Power tool and control system therefor

Abstract

This application relates to power tools, particularly power scissors, and their control systems. The power tool includes a motor (12), an actuating component (14), a transmission (16), and a trigger (30), wherein a moving component or actuating component in the transmission serves as a feedback component of the power tool. The control system includes: an association component (22) associated with the trigger and the feedback component and having feedback parameters that vary in response to actuation of the trigger and movement of the feedback component; the association component is configured such that when the actuating component reaches a position corresponding to a second position to which the trigger is actuated, the feedback parameters return to an initial value corresponding to a first position before the trigger is actuated; a sensor (24) for sensing the feedback parameters of the association component and generating a control signal based on its real-time value; and a motor controller (26) that selectively switches the motor to an active or inactive state in response to receiving the control signal from the sensor.

Description

Technical Field

[0001] This application relates to a control system for power tools and a power tool including the control system. Background Technology

[0002] Electric scissors are a type of portable power tool, specifically an electric cutting device. They can be used for pruning in agriculture, tree cultivation, grape cultivation, or horticulture, and can also be used for pruning and / or cutting workpieces made of hard materials such as metal.

[0003] When the electric shears are powered on, the operator actuates the trigger (or ignition point), causing the movable blade of the electric shears to move from the open position to the closed position, performing the cutting operation. In some applications, it may be desirable for the cutting operation to be performed in multiple stages or steps, and for the movable blade to be controllably stopped in one or more positions.

[0004] To ensure the moving blade stops promptly and accurately when the operator actuates the trigger, some power shears employ Hall effect sensors to control the blade's movement based on the trigger's position. However, power tools often contain other magnetic components near the control unit, including the Hall element. These magnetic components can interfere with the Hall sensor, accidentally activating the motor and causing the moving blade to move. Without the operator's knowledge, the moving blade could then make unintended cuts to the workpiece or cause injury.

[0005] Some power tools use other types of sensors, such as mechanical or optical sensors, to control the movement of the moving blade. However, a common problem is that the position of the trigger and the position of the moving blade do not correspond. For example, the trigger may be actuated, deviate from its initial position, and stop at the actuated position, but the moving blade may not rotate. Furthermore, when using power scissors, it is desirable for the moving blade to respond promptly and accurately to the stop of the trigger's actuation, remaining at the desired position. Summary of the Invention

[0006] The purpose of this application is to improve the control system of power tools, thereby solving at least one of the aforementioned technical problems.

[0007] Therefore, in the first aspect of this application, a control system for power tools is provided.

[0008] The power tool includes a motor, an actuator that outputs a desired motion driven by the motor, a transmission mechanism that transmits the motion output by the motor to the actuator, and a trigger adapted for actuation by an operator, wherein a moving part in the transmission mechanism or the actuator serves as a feedback mechanism for the power tool, and the control system includes:

[0009] An associated component, which is associated with both the trigger and the feedback component and has a feedback parameter having an initial value corresponding to a first position before the trigger is actuated and a real-time value that changes in response to both the actuation of the trigger and the movement of the feedback component, the associated component being configured such that the feedback parameter returns to the initial value when the execution component reaches a position corresponding to a second position actuated by the trigger;

[0010] A sensor configured to sense real-time values ​​of feedback parameters of the associated component, and to generate a first control signal when the real-time value deviates from the initial value and a second control signal when the real-time value returns to the initial value; and

[0011] A motor controller communicatively connected to the sensor is configured to switch the motor to an active state in response to receiving the first control signal from the sensor, and to switch the motor to an inactive state in response to receiving the second control signal from the sensor.

[0012] In one embodiment, each of the first position and the second position is an initial position corresponding to the power tool being in a resting state or a trigger position different from the initial position.

[0013] In one embodiment, when the trigger is moved from the first position to a second position in a direction away from the initial position, the motor controller causes the motor to output rotation in a first rotation direction based on receiving the first control signal; or when the trigger is moved from the first position to a second position in a direction toward the initial position, the motor controller causes the motor to output rotation in a second rotation direction opposite to the first rotation direction based on receiving the first control signal.

