CN115395823A - Electric tool and control method thereof - Google Patents

Abstract

The embodiment of the invention discloses an electric tool and a control method thereof. The electric tool includes: a motor; the battery pack is electrically connected with the motor and provides power supply voltage for the motor; the temperature detection unit is used for detecting and acquiring the temperature of the electric tool in real time; the voltage detection unit is used for detecting and obtaining voltage information of the battery pack in real time; the controller is used for outputting a control signal with a certain duty ratio to control the motor to start; the controller is configured to: acquiring temperature information of the electric tool and voltage information of a battery pack; the duty ratio of a control signal for controlling the start of the motor is changed according to the temperature of the power tool and the voltage information of the battery pack. Therefore, the problems that the prior art is not started at a low temperature or stalls in the starting process and the like can be solved, the problems that the starting voltage is too large, the starting current is too large and the like can be avoided from stalling, and the problem that the electric tool cannot be started due to too low environmental temperature and the like can be avoided, the normal starting of the electric tool is realized, and the electric tool can be normally started even under the low-temperature environment.

Description

Electric tool and control method thereof

technical field

The embodiments of the present invention relate to the technical field of electric tool control, in particular to an electric tool and a control method thereof.

Background technique

With the development of electric tools, the intelligent control technology of electric tools has been more and more widely used. For example, use the controller to drive the motor to realize the characteristics of fast starting and smooth braking of electric tools.

However, when the ambient temperature is low, the existing electric tools may fail to start or be difficult to start at low temperature, or may stall during the starting process, which affects the normal starting of the electric tool.

Contents of the invention

The invention provides an electric tool and a control method thereof to solve the problem that the electric tool does not start at low temperature or stalls during starting.

In a first aspect, an embodiment of the present invention provides an electric tool, including:

motor;

A battery pack electrically connected to the motor to provide a power supply voltage for the motor;

A temperature detection unit, used for real-time detection and acquisition of the temperature of the electric tool;

A voltage detection unit, configured to detect and obtain voltage information of the battery pack in real time;

a controller, configured to output a control signal with a certain duty cycle to control the motor to start;

The controller is configured as:

Obtaining the temperature of the electric tool and the voltage information of the battery pack;

The duty cycle of the control signal used to control the starting of the motor is changed according to the temperature of the electric tool and the voltage information of the battery pack.

Optionally, the controller is configured to:

When the temperature of the electric tool is lower than a preset temperature and the voltage of the battery pack is lower than a first preset voltage, the duty cycle of the control signal is maintained at the current duty cycle.

Optionally, the controller is configured to:

When the voltage of the battery pack is lower than the second preset voltage, the duty cycle of the control signal is reduced to be smaller than the current duty cycle.

Optionally, the first preset voltage is greater than the second preset voltage.

Optionally, the preset temperature includes a first preset temperature range and a second preset temperature range;

A first preset voltage in the first preset temperature range is greater than a first preset voltage in the second preset temperature range;

The second preset voltage in the first preset temperature range is greater than the second preset voltage in the second preset temperature range.

Optionally, the temperature of the electric tool includes the temperature of the battery pack and/or the temperature of the motor;

The temperature detection unit is used to detect the temperature of the battery pack; or, used to detect the temperature of the motor;

Or, for sensing the temperature of battery packs and motors.

In the second aspect, the embodiment of the present invention also provides a control method of an electric tool, the control method of the electric tool is executed by the electric tool, the electric tool includes a motor; a battery pack is electrically connected with the motor, and provides the The motor provides a power supply voltage; the temperature detection unit is used to detect and obtain the temperature of the electric tool in real time; the voltage detection unit is used to detect and obtain the voltage information of the battery pack in real time; the controller is used to output a voltage with a certain duty cycle The control signal controls the motor to start;

The control methods include:

Obtaining the temperature of the electric tool and the voltage information of the battery pack;

The duty cycle of the control signal used to control the starting of the motor is changed according to the temperature of the electric tool and the voltage information of the battery pack.

