Control system for a constant-on power tool

Abstract

A control system for a normally open power tool is disclosed. The power tool includes a tool head and a power device for powering the tool head, and the control system includes a collection circuit and a control circuit. The collection circuit is in electrical communication with the power device and is configured to collect at least one parameter associated with the power device, and the control circuit is configured to place the power device in an operating mode with a first output power or in a standby mode with a second output power according to the at least one parameter. The control system according to one or more embodiments of the present application can save energy loss, reduce mechanical wear, increase the service life of the power tool, and enhance the operation convenience and safety.

Description

Technical Field

[0001] This invention relates to the field of battery-powered power tools, and more particularly to control systems for normally open power tools. Background Technology

[0002] Various battery-powered power tools exist. These tools can be powered by a power system, which in turn can be battery-powered. Typically, a switching device triggers the power tool, causing it to begin operation and consuming power or electricity. Control of the power tool is usually necessary. However, existing technologies often suffer from improper control, leading to unnecessary power consumption, mechanical wear and tear on the tool, and potential safety issues. Summary of the Invention

[0003] In view of one or more technical shortcomings of the prior art, the present invention provides a control system for power tools.

[0004] According to one aspect of the present invention, a control system for a power tool is provided. The power tool includes a tool head and a power unit for providing power to the tool head. The control system includes a data acquisition circuit and a control circuit. The data acquisition circuit is in electrical communication with the power unit and is used to acquire at least one parameter associated with the power unit. The control circuit, based on the at least one parameter, places the power unit in an operating mode with a first output power or a standby mode with a second output power.

[0005] Alternatively or additionally, the acquisition circuitry includes one or more of a current sensor, a voltage sensor, a power sensor, and a speed sensor, and at least one parameter includes one or more of the current, output power, and rotational speed of the power unit.

[0006] Alternatively or additionally, in operating mode, the current of the power unit is in the range of 8A to 50A, the output power is in the range of 230W to 1050W, and the speed is in the range of 30RPM to 45RPM.

[0007] Alternatively or additionally, in standby mode, the current of the power unit is in the range of 2A to 5A, the output power is in the range of 58W to 144W, and the speed is in the range of 15RPM to 25RPM.

[0008] Alternatively or additionally, the control system may also include a timing circuit configured to monitor a time value associated with at least one parameter, and the control circuit to place the power unit into an operating mode or a standby mode based on the at least one parameter and the time value.

[0009] Alternatively or additionally, the acquisition circuit is configured to continuously acquire at least one parameter of the power unit in operating mode, and intermittently acquire at least one parameter of the power unit in standby mode.

[0010] Alternatively or additionally, the control system is configured to detect at least one state of the power tool that is different from at least one parameter, and the control circuit is configured to switch the power tool from standby mode to working mode based on the at least one state.

[0011] Alternatively or additionally, the control system is configured to detect at least one state of the power tool, and the control circuit is configured to switch the power tool from standby mode to working mode based on the at least one state before at least one parameter changes.

[0012] Alternatively or additionally, the control system may also include a feed sensor configured to monitor whether material is entering the feed inlet of the power tool.

[0013] Alternatively or additionally, the control system may also include a load indicator for indicating the load capacity of the power tool.

[0014] Alternatively or additionally, the control system is configured such that the load indicator indicates low load capacity within a predetermined time period after the power unit begins to switch from standby mode to operating mode.

[0015] Alternatively or additionally, the control system is configured such that the load indicator indicates low load capacity for a predetermined period of time after the control system detects at least one state of the power tool.

[0016] Alternatively or additionally, the control system is configured to detect one or more of the following in the power tool's tool head: total number of revolutions, total mileage, total operating time, and the control circuit determines whether the tool head needs to be replaced based on the detection of the power tool's tool head.

[0017] Alternatively or additionally, the control system further includes an indicator circuit configured to indicate at least one state. Preferably, the control system further includes an alarm circuit configured to issue an alarm signal in one or more of the at least one state. The alarm signal is a visual signal, an audible signal, or a combination of both.

[0018] Alternatively or additionally, the power tool is a wood chipper.

[0019] The control system for normally open power tools according to one or more embodiments of the present invention has several advantages. For example, the control system according to one or more embodiments of the present invention can place the power tool in different operating modes according to the state parameters of the power tool, thereby saving power or electricity when the power tool is not needed, reducing unnecessary use and wear of the power tool, improving safety, and extending the service life of the power tool. For example, the control system according to one or more embodiments of the present invention can monitor the fault status of the power tool in a timely manner, thereby enabling timely response and improving operational convenience and safety.

[0020] Further embodiments of the present invention and its beneficial technical effects will be described in detail below. Attached Figure Description

[0021] Figure 1 A schematic diagram of a control system according to some embodiments of the present invention is shown.

[0022] Figure 2 A schematic diagram of a control system according to other embodiments of the present invention is shown.

[0023] Figure 3 A schematic diagram of a system for detecting voltage associated with a motor is shown according to some embodiments of the present invention.

[0024] Figures 4A-4B A schematic diagram of a control system including a detection circuit according to some other embodiments of the present invention is shown.

[0025] Figure 4C A schematic diagram of a control system including a load indicator is shown according to some embodiments of the present invention.

[0026] Figure 4D-4E A load indicator is shown according to some embodiments of the present invention.

[0027] Figure 5 A schematic diagram of a control system including a detection circuit, an indication circuit, and an alarm circuit according to some embodiments of the present invention is shown.

