The present invention relates to a power tool with at least one control device.
The present invention also relates to a system comprising a power tool with at least one control device and a rechargeable battery with at least one set of control electronics, the battery being designed for supplying the power tool with electrical energy.
Modern power tools, such as for example hammer drills, saws, grinders or the like, nowadays have numerous components (for example a motor unit, transmission unit, transceiver, microcontroller, etc.) that exchange a great amount of information and data in the form of signals. A high level of information and data exchange now takes place in particular between a power tool and a rechargeable battery provided as a power supply.
Various communication networks or communication circuits are used for exchanging data (i.e. sending and receiving information). The communication between the individual components, i.e. the data exchange, usually takes place without any problem when the power tool is in an inoperative state. In the inoperative state, the power tool is not activated and the drive is only supplied with relatively little electrical energy (i.e. low current values or current intensity).
By contrast, in an operative mode of the power tool, a relatively great amount of electrical energy (i.e. high current values or current intensity) is supplied in order to produce a high power output of the power tool.
However, high current values, and especially relatively rapidly changing current values (i.e. great fluctuation), produce unwanted interference coupling (for example inductive coupling, capacitive coupling, electromagnetic radiation and/or line-bound interference) on a neighboring signal line in the communication network. Since the technical measures for suitable interference immunity on the communication networks usually cause a considerable amount of effort and increased costs, a consequence of this is to dispense with communication between the components during operation (i.e. in the active mode) of the power tool.
An object of the present invention is therefore to provide a power tool and also a system comprising a power tool and a rechargeable battery with which the aforementioned problem is solved and robust communication can be achieved during the operation of the power tool or the system.
The present invention provides a power tool with at least one control device.
According to the invention, the power tool comprises at least one communication circuit for exchanging signals in a half-duplex mode with a first and a second communication line for differential communication between at least a first transceiver and a second transceiver. This makes robust communication that is immune to interference possible even during the operation of the power tool.
The transceiver component may also be referred to as a transmitter-receiver or a microcontroller. In addition, it is also possible that, instead of a first and a second transceiver, a first and a second control unit or a microcontroller or a first and a second microcontroller is/are correspondingly provided for the differential communication.
According to an advantageous embodiment of the present invention, it may be possible that, in the case of differential communication, there is a first differential voltage of between 1.5 and 3 V for a first state and a second differential voltage of between −0.5 and 0.5 V for a second state. The first voltage difference may correspond in particular to a value of 2 V and the second voltage difference may correspond in particular to a value of 0 V.
In the case of differential communication, the first state may also be referred to as the dominant or high state. Furthermore, in the case of differential communication, the second state may also be referred to as the recessive or low state.
According to an advantageous embodiment of the present invention, it may be possible that at least one rechargeable battery is provided as a power supply for the power tool and a maximum voltage value in the first state is up to 12 V with respect to the ground potential of the rechargeable battery.
The ground potential of the rechargeable battery may also be referred to as ground, potential zero or mass.
According to an advantageous embodiment of the present invention, it may be possible that the at least first transceiver is positioned in the power tool and the at least second transceiver is positioned in the rechargeable battery.
The present invention also provides a system comprising a power tool with at least one control device and a rechargeable battery with at least one set of control electronics, the rechargeable battery being designed for supplying the power tool with electrical energy.
According to the invention, it comprises at least one communication circuit for exchanging signals in a half-duplex mode with a first and a second communication line for differential communication between at least a first transceiver and a second transceiver. This makes robust communication that is immune to interference possible even during the operation of the system.
The transceiver component may also be referred to as a transmitter-receiver or a microcontroller. In addition, it is also possible that, instead of a first and a second transceiver, a first and a second control unit or a microcontroller or a first and a second microcontroller is/are correspondingly provided for the differential communication.
According to an advantageous embodiment of the present invention, it may be possible that the at least first transceiver is positioned in the power tool and the at least second transceiver is positioned in the rechargeable battery.
According to an advantageous embodiment of the present invention, it may be possible that both the at least first transceiver and the at least second transceiver are positioned in the power tool.
According to an advantageous embodiment of the present invention, it may be possible that, in the case of differential communication, there is a first differential voltage of between 1.5 and 3 V for a first state and a second differential voltage of between −0.5 and 0.5 V for a second state.
In the case of differential communication, the first state may also be referred to as the dominant or high state. Furthermore, in the case of differential communication, the second state may also be referred to as the recessive or low state.