[0014] In one embodiment, the associated component is an elastically deformable element, the feedback parameter is an elastic deformation force, and the sensor is a force sensor.

[0015] In one embodiment, the elastically deformable element is a spring.

[0016] In one embodiment, the associated component is directly or indirectly associated with the trigger, and directly or indirectly associated with the feedback component via an intermediate component.

[0017] In one embodiment, the sensor is arranged on the associated component, on the end of the trigger that abuts the associated component, or on the end of the intermediate component or the feedback component that abuts the associated component.

[0018] In a second aspect of this application, an electric tool is provided, comprising: the aforementioned control system; the motor; the actuating component; the transmission device; and the trigger, wherein a moving component in the transmission device or the actuating component serves as a feedback component of the control system.

[0019] In one embodiment, the actuating element is a cutting tool configured to perform the intended operation on a workpiece.

[0020] In one embodiment, the actuating component rotates and / or translates when the trigger is activated.

[0021] In a third aspect of this application, an electric scissor is provided, comprising: a motor; a fixed blade; a movable blade pivoting relative to the fixed blade between an open position and a closed position; a transmission device for transmitting driving force output by the motor to the movable blade; a trigger adapted to be activated by an operator; and the aforementioned control system, wherein the movable blade serves as an actuating component of the control system, and one of the moving components in the transmission device or the movable blade constitutes a feedback component of the control system.

[0022] In one embodiment, the feedback component has a cam-shaped outer surface associated with the associated component, the cam-shaped outer surface being designed such that when the movable blade reaches a position corresponding to a second position of the trigger, the feedback parameter of the associated component returns to its initial value.

[0023] In one embodiment, the transmission includes: an output gear that directly drives the movable blade to pivot, a bevel gear that drives the output gear to rotate, and a shaft that rotates synchronously with the output gear and the bevel gear; the cam-shaped outer surface is provided by a cam-shaped portion integrally formed with or attached to one of the output gear, the bevel gear, and the shaft.

[0024] In one embodiment, the electric shears further include a slidably disposed pin, one end of which abuts against the cam-shaped outer surface and the other end of which abuts against the associated component.

[0025] In one embodiment, the associated component is a spring whose two ends respectively abut against a pin and a trigger, and the sensor is a force sensor.

[0026] In one embodiment, the force sensor is disposed at the end of the pin that abuts against the spring.

[0027] In the power tool control system provided in this application, on the one hand, an associated component is associated with a trigger, and in response to the actuation of the trigger, a feedback parameter changes from an initial value to a target value. A sensor, in response to this change, generates a first control signal that activates the motor controller. On the other hand, the associated component is associated with a feedback component in the drive train, and in response to the movement of the feedback component associated with the position of the actuator, the feedback parameter returns from the target value to the initial value. A sensor, in response to this return, generates a second control signal that switches the motor controller to a deactivated state. Thus, by setting the moving component in the drive train as a feedback component and associating it with the associated component, when the trigger is actuated from a first position and remains in a second position, once the actuating component reaches the desired position corresponding to the second position of the trigger, the sensor sensing the feedback parameter of the associated component can detect this and generate a signal to the motor controller. The motor controller then stops the operation of the motor, stopping the movement of the actuator. This allows the position of the actuator to correspond precisely to the position of the trigger, meaning the operator can better control the position of the actuator through the trigger. In the case where the associated component is a spring and the sensor is a force sensor that senses the elastic deformation force of the spring, the power tool of this application also avoids the unsafe situations that occur when using Hall sensors in the prior art. Attached Figure Description

[0028] This application will be more fully understood by referring to the following detailed description of specific embodiments in conjunction with the accompanying drawings, in which the same reference numerals refer to the same elements in the views.

[0029] Figure 1 This is an exemplary block diagram of a control system for an electric tool according to this application.

[0030] Figure 2 It is as a inclusion Figure 1 A schematic diagram of an example of a power tool with a control system, showing electric scissors with the active blade in the open position.

[0031] Figure 3 yes Figure 2 A partial sectional view.