[0028] Figure 6A A schematic diagram of a wood chipper according to some embodiments of the present invention is shown.

[0029] Figure 6B Show Figure 6A A schematic diagram of the tool head of a wood chipper.

[0030] Figure 7 A flowchart illustrating a control method for a power tool according to some embodiments of the present invention is shown.

[0031] Figure 8A flowchart of a control method for a power tool according to some other embodiments of the present invention is shown, wherein the power tool is initially in a working mode.

[0032] Figure 9 A flowchart of a control method for a power tool according to further embodiments of the present invention is shown, wherein the power tool is initially in a standby mode.

[0033] Figure 10 A flowchart illustrating a control method for a power tool according to further embodiments of the present invention is shown. Detailed Implementation

[0034] To facilitate understanding of the present invention, several exemplary embodiments will be described below in conjunction with the accompanying drawings.

[0035] According to one aspect of the invention, Figure 1 A schematic diagram of a control system according to some embodiments of the present invention is shown.

[0036] Figure 1 A schematic diagram of a power tool 110 is shown. The power tool 110 can be used to operate on an object, thereby promoting labor savings. The power tool 110 is, for example, an electric tool or other suitable type of power tool. This invention primarily focuses on electric tools powered by batteries, but is equally applicable to power tools using other power sources (e.g., gasoline or AC power). Among the many power tools 110, there is a class of "normally open" power tools. A normally open power tool is one that remains operational as long as the user operates the actuation switch without requiring continuous operation of the actuation switch. Examples of such power tools include, for example, a wood chipper. In contrast, a non-normally open power tool requires the user to continuously operate the actuation switch to remain operational. This is often for safety reasons. Examples of such power tools include, for example, a hedge trimmer and a chainsaw.

[0037] In normally-operated power tools, although the tool remains operational, it is not always effectively outputting power. For example, with a wood chipper, the user may briefly leave without feeding branches for chipping. Maintaining full power output during this time would result in wasted electricity. For battery-powered normally-operated power tools, this means reduced working time. Therefore, the power tool of the present invention aims to avoid this waste of electricity and thereby extend the effective working time of the power tool.

[0038] like Figure 1As shown, the power tool 110 includes a tool head 120, a power unit 130, and a power supply unit 140. The tool head 120 is used to operate on the workpiece. In this document, the term "tool head" should be interpreted broadly. The tool head 120 may be, for example, a cutter, a drill bit, a nozzle, or other types of work attachments, which achieve the desired purpose by directly acting on the workpiece (e.g., branches, shrubs, flowers, soil, boards, etc.).

[0039] Power unit 130 provides power to tool head 120. Power unit 130 includes, for example, a motor, or a combination of a motor and its corresponding transmission and output mechanisms. Power supply unit 140 provides electricity to power unit 130. Power supply unit 140 is, for example, a battery pack. Power supply unit 140 can also be a DC power source or AC power grid electrically connected to power unit 130 via wired or wireless means.

[0040] The control system 150 communicates electrically with the power tool 110, for example, by connecting to the power tool 110 via wired or wireless means, thereby enabling the control of the power tool 110. The control system 150 may be mounted on the power tool 110 (e.g., mounted on a housing or located inside a housing), or it may be located independently of the power tool 110.

[0041] like Figure 1 For example, the control system 150 includes a data acquisition circuit 160 and a control circuit 170. The data acquisition circuit 160 is electrically connected to the power tool 110 and is used to acquire at least one parameter of the power tool 110. The control circuit 170 places the power tool 110 into a first mode or a second mode based on the acquired at least one parameter. The first mode, for example, has a first output power, and the second mode, for example, has a second output power. The first output power is different from the second output power.

[0042] The at least one parameter may be associated with, for example, the operating state of the power tool 110, which may include whether the power tool 110 is operating on an object. In some embodiments, the at least one parameter may be associated with the power unit 130, for example, indicating the operating state or load state of the power unit 130. The at least one parameter may include, for example, one or more of the current, output power, and rotational speed of the power unit 130.

[0043] In many cases, the operating state of a power tool is associated with (e.g., consistent with) the operating state of a power unit. For example, the no-load state of a power unit also implies the no-load state of the power tool. Therefore, in many cases, the expression "at least one parameter of the power tool" and "at least one parameter of the power unit" have the same meaning. In some cases, "at least one parameter of the power tool" may have a broader meaning, that is, it may refer to a parameter associated with other components of the power tool. In many cases, the term "mode of the power tool" or similar terms are used interchangeably with the term "mode of the power unit" or similar terms.

[0044] The first mode is, for example, a working mode, and the second mode is, for example, a standby mode. For instance, when at least one collected parameter indicates that the power tool 110 or power unit 130 is under no-load or low-load conditions, the control circuit 170 can place the power tool 110 or power unit 130 into a standby mode. In standby mode, the power unit 130 is in a second state, in which the current drawn by the power unit is significantly reduced, and the rotational speed and output power are also significantly reduced. In some embodiments, in the second state, the current drawn by the power unit 130, the output power, and the rotational speed are all reduced to zero. Therefore, standby mode can significantly save power consumption. Furthermore, it reduces mechanical wear or damage to the power unit 130, which is beneficial for extending the service life of the power unit. Simultaneously, it increases safety, preventing unnecessary operation of the power unit 130 from causing accidental injury to personnel.

