JP6419569B2 - Automatic transmission - Google Patents

Description

  The present invention relates to an automatic transmission for a vehicle.

  If it is planned to be mounted on a relatively small vehicle, an automatic transmission that is small, light, and low in cost is desired. Patent Document 1 discloses an automatic transmission that achieves four forward speeds and one reverse speed using two planetary gear mechanisms, two clutches, and two brakes. Thus, if there are two planetary gear mechanisms, two clutches, and two brakes, it is relatively advantageous in terms of size reduction, weight reduction, and cost reduction.

Japanese Patent No. 5324610, FIG.

  The step ratio between the gears (high speed side gear ratio / low speed side gear ratio) may affect the ride comfort of the occupant during the shift. In Patent Document 1, the step ratio changes from the first speed to the fourth speed, which is relatively large → small → medium, and when the speed is changed from the second speed → the third speed, the shift shock of the third speed → the fourth speed is generated. The rider may feel uncomfortable with the ride comfort during shifting.

  An object of the present invention is to reduce the size, weight, and cost of an occupant while reducing the feeling that the occupant feels uncomfortable with the riding comfort during shifting.

According to the present invention, an input shaft that is rotatably supported in a transmission case and rotated by power from a drive source is provided, and the rotation of the input shaft is shifted in multiple stages and output from an output member. An automatic transmission for a vehicle,
A first planetary gear mechanism comprising three elements consisting of a sun gear, a carrier and a ring gear;
A second planetary gear mechanism comprising three elements consisting of a sun gear, a carrier and a ring gear;
A plurality of engagement mechanisms,
Of the three elements of the first planetary gear mechanism, the element located inside in the alignment order in the collinear diagram is the second element, the element located outside is the first element and the third element, and Among the three elements of the second planetary gear mechanism, when the element located on the inner side in the alignment order in the collinear diagram is the fifth element, and the elements located on the outer side are the fourth element and the sixth element,
The input shaft and the first element are connected,
The output member and the fifth element are connected,
The second element and the sixth element are connected;
The plurality of engagement mechanisms are:
A first clutch for releasably connecting the third element and the fourth element;
A second clutch for releasably connecting the first element and the fourth element;
A first brake for releasably fixing the third element to the transmission case;
A second brake for releasably fixing the second element and the sixth element to the transmission case;
Each shift stage is formed by bringing at least two of the plurality of engagement mechanisms into an engaged state,
The step ratio between gears is smaller at higher speeds.
An automatic transmission is provided.

Further, according to the present invention, an input shaft that is rotatably supported in the transmission case and rotated by the power from the drive source is provided, and the rotation of the input shaft is shifted to a plurality of stages from the output member. An automatic transmission for a vehicle that outputs,
A first planetary gear mechanism comprising three elements consisting of a sun gear, a carrier and a ring gear;
A second planetary gear mechanism comprising three elements consisting of a sun gear, a carrier and a ring gear;
A plurality of engagement mechanisms,
Of the three elements of the first planetary gear mechanism, the element located inside in the alignment order in the collinear diagram is the second element, the element located outside is the first element and the third element, and Among the three elements of the second planetary gear mechanism, when the element located on the inner side in the alignment order in the collinear diagram is the fifth element, and the elements located on the outer side are the fourth element and the sixth element,
The input shaft and the third element are connected,
The output member and the fifth element are connected,
The second element and the sixth element are connected;
The plurality of engagement mechanisms are:
A first clutch for releasably connecting the first element and the fourth element;
A second clutch for releasably connecting the third element and the fourth element;
A first brake for releasably fixing the first element to the transmission case;
A second brake for releasably fixing the second element and the sixth element to the transmission case;
Each shift stage is formed by bringing at least two of the plurality of engagement mechanisms into an engaged state,
The step ratio between gears is smaller at higher speeds.
An automatic transmission is provided.

  ADVANTAGE OF THE INVENTION According to this invention, size reduction, weight reduction, and cost reduction can be achieved, reducing that a passenger | crew feels uncomfortable about the riding comfort at the time of a gear shift.