[0032] Figure 4 yes Figure 2 A schematic diagram of an electric scissors, in which the movable blade of the electric scissors is in the closed position.

[0033] Figure 5 yes Figure 4 A partial sectional view. Detailed Implementation

[0034] This application relates to a feedback control system for power tools, particularly power cutting tools, and power tools, particularly power scissors, including the control system.

[0035] like Figure 1 As shown in the schematic diagram, a power tool equipped with this control system includes a motor 12 as a power source, an actuator 14 configured to perform or output a desired motion under the drive of the motor 12, and a transmission 16 that transmits the driving force or motion provided by the motor 12 to the actuator 14. The motor 12, transmission 16, and actuator 14 constitute a drive chain 10. For different power tools, the actuator 14 may have different structures, such as different types of cutting tools; the motion performed by the actuator 14 under the drive of the motor 12 may also be different, such as translation and / or rotation. The transmission 16 may also be any structure known in the art, such as a common gear structure, which includes a series of moving parts that convert the rotation output at the output shaft of the motor 12 into translation and / or rotation of the actuator 14, including, but not limited to, suitable types of gears.

[0036] The power tool also includes a trigger (or actuator) 30 configured to be activated, moved, or actuated by an operator's hand or foot. The trigger 30 has an initial position when not actuated by the operator, and an actuated position that the trigger 30 can reach when actuated by the operator. The initial position of the trigger 30 may correspond to the motor 12 being de-energized (rest position) or the motor being energized but the trigger 30 not yet actuated (the power tool may be equipped with a main switch for energizing the motor 12). The trigger 30 may have at least one, for example, one or more actuated positions. For example, in some embodiments, the trigger 30 may have only one actuated position. In some embodiments, the trigger 30 may have multiple actuated positions, such as a maximum travel position corresponding to a predefined maximum power output by the motor 12, and one or more intermediate positions between the initial position and the maximum travel position, for example, in the intermediate positions of the trigger 30, the motor operates with an intermediate power that is proportional or disproportionate to the degree of actuation of the trigger 30. In embodiments where the trigger 30 has multiple trigger positions, the multiple trigger positions may be multiple preset trigger positions set in a discrete manner. Alternatively, the trigger 30 may also have multiple trigger positions that vary infinitely. For different power tools, the trigger 30 may be a trigger or actuation element of any structure, such as, but not limited to, buttons, knobs, toggle switches, levers, triggers (see...). Figure 2-5 )wait.

[0037] In this application, actuation of the trigger 30 can move the trigger 30 from a first (before actuation) position to a second (after actuation) position, wherein the first or second position of the trigger 30 can be any position of the trigger 30, such as the aforementioned initial position or any trigger position of the trigger 30. Accordingly, the execution unit 14 can move (translate and / or rotate) from a position corresponding to the first position of the trigger 30 to a position corresponding to the second position of the trigger 30 in response to actuation of the trigger 30.

[0038] like Figure 1 The power tool also includes a control system 20 configured according to the principles of this application, which includes an associated component 22, a sensor 24, and a motor controller 26. The motor controller 26 is communicatively connected to the sensor 24 and configured to control the motor 12 (e.g., switching between an active and inactive state of the motor 12). The associated component 22 has a feedback parameter with a preset initial value corresponding to a first position of the trigger 30. Regardless of whether the first position of the trigger 30 is the initial position or any trigger position, the feedback parameter of the associated component 22 has the same initial value.

[0039] The associated component 22 of the control system 20 is associated with the trigger 30 and configured such that when the trigger 30 is actuated from a first position to a second position, the feedback parameter of the associated component 22 changes from an initial value to a (preset) target value corresponding to the second position. The associated component 22 is also associated with a feedback component in the drive chain 10 of the power tool. This feedback component can be a moving component in the drive chain from the output shaft of the motor to the actuator, such as the output shaft of the motor 12, the actuator 14, and any moving component of the transmission 16 coupled between the output shaft of the motor 12 and the actuator 14. Alternatively, the feedback component can be an additional component associated with the movement of the actuator 14 and thus capable of reflecting the real-time position of the actuator 14. The feedback component is designed and constructed in association with the associated component 22 and the actuator 14 such that when the actuator 14 reaches a predefined position corresponding to the second position of the trigger 30, the feedback parameter of the associated component 22 is returned from the target value to the initial value. In other words, no matter where the trigger 30 is actuated to, when the execution unit 14 reaches the predefined position corresponding to the (second) position of the trigger 30, the feedback parameter of the associated unit 22 returns to the initial value.

