Power tool with measurement of a penetration depth of a working tool

1. A power tool for driving a working tool ( 3 ) that penetrates at least axially into a to-be-machined material ( 2 ), comprising a signal processor ( 6 , 6 ′) designed to determine a penetration depth (T) of the working tool ( 3 ) into the material ( 2 ) based on high frequency electromagnetic waves ( 4 ); and a transducer ( 5 ) suitable for exciting and detecting a high-frequency electromagnetic wave ( 4 ) propagating axially along the working tool ( 3 ), which is a waveguide of the electromagnetic wave, and connected to the signal processor ( 6 , 6 ′);

wherein the transducer ( 5 ) is formed as a coaxial conductor system whose elongate inner conductor is formed at least partially by the high-frequency conducting power tool ( 3 ) and whose sleeve-shaped outer conductor is formed at least partially by a high-frequency conducting housing ( 7 ) of the power tool, the inner conductor and outer conductor being insulated from one another with respect to high frequency.

2. A power tool according to claim 1 , wherein the transducer ( 5 ) has a high-frequency conducting feed connection ( 11 a , 11 b ) at the inner conductor and at the outer conductor, respectively, in a power tool-side axial end area of the working tool ( 3 ).

3. A power tool according to claim 1 , wherein the outer conductor forms a radial widening ( 9 ) at a front on a working tool side thereof.

4. A power tool according to claim 2 , wherein the feed connection ( 11 a ) is freely rotatable.

5. A power tool for driving a working tool ( 3 ) that penetrates at least axially into a to-be-machined material ( 2 ), comprising a signal processor ( 6 , 6 ′) designed to determine a penetration depth (T) of the working tool ( 3 ) into the material ( 2 ) based on high frequency electromagnetic waves ( 4 ); and a transducer ( 5 ) suitable for exciting and detecting a high-frequency electromagnetic wave ( 4 ) propagating axially along the working tool ( 3 ), which is a waveguide of the electromagnetic wave, and connected to the signal processor ( 6 , 6 ′);

wherein the signal processor ( 6 ) has a clock generator ( 12 ), a high-frequency pulse generator ( 13 ) which is suitable for outputting voltage pulses with rise times of less than 120 ps, a fast measurement input ( 14 ) which is suitable for detecting voltage signals with sampling times of less than 12 ps, and computing means ( 15 ) which contain a controlling algorithm ( 16 ) having a runtime module ( 17 ) for determining a time difference (Δt) between at least two voltage pulses selected by the measurement input ( 14 ).

6. A power tool according to claim 5 , comprising a differentiation device ( 18 ) suitable for differentiating signal peaks of voltage signals.

7. A power tool for driving a working tool ( 3 ) that penetrates at least axially into a to-be-machined material ( 2 ), comprising a signal processor ( 6 , 6 ′) designed to determine a penetration depth (T) of the working tool ( 3 ) into the material ( 2 ) based on high frequency electromagnetic waves ( 4 ); and a transducer ( 5 ) suitable for exciting and detecting a high-frequency electromagnetic wave ( 4 ) propagating axially along the working tool ( 3 ), which is a waveguide of the electromagnetic wave, and connected to the signal processor ( 6 , 6 ′);

wherein the signal processor ( 6 ′) has a variable-frequency high-frequency oscillator ( 19 ) which is suitable for stationary oscillations with frequencies greater than 8 GHz, a demodulator ( 20 ) for amplitude modulation of the high-frequency signal, a measurement input ( 14 ) suitable for detecting the amplitude signal of the high-frequency signal, and computing means ( 15 ) containing a controlling algorithm ( 16 ) which has a standing wave module ( 21 ) for determining the high-frequency-specific standing wave ratio and a distance module ( 22 ) for determining a distance (d) based on at least two different high-frequency-specific standing wave ratios.

8. A measurement method of determining the penetration depth (T) of a working tool ( 3 ) penetrating at least axially into a to-be-machined material, comprising the steps of providing a power tool for driving a working tool ( 3 ) that penetrates at least axially into a to-be-machined material ( 2 ), comprising a signal processor ( 6 , 6 ′) designed to determine a penetration depth (T) of the working tool ( 3 ) into the material ( 2 ) based on high frequency electromagnetic waves ( 4 ); and a transducer ( 5 ) suitable for exciting and detecting a high-frequency electromagnetic wave ( 4 ) propagating axially along the working tool ( 3 ), which is a waveguide of the electromagnetic wave, and connected to a signal processor ( 6 , 6 ′), carrying out a distance measurement up to a free end of the working tool in a first step, with the working tool ( 3 ) being exposed, and carrying out a distance measurement up to a surface of the machined material ( 2 ) in a second step with the working tool ( 3 ) penetrating into the machined material ( 2 );

wherein a time difference (Δt) between a first positive signal peak and a first negative signal peak is measured.

