Variable-Displacement Press Brake Pump for Lower Motor Power
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Solution Overview
Problem
There is a growing need for energy saving in industrial hydraulic press brakes, particularly in reducing power consumption of rotary motors used in piston pumps, due to increasing environmental concerns.
Innovation Solution
The hydraulic press brake system adjusts the pump discharge volume of the piston pump by pivoting an inclined plate, reducing the torque of the rotary motor during high-load states by switching between reference and small-discharge volumes, and controlling the actuation of lift cylinders through a bi-directional piston pump with a servomotor and electromagnetic switch valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pump discharge volume is set to a large value for high-speed operation, then the productivity is improved, but the power consumption of the rotary motor increases
Solution Approach 1:
The pump discharge volume is made dynamically adjustable through the pivotal movement of the inclined plate, allowing the system to switch between high-speed/low-load mode and low-speed/high-load mode. This dynamic adjustment enables the pump to operate at optimal discharge volumes for different operational requirements, reducing unnecessary power consumption during high-load bending operations while maintaining high productivity during no-load positioning.
Solution Approach 2:
The inclination angle of the inclined plate is changed to vary the pump discharge volume. By pivoting the inclined plate between different angular positions, the pump discharge volume is adjusted between a first discharge volume (for high-speed operation) and a second discharge volume (for high-load operation), thereby optimizing the balance between productivity and power consumption based on real-time operational needs.
2Reliability
If the rotary motor is sized for high-load operation, then the reliability is improved, but the manufacturing cost increases
Solution Approach 1:
The system dynamically adjusts the pump discharge volume to match the actual load requirements. During no-load or light-load operations, the pump operates at high discharge volume for fast positioning. During high-load bending operations, the pump discharge volume is reduced, which consequently reduces the torque demand on the rotary motor. This allows a smaller, less expensive motor to be selected while still providing sufficient torque for high-load operations when needed.
Solution Approach 2:
By changing the pump discharge volume parameter through inclined plate adjustment, the motor torque requirements are optimized for different operational phases. This parameter change allows the selection of a motor with lower power rating and torque capacity, reducing manufacturing costs while maintaining adequate reliability for high-load bending operations through coordinated pump-motor operation.
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
This configuration effectively lowers the power consumption of the rotary motor and reduces manufacturing costs by optimizing motor capacity, achieving energy savings while maintaining efficient operation.
Implementation Method 1
A piston pump configured to supply pressure oil to the upper hydraulic chamber and the lower hydraulic chamber of each lift cylinder
Implementation Method 2
an inclined plate inclined with respect to the pump rotary shaft. The inclination angle of the inclined plate with respect to the pump rotary shaft is constant (unchanged), and the pump discharge volume is set based on this inclination angle
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(b)
Figure 3
AI summary
The pump discharge flow rate of a bidirectional piston pump (31) is set to a reference pump discharge flow rate Qa if the operation state of a lifting/lowering cylinders (15) is in a no-load state, and is set to a small-flow-rate pump discharge flow rate Qb that is smaller than the reference pump discharge flow rate Qa if the operation state of the lifting/lowering cylinders (15) is in a high-load state. The value Qb·Pb found by multiplying the pump discharge flow rate Qb and the pump discharge pressure Pb of the bidirectional piston pump (31) for when the operation state of the lifting/lowering cylinders (15) is in a high-load state is set substantially equal to or less than the value Qa·Pa found by multiplying the pump discharge flow rate Qa and the discharge pressure Pa of the bidirectional piston pump (31) for when the operation state of the lifting/lowering cylinders (15) is in a no-load state.