Optionally, the changing the duty cycle of the control signal used to control the starting of the motor according to the temperature of the electric tool and the voltage information of the battery pack includes:

When the temperature of the electric tool is lower than a preset temperature and the voltage of the battery pack is lower than a first preset voltage, the duty cycle of the control signal is maintained at the current duty cycle.

Optionally, after maintaining the duty ratio of the control signal at the current duty ratio when the temperature of the electric tool is lower than a preset temperature and the voltage of the battery pack is lower than a first preset voltage, Also includes:

When the voltage of the battery pack is lower than the second preset voltage, the duty cycle of the control signal is reduced to be smaller than the current duty cycle.

Optionally, the first preset voltage is greater than the second preset voltage.

Optionally, the preset temperature includes a first preset temperature range and a second preset temperature range;

A first preset voltage in the first preset temperature range is greater than a first preset voltage in the second preset temperature range;

The second preset voltage in the first preset temperature range is greater than the second preset voltage in the second preset temperature range.

Optionally, the temperature of the electric tool includes the temperature of the battery pack and/or the temperature of the motor;

The temperature detection unit is used to detect the temperature of the battery pack; or, used to detect the temperature of the motor; or, used to detect the temperature of the battery pack and the motor.

The invention provides an electric tool and a control method thereof. This electric tool can solve the existing problems in the prior art such as not starting at low temperature or stalling during starting, so that during the starting process of the electric tool, the temperature information of the electric tool and the voltage information of the battery pack can be obtained in real time, and according to the Real-time changes in temperature and battery pack voltage can adjust the duty cycle of the control signal required for motor startup in real time, which can avoid stalling due to excessive starting voltage, excessive starting current, etc., and failure to start when the ambient temperature is too low And other problems, in order to realize the normal start of the electric tool, so that the electric tool can start normally even in a low temperature environment.

Description of drawings

Fig. 1 is a block diagram of a circuit structure of an electric tool in an embodiment of the present invention;

Fig. 2 is a schematic diagram of signal changes during the starting process of the electric tool in the embodiment of the present invention;

Fig. 3 is a flowchart of a control method of an electric tool in an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, only some structures related to the present invention are shown in the drawings but not all structures.

Fig. 1 is a block diagram of a circuit structure of an electric tool provided in an embodiment of the present invention. Referring to Fig. 1, the electric tool includes: a motor 10; a battery pack 20 electrically connected to the motor 10 to provide a power supply voltage for the motor 10; a temperature detection unit 30 for real-time detection of the temperature of the electric tool; a voltage detection unit 40 for The voltage information of the battery pack 20 is obtained through real-time detection; the controller 50 is used to output a control signal with a certain duty cycle to control the motor 10 to start; the controller 50 is configured to: acquire the temperature of the electric tool and the voltage information of the battery pack 20 ; Change the duty cycle of the control signal used to control the start of the motor 10 according to the temperature of the electric tool and the voltage information of the battery pack 20 .

Wherein, the motor 10 may be a three-phase motor, and the battery pack 20 is electrically connected to the motor 10 for providing a power supply voltage for the motor 10 . The controller 50 is used to output a control signal with a certain duty ratio to control the starting of the motor 10 . Voltage detection unit 40 is electrically connected with battery pack 20 and controller 50 respectively, and voltage detection unit 40 is used for real-time detection and obtains the voltage information of battery pack 20 and sends to controller 50; Temperature detection unit 30 is electrically connected with controller 50, uses The temperature of the electric tool is obtained through real-time detection and sent to the controller 50; in the process of controlling the start of the electric tool, the controller 50 adjusts the duty ratio of the control signal for controlling the start of the motor according to the received voltage information and temperature information, so as to realize Normal startup of the tool. Wherein, the controller 50 may be a single chip microcomputer, an electronic control unit (ECU) or the like. The voltage detection unit 40 may be a voltage transformer. The temperature detection unit 30 may be a temperature sensor, a thermistor, or the like.

