JP6988784B2 - Automatic transmission - Google Patents

Description

The present invention relates to an automatic transmission mounted on a vehicle and belongs to the technical field of an automatic transmission for a vehicle.

As an automatic transmission mounted on a vehicle, a fluid transmission device such as a torque converter connected to a drive source such as an engine, a plurality of planetary gear sets (planetary gear mechanism) connected to the fluid transmission device, a clutch, a brake, etc. It is generally known that a transmission mechanism having a plurality of friction fastening elements is provided, and a plurality of friction fastening elements are selectively fastened by hydraulic control to achieve a plurality of gears having different reduction ratios. ing.

In recent years, there has been a tendency to abolish fluid transmission devices in response to the demand for multiple stages of automatic transmissions and weight reduction. In this case, it is conceivable to realize smooth starting while avoiding engine stall by slip-controlling at least one friction fastening element fastened at the first speed shift stage at the time of starting.

When slip-controlling the friction fastening element that is fastened at the 1st gear at the time of starting, the brake that does not rotate the hydraulic chamber has better controllability at the time of starting than the clutch that rotates the hydraulic chamber. It is conceivable to slip control the brakes engaged in the 1st gear.

In an automatic transmission configured in this way, for a brake that is fastened at the 1st speed shift stage at the time of starting, a piston that fastens a plurality of friction plates is urged by a spring and a hydraulic pressure for fastening to move in the fastening direction. It has been known.

For example, in Patent Document 1, a piston is urged by a spring from a release position to a zero clearance position where a plurality of friction plates are in a zero clearance state, and a plurality of frictions are urged from the zero clearance position to a fastening position by a fastening hydraulic pressure. A brake designed to fasten a plate is disclosed.

FIG. 17 is a cross-sectional view showing a brake of a conventional automatic transmission. As shown in FIG. 17, the brake 200 includes a plurality of friction plates 203 arranged between the hub member 201 and the drum member 202, an outer cylinder portion 204a of the housing 204 which is a part of the transmission case, and a flange. It has a piston 206 fitted to a cylinder 205 formed by a portion 204b and an inner cylinder portion 204c.

The brake 200 also has a fastening hydraulic chamber 207 to which the hydraulic oil for fastening that urges the piston 206 in the fastening direction is supplied, and a release hydraulic chamber 207 to which the hydraulic oil for releasing that biases the piston 206 in the release direction is supplied. It has a hydraulic chamber 208. A spring 210 for urging the piston 206 in the fastening direction is arranged in the fastening hydraulic chamber 207.

Then, when the brake 200 is fastened, the fastening hydraulic pressure is discharged from the fastening hydraulic pressure chamber 207, the release hydraulic pressure is supplied to the release hydraulic pressure chamber 208, and the piston 206 is in the release position where the spring 210 is compressed. When the release hydraulic pressure is discharged, the piston 206 is urged by the spring 210, and the plurality of friction plates 203 are moved from the release position to the zero clearance position where the zero clearance state is reached. After that, when the fastening hydraulic pressure is supplied, the piston 206 is urged by the fastening hydraulic pressure and moved to the fastening position where the plurality of friction plates 203 are fastened.

On the other hand, when releasing the brake 200, when the fastening hydraulic pressure is discharged and the releasing hydraulic pressure is supplied from the state where the piston 206 is in the fastening position, the piston 206 is urged in the releasing direction and the piston 206 is spring 210. Is moved to the compressed release position.

In the brake 200, the piston 206 can be moved from the release position to the zero clearance position more accurately by the spring 210 as compared with the case where the piston 206 is hydraulically moved from the release position to the zero clearance position.

Japanese Unexamined Patent Publication No. 2017-150533

In an automatic transmission configured to slip control the brakes that are engaged in the 1st gear at the time of starting, the hydraulic oil for lubrication supplied to the friction plate is used to suppress the heat generation of the friction plate due to the slip control. It is conceivable to increase the supply amount to improve the cooling performance.

However, in a brake in which a drum member to which a plurality of friction plates are spline-engaged is coupled to a transmission case and a hub member to which a plurality of friction plates are spline-engaged is coupled to a predetermined rotating member, the drum member Since the hydraulic oil for lubrication may stay near the inner peripheral surface and increase the rotational resistance, the drum member is coupled to a predetermined rotating member and the hub member is coupled to the transmission case to rotate the drum member. It is conceivable to prevent the hydraulic oil for lubrication from staying.

