Range switching device

A range switching device for performing switching among a drive range in which an oil pressure is transmitted to a forward driving element (D) of a transmission, a reverse range in which an oil pressure is transmitted to a reverse driving element (R), and a neutral range in which an oil pressure is substantially not transmitted to either of the forward driving element (D) and the reverse driving element (R), the range switching device comprising:

• a first control valve driven by a first actuator and configured to control an oil pressure transmitted from an oil pressure supply source to a downstream;
• a first switching valve driven by a second actuator and capable of selecting an oil channel for transmitting the oil pressure transmitted from the first control valve to the downstream;
• a second switching valve driven by a third actuator and capable of transmitting the oil pressure transmitted from the first switching valve to either one of the forward driving element (D) and the reverse driving element (R);
• a second control valve driven by the first actuator and capable of controlling the oil pressure from the oil pressure supply source to the downstream so as to deliver a characteristic opposite to that of the first control valve;
• a third switching valve driven by the second actuator and capable of selecting an oil channel for transmitting the oil pressure transmitted from the second control valve to the downstream;
• and
• a fourth switching valve driven by the third actuator and capable of transmitting the oil pressure transmitted from the third switching valve to either one of the forward driving element (D) and the reverse driving element (R), wherein
• the first switching valve and the second switching valve can cooperatively switch to any one of a state for transmitting the oil pressure transmitted from the first control valve to the forward driving element (D), a state for transmitting the oil pressure to the reverse driving element (R), and a state without transmitting of the oil pressure,
• the third switching valve and the fourth switching valve can cooperatively switch to any one of a state for transmitting the oil pressure transmitted from the second control valve to the forward driving element (D), a state for transmitting the oil pressure to the reverse driving element (R), and a state without transmitting the oil pressure, and
• the third switching valve and the fourth switching valve each perform a substantially same oil pressure transmission when a state of the second actuator and a state of the third actuator are reversed with respect to the first switching valve and the second switching valve, respectively.