JPS6272960A - Hydraulic control device for torque converter provided with direct-coupling clutch - Google Patents

Abstract

PURPOSE:To prevent output torque from temporarily dropping to improve the drive feeling of a vehicle incorporating a power transmission system including a torque converter provided with a direct-coupling clutch, by gradually disengaging the direct-coupling clutch with the use of a hydraulic control control unit. CONSTITUTION:Oil under regulated pressure is fed to a torque converter 6 and a direct coupling clutch 18 from a slip control device which is provided with a direct-coupling type clutch control valve 110 composed of a hydraulic oil change-over valve and a pressure regulating valve. Further, an engaging instruction for the direct-coupling clutch 18 is delivered to a direct-coupling solenoid valve 132 from an electronic control device 140. If fast releasing of the direct coupling clutch 18 is not required when the direct-coupling clutch 18 is changed over into an indirect control condition, the control system controls the control valve 110 to gradually decrease the releasing pressure for the direct- coupling clutch 18. With this arranged the pressure for direct-coupling is controlled so that the clutch 18 is released through such a step that it transmits power while it slips, and accordingly, it is possible to make variations in slip torque smooth upon change-over into the indirect coupling condition.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application> The present invention relates to a hydraulic control device for a torque converter equipped with a direct coupling clutch.

<Prior art> A torque converter is generally installed between a prime mover and an automatic transmission in automobiles, etc., and transmits torque using fluid. It consists of a turbine fixed to the shaft (output shaft) side and a stator etc. provided to the howe/song side via a one-way clutch.

In a torque converter that transmits torque only by fluid, problems such as poor fuel efficiency have been pointed out because the center is always accompanied by fluid. In order to solve this problem, in recent years, a direct coupling clutch has been installed between the input and output shafts of the torque converter.In some operating conditions, torque is mainly transmitted through this direct coupling clutch. Something has been developed that makes it possible. The general structure of such a direct coupling clutch is, as shown in FIG.
N? By pressing this piston 86 against the friction plate 80 using hydraulic pressure, the torque is transmitted while causing these to slide slightly.1Moreover, the impact torque from the prime mover is alleviated (damping effect) by these slides. In other words, as shown in FIG. Friction plate 80 of shell 78 and direct clutch 18
The turbine 10 is spline-fitted to the turbine shaft 20 and rotates integrally with the turbine shaft 20, and is also connected to the piston 86 via a transfer ring 84 so as to rotate integrally with the piston 86.
6 is fitted to be slidable and rotatable in the axial direction with respect to the turbine shaft 20, is disposed opposite to the grate 82, has a friction surface 88 that comes into contact with the friction plate 80, and has a friction surface 88 that contacts the friction plate 80.
A hydraulic chamber 90 is formed between the outer surface of the outer shell 92 of the coupling 10 and the piston 86. A hydraulic chamber 94 is formed between the outer surface of the outer shell 92 of the coupling 10 and the piston 86. The dynamic friction coefficients of the friction surfaces 88 and 88 are set so that the rate of change due to the speed difference is small.

A plurality of grooves are appropriately provided on the surface of the friction plate 80 along the radial direction, the circumferential direction, or a combination of the two, and the oil passing through the grooves makes the friction plate 80 and the friction surface 8
8 overheating is prevented. Oil is supplied to the torque converter 6 and the direct coupling clutch 18 with oil whose pressure is regulated by a slip control device. As shown by the arrow in FIG. 4, the oil is guided into the Torque Humbataro through an oil passage 97 formed on the inner surface of the sleeve 96 fitted over the turbine shaft 20 of the cylinder 7'8, and then circulated through the hydraulic chamber. 94, then through the gap between the friction plate 86 and the friction surface 88 of the direct coupling clutch 18, into the hydraulic chamber 90, and further discharged through the oil passage 98 drilled in the turbine shaft. Alternatively, it can be circulated in the opposite direction. In the figure, 12 is a stator, and 1.1 is a one-way clutch.

As shown in FIG. 5, the slip control device rF is equipped with a switching valve and a pressure regulating valve for medium oil supplied to the torque converter 6 and the direct coupling clutch 8, and a direct coupling clutch control valve +10. The control valve 110 has a spool valve 456 provided with four lands 442, 444, 446, 448 and annular grooves 450, 452, 454 formed between the lands, and has a pressure regulated by the direct solenoid valve 132. The control hydraulic pressure is applied to the pressure receiving surface 45 at one end of the land 442.
On the other hand, the supply oil passage 228 is directly connected to the annular groove 454, and the oil land 446° 448 whose pressure is regulated to a low pressure is connected to the annular groove 454.
, and acts on the spool valve 456 as a pushing force to the left in FIG. 4 due to the area difference between the two pressure receiving surfaces.
Moreover, the pressure receiving surface 458 of the land 442 is set smaller than the pressure receiving surface of the land 444, and the pressing force to the right in FIG. 454 caused by the hydraulic pressure in the fourth
The flow direction of the oil supplied to the torque converter 6 and the direct coupling clutch 18 and its oil pressure are controlled by the balance with the pressing force to the left in the figure.

