Starting control circuit, electric tool and starting control method of electric tool

Abstract

The invention relates to the technical field of electric tools, in particular to a starting control circuit, an electric tool and an electric tool starting control method.The starting control circuit comprises a first switching circuit, a direct current conversion circuit, a main control unit and a second switching circuit; the first driving control instruction is output to the driving unit of the electric tool to control the action unit of the electric tool not to work during non-standard operation of inserting the battery pack later, so that the reliable operation of the electric tool can be ensured, the safety of operators can be ensured, the safety performance of the electric tool is improved, and a user is more satisfied.

Description

Technical Field

[0001] The present application relates to the technical field of power tools, and particularly relates to a starting control circuit, a power tool, and a power tool starting control method. Background Art

[0002] Power tools have many advantages and benefits compared to traditional manual tools, which can effectively improve work efficiency, quality, and safety, and are becoming increasingly popular. Taking an electric chain saw as an example, it mainly consists of four parts: a motor that provides power, a battery pack that provides energy, a circuit board for drive control, and a saw chain that performs actions.

[0003] During the use of an electric chain saw, if the operator does not operate according to the normal operation method, when one hand first presses the trigger and then the other hand inserts the battery pack, at this time, the motor will drive the saw chain to work instantly when the battery pack is inserted, which is particularly likely to cause personal injury and property loss, and there are safety hazards.

[0004] Based on this, it is urgent to develop a starting control circuit to prevent safety hazards caused by the accidental start of the action unit due to non-standard operations when inserting the battery pack for power tools such as electric chain saws. Summary of the Invention

[0005] In view of the above-mentioned disadvantages of the prior art, the purpose of the present application is to provide a starting control circuit, a power tool, and a power tool starting control method, which can avoid the situation of accidental start of the action unit due to non-standard operations when inserting the battery pack, and increase the safety of the power tool.

[0006] To achieve the above object and other related objects, the present application provides a starting control circuit, which is applied to a power tool.

[0007] The starting control circuit includes:

[0008] A first switch circuit, a DC conversion circuit, a main control unit, and a second switch circuit;

[0009] The first switch circuit is connected to the battery pack and the DC conversion circuit, and is used to activate the DC conversion circuit to work and supply power to the second switch circuit and the main control unit after the first switch circuit is triggered.

[0010] The second switch circuit is respectively connected to the battery pack, the DC conversion circuit, and the main control unit. Based on the different timings of the current flowing out of the battery pack and the current flowing out of the DC conversion circuit reaching the second switch circuit, the second switch circuit outputs different voltage waveforms.

[0011] The master control unit is configured to output a first driving instruction when receiving a first voltage waveform, where the first voltage waveform is the voltage waveform output by the second switching circuit when first receiving the current flowing out of the DC conversion circuit.

[0012] In an alternative embodiment of the present application, the master control unit is further configured to output a second driving control instruction when receiving a second voltage waveform, where the second voltage waveform is the voltage waveform output by the second switching circuit when simultaneously receiving the current flowing out of the battery pack and the current flowing out of the DC conversion circuit.

[0013] In an alternative embodiment of the present application, the first voltage waveform is a voltage waveform that is low first and then high, and the second voltage waveform is a voltage waveform that is high first and then flat.

[0014] In an alternative embodiment of the present application, the first switching circuit includes a start switch, a first resistor, a second resistor, and a first control switch, and the first resistor and the second resistor form a voltage dividing circuit;

[0015] One end of the start switch is connected to the positive electrode of the battery pack, and the other end is grounded through the voltage dividing circuit;

[0016] The control end of the first control switch is connected to the voltage dividing circuit and the master control unit, the input end is connected to the negative input end of the DC conversion circuit, and the output end is grounded;

[0017] When the start switch is closed and the battery pack is inserted, the first control switch is closed, and the DC conversion circuit operates.

[0018] In an alternative embodiment of the present application, the first switching circuit further includes a voltage stabilizing diode, and the voltage stabilizing diode is connected between the start switch and the voltage dividing circuit.

[0019] In an alternative embodiment of the present application, the start control circuit further includes a first protection diode, the anode of the first protection diode is connected to the positive electrode of the battery pack, and the cathode is respectively connected to the DC conversion circuit, the first switching circuit, and the second switching circuit.

