Electric machining tool having intermediate circuit electronics

Abstract

The invention relates to an electric machining device (10) having a housing (14), an output mechanism (38) for an insert tool (32) for machining a workpiece, an electric motor (12) for driving the output mechanism (38), intermediate circuit electronics (42) for generating a rectified intermediate circuit voltage (Uic) from a supply voltage (Us) of the machining device (10), and power electronics (38) for controlling the electric motor (12) using a motor voltage signal (UM) generated from the intermediate circuit voltage (Uic), said power electronics (38), intermediate circuit electronics (42), and electric motor (12) forming a powertrain (44) which is received in the housing (14) together with at least one part of the output mechanism (28). According to the invention, a converter circuit (48) is connected upstream of the intermediate circuit electronics (42), said converter circuit providing a dynamically adaptable target value for the intermediate circuit voltage (Uic) from the supply voltage (Us).

Description

[0001]

[0002] title

[0003] Electrical processing device with intermediate circuit electronics

[0004] Description

[0005] The invention relates to an electric machining device comprising a housing, an output mechanism for a tool for machining a workpiece, and an electric motor for driving the output mechanism. According to the preamble of independent claim 1, intermediate circuit electronics for generating a rectified intermediate circuit voltage from a supply voltage of the machining device and power electronics for controlling the electric motor by means of a motor voltage signal generated from the intermediate circuit voltage are further provided, wherein the power electronics, the intermediate circuit electronics, and the electric motor form a drive train which is integrated with at least a part of the output mechanism in the housing of the machining device.

[0006] State of the art

[0007] Battery-powered power tools, especially handheld power tools, have increasingly replaced their mains-powered counterparts in recent years, primarily due to the lighter and more powerful versions of interchangeable battery packs and electric motors. Among electric motors, electrically commutated (EC) and brushless direct current (BLDC) motors have become particularly established. An EC motor is a multi-phase synchronous motor controlled by an inverter bridge circuit (e.g., an H6 bridge in a three-phase EC motor) within a power electronics unit. Such a bridge circuit typically consists of numerous semiconductor switches (e.g., MOSFETs, IGBTs, bipolar power transistors, etc.) that use an applied DC voltage to perform electronic commutation for the individual phases of the EC motor via pulse-width modulation (PWM).Due to the high switching frequency of the semiconductor switches (typically in the kHz range), the applied DC voltage is usually capacitively filtered by one or more capacitors connected in parallel. This filtered or smoothed voltage is also referred to as the intermediate circuit voltage.

[0008] It is known to increase the performance and / or operating time of electrical processing tools by means of various types of converter circuits for power supply. For example, for a battery-powered processing tool, an AC / DC converter can be used as an internal solution according to EP 2535149 A2, or as an external adapter connectable to an electromechanical interface for a replaceable battery pack, which converts the mains voltage into a rectified intermediate circuit voltage, according to EP 4297934 A1. Likewise, it is possible to convert the supply voltage, which is available as DC voltage from another DC voltage source (e.g., an external battery network or backpack), into a corresponding intermediate circuit voltage using an internal or external DC / DC converter. An internal step-up DC / DC converter is known, for example, from EP 2991807 A1, while EP 3070028 A1 discloses a DC / DC converter in the replaceable battery pack.For mains-powered processing equipment with a particularly high power requirement, it is also known to provide an internal power factor correction circuit (PFC) which increases the supply voltage to a higher intermediate circuit voltage, for example to achieve sinusoidal commutation.

[0009] With a constant DC link voltage, the power electronics can only adjust the operating point (speed and / or torque) of the EC motor to a limited extent using PWM, as the switching time of the semiconductor switches prevents the duty cycle from being reduced arbitrarily. Furthermore, a significantly reduced duty cycle has a detrimental effect on the drive train, since efficiency is highest at a duty cycle of 100% and decreases accordingly at reduced duty cycles. This increases losses in the power electronics and the EC motor, leading to higher heat generation and a shorter operating time. In addition, wired and / or electromagnetic interference (EMI) is typically lowest at 100% PWM and increases with a reduced duty cycle.Therefore, if the cycle time is too reduced, operation may no longer comply with standards, or stronger filtering may be necessary. Stronger filtering generally results in higher costs, a larger footprint, and increased weight of the electrical processing device.

