Power tool and control method

Abstract

The invention discloses a power tool and a control method, and the power tool comprises a power switch which is used for receiving an operation instruction of a user, and the power switch controls the on-off of a switching circuit according to the operation instruction; a change-over switch configured to set a rotation direction of the motor to a forward rotation direction or a reverse rotation direction; the controller is configured to continuously detect the configuration state of the change-over switch within a preset time when the power switch receives an operation instruction to enable the switching circuit to be switched on until a configuration signal of the change-over switch is determined, and then the motor is controlled to be started. And the control condition of the switching signal is optimized.

Description

Technical Field

[0001] The present application relates to a power tool, belonging to the field of electric tools. Background Art

[0002] Power tools are a type of electric tools. During operation, the power tool is adjusted between various states by adjusting the state of the switch element, so that the power tool has a stable output and can meet the needs of various working conditions.

[0003] In the related art, as the power tool is used for a longer period of time, the performance and connection of the internal switch elements are prone to failure, which causes the power tool to malfunction during use. Summary of the invention

[0004] 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 a method for optimizing the control conditions of the switch signal to alleviate the abnormality of the power tool caused by the failure of the switch element.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions: A power tool comprises: a motor, comprising a drive shaft rotating around a first axis; an output shaft for outputting torque to the outside; a switch circuit for transmitting electrical energy to the motor; a power switch for receiving an operation instruction from a user, wherein the power switch controls the on and off of the switch circuit according to the operation instruction; a switching switch configured to set the rotation direction of the motor to a forward direction or a reverse direction; and a controller for controlling the motor; the controller is configured such that when the power switch receives the operation instruction to turn on the switch circuit, if the controller does not receive the configuration status of the switching switch, the controller continuously detects the configuration status of the switching switch within a preset time until the configuration signal of the switching switch is determined, and then controls the motor to start.

[0006] In some embodiments, the preset time is greater than or equal to 1 ms and less than or equal to 2 s.

[0007] In some embodiments, the preset time is greater than or equal to 50 ms and less than or equal to 1 s.

[0008] In some embodiments, the preset time is greater than or equal to 100 ms and less than or equal to 800 ms.

[0009] In some embodiments, when the power switch receives the operation instruction to turn on the switch circuit, if the configuration state of the switch is not detected after a preset time, the motor is controlled not to start.

[0010] In some embodiments, a detection element is further included to detect the configuration state of the switch.

[0011] In some embodiments, the power switch comprises a signal switch.

[0012] In some embodiments, a DC power supply is also included, which cooperates with the switching circuit to power the motor.

[0013] A control method for a power tool, wherein the power tool comprises: a motor, comprising a drive shaft rotating around a first axis; an output shaft for outputting torque to the outside; a switching circuit for transmitting electrical energy to the motor; a power switch for receiving an operation instruction from a user, wherein the power switch controls the on and off of the switching circuit according to the operation instruction; a switching switch configured to set the rotation direction of the motor to a forward direction or a reverse direction; a controller for controlling the motor; the control method comprises the steps of: turning on the switching circuit according to the operation instruction received by the power switch; continuously detecting the configuration state of the switching switch within a preset time; after determining the configuration signal of the switching switch; and starting the motor.

[0014] In some embodiments, the preset time is greater than or equal to 1 ms and less than or equal to 2 s.

[0015] A power tool comprises: a motor, comprising a drive shaft rotating around a first axis; an output shaft for outputting torque to the outside; a switch circuit for transmitting electrical energy to the motor; a speed control circuit for controlling the speed of the motor; a power switch for receiving an operation instruction from a user; and a controller for controlling the motor; the controller is configured to: respond to a first type of signal sent by the power switch according to the operation instruction to control the switch circuit, and respond to a second type of signal sent by the power switch according to the operation instruction to control the speed control circuit; when the power switch receives an operation instruction to start, the power switch sends a first signal of the first type of signal; when at least one of the following preset conditions is detected, the controller sends a brake signal to the motor, the preset conditions comprising: a circuit parameter value corresponding to the second type of signal is less than a first preset value; the first signal is not detected within a second preset time or the first signal is continuously detected to be disconnected within a second preset time; the first signal is not detected or the first signal is detected to be disconnected and the circuit parameter value corresponding to the second type of signal is less than a third preset value; when it is detected that the power switch receives an operation instruction to stop, the power switch sends the second signal of the first type of signal.