[0020] In an alternative embodiment of the present application, the second switching circuit includes a first capacitor and an opto-coupler element. One end of the first capacitor is used to receive the current from the battery pack, and the other end of the first capacitor is connected to one end of the opto-coupler element. When the time when the current flowing out of the battery pack reaches one end of the first capacitor is the same as the time when the current flowing out of the DC conversion circuit reaches the other end of the opto-coupler element, the second switching circuit outputs the first voltage waveform;

[0021] When the time when the current flowing out of the battery pack reaches one end of the first capacitor is earlier than the time when the current flowing out of the DC conversion circuit reaches the other end of the optocoupler element, the second switch circuit outputs a second voltage waveform.

[0022] In an alternative embodiment of the present application, the second switch circuit further includes a second protection diode, and the second protection diode is connected to one end of the optocoupler element.

[0023] In an alternative embodiment of the present application, the startup control circuit further includes a relay, the relay is connected in series between the positive electrode of the battery pack and the drive unit, and the coil of the relay is powered by the DC conversion circuit.

[0024] In an alternative embodiment of the present application, the startup control circuit further includes a second capacitor, one end of the second capacitor is connected to the relay and the drive unit respectively, and the other end is grounded.

[0025] To achieve the above object and other related objects, the present application further provides a power tool, the power tool includes:

[0026] An action unit;

[0027] A battery pack, the battery pack supplies power to the action unit;

[0028] A startup control circuit, including:

[0029] A first switch circuit, a DC conversion circuit, a main control unit, a second switch circuit and a drive unit;

[0030] The first switch circuit is connected to the battery pack and the DC conversion circuit, and is used to activate the DC conversion circuit to work to supply power to the second switch circuit, the main control unit and the drive unit after the first switch circuit is triggered;

[0031] The second switch circuit is connected to the battery pack and the main control unit, and based on the different timings of the first switch circuit being triggered, the second switch circuit outputs different voltage waveforms;

[0032] The main control unit is used to output a first drive instruction to the drive unit when receiving a first voltage waveform, wherein the first voltage waveform is the voltage waveform output when the second switch circuit first receives the current flowing out of the DC conversion circuit;

[0033] The drive unit controls the action unit not to work based on the first drive control instruction.

[0034] In an alternative embodiment of the present application, the main control unit is further configured to output a second drive control instruction when receiving a second voltage waveform, where the second voltage waveform is a voltage waveform output when the second switch circuit simultaneously receives the current flowing out from the battery pack and the current flowing out from the DC conversion circuit;

[0035] The drive unit controls the operation of the action unit based on the second drive control instruction.

[0036] In an alternative embodiment of the present application, the power tool includes a chain saw, a pruning machine, a grass trimmer or a reciprocating saw.

[0037] To achieve the above object and other related objects, the present application further provides a method for controlling the start of a power tool, including the following steps:

[0038] When the battery pack is connected to the power tool, current flows out from the battery pack;

[0039] If the current reaches one end of the second switch circuit from the first path first and reaches the other end of the second switch circuit from the second path later, the second switch circuit outputs a first voltage waveform, and the main control unit outputs a first drive control instruction based on the detected first voltage waveform;

[0040] If the time when the current reaches one end of the second switch circuit from the first path is the same as the time when the current reaches the other end of the second switch circuit from the second path, the second switch circuit outputs a second voltage waveform, and the main control unit outputs a second drive control instruction based on the detected second voltage waveform.

[0041] In an alternative embodiment of the present application, the first path is the path through which the current flows from the positive pole of the battery pack to one end of the second switch circuit.

[0042] In an alternative embodiment of the present application, the second path is the path through which the current reaches the other end of the second switch circuit after flowing through the DC conversion circuit from the positive pole of the battery pack.

[0043] In an alternative embodiment of the present application, when the first switch circuit is triggered and the battery pack is connected to the power tool, the current flows through the DC conversion circuit from the positive pole of the battery pack and then reaches the other end of the second switch circuit.

