JP5373737B2 - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a friction loss of an automatic transmission that changes the speed of rotation of an input shaft in a plurality of stages through a plurality of planetary gear mechanisms arranged in a transmission case to output the changed speed of rotation from an output member. <P>SOLUTION: The automatic transmission includes four planetary gear mechanisms PGS1-PGS4, three clutches C1-C3, and three brakes B1-B3. A first element Sa is connected to the input shaft 2, a tenth element Rd is connected to the output member 3, a second element Ca is connected to a fifth element Cb, a third element Ra is connected to an eighth element Cc, and a sixth element Rb and a seventh element Rc are connected to a twelfth element Sd. The first clutch C1 is configured to freely connect the first element Sa to an eleventh element Cd, the second clutch C2 is configured to freely connect a first connecting body Ca-Cb to the eleventh element Cd, and the third clutch C3 is configured to freely connect a second connecting body Ra-Cc to a fourth element Sb. The first brake B1, the second brake B2 and the third brake B3 are configured to freely fix the second connecting body Ra-Cc, a ninth element Sc and the eleventh element Cd respectively to the transmission case 1. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an automatic transmission in which rotation of an input shaft is shifted to a plurality of stages via a plurality of planetary gear mechanisms arranged in a transmission case and output from an output member.

  Conventionally, an automatic operation capable of performing eight forward gears using the first planetary gear mechanism for input, the second and third planetary gear mechanisms for shifting, and the six engaging mechanisms. A transmission is known (see, for example, Patent Document 1).

  In Patent Document 1, the first planetary gear mechanism for input includes a first sun gear and a first ring gear that mesh with each other, one meshing with the first sun gear and the other meshing with the first ring gear. A so-called double pinion type planetary gear mechanism comprising a first carrier that rotatably supports and revolves one pinion (when the carrier is fixed, the sun gear and the ring gear rotate in the same direction. Incidentally, when the ring gear is fixed, the sun gear and the carrier rotate in different directions.

  The first planetary gear mechanism decelerates the rotational speed of a fixed element in which a first sun gear is fixed to a transmission case, an input element in which a first carrier is connected to an input shaft, and a first carrier in which a first ring gear is an input element. Output element.

  In addition, the two planetary gear mechanisms for shifting are engaged with the second sun gear, the third sun gear, and the second ring gear integrated with the third ring gear, and one of them meshes with the second sun gear and the second ring gear. The other is a Ravigneaux type planetary gear mechanism comprising a second carrier that pivotally supports and revolves a pair of second pinions meshing with the third sun gear.

  This Ravigneaux type planetary gear mechanism includes a first rotation element, a second rotation element, and a second rotation element in order with an interval corresponding to the gear ratio in a collinear diagram (a figure in which the ratio of relative speeds of the rotation elements can be represented by a straight line). When the rotating element, the third rotating element, and the fourth rotating element are used, the first rotating element is the second sun gear, the second rotating element is the second carrier integrated with the third carrier, and the third rotating element is the third ring gear. The integrated second ring gear and fourth rotation element become the third sun gear.

  In addition, as an engagement mechanism, a first wet multi-plate clutch that releasably connects a first ring gear that is an output element of the first planetary gear mechanism and a fourth rotation element that is a third sun gear, an input shaft, and a second carrier And a second wet multi-plate clutch for releasably connecting a first rotary element comprising a first ring gear and a second sun gear as output elements. A fourth wet multi-plate clutch for releasably connecting the first carrier as the input element and the first rotating element comprising the second sun gear, and the first rotating element comprising the second sun gear to be disengageable to the transmission case. A first brake for fixing, and a second brake for releasably fixing the second rotating element including the second carrier to the transmission case.

  According to the above configuration, the first speed is established by engaging the first wet multi-plate clutch and the second brake, and the second speed is established by engaging the first wet multi-plate clutch and the first brake. A stage is established, and a third speed stage is established by engaging the first wet multi-plate clutch and the third wet multi-plate clutch, and the first wet multi-plate clutch and the fourth wet multi-plate clutch are engaged. This establishes the fourth gear.

  Further, the fifth speed stage is established by engaging the first wet multi-plate clutch and the second wet multi-plate clutch, and 6 by engaging the second wet multi-plate clutch and the fourth wet multi-plate clutch. By establishing the first gear, engaging the second wet multi-plate clutch and the third wet multi-plate clutch, the seventh gear is established, and by engaging the second wet multi-plate clutch and the first brake. The eighth gear is established.

  In addition, the conventional automatic transmission forms eight rows on the axis of the input shaft. Specifically, in order from the torque converter side, the first row is the fourth clutch and the first brake, the second row is the first planetary gear mechanism, the third row is the first clutch, and the fourth row is the third clutch (the second clutch). The three clutches appear to be in the same row as the first planetary gear mechanism on the skeleton diagram, but in reality, the third clutch piston and the oil passage are formed between the first clutch and the output gear. ), The fifth row is the output gear, the sixth row is the second planetary gear mechanism, the seventh row is the third planetary gear mechanism, and the eighth row is the second clutch and second brake.

JP 2005-273768 A

  In the above-described conventional example, the number of engagement mechanisms engaged at each shift stage is two. Therefore, the friction loss due to dragging of the remaining four engagement mechanisms that are open increases, resulting in a problem that the efficiency of the automatic transmission deteriorates.

  An object of the present invention is to provide an automatic transmission which can reduce friction loss in view of the above points.

  [1] In order to achieve the above object, the present invention includes an input shaft that is rotatably supported in a transmission case and rotated by power from a drive source, and the rotation of the input shaft is performed in a plurality of stages. An automatic transmission that shifts and outputs from an output member is provided with first to fourth planetary gear mechanisms each including three elements including a sun gear, a carrier, and a ring gear, and the first planetary gear mechanism The second planetary gear mechanism has three elements as a first element, a second element, and a third element, respectively, in the order of arrangement at intervals corresponding to the gear ratio in the collinear chart in which the relative rotational speed ratio can be represented by a straight line. Are the fourth element, the fifth element, and the sixth element in the order of arrangement at intervals corresponding to the gear ratio in the nomograph, and the three elements of the third planetary gear mechanism are the relative rotational speed ratios. Collinear chart that can be represented by a straight line The seventh element, the eighth element, and the ninth element are arranged in the order corresponding to the gear ratio, and the three elements of the fourth planetary gear mechanism are arranged at the distance corresponding to the gear ratio in the alignment chart. The first element is connected to the input shaft, the tenth element is connected to the output member, and the second element and the fifth element are sequentially connected as a tenth element, an eleventh element, and a twelfth element, respectively. Connected to form a first connected body, connected the third element and the eighth element to form a second connected body, and connected the sixth element, the seventh element, and the twelfth element. Thus, the third connected body is configured.

  As an engagement mechanism, a first clutch that can connect the first element and the eleventh element, a second clutch that can connect the first connecting body and the eleventh element, and the second connection A third clutch that can connect the body and the fourth element, a first brake that can fix the second connection body to the transmission case, and a second clutch that can fix the ninth element to the transmission case. A brake and a third brake capable of fixing the eleventh element to the transmission case; a total of six engagements including the first to third clutches and the first to third brakes; Each shift stage is established by bringing at least three engagement mechanisms of the combined mechanism into a connected state or a fixed state.

