Power tool and method of operating power tool

Abstract

The invention discloses a power tool and a method for operating the power tool. The electric tool comprises a motor, a first shell and a second shell. Wherein the first housing provides a first switch and a tool is coupled at the front end, and the second housing provides a second switch; the method includes: generating a primary signal based on a state change of the first switch; setting a starting speed Nr and switching on an electric loop for the motor; the motor is operated at the starting speed Nr; generating an auxiliary signal based on a state change of the second switch; modifying the setting; and operating the electric machine at a speed not greater than the no-load speed N0; wherein the speed not greater than the idle speed N0 is determined by the second switch. The present application relates to a method of operation that maintains a power tool in a controlled state.

Description

Technical Field

[0001] The present application relates to a power tool and a method for operating a power tool. Background Art

[0002] The power tool drives a working head to perform operations such as impact or chipping through a motor drive mechanism. The working head runs at a high speed under the drive of the motor, which has certain risks. Especially under some working conditions, such as the start-up stage of the power tool, improper operation of the user, replacement of the working head, or restarting the power tool after power-off, accidental conditions or accidents are likely to occur.

[0003] On the other hand, as a component of the power tool, the efficiency of the motor is one of the important factors determining the performance of the power tool. Summary of the Invention

[0004] One aspect of the present application is to provide a method for operating a power tool. The power tool includes a motor, a first housing, and a second housing; wherein the first housing provides a first switch and couples the tool at the front end, and the second housing provides a second switch; the method includes:

[0005] a) Generating a main signal based on the state change of the first switch;

[0006] a1) Setting a starting speed Nr and turning on the electrical circuit for the motor;

[0007] a2) Operating the motor at the starting speed Nr;

[0008] b) Generating an auxiliary signal based on the state change of the second switch;

[0009] b1) Modifying the setting; and

[0010] b2) Operating the motor at a speed not greater than the no-load speed N0;

[0011] wherein the speed not greater than the no-load speed N0 is determined by the second switch.

[0012] The operating method involved in this application maintains the power tool in a controlled state. The power tool can be normally, safely, or effectively started in response to various situations or unexpected conditions. This application controls the operation of the motor during the startup phase by providing a first switch and a second switch on the power tool and based on two signals respectively from the first switch and the second switch. When both the main signal and the auxiliary signal are generated, the motor can operate at a constant speed in the normal working mode. On the premise of the main signal, when only the main signal is generated, the motor will operate in another mode set differently from the normal working mode. In this other mode, a speed limit is given to the motor, so that the power tool can be safely started. This limit can be lower than the full-speed working speed of the motor.

[0013] When the power tool is in the operation process of the normal working mode, when the auxiliary signal is interrupted, this application provides another mode different from the normal working mode to make the motor operate at a set constant speed.

[0014] Furthermore, the first switch and the second switch are respectively provided in different housings of the power tool, which is not convenient for the user to trigger with the same hand, thus avoiding misoperation.

[0015] In addition, the first switch is provided in the first housing of the power tool coupled with the front-end tool to sense whether the front-end tool is loaded. After the front-end tool contacts the work object, the tool is pressured, resulting in a change in physical quantity, and the first switch generates a signal based on the feedback of this change in physical quantity.

[0016] The first switch has a simple and reliable structure, and is easy to manufacture and implement. The first switch uses fewer component configurations and utilizes the internal space of the power tool, so the first switch can also be integrated into the housing by a simple transformation of the existing power tool.

[0017] Another aspect involved in this application is to provide a power tool that executes the above-mentioned operating method.

[0018] The power tool involved in this application is optimized in terms of structural performance, safety performance, and efficiency respectively.

