JPS63308266A - Control device for lockup clutch incorporated in torque converter - Google Patents

Abstract

PURPOSE:To prevent damage due to slippage at the time of high-speed running by supplying oil pressure corresponding to a car velocity to a lockup clutch incorporated in a torque converter when it reaches a designated car velocity. CONSTITUTION:A spool 40 of a pressure regulating valve S1 of a lockup clutch control device S is moved to an equilibrium position with a spring 42 due to a pressure difference between line pressure PL from a hydraulic control valve Q and governor pressure PG introduced into an oil chamber 41. Line pressure corresponding to such displacement is partially returned to a reservoir 30 through an orifice 43 and a passage 44. On the other hand, when it reaches a preset car velocity, a spool 45 of an on-off valve S2 is moved to the left by the equilibrium among a pressure drop, the governor pressure PG and a spring 46 to supply pressure corresponding to the car velocity to a lockup clutch 2a of a torque converter 2. Thus, when the clutch is connected, mechanical efficiency and fuel cost can be improved, a shock at the time of low-speed running is softened by temporary slippage, and damage due to slippage at the time of high-speed running can be prevented.

Description

[Detailed Description of the Invention] Field of Application in CJF Industry] This invention relates to a hydraulic control device for a lock-up clutch built into a torque converter for a vehicle.

[Conventional technology]

Conventionally, in a fluid torque converter used in heavy vehicles such as automobiles, when the "clutch point" of the fluid torque converter is reached, the pump Daito and the turbine wheel are mechanically connected to control the power transmission. In order to improve mechanical efficiency (that is, fuel consumption '4=), a lock-up clutch (directly connected clutch) is interposed between the two gears. As the type of lock-up clutch, a Masatsu clutch, a roller type one-way launch, etc. have been proposed.

Figure 2 shows the overall configuration of an example of the power transmission system of a conventional automobile, particularly an automobile equipped with a hydrodynamic crank converter and equipped with a V-belt continuously variable transmission and a built-in roller type one-way lock-up clutch. An explanatory model diagram is shown.

(Structure) In Fig. 4, 1 is an engine (prime mover), 2 is a hydraulic torque converter having a direct coupling (lock-up) clutch 2a in the roller type one-way clutch type, and 3 is an engaged (lock-up) clutch when the heavy vehicle moves forward. multi-plate hydraulic clutch unit that
4 is a multi-plate hydraulic clutch unit that is engaged (turned on) when reversing, 5 is a belt-type continuously variable transmission, 6 is a differential gear, and 7/8/9 are torque converter 2 units. Pump/turbine/stator, 10 is a turbine @ (input shaft of engine power to transmission 5), 11 is machine frame, 12.
13 is a pair of gears that mesh with each other; 14 is an idler gear; 15 is a reverse gear; 16.17 is a hydraulic multi-disc clutch plate consisting of ?V number of element plates that are in contact with each other alternately , 18/24 are the drive shaft/driven wheels of the transmission 5, and 19/20 are the drive side V.
The movable pulley/fixed pulley of pulley PI, 21 is an endless (j=Dg) V belt for power transmission, 22/23 is
The movable pulley/fixed pulley of the driven side V-pulley P2, 25/26, the pinion/ring gear of the final reduction gear, 27.degree., 28, each drive shaft, and 29.30, each drive heavy wheel tire. In addition, 19 a / 22 a is
Each movable pulley 19/22 of the driving/driven pulley P + / P 2, respectively, each fixed hydraulic piston, 19b
/22b is each cylinder cover, 19c /
22c indicates each piston oil chamber.

(Power transmission line) Next, the power transmission path during forward movement will be explained.

The power of the engine 1 is transmitted to the turbine shaft lO through the torque converter 2, and is transmitted to the gear 13 through the teeth 1t12, and each clutch plate 16 of the clutch 3 is turned on (each clutch plate 17 of the clutch 4 is turned off). Therefore, the signal is transmitted to the drive shaft 18, from the drive side V pulley P1 to the driven side V pulley P2 by the V heald 21, from the wave shaft 24, through the final reduction gear 25.26, and then by each drive shaft 27.28. Power is transmitted to the drive wheel tires 29.30.

Next, the power transmission path during reverse travel is transmitted from the gear 12 to the idler gear 14 and the reverse fjllttL15, the clutch 4 is turned on (clutch 3 is turned off), the power is transmitted to the driven shaft 24, and the final reduction gear 4125 ．．
26 to the drive wheel tires 29.30. The direction of rotation of the driven shaft 24 is determined by the idler t&*14.
The direction of rotation is in the opposite direction during navigation. At this time, the belt 21 rotates, but the clutch 3 is turned off, so no torque is transmitted.

