Electric tool

Abstract

The embodiment of the utility model provides an electric tool, which comprises a power input interface capable of being electrically connected to a power supply, a motor, a direct current-direct current power converter electrically connected with the motor, and a secondary energy storage device electrically connected with the direct current-direct current power converter, and a controller electrically connected with the DC-DC power converter. The controller is configured to control the DC-DC power converter to deliver braking current generated by the motor to the secondary energy storage device during regenerative braking operation.

Description

Technical Field

[0001] The embodiments described in this utility model relate to power tools. Background Technology

[0002] Power tool motors generate current during braking, but existing power tools do not utilize this current, resulting in waste. This application addresses this issue by incorporating a secondary energy storage device and a DC-DC power converter, with the converter controlled by a controller, to supply the current generated by the motor to the secondary energy storage device. Utility Model Content

[0003] The electric tool of this invention includes: a power input interface electrically connected to a power source; a motor; a DC-DC power converter electrically connected to the motor; a secondary energy storage device electrically connected to the DC-DC power converter; and a controller electrically connected to the DC-DC power converter, the controller being configured to control the DC-DC power converter to deliver braking current generated by the motor to the secondary energy storage device during regenerative braking operation.

[0004] In some respects, the DC-DC power converter is configured to regulate the power supplied from the motor to the secondary energy storage device during regenerative braking operation.

[0005] In some respects, a DC-DC power converter is a bidirectional DC-DC power converter configured to regulate the power released from a secondary energy storage device.

[0006] In some aspects, the power tool further includes a power switching network electrically connected to the motor and the DC-DC power converter, wherein the controller is configured to control the power switching network to perform regenerative braking operations.

[0007] In some respects, the controller is further configured to selectively supply energy stored in a secondary energy storage device to either the motor or the power source.

[0008] In some respects, the controller is configured to selectively supply energy stored in a secondary energy storage device to the motor as a motor reverse braking (plugging) current during the motor's braking operation.

[0009] In some respects, the controller is configured to selectively provide energy stored in a secondary energy storage device to the motor as supplemental power to drive the motor.

[0010] In some respects, the controller is configured to provide the motor with power from the power source and supplemental power from the secondary energy storage device at startup.

[0011] In some respects, the controller is configured to provide supplemental power in response to determining that the voltage of the power supply is below a threshold during motor drive operation.

[0012] In some respects, the controller is configured to provide supplemental power in response to determining that the motor’s power demand exceeds a threshold.

[0013] In some aspects, the power tool further includes a user input interface; wherein the controller is further configured to receive user input via the user input interface indicating a request for boost operation, and in response to determining that a boost operation has been requested, to provide energy stored in a secondary energy storage device to the motor as supplemental power for driving the motor.

[0014] In some respects, the controller is configured to selectively supply energy stored in a secondary energy storage device to the power source in response to determining that the motor is in an idle state.

[0015] In some respects, secondary energy storage devices include at least one of the group consisting of capacitors, supercapacitors, battery cells, and power tool battery packs.

[0016] In some respects, the power source is a removable battery pack.

[0017] The electric tool of this utility model includes: a battery pack interface that can be electrically connected to a battery pack; a motor; a DC-DC power converter electrically connected to the motor; a secondary energy storage device electrically connected to the DC-DC power converter; and a controller electrically connected to the DC-DC power converter, the controller being configured to control the DC-DC power converter to deliver the braking current generated by the motor to the secondary energy storage device during regenerative braking operation.

[0018] In some aspects, the controller is further configured to selectively supply energy stored in the secondary energy storage device to the motor in response to determining that a first operating condition of the power tool has been met; to selectively supply energy stored in the secondary energy storage device to the power tool battery pack in response to determining that the first operating condition of the power tool has not been met but a second operating condition of the power tool has been met; and to allow energy stored in the energy storage device to dissipate in response to determining that neither the first operating condition nor the second operating condition has been met.

[0019] A method for operating power tools, comprising a power input interface electrically connectable to a power source, a motor, a DC-DC power converter, and the secondary energy storage device described herein, the method comprising: during regenerative braking operation, controlling the DC-DC power converter to deliver braking current generated by the motor to the secondary energy storage device.

[0020] In some aspects, the method further includes selectively supplying energy stored in a secondary energy storage device to one of the group consisting of a motor and a power source.

