JPH038422B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to pressure regulating valves, particularly pressure regulating valves such as regulator valves and throttle valves for regulating the operating pressure of automatic transmissions. It is something.

(b) Conventional technology In hydraulic control devices for automatic transmissions, for example,
Pressure regulating valves such as throttle valves and regulator valves shown in Publication No. 59-7954 are used, but such conventional pressure regulating valves have the ability to vary oil pressure according to the temperature of the oil being regulated. No control mechanism is provided. Therefore, theoretically, if other conditions are constant, the oil pressure will always be regulated to the same value even if the oil temperature is different. In addition, Special Publication No. 47-23126,
The pressure regulating valves shown in Japanese Patent Publication No. 50-28684 and Japanese Patent Publication No. 51-46223 have an orifice type throttle valve in the feedback oil passage, so they do not have the function of increasing the oil pressure at low temperatures. , adjusts the oil pressure to the same value regardless of oil temperature.

(c) Problems to be Solved by the Invention However, when the above-mentioned pressure regulating valve is used in a regulator valve, a throttle valve, etc. of an automatic transmission, the temperature is extremely low (e.g. -
(approximately below 100℃), the viscosity of the oil increases, so
There is a problem in that the automatic transmission cannot be brought into a state where transmission is possible immediately. In other words, even if you set the select lever to the drive range immediately after starting operation of the automatic transmission in a cold state, the viscosity of the oil is high, so it takes time for the oil to flow into the clutch, brakes, etc. and act on them. The automatic transmission is not immediately ready to transmit power.

The purpose of the present invention is to solve the above-mentioned problems and to obtain a pressure regulating valve whose pressure regulating value is higher than in normal cases immediately after startup at low temperatures, thereby immediately starting the automatic transmission. Make it possible to transmit power.

(d) Means for Solving the Problems The present invention solves the above problems by delaying the action of feedback hydraulic pressure on the pressure regulating valve immediately after startup at low temperatures. That is, the pressure regulating valve according to the present invention has a choke-type throttle valve in the oil passage that feeds back the regulated hydraulic pressure. The choke-type throttle valve does not produce a substantial throttling effect when the viscosity is at the oil temperature (for example, about 80°C) under steady use in automatic transmissions, and when the oil temperature is at low temperatures (-10°C),
The viscosity is set to such a level that it generates flow path resistance to the extent that it impedes the smooth flow of oil.

(e) Effect With the above configuration, the resistance of the choke-type throttle valve increases at low temperatures, so the rise of the feedback hydraulic pressure that acts through the choke-type throttle valve immediately after startup is delayed, and the pressure regulating valve The state before the start of action is maintained, oil is not drained, and the oil pressure is at its highest state. If the regulator valve that regulates the line pressure of an automatic transmission is set to such a pressure regulating valve, the line pressure will become extremely high immediately after starting at low temperatures, and the clutch will become stuck even though the oil viscosity is high. Oil is rapidly supplied to the brakes, etc., and the automatic transmission is immediately ready to transmit power. Oil gradually flows into the feedback port through the choke-type throttle valve, and when the oil pressure in this port increases, the pressure regulating valve enters the pressure regulating state and the normal pressure regulating action is performed. In addition, if the engine is started with high oil temperature,
Since the resistance of the choke-type throttle valve is small, the feedback hydraulic pressure acts immediately, and the pressure regulating valve starts regulating the pressure. Therefore, at normal operating temperatures, the presence of the choke valve does not cause any adverse effects.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to Nos. 1 and 2 of the attached drawings.
This will be explained based on the diagram.

(First Embodiment) FIG. 1 shows a regulator valve 10 which is a pressure regulating valve of the present invention. Regulator valve 10
is a spool 14 inserted into a valve hole 12;
Similarly, it is composed of a hollow sleeve 16 inserted into the valve hole 12, a plug 18 fitted into the inner diameter of the sleeve 16, and a spring 22 that applies an upward force to the spool 14 in FIG. ing. The valve hole 12 has ports 12a-12h. Port 12a is a port to which line pressure is supplied as necessary. Port 12b,1
2c and 12e are connected to a line pressure oil passage 26 to which oil discharged from the oil pump 24 is supplied.
However, a choke-type throttle valve 20 is provided at the inlet of the feedback port 12b. The choke-type throttle valve 20 is a throttle valve that is long in length compared to its cross-sectional area. Port 12d is a port from which oil from port 12c is discharged;
The oil discharged at point d is supplied to, for example, a torque converter via an oil passage 27. Port 12f is a drain port from which oil is drained from port 12e. The port 12g is connected to an oil passage 28 to which hydraulic pressure is supplied when a manual valve (not shown) is in the R range (reverse travel range). The port 12h is connected to an oil passage 29 to which a throttle pressure that changes depending on the engine load is supplied.
The spool 14 has lands 14a to 14e. The lands 14c, 14d and 14e have the same diameter, and the land 14b has a smaller diameter than these,
The land 14a has a smaller diameter than the land 14b. The hydraulic pressure of the port 12a acts on the pressure receiving part formed between the land 14a and the land 14b,
Further, the hydraulic pressure of the port 12b acts on the feedback pressure receiving portion formed between the land 14b and the land 14c. The sleeve 16 has a stepped inner diameter portion into which lands 18a and 18b of the plug 18 are fitted. The land 18b has a smaller diameter than the land 18a. Sleeve 16
is provided with a passage penetrating the inner and outer peripheries, and the hydraulic pressure of the port 12h acts on the end face of the land 18b, and the hydraulic pressure of the port 12g acts on the pressure receiving part formed between the land 18a and the land 18b. It's like this.

