JPS6252184B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for controlling the on/off operation of a lock-up clutch incorporated in a torque converter for an automatic transmission.

(Prior art) Generally, this type of control device is
As shown in Japanese Patent No. 22456 and FIG. 3, a lock-up clutch piston B is supported on the turbine hub of a torque converter A so as to be freely slidable in the axial direction, and a lock-up clutch piston B is defined by the lock-up clutch piston B. A first oil supply passage D1 is connected to the first working chamber C1 located on the turbine side, and a second oil supply passage D2 is connected to the second working chamber C2 located on the pump housing side. Supply passages D1 and D2 are connected to the discharge line G from the oil pump F via the lock-up relay valve E.
The lock-up clutch is turned on and off by selectively introducing control pressure into the first working chamber C1 or the second working chamber C2 by switching the lock-up relay valve E. There is.

Specifically, the control pressure is introduced into the first working chamber C1 via the first oil supply passage D1, and the second
By opening the second working chamber C2 to the tank through the oil supply passage D2, the lock-up clutch is turned on, while the control pressure is applied to the second working chamber C2 through the second oil supply passage D2. and the introduction of
By opening the first working chamber C1 to the tank through the first oil supply passage D1, the lock-up clutch is turned off. Working chamber C
The control pressure introduced into 2 is controlled by the regulator valve H and orifice O1 provided in the discharge line G, as well as the orifice O2 provided in the branch path D3 branching from the second oil supply path D2 and connected to the oil cooler. The pressure is regulated by

(Problems to be Solved by the Invention) In the case of a torque converter for an automatic transmission equipped with a lock-up clutch, the above-mentioned 1 working chamber C
On the other hand, when the lock-up clutch is turned off, it is necessary to apply a relatively low internal pressure to the second working chamber C2 that is sufficient to cause the lock-up clutch piston B to move back. However, in the conventional control device shown in FIG. 3, the regulator valve H or orifice O1, O2
When the internal pressure acting on the first working chamber C1 is adjusted to a high level when the lock-up clutch is turned on, even when the lock-up clutch is turned off, the second working chamber has the same pressure as when the lock-up clutch is turned on. The same high internal pressure is applied, and as a result, when the lock-up clutch is turned off, the oil pump is driven more than necessary, resulting in power loss.

The present invention was developed in view of the above-mentioned problems, and its purpose is to supply the hydraulic pressure necessary for torque transmission when the lock-up clutch is turned on, and to apply the hydraulic pressure necessary for torque transmission when the lock-up clutch is turned off. It is an object of the present invention to provide a control device for a lock-up clutch that can apply the hydraulic pressure necessary for the clutch-off operation to the first and second working chambers, respectively.

(Means for Solving the Problems) In order to achieve the above-mentioned objects, the present invention provides a lock-up clutch and a first working chamber of the lock-up clutch to supply hydraulic oil to turn the clutch on. a first oil supply passage; a second oil supply passage for supplying hydraulic oil to the second working chamber of the lock-up clutch to turn off the clutch; and a second oil supply passage for supplying hydraulic oil to the first and second oil supply passages. A lock-up relay valve for switching the supply is provided, and a variable orifice is provided for controlling the internal pressure of the first and second working chambers in conjunction with the lock-up relay valve.

(Function) According to the control device according to the present invention, a desired control pressure is applied to the first or second working chamber through the variable orifice when the lock-up clutch is turned on and when it is turned off. It is possible.

(Embodiment) An embodiment of the lock-up clutch control device according to the present invention will be described below with reference to the drawings.

In the figure, 1 is a known torque converter consisting of a pump 11, a turbine 12, and a stator 13, and the pump 11 of the torque converter 1 is coupled to the crankshaft 2a of the engine via a pump housing 14, and the turbine 12 is spline-coupled to the output shaft 2b so that driving force from the engine is transmitted to the output shaft 2b via the torque converter 1.

and 3, the output shaft 2b is connected to the crankshaft 2a.
The clutch 3 is a lock-up clutch that is directly connected to the turbine 12 in the torque converter 1 and the pump by supporting a clutch piston 31 at the shaft end of the output shaft 2b so as to freely slide in the axial direction. The space between the housing 14 is divided into two chambers, and a first working chamber S1 is provided on the turbine 12 side.
A second working chamber S2 is provided on the side of the pump housing 14, and the clutch piston 31 is provided with a second working chamber S2.
A clutch facing 32 is attached to the outer peripheral edge of the clutch facing 32, and as the clutch piston 31 slides toward the pump housing 14 (rightward in FIG. 1), the piston 31 is moved toward the pump housing 14. The lock-up clutch 3 is turned on by pressing the clutch through the clutch facing 14, so that the output shaft 2b is directly connected to the crankshaft 2a, and the turbine 12 of the clutch piston 31 is connected directly to the crankshaft 2a. By sliding the clutch piston 31 away from the pump housing 14, the lock-up clutch 3 is turned off, and the output shaft 2b and the crankshaft 2a are separated. It is designed to release the direct connection between the two.

