KR0154073B1 - Cvt for 4-wheel driving vehicle - Google Patents

Abstract

Although the planetary gear set is additionally installed, an object of the present invention is to provide a continuously variable transmission for a vehicle capable of simultaneously driving front and rear wheels.

A torsional damper capable of attenuating torsional vibration of rotational power output from the engine; A continuously variable transmission mechanism disposed at the rear end of the first shaft on which the torsional damper is mounted and on the front end of the second shaft arranged in the same axial direction on the first shaft thereof to continuously change the rotational power of the first shaft; A forward and backward control mechanism disposed on the second shaft which is formed of a double pinion planetary gear set and arranged in the same line and controls forward and backward by selective operation of a plurality of friction members; A start control mechanism disposed on the same axis direction at a predetermined interval from the second axis and disposed on a third axis that receives rotational power of the second axis by gear transmission to control power transmission; A front wheel drive shaft configured to receive a rotational force from the third shaft through the differential to drive the front wheel; A rear wheel drive mechanism capable of driving rear wheels by receiving power from the front wheel drive shaft; It provides a continuously variable transmission for a four-wheel drive vehicle comprising a.

Description

Stepless transmission for four-wheel drive vehicles

1 is a block diagram of a first embodiment according to the present invention.

2 is a block diagram of a pulley diameter displacement generating means applied to the present invention.

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

The present invention relates to a continuously variable transmission for a four-wheel drive vehicle, and more particularly to a continuously variable transmission for a four-wheel drive vehicle to improve the shifting feeling by applying a planetary gear set, and to drive the front and rear wheels at the same time.

The transmission of the vehicle has a function of transmitting the driving force of the engine to the driving wheels. The transmission includes a manual transmission in which the driver directly selects a shift stage at the driver's will, and automatically shifts according to the driving conditions of the vehicle. It is roughly classified into an automatic transmission and a continuously variable transmission in which continuously continuous shifts are made without a specific shift range between each shift stage.

In the above-described transmission, the present invention relates to a continuously variable transmission having great advantages in terms of fuel economy, power performance, and weight by compensating for the disadvantages of the automatic transmission using hydraulic pressure.

In forming such a continuously variable transmission, conventionally, a drive and driven pulley capable of varying the diameters of the input shaft and the output shaft are simply mounted, and the pulleys are connected to each other by belts, thereby allowing endless displacement to the opposite diameter displacement of the drive and driven pulleys. It is common to allow shifting.

In addition, in the continuously variable transmission as described above, no particular problem arises in performing the continuously variable transmission. However, these continuously variable transmissions are generally developed to drive only current or rear wheels. This implies that it is not applicable.

Accordingly, an object of the present invention is to provide a continuously variable transmission for a four-wheel drive vehicle in which a planetary gear set is additionally installed and the front and rear wheels can be driven simultaneously.

In order to realize this, the present invention includes a torsional damper capable of attenuating torsional vibration of rotational power output from the engine; A continuously variable transmission mechanism disposed at the rear end of the first shaft on which the torsional damper is mounted and on the front end of the second shaft arranged in the same axial direction on the first shaft thereof to continuously change the rotational power of the first shaft; A forward and backward control mechanism disposed on the second shaft which is formed of a double pinion planetary gear set and arranged in the same line and controls forward and backward by selective operation of a plurality of friction members; A start control mechanism disposed on the same axis direction at a predetermined interval from the second axis and disposed on a third axis receiving rotational power of the second axis by gear transmission to control power transmission; A front wheel drive shaft configured to receive a rotational force from the third shaft through the differential to drive the front wheel; A rear wheel drive mechanism capable of driving rear wheels by receiving power from the front wheel drive shaft; It is characterized by providing a continuously variable transmission for a four-wheel drive vehicle comprising a.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described in detail.

1 is a configuration diagram of a first embodiment according to the present invention, in which a torsional damper 6 is disposed on a first shaft 4 that receives power from an engine 2 to convert torque of rotational power output from an engine. The torsional vibration of the first shaft 4 is attenuated and output.

In addition, the continuously variable transmission mechanism 10 disposed at the rear end of the first shaft 4 and the second shaft 8 includes a driving pulley 12 disposed at the rear end of the first shaft 4, and the second shaft. It is composed of a driven pulley 16 disposed at the front end of the shaft 8 and connected to the drive pulley 12 and the belt 14.

The drive and driven pulleys 12 and 16 are designed to allow endless speed change by a change in diameter, and FIG. 2 shows a configuration of an embodiment for enabling it.

That is, the driving pulley 12 is composed of a fixed side pulley 18 and a variable side pulley 20, the fixed side pulley 18 is formed integrally with the first shaft 4, the variable side pulley 20 ) Is coupled to the ball spline 21 disposed at equal intervals on the shaft 4 so as to move left and right on the first shaft 4.

