JP2008249038A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic transmission capable of reducing the full length of multi-disk brakes connected in the axial direction. <P>SOLUTION: The automatic transmission 1 equipped with a first brake pack 38 and a second brake pack 58 connected in series in the direction of spline grooves 83 and 85 comprises a first piston 31 to press the first brake pack 38, a first cylinder 35 containing the first piston 31 to slide in the axial direction, a second piston 51 to press the second brake pack 58, and a second cylinder 55 containing the second piston 51 to slide in the axial direction. The first and second cylinders 35 and 55 are disposed axially opposite to the second brake pack 58 relative to the first brake pack 38 and overlap with each other in the axial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automatic transmission suitable for mounting on a vehicle or the like, and more particularly, to an automatic transmission including at least two sets of multi-plate brakes each having a transmission case or a member fixed thereto as a fixing member.

  2. Description of the Related Art Conventionally, there is known an automatic transmission that includes a plurality of multi-plate frictional engagement elements and performs a shift by switching between these intermittent states. The frictional engagement element includes a clutch that interrupts power and a brake that switches between fixing and releasing of the rotating element.

  The structure of the multi-plate brake is roughly divided into a brake pack and a pressing mechanism that presses the brake pack. The brake pack is a plate group in which a plurality of rotating plates and a plurality of fixed plates are alternately arranged. The rotating plate rotates integrally with a rotating member to be fixed to the brake by, for example, spline fitting on the inner peripheral side thereof. The rotation of the fixed plate is restricted by a fixed member (such as a case) by spline fitting on the outer peripheral side thereof.

  The brake packs are fastened to each other by a frictional force when pressed in the axial direction (continuous direction), and the rotation elements are restricted (fixed to the case).

  The pressing mechanism is a mechanism for pressing and releasing the brake pack, and is a hydraulic piston / cylinder, a return spring, or the like.

Patent Document 1 discloses a plurality of such multi-plate brakes provided in series in the axial direction. In the automatic transmission disclosed in Patent Document 1, a spline groove is formed on the inner peripheral side of a case which is a fixed member, and a fixed plate is fitted to the spline. In general, since the brake pack and the pressing mechanism are provided adjacent to each other in the axial direction, when a multi-plate brake is connected, for example, as shown in FIG. However, they are arranged in series in the axial direction by the number provided in series.
International Publication No. WO03 / 087624A1 Pamphlet

  However, in recent years, there has been a particularly strong demand for downsizing of an automatic transmission, particularly a demand for shortening the overall length (shortening the axial length). In such a structure, in the structure in which the brake packs and the pressing mechanisms of a plurality of multi-plate brakes as shown in Patent Document 1 are arranged in series in the axial direction, the axial length of the automatic transmission is increased or the entire length is increased. This hinders shortening.

  The present invention has been made in view of the above circumstances, and provides an automatic transmission capable of reducing the total length (total of axial lengths) when a multi-plate brake is continuously provided in the axial direction. Objective.

  According to a first aspect of the present invention for solving the above problem, a transmission case having a spline groove formed on a cylindrical inner peripheral surface or a member fixed thereto, a plurality of rotating plates, and an outer periphery of the spline groove. Brake pack in which a plurality of fixing plates with which the portions are fitted are arranged alternately in the axial direction, and includes an automatic transmission including a first brake pack and a second brake pack that are continuously provided in the spline groove direction. A first piston that presses the first brake pack, a first cylinder that receives the first piston so as to be axially slidable, a second piston that presses the second brake pack, and the second A second cylinder that receives the piston in an axially slidable manner, wherein the first cylinder and the second cylinder are in the second brake pack with respect to the first brake pack. Together disposed axially opposite, characterized in that it is overlapped arranged axially to each other.

  According to a second aspect of the present invention, in the automatic transmission according to the first aspect of the present invention, the automatic transmission according to the first aspect includes a wall portion extending in a radial direction with respect to the axial center of the first cylinder, and the wall portion includes the first cylinder and the second cylinder. And the second cylinder is disposed on the outer peripheral side of the first cylinder.

  According to a third aspect of the present invention, in the automatic transmission according to the first or second aspect, the drum member having the outer peripheral side fixed to the transmission case or a member fixed thereto and the spline groove formed on the inner peripheral side is provided. It is characterized by providing.

  According to a fourth aspect of the present invention, in the automatic transmission according to the third aspect of the present invention, the automatic transmission includes a pressing communication member that passes through an outer peripheral side of the first brake pack, and the second piston is connected to the second via the pressing communication member. The brake pack is configured to press the brake pack.

  According to a fifth aspect of the present invention, in the automatic transmission according to the fourth aspect of the present invention, the drum member is formed with a press communication insertion portion for passing the press communication member in the axial direction.

