초록 ▼

A hydraulic control device controls hydraulic fluid for shifting an automatic transmission by a pressure control valve, and supplies operating hydraulic fluid diverted from the pressure control valve via a torque converter pressure passage to a lock up clutch of the torque converter. A lubrication p

A hydraulic control device controls hydraulic fluid for shifting an automatic transmission by a pressure control valve, and supplies operating hydraulic fluid diverted from the pressure control valve via a torque converter pressure passage to a lock up clutch of the torque converter. A lubrication passage which lubricates the automatic transmission is connected via an orifice to a torque converter pressure passage, and the pressure in this torque converter pressure passage is limited by a regulator valve to a predetermined upper limit value. Further, there is included a bypass valve which directly supplies hydraulic fluid from the torque converter pressure passage via the orifice to the lubrication passage when the pressure in the torque converter pressure passage rises above a predetermined pressure. On the one hand, at times of low speed vehicle operation, the engagement pressure for the lock up clutch is ensured by the orifice, while also at times of high load the amount of lubrication hydraulic fluid is increased by the bypass valve.

대표청구항 ▼

[ What is claimed:] [1.] A hydraulic control device for use with an automatic transmission which is connected to a torque converter comprising a lock up clutch, said device comprising:a pressure control valve which controls hydraulic pressure supplied to said automatic transmission;a torque converte

[ What is claimed:] [1.] A hydraulic control device for use with an automatic transmission which is connected to a torque converter comprising a lock up clutch, said device comprising:a pressure control valve which controls hydraulic pressure supplied to said automatic transmission;a torque converter pressure passage which supplies hydraulic fluid for operating said lock up clutch from said pressure control valve to said lock up clutch; a lock up control valve which is provided in said torque converter pressure passage and controls engagement and disengagement of said lock up clutch;a lubrication passage which supplies hydraulic fluid for lubrication to said automatic transmission;an orifice which is provided between said pressure control valve and said lock up control valve and joins said torque converter pressure passage to said lubrication passage;a regulator valve which limits the pressure in said torque converter pressurepassage to within a predetermined upper limit value; anda bypass valve detouring said orifice for supplying hydraulic fluid from said torque converter pressure passage to said lubrication passage when the pressure in said torque converter pressure passage rises above a predetermined value.