[0040] Sensor 24 of control system 20 is configured to sense real-time values ​​of feedback parameters of associated component 22, and generate a first control signal when the real-time value deviates from an initial value and a second control signal when the real-time value returns to the initial value. Motor controller 26 receives the first or second control signal from sensor 24, and activates motor 12 (or switches it to an active state) in response to receiving the first control signal to start movement of actuator 14, or deactivates motor 12 (or switches it to an inactive state) in response to receiving the second control signal to stop movement of actuator 14.

[0041] In this manner, during the operation of the power tool, the initial trigger 30 is in an initial position where it is not actuated by the operator, the feedback parameter of the associated component 22 has an initial value, and the motor 12 is in an inactive state. When the trigger 30 is actuated by the operator from the initial position (i.e., the first position) to a certain trigger position (a second position, such as the aforementioned maximum travel position or intermediate position), the feedback parameter of the associated component 22 changes from the initial value to the target value corresponding to that trigger position. The sensor 24 senses the change in the feedback parameter or the deviation of the real-time value and generates a first control signal. The motor controller 26 receives the first control signal from the sensor 24 and puts the motor 12 into an active state. The rotational motion output by the motor 12 is transmitted to the actuator 14 via the transmission device 16, and the actuator 14 begins to perform the expected motion.

[0042] When the actuator 14 reaches the position corresponding to the second position of the trigger 30, the feedback component acts on the associated component 22, causing its feedback parameter to return to its initial value. The sensor 24 senses that the feedback parameter of the associated component 22 has returned to its initial value and generates a second control signal. The motor controller 26 receives the second control signal and switches the motor 12 from the active state to the inactive state, stopping the motor 12, and the actuator 14 remains at the position corresponding to the second position of the trigger 30. In this way, the actuator 14 can quickly and accurately stop at a predefined position corresponding to the actuated position of the trigger, and the feedback parameter of the associated component 22 is reset to its initial value.

[0043] If the aforementioned trigger 30 remains in an intermediate position, and the operator desires the actuator 14 to continue moving and remain in the next predefined position, the operator can actuate the trigger 30 again to a new second position using the current position (not the initial position) of the trigger 30 as the first position. Similarly, the feedback parameters of the associated component 22 change, the sensor 24 generates a first control signal indicating this change, and the motor controller 26 reactivates the motor 12. When the actuator 14 reaches the predefined position corresponding to the new second position, the feedback component, due to its associated movement with the actuator 14, returns the feedback parameters of the associated component 22 to their initial values. The sensor 24 generates a second control signal again, and the motor controller 26 stops the operation of the motor 12 based on this signal.

[0044] As described above, in the control system of this application, the associated component 22 is associated with a feedback component that reflects the current position of the actuator 14. When the actuator 14 reaches the position corresponding to the second position after the trigger 30 is actuated, the change in the feedback parameter caused by the feedback component acting on the associated component 22 is equal in magnitude and opposite in direction to the change in the feedback parameter caused by the trigger 30 acting on the associated component 22. This ensures that no matter which second position the trigger 30 is actuated to and remains in, the actuator 14 accurately stops at the predefined position corresponding to that second position. This makes the actual position that the actuator 14 of the power tool can reach controllable and accurate.