  According to a sixth aspect of the present invention, in the automatic transmission according to any one of the third to fifth aspects, a first return spring that biases a return force to the first piston and a first spring retainer that holds the first return spring. And a second return spring that urges a return force to the second piston and a second spring retainer that holds the second return spring, and the first spring retainer and the second spring retainer are provided on the drum member. It is characterized by that.

  The invention according to claim 7 is the automatic transmission according to claim 6, wherein the drum member is fixed to the transmission case or a member fixed thereto by spline fitting and snap ring stopper. And

  According to an eighth aspect of the present invention, in the automatic transmission according to the sixth or seventh aspect, the first return spring is provided on the opposite side of the first piston in the axial direction with respect to the first brake pack. A spring communication member passing through the outer peripheral side of the brake pack is provided, and the first piston is configured to receive a biasing force from the first return spring via the spring communication member.

  According to a ninth aspect of the present invention, in the automatic transmission according to the eighth aspect, the drum member is formed with a spring communication insertion portion through which the spring communication member passes in the axial direction.

  According to a tenth aspect of the present invention, in the automatic transmission according to the ninth aspect of the present invention, the automatic transmission includes a pressing communication member that passes through an outer peripheral side of the first brake pack, and the second piston is connected to the second piston via the pressing communication member. The drum member is configured to press the brake pack, and the drum member is formed with a pressing communication insertion portion that passes the pressing communication member in the axial direction, and the pressing communication insertion portion and the spring communication insertion portion include the drum member. It is characterized by being formed intermittently at different positions in the circumferential direction.

  The invention according to an eleventh aspect is the automatic transmission according to any one of the third to tenth aspects, wherein the transmission case has an opening at an axial end and closes the opening. This is formed as the wall portion, and the drum member is fixed to the case cover.

  According to the first aspect of the present invention, since the first cylinder and the second cylinder are arranged to overlap in the axial direction, the first brake (the first brake pack, The total total length of the first piston and the first cylinder) and the second brake (including the second brake pack, the second piston, and the second cylinder) can be shortened. This also shortens the overall length of the automatic transmission.

  According to the invention of claim 2, the first cylinder and the second cylinder can be easily overlapped in the axial direction with a simple structure.

  According to the third aspect of the present invention, the use of the drum member separate from the transmission case can increase the degree of freedom in brake layout. For example, when the transmission case itself is a fixing member, the spline groove is often provided inside the outer wall. In that case, the outer diameter of the fixed plate is regulated by the outer shape of the transmission case. In that case, since the outer peripheral side of the brake pack is the outside of the case, it is difficult to dispose any member (such as a return spring) there.

  On the other hand, in the present invention, the outer diameter of the fixed plate can be easily changed only by changing the inner diameter of the drum member, and a gap is provided between the outer peripheral portion of the drum member and the inner peripheral portion of the case. It is also easy to dispose any member on the outer peripheral side of the brake pack using the gap.

  According to the invention of claim 4, the second brake pack can be pressed by the second piston remotely (remote operation). A first brake pack is disposed between the second piston and the second brake pack. However, the second piston can press the second brake pack by jumping over the first brake pack by the pressing communication member. The pressing communication member may be integrated with the first piston.

  According to the fifth aspect of the present invention, the pressure communication member can be easily disposed by passing the pressure communication member through the pressure communication insertion portion (hole, groove, or inner peripheral side bulging portion).

  According to the sixth aspect of the present invention, the structure can be simplified and the sub-assembly can be facilitated by centrally arranging the return spring and the spring retainer on the drum member. Further, the return spring is disposed on the outer peripheral side of the brake pack, that is, by overlapping in the axial direction, the overall length can be further shortened.

  According to the seventh aspect of the invention, the drum member can be easily fixed to the transmission case or a member (hereinafter referred to as a case or the like) fixed to the transmission case.

  By providing the spring retainer on the drum member, the drum member receives a reaction force of the return spring force. By receiving the reaction force by the snap ring, the axial movement of the drum member can be restricted. The rotation of the drum member is restricted by spline fitting.

  In this way, the drum member can be fixed to the case or the like by a simple structure and process in which the spline is fitted and stopped by the snap ring.

  According to the invention of claim 8, urging the first piston by the first spring can be performed remotely (remote operation). A first brake pack is disposed between the first piston and the first return spring (in the axial direction). However, the first return spring can jump over the first brake pack and urge the first piston by the spring connecting member. The spring connecting member may be integrated with the first piston or the first spring retainer.

  According to the ninth aspect of the present invention, the pressure communication member can be easily arranged by passing the spring communication member through the spring communication insertion portion (hole, groove, or inner peripheral side bulging portion).

  According to the invention of claim 10, the pressing communication insertion portion and the spring communication insertion portion can be arranged at a position close to the radial direction or a position overlapping in the radial direction (substantially the same diameter position), and is compact in the radial direction. Can be achieved.