Usually, the electric tool will stall during the starting process. The reasons for the stalling are: the output torque of the electric tool is insufficient, the rotor is blocked, the starting current is too large, the device is aging, or the voltage of the battery pack is insufficient during the starting process; or , In a low temperature environment, such as minus 10 degrees - minus 20 degrees, the power tool may start slowly or even fail to start at all. For this reason, according to the electric tool provided by the embodiment of the present invention, it can be realized that: the battery pack 20 provides a power supply voltage to the motor 10 to meet the normal startup of the electric tool and the normal working voltage after startup. When starting, the output of the controller 50 has a certain The control signal of the duty ratio (which can be a higher startup duty ratio) controls the motor to start. During the startup process of the electric tool, the temperature detection unit 30 detects and obtains the temperature of the electric tool in real time and sends it to the controller 50. The voltage detection unit 40 detects and obtains the voltage information of the battery pack 20 in real time and sends it to the controller 50. The controller 50 adjusts the starting of the electric tool by adjusting the duty cycle of the control signal according to the received voltage information and temperature information, so as to realize the electric tool at It can start normally under different temperature environment and starting voltage environment. For example, when the temperature of the electric tool is higher than zero, the controller can control the motor to start normally; Information and the ambient temperature of the electric tool, adjust the duty ratio of the control signal and then adjust the start of the electric tool. It can be seen that by obtaining the real-time changes in temperature information and voltage information, the duty cycle of the control signal required for motor startup can be adjusted in real time, which can avoid the occurrence of insufficient startup voltage, excessive startup current, etc. When it is difficult to start the electric tool, to realize the normal start of the electric tool, so that the electric tool can be started normally even in a low temperature environment.

An embodiment of the present invention provides an electric tool, which includes: a motor; a battery pack electrically connected to the motor to provide a power supply voltage for the motor; a temperature detection unit for detecting and obtaining the temperature of the electric tool in real time; a voltage detection unit, It is used to detect and obtain the voltage information of the battery pack in real time; the controller is used to output a control signal with a certain duty cycle to control the motor to start; the controller is configured to: obtain the temperature of the electric tool and the voltage information of the battery pack; The temperature and voltage information of the battery pack change the duty cycle of the control signal used to control the motor start. This electric tool can solve the existing problems in the prior art such as not starting at low temperature or stalling during starting, so that during the starting process of the electric tool, the temperature information of the electric tool and the voltage information of the battery pack can be obtained in real time, and according to the Real-time changes in temperature and battery pack voltage can adjust the duty cycle of the control signal required for motor startup in real time, which can avoid stalling due to excessive starting voltage, excessive starting current, etc., and failure to start when the ambient temperature is too low And other problems, in order to realize the normal start of the electric tool, so that the electric tool can start normally even in a low temperature environment.

Fig. 2 is a schematic diagram of signal changes during the starting process of the electric tool provided in the embodiment of the present invention. In Fig. 2, it shows the voltage signal change curve V0 of the battery pack during the starting process, the change curve D0 of the duty ratio of the control signal used to start the motor, the motor speed change curve N0 during the start process, and the change curve N0 during the start process. Current change curve I0.

In one embodiment, the controller is configured to: when the temperature of the electric tool is lower than a preset temperature and the voltage of the battery pack is lower than a first preset voltage, maintain the duty ratio of the control signal as the current duty ratio.

Usually, when the electric tool is just started, the voltage of the battery pack is relatively high, and the duty cycle of the control signal used to adjust the motor start is relatively small. As the starting process progresses, the duty cycle gradually increases (refer to The change curve of the duty cycle in Figure 2 D0), the speed also lags behind the increase of the duty cycle and gradually increases (refer to the motor speed change curve N0 in Figure 2), and the starting current gradually increases (refer to the current change curve in Figure 2 I0), the voltage of the battery pack gradually decreases (refer to the voltage signal change curve V0 of the battery pack in FIG. 2 ). When the voltage of the battery pack drops below the first preset voltage, the duty cycle of the control signal remains unchanged. Wherein, the current duty cycle refers to the duty cycle of the corresponding control signal when the voltage of the battery pack drops to just below the first preset voltage. For example, the voltage of the battery pack at time t1 in FIG. Assuming voltage, the duty cycle of the control signal at this time is the duty cycle at time t1, and the duty cycle at time t1 is maintained after t1. In addition, when the temperature of the electric tool is higher than or equal to the preset temperature, the electric tool can be started normally.

