KR100244747B1 - 4 speed automatic transmission - Google Patents

Abstract

An object of the present invention is to connect the respective gear elements to have a variable connection structure as well as a fixed connection structure in a gear train consisting of two sets of single pinion planetary gear mechanism and double pinion planetary gear mechanism, the entire planetary gear mechanism during the R stage (reverse) shifting It is to provide a four-speed automatic transmission in which the rotational speed of the element is rotated between the input rotational speed and the output rotational speed to reduce the power loss and the frictional loss by the arrangement characteristic of the conventional friction elements.

Means of the present invention for achieving the above object comprises a single pinion planetary gear mechanism (hereinafter referred to as a first gear mechanism) to which the input shaft is connected and a double pinion planetary gear mechanism (hereinafter referred to as a second gear mechanism) to which the output shaft is connected. A four-speed automatic transmission comprising: a first clutch for selectively connecting both input shafts connected to a ring gear of the first gear mechanism, carriers on both sides of the first and second gear mechanisms, and the first and second gear mechanisms. A second clutch for selectively connecting both ring gears of the first gear, a third clutch for selectively connecting two elements selected from a sun gear, a carrier and a ring gear of the first gear mechanism, and a ring gear of the second gear mechanism. A first brake for stopping rotation of the first brake, a second brake for stopping rotation of both sun gears fixedly connected to the first and second gear mechanisms, and a carrier of the second gear mechanism. And an output shaft directly connected to each other.

Description

4-speed automatic transmission

1 is a system diagram showing a first embodiment of a four-speed automatic transmission according to the present invention.

2 is a system diagram showing a second embodiment of a four-speed automatic transmission according to the present invention.

3 is a system diagram showing a third embodiment of a four-speed automatic transmission according to the present invention.

<Explanation of symbols for main parts of drawing>

PG ₁ : Single pinion planetary gear mechanism (first gear mechanism)

PG ₂ : Double pinion planetary gear mechanism (second gear mechanism)

1: Input shaft 2: First sun gear

3: first pinion gear 4: first carrier

5: 1st ring gear 6: 2nd sun gear

7: 2nd pinion gear (double type) 8: 2nd carrier

9: second ring gear 10,11,12,13: connecting member

14: output shaft B ₁ , B ₂ : brake

C ₁ , C ₂ , C ₃ : Clutch

[Industrial use]

The present invention relates to a four-speed automatic transmission in which a gear train is composed of an automatic transmission, in particular, a single pinion planetary gear mechanism and a double pinion planetary gear mechanism, and employs a variable connection structure together with a fixed connection structure between the gears.

[Private Technology]

As is well known, the transmission serves to increase or decrease the rotational force of the engine according to the change of the driving state of the vehicle, and also has a reverse device for reversing the vehicle. As a device for enabling this, a planetary gear mechanism is used.

The planetary gear mechanism has three elements, a sun gear and a ring gear, and a carrier for preserving the pinion gears engaged with the gears. The planetary gear mechanism has one element as an input element and the other as an output element and fixes the remaining elements. Therefore, it is possible to increase or decelerate the input rotation or reversely decelerate and output the gear. Usually, only one planetary gear mechanism makes it difficult to obtain a desired gear stage. It consists. In this case, the gear ratio of the planetary gear mechanism, the gear ratio of the planetary gear mechanism, and the single pinion type planetary gear mechanism or the double pinion type planetary gear mechanism and the friction factors controlling them vary. However, not all combinations thereof can be used practically, but are limited to the use of a gear train having practical viability that satisfies all conditions such as mounting on a vehicle, manufacturability, shift characteristics, and required power performance.

However, since such a gear train can be composed of a large number by the combination of the planetary gear mechanism and the gear ratio setting method, it is a very difficult task to find a product that satisfies the requirements for an automatic transmission for a vehicle.

Conventionally, a number of gear transmissions have been proposed under such a background. Among them, a four-speed automatic transmission is based on a three-speed automatic transmission composed of two planetary gear mechanisms, and an overdrive drive mechanism or an underbody planetary gear mechanism. By installing a driver mechanism, the gearbox has achieved 4 forward speeds.

However, in recent years, the automatic transmission used by the front engine and high horsepower is required to be further downsized, and the transmission torque capacity is also required to increase. However, three planetary gear mechanisms are installed by installing the overdrive mechanism. With a four-speed automatic transmission, it is difficult to meet the demand situation.

Therefore, based on the planetary gear mechanism and the Ravigneaux type of the Simpson type (Simpson type, US Patent No. 2,873,621), which is the original support of the automatic transmission, which has been conventionally used, it is modified little by little to meet the requirements. As an example, an automatic transmission that obtains four speeds by adding two clutches has been proposed in Japanese Patent Laid-Open No. 59-183147.

The automatic transmission mechanism interposes a third clutch between the sun gear of the first planetary gear mechanism and the sun gear of the second planetary gear mechanism, which is integrally connected in the conventional Simpson method, and simultaneously with the sun gear of the first gear mechanism. The carrier of the second gear mechanism is connected through the fourth clutch, the third clutch is released to separate the first gear unit and the second gear unit, and the fourth clutch is connected to the carrier of the second gear unit. At the same time as input, the sun gear of the second gear unit is fixed to output the overdrive from the ring gear, and the fourth speed is obtained in addition to the conventional three speeds.

Other four-speed automatic transmissions include Japanese Patent Publication No. 61-19866, Japanese Patent Publication No. 61-37493, Japanese Patent Publication No. 61-37494, and US Patent No. 4369672.

Among them, the automatic transmission described in Japanese Patent Laid-Open No. 61-19866 includes two single pinion planetary gear trains and one double pinion planetary gear train and the planetary gearbox. It consists of two clutches and three brakes for controlling the gear mechanism.

On the other hand, the automatic transmission device disclosed in Japanese Patent Laid-Open Publication No. 3-74658 includes three sets of single-pinion type planetary gear mechanisms and the ring gear of the first planetary gear mechanism and the carrier of the second planetary gear mechanism are always connected or engaged. The carrier of the first planetary gear mechanism and the ring gear of the third planetary gear mechanism are selectively connected via means, and are selectively connected through the constant connection or engagement means, and the sun gear and the third planetary gear of the first planetary gear mechanism are also selectively connected. The sun gear of the mechanism is selectively connected via always-connecting or engaging means. In addition, the ring gear of the first planetary gear mechanism and the carrier of the second planetary gear mechanism are integrally or individually with each other, and the carrier of the first planetary gear mechanism and the ring gear of the third planetary gear mechanism are integrally or individually with each other. The sun gear of the planetary gear mechanism and the carrier of the third planetary gear mechanism are integrally or individually with each other, and the sun gear of the second planetary gear mechanism and the sun gear of the third planetary gear mechanism are integrally or individually with each other. Element, and independent elements such as ring gears of the second gear mechanism become input elements or output elements or fixed elements, so that each planetary gear mechanism increases or decreases integrally or individually, and shifts or rotates the input shaft. Inverted or transmitted to the output shaft.

[Problems with Prior Art]

However, many of the conventional automatic transmission devices described above are not only complicated in structure, but also multiplied by 4 times (including 5 stages) in which the rotational speed of the output shaft becomes higher compared to the input shaft, and many times compared to the output rotation speed. There is a gear element of the planetary gear mechanism that rotates at a high speed at a considerable speed. It is pointed out that a problem that a loss occurs largely because there is a faster element in the direction, and also a power loss caused by the sliding of friction elements such as clutches and brakes that control the planetary gear mechanism.

On the other hand, the presence of an element with a higher rotational speed than the number of rotations of the input and output shafts causes noise, and also causes problems such as power loss and temperature rise due to the resistance of the transmission oil.

[Problem of invention]

Therefore, the present invention has been proposed in view of the above problems, and its object is to adopt two sets of planetary gear mechanisms together with a fixed connection structure and a variable connection structure at the same time. It is to provide a four-speed automatic transmission that reduces the power loss by allowing the speed to rotate below the output rotation speed, and in particular, all the elements of the first gear mechanism to rotate at the input rotation speed.

Another object of the present invention is a four-speed automatic transmission that minimizes sliding power loss of each friction element by properly arranging the clutch friction elements used for shift control to selectively connect the respective gears between the planetary gear mechanisms. To provide.

Another object of the present invention to provide a four-speed automatic transmission of the structure that can reduce the noise generation.

[Means for solving the problem]

The present invention provides a single pinion planetary gear mechanism (hereinafter referred to as a first gear mechanism) to which an input shaft is connected and a double pinion planetary gear mechanism (hereinafter referred to as a second gear mechanism) to achieve the above object as described in claim 1. A four-speed automatic transmission comprising: a first clutch for selectively connecting an input shaft connected to a ring gear of the first gear mechanism, and both carriers of the first and second gear mechanisms; A second clutch for selectively connecting both ring gears of the first and second gear mechanisms, a third clutch for selectively connecting two elements selected from a sun gear, a carrier and a ring gear of the first gear mechanism; A first brake for stopping rotation of the ring gear of the second gear mechanism and a second brake for stopping rotation of both sun gear fixedly connected to the first and second gear mechanisms; And, to a 4-speed automatic transmission, it characterized in that it is formed from the output shaft to be directly coupled to the carrier of the second gear mechanism, with a base.

In addition, according to claim 2 of the present invention, the first speed is obtained by combining only the first clutch and the first brake, and the second speed is released while the first brake is released while the second brake is engaged with the first clutch. The third speed is obtained by releasing the first and second brakes and combining the second clutch while maintaining the engaged state of the first clutch, and the fourth speed is obtained by releasing the first clutch. The second clutch is obtained by combining the second brake, and the reverse direction (R speed) is obtained by combining the third clutch and the first brake while the second clutch and the second brake are released.

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

[First Embodiment]

1 is a schematic diagram illustrating an embodiment of an automatic transmission of the present invention for achieving a shift stage of four forward reverse stages, and one end of the input shaft 1 is connected to a torque converter, not shown, and the other end thereof. It is connected to the first ring gear 5 of the first single-pinion planetary gear tool PG ₁ , hereinafter simply referred to as the first gear mechanism PG ₁ .

The first gear mechanism PG ₁ supports the first sun gear 2, the first single pinion pinion gear 3 and the pinion gear 3 meshed with the first sun gear 2 in a freely rotating manner. A second double pinion which is composed of a first carrier 4 rotatable and the first ring gear 5 engaged with the first pinion gear 3 and arranged in parallel with the first gear mechanism PG ₁ . The planetary gear mechanism PG ₂ (hereinafter referred to simply as the second gear mechanism PG ₂ ) is a second sun gear 6 and a second double pinion gear 7 meshing with the sun gear 6 [second double pinion]. The gear is composed of two to change the rotation direction, hereinafter referred to as second pinion gear or pinion gear]; A second carrier 8 and a second ring gear 9 engaged with the second pinion gear 7 are rotatable while supporting the second pinion gear 7 freely.

Both carriers 4 and 8 of the first and second gear mechanisms PG ₁ and PG ₂ are connected by a connecting member 10 via a first clutch C ₁ so that the first clutch When (C ₁ ) is coupled to both carriers (4) (8) is a fixed connection means to rotate together integrally and is driven separately when separated.

Since the sun gears 2 and 6 of the first and second gear mechanisms PG ₁ and PG ₂ are directly connected by the connecting member 11, they are actually formed as a single unit having a long length. 5 (9) are the second clutch is associated by a connecting member (12) via a (C ₂₎ and the second clutch (C ₂₎ is coupled state both sides of the ring gear (5) (9) in Like the same element, it rotates in the same direction at the same time and rotates individually in the disengaged state.

In addition, the first ring gear 5 and the first sun gear 2 of the first gear mechanism PG ₁ are connected by the connecting member 13 via the third clutch C ₃ to connect the third clutch ( ₃ ). When C ₃ ) is combined, the first ring gear 5, the first sun gear 2, and the input shaft 1 are integrally formed so that the first gear mechanism PG ₁ , in which two elements are connected as _one , is a whole. Will rotate.

