Electric tool and control method thereof

Abstract

The invention discloses an electric tool and a control method thereof, and the electric tool comprises a change-over switch which is used for switching the working mode of the electric tool; the working mode at least comprises a pulse working mode; in the pulse working mode, the control switch continuously sends out a starting signal, and the motor drives the output shaft to intermittently rotate and output; a controller for controlling the motor; the controller is configured to control the motor to operate at a first duty ratio when the working mode of the electric tool is switched to a pulse working mode; acquiring a load value of the output shaft; when the load value of the output shaft is larger than the preset load value, the motor is controlled to operate at a second duty ratio; wherein the second duty ratio is greater than the first duty ratio. According to the technical scheme, a user does not need to have the use experience of the electric tool, the output of the electric tool is easily controlled to enable the fastener to be flush with the workpiece, and therefore the universality of the electric tool is improved.

Description

Technical Field

[0001] The present application relates to the technical field of tool equipment, and in particular to an electric tool and a method for preparing the same. Background Art

[0002] In the dry construction process, it is usually necessary to use an electric tool to drive fasteners to install workpieces such as gypsum boards or light panels on walls or ceilings, and the fasteners must be flush with the workpieces. One type of electric tool in the related art only has a continuous working mode, that is, when the electric tool drives the fastener to install the workpiece, it outputs a fixed torque, which has high requirements on the user's ability and experience.

[0003] There is also an electric tool in the related art, which is provided with a "pulse" mode, so that after the user activates the trigger of the electric tool, the motor can be driven to rotate in an intermittent manner. However, in this "pulse" mode, the speed of the motor still depends on the user's experience.

[0004] This section provides background information related to the present application which is not necessarily prior art. Summary of the invention

[0005] One object of the present application is to solve or at least alleviate part or all of the above problems. To this end, one object of the present application is to provide an electric tool and a control method thereof that can easily control the operation of a fastener in a pulse mode.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] In one aspect, the present invention provides a power tool for drywall construction, comprising:

[0008] case;

[0009] a motor disposed at least partially within the housing, the motor including a drive shaft rotatable about a first axis;

[0010] A power supply, used to supply power to the motor;

[0011] An output mechanism, for outputting torque; the output mechanism comprises an output shaft rotating about an output axis;

[0012] A control switch for sending start and stop signals to the motor;

[0013] A switching switch is used to switch the working mode of the electric tool; the working mode includes at least a pulse working mode; in the pulse working mode, the control switch continuously sends a start signal, and the motor drives the output shaft to intermittently rotate and output;

[0014] A controller for controlling the motor;

[0015] The controller is configured to: when the working mode of the power tool is switched to the pulse working mode, control the motor to operate at a first duty cycle; obtain the load value of the output shaft; when the load value of the output shaft is greater than a preset load value, control the motor to operate at a second duty cycle; wherein the second duty cycle is greater than the first duty cycle.

[0016] In some embodiments, the controller is further configured to: when the motor operates at the second duty cycle, control the motor to continue operating at the second duty cycle until a stop signal is received.

[0017] In some embodiments, the controller is further configured to: if the load value of the output shaft is less than or equal to a preset load value, control the motor to continue to operate at the first duty cycle.

[0018] In some embodiments, the controller is configured to: obtain a load parameter of the output shaft when the output shaft is driven; and determine a load value of the output shaft according to the load parameter.

[0019] In some embodiments, the load parameters of the output shaft include at least one parameter value of the output shaft's rotation speed, the output shaft's rotation angle, the output shaft's rotation acceleration, the motor's speed-related parameters, and the motor's current-related parameters.

[0020] In some embodiments, the load parameter of the output shaft includes the number of pulses, and when the number of pulses is greater than a preset number of pulses, it is determined that the load value of the output shaft is greater than the preset load value.

[0021] In some embodiments, in the pulse working mode, the time for each time the motor drives the output shaft to rotate and output is the same, and the time for each time the motor stops driving the output shaft to rotate and output is the same.

[0022] In some embodiments, the working mode of the electric tool further includes a continuous working mode; in the continuous working mode, the motor drives the output shaft to continuously rotate and output.

[0023] In some embodiments, the switch is located above the housing.

[0024] In some embodiments, when the working mode of the electric tool is the pulse working mode, the control switch is in a locked state so that the control switch continues to send a start signal.

[0025] In some embodiments, the output shaft moves forward and backward along the output axis direction, and the control switch cooperates with the output shaft to control the start and stop of the motor.

[0026] On the other hand, the present invention further provides a control method of an electric tool, the electric tool being used for drywall construction, the control method of the electric tool comprising:

[0027] Obtaining the current working mode of the electric tool; the working mode at least includes a pulse working mode; in the pulse working mode, the motor continuously receives a start signal, and the motor drives the output shaft to intermittently rotate and output;

[0028] When the working mode of the electric tool is switched to the pulse working mode, the motor is controlled to operate at a first duty cycle;

[0029] Get the load value of the output shaft;

[0030] When the load value of the output shaft is greater than a preset load value, the motor is controlled to operate at a second duty cycle; wherein the second duty cycle is greater than the first duty cycle.

