Patent Application
20250073884
Embodiments described herein relate to a power tool.
Portable pipe threaders include a stand and a carriage mounted to the stand having multiple pipe threading tools. These tools are usually a die holder including multiple dies, a cutter, and a reamer. Typically, a motor transmits torque to a spindle to which a pipe is clamped for rotating the pipe with respect to the tools. The motor receives power from a remote power source (e.g., via a power cord) and is usually controlled using a pedal, which upon actuation, triggers the motor to begin rotating the pipe. During operation, a thermal load of one or more components (e.g., motor, capacitor, gear box, etc.) of the pipe threader begins to rise and approach or exceed a thermal overload threshold of the pipe threader provided to protect a component of the pipe threader.
Embodiments described herein provide power tools including a housing, an electrical circuit, and the housing. The housing includes a battery pack interface configured to receive a battery pack. The electrical circuit includes a resistor-capacitor (“RC”) circuit arrangement configured to store a voltage on a capacitor of the RC circuit arrangement. The voltage is proportional to a temperature of the power tool. The electronic controller is connected to the electrical circuit and includes an electronic processor and a memory. The electronic controller is configured to control voltage applied to the RC circuit arrangement, and determine, in response to determining a power off event of the power tool has ended, the temperature of the power tool based on the voltage of the capacitor of the RC circuit arrangement. The controller is also configured to control the power tool based on the voltage of the capacitor of the RC circuit arrangement and a temperature threshold.
Embodiments described herein provide methods for maintaining thermal information of a power tool during a power off event. The methods include receiving a voltage from a battery pack connected to the power tool, providing, by an electronic controller, the voltage from the battery pack to a resistor-capacitor (“RC”) circuit arrangement. The RC circuit arrangement includes a capacitor storing a voltage that is proportional to a temperature of the power tool. The methods also include determining, by the electronic controller and in response to determining the power off event of the power tool has ended. The temperature of the power tool is based on the voltage of the capacitor of the RC circuit arrangement. The methods also include controlling the power tool based on the voltage of the capacitor of the RC circuit arrangement and a temperature threshold.
Embodiments described herein provide a system for maintaining thermal information of a power tool during a power off event. The system includes a battery pack, an electrical circuit, and an electronic controller. The electrical circuit includes a resistor-capacitor (“RC”) circuit arrangement. The RC circuit arrangement is configured to store a voltage on a capacitor of the RC circuit arrangement. The voltage is proportional to a temperature of the power tool. The electronic controller is electrically connected to the electrical circuit. The electronic controller includes an electronic processor and a memory. The memory includes a model for an estimated temperature of the power tool. The estimated temperature of the model is proportional to the voltage of the capacitor of the RC circuit arrangement. The electronic controller is configured to control a voltage applied to the RC circuit arrangement. The electronic controller is further configured to determine a first voltage of the capacitor of the RC circuit arrangement. The first voltage is an initial voltage measurement. The electronic controller is further configured to determine a first estimated temperature of the power tool based on the first voltage of the capacitor of the RC circuit arrangement, update a state of the model based on the first voltage of the capacitor of the RC circuit arrangement, determine, in response to determining the power off event of the power tool ended, a second voltage of the RC circuit arrangement, determine a second estimated temperature of the power tool based on the second voltage of the capacitor of the RC circuit arrangement, and control operation of the power tool based on the second estimated temperature of the power tool and a temperature threshold value.
Before any embodiments are explained in detail, it is to be understood that the embodiments are not limited in application to the details of the configurations and arrangements of components set forth in the following description or illustrated in the accompanying drawings. The embodiments are capable of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.
Unless the context of their usage unambiguously indicates otherwise, the articles “a,” “an,” and “the” should not be interpreted as meaning “one” or “only one.” Rather these articles should be interpreted as meaning “at least one” or “one or more.” Likewise, when the terms “the” or “said” are 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 unambiguously indicates otherwise.