Even in an automatic transmission having a brake in which a hub member is coupled to a transmission case and a drum member is coupled to a predetermined rotating member, the piston is placed in a predetermined position by a spring as described in Patent Document 1. When moving the brake, the piston may be rotated in the circumferential direction along with the rotation of the rotating member when the brake is fastened, and the spring may be twisted in the circumferential direction. If the spring is twisted in the circumferential direction, the piston may be displaced from a predetermined position and the piston may press the friction plate to cause a shock, or the fastening timing for fastening the piston may be delayed and the responsiveness may be deteriorated.

Therefore, it is an object of the present invention to accurately move the piston to a predetermined position by suppressing the spring from twisting in the circumferential direction in an automatic transmission provided with a brake having a spring that urges the piston in the fastening direction. And.

In order to solve the above problems, the present invention is characterized in that it is configured as follows.

First, the invention according to claim 1 of the present application is arranged between the hub member coupled to the transmission case, the drum member coupled to the predetermined rotating member, and the hub member and the drum member. An automatic transmission having a brake having a plurality of friction plates, a piston for fastening the plurality of friction plates, and a spring for urging the piston in the fastening direction, wherein the piston is in a predetermined amount or more in the circumferential direction. e Bei piston rotation restricting member for restricting the pivoting, said hub member, said plurality of friction plates being coupled to the transmission case includes a spline portion to be spline engaged, the drum member, The plurality of friction plates are spline-engaged and coupled to a predetermined rotating member, and a hydraulic chamber to which hydraulic oil for urging the piston is supplied is arranged inside the plurality of friction plates in the radial direction. Provides a pressing portion that presses the friction plate, a hydraulic chamber forming portion that forms the hydraulic chamber, and a connecting portion that connects the pressing portion and the hydraulic chamber forming portion, and is a spline portion of the hub member. One side in the axial direction is arranged in a notch for the hub member, which is cut out in the connecting portion of the piston corresponding to the spline portion of the hub member, and the piston rotation restricting member is composed of the hub member. and said that you are.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the spring is a spring that exerts an urging force on the piston from the release position to the zero clearance position in the fastening direction. do.

Further, in the invention according to claim 3 , in the invention according to claim 1 or 2 , the notch portion for the hub member is arranged along the side surface of the tooth portion of the spline portion of the hub member. It is characterized by having a regulatory department.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the hydraulic chamber is supplied with hydraulic oil that urges the piston in the fastening direction. A fastening hydraulic chamber and a releasing hydraulic chamber to which hydraulic oil for urging the piston in the releasing direction is supplied, and the spring and the fastening hydraulic chamber and the releasing hydraulic chamber have a plurality of frictions. It is characterized in that it is arranged at a position where it overlaps in the radial direction on the inner side in the radial direction of the plate.

The invention according to claim 5 is the invention according to any one of claims 1 to 4 , wherein the hub member includes the spline portion and is spline-engaged with the transmission case. The first hub member is fitted to the transmission case so as to be connected to the valve body arranged on the other side in the axial direction of the first hub member and arranged below the transmission case. It is characterized by having two hub members.

According to the invention according to claim 1 of the present application, a plurality of friction plates arranged between a hub member coupled to a transmission case and a drum member coupled to a predetermined rotating member, and a plurality of friction plates. In an automatic transmission equipped with a brake having a spring for urging the piston to fasten the piston in the fastening direction, a piston rotation restricting member for restricting the rotation of the piston by a predetermined amount or more in the circumferential direction is provided.

As a result, the piston rotation restricting member regulates the rotation of the piston in the circumferential direction. Therefore, in an automatic transmission equipped with a brake having a spring that urges the piston in the fastening direction, the piston moves when the brake is fastened. It is possible to accurately move the piston to a predetermined position by rotating in the circumferential direction and suppressing the spring from twisting in the circumferential direction.
Further, a hydraulic chamber is arranged inside the plurality of friction plates in the radial direction, and the piston includes a pressing portion, a hydraulic chamber forming portion, and a connecting portion. Then, one side of the spline portion of the hub member in the axial direction is arranged in the notch portion for the hub member of the connecting portion of the piston, and the piston rotation restricting member is composed of the hub member. As a result, in a brake in which the hydraulic chamber is arranged radially inside a plurality of friction plates, the axial length of the spline portion is longer than that in the case where the piston extends radially through one axial side of the spline portion of the hub member. It can be configured compactly in the axial direction while ensuring the above effect, and the above effect can be obtained more effectively.