[0045] According to the principles of this control system, the associated component 22 can have any feasible structure, as long as it has feedback parameters that change precisely in response to the action of the feedback component and trigger in the drive chain. As an example, in the electric scissors 100 described below, the associated component 22 is an elastic element, such as a spring, the corresponding feedback parameter is the amount of elastic deformation or the corresponding elastic deformation force, and the corresponding sensor 24 is a force sensor. Those skilled in the art will understand that the associated component 22 is not limited to an elastic element whose feedback parameter is an elastic deformation force, as in the example below, nor is the elastic element limited to a spring. Furthermore, depending on the actual application or structural form, the associated component 22 can be directly or indirectly associated with the trigger 30 or the feedback component in the drive chain via one or more intermediate components.

[0046] The control system of this application can be applied to devices with motors and triggers suitable for operator operation or actuation, particularly to portable power tools such as electric cutters, where the triggers are suitable for actuation by the user's hand or foot. However, the application of the control system is not limited to this. Examples of electric cutters include pruning shears, sheet metal cutters, hedge trimmers, and lawn mowers.

[0047] The following is for reference. Figure 2-5The electric scissors 100 are used as an example to describe in detail the power tools equipped with the above-mentioned control system. Figure 2 and 3 This indicates that the electric scissors are in the open position. Figure 4 and 5 The electric scissors are in the closed position.

[0048] Specifically, refer to Figure 2-5 The electric scissors 100 includes a main body 110 as a grip, which has a housing 112 and a motor (not shown) and a transmission device 120 housed within the housing 112. Figure 2-5 (Only a portion of the transmission 120 is shown). A fixed blade 116 extends from the body 110, and a movable blade 118 is rotatable relative to the fixed blade 116 about a support shaft 115. The electric shears 100 includes a main switch (not shown) to power the motor and a trigger 130 for controlling the motor. The trigger 130 is rotatably supported by a support shaft 132 and includes an outer end 131 for operator hand operation and an inner end 133 opposite to the outer end 131 about the support shaft 132. When the main switch is activated, the operator actuates the trigger 130, causing the motor's output shaft to output rotational motion, which is transmitted to the movable blade 118 via the transmission 120, thereby causing the movable blade 118 to rotate relative to the fixed blade 116. Figure 2 and 3 The opening position and Figure 4 and 5 It pivots between closed positions.

[0049] The fixed blade 116 and the movable blade 118 each include a fixed cutting edge 117 and a movable cutting edge 119 facing each other. Figure 2 and 3 The fixed blade 117 of the fixed blade 116 and the movable blade 119 of the movable blade 118 are separated in the open position. Figure 4 and 5 The fixed blade 117 of the fixed blade 116 and the movable blade 119 of the movable blade 118 overlap in the closed position. The movable blade 119 completes the shearing operation when it contacts the item (e.g., a resin, metal, or non-metal workpiece) placed between the fixed blade 141 and the movable blade 143 during its rotation toward the fixed blade 117.

[0050] In the illustrated embodiment, a small or driving gear (not shown) may be integrally formed or fixedly mounted on the output shaft of the motor. The transmission device 120 includes a driven bevel gear 122 driven by the small gear. The number of teeth of the driven bevel gear 122 is greater than that of the small gear to achieve a speed reduction function. The driven bevel gear 122 passes through shaft 124 ( Figure 3 and 5The support shaft 115 is supported and fixed to the shaft 124 by a suitable means (e.g., key connection, screw connection, etc.) to drive the shaft 124 to rotate. A cylindrical output gear 126 is fixedly mounted on the shaft 124, and the output gear 126 is configured to mesh with and drive the teeth 138 formed on the movable blade 118. The teeth 138 of the movable blade 118 are formed on the sector portion or end 136, and the sector portion 136 and the movable blade 119 are located on opposite sides of the support shaft 115.

[0051] Shaft 124 may include a shaft segment 140 disposed between driven bevel gear 122 and output gear 126, the shaft segment 140 having a cam-shaped outer surface 142 in a cross-section perpendicular to the extending direction of shaft 124. Pin 150 ( Figure 3 and 5 The electric shears 100 are slidably supported by the housing of the electric shears 100 and include a first end abutting a cam-shaped outer surface 142 of the shaft 124 and an opposite second end. Spring 160 ( Figure 5 The pin 150 is positioned between the second end of pin 150 and the inner end 133 of trigger 130, and is in a pre-compressed initial state when trigger 130 is not actuated. Therefore, when trigger 130 is in the initial position (i.e., Figure 2 and 3 When the movable blade 118 is in the open position, the elastic deformation force of the spring 160 has an initial value. The spring 160 serves as an associated component, and the elastic deformation force serves as a feedback parameter for the feedback component.

