JPH0351575A - Fluid transmission device equipped with lock-up clutch - Google Patents

Abstract

PURPOSE:To improve the acceleration performance of a vehicle, speed change shock, and fuel consumption by suing one between a blade wheel oil chamber and a lock-up control chamber as a means for controlling the drain in lock-up mode and nonlock-up mode. CONSTITUTION:In the lock-up mode, a turning-ON instruction is outputted into the solenoid 21a of an electromagnetic selector valve 21 from outside, and a position different from that shown on the figure is set, and the pressurized working oil having a lock-up control pressure is supplied into a lock-up control chamber 15 from an oil passage 27, and the working oil is drained from a torque converter chamber 14 (blade wheel oil chamber) through an oil passage 26 and an oil cooler 23. In the nonlock-up mode, a turning-OFF signal is outputted into the solenoid 21a of the valve 21 from outside, and the position shown on the figure is set, and the working oil is drained into a reservoir 24 from the oil passage 26 through an oil cooler 23, and the working oil is drained into the reservoir 24 from a chamber 15 through an oil passage 27, supplying the pressurized working oil due to the torque converter supply pressure into the chamber 14 from an oil passage 25. Therefore, the weight of the device is reduced.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a fluid transmission device with a lock-up clutch (also referred to as a hydraulic The term "transmission device" refers to a torque converter or a fluid coupling.)

(Prior art) Conventionally, as a torque converter with a lockup, as shown in Figure 3.125 on page 215 of "Automotive Engineering Complete Book Volume 9 Power Transmission Device" (November 1980: ■ Sankaido Publishing) A torque converter equipped with a lock-up clutch using a single plate is known.

(Problem to be Solved by the Invention) However, in such a conventional torque converter with lockup, only one torque transmission surface is formed during lockup, so the torque transmission capacity during lockup is small. For example, when applied to a vehicle equipped with a large-displacement, high-torque engine, slipping may occur during lock-up due to insufficient torque transmission capacity.

Therefore, as shown in FIG. 3, a torque converter with a multi-disc lock-up clutch has been proposed in which the torque transmission capacity during lock-up is increased by providing a multi-disc lock-up clutch.

In FIG. 3, 01 is a multi-disc clutch, 02 is a lock-up piston, 03 is a torque converter chamber, 04 is a lock-up control chamber, and 05 is a front cover.

As shown in Fig. 4, the lock-up hydraulic pressure control circuit applied to this is to set the hydraulic pressure in the torque converter chamber at a predetermined pressure (approximately 4 kg/cm') and change the hydraulic pressure in the lock-up control chamber. Generally, the operation of a multi-disc clutch is controlled by

In other words, 4 kg/cm' is always stored in the torque converter chamber.
The torque converter supply pressure Pc, which has been reduced in pressure, acts on the oil and flows to the oil cooler.

The oil pressure PL/U in the lock-up control room is controlled by the lock-up control valve, and when the lock-up is not performed, it is released to the atmosphere (
drain), and line pressure PL at lock-up.
(For example, 5 to I Okg/cm2) acts, and the multi-disc clutch is engaged.

Incidentally, the line pressure characteristics with respect to the throttle opening are shown in FIG.

However, at the time of lockup, a line pressure PL greater than the torque converter supply pressure Pc is applied to the lockup control chamber, and both pressures P. , Pc is used to engage the multi-disc clutch, and in particular, at high loads, the line pressure P, which is about twice the torque converter supply pressure Pc, acts on the lock-up control chamber, so the lock-up control chamber is closed. As shown in FIG. 3, the constituent front cover 05 needs to have a large thickness in order to ensure strength and durability against high line pressure P.

As a result, the weight and moment of inertia of the torque converter increase, which deteriorates the acceleration performance, shift shock, fuel efficiency, etc. of the vehicle.

The present invention has been made with attention to the above-mentioned problems, and in a fluid transmission device with a lock-up clutch having a lock-up control chamber, by reducing the device weight and moment of inertia, the acceleration performance of the vehicle and shift shock can be improved. The challenge is to improve fuel efficiency, etc.

