JPH07109244B2 - Shift control method of transmission - Google Patents

Description

TECHNICAL FIELD The present invention relates to a shift control method for a transmission.

[Conventional technology]

The transmission includes a plurality of gear shift clutches and a forward / reverse clutch, and a speed stage valve and a forward / reverse valve that supply pressure oil to the clutches to engage the clutches are provided. 2. Description of the Related Art There is known a transmission that switches between forward and reverse valves and engages any one speed stage clutch and forward or reverse clutch to shift to one speed stage.

Then, the transmission is controlled in the following manner.

That is, the vehicle speed, accelerator opening, etc. are input to the controller, the set vehicle speed V _{1 at} each speed stage is compared with the actual vehicle speed V ₀ , and a deceleration command is issued when V ₁ > V ₀ , and an increase command is issued when V ₁ <V _0. After the speed command is output to release the currently engaged clutch, the clutch corresponding to the next speed stage is engaged to automatically shift the speed.

[Problems to be Solved by the Invention]

This speed change control method accelerates and decelerates when the acceleration and deceleration conditions are met, and the towing load is suddenly increased and decreased depending on the driving conditions of the vehicle, and the acceleration and deceleration conditions are repeatedly satisfied in a short time. However, as a result, so-called shift hunting occurs in which acceleration and deceleration are repeatedly performed in a short time, resulting in unstable shift control.

To solve this, a time difference may be provided after the speed change operation is completed and the speed increase and deceleration conditions are satisfied until the speed increase and deceleration commands are output.

That is, while a certain set time has elapsed after the end of the gear shifting operation, the gear shifting may be prohibited even if the speed increasing condition and the decelerating condition described above are satisfied, and this set time is referred to as the gear shifting disabling time.

However, if the unshiftable time is long, it takes time to complete the shift after the shift condition is satisfied, and when the vehicle starts to accelerate or the like, it is difficult to shift up (accelerate), resulting in poor acceleration. Then, the acceleration is improved, but the shift hunting described above is likely to occur.

Therefore, an object of the present invention is to provide a shift control method for a transmission, which can prevent shift hunting without deteriorating acceleration.

[Means and Actions for Solving the Problems]

In the case of deceleration after acceleration and acceleration after deceleration, the shift is performed after a long shift disable time has passed after the shift condition is satisfied, and in other cases, a short shift disable time has passed since the shift condition was satisfied. This is a shift control method for a transmission in which a shift is performed later, whereby shift hunting can be prevented and acceleration can be improved.

〔Example〕

As shown in FIG. 1, the rotation of the engine 1 is transmitted to a drive wheel from a differential (not shown) via a torque converter 2 and a transmission 3, and the transmission 3 is subjected to a shift control by a controller 4 and a controller 4 thereof. Is a gear shift position signal from the gear shift lever 5, an engine rotation signal from the rotation sensor 6 of the engine 1, a transmission input shaft rotation signal, an intermediate shaft rotation signal, and an output from the first, second and third rotation sensors 7, 8 and 9. When a shaft rotation signal or the like is input and a preset shift condition is satisfied, a shift command is output to the control valve group 10.

As shown in FIG. 2, the control valve group 10 includes a high speed clutch 11, a low speed clutch 12, a fourth clutch 13, and a third clutch.
Valve for high speed clutch 19, valve for low speed clutch 20, valve for fourth clutch 21, valve for third clutch, which supplies the pressure oil discharged from the pump 18 to the clutch 14, the reverse clutch 15, the second clutch 16, and the first clutch 17. 22, a reverse clutch valve 23, a second clutch valve 24, and a first clutch valve 25. Each clutch valve includes a pressure control valve 26 and a flow rate detection valve 27.

The pressure control valve 26 controls the hydraulic pressure by the electric current supplied to the proportional solenoid 26a, and the electric current is sent from the controller 4 to the proportional solenoid 26a.

The flow rate control valve 27 is actuated by a trigger from the pressure control valve 26, is in a communication state until the clutch pressure receiving chamber 28 is filled with oil, is in a closed state at the same time when it is filled, and outputs a filling signal to the controller 4 to While the hydraulic pressure is being applied to the pressure receiving chamber 28, a fill signal is output to the controller 4 to notify the presence or absence of the hydraulic pressure.

