KR100196803B1 - Cvt for a vehicle - Google Patents

Abstract

The present invention provides a continuously variable transmission for a vehicle, which is capable of providing various driving modes with a continuously variable speed by setting a low speed and a high speed stage and improving initial acceleration acceleration performance by a low speed stage. The present invention is characterized by comprising oscillating means for transmitting rotational power output from an engine to a first axis; A second planetary gear set including a first planetary gear set, a second planetary gear set, a second planetary gear set, a second planetary gear set, and a second planetary gear set; A continuously variable transmission disposed between an output end of the transmission means and a second shaft disposed at a predetermined distance below the transmission means and transmitted from the transmission means to the second shaft, Means; A longitudinal deceleration means for vertically decelerating a rotational power transmitted from the continuously-variable transmission means and distributing power to the front wheel drive wheels through a differential mechanism; The present invention provides a vehicular stepless speed change device comprising:

Description

Continuously variable transmission for vehicles

FIG. 1 is a configuration diagram of a first embodiment according to the present invention; FIG.

FIG. 2 is a configuration diagram showing one embodiment of the continuously-variable transmission means applied to the present invention. FIG.

FIG. 3 is an operation table of the friction element applied to the present invention. FIG.

FIG. 4 is a diagram for explaining the shifting process of the present invention by a lever analysis method; FIG.

FIG. 5 is a configuration diagram of a second embodiment according to the present invention. FIG.

FIG. 6 is a configuration diagram of a third embodiment according to the present invention. FIG.

FIG. 7 is a configuration diagram of a fourth embodiment according to the present invention. FIG.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission for a vehicle and, more particularly, to a continuously variable transmission for a vehicle which provides various traveling modes with a continuously variable transmission by setting a low speed and a high speed, .

The transmission of the vehicle has a function of transmitting the driving force of the engine to the drive wheels. The transmission includes a manual transmission device for directly selecting a transmission according to the driver's preference, an automatic transmission for automatically shifting in accordance with the driving conditions of the vehicle And a step-variable shifting device in which continuously variable shifting is performed without any specific shifting region between each gear range.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a continuously variable transmission having an advantage in fuel economy, power transmission performance, and weight by complementing the disadvantage of an automatic transmission using hydraulic pressure.

In forming the continuously variable transmission, conventionally, a continuously variable transmission means using a belt and a pulley having a variable diameter is usually used. This is accomplished by one or two continuously-variable shifting means.

However, in the continuously-variable transmission as described above, there is a limit in realizing the required transmission ratio at the initial stage of the oscillation, so that the initial oscillation performance and the acceleration performance are poor and are not practically used.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide various traveling modes with a continuously variable transmission by setting a low speed and a high speed, The present invention provides a continuously variable transmission for a vehicle.

In order to achieve the above object, the present invention is characterized by comprising: oscillating means for transmitting rotational power output from an engine to a first axis; A second planetary gear set including a first planetary gear set, a second planetary gear set, a second planetary gear set, a second planetary gear set, and a second planetary gear set; A shifting means for shifting the shifting means; Continuously-variable transmission means disposed between an output end of the transmission means and a second shaft disposed at a predetermined distance thereunder, for transmitting a rotational power transmitted from the transmission means to the second shaft; A longitudinal deceleration means for vertically decelerating a rotational power transmitted from the continuously-variable transmission means and distributing power to the front wheel drive wheels through a differential mechanism; The present invention provides a vehicular continuously variable transmission including a continuously variable transmission.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of a first embodiment according to the present invention, which shows an example in which the torque converter 4 is applied to the oscillation means 2.

The torque converter (4) includes a pump impeller (8) rotating directly on the crankshaft of the engine (6); A turbine runner 10 disposed opposite to the pump impeller 8 and rotated together by the oil to be jetted; And a stator 12 disposed between the pump impeller 8 and the turbine runner 10 to change the flow of the oil to increase the rotational force of the pump impeller 8.

Accordingly, when the engine rotates, the oil filled in the torque converter 4 is ejected from the pump impeller 8 and supplied to the turbine runner 10 to drive the turbine runner 10, and then flows into the stator 12 do.

The oil introduced into the stator 12 changes its direction and then flows into the pump impeller 8 repeatedly. At this time, the turbine runner (stator) 12, which is shared by the stator 12 by the rotation of the stator 12 10 and the rotational force of the pump, so that the torque conversion is performed.

The rotational power output through the oscillating means 2 is controlled by the transmission means 16 disposed on the first shaft 14 in accordance with the driver's will.

The transmission means 16 of this type is composed of a complex planetary gear set so as to control the forward two-speed and reverse one-stage speed change stages.

The complex planetary gear set consists of a first single pinion planetary gear set 18 and a second single pinion planetary gear set 20.

The first shaft 16 integrally formed with the sun gear 22 of the first single pinion planetary gear set 18 is configured such that the rear portion thereof is connected to the sun gear 34 of the second single pinion planetary gear set 20, Respectively.

