KR20050120991A - Multi stage automatic transmission for a vehicle - Google Patents

Abstract

It implements 8 forward speed and 2 reverse speed, and the rotation speed of the idler element is smaller than the output element at high speed to minimize the power loss. ;

A first input path having a fixed first speed ratio with respect to rotation of the input shaft; A second input path having a second speed ratio of deceleration to rotation of an input shaft through the simple planetary gear set; The first and second actuating elements of the composite planetary gearset with four actuating elements can optionally act as input and reaction elements, the third actuating element as actuating elements and the fourth actuating element as an optional input. First and second clutches that operate as elements, and independently transmit rotation from the second input path to the fourth and first operating elements, respectively; Third and fourth clutches each independently transmitting rotation from the first input path to the first and second operating elements; A first brake for actuating the first actuating element as a reaction force element; A second brake for actuating the second actuating element as a reaction force element; A vehicle multistage automatic transmission comprising an output member connected to the third operating element.

Description

Multi-speed automatic transmission for vehicles {MULTI STAGE AUTOMATIC TRANSMISSION FOR A VEHICLE}

The present invention relates to a multi-stage automatic transmission for a vehicle, and more particularly, to a gear train for implementing an eight-speed transmission stage.

The automatic transmission for a vehicle is required to have multiple stages in order to secure driving ability and to improve fuel efficiency. In order to comply with this, it is desirable to reduce the number of operating elements and friction elements of the gear train as much as possible.

From this point of view, four-speed and five-speed automatic transmissions are the mainstream automatic transmissions currently in use, but recently, six-speed automatic transmissions have been developed and applied to vehicles, while active development of seven-speed automatic transmissions is active. It's going on.

As described above, in developing a six-speed or higher transmission, it has conventionally been combined by using one composite planetary gear set, at least one simple pinion planetary gear set, and at least six friction elements.

Although many technical details have been proposed as examples, the six-speed automatic transmission disclosed in Japanese Patent Publication No. 2778278 and the seven-speed gear train of Korean Patent Application Nos. 2003-0077691 and 2003-0079735 proposed by the present applicant For example.

However, in the case of No. 278, since the high speed state of the output member increases at the 5th speed and the 6th speed of the speed increase state, the resistance due to the slippage of the friction element is generated largely, thereby improving the power transmission efficiency due to the power loss. There is a problem of lowering.

And '691 is a combination of one planetary gear set, one simple pinion planetary gear set, and at least six friction elements to implement the seventh speed, but as a technical configuration to implement the seventh speed There is a problem of using unnecessary friction elements.

In addition, in the case of the '735, four simple pinion gear sets are divided into two axes arranged in parallel with each other, and the combination is made using eight friction elements, so that the technical configuration for the seventh speed is very complicated. Of course, the weight is, and includes various problems such as increasing the production cost.

Therefore, the present invention has been invented to solve the above-mentioned conventional problems, and an object of the present invention is to combine one complex planetary gear set, one simple planetary gear set, and six friction elements to move forward 8 speed and reverse 2 It is to provide a multi-stage automatic transmission for a vehicle having a gear train that can realize a speed shift stage.

In addition, the rotational speed of the idler element is smaller than the output element in the high speed state to minimize the power loss, to provide a multi-stage transmission for a vehicle to increase the power transmission efficiency.

In order to realize the above object, the present invention is a first planetary gear set consisting of a simple planetary gear set;

A first input path having a fixed first speed ratio with respect to rotation of the input shaft;

A second input path having a second speed ratio of deceleration with respect to rotation of an input shaft through the first planetary gear set;

The first and second actuating elements of the composite planetary gearset with four actuating elements can optionally act as input and reaction elements, the third actuating element as actuating elements and the fourth actuating element as an optional input. Act as an element,

First and second clutches each independently transmitting rotation from the second input path to the fourth operating element and the first operating element;

Third and fourth clutches each independently transmitting rotation from the first input path to the first and second operating elements;

A first brake for actuating the first actuating element as a reaction force element;

A second brake for actuating the second actuating element as a reaction force element;

It is characterized by providing a multistage automatic transmission for a vehicle comprising an output member connected to the third operating element.

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

 1 to 3 show a first embodiment of an automatic transmission for a vehicle according to the present invention. In the first embodiment, a transmission mechanism 4 is disposed on an input shaft 2 connected to a torque converter (not shown). The output element of the transmission mechanism 2 is connected with the counter gear 6 which is an output member.

The transmission mechanism 2 has a first input path T1 having a first speed ratio equal to the rotation of the input shaft 2 and a second speed ratio decelerated from the first planetary gear set PG1. It has a second input path (T2) having a second planetary gear set (PG2), which is a combination type planetary gear set having four operating elements.

The four actuating elements of the second planetary gear set PG2 are the first actuating element S3, the second actuating element {PC2 (PC3)}, and the third actuating element {R2 (R3) as in the speed diagram of FIG. )}, The first clutch (C1) and the first operating element for transmitting the rotational power from the second input path (T2) to the fourth operating element (S2), when set to the fourth operating element (S2) A second clutch C2 for transmitting to S3, a third clutch C3 for transmitting rotational power from the first input path T1 to a first operating element S3, and the second operating element; And a fourth clutch C4 for transmitting to {PC2 (PC3)}.

And a first brake B1 for latching the first actuation element S3 and a second brake B2 for latching the second actuation element PC2 PC3.

In the above, the clutch is given a sign according to the order in which it is arranged from the rear side to the front side, and it is assumed that the same reference numeral is also applied to other embodiments below.

The first planetary gear set PG1 consists of a double pinion planetary gear set, so that the first sun gear S1 always operates as an input element, and the first planet carrier PC1 supporting two pinions is always a fixed element. In operation, the first ring gear R1 outputs the rotational power of the deceleration to the second input path T2.

In the four operating elements constituting the second planetary gear set (PG2), the first operating element is a large diameter sun gear (S3), the second operating element to support two pinions (P2) (P3) in common Planetary carrier {PC2 (PC3)}, the third operating element is a common ring gear {R2 (R3)}, the fourth operating element is made of a small diameter sun gear (S2), two pinions (P2) (P3) The long pinion (P3) and the short pinion (P2) are externally engaged with each other, the short pinion (P2) is externally meshed with the small sun gear (S2), and the long pinion (P3) is externally meshed with the large-diameter pinion (S3) and At the same time, it is internally engaged to the ring gears R2 and R2.

The first clutch (C1) is made of a multi-plate clutch, the drum side is connected to the first ring gear (R1) of the first planetary gear set (PG1), the second input path (T2), the hub portion It is connected to the small diameter sun gear S2 of the second planetary gear set PG2.

The second clutch C2 is formed of a multi-plate clutch, the drum side of which is connected to the ring gear R1 of the first planetary gear set PG1 which is the second input path T2, and the hub side of the second planetary gear It is connected to the large diameter sun gear S3 of the set PG2.

The third clutch C3 is formed of a multi-plate clutch, the hub side of which is connected to the large-diameter sun gear S3 of the second planetary gear set PG2, and the drum portion is the first input path T1. Connected with

The fourth clutch C4 is formed of a multi-plate clutch, the hub side of which is connected to the common planet carrier (PC2 (PC3)) of the second planetary gear set PG2, and the drum portion is the first input path T1. It is connected to the input shaft (2).

The first brake B1 includes a multi-plate brake in which a drum part is connected to the first planetary carrier PC1 of the first planetary gear set PG1 to transfer the small diameter sun gear S2 of the second planetary gear set PG2 to the transmission case. It is comprised so that it may latch on (8).

The second brake B2 consists of a multi-plate brake that connects the hub side with the common planet carrier of the second planetary gear set PG2 (PC2 (PC3)).

The automatic transmission made as described above is shifted based on the vehicle load in the range of the shift stage according to the shift range selected by the driver under the control of an electronic control unit (not shown) and the hydraulic system.

