JPH01199042A - 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 timing valve with a 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 No. 2 solenoid valve 56 from No.1 to No.2 oil pressure condition, only the spool 12 of a 1-2 shift valve 10 is changed over from No.1 to No.2 position, while the spool 42 of a 3-2 timing valve 40 is held in No.1 position. When No.3 oil pressure is put out, the spools of the two valves 10, 40 are both changed over to No.2 position. Accordingly the same speed change position is attained with No.2, No.3 oil pressure, but the condition of the valve 40 is different, and appropriate speed change timing is obtained according to the degree of opening 26 of a throttle valve, the car speed 60, etc. Safe running is secured even at the time of failure as long as such an arrangement is incorporated that the spool 1-2 of 12 shift valve 10 is put into No. 2 speed position when the adjusting oil pressure for the solenoid 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 something that is mentioned in the 101152 publication. The automatic transmission shift control device shown in this figure 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. This makes it possible to switch between four shift valves with one solenoid valve. , friction elements during gear shifting (clutches, brakes, etc.)
In order 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"), a separate solenoid valve is required. Namely, Sif!・In addition to the solenoid valve for use, a solenoid valve for adjusting the shift timing is required. For this reason, the size of the speed change control device increases, the price also increases, and the hydraulic circuit becomes complicated. The present invention aims to solve such problems, and the present invention has the following features:
The above problem is solved by controlling the timing valve 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 first shift valve (26) in which the spool switches between a first position and a second position corresponding to two gear stages, and a first shift valve. A first solenoid valve (76) that controls switching of the spool, and a first position and a second position that correspond to two gears different from the two gears of the first shift valve, respectively, when the spool is moved by switching pressure No. 15. a second shift valve (10) that switches between;
a timing valve (40) that adjusts the timing of hydraulic pressure supply to the friction element or hydraulic pressure discharge from the Pf friction element during gear shifting by switching the spool between a first position and a second position in response to a switching signal pressure; electricity given 1
A second solenoid valve (56) that outputs the switching No. 13 pressure according to No. 3, and an electric controller (56) that outputs an electric signal to the first solenoid valve and the second solenoid valve.
8), and the electronic control device adjusts at least three levels of hydraulic pressure, the first hydraulic pressure, the second hydraulic pressure, and the third hydraulic pressure, each having a different magnitude as the switching No. 43 pressure by the second solenoid valve. It is the ability to output an electric signal to
The hydraulic pressure (P,) is set to such a level that when this is output, the spool of the second shift valve is placed in the i1 position, and the spool of the timing valve is placed in the first position. The spool of the second shift valve is set to the second position and the spool of the timing valve is set to the first position when
The third oil 1E (Pl) is set to a size that, when output, causes the spool of the second shift valve to be in the second position and also causes the spool of the timing valve to be in the second position. Note that the symbols in parentheses indicate corresponding members or pressures in the embodiments described later.

(e) Operation When the second solenoid valve is actuated by an electric signal from the electronic control device and switches the first hydraulic output state to the second hydraulic output state, only the spool of the second shift valve shifts from the first position to the second position. During the switching operation, the timing valve spool is held in the first position. On the other hand, when the third hydraulic pressure is output, both the spools of the shift valve and the 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 timing valves are different from each other. As a result, the timing of the shift can be changed depending on conditions such as throttle opening and vehicle speed, and it is possible to obtain an appropriate timing of the shift according to the driving conditions.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3 of the accompanying drawings.

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 consists of a human power shaft ■ to which the rotational force from the engine output 41+E is transmitted via the torque converter T/C, an output shaft 0 which transmits the driving force to the final drive device, a first planetary gear set Gl, and a second planetary gear set Gl.
Planetary 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. 1st play 31-1 wheel vehicle group G
, is composed of a sun gear S, an internal gear R1, and a carrier PC1 that supports a pinion gear P1 that meshes with both gears S and R at the same time, and a planetary gear set G2 includes a sun gear S2 and an internal gear. Lugia R2
and a carrier PC2 that supports a pinion gear P2 that meshes with both gears 82 and R2 at the same time.

