JPH09112654A - Transmission control system - Google Patents

Abstract

PURPOSE: To provide a single pressure control structure to control a neutral idle condition and actuation of a torque converter clutch. CONSTITUTION: A shift valve 64 guides control fluid pressure to a clutch 76 for an advance from a control source 34 when a transmission ratio establishing means is not actuated, and guides the control fluid pressure to a torque converter clutch control valve 46 from the control source 34 when the transmission ratio establishing means is actuated. A pressure control valve 74 is positioned between the shift valve 64 and the control source 34, and controls engaging pressure of the clutch 76 for an advance when the transmission ratio establishing means is not actuated, and controls the engaging pressure of a torque converter clutch 44 when the transmission ratio establishing means is actuated. A pressure regulator 56 controls the control fluid pressure guided by the shift valve 64. The single pressure control valve and the pressure regulator 56 are demanded for neutral idling and control of the torque converter clutch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission control system for a vehicle transmission, and more particularly to a transmission control system in a transmission including both a torque converter clutch and a neutral idle subsystem.

[0002]

BACKGROUND OF THE INVENTION Transmissions that include both a torque converter clutch and a neutral idle control are designed to provide separate and separate controls for each subsystem. This has increased the number of solenoid control valves, complicating the electrical control module. Generally, the torque converter clutch is designed so that the clutch is not engaged in a low throttle state by controlling the pressure thereof. In a neutral idle control system, torque transmission is limited by controlling a pressure-actuated friction device in the disengaged or slip condition. Then, when the vehicle is stopped and the throttle is low, the engagement pressure is reduced.

As a general rule, the pressure control function of these subsystems is regulated by a valve mechanism controlled by another solenoid. The valve mechanism outputs a variable signal pressure proportional to the duty cycle of the voltage applied to the solenoid winding. Each subsystem has an assigned solenoid control valve mechanism, and by this solenoid control valve mechanism,
Engagement pressure is established within the subsystem.

Electronic control of the electrical control module or actuation of a digital computer provides the necessary signals to the solenoid controlled valve mechanism to provide the desired output pressure schedule.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved transmission control system having a single pressure regulating structure that controls both neutral idle conditions and torque converter clutch actuation.

[0006]

The present invention has been made in view of the above prior art, and is a transmission control system for a vehicle transmission having a brake system and a throttle system, which includes a torque converter clutch and a forward drive. Low ratio torque transmission means;
A drive ratio establishing means that is selectively operable; and a hydraulic pressure control unit, the hydraulic pressure control unit including a shift valve, a pressure adjusting valve, and a pressure regulator controlled by a solenoid. , The shift valve guides control fluid pressure from a control source to the forward low ratio torque transmitting means when the drive ratio establishing means is not operated, and controls when the drive ratio establishing means is operated. A control fluid pressure from a source to the torque converter clutch control means, the pressure regulating valve is positioned between the shift valve and the control source, and the pressure regulating valve is the throttle. At the first pressure schedule level, as indicated by the signals from the system and the braking system, as required.
When the drive ratio establishing means is operated, the engagement pressure of the forward low ratio torque transmitting means is controlled, and
Controlling the engagement pressure of the torque converter clutch at a pressure schedule level of, and the pressure regulator controlled by a solenoid responds to signals from the throttle system and the brake system by the shift valve. A transmission control system for controlling guided control fluid pressure is provided.

The present invention uses a single solenoid-controlled pressure regulator (preferably a variable release solenoid valve) and a single pressure regulating valve to provide a torque converter clutch and a forward clutch during neutral idle. The control pressure function for both is established. The pressure output signal of the pressure regulator controlled by a solenoid is adapted to be distributed by a shift valve. The shift valve guides a pressure output signal from the pressure regulating valve to the forward clutch in the low forward range. In addition, the shift valve, in all other forward range,
A pressure output signal is directed from the pressure regulating valve to the torque converter clutch. The solenoid controlled pressure regulator is controlled by the electronic control unit of the transmission to provide the desired output pressure for the valve mechanism based on the operating condition of the transmission. However, the electronic or electrical output from the electronic control unit to the pressure regulator, which is controlled by a solenoid, is guided to a single valve mechanism, which allows some reduction of control circuit components. Has become.