Fig. 2 shows the shift stage achieved by the operation of the clutch and brake indicated by the symbol in the figure (denoted by O in the figure) and the release of operation, and Fig. 3 shows the shift stage achieved by engagement of each clutch and brake, and The speed diagram of each operating element is shown.

Referring to the operation relationship of the automatic transmission of the present invention made as described above based on Figures 1 to 3 as follows.

In the first speed, it is achieved by the operation of the first clutch C1 and the second brake B2, in which case the decelerating rotation of the second input path T2 from the first planetary gear set PG1 is carried out by the first clutch. The small diameter sun gear S1 is input through C1, and the common planet carrier PC2 PC3 acts as a reaction force by the operation of the second brake B2, so that the common ring gear R2 R3 is maximum. It is decelerated by and output through the counter gear 6 which is an output member.

In the second speed, the first clutch C1 and the first brake B1 are operated. In this case, the rotation of the first speed ratio of the second input path T2 from the first planetary gear set PG1 is performed. 1 is input to the small diameter sun gear S2 through the clutch C1, and the large diameter sun gear S3 acts as a reaction force by the operation of the first brake B1, and the decelerating rotation of the common ring gear R2 (R3) is output. It is output through the counter gear 6 which is a member. The speed ratio at this time is equal to the first speed, but becomes larger than the first speed as the reaction force element is converted into the first brake B1.

In the third speed, the first and second clutches C1 and C2 are simultaneously operated, in which case the decelerating rotation of the second input path T2 from the first planetary gear set PG1 is performed by the first and second clutches. Since the second dominant gear set PG2 is directly connected to the small-diameter and large-diameter sun gear S2 and S3 through (C1) and (C2) at the same time, the rotation of the ring gear {R2 (R3)} is performed. As a result, the rotation as it is input is output through the counter gear 6 as the output member.

At this time, since there is no relative rotation of all elements of the second planetary gear set PG2, there is no power transmission loss, and since the relative speed ratios of the remaining clutches and brakes in the released state are also 1 or less, slip resistance is small.

In the fourth speed, it is achieved by the simultaneous operation of the first clutch C2 and the third clutch C3, in which case the second speed of the second input path T2 from the first planetary gear set PG1 is on the one hand. Non-rotation is input to the small diameter sun gear S2 through the first clutch C1, and on the other hand, the first speed ratio rotation of the first input path T1 is passed through the third clutch C3 to the large diameter sun gear S3. ), The rotation which is decelerated by the speed ratio of the small diameter sun gear S2 and the large diameter sun gear S3 through the counter gear 6 whose deceleration rotation of the ring gear {R2 (R3)} is an output member. Is output.

At this time, as shown in the velocity diagram of Fig. 3, the common planet carrier {PC2 (PC3)} does not participate in power transmission and revolves in the same direction as the common ring gear {R2 (R3)}, but the speed ratio is 1 The power loss is small because it is not large and rotates in the same direction as other operating elements.

At the fifth speed, the first clutch C1 and the fourth clutch C4 are simultaneously operated. In this case, the decelerating rotation of the second input path T2 from the first planetary gear set PG1 is performed by the first clutch. The small diameter of the small diameter sun gear S2 is input through C1 and the rotation of the input shaft, which is the first input path T1, is input to the common planet carrier PC2 PC3 through the fourth clutch C4. The intermediate rotation with respect to the rotation of the sun gear S2 and the common planet carrier PC2 (PC3) is output through the counter gear 6, which is an output member, through the common ring gear R2 (R3).

The sixth speed is achieved by simultaneous operation of the third clutch C3 and the fourth clutch C4. In this case, the co-rotation of the input shaft 2, which is the first input path T1, is performed by the third and fourth clutch C3. The second planetary gear set PG2 is directly connected to the large-diameter sun gear S3 and the common planet carrier {PC2 (PC3)} through C4), and the rotation of the ring gear {R2 ( R3)} is outputted through the counter gear 6, which is an output member.

In this case, as in the third speed, since there is no relative rotation of all operating elements of the second planetary gear set PG2, there is no power transmission loss, and there is no problem of slip resistance of the remaining clutches and brakes.

In the seventh speed, it is achieved by the simultaneous operation of the second clutch C2 and the fourth clutch C4, in which case the second speed of the second input path T2 from the first planetary gear set PG1 on the one hand. Non-rotation is input to the large-diameter sun gear S3 through the second clutch C2, and rotation of the input shaft 2, which is the first input path T1, on the other hand, is carried out through the fourth clutch C4. By inputting to {PC2 (PC3)}, the speed increase rotation with respect to the rotation of the large diameter sun gear S3 and the planet carrier {PC2 (PC3)} common to the counter gear 6 is carried out through the common ring gear {R2 (R3)}. Will be displayed.

At the eighth speed, the fourth clutch C4 and the first brake B1 are simultaneously operated. In this case, the rotation of the input shaft 2, which is the first input path T1, is performed through the fourth clutch C4. The large ring sun gear S3 acts as a reaction force element by being input to the common planet carrier PC2 (PC3), and the common ring gear R2 (R3) acts as the seventh speed by the operation of the first brake B1. As it is further increased, it is output through the counter gear 6 as an output member.

In addition, in the case of the reverse 1 speed, it is achieved by the engagement of the second clutch C2 and the second brake B2. In this case, the deceleration rotation through the second input path T2 is performed through the second clutch C2. It is transmitted to the large diameter sun gear S3, and the common planet carrier PC2 PC3 acts as a reaction force by the second brake B2, so that the reverse rotation of the common ring gear R2 R3 is an output member. It is output through the counter gear 6.

At the second reverse speed, the third clutch C3 and the second brake B2 are engaged by each other. In this case, rotation of the input shaft 2 through the first input path T1 is performed through the second clutch C2. The large planetary sun gear S3 is transmitted, and the common planet carrier PC2 PC3 acts as a reaction force by the second brake B2, so that the reverse rotation of the common ring gear R2 R3 is reversed. It is increased more than 1 speed and is output through the counter gear 6 which is an output member.

As described above, according to the gear train of the first embodiment, in all forward shifting steps except forward 1 speed, reverse rotation does not occur in each operating element of the second planetary gear set. Can be prevented.

And since the reverse rotation of each operating element is not generated in the forward shift stage except for the forward 1 speed as described above, the relative rotational speed between each operating element is suppressed, the resistance of the oil is reduced to improve the power transmission efficiency.

In addition, if the relative rotational speed between the operating elements is suppressed, the bearing loads installed between the operating elements are also reduced, which is advantageous in terms of durability, and since the speed ratio of each operating element is not extremely high, the slip of the friction element or the load of the bearings is reduced. Is also suppressed.

4 and 5 show a second embodiment, in which the second planetary gear set is a laminate type, as in the first embodiment, and a common ring gear in the first embodiment {R2 (R3)}. Is an output element, but in the second embodiment, a common planet carrier (PC2 (PC3)) is formed as an output element.

That is, the small diameter sun gear S2 of the second planetary gear set PG2 is connected to the hub side of the second and third clutches C2 and C3 and the hub side of the first brake B1 as the first operating element. The common ring gear R2 (R3) is connected to the hub side of the fourth clutch C4 and the hub side of the second brake B2 as the second operating element, and the common planet carrier {PC2 (PC3)} is the third. It is connected to the counter gear 6 which is an output member as an element, and the large diameter sun gear S3 is connected to the hub side of the 1st clutch C1 as a 4th element.

In the second embodiment of the present invention configured as described above, the operation of each friction element is shifted while the operation is performed in the same state as in FIG. 2 as in the first embodiment.

5 shows a relationship between a speed change step achieved by the operation of each clutch and brake and the speed ratio of the operating element, according to the same method as in the case of the first embodiment.

That is, the operation of the third clutch C3 in order to make the common planet carrier (PC2 (PC3)) constituting the third actuating element become the output element and the second actuating element constitute the common ring gear R2 (R3)}. The relationship between the operating element and the output element controlled by the operation of the second brake B2 is different from that of the first embodiment, and the speed ratio at each shift stage is different, but the operation of each friction element at each shift stage The behavior of the second and third sun gears S2 and S3 is almost the same.

6 and 7 show a fifth embodiment modified from the second embodiment, in which the sun gear and the ring gear are reversed in the second type planetary gear set PG2 of the second embodiment. It is made up.

That is, among the long pinion P3 and the short pinion P2 meshed with each other, the long pinion P3 is externally meshed with the common sun gear {S2 (S3)}, and the long pinion P3 is inscribed with the small diameter ring gear R2. 4 actuated elements in the form of being engaged, and the short pinion (P2) is internally engaged with the large-diameter ring gear (R3).

Accordingly, the common sun gear {S2 (S3)} is connected as a first element to the hub side of the second clutch C2 and the hub side of the fourth clutch C3 and the hub side of the first brake B2, and has a large diameter. The ring gear R3 is connected to the hub side of the fourth clutch C4 and the hub side of the second brake B2 as the second operating element, and the common planet carrier (PC2 (PC3) is the counter gear as the third operating element). (6), the small-diameter ring gear R2 is connected to the hub side of the first clutch C1 as a fourth actuating element.

And the operation of each friction element in the third embodiment configured as described above is carried out in the same state as in Fig. 2 as in the first embodiment to perform a shift, Figure 7 is achieved by the operation of each clutch and brake The relationship between the speed change step and the speed ratio of the operating element is shown in the speed diagram according to the same method as in the above-described embodiments.

Since the common planet carrier (PC2 (PC3)) constituting the third operating element is the output element, and the second operating element is composed of the large-diameter ring gear R3, the operation of the third clutch C3 and the second brake are performed. The relationship between the operating element and the output element controlled by the operation of (B2) is different from that in the second embodiment, and the speed ratio in each shift step is different, but the second and third for the operation of each friction element in each shift stage. The behavior of the sun gear S2 (S3) and the small-diameter ring gear R2 is almost the same.

Although a preferred embodiment of the gear 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 the present invention from the embodiment of the present invention. It includes all changes to the extent considered equivalent.

As described above, the automatic transmission of the present invention can be combined with one composite planetary gear set, one simple planetary gear set, and four clutches and two brakes to implement a shift stage of 8 forward speed and 1 reverse speed. Therefore, the overall length and weight can be made compact.

In addition, since the high speed rotation of the idler element does not occur at all shifting stages except for the first speed, the slip speed of the friction element and the gear transmission loss are minimized, thereby improving durability and minimizing power loss. do.

In addition, since the reverse rotation of the idler element does not occur in all the forward shift stages except the first speed, the friction element control during shift up and down can be easily performed, and the reverse shift can be performed at two speeds. It is an invention that can use power.

1 shows a gear train of a first embodiment of an automatic transmission according to the invention;

2 is an operating element table of the gear train according to the first embodiment.

3 is a speed diagram of the gear train according to the first embodiment;

4 shows a gear train of a second embodiment of an automatic transmission according to the invention;

5 is a speed diagram of the gear train according to the second embodiment;

6 shows a gear train of a third embodiment of an automatic transmission according to the invention;

7 is a speed diagram of the gear train according to the third embodiment.

Claims (9)

A first planetary gear set comprising a simple planetary gear set; A first input path having a fixed first speed ratio with respect to rotation of the input shaft; A second input path having a second speed ratio of deceleration with respect to rotation of an input shaft through the first planetary gear set; The first and second actuating elements of the composite planetary gearset with four actuating elements can optionally act as input and reaction elements, the third actuating element as actuating elements and the fourth actuating element as an optional input. Act as an element, First and second clutches each independently transmitting rotation from the second input path to the fourth operating element and the first operating element; Third and fourth clutches each independently transmitting rotation from the first input path to the first and second operating elements; A first brake for actuating the first actuating element as a reaction force element; A second brake for actuating the second actuating element as a reaction force element; A vehicle multistage automatic transmission comprising an output member connected to the third operating element. 2. The clutch of claim 1, wherein the first clutch and the second brake are operated at the first speed, the first clutch and the first brake are operated at the second speed, the first and second clutches are operated at the third speed, and the first clutch is operated at the fourth speed. The first and third clutches are operated, the first and fourth clutches are operated at the fifth speed, the third and fourth clutches are operated at the sixth speed, the second and fourth clutches are operated at the seventh speed, and the fourth clutch is operated at the eighth speed. And the first brake is operated, and the second clutch and the second brake are operated at the reverse speed 1, and the third clutch and the second brake are operated at the reverse speed 2, so that a shift stage of 8 forward speeds and 2 reverse speeds is achieved. Automotive multistage automatic transmission. 2. The first planetary gearset of claim 1, wherein the first planetary gearset consists of a double pinion planetary gearset, wherein the first sun gear is operated as an input element, the first planet carrier is always operated as a stationary element, and the ring gear is a second input path. Multi-speed automatic transmission for a vehicle, characterized in that connected with. 2. The second actuating gear set according to claim 1, wherein the second planetary gear set includes a first actuating element composed of a large diameter sun gear, a short pinion engaged with the small diameter sun gear, and a planetary carrier supporting the long pinion engaged with the short pinion. A vehicular planetary gear set comprising a planetary gear set comprising a element, a third operating element including a ring gear engaged with the long pinion, and a fourth operating element formed with a saw sun gear engaged with the short pinion. Multi-speed automatic transmission. The first clutch of claim 1 or 4, wherein the first clutch is formed of a multi-plate clutch, the drum side of which is connected to the second input path, and the hub portion of the second planetary gear set is connected to the small diameter sun gear, The second clutch consists of a multi-plate clutch, the drum side of which is connected to the second input path, the hub side of which is connected to the large diameter sun gear of the second planetary gear set, The third clutch is composed of a multi-plate clutch, the hub side of which is connected to the large diameter sun gear of the second planetary gear set, and the drum portion is connected to the input shaft which is the first input path. The fourth clutch is composed of a multi-plate clutch, the hub side of which is connected to the common planet carrier of the second planetary gear set, and the drum portion is connected to the input shaft which is the first input path. The first brake comprises a multi-plate brake in which a drum portion is connected to the first planetary carrier of the first planetary gearset, and is connected to engage the small diameter sun gear of the second planetary gearset to the transmission case. The second brake is a multi-stage automatic transmission for a vehicle, characterized in that the hub side is made of a multi-plate brake connected to the common planetary carrier of the second planetary gear set. 2. The second actuating gear set according to claim 1, wherein the first actuating element of the second planetary gear set includes a small diameter sun gear, the second actuating element is a common ring gear, the third actuating element is a common planetary carrier, and the fourth actuating element is a large diameter sun gear. Automotive multi-stage automatic transmission consisting of a planetary planetary gear set.  The small diameter sun gear of the second planetary gear set is connected to the hub side of the second and third clutches and the hub side of the first brake as a first actuating element, and the common ring gear is of the second actuation. The element is connected to the hub side of the fourth clutch and the hub side of the second brake, and the common planet carrier is connected to the counter gear as the output member as the third element, and the large diameter sun gear is connected to the drum side of the first clutch as the fourth element. Multi-stage automatic transmission for vehicle characterized in that the connection. According to claim 1, The second planetary gear set is composed of an inverted laminate type in which the sun gear and the ring gear is reversed in the conventional cabinet type, wherein the long pinion of the long pinion and the short pinion meshing with each other is externally meshed with the common sun gear. And the long pinion is internally engaged with the small diameter ring gear and the short pinion is internally engaged with the large diameter ring gear. 9. The second planetary gear set according to claim 1 or 2, wherein the second planetary gear set has a first sun element with a common sun gear, a second sun element with a large diameter ring gear, a third sun element with a common planet carrier, and a fourth sun element with a small diameter. Multi-speed automatic transmission for a vehicle characterized by consisting of a ring gear.