Hydraulic control method and apparatus for belt type continuously variable transmission

Abstract

Abstract PURPOSE:To improve speed change responsibility by continuously changing the feed quantity of operation oil and the discharge quantity of the operation oil to the first hydraulic cylinder for changing the effective diameter of a variable pulley. CONSTITUTION:A target rotation speed of an engine for driving an input shaft is determined depending upon the required load amount of the engine from a previously found relationship, and the actual rotation speed of the engine is detected to calculate a deviation between the target rotation speed and the actual rotation speed of the engine. On the other hand, a shift valve device is periodically operated repeatedly between two conditions, and the respective time rates in two conditions of the shift valve device are changed according to the degree of deviation. Thus, the quantity of operation oil fed to the first hydraulic cylinder for changing the effective diameter of a variable pulley or the quantity of operation oil from the first hydraulic cylinder can be changed continuously to properly improve the speed change responsibility.

Inventors

• 👤 Hiroshi Ito
• 👤 寛 伊藤
• 👤 Shigeki Hiraoka
• 👤 茂樹 平松
• 👤 Mitsuru Takada
• 👤 充 高田
• 👤 Tadashi Tamura
• 👤 忠司 田村

Bibliographic Details