[0044] This application relates to the technical field of power tools, and particularly to a start control circuit, a power tool, and a power tool start control method. The start control circuit includes a first switch circuit, a DC conversion circuit, a main control unit, and a second switch circuit. When the start switch is pressed first and then the battery pack is inserted in an improper operation, the first drive control instruction can be output to the drive unit of the power tool to control the action unit of the power tool not to work. This can not only ensure the reliable operation of the power tool, but also ensure the safety of the operator, improve the safety performance of the power tool, and make users more satisfied. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The circuit schematic diagram of the start control circuit of this application is shown.

[0046] Figure 2 The circuit diagram of the start control circuit of a specific embodiment of this application is shown.

[0047] Figure 3 The schematic diagram of one-way working state of the start control circuit of a specific embodiment of this application during normal operation is shown.

[0048] Figure 4 The schematic diagram of another one-way working state of the start control circuit of a specific embodiment of this application during normal operation is shown.

[0049] Figure 5 The schematic diagram of the two-way simultaneous working of the start control circuit of a specific embodiment of this application during improper operation is shown.

[0050] Figure 6 The flow schematic diagram of the power tool start control method of a specific embodiment of this application is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] The following specific examples are used to illustrate the embodiments of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application.

[0052] It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of this application in a schematic manner. Therefore, only the components related to this application are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components during actual implementation. The type, quantity, and ratio of each component during actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0053] In the high-end garden machinery series of products, a chainsaw is a mechanical device commonly seen in greening gardens and an essential tool in the logging industry. A good chainsaw can make the entire working process smoother and greatly improve efficiency. As one of the most widely used and frequently used power tools among many garden machinery products, especially the lithium battery brushless chainsaw, it mainly consists of four parts: an electric motor that provides power, a battery pack that provides energy, a circuit board for drive control, and a saw chain that performs actions.

[0054] The saw chain part consists of the following multiple components: The chain brake, also known as the brake, is a device used to quickly stop the rotation of the chain; the saw chain gear, also known as the sprocket, is a toothed part used to drive the saw chain; the front handle is the handle installed in front of the chainsaw, and the front handle baffle is also known as the safety baffle; the guide plate, also known as the chain plate, has a firm track structure that can be used to support and conduct the saw chain; the rear handle is the handle installed behind the chainsaw and belongs to the main handle.

[0055] All of the above belong to the safety function components of the saw chain part. Although so many safety function components are designed, there are still starting hazards in existing chainsaw products: If the operator does not operate according to the normal operation method, the chainsaw may cause personal injury and property loss due to sudden rotation or unexpected situations, which is relatively dangerous and unpredictable for the operator and the surrounding environment. Therefore, it is necessary to continuously optimize and improve the protection function of the power tool itself.

[0056] For this purpose, the present application provides a starting control circuit applied to an electric chainsaw to solve the safety hazard brought by the accidental operation of the motor, which is an action unit, when the electric chainsaw first holds down the start switch and then inserts the battery pack; of course, the starting control circuit of the present application can also be applied to other power tools with such safety hazards, such as pruning machines, lawn mowers, reciprocating saws, electric drills, electric hammers, electric grinders, electric scissors and other power tools.

[0057] As Figure 1 and Figure 2 shown, the present application discloses a starting control circuit applied to a power tool. The power tool includes a battery pack 10, an action unit 70 powered by the battery pack 10, and a starting control circuit including a start switch S1. The start switch S1 can be, for example, a trigger switch, a button switch, a touch switch, etc. In this embodiment, the action unit 70 includes but is not limited to an electric motor. The starting control circuit includes a first switch circuit 20, a DC conversion circuit 40, a main control unit 50, a second switch circuit 30, and a drive unit 60.

[0058] As Figure 1 and Figure 2As shown, the first switch circuit 20 is connected to the battery pack 10 and the DC conversion circuit 40, and is used to activate the DC conversion circuit 40 to work after the first switch circuit is triggered, so as to supply power to the second switch circuit 30, the main control unit 50 and the drive unit 60. Among them, the triggering condition of the first switch circuit 20 is that the start switch S1 is closed, and the battery pack 60 is inserted into the power tool and is reliably connected to the power tool.