  According to the present invention, as will be apparent from the description of the embodiment described later, three engagement mechanisms are engaged and connected in each shift stage among a total of six engagement mechanisms of three clutches and three brakes. Or it will be in a fixed state. Therefore, the number of engagement mechanisms that are not connected and fixed in each gear stage is released is three, and the number of engagement mechanisms that are released in each gear stage is less than that in the conventional case where four engagement mechanisms are opened. The friction loss due to the engaging mechanism can be reduced, and the transmission efficiency of the automatic transmission can be improved.

  [2] In the present invention, the sixth element is a ring gear of the second planetary gear mechanism, the seventh element is a ring gear of the third planetary gear mechanism, and the twelfth element is a sun gear of the fourth planetary gear mechanism. The fourth planetary gear mechanism is arranged radially outward of the second planetary gear mechanism or the third planetary gear mechanism, and the sun gear of the fourth planetary gear mechanism is connected to the ring gear of the second planetary gear mechanism or the third planetary gear mechanism. It is preferable to configure it integrally.

  According to this configuration, since the fourth planetary gear mechanism is disposed radially outward of the second planetary gear mechanism or the third planetary gear mechanism, the axial length of the automatic transmission can be shortened.

  Here, when the clutch is constituted by a wet multi-plate clutch, a piston that moves forward and backward with the hydraulic pressure is provided. The piston of this wet multi-plate clutch is provided on the input shaft or the main shaft that supports the input shaft, unlike the wet multi-plate brake piston provided in the transmission case. Cannot be placed outside the direction.

  Therefore, in the conventional example, a total of seven members including three planetary gear mechanisms and four wet multi-plate clutches are arranged on the input shaft or the main shaft that rotatably supports the input shaft. .

  However, as described above, if the fourth planetary gear mechanism is arranged radially outward of the second planetary gear mechanism or the third planetary gear mechanism, the present invention substantially includes three planetary gear mechanisms. A total of six members of the three clutches are arranged on the input shaft or the main shaft that rotatably supports the input shaft, and the shaft length can be shortened compared to the conventional example, The mounting property to a vehicle (especially FF type vehicle) can be improved.

  [3] In the present invention, the fourth planetary gear mechanism is disposed radially outward of the second planetary gear mechanism, and the sun gear of the fourth planetary gear mechanism is configured integrally with the ring gear of the second planetary gear mechanism for input. In the axial direction of the shaft, it is preferable that the second planetary gear mechanism is disposed between the first planetary gear mechanism and the third planetary gear mechanism.

  According to this, as will be apparent from the description of the embodiment described later, the axial center portion of the third planetary gear mechanism does not have a multi-tube structure, and the first brake or the second outwardly in the radial direction of the third planetary gear mechanism. Each planet can be easily arranged with two brakes, and the ratio of orange (minimum gear ratio / highest gear ratio) can be set to a relatively large value without increasing the outer diameter of the automatic transmission. The gear ratio of the gear can be set.

  [4] In the present invention, the fourth planetary gear mechanism is disposed radially outward of the second planetary gear mechanism, and the sun gear of the fourth planetary gear mechanism is configured integrally with the ring gear of the second planetary gear mechanism for input. In the axial direction of the shaft, the first planetary gear mechanism may be disposed between the second planetary gear mechanism and the third planetary gear mechanism. Also by this, the axial center portion of the third planetary gear mechanism does not have a multi-tube structure, and the first brake or the second brake can be easily disposed radially outward of the third planetary gear mechanism.

  [5] In the present invention, when the output member is constituted by an output gear, the output gear extends radially inward from the transmission case in order to increase the mechanical strength of the member that supports the output gear. It is conceivable to pivotally support a cylindrical portion provided on the side wall. At this time, if the second clutch is arranged radially inward of the cylindrical portion, the radial inner space of the cylindrical portion can be effectively utilized, and the axial length of the automatic transmission can be shortened. be able to.

  [6] In the present invention, a two-way switchable between a reverse rotation preventing state in which the ninth element is allowed to rotate forward and preventing reverse rotation, and a forward rotation blocking state in which the ninth element is prevented from rotating forward and allowed to reverse. It is preferable to provide a clutch. According to this, the friction loss can be further reduced, and the shift controllability between the shift stages can be improved.

  [7] In the present invention, it is preferable that the third brake is constituted by a meshing mechanism that suppresses friction loss as compared with a wet multi-plate clutch.

  [8] In the present invention, it is preferable that the second clutch is constituted by a meshing mechanism that suppresses friction loss as compared with a wet multi-plate clutch.

  [9] In the present invention, when the second clutch is connected to connect the first connecting body and the eleventh element, and the relative rotation direction of the first connecting body with respect to the eleventh element is the forward rotation direction. The first connector and the eleventh element are connected to each other, and when the relative rotation direction of the first connector relative to the eleventh element is the reverse direction, the connection between the first connector and the eleventh element is broken. A two-way clutch that can be switched to a one-way differential rotation blocking state that can sag can be formed. According to this, friction loss can be further reduced.

  [10] In the present invention, it is preferable to dispose the third brake on the outer side in the radial direction of the first clutch. According to this, the first clutch and the third brake can be arranged side by side in the radial direction, and the shaft of the automatic transmission can be compared with the case where the first clutch and the third brake are arranged side by side on the input shaft. The length can be shortened.

  [11] In the present invention, it is preferable that at least one of the first to third brakes is disposed at the shaft end of the input shaft. At the shaft end portion of the input shaft, the area of the adjacent transmission case can be secured relatively large without being obstructed by the planetary gear mechanism or the clutch. For this reason, if comprised as mentioned above, the freedom degree of design of the oil path for brakes can be improved.

  [12] In the present invention, the output member may be constituted by an output shaft, and the output shaft may be arranged concentrically with the input shaft. According to this, the mounting property to the FR type vehicle is improved.

  [13] In the present invention, the first to fourth planetary gear mechanisms are so-called single pinions comprising a sun gear, a ring gear, and a carrier that rotatably and revolves a pinion that meshes with the sun gear and the ring gear. Type planetary gear mechanism (when the carrier is fixed, the sun gear and the ring gear rotate in different directions, so it is also called a minus planetary gear mechanism or a negative planetary gear mechanism. Incidentally, when the ring gear is fixed, the sun gear and the carrier And rotate in the same direction.).

  According to this, the planetary gear mechanism is a so-called double gear comprising a sun gear, a ring gear, and a carrier that rotatably supports and rotates a pair of pinions that mesh with each other and one meshes with the sun gear and the other meshes with the ring gear. Pinion type planetary gear mechanism (Since the sun gear and the ring gear rotate in the same direction when the carrier is fixed, it is also called the plus planetary gear mechanism or the positive planetary gear mechanism. Incidentally, when the ring gear is fixed, the sun gear and the carrier are different from each other. Compared with the case where the power is transmitted from the input shaft to the output member, the number of places where the gear meshes can be reduced and the transmission efficiency can be further improved. it can.

  [14] In the present invention, a starting clutch that can transmit the power of the drive source to the input shaft may be provided.

  [15] In the present invention, the power of the drive source can be transmitted to the input shaft via the torque converter.

