Hammer Drill Guide Rod Aligns Coil Spring Load to Prevent Oblique Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vibration control structures in hammer drills, such as those described in JP2010-567, face challenges in effectively absorbing linear vibrations due to oblique loading of coil springs, which reduces their lifespan and efficiency.
Innovation Solution
A vibration control structure that aligns the coil spring's load direction with the axis using a guide rod, transforming rotational motion into linear motion, thereby maintaining constant spring constant and extending the spring's lifespan by preventing oblique loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the upper connector makes rotational motion around the rotation shaft relative to the work tool main body, then the grip can move relative to the main body for vibration control, but the coil spring is subjected to oblique loading which changes its spring constant and reduces its lifespan
Solution Approach 1:
The guide rod acts as an intermediary component between the coil spring and the moving connectors. It converts the rotational motion of the upper connector into linear motion along the guide rod's axis, ensuring the coil spring is only subjected to axial compression forces. This mediator prevents the oblique loading that would otherwise occur during rotational movement, maintaining constant spring constant and extending the spring's lifespan while still enabling effective vibration control.
Solution Approach 2:
The system dynamically transforms the type of motion from rotational to linear through the guide rod mechanism. The upper connector's rotational movement is converted into linear compression of the coil spring along the guide rod, allowing the spring to operate in its optimal loading condition while still providing dynamic vibration absorption functionality.
2Volume of moving object
If the interval between connectors is reduced for compact tool configuration, then the tool size is reduced, but the coil spring is more susceptible to oblique loading and property deterioration
Solution Approach 1:
The guide rod serves as a constraint mediator that maintains proper load alignment even in compact configurations. By forcing the upper connector to move linearly along the guide rod rather than rotate freely, it ensures the coil spring remains axially loaded regardless of the reduced distance between connectors, preventing oblique loading and property deterioration.
Solution Approach 2:
The guide rod constrains the motion to a specific linear dimension, transforming what would be multi-directional rotational movement into unidirectional linear compression. This dimensional constraint ensures that even in compact tool configurations, the coil spring experiences only axial loading, maintaining its properties while enabling smaller overall tool size.
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
This structure effectively absorbs vibrations linearly, maintaining the coil spring's properties and extending its lifespan, particularly in compact tool configurations where the interval between connectors is reduced.
Implementation Method 1
transforming rotational motion into linear motion
Implementation Method 2
absorbs vibrations transmitted from the housing to the handle
Implementation Method 3
linear vibration absorption
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A grip 3 is joined to a rear side of a main body 2 by a first connector 5 and a second connector. The first connector 5 rotatably joins the main body 2 and the grip 3. The second connector has a coil spring 12 provided between the main body 2 and the grip 3, and a guide rod 13 that maintains a direction of load on the coil spring 12 in alignment with a direction of a line of axis of the coil spring 12. The guide rod 13 has a first opening that a first rotation shaft 10 of the main body 2 is inserted in and a second opening 13b that a second rotation shaft 11 of the grip 3 is inserted in, and the second opening 13b is shaped such that the second rotation shaft 11 is slidable in a longitudinal direction of the guide rod 13.