Control method, device and TCU for synchronizer pre-engagement under sliding and downshift working condition

A control method and control device technology, which is applied in the direction of transmission control, clutch, and components with teeth, etc., to achieve the effect of avoiding different effects

Active Publication Date: 2017-06-30
SAIC MOTOR
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem solved by the present invention is to reduce the possibility of the noise generated by the synchronizer entering the gear when coasting downshift, and reduce the fuel consumption of DCT at the same time

Method used

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  • Control method, device and TCU for synchronizer pre-engagement under sliding and downshift working condition
  • Control method, device and TCU for synchronizer pre-engagement under sliding and downshift working condition
  • Control method, device and TCU for synchronizer pre-engagement under sliding and downshift working condition

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Embodiment Construction

[0043] At present, the synchronizer of the DCT vehicle can make the gears to be meshed reach a consistent speed for smooth meshing and shifting. However, when the speed difference between the two ends of the synchronizer is large, especially in the case of coasting downshifts, there is often the problem that the speed synchronization stage is difficult to control, resulting in gear-in noise. If the pre-engagement is performed as soon as the clutch interaction control is completed in the downshift condition, there will be synchronizers on the odd and even axles when the vehicle is running stably, resulting in high DCT fuel consumption.

[0044] In order to make those skilled in the art better understand the above-mentioned problems, figure 1 A schematic diagram of the downshifting process from the 4th gear down to the 2nd gear in the prior art is shown.

[0045] figure 1 (a) is a curve diagram of the throttle signal change; figure 1 (b) is the DCT rotational speed change cur...

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Abstract

The invention discloses a control method, device and TCU for synchronizer pre-engagement under the sliding and downshift working condition. The method comprises the steps that when the rotational speed difference of a power transmission shaft and a non power transmission shaft is larger than or equal to a first threshold value, a clutch corresponding to the power transmission shaft separates from a first set quantity, a clutch corresponding to the non power transmission shaft is combined with a second set quantity, and meanwhile an engine is requested to increase the rotational speed value to the first rotational speed to adjust the rotational speed of the non power transmission shaft, wherein values of the first set quantity and the second set quantity are negatively correlated with the rotational speed change rate of the power transmission shaft; when the adjusted rotational speed difference is smaller than a second threshold value, the engine is requested to stop increasing the rotational speed, the clutch corresponding to the power transmission shaft is combine with the first set quantity, and the control pressure of the clutch corresponding to the non power transmission shaft is reduced till the clutch is fully opened; and when the control pressure of the clutch corresponding to the non power transmission shaft is smaller than a third threshold value, a synchronizer moves up a gear, therefore production of gear moving noise is avoided, and DCT fuel consumption is reduced.

Description

technical field [0001] The invention relates to the field of automobiles, in particular to a method, device and TCU for controlling pre-engagement of a synchronizer under a sliding downshift working condition. Background technique [0002] DCT (Dual Clutch Transmission) is a kind of automatic transmission, because it has the advantages of uninterrupted power during the shifting process and low fuel consumption, it has become a popular automatic transmission for automobiles. [0003] Similar to the manual transmission, the DCT also has a synchronizer and a fork mechanism. The synchronizer can make the gears to be meshed reach a consistent speed and smoothly engage and shift gears, shortening the shift time. However, when the speed difference between the two ends of the synchronizer is large, especially in the case of coasting downshifts, there is often the problem that the speed synchronization stage is difficult to control, resulting in gear-in noise. If the pre-engagement ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F16H61/02F16H59/02F16D48/10
CPCF16D48/10F16H59/0208F16H61/02F16H2306/48F16H2306/54
Inventor 仇杰孙贤安
Owner SAIC MOTOR
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