[0031] In some embodiments, before obtaining the load value of the output shaft, the method further includes: obtaining a load parameter of the output shaft when the output shaft is driven; and determining the load value of the output shaft according to the load parameter.

[0032] In some embodiments, the control method of the electric tool further includes: when the motor is running at the second duty cycle, controlling the motor to continue running at the second duty cycle until a stop signal is received.

[0033] In some embodiments, the control method of the electric tool further includes: if the load value of the output shaft is less than or equal to a preset load value, controlling the motor to continue to operate at the first duty cycle.

[0034] The benefit of the present application lies in that: when the working mode of the electric tool is switched to the pulse working mode, the motor is controlled to operate at a first duty cycle and the load value of the output shaft is obtained. When the load value of the output shaft is greater than the preset load value, the motor is controlled to operate at a second duty cycle, wherein the second duty cycle is greater than the first duty cycle, so that when the load value of the output shaft increases to the preset load value, the duty cycle of the motor during operation is increased, thereby increasing the output capacity of the electric tool, so that each time the motor drives the output shaft to rotate and output, the electric tool can output an output speed suitable for the load, that is, output a suitable output load. This allows the electric tool to automatically match the output performance according to the load conditions when operating and outputting, providing users with a better user experience and improving the universality of the electric tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the structure of an electric tool provided by an embodiment of the present invention;

[0036] Figure 2 A cross-sectional view of an electric tool provided by an embodiment of the present invention;

[0037] Figure 3 A partial cross-sectional view of an electric tool provided by an embodiment of the present invention;

[0038] Figure 4 for Figure 2 A magnified image of area A;

[0039] Figure 5 A control circuit diagram of an electric tool provided by an embodiment of the present invention;

[0040] Figure 6 A flow chart of a control method of an electric tool provided by an embodiment of the present invention;

[0041] Figure 7 A flowchart of another method for controlling an electric tool provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above drawings.

[0043] In this application, the terms "comprises", "includes", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0044] In this application, the term "and / or" is a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects before and after are in an "and / or" relationship.

[0045] In the present application, the terms "connect", "combine", "couple", and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, direct connection refers to two parts or components being connected together without the need for an intermediate piece, and indirect connection refers to two parts or components being connected to at least one intermediate piece respectively, and the two parts or components being connected via the intermediate piece. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include electrical connections or couplings.

[0046] In the present application, it will be understood by those of ordinary skill in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerances caused by manufacturing, assembly, and use associated with a specific value, and the like. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0047] In this application, it will be understood by those skilled in the art that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0048] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, the bottom can include directly below, lower left, lower right, lower front, and lower back, etc.

[0049] In this application, the terms "controller", "processor", "central processing unit", "CPU", and "MCU" are interchangeable. When a unit "controller", "processor", "central processing unit", "CPU", or "MCU" is used to perform a specific function, unless otherwise specified, these functions can be performed by a single unit or multiple units.

[0050] In the present application, the terms “device”, “module” or “unit” may be implemented in the form of hardware or software to achieve specific functions.

[0051] In this application, the terms "calculate", "judge", "control", "determine", "identify", etc. refer to the operations and processes of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0052] In order to clearly illustrate the technical solution of the present application, an upper side, a lower side, a left side, a right side, a front side and a rear side are defined in the drawings of the specification.

[0053] like Figure 1 and Figure 2 The electric tool of one embodiment of the present application is shown. The electric tool is an electric screwdriver 100. The electric screwdriver 100 is a dry construction electric tool used to drive fasteners such as screws into gypsum drywall.

[0054] like Figures 1 to 4 As shown, the electric screwdriver 100 includes a power supply 30. In this embodiment, the power supply 30 is a DC power supply. The DC power supply is used to provide electrical energy to the electric screwdriver 100. The DC power supply is a battery pack, and the battery pack cooperates with the corresponding power supply circuit to power the electric screwdriver 100. Those skilled in the art should understand that the power supply 30 is not limited to the scenario of using a DC power supply, and can also be powered by AC power, AC power, and corresponding rectification, filtering and voltage regulation circuits to realize power supply to the corresponding components in the machine.

[0055] The electric screwdriver 100 includes a housing 11, a motor 12, a transmission mechanism 13, and an output mechanism 14. The motor 12 includes a drive shaft 121 that rotates about the first axis 101. In this embodiment, the motor 12 is specifically configured as an electric motor, and the motor 12 will be used to replace the motor, and the motor shaft 121 will be used to replace the drive shaft, but this cannot be used as a limitation to the present application.

[0056] The output mechanism 14 is used to drive a working accessory (not shown in the figure) to rotate and output torque. The output mechanism 14 includes an output shaft 141. A clamping assembly 142 is provided at the front end of the output shaft 141, which can clamp corresponding working accessories (not shown in the figure) when implementing different functions, such as screwdriver bits, drill bits, sleeves, etc., so as to drive fasteners such as screws into cement and wood. In this embodiment, the working accessory can be a screwdriver bit.