The oil passage 97 following the Torque Humpertaro is connected to the oil passage 460, the oil passage 98 following the direct coupling clutch 18 is connected to the oil passage 462, and the oil passage 462 is connected to the supply oil passage 194 by switching control of the direct coupling clutch control valve 110. Alternatively, the oil passage 460 is selectively communicated with the supply oil passage 436 or the oil drainage passage 466.

When an engagement command for the direct coupling clutch 18 is given to the direct coupling solenoid valve 132 by the electronic control unit @140, the fifth
Direct coupling clutch control valve 110 as shown by the solid arrow in the figure
Oil whose pressure has been regulated is supplied from the supply oil passage 194 to the oil passage 460, and the piston 86 of the direct coupling clutch 18 is pushed to the left by the hydraulic pressure acting on the hydraulic chamber 94, and is engaged with a basic slip amount. be done.

In addition, when starting or suddenly accelerating, it is necessary to release the direct coupling clutch 18 in order to utilize the characteristics of the torque pump for feeling. , the direct coupling clutch control valve 110 is switched and the oil flows in the opposite direction to the above direction indicated by the dashed arrow in FIG. In other words, the low oil pressure
6 to the oil passage 462, and the direct coupling clutch 18 moves the piston 86 to the right by the hydraulic pressure acting on the hydraulic chamber 90.
The engagement will be released. In the hydraulic control device shown in FIG. 5, the hydraulic pressure to the direct coupling clutch 18 is duty-controlled, but an electric control method may also be adopted.

<Essential Points to be Solved by the Invention> In the power transmission system as described above, direct coupling or non-direct coupling is selected depending on the driving situation of the vehicle.

Conventionally, direct coupling in the direct coupling clutch 18 has been released by instantly setting the direct coupling pressure to 0 kg/crit. However, when a direct connection (including a slip direct connection with a small slip-lag rotation difference) is made into a non-direct connection in this way, the engine rotation increases until the rotation difference reaches a point at which the torque converter 6 can transmit a predetermined torque. while,
As shown by the broken line in FIG. 3(a), there was a temporary drop in the transmitted torque, which was confused with a misfire or malfunction of the engine, which significantly affected the feeling. Incidentally, FIG. 3 shows changes in torque, direct coupling duty ratio, engine rotation speed, and direct coupling pressure with respect to time at the time of switching from direct coupling to non-direct coupling. On the other hand, when releasing the IYF coupling clutch in a power transmission system equipped with a torque converter with a direct coupling clutch, there are certain cases (when the accelerator is fully released, when the brake is depressed, when there is no driving force from the engine). (such as when the engine has entered), turn off the hydraulic pressure momentarily when releasing the direct connection to prevent poor vehicle operation and vibration generation, etc.
It is necessary to set it to l.

The present invention has been made in view of the above circumstances, and prevents the above-mentioned temporary torque down that occurs when switching between direct coupling and non-direct coupling in a power transmission system equipped with a torque converter with a direct coupling clutch, thereby improving the feeling. The purpose is to rotate.

Means to Solve the Disruption Point> The structure of the present invention that achieves the above object is to connect a direct coupling clutch between the input and output shafts, which is interposed between the engine and transmission of a vehicle, and which is engaged and disengaged by hydraulic pressure. A device for controlling hydraulic pressure when changing the direct coupling clutch from direct coupling to non-direct coupling in a torque converter provided for, a pressure regulating valve provided in an oil path guiding pressure oil from a hydraulic pressure source to the direct coupling clutch;
Depending on the driving situation of the vehicle, it is determined whether it is time to switch from direct coupling to non-direct coupling and the switching need not be made instantaneously, and the pressure regulating valve is controlled to gradually release the direct coupling clutch. The present invention resides in a hydraulic control device including a prompt control thread that controls hydraulic pressure to a clutch.

<Saku Kawa> According to the above-mentioned hydraulic control system of the Torque Fumverter with a direct coupling clutch, when the direct coupling clutch is switched from direct coupling to non-direct coupling and it is necessary to quickly release the clutch latch,
l;il;The pressure regulating valve is controlled by the system, and i
Since the rj coupling clutch release oil pressure is gradually changed (reduced) and the direct coupling clutch is released from the sluggish state, a sudden drop in torque is prevented.

<Embodiment> FIG. 1 shows a flowchart of an example of control contents in a hydraulic control device according to an embodiment of the present invention. The torque converter with a direct coupling clutch and the slip control device of the hydraulic control device according to the present invention are the same as those shown in FIGS. 4 and 5, and therefore their explanation will be omitted. Incidentally, FIG. 2 shows a direct non-turn map stored in the electronic control unit 140. This map is Torquefunbatallo's turbine rotation f&r.

