KR100482580B1 - A six-speed power train of an automatic transmission for a vehicle - Google Patents

Abstract

By applying a small number of friction elements, it realizes 6th forward speed and 1st reverse speed, but it is compact by reducing the overall length and weight, and it is durable by lowering the rotational speed of operating elements at low speed gears that are frequently used during acceleration. To increase the durability, reduce the slip speed of the friction element, and simplify the power transmission path, thereby improving durability and reducing power loss;

In combining the three simple planetary gear sets to form the power train of the automatic transmission, the first planetary gear set and the third planetary gear set of the six operating elements of each of the two operating elements fixedly connected to each other by the first It is formed of a compound planetary gear set having an operating element of, 2,3,4, wherein the first of the operating elements is operated only as an optional input element, and the second operating element is always operated as an output element. The third actuating element is selectively actuated by the input element and the stationary element, and the fourth actuating element is selectively actuated by the stationary element; The second planetary gear set has a fifth actuating element acting as a constant input element, a sixth actuating element acting as a constant output element, and a seventh actuating element acting as a constant fixing element, and the second planetary gear. A sixth speed train of an automatic transmission for a vehicle configured to output a rotation of a reduced speed relative to the rotational speed of an input shaft to a fourth operating element of the composite planetary gear set.

Description

Six speed power train of car automatic transmission {A SIX-SPEED POWER TRAIN OF AN AUTOMATIC TRANSMISSION FOR A VEHICLE}

The present invention relates to a six-speed powertrain of an automatic transmission for a vehicle applied to an automatic transmission for a vehicle to realize a six-speed transmission stage.

For example, the multi-speed gear mechanism of the automatic transmission is composed of a combination of a plurality of planetary gear sets, and a power train in which the plurality of planetary gear sets is combined is provided when rotational power is input from a torque converter that converts and transmits engine torque. It performs the function of transmitting to the output side by shifting to multiple stages.

Since the power train of the automatic transmission has more shift stages, it is advantageous in terms of power performance and fuel consumption rate, and thus, a power train capable of implementing more shift stages is required.

And even if the same number of gear stages are implemented, the durability, power transmission efficiency, size and weight of the planetary gear set vary greatly depending on the combination method of the planetary gear set, which makes the power train more compact and compact while minimizing power loss. Efforts for development are ongoing.

And when developing a power train using planetary gear sets, instead of developing any new planetary gear sets, how to combine the existing single pinion planetary gear sets and double pinion planetary gear sets, and the accompanying clutches Various studies are aimed at improving the transmission performance by arranging a plurality of brakes and one-way clutches at any position to realize a desired shift stage and a corresponding shift ratio without possible power loss.

In particular, in the case of a manual transmission, if there are too many shift stages, the driver should shift frequently. However, in the case of an automatic transmission, the transmission control unit automatically controls the operation of the power train in accordance with the driving state to change the shift. As a result, developing a power train that can implement more shifts is of great value.

In order to cope with this trend, various studies on the 4th and 5th speed power trains are being conducted, and recently, the power train of the automatic transmission that can realize the 6th forward and 1st speed shift stages has been provided. One example is the power train disclosed in US Pat. No. 6,071,208 (hereinafter referred to as Prior Art 1).

The prior art 1 shows the configuration of the power train and the operation table of the friction elements in FIGS. 5 and 6.

First, referring to the configuration of the power train, one double pinion planetary gear set PG1 and two single pinion planetary gear sets PG2 and PG3 are combined, but the input shaft 2 has a first planet carrier 4 and It is fixedly connected, and the third planet carrier 14 and the second ring gear 16 are variably connected via the second clutch C2 to act as an input element, and the second planet carrier 22 is always an output element. Done.

The first ring gear 6, the third ring gear 8, the second sun gear 12, the third sun gear 10, the second ring gear 16, and the third planet carrier 14 are fixedly connected, respectively. The first planet carrier is variably connected to the first sun gear 18 through the first clutch C1.

