Three-Valve Pneumatic Control for Vacuum Grip Power-Fail Hold
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Solution Overview
Problem
Existing control devices for pneumatic gripping elements in industrial manipulators lack both energy-saving functionality and effective safeguards against power failures, leading to unintended release of objects during electrical blackouts or pressure increases.
Innovation Solution
A control device comprising a normally closed monostable valve, a bistable valve, and a normally open monostable directional-control valve, arranged in parallel, with an electronic control unit to manage the valves, ensuring energy efficiency and safe operation by maintaining or restoring low pressure in the gripping element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a monostable valve is used to control compressed air supply, then the device structure is simple and cost-effective, but the object may be accidentally released during electrical blackout or pressure increase
Solution Approach 1:
The control system is segmented into two independent valves: a monostable valve for normal operation and a bistable valve for safety protection. Each valve has its own control circuit and functions, allowing the safety function to operate independently even when the main control fails during electrical blackout
Solution Approach 2:
The bistable valve is pre-configured in a normally closed state that blocks the compressed air supply line. This beforehand preparation ensures that if the monostable valve fails to close during electrical blackout or pressure increase, the bistable valve can immediately activate to cut off air supply and prevent object release
2Reliability
If compressed air supply is continuously maintained, then the pneumatic element remains active and ready, but energy is wasted during periods when gripping is not needed
Solution Approach 1:
The monostable valve operates periodically rather than continuously - it opens compressed air supply only when needed for gripping operations and closes it during non-operational periods. This periodic action maintains pneumatic element readiness when required while eliminating continuous compressed air consumption that would waste energy
Solution Approach 2:
The control system uses feedback signals from the manipulator's operational state to control the monostable valve. When the manipulator is in gripping mode, the valve opens to supply compressed air; when not in use, the valve closes to stop air supply, ensuring the pneumatic element is active only during necessary operations
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 provides both energy-saving and power failure protection, ensuring the pneumatic element remains active or inactive as needed, preventing accidental release of objects, with improved responsiveness compared to previous designs.
Implementation Method 1
an outlet hole for an air jet accelerated by the nozzle, and a suction hole arranged between the inlet hole and the outlet hole, through which air drawn by the air flow, which is moving between the inlet hole and the outlet hole, is sucked
Data Source
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AI summary
A control device of a pneumatic element such as a suction cup, ejector, etc. is described. The control device comprises a supply circuit supplying compressed air for connecting to an inlet of the pneumatic element. Three valves are provided in the circuit: a normally closed monostable valve having an inlet for connecting to a compressed air source and an outlet for connecting to the inlet of the pneumatic element, and having a first control port and a second control port, a bistable valve having an inlet connected to the source of compressed air and an outlet connected to the first control port of the normally closed monostable valve, where the first control port is configured to control the closing of the normally closed monostable valve, and a normally open monostable valve having a first inlet connected to the compressed air source and an outlet connected to the second control port of the normally closed monostable valve, where the second control port is configured to control the opening of the normally closed monostable valve. The valves can be opened or closed to allow or prevent, respectively, the flow of compressed air. Based on the open or closed configuration of each valve, corresponding configurations of the control device are obtained in order to selectively activate or deactivate the pneumatic element.