Electric tool with working head convenient to replace

Abstract

The utility model discloses an electric tool with a working head convenient to replace, which belongs to the technical field of electric tools, solves the problem that a tooth breaking phenomenon is easily caused when a lock shaft mechanism is clamped, and adopts the technical scheme that the electric tool with the working head convenient to replace comprises a shell and a driving motor arranged in the shell, the driving motor is in transmission connection with an output shaft, the output shaft is provided with a shaft locking mechanism, the shaft locking mechanism comprises a first clutch part, a second clutch part and a control push part, the control push part is in transmission connection with the second clutch part and controls the second clutch part to move in the axial direction of the output shaft, and a control switch is arranged in the shell. The control pushing system is provided with a starting position, a shutdown position and a shaft locking position, and the starting position, the shutdown position and the shaft locking position are sequentially arranged in the axial direction of the output shaft. The clutch device is mainly used for enabling the first clutch piece and the second clutch piece to be clamped after the output shaft is completely stopped.

Description

[Technical field]

[0001] The utility model shows an electric tool which is convenient for replacing a working head and belongs to the technical field of electric tools. [Background technology]

[0002] Electric tools with rotary drive output at the terminal, such as electric grinders, circular saws, angle grinders, electric wood milling machines, milling drills, and spiral saws, are electric tools for grinding, cutting, drilling, milling, polishing, etc. on wood, metal, stone and other processing objects. Most of the above electric tools need to be connected to a separate special working head (such as a cutter head, grinding head, drill bit, etc.) to effectively process the workpiece. The working head and the output shaft are often fixed together by a chuck or nut. When disassembling and replacing the working head, the rotation of the output shaft needs to be limited by a locking mechanism.

[0003] For example, the prior art CN215470918U discloses an electric tool, including a housing and a shaft locking mechanism, the shaft locking mechanism including a first clutch, a second clutch and a push plate, the first clutch is fixed to the output shaft, the push plate is used to push the second clutch, and make the second clutch move axially along the output shaft, the first clutch and the second clutch are respectively provided with grooves and protrusions, and the circumferential limit cooperation of the first clutch and the second clutch is realized through the clamping of the grooves and the protrusions to limit the rotation of the output shaft to facilitate the replacement of the working head, and a micro switch is also provided in the housing, the push plate is pushed to make the second clutch away from the first clutch, thereby releasing the lock on the output shaft, and the push plate also triggers the micro switch to start the electric tool.

[0004] For another example, CN209078476U discloses an electric grinder that is convenient for replacing grinding heads, comprising a shell, a drive motor and a push rod. The output shaft of the drive motor is provided with a clutch member that rotates synchronously with the output shaft and a clutch sleeve that slides forward and backward along the output shaft. When the push rod is in the forward state, the clutch sleeve is pushed to move forward to be disengaged from the clutch member and trigger the drive motor to work; when the push rod is in the backward state, the clutch sleeve is pushed to move backward to be engaged with the clutch member and disengaged from the trigger of the drive motor, so as to facilitate the replacement of the working head.

[0005] In the above-mentioned prior art, the push plate only has two positions: the power-on position and the shaft locking position. When the push plate moves from the power-on position to the shaft locking position, although the drive motor has been turned off, the output shaft is still rotating due to inertia. When the shaft locking mechanism is engaged, it will cause tooth jamming, which will in turn cause impact on the shaft locking mechanism, making the shaft locking mechanism more susceptible to damage, greatly reducing the service life of the shaft locking mechanism, and at the same time, a large noise will be generated during the engagement process, causing discomfort to the user and reducing the user's experience. [Utility Model Content]

[0006] The utility model aims to solve the problem that the locking shaft mechanism is prone to causing tooth snapping during engagement, and provides an electric tool that is convenient for replacing a working head, wherein the first clutch member and the second clutch member can be engaged after the output shaft is completely stopped.