The ring gear 26 of the first single pinion planetary gear set 10 is connected to the transmission housing 28 via a first friction element 30 and is connected to the first shaft 14 via a second friction element 30, Elements 32 are internally connected.

So that the ring gear 26 thereof selectively acts as a reaction force element and an input element.

The carrier 34 of the first single pinion planetary gear set 18 is connected to the ring gear 38 of the second single pinion planetary gear set 20 through the connecting member 36, The member 35 is connected to the transmission housing 28 through the third friction element 40 and the carrier 42 of the second single pinion planetary gear set 20 acts as an output element.

With the above-described configuration, the rotational power of the engine 6 is input to the continuously-variable transmission means 16 via the torque converter 4 to maintain the idling state in the neutral state.

In this state, the forward and backward shifting process will be described with reference to FIGS. 3 and 4.

4 is a diagram illustrating a lever analysis method for visually analyzing the operation of the complex planetary gear set. The first node N1 is connected to the sun gear 22 of the first and second single pinion planetary gear sets 18 The second node N2 is connected to the carrier 34 of the first pinion planetary gear set 18 and the ring gear 38 of the second single pinion planetary gear set 20, The carrier N2 of the second single pinion planetary gear set 20 and the fourth node N4 of the first single pinion planetary gear set 20 are indicated by the symbol N3 and the ring gear 26 of the first single pinion planetary gear set 20, respectively.

The setting of the node as described above is established by the connection relationship of the both single pinion planetary gear sets 18 and 20, and is known.

When the driver selects the select lever as the D range for the forward travel under the above-described precondition, the transmission control unit activates the first friction element 30.

Then, the rotational power of the engine is input through the sun gears 22 and 24 of the first and second single pinion planetary gear sets 18 and 20, and by the operation of the first friction element 30, The first speed change is achieved while the ring gear 26 of the single pinion planetary gear set 18 acts as a reaction force element.

That is, as shown in FIG. 4, the fourth node N4 acts as a reaction force element in a state in which the input is made to the speed input line of the first node N1. The straight line L1 interconnects the fourth node N4, The line connecting the third node N3 acting as the output element closest to the third node N3 becomes the low speed line D1.

If the output is made relatively smaller than the input, the rotational power thus shifted will be continuously changed by the continuously-variable shifting means described later.

When the throttle opening angle and the vehicle speed increase during the forward low-speed running, the transmission control unit releases the operation of the first friction element 30 and controls the operation of the second friction element 32. [

The input is made through the sun gear 22 of the first single pinion planetary gear set 18 and the sun gear 24 of the second single pinion planetary gear set 20 and the first single pinion planetary gear set 18 are input to the ring gear 26. [

As shown in FIG. 4, when the speed input line of the first node N1 and the speed input line of the fourth node N4 are connected to each other, as shown in FIG. 4, The line connecting the straight line L2 interconnecting the input speed lines and the third node N3 serving as the output element closest to each other becomes the high speed line D2.

This results in the same input and output, and the rotational power that is shifted in this way is the continuously variable transmission described later.

When the selector lever is set to the R range, the transmission control unit operates the third friction element (40).

Then, the rotational power of the engine is inputted through the sun gears 22 and 24 of the first and second single pinion planetary gear sets 18 and 20, , And the carrier 32 and the ring gear 38 of the two single pinion planetary gear set 18 (20) act as reaction elements.

That is, as shown in FIG. 4, the second node N2 acts as a reaction force element in a state in which the input is made to the speed input line of the first node N1. The straight line L3 interconnecting them, And the line connecting the third node N3 closest to the third node N3 acting as the output element is the reverse speed line R1.

Therefore, the output is made in the opposite direction to the input, so that the backward travel becomes possible.

In the transmission 16 of the present invention as described above, the outputs of the forward second stage and the reverse first stage are performed.

As described above, the rotational power that is shifted by the transmission 16 is subjected to the continuously-variable shifting by the continuously-variable shifting means 44. [

The continuously-variable shifting means 44 includes a carrier 42 forming an output end of the complex planetary gear set, and a second shaft 46 disposed on the lower side of the first shaft 14 at a predetermined interval in parallel with the second shaft 46 Driven and driven pulleys (48) and (50) having diameters displaced by hydraulic pressure, and a belt (52) for interconnecting the pulleys.

In the above, the drive and driven pulleys 38 and 40 cause the continuously variable shifting to be performed by a change in diameter, and the second and third embodiments show the construction of the embodiment.

The drive pulley 48 is composed of a fixed side sheave 54 and a variable side sheave 56. The fixed side sheave 54 is formed integrally with the carrier 42 and has a variable side sheave 56 are coupled on the carrier 42 so as to be movable left and right.

A casing member 58 is provided on the side of the variable side sheave 56 and a hydraulic chamber 60 is formed between the casing member 58 and the hydraulic chamber 60. The hydraulic chamber 60 is connected to the engine 42 through a flow path 62 formed in the carrier 42, So that the pressure fluid can be supplied.