Wherein, assuming that the full voltage of the battery pack is 20V, the first preset voltage can be 15V, and the specific value can be set according to the actual situation, and no specific limitation is made here. Wherein, the preset temperature can be zero degrees, and the specific value can be set according to the actual situation, and no specific limitation is made here.

On the basis of the above embodiment, when the temperature of the electric tool is lower than the preset temperature and the voltage of the battery pack is lower than the first preset voltage, after maintaining the duty cycle of the control signal at the current duty cycle, if the battery When the voltage of the packet is lower than the second preset voltage, the duty cycle of the control signal is reduced to be smaller than the current duty cycle. Wherein, the second preset voltage can be the lowest start-up voltage of the battery pack. It can be seen from Figure 2 that when the battery pack voltage is lower than the minimum start-up voltage, the start-up current reaches the maximum, and by reducing the duty cycle of the control signal, the motor speed can be It can be reduced in response to the reduction of the duty cycle, and the starting current is also reduced when the speed is reduced, which can effectively prevent the motor from failing to start and stop when the voltage is lower than the minimum starting voltage.

Optionally, the controller can decrease the duty ratio of the control signal at a certain rate, or set any duty ratio lower than the current duty ratio.

Wherein, referring to FIG. 2, at time t1, when the temperature of the electric tool is lower than the preset temperature and the voltage of the battery pack is lower than the first preset voltage, the duty cycle of the control signal is the duty cycle of the time t1, and after t1 Maintain the duty cycle of the control signal as the duty cycle at time t1, and the voltage of the battery pack continues to decrease. On the basis of this adjustment, when the voltage of the battery pack is lower than the second preset voltage (refer to the voltage of the battery pack at time t2 in Figure 2), the duty cycle of the control signal is reduced at this time to make it smaller than the duty cycle at the current moment (even if it is less than the duty cycle of the corresponding control signal when the voltage of the battery pack drops to just less than the first preset voltage), for example, referring to FIG. The ratio is smaller than the corresponding duty ratio at time t1.

Optionally, the first preset voltage is greater than the second preset voltage.

Wherein, assuming that the full voltage of the battery pack is 20V, the first preset voltage can be 15V, and the second preset voltage can be 10V. The specific values can be set according to the actual situation, and no specific limitation is made here.

Optionally, the preset temperature includes a first preset temperature range and a second preset temperature range;

The first preset voltage in the first preset temperature range is greater than the first preset voltage in the second preset temperature range;

The second preset voltage in the first preset temperature range is greater than the second preset voltage in the second preset temperature range.

Wherein, the first preset temperature range is higher than the second preset temperature range, for example, the first preset temperature range may be minus 10-0 degrees, and the second preset temperature range may be minus 15-minus 10 degrees. The specific temperature range can be set according to the actual situation, and no specific limitation is made here.

Wherein, the first preset voltage in the first preset temperature range is greater than the first preset voltage in the second preset temperature range; the second preset voltage in the first preset temperature range is greater than the second preset temperature range under the second preset voltage. Specifically, when the temperature of the electric tool is lower than the preset temperature and is in the first preset temperature range, when the voltage of the battery pack is lower than the first preset voltage, the duty ratio of the control signal is maintained as the current duty ratio; After that, when the voltage of the battery pack is lower than the second preset voltage, the duty cycle of the control signal is reduced to be smaller than the current duty cycle. Wherein, assuming that the full voltage of the battery pack is 20V, the first preset voltage in the first preset temperature range may be 15V, and the second preset voltage in the first preset temperature range may be 10V.

When the temperature of the electric tool is lower than the preset temperature and is in the second preset temperature range, when the voltage of the battery pack is lower than the first preset voltage, maintain the duty cycle of the control signal as the current duty cycle; thereafter , when the voltage of the battery pack is lower than the second preset voltage, reduce the duty cycle of the control signal to be smaller than the current duty cycle. Wherein, assuming that the full voltage of the battery pack is 20V, the first preset voltage in the second preset temperature range may be 10V, and the second preset voltage in the second preset temperature range may be 5V. It should be noted that, no matter in the first preset temperature range or the second preset temperature range, the specific values of the first preset voltage and the second preset voltage can be set according to actual conditions, and are not specifically limited here.