In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic-based aspects may be implemented in software (e.g., stored on non-transitory computer-readable medium) executable by one or more processing units, such as a microprocessor and/or application specific integrated circuits (“ASICs”). As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components, may be utilized to implement the embodiments. For example, “servers,” “computing devices,” “controllers,” “processors,” etc., described in the specification can include one or more processing units, one or more computer-readable medium modules, one or more input/output interfaces, and various connections (e.g., a system bus) connecting the components.
Relative terminology, such as, for example, “about,” “approximately,” “substantially,” etc., used in connection with a quantity or condition would be understood by those of ordinary skill to be inclusive of the stated value and has the meaning dictated by the context (e.g., the term includes at least the degree of error associated with the measurement accuracy, tolerances [e.g., manufacturing, assembly, use, etc.] associated with the particular value, etc.). Such terminology should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4”. The relative terminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10%) of an indicated value.
It should be understood that although certain drawings illustrate hardware and software located within particular devices, these depictions are for illustrative purposes only. Functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. In some embodiments, the illustrated components may be combined or divided into separate software, firmware and/or hardware. For example, instead of being located within and performed by a single electronic processor, logic and processing may be distributed among multiple electronic processors. Regardless of how they are combined or divided, hardware and software components may be located on the same computing device or may be distributed among different computing devices connected by one or more networks or other suitable communication links. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not explicitly listed.
Accordingly, in the claims, if an apparatus, method, or system is claimed, for example, as including a controller, control unit, electronic processor, computing device, logic element, module, memory module, communication channel or network, or other element configured in a certain manner, for example, to perform multiple functions, the claim or claim element should be interpreted as meaning one or more of such elements where any one of the one or more elements is configured as claimed, for example, to make any one or more of the recited multiple functions, such that the one or more elements, as a set, perform the multiple functions collectively.
Other aspects of the embodiments will become apparent by consideration of the detailed description and accompanying drawings.
This disclosure relates to maintaining thermal information of a power tool during a power off event. Embodiments of the present disclosure recognize that maintaining thermal information of a power tool can be achieved with an onboard battery (e.g., a coin cell) and a thermistor for components of the power tool where a temperature is modelled or an overload is added. A coin cell may be employed to provide power to store thermal information when a main battery pack of a power tool is removed from the power tool. However, various embodiments of the present disclosure recognize that challenges exist with initializing thermal overloads because the power tool loses ability to continue to model once the battery pack is removed. Thus, the models would produce inaccurate temperatures due to using initial conditions that fail to consider the cooling factor of the power tool when the battery pack is reconnected. Embodiments of the present disclosure solve these challenges with the use of a circuit (e.g., a resistor-capacitor [“RC”] circuit) that allows the power tool to store thermal information (e.g., temperature starting points) as a voltage of a capacitor of the RC circuit without use of an onboard battery cell. The circuit can also take a cooling factor of the power tool into consideration. Additionally, embodiments disclosed herein prevent a user from circumventing thermal protections of the power tool by merely power cycling the power tool.
In some embodiments, the present disclosure can be implemented in a power tool.
With reference to
In some constructions, the battery pack 38 and the motor 22 can be configured as an 18 Volt high power battery pack and motor, such as the 18 Volt high power system disclosed in U.S. Pat. No. 11,476,527, issued on Oct. 18, 2022, the entirety of which is incorporated herein by reference. In other constructions, the battery pack 38 and the motor 22 can be configured as an 80 Volt high power battery pack and motor, such as the 80 Volt battery pack and motor disclosed in U.S. Pat. No. 11,652,437, issued on May 16, 2023, the entirety of which is incorporated herein by reference. In such a battery pack 38, the battery cells within the battery pack 38 have a nominal voltage of up to about 80 V. Further, in another embodiment, the battery cells within the battery pack 38 have a nominal voltage of up to about 120 V. In some embodiments, the battery pack 38 has a weight of up to about 6 lb. In some embodiments, each of the battery cells has a diameter of up to 21 mm and a length of up to about 71 mm. In some embodiments, the battery cells within the battery pack 38 are cylindrical battery cells, prismatic battery cells, pouch battery cells, or a combination thereof. In some embodiments, the battery pack 38 includes up to twenty battery cells. In other embodiments, the battery pack 38 includes up to thirty battery cells, up to forty battery cells, up to forty-five battery cells, or greater. In some embodiments, the battery cells are disposed in a single battery pack. In other embodiments, the battery cells are disposed in multiple packs, i.e., two packs, three packs, four packs, etc. In some embodiments, the battery cells are connected in series. In some embodiments, the battery cells are operable to output a sustained operating discharge current of between about 20 A and about 140 A, for example, about 40 A and about 60 A. In some embodiments, each of the battery cells has a capacity of between about 1.7 Ah and about 15.0 Ah. And, in some embodiments of the motor 22 when used with the 80 Volt battery pack 38, the motor 22 has a power output of at least about 2760 W and a nominal outer diameter (measured at the stator) of up to about 80 mm, up to about 100 mm, up to about 120 mm, up to about 140 mm, or greater.
