JPH0538286Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a control device for an automatic transmission.

(b) Conventional technology As a conventional automatic transmission control device,
-There is one shown in Publication No. 143253. The automatic transmission control device shown here is configured so that the shift valve and timing valve are each controlled by a dedicated solenoid valve, and the signal pressure from the solenoid valve is controlled by the duty ratio. Both valves are controlled individually.

On the other hand, Japanese Patent Laid-Open No. 61-52461 discloses a structure in which two valves are controlled by one solenoid valve whose duty ratio is controlled. That is, a relatively low signal pressure provided by the solenoid valve switches the first valve, and a relatively high signal pressure provided by the solenoid valve switches the second valve. This allows one solenoid valve to control two valves.

(c) Problems to be solved by the invention However, in the former type of conventional automatic transmission control device, a solenoid valve is required for each valve, which increases the size of the device and complicates the hydraulic circuit. do.

On the other hand, in the latter prior art, two valves can be controlled by one solenoid valve, but there is no specific disclosure regarding how to switch the two valves. In other words, if there is a request to quickly switch one valve and then switch the remaining valves at a desired timing, for example, one valve is a shift valve that controls a predetermined gear shift, and the remaining valve is a torque converter. In the case of a lock-up control valve that controls lock-up, the shift valve is first switched quickly to shift to a high gear, and then the lock-up control valve is controlled to slowly increase the lock while maintaining a half-clutch state to prevent lock-up shock. Although it is necessary to adjust the switching timing of the valve, it has not been solved in the prior art how to achieve this. The present invention aims to solve such problems.

(d) Means for solving the problem When controlling two valves, the present invention first temporarily outputs a duty ratio signal corresponding to an oil pressure higher than the target oil pressure to rapidly control one valve. The switching timing of the other valve is controlled by switching and then maintaining the hydraulic pressure lower than the switching pressure of the other valve. That is, the automatic transmission control device according to the present invention includes a solenoid valve 8 that outputs a switching signal pressure in response to an applied electric signal.
0, an electronic control device 58 that provides electrical signals to the solenoid valves, and a first valve (2-3 shift valve 26) and a second valve (lock-up control valve 70) whose spool positions are switched by switching signal pressure. At least two valves are provided, and the electronic control device selects at least three of the first hydraulic pressure P ₃ , the second hydraulic pressure P ₂ , and the third hydraulic pressure P ₁ whose hydraulic pressure values increase in order as switching signal pressures by the solenoid valves. It is possible to output an electric signal to adjust the oil pressure of the stages, and these oil pressures are such that when the first oil pressure is output, the first valve and the second valve are in the first position, and the second valve is in the first position.
A size that sets the first valve to the second position and the second valve to the first position when hydraulic pressure is output, and sets both the first valve and the second valve to the second position when the third hydraulic pressure is output. When switching both the first valve and the second valve from the first position to the second position, the electronic control device first switches the third valve to the second position.
output an electrical signal corresponding to a hydraulic pressure higher than the hydraulic pressure; after a first predetermined time, output an electrical signal corresponding to a hydraulic pressure higher than the second hydraulic pressure and lower than the third hydraulic pressure; and then, after a second predetermined time, output an electrical signal corresponding to a hydraulic pressure higher than the third hydraulic pressure is configured to output an electrical signal corresponding to the . Note that the reference numerals in parentheses indicate corresponding members in the embodiments described later.

(E) Effect When switching the valve, an electric signal corresponding to a hydraulic pressure higher than the third hydraulic pressure is first output. This causes the signal pressure output by the solenoid valve to rise rapidly, causing the first valve to switch from the first position to the second position. After the first predetermined time period, that is, immediately before the second valve is switched from the first position to the second position, the electrical signal is switched to a value corresponding to a hydraulic pressure intermediate between the third hydraulic pressure and the second hydraulic pressure. Thereby, the second valve can be held in an intermediate state between the first position and the second position. By making the electrical signal correspond to the third oil pressure after the second predetermined time, the second valve is also finally switched to the second position. By doing so, it is possible to rapidly switch the first valve and adjust the switching timing of the second valve.

