Electric hammer and electric tool

Abstract

The embodiment of the utility model provides an electric hammer and an electric tool. The electric hammer comprises a motor, a transmission assembly, a working head, a detection unit, a controller and a data acquisition module. Wherein the controller is used for controlling the rotation of the motor; the motor transmits driving force to the working head through the transmission assembly. The controller assembly is connected with the detection unit and determines whether the motor is locked or not through the detection unit. The controller assembly is used for controlling the motor to carry out electronic clutch under the condition that the motor is locked, the electronic clutch comprises first rotation in the first rotation direction and second rotation in the second rotation direction, and the first rotation direction is opposite to the second rotation direction; the data acquisition module is used for acquiring operation parameters of the electric hammer; the controller is in communication connection with the data acquisition module and determines whether to stop the electronic clutch or not based on the operating parameters of the electric hammer; the operation parameters comprise the number of electronic clutch times, the electronic clutch duration and the temperature of the electric hammer.

Description

Technical Field

[0001] This application relates to the field of electromechanical technology, and in particular to electric hammers and power tools. Background Technology

[0002] Power tools such as electric hammer drills typically contain a mechanical clutch assembly, including a clutch, a pressure spring, and an adjusting nut. When the working head (such as an electric hammer drill bit) is subjected to axial pressure, the pressure spring compresses, causing the teeth on the driven end face of the clutch to engage with the teeth on the driving end face, thereby transmitting torque. When the working head reaches the set torque or the torque is too high, the driven part of the clutch compresses the spring, causing the driving and driven parts to disengage and slip, preventing damage to the working head. Simultaneously, vibration feedback is generated during the disengagement and slippage process to serve as a warning. When the torque of the working head decreases, the clutch automatically resumes torque transmission.

[0003] New power tools can use electronic clutches to disengage the drive force of the working head. Since electronic clutches use a switching motor to achieve disengagement and can generate electronic clutch feedback force to simulate a mechanical clutch, determining when to initiate and stop the electronic clutch to achieve a complete electronic clutch process and improve the user experience is a pressing issue.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0005] In view of this, embodiments of the present disclosure provide an electric hammer and a power tool.

[0006] According to a first aspect of the present disclosure, an electric hammer is provided, the electric hammer including a motor, a transmission assembly, a working head, a detection unit, a controller, and a data acquisition module; wherein...

[0007] The controller is used to control the rotation of the motor;

[0008] The motor transmits driving force to the working head through the transmission assembly;

[0009] The controller component is connected to the detection unit, and the detection unit determines whether the motor is stalled.

[0010] The controller assembly is used to control the motor to engage the electronic clutch when the motor is stalled, wherein the electronic clutch includes a first rotation along a first rotation direction and a second rotation along a second rotation direction, the first rotation direction and the second rotation direction being opposite;

[0011] The data acquisition module is used to acquire the operating parameters of the electric hammer;

[0012] The controller is communicatively connected to the data acquisition module and determines whether to stop the electronic clutch based on the operating parameters of the electric hammer.

[0013] The operating parameters include at least one of the following: number of electronic clutch cycles, duration of electronic clutch engagement, and hammer temperature.

[0014] In some embodiments, the data acquisition module includes a temperature sensing component, and the controller is specifically used for at least one of the following:

[0015] When the electronic clutch is engaged, if the first rotation number of the first rotation exceeds the first rotation threshold, the electronic clutch is stopped.

[0016] When the electronic clutch is engaged, if the number of rotations of the second rotation exceeds the second rotation threshold, the electronic clutch is stopped.

[0017] If the duration of the electronic clutch exceeds a first duration threshold during the electronic clutch operation, the electronic clutch operation is stopped.

[0018] When the electronic clutch is engaged, if the temperature sensed by the temperature sensing component of the electric hammer is greater than a first temperature threshold, the electronic clutch is stopped; the temperature sensing component is used to sense the temperature at a predetermined position of the electric hammer.

[0019] In some embodiments, the first rotation threshold is greater than or equal to 30 times; and / or

[0020] The second rotation threshold is greater than or equal to 30 times; and / or

[0021] The first duration threshold is greater than or equal to 7 seconds; and / or

[0022] The first temperature threshold is greater than or equal to 100 degrees Celsius.

[0023] In some embodiments, the temperature sensing component includes a fixed resistor and a thermistor disposed at the predetermined position, wherein a first end of the fixed resistor is connected to a power supply, a second end of the fixed resistor and the first end of the thermistor are connected to form a connection node, the connection node is connected to the controller, and the second end of the thermistor is connected to the power supply ground; the controller determines the temperature at the predetermined position by detecting the voltage of the connection node.

[0024] In some embodiments, a current-limiting resistor is provided between the connection node and the controller.

[0025] In some embodiments, the predetermined location includes at least one of the following:

[0026] The surface of the switching transistor that drives the motor to rotate;

[0027] The area within a predetermined distance from the switch.