[0019] Through the following detailed description with reference to the accompanying drawings, other aspects and features of this application become apparent. However, it should be understood that these drawings are designed only for the purpose of explanation and not as a limitation of the scope of this application, as it should be referred to the appended claims. It should also be understood that the drawings are only intended to conceptually illustrate the structures and processes described herein, and unless otherwise indicated, the drawings are not necessarily drawn to scale. Description of the Drawings

[0020] Referring to the following detailed description of the specific embodiments in conjunction with the accompanying drawings, the present application will be more fully understood. In the drawings, the same reference numerals always refer to the same elements in the views. Among them:

[0021] Figure 1 Schematic diagram of an embodiment of the power tool related to the present application;

[0022] Figure 2 Schematic diagram of the first embodiment of the method for operating the power tool related to the present application;

[0023] Figure 3 Schematic of the operating state of the power tool related to the present application when starting;

[0024] Figure 4 Schematic diagram of the second embodiment of the method for operating the power tool related to the present application;

[0025] Figure 5 Schematic structural diagram of an embodiment of the first switch related to the present application;

[0026] Figure 6 Circuit diagram of an embodiment of the second switch related to the present application;

[0027] Figure 7 Schematic diagram of the third embodiment of the method for operating the power tool related to the present application;

[0028] Figure 8 Schematic diagram of the fourth embodiment of the method for operating the power tool related to the present application;

[0029] Figure 9 Schematic diagram of the fifth embodiment of the method for operating the power tool related to the present application;

[0030] Figure 10 Schematic diagram of the sixth embodiment of the method for operating the power tool related to the present application. Specific Embodiments

[0031] To help those skilled in the art to accurately understand the subject matter claimed in the present application, the following specifically describes the specific embodiments of the present application in conjunction with the accompanying drawings.

[0032] Figure 1FIG. 0 is an overall schematic view of an embodiment of a power tool according to the present application. The power tool is shown as a hammer drill as a whole, and it includes a housing. A tool, i.e., a working head 24 (schematically shown), is connected to the front end of the housing, and the rear of the housing forms a grippable handle 12. In the present application, the directional term "front" means close to the working object 20, and "rear" means away from the working object 20. A space 14 is left in the housing to facilitate the user to hold the handle 12 through the space 14. The housing can be regarded as generally including two parts, i.e., a first housing 16 and a second housing 18, which are separated by the space 14 and are integral at the bottom. At the top, a corrugated structure 21 is provided between the first housing 16 and the second housing 18, which is used to cooperate with the housing to absorb part of the vibration energy generated by the operation of the front tool during the operation of the power tool. The electronic module can be arranged at the bottom end of the first housing 16, which receives a plurality of signals, processes these signals, and issues instructions. A display screen or a touchable screen or control buttons for human-machine interaction can also be integrated at the rear end of the first housing 16. A rotating shaft for coupling the tool is arranged in the first housing 16. The motor can be arranged in the second housing 18 to drive the rotating shaft. A detachable power source, such as a lithium battery 22, can also be provided at the bottom of the housing.

[0033] The first housing 16 provides a first switch 26, and the second housing 18 provides a second switch 28. The first switch 26 and the second switch 28 can both be mechanical switches or electronic control switches, or one of the switches is a mechanical switch and the other switch is an electronic control switch. The electronic control switch can be hidden in the first housing 16 or the second housing 18 so as not to be touched by the hand.

[0034] Figure 2 FIG. 7 is a schematic view of a first embodiment of a method for operating a power tool according to the present application.

[0035] At 201, a main signal is generated based on the state change of the first switch. The states of the first switch include "on" and "off". After changing from one state to the other state, the change is sensed and a main signal indicating the state change of the first switch is generated accordingly.

[0036] At 202, a starting speed Nr is set and an electrical circuit for the motor is turned on. When the electrical circuit is turned on, the rotating shaft is in a ready state to rotate / move.

[0037] At 203, the motor is operated at the starting speed Nr. When only the main signal is generated, the power tool remains in the set state while waiting for another signal until the state of this signal also changes. In one embodiment, a relatively low operating speed is given to the motor, which is lower than the maximum constant speed of the motor, to avoid the power tool running at high speed under misoperation. The starting speed Nr is a constant speed.

[0038] At 204, an auxiliary signal is generated based on the state change of the second switch. Similar to the first switch, the states of the second switch include "on" and "off". After changing from one state to the other, the change is sensed and an auxiliary signal indicating the state change of the second switch is generated accordingly.