In addition, the second and three-wire gears 12 and 10 fixedly connected to each other may include a first brake B1, a second ring gear 16 and a third planet carrier 14 including a second brake B2, The first and third ring gears 6 and 8 have a third brake B3 to selectively act as a fixing element, and the first planetary carrier 4 and the first sun gear 18 which are variablely connected are The fourth brake B4 is provided on the first sun gear 18 side.

Accordingly, as shown in FIG. 6, the friction element includes first and fourth brakes B1 and B4 at a first speed, and a first clutch C1 and a first brake B1 and a third speed at a second speed. In the second clutch C2 and the first brake B1, in the fourth speed the first and second clutches C1 and C2, in the fifth speed the second clutch C2 and the fourth brake B4, The second clutch C2 and the third brake B3 are operated at the sixth speed, and the shift is performed while the second and fourth brakes B2 and B4 are operated at the reverse shift stage.

That is, the prior art 1 combines one double pinion planetary gear set and two single pinion planetary gear sets with two clutches and four brakes to implement a shift speed of 6 forward speed and 1 reverse speed.

However, the prior art 1 has a problem that the six friction elements are used, which increases the volume and the weight.

In addition, the power train of the prior art 1 is the first sun gear 18 at the rotational speed of the input shaft at the third forward speed, which is frequently used during overtaking acceleration in the six-speed automatic transmission that typically has a speed ratio of 4: 1 to 1: 1. It rotates at a speed more than twice, and the fourth brake B4, which is a non-operating friction element, also causes slip at the same speed, which causes a decrease in durability.

In addition, the friction element is excessively slipped over all the shift stages, thereby reducing the durability and causing power loss. The improvement in the direction of reducing the slip speed of the friction element as a whole in the 2nd forward to 6th forward speeds is improved. This is required.

In particular, it can be seen that the problem of durability is large because the sum of the slip speeds of the friction elements at the sixth forward speed is too large.

In addition, as shown in b of FIG. 4, when considering the number of planetary gearsets that are responsible for the load in connection with power transmission, power transmission efficiency because two or more planetary gearsets are involved in power transmission at the forward 5 and 6 speeds. As this is lowered, there is a need for a power train for an automatic transmission that provides higher power transmission efficiency.

As another conventional example, US Patent No. 5,226,862 (1993.7.13; hereinafter referred to as Prior Art 2) disclosed in Figs.

The prior art 2 combines one double pinion planetary gear set (PG1) and two single pinion planetary gear sets (PG2) (PG3), but is fixedly connected to the first sun gear 32 to the input shaft 30, The second and third sun gears 34 and 36 are connected through the first clutch C1, and the second planet carrier 38 and the third ring gear 40 are variably connected through the second clutch C2. It acts as an element, and the third planet carrier 42 always acts as an output element.

That is, the second and third sun gears 34 and 36 are fixedly connected to each other and variably connected to the input shaft 30, and the second planet carrier 38 and the third ring gear 40 are fixed to each other and are connected to the input shaft. It is variablely connected to (30).

The third ring gear 40 may include a first brake B1, first and second ring gears 44 and 46 that are fixedly connected to each other, a second brake B2, and a first planet carrier 48. The third brake B3 is configured to selectively act as a fixing element.

Accordingly, as shown in FIG. 8, the friction element includes a first clutch C1 and a first brake B1 at a first speed, a first clutch C1 and a second brake B2 at a second speed, The first clutch C1 and the third brake B3 at the third speed, the first and second clutches C1 and C2 at the fourth speed, the second clutch C2 and the third brake B3 at the fifth speed ), The second clutch C2 and the second brake B2 are operated at the sixth speed, and the shift is performed while the first and third brakes B1 and B3 are operated at the reverse shift stage.

That is, the prior art 2 combines one double pinion planetary gear set and two single pinion planetary gear sets as in the prior art 1, but combines two clutches and three brakes to shift forward 6 speeds and reverse 1 speeds. You will implement a stage.

Accordingly, the prior art 2 has the advantage that the volume and weight can be reduced by using one friction element less than the prior art 1.

In addition, the power train of the prior art 2 cannot be used for a general automatic transmission because the relative slip of the first planet carrier 48 at the forward 4 speed is about 3.8 larger than that of the input.

In addition, a large amount of slip occurs between the third clutch C3 as the non-operating friction element at the first forward speed and the first clutch C1 as the non-operating friction element at the forward 6 speed, which causes the durability to be deteriorated.

In addition, the friction element is excessively slipped in all the shift stages except the forward three speeds, thereby deteriorating durability and causing power loss. Therefore, improvement in the direction of reducing the slip speed of the friction element is required. have.

In addition, as shown in c of FIG. 4, when considering the number of planetary gear sets that are in charge of power transmission and responsible for load, power transmission efficiency because two or more planetary gear sets are involved in power transmission at the forward 5 and 6 speeds. As this is lowered, there is a need for a power train for an automatic transmission that provides higher power transmission efficiency.

Therefore, the present invention was invented to meet the above demands, and an object of the present invention is to realize a shift speed of 6 forward speed and 1 reverse speed by combining three planetary gear sets and 5 friction elements, It is to provide a power train of an automatic transmission that can be made compact and compact.

In addition, by lowering the rotational speed of the operating element in the low-speed transmission stage often used during acceleration, it can increase the durability, lower the slip speed of the friction element, and simplify the power transmission path, thereby improving durability and reducing power loss Provide a power train.

In order to realize the above object, the present invention provides a combination of a first planetary gear set, which is a single pinion planetary gear set, a second planetary gear set, which is a double pinion planetary gear set, and a third planetary gear set, which is a single pinion planetary gear set. In the power train of the automatic transmission,

The first planetary gear set and the third planetary gear set of the six operating elements of each of the two operating elements are fixed to form a composite planetary gear set having the first, second, third and fourth operating elements, ,

The first actuating element of the actuating element is operated only as an optional input element, the second actuating element is operated as a constant output element, the third actuating element is selectively actuated as an input element and a fixed element, and a fourth The actuating element is optionally configured to act as a stationary element,

The second planetary gear set has a fifth operating element acting as a constant input element, a sixth actuating element acting as a constant output element, and a seventh actuating element acting as a constant fixing element,

A sixth operating element of the second planetary gear set provides a power train of an automatic transmission for a vehicle configured to output the rotation of the reduced speed with respect to the rotational speed of the input shaft to the fourth operating element of the composite planetary gear set. .

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

 1 shows an embodiment of a power train according to the present invention, which has an input shaft 100 connected to an engine output shaft via a torque converter and an output shaft 102 connected to a wheel or the like. .

First, second, and third planetary gear sets PG1, PG2, and PG3 may be combined between the input shaft 100 and the output shaft 102, and the first planetary gear set PG1 may include a first sun gear ( First planet carrier PC1 rotatably supporting S1, the first ring gear R1, and the pinion P1 meshed between the first sun gear S1 and the first ring gear R1. It consists of a single pinion planetary gear set including.

The second planetary gear set PG2 is fitted with a second sun gear S2, a second ring gear R2, and a pinion P2 meshed between the second sun gear S2 and the second ring gear R2. It consists of a double pinion planetary gear set including a second planetary carrier PC2 for rotatably supporting P2 '.

The third planetary gear set PG3 includes a third sun gear S3, a third ring gear R3, and a pinion P3 meshed between the third sun gear S3 and the third ring gear R3. It consists of a single pinion planetary gear set including a third planetary carrier (PC3) for rotatably supporting the.

The first, second and third planetary gear sets PG1 and PG2 and PG3 are arranged in the order of the second, first and third planetary gear sets PG2 and PG1 and PG3 from the input shaft 100. Among the operating elements, the first planet carrier PC1 and the third planet carrier PC3, the first ring gear R1 and the third sun gear S3 are fixedly connected to each other.

The second sun gear S2 is fixedly connected to the input shaft 100 and always operates as an input element, and the first sun gear S1 and the first planet carrier PC1 are first and second clutches C1 and C2. The first ring gear (R1) and the second ring gear (R2) is variably connected via a third clutch (C3).

In addition, the second planet carrier PC2 is fixedly connected to the housing 104 and always operates as a fixed element, and has a first ring gear connected to the third planet carrier PC3 and the third sun gear S3. R1) is connected to the housing 104 via the first and second brakes B1 and B2, respectively, and the third ring gear R3 always operates as an output element.

The power train configured as described above has the first clutch C1 and the first brake B1 at the first forward speed and the first clutch C1 and the second brake B2 at the second forward speed, as shown in the operation element table of FIG. 2. 1st, 3rd clutch (C1) (C3) at 3rd forward speed, 1st, 2nd clutch (C1) (C2) at 4th forward speed, 2nd, 3rd clutch (C2) (C3) at 5th forward speed, 6th at 6th forward speed By operating the second clutch C2 and the second brake B2 and the reverse, the third clutch C3 and the first brake B1 are operated to realize a shift stage of six forward speeds and one reverse speed.

In addition, the first planetary gear set PG1 and the third planetary gear set PG3 having the two operating elements connected to each other are configured to form one compound planetary gear set CPG by the fixed connection relationship. The planetary gear set (CPG) has two actuating elements fixedly connected to a total of six actuating elements, and includes four actuating elements, which form four nodes on the speed diagram.

3 is a speed diagram of a power train according to the embodiment of the present invention, wherein the first planetary gear set PG1 and the third planetary gear set PG3 are formed of a single pinion planetary gear set, and the first ring gear ( R1) and the first planet carrier PC1 are fixedly connected to the third sun gear S3 and the third planet carrier PC3, respectively, so that the first node N1 is the first sun gear S1 and the second node. N2 denotes the third ring gear R3, the third node N3 denotes the first and third planet carriers PC1 PC2, and the fourth node N4 denotes the first ring gear R1 and the third sun gear. (S3).

And the second planetary gear set (PG2) is input through the second sun gear (S2) at all gears, the second planetary carrier (PC2) is always operated as a fixed element and the second ring gear (R2) is input The output is always made in a state decelerated than the speed, and its output is connected to the planetary gear set (CPG) only at the forward, third, and fifth speed gears in which the third clutch C3 operates. Will affect.

Accordingly, for convenience of description, in FIG. 3, the second sun gear S2 is the fifth node N5, the second ring gear R2 is the sixth node N6, and the second planet carrier PC2 is the seventh node ( N7).

Looking at the shift process for the power train of the present invention, each node is set as described above, the second planetary gear set (PG2) is always input through the second sun gear (S2), the second planetary carrier (PC2) It is always operated as a fixed element, and always outputs at the same rotational speed as the arrow size between the fifth line (N5), which is an input element, and the seventh node (N7), which is a fixed element, and the sixth node (N6). This is done.

In the above state, the first clutch C1 and the first brake B1 operate at the first forward speed. In the composite planetary gear set CPG, the first clutch C1 is connected to the input shaft 100 by the first clutch C1. The first sun gear S1, that is, the first node N1 rotates at the same speed as the input shaft 100, and the third node N3 connected to the first brake B1 is in a stopped state.

 Accordingly, when the output is made as much as D1 between the first speed line L1 connecting the first node N1 and the third node N3 and the second node N2 as an output element, the speed of the first forward speed is made. You lose.

Of course, since the third clutch C3 does not operate, the second planetary gear set PG2 does not affect the first speed shift at all.

In addition, the first clutch C1 and the second brake B2 operate at the second forward speed, in which the fixing element is converted to the fourth node N4 in preparation for the first speed.

As a result, the fourth node N4 acts as a fixed element while the input is made through the first node N1. Thus, two connecting the first node N1 and the fourth node N4 is performed. The output is made as much as D2 between the speed line L2 and the second node N2, which is an output element, so that the speed of the second forward speed is made.

Of course, even when the second planetary gear set PG2 does not operate the third clutch C3, the second planetary gear set PG2 does not affect the second speed shift at all.

In the third forward speed, the first clutch C1 and the third clutch C3 are operated. In this case, the second planetary gear set PG2 is involved in the shift by the operation of the third clutch C3.