With reference to
With continued reference to
With continued reference to
In other embodiments, the power tool 10 is a different type of power tool. For example, the power tool 10 may be an impact wrench, a ratchet, a saw, a hammer drill, an impact driver, a rotary hammer, a grinder, a blower, a trimmer, etc. In this example, the power tool 10 may also be associated with a class of power tools, such as, vacuums, string trimmers, blowers, drills, saws, lights, power edgers, general trimmers, chainsaws, table saws, miter saws, reciprocating saws, powered sprayers, air compressors, outdoor power equipment, etc. In some embodiments, the power tool 10 is a power supply device or power source that receives one or more battery packs 38.
Referring to
In some embodiments, the controller 400 includes a plurality of electrical and electronic components that provide power, operational control, and protection to the components and modules within the controller 400 and/or the power tool 10. For example, the controller 400 includes, among other things, a processing unit 455 (e.g., a microprocessor, a microcontroller, an electronic processor, an electronic controller, or another suitable programmable device), a memory 460, input units 465, and output units 470. The processing unit 455 includes, among other things, a control unit 475, an arithmetic logic unit (“ALU”) 480, and a plurality of registers 485 (shown as a group of registers in
The memory 460 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 the data storage area can include combinations of different types of memory, such as a ROM, a RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, a hard disk, SSD, an SD card, or other suitable magnetic, optical, physical, or electronic memory devices. The processing unit 455 is connected to the memory 460 and executes software instructions that are capable of being stored in a RAM of the memory 460 (e.g., during execution), a ROM of the memory 460 (e.g., on a generally permanent basis), or another non-transitory computer readable medium such as another memory or a disc. Software included in the implementation of the power tool 10 can be stored in the memory 460 of the controller 400. The software includes, for example, firmware, one or more applications, program data, filters, models, rules, one or more program modules, and other executable instructions. The controller 400 is configured to retrieve from the memory 460 and execute, among other things, instructions related to the control processes and methods described herein. In other constructions, the controller 400 includes additional, fewer, or different components.
The battery pack interface 210 includes a combination of mechanical components (e.g., rails, grooves, latches, etc.) and electrical components (e.g., one or more terminals) configured to and operable for interfacing (e.g., mechanically, electrically, and communicatively connecting) the power tool 10 with a battery pack (e.g., battery pack 38, 200). For example, power provided by the battery pack to the power tool 10 is provided through the battery pack interface 210 to the power input module 440. The power input module 440 includes combinations of active and passive components to regulate or control the power received from the battery pack prior to power being provided to the controller 400. The battery pack interface 210 also supplies power to the PWM drivers 450 to selectively provide power to the motor 405. The battery pack interface 210 also includes, for example, a communication line 495 to provide a communication line or link between the controller 400 and the battery pack.
The circuitry 410 is an electrical circuit, including a combination of electrical components (e.g., passive component devices, resistors, capacitors) configured to and operable for storing power information (e.g., thermal information) received from the controller 400. In some embodiments, the circuitry 410 includes a resistor-capacitor (“RC”) circuit. The RC circuit includes resistors and capacitors, and is operable by a power source (e.g., current source or voltage source). An RC time constant of the RC circuit is measured in seconds and is equal to the product of the circuit resistance (in ohms) and the circuit capacitance (in farads). The capacitor stores energy, and the resistor of the RC circuit controls a rate of charging and discharging of the capacitor. The rate of charging of the capacitor of the RC circuit from an initial charge voltage of zero to a defined value (e.g., approximately 63.2% of the value of an applied DC voltage) or the rate of discharging of the capacitor of the RC circuit through the same resistor to a defined value (e.g., approximately 36.8% of its initial charge voltage) is based on an RC time constant of the RC circuit.