[0016] In some embodiments, the circuit parameter value corresponding to the second type signal includes a resistance value.

[0017] In some embodiments, the preset condition includes: the resistance value corresponding to the second type signal is less than a first preset value, and the first preset value is 3K.

[0018] In some embodiments, the preset condition includes: the first signal is not detected or the first signal is detected to be disconnected and the circuit parameter value corresponding to the second type signal is less than a third preset value, and the third preset value is 7K.

[0019] In some embodiments, the controller controls the motor based on a pulse width modulation signal, and the resistance value is positively correlated with a duty cycle of the pulse width modulation signal of the motor.

[0020] In some embodiments, the first signal is a normally open signal.

[0021] In some embodiments, the preset condition includes: no normally open signal is detected within a second preset time or the normally open signal is continuously detected to be disconnected within the second preset time, and the second preset time is greater than or equal to 1s and less than or equal to 3s.

[0022] In some embodiments, the second signal is a normally closed signal.

[0023] In some embodiments, the controller is configured to: when the first signal is detected and the circuit parameter value corresponding to the second type signal is greater than a second preset value, turn on the switch circuit and control the motor to start.

[0024] In some embodiments, the controller is configured to: when the first signal is detected and the resistance value corresponding to the second type signal is greater than 7K, turn on the switch circuit and control the motor to start.

[0025] A power tool, characterized in that it comprises: a motor, comprising a drive shaft rotating around a first axis; an output shaft for outputting torque to the outside; a switch circuit for transmitting electrical energy to the motor; A power switch, for receiving an operation instruction from a user, and controlling the on and off of the switch circuit according to the operation instruction; a switching switch, configured to set the rotation direction of the motor to a forward direction or a reverse direction; a controller, for controlling the motor; the controller is configured as follows: when the power switch receives an operation instruction to stop the motor to stop rotating, and when the motor receives a start signal again, it is determined that the configuration state of the switching switch has changed and the difference between the time when the motor receives the start signal and the time when the power switch receives the operation instruction to stop is less than a first time parameter, the motor does not start.

[0026] In some embodiments, the power tool further comprises a timer.

[0027] In some embodiments, the timer is used to detect the time difference between the time when the motor receives the start signal and the time when the power switch receives the shutdown operation instruction.

[0028] In some embodiments, the first time parameter is greater than or equal to twice the braking time.

[0029] In some embodiments, the braking time is a preset braking time, and the preset braking time is the time taken by the power tool to go from a maximum speed to a minimum speed when the power tool is under maximum load.

[0030] In some embodiments, the first time parameter is less than 2S.

[0031] In some embodiments, the timer is used to detect the braking time.

[0032] In some embodiments, the braking time is the time between the time when the power switch receives the shutdown operation instruction and the time when the speed of the motor reaches the minimum speed.

[0033] In some embodiments, the controller is configured such that: after the difference between the time when the motor receives the start signal and the time when the power switch receives the shutdown operation instruction is greater than or equal to a first time parameter, the motor starts.

[0034] In some embodiments, the motor starts if the motor detects a start signal after the difference between the time when the motor receives the start signal and the time when the power switch receives the shutdown operation instruction is greater than or equal to a first time parameter.

[0035] A power tool, characterized in that it includes: a motor, including a drive shaft rotating around a first axis; an output shaft for outputting torque to the outside; a switching circuit for supplying electrical energy to the motor; a speed control circuit for controlling the speed of the motor; a power switch for receiving user operation instructions; a controller for issuing a speed control signal according to the operation instruction to control the speed of the motor, and a speed maintaining element for keeping the motor at least at the speed corresponding to the speed control signal when an abnormal state occurs in the speed control circuit.

[0036] In some embodiments, the controller is further configured to: respond to a first type of signal sent by the power switch according to the operating instruction to control the switching circuit, and respond to a second type of signal sent by the power switch according to the operating instruction to control the speed control circuit.

[0037] In some embodiments, the power switch comprises a sliding rheostat.

[0038] In some embodiments, the speed maintaining element includes a resistor element.

[0039] In some embodiments, the speed maintaining element is a pull-up resistor.

[0040] In some embodiments, the pull-up resistor is connected in series with the sliding resistor.

[0041] In some embodiments, the speed control circuit includes a first resistor, which is connected in series with the sliding rheostat.

[0042] In some embodiments, the resistance of the speed maintaining element is greater than the resistance of the first resistor.

[0043] In some embodiments, the power switch comprises a signal switch.