Next, by the same inventor as the present invention, Japanese Patent Application Laid-Open No. 57-83
FIG. 3 shows a sectional view of a main part of a torque converter 2 including a lock-up clutch 2a disclosed in Japanese Patent No. 754.

Detailed explanation will be given to the above cited document, but to briefly explain, the pump (wide) 7 and the turbine (of the torque converter 2)
tA body) 8 is provided with driving/driven members 7a/8a having driving/driven circular surfaces on the inner and outer peripheries, respectively, and a plurality of wedges are provided between the driving/driven circular surfaces. A roller R is sandwiched and interposed between the cages. On the other hand, the driven member 8a has an integrally formed hydraulic piston 8b.
Hydraulic pressure is introduced/discharged from the oil passage A, which is disposed in the cylinder 8C so as to be movable in the axial direction and is bored along the central axis of the turbine shaft 10, to the back of the piston 8b via the sub passage Aa. By doing so, the driven member 8a is connected to the wedge roller R.
By pressing or loosening the drive member 7a through the lock-up clutch, the lock-up clutch can be connected/disconnected.

In the figure, 1a indicates the output shaft of the engine 1, that is, the torque converter input shaft, and B and C indicate the return oil passage from the torque converter and the one-side clutch oil supply passage of the stator 9, respectively.

In the case of the conventional Masatsu clutch, when the pump and turbine Daito are directly connected and switched to mechanical transmission, engine torque fluctuations are directly transmitted to the power transmission system, especially when
During deceleration, etc., there is a drawback that the accompanying thrust is transmitted and the ride quality deteriorates, but in the above configuration, the operating range after the so-called "clutch point" of the fluid torque converter is While power is transmitted through direct connection, the above-mentioned drawbacks can be eliminated by automatically releasing the piston hydraulic pressure and switching to fluid transmission during continuous or coasting.

[Problem that the invention seeks to solve]

However, in the conventional proposal example as in item -h, when sudden deceleration or coasting occurs during direct drive in the operating range above the clutch point of the torque converter, the accompanying impact can be alleviated as described above. However, in general, ideally, when the lock-up clutch is directly connected, it is desirable to have the ability to alleviate the impact γ in any case.Moreover, slipping of the lock-up clutch at high speeds is caused by heat generation/seizure, etc. Therefore, the present invention attempts to achieve the above object by configuring the lock-up clutch to vary its engagement force in accordance with the vehicle speed.

[Means for solving problems]

Therefore, in the present invention, a pressure regulating valve for regulating the hydraulic pressure supplied to the lock-up clutch actuating piston in accordance with heavy speed, and an output hydraulic pressure thereof, are provided at a predetermined i.
The above objective is achieved by providing an on/off valve for supplying or cutting off the lock-up clutch depending on the l-speed value.

[Effect]

With the configuration described below, the lock-up clutch of the torque converter is turned on/off according to a predetermined operating speed value, and when the lock-up clutch is in the on state,
Appropriate holding pressure is always supplied according to the jl speed, so
Normally, it performs a direct connection function at all speeds, and at the same time, when it receives a large impact at low speeds, it temporarily slips to alleviate the impact, and when the speed exceeds a predetermined speed, it is completely connected without slipping. It is possible to maintain a lock-up state and prevent heat generation and damage due to slipping.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A lock-up clutch control device according to the present invention will be described below based on embodiments.

FIG. 1 shows an overall system diagram of an automatic automatic transmission equipped with an embodiment of a lock-up clutch control device according to the present invention. In the figure, 1) Same as in Figure 2.3 from 1 (
Components (equivalent) are indicated by the same reference numerals, and duplicate explanations will be omitted.

(1 scene configuration) In the figure, 2 is a torque comparator with a built-in lock-up clutch 2a, P+/P2 are drive side/driven side pulleys, P is a surf mechanism for operating each movable pulley of both boars, T is a manual operation, Q is a 7111 pressure control valve, G is a vehicle speed governor valve, and S is a pressure regulating valve S according to the present invention, which will be described later.
, and an on/off valve S2.

Hydraulic pressure to the external system is supplied from the working reservoir 30 to the hydraulic pump 31.
A line pressure is supplied so that it is pumped by. p
6 is the output governor pressure from the heavy speed governor fr-G due to the centrifugal force of the three fly weights and the equilibrium effect with each spring, and PR is the output governor pressure from the torque controller 2 to the check valve P32.
Hydraulic lines are shown returning to reservoir 30 via cooler 33.

