Shift hydraulic apparatus for vehicular automatic transmission
AssigneesJATCO Ltd, Nissan Motor Co., Ltd.
InventorYoshiaki Katou
Life of this patent
Estimating the term…
Abstract
A shift hydraulic apparatus and method are provided for a vehicular automatic transmission constituted by a torque converter and a continuously variable transmission. A bypass circuit enables an upstream side hydraulic circuit of the hydraulic circuit to communicate with a downstream side hydraulic circuit. A switching valve enables a switching between a communication state of the bypass circuit and a non-communication state thereof. Through the switching valve, both communication state and the non-communication state of the bypass circuit are controlled.
Claims16
A shift hydraulic apparatus for a vehicular automatic transmission, the automatic transmission being constituted by a torque converter and a continuously variable transmission, the shift hydraulic apparatus comprising:
- an upstream oil pump that is always driven by means of an engine associated with the automatic transmission;
- a clamp pressure regulating section, disposed on an upstream side hydraulic circuit with the oil pump as a hydraulic source, that regulates a clamp pressure of a belt of the continuously variable transmission;
- a clutch pressure regulating section, disposed on a downstream hydraulic circuit with a drain pressure from the clamp pressure regulating section, that regulates a clutching pressure of a forward clutch;
- a bypass circuit which enables the upstream side hydraulic circuit to communicate with the downstream side hydraulic circuit;
- a switching valve which enables a switching between a communication state of the bypass circuit and a non-communication state of the bypass circuit;
- and
- a switching valve controlling section that controls the communication state and the non-communication state of the bypass circuit through the switching valve.
A shift hydraulic apparatus for a vehicular automatic transmission, the automatic transmission being constituted by a torque converter and a continuously variable transmission, the shift hydraulic apparatus comprising:
- an oil pump that is always driven by means of an engine associated with the automatic transmission;
- a clamp pressure regulating section, disposed on an upstream side hydraulic circuit with the oil pump as a hydraulic source, that regulates a clamp pressure of a belt of the continuously variable transmission;
- a clutch pressure regulating section, disposed on a downstream hydraulic circuit with a drain pressure from the clamp pressure regulating section, that regulates a clutching pressure of a forward clutch;
- a bypass circuit which enables the upstream side hydraulic circuit to communicate with the downstream side hydraulic circuit;
- a switching valve which enables a switching between a communication state of the bypass circuit and a non-communication state of the bypass circuit;
- a switching valve controlling section that controls the communication state and the non-communication state of the bypass circuit through the switching valve;
- and
- an upstream side hydraulic circuit oil pressure detecting section that detects a hydraulic at the upstream side hydraulic circuit,
- wherein the switching valve controlling section comprises a bypass circuit controlling section that turns the switching valve on to enable the bypass circuit to be in the communication state at the same time when the engine (ENG) is restarted after an idle stop and that turns the switching valve off to enable the bypass circuit to be in the non-communication state immediately before the detected oil pressure of the upstream side hydraulic circuit has reached to a predetermined hydraulic (PC1) approximately equal to a clutching pressure in the downstream side hydraulic circuit.
A shift hydraulic apparatus for a vehicular automatic transmission, the automatic transmission being constituted by a torque converter and a continuously variable transmission, the shift hydraulic apparatus comprising:
- an oil pump that is always driven by means of an engine associated with the automatic transmission;
- a clamp pressure regulating section, disposed on an upstream side hydraulic circuit with the oil pump as a hydraulic source, that regulates a clamp pressure of a belt of the continuously variable transmission;
- a clutch pressure regulating section, disposed on a downstream hydraulic circuit with a drain pressure from the clamp pressure regulating section, that regulates a clutching pressure of a forward clutch;
- a bypass circuit which enables the upstream side hydraulic circuit to communicate with the downstream side hydraulic circuit;
- a switching valve which enables a switching between a communication state of the bypass circuit and a non-communication state of the bypass circuit;
- and
- a switching valve controlling section that controls the communication state and the non-communication state of the bypass circuit through the switching valve,
- wherein the downstream side hydraulic circuit comprises:
- a pressure regulating valve section and a pressure regulating valve section controlling section that controls the pressure regulating valve section, both of the pressure regulating valve section and the pressure regulating valve section controlling section being interposed on the downstream side hydraulic circuit between a clutch pressure regulating valve and a forward clutch, that reduces the hydraulic of the clutching pressure regulating valve to enable a shelf pressure control for the forward clutch;
- and
- a pressure regulating valve controlling section that controls the pressure regulating valve section, the pressure regulating valve section controlling section executing a predetermined shelf pressure control when the engine is restarted after the engine idle stop.
A shift hydraulic apparatus for a vehicular automatic transmission, the automatic transmission being constituted by a torque converter and a continuously variable transmission, the shift hydraulic apparatus comprising:
- an oil pump that is always driven by means of an engine associated with the automatic transmission;
- a clamp pressure regulating section, disposed on an upstream side hydraulic circuit with the oil pump as a hydraulic source, that regulates a clamp pressure of a belt of the continuously variable transmission;
- a clutch pressure regulating section, disposed on a downstream hydraulic circuit with a drain pressure from the clamp pressure regulating section, that regulates a clutching pressure of a forward clutch;
- a bypass circuit which enables the upstream side hydraulic circuit to communicate with the downstream side hydraulic circuit;
- a switching valve which enables a switching between a communication state of the bypass circuit and a non-communication state of the bypass circuit;
- and
- a switching valve controlling section that controls the communication state and the non-communication state of the bypass circuit through the switching valve, the switching valve controlling section comprising:
- a brake operation determining section that determines whether a brake switch is turned on to determine whether a vehicular brake operation is carried out after an engine stopping section stops the engine;
- and
- an engine restart controlling section that controls the hydraulic of the upstream and downstream side hydraulic circuits during an engine restart when the brake operation determining section determines that the brake switch is turned off.
A shift hydraulic method for a vehicular automatic transmission, the automatic transmission being constituted by a torque converter and a continuously variable transmission, the shift hydraulic method comprising:
- providing an upstream oil pump that is always driven by means of an engine associated with the automatic transmission;
- providing a clamp pressure regulating section, disposed on an upstream side hydraulic circuit with the oil pump as a hydraulic source, that regulates a clamp pressure of a belt of the continuously variable transmission;
- providing a clutch pressure regulating section, disposed on a downstream hydraulic circuit with a drain pressure from the clamp pressure regulating section, that regulates a clutching pressure of a forward clutch;
- providing a bypass circuit which enables the upstream side hydraulic circuit to communicate with the downstream side hydraulic circuit;
- providing a switching valve which enables a switching between a communication state of the bypass circuit and a non-communication state of the bypass circuit;
- and
- controlling the communication state and the non-communication state of the bypass circuit through the switching valve.
Dependencies are inferred from the claim text.