Further, according to the second aspect of the present invention, the spring is a spring that exerts an urging force on the piston from the release position to the zero clearance position in the fastening direction, so that the spring moves the piston from the release position to the zero clearance position. It can be moved with high accuracy.

Further , according to the invention of claim 3 , the hub member notch portion is formed with high accuracy by having a regulating portion arranged along the side surface of the tooth portion of the spline portion of the hub member. The rotation of the piston can be accurately regulated by the restricting portion of the notch portion for the hub member arranged along the side surface of the tooth portion of the spline portion.

Further , according to the invention of claim 4 , the spring, the fastening hydraulic chamber and the releasing hydraulic chamber are arranged at positions where they overlap in the radial direction inside the plurality of friction plates in the radial direction. Compared with the case where the spring, the hydraulic chamber for fastening, and the hydraulic chamber for release do not overlap in the radial direction, the configuration can be made more compact in the radial direction.

Further , according to the invention of claim 5 , the hub member fits into the transmission case so as to be connected to the valve body and the first hub member which includes the spline portion and is spline-engaged with the transmission case. It is provided with a second hub member to be combined. As a result, the first hub member is spline-engaged with the transmission case, so that the first hub member rotates in the circumferential direction of the transmission case due to the force input from the friction plate via the spline portion when the brake is fastened. This can be suppressed and the hub member can be prevented from rotating. Further, since the second hub member is fitted to the transmission case, the second hub member can be fixed to the transmission case, and the circumferential direction of the transmission case at the connection portion between the second hub member and the valve body. It is possible to efficiently supply hydraulic oil from the valve body to the second hub member by eliminating the backlash.

It is a skeleton diagram of the automatic transmission which concerns on embodiment of this invention. It is a fastening table of friction fastening elements of an automatic transmission. It is sectional drawing of the brake of an automatic transmission and its periphery. It is another sectional view of the brake of an automatic transmission and its surroundings. It is still another sectional view of the brake of an automatic transmission and its periphery. It is still another sectional view of the brake of an automatic transmission and its periphery. It is a perspective view which shows the assembled state of a hub member of a brake and a piston. It is a perspective view which shows the assembled state of the 1st hub member, the 2nd hub member and the 3rd hub member of a brake. It is a perspective view which shows the assembled state of the 1st hub member and the 2nd hub member of a brake. It is a perspective view which shows the 1st hub member. It is a perspective view which shows the 2nd hub member. It is another perspective view which shows the assembled state of a hub member of a brake and a piston. It is a perspective view which shows the 3rd hub member. It is a front view which shows the hub member of a brake, and the main part of a piston. It is sectional drawing which shows the brake in the released state, the zero clearance state and the tightened state. It is sectional drawing of the modification of the brake of the automatic transmission which concerns on embodiment of this invention. It is sectional drawing which shows the brake of the conventional automatic transmission.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an outline diagram of an automatic transmission according to an embodiment of the present invention. The automatic transmission 10 is connected to a drive source such as an engine without a fluid transmission device such as a torque converter. The automatic transmission 10 is arranged in the transmission case 11 on the input shaft 12 connected to the drive source and arranged on the drive source side (left side in the figure) and on the anti-drive source side (right side in the figure). It has an output shaft 13. The automatic transmission 10 is a vertically installed type for front engines, rear drive vehicles, etc., in which the input shaft 12 and the output shaft 13 are arranged on the same axis.

On the axis of the input shaft 12 and the output shaft 13, from the drive source side, the first, second, third, and fourth planetary gear sets (hereinafter, simply "first, second, third, and fourth gear sets"". PG1, PG2, PG3, PG4 are arranged.

In the transmission case 11, the first clutch CL1 is arranged on the drive source side of the first gear set PG1, the second clutch CL2 is arranged on the drive source side of the first clutch CL1, and the drive source of the second clutch CL2. A third clutch CL3 is arranged on the side. Further, the first brake BR1 is arranged on the drive source side of the third clutch CL3, and the second brake BR2 is arranged on the drive source side of the third gear set PG3 and on the opposite drive source side of the second gear set PG2.

