DRILLING AND / OR CHILLING HAMMER AND METHOD FOR CONTROLLING IT

Description

State of the art

[0001] The present invention relates to a rotary hammer and / or chisel hammer according to the preamble of claim 1, as well as a method for controlling or regulating the speed of a drive unit of a rotary hammer and / or chisel hammer. Such a rotary hammer and / or chisel hammer and such a method are known from EP 1 607 186 A1.

[0002] Hand-held power tools are already known which have a control or regulating unit for controlling or regulating a drive unit and at least one sensor unit, wherein the sensor unit comprises at least one sensor element designed as an acceleration sensor.

[0003] EP 1 607 186 A1 discloses a handheld power tool designed as a drill and / or chisel hammer, which comprises a control or regulating unit and at least one sensor unit with at least one sensor element designed as an acceleration sensor and at least one further sensor element designed as a speed sensor for regulating the individual impact energy of an impact mechanism unit driven by a drive unit. The control or regulating unit is provided to regulate a target speed of the drive unit from a signal from the sensor element designed as a speed sensor. A trigger signal can be obtained from the signal from the sensor element designed as an acceleration sensor in order to enable calculation of the individual impact energy.

[0004] US 2013 / 269961 A1 further shows a hand-held power tool designed as a screwdriver, the control or regulating unit of which is intended to determine an actual speed of the drive unit from a signal of a sensor element designed as a speed sensor.

[0005] The object of the invention is to provide a speed control or regulation for a drilling and / or chisel hammer that is improved compared to the prior art. Disclosure of the invention

[0006] The object of the present invention is solved by the features of claim 1 and by the features of claim 8. Preferred embodiments of the present invention are defined by the dependent claims.

[0007] To achieve this object, it is proposed that the sensor element designed as an acceleration sensor is provided to record acceleration values ​​​​dependent on the impact mechanism unit. By means of the inventive design of the machine tool device, a cost-effective device for determining an actual speed of the drive unit can advantageously be realized. It is therefore advantageously possible to dispense with already known speed sensors, which are arranged, for example, on a fan wheel. This advantageously makes it possible to save production costs, assembly costs, and assembly effort, since the omission of a speed sensor arranged on the fan wheel allows high manufacturing tolerances in the area of ​​the fan wheel. In addition, reliable starting of the impact mechanism unit can advantageously be achieved, since the impact mechanism unit can be started up from a low starting impact rate.Furthermore, by adjusting the speed of the drive unit to an operating condition, an increase in the performance of the impact unit can be advantageously achieved. Furthermore, low-vibration behavior of the hand-held power tool during idle operation can be advantageously enabled due to the low speed.

[0008] "Provided" should be understood in particular to mean specially programmed, specially designed, and / or specially equipped. The fact that an element and / or unit is provided for a specific function should be understood in particular to mean that the element and / or unit fulfills and / or performs this specific function in at least one application and / or operating state. The control or regulating unit is preferably provided for regulating a target speed of the drive unit. The drive unit is preferably designed as an electric motor unit. In this case, the drive unit can be designed as an AC electric motor unit or as a DC motor unit. The control or regulating unit is preferably provided for controlling or regulating a speed of the drive unit. A "control or regulating unit" should be understood in particular to mean a unit with at least one control electronics unit."Control electronics" is understood, in particular, to mean a unit comprising a processor unit and a memory unit, as well as an operating program stored in the memory unit. The control or regulating unit preferably receives electrical signals from the sensor unit, which are taken into account when controlling or regulating the drive unit. For this purpose, the control or regulating unit is preferably connected to the sensor unit at least electrically and / or via data transmission. The control or regulating unit can be connected to the sensor unit in a wired and / or wireless manner. The control or regulating unit comprises, in particular, an operating program and / or an operating function, which has at least one algorithm for determining an actual speed of the drive unit from a signal from the sensor element designed as an acceleration sensor.Preferably, the actual speed of the drive unit can be determined from a signal of the sensor element designed as an acceleration sensor using a Fourier analysis, a phase-locked loop (PLL), and / or a frequency comb (covariance). Additionally, speed determination is conceivable using a method for determining a period from a time signal, in which a time between two signal peaks or two zero crossings of the acceleration signal can be measured, and a frequency can be determined from this. Depending on the signal quality, preprocessing using a bandpass filter is useful. Alternatively, the time between several signal peaks or zero crossings can be determined, whereby the calculated frequency is averaged over several periods.

