JPH05272555A - Control method for clutch oil pressure - Google Patents

Abstract

PURPOSE:To prevent double coupling by making the transmitting period of the opera tion signal of a pressure control valve at a low temperature longer than that at the ordinary temperature, setting the oil pressure to the pressure control valve at a low temperature higher than that at the ordinary temperature, and delaying the build-up start of a clutch at a low temperature than at the ordinary temperature. CONSTITUTION:A speed change command is received at S1, if the oil temperature is lower than the preset temperature T deg.C at S2, a controller 6 continuously feeds a trigger command I1 to a solenoid for a period t'1 longer than the period t1 at the ordinary temperature. The spool 15 of a pressure control valve 3 is moved to the left by this input, and the oil from a pump Pp flows into a clutch 1 through a valve 4. The initial pressure command current is set to Io' and the initial valve output pressure is set to P' at S4. The ordinary-temperature initial pressure command current Io < low-temperature initial pressure command Io', thus the ordinary-temperature initial valve output pressure P< low-temperature initial valve output pressure P', and the ordinary-temperature clutch oil pressure Pa < low-temperature clutch oil pressure Pa'. A filling completion signal is transmitted at S5, and the build-up is started after t2' sec at S7. The front-stage clutch command current is lowered to zero in t2, and the double coupling of the clutch can be avoided.

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 clutch hydraulic pressure of a transmission, and particularly to speeding up filling at low temperatures.

[0002]

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

The operation of the configuration shown in FIG. 4 is shown in FIG.
This will be described with reference to the time charts shown in (a), FIG. 6 (a), FIG. 7 (a), and FIG. 5A shows a command current I from the controller 106, and FIG. 6A shows an orifice 1
The oil pressure P ₁ of the oil chamber before 30 is shown in FIG.
Oil pressure (clutch pressure) P ₂ of the oil chamber after 0, FIG.
The output S of 05 is shown. When shifting, the controller 106 controls the solenoid 11 provided in the valve 102.
6, the trigger command current I ₁ is input (time t ₁ ), and then the command current I is applied to the initial pressure P _a of the clutch hydraulic pressure (FIG. 7A).
To the initial command I ₀ corresponding to, and wait in this state until the end of filling.

By the input of the trigger I ₁ , the spool 115 of the pressure control valve 103 moves leftward, and the oil from the pump P _p passes through the passage 129 and moves the spool 125 of the first valve 104 rightward. When the spool 125 moves to the right, the oil from the pump P _p flows into the clutch 101 through the first valve 104. This oil flow continues until the clutch pack is filled with oil. Filling time t _f
The middle spool 125 has moved to the right, and the sensor 105 outputs a voltage. When the clutch pack is filled with oil, the filling ends and the oil no longer flows, and the orifice 13
There is no pressure difference before and after 0, and the spool 125 has the spring 13
The restoring 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 the sensor 105 detects it, no voltage appears (time t ₂ ). The signal (see FIG. 8) in which this voltage disappears is input to the controller 106 as S. It is determined that the filling is completed due to the first fall of the voltage, and the controller 106 immediately gradually increases the command current I for the clutch from the initial pressure command I ₀ (FIG. 5).
(A)). When the controller 106 determines that the filling has ended, the controller 106 reduces the command current to the preceding clutch to zero as shown by the alternate long and short dash line in FIG. As a result, the clutch pressure of the clutch drops from the shoot 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. After that, the clutch pressure P ₂ exceeds the set load Th. As a result, the spool 125 moves leftward and the sensor 105
When is detected, the voltage does not appear and this level is maintained thereafter.

[0005]

In the prior art transmission clutch hydraulic pressure control method as described above, control can be performed at room temperature, but at low temperature, a command current from the controller 6 is input to the solenoid 116 of the second valve 103 to operate. Even if the oil is made to flow through the first valve 104, the viscosity of the oil is high, so that the first valve 104 does not open and the oil cannot be filled in the clutch 101 in a short time so that the smooth shift cannot be performed. Since the filled oil does not escape in a short time, double engagement of the clutch may occur.

