JPH04296250A - Controller for automatic transmission - Google Patents

Abstract

PURPOSE:To prohibit a reverse run even in the case where one solenoid valve comes to failure due to stick by making plural solenoid signals act at time of operation of a reverse shift, and prohibiting any control over a reverse control valve. CONSTITUTION:When an engine control unit 54 judges a fact that it is subjected to a reverse shift during forward traveling on the basis of each detection signal out of a car speed sensor 56 and a shift position sensor 58, it turns on each of solenoid valves 50, 52. If so, signal pressure in the solenoid valve 50 on one side is impressed on a port (a) of a reverse control valve 30, whereby each of spools 30a, 30b is depressed. In consequence, each connection of respective ports (c), (d) is interrupted by a land part of the spool 30a. Therefore hydraulic pressure out of the port (a) of a manual valve 26 will not act on a brake servo B2, thus the reverse shift is prohibited. Even when each of these solenoid valves 50, 52 has come to operational failure due to a stick, the reverse shift is prohibited.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a control device for an automatic transmission installed in an automobile, and more specifically, it prevents the shift lever from entering the reverse engagement state even if the shift lever is moved to the reverse range while driving forward. Reverse engagement prevention device when moving forward.

0002

[Prior Art] Conventionally, as a device for preventing reverse engagement during forward movement, a desired shift is established in an oil passage communicating between a reverse range port of a manual valve and a hydraulic servo mechanism for a plurality of frictional engagement elements that engage during reverse shifting. Some solenoid valves are provided with an inhibit valve that is controlled by one solenoid valve among a plurality of solenoid valves provided to achieve this (for example, Japanese Patent Application Laid-Open No. 2-80859).
.

0003

However, in the conventional device described above, the inhibit valve is controlled by one solenoid valve, so if the solenoid valve becomes inoperable due to the stake, In this case, there is a possibility that it will not be possible to prohibit reverse travel during forward travel, regardless of whether the signal to the solenoid valve is on or off.

SUMMARY OF THE INVENTION Therefore, the technical object of the present invention is to prohibit reverse travel even when one solenoid valve of the reverse engagement prevention device during forward travel becomes inoperable due to the stay.

[0005]

[Means for Solving the Problems] The present invention provides a hydraulic source, a regulator valve that controls the hydraulic pressure from the hydraulic source at a constant level, and a hydraulic pressure controlled by the regulator valve that is introduced to adjust the hydraulic pressure according to a shift. a manual valve that generates the pressure, a reverse control valve that controls the hydraulic pressure generated by the manual valve when the manual valve is in the reverse position, and a first brake servo that applies the hydraulic pressure controlled by the reverse control valve to a determined brake servo. Of the multiple clutch servos that achieve reverse shifting separately from the shift valve and brake servo, the first clutch servo is controlled by the hydraulic pressure generated by the manual valve, which acts directly through the accumulator, and the regulator valve. The second clutch servo is directly applied to the generated hydraulic pressure through the second shift valve, and a prohibition means is provided to apply at least two solenoid signals when a reverse shift is performed, thereby prohibiting control of the reverse control valve.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit diagram of a control device for an automatic transmission according to the present invention.

In the hydraulic circuit 10 shown in FIG. 1, T is a torque converter with a direct coupling clutch, and 12 is a torque converter T.
14 is a lock-up signal valve that applies hydraulic signal pressure to the lock-up control valve when the direct-coupled clutch is actuated; and 20 controls the hydraulic pressure acting on the direct-coupled clutch. This is a second regulator valve.

Signal pressure from an accumulator control valve 34 connected to a plurality of accumulators is applied to the second regulator valve 20, and the accumulator control valve 34 controls the second regulator valve 20 in accordance with the operation of the accumulators. The rise of hydraulic pressure is controlled over time. Furthermore, the signal pressure of the throttle valve 22 connected to the oil pump 16 is applied to one end of the accumulator control valve 34, allowing control according to the throttle opening degree.

Throttle valve 22 and oil pump 16
There is a second regulator valve 2 in the middle of the oil path connecting the
A first regulator valve 18 connected to 0 is interposed.

[0010]The first regulator valve 18 controls the oil pressure generated from the oil pump 16 at a constant level. As a result, it becomes possible to apply a constant hydraulic pressure to the throttle valve 22, manual valve 26, and modulator valve 36.

The modulator valve 36 is a lock-up valve.
While regulating the oil pressure to the lock-up signal valve 14 that applies signal pressure to the control valve 12,
Adjust the oil pressure to the 3rd shift timing valve 48.