[0044] In some embodiments, it also includes a DC power supply, which cooperates with the power supply circuit to power the motor.

[0045] The benefit of the present application lies in that when the power switch receives an operation instruction to turn on the switch circuit, if the configuration information of the switching switch is not received, continuous detection of the configuration signal of the switching switch is added within a preset time to reduce the occurrence of the motor not responding to starting, so as to reduce the occurrence of the motor not responding to starting or affecting the operation of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the structure of an embodiment of the present application; Figure 2 yes Figure 1 Schematic diagram of a cross-sectional view of some components; Figure 3 is a circuit block diagram of a power tool provided in an embodiment of the present application; Figure 4 is a flow chart of a control method of a power tool in the present application; Figure 5 is a flow chart of another method for controlling a power tool in the present application; Figure 6 is a schematic diagram of the electrical principle of the power switch in this application; Figure 7 is a flow chart of a third power tool control method in the present application; Figure 8 This is a circuit diagram of another power tool provided in an embodiment of the present application. Fig. 9 is a flow chart of a fourth power tool control method in the present application; Fig.10 is a schematic diagram of the electrical schematic diagram of the switch detection circuit in this application. DETAILED DESCRIPTION

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In this 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, etc. 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).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] In the present application, the terms “device”, “module” or “unit” may be implemented in the form of hardware or software to achieve specific functions.

[0056] 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.).

[0057] 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.

[0058] like Figure 1 and Figure 2A power tool of an embodiment of the present application is shown. The power tool is an impact wrench 100. In some embodiments, the power tool can also be a decoration tool, such as a screwdriver, a wrench, an electric hammer, a nail gun, a sander, etc. Alternatively, the power tool can also be a sawing tool, such as a reciprocating saw, a jigsaw, etc. Alternatively, the power tool can also be other bench-type tools, such as a bench saw, a metal cutter, a bakelite milling machine, etc. Alternatively, the power tool can also be a grinding tool, such as an angle grinder, a sander, etc. Alternatively, the power tool can also be other power tools, such as a lamp, a fan, etc. In some embodiments, the power tool can also be a garden tool, such as a pruning machine, a hair dryer, a lawn mower, a chain saw, a snow blower, a cleaning machine, etc.

[0059] It is understandable that any power tool with a switch element controlling the drive can adopt the technical solution disclosed in this embodiment, and any power equipment adopting the technical solution disclosed in this embodiment belongs to the scope of protection of this application. For example, the power tool can also be a power head, which includes a switch element controlling the energy device in the power head. The power head is used to adapt some output components to realize the function of the tool.

[0060] The impact wrench 100 includes a power supply. In this embodiment, the power supply is a DC power supply 30. The DC power supply 30 is used to provide electrical energy to the impact wrench 100. The DC power supply 30 is a battery pack, and the battery pack cooperates with a corresponding power supply circuit to power the impact wrench 100. Those skilled in the art should understand that the power supply is not limited to the scenario of using a DC power supply, and can also be powered by a mains power supply, an AC power supply, and corresponding rectification, filtering and voltage regulation circuits to realize power supply to corresponding components in the machine.

[0061] like Figure 1 to Figure 2 As shown, the impact wrench 100 includes a housing 11, a motor 12, an output mechanism 13, a transmission mechanism 14 and an impact mechanism 15. 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.

[0062] The output mechanism 13 includes an output shaft 131 for connecting a working accessory and driving the working accessory to rotate. A clamping assembly 132 is provided at the front end of the output shaft 131, which can clamp corresponding working accessories, such as screwdrivers, drill bits, sleeves, etc., when implementing different functions.

[0063] The output shaft 131 is used to output torque to operate the fastener, and the output shaft 131 rotates around the output axis. In this embodiment, the output axis is the second axis 102. In this embodiment, the first axis 101 coincides with the second axis 102. In other alternative embodiments, the second axis 102 is set at a certain angle to the first axis 101. In other alternative embodiments, the first axis 101 and the second axis 102 are parallel to each other but do not coincide.

[0064] The impact mechanism 15 is used to apply an impact force to the output shaft 131. The impact mechanism 15 includes a main shaft 151, an impact block 152 sleeved on the outer periphery of the main shaft 151, an anvil 153 and an elastic element 154 arranged at the front end of the impact block 152. Among them, the anvil 153 is connected to the output shaft 131. In this embodiment, the anvil 153 includes an anvil seat, and the output shaft 131 is formed at the front end of the anvil seat. It can be understood that the anvil seat and the output shaft 131 can be integrally formed or separately formed as independent parts.