(F) Embodiment FIG. 2 shows a schematic diagram of a power transmission mechanism of an automatic transmission with three forward speeds and one reverse speed. This power transmission mechanism includes an input shaft I to which rotational force from an engine output shaft E is transmitted via a torque converter T/C, an output shaft O to transmit driving force to a final drive device, a first planetary gear set G 1 , a first planetary gear set G 1 , and a first planetary gear set G ₁ . It has two planetary gear sets _G2 , a high and reverse clutch H&R/C, a forward clutch F/C, a band brake B, a low and reverse brake L&R/B, and a one-way clutch OWC. The torque converter T/C has a lock-up clutch L/C. The lock-up clutch L/C is configured to be compressed when hydraulic pressure is applied to the apply chamber T/A, and released when hydraulic pressure is applied to the release chamber T/R. The first planetary gear set G ₁ includes a sun gear S ₁ , an internal gear R ₁ , both gears S ₁ and
It consists of a carrier PC ₁ that supports a pinion gear P ₁ that meshes with R ₁ at the same time, and a planetary gear set G ₂ includes a sun gear S ₂ and an internal gear R ₂ .
and a carrier PC ₂ that supports a pinion gear P ₂ that meshes with both gears S ₂ and R ₂ at the same time. Each component is connected as shown. The above power transmission mechanism includes a high and reverse clutch H&R/C, a forward clutch F/C,
By operating band brake B and low and reverse brake L&R/B (one-way clutch OWC) in various combinations, each element (S ₁ , S _{2 , R 1} , R ₂ , PC ₁ and PC ₂ ), thereby making it possible to obtain three forward speeds and one reverse speed by varying the rotational speed of the output shaft O relative to the rotational speed of the input shaft I.

FIG. 1 shows only the parts of the hydraulic circuit that are directly related to the present invention. The 1-2 shift valve 10 is composed of a spool 12 and a spring 14, and the spool 12 communicates between the oil passage 16 and the oil passage 18 in the lower half position in the figure, and communicates with the oil passage 18 in the upper half position in the figure. drain. The position of the spool 12 is determined by the balance between the hydraulic force acting on the port 22 from the oil passage 20 and the force exerted by the spring 14. Line pressure is always supplied to the oil passage 16 from the manual valve 24 during forward movement. In addition, the oil passage 16 is a forward clutch F/C.
It is also connected.

The 2-3 shift valve 26 is composed of a spool 28 and a spring 30, and the spool 2
8 connects the oil passage 18 and the oil passage 32 at the upper half position in the figure, and drains the oil passage 32 at the lower half position in the figure. The state of the spool 28 is determined by the oil pressure acting on the port 34 from the oil passage 70. The oil passage 18 is connected to a servo apply chamber S/A for engaging the band brake B. An oil passage 32 in which an orifice 31 is provided is connected to a high and reverse clutch H&R/C and a servo release chamber S/R.

The lock-up control valve 70 is connected to the spool 71
and a spring 72, and when the spool 71 is in the upper half position, the oil passage 89 and the oil passage 81 communicate with each other, and the oil passage 82 is drained.
In addition, when the spool 71 is in the lower half position in the figure, the oil path 8
0 and the oil passage 82 communicate with each other, and the oil passage 81 communicates with the oil passage 83. The oil passage 89 is connected to a pressure regulator valve 84, from which torque converter supply pressure is constantly supplied. Oil road 81
is the application chamber T/A of the torque converter T/C.
is connected to. The oil passage 82 is connected to the release chamber T/R of the torque converter T/C.
The oil passage 83 is connected to an oil cooler 85. The state of the spool 71 is determined by the oil pressure acting on the port 76 from the oil passage 75.

The aforementioned oil passage 20 is connected via an orifice 52 to an oil passage 50 to which a constant pressure is always supplied from a pilot pressure valve 48. The oil passage 20 is provided with an opening 54, and a solenoid valve 56 that can open and close this opening 54 is provided.
The solenoid valve 56 is controlled on and off by a signal from an electronic control device 58. Thereby, the oil pressure of the oil passage 20 can be turned on and off.

Further, the aforementioned oil passage 75 is connected via an orifice 78 to an oil passage 50 to which a constant pressure is always supplied from the pilot pressure valve 48. Oil road 7
5 is provided with an opening 79, and this opening 79
A solenoid valve 80 that can be opened and closed is provided. The solenoid valve 80 is connected to the electronic control device 5
The duty ratio is controlled by the signal from 8.
This allows the electronic control device 58 to control the oil pressure in the oil passage 75.
The hydraulic pressure can be adjusted to a predetermined oil pressure commanded by the hydraulic pressure.

