短語詞組短語change e valve 換向閥hand change over valve 手動換向閥pneumatic change direction valve 氣動換向閥change direction valve 換向閥electromagnetism change direction valve 電磁換向閥the change over valve 調壓閥change -valve 轉換閥piston buffer change valve 活塞式緩變閥 返回 change valve