The first, second, third, and fourth gear sets PG1, PG2, PG3, and PG4 are all single pinion types in which the pinion supported by the carrier directly meshes with the sun gear and the ring gear. The first, second, third, and fourth gear sets PG1, PG2, PG3, and PG4 have sun gears S1, S2, S3, S4, ring gears R1, R2, R3, R4, and carriers C1, C2, respectively, as rotating elements. , C3, and C4.

The first gear set PG1 is a double sun gear type in which the sun gear S1 is divided into two in the axial direction. The sun gear S1 has a first sun gear S1a arranged on the drive source side and a second sun gear S1b arranged on the opposite drive source side. The first and second sun gears S1a and S1b have the same number of teeth and mesh with the same pinion supported by the carrier C1. As a result, the first and second sun gears S1a and S1b always rotate in the same rotation.

In the automatic transmission 10, the sun gear S1 of the first gear set PG1, specifically, the second sun gear S1b and the sun gear S4 of the fourth gear set PG4 are always connected, and the ring gear R1 of the first gear set PG1 and the sun gear of the second gear set PG2 are always connected. S2 is always connected, the carrier C2 of the second gear set PG2 and the carrier C4 of the fourth gear set PG4 are always connected, and the carrier C3 of the third gear set PG3 and the ring gear R4 of the fourth gear set PG4 are always connected. ..

The input shaft 12 is always connected to the carrier C1 of the first gear set PG1 through between the first sun gear S1a and the second sun gear S1b, and the output shaft 13 is always connected to the carrier C4 of the fourth gear set PG4.

The first clutch CL1 is disposed between the input shaft 12 and the carrier C1 of the first gear set PG1 and the sun gear S3 of the third gear set PG3 so as to connect and disconnect the first clutch CL1. It is arranged between the ring gear R1 of the first gear set PG1 and the sun gear S2 of the second gear set PG2 and the sun gear S3 of the third gear set PG3 so as to connect and disconnect them. The third clutch CL3 is the second gear set. It is disposed between the ring gear R2 of the PG2 and the sun gear S3 of the third gear set PG3 so as to connect and disconnect them.

The first brake BR1 is disposed between the transmission case 11 and the sun gear S1 of the first gear set PG1, specifically, the first sun gear S1a, so as to connect and disconnect the first brake BR1. Is disposed between the transmission case 11 and the ring gear R3 of the third gear set PG3 so as to connect and disconnect them.

With the above configuration, the automatic transmission 10 has a combination of the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2 in the engaged state, as shown in FIG. The 1st to 8th speeds in the range and the backward speeds in the R range are formed.

In the automatic transmission 10, the second brake BR2 fastened at the first gear at the time of starting is slip-controlled, and the second brake BR2 corresponds to the friction fastening element of the automatic transmission according to the present invention. Hereinafter, this brake BR2 will be described.

3 is a cross-sectional view of the automatic transmission brake and its surroundings, FIG. 4 is another cross-sectional view of the automatic transmission brake and its surroundings, and FIGS. 5 and 6 are the automatic transmission brake and its surroundings, respectively. Is yet another cross-sectional view of. FIG. 3 shows a cross section of the brake of the automatic transmission and its surroundings corresponding to the cross section along the Y3-Y3 line of FIG. 7, and FIGS. 4, 5, and 6 show the Y4-Y4 line of FIG. 12, respectively. The cross section of the brake of the automatic transmission corresponding to the cross section along the Y5-Y5 line and the Y6-Y6 line and its periphery is shown.

As shown in FIGS. 3 to 6, the brake BR2 is housed in a transmission case 11 formed in a substantially cylindrical shape, is connected to the sun gear S3 of the third gear set PG3, and is connected to the first, second, and third clutches. One of the pair of internal and external rotating members of CL1, CL2, and CL3 is arranged on the outer peripheral side of the integrated power transmission member 14.

The power transmission member 14 is arranged on the outer peripheral side of the power transmission member 15 connecting the carrier C2 of the second gear set PG2 and the carrier C4 of the fourth gear set PG4, and the power transmission member 15 is the sun gear S1 of the first gear set PG1. Specifically, it is arranged on the outer peripheral side of the power transmission member 16 that connects the second sun gear S1b and the sun gear S4 of the fourth gear set PG4.

