Swing Circuit Flushing Valve Sizing for Faster Deceleration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In construction machines with hydraulic closed circuits, the swing deceleration responsiveness is compromised due to the pressure loss delay in the flushing valve, leading to reduced operability when switching over the valve, especially in swing motor circuits where the pressure receiving area difference is minimal.
Innovation Solution
A construction machine design with a bidirectionally tiltable pump and a smaller minimum passage area in the flushing valve for the swing circuit, allowing for swift pressure rise and valve switching during deceleration, enhancing responsiveness and operability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flushing valve with the same shape is used in both cylinder closed circuit and swing closed circuit, then cost is reduced, but pressure loss in the flushing valve during swing deceleration is insufficient, causing delayed valve switching and reduced swing deceleration responsiveness
Solution Approach 1:
The patent applies different minimum passage areas to flushing valves in different circuits based on their specific requirements. The swing closed circuit flushing valve has a smaller minimum passage area (1/10 or less of the cylinder circuit valve) to generate sufficient pressure loss during swing deceleration, while the cylinder closed circuit flushing valve maintains a larger passage area to handle the higher flow rates required for cylinder operation. This local differentiation optimizes performance for each specific application.
Solution Approach 2:
The patent changes the geometric parameter (minimum passage area) of the flushing valve to alter its pressure-loss characteristics. By reducing the minimum passage area in the swing closed circuit flushing valve, the pressure loss during swing deceleration is increased, enabling timely valve switching and improving swing deceleration responsiveness without affecting the overall system cost structure significantly.
2Speed
If the minimum passage area of the flushing valve in the swing closed circuit is reduced, then pressure rise speed during deceleration is improved, but the valve size becomes smaller
Solution Approach 1:
The patent implements local quality by making the minimum passage area of the swing closed circuit flushing valve smaller than that of the cylinder closed circuit flushing valve. This localized dimensional differentiation enables the swing valve to generate sufficient pressure loss for rapid pressure rise during deceleration, while the cylinder valve maintains its larger size to accommodate higher flow rates during normal operation.
Solution Approach 2:
The patent applies parameter changes by specifically reducing the minimum passage area parameter of the swing closed circuit flushing valve to 1/10 or less of the cylinder closed circuit valve's minimum passage area. This parameter adjustment directly controls the pressure loss characteristics, enabling faster pressure rise speed during swing deceleration while keeping the valve physically compact.
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 design enhances swing deceleration responsiveness and operability by ensuring quicker pressure rise and valve switching, improving the construction machine's ability to stop the swing operation efficiently.
Implementation Method 1
the pressure loss in the flushing valve in the swing closed circuit is smaller, so that the rise of pressure on the pump suction side (low pressure side) at the time of starting swing deceleration is delayed
Data Source
AI summary
Provided is a construction machine on which a hydraulic closed circuit for driving a single rod-type hydraulic cylinder and a swing hydraulic motor is mounted and that has good swing deceleration responsiveness. In this construction machine that drives each of a single rod-type hydraulic cylinder and a swing hydraulic motor in a closed circuit, a minimum passage area from a second flushing valve to a tank in a case the second flushing valve is fully open is smaller than a minimum passage area from a first flushing valve to the tank in a case the first flushing valve is fully open.