(Means for Solving the Problems) In order to solve the above problems, in the fluid transmission device with a lock-up clutch of the present invention, one of the impeller oil chamber and the lock-up control chamber is operated during lock-up and non-lock-up. was used as a means of drain control.

That is, a pump invera connected to an input shaft via a front cover, a turbine runner facing the pump invera and connected to an output shaft, and the input/output shaft are arranged to be directly connected by a lockup piston. In a fluid transmission device with a lock-up clutch equipped with a multi-disc clutch, a lock-up control chamber surrounded by an impeller oil chamber in which the pump inflator and turbine runner are housed, the front cover, and a lock-up piston includes a The present invention is characterized in that a lock-up hydraulic pressure control means is connected to perform hydraulic control to reduce the hydraulic pressure in the impeller oil chamber to almost zero during lock-up and to substantially zero hydraulic pressure in the lock-up control chamber during non-lock-up.

Note that an orifice may be provided in a partition wall member that defines the impeller oil chamber and the lockup control chamber.

(Function) When the lock-up is not performed, the lock-up hydraulic control means supplies pressurized hydraulic oil to the impeller oil chamber from one communication oil passage while draining it from the other communication oil passage via an oil cooler, etc. , is drained from the lock-up control room via a communication oil passage.

Due to this hydraulic control, a pressure difference is generated between the impeller oil chamber and the lockup control chamber, the lockup piston strokes in the clutch release direction, and the multi-disc clutch is released.

If an orifice is provided in the partition wall member that separates the impeller oil chamber and the lock-up control chamber, after the multi-disc clutch is released, the hydraulic oil is locked from the impeller oil chamber through the orifice. The differential pressure between the impeller oil chamber and the lock-up control chamber is maintained due to the pressure loss as it flows into the lock-up control chamber and passes through the orifice.

At the time of lockup, pressurized hydraulic oil is supplied to the lockup control chamber through the communication oil passage by the lockup hydraulic control means, and hydraulic oil is drained from the communication oil passage from the impeller oil chamber via an oil cooler, etc. Ru.

Due to this hydraulic control, the lockup control chamber reaches the supply pressure level, the impeller oil chamber has almost zero oil pressure, a large pressure difference occurs between the lockup control chamber and the impeller oil chamber, and the lockup piston moves in the fastening direction. , and the multi-disc clutch is engaged by the engagement force obtained by multiplying this differential pressure by the pressure-receiving area of the lock-up piston.

If an orifice is provided in the partition wall member that defines the impeller oil chamber and the lock-up control chamber, after the multi-disc clutch is engaged, the hydraulic oil will flow from the lock-up control chamber to the impeller through the orifice. It flows into the vehicle oil chamber and functions to regulate the oil pressure level in the closed lock-up control chamber so that it does not exceed the supply pressure level.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an overall view showing a torque converter with a lock-up clutch according to an embodiment, in which a pump impeller 3 is connected to an input shaft 2 via a front cover 1, and an output shaft 5 is connected opposite to the pump impeller 3. a stator 7 supported by a coos 8 via a one-way clutch 9, and a multi-disc clutch 1 arranged to directly connect the input/output shafts 2, 5 through a lock-up piston 11.
0.

A torque converter chamber 14 (impeller oil chamber) in which the pump invera 3, turbine runner 4, and stator 7 are housed, and a lockup control chamber 15 surrounded by the front cover 1 and the lockup piston 11. An orifice 16 is provided in the lock-up piston 11 (partition wall member) that defines two orifices, a torque converter chamber 14 and a lock-up control chamber 15.
A lock-up hydraulic control circuit 20 is connected to the lock-up hydraulic pressure control circuit 20 which performs hydraulic control to reduce the hydraulic pressure in the torque converter chamber 14 to almost zero during lock-up and to substantially zero the hydraulic pressure in the lock-up control chamber 15 during non-lock-up.

