JP3250839B2 - Control method of clutch oil pressure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a clutch hydraulic pressure of a transmission, and more particularly to a method for quickly filling a clutch at a low temperature.

[0002]

2. Description of the Related Art A conventional clutch hydraulic pressure control method is disclosed in Japanese Patent Application Laid-Open No. 63-235732, which will be described with reference to FIG. The valve 102 has an orifice 13 at an output port 123 for the clutch 101.
0 is formed, and the spool 125 is opened by a pressure difference between the orifice 130 and the spool 125.
A first valve 104 which is closed by a return force of a spring 131 provided at one end of the first valve 104, and a pressure control valve which is operated by an electric signal, wherein the first valve 104 is opened by oil from a pump during shifting. A second valve 103 that operates to gradually increase the clutch oil pressure after the filling is completed,
Detecting means 1 for detecting completion of filling and clutch pressure based on the movement of spool 125 against spring 131 provided on the other end of spool 125 of first valve 104.
05.

FIG. 5 shows the operation of the configuration shown in FIG.
This will be described with reference to time charts shown in FIGS. 6 (a), 6 (a), 7 (a) and 8. FIG. 5A shows a command current I from the controller 106, and FIG.
The oil pressure P1 of the oil chamber 30 before, and FIG.
Oil pressure (clutch pressure) P2 of the oil chamber after 0, FIG.
5 shows an output S of FIG. At the time of shifting, the controller 106 controls the solenoid 11 provided on the valve 102.
6, a trigger command current I1 is input (time t1), and thereafter, the command current I is changed to an initial clutch pressure Pa (FIG. 7 (a)).
, And waits until filling is completed in this state.

In response to the input of the trigger I1, the spool 115 of the pressure control valve 103 moves to the left, and the oil from the pump Pp moves through the passage 129 to move the spool 125 of the first valve 104 to the right. When the spool 125 moves to the right, oil from the pump Pp flows into the clutch 101 through the first valve 104. This oil flow continues until the clutch pack is full of oil. Filling time tf
The middle spool 125 moves to the right, and the sensor 105 outputs a voltage. When the clutch pack is filled with oil, the filling is terminated, the oil stops flowing, and the orifice 13
The pressure difference before and after zero disappears and the spool 125
The return force of 1 moves to the left, and the shoot pressure shown in FIG. 7A is generated. When the spool 125 moves to the left and is detected by the sensor 105, no voltage appears (at time t2).
). The signal whose voltage has disappeared (see FIG. 8) is input to the controller 106 as S. It is determined that the filling is finished with the first fall of the voltage, and the controller 106 immediately increases the command current I for the clutch from the initial pressure command I0 gradually (FIG. 5).
(A)). When the controller 106 determines that the filling has been completed, the controller 106 lowers the command current for the preceding clutch to zero as shown by the one-dot chain line in FIG. As a result, the clutch pressure of the clutch falls from the chute pressure value to the initial pressure Pa as shown in FIG. 7A, and then gradually increases. Therefore, the spool 125 moves rightward to the neutral position. Thereafter, the clutch pressure P2 exceeds the set load Th. As a result, the spool 125 moves to the left and the sensor 105
Is detected, no voltage appears, and this level is maintained thereafter.

[0005]

According to the prior art transmission clutch hydraulic pressure control method, control can be performed at normal temperature. However, at low temperature, a command current from the controller 6 is input to the solenoid 116 of the second valve 103 to operate it. Even when the oil flows through the first valve 104, a high flow velocity of the oil passing through the orifice 130 cannot be obtained because the viscosity of the oil is high. Therefore, a sufficient differential pressure for switching the valve 104 cannot be obtained, and the first valve 104 does not open and the clutch 101 cannot be filled with oil, so that there is a possibility that the gear cannot be shifted to a new shift speed. In addition, since the valve 104 may open slowly, the clutch 101 cannot be filled in a short time, so that there is a problem that a smooth shift cannot be performed. Further, since the oil filled in the front clutch 101 does not come off in a short time due to the high viscosity of the oil, if the clutch of the new shift stage has been completely engaged, there is a possibility that double engagement of the clutch may occur. is there.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a spool having an orifice formed at an output port for a clutch, and is opened by a differential pressure across the orifice to open one end of the spool. A first valve that is closed by a return force of a spring provided on the first valve, and a pressure control valve that is operated by an electric signal. A second valve operable to open the valve and to gradually increase the clutch oil pressure after filling is completed;
A control means for controlling the clutch hydraulic pressure of the transmission, comprising a detecting means for detecting the end of the filling and the clutch pressure based on the movement of the spool provided on the other end side of the spool of the valve .
Increasing the electrical signal to activate the pressure control valve ;
The transmission time is longer than at normal temperature to clutch a large amount of oil.
And then actuate the pressure control valve
Signal is reduced and a small amount of oil flows into the clutch to detect
When the means detects that the clutch is full of oil,
Before and after the zero fall time of the electrical signal controlling the oil pressure in the switch
The build-up of the filling fluid starts . In addition, the pressure control
Predetermined from when transmission of the electric signal to activate the valve starts
Even if filling is not completed after the time has elapsed,
Configuration to forcibly start the switch build-up.
You.