In some embodiments, the resistor-capacitor (“RC”) circuit includes a circuit arrangement, for example, as depicted in
The indicators 430 include one or more visual, audio or haptic feedback devices to provide feedback to a user as to the status of the power tool 10. For example, indicators 430 can include one or more light-emitting diodes (“LEDs”). The indicators 430 can be configured to display conditions of, or information associated with, the power tool 10. For example, the indicators 430 are configured to indicate measured electrical characteristics of the power tool 10, a temperature of the power tool 10, etc. The user input module 435 is operably coupled to the controller 400 to, for example, select a forward mode of operation or a reverse mode of operation, a torque and/or speed setting for the power tool 10 (e.g., using torque and/or speed switches), etc. In some embodiments, the user input module 435 includes a combination of digital and analog input or output devices required to achieve a desired level of operation for the power tool 10, such as one or more knobs, one or more dials, one or more switches, one or more buttons, one or more touch or pressure sensitive sensors, etc.
The controller 400 controls operation of the power tool 10 using the circuitry 410 and a temperature threshold of the power tool 10. The controller 400 applies a voltage, proportional to a temperature, as a percentage of defined temperature to the circuitry 410 during operation of the power tool 10. The controller 400 is configured to determine a temperature of the power tool 10 using a stored voltage of the circuitry 410. Although the controller 400 is illustrated in
In some embodiments, the controller 400 disables operation of the power tool 10, when the controller 400 determines that the temperature of the power tool 10 exceeds the temperature threshold. The controller 400 disables the power tool 10 to prevent damage to components due to an overload indicated by the temperature threshold being exceeded. For example, the controller 400 utilizes a temperature threshold and a temperature of the power tool 10 to control a thermal overload switch (e.g., a FET, a relay, etc.) connected to the motor 405.
In some embodiments, the controller 400 determines a temperature of the power tool 10 based on a voltage of the capacitor of the RC circuit included in the circuitry 410 when the controller 400 is powered on after a power off event ends, for example, as depicted in
In some embodiments, the voltage of the capacitor of the RC circuit is proportional to a temperature of power tool 10 and a voltage decay rate (e.g., discharge rate) of the capacitor corresponds with a cooling off rate of the power tool 10. For prior power tools, thermal information (e.g., initial temperature condition) is lost during a power off event due to an onboard battery of the power tool 10 failing to power the controller 400. For such power tools, the voltage of the capacitor can provide an updated condition (e.g., a current temperature condition) of the power tool 10, and the controller 400 is configured to determine the temperature of the power tool 10 based on the voltage of the capacitor after the power off event ends.
In some embodiments, the controller 400 determines the temperature of the power tool 10 based on an initial voltage stored in the circuitry 410 and a model (e.g., Cauer thermal network) of a component of the power tool 10. The controller 400 receives a signal representative of a voltage of the capacitor of the RC circuit of the circuitry 410, sets initial starting points (e.g., temperature conditions) of the model based on the voltage, and adjusts or scales the voltage to the temperature determined using the model. The controller 400 estimates a temperature of the power tool 10 using the model and updates the voltage of the capacitor based on a state of the model. After a subsequent power off event ends, the controller 400 is configured to use the updated voltage of the capacitor to set a second set of starting points for the model.
In some embodiments, the controller 400 determines the temperature of the power tool 10 based on a voltage stored in the circuitry 410 and a current accumulator bucket fill. The controller 400 receives a signal representative of a current provided to the power tool 10. The controller 400 is configured to increment a voltage value of a bucket stored in memory 460 when the received current exceeds a current threshold. The voltage value of the bucket is proportional to a temperature of the power tool 10. The controller 400 is configured to enable an overload of the power tool 10 when the bucket is full.