  According to the invention of claim 11, the production efficiency can be increased by subassembly. For example, each cylinder, each piston, drum member, and each brake pack are sub-assembled in the case cover in advance, and only the sub-assembly is assembled to the transmission case in the final assembly line of the automatic transmission. . By doing so, a large number of members can be attached to the transmission case at a time, so that the manufacturing process at the final line can be greatly simplified.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram (skeleton diagram) showing a skeleton structure of an automatic transmission 1 according to an embodiment of the present invention. The automatic transmission 1 of this embodiment is connected to an engine (a crankshaft 90 thereof) and mounted on a vehicle. The automatic transmission 1 is a multistage automatic transmission having six forward speeds and one reverse speed, and is a so-called six-speed automatic transmission.

  In the following description, the axial crankshaft 90 side (the right side in FIG. 1) is referred to as the front side, and the opposite side is referred to as the rear side.

  A turbine shaft 4 (first input shaft) and a second input shaft 5 are arranged on a main axis coaxial with the crankshaft 90, and the torque converter 3, first, second, and third planetary gears having these as rotating shafts are arranged. A set GS1, GS2, GS3 and a counter drive gear 6 are provided.

  A counter shaft 15 is provided on a counter shaft arranged in parallel with the main axis, and a counter driven gear 12 and a differential drive gear 17 that rotate integrally therewith are provided.

  Further, a differential ring gear 19 and a differential mechanism 50 are provided on a differential axis line arranged in parallel with the counter shaft.

  The torque converter 3 includes a transmission-side pump 3a directly connected to the crankshaft 90, a driven-side turbine 3b that rotates integrally with the turbine shaft 4, and a transmission case 2 (more precisely, a transmission). And a stator 3c connected to a member fixed to the case 2. The torque converter 3 includes a lockup damper 3d that rotates integrally with the turbine shaft 4, and a lockup clutch 3e that fastens the pump 3a and the lockup damper 3d. The torque converter 3 is filled with working fluid (ATF).

  With this configuration, the torque converter 3 acts as a fluid coupling having a torque amplifying action when the lockup clutch 3e is released, and directly connects the crankshaft 90 and the turbine shaft 4 when the lockup clutch 3e is engaged.

  Three planetary gear sets (GS1, GS2, GS3) are arranged on the rear side of the torque converter 3. These are arranged in the order of the third planetary gear set GS3, the second planetary gear set GS2, and the first planetary gear set from the front side.

  The first, second and third planetary gear sets GS1GS2 and GS3 include first, second and third sun gears S1, S2 and S3, first, second and third ring gears R1, R2 and R3, First, second, and third pinions P1, P2, and P3 meshing with the sun gear and each ring gear, and first, second, and third supporting the first, second, and third pinions P1, P2, and P3. A single-pinion type planetary gear set including carriers C1, C2, and C3.

  The first sun gear S1 is connected to the turbine shaft 4 and rotates integrally therewith. The second sun gear S2 and the third sun gear S3 are connected to each other and rotate integrally.

  The first carrier C1 and the second ring gear R2 are connected to each other and rotate integrally. The second carrier C2 and the third ring gear R3 are connected to each other and rotate integrally. The third carrier C3 is connected to a counter drive gear 6 that is an output gear on the main axis side, and rotates integrally therewith.

  The counter driven gear 12 provided on the counter shaft 15 meshes with the counter drive gear 6 and is driven thereby. A differential drive gear 17 provided on the counter shaft 15 meshes with a differential ring gear 19 to drive it.

  The differential mechanism 50 is a known mechanism that transmits the drive wheels transmitted to the differential ring gear 19 to the pair of drive shafts 80 while distributing the drive wheels according to the rotational difference.

  The automatic transmission 1 includes five engagement elements, that is, a low clutch LC, a high clutch HC, an R35 brake B1, 2/6 brake B2, an L / R brake B3, and a one-way clutch W1. Except for the one-way clutch W1, it is a wet multi-plate type frictional engagement element. The low clutch LC rotates the turbine shaft 4 and the third sun gear S3 as a single unit when the low clutch LC is engaged. The high clutch HC integrally rotates the turbine shaft 4 and the second carrier C2 by the engagement. The R35 brake B1, 2/6 brake B2, and L / R brake B3 fix the first ring gear R1, the second ring gear R2, and the third ring gear R3 to the case 2 by fastening them. The one-way clutch W1 is unlocked when the third ring gear R3 tries to rotate in the same direction as the crankshaft 90, and is allowed when the third ring gear R3 rotates in the opposite direction. (The third ring gear R3 is fixed to the case 2).