[0057] The output shaft 141 can rotate with the output axis as the axis, so as to move forward and backward along the direction of the output axis to output power. In this embodiment, the output axis is the second axis 102. In this embodiment, the first axis 101 and the second axis 102 are parallel to each other but do not overlap. In this embodiment, the output shaft 141 is roughly arranged on the upper side of the motor shaft 121. In other alternative embodiments, the second axis 102 is arranged at a certain angle with the first axis 101. In other alternative embodiments, the first axis 101 and the second axis 102 overlap.

[0058] The output shaft 141 can be moved along the front-to-rear direction of the second axis 102 under the force, and can return to the original position when the external force is removed.

[0059] The housing 11 includes a main body shell 111 and a grip portion 113. The main body shell 111 is configured as a long hollow body, and the motor 12 and part of the output mechanism 14 are accommodated in the main body shell 111. The main body shell 111 is also formed or connected with a grip portion 113 for user operation. The grip portion 113 and the main body shell 111 form a T-shaped or L-shaped structure, which is convenient for the user to hold and operate. One end of the grip portion 113 is connected to a power supply 30.

[0060] The transmission mechanism 13 is used to transmit the power output by the motor shaft 121 to the output shaft 141. The transmission mechanism 13 includes a first transmission member 131 and a second transmission member 132. The first transmission member 131 is fixedly connected to the motor shaft or integrally formed, and the second transmission member 132 rotates synchronously with the output shaft 141. The first transmission member 131 and the second transmission member 132 are always in meshing connection. The second transmission member 132 always maintains at least partial contact during the process in which the output shaft 141 is forced to move along the second axis 102. A slide groove (not shown in the figure) is formed on the second transmission member 132 for reciprocating motion of the output shaft 141, and a sliding portion (not shown in the figure) is fixedly connected or integrally formed on the output shaft 141. The sliding portion and the slide groove are always matched to ensure that the second transmission member 132 and the output shaft 141 rotate synchronously.

[0061] The electric screwdriver 100 also includes an elastic member 15. When the input end 411 of the output shaft is forced to move along the second axis 102, so that the output end 412 of the output shaft moves backward along the second axis 102, the elastic member 15 is used to apply a force to the output shaft 141 to restore it to its original position, and the elastic member 15 is sleeved on the output shaft 141. One end of the elastic member 15 abuts on the protrusion formed on the output shaft 141, and the other end abuts on the second transmission member 132. The output shaft 141 is forced to move backward, so that the elastic member 15 is elastically deformed and generates a deformation force. When the external force is removed, the output shaft 141 returns to its original position due to the deformation force. In fact, we can easily find that the original position of the output shaft 141 is often not fixed due to installation or operation reasons. We don’t care here. As long as the position of the output shaft 141 is not affected by any external force, it can be understood as the original position.

[0062] Figure 5 A control circuit diagram of an electric tool provided by an embodiment of the present invention. Figure 5As shown, the motor 12 includes a stator winding and a rotor. In some embodiments, the motor 12 is a three-phase brushless motor, including a rotor with permanent magnets and three-phase stator windings U, V, and W that are electronically commutated. In some embodiments, the three-phase stator windings U, V, and W are connected in a star connection, and in other embodiments, the three-phase stator windings U, V, and W are connected in an angle connection. However, it must be understood that other types of brushless motors are also within the scope of the present disclosure. The brushless motor may include less than or more than three phases.

[0063] The electric screwdriver 100 includes a control component. The control component includes a switch circuit 171 and a controller 17. The switch circuit 171 is electrically connected to the stator windings U, V, and W of the motor 12, and is used to transfer the current from the power supply 30 to the stator windings U, V, and W to drive the motor 12 to rotate. In one embodiment, the switch circuit 171 includes a plurality of switch elements Q1, Q2, Q3, Q4, Q5, and Q6. The gate terminal of each switch element is electrically connected to the controller 17 for receiving a control signal from the controller 17. The drain or source of each switch element is connected to the stator windings U, V, and W of the motor 12. The switch elements Q1-Q6 receive control signals from the controller 17 to change their respective conduction states, thereby changing the current loaded by the power supply 30 on the stator windings U, V, and W of the motor 12. In one embodiment, the switch circuit 171 can be a three-phase bridge driver circuit including six controllable semiconductor power devices (such as FET, BJT, IGBT, etc.). It can be understood that the above-mentioned switching element can also be any other type of solid-state switch, such as an insulated gate bipolar transistor (IGBT), a bipolar junction transistor (BJT), etc.

[0064] In this embodiment, the controller 17 is used to control the motor 12. The controller 17 is arranged on a control circuit board, and the control circuit board includes: a PCB circuit board (Printed Circuit Board) and an FPC circuit board (Flexible Printed Circuitboard). The controller 17 uses a dedicated control chip, for example, a single chip microcomputer, a microcontroller unit MCU (Microcontroller Unit). The controller 17 specifically controls the on or off state of the switch element in the switch circuit 171 through the control chip. In some embodiments, the controller 17 controls the ratio between the on time and the off time of the drive switch based on a pulse width modulation (PWM) signal. It should be noted that the control chip can be integrated into the controller 17, or can also be set independently of the controller 17. As for the structural relationship between the drive chip and the controller 17, this embodiment does not limit it.