It can be seen from this that by setting different temperature range gradients, the corresponding first preset voltage and second preset voltage under different temperature range gradients, the controller adjusts the control signal according to the real-time temperature of the electric tool and the real-time voltage of the battery pack. The output of the duty cycle is used to adjust the starting of the motor, thereby improving the working efficiency and further ensuring that the electric tool can still be started normally under different temperature gradient environments.

Optionally, the temperature of the electric tool includes the temperature of the battery pack and/or the temperature of the motor; the temperature detection unit is used to detect the temperature of the battery pack; or is used to detect the temperature of the motor; or is used to detect the temperature of the battery pack and the motor temperature. It can be understood that the temperature of the electric tool may also include the temperature of the working environment where the tool is located. Therefore, the temperature detection unit can also detect the temperature of the working environment where the electric tool is located.

Exemplarily, the electric tool includes a host circuit board, on which a (negative temperature coefficient, Negative Temperature Coefficient) NTC temperature detection (such as MOS tube temperature detection) is set on the host circuit board, and the NTC on the host circuit board of the electric tool can detect the temperature of the motor. Real-time temperature and sent to the controller. The temperature of the battery pack can be directly detected by the temperature sensor and sent to the controller.

Wherein, the temperature detection unit can also be electrically connected with the battery pack and/or the motor, and used for real-time detection and acquisition of the temperature of the battery pack and/or the motor. Optionally, when the temperature of the electric tool only considers the temperature of the battery pack, the temperature detection unit is electrically connected to the battery pack. During the starting process of the electric tool, the temperature detection unit detects and obtains the temperature of the battery pack in real time and sends it to the controller. The voltage detection unit detects and obtains the voltage information of the battery pack in real time and sends it to the controller. The controller adjusts the duty cycle of the control signal for controlling the motor startup in real time according to the received temperature and voltage information of the battery pack, so that the power tool can meet Realize normal starting under different temperature and starting voltage.

When the temperature of the electric tool only considers the temperature of the motor, the temperature detection unit is electrically connected to the motor. During the starting process of the electric tool, the temperature detection unit detects and obtains the temperature of the motor in real time and sends it to the controller, and the voltage detection unit detects in real time to obtain the battery pack. The voltage information of the motor is sent to the controller, and the controller adjusts the duty ratio of the control signal for controlling the motor start in real time according to the received motor temperature and voltage information, so that the electric tool can meet the requirements of normal operation under different temperatures and starting voltages. start up.

When the temperature of the electric tool needs to consider the temperature of the battery pack and the motor at the same time, the temperature detection unit is electrically connected to the battery pack and the motor respectively. During the starting process of the electric tool, the temperature detection unit detects and obtains the temperature of the battery pack and the temperature of the motor in real time. And send it to the controller, the voltage detection unit detects and obtains the voltage information of the battery pack in real time and sends it to the controller, and the controller adjusts the control signal to control the starting of the motor in real time according to the received battery pack temperature, motor temperature and voltage information. Duty ratio, so that the electric tool can meet the normal starting under different temperatures and starting voltages. Exemplarily, the electric tool can take the temperature of the electric tool as the lower temperature of the temperature of the battery pack and the temperature of the motor, and adjust the duty ratio of the start control signal in combination with the voltage information of the battery pack.

Thus, by detecting and obtaining the temperature of the battery pack and/or the temperature of the motor to obtain the temperature of the electric tool, when the temperature detection device of the battery pack or the temperature detection device of the motor fails, the temperature detection device that does not have a fault can be detected. The equipment detects and acquires the temperature of the electric tool to ensure the normal start-up of the electric tool, and at the same time, it can also reduce or avoid affecting the working efficiency of the electric tool due to the replacement of the temperature detection element or equipment.