[0021] In some respects, during motor braking operations, energy stored in a secondary energy storage device is selectively supplied to the motor as a reverse braking current.

[0022] In some respects, the electricity stored in the secondary energy storage device is selectively supplied to the motor as supplementary power to drive the motor.

[0023] Before explaining any implementation in detail, it should be understood that the application of these implementations is not limited to the details of the component configuration and arrangement described in the following description or shown in the accompanying drawings. These implementations can be practiced or implemented in various ways. At the same time, it should be understood that the wording and terminology used in this invention are for illustrative purposes and should not be considered restrictive. The use of "comprising," "including," or "having," and variations thereof, is intended to cover the items listed thereafter, as well as equivalents and additional items. Unless otherwise stated or limited, the use of "mounting," "connecting," "supporting," and "coupling," and variations thereof, is broad and includes both direct and indirect mounting, connection, support, and coupling.

[0024] Unless the context clearly indicates otherwise, the articles “a,” “an,” and “the” should not be understood as “one” or “only one.” Instead, these articles should be understood as “at least one” or “one or more.” Similarly, when “the” or “said” is used to refer to a noun previously introduced by the indefinite article “a” or “an,” “the” and “said” mean “at least one” or “one or more” unless the usage clearly indicates otherwise.

[0025] Furthermore, it should be understood that implementations may include hardware, software, and electronic components or modules, which may be shown and described as if most components were implemented solely in hardware for ease of discussion. However, those skilled in the art will recognize upon reading this detailed description that in at least one implementation, the electronic aspects may be implemented in software (e.g., stored on a non-volatile computer-readable medium), which may be executed by one or more processing units (such as microprocessors and / or application-specific integrated circuits "ASICs"). Therefore, it should be noted that these implementations may be implemented using a plurality of hardware and software-based devices and a plurality of different structural components. For example, "server," "computing device," "controller," "processor," etc., as described in the specification may include one or more processing units, one or more computer-readable medium modules, one or more input / output interfaces, and various connectors (e.g., system buses) connecting these components.

[0026] Related terms, such as “about,” “approximately,” “generally,” etc., when used in conjunction with quantities or conditions, will be understood by those skilled in the art to include the stated values, and their meaning is determined by the context (e.g., the term includes at least the range of errors associated with measurement accuracy, tolerances associated with a particular value [e.g., manufacturing, assembly, use, etc.]). Such terms should also be considered to reveal a range defined by the absolute values ​​of two endpoints. For example, the expression “from about 2 to about 4” also reveals a range “from 2 to 4.” Related terms may refer to percentages added to or subtracted from the indicated value (e.g., 1%, 5%, 10%).

[0027] It should be understood that although some figures show hardware and software located within a particular device, these descriptions are for illustrative purposes only. The functions performed by one component as described in this invention can be performed by multiple components in a distributed manner. Similarly, functions performed by multiple components can be combined and performed by a single component. In some embodiments, the illustrated components can be combined or divided into different software, firmware, and / or hardware. For example, logic and processing are not performed and located by a single electronic processor, but can be distributed among multiple electronic processors. Regardless of how they are combined or divided, hardware and software components can reside on the same computing device or can be distributed among different computing devices connected via one or more networks or other suitable communication links. Similarly, components described as performing specific functions can also perform additional functions not described in this invention. For example, a device or structure "configured" in a certain way is at least configured in that way, but may also be configured in a way not explicitly listed.

[0028] Therefore, in a claim, if an apparatus, method, or system is claimed to include, for example, a controller, control unit, electronic processor, computing device, logic element, module, memory module, communication channel or network, or other elements configured in a certain way, for example, to perform multiple functions, then the claim or claim element should be interpreted as meaning that any one of these elements is configured as claimed to be one or more such elements, for example, to implement one or more of the listed multiple functions, such that one or more elements together perform the multiple functions as a set.

[0029] Other aspects of the various embodiments will become apparent upon careful reading of the detailed description and accompanying drawings. Attached Figure Description

[0030] Figure 1 Power tools according to some embodiments are shown.

[0031] Figure 2 A power tool according to some embodiments is illustrated schematically.

[0032] Figure 3 An energy management system for power tools is illustrated schematically according to some embodiments.