[0007] To solve the above technical problems, the utility model adopts the following technical solutions:

[0008] The second clutch is connected to the drive shaft and the second clutch is connected to the drive shaft via a locking mechanism, wherein the locking mechanism comprises a first clutch member fixed to the output shaft, a second clutch member sleeved on the output shaft and a control push member moving axially along the output shaft. The control push member is connected to the second clutch member and controls the second clutch member to move axially along the output shaft. A control switch for controlling the opening and closing of the drive motor is provided in the housing. The control push member has a power-on position for triggering the control switch and moving the second clutch member away from the first clutch member, a power-off position for disengaging the control switch and moving the second clutch member away from the first clutch member, and a lock shaft position for disengaging the control switch and forming a circumferential limit with the first clutch member. The power-on position, the power-off position and the lock shaft position are sequentially arranged along the axial direction of the output shaft. A positioning mechanism is provided between the control push member and the housing to position the control push member at the power-off position.

[0009] The beneficial effects of adopting the utility model are:

[0010] The control push system described in the utility model has an on position, an off position and a shaft locking position, which are arranged in sequence along the axial direction of the output shaft. When the control push system is in the on position, the control push system triggers the control switch to start the drive motor, and at the same time, the control push system drives the second clutch component away from the first clutch component, so that the first clutch component can rotate synchronously with the output shaft; when the control push system moves from the switch position to the off position, the control push system disengages from the control switch to shut down the drive motor, and the output shaft still keeps rotating due to inertia, and at this time the second clutch component is not engaged with the first clutch component, which can avoid the second clutch component from directly engaging with the first clutch component in a rotating state, thereby providing sufficient time for the output shaft to stop; after the output shaft stops, the control push system moves from the off position to the shaft locking position, and the control push system drives the second clutch component to engage with the first clutch component and form a circumferential limit, thereby limiting the rotation of the output shaft, thereby locking the output shaft, so as to facilitate the replacement of the working head.

[0011] In the process of the output shaft from the working state to the locking state described in the utility model, the control push system passes through the power-on position, the power-off position and the lock shaft position in sequence. The control push system can be positioned in the power-off position through the positioning mechanism, which can provide sufficient time for the output shaft to stop rotating, and can effectively avoid the second clutch component from being engaged with the first clutch component in the rotating state, thereby reducing the possibility of the first clutch component and the second clutch component being damaged by teeth hitting and impact, making the cooperation of the first clutch component and the second clutch component smoother and softer, which is conducive to improving the reliability and service life of the lock shaft mechanism, so that the power tool maintains a higher economy, and at the same time can also reduce the noise generated when the first clutch component and the second clutch component cooperate, thereby improving the user experience; in addition, the lock shaft mechanism is arranged along the axial direction of the output shaft, which is conducive to reducing the diameter of the power tool, making the power tool more compact as a whole, which is conducive to the user's carrying and use, and improving the user's experience. At the same time, it can also improve the utilization rate of the internal space of the shell, making the overall structure of the power tool more compact.

[0012] Preferably, one of the surfaces of the first clutch and the second clutch is provided with a plurality of slots at intervals, and the other is provided with a convex tooth. When the control pusher is in the shaft locking position, the convex tooth extends into the slot to form a circumferential limit for the first clutch and the second clutch. With the above technical solution, the convex tooth extends into the slot to improve the matching stability of the first clutch and the second clutch, reduce the possibility of relative rotation of the first clutch and the second clutch due to slipping, make the locking of the output shaft more firm and reliable, and facilitate the user to replace the working head.

[0013] Preferably, a plurality of protrusions are spaced apart on the outer peripheral side surface of the first clutch member, a slot is formed between two adjacent protrusions, and the protruding teeth are located on a side of the second clutch member close to the first clutch member and extend toward the first clutch member.

[0014] Preferably, the end of the protruding column close to the second clutch is provided with a first guide surface; and / or the end of the protruding tooth close to the first clutch is provided with a second guide surface. With the above technical solution, the first guide surface and / or the second guide surface can guide the protruding tooth to extend into the slot, so that the protruding tooth and the slot cooperate more smoothly, reducing the possibility of the protruding tooth abutting against the end of the protruding column, so that the protruding tooth can stably extend into the slot.