[0009] The sensor element configured as an acceleration sensor is preferably provided to record acceleration values ​​that are aligned at least substantially parallel to a drive axis, in particular a rotational axis, of the drive unit and / or that are aligned at least substantially parallel to a rotational axis of a tool holder of the machine tool. However, it is also conceivable that the sensor element configured as an acceleration sensor is alternatively or additionally provided to record acceleration values ​​that are aligned at least substantially perpendicular to a drive axis, in particular a rotational axis, of the drive unit."Substantially parallel" is understood here to mean, in particular, an orientation of a direction relative to a reference direction, in particular in a plane, wherein the direction has a deviation from the reference direction of, in particular, less than 8°, advantageously less than 5°, and particularly advantageously less than 2°. The term "substantially perpendicular" is intended here to define, in particular, an orientation of a direction relative to a reference direction, wherein the direction and the reference direction, in particular viewed in a plane, enclose an angle of 90°, and the angle has a maximum deviation of, in particular, less than 8°, advantageously less than 5°, and particularly advantageously less than 2°.

[0010] According to the invention, the control or regulating unit is at least designed to adjust a speed of the drive unit depending on a signal from the sensor element designed as an acceleration sensor. This allows for a simple adjustment of the speed of the drive unit. Furthermore, the costs of a device for adjusting the speed of the drive unit can thus be advantageously kept low.

[0011] Furthermore, it is proposed that the sensor unit comprise at least one further sensor element configured as a current sensor. Preferably, the further sensor element configured as a current sensor is provided for measuring a drive unit current, in particular a current consumed by the drive unit. Thus, an additional drive unit characteristic can advantageously be detected, which can be used for further processing by the control or regulating unit.

[0012] It is further proposed that the control or regulating unit be provided at least to adjust a rotational speed of the drive unit as a function of a signal from the sensor element configured as an acceleration sensor and as a function of a signal from the further sensor element configured as a current sensor. This advantageously enables detection of an operating state, in particular impact operation or idle operation of a percussion unit. Thus, an advantageous adjustment of the rotational speed of the drive unit to an operating state can be achieved.

[0013] It is also proposed that the sensor unit comprise at least one additional sensor element configured as a voltage sensor. The additional sensor element configured as a voltage sensor is preferably provided for measuring a drive unit voltage, in particular a voltage absorbed by the drive unit. Thus, an additional drive unit characteristic can advantageously be detected, which can be used for further processing by the control or regulating unit.

[0014] Furthermore, it is proposed that the control or regulating unit is at least provided to set a rotational speed of the drive unit as a function of a signal from the sensor element designed as an acceleration sensor, as a function of a signal from the further sensor element designed as a current sensor, and as a function of a signal from the additional sensor element designed as a voltage sensor. By means of the configuration according to the invention, an actual rotational speed of the drive unit can advantageously be determined, which can be used to precisely set a target rotational speed of the drive unit. Thus, a precise setting of a target rotational speed of the drive unit can advantageously be carried out during ongoing operation of the drive unit.

[0015] It is further proposed that the control or regulating unit comprise at least one voltage and / or current regulator for setting the speed of the drive unit, which is provided to take into account a speed characteristic generated from a signal of the sensor element designed as an acceleration sensor. In addition, the voltage and / or current regulator for setting the speed preferably also takes into account the signals of the further sensor element designed as a current sensor and the additional sensor element designed as a voltage sensor for setting the speed. A deviation from a target speed of the drive unit can advantageously be kept small, since an actual speed of the drive unit can be taken into account when regulating a speed by means of the voltage and / or current regulator.

[0016] The hammer drill and / or chisel hammer has, in particular, a mass of less than 40 kg, preferably less than 10 kg, and particularly preferably less than 5 kg. The hammer drill and / or chisel hammer can be designed as a battery-operated or power-cord-operated power tool.

