JPH05172201A - Automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To embody transmission of four forward stages and one reverse stage through two pairs of planetary gearing, and simultaneously shorten whole length of the device, simplify the structure of the input shaft, improve easiness of reinforcing the gear train, prevent temperature rise of oil due to heating of the clutch, made the transmission compact and increase the capacity of the clutch. CONSTITUTION:A first planetary gearing PG1 and a second planetary gearing PG2 are arranged on a first shaft SFT1, to which output from a power source is input. A second shaft SFT2 is arranged so as to be parallel to the first shaft SFT1. First, second and third transfer gear trains TG1, TG2 and TG3 are provided between the first shaft SFT1 and the second shaft SFT2. A first clutch C1 and a first brake B1 are provided on the first shaft side. Second to fourth clutches C2-C4, and a second brake B2 are provided on the second shaft side. Thus, the respective clutches and brakes are arranged so as to be distributed on the first and second shafts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for a vehicle, and more particularly to an automatic transmission capable of shifting four forward speeds and one reverse speed by two sets of planetary gears.

[0002]

2. Description of the Related Art Conventionally, two sets of planetary gears are used to move forward four speeds,
As an automatic transmission capable of shifting to the first reverse speed, the one disclosed in Japanese Patent Laid-Open No. 62-1645 is known as a laterally arranged type, and as the vertically arranged type. The one described in JP 61-290264 A is known. These are equipped with two sets of planetary gears consisting of sun gears, ring gears and pinion carriers,
It has a structure in which a plurality of clutches and brakes are provided coaxially with these planetary gear sets.

[0003]

However, in the prior art as described above, since the planetary gear set, the clutch and the brake are all arranged on one shaft, the problems listed below occur.

The longitudinal dimension becomes long. The arrangement density of planetary gears, clutches, and brakes is high, and it is difficult to strengthen the gear train.

The shaft has a triple structure on the input shaft, which is disadvantageous in terms of strength and difficult to center. Since the clutches are centrally located, heat builds up and the oil temperature easily rises. Since the clutch elements are centrally arranged as described above,
Since there is a large restriction on the axial dimension of the clutch and an attempt to increase the capacity of the clutch requires an increase in the outer diameter, the device becomes large in size, and it is difficult to make the device compact and increase the clutch capacity at the same time.

The present invention has been made in view of the above problems, and shortens the overall length of the device, simplifies the structure of the input shaft, improves the easiness of strengthening the gear train, prevents the oil temperature from increasing due to heating of the clutch, and improves the clutch. It is an object of the present invention to provide an automatic transmission for a vehicle that can achieve both miniaturization and increased capacity at the same time.

[0007]

According to the present invention, a second shaft is provided in parallel with a first shaft provided with two planetary gear sets, and necessary clutches and brakes are dispersedly arranged on the first shaft and the second shaft. In order to achieve the above purpose.

That is, in the vehicle automatic transmission according to the present invention, the first shaft to which the output of the power source is input, the second shaft arranged in parallel with the first shaft, and the first shaft are arranged. hand,
A first planetary gear set having a first sun gear, a first ring gear, and a first pinion carrier supporting a plurality of pinions that mesh with both gears; and a first planetary gear set disposed on the first shaft and rotating integrally with the first shaft. A second sun gear, a second ring gear, and a second pinion carrier that supports a plurality of pinions that mesh with both gears and that has a second pinion carrier that can rotate integrally with the first ring gear.
A planetary gear set, a first power transmission means for transmitting power between the first shaft and the second shaft, and a second power transmission means for transmitting power between the second shaft and the second ring gear. , The first
A first clutch that is provided on the shaft and that enables or blocks power transmission between the first shaft and the first sun gear; and a first clutch that enables or blocks power transmission of the first power transmission means. A second clutch and a second clutch provided on the second shaft,
A third clutch that enables or disconnects power transmission by the power transmission means, a first brake that is provided on the first shaft and can stop the first sun gear, and a third clutch that is provided on the second shaft. A second brake capable of stopping two axes, and the second brake
A third power transmission means for transmitting power between the shaft and the first pinion gear is provided.