[0045] When at least one acquired parameter indicates an increase in the load on the power tool 110 or power unit 130, the control circuit 170 can wake up the power tool 110 or power unit 130 and place it into operating mode. In operating mode, the power unit 130 is in a first state in which the current drawn by the power unit, the rotational speed, and the output power are significantly increased. This allows the desired power to be supplied to the tool head 120 to act on the workpiece.

[0046] In some embodiments, the power tool may be, for example, a wood chipper, and the power unit may include, for example, an electric motor. In operating mode, the motor draws current in the range of 8A to 50A, such as 8A, 10A, 15A, 20A, 25A, 30A, 40A, 45A, or 50A, and has an output power in the range of 230W to 1050W, such as 230W, 300W, 400W, 500W, 600W, 700W, 760W, 800W, 950W, or 1050W, and has a rotational speed in the range of 30RPM to 45RPM, such as 30RPM, 35RPM, 40RPM, or 45RPM. In standby mode, the motor draws current from 2A to 5A, for example, 2A, 2.5A, 3A, 3.5A, 4A, 4.5A, or 5A; the output power ranges from 58W to 144W, for example, 58W, 65W, 75W, 90W, 100W, 110W, 120W, 130W, or 144W; and the speed ranges from 15RPM to 25RPM, for example, 15RPM, 18RPM, 20RPM, 23RPM, or 25RPM. It is evident that switching the power tool to standby mode when it is not needed can significantly save power consumption. Furthermore, those skilled in the art should understand that these values ​​are illustrative, and the corresponding value ranges may differ for different types of power tools. Even for the same type of power tool, it may be designed for different types of objects being handled (for example, a shredder for branches of different thicknesses), and therefore the corresponding value ranges may also differ.

[0047] The acquisition circuit 160 can continuously acquire at least one parameter of the power tool 110, or it can acquire parameters intermittently. In some embodiments, in operating mode, the acquisition circuit 160 continuously acquires at least one parameter of the power unit 130, while in standby mode, the acquisition circuit 160 intermittently (e.g., periodically) acquires at least one parameter of the power unit 130. In operating mode, the power unit consumes a large amount of energy (e.g., electricity), so continuous or real-time acquisition allows for timely (e.g., immediate) switching of the power unit to standby mode when no work is required. In standby mode, energy consumption is low, and for typical scenarios, a short wake-up delay (e.g., a few hundred millimeters, 1-5 seconds, etc.) is acceptable and will not have a significant impact; therefore, intermittent parameter acquisition can be used. Parameter acquisition itself consumes energy, so this setup further reduces energy consumption.

[0048] Figure 2 Schematic diagrams of control systems according to other embodiments of the present invention are shown. For the sake of brevity, Figure 2 The entire power tool was not illustrated. Figure 2In this context, the power unit of the power tool is exemplified as a motor 230. The motor 230 can be, for example, a... Figure 1 One specific embodiment of the power unit 130.

[0049] The acquisition circuit 260 includes at least one of a current sensor 262, a power sensor 264, a speed sensor 266, and a voltage sensor 268. This is only for illustrative purposes; in some embodiments, the acquisition circuit 260 may include fewer or more sensors, for example, it may include more other types of sensors. In this document, the term "sensor" should be interpreted broadly as a discrete electronic device or a circuit module composed of multiple electronic devices configured appropriately to perform the purpose of detecting, sensing, detecting, acquiring, or collecting one or more physical parameters.

[0050] The acquisition circuit 260 communicates electrically with the motor 230 to acquire one or more parameters associated with the motor 230, thereby directly or indirectly indicating the state of the motor 230, such as load status. For example, a current sensor 262 can be used to acquire the current flowing through the motor 230. A power sensor 264 can be used to acquire the output power of the motor 230 (e.g., the power output to a tool head). A speed sensor 266 can be used to acquire the rotational speed of the motor 230. A voltage sensor 268 can be used to acquire the voltage associated with the motor 230.

[0051] The control circuit 270 receives one or more parameters acquired by the acquisition circuit 260, and then determines, based on these parameters, whether to place the motor 230 in a first mode (e.g., operating mode) or a second mode (e.g., standby mode). For example, in some embodiments, the motor 230 automatically enters standby mode when a first condition is met, and automatically wakes up from standby mode when a second condition is met. The first and second conditions can be set according to actual needs, and their meaning will become clearer to those skilled in the art after reading one or more examples below.

[0052] For example, control circuit 270 analyzes the collected parameters to determine the load state of motor 230, such as no-load or low-load state, and normal-load or high-load state. If no-load or low-load, it indicates that there is no work to be done and motor operation is not expected. If normal-load or high-load, it indicates that motor operation is expected to provide power to the tool head to handle the work. When no-load or low-load is indicated, control circuit 270 can keep motor 230 in standby mode or switch it from operating mode to standby mode. When normal-load or high-load is indicated, control circuit 270 can keep motor 230 in operating mode or wake it up from standby mode.