[0059] As Figure 2 shown, the first switch circuit 20 includes a start switch S1, a voltage dividing circuit and a first control switch 21; one end of the start switch S1 is connected to the positive electrode of the battery pack 10, and the other end is grounded through the voltage dividing circuit; the control end of the first control switch 21 is connected to the voltage dividing circuit and the main control unit 50, the input end is connected to the negative input end of the DC conversion circuit 40, and the output end is grounded. The positive input end of the DC conversion circuit 40 is connected to the positive electrode of the battery pack 10 through a first protection diode D1; when the start switch S1 is closed and the battery pack 10 is inserted, the battery pack 10 supplies power to the voltage dividing circuit, the first control switch 21 is closed, and the DC conversion circuit 40 starts to work and outputs a supply voltage. The first control switch 21 can be a triode or a MOS transistor.

[0060] As Figure 2 shown, the first switch circuit 20 further includes a voltage stabilizing diode ZD1. The voltage stabilizing diode ZD1 is connected between the start switch S1 and the voltage dividing circuit, and the voltage stabilizing diode ZD1 is used to stably transmit the voltage flowing out from the positive electrode of the battery pack 10 to the voltage dividing circuit. The voltage dividing circuit includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is sequentially connected to the positive electrode of the battery pack 10 through the voltage stabilizing diode ZD1, the start switch S1 and the first protection diode D1, and the other end is grounded through the second resistor R2. The control end of the first control switch 21 is connected to the connection between the first resistor R1 and the second resistor R2.

[0061] When the start switch S1 is pressed, that is, when the start switch S1 is closed and the battery pack 10 is inserted, the first switch circuit 20 is activated. After the positive voltage of the battery pack 10 is divided by the voltage dividing circuit composed of the first protection diode D1, the start switch S1, the voltage stabilizing diode ZD1, the first resistor R1 and the second resistor R2, it drives the first control switch 21 to conduct, so as to connect the negative input end of the DC conversion circuit 40 to the ground, make the DC conversion circuit 40 work, and convert the positive voltage of the battery pack 10 into the voltage required by the electrical components of the start control circuit for power supply, so that the electrical components such as the main control unit 50, the second switch circuit 30, the drive unit 60, and the relay 80 coil work normally. When the main control unit 50 starts to work, the first control switch 21 is provided with a drive voltage by the main control unit 50. At this time, the disconnection of the start switch S1 does not affect the operation of the entire power tool. Among them, the supply voltage output by the DC conversion circuit 40 can be set according to the voltage required by each electrical component.

[0062] As an example, the DC conversion circuit 40 can be, for example, a DC-DC circuit, which can output supply voltages such as 24V, 15V, 5V, etc. Among them, the 5V supply voltage is used to supply power to the main control unit 50, the 15V supply voltage is used to supply power to the drive unit 60, and the 24V supply voltage is used to supply power to the coil of the relay 80 to close the relay 80 and connect the power supply circuit between the battery pack 10 and the drive unit 60.

[0063] As Figure 1 and Figure 2 shown, the second switch circuit 30 is respectively connected to the battery pack 10, the DC conversion circuit 40 and the main control unit 50. Based on the different timings of the current flowing out of the battery pack 10 and the current flowing out of the DC conversion circuit 40 reaching the second switch circuit 30, the second switch circuit 30 outputs different voltage waveforms. Specifically, the first voltage waveform is output when the second switch circuit 30 first receives the current flowing out of the DC conversion circuit 40, and the second voltage waveform is output when the second switch circuit 30 simultaneously receives the current flowing out of the battery pack 10 and the current flowing out of the DC conversion circuit 40. It should be noted that the currents arriving simultaneously in this embodiment are basically the same without considering the self-turn-on delay of the circuit components and the current transmission delay.

[0064] The second switch circuit 30 includes a first capacitor C1 and an optocoupler element U1. One end of the first capacitor C1 is connected to the positive electrode of the battery pack 10 and is used to directly receive the current from the battery pack 10 for charging. The other end of the first capacitor C1 is connected to one end of the optocoupler element U1. Utilizing the basic characteristics of the first capacitor C1 of passing alternating current, blocking direct current, passing high-frequency current, and blocking low-frequency current, the first capacitor C1 is connected in series between the front and rear stages of the circuit as a coupling capacitor to achieve the purpose of blocking the bias direct current signal and coupling the high-frequency signal. The coupled voltage signal can be applied at point C to turn on the light-emitting diode in the optocoupler element U1. When the DC conversion circuit 40 supplies power to the fifth resistor R5, the phototransistor in the optocoupler element U1 is turned on, and the voltage waveform at point D outputs different voltage waveforms according to the corresponding operation mode.

