Control device for continuously variable transmission
An object of the present invention is to avoid unnecessary accumulation of a correction value during feedback control, even when a secondary pressure control valve enters a state of failure. A continuously variable transmission comprises a primary pulley supplied with a primary pressure that has bee...
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| Main Author | |
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| Format | Patent |
| Language | English |
| Published |
24.07.2012
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| Online Access | Get full text |
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| Summary: | An object of the present invention is to avoid unnecessary accumulation of a correction value during feedback control, even when a secondary pressure control valve enters a state of failure. A continuously variable transmission comprises a primary pulley supplied with a primary pressure that has been adjusted via a primary pressure control valve, a secondary pulley supplied with a secondary pressure that has been adjusted via the secondary pressure control valve, and a drive belt wound around the two pulleys. When a failure such as a disconnection occurs in the secondary pressure control valve, a lower limit value Imin of a target gear ratio is raised to a low side by a CVT control unit, and a setting region of the target gear ratio is set in a low region in which control is possible even during a failure. In so doing, divergence between the target gear ratio and an actual gear ratio can be avoided, and therefore unnecessary accumulation of the correction value during feedback control can be avoided. |
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