[0053] In some embodiments, the control circuit 270 can obtain an indication of the motor load state by comparing parameter values ​​with corresponding parameter thresholds. For example, when the current drawn by the motor 230 is equal to or lower than a first current threshold, it can indicate an no-load or low-load state. When the current drawn by the motor 230 is greater than a second current threshold, it can indicate a normal load or high-load state. The first and second current thresholds can be different. As another example, when the output power of the motor 230 is equal to or lower than a first power threshold, it can indicate an no-load or low-load state. When the output power of the motor 230 is greater than a second power threshold, it can indicate a normal load or high-load state. The first and second power thresholds can be different. Yet another example, when the rotational speed of the motor 230 is equal to or greater than a first rotational speed threshold, it can indicate an no-load or low-load state. When the rotational speed of the motor 230 is lower than a second rotational speed threshold, it can indicate a normal load or high-load state. The first and second rotational speed thresholds can be different. Still another example, when the voltage associated with the motor 230 is equal to or lower than a first voltage threshold, it can indicate an no-load or low-load state. When the voltage associated with motor 230 is greater than a second voltage threshold, it can indicate a normal load or high load condition. The first voltage threshold and the second voltage threshold can be different.

[0054] In some embodiments, to further improve the accuracy of the determination, it can be based on a combination of at least two parameters, such as a comparison of current with a current threshold and a comparison of output power with a power threshold. For example, an no-load or low-load state is indicated only when the current drawn by motor 230 is equal to or lower than the current threshold, and simultaneously the output power of motor 230 is equal to or lower than the power threshold. This combination can also be a combination of two, three, four, or more of current, output power, speed, voltage, or other suitable parameters.

[0055] These parameter thresholds, such as current threshold, voltage threshold, power threshold, and speed threshold, can be preset according to actual needs. These parameter thresholds may differ for different types of power tools and power devices. For example, even for the same type of power tool, different motor models may require different parameter thresholds. Specific parameter thresholds will be illustrated in the following example concerning a wood chipper. According to certain embodiments, in... Figure 2 In this embodiment, the control system also illustratively includes a timing circuit 280. The timing circuit 280 is in electrical communication with the acquisition circuit 260 and the control circuit 270 for detecting or monitoring a time value related to at least one parameter associated with the motor 230. The time value indicates the duration for which the at least one parameter continuously meets certain conditions, such as the duration for which the parameter maintains a parameter value or remains within a numerical range.

[0056] For example, a time value is the duration for which the current drawn by motor 230 continuously meets or falls below a current threshold (condition A). A time value is the duration for which the output power of motor 230 continuously meets or falls below a power threshold (condition B). A time value is the duration for which the rotational speed of motor 230 continuously meets or falls above a rotational speed threshold (condition C). A time value is the duration for which the voltage associated with motor 230 continuously meets or falls below a voltage threshold (condition D).

[0057] In some embodiments, the time value is, for example, the time when any two of conditions A, B, C, and D are satisfied simultaneously, the time when any three of the conditions are satisfied simultaneously, or the time when all four conditions are satisfied simultaneously.

[0058] The control circuit 270 compares the time value received from the timing circuit 280 with a time threshold. The time threshold is, for example, in the range of 1 second to 300 seconds, such as 1 second, 5 seconds, 10 seconds, 60 seconds, 180 seconds, 220 seconds, 280 seconds, or 300 seconds.

[0059] The control circuit 270 sets the motor 230 to a first mode or a second mode, or switches from one mode to another, based on at least one collected parameter and a time value. For example, the control circuit 270 will only keep the motor 230 in standby mode or switch it from operating mode to standby mode if the comparison between the at least one parameter value and the corresponding parameter threshold meets a specific preset condition and the time value is equal to or greater than the time threshold. Otherwise, it will switch to operating mode (if the current mode is standby mode) or continue to operate mode (if the current mode is operating mode) depending on the current mode of the motor 230.

[0060] During the operation of power tools, temporary no-load or low-load states may occur due to various reasons, such as the unevenness or discontinuity of the workpiece, operator interruptions (e.g., stopping to talk to others, light a cigarette), or other reasons. In such cases, the control system may, based on its judgment, place the power tool or power unit into standby mode, which is undesirable.

[0061] When a power tool or power unit is in standby mode, the operator or other personnel may accidentally touch the power unit, such as by accidentally touching the tool head or even moving or rotating it. If the control system determines that this indicates an increased load and switches the power tool to working mode, a hazard may occur.

[0062] Therefore, it is advantageous for the control system to include a timing circuit, which can more accurately place the power tool or power unit in the desired mode, avoiding or reducing unwanted mode switching, such as avoiding or reducing the unwanted situations exemplified above. This can further improve operational accuracy, convenience, and safety.

[0063] Figure 3 A schematic diagram of a system for detecting voltage associated with a motor is shown according to some embodiments of the present invention. Figure 3 Examples include motor 330, resistor 369, control circuit 370, and voltage sensor 368. Motor 330, control circuit 370, and voltage sensor 368 can, for example, correspond to... Figure 2 The motor 230, control circuit 270, and voltage sensor 268 shown are corresponding specific embodiments.

[0064] like Figure 3 For example, resistor 369 is connected in series with motor 330, so the current flowing through them is the same. When motor 330 is unloaded or under low load, the current drawn decreases, and therefore the voltage across resistor 369 decreases accordingly. Thus, by detecting the voltage across resistor 369 using voltage sensor 368, the load status of motor 330 can be indirectly indicated.

[0065] For example, when the terminal voltage of resistor 369 is equal to or less than a preset voltage threshold, it can indicate that motor 330 is in an unloaded or low-load state. For example, when the terminal voltage of resistor 369 is equal to or less than a preset voltage threshold for a time threshold (e.g., 1 second, 5 seconds, 10 seconds, 60 seconds, 180 seconds, 220 seconds, 280 seconds, or 300 seconds), it can indicate that motor 330 is in an unloaded or low-load state.