The skeleton figure which shows the upper half of the automatic transmission of 1st Embodiment of this invention. The alignment chart which shows ratio of the relative speed of each element of the 1st-4th planetary gear mechanism of the automatic transmission of 1st Embodiment. (A) is explanatory drawing which shows the state of each engagement mechanism in every gear stage of the automatic transmission of 1st Embodiment. (B) is explanatory drawing which shows an example of the gear ratio of each gear stage of 1st Embodiment. (C) is explanatory drawing which shows an example of the common ratio between each gear stage of 1st Embodiment. (D) is explanatory drawing which shows an example of the gear ratio of each planetary gear mechanism of 1st Embodiment, and the reciprocal orange of an automatic transmission. The skeleton figure which shows the upper half of the automatic transmission of 2nd Embodiment of this invention. The skeleton figure which shows the upper half of the automatic transmission of 3rd Embodiment of this invention. The skeleton figure which shows the upper half of the automatic transmission of 4th Embodiment of this invention. The skeleton figure which shows the upper half of the automatic transmission of 5th Embodiment of this invention. Sectional drawing which shows an example of a 2 way clutch.

[First Embodiment]
FIG. 1 shows a first embodiment of an automatic transmission according to the present invention. In the automatic transmission according to the first embodiment, the driving force output by a driving source ENG such as an internal combustion engine (engine) (not shown) that is rotatably supported in the transmission case 1 is generated by the lockup clutch LC and the damper DA. The input shaft 2 is transmitted via a torque converter TC having an output shaft, and the output member 3 is an output gear 3 arranged concentrically with the input shaft 2. The rotation of the output member 3 is transmitted to the left and right drive wheels of the vehicle via a differential gear and a propeller shaft (not shown). Instead of the torque converter TC, a single-plate or multi-plate start clutch configured to be frictionally engageable may be provided.

  In the transmission case 1, first to fourth planetary gear mechanisms PGS 1 to 4 are arranged concentrically with the input shaft 2.

  The first planetary gear mechanism PGS1 is a so-called single pinion type planetary gear mechanism (comprising a sun gear Sa, a ring gear Ra, and a carrier Ca that rotatably and revolves a pinion Pa meshing with the sun gear Sa and the ring gear Ra). When the carrier is fixed, the sun gear and the ring gear rotate in different directions, so it is also called a negative planetary gear mechanism or a negative planetary gear mechanism.When the ring gear is fixed, the sun gear and the carrier rotate in the same direction. .).

  Referring to the collinear diagram of the first planetary gear mechanism PGS1 shown in the first stage from the top of FIG. 2 (a figure in which the ratio of the relative rotational speeds of the three elements of the sun gear, the carrier, and the ring gear can be represented by a straight line) The three elements Sa, Ca, Ra of the first planetary gear mechanism PGS1 are arranged from the left side in the order in which they are arranged at intervals corresponding to the gear ratio (number of teeth of the ring gear / number of teeth of the sun gear) in the alignment chart. Assuming two elements and a third element, the first element is the sun gear Sa, the second element is the carrier Ca, and the third element is the ring gear Ra.

  Here, the ratio between the distance between the sun gear Sa and the carrier Ca and the distance between the carrier Ca and the ring gear Ra is set to h: 1, where h is the gear ratio of the first planetary gear mechanism PGS1. In the alignment chart, the lower horizontal line and the upper horizontal line indicate that the rotational speeds are “0” and “1” (the same rotational speed as the input shaft 2), respectively.

  The second planetary gear mechanism PGS2 is also configured by a so-called single pinion type planetary gear mechanism that includes a sun gear Sb, a ring gear Rb, and a carrier Cb that rotatably and revolves a pinion Pb that meshes with the sun gear Sb and the ring gear Rb. Is done.

  Referring to the collinear diagram of the second planetary gear mechanism PGS2 shown in the second stage from the top in FIG. 2, the three elements Sb, Cb, Rb of the second planetary gear mechanism PGS2 correspond to the gear ratios in the collinear diagram. Assuming that the fourth element, the fifth element, and the sixth element are arranged from the left side in the order in which they are arranged, the fourth element is the sun gear Sb, the fifth element is the carrier Cb, and the sixth element is the ring gear Rb. The ratio between the distance between the sun gear Sb and the carrier Cb and the distance between the carrier Cb and the ring gear Rb is set to i: 1, where i is the gear ratio of the second planetary gear mechanism PGS2.

  The third planetary gear mechanism PGS3 is also configured by a so-called single pinion type planetary gear mechanism that includes a sun gear Sc, a ring gear Rc, and a carrier Cc that rotatably and revolves a pinion Pc that meshes with the sun gear Sc and the ring gear Rc. Is done.

  With reference to the collinear diagram of the third planetary gear mechanism PGS3 shown in the third stage from the top in FIG. 2, the three elements Sc, Cc, Rc of the third planetary gear mechanism PGS3 correspond to the gear ratios in the collinear diagram. Assuming that the seventh element, the eighth element, and the ninth element are arranged from the left side in the order in which they are arranged, the seventh element is the ring gear Rc, the eighth element is the carrier Cc, and the ninth element is the sun gear Sc. The ratio between the distance between the sun gear Sc and the carrier Cc and the distance between the carrier Cc and the ring gear Rc is set to j: 1, where j is the gear ratio of the third planetary gear mechanism PGS3.

  The fourth planetary gear mechanism PGS4 is also configured by a so-called single pinion type planetary gear mechanism that includes a sun gear Sd, a ring gear Rd, and a carrier Cd that pivotally and revolves a pinion Pd that meshes with the sun gear Sd and the ring gear Rd. Is done.

  Referring to the collinear diagram of the fourth planetary gear mechanism PGS4 shown in the fourth stage from the top in FIG. 2, the three elements Sd, Cd, Rd of the fourth planetary gear mechanism PGS4 correspond to the gear ratios in the collinear diagram. Assuming that the tenth element, eleventh element, and twelfth element are arranged from the left side in the order in which they are arranged, the tenth element is the ring gear Rd, the eleventh element is the carrier Cd, and the twelfth element is the sun gear Sd. The ratio between the distance between the sun gear Sd and the carrier Cd and the distance between the carrier Cd and the ring gear Rd is set to k: 1, where k is the gear ratio of the fourth planetary gear mechanism PGS4.

  The sun gear Sa (first element) of the first planetary gear mechanism PGS <b> 1 is connected to the input shaft 2. The ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 is connected to the output member 3 serving as an output gear.

  Further, the carrier Ca (second element) of the first planetary gear mechanism PGS1 and the carrier Cb (fifth element) of the second planetary gear mechanism PGS2 are connected to form a first connected body Ca-Cb. Further, the ring gear Ra (third element) of the first planetary gear mechanism PGS1 and the carrier Cc (eighth element) of the third planetary gear mechanism PGS3 are connected to form a second connected body Ra-Cc. Further, the ring gear Rb (sixth element) of the second planetary gear mechanism PGS2, the ring gear Rc (seventh element) of the third planetary gear mechanism PGS3, and the sun gear Sd (twelfth element) of the fourth planetary gear mechanism PGS4 are connected. Thus, the third linked body Rb-Rc-Sd is configured.

  The automatic transmission according to the first embodiment includes first to third clutches C1 to C3 and first to third brakes B1 to B3 as engagement mechanisms.

  The first clutch C1 is a wet multi-plate clutch, and a connected state that connects the sun gear Sa (first element) of the first planetary gear mechanism PGS1 and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4; It is configured to be switchable to an open state in which this connection is broken.

  The second clutch C2 is a meshing mechanism including a dog clutch or a synchromesh mechanism having a synchronization function, and a coupling state coupling the first coupling body Ca-Cb and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4. And an open state in which this connection is cut off. The second clutch C2 may be a wet multi-plate clutch or a two-way clutch.

  The third clutch C3 is a wet multi-plate clutch, and a connected state in which the second connecting body Ra-Cc and the sun gear Sb (fourth element) of the second planetary gear mechanism PGS2 are connected, and an open state in which this connection is cut off. It is configured to be switchable.

