초록 ▼

A structure in which a hydraulic-pressure control applied pressure for controlling each engagement element of an automatic transmission is realized by using an electric signal such that combinations of engagement which encounter a tie-up in case of a failure of the signal lead to interlocking are in

A structure in which a hydraulic-pressure control applied pressure for controlling each engagement element of an automatic transmission is realized by using an electric signal such that combinations of engagement which encounter a tie-up in case of a failure of the signal lead to interlocking are inhibited to prevent deterioration in the durability of each engagement element. An automatic transmission incorporates a planetary gear transmission mechanism using selective engagement of at least five engagement elements to realize six gear ratios, and a hydraulic-pressure control apparatus for controlling the engagement elements of the transmission mechanism. Valves are provided which inhibit combinations of engagement of two or more engagement elements of the five engagement elements for interlocking the transmission mechanism.

대표청구항 ▼

1. A hydraulic pressure control apparatus for an automatic transmission including a planetary gear transmission mechanism incorporating at least five engagement elements arranged to be selectively engaged to realize a predetermined gear ratio; and a hydraulic-pressure control apparatus for controlli

1. A hydraulic pressure control apparatus for an automatic transmission including a planetary gear transmission mechanism incorporating at least five engagement elements arranged to be selectively engaged to realize a predetermined gear ratio; and a hydraulic-pressure control apparatus for controlling the engagement elements of the transmission mechanism, whereinwhen a first engagement element and a fourth engagement element are engaged, a first speed is realized; when the first engagement element and a fifth engagement element are engaged, a second speed is realized; when the first engagement element and a third engagement element are engaged, a third speed is realized; when the first engagement element and a second engagement element are engaged, a fourth speed is realized; when the second engagement element and the third engagement element are engaged, a fifth speed is realized; and when the second engagement element and the fifth engagement element are engaged, a sixth speed is realized, the hydraulic-pressure control apparatus further comprising a plurality of valves for inhibiting certain combinations of engaged engagement elements with which interlocking of the transmission mechanism occurs due to engagement of two or more engagement elements of the five engagement elements when each of forward gear ratios including the first speed to the sixth speed has been realized, wherein the combinations with which interlocking of the transmission mechanism occurs when the forward gear ratio has been realized and which are inhibited incorporate a first pattern having combinations of two engagements and a second pattern having combinations of three engagements, the first pattern at least incorporates combinations of engagements between the second engagement element and the fourth engagement element, between the third engagement element and the fifth engagement element, between the third engagement element and the fourth engagement element and between the fourth engagement element and the fifth engagement element, the second pattern incorporates a combination of engagements among the first engagement element, the second engagement element and the third engagement element and a combination among the first engagement element, the second engagement element and the fifth engagement element, and at least one valve of the plurality of valves inhibits at least six combinations.