[0028] In some embodiments, the controller further includes a storage unit for recording the first number of rotations and / or the second number of rotations;

[0029] The controller is also used for at least one of the following:

[0030] After the electronic clutch is stopped, if the temperature sensed by the temperature sensing component is less than the second temperature threshold, the first number of rotations and / or the second number of rotations recorded by the storage unit will be cleared to zero.

[0031] After the electronic clutch is stopped, if the duration of the third rotation of the motor along the first rotation direction is longer than the second duration threshold, the first rotation count and / or the second rotation count recorded in the storage unit will be cleared to zero.

[0032] After the electronic clutch is stopped, if the fourth rotation of the motor in the second rotation direction lasts for a duration longer than the third duration threshold, the first rotation count and / or the second rotation count recorded in the storage unit will be cleared to zero.

[0033] In some embodiments, the second temperature threshold is less than or equal to 30 degrees Celsius; and / or

[0034] The second duration threshold is greater than or equal to 5 seconds; and / or

[0035] The third duration threshold is greater than or equal to 5 seconds.

[0036] In some embodiments, the detection unit includes a Hall element for sensing the rotation angle of the motor by sensing the position change of the magnetic element on the motor rotor as the rotor rotates;

[0037] The controller is used to determine that the motor has stalled if the Hall element senses that the rotation angle of the motor is within a predetermined stall angle range within a predetermined time period.

[0038] According to a second aspect of the present disclosure, a power tool is provided, the power tool including a motor, a working head, a detection unit, a controller, and a data acquisition module; wherein...

[0039] The controller is used to control the rotation of the motor;

[0040] The motor transmits driving force to the working head;

[0041] The controller component is connected to the detection unit, and the detection unit determines whether the motor is stalled.

[0042] The controller assembly is used to control the motor to engage the electronic clutch when the motor is stalled, wherein the electronic clutch includes a first rotation along a first rotation direction and a second rotation along a second rotation direction, the first rotation direction and the second rotation direction being opposite;

[0043] The data acquisition module is used to acquire the operating parameters of the power tool;

[0044] The controller is communicatively connected to the data acquisition module and determines whether to stop the electronic clutch based on the operating parameters of the power tool.

[0045] This disclosure provides an electric hammer and a power tool. The electric hammer includes a motor, a transmission assembly, a working head, a detection unit, a controller, and a data acquisition module. The controller controls the rotation of the motor. The motor transmits driving force to the working head through the transmission assembly. The controller assembly is connected to the detection unit and determines whether the motor is stalled. When the motor is stalled, the controller assembly controls the motor to engage an electronic clutch, wherein the electronic clutch includes a first rotation along a first rotation direction and a second rotation along a second rotation direction, the first and second rotation directions being opposite. The data acquisition module acquires the operating parameters of the electric hammer. The controller is communicatively connected to the data acquisition module and determines whether to stop the electronic clutch based on the operating parameters of the electric hammer. The operating parameters include at least one of the following: the number of electronic clutch engagements, the duration of the electronic clutch engagement, and the temperature of the electric hammer. In this way, by determining whether to stop the electronic clutch based on the operating parameters of the electric hammer, it is possible to control the stopping of the electronic clutch based on the actual operating conditions, reduce the ineffective power consumption caused by prolonged use of the electronic clutch, or the situation where the electronic clutch fails to help the user escape or alert them, thus improving the user experience of the electric hammer. Attached Figure Description

[0046] Figure 1 This is an embodiment of an electric hammer architecture shown in an exemplary embodiment;

[0047] Figure 2 This is one of the schematic diagrams of a temperature profile according to an exemplary embodiment;

[0048] Figure 3 This is a schematic diagram of an electric hammer control circuit structure according to an exemplary embodiment;

[0049] Figure 4This is a schematic diagram of the temperature sensing component structure in an electric hammer control circuit according to an exemplary embodiment;

[0050] Figure 5 This is a second schematic diagram of a temperature curve according to an exemplary embodiment;

[0051] Figure 6 This is a schematic diagram of the cross-sectional structure of a motor according to an exemplary embodiment. Detailed Implementation

[0052] To make the technical solution and beneficial effects of this utility model more apparent and understandable, a detailed description is provided below by listing specific embodiments. The accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0053] This disclosure is not exhaustive, but merely illustrative of some embodiments, and is not intended to limit the scope of protection of this disclosure. Unless otherwise specified, each step in a particular embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a particular embodiment can also be implemented as an independent embodiment, and the order of the steps in a particular embodiment can be arbitrarily interchanged. Furthermore, the optional implementation methods in a particular embodiment can be arbitrarily combined; moreover, the embodiments can be arbitrarily combined, for example, some or all steps of different embodiments can be arbitrarily combined, and a particular embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0054] In each of the disclosed embodiments, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of the embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0055] The terminology used in the embodiments of this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the scope of this disclosure.

[0056] In this embodiment of the disclosure, unless otherwise stated, elements expressed in the singular form, such as "a," "an," "the," "the," "the," "the," "the," "the," "this," etc., can mean "one and only one," or "one or more," "at least one," etc. For example, when using articles such as "a," "an," "the," etc. in translation, the noun following the article can be understood as either a singular expression or a plural expression.