[0010] The object of the invention is to provide an electrical processing device that, compared to the prior art, ensures operation with higher energy efficiency in conjunction with the lowest possible interference radiation.

[0011] Advantages of the invention

[0012] To solve this problem, a converter circuit is connected upstream of the DC link electronics. This converter circuit provides a dynamically adjustable target value for the DC link voltage from the supply voltage. This allows for particularly advantageous optimized operation of the electrical processing device by increasing the voltage range in which the device can be operated, thus eliminating the dependence of the processing device's performance on deviations from the ideal voltage.

[0013] In the context of the invention, electrical processing equipment includes, among other things, machine tools that can be powered by mains voltage, battery voltage, or a hybrid system and are used to machine workpieces with an electrically driven tool. The electrical processing equipment can be designed as either a handheld or stationary machine tool. Typical machine tools in this context are hand-held or bench drills, rotary hammers, screwdrivers, impact drills, planers, angle grinders, orbital sanders, polishing machines, nailers, and the like. Electrical processing equipment also includes electrically driven garden and construction equipment such as lawnmowers, string trimmers, pruning saws, rotary tillers and trenchers, blowers, and the like. Furthermore, the invention is applicable to household appliances such as vacuum cleaners, blenders, etc., or to electrically powered vehicles, in particular e-bikes, e-scooters, etc.

[0014] In a further training course, it is specified that the electric motor is a brushless DC motor and that the power electronics include an inverter bridge circuit. This circuit pulse-width modulates the motor voltage signal for controlling the brushless DC motor in such a way that the switching ratio of the motor voltage signal is always 100%. A constant PWM with a maximum switching ratio of 100% offers the particular advantage of maximum energy efficiency combined with minimal EMI.

[0015] If the electrical processing device is supplied with mains voltage, the converter circuit is designed to include an AC / DC converter that dynamically adjusts the target value of the intermediate circuit voltage when the supply voltage is a maximum permissible AC voltage from a stationary power supply network or AC generator for the operation of the processing device. A maximum permissible AC voltage is understood to mean, in particular, that it is determined by the design and configuration of the drive train of the electrical processing device or that it is based on the maximum permissible value of the country- or region-specific mains voltage of a single-phase system (e.g., approximately 240 to 252 V for Europe) for the market in which the processing device is intended. Accordingly, the AC voltage generated by an AC generator will also be based on the country- or region-specific mains voltage.The term "AC generator" refers specifically to a device that uses an internal combustion engine, a comparable energy converter, or an energy storage device in conjunction with an inverter to generate an alternating voltage corresponding to the relevant country- or region-specific mains voltage. If the supply voltage is lower than the maximum permissible AC voltage of a stationary power grid or AC generator, an AC / DC converter in the converter circuit with integrated power factor correction generates the intermediate circuit voltage and dynamically adjusts its setpoint. This allows the electrical processing device to be operated very efficiently even with lower mains voltages.

[0016] Furthermore, a logic circuit is designed to regulate the target value of the DC link voltage in real time. This allows the DC link voltage to be adjusted promptly to the value necessary for maximum efficiency of the machining tool, depending on the operating point, power requirements, permissible temperature, rotational speed, torque, or other parameters of the workpiece. The target value of the DC link voltage can be set, for example, by a preferably analog control loop of the control electronics of the machining tool. Alternatively, a fixed, preset control element, particularly a potentiometer, can also be used to specify the target value.