[0015] Preferably, the positioning mechanism includes three positioning grooves arranged in the shell and a positioning block arranged on the control pusher, and the three positioning grooves correspond to the power-on position, the power-off position and the shaft locking position respectively. When the control pusher is in the power-on position, the power-off position or the shaft locking position, the positioning block is embedded in the positioning groove. With the above-mentioned technical solution, the cooperation of the positioning groove and the positioning block can keep the control pusher stably in the power-on position, the power-off position or the shaft locking position, without the need for the customer to keep pressing for a long time, which is convenient for the user to use and conducive to improving the user's use experience; in addition, when replacing the working head, there is no need to press the control pusher, and both hands can be operated, which makes the replacement of the working head more convenient and can improve the replacement efficiency; secondly, the positioning block is embedded in the positioning groove, so that the user can clearly feel that the control pusher has moved to the target position, which can improve the positioning accuracy of the control pusher, so that the user can use it with confidence, which can further improve the user's experience.

[0016] Preferably, the positioning block is an elastic body, and the two ends of the positioning block protrude from the two sides of the control pusher, and both ends of the positioning block are provided with smooth curved surfaces. The above technical solution can reduce the external force required for the positioning block to disengage from the positioning groove, thereby reducing the external force required for the user to push the control pusher, making it easier for the user to use; in addition, it can also reduce the possibility of the positioning block and the positioning groove getting stuck, making the sliding of the control pusher smoother.

[0017] Preferably, a protrusion is provided on the outer peripheral side of the second clutch, and a slot is provided on the control pusher, and the protrusion and the slot are engaged with each other to realize the connection between the control pusher and the second clutch. The above technical solution can improve the connection stability between the control pusher and the second clutch, reduce the possibility of the second clutch being separated from the control pusher, and enable the second clutch to move synchronously with the control pusher.

[0018] Preferably, the control pusher is provided with two extension plates which extend to both sides of the second clutch member respectively, the slot is provided on the extension plate, the front end of the extension plate has an abutment surface, when the control pusher is in the power-on position, the abutment surface abuts against the contact piece of the control switch to trigger the control switch. With the above technical solution, the second clutch member is connected to the control pusher through the protrusions on both sides, so that the positioning of the second clutch member is more stable, and the possibility of the second clutch member rotating in the circumferential direction is reduced.

[0019] Preferably, the housing is provided with a guide rail for guiding the sliding of the control pusher, the control pusher includes a push plate and a slide groove, the push plate is exposed on the outer surface of the housing, and the guide rail is slidably connected to the slide groove. With the above technical solution, the push plate is on the outer surface of the housing, which can facilitate the user to apply force to the control pusher, and the cooperation of the guide rail and the slide groove can make the sliding of the control pusher smoother.

[0020] Preferably, the end of the output shaft is connected with a locking nut and a sandwich core for installing a working head, the outer surface of the end of the output shaft is provided with a thread, the locking nut is threadedly connected to the output shaft, and the locking nut and the output shaft cooperate to adjust the clamping force of the sandwich core on the working head.

[0021] Other features and advantages of the present invention will be disclosed in detail in the following specific implementations and drawings.

Brief Description of the Drawings

[0022] The utility model is further described below in conjunction with the accompanying drawings:

[0023] Figure 1 This is an exploded view of an electric tool that is convenient for replacing a working head according to the utility model;

[0024] Figure 2 This is a schematic structural diagram of an electric tool that is convenient for replacing a working head according to the utility model;

[0025] Figure 3 This is a schematic diagram of the interior of a housing in an electric tool that is convenient for replacing a working head according to the utility model;

[0026] Figure 4 This is a cross-sectional view of an electric tool that is convenient for replacing a working head according to the utility model;

[0027] Figure 5 This is a schematic diagram of the structure of a control push mechanism in an electric tool that is convenient for replacing a working head according to the utility model;

[0028] Figure 6 This is a schematic structural diagram of a first clutch component in an electric tool that facilitates replacement of a working head according to the utility model;

[0029] Figure 7 This is a schematic structural diagram of a second clutch member in an electric tool that facilitates replacement of a working head according to the utility model;

[0030] Figure 8 It is a structural schematic diagram of a control pusher in a power tool for facilitating replacement of a working head according to the utility model, which is in a power-on position;

[0031] Fig. 9 It is a structural schematic diagram of a control pusher in a power tool for facilitating replacement of a working head according to the utility model, which is in a shutdown position;

[0032] Fig.10 The utility model is a schematic structural diagram of a control pusher in a shaft locking position in an electric tool for facilitating replacement of a working head.

