JPS587860B2 - Shiariyouyoujidou Hensokuki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic transmission for a vehicle, and more particularly to an automatic transmission for a vehicle equipped with a fluid transmission mechanism with a direct coupling clutch.

A torque converter is generally used as a fluid transmission mechanism in automatic transmissions for vehicles, and the torque converter includes a pump connected to the engine output shaft, a turbine connected to the gear transmission, and a pump connected to the turbine. It consists of a stator that converts torque appropriately by deflecting the flow of fluid returning to the engine, and generates rotational power while converting torque appropriately according to the rotational speed difference between the engine output shaft and the input shaft of the gear transmission. The transmitter is configured to communicate via fluid motion.

In such a torque converter, even in a transmission state where the turbine rotational speed is closest to the pump rotational speed, there is inevitably slippage between the pump and the turbine, so a direct coupling transmission mechanism using a mechanical clutch is required. The power transmission efficiency decreases compared to
There is a problem in that it brings considerable disadvantages from the viewpoint of resource conservation and exhaust gas purification measures.

To deal with this problem, we installed a direct drive section using a hydraulically operated friction clutch in parallel with the fluid drive section using the torque converter, and selectively activated the friction clutch depending on the driving condition of the vehicle to take advantage of the advantages of both. A fluid transmission mechanism with a direct coupling clutch has already been proposed.

One basic structure of such a fluid transmission mechanism with a direct coupling clutch is known as proposed in US Pat. No. 3,338,3585.

This U.S. patented fluid transmission mechanism with a direct coupling clutch is
The input shaft connected to the engine output shaft and the output shaft connected to the speed change input shaft of the gear transmission are configured to be directly mechanically connected by a friction clutch, and the operating state does not require an increase in torque. At the same time, the friction clutch is engaged as much as possible to avoid power loss due to the torque converter, and at the same time, the friction clutch is temporarily released when changing various gears, and the torque fluctuation caused by gear transmission switching is reduced to torque. This is absorbed by the converter to achieve smooth gear shifting.

However, in this structure, since the friction clutch is configured to directly connect the input shaft and output shaft of the fluid transmission mechanism, that is, the speed change input shaft of the gear transmission, even when the friction clutch is in the directly connected state, the gear speed change Engagement mechanisms such as clutches and brakes must be operated in a predetermined combination in order to achieve the required gear shift meshing of the device, and the hydraulic pressure supplied to such engagement mechanisms must be simultaneously supplied at a predetermined pressure. and must be controlled.

Therefore, the present invention eliminates the need to operate the engagement mechanism of the gear transmission when the direct coupling clutch is activated, and eliminates the need to control the hydraulic pressure to the engagement mechanism, thereby reducing transmission loss due to the torque converter. An object of the present invention is to provide an automatic transmission for a vehicle equipped with an improved torque converter with a direct coupling clutch that can reduce pump loss of a hydraulic system.

According to the present invention, the present invention provides a fluid transmission mechanism that fluidly connects an input shaft and an output shaft; In an automatic transmission for a vehicle equipped with a gear transmission that outputs the rotation shifted at one gear selected from among the gears from a gear output shaft, the input shaft of the fluid transmission mechanism and the gear shift This is achieved by an automatic transmission for a vehicle, which is characterized by being equipped with a direct coupling clutch device that selectively connects directly to a speed change output shaft of the device.

According to this configuration, the direct coupling clutch is controlled to operate particularly in the high speed range where the gear ratio of the gear transmission is 1, for example, the third speed range, and the input shaft of the fluid transmission mechanism,
In other words, if the engine output shaft and the transmission output shaft of the gear transmission are directly connected, the speed difference between the input shaft and the output shaft when the direct coupling clutch is engaged will be reduced by a small slippage during high-speed, low-torque operation of the torque converter. As the direct coupling clutch is engaged smoothly, the engine output is directly transmitted to the gear output shaft of the gear transmission without going through the fluid transmission mechanism or gear transmission mechanism. This not only avoids transmission loss due to slippage between the pump and turbine in the fluid transmission mechanism, but also eliminates the need to operate the engagement device of the gear transmission. There is no need to control the hydraulic pressure to.

Therefore, when the direct coupling clutch is operated, it is no longer necessary to maintain the line hydraulic pressure of the hydraulic circuit device for operating each engagement device of the gear transmission at a predetermined hydraulic pressure, and as a result, the load on the oil pump is reduced. Engine horsepower loss due to the oil pump is reduced.

By thus avoiding and reducing the transmission loss due to the fluid transmission mechanism and the horsepower loss due to the oil pump, the fuel consumption rate of the automobile is improved, and due to the improved fuel consumption rate, the exhaust gas characteristics are also improved.

