Vehicle Gear Shift Controller Thermal Load Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gear shift controllers for vehicles with stepped transmissions only consider thermal load and engine overspeed, leading to potential drivability issues due to excessive delay times during upshifts, causing hesitation.
Innovation Solution
A controller that adjusts the delay time for gear shifts based on the accelerator depression amount, shortening the delay when the accelerator is pressed lightly to minimize thermal load on friction materials and prevent drivability decreases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a fixed delay time is used for upshift to reduce thermal load on friction materials, then thermal load decreases, but drivability deteriorates due to hesitation when accelerator depression is small
Solution Approach 1:
The patent applies dynamics by making the delay time variable rather than fixed. The delay time is dynamically adjusted based on the accelerator depression amount: when the accelerator depression amount is small, a shorter delay time is used to prevent hesitation and maintain drivability; when the accelerator depression amount is large, a longer delay time is used to reduce thermal load on friction materials. This dynamic adaptation resolves the contradiction between thermal load reduction and drivability maintenance.
Solution Approach 2:
The patent changes the parameter of delay time based on the accelerator depression amount. By adjusting this temporal parameter according to driver input intensity, the system optimizes the balance between protecting friction materials from excessive thermal load and maintaining smooth drivability. This parameter change approach allows the system to adapt to different operating conditions and resolve the technical contradiction.
2Temperature
If a longer delay time is used for upshift, then thermal load on friction materials is reduced, but engine overspeed increases
Solution Approach 1:
The patent adjusts the delay time parameter based on accelerator depression amount to balance thermal load reduction and engine overspeed control. When accelerator depression is large, the system can tolerate longer delay times for thermal protection; when accelerator depression is small, shorter delay times prevent excessive engine overspeed. This conditional parameter adjustment resolves the contradiction between these two opposing effects.
Data Source
AI summary
When an engagement-side clutch taking charge of rotation control in an upshift is the same as a rotation control clutch of a previous gear shift, it is determined that there is a likelihood that a thermal load of a clutch friction material will increase, and the thermal load of the clutch friction material is decreased by delaying gear shift start. By setting a delay time by which the gear shift start is delayed when an accelerator depression amount is small to be shorter than when the accelerator depression amount is large depending on the accelerator depression amount, a gear shift which is an upshift can be performed without unnecessary waiting.