  The first brake B1 is a wet multi-plate brake, and is configured to be switchable between a fixed state in which the second coupling body Ra-Cc is fixed to the transmission case 1 and an open state in which this fixing is released.

  The second brake B2 is a wet multi-plate brake and can be switched between a fixed state in which the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 is fixed to the transmission case 1 and an open state in which this fixing is released. It is configured.

  Further, in the automatic transmission according to the first embodiment, the reverse rotation preventing state R is arranged side by side with the second brake B2, and allows the forward rotation of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 and prevents the reverse rotation. And a two-way clutch T1 that is switchable between a forward rotation prevention state F that prevents forward rotation and allows reverse rotation of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3.

  The third brake B3 is a meshing mechanism including a dog clutch or a synchromesh mechanism having a synchronization function, and a fixed state in which the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 is fixed to the transmission case 1, and this fixing. It is configured to be switchable to an open state in which is released.

  The states of the clutches C1 to C3, the brakes B1 to B3, and the two-way clutch T1 are switched by a transmission control unit (not shown) based on vehicle information such as the traveling speed of the vehicle.

  On the input shaft 2, from the drive source ENG and the torque converter TC side, the first clutch C1, the second clutch C2, the first planetary gear mechanism PGS1, the second planetary gear mechanism PGS2, the third clutch C3, and the third planetary gear. Arranged in the order of the mechanism PGS3. The first brake B1 is disposed radially outward of the third clutch C3, the second brake B2 and the 2-way clutch T1 are disposed radially outward of the third planetary gear mechanism PGS3, and the third brake B3 Is arranged radially outward of the first clutch C1.

  As a result, all of the first to third brakes B1 to B3 are arranged at the shaft end portion of the input shaft 2, and the planetary gear mechanism and the clutch are not easily obstructed. Design freedom is improved.

  The fourth planetary gear mechanism PGS4 is disposed radially outward of the second planetary gear mechanism PGS2. The ring gear Rb of the second planetary gear mechanism PGS2 and the sun gear Sd of the fourth planetary gear mechanism PGS4 are integrally configured. Since the fourth planetary gear mechanism PGS4 and the fourth planetary gear mechanism PGS4 overlap each other in the radial direction by disposing the fourth planetary gear mechanism PGS4 radially outward of the second planetary gear mechanism PGS2, as described above, The shaft length of the transmission can be shortened.

  The second planetary gear mechanism PGS2 and the fourth planetary gear mechanism PGS4 only have to overlap at least partially in the radial direction, and this can reduce the axial length, but both are completely in diameter. If they overlap in the direction, the axial length can be shortened the most.

  The output member 3 composed of the output gear is disposed on the outer side in the radial direction of the second clutch C2. The transmission case 1 is provided with a side wall 1a extending between the output member 3 and the first clutch C1 and extending radially inward. The side wall 1 a is provided with a cylindrical portion 1 b that extends inward in the radial direction of the output member 3. The output member 3 is pivotally supported by the cylindrical portion 1b via a bearing. By configuring in this way, the output member 3 can be firmly supported by the cylindrical portion 1b having high mechanical strength connected to the transmission case 1.

  Further, when the output member 3 is pivotally supported by the cylindrical portion 1b as described above, the second clutch C2 is positioned radially inward of the cylindrical portion 1b. For this reason, compared with the case where the output member 3 and the second clutch C2 are arranged side by side in the axial direction, the axial length of the cylindrical portion 1b is effectively utilized, and the axial length of the automatic transmission is shortened. Can be achieved.

  Next, with reference to FIG. 2 and FIG. 3, the case where each gear stage of the automatic transmission of 1st Embodiment is established is demonstrated.

  When establishing the first gear, the second clutch C2 is engaged, the third brake B3 is fixed, and the two-way clutch T1 is set to the reverse rotation prevention state R. By setting the second clutch C2 in the connected state, the first connected body Ca-Cb and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 rotate at the same speed. Further, by setting the third brake B3 in the fixed state, the rotation speed of the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 becomes “0”. Further, the rotation speed of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the 2-way clutch T1 in the reverse rotation prevention state R. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “1st” shown in FIG. 2, and the first gear is established.

  At the first speed, since the second brake B2 is in the released state, the number of engagement mechanisms released is “4”, but the sun gear Sc (first gear) of the third planetary gear mechanism PGS3 is operated by the action of the two-way clutch T1. (9 elements) is “0”, so no friction loss occurs in the second brake B2. Therefore, the substantial number of releases in the first gear is “3”.

  If the second brake B2 is also fixed at the first speed, the engine brake can be applied.

  When establishing the second speed, the second clutch C2 is set in the connected state, the first brake B1 is set in the fixed state, and the two-way clutch T1 is set in the reverse rotation prevention state R. By setting the second clutch C2 in the connected state, the first connected body Ca-Cb and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 rotate at the same speed. Further, by setting the first brake B1 in a fixed state, the rotation speed of the second coupling body Ra-Cc becomes “0”. Further, the rotation speed of the sun gear Sc (the ninth element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1 in the reverse rotation prevention state R.

  Accordingly, among the three elements Sc, Cc, Rc of the third planetary gear mechanism PGS3, the rotational speeds of the two elements of the sun gear Sc (ninth element) and the carrier Cc (eighth element) are the same speed “0”. Therefore, each element Sc, Cc, Rc of the third planetary gear mechanism PGS3 is in a locked state where relative rotation is impossible, and the rotation speed of the third coupled body Rb-Rc-Sd is also “0”. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “2nd” shown in FIG. 2, and the second gear is established.

  At the second speed, since the second brake B2 is in the released state, the number of released engagement mechanisms is “4”, but the sun gear Sc (second gear) of the third planetary gear mechanism PGS3 is operated by the two-way clutch T1. (9 elements) is “0”, so no friction loss occurs in the second brake B2. Therefore, the substantial number of releases at the second gear is "3".

  Further, if the second brake B2 is also fixed at the second speed, the engine brake can be applied.

  In order to establish the third speed, the second clutch C2 and the third clutch C3 are connected and the two-way clutch T1 is set to the reverse rotation prevention state R. By setting the second clutch C2 in the connected state, the first connected body Ca-Cb and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 rotate at the same speed. Further, by setting the third clutch C3 in the connected state, the second connecting body Ra-Cc and the sun gear Sb (fourth element) of the second planetary gear mechanism PGS2 rotate at the same speed. Further, the rotation speed of the sun gear Sc (the ninth element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1 in the reverse rotation prevention state R. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “3rd” shown in FIG. 2, and the third gear is established.

  At the third speed, since the second brake B2 is in the released state, the number of engagement mechanisms released is "4", but the sun gear Sc (first gear) of the third planetary gear mechanism PGS3 is operated by the action of the two-way clutch T1. (9 elements) is “0”, so no friction loss occurs in the second brake B2. Accordingly, the substantial number of releases at the third gear is "3".

  Further, if the second brake B2 is fixed at the third speed, the engine brake can be applied.

  When establishing the fourth speed, the first clutch C1 and the second clutch C2 are in the connected state, and the two-way clutch T1 is in the reverse rotation prevention state R. By bringing the first clutch C1 and the second clutch C2 into a connected state, the sun gear Sa (first element) of the first planetary gear mechanism PGS1, the first connecting body Ca-Cb, and the carrier Cd (fourth planetary gear mechanism PGS4). The eleventh element rotates at “1” at the same speed.

