Surface Texture Measuring Apparatus with Voice Coil Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional surface texture measuring apparatuses face challenges when measuring inner surfaces of cylindrical works, as the stylus may collide with the subject during posture switching, potentially damaging the stylus or the measurement subject due to lack of friction, leading to inefficient measurement processes.
Innovation Solution
A surface texture measuring apparatus with a posture switching mechanism that controls the switching speed of the measurement arm's posture, equipped with a pair of styli and a speed control mechanism using a voice coil and position detector to manage the switching speed, ensuring minimal impact during posture changes, allowing for safe measurement of both top and bottom inner surfaces without arm removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the measurement arm posture is switched quickly to improve measurement efficiency, then productivity increases, but the stylus may collide with the subject causing damage
Solution Approach 1:
The voice coil generates a preliminary urging force in the opposite direction before the measurement arm completes its switching motion. This preliminary action prepares the system to absorb the impact energy, preventing the stylus from colliding with the subject while maintaining efficient posture switching
Solution Approach 2:
The voice coil acts as a cushioning mechanism by generating an opposing urging force that absorbs the kinetic energy of the switching measurement arm before contact occurs. This beforehand cushioning prevents damage to both the stylus and the measurement subject
2Reliability
If friction between the measurement arm and axis of rotation is increased to prevent stylus collision, then reliability improves, but the stylus cannot follow the surface shape accurately
Solution Approach 1:
The patent replaces the traditional mechanical friction-based damping system with an active electromagnetic control system using a voice coil. This substitution allows for precise, dynamic control of the measurement arm's motion without the continuous friction that would interfere with surface shape detection
Solution Approach 2:
The voice coil dynamically changes the urging force parameter based on the real-time position and velocity of the measurement arm. By adjusting this parameter, the system provides just enough force to prevent collision while maintaining the low-friction conditions necessary for accurate surface shape following
3Reliability
If the stylus is retracted during posture switching to avoid collision, then reliability improves, but the measurement process becomes more complex
Solution Approach 1:
The patent extracts the collision prevention function from the mechanical structure and implements it through the voice coil's electromagnetic force. This eliminates the need for separate retracting mechanisms while maintaining stylus protection
Solution Approach 2:
The measurement arm system serves itself by using the voice coil to automatically control its own motion during posture switching. The system self-regulates the switching speed and generates appropriate urging forces without requiring external retracting mechanisms or complex control systems
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 apparatus effectively measures inner surfaces of holes by controlling the switching speed of the measurement arm, reducing damage to the stylus and the subject, and enabling efficient measurement of both top and bottom surfaces without arm reattachment, thus enhancing measurement precision and safety.
Implementation Method 1
a speed control mechanism configured to control a switching speed of posture switching of the measurement arm to a preset speed when the posture of the measurement arm is switched by the posture switching mechanism
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A surface texture measuring apparatus includes a stylus displacement detector (20) having a measurement arm (24) which is able to swing, a pair of styli (26A,26B) provided at a tip of the measurement arm, and a detection unit configured to detect swing amounts of the measurement arm, a stage configured to mount the subject of measurement thereon, and a relative movement mechanism configured to cause a relative movement between the detector and the stage. The apparatus includes a posture switching mechanism (60) configured to switch a posture of the measurement arm between a posture in which the measurement arm is urged in one swing direction and a posture in which the measurement arm is urged in the other swing direction, and a speed control mechanism (70) configured to control a switching speed of posture switching of the measurement arm to a preset speed when the posture of the measurement arm is switched by the posture switching mechanism.