[0065] Specifically, the second switch circuit 30 can charge the first capacitor C1 using the output of the battery pack 10, and control the on / off of the optocoupler element U1 based on the different timings of inserting the battery pack 10 and pressing the start switch S1 to output different voltage waveforms to the main control unit 50. When the start switch S1 is pressed first and then the battery pack 10 is inserted, the time when the current flowing out of the battery pack 10 reaches one end of the first capacitor C1 is earlier than the time when the current flowing out of the DC conversion circuit 40 reaches the other end of the optocoupler element U1 (the end connected to the resistor R5), and the second switch circuit 30 outputs a first voltage waveform of "low first and then high"; when the battery pack 10 is inserted first and then the start switch S1 is pressed, without considering the self-turn-on delay of the circuit components and the current transmission delay, the time when the current flowing out of the battery pack 10 reaches one end of the first capacitor C1 is basically the same as the time when the current flowing out of the DC conversion circuit 40 reaches the other end of the optocoupler element U1 (the end connected to the resistor R5), and the second switch circuit 30 outputs a second voltage waveform of "high first and then flat".

[0066] As Figure 2 shown, in a specific embodiment, the second switch circuit 30 further includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6 in addition to the first capacitor C1 and the optocoupler element U1. The optocoupler element U1 includes a light-emitting diode and a photosensitive triode; one end of the third resistor R3 is connected to the positive electrode of the battery pack 10 through a first protection diode D1, and the other end is connected to one end of the first capacitor C1. The fourth resistor R4 is connected in parallel across the two ends of the first capacitor C1 for discharging the first capacitor C1. The other end of the first capacitor C1 is grounded through the light-emitting diode of the optocoupler element U1. The output end of the optocoupler element U1 is respectively connected to one end of the fifth resistor R5 and one end of the sixth resistor R6. The other end of the fifth resistor R5 is connected to the output end of the DC conversion circuit 40, and the other end of the sixth resistor R6 is connected to the I / O port of the main control unit 50.

[0067] As Figure 2 shown, in a specific embodiment, the second switch circuit 30 further includes a second protection diode D2. The anode of the second protection diode D2 is grounded, and the cathode is connected to the end of the first capacitor C1 that is not connected to the third resistor R3. The second protection diode D2 is used to absorb clutter and play a protective role.

[0068] It should be noted that both the voltage waveform of "high first and then flat" and the voltage waveform of "low first and then high" are detected within a specific time period when the power tool is turned on. In this embodiment, after the main control unit 50 is powered on, it can detect Figure 2The voltage values at the first selected time point (e.g., 10 ms) and the second selected time point (e.g., 300 ms) at point D in the figure are obtained, and then based on these two voltage values, it is determined whether the current voltage waveform is "high first" or "low first". These two time points need to be selected according to the circuit parameters and the voltage waveforms within a period of time after the main control unit 50 is powered on under different operating modes, so as to be able to distinguish the voltage waveforms of these two different operating modes.

[0069] Specifically, when the start switch S1 is pressed first and then the battery pack 10 is inserted, the second switch circuit 30 outputs a first voltage waveform of "low first and then high". The main control unit 50 is configured to output a first drive control instruction to the drive unit 60 when receiving the first voltage waveform, and the drive unit 60 controls the action unit 70 not to work based on the first drive control instruction. When the battery pack 10 is inserted first and then the start switch S1 is pressed, the second switch circuit 30 outputs a second voltage waveform of "high first and then flat". The main control unit 50 is configured to output a second drive control instruction to the drive unit 60 when receiving the second voltage waveform, and the drive unit 60 controls the action unit 70 to work based on the second drive control instruction. In this way, not only the reliable operation of the power tool can be ensured, but also the safety of the operator can be guaranteed, improving the safety performance of the power tool and making the user more satisfied.

