KR20120031599A

KR20120031599A - Failsafe apparatus of automatic transmission

Info

Publication number: KR20120031599A
Application number: KR1020100093069A
Authority: KR
Inventors: 손현준; 이주항
Original assignee: 현대자동차주식회사
Priority date: 2010-09-27
Filing date: 2010-09-27
Publication date: 2012-04-04

Abstract

The present invention valve body (1); A valve spool (3) provided in the valve body (1) for linear sliding and having at least three lands; A normally closed type solenoid valve 5 connected to provide a hydraulic pressure to a land of the valve spool 3 at stages other than the D stage; An elastic member (7) provided to provide the valve spool (3) with an elastic force in a direction corresponding to the pressure provided by the solenoid valve (5); A D stage supply port (9) provided in the valve body (1) such that the pressure supplied at the D stage is cut off at the stage other than the D stage by another land of the valve spool (3); The hydraulic pressure supplied to the D stage supply port 9 is supplied to another land of the valve spool 3 to press the valve spool 3 in a direction corresponding to the elastic force of the elastic member 7. Provided a fail-safe device of an automatic transmission including a self-locking passage 11 provided in the valve body (1), if the vehicle was running in the 'D' stage when entering the limp home mode, the 'D' stage It is fixed and maintained, and in the case of other shift stages, it is maintained in a neutral state, so that a more improved failsafe function can be implemented.

Description

Failsafe Apparatus of Automatic Transmission

The present invention relates to a failsafe device of an automatic transmission, and more particularly, to a failsafe device that can act when a failure occurs in an automatic transmission mounted on a vehicle to which a shift by wire technology is applied.

The shift-by-wire vehicle transmits the shift lever operation of the driver to the automatic transmission as an electric signal instead of a mechanical operating element, so that the desired shift operation can be made.

Therefore, the automatic transmission of the shift-by-wire vehicle does not have a manual valve for mechanically distinguishing the shift range, and thus, when the vehicle enters the limp home mode due to a failure during driving of the vehicle, all electrical If the signal is lost, the controller cannot determine the current driving stage.

Therefore, in the related art, it is impossible to distinguish the transmission fixed stage by the current driving stage. Therefore, the vehicle is failsafe by a method of fixing it to one fixed stage such as neutral or 'D' unconditionally regardless of which state it is currently driving. It was to perform the function.

According to the present invention, when the vehicle is traveling in the 'D' stage when the vehicle enters the limp home mode, the vehicle is fixed to the 'D' stage and maintained in a neutral state when the shift stage is other, thereby improving failsafe. The object of the present invention is to provide a failsafe device of an automatic transmission in which a function can be implemented.

Fail-safe device of the present invention automatic transmission for achieving the object as described above

Valve body;

A valve spool provided in the valve body to linearly slide and having at least three lands;

A normally closed type solenoid valve connected to a land of the valve spool at a stage other than the stage D;

An elastic member provided to provide the valve spool with an elastic force in a direction corresponding to the pressure provided by the solenoid valve;

A D stage supply port provided in the valve body such that the pressure supplied at the D stage is interrupted at the stage other than the D stage by another land of the valve spool;

A self-locking passage provided in the valve body to supply the hydraulic pressure supplied to the D stage supply port to another land of the valve spool to press the valve spool in a direction corresponding to the elastic force of the elastic member;

Characterized in that configured to include.

According to the present invention, when the vehicle is traveling in the 'D' stage when the vehicle enters the limp home mode, the vehicle is fixed to the 'D' stage and maintained in a neutral state when the shift stage is other, thereby improving failsafe. Allows you to implement functionality.

1 is a view illustrating a failsafe device of an automatic transmission according to the present invention, illustrating a state of a P stage, an R stage, or an N stage other than the D stage;
FIG. 2 is a diagram illustrating a transient state of switching from the state of FIG. 1 to the state D of FIG. 3;
3 is a view illustrating a state in which the self-locking function is activated because the device of FIG. 1 is switched to the state of D stage;
4 is a view illustrating a state in which the apparatus of FIG. 1 enters the lymph groove mode in a state other than the D stage.

1, the embodiment of the present invention and the valve body (1); A valve spool (3) provided in the valve body (1) for linear sliding and having at least three lands; A normally closed type solenoid valve 5 connected to provide a hydraulic pressure to a land of the valve spool 3 at stages other than the D stage; An elastic member (7) provided to provide the valve spool (3) with an elastic force in a direction corresponding to the pressure provided by the solenoid valve (5); A D stage supply port (9) provided in the valve body (1) such that the pressure supplied at the D stage is cut off at the stage other than the D stage by another land of the valve spool (3); The hydraulic pressure supplied to the D stage supply port 9 is supplied to another land of the valve spool 3 to press the valve spool 3 in a direction corresponding to the elastic force of the elastic member 7. It comprises a self-locking passage 11 provided in the valve body (1).

The normally closed type solenoid valve 5 does not output hydraulic pressure by closing a flow path in a state in which control electricity is not supplied, and output hydraulic pressure is generated only when control electricity is supplied. In the case of the N stage, the parking stage P stage and the reverse stage R stage, the solenoid valve 5 has the elasticity of the valve spool 3 as shown in FIG. Hydraulic pressure is provided to overcome the elastic force of the member 7 and to move to the right.

At least three lands of the valve spool 3 consist of a first land 13, a second land 15, and a third land 17, which are provided in turn, and the hydraulic pressure from the solenoid valve 5 is It is supplied to act on the first land 13 provided at one end of the valve spool (3), and between the D stage supply port (9) and the self-locking passage (11) by the third land (17) The connection state is configured to be switched.

