Electric tool

Abstract

The utility model provides an electric tool. The electric tool comprises a driving motor; one end of the output shaft is connected with the driving motor, and the other end is connected with a tool head; the switch unit is used for controlling start and stop of the driving motor; the shaft lock mechanism comprises a moving part which comprises a pressing piece and a first clutch piece and is arranged to be switched between a working position and a shaft lock position; the second clutch piece is fixedly connected with the output shaft; when the moving part is located at the working position, the pressing piece abuts against the switch unit so that the switch unit can be closed, and the first clutch piece and the second clutch piece can be separated. When the moving part is located at the shaft locking position, the first clutch piece and the second clutch piece are mutually embedded to restrain rotation of the output shaft, and the pressing piece is separated from the switch unit; when the moving part is located in a first position interval between the working position and the shaft lock position, the switch unit is switched off, and the first clutch piece is separated from the second clutch piece. According to the utility model, the tooth breaking phenomenon in the operation process of the electric grinder switch and the shaft lock is solved, and the service life of the structure is prolonged.

Description

Technical Field

[0001] This application relates to the field of power tool technology, and more particularly to a power tool that facilitates tool head replacement. Background Technology

[0002] Electric tools such as bakelite milling machines, angle grinders, milling drills, engraving machines, and electric grinders are widely used in industrial production and various processing fields. For these types of electric tools, the output shaft is usually directly connected to the drive motor. When changing tool heads, it is necessary to lock the output shaft to restrict its rotation so that the lock nut can be tightened. Locking the output shaft can be achieved using a shaft locking mechanism.

[0003] One type of shaft locking mechanism in related technologies uses a shaft locking hole on the circumference of the output shaft and a circumferentially movable shaft locking pin. The user manually presses the shaft locking pin to engage with the corresponding shaft locking hole, thus locking the shaft. A spring is also included to help the shaft locking pin return to its original position and release the shaft lock. However, this type of shaft locking mechanism has the following disadvantages: 1. The movement of the shaft locking pin requires additional axial space, resulting in an increased size of the electric grinder head, which does not conform to the design concept of miniaturization of the electric grinder. 2. Every time the user changes the working head, they need to repeat the two-step operation of stopping the machine and manually locking the shaft, which is too cumbersome and results in a poor user experience, urgently requiring improvement.

[0004] To address the aforementioned issues, one type of shaft locking mechanism in related technologies includes a first clutch on the output shaft, a second clutch connected to it, and a push plate. The push plate can push the second clutch to move axially along the output shaft, causing the second clutch and the first clutch to engage and form a limit position. When the push plate is pushed to disengage the clutch, it triggers a micro switch to start the power tool. However, the above technical solution still has problems: in this solution, when the push plate moves from the power-on position to the shaft locking position, there are situations where the drive motor is not de-energized but the shaft locking mechanism is already engaged, or the drive motor is de-energized but the output shaft is still rotating due to inertia. In both cases, the shaft locking mechanism will experience tooth breakage during engagement, causing impact to the mechanism and making it more susceptible to damage. This will significantly reduce the service life of the shaft locking mechanism and also generate considerable noise during engagement, causing user discomfort and reducing the user experience. Utility Model Content

[0005] This application mainly provides an electric tool, and the following describes various aspects involved in the embodiments of this application.

[0006] In a first aspect, a power tool is provided, comprising: a drive motor; an output shaft, one end of which is connected to the drive motor and the other end of which is used to connect a tool head; a switching unit for controlling the start and stop of the drive motor; and a shaft locking mechanism, comprising: a moving part including a pressing member and a first clutch member, configured to switch between a working position and a shaft locking position; and a second clutch member fixedly connected to the output shaft; when the moving part is in the working position, the pressing member abuts against the switching unit to close the switching unit, and the first clutch member and the second clutch member disengage; when the moving part is in the shaft locking position, the first clutch member and the second clutch member engage with each other to constrain the rotation of the output shaft, and the pressing member is separated from the switching unit; when the moving part is in a first position range between the working position and the shaft locking position, the switching unit is disengaged, and the first clutch member and the second clutch member disengage. According to the above technical solution, when the moving part of the shaft locking mechanism is in the working position, the switch is closed, and the motor drives the output shaft to rotate. In the shaft locking position, the switch is open and the output shaft is constrained by the clutch, thus achieving interlocking between the start-up state of the drive motor and the locked state of the output shaft. A first position interval is set between the working position and the shaft locking position. Within this interval, the switch is open and the clutch is disengaged, which can further ensure operational safety and prevent malfunctions such as accidental motor start-up or clutch gear breakage.

[0007] In some embodiments, the power tool further includes: a housing forming a first cavity; the drive motor, the switch unit, the pressing member, the first clutch member, and the second clutch member are located within the first cavity, and one end of the output shaft away from the drive motor extends out of the first cavity; the moving part further includes an operating member at least partially disposed outside the first cavity, the operating member being connected to the pressing member and the first clutch member, for receiving user operation and driving the pressing member and the first clutch member to switch positions. The housing forming the cavity and surrounding the motor, the switch unit, the pressing member, the first clutch member, and the second clutch member results in a compact machine structure. Furthermore, the moving part including the operating member at least partially disposed outside the first cavity facilitates user operation.

[0008] In some embodiments, the switching operation of the moving part between the working position and the shaft lock position is any one of axial movement along the output shaft, radial movement along the output shaft, and circumferential movement along the output shaft. The axial movement design simplifies the overall structure and operation, and has minimal impact on the overall radial dimension of the power tool; while radial or circumferential movement designs can shorten the axial dimension of the machine, which is considered advantageous for tools requiring a short length design.

[0009] In some embodiments, the movable part is connected to the housing via a first pivot, allowing the movable part to swing around the first pivot; the switching operation of the movable part between the working position and the shaft lock position is to swing around the first pivot. This swinging movable part design makes the position transition more clearly perceptible to the user, resulting in an excellent user interaction experience.

[0010] In some embodiments, the pressing member and the first clutch member are arranged axially along the output shaft; one of the first clutch member and the second clutch member has a protrusion extending along the axial direction, and the other has at least one recess; when the moving part is in the shaft lock position, the protrusion extends into one of the at least one recess to restrain the rotation of the output shaft. The design of the protrusion and the recess makes the engagement of the two clutches more stable and reliable.

[0011] In some embodiments, the first clutch member includes the protrusion, which is a protrusion extending along the axial direction; the second clutch member is a clutch disc fixedly connected to the output shaft, and the recess is a shaft locking hole on the clutch disc. When the moving part is in the shaft locking position, the protrusion can extend into the shaft locking hole. The design of the protrusion and clutch disc greatly reduces the circumferential dimension along the output shaft, making the machine more compact in the circumferential dimension.

[0012] In some embodiments, the number of at least one shaft locking hole is at least two, and the at least two shaft locking holes are evenly distributed along the circumferential direction of the clutch disc. The design of at least two shaft locking holes makes it easier to align the protrusion with the clutch disc during shaft locking, reducing the difficulty for the user in rotating the shaft to align the holes.

[0013] In some embodiments, the length of the first position interval is greater than or equal to the conduction stroke of the switch unit; the conduction stroke of the switch is the distance the moving part travels from the moment the pressing member contacts the switch unit until the switch unit is activated. The design that the length of the first position interval is greater than or equal to the conduction stroke of the switch unit allows the switch's conduction stroke to be directly used as a buffer distance for the motor to stop if the switch's conduction stroke is long; if the switch's stroke is short, an additional redundant distance is provided to collectively constitute the buffer distance for the motor to stop.