[0033] Figure 4 A method for controlling power tools according to some embodiments is shown. Detailed Implementation

[0034] Figure 1 A power tool 100 including a brushless direct current (BLDC) motor is shown. The power tool 100 is, for example, a brushless hammer drill including a housing 102. The housing 102 includes a handle portion 104 and a motor housing portion 106. The power tool 100 further includes an output driver 108 (shown as a chuck), a trigger 110, and a power input interface 112. The power input interface 112 is configured to be mechanically and electrically connected to a power source to supply power to the tool 100. Although... Figure 1A hammer drill is shown, but in some embodiments, the components and control technology described in this invention are integrated into other types of power tools, including, for example, circular saws, jigsaws, reciprocating saws, band saws, grinders, cutting saws, tire grinders, mud mixers, belt files, polishers, sanders, cutting tools, rotary hammers, drill drives, hammer drills, right-angle drills, impact drives, impact wrenches, ratchet wheels, screwdrivers, wire cutters, pipe threading machines, pumps, cable cutters, cable strippers, bar cutters, pipe cutters, pipe shears, punching tools, PEX expanders, air compressors, compressors, sewer blowers, transfer pumps, drain cleaners, riveting tools, heat guns, grease guns, caulking guns, chain hoists, track saws, miter saws, table saws, multi-tools, grooving machines, planers, vacuum cleaners, fans, hair dryers, etc.

[0035] Figure 2 A control system 200 for a power tool 100 including a secondary energy storage system is shown. The control system 200 includes a controller 202. The controller 202 is electrically and / or communicatively connected to various modules or components of the power tool 100. For example, the controller 202 shown is electrically connected to a motor 204, a power input interface 112, a trigger switch 208 (connected to trigger 110), one or more sensors 212 (also referred to as sensing circuitry), one or more indicators 214, a user input module 216, a power switching network 220, a secondary energy storage device 222, and a DC-DC converter 224. The controller 202 includes a combination of hardware and software operable to control, in particular, the operation of the power tool 100, monitor the work of the power tool 100, activate one or more indicators 214 (e.g., LEDs), etc.

[0036] The power input interface 112 is electrically connected to a power source 242. The power source 242 may be, for example, a rechargeable and removable power tool battery pack. Although described herein as a battery pack 242, in some embodiments, the power source 242 may be, for example, a portable power source having a wired connection to the power input interface 112, an adapter for converting alternating current to direct current to supply the power input interface, a power cord providing alternating current input, or another type of power source. The power input interface 112 includes a combination of mechanical components (e.g., rails, grooves, latches, etc.) and electrical components (e.g., one or more terminals) configured and operable to interface with the battery pack 242 (e.g., mechanically, electrically, and communicatively). The power input interface 112 supplies power to a power switching network 220 for selective power supply to the motor 204 by switching FETs.

[0037] The controller 202 includes a plurality of electrical and electronic components that provide power, operational control, and protection to components and modules within the controller 202 or the power tool 100. For example, the controller 202 includes a processing unit 226 (e.g., a microprocessor, microcontroller, electronic controller, electronic processor, or other suitable programmable device, and collectively referred to as an electronic processor), a memory 228, an input unit 230, and an output unit 232. The processing unit 226 particularly includes a control unit 234, an arithmetic logic unit (ALU) 236, and a plurality of registers 238, and is implemented using a known computer architecture (e.g., a modified Harvard architecture, a von Neumann architecture, etc.). The processing unit 226, the memory 228, the input unit 230, and the output unit 232, as well as various modules or circuits connected to the controller 202, are connected via one or more control and / or data buses (e.g., a common bus 240). For illustrative purposes, Figure 2 The diagram generally illustrates the control and / or data bus. In view of the invention described herein, those skilled in the art will recognize the use of one or more control and / or data buses to achieve interconnection and communication between different modules, circuits, and components.

[0038] Memory 228 is a non-transitory computer-readable medium and includes, for example, a program storage area and a data storage area. The program storage area and data storage area may include combinations of different types of memory, such as ROM, RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, hard disk, SD card, or other suitable magnetic, optical, physical, or electronic storage devices. Processing unit 226 is connected to memory 228 and executes software instructions that can be stored in the RAM of memory 228 (e.g., during execution), software instructions in the ROM of memory 228 (e.g., based on a substantially permanent basis), or software instructions in another non-transitory computer-readable medium such as another memory or disk. Software included in an implementation of power tool 100 may be stored in memory 228 of controller 202. This software includes, for example, firmware, one or more application programs, program data, filters, rules, one or more program modules, and other executable instructions. Controller 202 is configured to retrieve from memory 228 and execute instructions, etc., related to the control processes and methods described herein. In other configurations, controller 202 includes additional, fewer, or different components.