Electrical signals from a vehicle speed sensor 60, a throttle opening sensor 62, etc. are input to the electronic control device 58, and the electronic control device 58 adjusts the oil pressure in the oil passage 75 to P ₁ , P ₂ , and P ₃ based on these signals. Outputs signals for adjustment in three stages. Note that the magnitude of the oil pressure is set as P ₃ <P ₂ <P ₁ . On the other hand, the 2-3 shift valve 26 is set so that when the oil pressure of the port 34 is less than or equal to P _B , it is in the lower half of the diagram, and when it is greater than P _B , it is in the upper half of the diagram. . Similarly, the lock-up control valve 70 is set so that when the oil pressure of the port 76 is less than or equal to P _A , it will be in the state shown in the lower half of the figure, and when it is greater than P _A , it will be in the state shown in the upper half of the figure. be. The magnitude of these oil pressures is set so that P _A > P _B. Further, the relationship between the hydraulic pressures P ₁ , P ₂ , and P ₃ and the hydraulic pressures PA and _PB is such that P ₃ < _{P B <} P ₂ <P _A <P ₁ . This relationship is illustrated in FIG. 3. Note that, in reality, P _A and P _B have a predetermined width. This is because the spool compresses the spring and moves.

Similarly, the solenoid valve 56 is turned on and off by a signal from the electronic control device 58, and when it is on, hydraulic pressure is generated in the oil passage 20, and when it is off, the oil pressure in the oil passage 20 is drained.

By setting the hydraulic characteristics as described above,
Shift control and lock-up clutch control can be performed.

First, for gear shifting, when the solenoid valve 56 is turned on and hydraulic pressure is generated in the oil passage 20, 1-
The 2-shift valve 10 is in the state shown in the upper half of the figure,
Regardless of the position of the 2-3 shift valve 26, only the forward clutch F/C is engaged, resulting in the first speed state. Next, when the oil pressure in the oil passage 20 is drained, the 1-2 shift valve 10 will be in the state shown in the lower half of the figure. On the other hand, the 2-3 shift valve 26 is in the lower half state when the output oil pressure of the solenoid valve 80 is _P1 . For this reason, hydraulic pressure is supplied to the servo apply chamber S/A in addition to the forward clutch F/C, and the band brake B is engaged, putting the automatic transmission into the second speed state. Next, when the output oil pressure of the solenoid valve 80 is set to P ₂ or P ₃ ,
The 2-3 shift valve 26 is in the upper half state in the figure. As a result, the high and reverse clutch H
Hydraulic pressure is supplied to &R/C and servo release chamber S/R, resulting in the third speed state.

Further, the lockup control valve 70 operates as follows. In other words, the oil pressure in the oil passage 75 is _P1 .
At _P2 , the state of the lockup control valve 70 is switched. At oil pressure P ₁ , the lock-up control valve 70 is in the upper half state, and the oil passage 81 of the oil passage 89 is in the upper half state.
and, on the other hand, the oil passage 82 is drained.
Therefore, hydraulic pressure is supplied to the apply chamber T/A side of the torque converter T/C, and the release chamber T/R is drained. As a result, the lock-up clutch L/C becomes engaged. On the other hand, when the output oil pressure of the solenoid valve 80 is switched to _P2 , the lock-up control valve 70 is switched to the state shown in the lower half of the figure. As a result, the oil passage 89 and the oil passage 82 communicate with each other, while the oil passage 81 communicates with the oil passage 83. Therefore, hydraulic pressure is supplied from the release chamber T/R side of the torque converter T/C, and the apply chamber T/A
The hydraulic pressure discharged from the side will be drained through the oil cooler 85. As a result, the lock-up clutch L/C becomes released. Therefore, the lock-up clutch L/C will be engaged or released in response to the output oil pressure becoming _P1 or _P2 . On the other hand, as mentioned above, the output oil pressure is P ₁
Alternatively, in the case of _P2 , the 2-3 shift valve 26 is in the third speed position, and the automatic transmission is in the third speed state. Therefore, the lock-up clutch is engaged and the lock-up clutch is released in the third gear.