That is, the sixth node N6 formed of the second ring gear R2 is connected to the fourth node N4 by the operation of the third clutch C3. In this case, the sixth node N6 is decelerated. Since the output is made at the bar, the rotational speed is not a fixed element of "0", but acts as a fixed element having a constant speed, even though the input is made in the same manner as the second speed, such as the third speed line L3 (L3). ) Is formed and is output as much as D3 between the third speed line L3 and the second node N2, thereby shifting forward three speeds.

At the fourth forward speed, the first clutch C1 and the second clutch C2 are operated. In this case, the first sun gear (2) forming two operating elements of the compound planetary gear set CPG, that is, the first node N1 ( S1) and the first and third planet carriers PC1 and PC3 forming the third node N3 are simultaneously input to lock the composite planetary gear set CPG while the fourth speed line L4 is locked. As the output is formed as D4, the shift of the fourth forward speed is made.

In other words, at the fourth forward speed, the composite planetary gear set (CPG) is locked and is directly connected to output the input as it is.

At the 5th forward speed, the second and third clutches C2 and C3 are operated. In this case, the second planetary gear set PG2 is engaged in the shift as in the third forward speed by the operation of the third clutch C3. As a result, the second ring gear R2 operates as a fixed element having a constant speed.

Accordingly, the third node N3 is operated as an input element by the operation of the second clutch C2, and the sixth node N6 at the input speed line of the third node N3 and the fourth node N4. A fifth speed line L5 connecting the input speed line is formed, and the output is made as much as D5 between the fifth speed line L5 and the second node N2, so that the fifth forward speed is shifted.

That is, in the forward 5 speed as described above, the output becomes an overdrive state in which the output is formed larger than the input.

At the sixth forward speed, the second clutch C2 and the second brake B2 are operated. In this case, an input is made through the third node N3 as in the fifth forward speed, and the fourth node N4 is It will act as a stationary element.

However, at the sixth forward speed, since the second planetary gear set PG2 is not involved in the shift, the fourth node N4 acts as a fixed element in a state where the rotation state is "0", whereby the sixth speed line L6 is formed. In this case, an output such as D6 is generated between the sixth speed line L6 and the second node N2, which is an output element, and the sixth speed shift, which is the highest shift stage, is performed.

In the reverse shift stage, the third clutch C3 and the first brake B1 are operated. In this case, the output rotation speed of the sixth node N6 acts as the input rotation speed by the operation of the third clutch C3. The first and second planet carriers PC1 and PC2 act as fixing elements by the operation of the first brake B1.

Accordingly, the input corresponding to the rotational speed of the second ring gear R2 of the second planetary gear set PG2 is made at the fourth node N4, and the third node N3 acts as a fixed element. A reverse speed line LR is formed, and an output such as R is performed between the reverse speed line LR and the second node N2 which is an output element, so that the reverse shift is made.

In the power train of the present invention in which the shift is made in this way, there is no friction element that rotates faster than the input shaft at the third speed which is frequently used during overtaking acceleration, and the slip speed of the non-operating friction element is also smaller than the rotation speed of the input shaft.

And as shown in Figure 4a it can be seen that the number of planetary gearsets involved in the power transmission for the transmission in a plurality of gear stages in the power transmission path of the power train of the present invention, and thus higher power transmission efficiency It can be seen that it provides.

Although the preferred embodiment of the power train of the present invention has been described above, the present invention is not limited to the above embodiment, and those skilled in the art can easily invent from the embodiments of the present invention. It includes all changes to the extent considered equivalent.

As described above, the power train of the present invention can be implemented by combining three planetary gear sets and five friction elements to realize a shift stage of 6 forward speeds and 1 reverse speed, and thus can be compacted by reducing the overall length and weight.

In addition, by lowering the rotational speed of the operating element in the low speed gear stage, which is frequently used during acceleration, the durability is increased, the slip speed of the friction element is reduced, and the power transmission path is simplified, thereby improving durability and minimizing power loss. It becomes possible.

In addition, all of the planetary gear sets forming the composite planetary gear set are formed of a single pinion planetary gear set, thereby reducing power loss, and the fixed operating elements of the second planetary gear set are formed of planetary carriers, thereby rotating rotational inertia of the rotating element. Can be reduced.