[0014] In some embodiments, the length of the first position interval is the sum of the conduction stroke of the switching unit and a preset gap; wherein the length of the preset gap is related to the rotational speed of the drive motor and / or the moment of inertia of the drive motor. By quantifying the length of the first position interval to be the sum of the switch conduction stroke and the preset gap, while the preset gap is related to the rotational speed and moment of inertia of the motor, the design of the first position interval is more reasonable. It is neither too small to serve as a buffer distance for the motor to stop, nor too large to result in an excessively long axial length of the machine, affecting the continuity of user operation.

[0015] In some embodiments, the operating member has a first positioning block; the housing is provided with a first positioning groove and a second positioning groove; when the moving part is in the working position, the first positioning block engages with the first positioning groove; when the moving part is in the shaft lock position, the first positioning block engages with the second positioning groove. The positioning block and the positioning groove can position the moving part at the two extreme positions of the working position and the shaft lock position, which can play a certain locking role; on the other hand, the engagement of the positioning block and the positioning groove can provide tactile feedback to the user and enhance the user's perception.

[0016] In some embodiments, a locking nut and a clamp for mounting the tool head are connected to the end of the output shaft away from the drive motor; the end of the output shaft is provided with an external thread, and the locking nut is connected to the external thread. The locking nut cooperates with the output shaft to adjust the clamping force of the clamp on the tool head. Using a locking nut and the external thread at the end of the output shaft for clamping results in a small and simple structure that provides effective clamping, making it particularly suitable for the head design of small tools.

[0017] In some embodiments, the power tool further includes a power supply for providing energy to the drive motor; and a control circuit board connected to the switching unit, the power supply, and the drive motor to control the opening and closing of the drive motor via the switching unit. Powering the machine via a power supply reduces its size and is less constrained by space compared to cable power. Furthermore, controlling the control circuit board via the switching unit to further control the drive motor simplifies the overall wiring.

[0018] In some embodiments, the housing includes a first housing and a second housing detachably connected to the first housing, and the power source is a removable battery. The removable battery design allows the machine to be recharged by directly replacing the battery pack, improving recharging efficiency.

[0019] In some embodiments, the power tool also includes a control panel connected to the control circuit board, at least a portion of which is disposed outside the housing;

[0020] The control panel has at least one indicator light and at least one control component. The indicator light displays the status information of the power tool, and the control component receives user input to control the power tool via the control circuit board. This external control panel uses lights to display tool status information, allowing users to quickly understand the tool's status and improving the user experience.

[0021] Secondly, a power tool is provided, comprising: a drive motor; an output shaft, one end connected to the drive motor and the other end for connecting a tool head; a switching unit for controlling the start and stop of the drive motor; a moving member configured to switch between a working position and a shaft-locked position; and a clutch unit disposed between the moving member and the output shaft. When the moving member is in the shaft-locked position, the clutch unit locks the output shaft; when the moving member is in the working position, the switching unit closes; when the moving member switches from the critical point of disengagement from the clutch unit to the working position, the distance the moving member moves is: Where n is the rotational speed of the drive motor, s is the stroke of the switching unit, and k1 and k2 are the first coefficient and the second coefficient, respectively. The value of the first coefficient k1 ranges from 0 to 6*10. -4 The second coefficient k2 ranges from 0.5 to 0.7. By quantifying the distance the moving part travels, the parameter relationship between it and the rotational speed and the stroke of the switching unit is limited, making the design of the moving part's travel distance more reasonable. It is neither too small to serve as a buffer distance for the motor to stop, nor too large to make the machine's axial length too long, affecting the continuity of user operation.

[0022] In some embodiments, the moving distance l of the movable component ranges from 0.25mm to 3.5mm. Limiting the value of l to between 0.25mm and 3.5mm makes the design of the moving distance of the movable component more reasonable. It is neither too small (0.25mm is usually the effective buffer distance for the motor to stop when it decelerates by more than 50%), thus failing to serve as a buffer distance for the motor to stop; nor too large (above 3.5mm, the response time of the machine operation will be clearly perceived by the user, causing a sluggish feel when the user switches the device on and off, thus affecting the operation) and affecting the continuity of the user's operation.

[0023] In some embodiments, the rotational speed of the drive motor ranges from 5000 to 30000 r / min, and the stroke s of the switching unit ranges from 0.1 mm to 5 mm. Selecting a suitable motor rotational speed of 5000-30000 r / min allows the machine to cover different cutting, grinding, and polishing conditions. Selecting s from 0.1 mm to 5 mm effectively avoids excessively long axial dimensions of the machine.

[0024] In some embodiments, the power tool further includes: a housing forming a first cavity; the drive motor, the switching unit, and the clutch unit are disposed within the first cavity, and one end of the output shaft away from the drive motor extends from the first cavity; the clutch unit includes a first clutch member and a second clutch member, the first clutch member being connected to the moving member, and the second clutch member being fixedly connected to the output shaft; the first clutch member and the second clutch member are configured such that when the moving member is in the shaft locking position, the first clutch member can engage with the second clutch member to lock the output shaft. The housing forming the cavity and enclosing the motor, the switching unit, the pressing member, the first clutch member, and the second clutch member results in a compact machine structure.

[0025] In some embodiments, the movable component includes an operating element located outside the housing and a pressing element located within the first cavity. The pressing element and the first clutch are arranged axially along the output shaft. The operating element is used to receive user operation to drive the pressing element and the first clutch to move along the axial direction. Furthermore, the movable component includes an operating element at least partially located outside the first cavity for easy user operation. The axial movement of the pressing element and the first clutch results in a compact machine structure.

[0026] In some embodiments, the first clutch member includes a protrusion, which is a protrusion extending along the axial direction; the second clutch member is a clutch disc fixedly connected to the output shaft, the clutch disc having a shaft locking hole, wherein when the moving member is in the shaft locking position, the protrusion can extend into the shaft locking hole. The design of the protrusion and clutch disc greatly reduces the circumferential dimension along the output shaft, making the machine more compact in the circumferential dimension.

[0027] In some embodiments, the number of at least one shaft locking hole is at least two, and the at least two shaft locking holes are evenly distributed along the circumferential direction of the clutch disc. The design of at least two shaft locking holes makes it easier to align the protrusion with the clutch disc during shaft locking, reducing the difficulty for the user in rotating the shaft to align the holes.

[0028] In some embodiments, the operating member has a first positioning block; the housing is provided with a first positioning groove and a second positioning groove; when the moving member is in the working position, the first positioning block engages with the first positioning groove; when the moving member is in the shaft lock position, the first positioning block engages with the second positioning groove. The positioning block and the positioning groove can position the moving part at the two extreme positions of the working position and the shaft lock position, which can play a certain locking role; on the other hand, the engagement of the positioning block and the positioning groove can provide tactile feedback to the user and enhance the user's perception.

[0029] According to the technical solution provided in the application embodiment, when the moving part of the shaft locking mechanism is in the working position, the switch is closed, and the motor drives the output shaft to rotate. In the shaft locking position, the switch is open and the output shaft is constrained by the clutch. The moving part can switch between the two positions through a one-button double-action method, realizing the interlocking of the drive motor starting state and the output shaft locking state. A creative one-button double-action operation mode is adopted, allowing for dual switching between the working mode and the locking mode with a single press. During operation, the moving part has a precisely designed first position transition zone on its conversion trajectory. Within this critical area, the microswitch is in the open state, but the clutch is not yet engaged, forming a dual protection mechanism: on the one hand, it ensures that the motor is completely de-energized during gear disengagement, avoiding accidental starting due to residual voltage; on the other hand, it provides sufficient buffer space for the clutch, effectively solving the gear collision and tooth breakage phenomena common in traditional structures. This progressive separation-engagement design not only significantly reduces mechanical wear but also significantly improves the safety of equipment operation.