[0065] The elastic element 154 provides a force for the impact block 152 to approach the anvil 153. In this embodiment, the elastic element 154 is a coil spring.

[0066] The housing 11 includes a motor housing 111 for accommodating the motor 12 and an output housing 112 for accommodating at least part of the output assembly 13, and the output housing 112 is connected to the front end of the motor housing 111. The housing 11 is also formed or connected with a grip 113 for user operation. The grip 113 and the motor housing 112 form a T-shaped or L-shaped structure, which is convenient for the user to hold and operate. One end of the grip 113 is connected to a power supply device 30. The motor 12, the transmission assembly 14, the impact assembly 15, and the output assembly 13 are arranged in the motor housing 111 and the output housing 112 in sequence along the front-to-back direction.

[0067] The transmission mechanism 14 is disposed between the motor 12 and the impact mechanism 15, and is used to realize the transmission of power between the motor shaft 121 and the main shaft 151. In this embodiment, the transmission mechanism 14 adopts a planetary gear reduction. Because the working principle of the planetary gear reduction and the reduction generated by this transmission mechanism have been fully disclosed to professionals in this field, a detailed description is omitted here for the purpose of brevity of the specification.

[0068] like Figure 1-3As 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.

[0069] The impact wrench 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 device 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 the control signal from the controller 17 to change their respective conduction states, thereby changing the current loaded by the power supply device 30 on the stator windings U, V, and W of the motor 12. In one embodiment, the switch circuit 171 may be a three-phase bridge driver circuit including six controllable semiconductor power devices (e.g., field effect transistors (FET), bipolar junction transistors (BJT), insulated gate bipolar transistors (IGBT), etc.). It is understood that the above-mentioned switch elements may also be any other type of solid-state switches, such as insulated gate bipolar transistors (IGBT), bipolar junction transistors (BJT), etc.

[0070] 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.

[0071] The impact wrench 100 further includes a power switch 16 and a switch 163. The power switch 16 is disposed on the grip 113 for user operation. The switch 163 is disposed on the upper side of the power switch 16, and the switch 163 is configured to be operated to set the rotation direction of the motor 12 to a forward direction or a reverse direction. Optionally, for the impact wrench 100, the switch 163 is configured to be operated to set the rotation direction of the motor 12 to a forward direction for tightening a fastener or a reverse direction for loosening a fastener.

[0072] The power switch 16 is used to control the power-on state of the motor 12. The power switch 16 includes an operating member 161 and a switch element 162 connected to the operating member. The operating member 161 is used to receive the user's operating instructions. The motor 12 starts or stops according to the operating instructions. Generally speaking, when the operating member 161 is activated, the switch element 162 is turned on, and the motor 12 is powered on. And when the operating member 161 is not activated, the motor 12 is powered off. In this embodiment, the operating member 161 is movably connected to the grip 113 so that the operating member 161 moves relative to the grip 113. In this embodiment, the user inputs the operating instruction by pressing and releasing the operating member 161. In some alternative embodiments, the user inputs the operating instruction to the operating member 161 by rotating, or toggling, or touching. In this embodiment, when the operating member 161 is pressed, the operating member receives the starting operating instruction, and the operating member is in an activated state. The operating member is in an activated state, and the switch element 162 is also turned on. And when the operating member 161 is released, the operating member receives the operation instruction of stopping, the operating member is in an unactivated state, and the switch element 162 is deactivated. The operating member 161 is biased (for example, having a biasing member, such as a spring) so that when the user releases the operating member 161, the operating member 161 moves away from the grip 113. Unless the user presses the operating member 161 and activates the switch element 162, the default state of the switch element 162 is deactivated.

[0073] In this embodiment, the controller 17 is configured as follows: when the power switch 16 receives an operation instruction to turn on the switch circuit 171, if the controller does not receive the configuration state of the switch, within a preset time, the configuration state of the switch 163 is continuously detected until the configuration signal of the switch 163 is determined, and the motor 12 is controlled to start. In the related art, when the power switch 16 receives an operation instruction to turn on the switch circuit 171, if the controller does not receive the configuration signal of the switch 163, the motor is not started. During use, the signal of the signal switch cannot be sent due to poor contact or a short circuit of the switch. Therefore, when the power switch 16 receives an operation instruction to turn on the switch circuit 171, the present application increases the continuous detection of the configuration signal of the switch 163 within a preset time to reduce the occurrence of the motor not responding to the start. In this embodiment, the preset time is greater than or equal to 1ms and less than or equal to 2s. Optionally, the preset time is greater than or equal to 50ms and less than or equal to 1s. Optionally, the preset time is greater than or equal to 100ms and less than or equal to 800ms. Optionally, the preset time is greater than or equal to 100 ms and less than or equal to 500 ms.