The output shaft 14 is connected to the second carrier 8, and the second ring gear 9 has a first brake B ₁ formed between the casing and the first brake for stopping its rotation. A second brake B ₂ for stopping rotation of the second sun gear 2 and 6 is provided between the casing.

Accordingly, the first and second clutches C ₁ and C ₂ selectively connect the carrier 4 and the carrier 8, the ring gear 5 and the ring gear 9 on both sides thereof (ie, the variable connection structure). In particular, the third clutch C ₃ is provided to selectively connect the ring gear 5 and the sun gear 2 directly connected to the input shaft 1, thereby providing the first gear mechanism PG _1. ) Rotates as a whole, which forms one of the important features for achieving the object of the present invention.

The automatic transmission device of FIG. 1 has a first speed stage according to engagement and release of the three clutches C ₁ , C ₂ , C ₃ and the two brakes B ₁ , B ₂ as summarized in Table 1. , Second speed stage, third speed stage (direct drive stage), fourth speed stage (overdrive stage) and reverse (R) are obtained.

In this table, 0 indicates that the clutch or brake is engaged (operated) while the engine is running, and blanks are released (disengaged).

Hereinafter, five shifts of the fourth forward speed and the first reverse speed will be described with reference to Table 1 below.

[1st speed stage]

The transmission is changed from neutral to the first speed stage by the combination of the first clutch C ₁ and the first brake B ₁ . At this time, since the rotation of the second ring gear 9 is stopped by the first brake B ₁ and the first and second carriers 4 and 8 are driven together by the first clutch C ₁ , the input shaft ( The rotation of 1) is transmitted to the output shaft 14 through the first ring gear 5, the first carrier 4, the second carrier 8 and both sun gears 2 and 6 fixedly connected to the output shaft 14, and the speed ratio is reduced. Get

[Second speed stage]

The transmission is changed from the first speed stage to the second speed stage by leaving the first clutch C ₁ engaged while additionally engaging the second brake B ₂ and releasing the first brake B ₁ . do.

When the second brake B ₂ is operated, the sun gears 2 and 6 on both sides are braked with respect to the casing, so the rotation is stopped and the first clutch C ₁ is engaged so that both ring gears 5 and 9 are engaged. The rotation of the input shaft 1 is output by reducing the gear ratio through the output shaft 14 by the rotation of the carrier 4 and 8 and the output of the rotational speed higher than the first speed stage.

[3rd speed stage]

The transmission is changed from the second speed stage to the third speed stage by maintaining the engaged state of the first clutch C ₁ while releasing the second brake B ₂ and engaging the second clutch C ₂ .

When the first and second clutches C ₁ and C ₂ are coupled, the carrier 4 and the carrier 8 are directly connected to each other, and the ring gear 5 and the ring gear 9 are directly connected to each other. Since the sun gears 2 and 6 are connected, the first gear mechanism PG ₁ and the second gear mechanism PG ₂ are in a direct driving state, and the transmission ratio becomes 1: 1 with the same input and output rotation speed.

[4th speed stage]

The transmission is changed from the third speed stage to the fourth speed stage, that is, the overdrive stage by releasing the first clutch C ₁ and engaging the second clutch C ₂ and the second brake B ₂ .

When the second brake B ₂ is engaged, both side gears 2 and 6 are braked with respect to the casing to stop rotation, and both ring gears 5 and 9 are 1: 1 by the second clutch C ₂ . Since the second carrier C ₂ rotates at an increased speed around the second sun gear 6, the output speed is increased compared to the input speed.

[Reverse step]

The transmission is changed from the neutral to the reversed stage by combining the third clutch C ₃ and the first brake B ₁ and releasing the rest.

Since the second ring gear 9 is stopped from rotating by the first brake B ₁ , the second gear mechanism PG ₁ rotates only the second carrier 8 and the second sun gear 6, The ring gear 5 and the first sun gear 2 are connected by the third clutch C ₃ and rotate at the same speed, so that the first sun gear 2 and the first carrier of the first gear mechanism PG ₁ are rotated. 4) and the first ring gear 5 both rotate at the same rotational speed, which causes the second carrier 8 to rotate in reverse with the second gear mechanism PG ₂ .

