JPH0674333A - Hydraulic control device for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent a speed change shock by branching an oil path for connection between a reverse inhibit (RI) valve and a reverse shift attaining friction engaging unit to a boost port of a primary regulator valve, when placed in a condition of traversing a speed change line at the time of RI control. CONSTITUTION:In a hydraulic control device for an automatic transmission, when a car speed is a predetermined slow speed or more, a reverse inhibit (RI) valve 300 is controlled to be switched by operating a solenoid valve 400, so that an R range line pressure from a manual valve 200 is not supplied to a friction engaging unit (clutch C3 and brake B2) for attaining a reverse shift. A primary regulator valve 100 for increasing a line pressure by feedback supplying it to a boost port 106 is provided. Here, an oil path 500A for connection between the RI valve 300 and the reverse shift attaining friction engaging units C3, B2 is branched and connected to the boost port 106, to ensure a large engaging pressure in the C3, B2 at the time of RI control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device for an automatic transmission equipped with a reverse inhibit (reverse speed achievement prohibition) valve.

[0002]

2. Description of the Related Art Normally, in a hydraulic control device for an automatic transmission, the line pressure for achieving the reverse gear is set to be about 1.5 times higher than the line pressure for achieving the forward gear ( For example, JP-A-3-89070). This is because the reverse gear has a larger gear ratio than the forward gear and requires a large engagement pressure, and there is a demand to reduce the number of friction plates of the friction engagement device in order to reduce the volume and weight, Even in that case, it is necessary to secure a large transmission torque.

Therefore, the reverse range (hereinafter, referred to as "the boost port" of the primary regulator for generating the line pressure)
By feeding back the line pressure generated during the "R range"), the generated line pressure is increased.

On the other hand, even if the reverse inhibit valve is incorporated in the hydraulic control device and the vehicle is traveling forward at a predetermined vehicle speed or higher (for example, traveling in the "D range"), even if the shift operation is accidentally made to the R range, the reverse gear is set. Is being achieved (reverse inhibit control).
This technique is also disclosed in JP-A-3-89070.

By the way, during reverse inhibit control, even if the shift range is the R range, the reverse stage is not actually achieved, so it is not necessary to secure a high line pressure during reverse.

However, conventionally, as disclosed in the above publication, the R range line pressure is directly introduced from the R range port of the manual valve to the boost port of the primary regulator valve, and when the shift operation is performed to the R range. , Regardless of whether the actual reverse range was achieved,
The line pressure was automatically increasing.

[0007]

Therefore, when the reverse inhibit control is performed, that is, when the achievement of the reverse gear is actually prohibited, the vehicle travels at a predetermined vehicle speed or higher in the second gear of the D range, for example. When the shift range is changed from D to R while the R range is changed, the R range is not achieved by the reverse inhibit control. Therefore, it is not necessary to increase the line pressure, but the line pressure fluctuates greatly. .

Even if the line pressure fluctuates in this manner, no particular problem occurs unless an actual gear shift (for example, gear shift from the second speed to the third speed) is performed during the fluctuation, but it happens by chance. If an actual shift is performed while the line pressure is fluctuating, a large shock may occur.

That is, if the vehicle is traveling forward in the D range and accidentally switches to the R range, and when the gear is actually crossed and the gear is actually shifted at that time, an accumulator (clutch or the like) is generated due to fluctuations in the line pressure. The back pressure of (for alleviating the shock at the time of engagement) has largely changed, which may cause a large shift shock. The same applies when returning from the R range during reverse inhibit control to the D range.

The present invention has been made in view of such a conventional problem, and when the reverse cross control is performed and the transmission line is crossed, the D range → R
An object of the present invention is to provide a hydraulic control device for an automatic transmission, which can prevent the occurrence of a shift shock when a shift switching operation such as a range or an R range → D range is performed.

[0011]

SUMMARY OF THE INVENTION The present invention, as shown in the outline of FIG. 1, generates a line pressure by a supply pressure from a pump, and feeds the line pressure back to a boost port to generate the line pressure. The primary regulator valve capable of increasing the line pressure, the manual valve for guiding the line pressure from the primary regulator valve to the reverse range port when the shift range is set to the reverse range, and the reverse range port and the reverse range for the manual valve. A line pressure is provided from the manual valve to the reverse stage achievement friction engagement device, which is interposed in the oil passage connecting to the stage achievement friction engagement device and is switch-controlled according to the reverse stage achievement prohibition command. In a hydraulic control device for an automatic transmission, which has a reverse inhibit valve that is prohibited, The boost port of Imari regulator valve, by an oil path connecting between said reverse inhibit valve and reverse stage achieved frictional engagement device and branch-connected, in which the above-mentioned problems are eliminated.