[0065] The electric screwdriver 100 further includes a power switch 16, which is used for a user to operate to control the power-on state of the motor 12. The power switch 16 includes a control switch 161 and a first switch 162, wherein the control switch 161 is arranged near the grip 113, and is used to send start and stop signals to the motor when manually operated by the user. The first switch 162 is arranged in the housing 111, and the signal of the first switch 162 responds to the motion state of the output shaft 141. In this embodiment, the control switch 161 and the signal of the first switch 162 are arranged in series.

[0066] The control switch 161 includes an operating member 1611 and a switch element 1612 connected to the operating member 1611. The operating member 1611 is used to receive an operation instruction from a user. Generally speaking, when the operating member 1611 is activated, the switch element 1612 is turned on, and when the operating member 1611 is not activated, the switch element 1612 is turned off. In this embodiment, the user inputs an operation instruction by pressing and releasing the operating member 1611. In some alternative embodiments, the user inputs an operation instruction to the operating member 1611 by operating actions such as rotating, toggling, or touching.

[0067] The first switch 162 includes a detection element 1621 and an activation element 1622. The detection element 1621 is coupled to the motor 12, and the activation element 1622 is used to activate the detection element 1621. In this embodiment, the activation element 1622 activates the detection element 1621 in response to the movement of the output shaft 141. The process of the movement of the detection element 1621 includes an activation state in which the activation element 1622 is activated and generates an activation signal and a sleep state in which the activation element is not activated. In this embodiment, when the detection element 1621 is in an activated state and the control switch 161 is in a conducting state, the motor 12 is started. That is, when the detection element 1621 is in a sleep state or the control switch 161 is in a closed state, the motor 12 cannot be started. It should be noted that the output shaft 141 driving the detection element 1621 to move can be understood as the output shaft 141 directly driving the detection element 1621 to translate, rotate, slide, etc., or the output shaft 141 can indirectly drive the detection element 1621 to translate, rotate, slide, etc. In this embodiment, the output shaft 141 drives the detection element 1621 to rotate around the first rotation axis 103 , and can be activated by the activation element 1622 during the rotation process, so that the detection element 1621 is in an activated state.

[0068] In this embodiment, the output shaft 141 drives the detection element 1621 to rotate. For example, when the input end 411 is forced to move along the second axis 102 so that the output end 412 moves backward along the second axis 102, the output end 412 can drive the detection element 1621 to rotate around the first rotation axis 103.

[0069] In this embodiment, the first switch 162 further includes: a rotating member 1623, a biasing member 1624 and a connecting member 1625. The rotating member 1623 is rotatably connected to the transmission housing 21 through the connecting member 1624. The rotating member 1623 is used to install the detection element 1621. It can also be understood that the output shaft 141 drives the rotating member 1623 to rotate around the first rotation axis 103, thereby driving the detection element 1621 to rotate. The biasing member 1624 is installed on the rotating member 1623. For example, when installed, the biasing member 1624 has a biasing force, which can keep the rotating member 1623 in the initial position when there is no external force. In this embodiment, the rotating member 1623 includes a connecting portion 1626 and a mounting portion 1627, wherein the mounting portion 1627 is formed with a receiving groove, and the detection element 1621 is installed in the receiving groove and rotates synchronously with the rotating member 1623. The connecting portion 1626 is fixedly connected or integrally formed with the mounting portion 1627, for example, the connecting portion 1626 is integrally formed with the mounting portion 1627. The biasing member 1624 can provide a biasing force that keeps the detection element 1621 in the initial position without external force driving, that is, when there is no external force driving the output shaft 141, the biasing member 1624 keeps the detection element 1621 in the initial position. Under the premise that the control switch 161 is in a state of being always on, when the input end 411 is forced to move along the first axis 101 in a direction close to the motor shaft 121, the output end 412 can drive the detection element 1621 to switch from a sleep state to an active state, wherein when the detection element 1621 is in the sleep state, the output end 412 is at least partially in contact with the connecting portion 1626. That is to say, when the detection element 1621 is in the active state, the detection element 1621 is at least partially in contact with the activation element 1622. The output shaft 141 has a driving member 1411. The driving member 1411 can drive the connecting portion 1626 to rotate the detecting element 1621. The driving member 1411 can be a rolling ball. The above arrangement can avoid damage to the connecting portion 1626 when the motor 12 drives the output shaft 141 to run at a high speed, thereby extending the service life. In this embodiment, the detecting element 1621 adopts a Hall sensor, and the activating element 1622 adopts a permanent magnet. It should be noted that the output end 412 described above can also be formed by the driving member 1411.