Depending on the engine/shin throttle opening TH, it is determined whether the engine is in the direct connection region or the non-direct connection region.

First, in the running state where the direct coupling clutch 18 is in direct connection in the torque converter, it is determined whether or not it is in the non-direct coupling region. This can be determined from the map shown in Figure 2 based on the throttle opening detected by the NT throttle opening sensor ((1) in the figure).

If it is determined that it is not in the non-direct connection region, the output shaft rotation speed N detected by the pulse generator
o Based on the throttle opening], the electronic control system rf 14
It is determined whether or not the gear should be changed based on the shift non-turn stored in 0 ((21) in the figure. If it is determined that the gear should not be changed ("No"), the process returns to (1).

or? If it is determined that I YesSn, the gear is shifted, and after the gear shift, it is determined whether or not it is in the non-direct coupling region in the same way as in (1) above.
(3) in the figure).

Here, if the determination is "No", an output is made so that the direct connection occurs during the gear shift, and the direct connection solenoid valve 132 is controlled ((4) in the figure). If so, the control is thereafter performed in the same manner as when the determination is "yes" in (1) above.

In step (11), it is determined that it is in the non-direct connection area, and then it is determined whether or not p(]f is in the 10FF area ((5) in the figure).This determination is made when the ignition This is done based on the engine speed detected by the pulse, the throttle opening T), and the map stored in the m controller 140.Here, it is determined that it is "yes", that is, the P/OFF state. , the direct-coupling solenoid valve 132 is controlled to instantly release the direct-coupling clutch 18, that is, to instantly bring the direct-coupling pressure to Okg/d (see (6, 6) in the figure).
, (7) ).

In (5) above, “NO” means P/OFF”
It is determined that the brake is not in the ON state based on the signal from the brake pedal switch ((8) in the figure), and it is determined that the brake is in the ON state ((8) in the figure). Then, the control in step 61 (7) is performed in the same manner as described above to instantly unload the direct coupling clutch 18.

If it is determined in (8) above that the brake is not in the ON state, then it is determined whether the accelerator is in the OFF state based on the signal from the accelerator toggle switch ((91) in the figure). If it is determined that the accelerator is in the OFF state, the control in (61(7)) is performed in the same way as described above to instantly release the direct coupling clutch J8.

”: If it is judged as “No” in step (9), if it is determined that it is completely in the non-direct connection region and does not fall under any of the cases where the direct connection clutch 18 should be released instantly, the direct connection is The direct connection solenoid valve 132 is controlled to gradually release the clutch 18, and the direct connection pressure is controlled (Q4 in the figure).
J (71).

The duty rate of the direct solenoid valve 132 is as shown in FIG. 3(b).
The pressure is controlled as shown by the solid line, and the direct connection pressure is gradually reduced as shown by the solid line in FIG. 3(d). By controlling the direct coupling pressure in this way, the direct coupling clutch 18 is released from the stage where it is transmitting force while slipping, so that the direct coupling clutch 18 is released from the stage where it is transmitting force while slipping. Torque fluctuations during switching are smoother, no shock occurs, and the feeling is improved.

In the above embodiment, the hydraulic pressure to the direct coupling clutch 18 is controlled by duty-controlling the direct coupling solenoid valve 132, but the hydraulic pressure may be controlled by other electrical methods.

<Effects of the Invention> According to the hydraulic control device for a torque converter with a direct coupling clutch according to the present invention, when changing from a direct coupling state to a non-direct coupling state, the hydraulic control is performed except in specific cases where it is necessary to immediately disengage the direct coupling clutch. Since the direct connection is gradually made non-direct, there is no large drop in torque, and the feeling is improved.

[Brief explanation of drawings]

Fig. 1 is a flowchart of the hydraulic control system according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the direct connection and turn map, and Fig. 3 is the torque and direct connection R needy ratio in the conventional case and in the case of the present invention. , a graph showing changes in engine speed and direct coupling pressure, Figure 4 is a cross-sectional view of a torque converter with a direct coupling clutch,
FIG. 5 is a hydraulic control circuit diagram for the direct coupling clutch. 18 is a direct coupling clutch, 132 is a direct coupling solenoid valve, and 140 is an electronic control device.

Claims (1)

[Claims] Controls hydraulic pressure when changing the direct coupling clutch from direct coupling to non-direct coupling in a torque converter that is provided between input and output shafts with a direct coupling clutch that is interposed between the engine and transmission of a vehicle and is engaged and disengaged by hydraulic pressure. The device is a pressure regulating valve installed in an oil passage that guides pressure oil from a hydraulic source to a direct coupling clutch, and is used to switch from direct coupling to non-direct coupling depending on vehicle driving conditions, even if the switching is not done instantaneously. A hydraulic control system for a torque converter with a direct coupling clutch, comprising: a control system that determines a good state and controls the hydraulic pressure to the direct coupled clutch by controlling the pressure regulating valve to gradually release the direct coupled clutch. .