Signal generator based on inductance characteristics of device, electric cutting tool, and method for controlling cutting opening degree of electric cutting tool

Abstract

To disclose a signal generator based on an inductance characteristic of a device, an electric cutting tool, and a cutting opening control method of the electric cutting tool.SOLUTION: An electric cutting tool obtains inductance of an inductive sensor which can be changed by relative position change of a trigger and the inductive sensor. Since increase and decrease of the inductance is linear, by linear change of the inductance, a control processor can accurately obtain relative position information between the trigger and the inductive sensor, and can obtain position information of a blade stroke control member. Each position point can be mapped to a current blade position. In addition, by adopting the inductive sensor and the trigger as control detection, the problem that an S pole or an N pole of a magnet needs to be checked during installation after model selection of the existing linear hall device is specified during the installation, which affects production efficiency, can be avoided, and installation convenience is improved.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to the technical field of electric cutting tools, and more specifically, to a signal generator based on the inductance characteristics of a device, an electric cutting tool, and a method for controlling the cutting opening degree of an electric cutting tool.

Background Art

[0002] The position control of the conventional electric pruning shear blade is mainly realized by the magnetic induction of a Hall device based on the Hall effect. Its operating principle is as follows. The Hall effect is essentially the deflection caused by the Lorentz force of moving charged particles in a magnetic field. When charged particles (electrons or holes) are confined in a solid material, this deflection causes positive and negative charges to accumulate in a direction perpendicular to the current and the magnetic field, thereby forming an additional transverse electric field, that is, a Hall electric field. By detecting the magnitude of the electromotive force of the electric field with modern technology, the distance from the trigger magnet to the Hall device can be determined, so the trigger of the pruning shear is associated with the blade position, and the position control of the blade of the pruning shear is realized.

[0003] Since the linear Hall effect IC responds proportionally to the magnetic flux density, as shown in FIG. 7, assume that the signal output range of the linear Hall device is from 0V to Vout. When there is no magnetic field, the analog output drive 1 / 2 is Vout. Since the north-south pole induction generates a unique voltage, after the model selection of the linear Hall device is specified, it is necessary to confirm the S pole or N pole of the magnet during installation. Therefore, the conventional electric pruning shear that uses the magnetic induction of the Hall element as a method for controlling the blade position is not excellent in terms of installation convenience, and its control part needs to be improved.

[0004] The north-south pole induction generates a unique voltage that affects the linearity of the magnetic induction of the Hall device. When realizing the position control of the blade of the electric shear by the magnetic induction of the Hall device, its linearity processing requires the MCU processor to perform complex mathematical calculations, and it is difficult to achieve the effect of moving freely.

SUMMARY OF THE INVENTION

[0005] An object of the present invention is to overcome the above drawbacks and provide a technical means capable of solving the above problems.

[0006] To achieve the above object, according to the present invention, there is provided a signal generator based on the inductance characteristics of a device including a signal generator attached to a power tool, The signal generator includes a substrate, a manual actuator, an air-core inductor, and a magnetizer, The manual actuator is movably connected to the substrate, Fixed portions are provided on both the manual actuator and the substrate, Due to the movement of the manual actuator, a relative approach or relative separation movement occurs between the two fixed portions, The air-core inductor and the magnetizer are respectively connected to the two fixed portions, There is provided a technical means of a signal generator based on the inductance characteristics of a device in which the magnetizer is inserted along the middle part of the air-core inductor or separated from the middle part of the air-core inductor by the relative approach or relative separation movement of the two fixed portions.

[0007] Compared with the prior art, the beneficial effects of the present invention are as follows. By manually driving the manual actuator, since the manual actuator moves based on the position movably connected to the substrate, when the fixed part on the manual actuator operates, it is realized that the two fixed parts move relatively closer or relatively apart due to the movement of the manual actuator. Utilizing this structural feature, by connecting the air-core inductor and the magnetizer to the two fixed parts respectively, the magnetizer is inserted along the middle part of the air-core inductor or separated from the middle part of the air-core inductor due to the relatively closer or relatively apart movement of the two fixed parts. During the process of pulling and loosening the state of the manual actuator, the entire magnetizer performs corresponding insertion and detachment operations inside the air-core inductor. Due to this operation, the magnetic permeability of the magnetizer material in the air-core inductor changes, so the inductance of the air-core inductor changes. That is, the purpose of separating and attaching the air-core inductor and the magnetizer and changing the inductance of the air-core inductor by changing the relative distance between the magnetizer and the air-core inductor can be achieved. Moreover, the change in the inductance is linear.