A one-way clutch and a fourth clutch may be provided in parallel in the middle of the second power transmission means. Further, the second clutch may be arranged on the second shaft.

[0010]

In the automatic transmission for a vehicle according to claim 1,
By operating the third clutches and the first and second brakes, it is possible to perform forward 4th speed and reverse 1st speed.
In this vehicle transmission, the second shaft is provided in parallel with the first shaft provided with the two sets of planetary gears, and the clutch and the brake are dispersedly arranged on the first shaft and the second shaft. The dimension in the direction can be shortened, and the structure around the shaft and around the clutch and brake can be simplified. In addition, the number of oil holes formed in one shaft is small, which is advantageous in strength, and the shaft does not need to have a triple structure, which is advantageous in strength and centering. ..

Further, the arrangement density of the planetary gears, the clutches and the brakes in the axial direction becomes low, the reinforcement of the gear train becomes easy, and the capacity of the clutch can be easily expanded without expanding the outer diameter. Becomes Moreover, since the heat generation portions of the clutch and the brake are dispersed, the heat is also easily dissipated and the rise in the oil temperature can be suppressed.

According to the second aspect of the present invention, since the one-way clutch and the fourth clutch in parallel with the one-way clutch are provided, the shift quality and fuel consumption are improved, and braking by engine braking can be obtained.

In the device according to the third aspect, the third clutch,
Since the second clutch is arranged on the second shaft in addition to the second brake, the action due to the dispersion is further strengthened.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a skeleton diagram showing an automatic transmission for a vehicle according to a first embodiment of the present invention. The vehicular automatic transmission of the first embodiment is a laterally-mounted type having four forward gears and one reverse gear, and SFT1 in the figure is the first shaft. The engine output is input to the first axis SFT1. Further, in the figure, SFT2 is the second axis and is arranged in parallel with the first axis SFT1.

A first planetary gear set PG1 is attached to the first shaft SFT1.
And the second planetary gear set PG2 are arranged in parallel. The first planetary gear set PG1 can be connected to and disengaged from the first shaft SFT1 by the first clutch C1, and can be fixed to the case CA by the first brake B1, and the first sun gear S1. First ring gear R1 provided outside and both gears S
First, which supports a plurality of first pinions P1 which mesh with R1
It consists of a pinion carrier PC1. Similarly, the second planetary gear set PG2 meshes with the second sun gear S2 coupled to the first shaft SFT1, the second ring gear R2 provided outside the second sun gear S2, and both gears S2, R2. The second pinion carrier PC2 supports a plurality of second pinions P2 and is coupled to the second ring gear R2. The second pinion carrier PC2 is
An output transfer gear train OUTG composed of a fourth drive transfer gear AT4 provided on the pinion carrier PC2 and a fourth driven transfer gear PT4 meshing with the fourth drive transfer gear AT4 is connected to the output shaft OUTS.

Between the first axis SFT1 and the second axis SFT2,
A first transfer gear train (first power transmission device) TG1, a second transfer gear train (second power transmission device) TG2 and a third transfer gear train (third power transmission device) TG3 capable of transmitting power between the two. Is provided. The first transfer gear train TG1 is composed of a first drive transfer AT1 coupled to the first shaft SFT1 and a first driven transfer gear PT2 which can be connected to and disconnected from the second shaft SFT2 by a second clutch C2. There is. The second transfer gear train TG2 is provided on the outer periphery of the second drive transfer gear AT2 coupled with the second ring gear R2 and the second shaft SFT2, and is connected and disconnected from the second shaft SFT2 by the third clutch C3. Possible second driven transfer gear PT2
It consists of and. A second one-way clutch W2 is interposed in series with the third clutch C3 between the second driven transfer gear PT2 and the second shaft SFT2, and a fourth clutch C4 is arranged in parallel with the third clutch C3. It is intervened in parallel. The third transfer gear train TG3 is composed of a third drive transfer gear AT3 connected to the first pinion carrier PC1 and a third driven transfer gear PT3 connected to the second shaft SFT2.