A casing member 22 is provided on the side of the variable side pulley 20 to form a hydraulic chamber 24 therebetween, and the hydraulic chamber 24 passes through a flow path 26 formed in the first shaft 4. The pressure fluid generated by the driving force of the engine can be supplied.

And the driven pulley 16 is composed of a fixed side pulley 28 and a variable side pulley 30 as described above, the fixed side pulley 28 is formed integrally with the second shaft 8, the variable side pulley 30 is coupled by a ball spline 31 to move left and right on the second axis 8.

The variable side pulley 30 has a casing member 32 interposed therebetween to form a hydraulic chamber 34, and the hydraulic chamber 34 has a driving force of the engine through a flow path 36 formed on the second shaft 8. The pressure fluid generated by the gas can be supplied.

In addition, in order to prevent slipping between the driving and driven pulleys 12 and 16 and the belt 14, an elastic member 35 in the hydraulic chamber 34 is provided so as to always be in contact.

Of course, the configuration of the drive and driven pulleys 12 and 16 is not limited to the above configuration and includes all that can be easily invented from the configuration.

The second shaft 8 is provided with a forward and backward control mechanism 38 consisting of a planetary gear set, and the forward and backward control mechanism 38 includes a planetary gear device having a double pinion.

In applying the forward and backward control mechanism 38, the second shaft 8 is formed of the first and second power transmission members 40 and 42 divided into the front and rear sides, and the sun gear 44 is formed as the second gear. The planetary carrier 50 formed integrally with the power transmission member 42 and interconnecting the first and second pinions 46 and 48 disposed at equal intervals on the outer circumference of the sun gear 44 has a front side part. 1 is connected to the power transmission member 40, the rear side is connected via the second power transmission member 42 and the first friction member 52.

In addition, the ring gear 54 in which the second pinion 48 is engaged with the inner ring is connected to the transmission housing 58 through the second friction member 56.

Accordingly, when the first friction member 52 is operated, the second shaft 8 is connected as a single body, so that forward driving can be performed. On the contrary, when the second friction member 56 is operated, the front side of the planet carrier 50 is operated. Becomes an input element, and outputs through the sun gear 44 while the ring gear 54 acts as a reaction force element, thereby driving backward.

In the above, the first friction member 52 may be a multi-plate clutch as a clutch means, and the second friction member 56 may be a brake plate, and a multi-plate clutch or a band brake may be used.

And the start control mechanism 64 disposed on the third shaft 62 receives power from the drive gear 60 formed at the rear end of the two shaft 8 is made of a multi-plate clutch as a clutch means, At the rear end and the front end of the third shaft 62, the driven gear 66 meshes with the drive gear 60, and the output gear 74 meshes with the ring gear 72 of the front wheel differential 68. Is formed.

Accordingly, when power is transmitted to the start control mechanism 64 of the third shaft 62, its rotational power is input through the ring gear 72 of the front wheel differential 68 to drive the front wheel and at the same time the rear wheel. Power transmission for driving is made.

The rear wheel drive mechanism 77 includes an idler shaft 80 that receives power from a gear 78 formed on the front wheel drive shaft 76, and a drive shaft 84 that receives power from the idler shaft 80 and transfers the power to the rear wheels. )

The idler shaft 80 is disposed in the same axial direction with a predetermined distance from the front wheel drive shaft 76, the gear 86 is meshed with the gear 78 of the front wheel drive shaft 76 on one side. On the other side, the bevel gear 88 is formed and engaged with the bevel gear 90 formed at the front end of the drive shaft 80 arranged in a direction orthogonal thereto.

In the continuously variable transmission of the present invention, when the engine 2 is started and power is transmitted to the first shaft 4 through the torsional damper 6, the rotational force of the first shaft 4 is continuously variable. By the operation of (10) the endless shift is made to drive the second shaft (8).

At this time, in the continuously variable transmission mechanism 10 is shifted by a change in the radius of contact with the belt 14 in accordance with the change in the outer diameter of the drive pulley 12 and the driven pulley 16, the rotation speed change condition, first, When the outer diameters of the driving pulley 12 and the driven pulley 16 are the same, the outer diameter of the second driving pulley 12 is larger than the diameter of the driven pulley 16, and the diameter of the third driving pulley 12 is driven. It can be considered to divide into a case smaller than the diameter of the pulley 16.

In the first condition, when the outer diameters of the driving and driven pulleys 12 and 16 are the same, the transmission ratio is 1: 1.

And secondly, if the outer diameter of the drive pulley 12 is larger than the diameter of the driven pulley 16, the speed of the driven pulley 16 is larger than the rotation speed of the drive pulley 12, so that the speed is increased, and the third drive pulley When the outer diameter of (12) becomes smaller than the diameter of the driven pulley 16, since the rotation speed of the drive pulley 12 becomes smaller than the rotation speed of the driven pulley 16, deceleration is made.

In this way, the driving range is gradually shifted from the starting point to the high speed without any gear stage division.

The change in the outer diameter of the drive pulley 12 and the driven pulley 16 is determined according to the hydraulic pressure supplied to the hydraulic chambers 24 and 34, and such hydraulic control is usually used in a continuously variable vehicle. Since it becomes possible to use the detailed description thereof will be omitted.

In addition, when the driven pulley 16 rotates due to the shift as described above, its rotational power is input to the forward and backward control mechanism 38 through the first power transmission member 40 of the second shaft 8. In this case, the first friction member 52 of the forward driving is operated, so that the second shaft 8 is connected as a single unit to transmit power in the forward direction, and in reverse, the second friction member 56 is operated. When the front side of the planet carrier 50 is an input element, the ring gear 54 acts as a reaction element, the output is made through the sun gear 44, the reverse rotational power is transmitted.

Then, when the forward and backward rotational power is transmitted in the above-described process, the forward and backward rotational power is forward wheel drive shaft 76 and the reverse drive mechanism 77 depending on whether the start control mechanism 64 of the third shaft 62 is operated. ) Enables forward and backward travel.

3 is a configuration diagram of the second embodiment according to the present invention, and unlike the first embodiment, the continuously variable transmission mechanism 38 is disposed on the second shaft 8 and the third shaft 62, and the first shaft 4 ) Is divided into first and second power transmission members 40 and 42 to arrange the forward and backward control mechanisms 10, and the operation thereof is the same as in the first embodiment, and thus detailed description thereof will be omitted.

As described above, the continuously variable transmission of the present invention has an advantage that it can be applied to a rear wheel drive vehicle by additionally installing a planetary gear set and arranging a rear wheel drive mechanism.

Claims (8)

A torsional damper capable of attenuating torsional vibration of rotational power output from the engine; A continuously variable transmission mechanism disposed at the rear end of the first shaft on which the torsional damper is mounted and on the front end of the second shaft arranged in the same axial direction on the first shaft thereof to continuously change the rotational power of the first shaft; A forward and backward control mechanism which is composed of a double pinion planetary gear set and is arranged on the second axis arranged in the same line and controls forward and backward by selective operation of a plurality of friction members; A start control mechanism disposed on the same axis direction at a predetermined interval from the second axis and disposed on a third axis receiving rotational power of the second axis by gear transmission to control power transmission; A front wheel drive shaft configured to receive the rotational force from the third shaft through the differential to drive the front wheel; A rear wheel drive mechanism capable of driving rear wheels by receiving power from the front wheel drive shaft; A continuously variable transmission for a four-wheel drive vehicle comprising a. The method of claim 1, wherein the continuously variable transmission mechanism comprises a drive pulley disposed on the first shaft and fixed and variable side pulleys so that the diameter can be variable, and a fixed and variable side pulley so that the diameter can be varied on the second axis. And a driven pulley arranged to be connected to the drive pulley and the belt. According to claim 1, wherein the forward and reverse control mechanism is composed of a double pinion planetary gear set, the second shaft is formed of the first and second power transmission member divided into the front and rear, the sun gear is integral to the second power transmission member. The planetary carrier interconnecting the first and second pinions, which are arranged at equal intervals on the outer circumference of the sun gear, connects the front part with the first power transmission part, and the rear part has the second power transmission member and the first friction. And a ring gear in which the second pinion is engaged with the inner pin is connected to the transmission housing via the second friction member. The continuously variable transmission device for a four-wheel drive vehicle is provided. 4. The continuously variable transmission for a four-wheel drive vehicle according to claim 3, wherein the first friction member uses a multi-plate clutch as the clutch means, and the second friction member uses a multi-plate clutch or a band brake as the brake means. 2. The continuously variable transmission for a four-wheel drive vehicle according to claim 1, wherein the start control mechanism uses a multi-plate clutch as the clutch means. The four-wheel drive vehicle according to claim 1, wherein the rear wheel drive mechanism comprises an idler shaft that receives power from a gear formed on the front wheel drive side, and a drive shaft that receives power from the idler shaft and transfers the power to the rear wheel. Continuously variable transmission. 7. The continuously variable transmission for a four-wheel drive vehicle according to claim 6, wherein the idler shaft and the drive shaft are arranged in mutually intersecting directions and connected to bevel gears. The continuously variable transmission mechanism according to claim 1, wherein the continuously variable transmission mechanism is disposed on the second and third axes, and the forward and backward control mechanisms are arranged by dividing the first shaft into the first and second power transmission members. Gearbox.