[0008] According to the present invention, there is provided a method for controlling the cutting opening degree of an electric cutting tool, comprising: a first step of moving a blade stroke control member in a forward movement, a reverse movement, or an alternating movement of a forward movement and a reverse movement in a predetermined route so that the relative position between an inductive sensor and a trigger changes; a second step of the inductive sensor generating a corresponding inductance according to the relative position of the trigger; a third step of a control processor obtaining the inductance of the inductive sensor, judging the current movement position of the blade stroke control member based on the inductance, judging the current relative position between the trigger and the inductive sensor, and outputting a control signal corresponding to the position of the blade stroke control member to an electric drive member of an electric drive assembly based on the judged position information; A fourth step of driving the electric drive assembly to cause the blade to reach a specified position and change the cutting opening formed by the first blade and the second blade is further provided, which is a technical means for a method of controlling the cutting opening of an electric cutting tool.

[0009] According to the present invention, there is provided an electric cutting tool, including an electric cutting tool body, and on the electric cutting tool body, a first blade and a second blade that engage with each other to cut, and the first blade and the second blade for engaging and cutting an object to be cut, an electric drive assembly for driving at least one blade and adjusting the cutting opening formed by the first blade and the second blade, a blade stroke control member provided to be reciprocally movable along a predetermined route so that a forward movement and a reverse movement are formed, a trigger and an inductive sensor, a control processor for receiving the inductance generated by the inductive sensor and controlling the driving distance and driving direction of the electric drive assembly with respect to the blade based on the inductance is provided, Here, the trigger or the inductive sensor is attached to the blade stroke control member. When the blade stroke control member moves along a predetermined route, the blade stroke control member moves the trigger or the inductive sensor, so that the relative position between the trigger and the inductive sensor changes. Therefore, a technical means of an electric cutting tool in which the inductance generated by the trigger induction of the inductive sensor changes is further provided.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows. An electric cutting tool, that is, a method for controlling the cutting opening degree of an electric cutting tool, obtains the inductance of an inductive sensor that can change according to the relative position change between a trigger and the inductive sensor. Since the increase and decrease of the inductance are linear, after the control processor determines the inductance, it can obtain the relative position information between the current trigger and the inductive sensor, so it is mapped to the position control of the blade, and the position of the blade and the response of the blade stroke control member are realized.

[0011] Due to the linear change of the inductance, the control processor can accurately obtain the relative position information between the trigger and the inductive sensor, and can obtain the position information of the blade stroke control member. Each position point can be mapped to the current position of the blade. Moreover, by adopting the inductive sensor and the trigger as control detections, when installing, after the model selection of the conventional linear holding device is specified, it is necessary to confirm the S pole or N pole of the magnet during installation, which can eliminate the problem of affecting the production efficiency and improve the convenience of installation.

[0012] Further aspects and advantages of the present invention will be given in part in the following description, some will become apparent from the following description, or will become known as a result of the implementation of the present invention.

Brief Description of the Drawings

[0013] To more clearly illustrate the technical means in the embodiments of the present invention or the prior art, the drawings required in the following description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to these drawings without creative efforts.

[0014]

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Embodiments for Carrying Out the Invention

[0015] The following clearly and completely describes the technical means in the embodiments of the present invention with reference to the drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0016] Referring to FIGS. 1 to 6, in the embodiment of the present invention, it is realized by the induction of the magnetizer 40 of the inductor. The structure of the inductor generally consists of a skeleton, windings, a shield case, a sealing material, a magnetizer 40, etc. The present invention changes the inductance by changing the relative position between the magnetizer 40 and the coil. When the magnetizer 40 completely detaches from the coil, air functions as the medium of the magnetizer 40. When the magnetizer 40 is slowly inserted into the central gap of the coil, the inductance also changes with the movement of the magnetizer 40. According to the above principle, the magnetizer 40 is fixed to the trigger of the pruning shears according to the drawing, and the coil is also fixed to a corresponding reasonable position. Specifically, according to the present invention, a signal generator based on the inductance characteristics of a device including a signal generator attached to a power tool is adopted. The signal generator includes a substrate 10, a manual actuator 20, an air-core inductor 30, and a magnetizer 40. The manual actuator 20 is movably connected to the substrate 10. Fixed parts are provided on both the manual actuator 20 and the substrate 10. The two fixed parts generate a relative approach or relative separation movement due to the movement of the manual actuator 20. The air-core inductor 30 and the magnetizer 40 are respectively connected to the two fixed parts. The magnetizer 40 is inserted along the middle part of the air-core inductor 30 or separated along the middle part of the air-core inductor 30 by the relative approach or relative separation movement of the two fixed parts.

