| 摘要 |
PROBLEM TO BE SOLVED: To acquire an actual characteristic to be the actual relationship between a voltage applied to a coil and a current flowing in the coil, while suppressing increase in servo pressure.SOLUTION: A decompression linear valve is provided between a control pressure chamber and a low-pressure source, and a pressure increase linear valve is provided between the control pressure chamber and a high-pressure source. When an actual characteristic about the coil of the decompression linear valve is acquired, a maximum current Ix, at which a poppet valve part does not become narrow, is used. Consequently, even when liquid pressure is supplied from the high-pressure source to the control pressure chamber by causing leakage of the pressure increase linear valve or the like, the liquid pressure of the control pressure chamber can be prevented from increasing, and thus servo pressure can be prevented from increasing. |