[0033] Figure numerals: 1 housing, 11 mounting groove, 12 guide rail, 13 positioning groove, 14 cap, 2 driving motor, 21 output shaft, 22 core, 23 locking nut, 24 working head, 25 bearing, 251 retaining ring, 252 shoulder, 31 first clutch, 311 boss, 312 slot, 313 first guide surface, 32 second clutch, 321 convex tooth, 322 protrusion, 323 second guide surface, 33 control push system, 331 push plate, 332 slide groove, 333 extension plate, 334 card slot, 335 positioning block, 4 control switch, 41 contact piece, 5 control circuit board, 6 power supply. [Specific implementation method]

[0034] The following is an explanation and description of the technical scheme of the embodiment of the utility model in conjunction with the drawings of the embodiment of the utility model, but the following embodiment is only a preferred embodiment of the utility model, not all. Based on the embodiment in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the utility model.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] like Figures 1 to 10As shown, this embodiment shows an electric tool that is easy to replace a working head 24, including a shell 1 and a driving motor 2 arranged in the shell 1, the shell 1 is formed by two splicing blocks spliced ​​together, the front end of the shell 1 is threadedly connected with a cap 14, the output end of the driving motor 2 is transmission-connected with an output shaft 21, a bearing 25 is provided on the output shaft 21, and the two sides of the bearing 25 are respectively positioned by a shoulder 252 and a retaining ring 251, a locking nut 23 and a core 22 for installing the working head 24 are connected to the front end of the output shaft 21, the outer surface of the end of the output shaft 21 is provided with a thread, the locking nut 23 is threadedly connected to the output shaft 21, the locking nut 23 cooperates with the output shaft 21 to adjust the clamping force of the core 22 on the working head 24, when the working head 24 needs to be replaced, the locking nut 23 is rotated relative to the output shaft 21, thereby reducing the clamping force of the locking nut 23 on the core 22, so as to facilitate the replacement of the working head 24.

[0039] In the present embodiment, a shaft locking mechanism is installed on the output shaft 21, which includes a first clutch 31 fixed on the output shaft 21, a second clutch 32 sleeved on the output shaft 21, and a control pusher 33 moving axially along the output shaft 21. The control pusher 33 is transmission-connected with the second clutch 32 and controls the second clutch 32 to move axially along the output shaft 21. A control switch 4 for controlling the opening and closing of the drive motor 2 is provided in the housing 1. The control pusher 33 has a start position for triggering the control switch 4 and moving the second clutch 32 away from the first clutch 31, a shutdown position for disengaging from the control switch 4 and moving the second clutch 32 away from the first clutch 31, and a shaft locking position for disengaging from the control switch 4 and forming a circumferential limit between the second clutch 32 and the first clutch 31. The start position, the shutdown position, and the shaft locking position are sequentially arranged along the axial direction of the output shaft 21. A positioning mechanism is provided between the control pusher 33 and the housing 1 to position the control pusher 33 in the start position, the shutdown position, and the shaft locking position in sequence.

[0040] In this embodiment, when the control pusher 33 is in the on position, the control pusher 33 triggers the control switch 4 to start the drive motor 2, and at the same time, the control pusher 33 drives the second clutch 32 away from the first clutch 31, so that the first clutch 31 can rotate synchronously with the output shaft 21; when the control pusher 33 moves from the switch position to the off position, the control pusher 33 disengages from the control switch 4 to shut down the drive motor 2, and the output shaft 21 still keeps rotating due to inertia, and at this time the second clutch 32 is not engaged with the first clutch 31, which can avoid the second clutch 32 directly engaging with the first clutch 31 in the rotating state, providing sufficient time for the output shaft 21 to stop; when the output shaft 21 stops, the control pusher 33 moves from the off position to the lock shaft position, and the control pusher 33 drives the second clutch 32 to engage with the first clutch 31 and form a circumferential limit, thereby limiting the rotation of the output shaft 21, and realizing the locking of the output shaft 21, so as to facilitate the replacement of the working head 24.