[0017] Furthermore, a method according to the invention is proposed according to claim 8, wherein the control or regulating unit determines at least one frequency of a periodic acceleration, by means of which an actual speed of the drive unit can be determined. Thus, a cost-effective detection of an actual speed of the drive unit can be realized, which can be used particularly advantageously for setting a target speed of the drive unit.

[0018] It is further proposed that the control or regulating unit perform at least one adaptation of a parameter map of the drive unit stored in a memory unit of the control or regulating unit to set a target speed of the drive unit. This advantageously enables application-dependent adaptation of a parameter map during ongoing operation, enabling precise setting of a target speed. This advantageously enables precise control of the drive unit.

[0019] The drill and / or chipping hammer according to the invention and / or the method according to the invention are not intended to be limited to the application and embodiment described above. In particular, the number of individual elements, components, and units may vary to fulfill a described function. drawing

[0020] Further advantages will become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0021] They show: Fig. 1 a drilling and / or chiseling hammer according to the invention in a schematic representation, Fig. 2 a detailed view of a machine tool device according to the invention of the drilling and / or chiseling hammer according to Figure 1in a schematic representation, Fig. 3 shows a detailed view of an alternative machine tool device according to the invention for the drilling and / or chiseling hammer in a schematic representation, Fig. 4 shows a detailed view of a further alternative machine tool device according to the invention for the drilling and / or chiseling hammer in a schematic representation and Fig. 5 shows a detailed view of a further alternative machine tool device according to the invention for the drilling and / or chiseling hammer in a schematic representation. Description of the embodiments

[0022] Figure 1shows a power tool 66a designed as a drilling and / or chisel hammer. Thus, the power tool 66a is designed as a handheld power tool. However, it is also conceivable that the portable power tool 66a, in an alternative embodiment not shown here, is designed as a demolition hammer or as another handheld power tool that would be considered appropriate by a person skilled in the art. The power tool 66a comprises at least one impact mechanism unit 34a. The impact mechanism unit 34a is in Figure 1shown only schematically to explain its functionality. Furthermore, the machine tool 66a comprises a machine tool housing 36a, on which a tool holder 40a of the impact mechanism unit 34a is arranged in a front region 38a for receiving an insert tool 42a. On a side 44a facing away from the front region 38a, the machine tool 66a comprises a main handle 46a for guiding the machine tool 66a and for transmitting a force, in particular a pressing force, from an operator to the machine tool 66a. The machine tool 66a is further designed with a detachable additional handle 48a. The additional handle 48a can be detachably attached to the machine tool housing 36a via a snap-in connection or other connection that appears appropriate to a person skilled in the art.

[0023] To generate a drive torque and an impact pulse by means of the impact unit 34a, the machine tool 66a has a drive unit 14a. A drive torque of the drive unit 14a is transmitted to the impact unit 34a via an output unit 50a of the machine tool 66a to generate an impact pulse. However, it is also conceivable for the portable machine tool 66a to be decoupled from the output unit 50a, and for the drive unit 14a to act essentially directly on the impact unit 34a to generate an impact pulse. An impact pulse of the impact unit 34a is generated in a manner already known to those skilled in the art.In this case, by means of a reciprocating movement of an impact impulse element 52a of the impact mechanism unit 34a, designed as a piston, in at least one impact operation of the impact mechanism unit 34a, a pressure is generated to move a further impact impulse element 54a of the impact mechanism unit 34a, designed as a striker, which is provided for transmitting an impact impulse to a firing pin 56a of the impact mechanism unit 34a. Furthermore, the drive torque for generating a rotational movement of the insert tool 42a is transmitted to the tool holder 40a via the output unit 50a via a guide element 58a of the impact mechanism unit 34a, designed as a hammer tube, and / or via a rotary drive element (not shown in detail here) arranged on the tool holder 40a.