The present invention is illustrated by way of example with reference to the following description and the accompanying drawings.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a vehicle is generally shown at 10. The vehicle 10 includes an engine 12 and a power transmission 14. The power transmission 14 includes an output shaft 16 capable of driving a normal differential device 18. The differential device 18 is drivably connected to a pair of drive wheels (that is, drive wheels) 20 and 22. The vehicle 10 also includes a pair of steerable front wheels (ie, front wheels) 24, 26. The engine 12 is controlled by a conventional throttle system having a throttle pedal 28.
The throttle system is effective in supplying fuel to the engine 12 to obtain a desired torque output as requested by the operator. The deceleration of the vehicle is controlled by a braking system having a conventional brake pedal 30. By operating the brake pedal 30, the wheels 20-26 are passed through the normal master cylinder 32.
The braking force can be applied to each of the.

The transmission 14 including the torque converter is preferably an electronic control unit. In the electronic control unit, shift signals and pressure levels are controlled by a normal digital computer. The digital computer is programmed to output the desired response and shift order within the transmission 14. Such devices are well known and those skilled in the art are familiar with such devices, so a more detailed description is not considered necessary in this regard. The transmission 14 and the torque converter not only receive various speed signals from sensors provided on the vehicle, but also input signals from the brake system and throttle system of the vehicle.

Referring to FIG. 2, a schematic control diagram of the transmission control 34 is shown. The transmission control 34 comprises a conventional hydraulic system (eg a hydraulic system) and a conventional programmable computer or CPU. The passage 3 is activated by the operation of the transmission control 34.
6, the main line pressure is supplied, the ratio signal pressure is output to the passage 38, the forward drive signal pressure is output to the passage 40, and other normal operations are performed. The hydraulic system also includes a flow path 42. Due to the function of the flow path 42, the fluid is changed to the torque converter control valve 46.
Through the conventional torque converter clutch 44.

As is well known, the operation of the torque converter causes the engagement of the torque converter clutch 44 to
The ratio is 1: 1. On the other hand, the slip torque is transmitted while the torque converter clutch is disengaged. The main passage 36 is connected to the operation limiting valve 48 and the pressure adjusting valve 74. The operation limiting valve 48 is essentially
It is a conventional downstream control valve, so that the output pressure in passage 52 is controlled to a level that is less than the pressure generally shown in main passage 36. As is well known, the main pressure of the transmission control 34 is a variable value that changes based on parameters such as vehicle speed, torque demand, and gear ratio during vehicle travel, and other parameters. However, it is desirable to provide a constant maximum pressure level to various actuated valves throughout the system. That is the purpose of the limiting valve 48.

The passage 52 is connected to a variable release solenoid valve 56 through a conventional filter 54.
The variable release solenoid valve 56 includes a conventional force motor adjuster 58.
The forced motor adjuster 58 receives the current signal from the transmission control 34 and opens and closes the variable orifice in the variable release solenoid valve 56. The variable release solenoid valve 56 thereby controls the pressure in the passage 60 located downstream of the constant throttle 62.

The pressure in the passage 52 is constant at the input to the throttle 62. On the other hand, the variable release solenoid valve 56 constitutes a variable output orifice that provides a pressure from 0 to a maximum to the passage 60. The passage 60 is
It is connected to the shift valve 64. Shift valve 64
Includes an exhaust connection 66, a torque converter clutch output passage 68, and a neutral idle output passage 70. The shift valve 64 is biased in one direction by a spring 72 and moves in response to the biasing force of the spring in response to the fluid pressure in the passage 38 that conveys the ratio. In addition, the passage 60 is connected to the pressure adjusting valve 74 and provides the pressure adjusting valve 74 with a control pressure.

