Rotary Switch Magnet Detection via Segmented Composite Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary switches and electronic timepieces face challenges in accurately detecting the rotation of operating members with large magnets, leading to potential damage due to positional collisions and inaccurate detection.
Innovation Solution
A rotary switch design that includes a stem with a small-diameter stepped recess section and a magnet member slidably attached to the stem, where the magnet is pressed by a magnet pressing section, allowing the magnet to rotate with the stem while maintaining a fixed position relative to the magnetic sensor, preventing damage and enabling accurate rotation detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnets are fixed to the stem in a through-hole structure, then the stem rotation can be detected, but large magnets cannot be attached and rotation detection accuracy is insufficient
Solution Approach 1:
The magnet member is divided into a magnetic substance portion and a non-magnetic substance portion that are separately formed and then integrated. This segmentation allows the magnetic substance to be optimized for detection accuracy while the non-magnetic substance provides structural support, enabling the use of larger effective magnet area without compromising the through-hole stem structure.
Solution Approach 2:
The magnet member uses a composite structure combining magnetic substance (for detection) and non-magnetic substance (for structure). This composite approach allows optimization of each material's properties - the magnetic substance provides strong magnetic field for accurate detection while the non-magnetic substance enables larger overall size without interfering with magnetic sensor operation.
2Ease of operation
If the projecting section of the crown faces the contact section of the permanent magnet when the knob is pulled out, then the rotary switch can operate, but the projecting section or permanent magnet may collide and become deformed or damaged
Solution Approach 1:
A non-magnetic substance portion is introduced as an intermediary between the magnetic substance and the stem. This intermediary prevents direct contact and potential collision between the magnet member and the stem during axial movement, while still allowing magnetic interaction for rotation detection. The non-magnetic material acts as a buffer that maintains operational functionality while preventing mechanical damage.
Solution Approach 2:
The magnet pressing section is designed to press the magnet member beforehand in a state that prevents excessive axial movement. This pre-positioning ensures that when the stem moves axially during operation, the magnet member is already constrained and cannot collide with the stem, preventing deformation or damage before it can occur.
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 allows for high-accuracy detection of the stem's rotation without damaging the magnet or operating member, even when moved axially, reducing power consumption and enabling quick time adjustments by continuously monitoring the magnet's rotation.
Implementation Method 1
a magnetic sensor which detects the rotation of the magnet member
Implementation Method 2
a magnet member which rotates together with the stem
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A rotary switch of the invention includes an operating member (4) operable to move from outside the case to first and second positions in the axial direction and operable in a rotation direction, a magnet member (6) that is rotated by rotation of the operating member, and a magnetic sensor (7) that detects rotation of the magnet member. In this switch, an engaging section (8) is formed in the operating member (4), an engaging hole is formed in the magnet member (6), and the magnet member is provided in a manner not to move in the axial direction of the operating member (4). When the operating member (4) is moved in the axial direction, the engaging section (8) moves inside the engaging hole (18) with the engaging section (8) being engaged with the engaging hole (18), and when the operating member (4) is rotated, the magnet member (6) rotates therewith.