During the above-described operation, when changing the oil pressure in the oil passage 75 from, for example, oil pressure P ₃ to oil pressure P ₁ (i.e., when engaging the lock-up clutch at the same time as the 2-3 gear shift), the solenoid is activated from the electronic control unit 58. The duty ratio signal applied to the valve 56 is not immediately outputted as a duty ratio signal corresponding to the oil pressure _P1 , but is outputted as shown in FIG.
In other words, as a duty ratio signal, first the hydraulic pressure is
A duty ratio signal D _X corresponding to P _X (which is a higher oil pressure than P ₁ ) is output. This duty ratio signal _DX is held for a first predetermined time _t1 .
Next, the duty ratio signal D _Y corresponding to the oil pressure P _Y
can be switched to Note that the oil pressure P _Y corresponds to the switching pressure P _A of the lock-up control valve 70. This duty ratio signal D _Y is held for a second predetermined time t ₂ . t After ₂ hours, the duty ratio is hydraulic pressure P ₁
is switched to the duty ratio signal _D1 corresponding to .
As a result, the actual oil pressure in the oil passage 75 changes as shown by the solid line in FIG. That is, the oil pressure rises relatively quickly at first, the 2-3 shift valve 26 is switched, then the oil pressure P _Y corresponding to the lock-up control valve switching pressure P _A is maintained for approximately _t2 hours, and then finally Hydraulic pressure becomes P ₁ . This allows for rapid switching of the 2-3 shift valve 26, and also maintains the spool 71 of the lock-up control valve 70 in an intermediate position between the release position and the engagement position for approximately time T2. The hydraulic pressure difference between /A and release chamber T/R can be controlled so that lock-up clutch L/C is in a half-clutch state. Note that the first predetermined time t ₁ and the second predetermined time t ₂ may be variable depending on the operating conditions. Further, the duty ratio during the second predetermined time _t2 does not have to be constant D _Y , and may be gradually increased as time passes, for example.

In the embodiment described, the 1-2 shift valve 10 is controlled by the solenoid valve 56, but it can also be controlled by the solenoid valve 80. That is, the oil pressure of the oil passage 75 may be supplied to the port 22 of the 1-2 shift valve 10, and the 1-2 shift valve 10 may be switched at a predetermined oil pressure value. Additionally, in the described embodiment, the 2-3 shift valve 2
6 and the lock-up control valve 70 are controlled by the solenoid valve 80, but instead of the lock-up control valve 70, a timing valve for adjusting the timing of gear change is controlled by the solenoid valve 80. Good too.

(g) Effects of the invention As explained above, according to the invention, at least one valve is switched by temporarily outputting a duty ratio signal corresponding to a hydraulic pressure higher than the target hydraulic pressure when switching the valves. Then, after maintaining the oil pressure approximately equal to the switching pressure of the remaining valves,
Since the remaining valves are finally switched, the rise of the signal pressure obtained by the solenoid valve is rapid in the first stage, and one valve can be switched quickly, and the remaining valves can be switched quickly. The valves can be switched at desired timing.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a hydraulic circuit according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of the automatic transmission, FIG. 3 is a diagram showing oil pressure characteristics obtained by a solenoid valve, and FIG. 4 is a diagram showing change characteristics of a duty ratio signal and oil pressure. 10...1-2 shift valve, 26...2-3
Shift valve, 58... Electronic control device, 70...
Lockup control valve, 80...Solenoid valve.

Claims (1)

[Claims for Utility Model Registration] A solenoid valve 80 that outputs a switching signal pressure in response to an applied electrical signal; an electronic control device 58 that provides an electrical signal to the solenoid valve 80; and a spool whose position is determined by the switching signal pressure. It has at least two valves, the first valve 26 and the second valve 70, which are switched, and the electronic control device 58 uses the first hydraulic pressure P 3 and the first hydraulic pressure P ₃ whose hydraulic pressure increases in order as the switching signal pressure by the solenoid valve 80. , the second hydraulic pressure P ₂ and the third hydraulic pressure P ₁ are capable of outputting electrical signals for adjusting at least three levels of oil pressure, and these oil pressures are outputted when the first oil pressure P ₃ is outputted, the first valve 26 and the second oil pressure are adjusted. When the valve 70 is set to the first position and the second hydraulic pressure P ₂ is output, the first valve 26
is set to the second position, the second valve 70 is set to the first position, and the first valve 26 and the second valve 70 are both set to the second position when the third hydraulic pressure _P1 is output. When the electronic control device 58 can switch both the first valve 26 and the second valve 70 from the first position to the second position, it first outputs an electric signal corresponding to a hydraulic pressure higher than the third hydraulic pressure _P1 . , output an electric signal corresponding to an oil pressure higher than the second oil pressure P _{2 and} lower than the third oil pressure P ₁ after the first predetermined time t 1 , and then output an electric signal corresponding to the oil pressure P ₁ after the elapse of the second predetermined time t ₂ . A control device for an automatic transmission configured to output an electrical signal.