[0070] As Figure 2 shown, the start control circuit further includes a relay 80. The relay 80 is connected in series between the positive electrode of the battery pack 10 and the drive unit 60, and is used to control the on / off of the power supply circuit between the battery pack 10 and the drive unit 60. Among them, the coil of the relay 80 is powered by the DC conversion circuit 40.

[0071] As Figure 2 shown, the start control circuit further includes a second capacitor C2. One end of the second capacitor C2 is respectively connected to the relay 80 and the drive unit 60, and the other end is grounded. The second capacitor C2 not only has an energy storage function but also has a filtering function, and is used to provide sufficiently stable and noise-free electrical energy to the drive unit 60 to drive the action unit 70 to work.

[0072] Under normal circumstances, the power tool has two operating modes. The first operating mode is to insert the battery pack 10 first and then press and hold the start switch S1. This operating mode can be called the normal operation mode. In the normal operation mode, the start control circuit can output a first control instruction to the drive unit 60 so that the drive unit 60 can drive the motor serving as the action unit 70 to operate normally. The second operating mode is to press and hold the start switch S1 first and then insert the battery pack 10. This operating mode can be called the non-standard operation mode (also called the error operation mode or abnormal operation mode). In the non-standard operation mode, the start control circuit can output a second control instruction to the drive unit 60 so that the drive unit 60 controls the motor serving as the action unit 70 not to work.

[0073] The working principles of the start control circuit in the normal operation mode and the abnormal operation mode will be described separately below.

[0074] As Figure 3 and Figure 4 shown, in the normal operation mode, when the battery pack 10 is inserted first, there are two working states in the start control circuit. One working state is that before the start switch S1 is pressed as Figure 3 shown, the positive voltage provided by the positive electrode of the battery pack 10 in the circuit first forms a loop through the first protection diode D1, the third resistor R3 and the light-emitting diode in the optocoupler element U1 to charge the first capacitor C1 in advance. The first capacitor C1 is in a fully charged state. The other working state is that after the start switch S1 is pressed as Figure 4 shown, the positive voltage provided by the positive electrode of the battery pack 10 is divided by the voltage dividing circuit composed of the first protection diode D1, the start switch S1, the voltage stabilizing diode ZD1, and the first resistor R1 and the second resistor R2 to drive the first control switch 21 to conduct, so that the DC conversion circuit 40 works to generate voltages such as 5V to supply power to the main control unit 50 and the fifth resistor R5, so that the optocoupler element U1 conducts and works. A second voltage waveform of "first high and then flat" is formed at point D and is supplied to the I / O port of the main control unit 50 after being limited by the sixth resistor R6. After receiving such a voltage waveform, since the program pre-stored in the main control unit 50 stipulates that such a voltage waveform of "first high and then flat" is an on signal, the main control unit 50 can control the output of the drive unit 60 to be a drive signal to drive the motor serving as the action unit 70 to operate normally.

[0075] As Figure 5As shown, in the non-standard operation mode, that is, first hold down the start switch S1 and then insert the battery pack 10. At this time, two paths in the start controller circuit work simultaneously. One path is that the positive voltage provided by the positive electrode of the battery pack 10 passes through the voltage dividing circuit composed of the first protection diode D1, the start switch S1, the voltage stabilizing diode ZD1, and the first resistor R1 and the second resistor R2 for voltage division, and then drives the first control switch 21 to conduct, enabling the DC conversion circuit 40 to work and generating voltages such as 5V to supply power to each component such as the main control unit 50 and the fifth resistor R5. The other path is that the positive voltage of the battery pack 10 forms a loop through the first protection diode D1, the third resistor R3, and the light-emitting diode in the optocoupler element U1 to charge the first capacitor C1. Since the first capacitor C1 is charged for the first time, the voltage inside the first capacitor C1 is a charging process of "first low and then high". Since the start switch S1 is held down first, the DC conversion circuit 40 works synchronously to generate voltages such as 5V to supply power to the main control unit 50 and the fifth resistor R5, enabling the photosensitive triode in the optocoupler element U1 to conduct, so that the first voltage waveform of "first low and then high" at point D is limited by the sixth resistor R6 and then supplied to the I / O port of the main control unit 50. After receiving such a voltage waveform, the program pre-stored inside the main control unit 50 stipulates that such a "first low and then high" voltage waveform is a turn-off signal, and then it can control the output of the drive unit 60 to be a turn-off signal to turn off the motor serving as the action unit 70.