[0024] The impact mechanism unit 34a for the machine tool 66a comprises at least the impact pulse element 52a, at least the guide element 58a for guiding the impact pulse element 52a, and at least one idle opening control unit 60a, which has at least one movably mounted idle opening control element 62a for opening and / or closing at least one idle opening 64a of the guide element 58a. The idle opening control unit 60a is designed as a sleeve control unit. Thus, the idle opening control element 62a is designed as an idle control sleeve. The impact pulse element 52a, designed as a piston, moves translationally from a front dead center to a rear dead center within the guide element 58a, designed as a hammer tube, during idle operation of the impact mechanism unit 34a, in which the idle opening 64a is open and thus not closed by the idle opening control element 62a.However, it is also conceivable for the impact pulse element 52a, designed as a piston, to be designed as a pot piston and, when the impact mechanism unit 34a is in idle operation, to move translationally from a front dead center to a rear dead center relative to other components of the impact mechanism unit 34a guided in the pot piston or relative to the machine tool housing 36a. As a result, an impact pulse is generated as a result of driving the impact pulse element 52a, designed as a piston. For vibration damping, it is conceivable for the machine tool 66a to include a damping unit (not shown in detail here). The damping unit is provided to dampen a vibration that can be transmitted to an operator of the machine tool 66a.

[0025] Furthermore, the machine tool 66a comprises at least one machine tool device 10a for controlling or regulating the machine tool 66a. The machine tool device 10a is designed as a handheld power tool device. The machine tool device 10a comprises at least one control or regulating unit 12a for controlling or regulating a drive unit 14a and at least one sensor unit 16a, which comprises at least one sensor element 18a designed as an acceleration sensor. By means of the sensor element 18a designed as an acceleration sensor, an acceleration of the machine tool 66a caused by the impact unit 34a can be detected. The sensor element 18a designed as an acceleration sensor is provided to detect at least one acceleration running in the impact direction and / or opposite to the impact direction of the impact unit 34a.In this case, the acceleration during impact operation of the impact mechanism unit 34a results from a periodic impact generated by the impact mechanism unit 34a. In idle operation, the acceleration results from a reciprocating movement of the impact impulse element 52a, designed as a piston. This acceleration can be detected by the sensor element 18a, designed as an acceleration sensor.

[0026] The control or regulation unit 12a is provided at least to determine at least one actual speed of the drive unit 14a from a signal of the sensor element 18a designed as an acceleration sensor. For this purpose, the control or regulation unit 12a has a phase-locked loop unit 68a ( Figure 2) which is intended to determine a frequency from a signal detected by the sensor element 18a designed as an acceleration sensor. Alternatively, it is conceivable that the control or regulating unit 12a, instead of the phase-locked loop unit 68a, comprises a Fourier analysis unit or a frequency comb unit for determining a frequency from a signal detected by the sensor element 18a designed as an acceleration sensor. In addition, a rotational speed determination is conceivable using a method for determining a period from a time signal, in which a time between two signal peaks or two zero crossings of the acceleration signal can be measured and a frequency can be determined therefrom. Depending on the signal quality, preprocessing using a bandpass filter is useful in this case.Alternatively, the time between multiple signal peaks or zero crossings can be determined, whereby the calculated frequency is averaged over multiple periods. The phase-locked loop unit 68a comprises at least one phase detector 70a, a loop filter 72a, and a voltage-controlled oscillator 74a. Thus, the phase-locked loop unit 68a is designed as an analog phase-locked loop unit 68a. In a diagram shown in . Figure 3 In the variant of the phase-locked loop unit 68a' shown, the phase-locked loop unit 68a' has a phase detector 70a', a loop filter 72a' and a numerically controlled oscillator 74a'. Thus, the Figure 3The variant of the phase-locked loop unit 68a' shown is designed as a digital phase-locked loop unit 68a'. Thus, a frequency can be determined in a structurally simple manner from a signal detected by the sensor element 18a designed as an acceleration sensor. From this frequency, the control or regulating unit 12a calculates an actual rotational speed of the drive unit 14a. Thus, in a method for controlling or regulating a rotational speed of the drive unit 14a of the machine tool 66a, at least one frequency of a periodic acceleration is determined by means of the control or regulating unit 12a, by means of which frequency an actual rotational speed of the drive unit 14a can be determined. In addition, the control or regulating unit 12a is at least provided to set a rotational speed of the drive unit 14a as a function of a signal from the sensor element 18a designed as an acceleration sensor.

