Drive Switching Mechanism for Utility Vehicles
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Solution Overview
Problem
Conventional utility vehicles require a stop to smoothly switch between two-wheel drive and four-wheel drive or to fix/release the differential device, limiting operational flexibility during vehicle operation.
Innovation Solution
A drive switching mechanism that includes a two-wheel drive and four-wheel drive switching device using a first clutch, controlled by a unit that switches from two-wheel drive to four-wheel drive when the rotation difference of the clutch reaches a predetermined value, and a differential lock device using a second clutch for smooth switching during vehicle operation, with sensors for rotation difference calculation and engine output adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dog clutch is used to switch between two-wheel drive and four-wheel drive, then the switching mechanism is simple and reliable, but the vehicle must stop to achieve smooth switching
Solution Approach 1:
The patent applies dynamics by making the clutch engagement condition adaptive rather than static. The control unit dynamically adjusts the clutch engagement threshold based on real-time rotation speed differences, allowing the system to switch between drive modes during vehicle operation when rotation difference is small, while maintaining reliable engagement when rotation difference is large.
Solution Approach 2:
The patent changes the parameter threshold for clutch engagement from a fixed value to a variable threshold based on rotation speed difference. The control unit monitors the rotation speed difference between the propeller shaft and final reduction device, and only permits clutch engagement when this difference falls below a predetermined threshold, enabling smooth switching during motion.
2Reliability
If the vehicle stops to switch drive modes, then clutch engagement is smooth and reliable, but vehicle productivity and operational efficiency decrease
Solution Approach 1:
The system dynamically evaluates the rotation speed difference condition in real-time and permits clutch engagement during vehicle operation when the condition is met, eliminating the need for mandatory vehicle stops and thereby maintaining operational efficiency while ensuring reliable clutch engagement.
Solution Approach 2:
The control unit continuously monitors the rotation speed difference between the propeller shaft and final reduction device and uses this feedback to determine the appropriate timing for clutch engagement. This feedback mechanism ensures that clutch engagement occurs only when rotation difference is within acceptable limits, maintaining reliability without requiring vehicle stops.
3Ease of operation
If clutch switching is attempted during vehicle operation, then operational flexibility improves, but switching smoothness and reliability deteriorate due to rotation difference
Solution Approach 1:
The patent introduces a dynamic parameter threshold based on rotation speed difference. The control unit permits clutch engagement during vehicle operation only when the rotation speed difference between the propeller shaft and final reduction device is below a predetermined threshold, thus maintaining switching smoothness while enabling operational flexibility.
Data Source
AI summary
A drive switching mechanism of a utility vehicle includes: a two-wheel drive and four-wheel drive switching device that switches between two-wheel drive and four-wheel drive of the utility vehicle; and a control unit that controls the drive switching mechanism. The two-wheel drive and four-wheel drive switching device switches between two-wheel drive and four-wheel drive by using a first clutch. The control unit permits the two-wheel drive and four-wheel drive switching device to switch from two-wheel drive to four-wheel drive when a rotation difference of the first clutch becomes equal to or smaller than a predetermined value.