JPH01199044A - Speed change control device for automatic transmission - Google Patents

Abstract

PURPOSE:To secure safe running by controlling changing-over of a 1-2 shift valve and a 3-2 and 2-3 timing valves with a single solenoid valve, and putting a 1-2 shift valve into the second speed position when the adjusting oil pressure is the lowest. CONSTITUTION:When a signal from an electronic control device 58 changes over a solenoid valve 56 from No.1 to No.2 oil pressure output condition, only a 1-2 shift valve 10 is changed over into No.2 speed position, while 3-2 and 2-3 timing valves 40, 80 are held in No.1 position to be put into No.2 position when the No.3 oil pressure is put out. Accordingly the same speed change position is attained with No.2, No.3 oil pressure, but the conditions of the two timing valves 40, 80 are different, so that a proper speed change timing is obtained according to the degree of opening 62 of throttle valve, car speed 60, etc., even in the case of down shift and up shift from the m'th speed. Safe running is secured even in the event of failure as long as such an arrangement is incorporated that the 12 shift valve 10 is put into No.2 speed position when the adjusting oil for the valve 56 is the lowest.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a speed change control device for an automatic transmission.

(b) Conventional technology As a conventional speed change control device for automatic transmission,
There is one shown in Japanese Patent No. 101152. The shift control device for the automatic transmission shown therein is configured to control four forward speeds by switching four shift valves using one solenoid valve. That is, the solenoid valve is capable of outputting four levels of oil pressure, and the switching characteristics of the shift valves are set so that one shift valve is switched for each step change in the oil pressure. As a result, it is possible to switch between four shift valves with one solenoid valve. However, in the conventional automatic transmission shift control device as described above, it is possible to control switching between gears with one solenoid valve. PtWX elements during gear shifting (clutches, brakes, etc.)
A separate solenoid valve is required to reduce the shift shock by adjusting the timing of hydraulic pressure supply to or discharge from the friction element (hereinafter referred to as "shift timing"). That is, in addition to the solenoid valve for shifting, a solenoid valve for adjusting the timing of gear change is required. This not only increases the size of the speed change control device, but also increases the price and makes the hydraulic circuit more complex. The present invention aims to solve these problems.

The present invention solves the above problem by controlling the two timing valves in addition to the shift valve by the same solenoid valve. That is, the shift control device for an automatic transmission according to the present invention includes a solenoid valve (56) that outputs a switching signal pressure in response to an applied electric signal;
Electronic control device (5) that provides an electrical signal to the solenoid valve
8), the spool moves to the mth speed and the first speed by the switching signal pressure.
A shift valve (1-2 shift valve 10) that switches between the n(2)th speed position and the n(1)th speed position corresponding to the speed (n=m+1 or n=m−1), respectively; A first timing for adjusting the timing of the shift by switching the spool between the first position and the second position using the switching signal pressure during an upshift from m speed to a higher gear (third gear). The timing of the shift is adjusted by switching the spool between the first position and the second position using the valve (80) and the switching signal pressure during a downshift shift from a gear higher than the m-th gear to the m-th gear. A second timing valve (40) is connected to the second timing valve (40), and the second timing valve (40) is controlled by a solenoid valve (the first hydraulic pressure (p+) and the 2 hydraulic pressure (P2
) and the third hydraulic pressure (P3), which can output an electric signal (rc) that adjusts the hydraulic pressure in at least three stages. The spools of the timing valve and the second timing valve are both set to the first position, and when the second hydraulic pressure is output, the spool of the shift valve is set to the m-th speed position, and the spool of the first timing valve and the second timing valve are set to the first position. The spools of the second timing valve are both set to the first position, and when the third hydraulic pressure is output, the spool of the shift valve is moved to the m-th speed position, and the first timing valve and the third hydraulic pressure are set to the first position. The size is set such that both spools of the two timing valves are in the second position.The symbols in parentheses indicate corresponding members and pressures in the embodiments described later.