[0030] From a system safety perspective, this shaft locking mechanism achieves triple protection: firstly, electrical interlocking ensures strict mutual exclusion between motor starting and output shaft locking; secondly, mechanical interlocking creates physical isolation; and finally, a transition zone design eliminates safety hazards during state transitions. This multi-layered protection mechanism is particularly suitable for fields with stringent operational safety requirements, such as high-power power tools and industrial automation equipment, ensuring both operator safety and extending the service life of critical equipment components. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the output shaft and clamping assembly of a power tool in the related technology;

[0032] Figure 2 A schematic structural diagram of the power tools provided in the embodiments of this application;

[0033] Figure 3 for Figure 2 AA section view;

[0034] Figure 4 A schematic diagram illustrating the position switching of the shaft locking mechanism in a power tool provided in an embodiment of this application;

[0035] Figure 5 This is a partial structural diagram of the second clutch in a power tool provided in an embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0038] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0039] Unless otherwise defined, 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 application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0040] This application relates to a power tool used in industrial production and various processing fields. Such a power tool can be, for example, a wood milling machine, angle grinder, milling drill, engraving machine, and electric grinder. The basic working principle of these various types of power tools is as follows: a drive motor generates rotational driving force, which drives the output shaft to rotate at high speed, causing various tool heads (such as cutting heads, grinding heads, drill bits, etc.) connected to the output shaft to rotate, thereby enabling diverse processing operations such as grinding, cutting, and drilling on various types of materials such as wood, metal, and stone.

[0041] The tool head and output shaft are usually connected by a mechanism such as a chuck and nut. Figure 1 This illustrates one connection method between the tool head and the output shaft in related technologies. For ease of understanding, Figure 1 The image only shows a portion of the structure of the output shaft and the clamping assembly at the shaft end of the power tool.

[0042] like Figure 1As shown, the front end of the output shaft 110 is provided with a locking nut 120 and a clamp 140 for mounting the tool head 130. The outer surface of the end of the output shaft 110 is provided with an external thread 111. The locking nut 120 is connected to the external thread 111 of the output shaft 110 through its internal thread. The locking nut 120 and the output shaft 110 cooperate to adjust the clamping force of the clamp 140 on the tool head 130. The longer the thread is screwed in, the greater the clamping force. When it is necessary to replace the tool head 130, rotate the locking nut 120 to move the locking nut 120 away from the output shaft 110, thereby reducing the clamping force of the locking nut 120 on the clamp 140, so as to remove the tool head 130. After installing a new tool head 130, rotate the locking nut 120 in the opposite direction to move the locking nut 120 closer to the output shaft 110, thereby increasing its clamping force on the clamp 140, thereby fixing the tool head 130 in place.

[0043] It should be noted that, Figure 1 The structure of the clamping component shown is only an example. The embodiments of this application do not limit its structural form. The clamping component can also be a spring chuck, a self-locking hexagonal chuck, a magnetic chuck, a chuck chuck, or other types of chuck.

[0044] For the various types of power tools mentioned above, their output shafts are usually directly connected to the drive motor. When changing the tool head, it is necessary to lock the output shaft to restrict its rotation so that the lock nut can be turned.

[0045] To address the aforementioned issues, related technologies have provided a technical solution of incorporating a shaft locking mechanism in power tools. This mechanism restricts the rotation of the output shaft, thereby facilitating the replacement of the tool head.

[0046] The technical solutions provided by the related technologies can achieve locking of the output shaft, but some problems still exist. The following will explain in detail the technical solutions and their problems with examples.

[0047] Power tools in related technologies are equipped with a shaft locking mechanism, which includes a first clutch, a second clutch, and a push plate. The first clutch is fixed to the output shaft, and the push plate pushes the second clutch, causing it to move axially along the output shaft. The first and second clutches are respectively provided with grooves and protrusions. Through the engagement of the grooves and protrusions, circumferential limiting cooperation is achieved between the first and second clutches, restricting the rotation of the output shaft to facilitate tool head replacement. A microswitch is also provided within the housing. Pushing the push plate to move the second clutch away from the first clutch, thus releasing the lock on the output shaft, simultaneously triggers the microswitch to start the power tool.

[0048] In the aforementioned technical solution, when the push plate moves from the power-on position to the shaft lock position, there are situations where the drive motor is not powered off but the shaft lock mechanism is already engaged, or the drive motor is powered off but the output shaft is still rotating due to inertia. In both cases, the shaft lock mechanism will experience tooth knocking during engagement, which will impact the shaft lock mechanism and make it more susceptible to damage. This will significantly reduce the service life of the shaft lock mechanism, and will also generate considerable noise during engagement, causing user discomfort and reducing the user experience.

[0049] This application provides a power tool to solve the problems existing in the related technologies. The technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0050] Figure 2 This is a schematic structural diagram of the power tool 200 provided in the embodiments of this application. Figure 3 yes Figure 2 AA sectional view. See also Figure 2 and Figure 3 The power tool 200 includes a drive motor 210, an output shaft 220, a switch unit 230, and a shaft locking mechanism 240.

[0051] The drive motor 210 is connected to the output shaft 220 and is used to drive the output shaft 220 to rotate. The drive motor 210 can be, for example, a... Figure 3 The structure shown has a rotating shaft 221 connected to the rotor of a drive motor 210. The rotor of the drive motor 210 interacts with the magnetic field of the stator, causing it to rotate the shaft. The aforementioned rotating shaft 221 can be connected to the output shaft 220 of the power tool via... Figure 3 The coupling 250 shown in the figure achieves a fixed connection. This application embodiment does not limit the connection method mentioned above. The rotating shaft 221 and the output shaft 220 can also be connected by flange connection, key connection (flat key, semi-circular key, wedge key, etc.), spline connection, tapered sleeve connection, welding or bonding, as long as a stable connection between the two shafts can be achieved.

[0052] As one possible implementation, the drive motor 210 can also be a hollow shaft motor, with the output shaft 220 of the power tool passing through the output hole of the drive motor 210. This type of motor has a compact structure, eliminating the need for a coupling between the drive motor 210 and the output shaft 220, and reducing the axial dimension when applied to power tools.

[0053] The type of the drive motor 210 is not limited in this application embodiment. The drive motor 210 can be any one of the following: a DC brushed motor, a DC brushless motor, an AC series motor, or a permanent magnet synchronous motor.

[0054] The end of the output shaft 220 away from the drive motor 210 is used to connect the tool head 222. In some implementations, the fixing device of the tool head 222 may be integrally formed with the output shaft 220; or, as another implementation, the fixing device of the tool head 222 may be detachably connected to the output shaft 220, and the fixing device may be, for example, a chuck.

[0055] The switching unit 230 is used to control the start and stop of the drive motor 210. The switching unit 230 is directly or indirectly connected to the drive motor 210. For example, the switching unit 230 can be directly connected to the drive motor 210 to control the drive motor 210 by controlling the on and off of the input power supply to the drive motor 210; or, the switching unit 230 can be connected to the control circuit of the drive motor 210, which is used to control the rotation direction and rotation speed of the drive motor 210.