9. A power tool for driving a working tool ( 3 ) that penetrates at least axially into a to-be-machined material ( 2 ), comprising a signal processor ( 6 , 6 ′) designed to determine a penetration depth (T) of the working tool ( 3 ) into the material ( 2 ) based on high frequency electromagnetic waves ( 4 ); and a transducer ( 5 ) suitable for exciting and detecting a high-frequency electromagnetic wave ( 4 ) propagating axially along the working tool ( 3 ) and connected to the signal processor ( 6 , 6 ′);

wherein the transducer ( 5 ) is formed as a coaxial conductor system whose elongate inner conductor is formed at least partially by the high-frequency conducting power tool ( 3 ) and whose sleeve-shaped outer conductor is formed at least partially by a high-frequency conducting housing ( 7 ) of the power tool, the inner conductor and outer conductor being insulated from one another with respect to high frequency.

10. A power tool according to claim 9 , wherein the transducer ( 5 ) has a high-frequency conducting feed connection ( 11 a , 11 b ) at the inner conductor and at the outer conductor, respectively, in a power tool-side axial end area of the working tool ( 3 ).

11. A power tool according to claim 10 , wherein the feed connection ( 11 a ) is freely rotatable.

12. A power tool according to claim 9 , wherein the outer conductor forms a radial widening ( 9 ) at a front on a working tool side thereof.

13. A power tool for driving a working tool ( 3 ) that penetrates at least axially into a to-be-machined material ( 2 ), comprising a signal processor ( 6 , 6 ′) designed to determine a penetration depth (T) of the working tool ( 3 ) into the material ( 2 ) based on high frequency electromagnetic waves ( 4 ); and a transducer ( 5 ) suitable for exciting and detecting a high-frequency electromagnetic wave ( 4 ) propagating axially along the working tool ( 3 ) and connected to the signal processor ( 6 , 6 ′);

wherein the signal processor ( 6 ) has a clock generator ( 12 ), a high-frequency pulse generator ( 13 ) which is suitable for outputting voltage pulses with rise times of less than 120 ps, a fast measurement input ( 14 ) which is suitable for detecting voltage signals with sampling times of less than 12 ps, and computing means ( 15 ) which contain a controlling algorithm ( 16 ) having a runtime module ( 17 ) for determining a time difference (Δt) between at least two voltage pulses selected by the measurement input ( 14 ).

14. A power tool according to claim 13 , comprising a differentiation device ( 18 ) suitable for differentiating signal peaks of voltage signals.

15. A power tool for driving a working tool ( 3 ) that penetrates at least axially into a to-be-machined material ( 2 ), comprising a signal processor ( 6 , 6 ′) designed to determine a penetration depth (T) of the working tool ( 3 ) into the material ( 2 ) based on high frequency electromagnetic waves ( 4 ); and a transducer ( 5 ) suitable for exciting and detecting a high-frequency electromagnetic wave ( 4 ) propagating axially along the working tool ( 3 ) and connected to the signal processor ( 6 , 6 ′);

wherein the signal processor ( 6 ′) has a variable-frequency high-frequency oscillator ( 19 ) which is suitable for stationary oscillations with frequencies greater than 8 GHz, a demodulator ( 20 ) for amplitude modulation of the high-frequency signal, a measurement input ( 14 ) suitable for detecting the amplitude signal of the high-frequency signal, and computing means ( 15 ) containing a controlling algorithm ( 16 ) which has a standing wave module ( 21 ) for determining the high-frequency-specific standing wave ratio and a distance module ( 22 ) for determining a distance (d) based on at least two different high-frequency-specific standing wave ratios.

16. A measurement method of determining the penetration depth (T) of a working tool ( 3 ) penetrating at least axially into a to-be-machined material, comprising the steps of providing a power tool for driving a working tool ( 3 ) that penetrates at least axially into a to-be-machined material ( 2 ), comprising a signal processor ( 6 , 6 ′) designed to determine a penetration depth (T) of the working tool ( 3 ) into the material ( 2 ) based on high frequency electromagnetic waves ( 4 ); and a transducer ( 5 ) suitable for exciting and detecting a high-frequency electromagnetic wave ( 4 ) propagating axially along the working tool ( 3 ) and connected to a signal processor ( 6 , 6 ′), carrying out a distance measurement up to a free end of the working tool in a first step, with the working tool ( 3 ) being exposed, and carrying out a distance measurement up to a surface of the machined material ( 2 ) in a second step with the working tool ( 3 ) penetrating into the machined material ( 2 );

wherein the time difference (Δt) between a first positive signal peak and a first negative signal peak is measured.