[0066] In some cases, adopt Figure 3 The illustrated resistor is advantageous for load condition indication. It eliminates the need for direct monitoring of the motor. The resistor can be installed separately from the motor 330. This is desirable in certain situations. For example, the space around the motor may be very limited, making monitoring difficult; thus, the resistor can be placed in another available space, providing convenience. Furthermore, the flexibility of selecting a wide range of resistance values ​​(e.g., 200 ohms to 10,000 ohms, 500 ohms to 2,000 ohms, 1,000 ohms to 100,000 ohms, etc.) to meet practical needs is also desirable.

[0067] Figures 4A-4B A schematic diagram of a control system including a detection circuit according to some other embodiments of the present invention is shown. Figure 4A The control circuit 470 is illustrated. The control circuit 470 could be, for example, a... Figure 1 The control circuit 170 shown, or Figure 2 The control circuit 270 shown, or Figure 3 One or more of the control circuits 370 shown are implemented in a specific way.

[0068] As illustrated, detection circuit 480 is electrically connected to control circuit 470. Detection circuit 480 communicates electrically with one or more other components of the power tool or with a device for monitoring one or more components (such as a monitoring circuit like a sensor) to detect or monitor at least one state of the power tool.

[0069] Furthermore, the inventors recognized that a blockage may occur when a power tool or device resumes operation from standby mode. This is because the resumption of operation from standby mode requires a process, during which the motor output gradually recovers from zero or low power to normal power. However, the increase in load may be faster than this process. Therefore, a blockage may occur when the motor output cannot match the load.

[0070] Therefore, the present invention envisions the ability to anticipate increases in load and proactively restore a power tool or power unit from standby mode to operating mode to avoid blockages. For example, in some embodiments, the control system also detects at least one state of the power tool that differs from at least one parameter (e.g., current, output power, speed, etc.) exemplified above, and the control circuit switches the power tool from standby mode to operating mode, or vice versa, based on this at least one state. This at least one state is, for example, associated with feeding the power tool. This at least one state, for example, indicates feeding the power tool.

[0071] In some embodiments, the control system detects at least one state of the power tool, and the control circuitry is configured to switch the power tool from a standby mode to an operating mode based on the at least one state before at least one parameter changes. For example, the at least one state may be associated with feeding the power tool. The at least one state may indicate feeding the power tool. The at least one parameter may be one or more of the parameters exemplified above, such as the current, output power, and rotational speed of the power unit (e.g., a motor). For example, in some embodiments, when material is detected entering the power tool, the control system causes the power tool to switch from a standby mode to an operating mode before the at least one parameter changes.

[0072] For example, in Figure 4BIn the example shown, the detection circuit 480 further includes a feed sensor 482 for sensing material entering the power tool. In some embodiments, the power tool includes a feeding device through which the material to be processed enters the interior of the power tool for processing. The power tool of the present invention may include a feed sensor 482 coupled to the feeding device. The feed sensor 482 may be one or more sensors for sensing when material passes through the feeding device. The one or more sensors are electrically connected to or configured as part of the detection circuit 480, so that once material is detected entering the feeding device, the detection circuit 480 communicates with the control circuit 470, causing the control circuit 470 to control the power tool to quickly resume from standby mode to operating mode. In some embodiments, the feed sensor 482 is, for example, a light sensor (e.g., an infrared sensor, a microwave sensor, etc.), an electromagnetic field sensor, etc. For example, in some embodiments, an infrared sensor is placed near the feed inlet of the power tool. When material such as a twig enters the feed inlet, the infrared sensor can sense the entry of the material and generate a sensing signal. Based on this sensing signal, the control circuit can quickly wake up the power tool.

[0073] In some embodiments, the detection circuit 480 can be used to detect whether the tool head needs to be replaced, whether the power tool is blocked, overloaded, overcurrent, overheated, tilted, or whether the remaining power of the power supply (e.g., battery pack) is too low. The control circuit 470 receives these status signals and processes and judges them. For example, for each status parameter, a corresponding status threshold can be preset. The control circuit 470 can compare the received status parameter with the corresponding status threshold to determine the corresponding status and instruct to take appropriate actions, such as replacing the tool head, clearing the blockage, powering off, or charging the battery pack, etc.

[0074] In some embodiments, such as Figure 4C As illustrated, the control system also includes a load indicator 490. The control circuit 470 can determine the load condition based on information acquired by the acquisition circuit 460 and indicate the load capacity of the power tool via the load indicator 490. For example, the load indicator 490 can be set independently or integrated into the user interface of the power tool. For example, the load indicator 490 can be configured as a device capable of providing visual indication, such as an LCD or LED. In some embodiments, the load indicator 490 indicates the load capacity based on the current drawn by the power unit (e.g., a motor) of the power tool.

[0075] Figure 4D An example of a user interface is shown. For example, such as... Figure 4DAs shown, the load indicator 490 is exemplified as an LED device 492 (e.g., an LED bar indicator). If the motor current is low, for example less than 5A, the LED device 492 displays red, indicating a low load capacity, and the operator should not add more material to the power tool. If the motor current is high, for example greater than 8A, the LED device 492 displays green, indicating a high load capacity, and the operator can add more material to the power tool.