[0056] The aforementioned switch unit 230 can be a normally open switch, which is closed under normal conditions and is in an open circuit state, and is closed when pressed or flipped; or, the switch unit 230 can also be a normally closed switch, which is the opposite of a normally open switch, where the switch contacts are closed under normal conditions and the circuit is in a closed state, and is opened when subjected to external force.

[0057] The present application does not limit the specific type of the switch unit 230. The switch unit 230 may be any of a variety of switch devices such as push-button switch, trigger switch, slide switch or inductive switch.

[0058] The shaft locking mechanism 240 includes a moving part 241 and a second clutch 242.

[0059] The movable part 241 includes a pressing member 2411 and a first clutch member 2412. The movable part 241 has a working position and a shaft lock position, and can switch between the two positions.

[0060] The moving part 241 can move between the aforementioned working position and the shaft lock position in many ways, for example, in Figure 2 and Figure 3 In the illustrated technical solution, the working position and the shaft lock position are arranged along the axis of the output shaft 220, and the movement mode of the moving part 241 is linear movement along the axial direction.

[0061] As one possible implementation, the movement of the moving part can be along the rotation direction of the rotating shaft, and the aforementioned working position and shaft lock position are set at different phases along the circumferential direction.

[0062] As another possible implementation, the movement of the moving part can also be rotation or oscillation around the first rotating shaft. The axial direction of the first rotating shaft can be consistent with or perpendicular to the axial direction of the output shaft. In this case, the movement of the moving part is similar to a rocker switch, which is in the working position when one end is pressed and in the shaft-locked position when the other end is pressed.

[0063] As another possible implementation, the movement of the moving part can also be along the diameter direction of the output shaft. In this case, the movement of the moving part is similar to a push-button switch. When the moving part approaches the output shaft in the radial direction, it is in the shaft lock position, and when it moves away from the output shaft, it is in the working position.

[0064] The second clutch is fixedly connected to the output shaft 220. When the output shaft 220 rotates under the drive of the drive motor 210, the second clutch 242 can rotate synchronously with the output shaft 220.

[0065] The fixed connection between the second clutch 242 and the output shaft 220 includes positioning along the circumferential and axial directions of the output shaft 220. Circumferential positioning can be achieved, for example, by providing keyways on both the second clutch 242 and the output shaft 220, and connecting them using flat keys within the keyways. Axial positioning can be achieved using set screws, or by utilizing shoulders and retaining rings provided on the output shaft 220.

[0066] As one possible approach, the second clutch 242 can also be integrally formed with the output shaft 220.

[0067] During the movement of the moving part 241, the pressing member 2411 and the first clutch member 2412 move synchronously. The pressing member 2411 of the moving part 241 is used to interact with the aforementioned switch unit 230. During the movement of the moving part 241, the pressing member 2411 can approach the switch unit 230 and apply a certain pressure to the switch unit 230, so that the switch unit 230 is pressed; when moving in the opposite direction, the pressing member 2411 can move away from the switch unit 230, releasing the switch unit 230. The first clutch member 2412 is used to cooperate with the second clutch member 242 to achieve constraint on the output shaft 220. During the movement of the moving part 241, the first clutch member 2412 can engage or disengage with the second clutch member 242. When the first clutch 2412 and the second clutch 242 are engaged, the first clutch 2412 can constrain the second clutch 242, thereby restricting the circumferential movement of the output shaft 220; when the first clutch 2412 and the second clutch 242 are disengaged, the constraint of the second clutch 242 will be released, allowing the output shaft 220 to rotate freely.

[0068] In the technical solution of this application, when the moving part 241 is in the working position, the pressing member 2411 can abut against the switching unit 230 to close the switching unit 230, and at the same time the first clutch member 2412 and the second clutch member 242 are separated from each other; at this time, the output shaft 220 can rotate freely under the drive of the drive motor 210.

[0069] When the moving part 241 is in the shaft lock position, the first clutch 2412 and the second clutch 242 can engage with each other, while the pressing part 2411 separates from the switch unit 230. In this case, the drive motor 210 stops rotating, and the first clutch 2412 and the second clutch 242 form a circumferential constraint on the output shaft 220, which facilitates the disassembly and assembly of the tool head.

[0070] The movable part 241 switches between the two positions mentioned above, realizing the two actions of turning the power tool on and off and switching the output shaft 220 locked and unlocked state with one key. This operation method is hereinafter referred to as "one-key dual action".

[0071] The first position interval is between the working position and the shaft lock position. When the moving part 241 is in the first position interval, the switch unit 230 is disconnected, and the first clutch 2412 and the second clutch 242 are separated.

[0072] The following is combined Figure 4 The technical solution of this application will be described in detail. It should be noted that... Figure 4 The following description is based on the example of the movement of the moving part 241 along the axial direction of the output shaft 220. At this time, the working position and the shaft lock position are spaced apart along the aforementioned axial direction. The moving part 241 can switch from the working position to the shaft lock position by moving along the axial direction, or switch from the shaft lock position to the working position by moving in the opposite direction. Figure 4 (a) and Figure 4 (c) are schematic diagrams showing the states of the shaft locking mechanism 240 when the moving part 241 is in the working position and the shaft locking position, respectively. Figure 4 (b) is a schematic diagram of the state when the moving part 241 is in the first position interval.

[0073] like Figure 4 As shown in (a), in the working position, the pressing member 2411 abuts against the switching unit 230, causing the switching unit 230 to close. Simultaneously, the first clutch member 2412 and the second clutch member 242 move away from each other, and the drive motor drives the output shaft 220 to rotate. When the moving part 241 is pushed to move in the direction of the arrow in the figure, the pressing member 2411 gradually moves away from the switching unit 230, reaching... Figure 4When the first position interval shown in (b) is at its starting position, the switch unit 230 is disconnected, and the power supply to the drive motor is disconnected. At this time, the drive motor will continue to rotate under inertia. Meanwhile, there is a certain distance between the first clutch 2412 and the second clutch 242, thereby ensuring that they do not engage with each other; continue to refer to Figure 4 In section (b), when the moving part 241 continues to move from the starting position of the first position interval to the ending position of the first position interval as shown by the dashed line in the figure, the drive motor stops completely; after passing the ending position of the first position interval, the moving part 241 continues to move to Figure 4 In the state shown in (c), the pressing member 2411 is away from the switching unit 230, and the first clutch member 2412 and the second clutch member 242 are engaged with each other, so that the output shaft 220 is locked.

[0074] In other words, during the process of switching the moving part 241 from the working position to the shaft lock position, the movement within the first position range provides sufficient time for the drive motor to stop, thus avoiding the risk of gear breakage caused by the first clutch 2412 engaging with the rotating second clutch 242. Alternatively, in this process, the disconnection of the switching unit 230 occurs earlier than the engagement of the first clutch 2412 and the second clutch 242, and the time difference between these two states provides sufficient time for the drive motor to stop.

[0075] The moving part 241 is moved from Figure 4 The shaft lock position shown in (c) is switched to Figure 4 During the operation in the working position shown in (a), the first clutch 2412 moves away from the second clutch 242; after passing through the first position interval, the first clutch 2412 and the second clutch 242 are completely disengaged; thereafter, the moving part 241 continues to move, causing the pressing part 2411 to control the switch unit 230 to close. In the above process, the drive motor will only start after the circumferential constraint of the output shaft 220 is completely released, thereby preventing the drive motor from stalling when switching from the shaft lock state to the working state.