[0074] The power switch 16 receives the operation instruction to turn on the switch circuit 171. After the preset time, the configuration state of the switch 163 is not detected, and the motor does not start. When the configuration state of the switch 163 is still not detected after the preset time, it is determined that the forward and reverse rotation information of the switch 163 is not selected or the switch 163 has a substantial fault, and the motor cannot be started to prevent damage to the motor.

[0075] In this embodiment, the power switch 16 is a signal switch, wherein the switch element 162 is a signal switch.

[0076] The control component also includes a detection element 18 for detecting the configuration state of the switch. In this embodiment, the detection element 18 determines the configuration state of the switch 163 by detecting the signal sent by the switch 163. Optionally, the detection element 18 can be other sensors, such as a Hall sensor, a position actuator, etc.

[0077] The detection element 18 can also be used to detect the signal status of the power switch 16. The detection element 18 is also used to detect the start-up state of the motor. The detection element 18 feeds back the detection data to the controller 17 in the form of a signal. Then the controller 17 adjusts the control of the motor 12.

[0078] like Figure 4 As shown, this embodiment also discloses a control method for a power tool, which specifically includes: S110 , turning on the switch circuit 171 according to the received operation instruction of the power switch 16 .

[0079] S120: The controller does not receive the configuration status of the switch.

[0080] S130, continuously detecting the configuration status of the switch 163 within a preset time.

[0081] S140 , determining the configuration signal of the switching switch 163 .

[0082] S150, start the motor.

[0083] like Figure 5 As shown, this embodiment also discloses another control method of a power tool, which specifically includes: S210, start.

[0084] S220, the motor 12 is in an unactivated state. At this time, the power switch 16 is in a default unactivated state.

[0085] S230: The power switch 16 receives the start-up operation instruction, that is, the operating member is pressed and the switch circuit 171 is turned on. If yes, execute S240; if not, execute S220.

[0086] S240: Detect the configuration status of the switch 163. If yes, execute S260; if no, execute S250.

[0087] S250, continue to detect the configuration state of the switch 163 until the configuration of the switch 163 is determined, and the detection time is greater than the preset time. If yes, execute S270, if not, execute S240.

[0088] S260 , the controller starts the motor 12 .

[0089] S270: Do not start the motor 12.

[0090] S280, end.

[0091] In this embodiment, the switch element 162 includes a sliding rheostat 1621. Therefore, the power switch 16 can also adjust the rotation speed of the motor 12. The rotation speed of the motor 12 is adjusted according to the trigger stroke of the operating member 161. Figure 6 and Fig.10 As shown, the control component also includes a speed regulating circuit 168 . When the trigger stroke of the operating member 161 is different, the sliding rheostat 1621 sends different output signals to the controller 17 through the speed regulating circuit 168 .

[0092] The trigger stroke of the operating member 161 is positively correlated with the duty cycle of the PWM signal of the motor 12, and the duty cycle of the PWM signal is positively correlated with the speed of the motor 12. When the trigger stroke of the trigger switch is small, the duty cycle of the PWM signal is also small, and at this time, the speed of the motor 12 is also small.

[0093] In some embodiments, the impact wrench 100 stores a mapping relationship between the trigger stroke of the operating member 161 and the PWM signal. The mapping relationship may be linear or non-linear, which is not limited in the embodiments of the present application.

[0094] In this embodiment, the controller is configured to: respond to the first type of signal sent by the power switch 16 according to the operation instruction to control the switch circuit 171, and respond to the second type of signal sent by the power switch 16 according to the operation instruction to control the speed control circuit 168. When the power switch 16 receives the start operation instruction, the power switch 16 sends the first signal of the first type of signal. The first type of signal is the signal type corresponding to when the power switch 16 receives the start or stop operation instruction.

[0095] When at least one of the following preset conditions is detected, the controller sends a brake signal to the motor 12, the preset conditions including: Condition 1: The circuit parameter value corresponding to the second type signal is less than the first preset value.

