KR100244944B1 - 4 speed automatic transmission - Google Patents

Abstract

An object of the present invention is to connect each gear element so as to have only a variable connection structure without the fixed connection structure in the gear train consisting of two sets of double pinion planetary gear mechanism and single pinion planetary gear mechanism, shifting the fourth gear and R (including three gears) It is to provide a four-speed automatic transmission that reduces the power loss by reducing the rotational speed of the entire element of the municipal planetary gear mechanism below the output rotational speed and the frictional loss by the arrangement characteristics of the other friction elements.

Means of the present invention for achieving the above object is configured to include a double pinion planetary gear mechanism (hereinafter referred to as a first gear mechanism) connected to the input shaft and a single pinion planetary gear mechanism (hereinafter referred to as a second gear mechanism) is connected to the output shaft A four-speed automatic transmission comprising: an input shaft connected to a carrier of the first gear mechanism, a first clutch for selectively connecting a ring gear of the first gear mechanism and a carrier of the second gear mechanism, and the first gear mechanism. A second clutch for selectively connecting the sun gear and the sun gear of the second gear mechanism, a third clutch for selectively connecting two elements selected from the ring gear, the sun gear and the carrier of the first gear mechanism, and the second clutch. A first brake for stopping rotation of the carrier of the gear mechanism, a second brake for stopping rotation of the sun gear of the second gear mechanism, and a ring gear of the second gear mechanism. Characterized in that is formed as a result that the output shaft and.

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 : Double pinion planetary gear mechanism (first gear mechanism)

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

1: Input shaft 2: First sun gear

3: first pinion gear (double type) 4: first carrier

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

7: 2nd pinion gear 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 constitutes a gear train with an automatic transmission, in particular a double pinion planetary gear mechanism connected to an input shaft and a single pinion planetary gear mechanism connected to an output shaft, and adopts only a variable connection structure without omitting a fixed connection structure between the gears. It only relates to a four-speed automatic transmission with one reverse gear.

[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 fixes one element as an input element and another as an output element. 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 also 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 practical train gear that satisfies all conditions such as mountability, manufacturability, shift characteristics, and required power performance in a vehicle.

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 of the Simpson type (US Patent No. 2,873,621) and the Ravigneaux type, which is the original support for 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 Application 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 that is integrally connected in the conventional Simpson method, and at the same time, the sun gear of the first planetary gear mechanism. And the carrier of the second planetary gear mechanism are connected through the fourth clutch, the third clutch is released to separate the first planetary gear mechanism and the second planetary gear mechanism, and the fourth clutch is connected to the second planetary gear. While inputting to the carrier of the gear mechanism, the sun gear of the second planetary gear mechanism 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 the independent element such as the ring gear of the second planetary gear mechanism becomes the input element or the output element or the fixed element, so that each planetary gear mechanism increases or decreases integrally or individually and shifts the rotation of the input shaft. It is transmitted as it is or inverted to the output shaft.

[Problems with Prior Art]

However, in the case of many of the conventional automatic transmission devices described above, the structures are not only too complicated, but also multiplied by the number of rotations in the fourth stage (including five stages) and R (reverse) where the rotation speed of the output shaft becomes higher than the input shaft. It is pointed out that the loss of the planetary gear mechanism that rotates at a high speed at a considerable speed compared to the output rotational speed causes a large loss. Also, the power caused by the sliding of friction elements such as clutches and brakes that control the planetary gear mechanism There is a problem that the loss is high.

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

[Problem of invention]

Accordingly, the present invention has been proposed in view of the above-mentioned problems, and its purpose is to adopt two variable planetary gear mechanisms by omitting fixed connection structure and adopting only variable connection structure. It is to provide a four-speed automatic transmission in which the speed of the entire element is rotated below the output rotation speed, and in particular, all the elements of the first gear mechanism rotate at the input rotation speed at four speed and R speed, thereby reducing the power loss.

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 second gear mechanism) to which an input shaft is connected, and a single pinion planetary gear mechanism (hereinafter referred to as a first gear mechanism) to which the input shaft is connected, as described in claim 1. A four-speed automatic transmission comprising: a first shaft selectively connecting an input shaft connected to a carrier of the first gear mechanism, and a ring gear of the first gear mechanism and a carrier of the second gear mechanism; A second clutch for selectively connecting a clutch, a sun gear of the first gear mechanism and a sun gear of the second gear mechanism, and selectively connecting two elements selected from a ring gear, a sun gear and a carrier of the first gear mechanism; A third clutch, a first brake for stopping rotation of the carrier of the second gear mechanism, and a second brake for stopping rotation of the sun gear of the second gear mechanism. , To which the first output shaft which is directly connected to the ring gear of the second gear mechanism, and a base a 4-speed automatic transmission, characterized in that it is formed from a.

According to the second aspect of the present invention, the first genus is obtained by combining only the first clutch, the second clutch, and the first brake, and the second genus is maintained while the first clutch and the second clutch are coupled to each other. The first brake is released and the second brake is engaged. The third speed is obtained by releasing the first and second brakes while the first, second and third clutches are engaged. The fourth speed is the second speed. Obtained by combining the first, third clutch and second brake in a state in which the clutch and the first brake are released, and the reverse (speed R) is the second and second in the state in which the first clutch and the second brake are released. The three-speed clutch and the first brake are combined to obtain a gear shift stage.

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

[First Embodiment]

1 is a skeleton diagram showing an embodiment of the automatic transmission of the present invention for achieving a shift stage of four forward reverse stages, one end of the input shaft 1 being connected to a torque converter (not shown) and the other end thereof. It is connected to the first sun gear 2 of the double pinion planetary gear mechanism PG ₁ , hereinafter simply referred to as the first gear mechanism PG ₁ .

The first gear mechanism PG ₁ is a first sun gear 2 and a first double pinion gear 3 that meshes with the first sun gear 2 and two pinion gears, hereinafter referred to as first pinion gear or pinion gear. And a first carrier 4 rotatably supporting the first pinion gear 3 and engaging the first pinion gear 3 and the first ring gear 5 which are rotatable. And the single pinion planetary gear mechanism PG ₂ (hereinafter referred to simply as the second gear mechanism PG ₂ ) arranged side by side with the first gear mechanism PG ₁ is a second sun gear 6 and the sun gear 6. The second pinion gear 7 engaged with the second pinion gear 7 and the second pinion gear 7 rotatably supporting the second pinion gear 7 and the second pinion gear 7 rotatable therewith; The ring gear 9 is comprised.

Both ring gears 5 and the carrier 8 of the first and second gear mechanisms PG ₁ and PG ₂ are connected by a connecting member 10 via the first clutch C ₁ . When the first clutch C ₁ is coupled, both ring gears 5 and the carriers 8 are fixedly connected to each other to rotate together and are driven separately when separated.

Both sun gears 2 and the sun gears 6 of the first and second gear mechanisms PG ₁ and PG ₂ are connected by a connecting member 11 via a second clutch C ₂ . Both sun gears 2 and sun gears 6 in the state in which the two clutches C ₂ are engaged also rotate in the same direction at the same time as the same elements, and in the uncoupled state, they rotate individually.

In addition, the first ring gear 5 and the first sun gear 2 of the first gear mechanism PG ₁ are connected by a connecting member 12 via a third clutch C ₃ to connect the third clutch ( ₃ ). When C ₃ ) is combined, the first ring gear 5 and the first sun gear 2 are integrally formed so that the first gear mechanism PG ₁ , in which two elements are connected as one, rotates as a whole. .

An output shaft 13 is connected to the second ring gear 9, and a second brake B2 is formed between the casing and the second carrier to stop the rotation of the second sun gear 6. The first brake B1 for stopping the rotation of 8) is provided between the casing.

Accordingly, the first and second clutches C ₁ and C ₂ selectively connect the ring gears 5 and the carriers 8 and the sun gears 2 and the sun gears 6 on both sides thereof (ie, a variable connection structure). In particular, the third clutch C ₃ is provided to selectively connect the sun gear 2 and the ring gear 5 of the first gear mechanism so that the entire first gear mechanism PG ₁ may be provided. Rotates into one, 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 , the second clutch C ₂ , and the first brake B ₁ . At this time, the second carrier 8 has a first brake (B _1), rotation is stopped at the same time the first clutch (C _1), the first ring gear (5) by the coupling is stopped with the second clutch (C ₂₎ by By combining the first sun gear 2 and the second sun gear 6 is driven at the same speed. Accordingly, the rotation of the input shaft 1 includes the second sun gear 6 rotating at the same speed as the first carrier 4, the first sun gear 2, and the first sun gear 2, and the second pinion gear 7 rotating. , And is transmitted to the output shaft 13 through the second ring gear 9 to obtain a reduced speed ratio.

[Second speed stage]

The transmission has the first clutch C ₁ and the second clutch C ₂ in a coupled state, while further engaging the second brake B2 and releasing the first brake B ₁ to the first speed stage. To change to the second speed stage.

When the second brake B ₂ is operated, the second sun gear 6 is braked with respect to the casing, so the rotation is stopped. At the same time, the rotation of the first sun gear is also stopped by the engagement of the second clutch C ₂ . By coupling, the first ring gear 5 and the second carrier 8 are integrally rotated 1: 1. Accordingly, the rotation of the input shaft 1 is transmitted to the output shaft 13 through the second carrier and the second ring gear rotating at the same rotational speed as the first carrier, the first ring gear, and the first ring gear, thereby reducing the reduction gear ratio. By outputting, a higher rotational speed than the first speed stage is obtained.

[3rd speed stage]

The transmission keeps the first and second clutches C ₁ and C ₂ engaged, while the second brake B ₂ is released and the third clutch C ₃ overlaps the first speed stage. It is changed to 3 speed stages.

When the first, second and third clutches C ₁ , C ₂ and C ₃ are coupled, the first ring gear 5 and the second carrier 8 are connected, and the ring gear 5 and the sun gear Since both sun gears 2 and sun gears 6 are connected at the same time, the first sun gear, the first ring gear, the second sun gear, and the second carrier all rotate at the same speed.

Accordingly, the first gear mechanism PG ₁ and the second gear mechanism PG ₂ are directly driven, and the transmission ratio is 1: 1 with the same input and output rotation speeds, and the entire element rotates at the input rotation speed.

[4th speed stage]

The transmission is engaged from the third speed stage to the fourth speed stage, ie overdrive, by releasing the second clutch C ₂ and engaging the second brake B ₂ while the first and third clutches remain engaged. You will be taken to a stage.

When the second brake B ₂ is engaged, the sun gear 6 is braked with respect to the casing to stop rotation, and the sun gear 2 and the ring gear 5 of the first gear mechanism PG ₁ are connected to the third clutch C _3. Since the first gear mechanism PG ₁ is rotated at an input rotational speed by the rotation of 1: 1, the ring gear 5 and the carrier 8 are rotated at the same speed by the first clutch coupling.

Accordingly, since the second ring gear 9 is driven and increased by the carrier 8 driven at the input rotation speed, the output rotation speed is increased compared to the input rotation speed. Therefore, except for the second ring gear, no element rotates faster than the input rotational speed, and all elements of the first gear mechanism rotate at the input rotational speed.

[Reverse step]

The transmission is shifted from neutral to reverse by engaging the second clutch C ₂ , the third clutch C ₃ , and the first brake B ₁ and releasing the rest.

The rotation of the second carrier 8 is stopped by the first brake B ₁ , and the first sun gear, the first ring gear, and the second sun gear rotate at the same speed by the connection of the second clutch and the third clutch. Accordingly, the first gear mechanism as a whole rotates at the input rotational speed, thereby reversing the second ring gear through the second sun gear and the rotating second pinion gear of the same speed, and the speed is decelerated.

Table 2 shows the power loss rates of the friction elements of an automatic transmission with two brake elements and three clutch elements, which are the conventional four-speed (four forward and one reverse) transmissions, including the Simpson type and Lavigno type. Slip loss) (specific model to be compared is Hyundai Motor Co., Ltd. A4BF1 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 according to the present invention is 43% of A4BF1, which is a comparison model at 1 speed and 2 speed, 60% at 4 speed, and 46% at backward, so it is about 55% overall. Rather, the power loss (loss due to the sliding of friction elements) is reduced by about 45%.

Second Embodiment

2 is a view showing another embodiment of the present invention, in which the third clutch C ₃ selectively connects the first sun gear 2 and the first ring gear 5 in the first embodiment (both elements are combined or Or to separate), in this embodiment, there is a difference that the first ring gear 5 and the first carrier 4 are selectively connected, i.e., combined or released. R, all elements 2, ₄ and 5 of the first gear mechanism PG ₁ rotate at the same speed.

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 this embodiment is 50% at 1st speed and 2nd speed, 60% at 4th speed and 46% at R speed, and the total is 58% level compared to the result of A4BF1. It can be seen that friction loss is reduced by about 42%.

Third Embodiment

3 is a view showing a third embodiment of the present invention. The third clutch C ₃ is configured to selectively engage or separate the first sun gear 2 and the first carrier 4, and the operation table and the four speed and The rotation of the entire element below the output speed in R speed (including 3 speed) 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 first ring gear, the second carrier, the first sun gear and the second sun gear of the first gear mechanism (double pinion planetary gear mechanism) and the second gear mechanism (single pinion planetary gear mechanism) are respectively clutched. By means of friction elements by means of the first and second gears, in particular by providing a clutch that selectively connects the carrier of the first gear mechanism with two elements selected from ring gears and sun gears. Since all the elements of the gear mechanism rotate at the input speed and the remaining elements rotate within the output speed, the gearbox with the conventional double pinion + single pinion planetary gear mechanism and five friction elements (clutch 3, brake 2) In comparison, the loss is greatly reduced, and the slip loss is reduced and the noise is reduced according to the arrangement characteristics of the friction elements.

Claims (2)

A four-speed automatic transmission comprising a double pinion planetary gear mechanism (hereinafter referred to as a first gear mechanism) to which an input shaft is connected and a single pinion planetary gear mechanism (hereinafter referred to as a second gear mechanism) to which an output shaft is connected, wherein the first gear mechanism An input shaft connected to a carrier of the first gear mechanism, a first clutch selectively connecting the ring gear of the first gear mechanism and the carrier of the second gear mechanism, and a sun gear of the first gear mechanism and a sun gear of the second gear mechanism. A second clutch for connecting, a third clutch for selectively connecting two elements selected from the ring gear, the sun gear and the carrier of the first gear mechanism, and a first for stopping the rotation of the carrier of the second gear mechanism; And a brake, a second brake for stopping rotation of the sun gear of the second gear mechanism, an output shaft directly connected to the ring gear of the second gear mechanism, and 4-speed automatic transmission that. The method of claim 1, wherein the first speed is obtained by combining only the first clutch, the second clutch, and the first brake, and the second speed is released while the first brake is maintained while the first clutch and the second clutch are coupled to each other. The second speed is obtained by combining two brakes, and the third speed is obtained by releasing the first and second brakes while the first, second and third clutches are engaged, and the fourth speed is obtained by removing the second clutch and the first brake. Obtained by combining the first, third clutch and second brake in the released state, the reverse (R-speed) is the second, third clutch and the first brake in the state in which the first clutch and the second brake is released Four-speed automatic transmission, characterized in that to obtain a gear shift by combining.