[0076] The axial movement of the moving part 241 described above is simple to operate and has minimal impact on the overall radial dimension of the power tool.

[0077] As a possible implementation, the movement of the moving part can also be a swing along a fixed axis. In this case, the switching between the working position and the shaft lock position of the moving part can be a swing between two extreme positions along a fixed axis. The aforementioned first position interval is a range of angles traversed during the swing.

[0078] Taking the movement of the moving part from the working position to the shaft lock position as an example, in the working position, the switch unit is closed and the clutches are separated; after the moving part starts to rotate, the pressing part gradually moves away from the switch unit. When it reaches the starting position of the first position interval, the switch unit is disconnected, the input power of the drive motor is disconnected, and the drive motor will continue to rotate under inertia, and the pressing part may remain in contact with the switch unit; the moving part continues to move through the first position interval, at which time there is still a distance between the first clutch and the second clutch, and the speed of the drive motor gradually decreases; when it reaches the ending position of the first position interval, the drive motor stops completely; in the shaft lock position, the first clutch and the second clutch contact each other and reach a mutually engaged state, thereby completing the circumferential constraint on the output shaft.

[0079] Based on the above methods, when the moving part of the shaft locking mechanism is in the working position, the switch is closed, and the motor drives the output shaft to rotate. In the shaft locking position, the switch is open and the output shaft is constrained by the clutch. The moving part switches between the two positions through a one-button double-action method, realizing the interlocking of the drive motor starting state and the output shaft locking state. A creative one-button double-action operation mode is adopted, allowing for dual switching between the working mode and the locking mode with a single press. During operation, the moving part has a precisely designed first position transition zone on its switching trajectory. Within this critical area, the microswitch is in the open state, but the clutch is not yet engaged, forming a dual protection mechanism: on the one hand, it ensures that the motor is completely de-energized during gear disengagement, avoiding accidental starting due to residual voltage; on the other hand, it provides sufficient buffer space for the clutch, effectively solving the gear collision and tooth breakage phenomena common in traditional structures. This progressive separation-engagement design not only significantly reduces mechanical wear but also significantly improves the safety of equipment operation.

[0080] In some embodiments, such as Figure 2 and 3 As shown, the power tool 200 also includes a housing 260, which encloses to form a first cavity 261.

[0081] The aforementioned drive motor 210, switch unit 230, pressing member 2411, first clutch member 2412 and second clutch member 242 are all located in the first cavity 261, and the end of the output shaft 220 away from the drive motor 210 extends out from the first cavity 261.

[0082] The aforementioned moving part 241 also includes an operating member 2413 at least partially disposed outside the first cavity 261. The operating member 2413 is connected to the pressing member 2411 and the first clutch member 2412 and is used to receive user operation to drive the pressing member 2411 and the first clutch member 2412 to switch positions.

[0083] The aforementioned operating component 2413 could be, for example, Figure 2 and Figure 3The push plate shown in the figure includes a first portion located outside the housing 260 and a second portion located inside the housing 260. The first portion is used for interaction with the user, and the second portion is used for connection with the pressing member 2411 and the first clutch member 2412.

[0084] In some embodiments, one or more strip-shaped protrusions are provided on the side of the push plate away from the housing 260, which can increase friction when the push plate is moved by pushing it with a finger.

[0085] In the embodiments of this application, the first part and the second part of the push plate can be integrally formed. For example, the push plate can be made by injection molding or other methods; or, as a possible implementation, the two parts can be connected by snap-fit ​​or bolts or other methods. The embodiments of this application do not specifically limit this.

[0086] It is understood that in the technical solution of this application embodiment, the pressing member 2411 can close or open the switching unit 230 when providing pressure to the switching unit 230; the switching unit 230 used in power tools is usually a micro switch, and its triggering pressure is usually small. The pressing member 2411 does not need to provide a large force when triggering the switching unit 230, so the pressing member 2411 can be made of materials such as plastic. As one implementation, the pressing member 2411 can be integrally formed with the aforementioned operating member 2413 by injection molding or other methods.

[0087] The first clutch element 2412 needs to cooperate with the second clutch element 242 to restrict the rotation of the output shaft 220. When changing the tool head, the first clutch element 2412 will be subjected to a large shear force in the circumferential direction, which places high demands on the strength of the first clutch element 2412. If the shear strength of the first clutch element 2412 is low, it may break and be damaged under large external forces, affecting the service life of the power tool. Therefore, the first clutch element 2412 can be made of high-strength polymer materials or metal materials.

[0088] When the material of the first clutch 2412 is different from that of the aforementioned operating member 2413, the first clutch 2412 can be fixedly connected to the operating member 2413 by means of threaded connection, bonding or snap-fit; or, the first clutch 2412, the pressing member 2411 and the operating member 2413 can be made of the same material by integral molding.

[0089] According to the above-mentioned technical means, the operating component 2413 is set outside the housing 260, which makes it convenient for the user to operate.

[0090] Continue reading Figures 2-4In this embodiment, the pressing member 2411 and the first clutch member 2412 are arranged along the axial direction of the output shaft 220. This arrangement minimizes the space occupied in the radial direction of the power tool, resulting in a smaller overall diameter.

[0091] One of the first clutch member 2412 and the second clutch member 242 has a protrusion extending axially, and the other has a recess. The number of recesses is at least one, meaning that either the first clutch member 2412 or the second clutch member 242 may have one or more recesses.

[0092] When the moving part 241 is in the shaft lock position, the protrusion can extend into any one of the at least one recess, thereby restricting the rotation of the output shaft 220.

[0093] This application does not specifically limit the shape and structure of the protrusions and recesses described above. For example, the protrusion can be a raised spherical or conical surface, and the recess can be a concave spherical or conical surface that matches the shape of the protrusion. When the first clutch contacts the second clutch, the engagement of the spherical or conical surface can serve as a guide, facilitating the engagement of the first and second clutches.

[0094] In some embodiments, to reduce the structural complexity of the first and second clutch components and facilitate processing, the protrusions and recesses can be configured as follows: Figures 2-4 The structure shown, Figure 5 It shows Figures 2-4 A partial view of the second clutch 242.

[0095] In this embodiment, the protrusion is disposed on the first clutch 2412 facing upward, and the recess is disposed on the second clutch 242.

[0096] The first clutch component 2412 includes a protrusion, which is a convex post extending axially.

[0097] like Figure 5 As shown, the second clutch element 242 is a clutch disc fixedly connected to the output shaft. The main body of the clutch disc is disc-shaped. The second clutch element 242 also includes a connecting part for connecting to the output shaft, which is a boss connected to the main body. The second clutch element 242 has a connecting hole for the output shaft. After the output shaft passes through the connecting hole, the second clutch element 242 can be fixedly connected to the output shaft by means of key connection, pin connection, or interference fit connection.

[0098] Alternatively, as one possible implementation, the second clutch 242 may be integrally formed with the output shaft.

[0099] When the second clutch 242 is a clutch disc, the aforementioned recess is the shaft lock hole 2423 on the clutch disc. When the moving part 241 is in the shaft lock position, the protrusion in the first clutch 2412 can extend into the shaft lock hole.

[0100] In some embodiments, the second clutch member 242 has at least two shaft locking holes 2423, which are evenly distributed along the circumferential direction of the clutch disc, for example, in Figure 5 The second clutch 242 shown has 6 shaft locking holes 2423, which are evenly distributed along the circumferential direction.