[0076] In some embodiments, the load indicator indicates low load capacity within a predetermined time period after the power unit switches from standby mode to operating mode. In other embodiments, the load indicator indicates low load capacity within a predetermined time period after the control system detects at least one state of the power tool (e.g., material entering). This prevents the operator from starting to feed excessive material into the power tool before it is fully started, which could cause blockages or damage to the power tool.

[0077] For example, when the power tool 110 is in standby mode, or in the process of switching from standby mode to working mode, the LED device 492 always displays red to remind the operator not to add too much material to the power tool. Only when the power tool 110 switches to working mode does the LED device 492 display green to remind the operator that it is safe to add material at this time.

[0078] Including load indication functionality in the control system is advantageous. For example, this can effectively prevent or mitigate load blockages in power tools. For instance, when the power tool is in standby mode, an LED displays red, informing the operator that further material filling is not expected. When the power tool wakes up from standby to operating mode, the LED will remain red for a period of time (e.g., 1 second, 5 seconds, or 10 seconds) until the power tool reaches or is close to its full load capacity. The operator then knows, based on the LED indication, that material filling is possible. This prevents the operator from filling material when the power tool's load capacity is insufficient, thus avoiding tool blockages.

[0079] LED device 492 is merely for illustrative purposes of load indicator 490. Depending on actual needs, load indicator 490 can take various forms. For example, in Figure 4EIn this embodiment, the load indicator 497 includes five LED devices arranged side-by-side. These five LED devices can be configured into different pattern patterns to indicate load capacity as needed. For example, the load capacity can be indicated by the number of LED devices lit. For instance, all five LED devices lit indicates full load capacity, while all dimmed indicates zero load capacity. Alternatively, the five LED devices can be lit in different colors, with each LED device (i.e., each color) indicating a preset corresponding level of load capacity. Furthermore, different load capacities can correspond to different flashing patterns on the LED devices. Many other indication schemes are also possible.

[0080] Figure 5 A schematic diagram of a control system including a detection circuit, an indication circuit, and an alarm circuit according to some embodiments of the present invention is shown. As illustrated, the detection circuit 580 and the control circuit 570 may, for example, be respectively corresponding to... Figures 4A-4C A specific embodiment of the detection circuit 480 and control circuit 470 shown.

[0081] exist Figure 5 The control system further includes an indicator circuit 590 and an alarm circuit 592. The indicator circuit 590 indicates at least one state detected by the detection circuit 580, such as indicating that the tool head needs replacement, the power tool is overloaded, experiencing overcurrent, overheating, tilting to a certain angle, or the remaining battery charge is below a certain threshold. In some embodiments, the indicator circuit 590 also includes... Figure 4C-4E The illustrated load indicator is used to indicate the load capacity of a power tool.

[0082] Alarm circuit 592 is used to issue an alarm signal in one or more states of the state, such as a visual signal (color, color combination, flashing light), or an audio signal (the pitch, length, or combination of different sounds), or a combination of both. Figure 6A A schematic diagram of a wood chipper according to some embodiments of the present invention is shown. Figure 6B Show Figure 6A A schematic diagram of the tool head of a wood chipper. The illustrated wood chipper 600 can be... Figure 1 This is one specific embodiment of the power tool 110 shown. Other types of power tools are also possible.

[0083] As illustrated, the wood chipper 600 includes a first part 602 and a second part 604. The first part 602 is provided with a tool head (e.g., Figure 6BThe illustrated cutting tool 6024 and the motor (not shown) for driving the tool head are housed in the first part 602, and a battery pack for powering the motor is also provided on the housing. The second part 604 is illustrated as including a collection box. The material to be shredded, such as branches, enters the channel in the first part 602 through the feed inlet 6022, then reaches the cutting tool 6024, is shredded by the cutting tool, and the shredded material falls into the second part 604. Near the feed inlet 6022, a structure such as... Figure 4B The illustrated feed sensor is used to sense material, such as tree branches, entering the shredder 600. The feed sensor may be, for example, one or more infrared sensors, microwave sensors, electromagnetic field sensors, or combinations thereof.

[0084] The wood chipper 600 is equipped with a control system (not shown). The control system may be, for example, as described in the reference... Figures 1 to 5 One or more, or suitable combinations thereof, of the illustrated and described control systems. The control system is used to acquire at least one parameter associated with the wood chipper 600 (e.g., the motor of the wood chipper 600) and, based on the parameter, to place the wood chipper 600 (or its motor) into different modes, such as an operating mode or a standby mode, thereby saving power consumption, extending the service life of the wood chipper, improving operational safety, etc.

[0085] Figure 7 A flowchart illustrating a control method for controlling a power tool according to some embodiments of the present invention is shown. The control method may be as described above. Figures 1 to 5 One or more methods, or a combination of one or more methods, performed in one or more of the illustrated and described control systems.

[0086] In box 702, at least one parameter associated with the power tool is acquired. Taking a wood chipper as an example, this could be at least one parameter associated with the motor of the wood chipper, such as the current drawn by the motor, output power, speed, or the terminal voltage of a resistor associated with the motor.

[0087] In block 704, the power tool is placed in a first mode or a second mode based on at least one parameter. The first mode is, for example, a working mode, and the second mode is, for example, a standby mode. Taking a wood chipper as an example, the motor of the wood chipper is placed in either a working mode or a standby mode based on a comparison of at least one parameter associated with the motor of the wood chipper with a corresponding parameter threshold. In some embodiments, the time value for which the corresponding parameter continuously meets the corresponding condition is also detected, and the decision to place the motor of the wood chipper in either a working mode or a standby mode is made based on a comparison of the time value with a time threshold.