[0017] If the supply voltage is provided by the battery voltage of at least one removable battery pack, the converter circuit includes a DC / DC converter that dynamically adjusts the target value of the intermediate circuit voltage. To supply the power to the electrical processing tool with the battery voltage, at least one electromechanical interface is provided on the tool housing for tool-free removal of a removable battery pack. The removable battery pack has a correspondingly complementary electromechanical interface. These interfaces allow the removable battery pack and the electrical processing tool to be detachably connected by force and / or form-fit. A connection that can be detached and reattached without tools is understood to mean, in particular, a connection that can be made and detached by hand.The precise design of the electromechanical interfaces with their mechanical guide elements for force-locking and / or form-locking connections and the electrical contacts used for energy and / or data transmission is not the subject of this invention. A person skilled in the art will select a suitable embodiment for the electromechanical interfaces depending on the power or voltage class of the electrical processing device and / or the interchangeable battery packs, so this will not be discussed in further detail.

[0018] The battery voltage can be generated by a plurality of interchangeable battery packs connected in series and / or parallel, which are inserted into a corresponding number of electromechanical interfaces of the electrical processing device. The invention thus enables not only the optional use of mains voltage or an interchangeable battery pack to power the processing device; in the case of multiple electromechanical interfaces, a varying number of interchangeable battery packs can be used depending on the availability of the interchangeable battery packs, the required power consumption, and the desired operating time. Furthermore, the invention advantageously enables, under appropriate boundary conditions, the operation of the processing device with interchangeable battery packs of different voltage classes or battery voltages.

[0019] The voltage class or battery voltage of a battery pack is determined by the connection (parallel or series) of the individual energy storage cells integrated into the pack and is generally an integer multiple (>= 1) of the voltage of the individual energy storage cells. An energy storage cell is typically designed as a galvanic cell with a configuration in which one cell terminal is located at one end and another at the opposite end. Specifically, the energy storage cell has a positive terminal at one end and a negative terminal at the opposite end. Preferably, the energy storage cells are designed as lithium-based cylindrical cells, e.g., Li-ion, Li-polymer, Li-metal, or the like. However, Ni-Cd, Ni-MH cells, or other suitable cell types can also be used.For common lithium-ion energy storage cells with a cell voltage of 3.6 V, voltage classes of 3.6 V, 7.2 V, 10.8 V, 14.4 V, 18 V, 36 V, etc., are possible. The DC voltage values ​​depend primarily on the typical cell voltages of the energy storage cells used. For example, voltage values ​​for pouch cells and / or cells with a different electrochemical composition are possible that differ from those of replaceable battery packs equipped with lithium-ion cells. The invention is not dependent on the type and design of the energy storage cells used, but can be used in conjunction with any replaceable battery packs that use prismatic cells, pouch cells, or the like instead of cylindrical cells.

[0020] Additionally, the converter circuit can be integrated into the housing of the processing device as part of the drive train. This allows for a particularly compact design combined with optimized cooling and reduced EMI emissions.

[0021] Alternatively, the converter circuit can be designed as a separate adapter, independent of the processing device, which can be inserted into at least one electromechanical interface for the interchangeable battery pack of the processing device without tools. This allows the DC link voltage to be dynamically adjusted even for battery-powered processing devices where this is not provided by design. Furthermore, it is conceivable that a processing device normally only operable with interchangeable battery packs could also be operated with mains voltage via a suitably designed adapter. Preferably, the adapter has a communication interface and / or electrical coding that identifies the processing device for setting the target value for the DC link voltage.This allows the operator of the processing device to use the adapter for different processing devices very easily, without having to worry about the optimal setpoint.

[0022] Examples of implementation

[0023] Drawing The invention is explained below by way of example with reference to Figures 1 to 6, where identical reference numerals in the figures indicate identical components with the same function.

[0024] They show:

[0025] Fig. 1 : a schematic representation of a first embodiment of an electric machining device designed as a battery-powered impact wrench,

[0026] Fig. 2: a block diagram for the power supply of a three-phase system

[0027] EC motor designed electric motor of the battery-powered impact wrench according to Figure 1 ,

[0028] Fig. 3 shows a schematic representation of a second embodiment of the electrical processing device designed as a hybrid-powered demolition hammer,

[0029] Fig. 4: a block diagram for the power supply of the three-phase system

[0030] EC motor designed electric motor of the demolition hammer according to Figure 3.