[0041] In the process of the output shaft 21 from the working state to the locking state described in this embodiment, the control pusher 33 passes through the power-on position, the power-off position and the lock shaft position in sequence. The control pusher 33 can be positioned at the power-off position through the positioning mechanism, which can provide sufficient time for the output shaft 21 to stop rotating, and can effectively avoid the second clutch 32 from being engaged with the first clutch 31 in the rotating state, thereby reducing the possibility of the first clutch 31 and the second clutch 32 being damaged by teething and impact, making the first clutch 31 and the second clutch 32 cooperate more smoothly and gently, which is conducive to improving the reliability and service life of the lock shaft mechanism, so that the electric tool maintains a higher economy, and can also reduce the noise generated when the first clutch 31 and the second clutch 32 cooperate, thereby improving the user experience; in addition, the lock shaft mechanism is arranged along the axial direction of the output shaft 21, which is conducive to reducing the diameter of the electric tool, making the electric tool more compact as a whole, which is conducive to the user's carrying and use, and improving the user's experience. At the same time, it can also improve the utilization rate of the internal space of the shell 1, making the overall structure of the electric tool more compact.

[0042] like Figure 6 and Figure 7As shown, in this embodiment, a plurality of bosses 311 are spaced apart on the outer peripheral side surface of the first clutch member 31, and a slot 312 is formed between two adjacent bosses 311. A convex tooth 321 is provided on the side of the second clutch member 32 close to the first clutch member 31, and the convex tooth 321 extends toward the first clutch member 31. When the control pusher 33 is in the shaft locking position, the convex tooth 321 extends into the slot 312 to form a circumferential limit for the first clutch member 31 and the second clutch member 32, thereby achieving the locking of the output shaft 21. The convex tooth 321 extending into the slot 312 can improve the matching stability of the first clutch member 31 and the second clutch member 32, reduce the possibility of relative rotation of the first clutch member 31 and the second clutch member 32 due to slipping, make the locking of the output shaft 21 more firm and reliable, and facilitate the user to replace the working head 24.

[0043] It should be noted that, in this embodiment, the boss 311 and the first clutch member 31 are an integrated structure. Of course, it is understandable that in other embodiments, the slot 312 can also be formed by a depression on the outer peripheral side of the first clutch member 31, or the slot 312 can also be formed by a depression on the side of the first clutch member 31 facing the second clutch member 32; in addition, the slot 312 can also be arranged on the second clutch member 32, and the corresponding convex tooth 321 can also be arranged on the first clutch member 31.

[0044] In order to make the cooperation between the protruding tooth 321 and the slot 312 smoother, the end of the protruding column 311 close to the second clutch member 32 in this embodiment is provided with a first guide surface 313, and the end of the protruding tooth 321 close to the first clutch member 31 is provided with a second guide surface 323. Both the first guide surface 323 can guide the protruding tooth 321 to extend into the slot 312, so that the cooperation between the protruding tooth 321 and the slot 312 is smoother, and the possibility of the protruding tooth 321 abutting against the end of the protruding column 311 is reduced, so that the protruding tooth 321 can stably extend into the slot 312; of course, it can be understood that in other embodiments, the first guide surface 313 may be provided only at the end of the protruding column 311, or the second guide surface 323 may be provided only at the end of the protruding tooth 321.

[0045] like Figure 5 As shown, the control push system 33 described in this embodiment includes a mounting seat, a push plate 331 and an extension plate 333. The shell 1 is provided with a mounting groove 11 for installing the control push system 33. Guide rails 12 for guiding the sliding of the control push system 33 are provided on both sides of the mounting seat. Slide grooves 332 slidably connected to the guide rails 12 are provided on both sides of the mounting seat. The guide rails 12 are embedded in the slide grooves 332 so that the control push system 33 can be slidably installed in the mounting grooves 11. The push plate 331 is fixed to the upper end of the mounting seat and exposed to the outer surface of the shell 1. The push plate 331 is on the outer surface of the shell 1, which can facilitate the user to apply force to the control push system 33. The cooperation between the guide rails 12 and the slide grooves 332 can make the sliding of the control push system 33 smoother.