1 is a view showing an embodiment of a power train to which the present invention is applied.

2 is an operation table of the power train according to the present invention.

3 is a shift diagram of a power train according to the present invention;

Figure 4 A, B, C is a view for comparing the power transmission path of the present invention and the prior art 1, 2.

5 shows a first embodiment of a conventional power train.

6 is an operating element table of the power train according to FIG. 5;

7 shows a second embodiment of a conventional power train.

8 is a table of operating elements of the power train according to FIG. 7.

Claims (8)

In the powertrain of an automatic transmission comprising a combination of a first planetary gear set, which is a single pinion planetary gear set, a second planetary gear set, which is a double pinion planetary gear set, and a third planetary gear set, which is a single pinion planetary gear set, The first planetary gear set and the third planetary gear set of the six operating elements of each of the two operating elements of the planetary gear set having the first, second, third, and fourth operating elements fixedly connected to each other, , The first actuating element of the actuating element is operated only by the optional input element, the second actuating element is operated by the constant output element, the third actuating element is selectively actuated by the input element and the fixed element, and the fourth The actuating element is optionally configured to act as a stationary element, The second planetary gear set has a fifth operating element acting as a constant input element, a sixth actuating element acting as a constant output element, and a seventh actuating element acting as a constant fixing element, The sixth operating element of the second planetary gear set is configured to output the rotation of the reduced speed with respect to the rotational speed of the input shaft to the fourth operating element of the composite planetary gear set. Genus power train. The six-speed power train of an automatic transmission for a vehicle according to claim 1, wherein the compound planetary gear set is disposed to the rear side of the second planetary gear set. 2. The composite planetary gear set of claim 1, further comprising: a first operating element comprising a first sun gear variably connected to the input shaft; A second actuating element acting as a third ring gear as a constant output element; A third actuating element in which the first planetary carrier and the third planetary carrier are fixedly connected and selectively act as input and stationary elements; A six-speed power train of an automatic transmission for a vehicle, characterized in that the first ring gear and the third sun gear are fixedly connected to each other and constitute a fourth operating element that selectively operates as an input and a fixed element. 4. A drive according to claim 1 or 3, wherein the first actuating element is connected to the input shaft via a clutch, the third actuating element is simultaneously connected to the input shaft and the transmission housing via a clutch and a brake, and the fourth actuating element is via a brake. A six-speed power train of an automatic transmission for a vehicle, characterized by being connected to a transmission housing. 5. The six-speed power train of an automatic transmission for a vehicle according to claim 4, wherein the clutch connecting the first operating element and the third operating element to the input shaft, respectively, is disposed on the front side of the second planetary gear set. 2. The second planetary gear set of claim 1, further comprising: a fifth operating element comprising a second sun gear fixedly connected to the input shaft; A sixth actuating element acting as a second ring gear as a constant output element; A six-speed power train of an automatic transmission for a vehicle, characterized by having a seventh actuating element fixedly connected to the transmission housing as a second planet carrier. The six-speed power train of an automatic transmission for a vehicle according to claim 1, wherein the fourth actuating element of the compound planetary gearset and the sixth actuating element of the second planetary gearset are connected via a clutch. A first planetary gear set, which is a single pinion planetary gear set having a first sun gear, a first planet carrier, and a first ring gear; A second planetary gear set, which is a double pinion planetary gear set having a second sun gear, a second planet carrier, and a second ring gear; A third planetary gearset, which is a single pinion planetary gearset having a third sun gear, a third planet carrier, and a third ring gear, is disposed in the order of the second, first, and third planetary gear sets from the input shaft; The first planetary carrier and the third planetary carrier, the first ring gear and the third sun gear are fixed to each other, The first sun gear and the first planet carrier are variably connected to an input shaft via first and second clutches, respectively, The third planetary carrier and the first ring gear are variably connected to the housing through the first and second brakes, respectively. The second sun gear and the second planet carrier are fixed to the input shaft and the transmission housing, respectively. And a sixth speed train of the vehicle automatic transmission, wherein the first ring gear and the second ring gear are variably connected via a third clutch.