[0052] A sensor (not shown) is positioned at the second end of the pin 150 abutting the spring 160 to sense changes in the elastic deformation force of the spring 160. The sensor is configured to generate a corresponding first or second control signal when the elastic deformation force of the spring 160 deviates from or returns to its initial value. The sensor communicates with the motor controller (not shown) of the control system (e.g., via a wired connection to a circuit board containing motor control circuitry) and transmits the generated control signal to the motor controller, which switches the motor from an inactive state to an active state or vice versa based on the control signal received from the sensor.

[0053] Specifically, when the trigger 130 is in its unacted initial position, the operator actuates the trigger 130 with their finger, that is, by flicking the outer end 131 of the trigger 130 toward the main body 110, causing the trigger 130 to deviate. Figure 2 The initial position, for example, actuated to Figure 4The maximum travel position is reached. During this process, the spring 160 extends, and the elastic deformation force increases to its maximum value corresponding to the maximum travel position of the trigger 130. The sensor senses the change in the elastic deformation force of the spring 160 from its initial value to its maximum value and generates a first control signal, which is then provided to the motor controller. The motor controller receives this control signal from the sensor and switches the motor from an inactive state to an active state. The motor is activated to drive the movable blade 118 to pivot from the open position toward the closed position as described above.

[0054] During this process, when shaft 124 is rotated by driven bevel gear 122, the synchronously rotating cam-shaped outer surface 142 drives pin 150 to translate in the direction that shortens spring 160, reducing the elastic deformation force of spring 160 and causing it to tend to return to its initial value. Cam-shaped outer surface 142 is specifically designed so that when the movable blade 118 reaches the position corresponding to the maximum stroke position of trigger 130... Figure 4 and 5 When the spring 160 is positioned correctly, pin 150 returns the elastic deformation force of spring 160 to its initial value. At this time, the sensor generates a second control signal instructing the motor controller to switch the motor to an inactive state. The motor stops working accordingly, and the movable blade 118 stops in the corresponding position in time.

[0055] It can be envisioned that trigger 130 can be actuated to the initial position and Figure 4 and 5 At any intermediate position between the maximum stroke positions, the cam-shaped outer surface 142 is designed in association with the trigger 130 and the movable blade 118 such that, regardless of where the trigger 130 is stopped, the elastic deformation force of the spring 160 returns to its initial value when the position of the movable blade 118 corresponds to the position of the trigger 130, thereby stopping the movable blade 118 in a timely and accurate manner at that position.

[0056] When the operator releases trigger 130, spring 160 shortens in response to the rotation of trigger 130 (inner end 133). The control signal generated by the sensor in response to the reverse change in the elastic deformation force of spring 160 causes the motor controller to control the motor output to rotate in the opposite direction, and the movable blade 118 will move towards... Figure 2 and 3 The open position rotates and stops precisely at the position corresponding to the position to which the trigger 130 is released (e.g., the initial position).

[0057] In other words, for the example of the electric scissors 100, when the trigger 130 is actuated from a first position (which could be the initial direction or an intermediate position) in a direction away from the initial position to a second position (which could be another intermediate position or the maximum stroke position), the trigger 130 causes the feedback parameter (elastic deformation force) of the associated component (spring 160) to deviate from its initial value in an increasing direction, and the feedback component (shaft segment 140 of shaft 124) causes the feedback parameter of the associated component to change in the opposite decreasing direction. The control signal generated by the sensor causes the motor controller to control the motor to output rotation in the first rotational direction. When the trigger 130 is actuated from the first position (which could be the intermediate position or the maximum stroke position) in a direction toward the initial position (return) to the second position (which could be the initial direction or an intermediate position), the trigger 130 causes the feedback parameter of the associated component to deviate from its initial value in a decreasing direction, and the feedback component causes the feedback parameter of the associated component to change in the opposite increasing direction. The control signal generated by the sensor causes the motor controller to control the motor to output rotation in the second rotational direction opposite to the first rotational direction.