Further, an oil pump is installed in the first working chamber S1.
A first oil supply passage 4a that circulates and supplies hydraulic oil from the torque converter 1 to the second working chamber S2 is also connected to the oil pump.
While connecting the second oil supply passage 4b for supplying the hydraulic oil from OP into the second working chamber S2,
A lock-up relay valve 5, which will be described later, is interposed between the first and second oil supply passages 4a, 4b and the discharge line 4c extending from the oil pump OP,
By switching the lock-up relay valve 5, the hydraulic oil discharged from the oil pump OP is transferred to the first working chamber S1 or the second working chamber S1 through the first oil supply passage 4a or the second oil supply passage 4b. It is configured to be supplied to the chamber S2.

Further, the first oil supply passage 4a is formed with a branch passage 4d which branches off from the middle and leads to the drain tank T, and a fixed orifice 41 is provided in the middle of the branch passage 4d.
and an oil cooler 42.

On the other hand, the lock-up relay valve 5 described above
uses a three-land type spool 51, a pressure chamber 52 is provided on one side of the spool 51, and a spring chamber 53 is provided on the other side, and the spool 51 is placed in the spring chamber 53 on the pressure chamber 52 side. A return spring 54 for urging is inserted,
A signal line 4e that generates a predetermined signal pressure depending on the running state of the vehicle is connected to the pressure action chamber 52, and the first and second lands 51 of the spool 51 are connected to each other.
the first oil supply passage 4a between the lands 51b and 51b, the discharge line 4c and the second oil supply passage 4b between the second and third lands 51b and 51c, and usually closed by the third land 51c. The pressure action chamber 52 is connected to the tank lines 4f that are
When the signal pressure is not introduced into the pressure chamber 52, the discharge line 4c is communicated with the second oil supply passage 4b with the tank line 4f closed, and the signal pressure is introduced into the pressure action chamber 52. By the forward movement of the spool 51, the discharge line 4c is communicated with the first hydraulic oil supply passage 4a, and at the same time, the second oil supply passage 4b is communicated with the tank line 4.
It is designed to communicate with f.

In the embodiment shown in FIG. 1, a lock-up relay valve 5 is connected to the discharge line 4c in the middle of the discharge line 4c.
A variable orifice 6 is provided to change the area of the oil passage c.

Specifically, the variable orifice 6 is connected to the throttle passage 61 and the needle 62 that enters the throttle passage 61.
The throttle passage 61 is formed in the middle of the discharge line 4c, and the needle 6
2 is provided on the spool 51 of the lock-up relay valve 5, and when the needle 62 enters the throttle passage 61, the throttle passage 61 is normally closed.
while reducing the oil passage area of the spool 51.
The throttle passage 6 of the needle 62 as the needle 62 moves forward.
1, the oil passage area of the throttle passage 61 is increased.

In addition, 40 in the figure shows a regulator valve.

Next, the operation of the control device having the above configuration will be explained.

For example, when the lock-up clutch does not need to be turned on, such as during idling,
Since no signal pressure is applied to the signal line 4e, the spool 51 of the lock-up relay valve 5
is kept biased toward the pressure action chamber 52 by the spring force of the return spring 54, and therefore the discharge line 4c communicates with the second oil supply passage 4b and is discharged from the oil pump OP. The hydraulic oil is supplied to the second working chamber S via the discharge line 4c or the second oil supply passage 4b.
2, the clutch piston 31 slides toward the turbine 12, and the lock-up clutch 3 is turned off.
At this time, the needle 62 constituting the variable orifice 6 enters the throttle passage 61, and the oil passage area of the throttle passage 61 becomes smaller, so that the hydraulic oil is not supplied to the second oil supply passage 4b. As the amount decreases, the control pressure on the secondary side of the variable orifice 6 interposed position in the discharge line 4c, in other words, the internal pressure of the second working chamber S2 also decreases accordingly.