[0017] By means of the above technical means, during use, by manually driving the manual actuator 20, the manual actuator 20 moves with reference to the position movably connected to the substrate 10. The manual actuator 20 includes a movable member 21 and a connector 22. The movable member 21 is movably connected to the substrate 10 via the connector 22. Since the fixed part of the manual actuator 20 is provided on the movable member 21, when the fixed part on the manual actuator 20 operates, it is realized that the two fixed parts move relatively closer or relatively apart due to the movement of the manual actuator 20. The movement of the manual actuator 20 generally adopts pulling, turning, pressing, pulling, etc. by hand. In order to realize self-return after manual operation, the substrate 10 carries a first return spring 11 docked to the movable member 21, and the movable member 21 is returned by the first return spring 11. By utilizing this structural feature and connecting the air-core inductor 30 and the magnetizer 40 to the two fixed parts respectively, the magnetizer 40 is inserted along the middle part of the air-core inductor 30 or separated along the middle part of the air-core inductor 30 due to the relatively closer or relatively apart movement of the two fixed parts. Since the relative position between the magnetizer 40 and the air-core inductor 30 changes, the inductance changes.

[0018] Referring to FIGS. 1 and 2, FIGS. 1 and 2 are the first and second embodiments of the signal generator in the present invention. The movement is realized by rotatably connecting the movable member 21 to the substrate 10. The connector 22 is fixed to the substrate 10, and a rotary shaft structure 23 is provided on the connector 22. The movable member 21 rotates around the rotary shaft structure 23. The air-core inductor 30 and the magnetizer 40 may be provided on the movable member 21 and the substrate 10 respectively, or may be provided on the substrate 10 and the movable member 21 respectively, and are provided according to actual needs.

[0019] Referring to FIG. 3, FIG. 3 is a third embodiment of the signal generator in the present invention. By providing such a structure, when the movable member 21 moves, the movement locus of the fixed part is an arc. As a result, the magnetizer 40 cannot be inserted along the middle part of the air-core inductor 30 or separated along the middle part of the air-core inductor 30. In contrast, the air-core inductor 30 is fixedly connected to the fixed part of the substrate 10, the magnetizer 40 is transmission-connected to the fixed part of the movable member 21, a guide sleeve 12 is provided on the substrate 10, the magnetizer 40 is connected to the guide sleeve 12 in a guidable manner, and the magnetizer 40 may be provided to be inserted along the center of the air-core inductor 30 by the guide sleeve 12 or separated along the center of the air-core inductor 30. The structure of the guide sleeve 12 can limit the moving direction of the magnetizer 40. The magnetizer 40 and the movable member 21 adopt a transmission connection. When the pushing is moved by abutting and pushing, the magnetizer 40 is provided with a second return spring 41 docked to the guide sleeve 12, and the magnetizer 40 is returned by the second return spring 41. Also, in order to simulate the structure in which the manual actuator 20 is triggered, the fixed part is set at one end of the movable member 21, the middle part of the movable member 21 is rotatably engaged with the rotating shaft structure 23, and the other end of the movable member 21 functions as a manual execution end, so that the manual actuator 20 can be operated by manually pulling.

[0020] Referring to FIGS. 4 and 5, FIGS. 4 and 5 are the fourth and fifth embodiments of the signal generator in the present invention. The movement is realized by slidably connecting the movable member 21 to the substrate 10. The connector 22 is fixed to the substrate 10, the connector 22 is provided with a guide hole structure 24, the movable member 21 is slidably connected to the guide hole structure 24, the upper end of the movable member 21 functions as a manual execution end, and the fixed part is provided at the lower end of the movable member 21. Similarly, the air-core inductor 30 and the magnetizer 40 may be provided on the movable member 21 and the substrate 10 respectively, or may be provided on the substrate 10 and the movable member 21 respectively.

[0021] Referring to FIG. 6, in actual application, it is based on the inductance calculation formula. L = N2μA / l

[0022] Here, L is the inductance, N is the number of turns of the coil, μ is the magnetic permeability of the magnetizer, A is the cross-sectional area of the magnetizer, and l is the length of the coil. As can be obtained from the above formula, the magnitude of the inductance of the air-core inductor 30 is proportional to the magnetic permeability of the magnetizer material. When the magnetic permeability of the magnetizer material increases, the inductance increases, and the increase is linear. Conversely, when the magnetic permeability of the magnet material decreases, the inductance decreases, and the decrease is also linear. Applying this to power tools, according to the present invention, power tools are employed. The power tool may be a power tool such as an electric shear, an electric wrench, or an electric saw, and includes a signal generator based on the inductance characteristics of the above-described device, and further includes a main body 3. At the front end of the main body 3, a working head 1 is provided. Inside the main body 3, a circuit control unit 2 is provided. The signal generator is provided in the main body 3, and moreover, both the signal generator and the working head 1 are electrically connected to the circuit control unit 2. By fixing and engaging the substrate 10 with the main body 3, or by directly integrating the substrate 10 with the main body 3, the air-core inductor 30 is provided inside the main body 3, the magnetizer 40 is provided at one end of the manual actuator 20, the other end of the manual actuator 20 is exposed outside the main body 3 as a manual execution end, and the middle part of the manual actuator 20 is movably connected to the main body 3.