[0039] At 205, the foregoing settings are modified. The modification includes canceling the previous setting. For example, in one embodiment, the setting of the starting speed Nr is canceled and the motor exits the state of running at the starting speed Nr. The modification also includes updating the previous setting. For example, the new setting replaces the old setting. In one embodiment, the starting speed Nr of the old setting is replaced with other speed.

[0040] At 206, the motor is run at a speed not greater than the no-load speed N0, where the speed not greater than the no-load speed N0 is determined by the second switch. The motor runs at a constant speed.

[0041] When both the main signal and the auxiliary signal are generated, the motor enters the normal operation mode and the motor runs at a speed depending on the second switch. Here, the normal operation mode is an operation state in which the motor runs at a speed depending on the state of the second switch (such as the stroke amount). This operation mode can define or obtain the no-load speed N0 of the motor based on the reset setting, default setting, or factory setting. The no-load speed is the maximum constant no-load speed that the motor can reach, or can also be the maximum constant speed of the motor set. The motor runs within the range not exceeding the no-load speed N0.

[0042] Whether it is the starting speed Nr or the no-load speed N0, the motor is always in a controlled state.

[0043] Figure 3 An embodiment shown is the motor starting process. The motor starting includes approximately two stages, and the motor runs at a defined maximum constant speed during the corresponding stages. The starting speed Nr is less than the no-load speed N0. In the first stage, from the time period of 0 to T0, the motor speed climbs from 0 to the starting speed Nr. In the time period from T0 to T1, the motor stabilizes at the starting speed Nr. In the second stage, from the time period of T1 to T2, the motor continues to climb from the starting speed Nr until it reaches the no-load speed N0 and stabilizes at this speed. In this embodiment, the motor runs at a certain speed in the first stage. In other embodiments, the motor does not run in the first stage, that is, the starting speed Nr is set to 0.

[0044] Back to Figure 2 , at 207, the locked speed N1 is set based on the second switch being held for more than a preset time period before the auxiliary signal is interrupted.

[0045] At 208, the motor is run at the locked speed N1.

[0046] At 209, modify the most recent setting based on the re-generation of the auxiliary signal; or at 210, disconnect the electrical circuit based on the interruption of the main signal.

[0047] If the auxiliary signal is only interrupted, or the interruption time of the auxiliary signal is less than the preset time period, at 211, set another speed N2 and operate the motor at this speed N2. This speed N2 is different from the locked speed N1.

[0048] When the power tool is in a specific situation, control the motor to run at a specified speed by assigning a locked speed N1 to the motor. The locked speed N1 is a constant speed. Although this situation is caused by one of the switches not generating a signal, the running speed of the motor can be set to be independent of both switches. That is to say, the motor speed can drop from the previous constant speed to another constant speed, or rise from the previous constant speed to another constant speed, or maintain the previous constant speed, in order to lock the speed to reduce manual control or save energy. When the interrupted signal is restored, the power tool returns to the normal working mode. When the main signal is interrupted, disconnect the electrical circuit for the motor. The power tool is completely powered off and shut down after a delay period, such as 10 s.

[0049] The starting speed Nr is set in the range between 0 and 70% N0 (0 ≤ Nr ≤ 70% N0). The locked speed N1 is set in the range between 30% and 100% N0 (30% N0 ≤ N1 ≤ 100% N0), or the locked speed N1 is set to the speed at which the motor was running before the auxiliary signal was interrupted. The speed N2 is set to be equivalent to the starting speed Nr, N2 = Nr.

[0050] The second switch is arranged on the handle 12, which includes a pressing part 30 with a stroke. The relationship between the running speed of the motor and the stroke will be described below with reference to the drawings. Figure 1 In the illustrated embodiment, the first switch 26 and the second switch 28 are arranged opposite to each other in the space 14. The first switch 26 is arranged at the bottom of the space 14, and the second switch 28 is arranged at the top of the space 14. The first switch 26 and the second switch 28 are far apart and are not convenient to trigger simultaneously, especially when both the first switch 26 and the second switch 28 are mechanical switches, it is difficult to open both the first switch 26 and the second switch 28 with one hand. In another embodiment, the first switch 26 is an electrically controlled switch, which is hidden in the first housing 16 and thus cannot be touched by hand either.

