematic view (in broken lines) of the electric tool 100 shown in fig. 2 at a.

In the first embodiment of the present invention, the limiting structure is a first retaining ring 213 protruding from the outer side surface of the limiting member 21, and the first retaining ring 213 is annularly disposed on the outer side surface of the limiting member 21; meanwhile, a second stop ring 222 is convexly arranged on the inner side surface of the screwing piece 22; the limiting member 21 limits the screwing member 22 at the first position by the abutting of the first retaining ring 213 against the second retaining ring 222.

That is, in the first embodiment of the present invention, the spacing implementation depends on the support between the protrusions.

Furthermore, one end of the limiting member 21 relatively close to the fastening member 15 is further provided with a plurality of first through holes 214 penetrating through the end surface, and the plurality of first through holes 214 are all arranged at intervals along the axial direction of the limiting member 21.

At this time, the limiting member 21 can form a radial expansion and contraction structure by opening the plurality of first through holes 214, so that when the screwing member 22 is switched between the first position and the second position, the second retaining ring 222 can smoothly slide over the surface of the first retaining ring 213, so that the blocking effect of the first retaining ring 213 is changed from rigid blocking to flexible blocking, and the position switching process of the screwing member 22 is not hindered.

In one embodiment of the present invention, the first groove 211 is opened on the outer side surface of the limiting member 21, and the first protrusion 221 is disposed on the inner side surface of the screwing member 22; the screw 22 is connected to the limiting member 21 in a rotation-stopping manner by the first protrusion 221 being inserted into the first groove 211.

It is understood that, in other embodiments, the first groove 211 may be opened on the screw 22, and the first protrusion 221 may be disposed on the limiting member 21.

Further, regarding the specific form of the first groove 211, the embodiment realizes the first groove 211 through a gap between two protrusions, that is, the outer side surface of the limiting member 21 is further provided with a plurality of second protrusions 212 protruding from the outer side surface, and the first groove 211 is formed between two adjacent second protrusions 212; meanwhile, the first protrusion 221 and the second protrusion 212 have the same height, so that the screw 22 can be inserted into the limiting member 21 in the first position, thereby improving the connection stability.

Referring to fig. 8 to 11, fig. 8 is a schematic structural diagram of a screwing device 20 according to a second embodiment of the present invention, fig. 9 is a schematic cross-sectional diagram of the screwing device 20 shown in fig. 8, fig. 10 is a schematic structural diagram of a limiting member 21 in the screwing device 20 shown in fig. 8, and fig. 11 is a schematic structural diagram of a screwing element 22 in the screwing device 20 shown in fig. 8.

The screw 22 has second through holes 223 formed on both sides of the first protrusion 221, and the portion where the first protrusion 221 is formed is configured as an elastic portion, so that the first protrusion 221 is disposed on the elastic portion capable of elastically expanding and contracting. At this time, the screw 22 will be engaged with the limiting member 21 by the elastic portion, and the elastic member has a pre-clamping function, so as to improve the stability of clamping.

Further, in the second embodiment of the present invention, the limiting structure is a third protrusion 224 formed in the first protrusion 221 in a protruding manner at an end relatively far away from the limiting member 21, and a step 215 is formed between the bottom wall of the first groove 211 and the outer side surface of the limiting member 21; when the screw 22 is in the first position, the third protrusion 224 of the screw 22 abuts against the step 215 of the limiting member 21.

Referring to fig. 7 and 9, in the first and second embodiments of the present invention, a fourth protrusion 216 is further protruded from one end of the limiting member 21 relatively close to the fastening member 15, the fourth protrusion 216 is disposed opposite to the first protrusion 221 of the screwing member 22, and the fourth protrusion 216 is used for supporting the screwing member 22 when the screwing member 22 is in the second position.

Referring to fig. 12, fig. 12 is an enlarged schematic view of the electric tool 100 shown in fig. 2 at B; the electric tool also comprises a deflector rod 31, a locking block 32 and an elastic piece 33; the switch 17 is arranged on the outer side surface of the shell 11 and connected with the driving lever 31; one end of the shifting rod 31 forms an inclined plane fit with the locking block 32, and the other end of the shifting rod 31 is connected with and used for controlling the opening and closing of the driving piece 13; one end of the elastic member 33 acts on the inner side surface of the housing 11, and the other end acts on the lock block 32; the lock block 32 can lock the drive shaft 131 of the driver 13;

when the switch 17 is closed, the driving shaft 131 of the driving piece 13 is locked by the locking block 32 through the shifting rod 31, and when the switch 17 is opened, the driving shaft 131 is unlocked by the locking block 32 through the shifting rod 31.

