KR19980017183A - Power train of car automatic transmission - Google Patents

Abstract

Friction elements that do not operate with integral rotation of a double pinion planetary gear set in a forward four-speed shift in a powertrain of an automatic transmission for a vehicle having a composite planetary gear unit consisting of a double pinion planetary gear set and a pinion planetary gear set. To minimize frictional losses of An input shaft that receives rotational power of the engine from the turbine of the torque converter and rotates the engine; A double pinion planetary gear set configured to receive the rotational power of the input shaft and adjust a rotation direction and an output rotational speed with respect to the input by a selective action of the input element and the reaction force element; Single pinion planetary gear that receives the output of the set of double pinion planetary gears and outputs them at different gear ratios and transmits them at different gear ratios in each gear stage except for the third forward speed. Set; Clutch means for transmitting the rotational power of the input shaft and simultaneously selecting any one or two of the elements of the double pinion planetary gear set as inputs; Another clutch means for selectively connecting any one element of said double pinion planetary gear set and any one element of said single pinion planetary gear set; It is characterized in that it provides a power train of an automatic transmission for a vehicle including brake means that operate to select another element as a reaction force element when the input is selected by the clutch means.

Description

Power train of car automatic transmission

1 is a view showing 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, in a power train employing a composite planetary gear device consisting of a double pinion planetary gear set and a single pinion planetary gear set, which does not operate in a forward four speed shift stage. The present invention relates to a power train capable of minimizing frictional losses of friction elements.

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 planetary gear unit 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 a planetary carrier is connected to each other in order for a vehicle to be used as a transmission means, 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 hok 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 the present embodiment directly connects the ring gear of the double pinion planetary gear set and the planetary carrier of the single pinion planetary gear set, and the planetary carrier of the double pinion planetary gear set and the single pinion planetary gear set. It is the most important object to provide a power train that minimizes the frictional loss of friction elements that do not operate by integrally rotating the double pinion planetary gear set at all four speed gears.

In order to realize the object of the present invention as described above, the input shaft for receiving the rotational power of the engine from the turbine of the torque converter to rotate; A double pinion planetary gear set configured to receive the rotational power of the input shaft and adjust a rotation direction and an output rotational speed with respect to the input by a selective action of the input element and the reaction force element; Single pinion planetary gear that receives the output of the set of double pinion planetary gears and outputs them at different gear ratios and transmits them at different gear ratios in each gear stage except for the third forward speed. Set; Clutch means for transmitting the rotational power of the input shaft and simultaneously selecting any one or two of the elements of the double pinion planetary gear set as inputs; Another clutch means for selectively connecting any one element of said double pinion planetary gear set and any one element of said single pinion planetary gear set; It is characterized in that it provides a power train of an automatic transmission for a vehicle including brake means that operate to select another element as a reaction force element when the input is selected by the clutch means.

The clutch means includes first clutch means for transmitting power between the input shaft and the sun gear of the double pinion planetary gear set; Second clutch means for selectively transferring power between the planetary carrier of the double pinion planetary gear set and the sun gear of the single pinion planetary gear set; It is characterized by providing a power train of an automatic transmission for a vehicle including a third clutch for selectively transmitting power between the input shaft and the planet carrier of the double 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 single-pinion planetary gear set and the transmission housing; It is characterized in that it provides a power train for an automatic transmission for a vehicle comprising a second brake means for selecting the sun gear reaction force element between the sun gear of the single-pinion planetary gear set and the transmission housing.

The ring gear of the double pinion planetary gear set and the planet carrier of the single pinion planetary gear set are characterized by providing a power train of an automatic transmission for a vehicle having a fixed coupling structure by a power transmission member.

The sun gear of the double-pinion planetary gear set and the single-pinion planetary gear set described above are characterized by providing a power train of an automatic transmission for a vehicle having a variable coupling structure by a 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 double pinion planetary gear set 4, and the double pinion planetary gear set 4 is a transfer drive gear 6. The clutch hook-up is made so that torque can be transmitted to the single pinion planetary gear set 10 having a ring gear 8 directly connected to

The ring gear 12 of the double pinion planetary gear set 4 and the planetary carrier 14 of the single pinion planetary gear set 10 are directly connected through the power transmission member 16 so as to transmit rotational power. It is composed.

The sun gear 18 of the double pinion planetary gear set 4 is configured to receive rotational power through the first clutch means 20 provided between the input shaft 2.

In addition, the planet carrier 22 of the double pinion planetary gear set 4 is integrated with each other by the second clutch means 26 provided between the sun gear 24 of the single pinion planetary gear set 10. It has a structure that can rotate or rotate individually.

In addition, the double pinion planetary gear set 4 is provided with a third clutch means 28 between the input shaft 2 and the planet carrier 22 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 30 is installed between the transmission housing 32 and the planet carrier 14 of the single pinion planetary gear set 10 so that the planet carrier 14 can be selected as a reaction element. It is composed.

The second brake means 34 is provided between the transmission housing 32 and the sun gear 24 of the single pinion planetary gear set 10 so as to select the sun gear 24 as a reaction element.

In FIG. 1, the transfer drive gear 6 of the power train is geared with the 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) as input and the other as counterattack element, the following transmission ratios of 4 forward speed and 1 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 unit is driven by a hydraulic control system (not shown) so that the gear train can output the first speed ratio. First, hydraulic pressure is supplied to the first clutch means 20 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 20 is operated, the rotational power of the input shaft 2 is transmitted to the sun gear 18 of the double pinion planetary gear set 4 to act as an input element.

In this state, since the second clutch means 26 and the first brake means 30 operate, the planetary gears of the ring gear 12 and the single pinion planetary gear set 10 of the double pinion planetary gear set 4 are operated. Together with the carrier 14 acts as a reaction element.

By the above operation, the ring gear 8 of the single-pinion planetary gear set 10 is rotated in the same direction as the input shaft 2 to output the largest reduction ratio that the gear train of the present embodiment can provide, thereby shifting at 1 speed. The stage is realized.

When the vehicle speed is increased in this first speed control state, the transmission control unit newly operates the second brake means 34 while stopping the operation of the first brake means 30 that has selected the reaction force element.

The input is then made via the sun gear 18 of the double pinion planetary gear set 4, the planet carrier 22 of which is operated by the second clutch means 26 and the second brake means 34. The sun gear 24 of the planetary gear set 10 acts as a reaction force element.

By this action, the ring gear 8 of the single-pinion planetary gear set 10 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 brake means 34 and newly operates the third clutch means 28 so that the sun gear of the single pinion planetary gear set 4 18) and the planetary carrier 22 allows the rotational power of the input shaft 2 to be made at the same time.

Then, both the double and single pinion planetary gear sets 4 and 10 rotate integrally, while the ring gear 8 of the output element of the single pinion planetary gear set 10 rotates at the same rotational speed as the input shaft 2. The speed ratio of three speeds is output.

In this way, when the vehicle speed is further increased in the third speed control state in which the input and output rotation speeds are the same, the transmission control unit stops the operation of the second clutch means 26 and newly operates the second brake means 34.

Due to this action, the double pinion planetary gear set 4 is inputted with two elements. The diameter of the single pinion planetary gear set 10 is rotated 1: 1 with the input shaft 2. Torque is transmitted to the two elements, where the second clutch means 26 is stopped, and the planetary carrier 14 and the ring gear 14 of the double pinion planetary gear set 6 are input elements. And input is made only through.

In the above state, the sun gear 24 of the single pinion planetary gear set 10 is operated as a reaction force element by the operation of the second brake means 34. The ring gear of the single pinion planetary gear set 10 is operated. (8) outputs a speed ratio of four speeds that rotate at a speed faster than the rotation speed of the input shaft (2).

Contrary to the above, when the selector lever is selected as the reverse (R) range, the transmission control unit operates the third clutch means 28 to select the input element and operates the first brake means 30 to select the reaction element. Done.

Then, the rotational power of the input shaft 2 is input to the planet carrier 22 of the double pinion planetary gear set 4, where the second clutch means 26 is actuated and the sun gear of the single pinion planetary gear set 10 is operated. (24) is operated as an input element, the operation of the first brake means 30, the planetary carrier 14 of the single pinion planetary gear set 10 and the ring gear of the double pinion planetary gear set (4) 12) acts as a reaction element.

Accordingly, since the ring gear 8 of the single pinion planetary gear set 10 rotates in the opposite direction to the input shaft 2, the reverse shift is made.

As described above, the power train according to the present invention can provide four forward gears and one reverse gear, in particular by incorporating a double pinion planetary gear set in the forward four gears, thereby not operating the friction elements. Since the slip of the friction element can be reduced, the frictional loss due to the slip 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 double pinion planetary gear set configured to receive the rotational power of the input shaft and adjust a rotation direction and an output rotational speed with respect to the input by a selective action of the input element and the reaction force element; Single pinion planetary gear that receives the output of the set of double pinion planetary gears and outputs them at different gear ratios and transmits them at different gear ratios in each gear stage except for the third forward speed. Set; Clutch means for transmitting the rotational power of the input shaft and simultaneously selecting any one or two of the elements of the double pinion planetary gear set as inputs; Another clutch means for selectively connecting any one element of the double pinion planetary gear set and the single pinion planetary gear set to any one element; Powertrain of a vehicular automatic transmission comprising brake means operative to select another element as a reaction force element when the input is selected by said clutch means. 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 double pinion planetary gear set; Second clutch means for selectively transmitting power between the sun gear of the double-pinion planetary gear set and the sun carrier of the single-pinion planetary gear set; And a third clutch for selectively transmitting power between the input shaft and the planet carrier of the double 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 single pinion planetary gear set and the transmission housing; A power train for a vehicular automatic transmission comprising a second brake means for selecting the sun gear reaction element between the sun gear of the single-pinion planetary gear set and the transmission housing. 2. The power train of an automatic transmission according to claim 1, wherein the double-pinion planetary gear set has a planetary carrier of the ring gear and the single-pinion planetary gear set 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 double-pinion planetary gear set and the sun gear of the single-pinion planetary gear set have a variable coupling structure by clutch means.