The pressure adjusting valve 74 receives the input pressure from the main passage 36 and transmits the pressure to the shift valve 64 through the clutch engagement passage 78. As shown, the clutch engagement passage 78 is connected to the neutral idle output passage 70 through the shift valve 64 when the shift valve 64 is spring-biased. The neutral idle output passage 70 is provided with a pressure forward clutch 76.
To supply.

The forward clutch 76 is a conventional friction device that operates in fluid within the transmission 14. The forward clutch 76 controls the torque transmission capacity of the clutch based on the fluid pressure acting on the piston. The neutral idle pressure adjusting valve 74 is a spring-biased valve, and is biased or biased by the spring force and the pressure of introducing the fluid from the main passage 36 into the clutch engagement passage 78.

Passage 60 connected to pressure regulating valve 74
The second urging pressure is applied to the pressure control valve 74. As previously mentioned, the pressure in passage 60 is proportional to the adjustment of variable release solenoid valve 56, and thus the variable bias pressure. Throttle pedal 2
8 is released and the brake pedal is depressed, the passage 60
Pressure is maximum. As a result, the maximum urging pressure is supplied to the pressure control valve 74, and the pressure control valve 74 is
It outputs a significantly reduced pressure which results in the forward clutch 76 slipping or disengaged.

In this way, the vehicle is stationary,
It is clear that when the brake is actuated and the throttle pedal 28 is released, the torque transmission capacity of the forward clutch 76 is reduced and less energy is absorbed in the torque converter.

The brake is released and the throttle pedal 2
When 8 is pushed, the pressure in the passage 60 rapidly decreases so that the pressure regulating valve 74 provides maximum pressure to the forward clutch 76, so that when the operator desires a running condition, the Sliding operation is performed.

When the parameters in the vehicle 10 determine that a higher speed ratio gear is desired, the ratio-carrying passage 38 is activated or pressurized and the normal drive ratio establishing device 77, such as a clutch or brake, is forced. Engage with. The drive ratio establishing device 77 generally controls establishment of the second ratio. Further, the pressure in the passage 38 for transmitting the ratio supplies an urging pressure to the shift valve 64, whereby the shift valve 64 is pressed against the spring 72, and the passage 60 and the torque converter clutch output passage 6
8 is connected. At this time, the neutral idle output passage 70 is separated from the clutch engagement passage 78 and is connected to the drive passage 40 by the shift valve 64. When the torque converter clutch output passage 68 is pressurized, the urging force is pressed against the torque converter control valve 46. As a result, the torque converter control valve 46 shifts, fluid flows in the torque converter,
The torque converter clutch 44 is engaged, which improves the operating efficiency of the torque converter. Torque converter control valve 46 is operable to shift at the minimum pressure level established in passage 68. It is understood that the desired level for shifting the torque converter control valve 46 to establish control pressure in the torque converter supply passage 80 through the pressure regulating valve 74 and the shift valve 64 is approximately 138 kPa (20 psi).

During this operating period, the pressure in passage 68 is
Equal to the pressure in passage 60. The pressure in passage 60 is established by variable release solenoid valve 56, as described above. Further, the pressure in the passage 60 establishes the biasing pressure in the pressure control valve 74, and thus the pressure in the clutch engagement passage 78. In this manner, the pressure control valve 74 exerts a desired control pressure function by being urged, so that the forward movement clutch 76 and the torque converter clutch 44 are provided.
It is a regulator that supplies to.