  Further, since the sun gear Sa (first element) and the carrier Ca (second element) of the first planetary gear mechanism PGS1 rotate at the same speed “1”, the three elements Sa, Ca and Ra are locked so that they cannot rotate relative to each other, and the rotational speed of the ring gear Ra (third element), that is, the second coupling body Ra-Cc becomes “1”.

  Further, the rotation speed of the sun gear Sc (the ninth element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1 in the reverse rotation prevention state R. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “4th” shown in FIG. 2, and the fourth speed stage is established.

  At the fourth speed, since the second brake B2 is in the released state, the number of engagement mechanisms released is “4”, but the sun gear Sc (first gear) of the third planetary gear mechanism PGS3 is operated by the action of the two-way clutch T1. (9 elements) is “0”, so no friction loss occurs in the second brake B2. Therefore, the substantial number of releases at the fourth gear is “3”.

  Further, if the second brake B2 is fixed at the fourth speed, the engine brake can be applied.

  When establishing the fifth gear, the first to third clutches C1 to C3 are connected and the two-way clutch T1 is set to the reverse rotation prevention state R. By bringing the first clutch C1 and the second clutch C2 into a connected state, the sun gear Sa (first element) of the first planetary gear mechanism PGS1, the first connecting body Ca-Cb, and the carrier Cd (fourth planetary gear mechanism PGS4). The eleventh element rotates at “1” at the same speed.

  Further, since the sun gear Sa (first element) and the carrier Ca (second element) of the first planetary gear mechanism PGS1 rotate at the same speed “1”, the three elements Sa, Ca and Ra are locked so that they cannot rotate relative to each other, and the rotational speed of the ring gear Ra (third element), that is, the second coupling body Ra-Cc becomes “1”.

  Further, by setting the third clutch C3 in the connected state, the sun gear Sb (fourth element) of the second planetary gear mechanism PGS2 rotates at “1” at the same speed as that of the second connected body Ra-Cc. For this reason, the sun gear Sb (fourth element) and the carrier Cb (fifth element) of the second planetary gear mechanism PGS2 rotate at “1” at the same speed, and the elements Sb and Cb of the second planetary gear mechanism PGS2 are rotated. , Rb are locked so that they cannot rotate relative to each other, and the rotation speed of the ring gear Rb of the second planetary gear mechanism PGS2, that is, the third coupling body Rb-Rc-Sd, is "1".

  Also, in the fourth planetary gear mechanism PGS4, since the sun gear Sd (the twelfth element) and the carrier Cd (the eleventh element) rotate at the same speed “1”, each element Sd, Cd of the fourth planetary gear mechanism PGS4. , Rd are in a locked state incapable of relative rotation, and the rotational speeds of the elements Sd, Cd, Rd are “1”. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected is also “1”, and the fifth gear is established.

  At the fifth speed, since the two-way clutch T1 is in the reverse rotation prevention state R, the forward rotation of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 is allowed.

  When the sixth speed is established, the first clutch C1 and the third clutch C3 are connected and the second brake B2 is fixed. By setting the first clutch C1 in the connected state, the sun gear Sa (first element) of the first planetary gear mechanism PGS1 and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 are “1” at the same speed. Rotate. Further, by setting the third clutch C3 in the connected state, the sun gear Sb (fourth element) of the second planetary gear mechanism PGS2 rotates at the same speed as the second connected body Ra-Cc. Further, by setting the second brake B2 in a fixed state, the rotational speed of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 becomes “0”. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “6th” shown in FIG. 2, and the sixth gear is established.

  At the sixth speed, the second brake B2 is in a fixed state, and the two-way clutch T1 may be in either the reverse rotation prevention state R or the forward rotation prevention state F. However, the transmission control unit (not shown) is a two-way clutch when a downshift from the sixth gear to the fifth gear is predicted based on vehicle information such as travel speed so that the gear can be smoothly shifted. When T1 is in the reverse rotation prevention state R and an upshift from the sixth gear to the seventh gear is predicted based on the vehicle information, the two-way clutch T1 is switched to the forward rotation prevention state F.

  When establishing the seventh gear, the first clutch C1 and the third clutch C3 are connected, the first brake B1 is fixed, and the two-way clutch T1 is set to the forward rotation prevention state F. By setting the first clutch C1 in the connected state, the sun gear Sa (first element) of the first planetary gear mechanism PGS1 and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 are “1” at the same speed. Rotate.

  Further, by setting the third clutch C3 in the connected state, the sun gear Sb (fourth element) of the second planetary gear mechanism PGS2 rotates at the same speed as the second connected body Ra-Cc. Further, by setting the first brake B1 in a fixed state, the rotation speed of the second coupling body Ra-Cc becomes “0”. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “7th” shown in FIG. 2, and the seventh gear is established.

  At the seventh speed, since the 2-way clutch T1 is in the forward rotation prevention state F, the reverse rotation of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 is allowed.

  When establishing the eighth gear, the first clutch C1 is set to the connected state, the first brake B1 and the second brake B2 are set to the fixed state, and the two-way clutch T1 is set to the forward rotation prevention state F. By setting the first clutch C1 in the connected state, the sun gear Sa (first element) of the first planetary gear mechanism PGS1 and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 are “1” at the same speed. Rotate. Further, by setting the first brake B1 in a fixed state, the rotation speed of the second coupling body Ra-Cc becomes “0”.

  Further, by setting the second brake B2 in a fixed state, the rotational speed of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 becomes “0”. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “8th” shown in FIG. 2, and the eighth gear is established.

  Since the second brake B2 is fixed at the eighth speed, the eighth speed can be established even when the two-way clutch T1 is in the reverse rotation prevention state R. However, in this embodiment, the two-way clutch T1 is in the forward rotation prevention state F at the eighth speed so that the downshift to the seventh speed can be performed smoothly.

  In order to establish the reverse gear, the third clutch C3 is engaged, the third brake B3 is fixed, and the two-way clutch T1 is set to the forward rotation prevention state F. By setting the third clutch C3 in the connected state, the sun gear Sb (fourth element) of the second planetary gear mechanism PGS2 rotates at the same speed as the second connected body Ra-Cc. Further, by setting the third brake B3 in the fixed state, the rotation speed of the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 becomes “0”. Further, the rotation speed of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the 2-way clutch T1 in the forward rotation prevention state F. Then, the rotational speed of the ring gear Rd (tenth element) of the fourth planetary gear mechanism PGS4 to which the output member 3 is connected becomes “Rvs” in the reverse direction (rotation in the direction in which the vehicle moves backward) shown in FIG. Established.

  It should be noted that the engine brake can be applied if the second brake B2 is fixed in the reverse gear.

  A speed line indicated by a dotted line in FIG. 2 represents that each element of the other planetary gear mechanisms rotates (idle) following the planetary gear mechanism that transmits power among the four planetary gear mechanisms PGS1 to PGS4. ing.

  FIG. 3A is a diagram summarizing and displaying the states of the clutches C1 to C3, the brakes B1 to B3, and the two-way clutch T1 at each of the above-described shift speeds. In the row of the clutches C1 to C3 and the brakes B1 to B3, “◯” indicates a connected state or a fixed state, and a blank indicates an open state. “R” in the row of the two-way clutch T1 indicates a reverse rotation prevention state, “F” indicates a forward rotation prevention state, and “F / R” indicates a reverse rotation prevention state or a forward rotation prevention state. What is shown shows a state in which the rotational speed of the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 becomes “0” by the action of the two-way clutch T1.

