Actuator Suction Sensing with Flow and Pressure Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional actuator systems face challenges in accurately determining whether a workpiece is properly suctioned to the tip of a shaft, especially with small workpieces and nozzles, leading to potential drops during transfer, and require efficient suction determination methods to minimize tact time.
Innovation Solution
A sensing device is integrated into the actuator system, featuring a flow sensor and a pressure sensor in the air passage to detect the flow rate and pressure, allowing for accurate suction determination by setting predetermined flow and pressure thresholds, independent of nozzle diameter, ensuring proper suction before reaching vacuum state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pressure sensor is used to detect suction status, then suction determination can be performed, but measurement precision deteriorates when using small diameter nozzles due to decreased pressure difference
Solution Approach 1:
A flow sensor is introduced as an intermediary measurement device between the suction nozzle and the control system. Instead of directly measuring pressure difference (which has low precision for small nozzles), the flow sensor measures air flow rate, which provides a more sensitive and accurate indicator of suction status for small diameter nozzles. The flow sensor acts as a mediator that converts the suction status into a more detectable parameter.
Solution Approach 2:
The invention changes the measurement parameter from pressure difference to air flow rate. For small diameter nozzles, the pressure difference is too small to detect accurately, but the air flow rate provides a more distinguishable signal between suctioned and non-suctioned states. This parameter change enables accurate suction determination across both large and small workpiece sizes.
2Reliability
If air suction is continued until vacuum state is reached, then reliable suction determination can be made, but tact time increases
Solution Approach 1:
The flow sensor provides real-time feedback on air flow rate during the suction process. The control system monitors this feedback and can determine suction status at any stage of the suction process, not only when vacuum is reached. This allows the system to make timely suction determination and proceed with workpiece transfer, reducing tact time while maintaining reliability.
Solution Approach 2:
The flow sensor enables preliminary suction determination before the suction process is complete. By monitoring air flow rate, the system can detect workpiece attachment early in the suction process, allowing preliminary confirmation of successful pickup without waiting for full vacuum to be achieved. This preliminary action reduces the time required for suction determination.
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 enables immediate and accurate suction determination for various workpieces, reducing tact time and ensuring reliable pickup operations without being influenced by nozzle size, thereby enhancing the actuator's performance in handling diverse workpieces.
Implementation Method 1
a flow sensor provided in a middle of an air passage to detect a flow rate of air flowing through the air passage
Implementation Method 2
a pressure sensor provided in a middle of the air passage, to detect a pressure in the air passage
Implementation Method 3
the actuator being configured to generate a negative pressure in the hollow part to suction a workpiece to a tip of the shaft
Data Source
AI summary
Provided is a sensing device to be applied to an actuator including a shaft that is movable in an axial direction, the shaft including a hollow part formed on at least a tip side of the shaft such that an interior of the shaft is hollow, the actuator being configured to generate a negative pressure in the hollow part to suction a workpiece to a tip of the shaft, thereby picking up the workpiece. The sensing device includes a flow sensor provided in a middle of an air passage to detect a flow rate of air flowing through the air passage, the air passage being a passage through which air sucked out from the hollow part flows when the negative pressure is applied to the hollow part, and a pressure sensor provided in a middle of the air passage, to detect a pressure in the air passage.