[0057] In the embodiments disclosed herein, "multiple" refers to two or more.

[0058] In some embodiments, the terms “at least one of”, “one or more”, “a plurality of”, “multiple”, etc., may be used interchangeably.

[0059] In some embodiments, the notation "at least one of A and B", "A and / or B", "A in one case, B in another", "A in one case, B in another", etc., may include the following technical solutions depending on the situation: in some embodiments, A (A is executed regardless of B); in some embodiments, B (B is executed regardless of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); in some embodiments, A and B (both A and B are executed). The same applies when there are more branches such as A, B, C, etc.

[0060] In some embodiments, the notation "A or B" may include the following technical solutions, depending on the situation: in some embodiments, A (execution of A regardless of B); in some embodiments, B (execution of B regardless of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). The same applies when there are more branches such as A, B, C, etc.

[0061] The prefixes "first," "second," etc., used in the embodiments of this disclosure are merely for distinguishing different descriptive objects and do not impose restrictions on the position, order, priority, value, or content of the descriptive objects. The description of the descriptive objects should be found in the claims or the context of the embodiments, and the use of prefixes should not constitute unnecessary restrictions. For example, if the descriptive object is a "field," the ordinal numbers preceding "field" in "first field" and "second field" do not restrict the position or order of the "fields." "First" and "second" do not restrict whether the "fields" they modify are in the same message, nor do they restrict the order of "first field" and "second field." Similarly, if the descriptive object is a "level," the ordinal numbers preceding "level" in "first level" and "second level" do not restrict the priority between "levels." Furthermore, the value of the descriptive object is not limited by ordinal numbers and can be one or more. For example, in "first device," the value of "device" can be one or more. Furthermore, the objects modified by different prefixes can be the same or different. For example, if the object being described is "device", then "first device" and "second device" can be the same device or different devices, and their types can be the same or different. Similarly, if the object being described is "information", then "first information" and "second information" can be the same information or different information, and their content can be the same or different.

[0062] In some embodiments, “including A,” “containing A,” “for indicating A,” and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0063] In some embodiments, terms such as “…”, “determine…”, “in the case of…”, “when…”, “when…”, “if…”, etc. can be used interchangeably.

[0064] In some embodiments, the terms “greater than,” “greater than or equal to,” “not less than,” “more than,” “more than or equal to,” “not less than,” “higher than,” “higher than or equal to,” “not lower than,” and “above” can be used interchangeably, as can the terms “less than,” “less than or equal to,” “not greater than,” “less than,” “less than or equal to,” “not more than,” “lower than,” “lower than or equal to,” “not higher than,” and “below”.

[0065] Furthermore, each element, each row, or each column in the embodiments of this disclosure can be implemented as an independent embodiment, and any combination of any element, any row, or any column can also be implemented as an independent embodiment.

[0066] This application provides an electric hammer 10, which includes a motor 11, a transmission assembly 12, a working head 13, a detection unit 14, a controller 15, and a data acquisition module 16; wherein,

[0067] The controller is used to control the rotation of the motor;

[0068] The motor transmits driving force to the working head through the transmission assembly;

[0069] The controller component is connected to the detection unit, and the detection unit determines whether the motor is stalled.

[0070] The controller assembly is used to control the motor to engage the electronic clutch when the motor is stalled, wherein the electronic clutch includes a first rotation along a first rotation direction and a second rotation along a second rotation direction, wherein the first rotation direction and the second rotation direction are opposite;

[0071] The data acquisition module is used to acquire the operating parameters of the electric hammer;

[0072] The controller is communicatively connected to the data acquisition module and determines whether to stop the electronic clutch based on the operating parameters of the electric hammer.

[0073] The operating parameters include at least one of the following: number of electronic clutch cycles, duration of electronic clutch engagement, and hammer temperature.

[0074] In one possible implementation, the second rotation is performed first in the electronic clutch.

[0075] Here, the working head may include, but is not limited to, one of the following: drill bit, screwdriver bit, etc.

[0076] The motor may include a brushless motor.

[0077] In some embodiments, a transmission assembly is used to transmit the driving force of the motor to the working head. For example, the transmission assembly may include a reduction gear set, etc.

[0078] Here, the electric hammer is not equipped with a mechanical clutch. When the resistance generated on the working head exceeds the predetermined torque, the working head cannot work (e.g., it cannot rotate). Since the electric hammer does not have a mechanical clutch, the resistance on the working head is transmitted to the motor, causing the motor to stall.

[0079] In some embodiments, the electric hammer also includes a detection unit for determining whether the motor is stalled.

[0080] When a motor is stalled, it cannot rotate normally, its back electromotive force remains zero, and current cannot form magnetic flux in the motor, thus failing to convert electromagnetic energy into mechanical energy, causing the current to continuously increase. The motor current during stall can be many times the motor's rated current.

[0081] The electric hammer also includes a controller. The controller can be used to control the drive current of the motor, thereby driving the motor to rotate and controlling the direction of rotation. The controller can be connected to a sensor assembly to obtain sensing information from the detection unit, and then determine whether the motor is stalled.