[0051] Figure 4 Schematic diagram of the second embodiment for operating a power tool according to the present application. Figure 4 The shown process is used for Figure 1Operation of the power tool shown. The main signal is generated by a first switch, which is arranged in a first housing and is associated with the tool and can sense whether the tool contacts the working object. The auxiliary signal is generated by a second switch, which is arranged in a second housing and is associated with the environment and operation. Both the first switch and the second switch can be normally open switches, and the first switch and the second switch can be automatically reset. In particular, the first switch is electrically controlled to reset (such as power-off reset), and the second switch is mechanically reset (such as a travel switch with a spring).

[0052] Figure 5 Schematic diagram of an embodiment of the first switch. A guide rod 32 as an intermediate member is arranged between the first housing 16 and the second housing 18. The front end of the guide rod 32 is movably installed in the first housing 16. As Figure 5 shown, the front end has an oblong hole 34, and the first post 36 of the first housing 16 is fitted in the oblong hole 34. The rear end has a round hole 38, and the second post 40 of the second housing 18 is fitted in the round hole 38. A magnet 42 is also arranged at the front end of the guide rod 32. A flange 44 is arranged in the first housing 16, and a circuit board 48 with a sensor 46 is installed on the flange 44. The sensor 46 can be a Hall sensor, and its position is set to correspond to the magnet 42. There is a buffer plate 50 between the flange 44 and the circuit board 48. When a force is applied to make the tool contact the working object, the force will press the second housing 18 to move forward, and relative movement occurs between the oblong hole 34 and the first post 36, so that the guide rod 32 moves forward relative to the first housing 16. The sensor 46 senses the approach of the magnet 42 to it and generates a signal. The buffer plate 50 protects the circuit board 48 from the vibration energy transmitted backward by the front-end tool.

[0053] The first switch 26 can also determine whether the tool is loaded by sensing changes in other physical quantities. For example, detecting whether the current in the circuit inside the housing increases, or detecting whether the housing generates vibration, and detecting whether there is force feedback on the rotating shaft, etc.

[0054] The second switch 28 is a travel switch. An embodiment of the second switch 28 is as Figure 6 shown. Figure 6A circuit diagram showing such a switch combined with a first switch to control a motor is shown. The motor 52 is powered by a battery 22. A driver 54 is arranged between the battery 22 and the motor 52. The driver 54 receives inputs from the first switch 26 and the second switch 28. There is a bridge circuit composed of multiple MOSFET switches between the driver 54 and the motor 52. The second switch 28 will only give an input to the driver on the premise that the first switch 26 gives an input to the driver. When the driver receives an input signal (such as the POTI value of a travel switch), it simultaneously controls the MOSFET bridge circuit for corresponding speed control, such as controlling the different voltages input to the motor by controlling the duty cycle to control the speed.

[0055] The above example provides a solution for steplessly adjusting the speed of the motor by the travel of the second switch. It should be understood that the speed adjustment of the motor is not limited to the above example. For example, the second switch is a travel wrench, and multiple gears are added to the second housing to adjust the speed of the motor step by step through these gears.

[0056] Back to Figure 4 . At 401, a main signal is generated. The generation of the main signal indicates that the first switch has detected that the front-end tool has pressed onto the workpiece. At 402, the electrical circuit of the motor is turned on. At 403, a starting speed Nr is set, and the starting speed Nr is set to be lower than the no-load speed N0 of the motor. In one embodiment, Nr = 0 - 70%N0. At 404, the MOSFET circuit between the driver and the motor is turned on to allow the motor to run. At 405, the motor runs at the starting speed Nr.