The hydraulic oil supplied to the second working chamber S2 circulates within the torque converter 1 and then flows from the first oil supply passage 4a to the tank via the branch passage 4d provided in the supply passage 4a. Returned to T.

On the other hand, when it is necessary to turn on the lock-up clutch, such as during high-speed operation, signal pressure is applied to the signal line 4e, and the spool 51 of the lock-up relay valve 5
The spring chamber 53 resists the return spring 54.
In order to move toward the side, the discharge line 4c communicates with the first oil supply passage 4a, and the oil pump
The hydraulic oil discharged from OP is connected to the discharge line 4.
The oil is introduced into the first working chamber S1 through the first oil supply passage 4a, and the clutch piston 31 slides toward the pump housing 14 to lock the lock-up clutch. 3 is turned on.

At this time, the needle 62 constituting the variable orifice 6 exits the throttle passage 61,
Since the oil passage area of the throttle passage 61 becomes larger, the amount of hydraulic oil supplied to the second oil supply passage 4b increases, thereby controlling the secondary side of the intervening position of the variable orifice 6 in the discharge line 4c. In other words, the internal pressure of the first working chamber S1 becomes higher accordingly, and the clutch piston 31 can be brought into strong pressure contact with the pump housing 14. Therefore, the pressure from the crankshaft 2a to the output shaft 2b is increased. Torque transmission can be performed reliably.

In the above embodiment, a variable orifice 6 that interlocks with the lock-up relay valve 5 is provided in the middle of the discharge line 4c, but the variable orifice 6 is not limited to this, and for example, as shown in FIG.
A variable orifice 60 interlocked with the lock-up relay valve 5 may be provided in the middle of the branch path 4d formed by branching off the first oil supply path 4a.

That is, in the embodiment shown in FIG. 2, the branch path 4d
The spring chamber 53 of the lock-up relay valve 5 is passed through the spring chamber 53, and the variable orifice 60 is provided in the spring chamber 53. Specifically, a small hole is formed at the shaft end of the spool 51. 63, and as the spool 51 moves forward against the return spring 54, the secondary side of the relay valve 5 interposed position in the branch path 4c is closed, and at the same time, the primary side and the secondary side are closed. Communication may be made only through the pores 63.

In addition, in FIG. 2, 42 indicates the discharge line 4.
This is a fixed orifice formed in the middle of c.

(Effects of the Invention) As described above, the lock-up clutch control device according to the present invention provides the first lock-up clutch control device according to the present invention.
a first oil supply passage that supplies hydraulic oil to a working chamber to turn the clutch on; a second oil supply passage that supplies hydraulic oil to a second working chamber of the lock-up clutch to turn the clutch off; , said first,
and a lock-up relay valve that switches the supply of hydraulic oil to the second oil supply passage, and a variable orifice that controls the internal pressure of the first and second working chambers in conjunction with the lock-up relay valve. When the lock-up clutch is turned on in accordance with the operation of the lock-up relay valve, the internal pressure of the first working chamber is increased through the variable orifice, and a sufficient transmission torque of the clutch can be obtained. When the lock-up clutch is turned off in conjunction with the operation of the up-relay valve, the internal pressure of the second working chamber is lowered to the minimum necessary level via the variable orifice, thereby eliminating unnecessary driving of the oil pump. It was reached.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing one embodiment of a lock-up clutch control device according to the present invention, and FIG.
The figure is a schematic explanatory diagram showing another embodiment, and FIG. 3 is a schematic explanatory diagram of a conventional control device. DESCRIPTION OF SYMBOLS 1... Torque converter, 3... Lock-up clutch, S1... First working chamber, S2... Second working chamber, 4a... First oil supply passage, 4b... Second oil supply passage, 5... Lock-up relay valve, 6
...Variable orifice.

Claims (1)

[Claims] 1 A lock-up clutch, a first oil supply passage that supplies hydraulic oil to a first working chamber of the lock-up clutch to turn on the clutch, and a second working chamber of the lock-up clutch. a second oil supply passage for turning off the clutch;
and a lock-up relay valve that switches the supply of hydraulic oil to the first and second oil supply passages.
A control device for a lock-up clutch in a torque converter for an automatic transmission, further comprising a variable orifice that controls the internal pressures of the first and second working chambers in conjunction with the lock-up relay valve.