[0082] In one possible implementation, the controller can be located on the control panel of the electric hammer. The controller can be combined with other components to control the electric hammer.

[0083] The controller described above may include a microcontroller unit (MCU). Of course, the controller may also include other devices capable of control functions. The controller is used to control the operation of the electric hammer.

[0084] In one possible implementation, the detection unit can be used to detect the motor current. When the motor current detected by the detection unit exceeds the stall current threshold (e.g., more than twice the motor's rated current), it can be determined that the motor is stalled. When the motor current detected by the detection unit is less than the stall current threshold (e.g., less than twice the motor's rated current), it can be determined that the motor is not stalled.

[0085] In one possible implementation, the data acquisition module can be a standalone module, a module within the controller, or a combination of some modules within the controller and modules outside the controller.

[0086] In one possible implementation, the data acquisition module can determine the number of times the electronic clutch is engaged by counting the electronic clutch engagements.

[0087] In one possible implementation, the data acquisition module can determine the duration of the electronic clutch by timing the electronic clutch.

[0088] In one possible implementation, the data acquisition module may include a temperature sensing component, etc., for determining the temperature of the electric hammer. The temperature of the electric hammer may include the temperature of at least one predetermined location within the electric hammer.

[0089] In one possible implementation, the electric hammer may have a handle for the user to hold while it is in operation.

[0090] The first rotation direction can be any rotation direction, and the second rotation direction can be the opposite of the first rotation direction.

[0091] For example, if the first rotation direction is clockwise, then the second rotation direction is counterclockwise. If the first rotation direction is counterclockwise, then the second rotation direction is clockwise.

[0092] When the controller determines that the motor is stalled based on information detected by the detection unit (such as motor current), it can control the motor to engage the electronic clutch. The electronic clutch can include a first rotation and a second rotation. Because the motor performs the first and second rotations in opposite directions, opposite torques are generated on the hammer handle, thus achieving stall force feedback.

[0093] Understandably, the vibration generated by an electronic clutch when the motor stalls due to resistance at the operating head can also be referred to as vibration and shock. The intensity of the electronic clutch can also be called the vibration and shock intensity.

[0094] In one possible implementation, the electronic clutch includes N sets of first rotations and M sets of second rotations, wherein the first rotations and the second rotations are performed at intervals between sets; wherein N is an integer greater than or equal to 1 and M is an integer greater than or equal to 1.

[0095] In one possible implementation, if the motor stalls while rotating in the first direction, the second rotation can be performed first. If the motor stalls while rotating in the second direction, the first rotation can be performed first.

[0096] Taking a stall when the motor is rotating in the first direction as an example, performing a second rotation after stalling reduces the likelihood of further stalling caused by continuing rotation in the first direction. Since the second rotation is a reversing direction, the probability of stalling when the working head moves in that direction is lower. Performing the second rotation first allows the working head to retract and provides space for the subsequent movement of the working head during the motor's first rotation. After the second rotation, the controller initiates the first rotation. This second rotation provides less resistance for the subsequent first rotation, allowing the working head to generate greater impact inertia, which helps it overcome the obstacle causing the stall.

[0097] Here, the operating parameters can be the operating parameters associated with at least one component inside the electric hammer when the electric hammer is in the electronically clutched state.

[0098] Operating parameters may include, but are not limited to, at least one of the following: electronic clutch duration, motor drive current in electronic clutch state, motor operating time in electronic clutch state, number of first rotations, number of second rotations, temperature of heat-sensitive components inside the power tool, motor rotation angle in electronic clutch state, battery current, and battery temperature. Since electronic clutch operation includes both first and second rotations, the number of electronic clutch engagements can be determined by the number of first and / or second rotations.

[0099] Electronic clutches typically serve two purposes: first, to free the working head from obstruction and prevent the swing motor from stalling; and second, to alert the user to motor stalling via force feedback on the handle.

[0100] In one possible implementation, a parameter that characterizes whether the working head is not stuck or has been stuck can be selected as the operating parameter for determining whether the electronic clutch needs to be stopped. For example, during the electronic clutch process, if the motor's rotation angle is 0 in the electronic clutch state, it indicates that the working head may be stuck, preventing the motor from rotating (first rotation and second rotation). If the electronic clutch state is maintained, it may cause damage to the motor, transmission components, and / or the working head. Therefore, the motor's rotation angle in the electronic clutch state can be used as the operating parameter to determine whether to stop the electronic clutch.

[0101] In one possible implementation, a parameter can be selected that characterizes the force feedback that the user can perceive when the electronic clutch engages or the force feedback that the user cannot perceive when there is dynamic impact, as the operating parameter for determining whether the electronic clutch needs to be stopped. For example, the user needs a certain amount of time to perceive the force feedback generated by the motor rotating in the forward and reverse directions. If the electronic clutch duration is too short, the motor will only rotate in one direction, leading to misjudgment by the user. Therefore, the controller can use the duration of the electronic clutch engagement as the operating parameter for determining whether to stop the electronic clutch.