Further, the second shaft SFT2 is a second brake.
It can be fixed to the case CA by B2, and a second one-way clutch W2 is provided in parallel with the second brake B2.

Next, the operation of the embodiment will be described. Each clutch C1, C2, C3, C4 and each brake B1 of this embodiment,
The operation control of B2 is performed by a control unit (not shown) as shown in the engagement logic table in Table 1 below. The symbol ◯ in the figure indicates the time of operation.

[0019]

[Table 1]

As described above, the clutches C1, C2, C3, which are transmission elements, are controlled by the control unit (not shown).
C4 and the brakes B1 and B2 are engaged to give a restraining condition, so that the automatic transmission for a vehicle according to the embodiment has the configuration shown in FIG.
As shown in the common line, the gear ratios of the forward 4th speed and the reverse 1st speed can be obtained. In this common line diagram, the axis of abscissas is the position of the rotating member that is assigned according to the set tooth ratio, and the axis of ordinate is the rotational speed ratio, which is drawn vertically through the positions of the rotating members. The shift elements of the brake and the clutch are displayed at the intersections of the straight line and the straight lines drawn in the lateral direction corresponding to the rotation speed ratio 0 and the rotation speed ratio 1, respectively, and drawn by the line connecting the operating shift elements.

As described above, in this embodiment,
Two planetary gear sets PG1, PG2 and four clutches C1, C2,
C3 and C4 and two brakes B1 and B2 and two one-way clutches W1 and W2 are provided to enable four forward and four reverse gear shifts, while the first and second planetary gear sets PR1, PG2
The second shaft SFT2 is provided in parallel with the first shaft SFT1 provided with, the first clutch C1 and the first brake B1 are provided as the fastening elements on the first shaft SFT1 side, and the second to the fourth axes SFT2 are provided on the second shaft SFT2 side. Clutch C2-C4
Since the clutches and brakes are dispersedly arranged on the first shaft SFT1 and the second shaft SFT2 by providing the second brake B2, the following effects can be obtained.

A) The size of the device in the long axis direction can be shortened to make it compact.

B) The arrangement density of the planetary gears, clutches, and brakes is low, and the gear train can be easily strengthened.
The structure around the shaft, around the clutch, and around the brake can be simplified.

C) Dispersion of heat-generating parts such as clutches and brakes to suppress an increase in oil temperature.

D) The restrictions on the axial dimensions of the clutches C1 to C4 are alleviated, and the clutch capacity can be increased without increasing the outer diameter. If the outer diameter is the same, the capacity can be increased.

E) The oil holes for passing the first and second both shafts SFT1 and SFT2 are small, and both shafts can be made compact in the radial direction.

According to the apparatus of the embodiment, the drive transfer gears AT1 and AT2 are used as the first to third drive transmission means.
, AT3 and driven transfer gears PT1, PT2, PT3
First to third transfer gear trains TG1 to T
Since G3 is used, by appropriately selecting the gear ratio of each transfer gear, it is possible to obtain the effect of increasing the degree of freedom in selecting the gear ratio of the entire device.

Next, an automatic transmission for a vehicle according to a second embodiment of the present invention shown in FIG. 3 will be described. The vehicular automatic transmission of the second embodiment is a vertical type that is often used in rear-wheel drive and four-wheel drive type vehicles. The difference from the first embodiment is the second pinion. First axis on carrier PC2
This is the point where the output shaft OUTS is coupled coaxially with SFT1. Since other configurations are the same as those of the first embodiment, the same configurations as those of the first embodiment device are denoted by the same reference numerals and the description thereof will be omitted.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and even if there is a design change or the like within the scope not departing from the gist of the present invention. Included in the present invention. For example, although the transfer gear train is shown as each power transmission means in the embodiment, it may be configured by other means such as a chain or a sprocket.