[0023] Taking the electric shear as an example, its working head 1 is an electric shear head. The air-core inductor 30 is electrically connected to the circuit control unit 2 of the electric shear, and the magnetizer 40 is attached to the manual actuator 20 of the electric shear. The manual actuator 20 of a general electric shear has a trigger structure. When the manual actuator 20 is in a loosened state, the magnetizer 40 is detached from inside the air-core inductor 30.

[0024] When the manual actuator 20 is repeatedly executed, the magnetizer 40 performs corresponding insertion and removal operations inside the air-core inductor 30. The operating speed of the magnetizer 40 inside the air-core inductor 30 follows the speed of related operations such as the manual actuator 20 being pulled or released.

[0025] To sum up, during the process of the manual actuator 20 being pulled and loosened, the entire magnetizer 40 performs corresponding insertion and removal operations inside the air-core inductor 30. Due to this operation, the magnetic permeability of the magnetizer material in the air-core inductor 30 changes, so the inductance of the air-core inductor 30 changes. Moreover, the change in the inductance is linear.

[0026] Therefore, in order to overcome the conventional technical defects caused by the use of Hall elements, the air-core inductor 30 and the magnetizer 40 can be separately installed, and the purpose of changing the inductance of the air-core inductor 30 by changing the relative distance between the magnetizer 40 and the air-core inductor 30 can be achieved. Based on this method, by processing with the corresponding signal adjustment circuit, the MCU can successfully detect the change in inductance and perfectly determine the operating range of the current operation of the manual actuator 20. More importantly, the MCU can perfectly detect the relative distance of the magnetizer 40 with respect to the air-core inductor 30. Since each distance point can be mapped to the current blade position of the electric saw, the correspondence between the blade position of the electric saw and the position of the manual actuator 20 is realized, and the blade position can be freely moved.

[0027] Referring to FIGS. 8 to 15, the method for controlling the cutting opening of an electric cutting tool is as follows: A first step of moving the blade stroke control member in a forward movement, a reverse movement, or an alternating movement of a forward movement and a reverse movement in a predetermined route so that the relative position between the inductive sensor and the trigger changes; A second step of the inductive sensor generating a corresponding inductance according to the relative position of the trigger; A third step in which a control processor obtains the inductance of an inductive sensor, determines the current movement position of a blade stroke control member based on the inductance, determines the current relative position between a trigger and the inductive sensor, and outputs a control signal corresponding to the position of the blade stroke control member to an electric drive member of an electric drive assembly based on the determined position information; A fourth step in which the electric drive assembly drives the blade to reach a specified position and changes a cut opening formed by a first blade and a second blade.

[0028] This cut opening control method obtains the inductance of an inductive sensor that can change due to a change in the relative position between a trigger and the inductive sensor. Since the increase and decrease of the inductance are linear, after the control processor determines the inductance, it can obtain the current relative position information between the trigger and the inductive sensor, so it is mapped to the position control of the blade, and the correspondence between the position of the blade and the blade stroke control member is realized.

[0029] Due to the linear change of the inductance, the control processor can accurately obtain the relative position information between the trigger and the inductive sensor and obtain the position information of the blade stroke control member. Each position point can be mapped to the current position of the blade. Moreover, by adopting the inductive sensor and the trigger for control detection, when installing, after the model selection of the conventional linear hall device is specified, it is necessary to confirm the S pole or N pole of the magnet during installation, which can eliminate the problem of affecting production efficiency and improve the convenience of installation.

[0030] Preferably, the control processor obtains the inductance of the inductive sensor in real time.

[0031] Based on the above cutting opening degree control method, the following electric cutting tools can be innovatively obtained. Or, it can be understood that the above cutting opening degree control method is innovatively obtained based on the following electric cutting tools. The electric cutting tools are provided as follows.

[0032] The electric cutting tool includes an electric cutting tool body 101. On the electric cutting tool body 101, A first blade 102 and a second blade 103 that engage with each other to cut, and the first blade 102 and the second blade 103 for engaging and cutting an object to be cut (such as a branch), An electric drive assembly 104 for driving at least one blade (the first blade and / or the second blade) and adjusting the cutting opening degree formed by the first blade 102 and the second blade 103, A blade stroke control member 105 provided to be reciprocally movable along a predetermined route so that a forward movement and a reverse movement are formed, A trigger 106 and An inductive sensor 107, and A control processor 108 for receiving the inductance generated by the inductive sensor 107 and controlling the driving distance and driving direction of the electric drive assembly 104 with respect to the blade based on the inductance are provided.