  FIG. 2 is a diagram illustrating an intermittent state of each fastening element at each gear position. In this figure, ◯ indicates that the frictional engagement element is engaged, and ● indicates that the one-way clutch W1 is in a locked state. Parentheses indicate that there are cases. No mark indicates that it is released or unlocked. In the automatic transmission 1 according to the present embodiment, the P (parking) range, the R (reverse) range, the N (neutral) range, and the D (travel) are used as shift lever positions (shift ranges) that are not shown in FIG. There is a range. In the D range, the M (manual) mode can be selected according to the driver's intention instead of the normal automatic transmission mode. In the M mode, the driver manually determines the gear position by operating the shift lever.

  At the first speed (1st), the low clutch LC is engaged, and the one-way clutch W1 is locked. This achieves the lowest speed. The L / R brake B3 is engaged (indicated by (◯)) in the M mode and released in the automatic transmission mode. When the L / R brake B3 is engaged, the reverse driving force can be transmitted from the drive shaft 80 side to the turbine shaft 4 side. Therefore, a strong engine brake can be obtained as a vehicle.

  On the other hand, when the L / R brake B3 is released, such a reverse driving force is not transmitted due to the idling of the one-way clutch W1. Therefore, a strong engine brake does not act as a vehicle.

  The automatic transmission mode and the M mode are common to the second speed (2nd) to the sixth speed (6th). At the second speed (2nd), the low clutch LC and the 2/6 brake B2 are engaged to achieve a higher speed than the first speed. At the third speed (3rd), the low clutch LC and the R35 brake B1 are engaged to achieve a higher speed than the second speed. At the fourth speed (4th), the low clutch LC and the high clutch HC are engaged to achieve a higher speed than the third speed. In the fourth speed, the counter drive gear 6 and the turbine shaft 4 are in a directly connected state in which the rotation speeds coincide with each other. At the fifth speed (5th), the high clutch HC and the R35 brake B1 are engaged to achieve a higher speed than the fourth speed. In the sixth speed (6th), the highest speed stage is achieved by engaging the high clutch HC and the 2/6 brake B2.

  In the R range, the drive shaft 80 can be driven in reverse rotation with respect to the crankshaft 90 by engaging the R35 brake B1 and the L / R brake B3. That is, the reverse stage is achieved.

  FIG. 3 is a partial longitudinal sectional view of the automatic transmission 1, and particularly shows the vicinity of the R35 brake B1 (first brake) and the 2/6 brake B2 (second brake) disposed around the rear end portion. Show. FIG. 4 is an enlarged view of a main part of FIG. In these drawings, cross-sectional views at three cross-sectional positions (VI-VI line, VII-VII line, and VIII-VIII line shown in FIG. 5) are appropriately used to explain the overall structure of the portion. It is shown synthesized. Portions that are not in the same cross-section (VI-VI cross-section shown in FIG. 5) position are indicated by a two-dot chain line.

  As shown in FIG. 3, the rear side end of the transmission case 2 (hereinafter also simply referred to as a case) is an opening, and the opening extends in the radial direction with respect to the axis of the turbine shaft 4. Part, case cover) and bolted up by a bolt 2h. The rear cover 2a is extended to the front side in a cylindrical shape in the vicinity of the outer periphery thereof (however, inside the case 2), and a spline portion 2b extending in the axial direction is formed on the inner peripheral side of the extended portion.

  A drum member 70 is provided as a member attached to the case 2 and integrated with the case 2 together with the rear cover 2a. As shown in FIG. 4, the drum member 70 mainly includes a substantially cylindrical cylindrical portion 81 and a flange portion 71 that protrudes from the vicinity of the axial center of the cylindrical portion 81 toward the outer peripheral side. Two sets of splines extending in the axial direction are provided on the inner peripheral side of the drum member 70. That is, the first spline 83 on the rear side and the second spline 85 on the front side. A spline groove is formed in the outer peripheral portion of the flange portion 71 of the drum member 70, and is fitted to the spline portion 2b of the rear cover 2a. The drum member 70 is also restricted in the axial direction by being stopped by a snap ring 77, and is fixed to the rear cover 2a.

  The R35 brake B1 includes a first brake pack 38. The first brake pack 38 has a plurality of rotating plates 38a and a plurality of fixed plates 38b (three in FIG. 4) alternately arranged in the axial direction, and a retaining plate 39 at the front side end thereof. Is arranged. The rotating plate 38a is an annular disk body, for example, in which a friction material is stuck on both surfaces of a metal plate. The rotating plate 38a is spline-fitted with a connecting member 49 which is connected to the first ring gear R1 and rotates integrally with the first ring gear R1 on the inner peripheral side thereof.

  The fixed plate 38b is an annular disk, and is made of, for example, a metal plate. The fixed plate 38b is spline-fitted with the first spline 83 on the outer peripheral side thereof.

