Switch valve

摘要

A switch valve which is configured such that a plurality of land sections and a valley section between the land sections are formed in a valve element that advances or retreats in an axial direction according to a manual operation, a plurality of port sections opened are provided in a cylinder section in which the valve element is inserted so as to be capable of advancing and retreating, and the prescribed port sections are made to communicate with each other via the valley section according to a position of the valve element in the axial direction or be blocked by the land section, the switch valve includes a seal section that seals a space between portions on both sides in the axial direction across either one of the land sections in a liquid-tight manner.

主权项

1. A switch valve which is configured such that a plurality of land sections and a valley section between the land sections are formed in a valve element that advances or retreats in an axial direction according to a manual operation, a plurality of port sections are provided in a cylinder section in which the valve element is inserted so as to be configured to advance or retreat, and the prescribed port sections are made to communicate with each other via the valley section according to a position of the valve element in the axial direction or be blocked by the land section, wherein
a seal section is provided in each of the two land sections that define the valley section, the plurality of port sections include an input port and an output port that open to the valley section in a state where the seal sections seal gaps between the respective land sections and the cylinder section in a liquid-tight manner, the output port includes a forward travel port that communicates with a forward travel engagement device and a reverse travel port that communicates with a reverse travel engagement device, the seal section is configured to seal the gaps between the two land sections and the cylinder section in a liquid-tight manner in a state where either one of the forward travel port and the reverse travel port and the input port are both allowed to open to the valley section, the valve element is configured to be moved to a position where both the forward travel port and the input port are allowed to open to the valley section and a position where both the reverse travel port and the input port are allowed to open to the valley section, and a supply-discharge oil passage which has a supply valve that makes the input port communicate with a hydraulic pressure source and be blocked against the hydraulic pressure source and a discharge valve that makes the input port communicate with a drain portion and be blocked against the drain portion communicates with the input port.