[0102] In this way, by determining whether to stop the electronic clutch based on the operating parameters of the electric hammer, it is possible to control the stopping of the electronic clutch based on the actual operating conditions, reduce the ineffective power consumption caused by prolonged use of the electronic clutch, or the situation where the electronic clutch fails to help the user escape or alert them, thus improving the user experience of the electric hammer.

[0103] In some embodiments, the controller is configured to stop the electronic clutch when the first rotation number exceeds a first rotation threshold while the electronic clutch is engaged; and / or, when the second rotation number exceeds a second rotation threshold while the electronic clutch is engaged, stop the electronic clutch.

[0104] Here, the decision to stop the electronic clutch can be based on the number of times the motor rotates.

[0105] Specifically, since the first and second rotations are performed alternately, the decision to stop the impact can be based on the number of first and / or second rotations. Electronic clutch engagement is stopped when the number of first rotations exceeds a first rotation threshold and / or the number of second rotations exceeds a second rotation threshold.

[0106] In one possible implementation, an adjacent first and second rotation can be defined as one electronic clutch engagement, and the decision to stop the electronic clutch engagement can be based on the number of engagements. Understandably, the number of engagements is the same as the number of first or second rotations.

[0107] The first rotation threshold and / or the second rotation threshold can be preset.

[0108] In some embodiments, the first rotation threshold is greater than or equal to 30 times; and / or the second rotation threshold is greater than or equal to 30 times.

[0109] The first rotation threshold and / or the second rotation threshold can be determined based on the force feedback effect of the electric hammer, the tolerance of the motor drive components, etc.

[0110] By limiting the number of first and / or second rotations, the effectiveness of the electronic clutch can be improved, such as increasing the working head's escape rate and enhancing the user's perception of electrode stall. On the other hand, it can reduce the risk of damage to the hammer drill components due to excessive first and / or second rotations.

[0111] In some embodiments, the controller is configured to stop the electronic clutch if the duration of the electronic clutch exceeds a first duration threshold during the engagement of the electronic clutch.

[0112] Here, the first duration threshold can be determined based on the force feedback effect of the electric hammer, the tolerance of the motor drive components, etc.

[0113] For example, if the electronic clutch exceeds the first time threshold, the motor drive components (such as the switching transistor) are prone to overheating and damage.

[0114] In some embodiments, the first duration threshold is greater than or equal to 7 seconds.

[0115] By limiting the duration of operation, the effectiveness of the electronic clutch can be improved, such as increasing the working head's ability to escape obstacles and enhancing the user's perception of electrode stall. On the other hand, it can reduce the risk of damage to the hammer drill components (such as the motor drive parts) due to excessive motor operation time.

[0116] In some embodiments, the controller is configured to stop the electronic clutch when the temperature sensed by the temperature sensing component of the electric hammer is greater than a first temperature threshold during the electronic clutch operation; the temperature sensing component is configured to sense the temperature at a predetermined location of the electric hammer.

[0117] During the electronic clutch operation of an electric hammer, the working head may still be stuck, meaning the motor may still experience stalling. Simultaneously, the motor continuously switches between first and second rotation during this process, resulting in a high operating current. The hammer's cooling components (e.g., the cooling fan is constantly reciprocating, unable to dissipate heat effectively) cannot adequately dissipate heat. The motor and / or its drive components are affected by the high current, causing a rapid temperature rise; furthermore, the low cooling efficiency leads to heat buildup. Therefore, during the electronic clutch operation of an electric hammer, the motor and / or its drive components are prone to overheating.

[0118] The predetermined location may include areas prone to overheating during the electronic clutch operation of the electric hammer. There may be at least one predetermined location, and the first temperature thresholds corresponding to different predetermined locations may be the same or different.

[0119] Here, a temperature sensing component can be used to detect the temperature at a predetermined location and send the temperature to the controller. If the control unit determines that the temperature at the predetermined location is greater than a first temperature threshold, the electronic clutch can be stopped.

[0120] In one possible implementation, the temperature sensing component can be implemented using a temperature sensor.

[0121] In some embodiments, the predetermined location includes at least one of the following:

[0122] The surface of the switching transistor that drives the motor to rotate;

[0123] The area containing control circuits and electronic components;

[0124] The area within a predetermined distance from the switch.

[0125] Here, the motor can be a multi-phase (e.g., three-phase) brushless motor. Each phase of the motor can be supplied with operating current through a switching transistor driven by a PWM drive signal. Therefore, the switching transistor bears all the current during motor operation, making it more prone to heat buildup. Furthermore, the switching transistor is a semiconductor device, susceptible to overheating and failure. Therefore, the temperature of the switching transistor can be used to determine whether to disengage the electronic clutch.

[0126] Here, the switching transistor may include at least one of the following: a metal-oxide-semiconductor field-effect transistor (MOS) or an insulated-gate bipolar transistor (MOS).

[0127] Here, a temperature sensing element can be used to directly measure the surface temperature of the switching transistor, or it can be used to measure the temperature around the switching transistor. The temperature of the area around the switching transistor is positively correlated with the surface temperature of the switching transistor.