(A) is a skeleton diagram of the automatic transmission according to the first embodiment, (B) is a diagram showing a λ value of the planetary gear mechanism, and (C) is a diagram showing an example of an engagement table of the engagement mechanism. (A) And (B) is a collinear diagram of the automatic transmission of FIG. 1 (A). (A) is a skeleton diagram of the automatic transmission according to the second embodiment, (B) is a diagram showing a λ value of the planetary gear mechanism, and (C) is a diagram showing an example of an engagement table of the engagement mechanism. (A) And (B) is an alignment chart of the automatic transmission of FIG. 3 (A). (A) is a skeleton diagram of the automatic transmission according to the third embodiment, (B) is a diagram showing a λ value of the planetary gear mechanism, and (C) is a diagram showing an example of an engagement table of the engagement mechanism. (A) And (B) is an alignment chart of the automatic transmission of FIG. 5 (A). (A) is a skeleton diagram of the automatic transmission according to the fourth embodiment, (B) is a diagram showing a λ value of the planetary gear mechanism, and (C) is a diagram showing an example of an engagement table of the engagement mechanism. (A) And (B) is an alignment chart of the automatic transmission of FIG. 7 (A).

<First embodiment>
FIG. 1 is a skeleton diagram of a vehicle automatic transmission 1A according to an embodiment of the present invention. The automatic transmission 1 </ b> A includes an input shaft 10 that is rotatably supported in the transmission case 12, and an output member 11 that is rotatably supported about the input shaft 10.

  The input shaft 10 receives power from a drive source (not shown) such as an internal combustion engine or an electric motor, and the input shaft 10 is rotated by the power. A starting device can be provided between the input shaft 10 and the driving source. Examples of the starting device include a clutch-type starting device (such as a single-plate clutch and a multi-plate clutch) and a fluid coupling-type starting device (such as a torque converter).

  The output member 11 includes an output gear concentric with the input shaft 10, and the rotation of the input shaft 10 is shifted to a plurality of stages by a speed change mechanism described below and output from the output member 11. The rotation of the output member 11 is transmitted to the drive wheels via, for example, a counter shaft (not shown) and a differential gear device.

  The automatic transmission 1A includes planetary gear mechanisms P1 and P2 and a plurality of engagement mechanisms CL1 and CL2 and BR1 and BR2 as transmission mechanisms. In the present embodiment, the planetary gear mechanism P1 is a double pinion type planetary gear mechanism, and the planetary gear mechanism P2 is a single pinion type planetary gear mechanism.

  The planetary gear mechanism P1 includes a sun gear S1, a ring gear R1, and a carrier C1 as rotational elements, and these are arranged coaxially with the input shaft 10. Between the sun gear S1 and the ring gear R1, pinion gears PG11 and PG12 are arranged while meshing with each other, and these pinion gears PG11 and PG12 are rotatably supported by the carrier C1.

  The planetary gear mechanism P2 includes a sun gear S2, a ring gear R2, and a carrier C2 as rotating elements, and these are arranged coaxially with the input shaft 10. A pinion gear PG2 is disposed between the sun gear S2 and the ring gear R2, and the pinion gear PG2 is rotatably supported by the carrier C2.

  The engagement mechanisms CL1 and CL2 are clutches, and the engagement mechanisms BR1 and BR2 are brakes. The engagement mechanisms CL1 and CL2 and BR1 and BR2 can be switched between an engaged state (fastened state) and a released state, and the power transmission path from the input shaft 10 to the output member 11 depends on the combination. Can be switched. The driving force input to the input shaft 10 can be output to the output member 12 at a gear ratio according to the combination of engagement and disengagement of these engagement mechanisms, and a plurality of shift speeds are realized.

  The plurality of engagement mechanisms CL1 and CL2 and BR1 and BR2 are assumed to be, for example, frictional hydraulic engagement mechanisms. Examples of the frictional hydraulic engagement mechanism include a wet multi-plate clutch.

  Next, the connection relationship between each structure is demonstrated. The input shaft 10 and the sun gear S1 are connected. The output member 11 and the carrier C2 are connected. Ring gear R1 and ring gear R2 are connected.

