Method for operating an electrically powered tool and electrically powered tool

Abstract

The invention relates to a method for operating an electrically operated tool (100) comprising a handle component (110) and a tool component (120), wherein the handle component (110) comprises an operating element (116) and a handle component control unit (112), and wherein the tool component (120) comprises a drive (124), a tool element (126) and a tool component control unit (122), the method comprising: during actuation of the operating element (116), causing the tool component control unit (122) to actuate the drive (124) to actuate the tool element (126) according to a predetermined operating strategy (230);Upon termination of the actuation of the control element (116) and / or upon the occurrence of an error, the tool component control unit (122) is instructed by the handle component control unit (112) to actuate the drive (124) to actuate the tool element (126) according to a predefined shutdown strategy (240).

Description

[0001] The present invention relates to a method for operating an electrically powered tool, a computing unit and a computer program for carrying it out, as well as such an electrically powered tool and components therefor. Background of the invention

[0002] Besides purely mechanical tools, especially hand tools such as tree shears or so-called pole pruners, there are also electrically operated tools such as so-called pole pruners with a shear, cutting blade or chainsaw unit. Disclosure of the invention

[0003] According to the invention, a method for operating an electrically powered tool, a computing unit and a computer program for its execution, as well as such an electrically powered tool and components therefor, are proposed, comprising the features of the independent claims. Advantageous embodiments are the subject of the dependent claims and the following description.

[0004] The invention relates generally to electrically powered tools (power tools) and their operation, and in particular to electrically powered tools comprising a handle component and a tool component. A specific example of this is a so-called pole pruner.

[0005] The handle component includes a control element and a handle component control unit. The control element could be, for example, a push button that the user can activate to operate the tool. However, it is conceivable that additional control elements may be provided. The handle component control unit serves, in particular, to detect activation of the control element and to transmit and receive signals to and from the tool component. The handle component may also be equipped, for example, to provide an electrical power supply; for this purpose, an (electrical and mechanical) interface for a battery may be provided, or a socket for a cable or a cable with a plug may be mounted.

[0006] The tool component comprises a drive, e.g., an electric motor, a tool element that can be actuated by the drive, and a tool component control unit. The tool element is the actual tool, e.g., pruning shears, a chainsaw or chainsaw attachment, or hedge trimmers. The tool component control unit serves to control the drive and also to receive and transmit signals from the handle component.

[0007] The handle component and the tool component are mechanically connected or connectable. For this purpose, a connecting rod, particularly a telescopic rod, may be provided. This is typical for a pole pruner. The handle component may be mechanically connectable to and detachable from the connecting rod. Similarly, the tool component may be mechanically connected to and detachable from the connecting rod.

[0008] The handle component and the tool component can also have electrical interfaces designed such that the drive can be supplied with electrical energy from the handle component via electrical lines, specifically exactly two electrical lines. For this purpose, for example, appropriate plug contacts or other electrical connection means can be provided. The aforementioned electrical lines can then, for example, be routed within the connecting rod. These electrical lines for power supply are such as those that may be required for the power supply of the drive (as well as the tool component control unit).

[0009] A conventional electrically powered tool of this type typically only has the electrical wiring for power supply and no tool component control unit. When the control element is activated, the power supply to the drive is established; when the control element is released, for example, the power supply to the drive is interrupted.

[0010] However, it has now become apparent that this is often unsatisfactory, as the tool can then jam, for example. For instance, a pair of pruning shears might have half-cut a branch when the user releases the handle. This can also raise safety concerns.

[0011] Against this background, communication between the handle component control unit and the tool component control unit is proposed. This communication is achieved by the handle component control unit, during actuation of the operating element, instructing the tool component control unit to activate the drive for actuating the tool element according to a predefined operating strategy. Such a predefined operating strategy could, for example, involve closing the cutting blade of a pruning shear with a specific force and speed. In the case of a chainsaw or chainsaw attachment, this could mean, for example, that the saw chain rotates at a specific speed.