[0057] At 406, if the starting speed Nr is 0 and lasts for a certain period of time, such as 10 s, then it transfers to 407. If not, it transfers to 408 and waits for the generation of an auxiliary signal. At 407, the main signal is disconnected, the electrical circuit of the motor is disconnected, and the first switch is reset to its normally open state, and it returns to 401. When the power tool loses power, such as when the lithium battery leaves the power tool at 418, at 407, the first switch is reset to its normally open state and returns to 401.

[0058] At 408, an auxiliary signal is generated. Subsequently, the validity of the generated auxiliary signal is checked. The auxiliary signal is generated by a travel switch. In the illustrated embodiment, at 409, the travel switch is checked through the potentiometer reading. At 410, when the potentiometer reading > 0, it indicates that the travel switch is triggered, and the travel amount is calculated. It transfers to 411. If the potentiometer reading ≤ 0, it returns to 408. After the second switch is pressed, the auxiliary signal is generated accordingly.

[0059] At 411, update the previous setting for the starting speed Nr. Reset the no-load speed N0 for the motor, and at 412, the motor operates at a speed not greater than the no-load speed N0. This speed is a constant speed and depends on the stroke size. When the stroke is at its maximum, the motor operates at the maximum constant speed, i.e., at the no-load speed N0.

[0060] At 413, the auxiliary signal is interrupted. The interruption of the auxiliary signal may be that the user releases the wrench. At 414, it is judged whether the stroke of the second switch has been maintained for a specified period before the auxiliary signal is interrupted. If the specified period has been reached, transfer to 415. If not, transfer to 419. Before the wrench is released, if the stroke has been maintained for the specified period, then the release of the wrench can be determined as the generation of a locking signal. At 415, set the locking speed N1. At 416, the motor operates at the locking speed N1. N 1＝ 30% - 100% of N0, or the speed at which the motor was operating before the auxiliary signal was interrupted. The locking speed N1 enables the motor to operate at a specified constant speed. For example, when the power is insufficient, the setting of the locking speed can make the motor operate at a lower speed for the operation to maintain the power tool to complete the current operation before the power runs out. Or when the current operation does not require high power, the setting of the locking speed can meet such a situation, and the motor maintains a lower output level until the operation is completed. Especially for a one-time long operation, after the user releases the wrench, the finger muscles can get a rest, thus realizing easy operation. When the motor uses either stepless speed regulation or stepped speed regulation, after the wrench is released, the motor speed does not drop to 0, and the specification of the locking speed N1 enables the motor to operate reasonably. At 417, when it is monitored that the auxiliary signal is re-generated, transfer to 412, and the motor resumes operating at a speed not greater than the no-load speed N0. At 419, modify the most recent setting. In one embodiment, set the constant speed N2. N2 ≠ N1. N2 can be set to be equivalent to the starting speed, i.e., N2 = Nr, so that the motor operates at a lower speed. If the wrench is released but the time held before release does not reach the specified period, and at this time the power tool is in a situation where only one signal, i.e., the main signal, is generated, then the motor can return to the speed state at startup.

[0061] The starting speed Nr, the no-load speed N0, the locking speed N1, and the speed N2 are all constant and can be set manually in addition to automatic setting. For example, these speeds can be set through the screen on the power tool, or in the case where the power tool is communicatively connected to a mobile terminal, through the application (APP) on the mobile terminal.

[0062] Figure 7 It is a schematic diagram of the third embodiment of the method for operating a power tool involved in this application.

[0063] At 701, when the second switch is pressed, an auxiliary signal is generated. However, at this time, there is no main signal, so the motor does not start.

[0064] At 702, a main signal is generated, the electrical circuit of the motor is turned on, and the starting speed Nr is set to 50% of the no-load speed N0. In this embodiment, when only the main signal is present, a low-speed gear is provided. On the one hand, this is beneficial for special applications such as pre-positioning for drilling / cutting / grinding or fine operations. On the other hand, it reduces the risk caused by the working head during full-speed start-up, such as keeping the working head in the unloaded position without generating a large impact force that could cause the working head to eject and pose a danger. At the same time, providing a certain speed can prevent the danger caused by the user using the adjustable travel switch to assemble the working head.