[0128] In some embodiments, the first temperature threshold is greater than or equal to 100 degrees Celsius.

[0129] For example, such as Figure 2 The figure shows the temperature change curve of the predetermined area. After the electric hammer triggers the electronic clutch, the temperature reaches a relatively high temperature within a short period of time. Therefore, it is possible to determine whether to stop the electronic clutch based on the number of times the electric hammer engages the electronic clutch, the duration of engagement, and / or the temperature of the switching transistor.

[0130] In this way, by sensing the temperature of a predetermined position (such as the temperature of the switching tube), the electronic clutch can be started and stopped, which can reduce the risk of overheating damage to the hammer components at the predetermined position and improve the durability of the hammer.

[0131] In some embodiments, the temperature sensing component includes a fixed resistor and a thermistor disposed at the predetermined position, wherein a first end of the fixed resistor is connected to a power supply, a second end of the fixed resistor and the first end of the thermistor are connected to form a connection node, the connection node is connected to the controller, and the second end of the thermistor is connected to the power supply ground; the controller determines the temperature at the predetermined position by detecting the voltage of the connection node.

[0132] Figure 3 This is a schematic diagram of the electric hammer control circuit, as shown below. Figure 3As shown, the control circuit includes controller U1. B+ and B- are used to connect to the power supply of the electric hammer. U2 is a voltage conversion element (e.g., generating 5V voltage) used to convert the power supply voltage into the operating voltage for controller U1. Q1 to Q6 constitute the three-phase drive circuit of the motor. Controller U1 drives the three-phase drive circuit to supply power to the motor and controls the rotation direction of the motor through PWM drive signals. P1 can be a connector for connecting the electric hammer trigger, and P1 can also be used to connect a control switch to control the forward or reverse rotation of the motor.

[0133] For example, such as Figure 4 As shown, the temperature at a predetermined location can be sensed by setting a fixed resistor R1 and a thermistor RT1. Here, the thermistor RT1 can be either a negative temperature coefficient (NTC) thermistor or a positive temperature coefficient (PTC) thermistor. The thermistor RT1 can be set at the predetermined location. When the temperature at the predetermined location changes, the voltage at the connection node changes. The controller U1 can determine the voltage based on AD sampling and determine the temperature at the predetermined location based on the voltage-temperature correlation.

[0134] For example, RT1 is a negative temperature coefficient thermistor. The resistance of R1 is 10K ohms. The higher the temperature at the predetermined location, the smaller the resistance of RT1, and therefore the smaller the sampling voltage of controller U1. When the temperature is 100 degrees Celsius, the resistance of RT1 is 0.74K ohms, and the AD value sampled by controller U1 is (4095*0.74 / (0.74+10)=282), where 4095 represents the AD value at 5V. When the AD value at the MCU terminal is less than 282, it is determined that the electric motor triggers the temperature protection, and controller U1 can stop the electronic clutch.

[0135] In some embodiments, a current-limiting resistor is provided between the connection node and the controller.

[0136] like Figure 4 As shown, a current-limiting resistor is provided between the connection node and the controller to reduce the current input to the controller, thereby reducing the risk of overcurrent in the controller and improving the durability of the electric hammer.

[0137] In some embodiments, the controller further includes a storage unit for recording the first number of rotations and / or the second number of rotations;

[0138] The controller is also used for at least one of the following:

[0139] After the electronic clutch is stopped, if the temperature sensed by the temperature sensing component is less than the second temperature threshold, the first number of rotations and / or the second number of rotations recorded by the storage unit will be cleared to zero.

[0140] After the electronic clutch is stopped, if the duration of the third rotation of the motor along the first rotation direction is longer than the second duration threshold, the first rotation count and / or the second rotation count recorded in the storage unit will be cleared to zero.

[0141] After the electronic clutch is stopped, if the fourth rotation of the motor in the second rotation direction lasts for a duration longer than the third duration threshold, the first rotation count and / or the second rotation count recorded in the storage unit will be cleared to zero.

[0142] Here, the number of times the electronic clutch engages (such as the first number of rotations and / or the second number of rotations) can be recorded in the controller's storage unit. The storage unit can be located inside or outside the controller.

[0143] The number of electronic clutch engagements recorded in the storage unit (such as the first and / or second number of rotations) can be an accumulated value. Therefore, the recorded value needs to be cleared when it is determined that continuing the current electronic clutch engagement is unnecessary. This reduces the impact on subsequent electronic clutch engagements.

[0144] For example, the electronic clutch operation stops after 20 engagements in the first round because the temperature at the predetermined position exceeds a first temperature threshold. If the electronic clutch engagement count recorded in the storage unit is not cleared before the subsequent second round of electronic clutch engagement, the second round of electronic clutch engagement will start counting from 20, resulting in a counting error.

[0145] Here, after the predetermined position temperature exceeds a first temperature threshold and stops, and when the predetermined position temperature returns to below a second temperature threshold, the first and / or second rotation counts recorded in the storage unit can be reset to zero. The second temperature threshold can be determined based on the temperature at which the electric hammer can perform a new round of electronic clutch engagement. If the predetermined position temperature is too high, the temperature at the predetermined position will quickly reach the first temperature threshold during electronic clutch engagement, thus failing to achieve the desired electronic clutch effect.