  3B, the gear ratio h of the first planetary gear mechanism PGS1 is 3.741, the gear ratio i of the second planetary gear mechanism PGS2 is 2.764, as shown in FIG. The gear ratio (the rotational speed of the input shaft 2 / the speed of the output member 3) when the gear ratio j of the third planetary gear mechanism PGS3 is 2.250 and the gear ratio k of the fourth planetary gear mechanism PGS4 is 1.896. Rotation speed). According to this, as shown in FIG. 3 (c), the common ratio (ratio of gear ratios between the respective gears) becomes appropriate, and the ratio orange (gear ratio / first gear) shown in FIG. The gear ratio of the 8th gear is also appropriate.

  According to the automatic transmission of the first embodiment, eight forward speeds can be changed. Further, at each shift stage, the number of wet multi-plate clutches and wet multi-plate brakes to be released is three or less, so that friction loss can be suppressed and driving force transmission efficiency can be improved.

  In addition, the 5th speed is a predetermined medium speed, the 1st speed to the 5th speed, which is a predetermined medium speed, and the 6th speed to the 8th speed exceeding the 5th speed, which is a predetermined medium speed. Is defined as the high speed range, and in the high speed range from the 6th speed to the 8th speed exceeding the predetermined 5th speed, which is the middle speed, the meshing mechanism has less friction loss than the wet multi-plate clutch. The configured second clutch C2 is released.

  Further, the third brake B3 that is opened at all the gear speeds except the first gear and the reverse gear is also constituted by a meshing mechanism. Therefore, in the high speed range, the number of wet multi-plate clutches and wet multi-plate brakes to be released is 1, and the friction loss when the vehicle is traveling at high speed can be reduced to improve the fuel efficiency.

  Further, the second clutch C2 composed of the meshing mechanism is only switched between the connected state and the released state between the fifth and sixth speeds, which are predetermined medium speed stages. Since the transmission torque (transmission driving force) in the second clutch C2 at the fifth speed (predetermined medium speed) is relatively small, even if the second clutch C2 is constituted by a dog clutch as a meshing mechanism, the fifth speed is It is possible to smoothly switch between the fixed state and the open state at the time of shifting between the sixth speeds.

  Further, since all the planetary gear mechanisms PGS1 to PGS4 are constituted by so-called single pinion type planetary gear mechanisms, a pair of sun gears and ring gears mesh with each other and one meshes with the sun gear and the other meshes with the ring gear. A so-called double pinion type planetary gear mechanism comprising a carrier that rotatably and revolves the pinion (when the carrier is fixed, the sun gear and the ring gear rotate in the same direction, so the plus planetary gear mechanism or the positive planetary gear mechanism Incidentally, when the ring gear is fixed, the number of meshing of the gear on the transmission path of the driving force can be reduced as compared with a configuration in which the sun gear and the carrier rotate in different directions. Efficiency can be improved.

  In addition, since the 2-way clutch T1 is provided together with the second brake B2, there is no need to switch the state of the second brake B2 when shifting between the 4th speed stage and the 5th speed stage, and the shift controllability is improved. The

  Further, the automatic transmission according to the first embodiment forms first to sixth rows on the axis of the input shaft 2 in order from the torque converter side. Specifically, the first row is the first clutch C1 and the third brake B3, the second row is the second clutch C2 and the output member 3, the third row is the first planetary gear mechanism PGS1, and the fourth row is , The second planetary gear mechanism PGS2 and the fourth planetary gear mechanism PGS4, the fifth row is the third clutch C2 and the first brake B1, the sixth row is the third planetary gear mechanism PGS3, the second brake B2 and the two-way clutch. T1. For this reason, the axial length of the automatic transmission can be shortened as compared with the conventional eight rows.

  In the first embodiment, the second clutch C2 and the third brake B3 are configured by the meshing mechanism. However, even if both are configured by the wet multi-plate clutch and the wet multi-plate brake, The effect of the present invention can be obtained in that the number of opened wet multi-plate clutches and wet multi-plate brakes can be suppressed to 3 or less, and friction loss can be suppressed.

  Further, the 2-way clutch T1 may be omitted. In this case, when establishing the first to fourth gears, the second brake B2 may be fixed.

  Further, the second clutch C2 is in a connected state in which the first connecting body Ca-Cb and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 are connected, and a one-direction differential rotation preventing state defined below. A two-way clutch that can be switched may be used. Here, the one-direction differential rotation prevention state is the first rotation when the relative rotation direction of the first coupling body Ca-Cb with respect to the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 is the normal rotation direction. The first connected body Ca-Cb and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 are connected, and conversely, the first connected body Ca-Cb for the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4. Is defined as a state in which the connection between the first coupling body Ca-Cb and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 is broken. This can also prevent the occurrence of friction loss in the second clutch C2.

  With reference to FIG. 8, an example of a two-way clutch as the second clutch C2 will be specifically described. The two-way clutch TW as the second clutch C2 of FIG. 8 is arranged with an inner ring TW1 coupled to the first coupling body Ca-Cb and a radially outer side of the inner ring TW1 with a gap therebetween. An outer ring TW2 connected to the carrier Cd (11th element) of the four planetary gear mechanism PGS4, and a holding ring TW3 disposed between the inner ring TW1 and the outer ring TW2.

  A plurality of cam surfaces TW1a are formed on the outer peripheral surface of the inner ring TW1. The retaining ring TW3 is provided with a plurality of cutout holes TW3a corresponding to the cam surface TW1a. A roller TW4 is accommodated in the cutout hole TW3a. The two-way clutch TW includes first and second electromagnetic clutches not shown. The first electromagnetic clutch is configured to connect the outer ring TW2 and the holding ring TW3 when energized. When the first electromagnetic clutch is not energized, the holding ring TW3 is configured to be rotatable relative to the inner ring TW1 and the outer ring TW2.

  Further, as shown in FIG. 8A, the diameter of the roller TW4 is such that when the roller TW4 is located at the center of the cam surface TW1a, a gap A is opened, and as shown in FIGS. 8B and 8C, When the roller TW4 is at the end of the cam surface TW1a, the roller TW4 is set to contact the inner ring TW1 and the outer ring TW2.

  When the first electromagnetic clutch is not energized, the holding ring TW3 can freely rotate with respect to the inner ring TW1 and the outer ring TW2, so that the roller TW4 is a cam as shown in FIG. It will be in the state which can continue being located in the center part of surface TW1a.

  When the first electromagnetic clutch is energized, the holding ring TW3 is connected to the outer ring TW2, so that the inner ring TW1 is rotated in either the forward rotation or the reverse rotation at the relative rotational speed with respect to the outer ring TW2. As shown in FIGS. 8B and 8C, the roller TW4 is positioned at the end of the cam surface TW1a.

  At this time, the roller TW4 is sandwiched between the cam surface TW1a and the inner peripheral surface of the outer ring TW2, and the inner ring TW1 is prevented from rotating relative to the outer ring TW2. That is, the two-way clutch TW is in a connected state.

  As shown in FIG. 8B, the second electromagnetic clutch has a first holding state in which the holding ring TW3 is connected to the inner ring TW1 in a state where the notch hole TW3a is located at one end of the cam surface TW1a, and FIG. A second holding state in which the holding ring TW3 is connected to the inner ring TW1 in a state where the notch hole TW3a is located at the other end of the cam surface TW1a as shown in (c), and the connection between the holding ring TW3 and the inner ring TW1 It is configured to be switchable to an open state that cuts off.

