Hydraulic Press Load Sharing to Cut Servo Motor Capacity
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Solution Overview
Problem
Conventional press systems driven by servo motors have high costs and energy inefficiencies due to the need for large servo motor capacity and power supply capacity to handle both press and die cushion loads, with existing solutions either increasing energy efficiency at the expense of motor capacity or reducing motor capacity at the cost of energy efficiency.
Innovation Solution
The press system design integrates hydraulic cylinders to cancel die cushion loads, allowing only forming loads to act on the slide, with a mechanical drive unit applying residual press loads, and uses solenoid valves and pressure adjustment mechanisms to control pressure and reduce servo motor capacity, achieving cost reduction and improved energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a servo motor with large capacity is used to handle both press and die cushion loads, then the press system can provide sufficient power for both operations, but the price, power receiving capacity, and control panel size increase significantly
Solution Approach 1:
The press system is divided into two independent drive systems: a mechanical drive unit (crank mechanism) for the press load and a servo motor-driven hydraulic cylinder for the die cushion load. This segmentation allows each subsystem to be optimized independently, with the servo motor sized only for die cushion operations rather than the total combined load, thereby reducing motor capacity requirements and overall system cost
Solution Approach 2:
The patent combines the mechanical drive unit and servo motor-driven hydraulic cylinder into a unified press system where both systems cooperate to deliver their respective loads to the slide. The mechanical drive unit handles the majority press load while the hydraulic cylinder handles the die cushion load, achieving cost-effective integration without requiring an oversized servo motor
2Power
If a servo motor with large capacity is used to handle both press and die cushion loads, then the press system can provide sufficient power for both operations, but the power receiving capacity and control panel size increase
Solution Approach 1:
By segmenting the drive system into a mechanical drive unit for press operations and a servo motor for die cushion operations, the power requirements are separated. The servo motor only needs to provide power for die cushion load adjustments, which are relatively small compared to the total press load, thereby significantly reducing power receiving capacity requirements
3Device complexity
If the die cushion load is not canceled by hydraulic cylinders, then the press system operates with conventional mechanical drive, but the servo motor capacity must be oversized to handle the combined press and die cushion loads
Solution Approach 1:
The hydraulic cylinder driven by the servo motor acts as a counterbalance system that generates a force opposing the die cushion load. By adjusting the hydraulic pressure, the system can cancel out the die cushion load, allowing the mechanical drive unit to handle only the net forming load and reducing the servo motor capacity requirements
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 system achieves a significant reduction in servo motor capacity by up to 60% and improves energy efficiency by ensuring that only forming loads are applied to the slide, effectively reducing overall system costs and energy consumption.
Implementation Method 1
a die cushion load generated by a first hydraulic cylinder (130) when the slide (110) descends cancels out the die cushion portion of a total load acting on the slide (110)
Implementation Method 2
solenoid valves and pressure adjustment mechanisms to control pressure
Data Source
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AI summary
A press system providing excellent energy efficiency for a whole press system and capable of achieving low prices is provided. A die cushion apparatus 160-1 constituting a press system 10 supports a cushion pad 128, includes a hydraulic cylinder 130 which generates a die cushion load on the cushion pad 128 when a slide 110 of a press machine 100-1 descends, the press machine 100-1 includes a hydraulic cylinder 137 which generates part of a press load on the slide 110 when the slide 110 descends. The pressure generation chamber 130b of the hydraulic cylinder 130 for generating a die cushion load and the pressure generation chamber 137b of the hydraulic cylinder 137 for generating part of the press load can communicate with each other via pipes 152, 155 and a first logic valve 171 for a period during which the die cushion load acts.