(E) Operation When the solenoid valve is actuated by an electric signal from the electronic control device and the first hydraulic output state is switched to the second hydraulic output state, only the spool of the shift valve changes from the nth position to the mth position.
The spools of the first timing valve and the second timing valve are held at the first position. On the other hand, when the third hydraulic pressure is output, in addition to switching the shift valve, both the spools of the first timing valve and the second timing valve switch to the second position.

Therefore, although the gear stage is the same when the second hydraulic pressure is output and when the third hydraulic pressure is output, the states of the first timing valve and the second timing valve are different. As a result, the shift timing can be changed depending on conditions such as throttle opening and vehicle speed in both downshifting and upshifting from the mth speed, and it is possible to obtain an appropriate shift timing according to the driving conditions. Can be done.

(To) Examples Hereinafter, examples of the present invention are shown in Figures 1 to 3 of the attached drawings.''
explain about.

FIG. 2 shows a schematic diagram of the power transmission mechanism of an automatic transmission with three forward speeds and one reverse speed. This power transmission mechanism includes a human power shaft I to which the rotational force from the engine output shaft E is transmitted via the torque converter T/C, an output shaft O which transmits the driving force to the final drive device, a second planetary gear G1, a second planetary gear G1, and a second planetary gear G1. It has gear set G2, high and reverse clutch H&R/C, forward clutch F/C, band brake B, low and reverse brake L&R/B, and one-way clutch OWC. The first planetary gear set G1 includes a sun gear S, an internal gear R1, and both gears SI and R.
The planetary gear set G2 includes a sun gear S2, an internal gear R2, and a carrier PC that supports a binion gear Pl that meshes with both gears 3 and 3 at the same time.
2 and a carrier PC2 that supports a pinion gear P2 that meshes with R2 at the same time. Each component is connected as shown.

The above power transmission mechanism is a high and reverse clubchi H&
R/C, forward clutch F/C, band brake B
By operating the low and reverse brake L&R/B (one-way clutch 0WC) in various combinations, each element (S
+, S2, Rt, R2, PC, and pc2), thereby varying the rotational speed of the output shaft O relative to the rotational speed of the human power shaft 1 to obtain three forward speeds and one reverse speed. Can be done.

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 the oil passage 16 and the oil passage 18 at the lower half position in the figure, and communicates the oil passage 18 with the oil passage 18 at 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 boat 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. Note that the oil passage 16 is also connected to the forward clutch F/C.

The 2-3 shift valve 26 is composed of a spool 28 and a spring 30, and when the spool 28 is in the upper half position in the figure, it connects the oil passage 18 and the oil passage 32, and when the spool 28 is in the lower half position in the figure, it communicates with the oil passage 32. drain. 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 3 provided with an orifice 31 (this orifice 31 can also be a one-sided orifice)
2 is connected to the 3-2 timing valve 40 and the 2-3 timing valve 80. Further, the oil passage 32 is connected to an oil passage 38 and an oil passage 88, respectively, by a one-sided orifice 36 and a one-way orifice 86, respectively.

The one-way orifice 36 is arranged in such a direction that it does not restrict the flow of oil from the oil passage 32 side to the oil passage 38 side, but restricts the flow of oil in the opposite direction. Furthermore, the one-way orifice 86 restricts the flow of oil from the oil passage 32 side to the oil passage 88 side;
The arrangement is oriented so that the flow of oil in the opposite direction is not restricted.

3-2 The timing pulp 40 is composed of a spool 42 and a spring 44. When the spool 42 is in the lower half position in the figure, the oil passage 32 and the oil passage 38 communicate with each other, and when the spool 42 is in the upper position in the figure, the oil passage 32 and the oil passage 38 are in communication with each other. 38 and oil passage 32 are blocked.

The position of the spool 42 is determined by the hydraulic pressure acting on the boat 46 from the oil passage 20. The oil passage 38 is connected to a servo release chamber S/R for releasing the band brake B. Note that since the pressure receiving area of the servo release chamber S/R is larger than the pressure receiving area of the servo apply chamber S/A, the band brake B is always released when hydraulic pressure acts on the servo release chamber S/R.