  In addition, although there is a gap between the frontmost rotation plate 38a and the retaining plate 39, this is a clearance between the plates, and this gap is actually distributed between the plates. When the R35 brake B1 is engaged, this gap is clogged, and the connecting member 49 (that is, the first ring gear R1) is fixed to the drum member 70 by the frictional force between the plates.

  On the other hand, the 2/6 brake B2 includes a second brake pack 58. The second brake pack 58, the same rotary plate 58a as the rotary plate 38a (four in FIG. 4) and the fixed plate 58b (three in FIG. 4) are alternately arranged in the axial direction. A retaining plate 59 is disposed at the side end. The rotating plate 58a is spline-fitted with a connecting member 89 which is connected to the first carrier C1 and rotates integrally with the first carrier C1 on the inner peripheral side thereof. The fixed plate 38b is spline-fitted with the second spline 85 on the outer peripheral side thereof. About the clearance between plates, it is the same as that of R35 brake B1. When the 2/6 brake B2 is engaged, the connecting member 89 (that is, the third carrier C3) is fixed to the drum member 70.

  An annular disk-shaped pressing plate 60 is provided further to the rear side of the rearmost rotation plate 58a. As will be described later, the second brake pack 58 is pressed against the second piston 51 via the pressing plate 60.

  The rear cover 2a is provided with a first cylinder 35 that functionally belongs to the R35 brake B1. The first cylinder 35 has an annular groove shape that opens to the front side. The opening is closed by the first piston 31 to form a first hydraulic chamber 36. The first piston 31 is provided with a seal member 32 that smoothly slides the first piston 31 in the axial direction while keeping the oil tightness of the first cylinder 35.

  The first piston 31 presses the first brake pack 38 adjacent thereto on the front side. However, a spring communication member 47 is interposed between the first piston 31 and the first brake pack 38. As a result, the first piston 31 can receive a biasing force from the first return spring 41 at a distant position, which will be described in detail later.

  A second cylinder 55 that functionally belongs to the 2/6 brake B2 is provided on the outer peripheral side of the first cylinder 35 of the rear cover 2a. The second cylinder 55 has an annular groove shape that opens to the front side. The second cylinder 55 is a stepped groove. Then, the opening of the second cylinder 55 is closed by the stepped second piston 51 to form the second A hydraulic chamber 56 and the second B hydraulic chamber 57. The second piston 51 is provided with seal members 52 and 54 for smoothly sliding the second piston 51 in the axial direction while keeping the oil tightness of the second cylinder 55. Further, a seal member 53 that separates the second A hydraulic chamber 56 and the second B hydraulic chamber 57 is provided.

  The second piston 51 presses the second brake pack 58 provided on the front side. However, the first brake pack 38 is provided between the second piston 51 and the second brake pack 58. Therefore, the second piston 51 is formed with a press communication portion 51a (press communication member) that extends to the front side and passes through the outer peripheral side of the first brake pack 38. The pressing communication portion 51 a abuts on the outermost peripheral portion of the pressing plate 60. The second piston 51 (the pressing communication portion 51 a thereof) can press the second brake pack 58 by pressing the pressing plate 60.

  The first return spring 41 and the first spring retainer 43 that functionally belong to the R35 brake B1, and the second return spring 61 and the second spring that functionally belong to the 2/6 brake B2 are provided on the outer peripheral side of the cylindrical portion 81 of the drum member 70. A retainer 73 is provided, and details thereof will be described later.

  FIG. 5 is a right side view (side view seen from the front side) of the drum member 70 and its peripheral members.

  As shown in this figure, the pressing communication portion 51a of the second piston 51 and the communication portion 47a of the spring communication member 47 (the portion extending to the first return spring 41 side of the spring communication member 47, see FIG. 8) are all around. It is provided in the circumferential direction intermittently (comb-tooth shape). That is, each of the press contact portions 51a and the contact portions 47a is provided at six locations at intervals of about 60 ° central angles. Moreover, the central angle is shifted by about 30 ° as a whole. Furthermore, the first return spring 41 (the second return spring 61 is also in the same position) is disposed at approximately 12 positions in the circumferential direction between the pressing communication portion 51a and the communication portion 47a.

  Therefore, although the pressing communication portion 51a, the communication portion 47a of the spring communication member 47, and the first return spring 41 (and the second return spring 61) are provided at substantially the same diameter position of the drum member 70, they are mutually connected. Does not interfere.

  The characteristic three types of cross sections will be described below with reference to FIG. 5 and FIGS.