  The engagement mechanism CL1 releasably connects the carrier C1 and the sun gear S2. The engagement mechanism CL2 removably connects the sun gear S1 and the sun gear S2.

  The engagement mechanism BR1 fixes the carrier C1 to the transmission case 12 so as to be freely engaged and disengaged. The engagement mechanism BR2 fixes the ring gear R1 and the ring gear R2 to the transmission case 12 so as to be detachable.

  FIG. 1B shows the number of sun gear teeth / ring gear teeth (referred to as a λ value in this document) of the planetary gear mechanisms P1 and P2, and FIG. 1C shows the engagement mechanisms CL1 and CL2 and BR1 and BR2. The engagement table (fastening table) is shown. 2A and 2B are collinear diagrams (speed diagrams) of the automatic transmission 1A.

  In the automatic transmission 1 </ b> A, at least two of the engagement mechanisms CL <b> 1 and CL <b> 2, BR <b> 1 and BR <b> 2 (all two in the present embodiment) are engaged at each shift stage, so that the four forward speeds (1st to 1st). 4th), the number of shift stages is 1 reverse (Rvs).

  In the example of the engagement table in FIG. 1C, “◯” indicates an engaged state (a state in which the components are connected), and no mark indicates a released state. “Gear ratio” indicates a gear ratio between the input shaft 10 and the output member 11. In the case of this embodiment, a general ratio setting suitable for each gear position is performed. “Step ratio” is a value of the high speed side gear ratio / low speed side gear ratio. For example, the step ratio between the first gear (1st) and the second gear (2nd) is 4.04 / 2.37 = 1.70.

  2A and 2B show the relative rotational speed ratios of the respective rotational elements at the respective shift speeds with respect to the input to the input shaft 10. The vertical axis indicates the speed ratio, “1” indicates the same rotational speed as the input shaft 10, and “0” indicates the stop state. The horizontal axis shows the distance corresponding to the gear ratio between the rotating elements. FIG. 2A shows a collinear diagram of the reverse speed and the first forward speed, and FIG. 2B shows a nomographic chart of the second forward speed to the fourth forward speed.

  When the three rotational elements of the planetary gear mechanism P1 are referred to as elements that are located on the inner side in the alignment order in the collinear diagram as second elements, and elements that are located outside are referred to as first and third elements, the ring gear R1 is The second element, one of the sun gear S1 and the carrier C1 is the first element, and the other is the third element.

  Similarly, when the three rotating elements of the planetary gear mechanism P2 are referred to as the fifth element and the elements positioned outside as the fourth element and the sixth element in the alignment order in the alignment chart, C2 is a fifth element, one of the sun gear S2 or the ring gear R2 is a fourth element, and the other is a sixth element.

  In the automatic transmission 1A of the present embodiment having the above-described configuration, four forward speeds and one reverse speed are realized by two planetary gear mechanisms, two clutches, and two brakes, and the automatic transmission 1A is downsized. Thus, weight reduction and cost reduction can be achieved.

  Here, for example, when the gear shift shock becomes large when switching to a higher gear, the passenger feels uncomfortable. In the case of the present embodiment, as shown in FIG. 1C, the step ratio changes relatively from large to medium to small from the first speed to the fourth speed. In other words, the step ratio between the respective gears is reduced as the speed increases, and the shift shock gradually decreases as the gear is shifted up, so that it is possible to reduce the passengers from feeling uncomfortable.

  In general, the λ value of the planetary gear mechanism is preferably in the range of 0.3 to 0.7. For example, if the λ value becomes too large, it is necessary to reduce the pinion gear, which is disadvantageous in terms of assembly and rigidity. If the λ value is too small, the pinion gear becomes too large.

  In the present embodiment, the λ value of the planetary gear mechanism P1 is within the above numerical range. Although the λ value of the planetary gear mechanism P2 is slightly higher, it can be said that it is within the numerical range when rounded off, and is substantially within the numerical range.