[0033] Here, the trigger 106 or the inductive sensor 107 is attached to the blade stroke control member 105. When the blade stroke control member 105 moves along a predetermined route, the blade stroke control member 105 moves the trigger 106 or the inductive sensor 107, so that the relative position between the trigger 106 and the inductive sensor 107 changes, and thus the inductance generated by the trigger of the inductive sensor 107 changes.

[0034] It is preferable that a transmission (not shown) is further provided in the electric cutting tool body. The blade stroke control member corresponds to the output end of the transmission, and a user controller is provided at the input end of the transmission. When the user operates the user controller by pushing, turning, pulling, etc., the transmission moves the blade stroke control member correspondingly through mechanical transmission. By changing the response amount of the blade stroke control member by the transmission (such as expanding the moving range or reducing the moving range), it becomes easy for the user to control the cutting opening to a desired opening size.

[0035] The electric drive member of the electric drive assembly 104 is generally a motor. The motor outputs power, and by the forward and reverse rotation of the motor, finally the corresponding blade can be made to move in the forward direction and the reverse direction. The motor may drive only one blade or may drive two blades simultaneously. When the motor drives the blade, the power output by the motor finally reaches the blade after passing through the gearbox 111, and changes in torque, speed, or direction can be achieved.

[0036] When the electric drive assembly 104 drives only one blade, if the driven blade is the first blade 102, the first blade 102 corresponds to the movable blade, and the second blade 103 corresponds to the fixed blade. The second blade 103 is attached to the electric cutting tool body 101. The form in which the first blade 102 is driven by the electric drive assembly 104 may be rotation. The first blade is rotatably provided on the electric cutting tool body via a rotating shaft, or is rotatably provided on the rotating shaft on the electric cutting tool body, or is connected to the power output shaft. The power output shaft may be the output shaft of the motor or the output shaft of the gearbox.

[0037] The electric drive member of the electric drive assembly 104 may also be an electric push rod, an air cylinder, a hydraulic cylinder, an electric spindle, etc. having a forward and reverse drive function.

[0038] The inductive sensor 107 may employ a commonly used variable-gap inductive sensor, variable-area inductive sensor, or solenoid iron-inserted inductive sensor.

[0039] The movement form of the blade stroke control member 105 may be a pressing type such as a button with a return function, a pushing type such as a slide sleeve or a slide push rod, a rotating type such as a trigger, a knob, or a rotatable grip.

[0040] The specific movement form of the blade stroke control member of this electric cutting tool and the specific settings of the inductive sensor can be arbitrarily combined from the means listed above and similar means that can be directly derived. One example of the combined electric cutting tool can be shown in FIGS. 9 and 10.

[0041] The blade stroke control member is a trigger 501 rotatably provided on the electric cutting tool main body 101. The inductive sensor is a hollow annular inductor or induction coil 701 attached to the electric cutting tool main body 101. The trigger is a magnetizer 601 attached to the trigger. When the trigger 501 rotates, the magnetizer 601 is in a moving state of being inserted into the hollow annular inductor or induction coil 701 or a moving state of escaping from the hollow annular inductor or induction coil 701.

[0042] When the trigger 501 is pulled, the magnetizer 601 is driven by the rotating trigger 501, so that the relative position between the magnetizer 601 and the hollow annular inductor or induction coil 701 changes, and the inductance generated by the hollow annular inductor or induction coil 701 changes. The control processor 108 acquires the inductance of the hollow annular inductor or induction coil 701, determines the current rotation position of the trigger 501 based on the inductance, determines the relative position between the magnetizer 601 and the hollow annular inductor or induction coil 701, and based on the determined position information, outputs a control signal corresponding to the position of the blade stroke control member 105 to the electric drive member of the electric drive assembly 104 (that is, drives the blade to the corresponding position), so that the cut opening 100 formed by the first blade 102 and the second blade 103 is adjusted to the corresponding opening degree.

[0043] The relative position between the magnetizer 601 and the hollow annular inductor or induction coil 701 changes as follows.

[0044] 1) When the blade stroke control member moves in the forward direction along a predetermined route, the magnetizer 601 is in a moving state of being inserted into the hollow annular inductor or induction coil 701. When the blade stroke control member moves in the reverse direction along a predetermined route, the magnetizer 601 is in a moving state of escaping from the hollow annular inductor or induction coil 701.

[0045] Or, 2) When the blade stroke control member moves in the forward direction along a predetermined route, the magnetizer 601 is in a moving state of escaping from the hollow annular inductor or induction coil 701. When the blade stroke control member moves in the reverse direction along a predetermined route, the magnetizer 601 is in a moving state of being inserted into the hollow annular inductor or induction coil 701.