  6 is a cross-sectional view taken along line VI-VI in FIG. This figure also reproduces the solid line portion of FIG. This VI-VI line cross section is a cross section characterized by the pressing communication portion 51 a, the pressing plate 60, and the bulging portion 74 of the drum member 70. As described above, the pressing communication portion 51a presses the pressing plate 60, and this is done at this cross-sectional position (a circumferential position where the pressing communication portion 51a exists). At the circumferential position, the outer diameter of the pressing plate 60 has a size capable of coming into contact with the pressing communication portion 51a, but at the other circumferential positions, it corresponds to the inner diameter of the second spline 85 (FIG. 7, (See FIG. 8). The contact between the press communication portion 51a and the press plate 60 is made inside the bulging portion 74 (press communication insertion portion) of the drum member 70. As shown in FIG. 5, the cylindrical portion 81 of the drum member 70 is formed so that the inner periphery bulges at the position where the pressing communication portion 51 a is present, and this is the bulging portion 74. The pressing communication part 51a reaches the pressing plate 60 by passing through the inside of the bulging part 74, and can press it.

  7 is a sectional view taken along line VII-VII in FIG. The section taken along line VII-VII is a section characterized by the first return spring 41 and the first spring retainer 43, and the second return spring 61 and the second spring retainer 73. The first return spring 41 and the second return spring 61 are small-diameter coil springs, each of which is provided in twelve. Each of the twelve springs provided in parallel functions as the first return spring 41 and the second return spring 61 as a whole.

  The first return spring 41 and the second return spring 61 are provided on the outer peripheral side of the cylindrical portion 81 of the drum member 70, not on the bulging portion 74, or on a location where the pressing communication portion 51 a is not present. So do not interfere with these.

  In addition, first and second spring retainers 43 and 73 (73a and 73b) that appropriately hold the first and second return springs 41 and 61 at the cross-sectional positions where the first and second return springs 41 and 61 exist are provided. It has been. The first spring retainer 43 is fixed to the bulging portion 74 of the drum member 70 by a snap ring 45 (see FIG. 6).

  The front side (73 b) of the second spring retainer 73 is a flange portion 71 of the drum member 70. That is, a portion where the second return spring 61 contacts the flange portion 71 is dug to a predetermined depth to form the second spring retainer 73b.

  8 is a cross-sectional view taken along line VIII-VIII in FIG. The section taken along line VIII-VIII is a section characterized by the connecting portion 47a of the spring connecting member 47 and the through hole 75 (spring connecting insertion portion) of the drum member 70.

  The outer periphery of the spring connecting member 47 is intermittently extended (bent) to the front side to form a connecting portion 47a. The front end portion of the connecting portion 47 a abuts on the first spring retainer 43. The first piston 31 is separated from the first brake pack 38 and the flange portion 71 of the drum member 70 and is far from the first spring retainer 43 (first return spring 41). However, the first return spring is formed by the connecting portion 47a. The urging force (return spring force) from 41 can be received.

  A through hole 75 (spring connection insertion portion) is formed at a circumferential position of the flange portion 71 of the drum member 70 where the communication portion 47a exists. By connecting the connecting portion 47 a through the through hole 75, communication between the first piston 31 and the first spring retainer 43 is achieved.

  Although the structure at each cross-sectional position has been described above, the functions as the R35 brake B1 and the 2/6 brake B2 are achieved by appropriately cooperating each member provided so as to be shifted in the circumferential direction. Hereinafter, each cross-sectional view is appropriately combined and described.

  FIG. 9 is a combined cross-sectional view focusing on the function of the R35 brake B1. When the hydraulic pressure is supplied to the first hydraulic chamber 36 and becomes higher than the pressure equivalent to the urging force (return spring force) of the first return spring 41, the first piston 31 slides to the front side via the spring connecting member 47. To press the first brake pack 38. Thereby, R35 brake B1 will be in a fastening state. When the hydraulic pressure in the first hydraulic chamber 36 is released and the urging force of the first return spring 41 becomes relatively strong, the first urging force (transmitted to the first piston 31 via the connecting portion 47a) is the first. The piston 31 is pushed back to the rear side. As a result, the R35 brake B1 is in an appropriate released state (clutch drag is suppressed).

  FIG. 10 is a composite sectional view showing the function of the 2/6 brake B2. When the 2/6 brake B2 is engaged, the hydraulic pressure is supplied only to the second A hydraulic chamber 56 at the initial stage (until or after the clutch meet is completed), and the hydraulic pressure is also supplied to the second B hydraulic chamber 57 in the latter period. .

  First, when the hydraulic pressure is supplied to the second A hydraulic chamber 56 and becomes higher than the pressure equivalent to the urging force (return spring force) of the second return spring 61, the second piston 51 slides to the front side, and the pressing communication portion 51a The second brake pack 58 is pressed through the pressing plate 60. As a result, the 2/6 brake B2 is clutch-meeted. When the hydraulic pressure is further supplied to the second B hydraulic chamber 57 in the latter half of the engagement, the engagement force becomes sufficiently large, and a clutch capacity with a margin against torque fluctuation can be secured.

  The reason why the hydraulic pressure is supplied in two stages in this way is to reduce the engagement force gain (ratio of change in engagement force with respect to change in hydraulic pressure) during clutch meet. When the fastening force gain is small, the fastening force variation with respect to the hydraulic pressure variation is small, so that a more delicate and highly accurate fastening force can be obtained. That is, torque fluctuations (also referred to as shift shocks or engagement shocks (N-R)) due to the engagement of the R35 brake B1 can be suppressed.

  Then, by supplying hydraulic pressure to the second B hydraulic chamber 57 and increasing the gain in the second half of engagement, a sufficient clutch capacity (engagement force) can be ensured even at a relatively low hydraulic pressure, and the concern about clutch slipping can be eliminated. it can.

  When the hydraulic pressure in the second A hydraulic chamber 56 and the second B hydraulic chamber 57 is released and the biasing force of the second return spring 61 becomes relatively strong, the second piston 51 is pushed back to the rear side by the biasing force. As a result, the 2/6 brake B2 is in an appropriate released state (clutch drag is suppressed).

  Next, design (layout) advantages and manufacturing advantages of the present embodiment will be described. First, in this embodiment, a drum member 70 separate from the case 2 is used, and by forming spline grooves (first spline 83 and second spline 85) for the fixing plate in the drum member 70, the R35 brake B1 and 2 / The degree of freedom in layout of the six brakes B2 can be increased. For example, the outer diameter setting values of the fixed plates 38b and 58b can be easily changed simply by changing the inner diameter of the drum member 70. In addition, it becomes easy to dispose the first return spring 41 and the second return spring 61 using the gap between the outer peripheral portion of the drum member 70 and the inner peripheral portion of the case 2. This also contributes to shortening the overall length.

  Further, since the drum member 70 can be assembled (sub-assembled) to the rear cover 2a in advance, it is advantageous in terms of manufacturing. At that time, the first piston 31, the second piston 51, the first brake pack 38, the second brake pack 58, the first return spring 41, the first spring retainer 43, the second return spring 61, and the second spring retainer 73 (73a ) Can be sub-assembled together. In the present embodiment, a part of the first planetary gear set GS1 and the second planetary gear set GS2 (the first carrier C1 (including the first pinion P1), the first ring gear R1 and the second ring gear R2) are also included. Can be sub-assembled together.

  The rotation of the drum member 70 in the rotational direction is restricted by the spline portion 2b of the rear cover 2a. The axial movement of the drum member 70 is also restricted by the urging force (return reaction force) of the first return spring 41 and the second return spring 61 and the snap ring 77. Therefore, the sub-assembly can be performed by a simple process (compared to bolting or the like) in which the drum member 70 is spline-fitted to the rear cover 2a and fastened by the snap ring 77.

  In this way, many members can be sub-assembled, and in the final assembly line (final line) of the automatic transmission 1, the sub-assembly can be simply assembled to the rear side opening of the case 2. By doing so, a large number of members can be attached to the case 2 at a time, so that the manufacturing process at the final line can be greatly simplified.

  As described above, in the present embodiment, the first cylinder 35 and the second cylinder 55 are disposed on the opposite side in the axial direction of the second brake pack 58 with respect to the first brake pack 38, and are axially connected to each other. The overlap is arranged. Accordingly, the total length of the R35 brake B1 and the 2/6 brake B2 can be shortened. As a result, the overall length of the automatic transmission 1 can be shortened.

  Moreover, although the 2nd piston 51 and the 2nd brake pack 58 are arrange | positioned by the structure in the distant position separated by the 1st brake pack 38, the remoteness is achieved by the press communication part 51a. Further, by providing the drum member 70 with a bulging portion 74 (press communication insertion portion), the layout is facilitated.

  Similarly, the first piston 31 and the first return spring 41 are disposed at a distant position separated by the first brake pack 38, but the remote connection is achieved by the spring connecting member 47 (the connecting portion 47a). Has been. Further, by providing the drum member 70 with a through hole 75 (spring communication insertion portion), the layout is facilitated.

  Further, the pressing communication part 51a, the communication part 47a of the spring communication member 47, and the first return spring 41 (and the second return spring 61) are disposed at substantially the same diameter positions at positions shifted from each other in the circumferential direction. Therefore, the downsizing in the radial direction is skillfully achieved without interfering with each other.

  By using the drum member 70, it is possible to obtain design advantages and manufacturing advantages in addition to the above advantages.

  As mentioned above, although embodiment of this invention was described, the said embodiment can be suitably changed in the range which does not deviate from the summary of this invention. For example, the automatic transmission 1 is a 6-speed automatic transmission with 6 forward speeds and 1 reverse speed, but is not limited thereto, and may be other types such as 5 forward speeds and 4 speeds. Further, instead of the torque converter 3, an electromagnetic clutch or the like may be provided.

