Die Cushion Device Using Closed Circuit Pressurization
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Solution Overview
Problem
Existing die cushion devices are complex and expensive due to the requirement of a compressed air supply source and a hydraulic pump and electric motor, leading to high power costs for each cycle of operation.
Innovation Solution
A die cushion device that uses a fluid-pressure closed circuit with an accumulator for low system pressure and a pilot drive type logic valve, eliminating the need for a fluid-pressure pump by utilizing die cushion force to pressurize hydraulic fluid, and incorporating solenoid valves for pressure control to reduce energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a hydraulic pump and electric motor are used to create high hydraulic pressure, then high pressure can be achieved, but the device becomes complicated and expensive with high power costs
Solution Approach 1:
The patent extracts and eliminates the hydraulic pump and electric motor from the system. Instead of using active pressurization devices, the invention uses the die cushion force itself to pressurize the hydraulic fluid through a pressurization chamber, thereby removing the complex and expensive pressurization subsystem while maintaining the ability to generate high hydraulic pressure when needed.
Solution Approach 2:
The die cushion mechanism serves a dual function: it not only provides the cushioning force but also acts as the pressurization source for the hydraulic system. The die cushion force directly pressurizes the hydraulic fluid in the closed circuit, making the system self-sufficient and eliminating the need for external power sources or dedicated pressurization equipment.
2Stress or pressure
If a compressed air supply source and hydraulic pump are continuously operated, then sufficient pressure is maintained, but power costs increase for each cycle of operation
Solution Approach 1:
The patent implements periodic pressurization instead of continuous operation. The hydraulic fluid is pressurized only during the die cushion operation when the pressurization chamber is activated by the die cushion force. During other phases, the system operates with stored pressure or at lower pressure states, eliminating continuous power consumption while maintaining sufficient pressure for each operational cycle.
Solution Approach 2:
The system uses the periodic die cushion operations to generate and store hydraulic pressure as needed. The accumulator stores pressure during pressurization phases and releases it during operation phases, creating a self-regulating pressure system that eliminates continuous power consumption while maintaining sufficient pressure for each operational cycle.
3Stress or pressure
If multiple pressure creation mechanisms are used, then both low and high pressure requirements are met, but the device becomes more complex
Solution Approach 1:
The die cushion mechanism is designed to perform multiple functions: it provides the primary cushioning force and simultaneously serves as the pressurization source for the hydraulic system. The pressurization chamber and accumulator work together to provide both low pressure (for extension and knockout operations) and high pressure (for cushioning operations) using the same fundamental mechanism, thereby reducing overall system complexity.
Solution Approach 2:
The patent uses hydraulic principles to create a closed circuit system where pressure is generated mechanically rather than through separate pneumatic or hydraulic subsystems. The hydraulic fluid circulates through the system, being pressurized by the die cushion force and stored in the accumulator, providing a unified pressure delivery system that replaces multiple separate pressure creation mechanisms.
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 results in a simpler, more cost-effective die cushion device that saves power costs by eliminating the need for a hydraulic pump and reducing operational complexity, while maintaining efficient die cushion pressure control.
Implementation Method 1
an accumulator which accumulates hydraulic fluid at low system pressure capable of knockout operation
Implementation Method 2
a pilot relief valve that creates pilot pressure for controlling the logic valve... pressurize the hydraulic fluid in the fluid-pressure closed circuit in one cycle period of the cushion pad, including the die cushion operation and the knockout operation, by using only die cushion force
Data Source
AI summary
There is provided a die cushion device that includes a cushion pad, a hydraulic cylinder configured to lift the cushion pad, and a hydraulic closed circuit connected to a die cushion pressure creation chamber of the hydraulic cylinder. The hydraulic closed circuit includes a pilot drive type logic valve that is operable as a main relief valve at the time of the die cushion operation, and a pilot relief valve configured to create pilot pressure for controlling the logic valve. Hydraulic oil is filled in the hydraulic closed circuit, in a pressurized manner, and the hydraulic oil in the hydraulic closed circuit is pressurized by only die cushion force applied from the cushion pad through the hydraulic cylinder, in one cycle period of the cushion pad.