[0046] The aforementioned blade stroke control member moves along a predetermined route. In this embodiment, the trigger 501 is supported by the electric cutting tool body 101 and rotates, and the forward movement can be understood as the rotation direction of the trigger when the trigger is pulled.

[0047] As one of the cutting opening adjustment operations, when the trigger 501 is pulled, the cutting opening between the first blade 102 and the second blade 103 becomes smaller, that is, it shows the cutting state with respect to the object to be cut.

[0048] The magnetizer is preferably a magnetic core or a metal member with high magnetic permeability such as iron, nickel, or manganese.

[0049] It is preferable that the electric cutting tool is further provided with an elastic member 109 corresponding to the trigger 501. When the user pulls the trigger 501, the elastic member 109 is elastically deformed by the force of the trigger 501, and when the user releases the trigger 501, the elastic member 109 is restored by elastic deformation, so the trigger 501 is moved to automatically return. The elastic member may adopt an elastic object such as a compression spring, a tension spring, a torsion spring, or an elastic piece.

[0050] Similarly, as the same or similar embodiment, the mounting position of the magnetizer 601 and the mounting position of the hollow annular inductor or induction coil 701 may be interchangeable. That is, the magnetizer 601 is attached to the electric cutting tool body 101, and the hollow annular inductor or induction coil 701 is attached to the trigger 501.

[0051] In this embodiment, in order for the control processor 108 to more accurately obtain the inductance information of the hollow annular inductor or induction coil 701, the control processor (MCU) has a signal conditioning circuit. The signal conditioning circuit includes a second-order integration circuit, a detection circuit, and an operational amplifier. The second-order integration circuit is used to replace a square wave with a sine wave whose positive and negative amplitudes change with the change in the inductance of the inductive sensor. The detection circuit is used to change the sine wave replaced by the second-order integration circuit into a relatively stable DC voltage. The operational amplifier is used to amplify the DC voltage obtained by the detection circuit. Finally, it is input to the control processor (MCU) for sampling and AD conversion, whereby the control processor (MCU) can more accurately determine the relative position between the magnetizer and the hollow annular inductor or induction coil. The waveform change can be referred to FIG. 12. The waveform change shown in FIG. 12 should be understood as an example, and it should be noted that the waveform change can be deformed according to changes in data such as frequency and amplitude.

[0052] As shown in FIG. 11, the second-order integration circuit includes a resistive load R2, a resistive load R8, and a capacitive load C5. The detection circuit includes a diode D2, a resistive load R7, and a capacitive load C4. Taking as an example the input of a rectangular wave with a frequency of 1 MHz, an amplitude of 5 V, and a duty cycle of 50% from the HPWM terminal. The resistive load R2, the resistive load R8, and the capacitive load C5 cooperate with the hollow annular inductor or induction coil (J1 in FIG. 11) to convert this square wave into a sine wave whose positive and negative amplitudes change with the change in the inductance of the hollow annular inductor or induction coil. When the inductance of the hollow annular inductor or induction coil increases, the amplitude of the sine wave decreases. The diode D2 is in a slightly conducting state, and the sine wave obtained by the above conversion becomes a relatively stable DC voltage after passing through the detection circuit. Moreover, the DC voltage follows the amplitude of the positive cycle of the above sine wave. Finally, the weak DC voltage output by the detection circuit enters the AMP0 operational amplifier, the DC voltage is amplified by the AMP0 operational amplifier, and is input to the control processor (MCU) for sampling and AD conversion.

[0053] Specifically, referring to FIGS. 13 to 15, in this embodiment, when the inductive sensor is applied to the cut opening control of the electric cutting tool, its reliability and stability can be made in a good state, and in order to be well adapted to the control of the cut opening, the control processor is provided with an oscillation circuit that cooperates with a hollow annular inductor or an induction coil. The inductance generated by the hollow annular inductor or the induction coil according to the relative position of the magnetizer is converted corresponding to the oscillation frequency, and the change in the displacement amount of the magnetizer corresponds to the change in the oscillation frequency. When moving the blade stroke control member, in response to a specific displacement amount of the magnetizer having a specific magnetic permeability, a frequency in a specific detection frequency band is output. After receiving the frequency located in the specific detection frequency band, the control processor correspondingly controls the output of the cut opening corresponding to the frequency.

[0054] Based on the inductance calculation formula, L = N 2 μA / l Here, L is the inductance, N is the number of turns of the coil, μ is the magnetic permeability of the magnetizer, A is the cross-sectional area of the magnetizer, and l is the length of the coil.