[0046] The control pusher 33 described in this embodiment is provided with two extension plates 333 and extends to the two sides of the second clutch member 32 respectively. The extension plate 333 is provided with a slot 334. The outer peripheral side of the second clutch member 32 is provided with a protrusion 322. The protrusion 322 and the slot 334 are engaged with each other to realize the connection between the control pusher 33 and the second clutch member 32, which can improve the connection stability between the control pusher 33 and the second clutch member 32, reduce the possibility of the second clutch member 32 being separated from the control pusher 33, and enable the second clutch member 32 to move synchronously with the control pusher 33; in addition, the second clutch member 32 is connected to the control pusher 33 through the protrusions 322 on both sides, so that the positioning of the second clutch member 32 is more stable, and the possibility of the second clutch member 32 rotating circumferentially is reduced.

[0047] like Figure 3 and Figure 5 As shown, the positioning mechanism in this embodiment includes three positioning grooves 13 arranged in the housing 1 and a positioning block 335 arranged on the control pusher 33, the three positioning grooves 13 correspond to the power-on position, the power-off position and the locking shaft position respectively, the positioning block 335 is an elastic body, and the two ends of the positioning block 335 protrude from the two sides of the control pusher 33 respectively, when the control pusher 33 is in the power-on position, the power-off position or the locking shaft position, the positioning block 335 is embedded in the positioning groove 13, and the cooperation of the positioning groove 13 and the positioning block 335 can keep the control pusher 33 stably in the power-on position. The control pusher 33 can be adjusted to the desired position or the off position or the locked shaft position without the need for the customer to keep pressing for a long time, which is convenient for users to use and helps to improve the user experience. In addition, when replacing the working head 24, there is no need to press the control pusher 33, and both hands can be used for operation, which makes the replacement of the working head 24 more convenient and improves the replacement efficiency. Secondly, the positioning block 335 is embedded in the positioning groove 13, so that the user can clearly feel that the control pusher 33 has moved to the target position, which can improve the positioning accuracy of the control pusher 33, so that the user can use it with confidence, which can further improve the user experience.

[0048] In order to make the movement of the control pusher 33 more labor-saving, both ends of the positioning block 335 described in this embodiment are provided with smooth curved surfaces. The smooth curved surfaces can reduce the external force required for the positioning block 335 to disengage from the positioning groove 13, thereby reducing the external force required for the user to push the control pusher 33, making it more convenient for the user to use; in addition, it can also reduce the possibility of the positioning block 335 and the positioning groove 13 getting stuck, making the sliding of the control pusher 33 smoother.

[0049] like Figure 1 and Figure 4As shown, in this embodiment, the housing 1 is provided with a control switch 4, a control circuit board 5 and a power supply 6. The power supply 6 provides energy for the operation of the electric tool. The control switch 4 is connected to the control circuit board 5 through a line to control the opening and closing of the drive motor 2. The control switch 4 is located at the front end of the control pusher 33. The control switch 4 is provided with a contact piece 41 on one side of the control switch 4 facing the control pusher 33. Figure 8 As shown, when the control pusher 33 is in the power-on position, the abutting surface at the front end of the extension plate 333 abuts against the contact piece 41 and triggers the control switch 4, so that the drive motor 2 starts and drives the output shaft 21 to rotate, so that the power tool is in the power-on state. At this time, the second clutch member 32 is driven away from the first clutch member 31 by the control pusher 33.

[0050] like Figure 8 As shown, when the control pusher 33 moves from the on position to the off position, the control pusher 33 moves away from the control switch 4, causing the contact piece 41 to automatically rebound, and the control switch 4 cuts off the power supply 6 to shut down the drive motor 2, and at the same time sends a power-off signal to the control circuit board 5. The control circuit board 5 will give a reverse electromotive force in a very short time to control the reverse braking of the drive motor 2, thereby causing the output shaft 21 to stop quickly, reducing the possibility of tooth jamming and impact between the first clutch 31 and the second clutch 32, and at the same time can also reduce the time the user waits for the output shaft 21 to stop, which is beneficial to improving the efficiency of the user in replacing the working head 24.

[0051] like Fig.10 As shown, when the control pusher 33 moves from the shutdown position to the locking shaft position, the control pusher 33 drives the second clutch member 32 to approach the first clutch member 31, and the convex tooth 321 extends into the slot 312 and forms a circumferential limit with the slot 312, thereby limiting the rotation of the output shaft 21. At this time, when the locking nut 23 is rotated, the output shaft 21 will not rotate with the locking nut 23, so that the locking nut 23 can adjust the clamping force of the core 22 on the working head 24, so as to facilitate the disassembly and installation of the working head 24, thereby completing the replacement of the working head 24.