[0101] In some embodiments, the length of the aforementioned first position interval is greater than or equal to the conduction stroke of the switch unit 230. The conduction stroke of the switch unit 230 is the distance traveled from the contact between the pressing member 2411 and the switch unit 230 to the conduction moving part 241 of the switch unit 230.

[0102] Combination Figure 4 For example, if the pressing member 2411 moves 1mm closer to the switch unit 230 after contacting the switch unit 230, then the switch unit 230 is turned on, indicating that the conduction stroke of the switch unit 230 is 1mm.

[0103] The length of the first position interval could be, for example, 3mm. In this case, such as... Figure 4 As shown by the dashed line in diagram (b), when the moving part 241 moves from the shaft lock position to the working position to the moment when the first clutch 2412 and the second clutch 242 are separated, the distance between the end of the pressing member 2411 near the switch unit 230 and the end of the switch unit 230 near the pressing member 2411 is the difference between the length of the first position interval and the conduction stroke of the switch unit 230, which is 2mm. When the moving part 241 moves within this 2mm range, the first clutch 2412 and the second clutch 242 are separated, and the pressing member 2411 does not contact the switch unit 230. The moving part 241 moves 2mm from the position shown by the dashed line until the pressing member 2411 initially contacts the switch unit 230, while there is a 2mm gap between the first clutch 2412 and the second clutch 242. At this time, the switch unit 230 is still in the open state. After this, the moving part moves 1mm to... Figure 4 As shown by the solid line in (b), the switch unit 230 is turned on when it is pressed a certain distance, which is its conduction stroke. That is, when the moving part 241 moves within a 3mm range of the first position interval, the switch unit 230 is in the off state, and the first clutch 2412 and the second clutch 242 are separated from each other.

[0104] Conversely, during the movement of the moving part 241 from the working position to the shaft lock position, after the moving part 241 begins to move, the switch unit 230 is disengaged. At this time, the pressing member 2411 remains in contact with the switch unit 230, and the closest distance between the first clutch member 2412 and the second clutch member 242 is 3mm. After moving 1mm closer to the second clutch member 242, the pressing member 2411 separates from the switch unit 230, and the distance between the first clutch member 2412 and the second clutch member 242 is 2mm. After the moving part 241 continues to move 2mm, the first clutch member 2412 and the second clutch member 242 engage, completing the locking of the output shaft 220.

[0105] The above describes the case where the length of the first position interval is greater than the conduction stroke of the switch unit 230. The following describes the case where the length of the first position interval is the same as the conduction stroke of the switch unit 230. If the length of the first position interval is the same as the conduction stroke, when switching from the shaft lock position to the working position, while the first clutch 2412 and the second clutch 242 separate, the end of the pressing member 2411 abuts against the switch unit 230. At this time, the output shaft 220 can rotate freely, but the switch unit 230 is not closed. After the moving part 241 moves 1 mm, there is a 1 mm gap between the first clutch 2412 and the second clutch 242. At this time, the switch unit 230 is turned on, and the drive motor drives the output shaft 220 to rotate. The first clutch 2412 and the second clutch 242 have no effect on the rotation of the output shaft 220.

[0106] During the process of switching from the working position to the shaft lock position, after the switch unit 230 is disconnected, the moving part 241 continues to move 1mm closer to the second clutch 242 before the first clutch 2412 engages with the second clutch 242, thereby locking the output shaft 220.

[0107] According to the above technical means, the length of the first position interval is set to be greater than or equal to the conduction stroke of the switch unit, so that the moving part can move a certain distance after the engagement of the first clutch and the second clutch is disengaged before the switch unit can be turned on, and after the switch unit is turned off, it can move a certain distance before the first clutch and the second clutch can be engaged. This can improve the safety of power tools and avoid malfunctions such as motor stalling or gear breakage.

[0108] It is understandable that after the switch unit is disconnected, the drive motor will continue to rotate due to inertia, and it will still take a certain amount of time for the drive motor to stop completely after the power is cut off. However, in the technical solution of this application, the length of the first position interval can be reasonably set so that the time for the moving part to move within the first position interval is greater than the time required for the motor to stop, thereby ensuring that the drive motor is in a stopped state when the first clutch and the second clutch are engaged.

[0109] Based on this, in some embodiments of this application, the length of the first position interval can be set as the sum of the conduction stroke of the switching unit and a preset gap. The length of the preset gap is related to the rotational speed of the drive motor and / or the moment of inertia of the drive motor.

[0110] More specifically, the length of the first position interval is directly proportional to the time required for the drive motor to stop. The time required for the drive motor to stop is positively correlated with the motor speed and / or the moment of inertia of the drive motor. Higher motor speeds require longer stops, and greater moment of inertia results in greater rotor inertia and a longer stop time. Therefore, the length of the first position interval is positively correlated with the drive motor speed and / or the moment of inertia of the drive motor.

[0111] In some embodiments, the length of the first position interval is also related to the type of drive motor. For example, when the drive motor is an AC series motor or a wound-rotor induction motor, it may take a long time to stop rotating after power is cut off. If the length of the first position interval is small, the moving part may have moved to the critical point before the motor stops rotating, which can easily cause the clutch unit to break. For brushless DC motors, switched reluctance motors, or stepper motors, these types of motors can usually stop rotating in a short time after power is cut off. In this case, the length of the first position interval can be set to be smaller, which can shorten the moving distance of the moving part and thus facilitate the miniaturization of the overall structure of the power tool.

[0112] It should also be noted that the speed of the drive motor mentioned in the embodiments of this application can be the rated speed or the maximum speed of the drive motor.

[0113] In some embodiments, the length of the first location interval can be determined according to the following formula:

[0114]

[0115] In the above formula, n is the rotational speed of the drive motor, s is the stroke of the switching unit, k1 is the first coefficient, and k2 is the second coefficient.

[0116] The value of k1 is related to the maximum speed of the motor and / or the moment of inertia of the motor. For electric grinders, the speed of the drive motor is usually 5000-30000 r / min; for this type of power tool, the value of k1 can be 6*10. -4 The value of k2 is related to the structure of the switching unit. The product of the travel of the switching unit and the second coefficient is the conduction travel of the switching unit. The value of the second coefficient k2 can be 0.5-0.7.

[0117] The above formula can also be written as: Where s1 is the conduction stroke of the switching unit.

[0118] For example, when the speed of the drive motor is 30,000 r / min and the stroke of the switching unit is 2 mm, the length of the first position interval is 2 mm according to the above formula.

[0119] In some embodiments, the operating member has a first positioning block, and correspondingly, the housing has a first positioning groove and a second positioning groove. The first positioning block is located on the side of the operating member near the housing, and this first positioning block can be a strip-shaped protrusion extending from the surface of the operating member; correspondingly, the first positioning groove and the second positioning groove are strip-shaped grooves formed by recesses downward from the surface of the housing.

[0120] When the moving part is in the working position, the first positioning block engages with the first positioning groove. When the moving part is in the shaft lock position, the first positioning block can engage with the second positioning groove.

[0121] The aforementioned positioning block and positioning groove can position the moving part at the two extreme positions of the working position and the shaft lock position, and can play a certain locking role; on the other hand, the engagement of the positioning block and the positioning groove can provide tactile feedback to the user and enhance the user's perception.

[0122] In some embodiments, such as Figure 3 As shown, a locking nut 221 and a clamp 223 for mounting the tool head 222 are connected to the end of the output shaft 220 away from the drive motor 210. The end of the output shaft 220 is provided with an external thread, and the locking nut 221 is connected to the external thread. The clamping force of the clamp 223 on the tool head 222 is adjusted by cooperating with the output shaft 220.