Each component is connected as shown. The above power transmission mechanism operates the planetary gear set G, and each element of G2 (S+, S2,
R+, R2, PC, and pc2) can be changed, thereby making it possible to obtain three forward speeds and one reverse speed by varying the rotational speed of the output shaft 0 relative to the rotational speed of the human power 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 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, the oil passage 18 and the oil passage 32 are communicated with each other. train. The state of the spool 28 is determined by the oil pressure acting on the boat 34 from the oil passage 70h). 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. Further, the oil passage 32 is connected to an oil passage 38 by a check valve 36. The check valve 36 is arranged to allow oil to flow from the oil path 32 side to the oil path 38 side, or to not allow oil to flow in the opposite direction.

3-2 The timing valve 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 half position in the figure, the oil passage 32 and the oil passage 38 are in communication with each other. The passage 38 and the oil passage 32 are cut off.

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 surface h1 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 is applied to the servo release chamber S/R.

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 the pilot pressure valve 48. The oil passage 20 is provided with an opening 54, and a second solenoid valve 5 that can open and close this opening 54
6 is provided. The duty ratio of the second solenoid valve 56 is controlled by No. 13 from the electronic control device 58. 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 aforementioned oil passage 70 is connected via an orifice 72 to an oil passage 50 to which constant pressure is always supplied from the pilot pressure valve 48 . The oil passage 70 is provided with an opening lower 4, and a first solenoid valve 76 capable of opening and closing the opening lower 4 is provided. The first solenoid valve 76 is controlled on/off by the numbers I and - from the electronic control device 58.

The first 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.

``1'' is connected to the R-control device 58 (electricity No. 15 from the speed sensor 60, throttle opening sensor 62, etc. is supplied manually), and ``C'' is connected to the R-control device 58 by the oil passage 20. Outputs a signal to adjust the oil pressure in three stages: P, , P2., and P3.The magnitude of the oil pressure is P3.
> P 2 > P +. On the other hand, the 1-2 shift valve 10 is set so that when the oil pressure of the boat 22 is below PA, it will be in the lower half of the diagram, and when the oil pressure is higher than PA, it will be in the upper half of the diagram. . Also, 3-2
Regarding the timing valve 40, when the hydraulic pressure acting on the port 46 is PI% or more, the state shown in the upper half of the figure is reached, and P
It is designed so that when 7 becomes larger than B, the state shown in the upper half of the figure will occur. The magnitude of these oil pressures is such that PA>PIN. Also, P+, P2 and P3, and P
The relationship of the hydraulic pressure with A and Pn is P* > PA
>P2 >PR>P l. This relationship is illustrated in FIG. 3.

By setting the hydraulic characteristics as described above, it is possible to perform shift control and adjustment of the 3-2 shift timing.

First, regarding gear shifting, when the oil pressure in the oil passage 20 reaches P3, the 1-2 shift valve 10 is in the upper main position in 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 of the oil passage 20 is set to 22 or P, 1-2
The shift valve IO is in the state shown in the lower half of the figure. On the other hand 2-
The third shift valve 26 is in the lower half state when the first solenoid valve 76 is on. Therefore, in addition to the forward clutch F/C, hydraulic pressure is also 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 first solenoid valve 76 is turned off, the 2-
The third shift valve 26 is in 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. Since the reverse +h valve 36 is provided, the oil pressure in the oil passage 32 is supplied to the servo release chamber S/R regardless of the state of the 3-2 timing valve 40.

Further, the 3-2 timing valve 4o operates as follows. In other words, the oil pressure in the oil passage 20 is 3 in 22 and 21.
-2 The position of the timing valve 40 is switched. That is, at the oil pressure P2, the 3-2 timing valve 40 is in the upper half state, the oil passage 38 is in the blocked state, and conversely, when the oil pressure P1
In this case, 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, the first solenoid valve 76 is switched from off to on, and the 2-3 shift is commanded.
If the oil pressure in the oil passage 20 is maintained at the P2 state even after the shift valve 26 switches from the third speed state to the second speed state, the 3-2 timing valve 40 is maintained at the upper half position. Ru.