[0012] When the user releases the control element, for example, the handle component control unit instructs the tool component control unit to activate the drive for actuating the tool element according to a predefined shutdown strategy. This means the power supply is not simply interrupted; rather, a specific shutdown strategy can be implemented. This is made possible by the tool component control unit within the tool component, which can selectively control the drive. It has also been shown that this shutdown strategy can be triggered not only when the control element is released, but also, for example, when a fault occurs.

[0013] In one embodiment, the electrical interfaces are designed such that communication between the handle component control unit and the tool component control unit can take place via a data communication line, specifically exactly one data communication line. The data communication line is, in particular, an electrical line through which signals can be transmitted. It is conceivable, for example, that one of the electrical lines for power supply is used as a ground connection. However, instead of a data communication line, wireless communication between the handle component control unit and the tool component control unit can also be provided, for example, via Bluetooth.

[0014] In one embodiment, the specified shutdown strategy includes reopening the tool element, particularly in the case of pruning shears, if it is at least partially closed at the time the control element is deactivated. The shutdown strategy can also include slowing the speed of the tool element, particularly to a standstill, by reversing the direction of movement of the drive, i.e., changing the direction of rotation of the electric motor. This can also apply to pruning shears, preventing them from jamming due to an immediate stop. This can also apply to, for example, a chainsaw or hedge trimmer, which can thus be stopped safely. In particular, rapidly rotating or moving tools such as chainsaws or hedge trimmers can be brought to a standstill more quickly in this way than if the tool element were to continue moving due to inertia.

[0015] Due to the communication between the handle component control unit and the tool component control unit, only three electrical wires and one data communication wire are required, rather than a multitude of data communication wires. Furthermore, using a tool component control unit within the tool component reduces EMC emissions, as the tool component control unit (i.e., the control unit for the drive) is located near the drive or motor, rather than within the handle component itself, thus avoiding the need for long electrical wires running from the drive control unit to the drive.

[0016] In one embodiment, it is further provided that, once a safe state has been reached after the completion of the predefined shutdown strategy, the tool component control unit causes the handle component control unit to activate a switch in the handle component to interrupt the power supply to the drive. For this purpose, a suitable semiconductor switch or a relay can be provided, for example. In this way, the power supply to the drive can then be safely interrupted, but only after the predefined shutdown strategy has been executed and a safe state has been reached, and not immediately upon releasing the operating element.

[0017] In one embodiment, it is further provided that, particularly while the drive is being activated to actuate the tool element according to the specified shutdown strategy, the tool component control unit instructs the handle component control unit to activate the handle component to output information about at least one error that has occurred, via a human-machine interface, in particular a display. In this way, the user can be informed that a safe shutdown is taking place.

[0018] In one embodiment, it is also provided that during communication between the handle component control unit and the tool component control unit, the handle component control unit acts as the master and the tool component control unit as the slave. In this way, control remains with the handle component control unit, which also manages, for example, the power supply.

[0019] In one embodiment, it is further provided that if a critical fault is present or detected in the tool component, the tool component control unit causes the handle component control unit to activate a switch in the handle component to interrupt the power supply to the drive. This can be the aforementioned switch, i.e., the semiconductor switch or the relay.

[0020] A computing unit according to the invention, e.g. a handle component control unit or a tool component control unit of an electrically operated tool, is, in particular in terms of programming, equipped to carry out those process steps of a method according to the invention which process steps are carried out by the handle component control unit or by the tool component control unit.

[0021] As already mentioned and described, the invention also relates to an electrically operated tool. The handle component control unit and the tool component control unit are configured to carry out a method according to the invention.

[0022] The invention further relates to a tool component for use in an electrically operated tool as described. The tool component comprises a drive, a tool element, and a tool component control unit, wherein the tool component control unit is configured to perform the process steps of a method according to the invention, which process steps are performed by the tool component control unit. In particular, the tool component also has mechanical and / or electrical interfaces for connection with a handle component, optionally indirectly via a connecting rod.

[0023] The invention further relates to a handle component for use in an electrically powered tool as described. The handle component is configured to provide an electrical power supply and includes an operating element and a handle component control unit. The handle component control unit is configured to carry out the process steps of a method according to the invention, which process steps are carried out by the handle component control unit. In particular, the handle component also has mechanical and / or electrical interfaces for connection to a tool component, optionally indirectly via a connecting rod.