[0096] In this embodiment, since the power switch 16 controls the speed of the motor 12 through different trigger strokes of the sliding rheostat 1621, the circuit parameter value corresponding to the second type signal is a resistance value. In other embodiments, the circuit parameter value corresponding to the second type signal may include a current value or a voltage value.

[0097] Condition 2: the first signal is not detected within the second preset time or the first signal is continuously detected to be disconnected within the second preset time.

[0098] Condition 3: the first signal is not detected or the first signal is detected to be disconnected and the circuit parameter value corresponding to the second type signal is less than the third preset value.

[0099] Condition 4: when it is detected that the power switch 16 receives a shutdown operation instruction, the power switch 16 sends a second signal in the first type of signal.

[0100] It needs to be explained that "braking" means the rapid shutdown of the motor 12 during operation. Since the motor 12 has a high speed during operation, when the shutdown signal is received, the motor 12 can only rely on itself to overcome the inertia and reduce the speed of the motor 12 to the required minimum speed that meets the shutdown requirements, which takes a long time. Braking is the use of external force to quickly stop the motor 12 during operation. There are many specific implementation methods. For those skilled in the art, the braking method has been fully disclosed, so the detailed description is omitted here for the purpose of brevity of the specification. The brake signal is a signal to start the brake. The required "minimum speed that meets the shutdown requirements" can be 0 or close to 0.

[0101] like Figure 6 As shown, the electrical schematic diagram of the switch element of the power switch 16. Among them, contact A, contact B+ and contact C are contacts for controlling the motor 12 to send a first type of signal. Among them, the first signal in the first type of signal is a signal sent when AC is closed. The signal sent by the AC contact closure is a normally open signal. When it is detected that the power switch 16 receives an operation instruction to shut down, that is, the power switch 16 is released, the AB+ contact is closed. Among them, the signal sent by the AB+ contact closure is a normally closed signal.

[0102] In this embodiment, compared with the related art, the motor 12 is simply started when the AC contact is detected to be closed, and the motor 12 is stopped when the AC contact is detected to be loose. This switch signal recognition method controls the motor 12, which is easy to stop the motor 12 when the contact A, contact B+ and contact C have poor contact or other short-term abnormalities. This easily causes the power tool to stop abnormally frequently, affecting the user's use effect. The present application optimizes the recognition time and recognition conditions to reduce the impact of non-substantial abnormalities of the switch element on the operation of the motor 12.

[0103] In this embodiment, the resistance value corresponding to the second type signal in condition 1 is less than 3K. Optionally, the resistance value corresponding to the second type signal in condition 1 is less than 2K. In condition 3, the first signal is not detected or the first signal is detected to be disconnected and the resistance value corresponding to the second type signal is less than 7K. In condition 3, the first signal is not detected or the first signal is detected to be disconnected and the resistance value corresponding to the second type signal is less than 6.5K.

[0104] In this embodiment, the normally open signal is not detected within the second preset time or the normally open signal is continuously detected to be disconnected within the second preset time, and the second preset time is greater than or equal to 1s and less than or equal to 3s.

[0105] The controller is further configured to: when the first signal is detected and the circuit parameter value corresponding to the second type signal is greater than the second preset value, the switch circuit 171 is turned on to control the motor to start. In this embodiment, when the first signal is detected and the resistance value corresponding to the second type signal is greater than 7K, the switch circuit 171 is turned on to control the motor to start. Optionally, when the first signal is detected and the resistance value corresponding to the second type signal is greater than 8K, the switch circuit 171 is turned on to control the motor to start.

[0106] like Figure 7 As shown, this embodiment also discloses another control method of a power tool, which specifically includes: S310, start.

[0107] S320, the motor 12 is in the unactivated state. At this time, the power switch 16 is in the default unactivated state. In this embodiment, the AB+ contact is closed.

[0108] S330: Detect the first signal and the circuit parameter value corresponding to the second type signal is greater than the second preset value. The first signal is a signal emitted by the AC contact closure, which is a normally open signal. The resistance value corresponding to the second type signal is greater than the second preset value. If yes, execute S340; if no, execute S320.

[0109] S340, the motor 12 starts to run.

[0110] S351: The circuit parameter value corresponding to the second type signal is less than the first preset value. If yes, execute S360; if no, execute S340. The resistance value corresponding to the second type signal is less than 3K.