However, in automatic transmissions for vehicles that have a torque converter with a direct coupling clutch, the direct coupling clutch is generally engaged when the gear transmission mechanism is set to the highest speed gear. When the vehicle is driven smoothly even without the torque buffering effect of the torque converter, such as when the vehicle is being operated at a relatively high speed above a certain predetermined speed, Even when the gear transmission mechanism is set to the optimum speed stage, when the vehicle speed is relatively low and does not reach the predetermined speed, the direct clutch is released and the torque converter is made to exert its torque buffering ability. things are being done.

Therefore, as mentioned above, releasing the supply of hydraulic pressure to each engagement device of the gear transmission is only permitted while the direct coupling clutch is engaged, and depending on the driving condition of the vehicle, the direct coupling clutch may be released. the gear transmission mechanism to the highest speed,
That is, when operating at a gear ratio of 1, a predetermined hydraulic pressure must of course be supplied to the engagement device of the gear transmission mechanism for achieving the gear ratio of 1.

It is already known in various configurations to control the on/off of a direct coupling clutch depending on the driving state of the vehicle.

According to the configuration of the present invention, the direct coupling state can only be achieved when the gear ratio is 1, for example, in the third gear, but the frequency of use of the third gear (direct coupling state) in general driving is extremely high. This ratio is high (usually 60%) and makes a large contribution to improving the fuel consumption rate as described above.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

The figure is a schematic diagram showing a combination of a fluid transmission mechanism with a direct coupling clutch and a gear transmission according to the present invention.

In the figure, a fluid transmission mechanism with a direct coupling clutch, generally indicated at 1, has a housing 3 that is rotationally driven around the axis by an output shaft 2 of an engine located in front of it (on the left side in the figure). It is equipped with

This housing houses the main part of the fluid transmission mechanism with a direct coupling clutch, and also constitutes the main transmission element, that is, the front part of the housing houses a cylinder for the direct coupling clutch (lockup clutch). 4, and at the rear thereof a pump housing 7 constituting a pump 6 of a hydraulic torque converter, generally indicated at 5.

The torque converter 5 includes a turbine 8 driven by the pump 6 and a stator 9 that gives the necessary deflection to the fluid exiting the turbine and returns it to the pump 6. Furthermore, the stator 9 is supported by a sleeve 12 concentric with the hollow output shaft 10 via a one-way clutch 11.

The sleeve 12 is also fixedly supported by an outer fixed housing 13, as shown diagrammatically in the figures.

Further, the torque converter 5 is configured to be supplied with working fluid from a pump inlet space 15 communicating with the oil passage 14a, and the working fluid supplied to the pump inlet space is supplied to the pump 6, the turbine 8, The oil is introduced into the annular flow path around the stator 9 and is shown to be returned from the turbine outlet space 16 to the drain oil path 14b.

A piston disk 17 is disposed slidably in the axial direction in the cylinder 4 defined at the front part of the housing 3, and the front side of the cylinder 4 divided by the piston disk 17 (on the left side in the figure) A predetermined hydraulic pressure is supplied to the pressure chamber located in the pressure chamber from a hydraulic circuit device (not shown) through a fluid passage 18 only during high-speed operation such as during third speed.

Further, an annular clutch element 19 protruding radially inward from the inner circumferential surface of the housing 3 is provided at a portion located on the rear side (on the right side in the figure) of the cylinder chamber 4 partitioned by the piston disk 17. A clutch disc 20 is provided between this and the piston disc 17 and has a peripheral edge that overlaps the annular clutch element 19.

The clutch disc 20 is fixed with respect to the rotational direction by a spline or the like to the front end of a speed change output shaft 23 of a planetary gear transmission 22, which will be described later, which extends through the hollow part of the hollow output shaft 10 to the fluid transmission mechanism part. Supported.

Specifically, the clutch disc 20 includes an outer peripheral portion 20a overlapping the annular clutch element 19 and the speed change output shaft 2.
3 and a central hub portion 20b supported by a plurality of compression coil springs 20b extending along the circumferential direction.
1, which provides a buffering effect on the path through which the rotational power transmitted to the outer peripheral portion 20a of the clutch disc is transmitted to the transmission output shaft 23,
It is designed to soften the impact when the clutch is activated.

Next, the planetary gear transmission 22 will be explained.

The hollow output shaft 10 of the fluid transmission mechanism 1 serves as an input shaft of a planetary gear transmission 22, and is directly connected to an input member of a first clutch 24 that operates a subsequent planetary gear train in a predetermined combination. ing.

