JPS6357946A - Electronic controlled automatic transmission - Google Patents

Abstract

PURPOSE:To permit the smooth automatic speed change operation by installing an electromagnetic opening/closing valve for duty control between a tank and the solenoid valves for driving a shift actuator and a selecting actuator and duty-operating said valve when a gear is set. CONSTITUTION:An electromagnetic opening/closing valve V6 for duty control is installed between a tank T and the solenoid valves V1-V5 for driving a shift actuator 10 and a selecting actuator 20, and a control means for duty controlling said solenoid valve is installed. When a gear speed change instruction is transmitted, selection to an aimed stage is performed through shift release, and when the car speed with the gear set is not zero, the electromagnetic opening/closing valve V6 for duty control is duty-operated after synchronization. Therefore, the actuators 20 and 20 for shifting and selection can gently operated, and the speed change mechanism can be protected from damage through the smooth automatic speed change operation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electronically controlled automatic transmission, and more particularly to an electronically controlled automatic transmission that smoothly performs gear shifting operations.

(Prior Art) In recent years, automatic transmissions for vehicles have been developed, and the gear shift operation of the transmission is not performed manually by the driver, but is operated by an actuator operated by fluid pressure, for example, based on commands from an electronic control device installed in the vehicle. The transmission is being shifted.

Then, a pair of fluid pressure actuators that operate in the select direction and shift direction of the transmission mechanism are provided, and a position sensor that detects the operating positions of these pair of actuators is provided to accurately know the operating position of the actuator. JP-A-58-170954 discloses a proposal for an actuator for a transmission in which position control is performed by a rotary part.

(Problem to be solved by the invention) In the above proposal, fluid pressure is applied to the fluid pressure actuator by a solenoid valve. Impact forces may be applied, which may damage the above-mentioned components and shorten their lifespan.

In addition, shift actuators using differential pressure pistons,
When a select actuator is configured, even if two or more solenoid valves are turned on or off at the same time, the cylinder piston position will shift due to the difference in response and will be outside the detection range of the position switch, causing the inconvenience that the shift position will be unknown. There are also drawbacks.

Therefore, it is an object of the present invention to provide a duty control solenoid on-off valve between a shift actuator and a select actuator drive solenoid valve and a tank, and to operate the duty control solenoid on-off valve in a gear shift operation. Therefore, it is an object of the present invention to provide an electronically controlled automatic transmission that restricts sudden piston movement and performs smooth automatic gear shifting operations.

Another object of the present invention is to provide an automatic transmission of the type described above, in which the operating position of the shift actuator is detected by a stroke sensor, and preferably the operating position of the select actuator is also detected by a stroke sensor. Another object of the present invention is to provide an electronically controlled automatic transmission in which the selection position can be clearly grasped.

(Means for Solving the Problems) According to the present invention, in an electronically controlled automatic transmission that controls the fluid pressure using an electronic control unit to operate the transmission in the shift direction and the select direction to control the speed change, A driving solenoid valve disposed between a pressure source and a speed change actuator, an electromagnetic on-off valve disposed between the solenoid valve and a fluid pressure tank, and a control means for duty-controlling the on-off valve. An electronically controlled automatic transmission is provided.

(Operation) When a gear shift command is given, a shift is made and a target gear is selected. During gear shift, if the vehicle speed is not zero, the duty control electromagnetic on-off valve is operated on duty after synchronization to suppress sudden movement of the piston. After that, when the shift is completed and the clutch is engaged, the release of hydraulic pressure from the pressure oil supply line to the tank is prohibited to prevent gear slippage.

(Example) Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic block diagram showing the relationship between an automatic transmission and an electronic control device, and FIG. 2 is a configuration diagram showing a transmission actuator.

In Fig. 1, 1 is a parallel shaft gear type transmission, and 2 is an electronic control device composed of a microcomputer, which controls calculation of the appropriate gear of the transmission, signals to drive the transmission, signals to control the clutch, etc. (vehicle speed sensor), and 5.6 is a shift actuator and a select actuator, respectively, of transmission actuators that drive the transmission l. 7 is a select lever, which sends a signal based on the select position to the electronic control device 2 from the select switch 7a, and 8 is an accelerator pedal, which sends a signal corresponding to the amount of pedal depression to the electronic control device 2 by an accelerator sensor 8a. input.

The electronic control device 2 includes a central processing unit (CPU) that performs arithmetic processing based on input signals, various memories (MEMO) that store arithmetic results and register values, and store shift maps, as well as control signals. Il becomes the input/output circuit of
It has o.

In FIG. 2, lO indicates a shift actuator, which is used for L, N, R stages, or 2. N2, 3rd stage, or 4. N,
, 5 stages, or 6 + N4 + empty position. 20 indicates a selection actuator, N l +
Switch between 4 positions: N 2 * N 5 and N4.

30 indicates a shift stroke sensor, which detects the position of a piston rod ib of a shift actuator 1 having a cylinder 1a and a piston rod 1b.

40 indicates a select stroke sensor, which is connected to the cylinder 2a.
Detection signals from the shift stroke sensor 30 and the select stroke sensor 40 are input to the electronic control device 2 described above.