[0055] As an electric cutting tool that can be used for a long time, the coil is usually not replaced when it is normally used. As can be obtained from the above formula, when actually applied, the inductance is mainly determined by the magnetic permeability of the magnetizer, the cross-sectional area of the magnetizer, and the depth of the magnetizer entering the coil. That is, for a magnetizer with a specific cross-sectional area and a specific magnetic permeability, when the distance of the magnetizer entering the coil is a value within a specific range (that is, the above specific displacement amount), the generated inductance becomes a specific inductance. After the specific inductance is converted by the oscillation circuit, a frequency located in a specific detection frequency band is obtained. When applied to an electric pruning shear that can be held with one hand, the magnetizer may be a cylindrical nickel-zinc ferrite with a diameter of 3 mm.

[0056] In the cut opening control of an electric cutting tool, especially in the cut opening control of an electric cutting tool for pruning, the working environment of the electric cutting tool is very complex. For example, when fragments with the same magnetic permeability but different cross-sectional areas accidentally fall into the coil, or when fragments with the same cross-sectional area but different magnetic permeabilities accidentally fall into the coil, if the electric cutting tool accidentally cuts due to a false trigger, it is easy to cause injuries and losses. Therefore, the control system of the electric cutting tool needs to very surely and stably identify whether the trigger is activated or not so as to reduce the occurrence of injuries and losses. Therefore, by setting a specific detection frequency band, the control processor performs the corresponding cut opening control only when a frequency belonging to the specific detection frequency band is acquired, the influence of frequencies outside the specific detection frequency band on the cut opening control is eliminated, and the reliability and stability of the cut opening control are effectively improved.

[0057] The above-mentioned specific detection frequency setting and the control of the control processor for the specific detection frequency, on the premise of improving the reliability and stability of the control, except for the hardware such as the coil, magnetizer, oscillation circuit, and control processor it has, there is no need to add extra hardware control. It is only necessary to make corresponding settings for the control program, which is more beneficial for cost reduction.

[0058] Furthermore, all the frequency point information of the specific detection frequency band is pre-stored in the memory of the control processor, and each frequency point corresponds to a cut opening. After receiving the oscillation frequency, the control processor first determines whether the received oscillation frequency is located within the specific detection frequency band. If it is located within the specific detection frequency band, it compares and acquires the corresponding cut opening information and correspondingly controls the output of the corresponding cut opening. Furthermore, after receiving the oscillation frequency, if the control processor determines that the received oscillation frequency is not located within the specific detection frequency band, it does not output the cut angle control correspondingly or maintains the current cut angle control.

[0059] Not outputting the cutting angle control may mean restoring the cutting opening to the initial angle. For example, when the initial angle is set to open to the maximum opening, if the received oscillation frequency is not a frequency within a specific detection frequency band, the control processor automatically executes this control. That is, by controlling the blade to be restored to the initial position by the electric drive assembly, the cutting opening is effectively ensured to be restored to the initial maximum angle, the blade is safely and timely retracted and returned to the original position, the safety is improved, secondary damage to the human body is effectively avoided, and secondary damage to the electric cutting tool is effectively reduced.

[0060] Preferably, the specific detection frequency band is a low-frequency band. As an electric cutting tool for pruning, its cutting force is large. By setting the specific detection frequency band to a low-frequency band, the number of pulses after conversion is appropriate, it is easy to count the specific detection frequency, and it is easier to more accurately control the corresponding cutting opening. Therefore, the applicability of the inductive sensor is better when applied to the cutting opening control of the electric cutting tool. More preferably, the specific detection frequency band is 40KHz - 55KHz. When the cutting opening is gradually adjusted to be smaller, the frequency of the specific detection frequency band is expressed as gradually decreasing. For example, when the obtained frequency is 55KHz, correspondingly, the cutting opening is controlled to be the maximum. When the obtained frequency is 40KHz, correspondingly, the cutting opening is controlled to be the minimum. The above frequency band range is a low-frequency band, and the linear proportion gradually decreasing from 55KHz to 40KHz is closer to the blade proportion. When the above frequency band is applied to the cutting opening control of the electric cutting tool, its applicability is better, and the selection of the above specific detection frequency band is more advantageous for improving the accuracy of the cutting opening control.

[0061] A static operating frequency is provided to represent the influence of external foreign objects, and the frequency of the specific detection frequency band is less than the static operating frequency. The amplitude of oscillation is preferably a value greater than 150% at the detection point, and the anti-interference performance is better. When the specific detection frequency band is selected to be 40KHz to 55KHz, the static operating frequency is preferably 60KHz. There is a large safety margin between the specific detection frequency band and the static operating frequency. Moreover, in the cut opening control of the electric garden cutting tool for pruning, common metal foreign objects include copper, iron, aluminum, contaminated water, water pollution, tree leaves, oil stains, etc. The frequency band affected is close to the static operating point, and by setting it, the influence of common foreign objects can be effectively avoided. That is, the setting and selection of the above specific detection frequency band and static operating frequency can, on the one hand, ensure good applicability and control accuracy when the inductive sensor is applied to the cut opening control of the electric cutting tool, and on the other hand, have a large safety margin when setting the static operating frequency.