[0146] For example, if the predetermined position temperature exceeds the first temperature threshold and stops, the electronic clutch will be engaged again when the predetermined position temperature drops by 10 degrees. The electronic clutch will be engaged twice before the temperature protection is triggered (i.e., the predetermined position temperature exceeds the first temperature threshold again).

[0147] In some embodiments, the second temperature threshold is less than or equal to 30 degrees Celsius;

[0148] Therefore, the number of electronic clutches in the storage unit (such as the first number of rotations and / or the second number of rotations) can be reset to zero when the temperature sensed by the temperature sensing component is less than the second temperature threshold, so as to reduce the impact of multiple subsequent electronic clutches.

[0149] If, after one round of electronic clutch engagement, the motor can continue to rotate in one direction (either the first or second direction) for a relatively long period of time (e.g., the first rotation exceeds the second time threshold, and the second rotation exceeds the third time threshold), the temperature at the predetermined location can be rapidly reduced to meet the requirement of re-engaging the electronic clutch, since the motor rotation can drive cooling devices such as fans to dissipate heat from the electric hammer. At this time, the electronic clutch engagement count (e.g., the first rotation count and / or the second rotation count) in the storage unit can be reset to zero.

[0150] In some embodiments, the second duration threshold is greater than or equal to 5 seconds; and / or the third duration threshold is greater than or equal to 5 seconds.

[0151] For example, such as Figure 5 The figure shows the temperature change curve of the predetermined area. After the electronic clutch is triggered, the temperature of the predetermined area rises rapidly. When the electronic clutch is released from the stall, the motor runs rapidly, which causes the electric hammer to dissipate heat quickly. The measured data shows that after the motor runs for 5 seconds, the temperature returns to the normal operating temperature, which meets the temperature requirements of the subsequent electronic clutch.

[0152] In some embodiments, the detection unit includes a Hall element for sensing the rotation angle of the motor by sensing the position change of the magnetic element on the motor rotor as the rotor rotates;

[0153] The controller is used to determine that the motor has stalled if the Hall element senses that the rotation angle of the motor is within a predetermined stall angle range within a predetermined time period.

[0154] Figure 3 This is a schematic diagram of the electric hammer control circuit, as shown below. Figure 3 As shown, the control circuit includes controller U1. B+ and B- are used to connect to the power supply of the electric hammer. U2 is a voltage conversion element used to convert the power supply voltage into the operating voltage for controller U1. Q1 to Q6 constitute the three-phase drive circuit of the motor. Controller U1 drives the three-phase drive circuit to supply power to the motor and controls the rotation direction of the motor through PWM drive signals. P2 can be a connector used to connect at least one Hall element. The rotation of the motor (rotor rotation angle) sensed by the Hall element is transmitted to controller U1 through P2, so that controller U1 can determine whether the motor is stalled.

[0155] Figure 6 This is a radial cross-sectional view of the motor. The motor 100 includes a stator 110 and a rotor 120. A permanent magnet 121 is disposed on the rotor. When the motor is operating normally, the rotor rotates relative to the stator. When the motor is stalled, the rotor does not rotate relative to the stator, or rotates at a very low speed. One or more Hall elements 130 can be disposed within the motor to sense the change in the magnetic field of the permanent magnet as the rotor rotates, thereby determining the rotation angle of the rotor.

[0156] The predetermined stall angle range can be set based on the rotor rotation angle of the motor within a predetermined time when stall occurs.

[0157] When the Hall element senses that the rotation angle of the motor is within the predetermined stall angle range within a predetermined time period, such as when the rotation angle is 0, it can be determined that the motor has stalled.

[0158] This application embodiment also provides an electric tool, which includes a motor, a working head, a detection unit, a controller, and a data acquisition module; wherein, the controller is used to control the rotation of the motor; the motor transmits driving force to the working head; the controller assembly is connected to the detection unit and determines whether the motor is stalled through the detection unit; the controller assembly is used to control the motor to perform electronic clutch operation when the motor is stalled, wherein the electronic clutch includes a first rotation along a first rotation direction and a second rotation along a second rotation direction, the first rotation direction and the second rotation direction being opposite;

[0159] The data acquisition module is used to acquire the operating parameters of the power tool;

[0160] The controller is communicatively connected to the data acquisition module and determines whether to stop the electronic clutch based on the operating parameters of the power tool.

[0161] The operating parameters include at least one of the following: number of electronic clutch engagements, duration of electronic clutch engagement, and power tool temperature.

[0162] Power tools can include tools with motor-driven working heads, including but not limited to: drive screwdrivers, miter saws, electric drills, electric hammers (such as smart hammers), polishers, cutting machines, and engraving machines.

[0163] Here, the working head may include, but is not limited to, one of the following: drill bit, screwdriver bit, etc.

[0164] In one possible implementation, the motor in the power tool can directly drive the working head.