[0027] Furthermore, the sensor unit 16a has at least one further sensor element 20a designed as a current sensor. The further sensor element 20a designed as a current sensor is intended to detect a current consumed by the drive unit 14a. A current value detected by the further sensor element 20a designed as a current sensor is transmitted to the control or regulating unit 12a. The control or regulating unit 12a is intended at least to set a rotational speed of the drive unit 14a as a function of a signal from the sensor element 18a designed as an acceleration sensor and as a function of a signal from the further sensor element 20a designed as a current sensor. Furthermore, the sensor unit 16a comprises at least one additional sensor element 22a designed as a voltage sensor.The additional sensor element 22a, designed as a voltage sensor, is provided to detect a voltage received by the drive unit 14a. A voltage value detected by the additional sensor element 22a, designed as a voltage sensor, is transmitted to the control or regulating unit 12a. The control or regulating unit 12a is thus provided at least to adjust a rotational speed of the drive unit 14a depending on a signal from the sensor element 18a, designed as an acceleration sensor, depending on a signal from the further sensor element 20a, designed as a current sensor, and depending on a signal from the additional sensor element 22a, designed as a voltage sensor.

[0028] In addition, the control or regulation unit 12a comprises at least one voltage and / or current regulator 24a for setting the speed of the drive unit 14a, which is provided to take into account a speed parameter generated from a signal of the sensor element 18a designed as an acceleration sensor ( Figure 4). In this case, the voltage and / or current regulator 24a is provided to take into account at least one actual speed of the drive unit 14a calculated by means of the control or regulating unit 12a from the signal of the sensor element 18a designed as an acceleration sensor. In addition, the voltage and / or current regulator 24a takes into account the signals of the further sensor element 20a designed as a current sensor and the additional sensor element 22a designed as a voltage sensor for setting the speed of the drive unit 14a. However, it is also conceivable for the control or regulating unit 12a to calculate a drive unit voltage from an ignition point of the drive unit 14a for setting the speed of the drive unit 14a, which can be made available to the voltage and / or current regulator 24a as an alternative to the signal of the additional sensor element 22a designed as a voltage sensor for setting the speed of the drive unit 14a.

[0029] The speed of the drive unit 14a is thus controlled by means of the voltage and / or current regulator 24a. At regular intervals, an actual speed of the drive unit 14a is determined from a signal of the sensor element 18a, which is designed as an acceleration sensor, and transmitted to the voltage and / or current regulator 24a. The actual speed of the drive unit 14a is further compared by means of the voltage and / or current regulator 24a with a target speed of the drive unit 14a stored in a memory unit 26a of the control or regulation unit 12a and specific for an operation, such as impact operation and / or idle operation. If the control or regulation unit 12a detects a deviation, the control parameters are modified in such a way that the deviation is kept to a minimum.The change (adaptation) of the control parameters takes place by at least one order of magnitude, which is slower than a control of the voltage and / or current regulator 24a, so that the adaptation does not have any effect on the control by means of the voltage and / or current regulator 24a. The adaptation is preferably only carried out in a stationary state, i.e. when an output signal of the voltage and / or current regulator 24a no longer changes or changes only slightly. For this purpose, a plurality of parameter maps 28a, 30a, 32a are stored in the memory unit 26a. The voltage and / or current regulator 24a accesses the parameter maps 28a, 30a, 32a stored in the memory unit 26a to set the speed of the drive unit 14a. The parameter maps 28a, 30a, 32a can be evaluated to calculate an ignition point of the drive unit 14a.In order to precisely achieve a desired target speed of the drive unit 14a during stationary operation, at least one of the parameter maps 28a, 30a, 32a can be adapted by means of the control or regulating unit 12a. For example, if an actual speed is greater than a target speed of the drive unit 14a, an applied drive unit voltage is too high and thus a value for the ignition timing is too low. One of the parameter maps 28a, 30a, 32a, in particular a parameter map defining a target ignition timing, is adapted by shifting it upward by an offset. The offset is, for example, proportional to a difference between a target speed and an actual speed of the drive unit 14a calculated from the signal of the sensor element 18a designed as an acceleration sensor.After several adaptation steps, one of the parameter maps 28a, 30a, 32a is adjusted so that the ignition timing calculated by the voltage and / or current regulator 24a delivers a precise drive unit voltage, so that the drive unit 14a runs at the desired target speed. Alternatively, it is conceivable that several parameter maps 28a, 30a, 32a are adapted simultaneously or sequentially, or that the parameter maps 28a, 30a, 32a are not only shifted up or down by an offset, but that a gradient of the stored parameter maps 28a, 30a, 32a is varied. Thus, the control or regulation unit 12a carries out at least one adaptation of a parameter map 28a, 30a, 32a of the drive unit 14a stored in a memory unit 26a of the control or regulation unit 12a to set a target speed of the drive unit 14a.In addition, it is conceivable that at least one operating state-dependent speed is stored in the memory unit 26a, which is adapted to a speed setting of the drive unit 14a depending on an operating state of the impact mechanism unit 34a.

