Percussion unit

Patent metadata

Field	Value
Publication number	US-9969071-B2
Application number	US-201314403258-A
Country	US
Kind code	B2
Filing date	Apr 24, 2013
Priority date	May 25, 2012
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

Percussion unit, especially for a rotary hammer and/or percussion hammer, comprising a control unit which is designed for open-loop and/or closed loop control of a pneumatic percussion mechanism, and at least one operating condition sensor unit. According to the disclosure, the control unit is designed to detect at least one percussion mechanism parameter depending on measurement values of the operating condition sensor unit.

First claim

The invention claimed is:

1. A percussion mechanism unit for at least one of a rotary hammer and a percussion hammer comprising:
a pneumatic percussion mechanism configured to generate percussive impulses; and
a control unit having at least one operating-condition sensor configured to sense at least one of a temperature and an ambient air pressure, the control unit being configured to:
determine a maximum frequency of the pneumatic percussion mechanism based on the at least one of the temperature and the ambient air pressure, the maximum frequency being a frequency at which a kinetic energy of the percussive impulses stops increasing with increased frequency of the percussive impulses;
determine at least one operating parameter of the pneumatic percussion mechanism based on the determined maximum frequency; and
operate the pneumatic percussion mechanism with the at least one operating parameter.

2. The percussion mechanism unit as claimed in claim 1 , wherein:
the operating-condition sensor unit is configured to sense the temperature and the ambient air pressure; and
the control unit is configured to determine the maximum frequency of the pneumatic percussion mechanism based on the temperature and the ambient air pressure.

3. The percussion mechanism unit as claimed in claim 1 , wherein the control unit is configured to determine a limit frequency of the pneumatic percussion mechanism, the limit frequency being a frequency below which a starting of the pneumatic percussion mechanism to generate the percussive impulses is ensured.

4. The percussion mechanism unit as claimed in claim 1 , wherein the at least one operating parameter is a throttle characteristic quantity of a venting unit.

5. The percussion mechanism unit at claimed in claim 1 , wherein the at least one operating parameter is at least one of a percussion frequency and a percussion-mechanism rotational speed.

6. The percussion mechanism unit as claimed in claim 1 , wherein the control unit is configured to determine the at least one operating parameter using a computing unit.

7. The percussion mechanism unit as claimed in claim 1 , wherein the control unit is configured to determine the maximum frequency with reference to at least one of a characteristic curve and a family of characteristics stored in a memory unit.

8. The percussion mechanism unit as claimed in claim 1 , wherein the control unit is configured to take account of at least one of positional information, an operating mode, and an application case in determining at least one of the maximum frequency and the at least one operating parameter.

9. The percussion mechanism unit as claimed in claim 1 , wherein the control unit is configured to take account of at least one wear parameter in determining at least one of the maximum frequency and the at least one operating parameter.

10. The percussion mechanism unit as claimed in claim 1 , wherein the control unit is configured, in at least one operating state, to set the at least one operating parameter temporarily to a starting value to change from an idling operating state to a percussive operating state.

11. The percussion mechanism unit as claimed in claim 1 , wherein the control unit is configured, in at least one operating state, to set the at least one operating parameter to an above-critical working value in a percussive operating state.

12. The percussion mechanism unit as claimed in claim 1 , wherein the control unit is configured, in at least one operating state, to set the at least one operating parameter directly to a working value, to change from an idling operating state to an percussive operating state.

13. The percussion mechanism unit as claimed in claim 1 , further comprising:
an operation change sensor configured to signal a change of the operating mode.

14. The percussion mechanism unit as claimed in claim 1 , wherein the control unit has at least one delay parameter, which is configured to influence a time period for a change between two values of the at least one operating parameter.

15. The percussion mechanism unit as claimed in claim 1 , wherein a hand power tool comprises the percussion mechanism unit.

16. A method for operating a percussion mechanism unit for at least one of a rotary hammer and a percussion hammer, the percussion mechanism unit having (i) a pneumatic percussion mechanism configured to generate percussive impulses and (ii) a control unit having at least one operating-condition sensor configured to sense at least one of a temperature and an ambient air pressure, the method comprising:
sensing, with the at least one operating-condition sensor, the at least one of the temperature and the ambient air pressure;
determining, with the control unit, a maximum frequency of the pneumatic percussion mechanism based on the at least one of the temperature and the ambient air pressure, the maximum frequency being a frequency at which a kinetic energy of the percussive impulses stops increasing with increased frequency of the percussive impulses; and
determining, with the control unit, at least one operating parameter of the pneumatic percussion mechanism based on the determined maximum frequency; and
operating, with the control unit, the pneumatic percussion mechanism with the at least one operating parameter.

Assignees

• Bosch Gmbh Robert

Inventors

• Nitsche Rainer
• Tauber Matthias
• Schlesak Gerd
• Vandamme Antoine
• Winkler Thomas
• Bertsch Christian
• Duesselberg Achim
• Hoffmann Ulli
• Henke Thilo
• Lennartz Juergen
• Sprenger Helge

Classifications

• B25D2250/221

  Sensors · CPC title

• B25D2250/201

  for speed, e.g. drilling or percussion speed · CPC title

• B25D2250/145

  Electro-magnetic parts · CPC title

• B25D2250/131

  Idling mode of tools · CPC title

• B25D2250/035

  Bleeding holes, e.g. in piston guide-sleeves · CPC title