[0012]

When the manual valve is operated to the R range position, the line pressure is led to the R range port. At this time, if the reverse inhibit control is not performed, the reverse inhibit valve is in the "conduction", and the R range line pressure from the R range port of the manual valve is supplied to the reverse stage achievement friction engagement device, Reverse gear is achieved.

At this time, since the R range line pressure is input to the boost port of the primary regulator valve via the reverse inhibit valve, the line pressure output from the primary regulator valve rises.
Therefore, a large line pressure is introduced to the friction engagement device,
A large engagement pressure is secured.

On the other hand, during reverse inhibit control,
Since the reverse inhibit valve is "non-conducting", the manual valve is operated to the R range position and R
Even if the line pressure is generated in the range port, the line pressure is not supplied to the reverse-step achieving friction engagement device, and the reverse step is not achieved.

Further, since the reverse inhibit valve is "non-conductive", the R range line pressure is not introduced into the boost port of the primary regulator valve. Therefore, the line pressure does not rise and remains the same value as when moving forward.

Therefore, even if the shift operation such as the D range → R range is accidentally performed in a situation where the transmission line is crossed, the line pressure does not change, so that the conventional shift shock does not occur.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a skeleton diagram of an example of an automatic transmission to which the hydraulic control system according to the embodiment is applied.

This automatic transmission is provided with two sets of first and second planetary gear mechanisms 1, 2 and is shown in the right side of the drawing, the ring gear 3 of the first planetary gear mechanism 1 and the left side of the drawing. The carrier 4 of the second planetary gear mechanism 2 is integrally connected, and
Carrier 5 of first planetary gear mechanism 1 and second planetary gear mechanism 2
Ring gear 6 is integrally connected.

A clutch C1 having a multi-plate structure is arranged between the sun gear 7 and the input shaft 8 of the first planetary gear mechanism 1. Further, the carrier 5 is connected to a counter drive gear 9 which is an output member.

The input shaft 8 is integrally connected to an intermediate shaft 10, and a multi-plate clutch C2 is arranged between the intermediate shaft 10 and the carrier 4 of the second planetary gear mechanism 2.
Further, a clutch C3 having a multi-plate structure is arranged between the intermediate shaft 10 and the sun gear 11 of the second planetary gear mechanism 2.

A clutch C4 having a multi-plate structure and a one-way clutch F1 are arranged in series between the sun gear 11 of the second planetary gear mechanism 2 and the carrier 4, and the one-way clutch F1 and the case are arranged. A brake B1 having a multi-plate structure is arranged in series between the two and the one-way clutch F2.
Are arranged in series. A brake B2 having a multi-plate structure is arranged between the ring gear 3 of the first planetary gear mechanism 1 and the carrier 4 of the second planetary gear mechanism 2 and the case 12 which are connected to each other.

As shown in the operation table of FIG. 3, the above-mentioned friction engagement elements are engaged or released to set the forward speed of the first speed to the fourth speed and the reverse speed (Rev). . In FIG. 3, ◯ indicates engagement, ⊚ indicates engagement during engine braking, and blank indicates release.

Next, the hydraulic control system of the embodiment will be described with reference to FIG.

This hydraulic control device controls the reverse inhibit valve 300 to be switched by operating the solenoid valve 400 when the vehicle speed is equal to or higher than a predetermined slight speed, whereby the R range line pressure from the manual valve 200 is changed to the reverse gear. Friction engagement device for achieving (clutch C3
And the brake B2) is not supplied.

A primary regulator valve 100 and a manual valve 20 provided in this hydraulic control device.
Since 0 and the reverse inhibit 300 are all publicly known, the structure and operation of themselves will be briefly described.

The primary regulator valve 100 is
The line pressure is generated at the outlet port 104 by adjusting the supply pressure from the pump P by the balance between the downward hydraulic pressure introduced from the upper port 101 and applied to the spool 102 and the upward force by the spring 103. is there.

Actually, the throttle pressure is introduced into the lower control port 105 and the R range line pressure is introduced into the boost port 106, and these hydraulic pressures are applied to the spool 102 in the same direction as the force by the spring 103. By acting, the line pressure is adjusted by the engine output, and the line pressure is increased in the R range.

The line pressure output from the outlet port 104 of the primary regulator valve 100 is applied to the input port 201 of the manual valve 200.

The manual valve 200 has a spool 202 that is manually operated. The line pressure applied to the input port 201 is transferred to the D port 203 in the D range, to the S port 204 in the 2 range, and to the L port 205 in the L range. At the time of the R range, it is led to the R port (reverse range port) 206.