The stationary sheave 64 and the variable-side sheave 66 are formed integrally with the second shaft 46, and the stationary sheave 64 and the variable- The variable-side sheave 66 is coupled to the second shaft 46 so as to be movable left and right.

A casing member 68 is interposed in the variable side sheave 66 and forms a hydraulic chamber 70. The hydraulic chamber 70 is connected to the variable shaft sheave 66 through a flow path 72 formed in the second shaft 46 So that the pressure fluid generated by the driving force of the engine can be supplied.

When the rotational power output from the transmission means 16 is transmitted to the continuously-variable transmission means 44, the second shaft 46 is driven while the continuously-variable shifting is performed. At this time, the drive pulley 38 and the driven pulley 40, The shifting is performed in accordance with the change of the outer diameter of the clutch.

The rotational speed change conditions are as follows: first, when the outer diameters of the drive pulley 38 and the driven pulley 40 are the same, when the outer diameter of the second drive pulley 38 is larger than the diameter of the driven pulley 40, And the case where the diameter of the drive pulley 38 is smaller than the diameter of the driven pulley 40 can be considered.

Under the first condition, when the driving and driven pulleys 38 and 40 have the same outer diameter, the transmission ratio is 1: 1.

Secondly, when the outer diameter of the drive pulley 38 is larger than the diameter of the driven pulley 40, the rotation speed of the driven pulley 40 becomes larger than the rotation number of the drive pulley 38, When the outer diameter of the driven pulley 30 is smaller than the diameter of the driven pulley 40, the rotation speed of the drive pulley 38 becomes smaller than that of the driven pulley 40, so that the deceleration is performed.

With this operation, the shift range is gradually shifted from the starting point to the high speed running speed without the gear stage.

The rotational power for which the continuously-variable shifting is performed is transmitted to the longitudinal decelerating means 74. The longitudinal decelerating means 74 includes an output gear 76 disposed on the second shaft 46, A transfer shaft 80 disposed in parallel with the output gear 76 and being engaged with the output gear 76 on the rear side thereof and a front end gear 82 of the transfer shaft 80, And a differential mechanism 90 for distributing the rotational power input to the ring gear 84 to the both-wheel drive shafts 86 and 88 while performing a differential action according to a load applied to the both-wheel drive shafts 86 and 88 .

Accordingly, the front wheel can be driven by the rotational power output through the second shaft 46.

As described above, according to the present invention, in the state where the primary speed change is performed in the speed change unit 16, the continuously-variable shifting unit 44 changes the speed from low speed to high speed and provides various driving modes.

Since the reduction ratio can be largely realized at a low speed, the initial oscillation and acceleration performance can be greatly improved.

5 shows a second embodiment according to the present invention. In the first embodiment, the oscillation means 2 is formed by a local damper 100, and its operation and effect are the same as those of the first embodiment .

6 and 7 show the third and fourth embodiments according to the present invention. In the first and second embodiments, the continuously-variable transmission means 16 is disposed on the second shaft 46, In the first and second embodiments, the position of the continuously-variable transmission mechanism 16 is shifted, and the operation and effect of the second embodiment are the same as those of the first and second embodiments.

As described above, according to the present invention, it is possible to provide a variety of running modes with a continuously variable shifting by setting low and high speed stages, and to improve initial acceleration acceleration performance by a low speed.

Claims (3)

Oscillation means for transmitting the rotational power output from the engine to the first axis; A second planetary gear set including a first planetary gear set, a second planetary gear set, a second planetary gear set, a second planetary gear set, and a second planetary gear set; A shifting means for shifting the shifting means; Continuously-variable transmission means disposed between an output end of the transmission means and a second shaft disposed at a predetermined distance thereunder, for transmitting a rotational power transmitted from the transmission means to the second shaft; A longitudinal deceleration means for vertically decelerating a rotational power transmitted from the continuously-variable transmission means and distributing power to the front wheel drive wheels through a differential mechanism; And a continuously variable transmission for a vehicle. The planetary gear set according to claim 1, wherein the first planetary gear set is integrally formed with the sun gear of the first single pinion planetary gear set, the first shaft integrally connects the sun gear of the second single pinion planetary gear set, The ring gear of the single pinion planetary gear set selectively acts on the reaction force and the input element by the operation of the first and second friction elements and the carrier of the first single pinion planetary gear set is engaged with the second single pinion gear, Wherein the carrier of the second single pinion planetary gearset is formed to be able to act as an output element, the ring gear of the second single pinion planetary gear set being selectively connected to the ring gear of the planetary gear set and acting as a reaction force element by operation of the third friction element. Continuously variable transmission. 4. The vehicular stepless transmission of claim 3, wherein the first and third friction elements use a band brake as a brake means and the second friction element uses a multi-plate clutch as a clutch means.