[0006]

In order to solve the above problems, the present invention has a spool having an orifice formed in an output port for a clutch, and the spool is opened by a differential pressure before and after this orifice, and one end of the spool is opened. A first valve that is closed by a restoring force of a spring provided in the first valve and a pressure control valve that is operated by an electric signal, and supplies oil from the pump during shifting to the first valve. When the valve is opened, the second valve is operated to gradually increase the clutch hydraulic pressure after the completion of filling, and the filling operation is completed based on the movement of the spool against the spring provided at the other end of the spool of the first valve. A method for controlling a clutch hydraulic pressure of a transmission, comprising: a clutch pressure detecting means, wherein an electric signal for operating the pressure control valve at a low temperature is used. The outgoing time longer than normal temperature, and with a higher valve outlet pressure of the pressure control valve from the normal temperature, delayed from normal temperature to the beginning of the build-up clutch.

[0007]

[Function] By making the transmission time of the electric signal for operating the pressure control valve at a low temperature longer than that at the normal temperature and making the outlet pressure of the pressure control valve higher than that at the normal temperature, the first valve is surely opened and the oil is not applied to the clutch. Fills quickly and delays the start-up of build-up from that at room temperature, so that the clutch after the shift is engaged after the front-stage clutch is released, so double engagement does not occur.

[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 that drives the clutch 1, and FIG. 2 is a diagram showing an internal cross-sectional configuration of the clutch hydraulic control valve 2. 1 and 2, the clutch hydraulic pressure control valve 2 is a pressure control valve 3 that controls the clutch hydraulic pressure.
A flow rate detection valve 4, a sensor section 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 pressure control valve 2 inputs oil from a pump (not shown) through the input port 10 and supplies oil to the clutch through the 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 spool 15 has a right end abutted against a plunger 17 of a proportional solenoid 16 and a left end provided with a spring 18. The oil pressure in the oil passage 22 is piloted into an oil chamber 20 defined by the spool 15 and the piston 19 via an oil passage 21 formed in the spool 15. The oil amount detection valve 4 has a spool 25, and the spool 25 defines oil chambers 26, 27, and 28. This spool 2
An orifice 30 is formed between the five oil chambers 27 and 28. This spool 25 has three different pressure receiving areas A ₁ , A
₂ and A ₃ , and there is a relationship of A ₁ + A ₃ > A ₂ and A ₂ > A ₃ between these areas. A spring 31 is provided at the left end of the spool 25.
However, a spring 32 is provided at the right end, and when the spool 25 has no pressure in the oil chambers 27 and 28,
The free positions of the springs 31 and 32 hold the neutral position shown in FIG. Therefore, when the spool 25 is in the neutral state, the oil flowing from the oil passage 29 into the flow rate detection valve 3 via the input port 10 remains in the oil chamber 26.

When the spring constants of the springs 31 and 32 are k ₁ and k ₂ , the hydraulic pressures of the oil chambers 27 and 28 are P ₁ and P ₂ , respectively, and the displacement from the neutral position of the spool 25 is x. When the spool 25 is on the left side of the neutral position shown in FIG. 1, the force F shown in the following formula (1) is applied to the spool 25.
₁ works to the right, and F ₁ = k ₁ x + A ₁ P ₂ + P ₁ (A ₃ −A ₂ ) ... (1) Further, when the spool 25 is on the right side of the neutral position, it is below the spool 25. The force F ₂ shown in equation (2) acts to the left. _{F 2 = k 2 x-A} 1 P 2 -P 1 (A 3 -A 2) Note (2), and in this case k _2> k _1. That is, in this case, the spring 31 acts as a return spring for the spool 25. A metal detection pin 34 is provided on the upper right side of the valve body 33. The detection pin 34 is provided so that the spool 25 resists the spring force of the spring 32 from the neutral position shown in FIG. It is detected that it has moved further to the right. The detection pin 34 is attached to the body 33 by a cover 35 via an insulating sheet 36, and a lead wire 37 is drawn out from the detection pin 34.