[0007]

When the temperature is low, the electric signal for operating the pressure control valve is made larger than that at the normal temperature.
The opening area toward
Oil flow is high and the oil viscosity is high
But there is enough pressure difference to open the first valve
You. Further, by making the transmission time of the electric signal longer than that at normal temperature, the first valve is reliably opened. First
The two valves are provided for each individual clutch and control the pressure, the flow rate, and the flow time of the fluid applied to the clutch when the clutch is engaged. Since the first valve is reliably opened, even when the viscosity of the oil at a low temperature increases, the clutch of the new gear is filled with the oil, so that the gear can be surely shifted to the new gear. Also, when oil fills the clutch
From the front stage to control the oil pressure of the front stage clutch
Start to decrease, and when the previous-stage electrical signal becomes zero,
Since the build-up of the filling fluid starts , double engagement of the clutch does not occur. Operating the pressure control valve;
After a predetermined time has passed since the transmission of the electrical signal
Even if the clutch is not finished, the clutch
Even if the filling time is
The gear can be shifted reliably even when the vehicle is abnormally long, and the vehicle runs.
There is no impossibility.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the accompanying drawings. FIG. 1 shows a hydraulic circuit configuration of an electronic clutch hydraulic control valve 2 for driving a clutch 1, and FIG. 2 is a diagram showing an internal sectional configuration of the clutch hydraulic control valve 2. 1 and 2, a clutch hydraulic pressure control valve 2 is a pressure control valve 3 for controlling a clutch hydraulic pressure.
And a flow rate detection valve 4, a sensor unit 5 for detecting filling and clutch pressure, and an oil temperature sensor 38 provided in a pipeline for supplying oil from a pump. The pressure control valve 3 is controlled by the controller 6, and the detection signal S of the sensor unit 5 and the signal C of the oil temperature sensor 38 are input to the controller 6. The clutch hydraulic control valve 2 flows oil from a pump (not shown) through an input port 10 and supplies oil to the clutch through an output port 11. Port 1
2 is closed, and ports 13 and 14 are drain ports.

The electronic pressure control valve 3 has a spool 15, the right end of which is in contact with a plunger 17 of a proportional solenoid 16, and the left end of which is provided with a spring 18. An oil chamber 20 defined by the spool 15 and the piston 19 is piloted with an oil pressure in an oil passage 22 via an oil passage 21 formed in the spool 15. The oil amount detection valve 4 has a spool 25, which defines oil chambers 26, 27 and 28. This spool 2
An orifice 30 is formed between the fifth oil chambers 27 and 28. This spool 25 has three different pressure receiving areas A1, A
2 and A3, and A1 + A3> A2 and A2> A3 are established between these areas. A spring 31 is provided at the left end of the spool 25.
However, a spring 32 is provided on the right end, and when the spool 25 is not under pressure on the oil chambers 27 and 28,
The neutral position shown in FIG. 1 is maintained at each free length position of the springs 31 and 32. Therefore, when the spool 25 is in the neutral state, the oil flowing into the flow rate detection valve 3 from the oil passage 29 via the input port 10 remains in the oil chamber 26.

Here, assuming that the spring constants of the springs 31 and 32 are k1 and k2, the oil pressures of the oil chambers 27 and 28 are P1 and P2, respectively, and the displacement of the spool 25 from the neutral position is x, When the spool 25 is located on the left side of the neutral position shown in FIG.
1 acts rightward, and F1 = k1x + A1 P2 + P1 (A3-A2) (1) When the spool 25 is located on the right side of the neutral position, the force expressed by the following equation (2) is applied to the spool 25. F2 works to the left. F2 = k2 x-A1 P2-P1 (A3-A2) (2) In this case, k2> k1. That is, in this case, the spring 31 functions as a return spring for the spool 25. A detection pin 34 made of metal is provided on the upper right side of the valve body 33, and the detection pin 34 is provided. The detection pin 34 causes the spool 25 to move from the neutral position shown in FIG. It detects that it has moved further to the right. The detection pin 34 is attached to the body 33 via a cover 35 via an insulating sheet 36, and a lead wire 37 extends from the detection pin 34.

This lead wire 37 is connected to a resistor R connected in series.
It is connected to point a between R1 and R2. These resistors R1,
A predetermined DC voltage V (for example, 12 V) is applied between R2 and the body 33 is grounded. That is, the sensor unit 5 for detecting the filling and clutch pressure.
Is constituted by a detection pin 34 serving as a contact point between the spring 32 and the spool 25, resistors R1, R2, and the like.

The operation of the configuration shown in FIGS. 1 and 2 will be described with reference to the flowchart shown in FIG. 3 and FIGS. 5 (b), 6 (b), and 6 (b).
This will be described with reference to the time chart shown in FIG.

