Shift direction change-over valve device in hydraulic unit for belt-type continuously variable transmission

Abstract

Abstract PURPOSE:To enhance the response of a shift speed control valve, by setting at least one of positions for positioning a spool valve element, to a half-opening position where the spool valve element opens in part a predetermined port, so that the moving stroke of the spool valve element is made short. CONSTITUTION:A spool valve element 124 comprising a spool shaft 132 and a plurality of spool lands 134A, 134B, 134S having a partly increased diameter in the axial direction of the spool shaft 132, is slidably fitted in a cylinder bore 138 formed in a valve body 136. In comparison with a conventinal arrangement in which the spool valve element 124 is moved until it fully open an input port 139 or a discharge port 141, the stroke of the instant spool valve element 124 is set to such a degree that each port is opened in part, and therefore is made short, thereby it is possible to enhance the response of a spool valve 118.

Inventors

• 👤 Mitsuo Akashi
• 👤 明石　光生
• 👤 Hiroshi Ito
• 👤 寛 伊藤

Bibliographic Details