KR100244940B1 - 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 to the gear train consisting of two sets of single pinion planetary gear mechanism and single pinion planetary gear mechanism to rotate the entire planetary gear mechanism when R stage shifting It is to provide a four-speed automatic transmission that reduces the power loss by reducing the power loss by allowing the speed to rotate below the output rotation speed and the arrangement characteristics of the conventional friction elements.

Means of the present invention for achieving the above object is configured to include a single 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 sun gear of the first gear mechanism, a first clutch selectively connecting between a carrier of the first gear mechanism and a ring gear of the second gear mechanism, and the first gear. A second clutch for selectively connecting the sun gear of the mechanism and the sun gear of the second gear mechanism, a third clutch for selectively connecting two elements selected from the ring gear, the carrier and the sun gear of the first gear mechanism, and the first clutch. (2) A first brake for stopping rotation of the carrier of the gear mechanism, and for stopping rotation of both ring gears and sun gears fixedly connected to the first and second gear mechanisms. And a second brake, an output shaft directly connected to the ring gear of the second gear mechanism, 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 : Single 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 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 is a four-speed automatic transmission in which a gear train is composed of an automatic transmission, in particular, a single-pinion planetary gear mechanism connected to an input shaft and a single-pinion planetary gear mechanism connected to an output shaft, and employs a variable connection structure together with a fixed connection structure between the gears. It is about.

[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 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 of them can be used practically, but are limited to the use of a gear train having practical feasibility 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 very difficult 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, and the four-speed automatic transmission is based on a three-speed automatic transmission composed of two planetary gear mechanisms, and an overdrive drive mechanism or a hill consisting of one 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 increased. With a four-speed automatic transmission, it is difficult to meet the requirements.

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 type of automatic transmission, which has been used conventionally, it is modified little by little to meet the requirements. As an example, an automatic transmission that obtains four speeds by adding two clutches is 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 are integrally connected in the conventional Simpson method, and at the same time, the sun gear and the first gear of the first gear mechanism are interposed. 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, 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 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, 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. In particular, there is a problem that a large loss occurs due to an element that turns faster in the (-) direction than the output speed in the R stage. There is a problem in that a high power loss due to the sliding of friction elements such as clutches and brakes for controlling the mechanism.

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]

Therefore, the present invention has been proposed in view of the above problems, and its purpose is to adopt two sets of planetary gear mechanisms together with a fixed connection structure and a variable connection structure at the same time. The present invention provides a four-speed automatic transmission in which a power loss is reduced by rotating below the rotational speed, and in particular, allowing the entire element of the first gear mechanism to rotate at the input rotational 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 single 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 configured to include a first mechanism for selectively connecting an input shaft connected to the sun gear of the first gear mechanism and a carrier of the first gear mechanism and a carrier of the second gear mechanism; And a second clutch for selectively connecting the sun gear of the first gear mechanism and the carrier of the second gear mechanism, and selectively connecting two elements selected from the ring gear, the sun gear and the carrier of the first gear mechanism. A third clutch, a first brake for stopping the rotation of the carrier of the second gear mechanism, and both side ring gears and the sunshaft fixedly connected to the first and second gear mechanisms; And to a second brake for stopping the rotation of the four-speed automatic transmission, it characterized in that it is formed with the output shaft and directly connected to the ring gear of the second gear mechanism to the base.

According to the second aspect 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 speed is maintained in the engaged state of the first clutch. The third speed is obtained by engaging the brake, the third speed is obtained by releasing the first and second brakes and engaging the second clutch while maintaining the engagement state of the first clutch, and the fourth speed is obtained by releasing the first clutch. Obtained by combining the second clutch and the second brake, the reverse (R speed) is obtained by combining the third clutch and the first brake in a state in which the second clutch and the second brake is released.

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, 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 sun gear 2 of the single pinion planetary gear mechanism PG ₁ , hereinafter simply referred to as the first gear mechanism PG ₁ .

The first gear mechanism PG ₁ may freely support the first sun gear 2, the first pinion gear 3 and the pinion gear 3 meshed with the first sun gear 2, and rotate freely. A single pinion planetary gear mechanism composed of a rotatable first carrier 4 and the first ring gear 5 engaged with the first pinion gear 3 and arranged in parallel with the first gear mechanism PG ₁ . PG ₂ ) [hereinafter referred to simply as second gear mechanism PG ₂ ] refers to the second sun gear 6, the second pinion gear 7 meshing with the sun gear 6, and the second pinion gear 7. It is composed of a second carrier (8) rotatably supporting itself and a second ring gear (9) engaged with the second pinion gear (7).

The carrier 4 of the first gear mechanism PG2 and the ring gear 9 of the second gear mechanism PG ₂ are connected by a connecting member 10 via the first clutch C ₁ . When the first clutch C ₁ is coupled, both carriers 4 and 8 become fixed connection means, which rotate together with each other and are driven separately when separated.

The ring gear 5 and the sun gear 6 of the first and second gear mechanisms PG ₁ and PG ₂ are fixedly connected by the connecting member 11, and the first sun gear 2 and the second sun gear 2 are fixed. carriers (8) are the second clutch is associated by a connecting member (12) via a (C ₂₎ is a vehicle automatic transmission on both sides in the (C ₂₎ is coupled state the sun gear 2 and the carrier 8 also Like the same element, it rotates in the same direction at the same time, and in separate state, it rotates individually.

In addition, the first ring gear 5 and the first carrier 4 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 and the first carrier 4 are integrally formed so that the first gear mechanism PG ₁ having two elements connected together rotates as a whole. When the first clutch and the second clutch are coupled at the same time, all the elements of the first and second gear mechanisms rotate at the input rotational speed.

In addition, the three clutches are all located on the left side of the first gear mechanism, and the connecting members 10 and 12 share a part.

The output shaft 14 is connected to the second ring gear 8, and the second carrier 8 has a first brake B ₁ formed between the casing and fixedly connected at all times to stop its rotation. A second brake B ₂ for stopping rotation of both ring gear 5 and sun gear 6 is provided between the casing.

As such, the first and second clutches C ₁ and C ₂ selectively connect the carrier 4 and the carrier 8 on both sides, and the sun gear 2 and the carrier 8 (that is, a variable connection structure). In particular, the third clutch C ₃ is provided to selectively connect the carrier 4 and the ring gear 5 of the first gear mechanism so that the entire first gear mechanism PG ₁ is one. Rotation, 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 indicate that it is released (unoperated).

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 the first carrier rotational of 4 and the second carrier 8 is connected by a first clutch first stops doemeurosseo rotation at the same time by the brake (B ₁₎ an input shaft (1) has a first sun gear (2), Rotating first pinion gear (3), first ring gear (5), second sun gear (6), rotating second pinion gear (7), second ring gear (9) in order to the output shaft (14) ) To obtain a reduced speed ratio.

[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, since the second sun gear 6 and the first ring gear 5 are braked with respect to the casing, the rotation is stopped and the first clutch C ₁ is engaged so that both carriers 4 ) And the ring gear 9 are rotated 1: 1. Accordingly, the rotation of the input shaft 1 is transmitted to the output shaft 14 through the first sun gear 2, the first carrier 4, the second carrier 8, and the second ring gear 9 to reduce the reduction gear ratio. By outputting the power, a higher rotational speed than the first speed stage is obtained.

[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 first carrier 4, the first sun gear 2, and the second carrier 8 are connected to one and rotate at the same speed. The first gear mechanism PG ₁ and the second gear mechanism PG ₂ , in which two elements are directly connected by 10 and 11, are directly driven, 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, the ring gear 5 and the sun gear 6 are braked with respect to the casing to stop rotation, and the sun gear 2 of the first gear mechanism PG1 and the carrier of the second gear mechanism ( Since 8) rotates 1: 1 by the second clutch C ₂ , the second ring gear 9 is driven to increase speed by driving the second carrier 8 through the first sun gear 2. 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.

The first carrier 4 and the second ring gear 5 are connected by the third clutch C ₃ while the first carrier 8 is stopped from rotating by the first brake B ₁ . The entire element of the first gear mechanism and the second sun gear 6 are rotated at the input speed. Accordingly, the second ring gear 9 is reversed through the second pinion gear 7 rotating, 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 72% level of A4BF1, which is the comparison model at 1 speed and 2 speed, and 4 speed is 60% level and 70% at backward speed, so it is about 72% as a whole. It can be seen that power loss (loss due to sliding of friction elements) is reduced by about 28%.

Second Embodiment

2 is a view showing another embodiment of the present invention, in which the second clutch C2 selectively connects the first carrier 4 and the first ring gear 5 in the first embodiment (combines both elements, or In the present embodiment, there is a difference in that the first carrier 4 and the first sun gear 2 are selectively connected, i.e., coupled or released. It is the same as before that the entire elements 2, 4, 5 of the first gear mechanism PG1 rotate at the same speed and the remaining elements rotate below the output 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 78% at 1st speed and 2nd speed, 64% at 4th speed and 70% at R speed, and the total is 76% level compared to the result of A4BF1. It can be seen that the friction loss is reduced by about 24%.

Third Embodiment

3 is a view showing a third embodiment of the present invention. The second clutch C2 is configured to selectively engage or separate the first sun gear 2 and the first carrier 4, and the connecting member 13 is a connecting member 11. It is possible to connect in a form of sharing a part of the structure because it can not be installed to pass through the connecting member 10, the rotation of all the elements of the first gear mechanism in the operating table and the R in the operating speed and R in the above embodiments Is the same as

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 and the second sun gear of the first gear mechanism (single-pinion planetary gear mechanism) and the second gear mechanism (single-pinion planetary gear mechanism) are fixedly connected, and the first carrier and the second carrier are fixed. Between and between the first sun gear and the second carrier are selectively engageable or detachable as friction elements, respectively, and in particular a clutch for selectively connecting two elements selected from the carrier, ring gear and sun gear of the first gear mechanism. All elements of the first gear mechanism rotate at the input speed in R stage and the remaining elements also rotate within the output speed by providing a conventional single pinion + single pinion planetary gear mechanism and 5 friction elements ( Compared to the transmission with clutch 3 and brake 2), the loss is greatly reduced, and the slip loss is reduced according to the arrangement characteristics of the friction elements. The sound is reduced.

Claims (2)

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