[0024] Implementing a method according to the invention in the form of a computer program or computer program product with program code for carrying out all method steps is also advantageous, as this incurs particularly low costs, especially if an executing control unit is already available for other tasks. Finally, a machine-readable storage medium is provided with a computer program stored on it as described above. Suitable storage media or data carriers for providing the computer program are, in particular, magnetic, optical, and electrical storage media, such as hard drives, flash memory, EEPROMs, DVDs, etc. Downloading a program via computer networks (Internet, intranet, etc.) is also possible. Such a download can be wired or wireless (e.g., via a WLAN network, a 3G, 4G, 5G, or 6G connection, etc.).

[0025] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawing.

[0026] The invention is schematically illustrated in the drawing using an exemplary embodiment and is described below with reference to the drawing. Brief description of the drawings Fig. Figure 1 schematically shows an electrically operated tool in one embodiment. Fig. Figure 2 schematically shows the sequence of a procedure in one embodiment. Fig. 3, Fig. 4, Fig. 5 show different aspects of the procedure according to Fig. 2. embodiment(s) of the invention

[0027] In Fig. Figure 1 schematically and exemplarily illustrates an electrically operated tool 100 in one embodiment and for the purpose of explaining the invention. The electrically operated tool 100 is, by way of example, a pole pruner with tree shears.

[0028] The pole pruner 100 has a handle component 110, a tool component 120 and a connecting rod 130 (or a connecting rod, e.g. a telescopic rod).

[0029] The handle component 110 comprises an operating element 116, a handle component control unit 112, a battery 114, and a housing 111 in which the aforementioned components are arranged. The battery 114 can, for example, be removable, meaning that corresponding electrical and mechanical interfaces are provided in the housing 111. The handle component control unit 112 is also configured to detect actuation of the operating element 116.

[0030] The tool component 120 comprises a drive 124, e.g., an electric motor, a tool element 126, here the tree shear (i.e., a cutting blade movably attached to a counterpart), a tool component control unit 122, and a housing 121 in which the aforementioned components are arranged. The drive 124 is configured to actuate the tool element 126, i.e., to control its opening and closing. A suitable gearbox may be provided for this purpose. The tool component control unit 122 is also configured to actuate the drive 124.

[0031] The connecting rod 130 can, for example, be mechanically connected to both the handle component 110 and the tool component 120. For this purpose, an interface 119 of the handle component 110 and an interface 129 of the tool component 120 are indicated. It is also conceivable that the connecting rod is mechanically fixed to one or both of the aforementioned components.

[0032] The connecting rod 130 provides three electrical lines: two electrical lines 131 and 132 for supplying power to the drive 124, and one data communication line 133. For this purpose, interface 119 and interface 129 can also have corresponding electrical contacts, i.e., be designed as mechanical and electrical interfaces.

[0033] Furthermore, the handle component 110 has a switch 117 by means of which at least one of the electrical lines, e.g. the electrical line 131 (typically the positive line), can be disconnected. The handle component 110 also has a human-machine interface 115 designed as a display, by means of which a user can be informed about any errors, for example.

[0034] In Fig. Figure 2 schematically illustrates the sequence of a process in one embodiment. This includes, in particular, the communication between the handle component control unit and the tool component control unit, which is, for example, in Fig. 1 are shown.

[0035] In particular, a protocol can be used for this purpose that implements a point-to-point communication path between the handle component control unit and the tool component control unit.

[0036] The handle component control unit is responsible, for example, for battery management, processing user input and the signals generated by it (e.g., via the control element), and also for speed settings. The tool component control unit is responsible for the drive and its control, including speed and power control, special motor functions, etc.

[0037] The handle component or handle component control unit supplies the tool component or tool component control unit with power and, as mentioned, has the capability to interrupt the current flow or energy supply via a switch. This switch could, for example, be an electronic main switch MOSFET (EMS). This switch is controlled, for example, by software; therefore, the power supply to the tool component, along with the drive, remains active until the tool element reaches its safe state (i.e., a safe position).

[0038] The protocol used can, in particular, represent a standardized interface that is independent of the specific properties of a tool element or tool. This allows the use of various tool components with a single handle component and creates the possibility of developing new tool components that are compatible with older G handle components.