The command current to the proportional solenoid 26a is controlled as shown in FIG. 3 (a), and the hydraulic pressure in the clutch chamber 28 is shown in FIG. 3 (b).
And the charging completion signal changes as shown in FIG.
Turn it on and off as shown in.

In FIG. 3, A is before shifting (when the clutch chamber 28 is drained), B is starting to fill the oil in the clutch chamber 28 (during triggering), C is filling complete, D is gradually increasing hydraulic pressure, and E is filling.

When the forward first speed command is output from the controller 4, a command current is supplied to the proportional solenoid 26a of the low speed clutch valve 20 and the first speed clutch valve 25 so that the low speed clutch 12 and the first speed clutch 17 come into contact with each other. It shifts to the first forward speed. Similarly, the speed is changed as shown in the table below.

For reverse, reverse clutch 15 and first speed clutch 17
Are in contact with.

Next, the shift control method will be described.

When the speed-up condition is satisfied while the vehicle is traveling at a predetermined speed stage, the controller 4 determines whether the previous shift is speed-up or speed-down, and in the case of speed-up, issues a speed-up command after a short shift-disabled time has elapsed. In the case of deceleration, the deceleration command is output after a long time during which gear shifting is impossible.

Similarly, if the deceleration condition is satisfied while the vehicle is traveling at a predetermined shift speed, the controller 4 determines whether the previous shift is deceleration or acceleration, and in the case of deceleration, the acceleration command is issued after a short shift impossible time. If the speed is increased, the speed increase command is output after a long time during which the gear cannot be changed.

The above-mentioned shift control is shown in a table below, and is shown in a flowchart in FIG.

As described above, in the case of deceleration after acceleration, for example, F ₁ → F ₂ → F ₁ , and acceleration after deceleration, for example, F ₃ → F ₂ → F ₃ , the unshiftable time is extended, so shift hunting is performed. In addition to the above, the non-shiftable time is shortened during the other shifts, so that the acceleration performance can be improved.

Further, when the shift control is performed as described above using the clutch valve including the pressure control valve 26 and the flow rate detection valve 27 as described above, the same speed increase after deceleration and deceleration after speed increase are performed. When shifting the clutch intermittently, the oil in the clutch chamber of one clutch cannot be completely drained, so that the clutch chamber is filled with oil during the trigger. Since the hydraulic pressure in the clutch chamber does not increase gradually and rises rapidly to engage the clutch, there is a problem that the shift shock becomes large or the clutch is damaged. Since the oil in the clutch chamber can be completely drained, the aforementioned problems can be prevented.

For example, forward 2nd speed (2nd speed clutch and low speed clutch contact) →
When shifting from 3rd forward speed (2nd speed clutch and high speed clutch contact) to 2nd forward speed (2nd speed clutch and low speed clutch contact), the low speed clutch is disengaged. When the shift command is input when the oil in the clutch chamber is not completely drained and the clutch chamber is filled with oil during the trigger, the hydraulic pressure rises without gradually increasing the pressure oil.

On the other hand, if the unshiftable time is lengthened, the shift command is input after the oil in the clutch chamber of the low speed clutch is completely drained, so that the pressure oil can be gradually increased.

〔The invention's effect〕

In the case of deceleration after speed-up or speed-up after deceleration, the gear shifts after the elapse of a long shift-incapable time, so acceleration / deceleration is not repeated in a short time, and shift hunting does not occur, so safe shifting is possible. Not only is the control performed, but in the case of other shifts, the shift is performed after a short shift disabled time, so that the acceleration performance can be improved.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is an overall schematic view of a transmission, FIG. 2 is a hydraulic circuit diagram, and FIG. 3 is an explanatory view of proportional solenoid command current value, clutch chamber pressure, filling signal output, FIG. 4 is an operation flowchart of shift control.

Claims (1)

[Claims] 1. A transmission is accelerated when a speed-up condition is satisfied,
When the deceleration condition is satisfied, the transmission is decelerated, and in the case of deceleration after acceleration and acceleration after deceleration, gear shifting is performed after a long unshiftable time has elapsed after the gear shifting condition is satisfied. A shift control method for a transmission, wherein a shift is performed after a lapse of a short shift disabled time after a shift condition is satisfied.