2-3 The timing valve 80 is composed of a spool 82 and a spring 84. At the spool 82 in the lower half position in the figure, the oil passage 32 and the oil passage 88 communicate with each other, and at the upper half position in the figure, the oil passage 32 and the oil passage 88 communicate with each other. The passage 32 and the oil passage 88 are cut off.

The position of the spool 82 is determined by the hydraulic pressure acting on the boat 85 from the oil passage 20. The oil passage 88 is connected to a high and reverse clutch H&R/C.

The aforementioned oil passage 20 is always connected to the pilot pressure valve 48.
It is connected via an orifice 52 to an oil passage 50 to which constant pressure is supplied. The oil passage 20 is provided with an opening 1-154, and a solenoid valve 56 capable of opening and closing this opening 54 is provided. The solenoid valve 56 has a duty ratio determined by a signal from the electronic control device 58.
J is controlled. Thereby, the oil pressure in the oil passage 20 can be adjusted to a predetermined oil pressure commanded by the electronic control device 58.

The oil passage 70 described in 11η is connected to the oil passage 50 and the orifice 7 to which constant pressure is always supplied from the pilot pressure valve 48h1.
Connected via 2. The oil passage 70 is provided with a lower opening 4, and a solenoid valve 76 capable of opening the lower opening 4 is provided. The solenoid valve 76 is controlled on and off by a signal from the electronic control device 58. The solenoid valve 76 opens the opening lower 4 when it is on, and closes it when it is off. This allows the oil pressure in the oil passage 70 to be turned on and off.

The electronic control device 58 receives electric signals from a vehicle speed sensor 60, a throttle opening sensor 62, etc.
The electronic control unit 58 outputs a signal to adjust the oil pressure in the oil passage 20 to three levels: p, , p2, and P3 based on the stiffness. In addition, the magnitude of hydraulic pressure is P I > P 2 > P
It is listed as 3. On the other hand, the 1-2 shift valve 10 is set so that when the oil pressure of the boat 22 is less than PA, it is in the upper half of the figure, and when it is greater than PA, it is in the upper part of the figure. Also, 3-2 timing valve 40
Also, when the hydraulic pressure acting on the boat 46 is less than or equal to Pa, the state is shown in the lower half of the figure, and when it is greater than PB, the state is shown in the upper half of the figure. Furthermore, 2-
3 timing valve 80 is also in the state shown in the lower half of the figure when the oil pressure acting on the boat 85 is less than Pa, and p
When it becomes larger than B, the state shown in the upper half of the figure is set. The magnitude of these oil pressures is set such that PA>Pa. Also, p, , p2 and P3, and P
The relationship of Aburanooh's size with A and P,% is P + >
P A > P 2 > P a > P 3. This relationship is illustrated in FIG. 3.

By setting the hydraulic characteristics as described above, shift control, 3-2 shift timing, and 2-3 shift timing can be adjusted.

First, regarding gear shifting, when the oil pressure in the oil passage 20 reaches Pl, the 1-2 shift valve IO 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, if the oil pressure of the oil passage 20 is set to P2 or P3, 1-2
The shift valve 10 is in the state shown in the lower half of the figure. On the other hand 2-
The 3-shift valve 26 is in the lower half state when the solenoid valve 76 is on. Therefore, in addition to the forward clutch F/C, hydraulic pressure is supplied to the servo apply chamber S/A, and the band brake B is engaged, so that the automatic transmission enters the second speed state. Next, when the solenoid valve 76 is turned off, the 2-3 shift valve 26 enters the state shown in the upper half of the figure. As a result, hydraulic pressure is supplied to the high and reverse clutch H&R/C and the servo release chamber S/R, resulting in the third speed state. Note that since the one-way orifice 36 and the one-way orifice 86 are provided, the oil pressure in the oil passage 32 is maintained in the servo release chamber S/ regardless of the states of the 3-2 timing valve 40 and the 2-3 timing valve 8o.
Supplied to R and high and reverse clutch H&R/C.