[0039] In the illustrated embodiment, motor 204 is a three-phase brushless motor. In some embodiments, the number of phases of motor 204 may be more or fewer. Power switching network 220 includes, for example, an inverter having a plurality of switching FETs for driving motor 204. In one embodiment, power switching network 220 is formed as an inverter bridge, which includes three high-side switching FETs connected between the positive power supply terminal and the motor terminal, and three low-side switching FETs connected between the motor terminal and the negative power supply terminal or ground. In other embodiments, motor 204 is a DC motor or a brushed motor, and power switching network 220 is modified accordingly. In some embodiments, sensor 212 measures or detects the current in power switching network 220 (e.g., the current in one or more phases of the inverter).

[0040] Trigger switch 208 provides controller 202 with information related to trigger 110. In some embodiments, trigger 110 is an on / off power switch. In these embodiments, trigger switch 208 may be connected between power input interface 112 and power switching network 220, and may include a relay that closes when trigger 110 is on and opens when trigger 110 is off. In other embodiments, trigger 110 may include a variable speed trigger. In these embodiments, trigger switch 208 may include a wiper as an alternative to or supplement to the relay. As the variable speed trigger is pressed, the contacts of the variable speed trigger move along the wiper of trigger switch 208, thereby providing the controller 202 with the required speed information.

[0041] Sensor 212 includes one or more current sensors, one or more speed sensors, one or more Hall effect sensors, one or more temperature sensors, etc. Indicator 214 includes, for example, one or more light-emitting diodes (LEDs). Indicator 214 can be configured to display the status of the power tool 100 or information related to the power tool 100. For example, indicator 214 is configured to indicate the measured electrical characteristics of the power tool 100, the status of the power tool, the status of the secondary energy storage device 222, etc. User input module 216 is operatively coupled to controller 202 to, for example, select a forward or reverse operating mode, set the torque and / or speed of the power tool 100 (e.g., using a torque and / or speed switch), etc. In some embodiments, user input module 216 includes a combination of digital and analog input or output devices required to achieve a desired operating level of the power tool 100, such as one or more knobs, one or more dials, one or more switches, one or more buttons, etc.

[0042] See Figure 2 and Figure 3The secondary energy storage device 222 may include, for example, capacitors, supercapacitors, battery packs (e.g., secondary battery packs in addition to battery pack 242), etc. In some embodiments, the controller 202 may be directly connected to the secondary energy storage device 222. In other embodiments, the controller 202 may use sensor 212 to determine the state of the energy storage device. A DC-DC power converter 224 is electrically connected to the secondary energy storage device 222, the power switching network 220, and the controller 202. In some embodiments, the DC-DC power converter 224 is connected between the power switching network 220 (e.g., an inverter) and the secondary energy storage device 222. In other embodiments, the DC-DC power converter 224 may be directly connected to the motor 204, or connected to the motor via another intermediate power converter (e.g., a rectifier). In some embodiments, the DC-DC power converter 224 may also be connected to the power supply 242 via power input interface 112. Although... Figure 3 The main power supply 242 is shown as a battery, and the secondary energy storage device 222 is shown as a supercapacitor, but the power supply 242 and / or the secondary energy storage device 222 may take other forms as described above.

[0043] Figure 3 An energy management system for a power tool 100 is shown. A power switching network 220 is connected between a DC bus 312 and a motor 204. The power switching network 220 may include bidirectional circuitry capable of selectively supplying power from the DC bus 312 to the motor 204 (e.g., when driving the motor) and from the motor 204 to the DC bus 312 (e.g., when braking the motor). The DC bus 312 is also connected to a power source 242, a secondary energy storage device 222, and a DC-DC power converter 224. The DC-DC power converter 224 may be a bidirectional DC-DC power converter 224 that supplies DC power from the secondary energy storage device 222 to the DC bus 312 and from the DC bus 312 to the secondary energy storage device 222.