  The frame structure (skeleton) of the speed change mechanism is not limited to that shown in FIG. Further, the combination and arrangement of the frictional engagement elements (clutch and brake) are not limited to those shown in FIGS.

  In the above embodiment, the second piston 51 is a stepped piston, but it may be the same type as the first piston 31. The first piston 31 may be a stepped type.

  In the said embodiment, although it comprised so that the press communication part 51a might be a part of 2nd piston 51, it is good also as a member different from the 2nd piston 51. Conversely, the spring communication member 47 may be a part of the first piston 31.

It is a figure which shows the frame | skeleton structure of the automatic transmission which concerns on one Embodiment of this invention. It is a figure which shows the intermittent state of each friction fastening element. It is a partial longitudinal cross-sectional view of the said automatic transmission. FIG. 4 is a partially enlarged view of FIG. 3. It is a right view of a drum member and its peripheral member. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is the VII-VII sectional view taken on the line of FIG. It is the VII-VII sectional view taken on the line of FIG. It is a synthetic sectional view shown paying attention to the function of the 1st brake. It is a synthetic sectional view shown paying attention to the function of the 2nd brake.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic transmission 2 Transmission case 2a Rear cover (wall part, case cover)
2b Spline portion 31 1st piston 35 1st cylinder 38 1st brake pack 38a Rotating plate 38b Fixed plate 41 1st return spring 43 1st spring retainer 47 Spring connecting member 51 2nd piston 51a Press connecting member 55 2nd cylinder 58 1st 2 Brake pack 58a Rotating plate 58b Fixed plate 61 Second return spring 70 Drum member 73 Second spring retainer 74 Swelling part (press communication insertion part)
75 Through hole (spring connection insertion part)
83 1st spline (spline groove)
85 Second spline (spline groove)

Claims (11)

A transmission case having spline grooves formed on a cylindrical inner peripheral surface or a member fixed to the transmission case;
A brake pack in which a plurality of rotating plates and a plurality of fixed plates whose outer peripheral portions are fitted in the spline grooves are alternately arranged in the axial direction, and the first brake pack is provided continuously in the spline groove direction, and In an automatic transmission comprising a second brake pack,
A first piston for pressing the first brake pack;
A first cylinder for axially slidably receiving the first piston;
A second piston for pressing the second brake pack;
A second cylinder for axially slidably receiving the second piston,
The first cylinder and the second cylinder are disposed on the opposite side in the axial direction of the second brake pack with respect to the first brake pack, and are overlapped with each other in the axial direction. Automatic transmission to do. A wall portion extending in a radial direction with respect to the axis of the first cylinder;
The automatic transmission according to claim 1, wherein the wall is provided with the first cylinder and the second cylinder, and the second cylinder is disposed on an outer peripheral side of the first cylinder.   3. The automatic transmission according to claim 1, further comprising a drum member having an outer peripheral side fixed to a transmission case or a member fixed thereto, and the spline groove formed on the inner peripheral side. A pressing communication member passing through the outer peripheral side of the first brake pack;
4. The automatic transmission according to claim 3, wherein the second piston is configured to press the second brake pack via the pressing communication member.   5. The automatic transmission according to claim 4, wherein the drum member is formed with a press communication insertion portion for passing the press communication member in the axial direction. A first return spring that urges a return force to the first piston, and a first spring retainer that holds the first return spring;
A second return spring that urges a return force to the second piston and a second spring retainer that holds the second return spring;
6. The automatic transmission according to claim 3, wherein the first spring retainer and the second spring retainer are provided on the drum member.   The automatic transmission according to claim 6, wherein the drum member is fixed to the transmission case or a member fixed thereto by spline fitting and snap ring stopper. The first return spring is provided on an axially opposite side of the first piston with respect to the first brake pack,
A spring communication member passing through the outer periphery of the first brake pack;
The automatic transmission according to claim 6 or 7, wherein the first piston is configured to receive an urging force from the first return spring via the spring connecting member.   9. The automatic transmission according to claim 8, wherein the drum member is formed with a spring communication insertion portion through which the spring communication member passes in the axial direction. A pressing communication member passing through the outer peripheral side of the first brake pack;
The second piston is configured to press the second brake pack via the pressing communication member,
The drum member is formed with a press communication insertion portion for passing the press communication member in the axial direction,
10. The automatic transmission according to claim 9, wherein the pressing communication insertion portion and the spring communication insertion portion are intermittently formed at different positions in the circumferential direction on the drum member. The transmission case has an opening at an axial end,
Provided with a case cover that closes the opening, this is the wall,
The automatic transmission according to claim 3, wherein the drum member is fixed to the case cover.

Images