Industrial Vehicle Gear Shifting Control with Delay Mode
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Solution Overview
Problem
The existing shift control systems for industrial vehicles, such as wheel loaders, often result in unintended vehicle drifting and reduced work efficiency due to premature shifting of gear stages during backward travel after excavation work and forward travel for loading soil onto a dump truck, leading to increased braking distances and operator inconvenience.
Innovation Solution
A shift control system that includes a vehicle speed detection device, transmission device, height position detection device, forward/backward switch device, and shift up control switch selection device, allowing for normal control and delay control modes. The system sets different shift up permission vehicle speeds based on vehicle direction and bucket height, delaying the shift up timing from speed 2 to speed 3 during delay control to prevent premature shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the shift control system lowers the setting speed for determining shift timing as engine rotation number decreases, then fuel consumption is improved, but vehicle drifting during backward travel deceleration increases and work efficiency is reduced
Solution Approach 1:
The patent applies dynamics by making the shift control system adaptive to changing operating conditions. The control device dynamically adjusts shift timing based on detected vehicle speed, engine rotation number, and accelerator pedal depressing amount, allowing the system to optimize fuel consumption during cruising while preventing premature shifting during work operations. This dynamic adaptation resolves the contradiction between fuel efficiency and work efficiency.
Solution Approach 2:
The patent changes the parameter of shift timing threshold based on operating conditions. When the accelerator pedal is fully depressed or vehicle speed exceeds a predetermined value, the control device prohibits shift up regardless of the setting speed, effectively changing the shift timing parameter to prevent premature shifting during work operations. This parameter change resolves the contradiction by allowing fuel-efficient operation during normal cruising while maintaining work efficiency during operational phases.
2Device complexity
If the shift control system uses a fixed setting speed for shift timing, then control simplicity is maintained, but premature shifting occurs when accelerator pedal depressing amount is small and engine rotation number is small
Solution Approach 1:
The patent changes the shift timing parameter from a fixed setting speed to a conditional parameter that varies with accelerator pedal depressing amount and vehicle speed. The control device prohibits shift up when the accelerator pedal is fully depressed or when vehicle speed exceeds a predetermined value, creating an adaptive shift timing system. This resolves the contradiction by maintaining control simplicity through clear conditional logic while significantly improving shift timing accuracy to prevent premature shifting.
3Speed
If the speed stage is shifted up during backward travel after excavation work, then vehicle speed increases, but backward travel deceleration drifting becomes greater and work efficiency is reduced
Solution Approach 1:
The patent changes the shift timing parameter based on vehicle travel direction and operational context. When the forward/backward switch indicates backward travel and the accelerator pedal is fully depressed, the control device prohibits shift up, effectively changing the shift timing parameter to maintain lower speed during backward travel. This resolves the contradiction by allowing speed increases during forward travel while preventing premature shifting during backward travel, thereby maintaining work efficiency.
Data Source
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AI summary
A shift control system for industrial vehicle includes: a vehicle speed detection device that detects a vehicle speed of an industrial vehicle; a transmission device that shifts up and shifts down a speed stage of a transmission; a shift control device that permits shift up by the transmission device when a vehicle speed detected by the vehicle speed detection device becomes equal to or greater than a shift up permission vehicle speed; a height position detection device that detects a height position of a working machine device; a forward/backward switch device that switches the industrial vehicle between forward travel and backward travel; and a shift up control switch selection device that switches between normal control, in which shift up is performed by the transmission device when the vehicle speed becomes equal to or greater than the shift up permission vehicle speed, and delay control, in which shift up timing is delayed with respect to the normal control.