Parallel Valve Assembly for Stable Minimum Pressure Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluid pressure regulation systems, particularly in applications like laser cutting and blow-molding, face challenges in maintaining a specific target or minimum pressure due to the limitations of proportional valves, especially in open volumes and rapid refilling tasks, where the maximum achievable pressure is not effectively detectable and the integration of sensor systems is complex.
Innovation Solution
A valve arrangement with a proportional valve and a parallel switching valve, where a digital control device calculates the maximum achievable working pressure based on current system states and automatically opens the switching valve when the target pressure is undershot, using a technical calculation model that accounts for pneumatic resistance, outflow characteristics, and supply pressure drop to ensure precise pressure control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a proportional valve with larger maximum opening cross-section is used to achieve higher target pressure, then the maximum achievable pressure is improved, but the control accuracy within the performance range deteriorates
Solution Approach 1:
The valve arrangement divides the single proportional valve into two separate valves: a first proportional valve for precise pressure control in the normal range, and a second proportional valve (booster) for achieving higher target pressures. This segmentation allows each valve to operate within its optimal performance range, maintaining control accuracy while enabling higher maximum pressures.
2Stress or pressure
If a switching valve (booster) is added in parallel to increase maximum system performance, then the maximum achievable pressure is improved, but the device complexity increases
Solution Approach 1:
The control units of both proportional valves are merged into a single integrated control unit that receives one unified control signal. This merging approach simplifies the overall system architecture by eliminating the need for separate control circuits, reducing wiring complexity, and enabling coordinated operation of both valves through a single control interface.
3Measurement precision
If application-specific sensors are provided to detect actual pressure in expanding molded part, then the pressure control precision is improved, but the design complexity increases
Solution Approach 1:
The pressure sensor is positioned to serve multiple functions: it detects pressure in the molded part during blow molding, monitors pressure in the refilling process, and provides feedback for both proportional valves. This multi-functional usage eliminates the need for separate sensors for different processes, reducing design complexity while maintaining measurement precision.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a valve assembly and a method for regulating the pressure of a fluid. A valve assembly with a proportional valve is provided, for which the maintenance of a specified target or minimum pressure in a volume connected to said assembly is guaranteed. The essence of the invention is formed by a valve assembly (1) having: a proportional valve (2), comprising an opening cross section that can be continuously varied by an actuator; a sensor means for sensing the valve output pressure; a digital regulating device; and a switching valve (2) disposed parallel to the proportional valve (2), wherein the opening cross section of the switching valve is smaller than the maximum opening cross section of the proportional valve (2) and wherein the regulating device is programmed to automatically calculate, at runtime, using the currently given valve output pressure and the current position of the actuator, the maximum working pressure achievable at the maximum opening of the proportional valve (2) with said valve and, where the computed, maximum achievable working pressure falls below a predefinable target working pressure by a definable deviation value, to additionally open the switching valve (3).