Pneumatic Hammer Valve Deactivation for Striker Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In hand-held chiseling power tools, the pneumatic hammer mechanism fails to deactivate properly when the chisel is lifted off a workpiece due to the striker bouncing off a front stop, leading to inefficient energy transfer and reduced control.
Innovation Solution
A self-medium-actuated valve device with a pivotable sealing element is used, which changes volume in response to the striker's movement, controlling the pneumatic chamber to deactivate the air spring when the striker is lifted, ensuring efficient energy transfer and tool control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional ventilation openings are used to deactivate the air spring when the chisel is lifted, then the pneumatic hammer mechanism can be deactivated, but the peen striker may rebound off the front stop and fail to remain away from the ventilation openings
Solution Approach 1:
A dimple is introduced as an intermediary component between the peen striker and the ventilation openings. The dimple absorbs the rebound motion of the peen striker and prevents it from interfering with the ventilation openings, thereby ensuring reliable deactivation while maintaining proper striker positioning.
Solution Approach 2:
The pneumatic chamber volume changes automatically with the movement of the peen striker along the axis, creating a self-regulating system. When the peen striker moves forward, the pneumatic chamber volume decreases, and when it rebounds, the volume increases, automatically controlling the air spring activation without additional control mechanisms.
2Device complexity
If the peen striker is allowed to rebound off the front stop, then the striker can be simple in design, but the energy transfer becomes inefficient and control is reduced
Solution Approach 1:
The dimple acts as a mediator that captures and dissipates the rebound energy of the peen striker. By providing a controlled stopping point for the rebound motion, the dimple prevents energy loss while maintaining a simple striker design without complex damping mechanisms.
3Reliability
If the sealing element remains in the extended position, then the pneumatic chamber remains closed and the air spring remains active, but the tool cannot be deactivated when the chisel is lifted
Solution Approach 1:
The sealing element is designed to be dynamic rather than static, automatically changing position based on the pneumatic pressure differential. The sealing element pivots between extended and retracted positions in response to pressure changes, enabling automatic on-off control without external actuation mechanisms.
Solution Approach 2:
The system uses pneumatic pressure feedback to control the sealing element position. When the pneumatic chamber volume changes due to peen striker movement, the resulting pressure differential automatically actuates the sealing element to open or close the ventilation openings, creating a self-regulating feedback loop.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively deactivates the pneumatic hammer mechanism when the chisel is lifted, preventing unnecessary energy consumption and improving user control by ensuring the striker remains away from ventilation openings, thus optimizing the chiseling process.
Implementation Method 1
When the volume of the pneumatic chamber increases during movement of the dopper in the direction of impact, the pivotable sealing element pivots into the folded position when the pressure gradient decreases towards the pneumatic chamber and into the unfolded position when the pressure gradient increases towards the pneumatic chamber
Implementation Method 2
The pneumatic chamber acts as a tapping brake, controlled by the tapping direction. The pressure change in the pneumatic chamber, which occurs with the movement of the tapping element, causes the tapping element to decelerate.
Implementation Method 3
an air spring can be deactivated by means of additional ventilation openings
Data Source
Figure 1
Figure 2
Figure 3~7
AI summary
The machine tool has a rivet set (20), a guide tube (31), in which the rivet set is guided along an axis (8), and a pneumatic chamber (40), which is closed by the rivet set, the guide tube and a valve device (100) actuated by its own medium. A volume of the pneumatic chamber changes in the case of a movement of the rivet set along the axis. The valve device has a pivoted sealing element (101) between the rivet set and the guide tube. An independent claim is also included for a tool retainer provided with a pivoted joint formed by a solid joint.