[0031] Fig. 5: a block diagram of a third embodiment for the power supply of the electrical processing device and

[0032] Fig. 6: a block diagram of a fourth embodiment for the power supply of the electrical processing device.

[0033] Description of the exemplary implementations

[0034] Figure 1 shows an example of an electric power tool 10 designed as a battery-powered impact wrench with an electric motor 12. The impact wrench has a housing 14 with a handle 16 and a tool holder 18 and can be mechanically and electrically connected to a complementary electromechanical interface 20 of an interchangeable battery pack 22 via a corresponding electromechanical interface 20 provided on the housing 14. In this example, the interchangeable battery pack 22 supplies the impact wrench with a supply voltage Us, which is configured as a battery voltage UDC of 18 V DC. However, as explained below, the invention can also be advantageously applied to electric power tools 10 with interchangeable battery packs 22 of other voltage classes.Furthermore, it should be noted that the invention is not limited to impact wrenches or hand-held power tools in general, but – as already mentioned at the outset – can be applied to various mains-independent and / or mains-dependent electrical processing devices.

[0035] The housing 14 contains, by way of example, the electric motor 12, powered by the interchangeable battery pack 22, along with a gear unit 24 including a clutch and an impact mechanism 26. The gear unit 24, the impact mechanism 26, and the tool holder 18 together form an output unit 28, which is driven by a motor shaft 30 of the electric motor 2. The impact mechanism 26 is designed, by way of example, as a rotary impact mechanism that generates sudden, high-intensity rotational impulses and transmits them to the tool holder 18, which serves to interchangeably hold an insert tool 32. Since the output unit 28 is not essential to the invention as such, it will not be discussed in detail here. The possible embodiments are well known to those skilled in the art.

[0036] The electric motor 12 is designed as a three-phase EC motor and can be controlled via a main switch 34 of the impact wrench, i.e., it can be switched on and off and its speed and / or torque can be varied. For this purpose, the electric motor 12 is supplied with a pulse-width modulated motor voltage signal UM by an inverter bridge circuit 36 ​​of a power electronics unit 38. A control electronics unit 40 controls the individual power transistors of the inverter bridge circuit 36 ​​according to a signal specified by the travel of the main switch 34 to generate the PWM voltage UM. The control electronics unit 40 can be, for example, a microcontroller, DSP, ASIC, or the like. The inverter bridge circuit 36 ​​has various power transistors (e.g., bipolar transistors, field-effect transistors, IGBTs, or the like), which are preferably connected as an H6 bridge.Depending on the design of the electric motor 12, other configurations of the inverter bridge circuit 36 ​​are also conceivable, e.g. as an H-bridge, B6-bridge or the like.

[0037] The housing 14 of the cordless impact wrench also includes an intermediate circuit electronics unit 42, which generates a rectified intermediate circuit voltage Uic from the battery voltage UDC supplied by the inserted interchangeable battery pack 22. This voltage is used to supply the power electronics unit 38 and the electric motor 12. The electric motor 12, the power electronics unit 38, and the intermediate circuit electronics unit 42 together form a drive train 44, which—as indicated in Figure 1—can consist of spatially separated components. Alternatively, it is also conceivable that the drive train 44 is partially or completely integrated into a stator assembly 46 of the electric motor 12 (see Figure 2). This allows the drive train 44 to be designed as a single, compact module, preferably utilizing the stator assembly 46 as a common heat sink. Furthermore, a particularly compact design of the drive train 44 enables reduced EMI emissions.Since the various design possibilities of the electric motor 12, the power electronics 38 and the control or regulation electronics 40 are known to the person skilled in the art, they will not be discussed in more detail here.

[0038] According to the invention, a converter circuit 48 is connected upstream of the DC link electronics 42. This converter circuit provides a dynamically adjustable setpoint for the DC link voltage Uic from the battery voltage UDC, thus enabling particularly advantageous optimized operation of the impact wrench. This increases the voltage range in which the impact wrench can be operated, so that its performance no longer depends on a deviation from the ideal voltage. Preferably, the motor voltage signal UM for controlling the EC motor is pulse-width modulated as a function of the adjusted DC link voltage Uic such that its duty cycle is always 100%, in order to achieve maximum energy efficiency combined with minimal EMI. The converter circuit 48 can be configured either separately from the DC link electronics 42 and thus from the drive train 44, or alternatively as part of the drive train 44.