In S1, the process is started in response to a shift command. S
In step S2, it is determined whether the oil temperature is lower than the set temperature T.degree. C. If the oil temperature is not lower than the set temperature T.degree. Starts inputting a trigger command I1 (time t1) and a normal temperature time tt (see FIG. 5 (a)).
The input of the trigger I1 causes the spool 15 of the pressure control valve 3 to move to the left and the oil from the pump PP to pass through the passage 29 for a longer time tt '(see FIG. 5B).
And flows into the clutch 1 through the first valve 4. S
In step 4, an initial pressure command current I0 'larger than the initial pressure command current I0 at normal temperature is input to the solenoid 16. Since the relationship between the initial pressure command current I0 at normal temperature and the initial pressure command current II0 'at low temperature is I0'> I0 as shown in FIGS. 5A and 5B, the initial valve outlet pressure P at normal temperature. As shown in FIGS. 6A and 6B, the relationship between the initial valve outlet pressure P ′ at low temperature and P ′>
P, and the relationship between the clutch oil pressure Pa at normal temperature and the clutch oil pressure Pa 'at low temperature is Pa as shown in FIGS. 7 (a) and 7 (b).
'> Pa. In S5, it is determined whether or not the filling end signal is transmitted. If the filling end signal is transmitted, in S7, the command current is increased after t2 'seconds, and the build-up is started. Since it is the time required for the command current of the preceding clutch to fall to zero as indicated by the dashed line, double engagement of the clutch can be avoided. The set hydraulic pressure is set in S10, and the gear shift is completed in S11. If the filling completion signal is not transmitted in S5, it is determined in S8 whether or not the trigger command I1 is input to the solenoid 16 within t3 'seconds.
If it is not within t3 'seconds, the command current I is gradually increased at S9 as shown by the dotted line in FIG. The time t3 'is a time for judging whether or not to forcibly start the command current I even if the filling is not completed. If it is within t3 'seconds in S8, the process returns to S4. If it is not within t3 'seconds in S6, the command current I is gradually increased in S9 to start the build-up.

[0014]

The electric signal for operating the pressure control valve at a low temperature is made larger than that at a normal temperature.
The opening area toward the valve opens greatly, and the orifice of the first valve
If the flow rate through the
In this case, there is enough pressure difference to open the first valve.
You. Further, by making the transmission time of the electric signal longer than at normal temperature, the first valve is reliably opened and the clutch is quickly filled with the oil, and the charging time is equivalent to that at normal temperature.
Then, when the detecting means detects that the clutch is full of oil.
Of the electrical signal that controls the oil pressure of the front clutch from the zero
So that the build-up of the filling fluid starts
As a result , double engagement does not occur and smooth gear shifting can be performed. Also, even if the filling is not completed after a predetermined time has elapsed since the start of the transmission of the electric signal,
Even if filling is done because the build-up is forcibly started
Even when the time is abnormally long , the gear can be shifted to the new shift speed without fail , and the vehicle does not become unable to travel .

[Brief description of the drawings]

FIG. 1 shows a hydraulic circuit configuration of an electronic clutch hydraulic control valve 2 that drives a clutch 1. FIG.

FIG. 2 is a diagram showing an internal cross-sectional configuration of an electronic clutch hydraulic control valve 2.

FIG. 3 is a flowchart of a clutch hydraulic pressure control method according to the present invention.

FIG. 4 is a diagram for explaining a conventional clutch oil pressure control method.

FIG. 5 is a time chart of a command current.

FIG. 6 is a time chart of a valve outlet pressure.

FIG. 7 is a time chart of clutch pressure.

FIG. 8 is a time chart of a sensor output.

[Explanation of symbols]

 Reference Signs List 1 clutch 2 electronic clutch hydraulic control valve 3 pressure control valve 4 flow detection valve 5 sensor unit 6 controller 11 output port 25 spool 30 orifice 31 spring

Claims (2)

(57) [Claims] A first valve having a spool formed with an orifice at an output port for the clutch, the first valve being opened by a differential pressure across the orifice and being closed by a return force of a spring provided at one end of the spool; A pressure control valve operated by an electric signal, wherein oil is supplied from a pump to the first valve during gear shifting to open the first valve and gradually increase the clutch oil pressure after filling is completed. And a detecting means for detecting the end of the filling and the clutch pressure based on the movement of the spool against the spring provided on the other end of the spool of the first valve. In the method for controlling clutch oil pressure according to the above, at low temperatures, an electric signal for operating the pressure control valve is increased.
Make the transmission time longer than at room temperature and increase the amount of oil
Into the clutch, and then actuate the pressure control valve
A small amount of oil to the clutch
The time when the detecting means detects that the clutch is full of oil.
Signal drop for controlling the oil pressure of the previous clutch
After a certain time, the build-up of
A method of controlling a clutch hydraulic pressure. 2. The clutch hydraulic pressure control method according to claim 1, wherein the clutch build-up is forcibly performed even when filling is not completed after a predetermined time has elapsed from when transmission of the electric signal for operating the pressure control valve is started. A method for controlling clutch oil pressure, characterized in that: