KR19980017189A - Power train of car automatic transmission - Google Patents

Abstract

A power train of a vehicular automatic transmission having a composite planetary gear device consisting of a single pinion planetary gear set and a double pinion planetary gear set, comprising: a purpose of minimizing frictional loss of an inoperative clutch and brake; An input shaft that receives rotational power of the engine from the turbine of the torque converter and rotates the engine; A single pinion planetary gear set which receives the rotational power of the input shaft and converts the rotational force of the output of the input element and the reaction force element to the transfer drive gear; A double pinion planetary gear set that receives the output of the single pinion planetary gear set and acts as a reaction element, outputs at a different transmission ratio, and delivers it back to the single pinion planetary gear set; Clutch means for transmitting the rotational force of the input shaft to simultaneously select one of the three elements of the single and double pinion planetary gear sets or two of the elements as inputs; By selectively connecting any one element of the single pinion planetary gear set and any element of the double pinion planetary gear set, only the single pinion planetary gear set can rotate integrally or at the same time Another clutch means for allowing the input to be selected; A vehicle comprising brake means for selecting one element of the double pinion planetary gear set as a reaction element when the input is selected by the clutch means, or actuating the operation of its double pinion planetary gear set to be stopped. Provides a power train for automatic transmission.

Description

Power train of car automatic transmission

1 shows a power train of a transmission according to the present invention.

2 shows a friction element operation table for each shift stage of the transmission according to the present invention.

The present invention relates to an automatic transmission, and more particularly, to minimize frictional losses of friction elements that do not operate in a power train to which a composite planetary gear device including a single pinion planetary gear set and a double pinion planetary gear set is applied. It's all about power trains.

BACKGROUND ART In general, an automatic transmission for a vehicle includes a transmission control unit that automatically controls a transmission ratio in accordance with a change in a traveling speed and a load of a vehicle.

The transmission control unit controls a plurality of friction elements installed in the gear train in an active or non-operating state so that any one of the three elements of the planetary gear set (sun gear, ring gear, planet carrier) is an input element, and other elements. Select as the reaction force element to adjust the output speed.

In order to design a gear train that can output a gear ratio of four forward speeds and one reverse speed, one compound planetary gear unit and at least five friction elements must be used.

Among these friction elements, the rotation radius of the friction element used as the clutch means has a structural constraint that the clutch means must be smaller than the rotation radius of the output element in order to be connected to the input shaft, and smaller than the rotation radius of the reaction force element.

In general, a compound planetary gear device has a direct structure in which at least two different elements can be used in common.

In the case of the four-speed automatic transmission, since the compound planetary gear unit has four independent speeds, the six planetary gear units using two simple planetary gear units having three independent speeds cannot obtain six independent speeds. Because.

In general, a compound planetary gear device that is used as an automatic transmission of a vehicle includes a lavender type, a Simpson type, and a two-simpson type planetary gear device.

Such a compound planetary gear device has a structure in which planetary carriers are connected to each other to be used as a transmission means of a vehicle, a structure in which a sun gear is shared and a planetary carrier and a ring gear are directly connected, or a planetary carrier and a ring gear are mutually connected. It has a structure directly connected.

Therefore, at some gear stages, the clutch means or brake means, which does not substantially affect the gear shift, causes friction between the drive side and the driven side, resulting in power loss.

The present invention has been invented to solve the problems of the prior art as described above, and an object of the present invention is to propose a clutch hook up, which has not been proposed so far, to minimize frictional loss of a friction element that does not work. To provide a power train of an automatic transmission for a vehicle.

Specifically, the clutch hook-up provided by this embodiment includes a single pinion planetary gear set directly connecting a sun gear and a double pinion planetary gear set sun gear, and a single pinion planetary gear set planetary carrier and a double pinion planetary gear set ring gear. As a variablely connected structure, the most important object is to provide a power train that minimizes frictional losses of the friction elements at the forward four speed shift stage.

In order to realize the object of the present invention as described above, the input shaft is rotated by receiving the rotational power of the engine from the turbine of the torque converter and the rotational power of the input shaft is received to the input by the selection action of the input element and the reaction force element A single pinion planetary gear set for converting the number of rotations of the output power to the transfer drive gear; It receives the output of the single pinion planetary gear set and acts as a reaction element, and outputs it with a different transmission ratio, and delivers it back to the single pinion planetary gear set and delivers the rotational power of the input shaft. Clutch means for selecting any one of the three elements of the single and double pinion planetary gear sets or two elements simultaneously as an input, and any one element of the single pinion planetary gear set described above. Another clutch means for selectively connecting one element of the double pinion planetary gear set and one element of the double pinion planetary gear set as a reaction element when the input is selected by the clutch means described above, or Wave of an automatic transmission for a vehicle comprising brake means operative to stop operation of its pinion planetary gear set Provide the war train.

The clutch means includes a first clutch means for transmitting power between the input shaft and the sun gear of the single pinion planetary gear set, and a power between the planet carrier of the single pinion planetary gear set and the ring gear of the double pinion planetary gear set. Second clutch means for selectively transmitting a; Provided is a power train of an automatic transmission for a vehicle including a third clutch selectively transmitting power between the input shaft and a planet carrier of a single pinion planetary gear set.

The brake means includes first brake means for selecting the planetary carrier as a reaction element between the planetary carrier of the double pinion planetary gear set and the transmission housing; Provided is a power train for an automatic transmission for a vehicle comprising a first brake means for selecting the ring gear as a reaction element between the ring gear of the double pinion planetary gear set and the transmission housing.

The sun gear of the single pinion planetary gear set and the sun gear of the double pinion planetary gear set provide a power train of an automatic transmission for a vehicle having a fixed coupling structure by a power transmission member.

The planetary carrier of the single-pinion planetary gear set and the ring gear of the double-pinion planetary gear set described above provide a power train of an automatic transmission for a vehicle having a variable coupling structure by clutch means.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing the power train of the automatic transmission according to the present invention, the rotational power of the engine (E) has a structure that can be torque converted in the torque converter (T) to be transmitted to the input shaft (2) of the transmission.

In the present embodiment, the input shaft 2 transfers torque from the turbine of the torque converter T to the single pinion planetary gear set 4, and the single pinion planetary gear set 4 is a double pinion planetary gear. Torque is transmitted to the set 6, and a clutch hook up is formed in which the ring gear 8 and the transfer drive gear 10 are integrally formed.

The sun gear 12 of the single pinion planetary gear set 4 and the sun gear 14 of the double pinion planetary gear set 6 are directly connected through the power transmission member 16 so as to transmit rotational power. .

The sun gear 12 of the single pinion planetary gear set 4 is configured to receive rotational power through the first clutch means 18 provided between the input shaft 2.

And the planet carrier 20 of this single pinion planetary gear set 4 is integrally mutually connected by the second clutch means 24 provided between the ring gear 22 of the double pinion planetary gear set 10. It has a structure that can rotate or rotate individually.

The single pinion planetary gear set 4 is provided with a third clutch means 26 between the input shaft 2 and the planet carrier 20 so that two elements can be selected as inputs to be integrally rotated.

As the first, second and third clutch means described above, a multi-plate clutch which is generally used may be used.

Brake means are provided to enable the planetary gear set to adjust the number of revolutions of the output relative to the input when one or more of the above clutch means are actuated.

Among the brake means, the first brake means 28 is provided between the transmission housing 30 and the planet carrier 32 of the double pinion planetary gear set 6 so that the planet carrier 32 can be selected as a reaction element. It is composed.

The second brake means 34 is provided between the transmission housing 32 and the ring gear 22 of the double pinion planetary gear set 6 so as to select the ring gear as a reaction force element.

In FIG. 1, the transfer drive gear 10 of the power train is geared with a transfer driven gear (not shown) to omit a structure in which power is transmitted to the differential device through the final reduction gear. It is possible to realize the object of the present invention even if any structure is used, so that description is omitted.

The power train of the automatic transmission of the present invention made in this way comprises three sets of planetary gears depending on the presence or absence of friction elements (clutch means and brake means) that are activated and deactivated by a transmission control unit (not shown). By selecting one of the elements (sun gear, planet carrier, ring gear) and the other element as the reaction force element, the following transmission ratios of the 4th forward and the 1st reverse speed are output.

An operating table relating to the friction elements for which actuation and non-actuation are selected by the transmission control unit is shown in FIG. 2.

When the selector lever (not shown) is selected as the forward (D) range and the opening amount of the throttle valve starts to increase, the transmission control transmission is carried out via a hydraulic control system (not shown) so that the gear train can output a speed ratio of 1 speed. First, hydraulic pressure is supplied to the first clutch means 18 to operate the clutch means.

Hereinafter, the operation of the clutch means or the brake means means that the hydraulic pressure is supplied from the hydraulic control system.

When the first clutch means 18 is operated, the rotational power of the input shaft 2 is transmitted to the sun gear 12 of the single pinion planetary gear set 4 while the sun gear 12 and the power transmission member 16 thereof. It is transmitted to the sun gear 14 of the double pinion planetary gear set 6 through.

At this time, since the second clutch means 24 acts, the planet carrier 22 of the single pinion planetary gear set 4 and the ring gear 22 of the double pinion planetary gear set 6 are connected to each other. Since the brake means 28 is operating, the planet carrier 32 of the double pinion planetary gear set 6 acts as a reaction force element.

By this action, the ring gear 8 of the single-pinion planetary gear set 4 rotates in the same direction as the input shaft 2 while outputting the largest reduction ratio that the gear train of the present embodiment can provide, thereby shifting at one speed. The stage is realized.

In this first speed control state, the vehicle speed is increased, and the transmission control unit newly operates the third clutch means 26 while stopping the operation of the first clutch means 18 which has selected the reaction force element.

Accordingly, power is transmitted from the planetary carrier 20 of the single-pinion planetary gear set 4 to the ring gear 22 of the double-pinion planetary gear set 6, and the input is made, and the double-pinion planetary gear set ( The planetary carrier 32 of 6) acts as a reaction element.

By this action, the ring gear 8 of the single-pinion planetary gear set 4 rotates faster than the first speed and outputs a speed ratio of two speeds.

When the vehicle speed increases in this two-speed control state, the transmission control unit deactivates the second clutch means 24 and newly activates the first clutch means 18 so that the input of the single pinion planetary gear set 4 is reduced. The sun gear 12 and the planet carrier 20 are simultaneously made so that the single pinion planetary gear set 4 rotates integrally.

In the above-described operation, the ring gear 8 outputs a speed ratio of three speeds rotating at the same rotational speed as the input shaft 2.

If the vehicle speed is further increased in the three-speed control state in which the rotation speed of the input and the output is the same, the transmission control unit stops the operation of the first clutch means 18 and newly operates the second brake means 34. .

By this action, the operation of the carrier 32 and the ring gear 22 of the double pinion planetary gear set 6 is stopped, whereby the overall operation of the double pinion planetary gear set 6 is stopped. In the state where the sun gear 12 of the single pinion planetary gear set 4 connected to 14) acts as a reaction element, the input is made through the planet carrier 20 of the single pinion planetary gear set 4.

Therefore, the ring gear 8 of the single pinion planetary gear set 4 outputs a speed ratio of four speeds that rotate at a speed faster than the rotation speed of the input shaft 2.

Since the second clutch means 24 do not operate in the four-speed shift as described above, even if an input is made to the planet carrier 20 of the single-pinion planetary gear set 4, the double-pinion planetary gear set 6 Power is not transmitted to the ring gear 22.

When the selector lever is selected as the reverse range, the transmission control unit operates the first and second clutch means 18 and 24 to select the input element and the second brake means 32 to operate the reaction element. Will be chosen.

Therefore, the rotational power of the input shaft 2 is input to the castle gear 12, the carrier 20 acts as a reaction element, the output gear ring gear 8 is decelerated while rotating in the direction opposite to the input shaft (2) Will be

As described above, the power train according to the present invention can provide four forward gear stages and one reverse gear stage, in particular, by stopping the operation of the double pinion planetary gear set at the four-speed gear stage, thereby reducing friction. Since the slip of the element can be reduced, the frictional loss due to the slip of the friction element of the friction element can be minimized.

Claims (5)

An input shaft that receives rotational power of the engine from the turbine of the torque converter and rotates the engine; A single pinion planetary gear set which receives the rotational power of the input shaft and converts the rotational speed of the output to the transfer drive gear by a selective action of the input element and the reaction force element and transmits it to the transfer drive gear; A double pinion planetary gear set that receives the output of the single pinion planetary gear set and acts as a reaction element, outputs at a different transmission ratio, and delivers it back to the single pinion planetary gear set; Clutch means for transmitting the rotational power of the input shaft so that the single and double pinion planetary gear sets select any one of three elements or two elements at the same time; By selectively connecting any one element of the single pinion planetary gear set and any element of the double pinion planetary gear set, only the single pinion planetary gear set can rotate integrally or at the same time Another clutch means for allowing the input to be selected; A vehicle comprising brake means for selecting one element of the double pinion planetary gear set as a reaction element when the input is selected by the clutch means, or actuating the operation of its double pinion planetary gear set to be stopped. Provides a power train for automatic transmission. 2. The clutch of claim 1, wherein the clutch means comprises: first clutch means for transmitting power between the input shaft and the sun gear of the single pinion planetary gear set; Second clutch means for selectively transferring power between the planetary carrier of the single-pinion planetary gear set and the ring gear of the double-pinion planetary gear set; And a third clutch for selectively transmitting power between the input shaft and the planetary carrier of the single-pinion planetary gear set. 2. The brake device of claim 1, wherein the brake means comprises: first brake means for selecting the planetary carrier as a reaction element between the planetary carrier of the double pinion planetary gear set and the transmission housing; A power train for a vehicular automatic transmission comprising a first brake means for selecting the ring gear as a reaction element between the ring gear of the double pinion planetary gear set and the transmission housing. The power train of an automatic transmission for a vehicle according to claim 1, wherein the sun gear of the single pinion planetary gear set and the sun gear of the double pinion planetary gear set have a fixed coupling structure by a power transmission member. 2. The power train of an automatic transmission for a vehicle according to claim 1, wherein the planetary carrier of the single-pinion planetary gear set and the ring gear of the double-pinion planetary gear set have variable coupling structures by clutch means.