Proportional Slide Valve Layout for Hydraulic Pressure Peak Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing proportional slide valves in mobile hydraulics face issues with pressure peaks causing problems, particularly in protecting the steel structure of work vehicles like forest harvesters, where pressure relief valves are used to limit maximum load pressure.
Innovation Solution
A proportional slide valve design with a pressure relief valve that includes a third load pressure line with a check valve, allowing hydraulic fluid to flow out to the tank during pressure peaks, and a second check valve preventing fluid flow to the slide piston, along with a pilot control pressure aiding in opening the pressure relief valve, enhancing its functionality as a shock valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pressure relief valve is used to limit maximum load pressure, then the steel structure of the work vehicle is protected, but pressure peaks at the pressure outputs can still cause problems
Solution Approach 1:
A third load pressure line is introduced as an intermediary pathway between the first load pressure line and the second load pressure line. This intermediary line includes a check valve that allows pressure peaks to be redirected to the pressure relief valve, preventing direct transmission of pressure peaks to the pressure outputs while maintaining normal pressure transmission when needed.
Solution Approach 2:
The load pressure line is segmented into multiple paths: the first load pressure line for normal operation, the second load pressure line for pressure relief, and the third load pressure line as a dedicated pressure peak bypass path. This segmentation allows different functions to be performed simultaneously without interference, directing pressure peaks away from vulnerable components.
2Reliability
If a check valve is added to the third load pressure line to manage pressure peaks, then pressure control is improved, but the device complexity increases
Solution Approach 1:
The pressure relief valve serves multiple functions: it limits the maximum load pressure under normal operation and simultaneously acts as a shock valve to relieve pressure peaks through the third load pressure line. The check valve in the third load pressure line universally manages both normal pressure flow and pressure peak relief scenarios, reducing the need for separate dedicated components.
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 effectively manages pressure peaks by allowing hydraulic fluid to escape safely, preventing damage to the vehicle's steel structure and ensuring the pressure relief valve can handle high volume flows while maintaining control over fluid flow.
Implementation Method 1
a first check valve is arranged in the third load pressure line
Implementation Method 2
a pressure relief valve is arranged in the second load pressure line
Implementation Method 3
a spool that can be switched from a neutral position into at least one first switching position via a pilot control that generates a pilot force
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a proportional slide valve 1 with a slide piston 4 switchable from a neutral position N to at least one first switching position S1 via a pilot control 3 generating a pilot force, a pressure port 5, a first pressure outlet A, a return line 6 and a first load pressure line 8 connected to a load pressure outlet 7. In the first switching position S1, the pressure port 5 is connected to the first pressure outlet A and the first load pressure line 8. A second load pressure line 9 branches off from the first load pressure line 8, the second load pressure line 9 being connected to the return line 6 and a pressure relief valve 2' being arranged in the second load pressure line 9.A third load pressure line 16 branches off downstream of the spool piston 4 and upstream of the first pressure outlet A, wherein the third load pressure line 16 opens into the second load pressure line 9 upstream of the pressure relief valve 2' and a first check valve 17 is arranged in the third load pressure line 16. The invention further relates to a pressure relief valve and a hydraulic system 100‴.