Sequence Valve Clamp Control for Fast Lift Truck Closure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic control systems for lift truck clamp attachments face challenges in achieving high-speed closure without damaging loads, as low initial pressure limits productivity and the use of flow dividers restricts closing speed due to the need for higher pressures and potential oil contamination issues.
Innovation Solution
A hydraulic control circuit that alternates between hydraulically linked and unlinked modes for hydraulic actuators, using a sequence valve to coordinate clamp movement without flow dividers, allowing high-speed closure while minimizing load damage by adjusting clamp force effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If low initial pressure is used to minimize load damage, then load protection is improved, but closing speed is limited and productivity decreases
Solution Approach 1:
The system dynamically switches between two operational modes: a first mode where clamps are hydraulically linked for synchronized movement at high speed with minimal force, and a second mode where clamps are unlinked to apply full clamping force. This dynamic transition allows the system to achieve both high closing speed and load protection without compromise.
Solution Approach 2:
The sequence valve is configured to automatically transition the system from the first hydraulic mode to the second hydraulic mode upon detecting that clamps have contacted the load. This preliminary automatic transition ensures that high-speed closure is maintained until load contact, at which point force application is optimized without manual intervention.
2Stability of the object's composition
If flow dividers are used to coordinate clamp movement, then synchronized movement is improved, but closing speed is restricted due to pressure requirements and oil contamination risks
Solution Approach 1:
The hydraulic system is segmented into two distinct operational modes with different connectivity configurations. During the approach phase, clamps are hydraulically linked through the sequence valve for synchronized movement. During the clamping phase, clamps are unlinked to allow independent force application. This segmentation eliminates the need for flow dividers while maintaining synchronization where needed.
Solution Approach 2:
The sequence valve acts as an intermediary component that automatically controls the hydraulic linkage between clamps. It mediates the transition from synchronized movement mode to independent clamping mode based on load contact detection, eliminating the need for continuous flow divider intervention and enabling higher closing speeds.
3Speed
If complex relief settings are implemented to enable high-speed closure with low initial clamp force, then closing speed is improved, but device complexity increases
Solution Approach 1:
The sequence valve is configured to automatically detect load contact and trigger the mode transition without external control signals or complex electronic systems. The hydraulic system self-regulates by using the load contact event itself to activate the transition, eliminating the need for sensors, controllers, or complex relief valve settings.
Solution Approach 2:
The system uses inherent hydraulic feedback through the sequence valve to detect when clamps contact the load. The pressure change caused by load contact automatically triggers the transition from the first hydraulic mode to the second mode, creating a simple yet effective closed-loop control without additional complexity.
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 high-speed, synchronized closure of clamps without damaging loads and improves efficiency by optimizing clamp force application, reducing the need for complex relief settings and minimizing the risk of oil contamination.
Implementation Method 1
A hydraulic control circuit that alternates between hydraulically linked and unlinked modes for hydraulic actuators, using a sequence valve to coordinate clamp movement
Data Source
AI summary
A hydraulic control circuit operable to selectively hydraulically link first and second hydraulic actuators and to bypass that hydraulic link.