In this case, the electric power tool 100 can mechanically lock the drive shaft 131 when it is stopped, and can contact the lock on the drive shaft 131 when it is opened, so that the electric operation and the mechanical lock/unlock operation can be interlocked, which contributes to improvement of safety in use.

The utility model provides an electric tool 100 revolves wrong device 20 through setting up on casing 11, can be through the condition of no external instrument user revolve twist owner and independent change that carries out working head 16, has saved the requirement that needs carry appurtenance, and is also very convenient when dismantling, has improved the efficiency when electric tool 100 operates.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

It will be appreciated by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be taken as limiting the present invention, and that suitable modifications and variations of the above embodiments are within the scope of the invention as claimed.

Claims (10)

1. A power tool comprises a housing, a driving part, a tool holder and a fastener, wherein the driving part is arranged in the housing, a first end of the tool holder is fixedly connected to a driving shaft of the driving part, a second end of the tool holder is configured to be a clamping part capable of expanding and contracting in a radial direction, and the fastener is sleeved on the clamping part; it is characterized in that the preparation method is characterized in that,

the electric tool further comprises a screwing device, the screwing device comprises a limiting piece, a screwing piece and a fastening matching piece, the limiting piece is fixedly connected to the shell, and the fastening matching piece is mounted on the screwing piece and sleeved with the tool holding piece; the screwing piece is sleeved with the limiting piece, one of the inner side surface of the screwing piece and the outer side surface of the limiting piece is provided with a first groove, and the other one of the inner side surface of the screwing piece and the outer side surface of the limiting piece is provided with a first bulge which can be correspondingly clamped in the first groove; the first groove and the first protrusion both extend in the axial direction of the tool holder;

the screwing piece is provided with a first position which is connected with the limiting piece in a rotation stopping mode, and a second position which is connected with the fastening piece in a rotation stopping mode through the fastening matching piece.

2. The power tool of claim 1, wherein the outer side surface of the retaining member is further provided with a retaining structure; when the screwing piece is at the first position, the limiting piece limits the screwing piece through the limiting structure.

3. The power tool of claim 2, wherein the limiting structure is a first retaining ring protruding from the outer side surface of the limiting member, and a second retaining ring protruding from the inner side surface of the screw member;

the limiting part limits the screwing part at the first position through the abutting of the first check ring to the second check ring.

4. The power tool of claim 3, wherein the end of the limiting member opposite to the fastening member is further provided with a plurality of first through holes penetrating through the end surface, and the plurality of first through holes are spaced from each other and are formed along the axial direction of the limiting member.

5. The power tool of claim 2, wherein the first recess is disposed on an outer side of the retaining member, and the first protrusion is disposed on an inner side of the screw member; the screwing piece is connected to the limiting piece in a rotation stopping mode through the embedding of the first protrusion into the first groove.

6. The power tool of claim 5, wherein the outer side surface of the limiting member is provided with a plurality of second protrusions spaced apart from each other, and the first groove is formed between two adjacent second protrusions; the first protrusion and the second protrusion have the same height.

7. The electric tool according to claim 5, wherein the screw member has second through holes formed in both sides of the first protrusion, respectively, and the portion where the first protrusion is formed is configured as an elastic portion.

8. The power tool of claim 7, wherein the limiting structure is a third protrusion formed by protruding at an end of the first protrusion relatively far from the limiting member, and a step is formed between a bottom wall of the first groove and an outer side surface of the limiting member;

when the screwing piece is at the first position, the third bulge of the screwing piece is abutted against the step of the limiting piece.

9. The power tool of claim 5, wherein the retaining member further includes a fourth protrusion protruding from an end of the retaining member relatively close to the fastening member, the fourth protrusion being disposed opposite to the first protrusion of the screw member, and the fourth protrusion being configured to abut against the screw member when the retaining member is in the second position.

10. The power tool of claim 1, further comprising a switch, a lever, a lock block, and an elastic member; the switch is arranged on the outer side surface of the shell and connected to the shifting lever; one end of the shifting lever is in inclined plane fit with the locking block, and the other end of the shifting lever is connected with the driving piece and used for controlling the opening and closing of the driving piece; one end of the elastic piece acts on the inner side surface of the shell, and the other end of the elastic piece acts on the locking block; the locking block can lock a driving shaft of the driving piece;

when the switch is closed, the driving shaft of the driving piece is locked by the locking block under the control of the deflector rod, and when the switch is opened, the driving shaft is unlocked by the locking block under the control of the deflector rod.

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