This lead wire 37 has a resistance R connected in series.
It is connected to point a between ₁ and R ₂ . These resistors R ₁ ,
A predetermined DC voltage V (for example, 12 V) is applied between R ₂ and the body 33 is grounded. That is, the sensor unit 5 for detecting filling and clutch pressure
Is composed of a detection pin 34 serving as a contact point between the spring 32 and the spool 25, resistors R ₁ and R ₂ , and the like.

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

In S1, the shift command is received to start. S
In step 2, it is determined whether the oil temperature is lower than the set temperature T degrees C, and if it is not lower than the set temperature T degrees C, the normal command is issued at normal temperature. If the temperature is lower than the set temperature T degrees C, the controller 6 causes the solenoid 16 to operate in S3. To start inputting the trigger command I ₁ to time (time t ₁ ) and time t _{t at} room temperature (see FIG. 5 (a))
More continuously input for a long time t _t 'see FIG. 5 (b)), the trigger I ₁ pressure control valve 3 of the spool 15 by the input of the oil from the pump P _P moves leftward passage 29
Through the first valve 4 into the clutch 1. S
In step 4, the initial pressure command current I ₀ 'is set to the initial valve outlet pressure P'. The relationship between the initial pressure command current I ₀ at room temperature and the initial pressure command current I ₀ 'at low temperature is I as shown in FIGS. 5 (a) and 5 (b).
_{Since 0} ′> I ₀ , the relationship between the initial valve outlet pressure P at room temperature and the initial valve outlet pressure P ′ at low temperature is P ′> P as shown in FIGS. The relationship between the clutch hydraulic pressure P _a and the low temperature clutch hydraulic pressure P _a 'is P _a '> P _a as shown in FIGS. 7 (a) and 7 (b). Filling completion signal determines whether originated in S5, the filling end signal 'starts built-up Yuki raise the command current in seconds, t _2' t ₂ in S7 if originated seconds Fig 5 (b ) It is the time for the command current of the preceding clutch indicated by the alternate long and short dash line to drop to zero, so double engagement of the clutch can be avoided. The set hydraulic pressure is set in S10, and the shift is completed in S11. T ₃ 'is determined whether within seconds, t _3' in S8 if the filling completion signal is transmitted in S5 Yuki incrementally command current I as indicated by the dotted line shown in FIG. 5 (b) in S9 if not within seconds Start building up. t ₃ 'seconds is the time when the filling is completed. S8
If it is within t ₃ 'seconds, the process returns to S4. If it is not within t ₃ 'seconds in S6, the command current I is gradually increased in S9 and build-up is started.

[0014]

As described above, the transmission time of the electric signal for operating the pressure control valve at a low temperature is set longer than that at the normal temperature, and the outlet pressure of the pressure control valve is set higher than the normal temperature, so that the first valve is surely opened and the clutch is released. Since the oil is quickly filled with the oil, the build-up start time is delayed from the normal temperature and the clutch is engaged after the oil in the pre-stage clutch is drained, double engagement does not occur and smooth gear shifting is possible.

[Brief description of drawings]

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 structure of an electronic clutch hydraulic control valve 2.

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

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

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

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

FIG. 7 is a time chart of clutch pressure.

FIG. 8 is a time chart of sensor output.

[Explanation of symbols]

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

Claims (1)

[Claims] 1. A first valve having a spool having an orifice formed in an output port for a clutch, the valve being opened by a differential pressure before and after the orifice and being closed by a restoring force of a spring provided at one end of the spool. A pressure control valve that is operated by an electric signal, and supplies oil from the pump to the first valve at the time of shifting to open the first valve and gradually increase the clutch hydraulic pressure after completion of filling. A clutch hydraulic pressure for a transmission, which includes a second valve that operates and a means for detecting the end of filling and clutch pressure based on the movement of the spool against a spring provided at the other end of the spool of the first valve. In the control method of (1), the transmission time of the electric signal for operating the pressure control valve at low temperature is set longer than that at room temperature, and A method for controlling clutch hydraulic pressure, characterized in that the pressure of supplied oil is set higher than that at room temperature and the build-up start of the clutch is delayed from that at room temperature.