[0088] In existing technologies, for example, when unloaded, the operator typically shuts off the power supply to the power unit (e.g., the motor) and reconnects it when needed. This usually requires additional manpower and is inconvenient. Furthermore, due to limitations in human reaction speed, it is often not quick enough. Speed ​​is important in certain safety situations. According to... Figure 7 This method allows power tools to automatically switch between modes, for example, automatically putting the motor into standby mode when not in use and automatically waking it up when needed. This is advantageous and desirable in many ways.

[0089] Figure 8 A flowchart of a control method for a power tool according to some other embodiments of the present invention is shown, wherein the power tool is initially in a working mode.

[0090] For illustrative purposes only, Figure 8 Taking a wood chipper as an example, and merely illustrating mode switching based on the motor current of the wood chipper, those skilled in the art, especially with reference to the above description, should understand that other parameters associated with the motor, or combinations of one or more of these parameters, can also be used as the basis for mode switching. Furthermore, the ideas illustrated in this example can be applied to other or one other power tools.

[0091] exist Figure 8 In the initial phase, the motor is in operating mode. In box 802, the current I drawn by the motor is collected. In box 804, the current I is compared with a current threshold I0. The current threshold I0 is, for example, in the range of 8A to 50A, and is, for example, 8A, 10A, 20A, 30A, 40A, or 50A. If the current I is greater than the current threshold I0, the process proceeds to box 820, and the motor remains in operating mode.

[0092] If the current I is determined to be less than or equal to the current threshold I0 in box 804, then proceed to box 806 to monitor the time value t1 for which I <= I0 is continuously satisfied. In box 808, the time value t1 is compared with the time threshold t0, which is, for example, in the range of 1 second to 300 seconds, and t0 is, for example, 1 second, 10 seconds, 30 seconds, 60 seconds, 120 seconds, 200 seconds, 250 seconds, or 300 seconds. If t1 is less than t0, that is, the time for the current I to be less than or equal to the current threshold I0 is not long enough, this means that it may be due to load state disturbances or state noise generated during operation, rather than a true no-load or low-load state. Therefore, proceed to box 820, and the motor continues to remain in the operating mode.

[0093] If it is determined in box 808 that t1 is greater than or equal to t0, that is, the current I is less than or equal to the current threshold I0 for a long enough time, this usually means that the motor becomes an unloaded or low-load state. Then, proceed to box 810 to switch the motor to standby mode to save power.

[0094] Figure 9 A flowchart of a control method for a power tool according to further embodiments of the present invention is shown, wherein the power tool is initially in a standby mode.

[0095] For illustrative purposes only, Figure 9 Taking a wood chipper as an example, and merely illustrating mode switching based on the motor current of the wood chipper, those skilled in the art, especially with reference to the above description, should understand that other parameters associated with the motor, or combinations of one or more of these parameters, can also be used as the basis for mode switching. Furthermore, the ideas illustrated in this example can be applied to other or one other power tools.

[0096] exist Figure 9 In the initial setup, the motor is in standby mode. In box 902, the current I drawn by the motor is measured. In box 904, the current I is compared to a current threshold I0. The current threshold I0 is, for example, in the range of 2A to 5A, and is, for example, 3A. If the current I is less than or equal to the current threshold I0, the process proceeds to box 920, and the motor continues in standby mode.

[0097] If it is determined in box 904 that the current I is greater than the current threshold I0, then proceed to box 906 to monitor the time value t2 for which I > I0. In box 908, compare the time value t2 with the time threshold t0, where t0 is, for example, in the range of 0.1 to 1 second, and t0 is, for example, 0.5 seconds. If t2 is less than t0, that is, the time for the current I to be greater than the current threshold I0 is not long enough, this may mean that the load state disturbance or state noise generated during standby is not a true normal load or high load state, and therefore the motor does not need to work. Then proceed to box 920, and the motor continues to be in standby mode.

[0098] If it is determined in box 908 that t2 is greater than or equal to t0, that is, the current I is greater than the current threshold I0 for a long enough time, this usually means that the motor has entered a normal no-load or high-load state and needs to work. So, the process moves to box 910 to wake up the motor from standby mode and start working.

[0099] according to Figure 8 and 9 The example method incorporates the time the motor's state parameters remain in a certain state, thereby avoiding or reducing misjudgments and further increasing the accuracy and effectiveness of load state assessment. Furthermore, switching or maintaining between modes can be completed automatically without human intervention, offering operational convenience and speed.

[0100] Figure 10 A flowchart illustrating a control method for a power tool according to further embodiments of the present invention is shown.

[0101] For illustrative purposes only, Figure 10 Taking a wood chipper as an example, and merely illustrating the condition monitoring of the blades of a wood chipper. Those skilled in the art, especially with reference to the above description, should understand that the ideas illustrated in this example can be applied to monitoring one or more other conditions of a wood chipper. Furthermore, the ideas illustrated in this example can be applied to one or more other power tools.