[0039] By means of a logic circuit 50 of the control electronics 40, the setpoint of the DC link voltage Uic can be adjusted in real time, depending on the operating point of the EC motor with regard to its power requirement, a permissible temperature, the speed, the torque, or the like, depending on the workpiece being machined, to the value that enables the impact wrench to operate at maximum efficiency. The setpoint of the DC link voltage Uic can be predefined by a preferably analog control loop of the power electronics 38. Alternatively, a fixed preset control element 52, in particular a potentiometer, is also conceivable for setting the setpoint.

[0040] Figure 2 shows a block diagram for the power supply of the electric motor 12 of the cordless impact wrench from Figure 1, which is designed as a three-phase EC motor. As already explained with regard to Figure 1, the electric motor 12, the power electronics 38, and the DC link electronics 42 form the drive train 44 of the cordless impact wrench. The power electronics 38 are controlled by the control electronics 40 to adjust the speed and / or torque of the electric motor 12 such that a pulse-width modulated motor voltage signal UM generated by it for the three phases of a stator winding 54 wound on the stator core 46 sets a rotor 56, which is rigidly connected to the motor shaft 30 and equipped with permanent magnets, into a rotational movement.Furthermore, the electric motor 12 has a sensor system (not shown in detail) for determining the speed and position of the rotor 56, which provides the corresponding sensor signals for the control electronics 40. However, the invention is not explicitly limited to three-phase, brushless DC motors, but can also be applied to other types of electric motors 12, such as synchronous motors or universal motors. The drive train 44 is powered by the interchangeable battery pack 22 inserted into the electromechanical interface 20.The target value of the intermediate circuit voltage Uic is dynamically adjusted from the applied battery voltage UDC by means of a DC / DC converter 58 of the converter circuit 48. In a particularly preferred manner, the switching ratio of the pulse-width modulated motor voltage signal UM is always 100%. In addition, the intermediate circuit voltage Uic is smoothed, either regulated or unregulated, by means of the intermediate circuit stage 42, which in the simplest case consists of at least one capacitor. In the illustrated embodiment, the converter circuit 48 is designed separately from the drive train 44. However, it is also conceivable that it is an integral part of the drive train 44.

[0041] Figure 3 shows another embodiment of the electric processing device 10 in the form of a demolition hammer. A significant difference from the cordless impact wrench according to Figure 1, besides the mechanical design of the output unit 28, which consists of the gear unit 24, the impact mechanism 26, and the tool holder 18, and the performance of the demolition hammer, lies in its power supply. The demolition hammer is designed as a hybrid device that can be supplied either via a mains cable 60 with energy from a stationary power grid or AC generator and / or via two interchangeable battery packs 22 that can be inserted into corresponding electromechanical interfaces 20 arranged laterally on the housing 14.In this way, the drive train 44, comprising the electric motor 12 (designed as an EC motor), the power electronics 38, and the DC link electronics 42, can be supplied. According to the output unit 28, this drive train belongs to a significantly higher performance class than the impact wrench shown in Figure 1. A detailed description of the output unit 28 and the tool 32, which is mounted in the tool holder 18, will be omitted here, as these are of minor importance to the invention. Although the drive train 44 is designed for higher performance according to the output unit 28, its basic structure does not otherwise differ from previously known solutions in the art. For example, in the case of two 18 V interchangeable battery packs 22 connected in series, the resulting battery voltage (UDC) is 36 V DC.Analogous to the first embodiment, the converter circuit 48 is connected upstream of the DC link electronics 42 to provide a dynamically adjustable setpoint for the DC link voltage Uic from the battery voltage UDC for optimized operation of the demolition hammer. If the demolition hammer is alternatively or additionally supplied with a mains voltage UACI of, for example, approximately 230 to 240 V via the mains cable 60, the converter circuit 48 dynamically adjusts the setpoint for the DC link voltage Uic accordingly. A more detailed description of the dynamic adjustment using the converter circuit 48 will follow with reference to Figure 4. The motor voltage signal UM, which is used to control the EC motor, can thus be pulse-width modulated based on the dynamically adjusted DC link voltage Uic such that its duty cycle is always 100% in order to achieve maximum energy efficiency in conjunction with minimal EMI.