Table 2 shows the power loss ratios of the friction elements of an automatic transmission having two brake elements and three clutch elements, which are the conventional four-speed (four forward and one reverse) transmissions, Simpson type and Lavigno type. Relative slip loss during non-operation) (specific model to be compared is Hyundai A4 BF1 transmission) Table 3 shows the power loss rate of each friction element of the present invention having the same conditions.

The gear ratios of the two sides to be compared were used as 2.846 in the first stage, 1.581 in the second stage, 0.685 in the first and fourth stages, and 0.685 in the fourth stage.

Since the method of calculating the power loss rate due to the sliding of the friction elements is well known, a description of the calculation formula is omitted here and only the results are compared.

As shown in the above table, the power loss by the present invention is about 85% of the A4BF1 model compared to 4 speeds and 80% when backing, so the overall power loss is about 91%. You can see the savings.

Second Embodiment

2 is a view showing another embodiment of the present invention in which the third clutch C ₃ selectively engages or separates the first ring gear 5 and the first sun gear 2 in the first embodiment. In this embodiment, there is a difference that the first ring gear 5 and the first carrier 4 are selectively connected, i.e., coupled or released, except that the entire elements of the first gear mechanism in the operating table and the R stage are input rotational speeds. Being rotated is the same.

Table 4 below is a chart showing the power loss due to the sliding of the friction elements of the embodiment.

As described above, the power loss due to the sliding of the friction element of the embodiment is compared with the result of A4BF1.

1 speed: 68% level

2 Speed: 68% level

4 speed: 66%

R hour: 80% level

Total: 76%, friction loss is reduced by 24%.

Third Embodiment

3 is a view showing a third embodiment of the present invention. The third clutch C ₃ is configured to selectively couple or separate the first sun gear 2 and the first carrier 4, and the operation table and the R stage ( The rotation of all the elements of the first gear mechanism at the input speed in reverse is also the same as in the previous embodiments.

Table 5 shows the power loss due to the sliding of the friction elements of the embodiment.

[effect]

According to the present invention as described above, the sun gear and the sun gear of the first gear mechanism (single-pinion planetary gear mechanism) and the second gear mechanism (double pinion planetary gear mechanism) are fixedly connected, and between each ring gear and between the carriers are respectively connected to the clutch. By means of friction elements to selectively engage or disengage, in particular by providing a clutch for selectively connecting two elements selected from among the sun gear, the ring gear and the carrier of the first gear mechanism. Since all elements rotate between the input and output speeds, the loss is greatly reduced compared to a transmission having a conventional single pinion + double pinion planetary gear mechanism and five friction elements (clutch 3, brake 2) and also a friction element. According to the arrangement characteristics of these, the slip loss is reduced and the noise is effective.

Claims (2)

A four-speed automatic transmission comprising a single pinion planetary gear mechanism (hereinafter referred to as a first gear mechanism) to which an input shaft is connected and a double pinion planetary gear mechanism (hereinafter referred to as a second gear mechanism) to which an output shaft is connected, wherein the first gear mechanism A second clutch for selectively connecting an input shaft connected to a ring gear of the first gear, a first clutch selectively connecting both carriers of the first and second gear mechanisms, and both ring gears of the first and second gear mechanisms. A third clutch for selectively connecting two elements selected from among the sun gear, the carrier and the ring gear of the first gear mechanism, a first brake for stopping rotation of the ring gear of the second gear mechanism, and And a second brake for stopping rotation of both sun gears fixedly connected between the first and second gear mechanisms, an output shaft directly connected to the carrier of the second gear mechanism, and 4-speed automatic transmission as. The method of claim 1, wherein the first speed is obtained by combining only the first clutch and the first brake, and the second speed is obtained by releasing the first brake and engaging the first brake while maintaining the engaged state of the first clutch. The third speed is obtained by releasing the first and second brakes while engaging the first clutch and engaging the second clutch, and the fourth speed is obtained by releasing the first clutch and the second clutch and the second clutch. Obtained by engaging the brake, the reverse (R speed) is a four-speed automatic transmission, characterized in that to obtain a gear stage by combining the third clutch and the first brake in a state in which the second clutch and the second brake is released.