Further, the 3-2 timing valve 40 operates as follows. That is, the oil pressure of the oil passage 20 is 3 at P2 and P3.
-2 The position of the timing valve 40 is switched. That is, at oil pressure P2, the 3-2 timing valve 40 is in the upper half state, and the oil passage 32 and the oil passage 38 are in a blocked state.
Conversely, at oil pressure P3, the oil passage 32 and the oil passage 38 communicate with each other. Utilizing this, for example, the timing of the 3-2 shift can be adjusted as follows. That is, the 3-2 gear shift is commanded and the solenoid valve 76 is switched from off to on.
Even after the 2-3 shift valve 26 switches from the third speed state to the second speed state, if the oil pressure in the oil passage 20 is maintained at the P2 state, the 3-2 timing valve 40 is in the upper half position. will be maintained as is. Therefore, although the hydraulic pressure of the high and reverse clutch H&R/C begins to be rapidly discharged through the orifice 86 on one side, the hydraulic pressure in the servo release chamber S/R is restricted by the orifice 38 on one side and is gradually discharged. go. After maintaining this state for a predetermined time, the oil pressure in the oil passage 20 is switched from 22 to P3. As a result, the 3-2 timing valve 40 is switched from the upper half state to the lower half state, and the oil passage 38 and the oil passage 32 are brought into communication.

As a result, the oil pressure in the servo release chamber S/R also begins to be rapidly discharged. servo release chamber S/R like this
Hydraulic pressure discharge by high and reverse clutch H&R/C
By delaying the discharge of hydraulic pressure by a predetermined period of time, the automatic transmission can be temporarily placed in a neutral state.
During this time, the engine rotational speed is increased, and then the second speed state is established. As a result, a neutral state is inserted between the 3rd and 2nd gear shifts, and the gear can be shifted while reducing the rotational speed difference between the engine side and the automatic transmission side, thereby reducing shift shock. As described above, the neutral time inserted during the 3-2 shift is controlled by the electronic control unit 58 according to the driving conditions, and is always appropriately controlled according to the vehicle speed and throttle opening conditions.

Further, the 2-3 timing valve 80 operates as follows. That is, when the oil pressure of the oil passage 20 is 22 and P3, 2
-3 The position of the timing valve 80 is switched. That is, at oil pressure P2, the 2-3 timing valve 80 is in the upper half state, and the oil passage 32 and the oil passage 88 are in a blocked state.
Conversely, at oil pressure P3, the oil passage 32 and the oil passage 88 communicate with each other. Using this, for example, in the following way, when the accelerator pedal is returned from an accelerating state to a fully closed throttle state, 2-3
You can adjust the timing of gear changes. That is,
By releasing the accelerator pedal, a 2-3 gear shift is commanded and the solenoid valve 76 is switched from on to off, and the 2-3 gear shift is commanded.
If the oil pressure in the oil passage 20 is maintained at P2 even after the 3rd shift valve 26 switches from the 2nd speed state to the 3rd speed state, the 2-3 timing valve 80 will remain in the upper half position. be done. Therefore, high and reverse clutch H&R
Although oil pressure begins to be supplied to /C, since it is through the one-way orifice 86, the oil pressure increases slowly. On the other hand, hydraulic pressure is rapidly supplied to the servo release chamber S/R through the orifice 36 on one side. After maintaining this state for a predetermined time, the oil pressure in the oil passage 20 is switched from 22 to P3. As a result, the 2-3 timing valve 80 switches from the lower half state to the lower half state, and the oil passage 88 and the oil passage 3
2 communicates with each other. As a result, the oil pressure of the high and reverse clutch H&R/C also starts to rise rapidly. In this way, by causing the increase in the oil pressure in the servo release chamber S/R to precede the increase in the oil pressure in the high and reverse clutch H&R/C for a predetermined period of time, the automatic transmission can be temporarily placed in a neutral state. During this time, the engine rotational speed is reduced, and then the third speed state is established. This results in
A neutral state is inserted between the 2nd and 3rd gear shifts, and the speed change can be performed while reducing the rotational speed difference between the engine side and the automatic transmission side, thereby reducing shift shock. As mentioned above, the neutral time inserted during the 2-3 gear shift is controlled by the electronic control unit 58 according to the driving conditions, and is always appropriately controlled according to the vehicle speed and throttle opening conditions. In addition, in the case of normal 2-3 upshift shifting (upshifting other than by returning the accelerator pedal), the oil pressure in the oil passage 20 is set to P3, and the high and reverse shift is performed without being affected by the one-way orifice chair 86. Supply hydraulic pressure to the scratch H&R/C.