[0102] In box 1002, the status parameters of the blades of the wood chipper are detected. These status parameters can indicate the blade's usage status, wear condition, etc. They can be, for example, the total number of blade rotations, total operating mileage, and total operating time. For instance, the control system may include a circuit module for recording or calculating the total number of blade rotations, total operating mileage, and total operating time since the blade's first use. The total operating mileage is, for example, the total number of rotations multiplied by the length of one rotation of the blade. The status parameters can be compared with corresponding preset parameter thresholds. For example, when the total number of rotations exceeds the total number of rotations threshold (e.g., 10 million rotations), it can indicate that the blades need to be replaced.

[0103] In some embodiments, to more accurately indicate when a tool needs to be replaced, the driving voltage, current, power, etc., during tool use can be considered. For example, in some embodiments, an appropriate function F can be constructed, which is a function of one or more of the following: total revolutions, total operating mileage, total operating time, driving power, voltage, current, etc. The value of function F is then calculated and compared with a function threshold F0. When F reaches F0, it indicates that the tool needs to be replaced.

[0104] In box 1004, determine whether the tool needs to be replaced. The determination can be based on, for example, the criteria described above, or other suitable benchmarks. If the tool does not need replacement, return to box 1002 to continue monitoring the tool. If the tool needs replacement, proceed to box 1006 to indicate the status and issue an alarm. For example, an audible alarm may be issued to prompt the operator to replace the tool. Then proceed to box 1008 to replace the tool.

[0105] In some embodiments, the detection stops when it is determined in block 1004 that the tool does not need to be replaced. Instead, the detection is restarted after a certain period of time, such as one month. Furthermore, Figure 10 Some of the steps shown are merely optional or additional; for example, in some embodiments, the wear condition of the tool is merely indicated without issuing an alarm.

[0106] It will be understood by those skilled in the art that the embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0107] Furthermore, a single drawing may depict multiple elements. It will be understood by those skilled in the art that this is for simplicity only and does not imply that every element is necessary. It will also be understood by those skilled in the art that one or more elements in the same drawing may be alternative or additional elements.

[0108] Those skilled in the art should also understand that the above embodiments attempt to illustrate one or more ideas of the present invention from different aspects, and they are not isolated; rather, those skilled in the art can appropriately combine different embodiments based on the above examples to obtain other technical solution examples.

[0109] Unless otherwise specified, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Embodiments of the invention are illustrated in non-limiting examples. Various modifications that may be conceived by those skilled in the art based on the disclosed embodiments fall within the scope of this invention.

Claims

1. A control system for a normally open power tool, the power tool comprising a tool head and a power unit for providing power to the tool head, characterized in that, The control system includes: The acquisition circuit is configured to electrically communicate with the power unit and to acquire at least one parameter associated with the power unit; and the control circuit is configured to place the power unit in an operating mode with a first output power or a standby mode with a second output power according to the at least one parameter; wherein the acquisition circuit is configured to continuously acquire the at least one parameter of the power unit in the operating mode and intermittently acquire the at least one parameter of the power unit in the standby mode.

2. The control system according to claim 1, characterized in that, The acquisition circuit includes one or more of a current sensor, a voltage sensor, a power sensor, and a speed sensor, and the at least one parameter includes one or more of the current, output power, and rotational speed of the power unit.

3. The control system according to claim 2, characterized in that, In the operating mode, the current of the power unit is in the range of 8A to 50A, the output power is in the range of 230W to 1050W, and the speed is in the range of 30RPM to 45RPM.

4. The control system according to claim 2, characterized in that, In the standby mode, the current of the power unit is in the range of 2A to 5A, the output power is in the range of 58W to 144W, and the speed is in the range of 15RPM to 25RPM.

5. The control system according to claim 1, characterized in that, The control system further includes a timing circuit configured to monitor a time value associated with the at least one parameter, and the control circuit sets the power unit to the operating mode or the standby mode based on the at least one parameter and the time value.

6. The control system according to claim 1, characterized in that, The control system is configured to detect at least one state of the power tool that is different from the at least one parameter, and the control circuit is configured to switch the power tool from the standby mode to the working mode based on the at least one state.

7. The control system according to claim 1, characterized in that, The control system is configured to detect at least one state of the power tool, and the control circuit is configured to switch the power tool from the standby mode to the working mode based on the at least one state before the at least one parameter changes.

8. The control system according to claim 1, characterized in that, The control system also includes a feed sensor configured to monitor whether material is entering the feed inlet of the power tool.

9. The control system according to claim 1, characterized in that, The control system also includes a load indicator for indicating the load capacity of the power tool.

10. The control system according to claim 9, characterized in that, The control system is configured such that the load indicator indicates low load capacity during a predetermined period of time when the power unit switches from standby mode to operating mode.

11. The control system according to claim 9, characterized in that, The control system is configured such that the load indicator indicates low load capacity for a predetermined period of time after the control system detects at least one state of the power tool.

12. The control system according to claim 1, characterized in that, The control system is configured to detect one or more of the following items of the tool head of the power tool: total number of revolutions, total mileage, and total operating time; and the control circuit determines whether the tool head needs to be replaced based on the detection of the tool head of the power tool.

13. The control system according to claim 12, characterized in that, The control system further includes an indicator circuit configured to indicate at least one state of the power tool.

14. The control system according to claim 13, characterized in that, The control system further includes an alarm circuit configured to issue an alarm signal in one or more of the at least one state, the alarm signal being a visual signal, an audio signal, or a combination of both.

15. The control system according to any one of claims 1 to 14, characterized in that, The power tool mentioned is a wood chipper.

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