[0030]

As described above, in the automatic transmission for a vehicle of the present invention, two planetary gear sets are provided to enable four forward speeds and one reverse speed, and Since the second shaft is provided in parallel with the first shaft provided with two planetary gear sets, and the necessary clutches and brakes are distributedly arranged on the first shaft and the second shaft, the dimension in the long axis direction can be shortened and the circumference of the shaft can be reduced. , The effect of simplifying the structure around the clutch and brake, the effect of reducing the number of oil holes formed in one shaft, which is advantageous in terms of strength, and eliminating the need for a triple shaft structure. An effect that it is advantageous in terms of strength and centering is obtained.

Furthermore, the arrangement density of the planetary gears, clutches and brakes in the axial direction is reduced, and the effect of facilitating the strengthening of the gear train is obtained. In the case of the clutch, the capacity can be increased without increasing the outer diameter. The effect of facilitating the operation is obtained, and moreover, since the heat generating portions of the clutch and the brake are dispersed, the heat is also easily dissipated and the rise in oil temperature can be suppressed.

With the device according to the second aspect, it is possible to obtain the effect of improving the shift quality and the fuel consumption.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing an automatic transmission for a vehicle according to a first embodiment of the present invention.

FIG. 2 is a collinear chart showing a gear shift relationship in the vehicle automatic transmission according to the embodiment of the present invention.

FIG. 3 is a skeleton diagram showing an automatic transmission for a vehicle according to a second embodiment of the present invention.

[Explanation of symbols]

 SFT1 1st shaft SFT2 2nd shaft PG1 1st planetary gear set PG2 2nd planetary gear set S1 1st sun gear S2 2nd sun gear R1 1st ring gear R2 2nd ring gear P1 1st pinion gear P2 2nd pinion gear PC1 1st pinion carrier PC2 2nd pinion carrier C1 1st clutch C2 2nd clutch C3 3rd clutch C4 4th clutch W1 1st one-way clutch W2 2nd one-way clutch B1 1st brake B2 2nd brake TG1 1st transfer gear train (1st power transmission means) ) TG2 second transfer gear train (second power transmission means) TG3 third transfer gear train (third power transmission means)

Claims (3)

[Claims] 1. A first shaft to which an output of a power source is input, a second shaft arranged in parallel with the first shaft, a first sun gear, a first ring gear, and a second shaft arranged on the first shaft. A first planetary gear set having a first pinion carrier supporting a plurality of pinions meshing with both gears; a second sun gear arranged on the first shaft and rotating integrally with the first shaft; a second ring gear; A second planetary gear set that supports a plurality of pinions that mesh with gears and that has a second pinion carrier that is integrally rotatable with the first ring gear; and a second planetary gear set that transmits power between the first shaft and the second shaft. A first power transmission means, a second power transmission means for transmitting power between the second shaft and the second ring gear, and a second power transmission means provided on the first shaft between the first shaft and the first sun gear. A first clutch that enables or disconnects power transmission; A second clutch that enables or disconnects the power transmission of the power transmission means; and a third clutch that is provided on the second shaft and that enables or disconnects the power transmission by the second power transmission means, A first brake provided on the first shaft and capable of stopping the first sun gear, a second brake provided on the second shaft and capable of stopping the second shaft, the second shaft and the first pinion gear And a third power transmission means for transmitting power between the vehicle and the automatic transmission for a vehicle. 2. The automatic transmission for a vehicle according to claim 1, wherein a one-way clutch and a fourth clutch are provided in parallel in the middle of the second power transmission means. 3. The automatic transmission for a vehicle according to claim 1, wherein the second clutch is arranged on a second shaft.