The output member of the first clutch 24 is carried by an internal rotating housing 25, which in turn carries a first link gear 26.

A first planetary pinion 28 supported by a carrier 27 supported by the speed change output shaft 23 meshes with the first link gear 26 .

The speed change output shaft 23 carries a second link gear 30 via a ring gear supporting element 29, and the second link gear is supported by a one-way clutch 31 so as to be rotatable in only one direction. A second planetary pinion 33 carried by one carrier 32 is engaged.

Sangyas 34 and 35 that mesh with those of the first and second planetary pinions 28 and 33 are mounted so as to be rotatable concentrically with the speed change output shaft 23 together with an external rotary housing 36 integral therewith.

The input member of the first clutch 24 also serves as the input member of the second clutch 37), and the output member of the second clutch 37 is integrally formed with the external rotating housing 36. .

The rotation of the carrier 32 is selectively braked by a first brake 38, and the rotation of the external rotating housing 36 is selectively controlled by the operation of a second brake 39. It looks like this.

The planetary gear transmission having the above configuration operates as follows.

D range, first speed...The first clutch 24 is engaged.

As a result, the rotation (clockwise rotation) is transmitted to the first link gear 26 via the internal rotation housing 25, and drives the first planetary pinion 28 to the right.

As a result, the sun gear 34 that meshes with the first planetary pinion 28 receives a rotational force in the left direction, and the rotational force is transmitted to the second planetary pinion 33 via the other sun gear 35, so that the second planetary pinion And the carrier 32 carrying this is about to be rotated to the left.

However, since such rotation is prevented by the action of the one-way clutch 31, the carrier 27 is driven rightward and the speed change output shaft 23 is rotationally driven rightward.

D range, second speed: Output shaft 10 in which the first clutch 24 is engaged and the second brake 39 is also operated.
The zero rotation is transmitted to the first link gear 26 via the internal rotating housing 25, driving the first planetary binion 28 to the right.

However, at this time, the external rotary housing 36 carrying the sangyas 34 and 35 is prevented from rotating by the second brake 39.
As a result, the first planetary pinion 28 is rotationally driven around the sun gear 34, and accordingly, the carrier 27 carrying the first planetary pinion 28 and the speed change output shaft 23 integrated therewith are rotated. Driven to the right.

D range, third speed...The first clutch 24 and the second clutch 37 are engaged.

Therefore, the internal rotating housing 25 and the sun gear 34 or the external rotating housing 36 rotate together, the planetary gear train does not substantially operate, and the carrier 27 and the speed change output shaft 23 are the output of the hydrodynamic transmission mechanism 1. It is driven to the right together with the shaft without being decelerated.

R (reverse) range: the second clutch 37 is engaged, and the first brake 38 is also operated.

The clockwise rotation of the output shaft 10 is transmitted to the sun gear 35 through the external rotary housing 36, causing the second planetary pinion 33 as a whole to rotate clockwise around the sun gear 35.

However, since its rotation is prevented by the first brake 38, the second planetary pinion 33 is rotated to the left around its axis, and thereby the second planetary pinion 33 is rotated to the left through the second link gear 30. The ring gear carrying element 29 and the speed change output shaft 23 are rotated to the left.

S (second) range, fourth speed: the first clutch 24 is engaged and the first brake 38 is operated.

At this time, when the engine is driving, in which the driving force is transmitted from the output shaft 10 to the shift output shaft 23, it is exactly the same as when in D range and 1st speed. During so-called engine braking, when the output shaft 10 is driven, the one-way clutch 31 slips and no power is transmitted; however, in this range, the driving force is transmitted from the variable speed output shaft 23 to the output shaft 10. This is different from the D range and 1st speed in the way it is carried out.

S range, second speed...The first clutch 24 is engaged and the second brake 39 is operated.

Therefore, this case is exactly the same as the D position and second speed.

L (fixed to 1st forward speed) range: In this range, the operating state of the clutch and brake is S range, 1st
It is exactly the same as speed.

Now, when the gear transmission device 22 described above and the fluid transmission mechanism 1 with a direct coupling clutch are combined to actually operate the device of the present invention, the operating state in which fluid transmission by the torque converter 5 is to be performed, that is, the D range. In operating states other than the third speed, a predetermined amount of working fluid flow is maintained within the torque converter, ensuring normal operation of the torque converter.

