Working Machine Speed Transition Control via Prime Mover Reduction
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Solution Overview
Problem
Existing working machines face inefficiencies in deceleration and acceleration processes due to lack of precise control over prime mover speed transitions, leading to shifting shocks and reduced workability.
Innovation Solution
A hydraulic system with a prime mover, traveling pumps, traveling motors, a switching valve, and a controller device that sets target speeds and adjusts actual speeds through a third target speed intermediate step during state transitions, allowing smoother speed changes and reduced shifting shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the switching valve switches between first state and second state to change traveling motor speed, then the working machine can operate at different speeds, but shifting shocks occur during speed transitions
Solution Approach 1:
The controller device performs preliminary speed reduction of the prime mover before the switching valve changes state. Specifically, when acceleration occurs from first state to second state, the controller reduces the prime mover speed to a predetermined speed before the switching valve switches, ensuring smooth transition without shock.
Solution Approach 2:
The system cushions the upcoming speed transition by reducing prime mover speed in advance. The controller device calculates and applies speed reduction timing and magnitude beforehand, so that when the switching valve actually switches states, the speed difference is minimized, cushioning the potential shock.
2Object-affected harmful factors
If the prime mover speed is reduced during acceleration from first state to second state, then shifting shocks are reduced, but the acceleration time increases
Solution Approach 1:
The controller device dynamically adjusts the prime mover speed parameter during the transition process. By changing the speed parameter to a predetermined reduction value before switching, and then restoring it after switching, the system achieves smooth transition while minimizing time loss through optimized parameter management.
Solution Approach 2:
The system employs dynamic speed adjustment rather than static speed maintenance. The prime mover speed is temporarily reduced during the transition phase and then restored, creating a dynamic response that balances shock reduction with acceptable acceleration time.
3Ease of operation
If the controller device manages speed transitions through preliminary reduction and restoration, then operational smoothness improves, but control complexity increases
Solution Approach 1:
The controller device uses feedback from the switching valve state and prime mover speed to determine when to reduce and restore speed. By monitoring the actual state and speed, the controller applies feedback control to manage the preliminary reduction and restoration timing, achieving smooth operation through intelligent control.
Data Source
AI summary
A working machine includes a switching valve to switch between a first state and a second state, the first state allowing a revolving speed of a traveling motor to be a first speed, the second state allowing the revolving speed of the traveling motor to be a second speed, and a controller device to reduce the revolving speed of the prime mover in either acceleration to switch from the first state to the second state or deceleration to switch from the second state to the first state. The controller device associates a return timing with a switch timing in either the acceleration or deceleration, the return timing allowing an actual revolving speed of a prime mover to start returning toward a first target revolving speed after the actual revolving speed is reduced, the switch timing allowing the switching valve to switch to either an acceleration side or a deceleration side.