[0070] In this embodiment, the electric screwdriver 100 further includes a switch 18, which is used for the user to operate to switch the working mode of the electric screwdriver. The working mode of the electric screwdriver includes at least a pulse working mode. In this embodiment, the electric screwdriver also includes a continuous working mode. In the pulse working mode, the motor 12 drives the output shaft to rotate and output intermittently. For example, when the power switch controls the motor 12 to be powered on, the motor 12 runs at a certain on-off ratio. When the motor 12 rotates, the output shaft is driven to output power. It should be explained that the on-off ratio is the ratio of the motor 12 downtime or the motor 12 running time to the total running time in the pulse working mode, so as to ensure that the motor 12 drives the output shaft 141 to rotate and output intermittently in a certain regularity. In the continuous working mode, the motor 12 drives the output shaft 141 to rotate and output continuously. For example, when the power switch controls the motor 12 to be powered on, the motor 12 runs continuously to drive the output shaft to continuously output power.

[0071] The switch 18 is disposed above the housing for manual operation by the user. In the present embodiment, the switch 18 is located above the output axis. In the present embodiment, the user inputs the operation instruction of switching the working mode by pressing the switch 18. In some alternative embodiments, the user inputs the operation instruction of switching the working mode by operating actions such as rotation, toggling or touching.

[0072] In this embodiment, when the working mode of the electric screwdriver is the pulse working mode, the control switch 161 is in a locked state. In this embodiment, the control switch 161 is locked in a normally open state after being activated, that is, the control switch is locked to continuously send a start signal, but the user does not need to continuously input instructions. Take the user inputting an operation instruction by pressing and releasing the operating member 1611 as an example. When the user presses and releases the operating member once, the operating member is activated, the switch element is turned on, and the control switch continuously sends a start signal to the controller or the motor 12. When the user presses and releases the operating member again, the operating member is not activated and the switch element is turned off.

[0073] In one embodiment, in the pulse working mode, each time the motor 12 runs, the running time of the motor 12 is the same. That is to say, the duration of each time the motor 12 drives the output shaft 141 to rotate and output is the same. This duration is pre-set according to laboratory data or simulation. The interval time between each two occurrences of the motor 12 operation is the same. That is to say, each time the motor 12 stops driving the output shaft 141 to rotate and output is the same. For example, the end time of the nth time the motor 12 drives the output shaft 141 to rotate and output is T1, and the start time of the n+1th time the motor 12 drives the output shaft to rotate and output is T2. Then the difference between T2 and T1 is a preset constant, that is, each time the motor 12 stops driving the output shaft 141 to rotate and output is the same.

[0074] In one embodiment, the control switch may be a travel switch, and the travel size of the travel switch corresponds to its conduction degree. In the pulse working mode, when the number of operations of the motor 12 is less than the preset number, if the conduction degree of the control switch 161 is less than or equal to the preset conduction degree, the operation duty cycle of the motor 12 is controlled according to the conduction degree of the control switch 161. When the conduction degree of the control switch 161 is equal to the preset conduction degree, the operation duty cycle of the motor 12 determined according to the conduction degree of the control switch 161 is the preset duty cycle; if the conduction degree of the control switch 161 is greater than the preset conduction degree, the operation duty cycle of the motor 12 is controlled to be the preset duty cycle. In an optional embodiment, the number of operations of the motor 12 is determined by a counter, and each time the motor 12 starts to drive the output shaft 141 to rotate and output until the motor 12 stops driving the output shaft 141 to rotate and output, the motor 12 runs once. In an optional embodiment, the preset number of times and the preset duty cycle are determined according to the application scenario of the electric screwdriver. When the application scenario of the electric screwdriver is different, the preset number of times and the preset duty cycle may be different or the same. Exemplarily, the preset number of times may be 4 times, and the preset duty cycle may be 40%, that is, when the motor 12 rotates for the first 4 times, the operating duty cycle of the motor 12 is less than 40% to meet the operating requirements under light load conditions. When the number of rotations of the motor 12 is greater than the preset number of times, the operating duty cycle of the motor 12 is controlled according to the conduction degree of the control switch 161. The greater the conduction degree of the control switch 161, the greater the operating duty cycle of the motor 12 to meet the operating requirements under heavy load conditions. In some embodiments, when the time of the drive output of the motor 12 is less than the preset time, if the conductivity of the control switch 161 is less than or equal to the preset conductivity, the operating duty cycle of the motor 12 is controlled according to the conductivity of the control switch 161; when the conductivity of the control switch 161 is equal to the preset conductivity, the operating duty cycle of the motor 12 determined according to the conductivity of the control switch 161 is the preset duty cycle; if the conductivity of the control switch 161 is greater than the preset conductivity, the operating duty cycle of the motor 12 is controlled to be the preset duty cycle.

[0075] In one embodiment, the controller is configured to: when the working mode of the power tool is switched to the pulse working mode, control the motor to operate at a first duty cycle; obtain the load value of the output shaft; when the load value of the output shaft is greater than a preset load value, control the motor to operate at a second duty cycle; wherein the second duty cycle is greater than the first duty cycle.