[0111] S352: If the first signal is not detected within the second preset time or the first signal is continuously detected to be disconnected within the second preset time, then S360 is executed; if not, then S340 is executed. The second preset time is greater than or equal to 1s and less than or equal to 3s.

[0112] S353: The first signal is not detected or the first signal is detected to be disconnected and the circuit parameter value corresponding to the second type signal is less than the third preset value. If yes, execute S360; if no, execute S340. The first signal is not detected or the first signal is detected to be disconnected and the resistance value corresponding to the second type signal is less than 7K.

[0113] S354: When it is detected that the power switch 16 receives the shutdown operation instruction, the power switch 16 sends the second signal in the first type of signal. If yes, S360 is executed; if no, S340 is executed. The power switch 16 is released and the AB+ contact is closed. The signal sent by the AB+ contact closure is a normally closed signal.

[0114] S360, the motor 12 brakes.

[0115] In this embodiment, when at least one of S351, S352, S353, and S354 is judged to be yes, S360 is executed.

[0116] As an embodiment of the present application, the controller is configured as follows: after the power switch 16 receives the shutdown operation instruction to stop the motor 12, when the motor 12 receives the start signal again, it is determined that the configuration state of the switch 163 has changed and the difference between the time when the motor 12 receives the start signal and the time when the power switch 16 receives the shutdown operation instruction is less than the first time parameter, and the motor 12 does not start. Since the power switch 16 receives the shutdown operation instruction to stop the motor 12, the user needs to start the motor 12 again and switch the direction of the motor 12. At this time, if the motor 12 has not completely stopped or has just stopped, it will cause damage to the components of the motor 12. Therefore, when the motor 12 receives the start signal again, the present application determines that the configuration state of the switch 163 has changed, and at the same time determines that the difference between the time when the motor 12 receives the start signal and the time when the power switch 16 receives the shutdown operation instruction is less than the first time parameter, the motor 12 is controlled not to start. When the difference between the time when the motor 12 receives the start signal and the time when the power switch 16 receives the shutdown operation instruction is greater than or equal to the first time parameter, the motor 12 starts. That is, in the present application, when the standby time of the motor 12 is less than the first time parameter, the motor 12 is delayed until the standby time reaches the first time parameter before starting, so that the motor 12 has sufficient stop and switch time to protect the safety of the motor 12.

[0117] like Figure 8As shown, the detection element 18 also includes a timer 181. The timer 181 is used to detect the time difference between the time when the motor 12 receives the start signal and the time when the power switch 16 receives the shutdown operation instruction. It can be understood that the difference between the time when the detection motor 12 receives the start signal and the time when the power switch 16 receives the shutdown operation instruction is the standby time.

[0118] In this embodiment, the first time parameter is greater than or equal to twice the braking time. In some embodiments, the braking time is a preset braking time, that is, a maximum braking time pre-measured in a laboratory or production line. The preset braking time is the time it takes for the power tool to go from the maximum speed to the minimum speed when the power tool is under maximum load.

[0119] In some alternative embodiments, the braking time is the detection braking time, that is, the time when the power switch 16 receives the shutdown operation instruction and the time when the speed of the motor 12 reaches the minimum speed are measured by the timer 181. The control of the motor 12 by real-time detection of the detection braking time is more accurate.

[0120] In some embodiments, the first time parameter is less than 2 seconds. Optionally, the first time parameter is less than 1 second. Optionally, the first time parameter is greater than or equal to 150 ms and less than or equal to 1 second.

[0121] like Fig. 9 As shown, this embodiment also discloses another control method of a power tool, which specifically includes: S410, start.

[0122] S420, the motor 12 is in operation.

[0123] S430: The motor 12 meets the braking or stopping state. The power switch 16 is released. If yes, execute S440; if no, execute S420.

[0124] S440, the time difference between the time when the configuration state of the switching switch 163 changes and the motor receives the start signal and the time when the power switch 16 receives the shutdown operation instruction is recorded as the standby time T1.

[0125] S450: Determine whether the configuration state of the switch 163 has changed. If yes, execute S470; if no, execute S460.

[0126] S460: Determine whether the standby time T1 is greater than the first time parameter T2. If yes, execute S480; if no, execute S440.

[0127] S470, delayed start.

[0128] S480, end.

[0129] As an embodiment of the present application, the control component further includes a speed maintaining element. The speed maintaining element is used to keep the motor at least at the speed corresponding to the speed regulating signal when the speed regulating circuit 168 is in an abnormal state.