Further, the surf mechanism P is operated via the throttle signal lever 34, and the hydraulic control j? Q is actuated by the movement of the gear ratio detection lever 35 and the torque detection lever 36, respectively, and the balance of their respective built-in springs.

Since the configuration/operation of each mechanism described above is already known, detailed explanation will be omitted.

(Configuration of lock-up clutch control device) Next, the lock-up clutch control device S according to the present invention will be explained.

The pressure regulating valve S has a spool 40 that can slide in the axial direction within the L1 diameter that defines each hydraulic passage within the valve body, an oil chamber 41 is formed at the right end in the figure, and the spool 40 It is biased to the left in the figure by a spring 42 with a predetermined elastic force. The hydraulic oil is introduced into the oil chamber 41 from the 1i speed governor valve G at a governor pressure ρ6 corresponding to heavy speed. In a part of the spool 40, the runt part is slightly narrowed and has a small gap so that an orifice part 43 that narrows the space between the spool 40 and the inner diameter is formed. The oil passage 44 in the caliber of the valve body is a return passage communicating with the reservoir 30.

On the other hand, the on/off valve S2 has a compression coil spring 46 in the valve body diameter, which has oil passages communicating with the pressure regulating valve SI and the lock-up clutch of the torque converter 2, respectively.
The spool 45 has a spool 45 that is elastically biased to the right in the axial direction in the drawing. The illustrated spool 45 is cut above/below the axial centerline to indicate the top/bottom or off/on positions, respectively.

(Operation) Line pressure PL conduit from hydraulic control valve Q to pressure regulating valve S
Line pressure PL introduced from the illustrated main body passage No. 1 and governor pressure P introduced into the oil chamber 41 on the right side of the valve. The pressure difference causes the spool 40 to move to a position in equilibrium with the force of the spring 42.

Depending on the displacement, part of the line pressure flows back to the reservoir 30 via the orifice portion 43 and the passage 44. - On the other hand, when the spool 45 of the on/off valve reaches a preset vehicle speed value (for example, 15 m/h) due to the balance between the pressure drop, the governor pressure Pa, and the elastic force of the spring 46,
The spool 45 is moved to the left in the figure, and the pressure is supplied to and/or cut off from the hydraulic chamber behind the piston 2b of the lock-up clutch 2a of the torque converter 2 through the passage 47 and Aa.

As a result of the above operation, while the on/off valve S2 of the governor pressure p6 is on, the engagement pressure of the lock-up clutch 2a is always a predetermined pressure proportional to the vehicle speed. This can be alleviated by the slippage, and can also be prevented from slipping at high speeds higher than a predetermined speed.

In the above embodiments, (1) an example of an automobile equipped with a belt-type continuously variable transmission has been described; however, it goes without saying that the principles of the invention are not limited thereto;

〔Effect of the invention〕

As explained above, according to the present invention, when a predetermined vehicle speed is reached, hydraulic pressure corresponding to the vehicle speed is supplied to the lock-up clutch with a built-in fluid torque converter, so that when the clutch is directly engaged, the lock-up clutch has a built-in hydraulic torque converter. In addition to improving mechanical efficiency and fuel consumption, it has also become possible to reduce impact at low speeds through temporary slipping, and to prevent damage due to slipping at high speeds.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram of an automobile speed system equipped with an embodiment of a lock-up clutch control device according to the present invention, and FIG. 2 is a diagram of a conventional torque converter with a built-in lock-up clutch to which the present invention can be applied. FIG. 3, which is an explanatory view of the overall configuration of an example of a power transmission system for a motorized vehicle, is a cross-sectional view of a main part of the torque converter. 2...Fluid torque converter 2a...
・Lock-up clutch 8b...Piston R...Wedge roller 47...Oil passage PL...Line pressure Pa""...Governor pressure G -- --- Heavy speed governor valve S...Lock-up clutch control device S1...
...Pressure regulating valve S2 ---On/off valve

Claims (1)

[Claims] In a belt-type continuously variable transmission for a vehicle, which receives input via a fluid torque converter with a built-in lock-up clutch, a pressure regulating valve for regulating the operating hydraulic pressure of the lock-up clutch in accordance with the traveling speed of the vehicle; A control device for a lock-up clutch with a built-in torque converter, comprising an on/off valve for supplying or cutting off hydraulic pressure to the lock-up clutch in response to a predetermined vehicle speed value.