Material Handling Vehicle Passage Valve for Load-Adaptive Lowering
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Solution Overview
Problem
Existing material handling vehicles face limitations in lowering speed due to safety mechanisms that restrict operation effectiveness, especially when loads are less than maximum, and mechanical valves may fail to activate correctly at lower loads.
Innovation Solution
Incorporation of an electronically controlled passage valve and pressure sensors to manage hydraulic fluid flow, allowing variable lowering speeds based on load weight and hydraulic system integrity, with redundant pressure detection for enhanced safety and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical valve is used to limit lowering speed, then safety is improved, but material handling effectiveness deteriorates at lower loads
Solution Approach 1:
The valve system transitions from a static mechanical valve with fixed limiting characteristics to a dynamic electronically controlled valve that can adjust its flow restriction based on real-time conditions. The control unit receives signals from the load sensor and pressure sensor, then dynamically adjusts the valve opening to optimize both safety and productivity for each specific operating condition.
Solution Approach 2:
The system changes the operational parameters of the valve based on detected load conditions. When the load sensor detects lighter loads, the control unit modifies the valve's flow characteristics to allow higher lowering speeds, whereas under maximum load conditions, the valve maintains restricted flow for safety. This parameter adaptation resolves the contradiction between safety and productivity.
2Reliability
If a mechanical valve limits lowering speed to maximum safety threshold, then safety is improved, but lowering speed is reduced even when not needed
Solution Approach 1:
The electronically controlled valve dynamically changes its flow restriction parameters based on actual load conditions detected by sensors. Instead of maintaining a fixed maximum safety threshold, the system adjusts the lowering speed parameter in real-time - allowing higher speeds when loads are light and maintaining restricted speeds only when actually needed for safety, thus eliminating unnecessary speed limitations.
Solution Approach 2:
The patent replaces the purely mechanical valve system with an electronically controlled valve that uses electrical signals from sensors and a control unit to regulate flow. This substitution enables precise, adaptive control of lowering speed based on actual operating conditions rather than fixed mechanical characteristics.
3Device complexity
If mechanical valves are used for flow control, then device simplicity is improved, but reliability deteriorates due to potential activation failures
Solution Approach 1:
The system replaces mechanical valve actuation with an electronically controlled valve that responds to electrical signals from the control unit. This substitution eliminates the reliability issues associated with mechanical activation mechanisms while maintaining relatively simple overall system architecture through the use of modern electronic control components.
Solution Approach 2:
The control unit receives feedback signals from load sensors and pressure sensors to monitor system state and adjust valve operation accordingly. This feedback mechanism ensures reliable activation and operation of the valve under varying conditions, preventing the activation failures that can occur with purely mechanical systems.
4Adaptability or versatility
If electronically controlled passage valve is implemented, then lowering speed control flexibility is improved, but device complexity increases
Solution Approach 1:
The electronically controlled passage valve serves multiple functions: it controls lowering speed, responds to load variations, monitors system pressure, and provides safety protection. This multi-functionality consolidates what would otherwise require multiple separate components into a single integrated system, managing complexity while maximizing flexibility.
Solution Approach 2:
The control unit acts as an intermediary that processes sensor information and translates it into appropriate valve control signals. This intermediary layer simplifies the overall system architecture by centralizing the decision-making logic, allowing the passage valve itself to remain a relatively simple execution component while achieving complex control flexibility.
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
Enables efficient and safe operation by allowing higher lowering speeds when loads are lighter, improving material handling efficiency and safety by preventing mechanical valve failures.
Implementation Method 1
A hydraulic pump pressurizes a hydraulic fluid which is fed to the hydraulic cylinder that is mechanically coupled to the load carrier. The increased pressure in the hydraulic cylinder provides for that the cylinder is extended and thus will lift the load carrier.
Implementation Method 2
the risk a raised load will by gravity press down the load carrier and empty the hydraulic cylinder through the rupture
Implementation Method 3
A passage valve is also comprised in the hydraulic system. The passage valve is arranged such that it is able to close the passage. The load carrier is connected to the hydraulic lift cylinder such that the load carrier is lowered when hydraulic fluid flows out of the hydraulic lift cylinder through the passage
Data Source
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AI summary
Material handling vehicle (1) comprising, a load carrier (2), a control unit (6), a hydraulic system (20) for operation of hydraulic functions of the material handling vehicle (1), including the lifting and lowering of the load carrier (2), wherein control unit (6) is connected to a passage valve (5), such that the control unit (6) is able to control the hydraulic fluid flow through the passage valve (5) by sending control commands to the passage valve (5), wherein the passage valve (5) is positioned directly in the hydraulic lift cylinder (3) and/or in the passage (9) of the hydraulic lift cylinder (3). There is also disclosed a method and a computer software executing the method.