[0052] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Those skilled in the art should understand that the utility model includes but is not limited to the contents described in the drawings and the above specific implementation. Any modification that does not deviate from the functional and structural principles of the utility model will be included in the scope of the claims.

Claims

1. An electric tool for facilitating replacement of a working head, comprising a housing and a driving motor disposed in the housing, the driving motor being drivingly connected to an output shaft for mounting the working head, the output shaft being provided with a shaft locking mechanism, the shaft locking mechanism comprising a first clutch member fixed to the output shaft, a second clutch member sleeved on the output shaft, and a control pusher for axial movement along the output shaft, characterized in that: The control push system is transmission connected with the second clutch and controls the second clutch to move axially along the output shaft. A control switch for controlling the opening and closing of the drive motor is provided in the shell. The control push system has a start position for triggering the control switch and moving the second clutch away from the first clutch, a shutdown position for disengaging the control switch and moving the second clutch away from the first clutch, and a lock shaft position for disengaging the control switch and forming a circumferentially limited position with the first clutch. The start position, shutdown position and lock shaft position are sequentially arranged along the axial direction of the output shaft. A positioning mechanism is provided between the control push system and the shell to position the control push system at the shutdown position.

2. The electric tool for facilitating replacement of a working head according to claim 1, characterized in that: One of the surfaces of the first clutch member and the second clutch member is provided with a plurality of slots at intervals, and the other is provided with convex teeth. When the control pusher is in the shaft locking position, the convex teeth extend into the slots to form a circumferential limit for the first clutch member and the second clutch member.

3. The electric tool for facilitating replacement of a working head according to claim 2, characterized in that: A plurality of convex columns are spaced apart on the outer peripheral side surface of the first clutch member, and a slot is formed between two adjacent convex columns. The convex teeth are located on a side of the second clutch member close to the first clutch member and extend toward the first clutch member.

4. The electric tool for facilitating replacement of a working head according to claim 3, characterized in that: The end of the protruding column close to the second clutch member is provided with a first guide surface; and / or the end of the protruding tooth close to the first clutch member is provided with a second guide surface.

5. The electric tool for facilitating replacement of a working head according to claim 1, characterized in that: The positioning mechanism includes three positioning grooves arranged in the shell and a positioning block arranged on the control pusher. The three positioning grooves correspond to the power-on position, the power-off position and the shaft locking position respectively. When the control pusher is in the power-on position, the power-off position or the shaft locking position, the positioning block is embedded in the positioning groove.

6. The electric tool for facilitating replacement of a working head according to claim 5, characterized in that: The positioning block is an elastic body, and the two ends of the positioning block protrude from the two sides of the control pusher respectively, and the two ends of the positioning block are provided with smooth curved surfaces.

7. The electric tool for facilitating replacement of a working head according to claim 1, characterized in that: A convex block is arranged on the outer peripheral side of the second clutch member, and a clamping groove is arranged on the control push member. The convex block and the clamping groove are clamped and matched to realize the connection between the control push member and the second clutch member.

8. The electric tool for facilitating replacement of a working head according to claim 7, characterized in that: The control pusher is provided with two extension plates which extend to both sides of the second clutch member respectively. The card slot is provided on the extension plate. The front end of the extension plate has an abutment surface. When the control pusher is in the power-on position, the abutment surface abuts against the contact piece of the control switch to trigger the control switch.

9. The electric tool for facilitating replacement of a working head according to claim 1, characterized in that: The shell is provided with a guide rail for guiding the sliding of the control push system. The control push system includes a push plate and a slide groove. The push plate is exposed from the outer surface of the shell, and the guide rail is slidably connected with the slide groove.

10. The electric tool for facilitating replacement of a working head according to claim 1, characterized in that: The end of the output shaft is connected with a locking nut and a sandwich core for installing a working head. The outer surface of the end of the output shaft is provided with a thread. The locking nut is threadedly connected to the output shaft. The locking nut cooperates with the output shaft to adjust the clamping force of the sandwich core on the working head.

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