[0062] As shown in FIG. 15, in the oscillation circuit, the resistive load R2 is an output current limiting resistor, which is connected to a hollow annular inductor or an induction coil (J1 in FIG. 15). The detection point may be point A or point B. Point A is a high-potential frequency output point, and point B is a low-potential frequency output point. It is preferable to perform frequency control by PWM.

[0063] In an embodiment of the present invention, by the blade stroke control member being performed in a predetermined route, the magnetizer moves in the direction of escaping from the hollow annular inductor or the induction coil. When reaching the end point, the magnetizer approaches the opening of the hollow annular inductor or the induction coil and forms a state of partially blocking the opening.

[0064] The partial blocking of the opening by the magnetizer satisfies that foreign objects with a cross-section larger than that of the magnetizer cannot pass through the opening.

[0065] For example, when having the elastic member 109 and the trigger 501, and when the trigger is loosened, the elastic member moves the trigger so as to return to the original position, and moves the magnetizer 601 so as to move in the direction of escaping from the hollow annular inductor or the induction coil corresponding to the return of the trigger to the original position. When the trigger is loosened, the magnetizer moves in the direction of escaping from the hollow annular inductor or the induction coil. However, after the trigger is completely loosened (after the trigger is completely returned to the original position), the interval secured between the magnetizer and the opening of the hollow annular inductor or the induction coil is maintained as a small interval, and the small interval prevents foreign matter with a cross-section larger than that of the magnetizer from passing through.

[0066] Since the original position to which the trigger is returned can be restricted by setting the corresponding restricting member, the interval secured between the magnetizer and the opening of the coil after the trigger is completely loosened (after the trigger is completely returned to the original position) can be maintained as the aforementioned small interval, preventing foreign matter with a cross-section larger than that of the magnetizer from passing through, effectively avoiding the generation of a trigger due to incorrect identification, and improving the safety when applied to the cut opening control of the electric cutting tool.

[0067] In addition, when manufacturing the electric cutting tool, in order to supply power to the power consumption members (such as the control processor and the electric drive members of the electric drive assembly) of the electric cutting tool to operate it normally, the electric cutting tool further includes a power supply module 110. The power supply module 110 may be provided to supply power to the power consumption members of the electric cutting tool by being connected to the main power supply. Also, the power supply module 110 may be provided to supply power to the power consumption members of the electric cutting tool via an attached battery.

[0068] The communication between the control processor and the electric drive assembly may be wired or wireless. The wired and wireless communication technologies are common technologies and will not be described here.

[0069] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, from any perspective, the embodiments should be regarded as illustrative and non-limiting, and the scope of the present invention is limited by the appended claims rather than the above description. Therefore, all modifications within the meaning and scope equivalent to the claims are intended to be included in the present invention. Any drawing notations in the claims should not be regarded as limiting the claims to which they are related.

Claims

【Claim 1】 A signal generator based on the inductance characteristics of a device including a signal generator attached to a power tool, The signal generator includes a substrate, a manual actuator, an air-core inductor, and a magnetizer, The manual actuator is movably connected to the substrate, Fixed parts are provided on both the manual actuator and the substrate, Relative approach or relative separation movement occurs between the two fixed parts due to the movement of the manual actuator, The air-core inductor and the magnetizer are respectively connected to the two fixed parts, The magnetizer is inserted along the middle of the air-core inductor or separated from the middle of the air-core inductor by the relative approach or relative separation movement of the two fixed parts, The manual actuator includes a movable member and a connector, The movable member is movably connected to the substrate via the connector, The fixed part of the manual actuator is provided on the movable member, A first return spring docked to the movable member is carried on the substrate, The movable member is returned by the first return spring, The connector is fixed to the substrate, a rotary shaft structure is provided on the connector, and the movable member rotates around the rotary shaft structure, The air-core inductor is fixedly connected to the fixed part of the substrate, the magnetizer is transmitably connected to the fixed part of the movable member, a guide sleeve is provided on the substrate, the magnetizer is guidably connected to the guide sleeve, and the magnetizer is inserted along the center of the air-core inductor or separated from the center of the air-core inductor by the guide sleeve, The magnetizer is abutted and connected to the fixed part of the movable member, a second return spring docked to the guide sleeve is provided on the magnetizer, and the magnetizer is returned by the second return spring, A signal generator based on the inductance characteristics of a device, characterized in that.

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