[0076] As Figure 6 shown, this embodiment also discloses an electric tool start control method based on the above start control circuit, including the following steps:

[0077] Step S10, when the battery pack is connected to the electric tool, current flows out from the battery pack;

[0078] Step S20, if the current reaches one end of the second switch circuit from the first path first and reaches the other end of the second switch circuit from the second path later, the second switch circuit outputs a first voltage waveform, and the main control unit outputs a first drive control instruction based on the detected first voltage waveform;

[0079] Step S30, if the time when the current reaches one end of the second switch circuit from the first path is the same as the time when the current reaches the other end of the second switch circuit from the second path, the second switch circuit outputs a second voltage waveform, and the main control unit outputs a second drive control instruction based on the detected second voltage waveform.

[0080] Among them, the first path is the path where the current flows from the positive electrode of the battery pack to one end of the second switch circuit. Specifically, corresponding to Figure 2 the path where the current flows from the positive electrode of the battery pack 10 through the first protection diode D1 to the end (point B) of the third resistor R3 that is not connected to the first capacitor C1 in sequence.

[0081] The second path is the path where the current flows from the positive electrode of the battery pack through the DC conversion circuit and then reaches the other end of the second switch circuit. Specifically, the second path corresponds to Figure 2 the path where the current flows from the positive electrode of the battery pack 10 through the first protection diode D1 and the DC conversion circuit 40 in sequence and then is output to one end of the fifth resistor R5 connected to the DC conversion circuit 40; when the first switch circuit 20 is triggered and the battery pack 10 is connected to the power tool, the DC conversion circuit 40 starts to work and can supply power externally. The current flows from the positive electrode of the battery pack 10 through the first protection diode D1 and the DC conversion circuit 40 and then reaches one end of the fifth resistor R5 connected to the DC conversion circuit 40 to supply power to the fifth resistor R5.

[0082] In summary, the starting control circuit composed of the first switch circuit, the DC conversion circuit, the main control unit, the second switch circuit and the driving unit in this application can control the action unit of the power tool not to work during the non-standard operation of first pressing the start switch and then inserting the battery pack. This can not only ensure the reliable operation of the power tool, but also ensure the safety of the operator, improve the safety performance of the power tool, and make users more satisfied.

[0083] For those skilled in the art, it is obvious that this application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of this application.

[0084] The above embodiments are only used to illustrate the technical solutions of this application and not to limit them. Although this application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of this application can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A startup control circuit, characterized in that, Applied to a power tool, the start control circuit includes: A first switch circuit, a DC conversion circuit, a main control unit, and a second switch circuit; The first switch circuit is connected to the battery pack and the DC conversion circuit, and is configured to activate the DC conversion circuit to supply power to the second switch circuit and the main control unit after the first switch circuit is triggered; The second switch circuit is respectively connected to the battery pack, the DC conversion circuit, and the main control unit. Based on the different timings of the current flowing out of the battery pack and the current flowing out of the DC conversion circuit reaching the second switch circuit, the second switch circuit outputs different voltage waveforms; The main control unit is configured to output a first drive instruction when receiving a first voltage waveform, wherein the first voltage waveform is the voltage waveform output when the second switch circuit first receives the current flowing out of the DC conversion circuit.

2. The startup control circuit according to claim 1, wherein The main control unit is further configured to output a second drive control instruction when receiving a second voltage waveform, wherein the second voltage waveform is the voltage waveform output when the second switch circuit simultaneously receives the current flowing out of the battery pack and the current flowing out of the DC conversion circuit.

3. The startup control circuit according to claim 1, characterized in that The first switch circuit includes a start switch, a voltage dividing circuit, and a first control switch; One end of the start switch is connected to the positive electrode of the battery pack, and the other end is grounded through the voltage dividing circuit; The control end of the first control switch is connected to the voltage dividing circuit and the main control unit, the input end is connected to the negative input end of the DC conversion circuit, and the output end is grounded; When the start switch is closed and the battery pack is inserted, the first control switch is closed, and the DC conversion circuit starts to work.

