JPH1194060A - Select time lag improving valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To feed a hydraulic fluid early to a clutch at the time of low temperature by providing a shape memory spring submerged in the hydraulic fluid and operating a valve in an opening direction at the time of low temperature of the hydraulic fluid in the valve opening a by-pass circuit at the time of low temperature of the hydraulic fluid so as to rapidly feed the hydraulic fluid to the clutch. SOLUTION: A manual valve 1 and a forward clutch 3 of an automatic transmission are connected by a hydraulic fluid circuit 2. When a driver operates a select lever to select a D-range from a P-range and to operate the manual valve 1, a hydraulic fluid is fed to the forward clutch 3 through the hydraulic fluid circuit 2, but at the time of low temperature of the hydraulic fluid, the length of a shape memory spring 9A provided at a valve 8 in a by-pass circuit 5 is changed to operate the valve 8 in an opening direction, so that the hydraulic fluid is fed early to the forward clutch through the by-pass circuit 5. A select time lag at the time of low temperature of the hydraulic fluid is therefore improved so as to be able to connect the forward clutch 3 satisfactorily.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve capable of satisfactorily improving a select time lag.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
A hydraulic valve circuit 2 is connected to a manual valve 1 which is operated by operating a select lever provided in a driver's seat of an automobile, and a forward clutch 3 of an automatic transmission is connected to the hydraulic circuit 2. A bypass circuit 5 is formed in the hydraulic oil circuit 2, and a valve 8 that can open and close the bypass circuit 5 is provided in the bypass circuit 5.
A spring 9 is provided at one end of the valve 8, and a solenoid valve 11 is connected to the other end of the valve 8 so that an electric signal from the control unit 12 is input to the solenoid valve 11. The control unit 12 is connected to an oil temperature sensor 13 for detecting the oil temperature of the operating oil. When the operating oil is at a low temperature, the driver operates the select lever to operate the manual valve 1. Even so, the hydraulic oil has a low viscous resistance at a low temperature, it takes time to pass through the orifice provided in the circuit 2, and it takes too much time to supply the hydraulic oil to the forward clutch 3. From P range to D
Since the clutch may not be engaged even if the range is selected, in such a case, the control unit 12 sends a signal to the solenoid valve 11 in response to a detection signal from the oil temperature sensor 13, thereby operating the solenoid valve 11. Then, the valve 8 is operated in the opening direction,
As a result, the bypass circuit 5 is opened, and the bypass circuit 5 is opened.
, The hydraulic oil is supplied to the forward clutch 3 at an early stage to eliminate a time lag at the time of selection. Conventionally, an oil temperature sensor 1 for detecting the temperature of the hydraulic oil is provided.
3 and a solenoid valve 11 that is operated at low temperature is required, the circuit configuration is complicated, the number of parts is large, and the cost is high.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a select time lag improvement valve which can reduce the cost by eliminating an oil temperature sensor and the like. The gist of the
A valve that is disposed in a bypass circuit formed in a circuit that supplies hydraulic oil to a clutch of the automatic transmission and that can open the bypass circuit and quickly flow hydraulic oil to the clutch when the temperature of the hydraulic oil is low. The valve is provided with a shape memory spring that is immersed in the hydraulic oil and operates the valve in the opening direction when the hydraulic oil is at a low temperature.

[0004]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a valve 8 that improves the select time lag.
The manual valve 1 and the forward clutch 3 of the automatic transmission are connected by a hydraulic oil circuit 2, and when the driver operates the select lever to select from the P range to the D range, The manual valve 1 is actuated, the hydraulic oil is supplied to the forward clutch 3 through the hydraulic oil circuit 2 and the clutch is connected, and the hydraulic oil circuit 2 is further provided with a sub-circuit 4. Further, a bypass circuit 5 is provided so as to make a detour, and a bypass circuit 5 is provided in the bypass circuit 5.
A valve 8 which can be opened and closed is provided. In this embodiment, the valve 8 has a shape memory spring 9 made of a shape memory alloy.
A is provided so that the valve 8 can be opened and closed by the spring force of the shape memory spring 9A. The shape memory spring 9A is disposed so as to be immersed in hydraulic oil. When the temperature is low, the length of the shape memory spring 9A changes due to the low temperature, whereby the valve 8 is operated in the opening direction and the bypass circuit 5
Is set to open. Check valves 6a and 6b are provided in the hydraulic oil circuit 2, and orifices 7a and 7b are provided in the sub-circuit 4.
In the figure, reference numeral 10 denotes an accumulator.

In such a configuration, when the manual valve 1 is operated, the operating oil passes through the check valve 6a and the sub-circuit 4
When the forward clutch 3 is released, the hydraulic oil flows through the check valve 6b and the orifice 7a of the sub-circuit 4 when the proper hydraulic pressure is supplied to the forward clutch 3 through the orifice 7b. When the hydraulic oil is at a low temperature, the viscous resistance of the hydraulic oil is large, and it takes too much time for the hydraulic oil to flow to the forward clutch 3 due to the presence of the orifice 7b. In this example, when the operating oil is at a low temperature, the shape memory spring 9A changes the length to reliably operate the valve 8 in the opening direction.
When the operating oil is at a low temperature, the operating oil passes through the bypass circuit 5 and is supplied to the forward clutch 3 early with less time delay. Therefore, even at a low operating oil, the select time lag is favorably improved. The forward clutch 3 is connected well.

As described above, in this embodiment, the valve 8 can be reliably opened when the operating oil is at a low temperature, and the bypass circuit 5 can be opened to allow the operating oil to flow.
1 or the oil temperature sensor 13 can be eliminated, so that the circuit can be simplified and the cost can be reduced.

[0007]

The select time lag improvement valve of the present invention is disposed in a bypass circuit formed in a circuit for supplying hydraulic oil to the clutch of the automatic transmission, and opens the bypass circuit when the temperature of the hydraulic oil is low. In a valve that can quickly flow hydraulic oil to the clutch, the valve is provided with a shape memory spring that is immersed in the hydraulic oil and operates the valve in the opening direction when the hydraulic oil is at a low temperature. When the hydraulic oil is cold, the shape memory spring changes the length to reliably operate the valve in the opening direction, which ensures that the bypass circuit is opened at low temperatures and supplies hydraulic oil to the clutch early. And improved select time lag when the operating oil temperature is low, eliminating the need for conventional temperature sensors and solenoid valves. Te has an effect capable of reducing the cost by simplifying the circuit configuration.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a circuit provided with a select time lag improvement valve.

FIG. 2 is a schematic configuration diagram of a conventional circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Manual valve 2 Hydraulic oil circuit 3 Forward clutch 4 Subcircuit 5 Bypass circuit 6a, 6b Check valve 7a, 7b Orifice 8 Valve (select time lag improvement valve) 9A Shape memory spring

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsuo Wakahara Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa

Claims (1)

[Claims] An automatic transmission is provided in a bypass circuit formed in a circuit for supplying hydraulic oil to a clutch, and when hydraulic oil is at a low temperature, the bypass circuit is opened to flow hydraulic oil to the clutch quickly. 3. A select time lag improvement valve according to claim 1, wherein said valve is provided with a shape memory spring which is immersed in said hydraulic oil and operates said valve in an opening direction when said hydraulic oil is at low temperature.