JPS61124754A - Hydraulic controller having solenoid - Google Patents

Abstract

PURPOSE:To improve the response performance of a valve by forming a throttle valve for branching a hydraulic source oil passage to a signal pressurized oil passage, into a choke-type throttle valve and lowering the residual pressure in the signal pressurized oil passage. CONSTITUTION:When the oil temperature becomes an ordinary using temperature, a lock-up control valve 32 is not switched to the lock-up side. When a solenoid 36 is turned-ON in this state, the hydraulic pressure in a signal pressurized oil passage 74 immediately increases up to the value equal to the hydraulic pressure in a line pressurized oil passage 58, since the dynamic viscosity of the oil is little, and a sufficient flow-rate of oil is supplied into the signal pressurized-oil passage 74 through a chock-type throttle valve 72. In other words, the response performance of the signal pressurized oil passage 74 for the switching to the turning-ON of the solenoid 36 is improved markedly.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is directed to a hydraulic control device having a solenoid.

(B) Prior Art Conventional hydraulic control devices having a solenoid include, for example, an overdrive release valve and an overdrive release solenoid disclosed in Japanese Utility Model Application Laid-Open No. 59-7954. This hydraulic control device uses an overdrive release solenoid to open and close an opening provided in a signal pressure oil path connected to a line pressure oil path via an orifice type throttle valve, and uses the oil pressure in this signal pressure oil path to open and close an opening provided in a signal pressure oil path. The drive release valve is switched.

This allows the overdrive release valve to be switched in accordance with whether the solenoid is turned on or off.

(c) Problems to be solved by the invention However, in the conventional hydraulic control device as described above, even though the solenoid is open, a certain amount of hydraulic pressure is generated at low temperatures, and the valve does not operate as expected. There was a problem that there were cases. In other words, the opening opened and closed by the solenoid is relatively small so that it can be closed even with a small pushing force from a small solenoid, and the throttle valve is installed between the line pressure oil path and the signal pressure oil path. Due to the throttling effect of the opening and the throttling effect of this opening, a certain amount of oil pressure is generated in the signal pressure oil path even in normal conditions, but at low temperatures the viscosity of the oil increases and the oil does not flow smoothly, so the signal pressure Higher pressure than normal occurs in the oil line. If this pressure exceeds the switching pressure of the valve,
The valve will switch even though the solenoid has not closed the opening. If such a hydraulic control device is applied to switching control of the torque converter lock-up mechanism of an automatic transmission, the lock-up mechanism will always be activated at low temperatures, making it impossible for a vehicle equipped with an automatic transmission to run. This problem occurs. In order to reduce the oil pressure in the @ pressure oil passage, the diameter of the throttle valve installed between the line pressure oil passage and the signal pressure oil passage can be made smaller to increase the throttling effect, but in this case, The flow rate of oil passing through the throttle valve decreases, and even if the opening is closed by the solenoid, the oil pressure in the signal pressure oil path does not rise immediately. In other words, the responsiveness of changes in oil pressure in the signal pressure oil path to on/off of the solenoid decreases. , this problem occurs.

The present invention solves the above-mentioned problems and provides a hydraulic control device that does not generate residual pressure above a predetermined level in the signal pressure oil path at low temperatures and has sufficient responsiveness at normal operating temperatures. The purpose is to

(d) Means for solving the problems The present invention solves the above problems by using a choke type throttle valve as the throttle valve. That is, the hydraulic control device having a solenoid according to the present invention is characterized in that the throttle valve that connects the signal pressure oil path to the oil pressure source oil path is a choke-type throttle valve that is long in length compared to its cross-sectional area. .

(e) Effect By adopting the above configuration, the resistance of the choke type throttle valve increases as the viscosity of the oil increases at low temperatures, and the flow rate passing through it decreases, so the signal pressure oil path is The residual pressure generated will be very small. Therefore, the problem that the valve to which the oil pressure of the signal pressure oil path acts is switched regardless of the operating state of the solenoid is prevented from occurring. on the other hand,
When the oil temperature rises to the temperature during normal use, the resistance of the twist-type throttle valve decreases as the viscosity of the oil decreases, so sufficient flow is supplied from the line pressure oil path to the signal pressure oil path. However, since the viscosity of the oil has decreased, residual pressure above the specified level will not occur.Moreover, in this case, sufficient flow is being supplied, so the signal pressure oil when the solenoid closes its opening The hydraulic response of the road is very good.