<Second embodiment>
Another configuration example in which the automatic transmission 1A of the first embodiment and the planetary gear mechanism, the number of engagement mechanisms, and the gear ratio are the same will be described. FIG. 3A is a skeleton diagram of the automatic transmission 1B of the present embodiment. The automatic transmission 1B of the present embodiment is basically the same as the first embodiment in constituent elements, and the corresponding constituent elements are denoted by the same reference numerals. In the following, different configurations will be mainly described.

  The connection relationship between each component in this embodiment is demonstrated. The input shaft 10 and the carrier C1 are connected. The output member 11 and the carrier C2 are connected. Ring gear R1 and ring gear R2 are connected.

  The engagement mechanism CL2 removably couples the carrier C1 and the sun gear S2. The engagement mechanism CL1 connects the sun gear S1 and the sun gear S2 so as to be freely disengaged.

  The engagement mechanism BR2 fixes the ring gear R1 and the ring gear R2 to the transmission case 12 so as to be detachable. The engagement mechanism BR1 fixes the sun gear S1 to the transmission case 12 so as to be freely engaged and disengaged.

  FIG. 3B shows the λ values of the planetary gear mechanisms P1 and P2. FIG. 3C shows an engagement table (fastening table) of the engagement mechanisms CL1 and CL2 and BR1 and BR2, which is the same as in the first embodiment. 4A and 4B are collinear diagrams (speed diagrams) of the automatic transmission 1B.

  When the three rotational elements of the planetary gear mechanism P1 are referred to as elements that are located on the inner side in the alignment order in the collinear diagram as second elements, and elements that are located outside are referred to as first and third elements, the ring gear R1 is The second element, one of the sun gear S1 and the carrier C1 is the first element, and the other is the third element.

  Similarly, when the three rotating elements of the planetary gear mechanism P2 are referred to as the fifth element and the elements positioned outside as the fourth element and the sixth element in the alignment order in the alignment chart, C2 is a fifth element, one of the sun gear S2 or the ring gear R2 is a fourth element, and the other is a sixth element.

  In the automatic transmission 1B of the present embodiment configured as described above, four forward speeds and one reverse speed are realized by two planetary gear mechanisms, two clutches, and two brakes, thereby reducing the size of the automatic transmission 1B. Thus, weight reduction and cost reduction can be achieved.

  Further, the step ratio between the respective gears is reduced as the speed is increased, and the shift shock gradually decreases as the gear is shifted up, so that the passenger can be prevented from feeling uncomfortable.

  The λ value of the planetary gear mechanism P1 is within the above-described numerical range of 0.3 to 0.7. Although the λ value of the planetary gear mechanism P2 is slightly higher, it can be said that it is within the numerical range when rounded off, and is substantially within the numerical range.

<Third embodiment>
In the automatic transmission 1A of the first embodiment, another configuration example in which both the planetary gear mechanisms P1 and P2 are double pinion type planetary gear mechanisms will be described. FIG. 5A is a skeleton diagram of an automatic transmission 1C for a vehicle according to a third embodiment of the present invention. The automatic transmission 1C of the present embodiment is basically the same as the first embodiment in constituent elements, and the corresponding constituent elements are denoted by the same reference numerals. In the following, different configurations will be mainly described.

  The planetary gear mechanism P1 includes a sun gear S1, a ring gear R1, and a carrier C1 as rotational elements, and these are arranged coaxially with the input shaft 10. Between the sun gear S1 and the ring gear R1, pinion gears PG11 and PG12 are arranged while meshing with each other, and these pinion gears PG11 and PG12 are rotatably supported by the carrier C1.

  The planetary gear mechanism P2 includes a sun gear S2, a ring gear R2, and a carrier C2 as rotating elements, and these are arranged coaxially with the input shaft 10. Pinion gears PG21 and PG22 are arranged between the sun gear S2 and the ring gear R2 while meshing with each other, and these pinion gears PG21 and PG22 are rotatably supported by the carrier C2.

  The connection relationship between each component in this embodiment is demonstrated. The input shaft 10 and the sun gear S1 are connected. The output member 11 and the ring gear R2 are connected. The ring gear R1 and the carrier C2 are connected.