  Assuming that the clockwise direction in FIG. 8 is the reverse direction, as shown in FIG. 8C, the two-way clutch TW has a state in which the first electromagnetic clutch is not energized (energization off state) and the outer ring TW2. By disconnecting the connection with the holding ring TW3 and setting the second electromagnetic clutch in the second holding state, the one-way differential rotation preventing state is established.

  When the second brake C2 is configured by such a 2-way clutch TW, the 2-way clutch TW is connected from the first forward speed to the fifth speed, and the sixth forward speed to the eighth speed and the reverse speed are set. Then, each shift stage can be established by setting the one-direction differential rotation prevention state. When an upshift to the sixth speed is predicted at the fifth speed, the rotation speed of the first coupling body Ca-Cb is set so that the carrier Cd (4 of the fourth planetary gear mechanism PGS4) can be smoothly shifted. You may make it switch beforehand from a fixed state to the one-way difference rotation prevention state which can accept | permit the state which becomes slower than the rotational speed of (11th element). According to this, when upshifting from the 5th speed to the 6th speed, as in the effect of the 2-way clutch T1 provided to the second brake B2 when upshifting from the 4th speed to the 5th speed, Since the switching of the state of the two-way clutch as the second clutch C2 has been completed, the shift can be performed smoothly and the shift controllability of the automatic transmission is improved.

  Further, if the second clutch C2 is configured by the above-described two-way clutch, unlike the case where the second clutch C2 is configured by a friction engagement type clutch, no friction loss occurs in the second clutch C2. Therefore, as in the case where the second clutch C2 is configured by a meshing mechanism, the friction loss can be suppressed as the whole automatic transmission.

  According to the two-way clutch TW configured as described above, in addition to the above-described connected state and the one-way differential rotation preventing state, the carrier Cd (1) of the first connected body Ca-Cb and the fourth planetary gear mechanism PGS4 is used. In the open state in which the connection with the eleventh element) is broken, and when the relative rotation direction of the first connection body Ca-Cb with respect to the carrier Cd (the eleventh element) of the fourth planetary gear mechanism PGS4 is the reverse rotation direction, The first connected body Ca-Cb and the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4 are connected, and conversely, the first connected body Ca-Cb for the carrier Cd (11th element) of the fourth planetary gear mechanism PGS4. When the relative rotation direction is the forward rotation direction, the first state in which the connection between the first coupling body Ca-Cb and the carrier Cd (the eleventh element) of the fourth planetary gear mechanism PGS4 is broken. Configure to be switchable It can be.

  Specifically, when the first electromagnetic clutch is turned off and the second electromagnetic clutch is released, the two-way clutch TW has a roller TW4 mounted on the cam surface TW1a as shown in FIG. It will be in the state which continues being located in a center part, and will be in the state which can rotate inner ring TW1 freely with respect to outer ring TW2, ie, an open state.

  Moreover, it will be in a 1st state by making a 1st electromagnetic clutch into an energization OFF state, and making a 2nd electromagnetic clutch into a 1st holding state.

  Therefore, the above-described second electromagnetic clutch of the two-way clutch TW is omitted, and the two-way clutch TW as the second clutch C2 can be switched only between the connected state and the released state by switching the first electromagnetic clutch. You can also. In this case, each shift stage can be established by switching from the first to fifth gears and switching from the sixth to eighth gears and the reverse gear to the open state.

  In the automatic transmission according to the first embodiment, for example, the second and sixth speed stages may be omitted and the forward sixth speed may be changed.

[Second Embodiment]
The automatic transmission according to the second embodiment of the present invention will be described with reference to FIG. In the automatic transmission according to the second embodiment, the fourth planetary gear mechanism PGS4 is disposed radially outward of the third planetary gear mechanism PGS3, and the sun gear Sd (the twelfth element) of the fourth planetary gear mechanism PGS4 and the third planetary gear mechanism PGS4 are arranged. A single-plate type or a multi-plate that is configured by integrally connecting a ring gear Rc (seventh element) of the planetary gear mechanism PGS3 and that can transmit power by a damper DA and friction engagement instead of the torque converter of the first embodiment. Except for the point that the type start clutch C0 is provided, the same configuration as that of the first embodiment is provided, and the respective shift stages can be established in the same manner.

  In the automatic transmission according to the second embodiment, since the fourth planetary gear mechanism PGS4 is disposed radially outward of the third planetary gear mechanism PGS3, the first brake B1, the second In some cases, the brake B2 and the two-way clutch T1 cannot be disposed radially outward of the fourth planetary gear mechanism PGS4. In this case, the first planetary gear mechanism PGS3 and the fourth planetary gear mechanism PGS4 are adjacent to each other. The row composed of the brake B1, the second brake B2, and the 2-way clutch T1 increases by one row. For this reason, compared with the first embodiment, there is a possibility that the number of columns is increased by one row, but the same effect as that of the first embodiment can be obtained except for this point.

  As in the first embodiment, a torque converter TC may be used instead of the starting clutch C0.

[Third Embodiment]
An automatic transmission according to a third embodiment of the present invention will be described with reference to FIG. In the automatic transmission of the third embodiment, the positions of the first planetary gear mechanism PGS1 and the second planetary gear mechanism PGS2 of the first embodiment are exchanged, and the third clutch C3 is replaced by the first planetary gear mechanism PGS1 and the second planetary gear. It is arranged between the mechanism PGS2 and has the same effect as that of the first embodiment.

  In the third embodiment, the radially inner portion of the second planetary gear mechanism PGS2 in which the fourth planetary gear mechanism PGS4 is disposed radially outwardly has a triple pipe structure (specifically, the input The shaft 2, the first connecting member Ca-Cb, and the portion connecting the sun gear Sb and the third clutch C3 of the second planetary gear mechanism PGS2 are three), and the outer diameter of the automatic transmission may increase. Yes, when the outer diameter is kept small, it becomes difficult to set a large reciprocal orange.

  In other words, compared with the third embodiment, the first embodiment has an effect of preventing an increase in the outer diameter of the automatic transmission and easily setting a large ratio orange.

[Fourth Embodiment]
An automatic transmission according to a fourth embodiment of the present invention will be described with reference to FIG. The automatic transmission of the fourth embodiment is the same as that of the third embodiment except that the positions of the third planetary gear mechanism PGS3 and the first planetary gear mechanism PGS1 of the third embodiment are interchanged. The same effects as those of the third embodiment can be obtained.

  In the fourth embodiment, the radially inner portion of the third planetary gear mechanism PGS3 has a quadruple tube structure (specifically, the input shaft 2, the first coupling body Ca-Cb, the second coupling body Ra). -Cc, which is a member connecting the sun gear Sc (9th element) of the third planetary gear mechanism PGS3 and the second brake B2), so that an oil passage in the input shaft 2 of the quadruple pipe structure portion is secured. To do so, it is necessary to increase the outer diameter of the automatic transmission. In other words, in the first to third embodiments, since the radially inner portion of the third planetary gear mechanism PGS3 does not have a multi-tube structure, the automatic transmission is compared to the fourth embodiment. The effect of being able to easily secure the oil passage arranged radially inward of the third planetary gear mechanism PGS3 without increasing the outer diameter of the third planetary gear mechanism PGS3 is obtained.