According to an advantageous embodiment of the present invention, it may be possible that a maximum voltage value in the first state is up to 12 V with respect to the ground potential of the rechargeable battery.
The first and second communication lines for differential communication between the rechargeable battery and the power tool are component parts of a communication system. In this case, the communication system can be configured as a CAN data bus. However, it is also possible to use some other suitable communication system for differential communication between the rechargeable battery and the power tool.
Further advantages can be found in the following description of the figures. Various exemplary embodiments of the present invention are shown in the figures. The figures, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to produce useful further combinations.
In the figures:
According to an alternative embodiment of the present invention, the power tool 2 may not be supplied with electrical energy by a rechargeable battery but by a network connection. The network connection may also be referred to as a power cable. This alternative embodiment of the present invention is not shown in the figures.
As illustrated in
The power tool 2 designed as a rechargeable battery-operated screwdriver substantially comprises a housing 4, a handle 5, a base part 6, a tool fitting 7, an electrical drive 8 in the form of an electric motor, a control device 9, a transmission 9a, an input shaft 11, an output shaft 12 and an activation switch 13.
The electrical drive 8 designed as an electric motor, the transmission 10, the input shaft 11, the output shaft 12 and the control device 9 are positioned in the housing 4. The drive 8, the transmission 10, the input shaft 11 and the output shaft 12 are positioned in relation to one another and in the housing 10 such that a torque generated by the drive 8 is transmitted to the output shaft 12. The output shaft 12 transmits the torque to the transmission 10, which in turn passes on a torque to the input shaft 11. The tool fitting 7 is driven by way of the input shaft 11 by the transmission of the torque. As illustrated in
As also shown in
As can be seen from
The control device 9 of the power tool 2 in this case comprises a microcontroller 18 (see
The rechargeable battery 3 substantially comprises a housing 21 with a rechargeable battery interface 22. In the housing 21 of the rechargeable battery 3 there are a multiplicity of energy storage cells 23 and also a set of control electronics 24 with a microcontroller 25.
The rechargeable battery 3 also comprises a data interface 29 with a second transceiver 30 as a component part of a communication circuit KS for differential communication between the rechargeable battery 3 and the power tool 2.
The energy storage cells 23 may also be referred to as rechargeable battery cells and serve for taking up, storing and providing electrical energy or an electrical voltage.
The rechargeable battery interface 22 is positioned on one side of the housing 21. The rechargeable battery interface 22 comprises a number of power connectors 27 for taking up and delivering electric current and also data connectors 28 for transmitting and receiving signals between the power tool 2 and the rechargeable battery 3. The electric current from the energy storage cells 23 can be delivered by way of the power connectors 27.
As shown in
Through the connection, electric current can flow from the energy storage cells 23 of the rechargeable battery 3 to the power tool 2. Furthermore, signals can be exchanged for communication between the rechargeable battery 3 and the power tool 2.
As can be seen from
In order to transmit a signal corresponding to the travel of the activation switch 13 in direction A to the controller 9, the activation switch 13 comprises a potentiometer.
If the activation switch 13 moves again in direction B, a corresponding signal is transmitted to the controller 9 by means of the potentiometer, with the result that electric current (and consequently electrical energy) no longer flows from the rechargeable battery 3 to the power tool 2.
The differential communication between the rechargeable battery 3 and the power tool 2 takes place by way of a communication circuit KS. To participate in the communication circuit KS, both the rechargeable battery 3 and the power tool 2 respectively comprise a data interface 19, 29 with a transceiver 20, 30. The transceivers 20, 30 may in this case be designed as CAN transceivers. As indicated in
According to an alternative embodiment of the present invention, the communication circuit KS with a first and a second transceiver may merely be positioned in the housing 4 of the power tool 2. As a result, the differential communication merely takes place within the power tool, i.e. between components of the power tool 2.
The transceiver 20 of the power tool 2 can transmit signals (for example a bit) by way of the data interface 19 and the first and second communication lines 31, 32 to the data interface 29 and the transceiver 30 of the rechargeable battery 3.
As illustrated in
The second state NZ for the COM high line 31 and for the COM low line 32 is the low state, i.e. at which there is a second differential voltage of between −0.5 and 0.5 V. An optimum value for the second differential voltage is in this case 0 V. In the exemplary embodiment in
As correspondingly illustrated in
Number | Date | Country | Kind |
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19198849.2 | Sep 2019 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/075637 | 9/14/2020 | WO |