[0039] The process can comprise various operating phases or steps. As mentioned, the handle component control unit can be configured as the master and the tool component control unit as the slave. The general sequence of the process is described in Fig. 2 shows different operating phases or steps in the Fig. 3, Fig. 4 and Fig. 5 shown in a slightly more detailed way.

[0040] First, for example, in step 200, the tool can be switched on, thus pre-activating it. This is followed by a negotiation phase 210. In this phase, the handle component or the handle component control unit verifies that a device, i.e., a tool component or a tool component control unit, is (communicatively) connected. Both control units verify, for example, that the connected tools are compatible with each other regarding the version of the communication protocol used (request 211, confirmation 212), battery platform (request 213, confirmation 214), security level (request 215, confirmation 216), and battery parameters (request 217, confirmation 218). As in Fig. As can be seen in step 3, the request is made by the handle component control unit, i.e., the master, while the tool component control unit, i.e., the slave, confirms it.

[0041] If the mutual requirements are met, the negotiation phase is successful. If the negotiation fails at any point, the handle components or the handle component control unit shuts down, step 250.

[0042] If the negotiation phase was successful, a status evaluation (220) follows. Here, the handle component or handle component control unit waits for the user to start the drive or motor by actuating the control element. During this phase, the handle component control unit regularly queries the status of the tool component control unit to check the continuity of the communication line.

[0043] When the tool is activated, i.e., when the control element is actuated and as long as this is the case, the drive to actuate the tool element is controlled according to a predefined operating strategy, step or phase 230.

[0044] During this phase, the handle component control unit periodically sends various requests or information to the tool component control unit, which acknowledges them (if applicable), as described in Fig. 4 shown. These are, for example, control data such as on / off operating status (this concerns, for example, the status of the switch and / or the control element) and a speed request (sending information 231, confirmation 232), a battery status with, for example, temperature and state of charge (sending information 233, confirmation 234), as well as a request for the status of the tool component, for example, regarding system status, motor status, supply requirements (request 235, confirmation and sending information 236).

[0045] As soon as the tool is deactivated, i.e., an actuation of the control element is terminated, or an error occurs, e.g., in one of the components, the handle component control unit or the tool component control unit initiates the drive to actuate the tool element according to a predefined shutdown strategy, step or phase 240.

[0046] In this phase, the handle component control unit periodically sends various requests 241 (e.g., regarding system status, motor status, supply requirements) to the tool component control unit, which confirms or answers them (if applicable), as shown in Fig. Figure 5 shows this. This serves in particular to determine the cause of the shutdown and to obtain data on the power supply requirements of the tool component. During this phase, the tool component brings the drive or motor into its safe state. The grip components only interrupt the power supply to the tool component once the latter reports that it has reached its safe state and no longer requires power.

[0047] Once all tasks are completed, the tool shuts down, step 250. If the tool is reactivated during this phase, operation can resume without further negotiations, i.e., it can proceed to phase 230, at least if no error has occurred.

[0048] During this phase, the tool component control unit can also cause various error messages to be displayed on the handle component's display. This can be done via error message request 243 transmitted by the handle component control unit, as shown in Fig. 5 shown, to which the tool component control unit responds with a tool-specific error message 244.

[0049] The master is responsible for controlling communication. If a transaction fails, the master attempts to retry it. There is, for example, a limited number of retry attempts before the communication is considered faulty. Each frame in the communication protocol contains, for example, redundant error checking, which is performed by both the master and the slave. If the master detects an error in the slave's response, the transaction is faulty and should be retried if possible. If the slave detects an error in the master's message, it may refuse to respond. This results in a timeout error in the master, causing the transaction to fail.

[0050] Such an error can lead to the aforementioned predetermined shutdown strategy.

[0051] If a critical fault occurs in the tool component or its control unit that could damage the hardware, the control unit can indicate this without waiting for the master to query its status. This signal is generated, for example, at the physical layer by setting the data communication line to the dominant level for at least a certain period of time. This can be done asynchronously at any time. The master detects this event and immediately shuts down the tool component by switching off the relevant switch.

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