[Fifth Embodiment]
With reference to FIG. 7, the automatic transmission of 5th Embodiment of this invention is demonstrated. In the automatic transmission according to the fifth embodiment, the fourth planetary gear mechanism PGS4 is disposed between the first clutch C1 and the second clutch C2 in the third embodiment, and the output member 3 is configured as an output shaft. The second clutch C2 and the third brake B3 are composed of a wet multi-plate clutch and a wet multi-plate brake, except for these points, and the same as in the third embodiment. Composed.

  Also with the automatic transmission of the fourth embodiment, the number of engagement mechanisms of each gear stage can be reduced to three or less, and friction loss can be suppressed. When an automatic transmission is mounted on an FR type vehicle, if the output member 3 is an output gear, it is necessary to provide a countershaft to which the rotation of the output gear is transmitted to transmit power to the propeller shaft. However, if the output member 3 is an output shaft, the propeller shaft can be directly connected to the output shaft. For this reason, according to the automatic transmission of 5th Embodiment, the mounting property to FR type vehicle can be improved.

DESCRIPTION OF SYMBOLS 1 ... Transmission case, 2 ... Input shaft, 3 ... Output member, ENG ... Drive source, LC ... Lock-up clutch, DA ... Damper, TC ... Torque converter, PGS1 ... First planetary gear mechanism, Sa ... Sun gear (first Element), Ca ... carrier (second element), Ra ... ring gear (third element), Pa ... pinion, PGS2 ... second planetary gear mechanism, Sb ... sun gear (sixth element), Cb ... carrier (fifth element) , Rb ... ring gear (fourth element), Pb ... pinion, PGS3 ... third planetary gear mechanism, Sc ... sun gear (9th element), Cc ... carrier (8th element), Rc ... ring gear (7th element), Pc ... Pinion, PGS4 ... 4th planetary gear mechanism, Sd ... Sun gear (12th element), Cd ... Carrier (11th element), Rd ... Ring gear (10th element), Pd ... Pinion, C1-C3 ... No. To third clutch, B1 to B3 ... first to third brake, T1 ... 2-way clutches.

Claims (15)

An automatic transmission that includes an input shaft that is rotatably supported in a transmission case and that is rotated by power from a drive source, and that rotates the input shaft in multiple stages and outputs the output shaft from an output member. ,
There are provided first to fourth planetary gear mechanisms each having three elements including a sun gear, a carrier, and a ring gear,
The three elements of the first planetary gear mechanism are a first element, a second element, and a third element, respectively, in the order of arrangement at intervals corresponding to the gear ratio in the collinear chart in which the relative rotational speed ratio can be represented by a straight line. ,
The three elements of the second planetary gear mechanism are a fourth element, a fifth element, and a sixth element, respectively, in order of arrangement at intervals corresponding to the gear ratio in the collinear diagram,
The three elements of the third planetary gear mechanism are a seventh element, an eighth element, and a ninth element, respectively, in the order of arrangement at intervals corresponding to the gear ratio in the collinear chart in which the relative rotational speed ratio can be represented by a straight line. ,
As the tenth element, the eleventh element, and the twelfth element, the three elements of the fourth planetary gear mechanism are arranged in the order corresponding to the gear ratio in the alignment chart, respectively.
The first element is coupled to the input shaft, the tenth element is coupled to the output member, the second element and the fifth element are coupled to form a first coupled body, and the third element And the eighth element are connected to form a second connecting body, the sixth element, the seventh element, and the twelfth element are connected to form a third connecting body,
As an engagement mechanism,
A first clutch capable of connecting the first element and the eleventh element;
A second clutch capable of connecting the first connector and the eleventh element;
A third clutch capable of connecting the second connector and the fourth element;
A first brake capable of fixing the second connector to the transmission case;
A second brake capable of fixing the ninth element to the transmission case;
A third brake that can fix the eleventh element to the transmission case;
By bringing at least three engagement mechanisms out of a total of six engagement mechanisms of the first to third clutches and the first to third brakes into a connected state or a fixed state, An automatic transmission characterized by establishing a gear position. The automatic transmission according to claim 1, wherein
The sixth element is a ring gear of the second planetary gear mechanism;
The seventh element is a ring gear of the third planetary gear mechanism;
The twelfth element is a sun gear of the fourth planetary gear mechanism;
The fourth planetary gear mechanism is disposed radially outward of the second planetary gear mechanism or the third planetary gear mechanism;
A sun gear of the fourth planetary gear mechanism is configured integrally with a ring gear of the second planetary gear mechanism or the third planetary gear mechanism. The automatic transmission according to claim 2, wherein
The fourth planetary gear mechanism is disposed radially outward of the second planetary gear mechanism;
The sun gear of the fourth planetary gear mechanism is configured integrally with the ring gear of the second planetary gear mechanism,
In the axial direction of the input shaft, the second planetary gear mechanism is disposed between the first planetary gear mechanism and the third planetary gear mechanism. The automatic transmission according to claim 2, wherein
The fourth planetary gear mechanism is disposed radially outward of the second planetary gear mechanism;
The sun gear of the fourth planetary gear mechanism is configured integrally with the ring gear of the second planetary gear mechanism,
In the axial direction of the input shaft, the first planetary gear mechanism is disposed between the second planetary gear mechanism and the third planetary gear mechanism. The automatic transmission according to any one of claims 1 to 4,
The output member is an output gear;
The output gear is pivotally supported by a cylindrical portion provided on a side wall extending radially inward from the transmission case,
The automatic transmission, wherein the second clutch is disposed radially inward of the cylindrical portion. The automatic transmission according to any one of claims 1 to 5,
A two-way clutch that is switchable between a reverse rotation preventing state that allows forward rotation of the ninth element and prevents reverse rotation and a forward rotation blocking state that prevents forward rotation of the ninth element and allows reverse rotation is provided. Automatic transmission featured. The automatic transmission according to any one of claims 1 to 6,
The automatic transmission is characterized in that the third brake is constituted by a meshing mechanism. The automatic transmission according to any one of claims 1 to 7,
The automatic transmission is characterized in that the second clutch is constituted by a meshing mechanism. The automatic transmission according to any one of claims 1 to 7,
The second clutch is connected to connect the first connecting body and the eleventh element;
When the relative rotation direction of the first coupling body with respect to the eleventh element is a normal rotation direction, the first coupling body and the eleventh element are coupled, and the first coupling body with respect to the eleventh element When the relative rotation direction is the reverse rotation direction, the two-way clutch can be switched to a one-direction differential rotation blocking state in which the first connection body and the eleventh element are disconnected. Automatic transmission featured. The automatic transmission according to any one of claims 1 to 9,
The automatic transmission, wherein the third brake is disposed radially outward of the first clutch. The automatic transmission according to any one of claims 1 to 10,
The automatic transmission according to claim 1, wherein at least one of the first to third brakes is disposed at a shaft end portion of the input shaft. The automatic transmission according to any one of claims 1 to 11,
The output member is an output shaft;
The automatic transmission is characterized in that the output shaft is disposed concentrically with the input shaft. The automatic transmission according to any one of claims 1 to 12,
The first to fourth planetary gear mechanisms are constituted by a single pinion type planetary gear mechanism that includes a sun gear, a ring gear, and a carrier that rotatably and revolves a pinion that meshes with the sun gear and the ring gear. An automatic transmission characterized by that. The automatic transmission according to any one of claims 1 to 13,
2. An automatic transmission comprising a starting clutch capable of transmitting power of the driving source to the input shaft. The automatic transmission according to any one of claims 1 to 13,
The automatic transmission is characterized in that the power of the drive source is transmitted to the input shaft via a torque converter.

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