Note that even if the electronic control device 58, the solenoid valve 56, etc. fail and the oil pressure in the oil passage 20 becomes 0, the second speed is maintained and the vehicle can be driven safely. Also,
Switching the solenoid valve 76 from OFF to ON and switching the hydraulic pressure of the solenoid valve 56 from P2 to P3 are as follows:
Can be controlled completely independently. Therefore, for example 2
It is also possible to switch the 3-2 timing valve 40 prior to switching the -3 shift valve 26. In addition, by setting the oil pressure to P2 for a short time from the start of the 1-2 shift and then switching to oil pressure P3, the oil pressure in the servo release chamber S/R is temporarily reduced to obtain a cushioning effect. It can also be done.

(G) As described in detail, according to the present invention, one solenoid valve controls the switching of a shift valve and two timing valves, so that one solenoid valve and one timing valve can be used, respectively. Compared to the case where a solenoid valve is used, the cost is reduced and the device is also made smaller. In addition, as a shift valve 1-2
If you use a shift valve and set the spool of the 1-2 shift valve to the 2nd speed position when the oil pressure adjusted with the solenoid/ The second speed or the third speed can be set to ensure safe running of the vehicle.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a schematic diagram of an automatic transmission, and FIG. 3 is a diagram showing hydraulic characteristics of the embodiment. - 10...1-2 shift valve, 26...2-3 shift valve, 40...3-2 timing valve, 56...
... Solenoid valve, 58 ... Electronic control device, 76
...Solenoid valve, 80...2-3 timing valve. Patent applicant: Japan Automatic Transmission Co., Ltd.

Claims (1)

[Scope of Claims] A shift control device for an automatic transmission that performs shift control of three or more forward gears using one or more shift valves, comprising: a solenoid valve that outputs a switching signal pressure in response to an applied electric signal; An electronic control device that gives an electric signal to the solenoid valve and a switching signal pressure cause the spool to move to the m-th speed position and the n-th speed position corresponding to the m-th speed and the n-th speed (n=m+1 or n=m-1), respectively. The timing of the shift is determined by the shift valve switching between the first and second positions and the spool switching between the first position and the second position by the switching signal pressure during an upshift from the m-th gear to a higher gear. The timing of the shift is determined by the first timing valve to be adjusted and the spool being switched between the first position and the second position by the switching signal pressure during a downshift from a gear higher than the m-th gear to the m-th gear. and a second timing valve for adjusting the timing valve, and the electronic control device adjusts at least three levels of oil pressure, the first oil pressure, the second oil pressure, and the third oil pressure, each having a different magnitude as a switching signal pressure by the solenoid valve. It is possible to output an electric signal to cause the first oil pressure to be outputted, and the first hydraulic pressure has a size that causes the spool of the shift valve to move to the nth speed device and also causes the spools of the first timing valve and the second timing valve to be in the first position. When the second oil pressure is output, the spool of the shift valve is set to the mth speed position, and the spools of the first timing valve and the second timing valve are both set to the first position.
When the third hydraulic pressure is output, the spool of the shift valve is set to the mth speed position, and the spools of the first timing valve and the second timing valve are both set to the second position. A speed change control device for an automatic transmission, characterized in that the size is set. 2. The shift valve is a 1-2 shift valve that controls speed change between 1st speed and 2nd speed, and is set so that the spool is located at the 2nd speed position when the lowest oil pressure among the three oil pressure levels is generated. A speed change control device for an automatic transmission according to claim 1. 3. The automatic transmission shift according to claim 1, wherein the first timing valve and the second timing valve adjust the timing of hydraulic pressure supply to the friction element or hydraulic pressure discharge from the friction element during gear shifting. Control device.