Impact Rotation Tool Switching Mechanism Stopper Wear
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Solution Overview
Problem
Existing impact rotation tools can shorten the life of the stopper due to excessive force from the coupling member, caused by friction and manufacturing or assembly errors, leading to premature wear.
Innovation Solution
Incorporating a relief in the drive shaft hole to reduce contact area with the coupling member and using an elastic member between the coupling member and the stopper to absorb forces, preventing excessive load on the stopper and extending its lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the coupling member is engaged with the wall of the drive shaft hole to switch between impact mode and drill mode, then the switching mechanism can change operational modes, but friction and manufacturing errors cause excessive force on the stopper, shortening its life
Solution Approach 1:
A resin layer is introduced as an intermediary between the coupling member and the drive shaft hole wall. This resin layer absorbs friction forces and manufacturing errors, preventing excessive forces from being transmitted to the stopper while still allowing the coupling member to engage and disengage for mode switching.
Solution Approach 2:
The resin layer is applied in advance to the drive shaft hole wall before assembling the coupling member. This pre-applied cushioning layer absorbs unexpected forces and friction that occur during operation, protecting the stopper from excessive loads before they can cause damage.
2Ease of operation
If a regulated clearance is provided between the drive shaft and anvil to permit axial movement during impact action, then the impact mode can function properly, but the coupling member may be strongly forced against the drive shaft hole wall due to friction and errors
Solution Approach 1:
The resin layer serves as a mediator between the coupling member and the drive shaft hole wall, absorbing the excessive forces generated during impact action while allowing the regulated clearance to function properly for axial movement.
Solution Approach 2:
The resin layer changes the friction parameters at the interface between the coupling member and drive shaft hole wall, reducing the coefficient of friction and absorbing force variations that occur during impact operation.
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 reduces the force applied to the stopper, thereby prolonging its life and preventing premature wear, while maintaining the tool's operational efficiency in both impact and drill modes.
Implementation Method 1
an elastic member between the coupling member and the stopper to absorb forces
Implementation Method 2
A hammer spring 85 urges the hammer 84 toward the anvil 82
Implementation Method 3
friction would occur where the coupling member 93 contacts the wall of the drive shaft hole 91
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3(a)~3(b)
AI summary
An impact rotation tool (1) includes a switching shaft (73) (73), which extends through a drive shaft (6), and a coupling member (72), which is coupled to the switching shaft (73). The switching shaft (73) moves the coupling member (72) to a position where the coupling member (72) is engaged with the wall of only the drive shaft hole (54) to switch the impact rotation tool (1) to an impact mode. The switching shaft (73) moves the coupling member (72) to a position where the coupling member (72) is engaged with the walls of both of the drive shaft hole (54) to switch the impact rotation tool (1) to a drill mode. The wall of the drive shaft hole (54) includes an engagement portion (75), which is engaged with the coupling member (72) in the impact mode, and a relief (76), which does not contact the outer circumferential surface of the coupling member (72) in the impact mode.