[0165] In one possible implementation, the motor in the power tool can drive the working head via a transmission assembly.

[0166] The specific implementation of the electronic clutch control for power tools is similar to any of the embodiments of the electronic clutch control for electric hammers described above, and will not be repeated here.

[0167] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0168] In the description of this specification, references to "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An electric hammer characterized by comprising: The electric hammer comprises a motor, a transmission assembly, a working head, a detection unit, a controller and a data acquisition module, wherein The controller is configured to control rotation of the motor; The motor transmits driving force to the working head through the transmission assembly; The controller assembly is connected with the detection unit and determines whether the motor is locked through the detection unit; The controller assembly is configured to control the motor to perform electronic clutching in the case that the motor is locked, wherein the electronic clutching comprises first rotation in a first rotation direction and second rotation in a second rotation direction, and the first rotation direction and the second rotation direction are opposite; The data acquisition module is configured to acquire operating parameters of the electric hammer; The controller is in communication connection with the data acquisition module, and determines whether to stop the electronic clutching based on the operating parameters of the electric hammer; The operating parameters comprise at least one of the following: electronic clutching frequency, electronic clutching duration and electric hammer temperature.

2. The hammer drill according to claim 1, characterized in that The data acquisition module comprises a temperature sensing assembly, and the controller is specifically configured to at least one of the following: In the case of performing the electronic clutching, if the first rotation frequency of the first rotation is greater than a first rotation threshold, the electronic clutching is stopped; In the case of performing the electronic clutching, if the second rotation frequency of the second rotation is greater than a second rotation threshold, the electronic clutching is stopped; In the case of performing the electronic clutching, if the duration of the electronic clutching is greater than a first duration threshold, the electronic clutching is stopped; In the case of performing the electronic clutching, if the temperature sensed by the temperature sensing assembly of the electric hammer is greater than a first temperature threshold, the electronic clutching is stopped; the temperature sensing assembly is configured to sense the temperature of a predetermined position of the electric hammer.

3. The electric hammer of claim 2, wherein The first rotation threshold is greater than or equal to 30 times; and / or The second rotation threshold is greater than or equal to 30 times; and / or The first duration threshold is greater than or equal to 7 seconds; and / or The first temperature threshold is greater than or equal to 100 degrees Celsius.

4. The hammer drill of claim 2, wherein, The temperature sensing assembly comprises a constant resistance and a temperature-sensitive resistance arranged at the predetermined position, wherein a first end of the constant resistance is connected with a power supply, a second end of the constant resistance and a first end of the temperature-sensitive resistance are connected to form a connection node, the connection node is connected with the controller, and a second end of the temperature-sensitive resistance is connected with a power ground; the controller determines the temperature of the predetermined position by detecting the voltage of the connection node.

5. The hammer drill of claim 4, wherein A current-limiting resistor is arranged between the connection node and the controller.

6. The hammer drill of claim 2, wherein, The predetermined position comprises at least one of the following: A surface of a switch tube driving the rotation of the motor; An area within a predetermined distance from the switch tube.

7. The electric hammer of claim 2, wherein The controller further comprises a storage unit for recording the first rotation frequency and / or the second rotation frequency; The controller is further configured to at least one of the following: After stopping the electronic clutching, if the temperature sensed by the temperature sensing assembly is less than a second temperature threshold, the first rotation frequency and / or the second rotation frequency recorded by the storage unit is cleared. When the electronic clutch is stopped, if a third rotation of the motor in a first rotation direction lasts longer than a second duration threshold, the first rotation count and / or the second rotation count recorded by the storage unit are cleared; When the electronic clutch is stopped, if a fourth rotation of the motor in a second rotation direction lasts longer than a third duration threshold, the first rotation count and / or the second rotation count recorded by the storage unit are cleared.

8. The electric hammer of claim 7, wherein, the second temperature threshold is less than or equal to 30 degrees Celsius; and / or the second duration threshold is greater than or equal to 5 seconds; and / or the third duration threshold is greater than or equal to 5 seconds.

9. The hammer drill according to any one of claims 1 to 8, characterized in that The detection unit comprises a Hall element for sensing the rotation angle of the motor by sensing the position change of a magnetic element on the motor rotor with the rotation of the rotor; The controller is configured to determine that the motor is stalled when the Hall element senses that the rotation angle of the motor is within a predetermined stall angle range within a predetermined duration.

10. An electric power tool characterized by comprising: The electric tool comprises a motor, a working head, a detection unit, a controller and a data acquisition module; wherein, the controller is configured to control the rotation of the motor; the motor transmits driving force to the working head; the controller assembly is connected with the detection unit and determines whether the motor is stalled through the detection unit; the controller assembly is configured to control the motor to perform electronic clutching when the motor is stalled, wherein the electronic clutching comprises a first rotation in a first rotation direction and a second rotation in a second rotation direction, and the first rotation direction and the second rotation direction are opposite; the data acquisition module is configured to acquire the operating parameters of the electric tool; the controller is communicatively connected with the data acquisition module and determines whether to stop the electronic clutching based on the operating parameters of the electric tool.

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