  The engagement mechanism CL1 releasably connects the carrier C1 and the sun gear S2. The engagement mechanism CL2 removably connects the sun gear S1 and the sun gear S2.

  The engagement mechanism BR1 fixes the carrier C1 to the transmission case 12 so as to be freely engaged and disengaged. The engagement mechanism BR2 fixes the ring gear R1 and the carrier C2 to the transmission case 12 so as to be freely engaged and disengaged.

  FIG. 5B shows the λ values of the planetary gear mechanisms P1 and P2. FIG. 5C shows an engagement table (fastening table) of the engagement mechanisms CL1 and CL2 and BR1 and BR2. Although the gear ratio and the step ratio are different from those of the automatic transmissions 1A and 1B, the engagement relationship of each gear stage is the same. 6 (A) and 6 (B) are collinear diagrams (speed diagrams) of the automatic transmission 1C.

  When the three rotational elements of the planetary gear mechanism P1 are referred to as elements that are located on the inner side in the alignment order in the collinear diagram as second elements, and elements that are located outside are referred to as first and third elements, the ring gear R1 is The second element, one of the sun gear S1 and the carrier C1 is the first element, and the other is the third element.

  Similarly, when the three rotating elements of the planetary gear mechanism P2 are designated as the fifth element and the elements located outside as the fourth element and the sixth element in the alignment order in the alignment chart, The gear R2 is the fifth element, one of the sun gear S2 or the carrier C2 is the fourth element, and the other is the sixth element.

  In the automatic transmission 1C of the present embodiment configured as described above, four forward speeds and one reverse speed are realized by two planetary gear mechanisms, two clutches, and two brakes, thereby reducing the size of the automatic transmission 1C. Thus, weight reduction and cost reduction can be achieved.

  Further, the step ratio between the respective gears is reduced as the speed is increased, and the shift shock gradually decreases as the gear is shifted up, so that the passenger can be prevented from feeling uncomfortable.

  Further, the λ values of the planetary gear mechanisms P1 and P2 are within the above-described numerical range of 0.3 to 0.7, which is advantageous in terms of the λ value with respect to the automatic transmissions 1A and 1B. . However, the double pinion type planetary gear mechanism generally has more meshing portions than the single pinion type planetary gear mechanism, and is likely to affect the fuel consumption of the vehicle. In this respect, the automatic transmissions 1A and 1B that employ one planetary gear mechanism of a single pinion type are advantageous.

<Fourth embodiment>
Another configuration example in which the automatic transmission 1C of the third embodiment and the planetary gear mechanism, the number of engagement mechanisms, and the gear ratio are common will be described. FIG. 7A is a skeleton diagram of the automatic transmission 1D of the present embodiment. The automatic transmission 1D of the present embodiment has basically the same components as the third embodiment, and the corresponding components are denoted by the same reference numerals. That is, both the planetary gear mechanisms P1 and P2 are double pinion type planetary gear mechanisms. This embodiment is also a modification of the automatic transmission 1B of the second embodiment in which both planetary gear mechanisms P1 and P2 are double pinion type planetary gear mechanisms. Hereinafter, a description will be given focusing on the configuration different from the third embodiment.

  The connection relationship between each component in this embodiment is demonstrated. The input shaft 10 and the carrier C1 are connected. The output member 11 and the ring gear R2 are connected. The carrier C2 and the ring gear R1 are connected.

  The engagement mechanism CL1 connects the sun gear S1 and the sun gear S2 so as to be freely disengaged. The engagement mechanism CL2 removably couples the carrier C1 and the sun gear S2.

  The engagement mechanism BR1 fixes the sun gear S1 to the transmission case 12 so as to be freely engaged and disengaged. The engagement mechanism BR2 fixes the ring gear R1 and the carrier C2 to the transmission case 12 so as to be freely engaged and disengaged.

  FIG. 7B shows the λ values of the planetary gear mechanisms P1 and P2. FIG. 7C shows an engagement table (fastening table) of the engagement mechanisms CL1 and CL2 and BR1 and BR2, which is the same as that of the third embodiment. FIGS. 8A and 8B are collinear diagrams (speed diagrams) of the automatic transmission 1D.