[0058] In this embodiment, the motor, transmission device 120 and movable blade 118 of the electric scissors 100 constitute the drive chain of the electric scissors 100. The shaft 124 of the transmission device 120 serves as a feedback component and is associated with the spring 160, which serves as an association component, via an intermediate member - pin 150.

[0059] In the illustrated embodiment, shaft 124 and output gear 126 are integrally formed, or shaft 124 extends from output gear 126, and driven bevel gear 122 is fastened to shaft 124 to drive shaft 124 (shaft segment 140 with cam-shaped outer surface 142) and output gear 126 to rotate synchronously. Those skilled in the art can conceive of any structure that enables driven bevel gear 122 to drive output gear 126 to rotate coaxially and synchronously, for example, output gear 126 and driven bevel gear 122 are both fixed to the same separately formed shaft, or output gear 126 and driven bevel gear 122 are fastened together and fitted onto a stationary shaft, or driven bevel gear 122 and shaft 124 are integrally formed.

[0060] In the illustrated embodiment, the cam-shaped outer surface 142 is provided via a section (shaft segment 140) of the shaft 124, which serves as the feedback component of the electric scissors 100. Alternatively, the cam-shaped outer surface 142 can be provided by a separate cam-shaped member, for example, formed independently of the shaft 124, the driven bevel gear 122, and the output gear 126, and fixed to any one of them to achieve synchronous rotation. Alternatively, the cam-shaped outer surface 142 can be provided by a cam-shaped portion integrally extending from either the output gear 126 or the driven bevel gear 122. It is also conceivable that the cam-shaped outer surface 142 can be provided by a cam-shaped portion integrally projecting from the fan-shaped portion 136 of the movable blade 118. In this case, the feedback component of the electric scissors 100 is provided by the movable blade 118 itself, or optionally by a separate cam-shaped member attached to the movable blade 118.

[0061] In the illustrated example of the electric scissors 100, the spring 160 serves as a connecting component, the elastic deformation force of the spring 160 is used as a feedback parameter, and the force sensor serves as a sensor for sensing changes in the feedback parameter. Thus, the spring 160, the force sensor, and the motor controller constitute the control system of the electric scissors 100.

[0062] In an embodiment of the electric scissors, the spring 160, as an associated component, directly abuts against or is associated with the trigger 130. It is conceivable that the associated component of the control system can also be indirectly associated with the trigger 130 of the electric scissors 100. In another embodiment of the electric scissors, the spring 160, as an associated component, is indirectly associated with the feedback component—shaft 124—of the electric scissors 100 via a pin 150. Those skilled in the art will understand that the associated component of the control system can also be directly associated with (e.g., abut against) the feedback component of the electric scissors 100. The pin 150 is not essential, or can be replaced by any other possible structural form, as long as it ensures that the feedback component in the drive train can act on the associated component to change its feedback parameters.

[0063] Although certain specific embodiments have been described above for illustrative purposes, the teachings of this patent document are of general applicability and are not limited to the specific embodiments described above. Therefore, various modifications, adaptations, and combinations of the features of the described embodiments can be made without departing from the scope of the invention as set forth in the claims.

Claims

1. A control system (20) for a power tool, the power tool including a motor (12), an actuator (14) that outputs a desired motion under the drive of the motor, a transmission (16) that transmits the motion output by the motor to the actuator, and a trigger (30) suitable for actuation by an operator, wherein a moving part in the transmission or the actuator serves as a feedback part of the power tool, the control system (20) comprising: An associated component (22) is associated with both the trigger (30) and the feedback component and has a feedback parameter having an initial value corresponding to a first position before the trigger (30) is actuated and a real-time value that changes in response to both the actuation of the trigger (30) and the movement of the feedback component. The associated component (22) is configured such that the feedback parameter returns to the initial value when the execution component (14) reaches a position corresponding to a second position actuated by the trigger (30). A sensor (24) is configured to sense a real-time value of a feedback parameter of the associated component (22), and to generate a first control signal when the real-time value deviates from the initial value and a second control signal when the real-time value returns to the initial value; and A motor controller (26) communicatively connected to the sensor (24) is configured to switch the motor (12) to an active state in response to receiving the first control signal from the sensor (24), and to switch the motor to an inactive state in response to receiving the second control signal from the sensor (24).