Therefore, the rotation of the output shaft 2 of the engine is transmitted to the output shaft 10 through the torque converter, and the rotation of the output shaft 2 of the engine is transmitted to the output shaft 10 through the torque converter, and the rotation is transmitted to the output shaft 10 through the torque converter, and the rotation is transmitted to the output shaft 10 as required by the planetary gear train of the planetary gear transmission 22, in which a predetermined gear shift mesh is achieved by each of the clutches and brakes. After being shifted at a gear ratio of , the transmission is transmitted to the gear output shaft 23 .

At this time, the piston disk of the fluid transmission mechanism 1 is in a non-operating state, and the outer peripheral surface of the clutch disk 2 is in a state where it can freely slide on the annular clutch element 19. Power is not directly transmitted to the speed change output shaft 23 via.

On the other hand, in the D range and third speed, when the vehicle is in a driving state that allows the direct coupling clutch to be engaged and the direct coupling clutch is engaged, working fluid is supplied from the fluid passage 18 into the cylinder 4. Then, the clutch piston 17 is deflected to the right in the figure, thereby pressing the outer peripheral portion of the clutch disc 20 against the annular clutch element 19 with a predetermined pressing force.

As a result, an engaged state is achieved between the annular clutch element 19 and the clutch disc 29 due to friction between the two, and the rotational force transmitted from the output shaft 2 of the engine to the housing 3 is transferred directly from the annular clutch element 19 to the clutch disc. 20 and is directly transmitted to the speed change output shaft 23.

Therefore, at this time, there is no need to supply working fluid to the torque converter 5 to operate it, and it is also necessary to operate each clutch and brake of the planetary gear transmission 22 in the above-mentioned combination to achieve a predetermined gear shift mesh. do not have.

In this way, when the vehicle is being driven with the direct coupling clutch engaged, when the direct coupling clutch should be released due to a change in the operating condition of the vehicle, the supply of working fluid to the cylinder 4 is released. At the same time, or preferably prior to that, the supply of hydraulic pressure to each clutch and brake of the torque converter 5 and the planetary gear transmission 22 is restarted in accordance with the operating state at that time.

It should be noted that appropriately controlling the supply of hydraulic pressure in accordance with the operating condition of the vehicle in this way is not within the scope of the present invention, and may be implemented in various ways within the range known in this field. This is something that can be done.

The table below summarizes an example of the operation combination of the direct coupling clutch of the fluid transmission mechanism and the clutch and brake of the planetary gear transmission, as well as the speed ratio at each speed change.

As described above, according to the present invention, the engine output shaft and the speed change output shaft are selectively directly connected, and the torque converter and the gear transmission are bypassed, so that the torque converter and the gear transmission are connected during the direct coupling operation. There is no need to actuate any coupling device to achieve the variable speed mesh.

Although the present invention has been described in detail with respect to preferred embodiments above, the present invention is not limited to these embodiments, and various modifications and embodiments are possible within the scope of the present invention. will be clear to those skilled in the art.

[Brief explanation of drawings]

The figure is a schematic diagram showing an example of an automatic transmission for a vehicle that combines a fluid transmission mechanism with a direct coupling clutch and a planetary gear transmission mechanism according to the present invention. DESCRIPTION OF SYMBOLS 1... Fluid transmission mechanism, 2... Engine output axis meter... Housing, 4... Cylinder, 5... Torque converter, 6・・・・・・
・Pump, 7...Pump housing, 8...
...Turbine, 9...Stator, 10...
...Hollow output shaft, 11...One-way clutch,
12...Sleeve, 13...Fixed housing, 14a, 14b...Oil passage, 15...
... Pump inlet space, 16... Turbine outlet space, 17... Piston disk, 19...
... annular clutch element, 20 ... clutch disk, 22 ... planetary gear transmission, 23 ...
... Speed change output shaft, 24 ... First clutch, 25 ... Internal rotation housing, 26 ...
...First Link Gya, 27...Carya, 2
8...First planetary pinion, 29...
...Link gear carrying element, 30...Second link gear, 31...One-way clutch, 32...
...Carya, 33...Second planetary pinion, 34, 35...Sanghya, 36
......External rotating housing, 37...Second clutch, 38...First brake, 39
...Second brake.

Claims (1)

[Claims] 1 A fluid transmission mechanism that fluidly connects an input shaft and an output shaft, and a gear train that changes the rotation of the output shaft of the fluid transmission mechanism by a transmission gear train and selects one of a plurality of gear stages including a gear ratio of 1. In an automatic transmission for a vehicle equipped with a gear transmission that outputs the rotation changed in two gears from the transmission output shaft,
An automatic transmission for a vehicle, comprising a direct coupling clutch device that selectively directly couples an input shaft of the fluid transmission mechanism to a speed change output shaft of the gear transmission.