The lockup hydraulic control circuit 20 includes a solenoid 21
Reduce the line pressure P created by the electromagnetic switching valve 21, which switches the oil passage in response to an external ON-OFF command to a, and the pressure regulator valve (not shown) to a constant control pressure (4 kg/cm'). a pressure reducing valve 22 that cools the hydraulic oil heated by the flow within the torque converter chamber 14, a reservoir 24 that stores the hydraulic oil, and a torque converter chamber 14 via the electromagnetic switching valve 21. A return oil passage 26 communicates with the torque converter chamber 14 via the oil cooler 23, and a lock-up control pressure passage communicates with the lock-up control chamber 15 via the electromagnetic switching valve 21. It is equipped with an oil passage 2Y.

1 0 FIG. 2 is a cross-sectional view showing a mechanical part of a torque converter with a lock-up clutch according to an embodiment. The input shaft 2 is connected to an engine (not shown), and the driving force from the engine is input. The pump impeller 3 has a bomb shell 3a fixed to the front cover 1. The turbine runner 4 has a turbine shell 4a and is connected to the output shaft 5 via a turbine hub 6.

The multi-disc clutch 10 includes two dry bullets 10a that engage with spline portions formed in the pump shell 3a;
It has two driven plates +ob that engage with the spline portion of the torsion damper 12 fixed to the turbine huff 6.

The lockup piston 11 is provided so as to be slidable in the axial direction in an oil-tight manner with respect to a piston huff 13 fixed to the front cover 1 and the output shaft 5.

The torque converter chamber 14 has a torque converter supply pressure oil passage 2 formed between the case 8 and the pump hub 17.
5 and a return oil passage 26 formed between the output shaft 4 and the case 8 communicate with each other. 27 are connected.

Next, the effect will be explained.

Each mode will be explained when switching control is performed between the torque converter mode and the lockup mode depending on the driving state.

(a) Torque converter mode When in torque converter mode (non-lockup mode), external O
FF command is output.

With this command, the electromagnetic switching valve 21 of the lock-up hydraulic control circuit 20 is placed in the position shown in FIG. At the same time, hydraulic oil is drained from the other return oil passage 26 to the reservoir 24 via the oil cooler 23, and hydraulic oil is drained from the lockup control chamber 15 to the reservoir 24 via the lockup control pressure oil passage 27.
Hedrained.

1 2 Through this hydraulic control, a torque converter chamber 14 is supplied with a torque converter supply pressure Pc of approximately 4 kg/crn', and a lock-up control chamber 15 is provided with a hydraulic pressure approximately zero due to the drain.
A differential pressure is generated between the two, and the lockup piston 11 strokes in the clutch release direction, so that the multi-disc clutch 10 becomes released.

After the multi-disc clutch 10 is released, the hydraulic oil in the torque converter chamber 14 is drained via the return oil passage 26, so that the internal pressure of the torque converter chamber 14 is lower than the hydraulic level of the torque converter supply pressure Pc. However, the hydraulic oil flows from the torque converter chamber 14 to the lockup control chamber 15 through the orifice 16, and the orifice 16
Torque due to pressure loss during
The differential pressure between the lockup control chamber 15 and the lockup control chamber 15 is maintained.

Therefore, the differential pressure between the torque converter chamber 14 and the lockup control chamber 15 pushes the lockup piston 11 in the releasing direction (leftward in the drawing), ensuring torque converter operation with the multi-disc clutch 10 in the disengaged state. Ru.

1 3 (Ex) Lock-up mode When in the large-capacity lock-up mode, an external ON command is output to the solenoid 21a of the electromagnetic switching valve 21.

With this command, the electromagnetic switching valve 21 of the lockup hydraulic control circuit 20 is placed in a position different from that shown in FIG. Oil is supplied, and hydraulic oil is drained from the torque converter chamber 14 via a return oil passage 26 and an oil cooler 23.

Due to this hydraulic control, the lock-up control room 15 is approximately 4k
g/cm2, the hydraulic pressure in the torque converter chamber 14 becomes almost zero due to the drain, and the lock-up control chamber 15 and the torque converter chamber 14
A large pressure difference is generated between the lockup pistons 11 and the lockup piston 11, and the multi-disc clutch 10 is fastened by the fastening force obtained by multiplying this pressure difference by the pressure receiving area of the lockup piston 11.