[0123] In some embodiments, continue reading Figure 3 The power tool also includes:

[0124] Power supply 270 is used to provide energy to drive motor 210.

[0125] The control circuit board 280 is connected to the aforementioned switch unit 230, power supply 270 and drive motor 210, and is used to control the opening and closing of the drive motor 210 through the switch unit 230.

[0126] The aforementioned power source 270 can be a battery for a power tool, which can be built into the power tool.

[0127] Alternatively, as an alternative, the battery can be detachably connected to the body of the power tool.

[0128] When the power supply 270 is a removable battery, the bottom cover of the housing 260, located away from the output shaft 220, can be detachably connected to the housing 260. When installing the battery, remove the bottom cover, insert the battery into the housing 260, and then reattach the bottom cover to the housing 260.

[0129] Alternatively, the end of the housing 260 away from the output shaft 220 can be configured as an open structure, with a bottom shell at the end of the battery that matches the shape of the housing 260 of the power tool. After the battery is inserted into the preset position, the bottom shell of the battery and the housing 260 of the power tool fit together to form a complete outer shell.

[0130] In some embodiments, such as Figure 2 As shown, the power tool also includes a control panel 290, at least a portion of which is disposed outside the housing 260.

[0131] The control panel 290 can be connected to the control circuit board 280 for controlling the power tools and displaying the status information of the power tools.

[0132] For example, the control panel 290 has multiple indicator lights 291 that can be used to display status information of the power tool. This status information may include, for example, the rotational speed of the output shaft 220, battery level, etc. For instance, the remaining battery level or rotational speed can be displayed by changing the color of the indicator lights 291 or by the number of indicator lights 291 that are illuminated; similarly, when charging the battery, the charging progress can be displayed by the breathing frequency or color change of the indicator lights 291.

[0133] The control panel 290 also includes at least one control component 292, which may be, for example, Figure 5 The button shown can receive user operations. For example, the power can be turned on / off by long-pressing the button; or the motor speed can be controlled by single-clicking; or, in the power-off state, the aforementioned indicator light 291 can be made to display the battery level by double-clicking.

[0134] As one possible implementation, the control component 292 described above can also be a knob.

[0135] It should be noted that the embodiments of this application do not specifically limit the display and operation logic of the indicator light 291 and the control component 292. The above description is only an example and does not constitute a limitation on the technical solution of this application.

[0136] This application also provides a power tool. The power tool includes a drive motor, an output shaft, a switching unit, a moving part, and a clutch unit. One end of the output shaft is connected to the drive motor, and the other end is used to connect to the tool head. The switching unit controls the start and stop of the drive motor. The moving part is configured to switch between a working position and a shaft-locked position. The clutch unit is disposed between the moving part and the output shaft.

[0137] When the moving part is in the shaft lock position, the clutch unit can lock the output shaft to facilitate tool head replacement; when the moving part is in the working position, the switch unit closes to drive the drive motor to rotate the output shaft.

[0138] When the moving part switches from the critical point of disengagement from the clutch unit to the working position, the distance the moving part travels is:

[0139]

[0140] Where n is the rotational speed of the drive motor, s is the stroke of the switching unit, and k1 and k2 are the first coefficient and the second coefficient, respectively. The value of the first coefficient k1 ranges from 0 to 6*10. -4 The second coefficient k2 ranges from 0.5 to 0.7.

[0141] In other words, the moving distance of the moving part is set to be positively correlated with the rotational speed of the drive unit and the stroke of the switching unit.

[0142] A clutch unit typically consists of two parts, one of which is fixedly connected to the output shaft, and the other moves with the moving parts. The two parts of the clutch unit have structures that can be interlocked with each other. The locking and unlocking of the clutch unit is the interlocking or unlocking of the two parts of the clutch unit.

[0143] The critical point at which the clutch unit separates from its interlocked state to its just-completely separated state is the point at which the clutch unit separates. Before this critical point, the two parts of the clutch unit are interlocked, locking the output shaft; after this critical point, the clutch unit separates, and the constraint on the output shaft is released.

[0144] On the other hand, the critical point at which the clutch unit separates can also be called the critical point at which the clutch unit engages.

[0145] The two parts of the clutch unit gradually approach each other from a separated state, and the distance between them continuously decreases. The critical point at which the clutch unit engages is the moment when they are about to touch but have not yet touched. Before this critical point, the clutch unit is disengaged, and the drive unit can drive the output shaft to rotate. After this critical point, the two parts of the clutch unit will engage with each other, thus locking the output shaft.

[0146] The specific value of the first coefficient mentioned above is related to one or more factors, including the type of drive motor, the speed of the drive motor, and the moment of inertia.

[0147] Taking the type of drive motor as an example, when the drive motor is an AC series motor or a wound-rotor asynchronous motor, it may take a long time to stop rotating after a power outage. If the first coefficient is set to a small value, the moving part may have moved to the critical point, but the motor has not stopped, which can easily cause the clutch unit to break. For DC brushless motors, switched reluctance motors, or stepper motors, these types of motors can usually stop rotating in a short time after a power outage. In this case, the first coefficient can be set to a small value, which can shorten the moving distance of the moving part and thus facilitate the miniaturization of the overall structure of the power tool.

[0148] Taking the speed and moment of inertia of the drive motor as an example, the speed can be the maximum speed or the rated speed. The higher the motor speed and the greater the moment of inertia, the greater the kinetic energy of the rotor, and the longer the time required for the motor to stop rotating from power failure. Correspondingly, the moving distance of the moving part needs to be set to be larger to avoid the motor not stopping rotating when the moving part reaches the aforementioned critical point. With the second coefficient unchanged, in order to ensure that the length of the first position interval meets the requirements, the first coefficient needs to be set to be larger.

[0149] The second coefficient is the ratio of the conducting stroke of the switching unit to the total stroke, and its specific value depends on the type of switching unit. For example, a certain type of micro switch used in power tools has a total stroke of 0.6 mm and a conducting stroke of approximately 0.3 mm, so the second coefficient is 0.5; for a certain type of trigger switch, the total stroke is 5 mm and the conducting stroke is 3.5 mm, so the second coefficient can be 0.7.

[0150] In some embodiments, the electric switch further includes a housing that encloses a first cavity.

[0151] The aforementioned drive motor, switching unit, and clutch unit are all housed in the first cavity, with the end of the output shaft away from the drive motor extending out from the first cavity.

[0152] The clutch unit includes a first clutch component and a second clutch component, wherein the first clutch component is connected to a moving component, and the second clutch component is fixedly connected to an output shaft. The first and second clutch components are configured such that when the moving component is in the shaft lock position, the first clutch component can engage with the second clutch component to lock the output shaft.

[0153] In some embodiments, the movable element includes an operating element located outside the housing and a pressing element located inside the first cavity. The pressing element and the first clutch are arranged axially along the output shaft. The operating element is used to receive user operation to drive the pressing element and the first clutch to move axially.

[0154] In some embodiments, the first clutch includes a protrusion, which is a protrusion extending axially; the second clutch is a clutch disc fixedly connected to the output shaft, and the clutch disc has a shaft locking hole, wherein when the moving member is in the shaft locking position, the protrusion can extend into the shaft locking hole.

[0155] The possible structural forms of the protrusions and recesses can be found in the description of the embodiments above, and will not be repeated here.