(F) Embodiment FIG. 2 shows a skeleton diagram of a transmission mechanism section of an automatic transmission with an overdrive to which the present invention is applied. This transmission mechanism section includes a torque converter section 1, an overdrive gear train section 2,
and a third speed gear train section 3. The torque converter 4 with a lock-up mechanism of the torque converter section 1 is
Torque from the engine (not shown) is input from the rotating shaft 4a, and the overdrive tooth 1 is driven by the rotating shaft 4b.
．． It is designed to output torque to the vehicle convoy section 2.

The torque converter 4 with a lock-up mechanism has a lock-up clutch 4C, which allows the rotating shafts 4a and 4b to be mechanically connected. The overdrive gear train section 2 includes a planetary gear set 5. It has a gear left clutch 6 and an overdrive brake 7, and the third speed gear train section 3 is a well-known gear train with three forward speeds and one backward speed, and includes two planetary gear sets 9 and 10, two planetary gear sets 9 and 10, clutches 11 and 12, two brakes 13 and 14,
and a one-way clutch 15, and the one-way clutch 15. By operating the clutches 6, 11, and 12 in appropriate combinations, four forward speeds and one reverse speed are realized.

FIG. 1 shows the entire hydraulic control system for an automatic transmission including the hydraulic control system according to the present invention.Hereinafter, valves and the like directly related to the present invention will be explained, and detailed explanations of other parts will be omitted. In addition, oil pump 20. Pressure regulator valve 21, manual valve 22.1-
2 shift valve 23.2-3 shift valve 24.3-4
Shift pulp 25. Pressure modifier valve 2
．． 6. Throttle valve 27. Throttle backup valve 28. Solenoid downshift valve 29. Second lock valve 30.00 Control Vasive 31. Regarding the structure and operation of the governor valve 33, accumulator 34, etc., see, for example, JP-A-54-132062 and JP-A-58-1.
It is similar to that disclosed in No. 96373.

The lock-up control valve 32 has a spool 32a and a spring 32b, and switches between a state in which the oil passage 68 communicating with the lock-up oil chamber 4d is connected to the oil passage 70 and a state in which it is connected to the drain port 72. It is possible. A pressure regulator valve 21 is installed in the oil passage 70.
Torque converter supply pressure is supplied from Switching of the lockup control valve 32 is effected by a lockup control solenoid 36. The lock-up control solenoid 36 is a signal pressure oil path 7 branched from a line pressure oil path 58 (hydraulic source oil path) via a choke type throttle valve 72.
The lock-up control valve 32 is switched by controlling the discharge of the hydraulic pressure of 4. That is, when the lock-up control solenoid 36 is off, the oil in the signal pressure oil passage 74 is discharged from the opening 80, and the lock-up control valve 32
Hydraulic pressure does not act on the port 76, and the lock-up control valve 32 is in a position that communicates the oil passage 68 with the oil passage 70. Conversely, when the lock-up control solenoid 36 is turned on, the discharge of oil from the opening 80 is stopped. Therefore, line pressure acts on the port 76 of the lock-up control valve 32, and the lock-up control valve 32 is switched to drain the oil passage 68 from the drain port 72. When the lock-up control valve 32 communicates the oil passage 68 and the oil passage 70, the same oil pressure as the torque converter supply pressure acts on the lock-up oil chamber 4d, so the lock-up mechanism is in the released state, and the lock-up control valve 32 When the oil passage 68 is drained, the oil pressure in the lock-up oil chamber 4d is drained, and the lock-up clutch 4C is engaged to enter the lock-up state.

The lock-up control solenoid 36 is turned on by a signal from a lock-up control unit (not shown) when the vehicle speed is equal to or higher than a predetermined vehicle speed in, for example, fourth gear (or equal to or higher than a predetermined vehicle speed in each gear).