Fig. 3 is a flow chart of a control method for an electric tool provided by an embodiment of the present invention. This embodiment is applicable to the implementation process of the control method for an electric tool, and the method can be executed by the electric tool provided by the embodiment of the present invention. The electric tool includes a motor; a battery pack electrically connected to the motor to provide a power supply voltage for the motor; a temperature detection unit for detecting and obtaining the temperature of the electric tool in real time; a voltage detection unit for detecting and obtaining voltage information of the battery pack in real time; The device is used to output a control signal with a certain duty cycle to control the motor to start;

Referring to Fig. 3, the control method of the electric tool includes:

Step 110, obtaining the temperature of the electric tool and the voltage information of the battery pack;

Among them, the electric tool includes a motor, a battery pack, a temperature detection unit, a voltage detection unit, and a controller. Specifically, the temperature of the electric tool can be obtained through real-time detection by the temperature detection unit and sent to the controller; the voltage information of the battery pack can be obtained through The voltage detection unit detects and obtains it in real time and sends it to the controller; the controller controls and adjusts the output of the duty cycle of the control signal according to the received temperature and voltage information, so as to regulate the starting of the electric tool.

Step 120, changing the duty ratio of the control signal used to control the starting of the motor according to the temperature of the electric tool and the voltage information of the battery pack.

Specifically, the temperature detection unit detects and obtains the temperature of the electric tool in real time and sends it to the controller, and the voltage detection unit detects and obtains the voltage information of the battery pack in real time and sends it to the controller. voltage, varying the duty cycle of the control signal used to control motor startup. It can be seen that the controller can adjust the duty ratio of the control signal used to control the starting of the motor according to the real-time temperature of the electric tool and the real-time voltage information of the battery pack, so as to adjust the starting of the electric tool, which can solve the problem of the existing technology that does not work at low temperatures. Problems such as starting or stalling during starting, so that the electric tool can obtain the temperature information of the electric tool and the voltage information of the battery pack in real time during the starting process, and adjust the motor in real time according to the real-time changes in the temperature of the electric tool and the voltage of the battery pack. The duty cycle of the control signal required for starting can avoid problems such as excessive starting voltage, excessive starting current, etc., and failure to start when the ambient temperature is too low, so as to realize the normal start of the electric tool and make the electric tool The tool can start normally even in low temperature environment.

An embodiment of the present invention provides a control method for an electric tool. The control method for the electric tool is executed by the electric tool. The electric tool includes a motor; a battery pack electrically connected to the motor to provide a power supply voltage for the motor; a temperature detection unit for The temperature of the electric tool is obtained by real-time detection; the voltage detection unit is used for real-time detection to obtain the voltage information of the battery pack; the controller is used for outputting a control signal with a certain duty cycle to control the start of the motor; the control method includes: obtaining the temperature of the electric tool Temperature and battery pack voltage information; change the duty cycle of the control signal used to control the start of the motor according to the temperature of the electric tool and the voltage information of the battery pack. This control method can solve the existing problems in the prior art such as not starting at low temperature or stalling during starting, so that during the starting process of the electric tool, the temperature information of the electric tool and the voltage information of the battery pack can be obtained in real time, and according to the power tool Real-time changes in temperature and battery pack voltage can adjust the duty cycle of the control signal required for motor startup in real time, which can avoid stalling due to excessive starting voltage, excessive starting current, etc., and failure to start when the ambient temperature is too low And other problems, in order to realize the normal start of the electric tool, so that the electric tool can start normally even in a low temperature environment.

Optionally, changing the duty cycle of the control signal used to control the starting of the motor according to the temperature of the electric tool and the voltage information of the battery pack includes:

When the temperature of the electric tool is lower than the preset temperature and the voltage of the battery pack is lower than the first preset voltage, the duty ratio of the control signal is maintained at the current duty ratio.

Optionally, after maintaining the duty ratio of the control signal as the current duty ratio when the temperature of the electric tool is lower than the preset temperature and the voltage of the battery pack is lower than the first preset voltage, the method further includes:

When the voltage of the battery pack is lower than the second preset voltage, the duty cycle of the control signal is reduced to be smaller than the current duty cycle.