[0156] In some embodiments, the number of at least one shaft lock hole is at least two, and the at least two shaft lock holes are evenly distributed along the circumferential direction of the clutch disc.

[0157] In some embodiments, the operating member has a first positioning block; the housing is provided with a first positioning groove and a second positioning groove; when the moving member is in the working position, the first positioning block is engaged with the first positioning groove; when the moving member is in the shaft lock position, the first positioning block is engaged with the second positioning groove.

[0158] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0159] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0160] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0161] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0162] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A power tool, characterized in that, include: Drive motor; The output shaft has one end connected to the drive motor and the other end used to connect to the tool head; A switching unit is used to control the start and stop of the drive motor; Axis locking mechanism, including: The moving part, including a pressing element and a first clutch element, is configured to switch between a working position and a shaft lock position; The second clutch element is fixedly connected to the output shaft. When the moving part is in the working position, the pressing member abuts against the switching unit to close the switching unit, and the first clutch member and the second clutch member separate. When the moving part is in the shaft lock position, the first clutch and the second clutch engage with each other to constrain the rotation of the output shaft, and the pressing member is separated from the switch unit; When the moving part is located within a first position range between the working position and the shaft lock position, the switching unit is disconnected, and the first clutch is separated from the second clutch.

2. The power tool according to claim 1, characterized in that, Also includes: The shell, enclosing and forming the first cavity; The drive motor, the switch unit, the pressing member, the first clutch member, and the second clutch member are located in the first cavity, and the end of the output shaft away from the drive motor extends out from the first cavity; The moving part further includes an operating component at least partially disposed outside the first cavity. The operating component is connected to the pressing component and the first clutch component, and is used to receive user operation and drive the pressing component and the first clutch component to switch positions.

3. The power tool according to claim 2, characterized in that, The switching operation of the moving part between the working position and the shaft lock position is any one of axial movement along the output shaft, radial movement along the output shaft, and circumferential movement along the output shaft.

4. The power tool according to claim 2, characterized in that, The movable part is connected to the housing via a first rotating shaft, so that the movable part can swing around the first rotating shaft; The switching operation of the moving part between the working position and the shaft lock position is to swing around the first rotating shaft.

5. The power tool according to claim 2, characterized in that, The pressing member and the first clutch member are arranged along the axial direction of the output shaft; One of the first clutch and the second clutch has a protrusion extending along the axial direction, and the other has at least one recess. When the moving part is in the shaft lock position, the protrusion extends into one of the at least one recessed parts to constrain the rotation of the output shaft.

6. The power tool according to claim 5, characterized in that, The first clutch includes the protrusion, which is a protrusion extending along the axial direction; The second clutch component is a clutch disc fixedly connected to the output shaft. The recessed portion is a shaft lock hole on the clutch disc. When the moving portion is in the shaft lock position, the protrusion can extend into the shaft lock hole.

7. The power tool according to claim 6, characterized in that, The number of at least one shaft locking hole is at least two, and the at least two shaft locking holes are evenly distributed along the circumferential direction of the clutch disc.

8. The power tool according to any one of claims 5-7, characterized in that, The length of the first position interval is greater than or equal to the conduction stroke of the switching unit; The conduction stroke of the switch is the distance the moving part moves from the moment the pressing member contacts the switch unit until the switch unit is turned on.

9. The power tool according to claim 8, characterized in that, The length of the first position interval is the sum of the conduction stroke of the switching unit and the preset gap; The length of the preset gap is related to the rotational speed of the drive motor and / or the moment of inertia of the drive motor.

10. The power tool according to any one of claims 2-7, characterized in that, The operating component has a first positioning block; The housing is provided with a first positioning groove and a second positioning groove; When the moving part is in the working position, the first positioning block is engaged with the first positioning groove; When the moving part is in the shaft lock position, the first positioning block engages with the second positioning groove.

11. The power tool according to any one of claims 1-7, characterized in that, The end of the output shaft away from the drive motor is connected to a lock nut and a clamp for mounting the tool head; The output shaft has an external thread at its end, and the locking nut is connected to the external thread. The locking nut cooperates with the output shaft to adjust the clamping force of the clamp on the tool head.

12. The power tool according to any one of claims 2-7, characterized in that, Also includes: A power source, used to provide energy to the drive motor; A control circuit board is connected to the switching unit, the power supply, and the drive motor to control the opening and closing of the drive motor through the switching unit.

13. The power tool according to claim 12, characterized in that, The housing includes a first housing and a second housing detachably connected to the first housing, and the power source is a removable battery.

14. The power tool according to claim 12, characterized in that, Also includes: A control panel connected to the control circuit board, at least a portion of which is disposed outside the housing; The control panel has at least one indicator light and at least one control component. The at least one indicator light is used to display the status information of the power tool, and the at least one control component is used to receive user operations to control the power tool through the control circuit board.

15. A power tool, characterized in that, include: Drive motor; The output shaft has one end connected to the drive motor and the other end used to connect to the tool head; A switching unit is used to control the start and stop of the drive motor; The moving part is configured to switch between the working position and the shaft lock position; The clutch unit is located between the moving part and the output shaft; When the moving part is in the shaft lock position, the clutch unit locks the output shaft; When the moving part is in the working position, the switching unit is closed; When the moving component switches from the critical point of disengagement from the clutch unit to the working position, the distance the moving component moves is: Where n is the rotational speed of the drive motor, s is the stroke of the switching unit, and k1 and k2 are the first coefficient and the second coefficient, respectively. The value of the first coefficient k1 ranges from 0 to 6*10. -4 The value of the second coefficient k2 ranges from 0.5 to 0.

7.

16. The power tool according to claim 15, characterized in that, The moving distance l of the moving component ranges from 0.25 mm to 3.5 mm.

17. The power tool according to claim 15, characterized in that, The speed of the drive motor ranges from 5000 to 30000 r / min, and the stroke s of the switching unit ranges from 0.1 mm to 5 mm.

18. The power tool according to claim 15, characterized in that, Also includes: The shell, enclosing and forming the first cavity; The drive motor, the switching unit, and the clutch unit are disposed in the first cavity, and the end of the output shaft away from the drive motor extends out from the first cavity; The clutch unit includes a first clutch component and a second clutch component, the first clutch component is connected to the moving component, and the second clutch component is fixedly connected to the output shaft; The first clutch and the second clutch are configured such that when the moving member is in the shaft lock position, the first clutch can engage with the second clutch to lock the output shaft.

19. The power tool according to claim 18, characterized in that, The movable component includes an operating component located outside the housing and a pressing component located inside the first cavity. The pressing component and the first clutch component are arranged along the axial direction of the output shaft. The operating component is used to receive user operation to drive the pressing component and the first clutch component to move along the axial direction.

20. The power tool according to claim 18 or 19, characterized in that, The first clutch element includes a protrusion, which is a protrusion extending along the axial direction; The second clutch component is a clutch disc fixedly connected to the output shaft. The clutch disc has a shaft locking hole, and when the moving component is in the shaft locking position, the protrusion can extend into the shaft locking hole.

21. The power tool according to claim 20, characterized in that, The number of at least one shaft locking hole is at least two, and the at least two shaft locking holes are evenly distributed along the circumferential direction of the clutch disc.

22. The power tool according to claim 19, characterized in that, The operating component has a first positioning block; The housing is provided with a first positioning groove and a second positioning groove; When the movable component is in the working position, the first positioning block engages with the first positioning groove. When the moving part is in the shaft lock position, the first positioning block engages with the second positioning groove.

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