[0044] Controller 202 is configured to monitor the status of power supply 242, secondary energy storage device 222, and motor. For example, controller 202 can monitor the voltage level (e.g., state of charge), power consumption, temperature, error conditions, etc., of power supply 242 and secondary energy storage device 222. Controller 202 can also monitor the power demand (e.g., load) on the motor, for example, using load sensors, vibration sensors, etc. Controller 202 provides control signals to DC-DC power converter 224 to control the power flow between DC bus 312 and secondary energy storage device 222.

[0045] In some embodiments, switches (e.g., FETs) may be arranged on the current path between the DC bus 312 and each of the power supply 242, the power switching network 220, and the DC-DC power converter 224. These switches selectively connect or disconnect the power supply 242, the power switching network 220, and the DC-DC converter from the DC bus 312.

[0046] In some embodiments, the DC-DC power converter 224 is a bidirectional power converter configured to automatically or based on control signals received from the controller 202 regulate the power supplied to the secondary energy storage device 222 (e.g., boost or buck voltage) and the power released from the secondary energy storage device 222. For example, the DC-DC power converter 224 may regulate the power released from the secondary energy storage device 222 and supplied to the motor 204 (e.g., via the power switching network 220) and / or the power source 242 (e.g., via the power input interface 112).

[0047] Figure 4 A method 400 for energy management of a power tool 100 is illustrated. This method 400 can be performed by, for example, a controller 202 of the power tool 100. The method 400 includes detecting motor drive events (at block 404) using the controller 202. Motor drive events can include, for example, actuation of a power switch, a variable speed trigger (e.g., trigger 110), actuation of a power switch and a speed dial, etc. The controller 202 can detect motor drive events based on signals from trigger switch 208 or sensor 212.

[0048] Method 400 includes driving motor 204 (at block 408) using power switching network 220 in response to detecting a motor drive event, based on the motor drive event (e.g., based on speed and / or torque associated with the motor drive event). During operation of power tool 100, controller 202 is configured to control power switching network 220 to drive motor 204 in response to actuation of, for example, trigger 110. As described above, power switching network 220 may be configured as an inverter connected between DC bus 312 and motor 204. Controller 202 may provide pulse width modulation (PWM) signals to the FETs of power switching network 220 to drive motor 204 according to the motor drive event. Driving motor 204 causes motor drive current to flow from, for example, DC bus 312 through power switching network 220 to motor 204.

[0049] Method 400 also includes detecting motor braking events using controller 202 (at block 412). Motor braking events may include, for example, the release of trigger 110, actuation of a power switch to the off state, deceleration according to the speed dial of tool 100, springback of tool 100, actuation of an emergency stop input included in user input module 216, reaching the torque limit of motor 204, etc. Controller 202 may detect motor drive events based on signals from trigger switch 208 or sensor 212.

[0050] Method 400 includes braking a motor using controller 202 in response to a motor braking event (at block 416). Controller 202 can brake the motor by disconnecting power supply 242 from DC bus 312. Method 400 further includes controlling DC-DC power converter 224 to supply current generated by motor 204 to secondary energy storage device 222, which is generated during motor braking (at block 420). Controller 202 can control power switching network 220 to perform regenerative braking operation of motor 204, causing the braking current generated by motor 204 to be redirected to secondary energy storage device 222 via DC-DC power converter. For example, controller 202 can control a switch disposed between power supply 242 and power switching network 220 to open, allowing the braking current generated by motor 204 to be delivered to secondary energy storage device 222 via DC-DC power converter 224. During regenerative braking operation, DC-DC power converter 224 can convert the regenerative braking current received via power switching network 220 to an appropriate voltage for charging secondary energy storage device 222. In some embodiments, the power switching network 220 can be bypassed (e.g., using a bypass switching arrangement), which allows the DC-DC power converter 224 to be connected directly or via a rectifier to the motor 204 (i.e., the motor coil).

[0051] Method 400 further includes using controller 202 to selectively supply energy stored in secondary energy storage device 222 to one of motor 204 or power source 242 (at block 424). Based on state information received from secondary energy storage device 222, battery pack 242, motor 204 and / or other components of tool 100, controller 202 may supply energy stored in secondary energy storage device 222 to one of motor 204 or power source 242. For example, controller 202 may determine the state of charge (e.g., voltage level) of battery pack 242, the state of charge of secondary energy storage device 222, the power demand of motor 204, user input of tool 100 and / or one or more operations performed by motor (e.g., motor braking operation, motor drive operation, etc.), and output control signals to power switching network 220 to control whether and how to discharge from secondary energy storage device 222.