2. The control system (20) according to claim 1, wherein, Each of the first position and the second position is either an initial position corresponding to the power tool being in a resting state or a trigger position different from the initial position.

3. The control system (20) according to claim 2, wherein, When the trigger (30) is moved from the first position to the second position in a direction away from the initial position, the motor controller (26) causes the motor (12) to output rotation in the first rotation direction based on the received first control signal; or When the trigger (30) is moved from the first position to the second position in the direction toward the initial position, the motor controller (26) causes the motor (12) to output rotation in the second rotation direction opposite to the first rotation direction based on the received first control signal.

4. The control system (20) according to any one of claims 1-3, wherein, The associated component (22) is an elastically deformable element, the feedback parameter is an elastic deformation force, and the sensor is a force sensor.

5. The control system (20) according to claim 4, wherein, The elastically deformable element is a spring.

6. The control system (20) according to any one of claims 1-3, wherein, The associated component (22) is directly or indirectly associated with the trigger (30) and is directly or indirectly associated with the feedback component via an intermediate component.

7. The control system (20) according to claim 6, wherein, The sensor (24) is arranged on the associated component (22), on the end of the trigger (30) that abuts the associated component (22), or on the end of the intermediate component or the feedback component that abuts the associated component (22).

8. An electric tool, comprising: The control system (20) according to any one of claims 1-7; The motor (12), The execution component (14), The transmission device (16), and The trigger (30) wherein a moving part in the transmission device (16) or the actuating part (14) serves as a feedback part of the control system.

9. The power tool according to claim 8, wherein, The actuating component (14) is a cutting tool configured to perform the intended operation on the workpiece.

10. The power tool according to claim 9, wherein, The actuating component (14) rotates and / or translates when the trigger (30) is triggered.

11. An electric scissors (100), comprising: motor, Fixed blade (116), The movable blade (118) pivots between the open and closed positions relative to the fixed blade (116); The transmission device (120) transmits the driving force output by the motor to the movable blade (118). A trigger (130) suitable for being triggered by the operator, and In the control system (20) according to any one of claims 1-7, the movable blade (118) serves as an actuating component (14) of the control system, and one of the moving components in the transmission device (120) or the movable blade (118) constitutes a feedback component of the control system.

12. The electric scissors (100) according to claim 11, wherein, The feedback component has a cam-shaped outer surface (142) associated with the associated component, the cam-shaped outer surface (142) being designed such that when the movable blade (118) reaches a position corresponding to the second position of the trigger (130), the feedback parameter of the associated component (22) returns to its initial value.

13. The electric scissors (100) according to claim 12, wherein, The transmission device (120) includes: an output gear (126) that directly drives the movable blade (118) to pivot, a bevel gear (122) that drives the output gear (126) to rotate; and a shaft (124) that rotates synchronously with the output gear (126) and the bevel gear (122). The cam-shaped outer surface (142) is provided by a cam-shaped portion integrally formed with or attached to one of the output gear (126), the bevel gear (122) and the shaft (124).

14. The electric scissors according to claim 13 further includes a slidably disposed pin, one end of the pin abutting the cam-shaped outer surface (142) and the other end abutting the associated component (22).

15. The electric scissors according to claim 14, wherein, The associated component (22) is a spring (160) whose two ends respectively abut against the pin and the trigger (130), and the sensor (24) is a force sensor.

16. The electric scissors according to claim 15, wherein, The force sensor is disposed at the end of the abutting spring (160) of the pin.

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