[0042] Switching between the power supply modes can be done either manually via a selector switch 62 operated by the user and / or automatically by means of a sensor 64 on the demolition hammer. Switching via a human-machine interface (HMI) 66 located on a handle 16 of the demolition hammer or via an app connected to a communication module (not shown) of the demolition hammer is also conceivable. In this case, the control electronics 40 can evaluate a request signal from the selector switch 62, the sensor 64, the HMI 66, and / or the app to switch between the power supply modes via the logic circuit 50. The request signal can be generated, for example, via a cover flap 68 for a mains interface 70 of the demolition hammer. This flap is closed when powered by the interchangeable battery pack 22 and open when the mains power is supplied by a plugged-in mains connector 72 of the mains cable 60.The position of the cover flap 68 is detected by means of the sensor 64, for example in the form of a reed contact or microswitch, and the corresponding request signal for operation with the mains voltage UACI is sent to the control electronics 40. It is also conceivable that the sensor 64 directly detects the applied voltage. Operation with the mains voltage UACI takes priority over operation with the battery voltage UDC, even with interchangeable battery packs 22 inserted. Alternatively, it is also conceivable that the power supply with the highest performance takes precedence, since very powerful interchangeable battery packs 22 sometimes have a higher current delivery capacity than a supply via a stationary power grid or an AC generator. Thus, the use of the correspondingly hybrid-powered demolition hammer can be simplified for the operator, as they do not have to manually switch to the respective power source.Furthermore, prioritizing the mains voltage UACI prevents the inserted interchangeable battery pack 22 from being unnecessarily discharged. Additionally, it can be provided that, in the event the demolition hammer is powered by the mains voltage UACI, an interchangeable battery pack 22 inserted into the electromechanical interface 20 is charged. Thus, if the demolition hammer is used in a location where no mains voltage UACI is available, a charged interchangeable battery pack 22 is available.

[0043] Figure 4 shows a block diagram of the power supply for the demolition hammer according to Figure 3. Despite its higher performance, the drive train 44 is fundamentally the same as that of the impact wrench shown in Figures 1 and 2. Therefore, it will not be discussed again here. Regarding the switching between the power supply modes, please refer to the explanations for Figure 3. If the power supply for the drive train 44 is provided by the two interchangeable battery packs 22 inserted into the electromechanical interfaces 20, the respective battery voltages UDCI and UDC2, for example 18 V, are converted to a resulting battery voltage UDC of 36 V by means of two DC / DC converters 58 of the converter circuit 48 (e.g., by connecting the two interchangeable battery packs 22 in series). This voltage is then used to dynamically adjust the target value of the intermediate circuit voltage Uic.

[0044] If the power supply is provided via the network interface 70 with an AC voltage UACI, SO that is the maximum permissible for operating the demolition hammer, it is sufficient to rectify the DC link voltage Uic before dynamic adjustment by means of a rectifier 72 of the converter circuit 48. If the supply voltage Us is a lower AC voltage UAC2 from a stationary power supply network or AC generator than the maximum permissible AC voltage UACI, an AC / DC converter with an integrated power factor correction circuit 74 generates the dynamically adjusted DC link voltage Uic. Thus, the demolition hammer can also be operated very efficiently with lower network voltages in the optimal range. If one of the AC voltages UACI or UAC2 is present at the network interface 70, this is detected by the sensor 64 and prioritized over the battery voltage UDC.The rectified and dynamically adjusted intermediate circuit voltage Uic is then smoothed by means of the regulated or unregulated intermediate circuit electronics 42. In the simplest case, the intermediate circuit electronics 42 consist of at least one capacitor.