[0052] In some embodiments, the controller 202 selectively (e.g., by controlling the power switching network 220) provides energy stored in the secondary energy storage device 222 to the motor 204 as a reverse braking current to brake the motor 204 more quickly during braking operations (e.g., in response to detecting a motor braking event).

[0053] In some embodiments, controller 202 selectively provides energy stored in secondary energy storage device 222 to motor 204 as supplementary power for driving motor 204. During the driving operation of motor 204, this supplementary power is provided to motor 204 in addition to the power provided by power source 242. For example, in some embodiments, controller 202 controls power conversion network 220 to provide power from power source 242 and supplementary power from secondary energy storage device 222 when motor 204 starts.

[0054] In some embodiments, controller 202 provides supplemental power from secondary energy storage device 222 in response to determining that the voltage of power source 242 is below a threshold voltage required to drive motor 204 and / or power tool 100. In such embodiments, controller 202 may use the supplemental power from secondary energy storage device 222 as part or all of the total power provided to motor 204. For example, controller 202 may control power switching network 220 to discharge secondary energy storage device 222 based on the difference between the power demand of the tool and the power available from power source 242 (e.g., based on a determined voltage state of power source 242).

[0055] In some embodiments, controller 202 provides supplemental power from secondary energy storage device 222 based on the power demand of motor 204. For example, in response to determining that the power demand of motor 204 is greater than a threshold (e.g., during different types of drive operation or modes of tool 100), controller 202 may control power conversion network 220, which causes power to be supplied simultaneously from power source 242 and secondary energy storage device 222 to drive motor 204.

[0056] In some embodiments, the user input module 216 of tool 100 includes a boost operation input (e.g., a button, switch, and / or similar device) for triggering a boost mode of tool 100 (e.g., driving motor 204 at higher power). In response to receiving a user input indicating a request for boost operation via user input module 216, controller 202 controls power switching network 220 to selectively provide energy stored in secondary energy storage device 222 as supplemental power to drive motor 204 during boost operation. Controller 202 may drive motor 204 for boost operation until controller 202 receives a user input to exit boost mode, until the energy in energy storage device 222 is depleted, or until a predetermined period of time for performing boost operation has elapsed, etc.

[0057] In some embodiments, the controller 202 selectively supplies energy stored in the secondary energy storage device 222 to the power supply 242 in response to determining that the motor 204 is idle (e.g., during the power-off period of the tool 100 and / or when the motor 204 is not otherwise driven) and that the charging state of the power supply 242 is below a threshold. For example, in response to determining that the power supply 242 is not fully charged, the controller 202 controls the DC-DC power converter 224 to use the energy stored in the secondary energy storage device 222 to charge the power supply 242, for example, by converting the electrical energy stored in the secondary energy storage device 222 into a voltage level higher than that of the power supply 242, which causes a charging current to flow from the secondary energy storage device 222 to the power supply 242.

[0058] In some embodiments, controller 202 controls DC-DC power converter 224 to regulate the power released from secondary energy storage device 222, causing the energy stored in secondary energy storage device 222 to gradually dissipate over time. For example, in response to determining that motor 204 is idle and the state of charge of power supply 242 is greater than a threshold (e.g., fully charged), controller 202 controls power switching network 220 to dissipate the energy stored in secondary energy storage device 222. In some embodiments, in response to determining that power supply 242 is not connected to tool 100, controller 202 dissipates the energy stored in secondary energy storage device 222.

[0059] In some embodiments, in response to determining that a first operating condition has been met, the controller 202 may selectively supply energy stored in the secondary energy storage device 222 to the motor 204 (e.g., as supplemental current or as reverse braking current for the motor). The first operating condition may include, for example, braking operation of the tool 100, increased power demand of the motor 204, starting operation of the motor 204, low voltage condition of the power supply 242 during driving the motor 204, request for boost operation of the tool 100, etc.