The manual valve 26 includes a 2-3 shift valve 28, a reverse control valve 30, a 12-shift valve 32, and a 3-shift valve 28, which are provided to accomplish each shift.
-4 shift valve 40 and C0 exhaust valve 42, and applies hydraulic pressure to a predetermined shift valve according to the shift.

According to the above embodiment, the automatic transmission of the present invention has four forward speeds (with overdrive) and one reverse speed, and
The engagement and disengagement relationships for each shift of the brake servos B0, B1, B2 for frictional engagement elements and the clutch servos C0, C1, C2 are as shown in the table of FIG.

Next, among the above-mentioned components, the structure of the forward reverse engagement prevention device of the present invention will be explained below with reference to FIGS. 3 and 4.

The structure of the forward reverse engagement prevention device of the present invention includes an oil pump (hydraulic power source) 16 and an oil pump 1.
a first regulator valve (regulator valve) 18 that controls the oil pressure from 6 to a constant level; and a manual that introduces the oil pressure controlled by the first regulator valve 18 and generates oil pressure according to the shift. When the valve 26 and the manual valve 26 are in the reverse position, the manual valve 26
a reverse control valve 30 that controls the hydraulic pressure generated by the reverse control valve 30; a 1-2 shift valve (first shift valve) 32 that applies the hydraulic pressure controlled by the reverse control valve 30 to a predetermined brake servo B2; Among the plurality of clutch servos that accomplish reverse shifting separately from servo B2, there is a clutch servo (first clutch servo) C2 on which the hydraulic pressure generated by the manual valve 26 acts directly via an accumulator, and a first clutch servo.
The oil pressure controlled by the regulator valve 18 is 3-
4 Another clutch servo (second clutch servo) C acting directly via the shift valve (second shift valve) 40
0, and solenoid valves 50 and 52 that apply at least two solenoid signals to inhibit control of the reverse control valve 30 when a reverse shift is activated.

[0016] The solenoid valves 50 and 52 are connected to the ECU 5.
4 is applied, and detection signals from the vehicle speed sensor 56 and shift position sensor 58 are applied to the ECU 54. As a result, solenoid valves 50 and 52 are operated in response to detection signals from vehicle speed sensor 56 and shift position sensor 58.

The oil passage connections between each component are shown in FIG.
The reverse range port a of the manual valve 26 is connected to the clutch servo C2 by an oil passage L1, and
A plurality of branch oil passages L2, L3, and L4 are provided in the oil passage L1. Of these, oil passage L2 is connected to port c of reverse control valve 30. The oil pressure in oil path L3 is 3-
It is connected to port b of the 4-shift valve 40. and,
Oil passage L4 is connected to port b of 1-2 shift valve 32. In addition, the line pressure oil path L0 from the oil pump 16
is connected to port a of regulator valve 18, while it is connected to port d of 3-4 shift valve 40.

The signal pressure of the solenoid valve 50 is in the oil passage S1.
is connected to port a provided at the upper end of the reverse control valve 30. On the other hand, the signal pressure of the solenoid valve 52 is applied to the 3-4 shift valve 4 by the oil passage S2.
It is connected to port a provided at the upper end of 0. The signal pressure of this solenoid valve 52 is further connected to port a provided at the upper end of the 1-2 shift valve 32 and port b of the reverse control valve 30 by oil passages S3 and S4.

Further, the port d of the reverse control valve 30 is connected to the port d of the 1-2 shift valve 32 by an oil passage U1, and the port d of the 1-2 shift valve 32
Port c is connected to brake servo B2 by oil passage U2. In the 3-4 shift valve 40, the port c is connected to the port b of the C0 exhaust valve 42 through the oil passage W1, and the port c is connected to the port b of the C0 exhaust valve 42.
Port a of No. 2 is connected to clutch servo C0 by oil passage W2.

The operation of the present invention will be explained below based on the above configuration.

FIG. 3 shows a normal reverse shift operation. If the ECU 54 determines based on the vehicle speed sensor 56 and shift position sensor 58 that the vehicle is not moving forward, it turns off the solenoid valves 50 and 52. Therefore, the hydraulic pressure generated from the reverse range port a of the manual valve 26 is applied to the clutch servo C2 through the oil passage L1, so that the clutch servo C2 is engaged in accordance with the operation of the accumulator. In addition, an oil path L branched from the oil path L1
2 oil pressure is from port c of reverse control valve 30.
will be applied. At this time, the reverse control valve 30 receives the oil pressure of the oil passage L0 through the port e provided at the lower end, so it becomes in the right half state where it is biased upward, and communicates between the ports c and d, and also connects ports 1-2. It is communicated with port d of the shift valve 32.