4. The startup control circuit according to claim 3, wherein The first switch circuit further includes a voltage stabilizing diode, which is connected between the start switch and the voltage dividing circuit.

5. The startup control circuit according to claim 1, wherein The start control circuit further includes a first protection diode, the anode of which is connected to the positive electrode of the battery pack, and the cathode is respectively connected to the DC conversion circuit, the first switch circuit, and the second switch circuit.

6. The start control circuit according to claim 1, wherein The second switch circuit includes a first capacitor and an optocoupler element. One end of the first capacitor is used to receive the current from the battery pack, and the other end of the first capacitor is connected to one end of the optocoupler element. When the time when the current flowing out of the battery pack reaches one end of the first capacitor is the same as the time when the current flowing out of the DC conversion circuit reaches the other end of the optocoupler element, the second switch circuit outputs the first voltage waveform; When the time when the current flowing out of the battery pack reaches one end of the first capacitor is earlier than the time when the current flowing out of the DC conversion circuit reaches the other end of the optocoupler element, the second switch circuit outputs a second voltage waveform.

7. The startup control circuit according to claim 6, wherein The first voltage waveform is a voltage waveform that is low first and then high, and the second voltage waveform is a voltage waveform that is high first and then flat.

8. The startup control circuit according to claim 6, wherein The second switch circuit further includes a second protection diode, which is connected to one end of the optocoupler element.

9. The startup control circuit according to claim 1, wherein The starting control circuit further includes a relay, which is connected in series between the positive electrode of the battery pack and the driving unit, and the coil of the relay is powered by the DC conversion circuit.

10. An electric tool, characterized in that, Comprising: An action unit; A battery pack that powers the action unit; A starting control circuit, including: A first switch circuit, a DC conversion circuit, a main control unit, a second switch circuit, and a driving unit; The first switch circuit is connected to the battery pack and the DC conversion circuit, and is used to activate the DC conversion circuit to work and supply power to the second switch circuit, the main control unit, and the driving unit after the first switch circuit is triggered; The second switch circuit is connected to the battery pack and the main control unit, and based on the different timings of the triggering of the first switch circuit, the second switch circuit outputs different voltage waveforms; The main control unit is used to output a first driving instruction to the driving unit when receiving a first voltage waveform, wherein the first voltage waveform is the voltage waveform output when the second switch circuit first receives the current flowing out of the DC conversion circuit; The driving unit controls the action unit not to work based on the first driving control instruction.

11. The power tool according to claim 10, characterized in that, The main control unit is further used to output a second driving control instruction when receiving a second voltage waveform, wherein the second voltage waveform is the voltage waveform output when the second switch circuit simultaneously receives the current flowing out of the battery pack and the current flowing out of the DC conversion circuit; The driving unit controls the action unit to work based on the second driving control instruction.

12. The electric tool according to claim 10, characterized in that, The power tool includes a chain saw, a pruning machine, a grass trimmer, or a reciprocating saw.

13. A starting control method for a power tool, characterized in that, Including the following steps: When the battery pack is connected to the power tool, current flows out of the battery pack; If the current first reaches one end of the second switch circuit from a first path and then reaches the other end of the second switch circuit from a second path, the second switch circuit outputs a first voltage waveform, and the main control unit outputs a first driving control instruction based on the detected first voltage waveform; If the time when the current reaches one end of the second switch circuit from the first path is the same as the time when the current reaches the other end of the second switch circuit from the second path, the second switch circuit outputs a second voltage waveform, and the main control unit outputs a second driving control instruction based on the detected second voltage waveform.

14. A method for controlling the start of a power tool according to claim 13, characterized in that, The first path is the path for the current to flow from the positive electrode of the battery pack to one end of the second switch circuit.

15. A method for controlling the start of a power tool according to claim 13, characterized in that, The second path is the path for the current to reach the other end of the second switch circuit after flowing through the DC conversion circuit from the positive electrode of the battery pack.

16. A starting control method for a power tool according to claim 15, characterized in that, When the first switch circuit is triggered and the battery pack is connected to the power tool, the current flows from the positive electrode of the battery pack through the DC conversion circuit and then reaches the other end of the second switch circuit.

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