1 4 After the multi-disc clutch 10 is engaged, the hydraulic oil flows through the orifice 16 into the lock-up control chamber 15.
flows into the torque converter chamber 14, and the oil pressure level in the lock-up control chamber 15 in the closed state is approximately 4 kg/cm.
It functions to regulate the pressure so that it does not exceed the pressure level 2.

Therefore, the lockup piston 11 is pushed in the engagement direction (rightward in the drawing) due to the differential pressure between the lockup control chamber 15 and the torque converter chamber 14, and the multi-disc clutch 10 is pushed approximately 4k
The fastening force is obtained by multiplying the differential pressure of g/cm2 by the pressure receiving area of the lockup piston 11, thereby ensuring a large-capacity lockup operation with high torque transmission capacity.

As explained above, in the torque converter with a lock-up clutch according to the embodiment, the torque converter chamber 14 and the lock-up control chamber 15 are communicated through the orifice 16, and the lock-up and non-lock-up conditions are Since one of the torque converter chamber 14 and the lockup control chamber 15 is drain-controlled, the hydraulic pressure acting on the lockup control chamber 15 maintains a predetermined differential pressure between the clutch engagement force and the compartments 14 and 15 of 15. As can be seen by comparing FIG. 2 and FIG. 3, the wall thickness of the front knob 1 can be reduced without exceeding 4 kg/km2.

As a result, the weight and moment of inertia of the torque converter are reduced, and the acceleration performance, shift shock, fuel efficiency, etc. of the vehicle can be improved.

Although the present invention has been described above based on the embodiments shown in the drawings, the specific configuration is not limited to the embodiments.

For example, in the embodiment, an example was shown in which the orifice 16 was provided in the lockup piston, but the torque converter chamber 14
An orifice may be provided in the piston huff 13 or the like as long as it is a partition wall member that defines the lockup control chamber 15.

Further, in the embodiment, an example of application to a torque converter having a stator and exhibiting a torque increasing effect has been shown, but it goes without saying that the present invention can be applied to a fluid coupling that does not have a stator.

1 6 (Effects of the Invention) As explained above, in the present invention, in a fluid transmission device with a lock-up clutch having a lock-up control chamber, the impeller oil chamber is changed between lock-up and non-lock-up. Since one of the lock-up control chamber and the lock-up control chamber is used as a drain control means, the weight and moment of inertia of the device are reduced, and the acceleration performance, gear shift shock, fuel efficiency, etc. of the vehicle can be improved.

[Brief explanation of drawings]

Fig. 1 is an overall view showing a torque converter with a lock-up clutch according to an embodiment of the present invention, Fig. 2 is a sectional view of a mechanical part showing a torque converter with a lock-up clutch of the embodiment, and Fig. 3 is a conventional FIG. 4 is a cross-sectional view of a mechanical part showing a torque converter with a lock-up clutch, FIG. 4 is an overall view showing a conventional torque converter, and FIG. 5 is a line pressure characteristic diagram with respect to throttle opening. 1... Front cover 2... Input shaft 1 7 3... Pump inverter 4... Turbine runner 5... Output shaft 10... Multi-disc clutch 11... Lock-up piston 14...・Torque converter chamber (impeller oil chamber) 15...Lockup control chamber 16...-orifice 20...Lockup hydraulic pressure control circuit (lockup hydraulic pressure control means)

Claims (1)

[Claims] 1) A pump impeller connected to an input shaft via a front cover, a turbine runner facing the pump impeller and connected to an output shaft, and the input/output shaft directly connected by a lock-up piston. In a fluid transmission device with a lock-up clutch, the lock-up control unit is surrounded by the impeller oil chamber in which the pump impeller and the turbine runner are housed, the front cover, and the lock-up piston. The chamber is characterized in that a lock-up hydraulic pressure control means is connected to the chamber for performing hydraulic control to reduce the hydraulic pressure in the impeller oil chamber to almost zero during lock-up and to substantially zero hydraulic pressure in the lock-up control chamber during non-lock-up. Fluid transmission device with lock-up clutch. 2) The fluid transmission device with a lock-up clutch according to claim 1, wherein an orifice is provided in a partition wall member that defines the impeller oil chamber and the lock-up control chamber.