Next, the operation of this embodiment will be explained. At normal operating temperatures, the regulator valve 10 operates as follows. Regulator valve 1
0 spool 14 has port 12a and port 1
The hydraulic pressure acting on port 2b exerts a downward force, while the hydraulic pressure acting on ports 12g and 12h exerts an upward force of the force acting through the plug 18 and the force due to the spring 22. The spool 14 discharges the oil from the ports 12c and 12e to the ports 12d and 12f so that the downward force and the upward force are balanced, thereby performing a well-known pressure regulating action. As a result, the line pressure of the oil passage 26 is regulated as specified.

Immediately after starting at low temperatures, the following effects are obtained. Since no hydraulic pressure is applied to the port 12b before starting, the spool 14 is pushed by the spring 22 and has moved to the uppermost position in FIG. 1. When started in this state, the oil pump 24 starts discharging oil into the oil passage 26. Since the temperature of the oil is low, the resistance of the throttle valve 20 is very large, and it takes some time for the oil to flow into the port 12b through the throttle valve 20 and push down the spool 14. Until the spool 14 is pushed down to the pressure regulating position, the ports 12d and 12f are closed by the lands 14d and 14e, respectively, so the oil in the oil passage 26 is not drained and the line pressure in the oil passage 26 is extremely low. has a high value. Therefore, even though the viscosity of the oil is high, the oil can rapidly flow into the clutch, brake, etc., and the automatic transmission can immediately be brought into a state in which transmission is possible. After oil flows into the port 12b and the regulator valve 10 enters the pressure regulating state, the normal pressure regulating action is performed. Note that when starting with a rise in oil temperature, the flow rate passing through the choke-type throttle valve 20 increases significantly, so the regulator valve 10 immediately goes into a pressure regulating state and does not output unnecessarily high oil pressure. Therefore, there are no harmful effects caused by the presence of the choke valve 20.

(Second example) FIG. 2 shows a second embodiment of the invention.

In this embodiment, the present invention is applied to a throttle valve 30 of an automatic transmission. The throttle valve 30 has a spool 34 inserted into a valve hole 32. Valve hole 32 is port 32
It has a to 32d. The ports 32b and 32d communicate with a throttle pressure oil passage 44 to which regulated throttle pressure is supplied. port 3
A choke valve 46 is provided at the inlet 2d. Line pressure serving as a hydraulic pressure source is supplied to the port 32c from an oil passage 42. Port 32a is a drain port. The spool 34 has lands 34a and 34b of the same diameter. Both lands 34a
The axial dimension of the groove between port 32a and 34b is
The wall distance between the port 32c and the port 32c is approximately equal. A pushing force from a vacuum diaphragm 50 is applied to the spool 34 via a rod 48. Vacuum diaphragm 50
has the function of applying a force to the rod 48 that is inversely proportional to the engine intake pipe negative pressure acting from the pipe 52. With this configuration, the slot valve 30 regulates the oil pressure in the oil passage 44 so that the downward force acting from the rod 48 and the upward force due to the oil pressure in the port 32d are balanced. port 32
Since a choke valve 46 similar to the first embodiment is provided at the inlet of port 32d, the rise of the oil pressure at port 32d is delayed immediately after starting at low temperatures, and ports 32b and 32c are in communication with each other. Therefore, the throttle pressure in the oil passage 44 becomes an oil pressure equal to the line pressure in the oil passage 42. This throttle pressure is used to regulate the line pressure by a regulator valve (not shown), so the line pressure is at its highest immediately after startup at low temperatures, and the first
The same actions and effects as in the embodiment can be obtained.

(g) Effects of the Invention As explained above, according to the present invention, the feedback oil passage of the pressure regulating valve is provided with a choke having a characteristic that does not produce a throttling effect at steady oil temperature but inhibits oil flow at low temperature. Since the type throttle valve is provided, the pressure regulation value can be increased only immediately after starting at low temperatures.For example, when the present invention is applied to a regulator valve or a throttle valve, the line pressure can be increased immediately after starting at low temperatures. This makes it possible to rapidly supply oil to clutches, brakes, etc., and immediately bring the automatic transmission into a state in which power can be transmitted.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a first embodiment of the invention, and FIG. 2 is a diagram showing a second embodiment of the invention. 10...regulator valve (pressure regulating valve),
20, 46...Tyoke type throttle valve, 30...Throttle valve (pressure regulating valve).

Claims (1)

[Scope of Claims] 1. A pressure regulating valve for an automatic transmission that regulates the hydraulic pressure by feeding back the regulated hydraulic pressure and applying it to the spool to adjust the gap for the drain, the regulated hydraulic pressure being fed back. A choke-type throttle valve is installed in the oil passage, and the choke-type throttle valve does not produce a substantial throttling effect when the viscosity of the oil is at the temperature in steady use of an automatic transmission, but when the viscosity of the oil is at low temperatures. A pressure regulating valve for an automatic transmission, characterized in that it is set to a characteristic that generates flow path resistance to the extent that it impedes smooth flow.