HYDRAULIC CONTROL DEVICE OF AUTOMATIC TRANSMISSION
First Claim
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 to 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 Assignments
0 Petitions
Accused Products
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.
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Citations
7 Claims
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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:
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a solenoid valve that provides a hydraulic pressure upon to 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. - View Dependent Claims (2, 3, 4)
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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:
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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. - View Dependent Claims (6)
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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:
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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.
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Specification