Optionally, the first preset voltage is greater than the second preset voltage.

Optionally, the preset temperature includes a first preset temperature range and a second preset temperature range;

The first preset voltage in the first preset temperature range is greater than the first preset voltage in the second preset temperature range;

The second preset voltage in the first preset temperature range is greater than the second preset voltage in the second preset temperature range.

Optionally, the temperature of the electric tool includes the temperature of the battery pack and/or the temperature of the motor;

The temperature detection unit is used for detecting the temperature of the battery pack; or for detecting the temperature of the motor; or for detecting the temperature of the battery pack and the motor.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention, and the present invention The scope is determined by the scope of the appended claims.

Claims (10)

1. A power tool, comprising:

a motor;

the battery pack is electrically connected with the motor and provides power supply voltage for the motor;

the temperature detection unit is used for detecting and obtaining the temperature of the electric tool in real time;

the voltage detection unit is used for detecting and acquiring voltage information of the battery pack in real time;

the controller is used for outputting a control signal with a certain duty ratio to control the motor to start;

the controller is configured to:

acquiring temperature information of the electric tool and voltage information of the battery pack;

and changing the duty ratio of the control signal for controlling the motor to start according to the temperature of the electric tool and the voltage information of the battery pack.

2. The power tool of claim 1, wherein the controller is configured to:

when the temperature of the electric tool is lower than a preset temperature and the voltage of the battery pack is lower than a first preset voltage, the duty ratio of the control signal is maintained to be the current duty ratio.

3. The power tool of claim 2, wherein the controller is configured to:

and when the voltage of the battery pack is smaller than a second preset voltage, reducing the duty ratio of the control signal to be smaller than the current duty ratio.

4. The power tool according to claim 3,

the first preset voltage is greater than the second preset voltage.

5. The power tool of claim 3, wherein the preset temperature includes a first preset temperature range and a second preset temperature range;

a first preset voltage in the first preset temperature range is greater than a first preset voltage in the second preset temperature range;

the second preset voltage in the first preset temperature range is greater than the second preset voltage in the second preset temperature range.

6. The power tool of claim 1, wherein the temperature of the power tool includes a temperature of a battery pack and/or a temperature of a motor;

the temperature detection unit is used for detecting the temperature of the battery pack; or, for detecting the temperature of the motor; or for detecting the temperature of the battery pack and the motor.

7. A control method of an electric tool, characterized by being executed by an electric tool including a motor; the battery pack is electrically connected with the motor and provides power supply voltage for the motor; the temperature detection unit is used for detecting and obtaining the temperature of the electric tool in real time; the voltage detection unit is used for detecting and acquiring voltage information of the battery pack in real time; the controller is used for outputting a control signal with a certain duty ratio to control the motor to start;

the control method comprises the following steps:

acquiring temperature information of the electric tool and voltage information of the battery pack;

and changing the duty ratio of the control signal for controlling the motor to start according to the temperature of the electric tool and the voltage information of the battery pack.

8. The control method of the electric power tool according to claim 7,

the changing of the duty ratio of the control signal for controlling the motor to start according to the temperature of the power tool and the voltage information of the battery pack includes:

when the temperature of the electric tool is lower than a preset temperature and the voltage of the battery pack is lower than a first preset voltage, the duty ratio of the control signal is maintained to be the current duty ratio.

9. The control method of an electric power tool according to claim 8,

when the temperature of the electric tool is lower than a preset temperature and the voltage of the battery pack is lower than a first preset voltage, after the duty ratio of the control signal is maintained as the current duty ratio, the method further comprises:

and when the voltage of the battery pack is smaller than a second preset voltage, reducing the duty ratio of the control signal to be smaller than the current duty ratio.

10. The control method of the electric power tool according to claim 9, wherein the preset temperature includes a first preset temperature range and a second preset temperature range;

the first preset voltage in the first preset temperature range is greater than the first preset voltage in the second preset temperature range;

the second preset voltage in the first preset temperature range is greater than the second preset voltage in the second preset temperature range.

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