[0045] An automatic switchover from battery to mains operation can also be provided if, in particular, the demolition hammer is powered by several series-connected interchangeable battery packs 22 and experiences a sudden temperature increase in one of the inserted interchangeable battery packs 22. A similar situation is conceivable if there is an abrupt drop in the battery voltage UDC or if it falls outside a permissible voltage range. Furthermore, the logic circuit 50 can be designed such that it prevents the demolition hammer from being used if two interchangeable battery packs 22 of different voltage classes are inserted.In an electrical processing device 10 with more than two electromechanical interfaces 20, the logic circuit 50 may be configured to connect only interchangeable battery packs 22 of the same voltage class in parallel, in order to prevent interchangeable battery packs 22 of a higher voltage class from being unnecessarily partially discharged by interchangeable battery packs 22 of a lower voltage class. For this purpose, the converter circuit 48 preferably includes several DC / DC converters 58 for the different battery voltages or a controllable DC / DC converter 58 for setting to the same intermediate circuit voltage Uic.

[0046] Figure 5 shows a block diagram of a third embodiment for the power supply of a purely mains-powered electrical processing device 10. The third embodiment differs from the previous embodiment primarily in that the converter circuit 48 does not include DC / DC converters. Furthermore, the AC / DC converter with integrated power factor correction circuit 74 can be optionally provided, depending on whether the processing device 10 needs to be supplied with an AC voltage UAC2 that is lower than the maximum permissible AC voltage UACI.Depending on the intended application of the electrical processing device 10, the converter circuit 48 can be flexibly designed through appropriate modularity. For example, certain hybrid-specific components can be omitted if the processing device 10 is intended for pure mains operation or pure battery operation, or if it is to be operated exclusively with a specific mains and / or battery voltage UACI, UAC2, UDC. A detailed description of the block diagram shown is omitted, as it otherwise essentially corresponds to the circuit in Figure 4.

[0047] Instead of a solution integrated into the electrical processing device 10, the converter circuit 48, according to a fourth embodiment shown in Figure 6, can alternatively be designed as an adapter 76 separate from the processing device 10. For this purpose, the adapter 76 preferably has two different electromechanical interfaces 20, a first of which is essentially identical to the electromechanical interface 20 of the interchangeable battery pack 22, and a second of which is essentially identical to the electromechanical interface 20 of the processing device 10. Thus, the adapter 76 can be detachably inserted into the electromechanical interface 20 of the processing device 10 without tools via its first electromechanical interface 20, and the interchangeable battery pack 22 can be inserted into its second electromechanical interface 20.In the illustrated embodiment, the adapter 76 has three secondary electromechanical interfaces 20 for accommodating three interchangeable battery packs 22. The individual battery voltages UDCI, UDC2, and UDC3 are combined to form the resulting battery voltage UDC via the DC / DC converters 58 integrated in the converter circuit 48. For a processing device 20 that is typically supplied with a battery voltage UDC of, for example, 18 V via its electromechanical interface 20, the converter circuit 48 connects the three inserted interchangeable battery packs 22 in parallel. This enables dynamic adjustment of the intermediate circuit voltage Uic, even for processing device 10, where this was not originally intended.

[0048] Alternatively, it is also conceivable that a processing device 10, which is normally only operable by means of interchangeable battery packs 22, can also be operated with a mains voltage via an adapter 76 designed analogously to Figure 5. Preferably, the adapter 76 has a communication interface 78 and / or an electrical encoding 80, via which the processing device 10 is identified to determine the permissible battery voltage UDC and to define the setpoint for the intermediate circuit voltage Uic. The information of the electrical encoding 80 can, in a particularly preferred manner, be exchanged with the processing device 10 via the first electromechanical interface 20. For this purpose, the electrical encoding 80 can, for example, be designed as an encoding resistor in the adapter 76 and / or in the processing device 10, the resistance value of which is determined by the control electronics 40 of the processing device 10.The processor of adapter 76 (not shown) can be read and compared with a look-up table. The evaluation can then be performed via the communication interface 78. This allows the operator of the machining device 10 to use adapter 76 for different battery-powered machining devices 10 without having to worry about the optimal setpoint and the permissible battery voltage UDC.