[0076] The preset load value is determined according to the application scenario of the electric screwdriver. For example, when the electric screwdriver is a low-torque electric screwdriver, the preset load value is set to a smaller load value. When the electric screwdriver is a high-torque electric screwdriver, the preset load value is set to a larger load value. The specific value is set according to different products. By comparing the output shaft load value obtained by the controller with the preset load value, it is possible to distinguish between light load and heavy load of the electric screwdriver in the current application scenario.

[0077] Specifically, when the working mode of the power tool is switched to the pulse working mode, the motor is controlled to operate with a smaller first duty cycle. By obtaining the load value of the output shaft, as the power tool continuously drives the fastener in, the load value of the output shaft will become larger and larger. When the load of the output shaft is greater than the preset load value, the motor is controlled to operate with a larger second duty cycle.

[0078] In this embodiment, when the working mode of the electric tool is switched to the pulse working mode, the motor is controlled to operate at a first duty cycle and the load value of the output shaft is obtained. When the load value of the output shaft is greater than the preset load value, the motor is controlled to operate at a second duty cycle, wherein the second duty cycle is greater than the first duty cycle, so that when the load value of the output shaft increases to the preset load value, the duty cycle of the motor during operation is increased, thereby increasing the output capacity of the electric tool, so that when the motor drives the output shaft to rotate and output, an output speed suitable for the load can be output, so that the electric tool automatically matches the output performance according to the load condition when driving the output shaft to rotate and output. On the other hand, since the output capacity is matched with the load, it is easier to control the depth of the fastener driven by the electric tool in a unit time, improve the consistency of the fastener screwing depth, so that the user can control the fastener screwing depth without experience, thereby making the fastener flush with the workpiece, and improving the universality of the electric tool.

[0079] Optionally, the controller is further configured to: if the load value of the output shaft is less than or equal to the preset load value, control the motor to continue to operate at the first duty cycle and continue to obtain the load value of the output shaft. When the motor operates at the second duty cycle, control the motor to continue to operate at the second duty cycle until a stop signal is received.

[0080] When at least one of the first switch 162 and the control switch 161 is in an inactive state, a shutdown operation instruction is sent to the motor, and the motor receiving the shutdown operation instruction means that the motor receives a shutdown signal.

[0081] In this embodiment, when the load value of the output shaft is less than or equal to the preset load value, the motor is controlled to continue to operate at the first duty cycle and the load value of the output shaft is continuously obtained; when the load value of the output shaft is greater than the preset load value, the motor is controlled to operate at the second duty cycle. As the power tool continues to drive the fastener in, the load value of the output shaft will become larger and larger. Therefore, when the load value of the output shaft is less than or equal to the preset load value, the motor is controlled to continue to operate at the smaller first duty cycle. When the load value of the output shaft reaches the preset load value, there is no need to continue to obtain the load value of the output shaft. The motor is directly controlled to continue to operate at the second duty cycle until a stop signal is received. This allows the power tool to save resources while meeting working conditions.

[0082] In some embodiments, according to the requirements of the working conditions, a third duty cycle or more duty cycles different from the first duty cycle and the second duty cycle may be set, so that the control can be more precise.

[0083] Optionally, the controller is specifically configured to: obtain a load parameter of the output shaft when the output shaft is driven; and determine a load value of the output shaft according to the load parameter.

[0084] In this embodiment, the load parameter of the output shaft includes at least one parameter value of a current-related parameter of the motor 12 , a speed-related parameter of the motor 12 , and a rotation parameter of the output shaft.

[0085] It should be explained that the current-related parameters of the motor 12 include the current when the motor 12 is running and the parameters obtained by calculating the current of the motor 12. The current when the motor 12 is running is obtained through the first detection component. The first detection component includes a current sensing resistor, a Hall current sensor or a MOSFET (metal oxide semiconductor field effect transistor) on-resistance, etc.

[0086] It should be explained that the speed-related parameters of the motor 12 include the speed of the motor 12 when it is running and the parameters obtained by calculating the speed of the motor 12, such as the torque of the motor 12. When the output shaft load is large, the speed of the output shaft decreases, and the speed of the motor 12 when it is running also decreases. When the output shaft load is small, the speed of the output shaft increases, and the speed of the motor 12 when it is running also increases. The speed of the motor 12 is detected by a magnetic ring, a magnetic steel or a photoelectric encoder, by an inductor, a Hall sensor or a photoelectric sensor.

[0087] The rotation parameter of the output shaft includes at least one parameter value of the rotation speed, rotation angle, and rotation acceleration when the output shaft rotates to output. The second detection component is used to detect the rotation parameter of the output shaft. The second detection component includes a position sensor, which can be a photodiode sensor, a magnetic sensor, or a potentiometer. The second detection component can also be a rotation sensor, which can be a gyroscope sensor. The gyroscope sensor can be a single-axis, two-axis, or three-axis micro-electromechanical system (MEMS) sensor or a rotation sensor.