The self-locking passage 11 is formed to connect the space between the second land 15 and the third land 17 to the space between the first land 13 and the second land 15, The second land 15 is formed to a larger diameter than the first land 13.

The valve spool 3 is provided with a fourth land 19 adjacent to the third land 17, and the fourth land 19 has the valve spool 3 having an elastic force of the elastic member 7. The hydraulic element is supplied to the friction element 21 acting at the D stage in the moved state, and the friction element acting at the D stage in the state where the valve spool 3 is moved by the elastic member 7. It is formed to interrupt the hydraulic pressure supplied to the 21.

That is, the valve composed of the valve spool 3 and the valve body 1 is such that the fourth land 19 controls the hydraulic pressure supplied to the friction element 21 essential for the implementation of the D stage.

In the failsafe device of the automatic transmission configured as described above, in the case of stages other than the D stage, that is, P, R, and N stages in a normal state, the pressure provided by the solenoid valve 5 is shown in FIG. The valve spool 3 has a state in which the elastic member 7 is compressed and moved to the right.

When the D stage shift is made from the above state, the hydraulic pressure supplied to the D stage supply port 9 is supplied between the first land 13 and the second land 15 via the self-locking passage 11. Thus, the valve spool 3 is the solenoid acting on the left side of the first land 13 due to the difference in the effective working pressure due to the difference in diameter between the first land 13 and the second land 15. Even if there is no hydraulic pressure from the valve 5, it is possible to continuously maintain the state in which the valve spool 3 is in close contact with the right side while compressing the elastic member 7, which is the self-locking illustrated in FIG. State (self locking state).

In the above state, the solenoid valve 5 is of course the D stage, and thus does not provide hydraulic pressure, and the friction element that must be essentially operated in the D stage between the third land 17 and the fourth land 19. 21) when the operating pressure is smoothly supplied, and when the vehicle enters the lymph groove mode due to a failure while driving the vehicle in the above state, the valve spool (3) is irrelevant to the operation of the solenoid valve (5). Since the state where) is moved to the right is continuously maintained by the self-locking function, the shift stage continues to perform the failsafe function fixed to the D stage.

However, as described above, during the transition from the state of FIG. 1 to the state of FIG. 3, a transient state as shown in FIG. 2 is required.

That is, when the hydraulic pressure of the solenoid valve 5 is blocked from the beginning when shifting from the P, R and N stages to the D stage, the hydraulic pressure is supplied from the D stage supply port 9 through the self-locking passage 11. Since the valve spool 3 can be moved to the left by the elastic member 7 even before the self-locking function is exerted, the solenoid for a period of time during which the self-locking action can be sufficiently exhibited at the beginning of the D stage shifting. The output hydraulic pressure of the valve (5) must be maintained.

On the other hand, when entering the lymph groove mode in the stage other than the D stage is the state of Figure 4 from the state of Figure 1, when entering the lymph groove mode when the control electricity supplied to the solenoid valve 5 is cut off Since the solenoid valve 5 is normally closed, no output hydraulic pressure is generated, and thus the valve spool 3 is moved to the left side by the elastic force of the elastic member 7 to be in the state of FIG. 4.

In this state, since the third land 17 blocks the D stage supply port 9, the self-locking action does not occur, and the fourth land 19 has to be operated at the D stage. Since the hydraulic pressure supplied to the element 21 is blocked, the neutral state is stably implemented to perform a failsafe function.

One; Valve body
3; Valve spool
5; Solenoid valve
7; Elastic member
9; D stage supply port
11; Self-locking passage
13; First land
15; Second land
17; Third Land
19; 4th Land
21; Friction element

Claims

Valve body;
A valve spool provided in the valve body to linearly slide and having at least three lands;
A normally closed type solenoid valve connected to a land of the valve spool at a stage other than the stage D;
An elastic member provided to provide the valve spool with an elastic force in a direction corresponding to the pressure provided by the solenoid valve;
A D stage supply port provided in the valve body such that the pressure supplied at the D stage is interrupted at the stage other than the D stage by another land of the valve spool;
A self-locking passage provided in the valve body to supply the hydraulic pressure supplied to the D stage supply port to another land of the valve spool to press the valve spool in a direction corresponding to the elastic force of the elastic member;
Fail-safe device of an automatic transmission, characterized in that configured to include.

The method according to claim 1,
At least three lands of the valve spool consist of a first land, a second land and a third land provided in turn;
Hydraulic pressure from the solenoid valve is supplied to act on the first land provided at one end of the valve spool;
Configured to switch the connection state between the D stage supply port and the self-locking passage by the third land;
Fail-safe device of an automatic transmission, characterized in that.

The method according to claim 2,
The self-locking passage is formed to connect the space between the second land and the third land to the space between the first land and the second land;
The second land is formed with a larger diameter than the first land
Fail-safe device of an automatic transmission, characterized in that.

The method according to claim 3,
The valve spool is provided with a fourth land adjacent to the third land;
The fourth land supplies hydraulic pressure to a friction element that operates at the D stage while the valve spool overcomes the elastic force of the elastic member and moves the D spool when the valve spool is moved by the elastic member. Formed to block hydraulic pressure supplied to friction elements acting on
Fail-safe device of an automatic transmission, characterized in that.

In the method for controlling the failsafe device according to any one of claims 1 to 4,
To maintain the output hydraulic pressure of the solenoid valve until a sufficient amount of hydraulic pressure is supplied from the D stage supply port to the land of the valve spool through the self-locking passage when shifting from the stage other than the D stage to the D stage;
Fail-safe device control method of an automatic transmission characterized in that.