[0130] In this embodiment, the speed maintaining element includes a resistor element. Optionally, the speed maintaining element is a pull-up resistor 1622 .

[0131] like Fig.10 As shown, it is an electrical schematic diagram of the switch detection circuit. The sliding rheostat 1621 is connected to the controller through the speed control circuit 168. The speed control circuit 168 includes a first resistor 1623 and a sliding rheostat 1621 connected in series. The pull-up resistor 1622 is connected in series with the sliding rheostat 1621. The resistance of the pull-up resistor 1622 is greater than the resistance of the first resistor 1623. The pull-up resistor 1622 is connected in parallel with the first resistor 1623. When the switch is worn, a temporary poor contact occurs inside, resulting in a reduction in the speed of the motor 12. The speed of the motor 12 is reduced by the pull-up resistor 1622 to maintain or increase the speed. Reduce the reduction in the speed of the motor 12 to reduce the impact on the use of the power tool.

[0132] 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. A power tool, characterized in that: include: a motor including a drive shaft that rotates about a first axis; Output shaft, used for outputting torque externally; a switching circuit for delivering electrical energy to the motor; A power switch, used to receive an operation instruction from a user, and the power switch controls the on and off of the switch circuit according to the operation instruction; A switch configured to set the rotation direction of the motor to a forward direction or a reverse direction; A controller, used for controlling the motor; The controller is configured to: When the power switch receives the operation instruction to turn on the switch circuit, if the controller does not receive the configuration status of the switching switch, the controller continues to detect the configuration status of the switching switch within a preset time until the configuration signal of the switching switch is determined, and then controls the motor to start.

2. The power tool according to claim 1, characterized in that: The preset time is greater than or equal to 1 ms and less than or equal to 2 s.

3. The power tool according to claim 1, characterized in that: The preset time is greater than or equal to 50 ms and less than or equal to 1 s.

4. The power tool according to claim 1, characterized in that: The preset time is greater than or equal to 100 ms and less than or equal to 800 ms.

5. The power tool according to claim 1, characterized in that: When the power switch receives the operation instruction to turn on the switch circuit, if the configuration state of the switch is not detected after a preset time, the motor is controlled not to start.

6. The power tool according to claim 1, characterized in that: The controller is also configured as follows: when the power switch receives a shutdown operation instruction, the switch circuit is disconnected to shut down the motor; when the motor receives a start signal again, it is determined that the configuration state of the switching switch has changed and the difference between the time when the motor receives the start signal and the time when the power switch receives the shutdown operation instruction is less than a first time parameter, and the motor does not start.

7. The power tool according to claim 6, characterized in that: The first time parameter is greater than or equal to twice the braking time.

8. The power tool according to claim 6, characterized in that: The braking time includes any one of a preset braking time and a detected braking time.

9. The power tool according to claim 1, characterized in that: The power switch includes a signal switch.

10. A power tool, characterized in that: include: a motor including a drive shaft that rotates about a first axis; Output shaft, used for outputting torque externally; a switching circuit for delivering electrical energy to the motor; A power switch, used to receive an operation instruction from a user, and the power switch controls the on and off of the switch circuit according to the operation instruction; A switch configured to set the rotation direction of the motor to a forward direction or a reverse direction; A controller, used for controlling the motor; The controller is configured to: The power switch receives a shutdown operation instruction to drive the switch circuit to disconnect to stop the motor. When the motor receives a start signal again, it is determined that the configuration state of the switching switch has changed and the difference between the time when the motor receives the start signal and the time when the power switch receives the shutdown operation instruction is less than a first time parameter, and the motor does not start.

11. A method for controlling a power tool, the power tool comprising: a motor including a drive shaft that rotates about a first axis; Output shaft, used for outputting torque externally; a switching circuit for delivering electrical energy to the motor; A power switch, used to receive an operation instruction from a user, and the power switch controls the on and off of the switch circuit according to the operation instruction; A switch configured to set the rotation direction of the motor to a forward direction or a reverse direction; A controller, used for controlling the motor; It is characterized in that The control method comprises the steps of: Turning on the switch circuit according to the received operation instruction of the power switch; The controller did not receive the configuration status of the toggle switch; Continuously detect the configuration status of the switch within a preset time; After determining the configuration signal of the switching switch; The motor is started.

12. The control method according to claim 11, characterized in that: The preset time is greater than or equal to 1 ms and less than or equal to 2 s.

Images