Vt+V2 is a solenoid valve that operates the shift actuator IO, and V5*V4+V5 is a solenoid valve that operates the select actuator 20. Pin
is the main hydraulic power source, P is the hydraulic power source for the normal hydraulic circuit system, and P' is the hydraulic power source for the emergency hydraulic circuit system. Note that the present invention includes not only hydraulic pressure but also pneumatic pressure. Vel is an emergency solenoid valve of the select actuator 20, and Vs2. Vs5 is an emergency solenoid valve of the shift actuator 10, and Vs4 is
This is a solenoid valve for switching the hydraulic circuit system.

Although the above-described embodiments have been described including an emergency hydraulic circuit system, the present invention can also be applied to systems that do not include an emergency hydraulic circuit system.

In addition, vs is an electromagnetic on-off valve for duty control, and in addition to on/off control, a predetermined duty operation is performed.
The hydraulic oil is returned to the tank T.

Next, Figs. 3 and 4 show shift stroke values (TMS).
) and time, a characteristic diagram showing the relationship between top gear rotation speed (T
Characteristic diagrams showing the relationship between MN) and time are each shown. As is clear from these figures, during a shift, these values are:

(1) Before synchronization (0” t 1) (dTMs)/dt # 0, (dTMN)/dt
= 00≦T M S < ayo (2) During synchronization (t1 to t2) (dTllIs)/dt = O, (dT)18)/l
it # OTMS=al (3) After synchronization (t2-t3) (dTMs)/dt-〇, (dTMN)/dt=
Oa1≦TMS≦a2 Next, FIG. 5 is a flowchart showing an example of the processing of this embodiment, and the present invention will be described in detail with reference to FIG. fiIJ5.

First, shift stroke sensor 30. Select stroke sensor 40, input shaft rotation sensor 3. The shift stroke value, select stroke value, engine speed, vehicle speed, and top gear rotation speed are read into the electronic control unit 2 from the output rotation sensor 4 etc. (Step S
1).

When a gear shift command is issued from the electronic control unit 2 (step S2), the clutch is disengaged (step S3), and Vg
, V4 *? , V5 is turned on, vs is turned off, and the selection operation is held (step S4).

vl and vl are turned on and the gear of the shift actuator 10 is released (step S5), and Vg.

V4 or vs is turned on and the selection actuator 20 is selected to the target stage (step S6).

It is determined whether the vehicle speed is zero or not based on the signal from the output rotation sensor 4 (step S7), and when it is not zero, ■□
Or vl is turned on and Vs is operated on duty (
Step S8).

When the vehicle speed is zero, vl or V2 is turned on, and after the 7th is turned off, the process moves to step S13 (step S9).
.

Next, it is determined whether the synchronization operation is during synchronization or after synchronization (step 510), and during synchronization, Vl or ■2 is turned off, vs is turned off (step 5ll), and a normal shift operation is performed.

After synchronization, vl or vl is turned off and vs
is activated on duty, which limits the rapid movement of the piston and prevents damage to the dog teeth.
12), this state is maintained until the shift stroke is completed (step 513).

When the shift stroke becomes complete according to the signal from the shift stroke sensor 30, vs is turned on (step 5).
14), the clutch is engaged (steps S15, 51)
6).

After Sono, v,, vl, V5. v, t or V5 are turned off (step 517) and V6 is turned off (step 5
lB).

(Effects of the Invention) As explained in detail above, the present invention provides an electromagnetic on-off valve that duty-controls the flow rate of hydraulic oil and returns the hydraulic oil to the tank, so the operation of the actuator can be controlled gently. This has the effect of preventing damage to the transmission mechanism.

Further, according to the present invention, since a stroke sensor is provided to detect the select position, in conjunction with the action of the solenoid valve that performs duty control, it is possible to prevent deviations in actuator operation due to response differences, and ensure reliable gear shifting. There is also the effect of being able to control.

[Brief explanation of drawings]

Figure 1 is a schematic block diagram showing the relationship between the automatic transmission and the electronic control device, Figure 2 is a configuration diagram showing the transmission actuator, Figure 3 is a diagram of the relationship between shift stroke value and time, and Figure 4 is a diagram showing the relationship between the shift stroke value and time. FIG. 5, which is a diagram showing the relationship between top gear rotational speed and time, is a flowchart of an example of the operation of this embodiment. l...Transmission, 2...Electronic control device, 10...Shift actuator, 20...Select actuator, 30...Shift stroke sensor, 40...
・Select stroke sensor, V6...Solenoid on-off valve. Patent applicant: IsuC Automobile Co., Ltd. Representative: Patent attorney Minoru TsujiFigure 5

Claims (2)

[Claims] (1) In an electronically controlled automatic transmission that controls fluid pressure by an electronic control device to operate the transmission in the shift direction and select direction to control the speed change, a drive disposed between the fluid pressure source and the speed change actuator. 1. An electronically controlled automatic transmission comprising: a solenoid valve, an electromagnetic on-off valve disposed between the solenoid valve and a fluid pressure tank, and control means for duty-controlling the on-off valve. (2) The electronically controlled automatic transmission according to claim (1), further comprising a stroke sensor as means for detecting the position in the select direction.