Hydraulic control device of automatic transmission

• US 8,210,977 B2
• Filed: 01/20/2010
• Issued: 07/03/2012
• Est. Priority Date: 02/12/2009
• Status: Active Grant

• Current Assignee: Jatco Limited (Nissan Motor Co., Ltd.), Nissan Motor Co., Ltd.
• Original Assignee: Jatco Limited (Nissan Motor Co., Ltd.)
• Inventors: Hirose, Ikuo
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US12/690,507
• Publication Number:
  US 20100204009A1
• Time in Patent Office: 895 Days
• Field of Search: 475/119
• US Class Current: 475/119
• CPC Class Codes: F16H 2061/1232 Bringing the control into a predefined state, e.g. giving priority to particular actuators or gear ratios
• CPC Class Codes: F16H 2061/1292 the failing part is the power supply, e.g. the electric power supply
• CPC Class Codes: F16H 61/0206 Layout of electro-hydraulic control circuits, e.g. arrangement of valves for control of actuators selecting and moving final output members, e.g. shift forks F16H61/2807
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures

Abstract

A dual purpose pressure adjusting valve provides a hydraulic pressure upon failure of electric power supply and controls the hydraulic pressure selectively directed toward a high clutch and a low & reverse brake using a line pressure, that bypasses a manual valve, as a source pressure. A switching valve switches hydraulic pressure feeding passages of the high clutch and low & reverse brake in response to selection of a range position between D-range position and R-range position. A first rotation member and a transmission input shaft are connected to each other when the high clutch is engaged. The first rotation member is a member other than a transmission output gear. A high clutch inhibitor valve uses D-range pressure PD as a signal pressure and is arranged between the switching valve and the high clutch. The high clutch inhibitor valve opens a communication between the dual purpose pressure adjusting valve and the high clutch when the signal pressure is applied thereto and doses the communication between the dual purpose pressure adjusting valve and the high clutch when the signal pressure is not applied thereto.

Claims

1. A hydraulic control device of an automatic transmission, the transmission including first and second frictional elements that are respectively engaged at different range positions and first and second rotation members that are connected to each other when the first frictional element is engaged, the first and second rotation members being members other than a transmission output member, the hydraulic control device comprising:

a solenoid valve that provides a hydraulic pressure upon failure of an electric power supply of the transmission and controls the hydraulic pressure selectively directed toward the first and second frictional elements by using a line pressure, that bypasses a manual valve, as a source pressure;

a first switching valve that leads the hydraulic pressure is from the solenoid valve to the first frictional element when a forward range position is selected and leads the hydraulic pressure from the solenoid valve to the second frictional element when a reverse range position is selected;

a second switching valve that is arranged between the first switching valve and the first frictional element, the second switching valve using a hydraulic pressure, which is provided when the forward range position is selected, as a signal pressure,

wherein the second switching valve opens a fluid communication between the solenoid valve and the first frictional element through the first switching valve when applied with the signal pressure and closes the fluid communication with applied with no signal pressure.

2. A hydraulic control device of an automatic transmission as claimed in claim 1, in which when the first switching valve takes a position to lead the hydraulic pressure provided by the solenoid valve to the second switching valve, the first switching valve opens port through which a hydraulic pressure, that is provided by the manual valve when the reverse range position is selected, is led to the second frictional element.

3. A hydraulic control device of an automatic transmission as claimed in claim 1, in which the second switching valve uses D-range pressure, which is provided when the manual valve is shifted to D-range position, as the signal pressure, the manual valve being a valve actuated in accordance with an operational movement of a select lever manipulated by a driver.

4. A hydraulic control device of an automatic transmission as claimed in claim 3, in which the second rotation member is an input shaft of the transmission and in which the second frictional element is a member that selectively connects and disconnects the input shaft and the first rotation member.

5. A hydraulic control device of an automatic transmission, the transmission including first and second frictional elements that are respectively engaged at different range positions and first and second rotation members that are connected to each other when the first frictional element is engaged, the first and second rotation members being members other than a transmission output member, the hydraulic control device comprising:

a manual valve through which line pressure is directed toward various frictional elements selectively when the transmission is in a proper working condition;

a solenoid valve that provides a hydraulic pressure upon failure of an electric power supply of the transmission and controls the hydraulic pressure that is selectively directed toward the first and second frictional elements, the hydraulic pressure being the line pressure that bypasses the manual valve;

a first switching valve that, upon selection of a forward range position, feeds the hydraulic pressure from the solenoid valve to the first frictional element and upon selection of a reverse range position, feeds the hydraulic pressure from the solenoid valve to the second frictional element; and

a second switching valve arranged between the first switching valve and the first frictional element, the second switching valve using a hydraulic pressure, which is provided when the forward range position is selected, as a signal pressure,

wherein the second switching valve opens a given fluid communication between the solenoid valve and the first frictional element through the first switching valve when applied with the signal pressure, and closes the given fluid communication when applied with no signal pressure.

6. A hydraulic control device of an automatic transmission as claimed in claim 5, in which when taking a position to lead the hydraulic pressure provided by the solenoid valve to the second switching valve, the first switching valve opens a port through which a hydraulic pressure, that is provided by the manual valve when the reverse range position is selected, is led to the second frictional element.

7. A hydraulic control device of an automatic transmission, the transmission including a clutch and a brake that are respectively engaged at different range positions and a first rotation member other than a transmission output member and a transmission input shaft that are connected to each other when the clutch is engaged, the hydraulic control device comprising:

a dual purpose pressure adjusting valve that provides a hydraulic pressure upon failure of electric power supply of the transmission and controls the hydraulic pressure selectively directed toward the clutch and brake by using a line pressure, that bypasses a manual valve, as a source pressure;

a switching valve that leads the hydraulic pressure from the dual purpose pressure adjusting valve to the clutch when D-range position is selected and leads the hydraulic pressure from the dual purpose pressure adjusting valve to the brake when R-range position is selected; and

a clutch inhibitor valve that is arranged between the switching valve and the clutch, the clutch inhibitor valve using a hydraulic pressure, which is provided when the D-range position is selected, as a signal pressure,

wherein the clutch inhibitor valve opens a given fluid communication between the dual purpose pressure adjusting valve and the clutch through the switching valve when applied with the signal pressure and closes the given fluid communication when applied with no signal pressure.