[0060] In response to determining that a second operating condition is met (or that the second operating condition is met while the first operating condition is not met), the controller 202 may selectively supply energy stored in the secondary energy storage device 222 to the power supply 242. The second operating condition may include, for example, a low voltage state of the power supply 242 (e.g., in the idle state of the motor 204).

[0061] In some embodiments, in response to determining that neither the first nor the second operating conditions are met, the controller 202 may dissipate the energy stored in the secondary energy storage device 222.

[0062] Method 400 illustrates only an exemplary implementation. The steps described in connection with this method need not be performed in all or in the order described to implement the method. Those skilled in the art will understand that method 400 can be performed in any order, or by omitting certain steps entirely.

[0063] Therefore, the embodiments described in this utility model provide power tools including a secondary energy storage device. Various features and advantages of these embodiments are described below.

Claims

1. A power tool, characterized in that, include: A power input interface that can be electrically connected to a power source; motor; A DC-DC power converter, wherein the DC-DC power converter is electrically connected to the motor; A secondary energy storage device, wherein the secondary energy storage device is electrically connected to the DC-DC power converter; as well as A controller electrically connected to the DC-DC power converter is configured to control the DC-DC power converter to supply current generated by the motor to the secondary energy storage device, the current being generated during motor braking.

2. The power tool according to claim 1, characterized in that, The DC-DC power converter is configured to regulate the power supplied from the motor to the secondary energy storage device during motor braking.

3. The power tool according to claim 1, characterized in that, The DC-DC power converter is a bidirectional DC-DC power converter, and the bidirectional DC-DC power converter is configured to regulate the power released from the secondary energy storage device.

4. The power tool according to claim 1, characterized in that, Further includes: A power switching network electrically connected to the motor and the DC-DC power converter, wherein the controller is configured to control the power switching network to perform motor braking.

5. The power tool according to claim 4, characterized in that, The controller is further configured to selectively supply energy stored in the secondary energy storage device to one of the components selected from the group consisting of the motor and the power source.

6. The power tool according to claim 5, characterized in that, The controller is configured to selectively provide energy stored in the secondary energy storage device to the motor as a reverse braking current during the braking operation of the motor.

7. The power tool according to claim 5, characterized in that, The controller is configured to selectively provide the energy stored in the secondary energy storage device to the motor as supplementary power to drive the motor.

8. The power tool according to claim 7, characterized in that, The controller is configured to provide the motor with power from the power source and supplemental power from the secondary energy storage device upon startup.

9. The power tool according to claim 7, characterized in that, The controller is configured to provide supplemental power during the driving operation of the motor in response to determining that the voltage of the power supply is below a threshold.

10. The power tool according to claim 7, characterized in that, The controller is configured to provide supplemental power in response to determining that the motor's power demand is greater than a threshold.

11. The power tool according to claim 7, characterized in that, Further includes: User input interface; The controller is further configured as follows: The user input requesting the boost operation was received via the user input interface, and In response to the confirmed request for boost operation, energy stored in the secondary energy storage device is selectively supplied to the motor as supplemental power for the drive motor.

12. The power tool according to claim 1, characterized in that, The controller is configured to selectively supply energy stored in the secondary energy storage device to a power source in response to determining that the motor is in an idle state.

13. The power tool according to claim 1, characterized in that, The secondary energy storage device includes at least one of the following: selected from capacitors, supercapacitors, battery cells, and power tool battery packs.

14. The power tool according to claim 1, characterized in that, The power source is a removable battery pack.

15. A power tool, characterized in that, include: Battery pack interface, which can be electrically connected to the battery pack; motor; A DC-DC power converter, wherein the DC-DC power converter is electrically connected to the motor; A secondary energy storage device, wherein the secondary energy storage device is electrically connected to the DC-DC power converter; as well as A controller electrically connected to the DC-DC power converter is configured to control the DC-DC power converter to provide the braking current generated by the motor to the secondary energy storage device during motor braking.

16. The power tool according to claim 15, characterized in that, The controller is further configured as follows: In response to determining that a first operating condition of the power tool is met, energy stored in the secondary energy storage device is selectively supplied to the motor; In response to determining that a first operating condition of the power tool is not met while a second operating condition of the power tool is met, energy stored in the secondary energy storage device is selectively supplied to the battery pack; as well as In response to determining that neither the first operating condition nor the second operating condition is met, the energy stored in the secondary energy storage device is selectively dissipated.

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