The R port 206 is finally connected to the clutch C3 and the brake B2 via the oil passage 500, and the solenoid valve 40 is provided in the middle of the oil passage 500.
A reverse inhibit valve 300 whose opening and closing is controlled by 0 is interposed.

The reverse inhibit valve 300 is controlled by the signal oil pressure from the solenoid valve 400 to the left half position in the figure at the time of reverse inhibit, and cuts off the communication between the input port 301 and the output port 302, and the line pressure changes to the clutch C3 and the brake. It is prevented from being supplied to B2. That is, the achievement of the reverse gear is prohibited.

At other times, it is controlled to the right half position in the drawing to connect the input port 301 and the output port 302 to allow the line pressure to be supplied to the clutch C3 and the brake B2. In other words, the state is such that the reverse stage is achieved.

It should be noted that the solenoid valve 400 performs the reverse inhibit operation when the vehicle speed is equal to or higher than a predetermined value during forward movement. This solenoid valve 40
0 is also used as a solenoid valve for controlling the operation of a lockup clutch (not shown).

The characteristic of this hydraulic control device is that the boost port 106 of the primary regulator valve 100 is directly connected to the R of the manual valve 200 in the conventional case.
Although it was connected to the port 206 (shown by a dotted line in the drawing), it is stopped and the boost port 106 is connected to the output port 302 of the reverse inhibit valve 300 or the oil passage 500A connected to the output port 302.

Next, the operation will be described.

In this hydraulic control device, when the manual valve 200 is operated to the R range position, the line pressure is led to the R port 206 of the manual valve 200. At this time, if the reverse inhibit control is not performed, the reverse inhibit valve 300 is open and the R port 20 of the manual valve 200 is open.
The R range line pressure from 6 is supplied to the clutch C3 and the brake B2 (friction engagement device for achieving reverse gear), and the reverse gear is achieved.

At that time, the primary regulator valve 1
Since the R range line pressure is input to the boost port 106 of 00 through the reverse inhibit valve 200, the line pressure output from the primary regulator valve 100 is higher than the line pressure during forward movement. Therefore, a large line pressure is introduced into the clutch C3 and the brake B2, whereby a large engagement pressure is secured.

On the other hand, during reverse inhibit control,
Since the reverse inhibit valve 300 is in the “non-conduction” state, even if the manual valve 200 is erroneously turned to R
Even if the R port 206 is shifted to the range position to generate a line pressure, the line pressure is not supplied to the clutch C3 and the brake B2, and the reverse speed is not achieved.

Further, at that time, the reverse inhibit valve becomes "non-conductive", so that the line pressure is not introduced into the boost port of the primary regulator valve. Therefore, the line pressure does not rise and remains the same value as when moving forward.

Therefore, in a situation where a shift line is crossed (a situation where a shift is executed), even if a shift operation such as a forward range → reverse range is accidentally performed, the line pressure does not change. The gear shift shock as described above will not occur.

[0042]

As described above, according to the hydraulic control system for an automatic transmission of the present invention, the line pressure does not increase when the reverse inhibit control functions even if the shift operation is accidentally performed in the reverse range. , Remains in the forward range. Therefore, during reverse inhibit control,
Even if a situation of crossing the shift line occurs, the line pressure does not change, and the effect that shift shock does not occur can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the gist of the present invention.

FIG. 2 is a skeleton diagram showing an outline of an automatic transmission to which an embodiment of the present invention is applied.

FIG. 3 is an operation table for achieving each shift speed of the automatic transmission.

FIG. 4 is a system diagram showing a main part of a hydraulic control device according to an embodiment of the present invention.

[Explanation of symbols]

 100 ... Primary regulator valve 106 ... Boost port 200 ... Manual valve 206 ... R port (reverse range port) 300 ... Reverse inhibit valve 500A ... Oil passage C3 ... Clutch (friction engagement device for achieving reverse gear) B2 ... Brake (reverse gear) Achievement friction engagement device)

Claims (1)

[Claims] 1. A primary regulator valve capable of increasing a generated line pressure by generating a line pressure by a supply pressure from a pump and feeding the line pressure back to a boost port, and a shift range in reverse. When a range is set, a manual valve that guides the line pressure from the primary regulator valve to the reverse range port and an intermediate oil passage that connects the reverse range port of the manual valve and the reverse stage achievement friction engagement device are interposed. A reverse inhibit valve that is switch-controlled according to a reverse speed achievement prohibition command to prohibit the supply of line pressure from the manual valve to the reverse speed achievement friction engagement device, and a hydraulic control device for an automatic transmission having: , The boost port of the primary regulator valve An oil pressure control device for an automatic transmission, characterized in that an oil passage connecting between a verse inhibit valve and a friction engagement device for achieving reverse gear is branched and connected.