# US 10,119,610 B2 · Method for controlling line pressure of automatic transmission

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- Number: US 10,119,610 B2
- Document ID: US10119610B2
- Status: Granted
- Kind: B2
- Application number: 15/187,282
- Filed: 2016-06-20
- Published: 2017-05-11
- Granted: 2018-11-06
- Earliest claimed: 2015-11-05
- Assignees: Hyundai Motor Company; Kia Motors Corporation
- Applicants: Hyundai Motor Company; Kia Motors Corporation
- Inventors: Hyun Ku Lee; Sa Man Hong; Moo Suk Kim; Jin Seung Lim; Seung Jin Lee
- Web page: https://patentgrep.com/patent/US10119610B2

## CPC

- F16H 61/0021: {Generation or control of line pressure}
- F16H 57/0006: {Vibration-damping or noise reducing means specially adapted for gearings (devices for varying tension of belts, ropes or chains with damping means F16H7/0829; toothed members with construction providing vibration damping F16H55/14; reducing vibrations or noise of the gearbox casing F16H57/028; suppression of vibrations or noise of gear selectors F16H59/0208; control of hydrostatic fluid gearing preventing or reducing vibrations or noise F16H61/4183)}
- F16H 57/0435: {Pressure control for supplying lubricant; Circuits or valves therefor}
- F16H 57/0446: {the supply forming part of the transmission control unit, e.g. for automatic transmissions}
- F16H 2061/0037: {characterised by controlled fluid supply to lubrication circuits of the gearing}
- F16H: GEARING

## Abstract

A method for controlling a line pressure of an automatic transmission, and controlling the line pressure when oil is supplied to elements of the automatic transmission through hydraulic passages and valves of a valve body at the time of initially starting a vehicle includes a line pressure setting operation of setting the line pressure of the automatic transmission to be equal to or lower than a set pressure when a vehicle is initially started, and a line pressure converting operation of converting the line pressure into a pressure equal to or higher than the set pressure when the automatic transmission is operated for shifting or when a set time has lapsed since initial vehicle starting.

## Claims

### Claim 1

A method for controlling a line pressure of an automatic transmission, which has a regulator valve, a torque converter control valve, an oil pan, and an oil pump, for a vehicle, the method comprising:
a line pressure setting operation of setting the line pressure of the automatic transmission to be equal to or lower than a set pressure when the vehicle starts; and
a line pressure converting operation of converting the line pressure into a pressure higher than the set pressure when the automatic transmission is operated for shifting or when a set time has lapsed since the vehicle starting,
wherein, in the line pressure setting operation, the set pressure is a pressure at which oil is introduced to re-circulation passages that have not been filled with oil before the vehicle starting,
wherein the re-circulation passages comprise:
a first re-circulation passage extending from the regulator valve to the oil pan; and
a second re-circulation passage extending from the torque converter control valve to the oil pan, and
wherein the first re-circulation passage and the second re-circulation passage adjoin at one point and then extend to the oil pan.

### Claim 2 (depends on 1)

The method according to claim 1, wherein, in the line pressure converting operation, the line pressure is converted into a pressure higher than the set pressure within a range in which the line pressure does not exceed a maximum allowable line pressure.

### Claim 3 (depends on 2)

The method according to claim 2, wherein the line pressure is converted into a predetermined line pressure in accordance with an operation of elements of the automatic transmission.

### Claim 4 (depends on 1)

The method according to claim 1, wherein, in the line pressure setting operation, when the vehicle starts in a state in which a change lever thereof is positioned in a neutral mode or in a parking mode, the line pressure of the automatic transmission is set to be equal to or lower than the set pressure.