[0030] Furthermore, impact detection is possible using the machine tool device 10a. This is achieved via the sensor element 18a, designed as an acceleration sensor, in combination with the sensor element 20a, designed as a current sensor. The sensor element 18a, designed as an acceleration sensor, can detect an increase in an acceleration value from the idle operation of the impact mechanism unit 34a relative to the impact operation of the impact mechanism unit 34a. The increase in the acceleration value occurs in an impact direction of the inserted tool 42a and lies within a frequency range of an impact frequency. The sensor element 20a, designed as a current sensor, can detect the impact operation of the impact mechanism unit 34a via an increased current consumption of the drive unit 14a. The current level depends on a rotational speed of the drive unit 14a and on an operating state of the impact mechanism unit 34a.As already described above, an actual rotational speed can be determined based on a signal from sensor element 18a, which is designed as an acceleration sensor. Furthermore, by detecting a current consumption of drive unit 14a using sensor element 20a, which is designed as a current sensor, an operating state of percussion unit 34a can be determined. Because the current level depends on a rotational speed of drive unit 14a and on an operating state of percussion unit 34a, a reliable and precise detection of an operating state of percussion unit 34a is possible.

[0031] Figure 5shows a further embodiment of the invention. The following descriptions and the drawings are essentially limited to the differences between the embodiments, whereby with regard to components with the same designation, in particular with regard to components with the same reference numerals, reference is also made to the drawings and / or the description of the other embodiments, in particular to the Figures 1 to 4 To distinguish the embodiments, the letter a is added to the reference numerals of the embodiment in the Figures 1 to 4 In the example of the Figure 5 the letter a is replaced by the letter b.

[0032] In the Figure 5 An alternative machine tool device 10b is shown. The machine tool device 10b is analogous to the one described in the Figures 1 to 4in a hand-held power tool (not shown in detail here). The power tool device 10b comprises at least one control or regulating unit 12b for controlling or regulating a drive unit 14b and at least one sensor unit 16b, which comprises at least one sensor element 18b designed as an acceleration sensor. The control or regulating unit 12b is provided at least to determine at least one actual speed of the drive unit 14b from a signal of the sensor element 18b designed as an acceleration sensor. A speed setting of the drive unit 14b is carried out at least substantially analogously to the method described in the description of the Figures 1 to 4 In contrast to the speed setting described in the Figures 1 to 4 The speed setting described is carried out in the Figure 5The described machine tool device 10b performs a speed setting by adapting a target speed of the drive unit 14b that is transferred to a voltage and / or current regulator 24b of the control or regulating unit 12b. The target speed of the drive unit 14b is transferred to the voltage and / or current regulator 24b, which calculates an ignition point of the drive unit 14b therefrom. A control loop is expanded such that the voltage and / or current regulator 24b does not access a target speed desired by an operator, but rather an adapted target speed of the drive unit 14b. If, in the steady state, an actual speed of the drive unit 14b is greater than the target speed desired by the operator, the adapted target speed is reduced by one step.The voltage and / or current regulator 24b thus registers a lower target speed in a next calculation step and sets a drive unit voltage of the drive unit 14b to a lower value using the ignition timing. Such an adaptation step is selected, for example, proportional to a difference between the target speed desired by an operator and the actual speed of the drive unit 14b. As a result, an adapted target speed is established in the long term such that the actual speed is equal to the target speed desired by the operator. When changing from idle operation to impact operation or vice versa, a separate value for an adapted target speed of the drive unit 14b is set for each speed level. When changing again from idle operation to impact operation or vice versa, a new adaptation is carried out.If you switch back to a previously selected operating mode, the previously adapted value of the adapted target speed continues to be used. For further features and functions of the machine tool device 10b, please refer to the description of the . Figures 1 to 4 be referred to.