[0088] In the present embodiment, the load parameter of the output shaft includes the number of pulses. When the number of pulses is greater than the preset number of pulses, it is determined that the load value of the output shaft is greater than the preset load value. Optionally, the number of pulses can be determined by a counter. Each time the motor 12 starts to drive the output shaft to rotate and output, the motor 12 stops driving the output shaft to rotate and output, and the motor 12 starts to drive the output shaft to rotate and output for the second time, a pulse is completed. Optionally, the number of pulses can also be calculated by detecting the duration of the pulse operation, the current change, the commutation-related parameters of the motor 12, and the follow-up time. When the number of pulses of the power tool is less than the preset number, it can be characterized that the fastener is screwed in shallowly, and the load on the output shaft is generally small at this time. As the number of pulses increases, the fastener screw-in depth also increases, and the load on the output shaft increases at this time.

[0089] In this embodiment, when the parameter value satisfies the first preset parameter value, the load value is determined to be the first load value; when the parameter value does not satisfy the first preset parameter value, the load value is determined to be the second load value; wherein the first load value is less than the preset load value, and the preset load value is less than the second load value.

[0090] In an exemplary embodiment, when the parameter value is the rotational speed of the output shaft when it rotates to output, if the rotational speed of the output shaft when it rotates to output is greater than a first preset parameter, the load value is determined to be a first load value, thereby continuing to control the motor to operate at a first duty cycle; if the rotational speed of the output shaft when it rotates to output is less than or equal to the first preset parameter, the load value is determined to be a second load value, thereby controlling the motor to operate at a second duty cycle.

[0091] In another exemplary embodiment, when the parameter value is the current when the motor 12 is running, if the current when the motor 12 is running is less than the first preset parameter, the load value is determined to be the first load value; if the current when the motor 12 is running is greater than or equal to the first preset parameter, the load value is determined to be the second load value.

[0092] In another exemplary embodiment, when the parameter value is the number of pulses when the motor 12 is running, if the number of pulses when the motor 12 is running is less than the first preset parameter, the load value is determined to be the first load value; if the number of pulses when the motor 12 is running is greater than or equal to the first preset parameter, the load value is determined to be the second load value.

[0093] Based on the same inventive concept, this embodiment also provides a control method for an electric tool. Figure 6 A flowchart of a control method of an electric tool provided by an embodiment of the present invention, referring to Figure 6 As shown, the control method of the electric tool includes:

[0094] S110: Obtain the current working mode of the electric tool.

[0095] Among them, the working mode at least includes a pulse working mode; in the pulse working mode, the motor continuously receives a start signal, and the motor drives the output shaft to rotate intermittently for output.

[0096] S120. When the working mode of the electric tool is switched to the pulse working mode, the motor is controlled to operate at a first duty cycle.

[0097] S130. Obtain the load value of the output shaft.

[0098] S140: When the load value of the output shaft is greater than a preset load value, the motor is controlled to operate at a second duty cycle.

[0099] The second duty cycle is greater than the first duty cycle.

[0100] Optional, Figure 7 This is a flow chart of another control method of an electric tool provided by an embodiment of the present invention. Based on the above embodiment, this embodiment further adds a step of determining the load value of the output shaft, referring to Figure 7 As shown, the control method specifically includes:

[0101] S210: Obtain the current working mode of the electric tool.

[0102] Among them, the working mode at least includes a pulse working mode; in the pulse working mode, the motor continuously receives a start signal, and the motor drives the output shaft to intermittently rotate and output.

[0103] S220: When the working mode of the electric tool is switched to the pulse working mode, the motor is controlled to operate at a first duty cycle.

[0104] S230: When the output shaft is driven, obtain a load parameter of the output shaft.

[0105] S240: Determine the load value of the output shaft according to the load parameter.

[0106] In an optional embodiment, the load parameter of the output shaft includes at least one parameter value of the rotation speed, rotation angle, rotation acceleration, speed-related parameters when the motor is running, and current-related parameters when the motor is running when the output shaft is driven. The load parameter of the output shaft also includes the number of pulses. S240 includes: when the parameter value meets the first preset parameter value, determining the load value to be a first load value; when the parameter value does not meet the first preset parameter value, determining the load value to be a second load value; wherein the first load value is less than the preset load value, and the preset load value is less than the second load value.

[0107] S250. Obtain the load value of the output shaft.

[0108] S260, determining whether the load value of the output shaft is greater than a preset load value; if so, executing S270; if not, executing S280.

[0109] S270, controlling the motor to operate at a second duty cycle.

[0110] The second duty cycle is greater than the first duty cycle. When the motor runs at the second duty cycle, the motor is controlled to continue running at the second duty cycle until a stop signal is received.

[0111] S280: Control the motor to continue running at the first duty cycle.

[0112] Specifically, when the motor is controlled to continue to operate at the first duty cycle, the process returns to S230 so that when the load value of the output shaft is greater than a preset load value, the motor is controlled to operate at the second duty cycle.