  When the three rotational elements of the planetary gear mechanism P1 are referred to as elements that are located on the inner side in the alignment order in the collinear diagram as second elements, and elements that are located outside are referred to as first and third elements, the ring gear R1 is The second element, one of the sun gear S1 and the carrier C1 is the first element, and the other is the third element.

  Similarly, when the three rotating elements of the planetary gear mechanism P2 are designated as the fifth element and the elements located outside as the fourth element and the sixth element in the alignment order in the alignment chart, The gear R2 is the fifth element, one of the sun gear S2 or the carrier C2 is the fourth element, and the other is the sixth element.

  In the automatic transmission 1D of the present embodiment configured as described above, four forward speeds and one reverse speed are realized by two planetary gear mechanisms, two clutches, and two brakes, thereby reducing the size of the automatic transmission 1D. Thus, weight reduction and cost reduction can be achieved.

  Further, the step ratio between the respective gears is reduced as the speed is increased, and the shift shock gradually decreases as the gear is shifted up, so that the passenger can be prevented from feeling uncomfortable.

  Further, the λ values of the planetary gear mechanisms P1 and P2 are within the above-described numerical range of 0.3 to 0.7, which is advantageous in terms of the λ value with respect to the automatic transmissions 1A and 1B. . However, as described in the third embodiment, the automatic transmissions 1A and 1B that employ one single pinion type planetary gear mechanism are advantageous in terms of fuel consumption of the vehicle.

<Summary of Embodiment>
1. The automatic transmission (e.g. 1A, 1C) of the above embodiment is
An input shaft (e.g., 10) that is rotatably supported in a transmission case (e.g., 12) and is rotated by power from a drive source, and the output member is rotated by shifting the rotation of the input shaft into a plurality of stages. For example, an automatic transmission for a vehicle that outputs from 11),
A first planetary gear mechanism (e.g. P1) comprising three elements consisting of a sun gear (e.g. S1), a carrier (e.g. C1) and a ring gear (e.g. R1);
A second planetary gear mechanism (e.g. P2) comprising three elements consisting of a sun gear (e.g. S2), a carrier (e.g. C2) and a ring gear (e.g. R2);
A plurality of engagement mechanisms (e.g., CL1, CL2, BR1, BR2),
Of the three elements of the first planetary gear mechanism, the element located inside in the alignment order in the collinear diagram is the second element (for example, R1 of 1A, R1 of 1C), and the element located outside is the first An element and a third element (e.g., S1 and C1 of 1A, S1 and C1 of 1C), and among the three elements of the second planetary gear mechanism, an element positioned on the inner side in the arrangement order in the alignment chart When the fifth element (e.g., 1A C2, 1C R2)) and the outer element as the fourth element and sixth element (e.g., 1A S2 and R2, 1C S2 and C2),
The input shaft and the first element (for example, 1A S1, 1C S1) are connected,
The output member and the fifth element (for example, 1A C2, 1C R2) are connected,
The second element (e.g. 1A R1, 1C R1) and the sixth element (e.g. 1A R2, 1C C2) are connected,
The plurality of engagement mechanisms are:
A first clutch (e.g., CL1) that releasably connects the third element (e.g., C of 1A, C1 of 1C) and the fourth element (e.g., S2 of 1A, S2 of 1C);
A second clutch (e.g., CL2) that releasably connects the first element (e.g., S1 of 1A, S1 of 1C) and the fourth element (e.g., S2 of 1A, S2 of 1C);
A first brake (e.g. BR1) for releasably fixing the third element (e.g. C1 of 1A, C1 of 1C) to the transmission case;
A second brake (e.g. BR2) for releasably fixing the second element (e.g. 1A R1, 1C R1) and the sixth element (e.g. 1A R2, 1C C2) to the transmission case; With
Each shift stage is formed by bringing at least two of the plurality of engagement mechanisms into an engaged state,
The step ratio between gears is smaller at higher speeds.
It is characterized by that.

  According to this configuration, it is possible to reduce the size, the weight, and the cost, while reducing the feeling that the occupant feels uncomfortable with the riding comfort during shifting.

2. The automatic transmission (e.g. 1B, 1D) of the above embodiment is
An input shaft (e.g., 10) that is rotatably supported in a transmission case (e.g., 12) and is rotated by power from a drive source, and the output member is rotated by shifting the rotation of the input shaft into a plurality of stages. For example, an automatic transmission for a vehicle that outputs from 11),
A first planetary gear mechanism (e.g. P1) comprising three elements consisting of a sun gear (e.g. S1), a carrier (e.g. C1) and a ring gear (e.g. R1);
A second planetary gear mechanism (e.g. P2) comprising three elements consisting of a sun gear (e.g. S2), a carrier (e.g. C2) and a ring gear (e.g. R2);
A plurality of engagement mechanisms (e.g., CL1, CL2, BR1, BR2),
Of the three elements of the first planetary gear mechanism, the element located inside in the alignment order in the collinear diagram is the second element (for example, R1 of 1B, R1 of 1D), and the element located outside is the first An element and a third element (e.g., C1 and S1 of 1B, C1 and S1 of 1D), and among the three elements of the second planetary gear mechanism, an element positioned inside in the alignment order in the collinear diagram When the fifth element (e.g., 1B C2, 1D R2) and the outer elements are the fourth and sixth elements (e.g., 1B S2 and R2, 1D S2 and C2),
The input shaft and the third element (for example, C of 1B, C1 of 1D) are connected,
The output member and the fifth element (e.g., 1B C2, 1D R2) are connected,
The second element (e.g. 1B R1, 1D R1) and the sixth element (e.g. 1B R2, 1D C2) are connected,
The plurality of engagement mechanisms are:
A first clutch (e.g., CL1) that releasably connects the first element (e.g., 1B, S1, 1D, S1) and the fourth element (e.g., 1B, S2, 1D, S2);
A second clutch (e.g. CL2) that releasably connects the third element (e.g. C1 of 1B, C1 of 1D) and the fourth element (e.g. S2 of 1B, S2 of 1D);
A first brake (e.g. BR1) for releasably fixing the first element (e.g. S1 of 1B, S1 of 1D) to the transmission case;
A second brake (e.g., BR2) for releasably fixing the second element (e.g., R1 of 1B, R1 of 1D) and the sixth element (e.g., R2 of 1B, C2 of 1D) to the transmission case; With
Each shift stage is formed by bringing at least two of the plurality of engagement mechanisms into an engaged state,
The step ratio between gears is smaller at higher speeds.
It is characterized by that.

  According to this configuration, it is possible to reduce the size, the weight, and the cost, while reducing the feeling that the occupant feels uncomfortable with the riding comfort during shifting.

3. The automatic transmission (e.g. 1A, 1B) of the above embodiment is
The first planetary gear mechanism (e.g., P1) is a double pinion type planetary gear mechanism,
The second planetary gear mechanism (e.g., P2) is a single pinion type planetary gear mechanism,
It is characterized by that.

  According to this structure, the bad influence with respect to a fuel consumption can be decreased rather than the case where both the 1st and 2nd planetary gear mechanisms are made into a double pinion type.

4). The automatic transmission (e.g., 1C, 1D) of the above embodiment is
The first planetary gear mechanism (e.g., P1) is a double pinion type planetary gear mechanism,
The second planetary gear mechanism (e.g., P1) is a double pinion type planetary gear mechanism,
It is characterized by that.

  According to this configuration, it is possible to keep the λ values of both the first and second planetary gear mechanisms within a preferable range.

5. The automatic transmission (e.g., 1C, 1D) of the above embodiment is
The value of each sun gear tooth number / ring gear tooth number of the first and second planetary gear mechanisms is not less than 0.3 and not more than 0.7.
It is characterized by that.

  According to this configuration, it can be avoided that the pinion gear of the planetary gear mechanism is too large or too small.