The electronic portion of the transmission control 34 operates at a first forward speed, that is, the lowest forward speed, so that when the throttle pedal 28 is released and the brake pedal 30 is pressed, the pressure including the maximum pressure output is reached. Providing a schedule to the aisle 60. The desired pressure characteristic during operation of the torque converter clutch 44 is such that a minimum pressure is desired when the throttle is closed. When the throttle opening is increased by pressing down the throttle pedal 28, the pressure increases until it reaches a predetermined value. At the shift point of shift valve 64, the pressure in passage 60 is controlled to a minimum value and torque converter clutch 44 is not immediately engageable. The transmission control 34 sends a signal to the variable release solenoid valve 56 which causes the pressure schedule to bring the pressure in the passage 68 to the desired operating level based on the vehicle parameters available for the transmission control 34. It is becoming established. As a result, the engagement of the torque converter clutch 44 can be controlled.

In this regard, actuation of a single variable release solenoid valve and a single pressure regulating valve allows the neutral idle condition of the forward clutch and the desired operating pressure of the torque converter clutch to be established. It is clear that

As pointed out in the prior art systems,
Mutually exclusive operation of these devices is controlled by another valve member, which requires increasing the number of variable pressure valve mechanisms provided in the control system. The use of a single variable release solenoid valve and a single pressure regulating valve reduces the operating complexity of the valve and simplifies its operation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a vehicle including an engine transmission and a drive mechanism.

2 is a schematic diagram illustrating a portion of a control mechanism that controls operation of the transmission of FIG. 1 in accordance with the present invention.

[Explanation of symbols]

10 Vehicle 12 Engine 14 Power Transmission 18 Differential 16 Output Shaft 20 Drive Wheel 22 Drive Wheel 24 Front Wheel 26 Front Wheel 30 Brake Pedal 34 Transmission Control 36 Passage 38 Passage 40 Passage 42 Passage 44 Torque Converter Clutch 46 Torque Converter Control Valve 48 Operation Limiting Valve 52 Passage 54 Filter 56 Variable Discharge Solenoid Valve 58 Force Motor Adjuster 62 Throttle 60 Passage 64 Shift Valve 66 Discharge Connection 68 Torque Converter Clutch Output Passage 70 Neutral Idle Output Passage 72 Spring 74 Pressure Control Valve 76 Forward clutch 77 Drive ratio establishing device 78 Clutch engagement passage 80 Torque converter Supply passage

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display F16H 59:68

Claims (4)

[Claims] 1. A transmission control system for a vehicle transmission having a braking system and a throttle system, the transmission control system comprising a torque converter clutch (44); a low forward ratio torque transmitting means (76); Drive ratio establishing means (7) that can be selectively operated
7) and; a hydraulic pressure control unit, the hydraulic pressure control unit including a shift valve (64), a pressure control valve (74), and a pressure regulator (56) controlled by a solenoid. The shift valve (64) guides the control fluid pressure from the control source (34) to the forward low ratio torque transmitting means when the drive ratio establishing means is not operated, and the drive ratio establishing means operates. When activated, control source (34)
From the torque converter clutch control means (46) to the control fluid pressure, the pressure control valve (74) is positioned between the shift valve and the control source, and the pressure control valve. A valve (74) controls the engagement pressure of the forward low ratio torque transmitting means at a first pressure schedule level when indicated as required by signals from the throttle system and the braking system, Further, when the drive ratio establishing means is operated, the engagement pressure of the torque converter clutch is controlled at a second pressure schedule level, and the pressure regulator (56) controlled by a solenoid is Guided by the shift valve in response to signals from the throttle system and the braking system. Transmission control system and controls the control fluid pressure. 2. The transmission control system according to claim 1, wherein the forward low ratio torque transmission means is a clutch (76). 3. The transmission control system according to claim 1, wherein the pressure regulator (56) controlled by a solenoid is a predetermined vehicle operating parameter having a signal from the throttle system and the brake system. In response, the shift valve (6) from the control source (34) at the first and second pressure schedule levels.
Transmission control system characterized in that the pressure to 4) is selectively controlled. 4. The transmission control system according to claim 1, wherein the pressure regulator controlled by a solenoid is a variable release solenoid valve (56). .