[0113] In this embodiment, when the working mode of the electric tool is switched to the pulse working mode, the motor is controlled to operate at the first duty cycle and the load value of the output shaft is obtained. When the load value of the output shaft is greater than the preset load value, the motor is controlled to operate at the second duty cycle, wherein the second duty cycle is greater than the first duty cycle, so that when the load value of the output shaft increases to the preset load value, the duty cycle of the motor during operation is increased, thereby increasing the output capacity of the electric tool, so that the depth of the fastener driven by the electric tool is consistent during each rotation output, so that the user can control the depth of the fastener without experience, thereby making the fastener flush with the workpiece, thereby improving the universality of the electric tool. In addition, when the load value of the output shaft is less than or equal to the preset load value, the motor is controlled to continue to operate at a smaller first duty cycle. When the load value of the output shaft reaches the preset load value, there is no need to continue to obtain the load value of the output shaft, and the motor is directly controlled to continue to operate at the second duty cycle until a shutdown signal is received, so that the electric tool can save resources while meeting the working condition requirements.

[0114] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the above embodiments do not limit the present application in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. An electric tool for dry wall construction, characterized in that: include: case; a motor disposed at least partially within the housing, the motor including a drive shaft rotatable about a first axis; A power supply, used to supply power to the motor; An output mechanism, for outputting torque; the output mechanism comprises an output shaft rotating about an output axis; A control switch for sending start and stop signals to the motor; A switching switch for switching the working mode of the electric tool; the working mode at least includes a pulse working mode; in the pulse working mode, the control switch continuously sends a start signal, and the motor drives the output shaft to intermittently rotate and output; A controller, used for controlling the motor; The controller is configured to: when the working mode of the electric tool is switched to the pulse working mode, control the motor to operate at a first duty cycle; and obtain a load value of the output shaft; When the load value of the output shaft is greater than a preset load value, the motor is controlled to operate at a second duty cycle; wherein the second duty cycle is greater than the first duty cycle.

2. The electric tool according to claim 1, characterized in that: The controller is further configured to: when the motor is running at a second duty cycle, control the motor to continue running at the second duty cycle until a stop signal is received.

3. The electric tool according to claim 1, characterized in that: The controller is further configured to control the motor to continue to operate at the first duty cycle if the load value of the output shaft is less than or equal to the preset load value.

4. The electric tool according to claim 1, characterized in that: The controller is configured to: When the output shaft is driven, a load parameter of the output shaft is acquired; and a load value of the output shaft is determined according to the load parameter.

5. The electric tool according to claim 4, characterized in that: The load parameters of the output shaft include at least one parameter value of the rotation speed of the output shaft when rotating and outputting, the rotation angle of the output shaft when rotating and outputting, the rotation acceleration of the output shaft when rotating and outputting, the speed-related parameters of the motor, and the current-related parameters of the motor.

6. The electric tool according to claim 4, characterized in that: The load parameter of the output shaft includes the number of pulses. When the number of pulses is greater than a preset number of pulses, it is determined that the load value of the output shaft is greater than a preset load value.

7. The electric tool according to claim 1, characterized in that: In the pulse working mode, the time for each time the motor drives the output shaft to rotate and output is the same, and the time for each time the motor stops driving the output shaft to rotate and output is the same.

8. The electric tool according to claim 1, characterized in that: The working mode of the electric tool also includes a continuous working mode; in the continuous working mode, the motor drives the output shaft to continuously rotate and output.

9. The electric tool according to claim 1, characterized in that: The switch is located above the housing.

10. The electric tool according to claim 1, characterized in that: When the working mode of the electric tool is the pulse working mode, the control switch is in a locked state so that the control switch continues to send a start signal.

11. The electric tool according to claim 1, characterized in that: The output shaft moves forward and backward along the output axis direction, and the control switch cooperates with the output shaft to control the start and stop of the motor.

12. A method for controlling an electric tool, the electric tool being used for dry wall construction, characterized in that: The control method of the electric tool comprises: Acquire the current working mode of the electric tool; the working mode at least includes a pulse working mode; in the pulse working mode, the motor continuously receives a start signal, and the motor drives the output shaft to intermittently rotate and output; When the working mode of the electric tool is switched to the pulse working mode, the motor is controlled to operate at a first duty cycle; Obtaining a load value of the output shaft; When the load value of the output shaft is greater than a preset load value, the motor is controlled to operate at a second duty cycle; wherein the second duty cycle is greater than the first duty cycle.

13. The control method according to claim 12, characterized in that: Before obtaining the load value of the output shaft, the method further includes: When the output shaft is driven, obtaining a load parameter of the output shaft; According to the load parameter, a load value of the output shaft is determined.

14. The control method according to claim 12, characterized in that: Also includes: When the motor is operated at the second duty cycle, the motor is controlled to continue to operate at the second duty cycle until a stop signal is received.

15. The control method according to claim 12, characterized in that: Also includes: If the load value of the output shaft is less than or equal to the preset load value, the motor is controlled to continue to operate at the first duty cycle.

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