When the solenoid 36 is in the OFF state and opens the opening 80 of the signal pressure oil passage 74, as described above,
Oil that has flowed from the line pressure oil passage 58 into the signal pressure oil passage 74 through the cross-shaped throttle valve 72 is discharged through the opening 80. In this case, the oil pressure of the signal pressure oil passage 74 is determined by the flow characteristics of the choke-type throttle valve 72 and the flow rate characteristics of the opening 80, which is an orifice-type throttle valve. Choke type throttle valve 72
The flow rate characteristics of is expressed by the following equation.

Q=AXΔP/ν Q: Passing flow rate A: Constant ΔP: φ Pressure difference ν: Kinematic viscosity coefficient Therefore, when the oil temperature is very low and the kinematic viscosity coefficient ν is large, In this case, the flow rate passing through the choke-type throttle valve 72 is significantly reduced. Therefore, the oil pressure in the signal pressure oil passage 74 becomes extremely small. In this way, the lower the oil temperature, the lower the oil pressure in the signal pressure oil passage 74, so the oil pressure acting on the port 76 of the lock-up control valve 32 becomes extremely small.
The spool 32a is not switched against the force of the spring 32b. In this state, when the solenoid 36 is turned on and the opening 80 is closed, the oil pressure in the signal pressure oil passage 74 increases, but the choke-type throttle Since the amount of oil supplied through valve 72 is small, there is some time delay in the increase in oil pressure. However, in general, the lock-up mechanism is controlled so as not to operate when the temperature is low immediately after starting, so the solenoid 36 is not turned on when the oil temperature is low, and the solenoid 36 is not turned on when the oil temperature is low.
Even if control is performed to turn on the oil pressure, the time when the oil temperature is low and there is a response delay when the oil pressure rises is not that long, so even if there is a delay in the oil pressure response, it is not a practical problem. .

On the other hand, when the oil temperature rises, the oil pressure in the signal pressure oil passage 74 increases, but this oil pressure is set to be lower than the switching pressure of the lock-up control valve 32. Therefore, even if the oil temperature reaches the normal operating temperature, the lock-up control valve 32 will not switch to the lock-up side even though the solenoid 36 is not turned on.In this state, the solenoid 36 is turned on. In this case, the oil has a small kinematic viscosity coefficient ν and a sufficient flow rate of oil is supplied to the No. 48 pressure oil passage 74 through the choke type throttle valve 72, so that the oil pressure in the signal pressure oil passage 74 immediately changes to the line pressure oil passage 58. The response of the oil pressure of the signal pressure oil line 74 to the switching on of the solenoid 36 is very good, and therefore, at steady operating temperatures, the choke type throttle valve increases to the same value as the oil pressure. Even if 72 is used, the same hydraulic responsiveness as the conventional one can be obtained.

In this embodiment, the present invention is applied to the case where the switching of the lock-up control valve 32 is controlled by the oil pressure of the signal pressure oil passage 74 controlled by the solenoid 36, but the present invention can be applied to valves other than the lock-up control valve. It is clear that it can be applied to the switching of
It goes without saying that the present invention is also applicable to the case where the signal pressure oil passage is duty-controlled by a solenoid.

(to)! As explained above, according to the present invention, the throttle valve that branches the signal pressure oil passage from the oil pressure source oil passage is a choke type throttle valve, so that the residual pressure in the No. 4g pressure oil passage at low temperatures is reduced. This allows valves, etc. controlled by the oil pressure in the signal pressure oil path to operate as specified, and also provides the same responsiveness as using an orifice type throttle valve at normal operating temperatures. be able to.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a hydraulic circuit including a hydraulic control device according to the present invention, and FIG. 2 is a skeleton diagram of an automatic transmission. 36...-Solenoid, 5811...Line pressure m path (hydraulic source oil path), 72...Choke type throttle valve, 74・φ・
Signal pressure oil line.

Claims (1)

[Claims] In a hydraulic control device having a solenoid that controls the hydraulic pressure of the signal pressure oil path by controlling the opening and closing of an opening provided in the signal pressure oil path connected to the oil pressure source oil path via a throttle valve, a solenoid is used. A hydraulic control device having a solenoid, characterized in that the valve is a choke-type throttle valve.