Claims

1. Drilling hammer and / or chipping hammer with a drive unit (14a; 14b), with a striking-mechanism unit (34a) driven by the drive unit (14a; 14b), with at least one control or regulation unit (12a; 12b) for regulation of the drive unit (14a; 14b) and with at least one sensor unit (16a; 16b) which includes at least one sensor element (18a; 18b) taking the form of an acceleration sensor, characterized in that the control or regulation unit (12a; 12b) is provided at least to determine at least one actual rotational speed of the drive unit (14a; 14b) from a signal of the sensor element (18a; 18b) taking the form of an acceleration sensor, wherein the sensor element (18a; 18b) taking the form of an acceleration sensor is provided to record acceleration values caused by a striking-mechanism unit.

2. Drilling hammer and / or chipping hammer according to Claim 1, characterized in that the control or regulation unit (12a; 12b) is provided at least to adjust a rotational speed of the drive unit (14a; 14b) as a function of a signal of the sensor element (18a; 18b) taking the form of an acceleration sensor.

3. Drilling hammer and / or chipping hammer according to either of the preceding claims, characterized in that the sensor unit (16a; 16b) exhibits at least one further sensor element (20a; 20b) taking the form of a current sensor.

4. Drilling hammer and / or chipping hammer according to Claim 3, characterized in that the control or regulation unit (12a; 12b) is provided at least to adjust a rotational speed of the drive unit (14a; 14b) as a function of a signal of the sensor element (18a; 18b) taking the form of an acceleration sensor and as a function of a signal of the further sensor element (20a; 20b) taking the form of a current sensor.

5. Drilling hammer and / or chipping hammer according to any of the preceding claims, characterized in that the sensor unit (16a; 16b) exhibits at least one additional sensor element (22a; 22b) taking the form of a voltage sensor.

6. Drilling hammer and / or chipping hammer according to Claim 5, characterized in that the control or regulation unit (12a; 12b) is provided at least to adjust a rotational speed of the drive unit (14a; 14b) as a function of a signal of the sensor element (18a; 18b) taking the form of an acceleration sensor, as a function of a signal of the further sensor element (20a; 20b) taking the form of a current sensor, and as a function of a signal of the additional sensor element (22a; 22b) taking the form of a voltage sensor.

7. Drilling hammer and / or chipping hammer according to any of the preceding claims, characterized in that the control or regulation unit (12a; 12b) includes at least one voltage and / or current regulator (24a; 24b) for adjustment of the rotational speed of the drive unit (14a; 14b), which is provided to take into account a characteristic quantity of the rotational speed that has been generated from a signal of the sensor element (18a; 18b) taking the form of an acceleration sensor.

8. Method for control or regulation of a rotational speed of a drive unit (14a; 14b) of a drilling hammer and / or chipping hammer according to one of the preceding Claims 1 to 8, characterized in that the control or regulation unit (12a; 12b) determines at least one frequency of a periodic acceleration, by means of which an actual rotational speed of the drive unit (14a; 14b) can be determined.

9. Method according to Claim 9, characterized in that the control or regulation unit (12a) carries out at least one adaptation of a parameter characteristic (28a, 30a, 32a) of the drive unit (14a), saved in a memory unit (26a) of the control or regulation unit (12a), for adjustment of a set rotational speed of the drive unit (14a).