[0022] The oil pressure of the oil path L4 is the 1-2 shift valve 32.
is applied to port b of. In this case, since the spools of the 1-2 shift valve 32 are formed as separate bodies 32a and 32b, the lower spool 32a is in the right half state pushed down by the hydraulic pressure applied to port b. As a result, port d and port c of the 1-2 shift valve 32 are communicated with each other, so that hydraulic pressure is applied to the brake servo B2. Therefore, brake servo B2 is engaged.

Further, the oil pressure in the oil passage L3 is applied to port b of the 3-4 shift valve 40. Again, 3-
Since the spools of the 4-shift valve 40 are formed as separate bodies 40a and 40b, the lower spool 40a is connected to port b.
It is pushed down by the hydraulic pressure applied to the right half. As a result, port d and port c, which are connected to oil path L0, are communicated with each other, so that hydraulic pressure is applied to clutch servo C0.
It will be affected by Therefore, clutch servo C0
is engaged.

Therefore, brake servo B2 and clutch servos C0 and C2 are engaged, and a reverse shift is achieved.

Next, FIG. 4 shows a state in which the vehicle is reverse shifted during forward travel.

When the ECU 54 determines by the vehicle speed sensor 56 and shift position sensor 58 that a reverse shift has been made during forward travel, it turns on the solenoid valves 50 and 52. Therefore, since the signal pressure of the solenoid valve 50 is applied to the port a provided at the upper end of the reverse control valve 30, the spool 30a, which is a separate body of the reverse control valve 30,
30b is pushed down against the spring force of a spring arranged at the lower end. As a result, the spools 30a and 30b of the reverse control valve 30 are placed in the left half position, and the connection between ports c and d is cut off by the land formed on the spool 30a. Therefore, the hydraulic pressure from port a of the manual valve 26 is applied to the brake servo B2.
Therefore, brake servo B2 remains disengaged, and reverse shifting is prohibited.

Further, even if one of the solenoid valves 50, 52 becomes inoperable due to the stay, reverse shifting is prohibited. That is, when the solenoid valve 52 is in an inoperable state, the other solenoid valve 50 is turned on, and the same reverse shift as described above is prohibited. When the solenoid valve 50 is inoperable, the solenoid valve 52 is turned on, and signal pressure acts on port b of the reverse control valve 30 through oil passages S2, S3, and S4. As a result, the lower spool 30a of the reverse control valve 30 is pushed down, and the connection between ports c and d is cut off by the land formed on the spool 30a. Therefore, the hydraulic pressure from port a of the manual valve 26 does not act on the brake servo B2, so the brake servo B2 remains disengaged and reverse shifting is prohibited.

[0028]

As explained above, the automatic transmission control device of the present invention can be used even when at least one solenoid valve related to the forward reverse engagement prevention device becomes inoperable due to the stay. Since reverse travel can be reliably prohibited, a highly reliable reverse engagement prevention device during forward movement can be obtained.

Furthermore, since there is no need to add any special parts for the reverse engagement prevention device, the device becomes compact and inexpensive.

[Brief explanation of drawings]

FIG. 1 is a hydraulic circuit diagram of a control device for an automatic transmission according to the present invention.

FIG. 2 is an engagement table of the clutch servo and brake servo in FIG. 1;

FIG. 3 is a circuit diagram of a reverse engagement prevention device during normal reverse shifting.

FIG. 4 is a circuit diagram of a reverse engagement prevention device when reverse shift is prohibited.

[Explanation of symbols]

16 Oil pump (hydraulic source) 18 First regulator valve (regulator valve) 26 Manual valve 26 30 Reverse control valve 32 1-2 shift valve (first shift valve) B2
brake servo

Claims (1)

[Claims] 1. A hydraulic source, a regulator valve that controls hydraulic pressure from the hydraulic source at a constant level, and a manual valve that receives hydraulic pressure controlled by the regulator valve and generates hydraulic pressure according to a shift. a reverse control valve that controls hydraulic pressure generated by the manual valve when the manual valve is in a reverse position; a first shift valve that applies the hydraulic pressure controlled by the reverse control valve to a determined brake servo; Among a plurality of clutch servos that accomplish reverse shifting separately from the brake servo, a first clutch servo is controlled by the hydraulic pressure generated by the manual valve directly through an accumulator, and a first clutch servo is controlled by the regulator valve. a second clutch servo on which the generated hydraulic pressure acts directly through a second shift valve; and a prohibition means for inhibiting control of the reverse control valve by applying at least two solenoid signals when a reverse shift is activated. Device.