[0065] The first switch and the second switch are separated. The first switch is a mechanical switch, and it is not easy for the first switch and the second switch to be activated simultaneously. Although the second switch is prone to accidental triggering, the start-up of the power tool is based on the first switch. The second switch is a self-resetting normally open switch.

[0066] At 703, the second switch is activated, generating an auxiliary signal. The speed of the motor running from 0 to N0 is determined according to its stroke, and the speed is locked or unlocked according to the subsequent state of the second switch.

[0067] In this embodiment, the power tool implements a two-step start-up, greatly reducing the risk caused by the working head due to accidental start-up of the power tool.

[0068] Figure 8 It is a schematic diagram of the fourth embodiment of the method for operating a power tool according to the present application.

[0069] At 801, when the second switch is pressed, an auxiliary signal is generated. However, at this time, there is no main signal, so the motor does not start.

[0070] At 802, a main signal is generated, the electrical circuit of the motor is turned on, and the starting speed is set to 0.

[0071] At 803, the second switch is activated, generating an auxiliary signal. The speed of the motor running from 0 to N0 is determined according to its stroke, and the speed is locked or unlocked according to the subsequent state of the second switch.

[0072] In this embodiment, the power tool implements a two-step start-up, and the first switch is hidden and not prone to accidental activation, greatly reducing the risk caused by the working head due to accidental start-up of the power tool. For example, when the power tool is squeezed in a backpack or the switch is accidentally pressed during the assembly of the tool head, the starting speed is set to 0 at this time, avoiding accidental start-up. The second switch is a self-resetting normally open switch.

[0073] Figure 9Schematic diagram of the fifth embodiment of the method for operating an electric tool according to the present application.

[0074] At 901, a main signal is generated, the electrical circuit of the motor is turned on, and the starting speed Nr is set to 0. The first switch is a distance switch and is hidden to prevent accidental activation. When the first switch generates the main signal, the working head has contacted the workpiece.

[0075] At 902, an auxiliary signal is generated, and the no-load speed N0 is set. The second switch is a travel switch, and the motor operates at a speed determined by the travel between 0 and N0. At maximum travel, the motor speed is 100% N0.

[0076] At 903, after the second switch is held for a period of time and then released, the auxiliary signal is disconnected, the tool remains pressed against the workpiece, and the locked speed N1 is set. The motor operates at the locked speed N1. This speed is 70% N0.

[0077] At 904, when the electric tool leaves the workpiece, the main signal is disconnected and the electric tool is turned off; or when the second switch is pressed again and the auxiliary signal is re-generated, the motor resumes operating at a speed determined by the travel of the second switch, and the maximum constant speed is the no-load speed N0.

[0078] In this embodiment, when the electric tool is started, the working head has already contacted the workpiece, which greatly reduces the risk caused by a full-speed start with the working head, such as cutting injuries from grinding / slicing discs or the ejection direction of drill bits. At the same time, it can reduce / avoid the energy consumption of the electric tool during movement before the working head contacts the workpiece, which is more beneficial for cordless tools. In step 903, if the second switch has maintained a certain travel for a period of time before being released, such as 3 s, it is determined that the setting of the locked speed N1 takes effect.

[0079] Figure 10 Schematic diagram of the sixth embodiment of the method for operating an electric tool according to the present application.

[0080] At 1001, a main signal is generated, the electrical circuit of the motor is turned on, and the starting speed Nr is set to 50% N0. The first switch is a distance switch and is hidden to prevent accidental activation. When the first switch generates the main signal, the working head has contacted the workpiece.

[0081] At 1002, an auxiliary signal is generated, and the no-load speed N0 is set. The second switch is a travel switch, and the motor operates at a speed determined by the travel between 0 and N0. At maximum travel, the motor speed is 100% N0.

[0082] At 1003, the second switch is released after remaining in a certain stroke for a period of time, the auxiliary signal is disconnected, the tool remains pressed against the work object, and the locking speed N1 is the speed at which the motor was running before the auxiliary signal was disconnected. A certain stroke should be understood as a corresponding motor speed. For example, a stroke variable of + / -5 corresponds to a certain motor speed, so it is a certain stroke. In this embodiment, the user can release the second switch after pressing it for a period of operation, and the motor speed will remain at the original operating level.