[0049] Finally, it should be noted that the exemplary embodiments shown are not limited to Figures 1 to 6, nor to the voltage values ​​mentioned and / or the absolute number of electromechanical interfaces 20 or of the interchangeable battery packs 22.

Claims

Claims 1. An electric machining device (10) comprising a housing (14), an output mechanism (38) for a tool (32) for machining a workpiece, an electric motor (12) for driving the output mechanism (38), an intermediate circuit electronics (42) for generating a rectified intermediate circuit voltage (Uic) from a supply voltage (Us) of the machining device (10), and a power electronics (38) for controlling the electric motor (12) by means of a motor voltage signal (UM) generated from the intermediate circuit voltage (Uic), wherein the power electronics (38), the intermediate circuit electronics (42), and the electric motor (12) form a drive train (44) which is incorporated in the housing (14) with at least a part of the output mechanism (28), characterized in that a converter circuit (48) is connected upstream of the intermediate circuit electronics (42), which provides a dynamically adjustable setpoint of the intermediate circuit voltage (Uic) from the supply voltage (Us).

2. Electrical processing device (10) according to claim 1, characterized in that the electric motor (12) is a brushless DC motor and that the power electronics (38) has an inverter bridge circuit (36) which pulse-width modulates the motor voltage signal (UM) for controlling the brushless DC motor as a function of the adapted intermediate circuit voltage (Uic) such that a clock ratio of the motor voltage signal (UM) is always 100%.

3. Electrical processing device (10) according to one of the preceding claims, characterized in that the converter circuit (48) comprises an AC / DC converter (72) which dynamically adjusts the setpoint of the intermediate circuit voltage (Uic) when the supply voltage (Us) is a maximum permissible AC voltage (UACI) of a stationary supply network or AC voltage generator for the operation of the processing device (10). rators is 4. Electrical processing device (10) according to one of the preceding claims, characterized in that the converter circuit (48) comprises an AC / DC converter with an integrated power factor correction circuit (72) which generates the intermediate circuit voltage (Uic) and dynamically adjusts its setpoint when the supply voltage (Us) is a lower AC voltage (UAC2) than the maximum permissible AC voltage (UACI) of a stationary supply network or AC voltage generator.

5. Electrical processing device (10) according to one of the preceding claims, characterized in that a logic circuit (50), preferably a control or regulating electronics (40), regulates the setpoint of the intermediate circuit voltage (Uic) in real time.

6. Electrical processing device (10) according to one of the preceding claims 1 to 4, characterized in that the setpoint of the intermediate circuit voltage (Uic) can be preset by an analog control loop of the control electronics (40) or a fixed preset control element (52), in particular a potentiometer.

7. Electrical processing device (10) according to one of the preceding claims, characterized in that at least one electromechanical interface (20) for tool-free detachable mounting of at least one interchangeable battery pack (22) is provided on the housing (14) of the processing device (10).

8. Electrical processing device (10) according to claim 7, characterized in that the supply voltage (Us) is formed by a battery voltage (UDC) of the at least one incorporated interchangeable battery pack (22) and the converter circuit (48) has a DC / DC converter (58) which dynamically adjusts the setpoint of the intermediate circuit voltage (Uic).

9. Electrical processing device (10) according to one of the preceding claims, characterized in that the converter circuit (48) is included as part of the drive train (44) in the housing (14) of the processing device (10).

10. Electrical processing device (10) according to claim 7, characterized in that the converter circuit (48) is designed as an adapter (76) separate from the processing device (10), which can be inserted into the at least one electromechanical interface (20) of the processing device (10) without tools.

11. Electrical processing device (10) according to claim 10, characterized in that the adapter (76) has a communication interface (78) and / or an electrical coding (80) via which the processing device (10) is identified for setting the target value for the intermediate circuit voltage (Uic).

12. Electric processing device (10) according to one of the preceding claims, characterized in that the electric processing device (10) is a hand-held power tool, in particular an electrically hybrid powered hand-held power tool.

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