In some embodiments, the controller 400 is configured to control a voltage applied to a capacitor of the circuitry 410 and determine a voltage of the capacitor of the circuitry 410, for example, as depicted in
In some embodiments, the controller 400 is configured to control a voltage applied to a capacitor of the circuitry 410 and determine a voltage of the capacitor of the circuitry 410, for example, as depicted in
In some instances, the battery pack 200 is disconnected from the power tool 10 (STEP 915). In some embodiments, a power off event occurs and the battery pack 200 of the power tool 10 fails to provide a sufficient amount of power to operate the controller 400. In some instances, the battery pack 200 is reconnected to the power tool 10 (STEP 920). In some embodiments, a power off event ends and the battery pack 200 of the power tool 10 provides a sufficient amount of power to operate the controller 400.
The controller 400 reads a voltage of a capacitor of a RC circuit arrangement of the circuitry 410 (STEP 925). In some embodiments, the controller 400 determines a voltage of a capacitor of a RC circuit arrangement of the circuitry 410. In some embodiments, the controller 400 determines a voltage of a capacitor of a RC circuit arrangement of the circuitry 410 in response determining a power off event of the power tool 10 has ended.
The controller 400 controls the power tool 10 based on the voltage of the capacitor of the RC circuit arrangement of the circuitry 410 (STEP 930). In some embodiments, the controller 400 determines a temperature of the power tool 10 based on a voltage of a capacitor of a RC circuit arrangement of the circuitry 410 using the relationship between the voltage of the capacitor and the temperature of the power tool 10. The controller 400 compares the determined temperature of the power tool 10 to a temperature threshold. If, at STEP 930, the controller 400 determines that the determined temperature of the power tool 10 is greater than or equal to the temperature threshold, the controller 400 disables operation of the power tool 10. If, at STEP 930, the controller 400 determines that the determined temperature of the power tool 10 is less than the temperature threshold, the controller 400 continues to monitor/update the voltage of the capacitor of the RC circuit arrangement of the circuitry 410 during operation of the power tool 10.
The controller 400 then updates initial conditions of the model (STEP 1015). In some embodiments, the controller 400 sets an initial temperature (e.g., starting point) of the power tool 10 for the model and stores the initial temperature by applying the scaled voltage to the capacitor of the RC circuit arrangement of the circuitry 410. The controller 400 runs the model (STEP 1020). In some embodiments, the controller 400 runs the model to estimate a temperature of the power tool 10 during operation. The controller 400 then updates the voltage applied to the capacitor of the RC circuit arrangement of the circuitry 410 (STEP 1025). In some embodiments, the controller 400 continuously applies the scaled voltage to the capacitor of the RC circuit arrangement of the circuitry 410 during operation of the power tool 10. In some instances, the controller 400 can fail due to a power off event of the power tool 10, which can cause the model to operate with conditions that are inaccurate. In those instances, the controller 400 determines a voltage of the capacitor of the RC circuit arrangement of the circuitry 410 after the power off event of the power tool 10 ends and updates (i.e., sets another starting point) the initial conditions of the model based on a temperature proportional the voltage of the capacitor.
The controller 400 controls the power tool 10 based on a temperature of the power tool 10 provided by the model (STEP 1030). In some embodiments, the controller 400 determines a temperature of the power tool 10 based on the model of the power tool 10. The controller 400 compares the determined temperature of the power tool 10 to a temperature threshold. If, at STEP 1030, the controller 400 determines that the determined temperature of the power tool 10 is greater than or equal to the temperature threshold, the controller 400 disables operation of the power tool 10 (STEP 1035). If, at STEP 1030, the controller 400 determines that the determined temperature of the power tool 10 is less than the temperature threshold, the controller 400 continues to run the model and update the voltage of the capacitor of the RC circuit arrangement of the circuitry 410 during operation of the power tool 10.
Thus, embodiments described herein provide, among other things, devices, methods, and systems for maintaining thermal information of a power tool during a power off event. Various features and advantages are set forth in the following claims.
This application claims the benefit of U.S. Provisional Patent Application No. 63/580,082, filed Sep. 1, 2023, the entire content of which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63580082 | Sep 2023 | US |