[0083] At 1004, the second switch is pressed, the auxiliary signal is re-generated, the motor resumes running at the speed determined by the stroke of the second switch, and the maximum constant speed is the no-load speed N0.

[0084] The power tool involved in this application can implement the operation method of any one of the above embodiments. The power tool involved in this application is applicable to cordless power tools, also known as battery-powered power tools, mobile power tools, or hand-held power tools.

[0085] The power tools involved in this application include but are not limited to angle grinders, circular saws, impact drills, electric hammers, electric pickaxes, etc.

[0086] Although specific embodiments of the present application have been shown and described in detail to illustrate the principles of the present application, it should be understood that the present application can be implemented in other ways without departing from such principles.

Claims

1. A method of operating a power tool, the power tool including an electric motor, a first housing (16) and a second housing (18); wherein the first housing (16) provides a first switch and is coupled to the tool at a front end, and the second housing (18) provides a second switch; characterized in that The method includes: a) Generating a main signal based on a state change of the first switch; a-1) Setting a starting speed Nr and turning on an electrical circuit for the motor; a-2) Operating the motor at the starting speed Nr; b) Generating an auxiliary signal based on a state change of the second switch; b1) Modifying the setting; and b2) Operating the motor at a speed not greater than the no-load speed N0; wherein the speed not greater than the no-load speed N0 is determined by the second switch.

2. The method according to claim 1, characterized in that It further includes: c) Setting a locking speed N1 based on the second switch being held for more than a preset time period before the auxiliary signal is interrupted; c1) Operating the motor at the locking speed N1; and c2) Modifying the most recent setting based on the re-generation of the auxiliary signal; or c3) Disconnecting the electrical circuit based on the interruption of the main signal.

3. The method according to claim 2, wherein: The starting speed Nr satisfies the formula 0 ≤ Nr ≤ 70% N0; The locking speed N1 satisfies the formula 30% N0 ≤ N1 ≤ 100% N0 or the locking speed N1 is set to the speed at which the motor is operating before the auxiliary signal is interrupted.

4. The method according to claim 2 or 3, wherein: The starting speed Nr, the no-load speed N0, and the locking speed N1 are constant speeds; The setting is also implemented through a human-machine interface or a mobile device application; The modification includes canceling or updating the setting.

5. The method according to claim 1, characterized in that: The second housing includes a handle (12), and the second switch is provided on the handle (12) and includes a pressing portion (30) having a stroke.

6. The method according to claim 5, characterized in that: There is a hand-accessible space (14) between the first housing and the second housing, the first switch and the second switch are arranged opposite to each other in the space (14), the first switch is arranged at the bottom of the space (14), and the second switch is arranged at the top of the space (14).

7. The method according to any one of claims 1-3 and 5-6, characterized in that: Based on the motor operating at a speed of 0 and remaining so for more than a preset second time period during the electrical circuit being turned on, or based on the power failure of the power tool, reset the first switch to its normally open state; the second switch is a switch that can automatically reset to its normally open state.

8. The method according to any one of claims 1-3 and 5-6, characterized in that: The first housing provides a sensor (46), and the first switch determines whether to generate the main signal through displacement, force, current, or vibration.

9. The method according to claim 8, wherein: The power tool further includes an intermediate member connected between the first housing and the second housing, and the sensor (46) senses the movement of the intermediate member to change the state of the first switch.

10. The method according to claim 8, characterized in that: A Hall sensor is provided as the sensor, the Hall sensor is installed at the rear end of the first housing away from the tool via a circuit board (48), a buffer board is provided on the back of the circuit board (48); a guide rod (32) is provided as the intermediate member between the first housing and the second housing, one end of which is movably installed in the first housing and the other end is installed in the second housing, and a magnet (42) is provided on the guide rod (32).

11. An electric tool, characterized in that The power tool performs the method according to any one of claims 1-10.

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