6). The automatic transmission (e.g. 1A-1D) of the above embodiment is
By forming at least two of the plurality of engagement mechanisms in an engaged state, each of the four forward speeds and one reverse speed is formed.
It is characterized by that.

  According to this configuration, it is possible to obtain a necessary number of shift stages in a small vehicle.

1A to 1D automatic transmission, 10 input shaft, 11 output member, 12 transmission case, P1 and P2 planetary gear mechanism, CL1 and CL2 engagement mechanism (clutch), BR1 and BR2 engagement mechanism (brake)

Claims (6)

An automatic transmission for a vehicle having an input shaft rotatably supported in a transmission case and rotated by power from a drive source, and shifting the rotation of the input shaft in a plurality of stages and outputting from an output member Because
A first planetary gear mechanism comprising three elements consisting of a sun gear, a carrier and a ring gear;
A second planetary gear mechanism comprising three elements consisting of a sun gear, a carrier and a ring gear;
A plurality of engagement mechanisms,
Of the three elements of the first planetary gear mechanism, the element located inside in the alignment order in the collinear diagram is the second element, the element located outside is the first element and the third element, and Among the three elements of the second planetary gear mechanism, when the element located on the inner side in the alignment order in the collinear diagram is the fifth element, and the elements located on the outer side are the fourth element and the sixth element,
The input shaft and the first element are connected,
The output member and the fifth element are connected,
The second element and the sixth element are connected;
The plurality of engagement mechanisms are:
A first clutch for releasably connecting the third element and the fourth element;
A second clutch for releasably connecting the first element and the fourth element;
A first brake for releasably fixing the third element to the transmission case;
A second brake for releasably fixing the second element and the sixth element to the transmission case;
Each shift stage is formed by bringing at least two of the plurality of engagement mechanisms into an engaged state,
The step ratio between gears is smaller at higher speeds.
An automatic transmission characterized by that. An automatic transmission for a vehicle having an input shaft rotatably supported in a transmission case and rotated by power from a drive source, and shifting the rotation of the input shaft in a plurality of stages and outputting from an output member Because
A first planetary gear mechanism comprising three elements consisting of a sun gear, a carrier and a ring gear;
A second planetary gear mechanism comprising three elements consisting of a sun gear, a carrier and a ring gear;
A plurality of engagement mechanisms,
Of the three elements of the first planetary gear mechanism, the element located inside in the alignment order in the collinear diagram is the second element, the element located outside is the first element and the third element, and Among the three elements of the second planetary gear mechanism, when the element located on the inner side in the alignment order in the collinear diagram is the fifth element, and the elements located on the outer side are the fourth element and the sixth element,
The input shaft and the third element are connected,
The output member and the fifth element are connected,
The second element and the sixth element are connected;
The plurality of engagement mechanisms are:
A first clutch for releasably connecting the first element and the fourth element;
A second clutch for releasably connecting the third element and the fourth element;
A first brake for releasably fixing the first element to the transmission case;
A second brake for releasably fixing the second element and the sixth element to the transmission case;
Each shift stage is formed by bringing at least two of the plurality of engagement mechanisms into an engaged state,
The step ratio between gears is smaller at higher speeds.
An automatic transmission characterized by that. The automatic transmission according to claim 1 or 2,
The first planetary gear mechanism is a double pinion type planetary gear mechanism,
The second planetary gear mechanism is a single pinion type planetary gear mechanism.
An automatic transmission characterized by that. The automatic transmission according to claim 1 or 2,
The first planetary gear mechanism is a double pinion type planetary gear mechanism,
The second planetary gear mechanism is a double pinion type planetary gear mechanism.
An automatic transmission characterized by that. The automatic transmission according to claim 4,
The value of each sun gear tooth number / ring gear tooth number of the first and second planetary gear mechanisms is not less than 0.3 and not more than 0.7.
An automatic transmission characterized by that. The automatic transmission according to any one of claims 1 to 5,
By forming at least two of the plurality of engagement mechanisms in an engaged state, each of the four forward speeds and one reverse speed is formed.
An automatic transmission characterized by that.

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