Therefore, although the hydraulic pressure of the high and reverse clutch H&R/C begins to be discharged, the hydraulic pressure of the servo release chamber S/R is not discharged. After maintaining this state for a predetermined time, the oil pressure in the oil passage 20 is switched from P2 to Pl. This results in
3-2 The timing valve 40 switches from the upper half state to the lower half state, and the oil passage 38 and the oil passage 32 communicate with each other. As a result, the hydraulic pressure in the servo release chamber S/R also begins to be discharged. In this way, by delaying the discharge of the hydraulic pressure from the servo release chamber S/R by a predetermined period of time compared to the discharge of the hydraulic pressure from the high and reverse clutch H&R/C, the automatic transmission can be placed in the neutral state at 7 o'clock. 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 mentioned above, the neutral time inserted during the 3-2 gear shift is controlled by the electric f/control device 58 according to the driving conditions, and is always appropriately controlled according to the vehicle speed and throttle opening conditions. In addition, if the electronic control device 58, the second solenoid valve 56, etc. malfunction, the oil pressure in the oil passage 20 becomes zero.
Even if the vehicle reaches 2), the vehicle will be in 2nd gear, making safe eastbound driving possible.

It should be noted that switching the first solenoid valve 76 from off to on and changing the oil pressure of the second solenoid valve 56 from P2 to Pl
The switching to can be controlled completely independently. Therefore, for example, the 3-2 timing valve 40 may be switched prior to switching the 2-3 shift valve 26. In addition, by setting the oil pressure to P2 for a short time from the start of the 1-2 gear shift, and then switching to the oil pressure P, the release of the oil pressure in the servo release chamber S/R is temporally delayed to obtain a cushioning effect. You can also do it like this. Further, in the above embodiment, the 3-2 timing valve 40 was used as the timing valve, but the present invention can be used to adjust the timing not only for downshifts but also for upshifts. Further, the present invention can be applied to a timing valve that switches between an oil passage that passes through an orifice and an oil passage that does not pass through an orifice.

(G) As described in detail, according to the present invention, the switching of the shift valve and the timing valve is controlled by one solenoid valve, so that the solenoid valves for the shift valve and the timing valve are respectively controlled. The cost is reduced and the device is also made smaller compared to when using the conventional method. In addition, at least one solenoid valve
- If you use the 2 shift valve and set the spool of the 1-2 shift valve to the 2nd gear position when the oil pressure adjusted by the solenoid valve is at its lowest, then when the oil pressure becomes 0 due to a solenoid valve failure, Safe running of the vehicle can be ensured by shifting to second or third gear instead of first gear as in the conventional example. Furthermore, if the timing valve is controlled by the same solenoid valve, and the shift timing includes at least one of the first and second position gears, the solenoid on the shift valve side will fail. Also, it is possible to prevent the solenoid on the timing valve side from being driven needlessly as in the conventional example.

BRIEF DESCRIPTION OF THE DRAWINGS 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. Patent Applicant: Toshiyuki Miyauchi, Patent Attorney, 1-Piece Automatic Transmission Co., Ltd. Figure 3

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, wherein the spool is in a first position and a second position corresponding to two gears, respectively. a first solenoid valve that controls switching of the spool of the first shift valve; and a first solenoid valve that controls switching of the spool of the first shift valve; and a first solenoid valve that controls switching of the spool of the first shift valve; A second shift valve that switches between a first position and a second position corresponding to each stage, and a friction element during gear shifting by switching the spool between the first position and the second position in response to switching signal pressure. a timing valve that adjusts the timing of hydraulic pressure supply to the friction element or hydraulic discharge from the friction element; a second solenoid valve that outputs a switching signal pressure in response to an applied electric signal; It has an electronic control device that gives a signal,
The electronic control device is capable of outputting an electric signal as a switching signal pressure by the second solenoid valve to adjust at least three levels of oil pressure, a first oil pressure, a second oil pressure, and a third oil pressure, each having a different magnitude, and the first oil pressure is When this is output, the spool of the second shift valve is set to the first position, and the spool of the timing valve is set to the first position. The spool is set to the second position and the spool of the timing valve is set to the first position. When this third hydraulic pressure is output, the spool of the second shift valve is set to the second position and the timing valve is set to the first position. A speed change control device for an automatic transmission that is sized to place a spool in a second position. 2. The second shift valve is a 1-2 shift valve that controls the shift between the first speed and the second speed, and the spool is positioned at the second speed position when the lowest oil pressure among the three oil pressures is generated. The first claim characterized in that
A speed change control device for an automatic transmission as described in . 3. The timing valve is configured to supply hydraulic pressure to or from the friction element during a gear shift including at least one of the gear gear in the first position and the gear gear in the second position of the second shift valve. 2. A shift control device for an automatic transmission according to claim 1, wherein the timing of hydraulic discharge is adjusted.