The brake BR2 includes a hub member 20 coupled to the transmission case 11, a drum member 60 arranged on the opposite drive source side of the hub member 20 and coupled to the ring gear R3 of the third gear set PG3, and the hub member 20 and the drum. It has a plurality of friction plates 70 arranged side by side in the axial direction between the members 60 and a piston 80 arranged on the anti-drive source side of the plurality of friction plates 70 to fasten the plurality of friction plates 70. ..

The brake BR2 has a hydraulic chamber 90 to which hydraulic oil for urging the piston 80 is supplied inside the friction plate 70 in the radial direction. The hydraulic chamber 90 includes a fastening hydraulic chamber 91 to which a fastening hydraulic oil for urging the piston 80 in the fastening direction is supplied, and a releasing hydraulic chamber to which the releasing hydraulic oil for urging the piston 80 in the releasing direction is supplied. It is equipped with 92.

The brake BR2 also has an urging unit 100 that urges the piston 80 inside the friction plate 70 in the radial direction, as shown in FIG. The urging unit 100 includes a spring 101 that exerts an urging force on the piston 80 in the fastening direction as an urging member for urging the piston 80.

7 is a perspective view showing the assembled state of the hub member and the piston of the brake, and FIG. 8 is a perspective view showing the assembled state of the first hub member, the second hub member and the third hub member of the brake, FIG. 9; Is a perspective view showing the assembled state of the first hub member and the second hub member of the brake, FIG. 10 is a perspective view showing the first hub member, and FIG. 11 is a perspective view showing the second hub member. Is another perspective view showing the assembled state of the hub member and the piston of the brake, and FIG. 13 is a perspective view showing the third hub member.

As shown in FIGS. 3 to 13, the hub member 20 has a first hub member 21 in which the friction plate 70 is spline-engaged and the transmission case 11 is spline-engaged, and a drive source for the first hub member 21. The second hub member 31 is arranged on the side and fitted to the transmission case 11 and extends radially inward from the first hub member 21, and the second hub member 31 is radially inward from the first hub member 21. A third hub member 41 coupled to the drive side and a fourth hub member 51 coupled to the anti-drive source side of the third hub member 41 radially inside the first hub member 21 are provided.

As shown in FIG. 3, the first hub member 21 extends in a direction orthogonal to the axial direction of the transmission case 11 and is formed in a substantially disk shape, and inside the vertical wall portion 22 in the radial direction. It is provided with a cylindrical portion 23 extending from the vertical wall portion 22 toward the anti-drive source side in a substantially cylindrical shape.

The first hub member 21 has a spline portion 24 having a spline formed on the outer peripheral surface of the vertical wall portion 22, and the spline portion 24 has a spline on the spline portion 11a having a spline formed on the inner peripheral surface of the transmission case 11. Engaged and coupled to the transmission case 11.

The cylindrical portion 23 of the first hub member 21 has a spline portion 25 having a spline formed on the outer peripheral surface thereof, and the fixed side friction plate 71 constituting the friction plate 70 is spline-engaged with the spline portion 25. As shown in FIG. 10, the spline portion 25 has a first tooth portion 26 having a predetermined axial length in which the spline portion 25 is spline-engaged with the plurality of friction plates 70 even in the open state of the plurality of friction plates 70. It has a second tooth portion 27 which is formed to have a shorter axial length than the first tooth portion 26 and which is spline-engaged with a plurality of friction plates 70. A plurality of, specifically, three first tooth portions 26 are arranged on the first hub member 21 at substantially equal intervals in the circumferential direction.

As shown in FIG. 3, the second hub member 31 includes a vertical wall portion 32 extending in a direction orthogonal to the axial direction of the transmission case 11 and formed in a substantially disk shape. As shown in FIG. 4, the vertical wall portion 32 of the second hub member 31 is formed with a lubrication supply oil passage L1 for supplying lubricating hydraulic oil to the friction plate 70.

The outer peripheral surface of the vertical wall portion 32 of the second hub member 31 is fitted to the inner peripheral surface 11b of the transmission case 11 on the drive source side of the spline portion 24 of the first hub member 21. The second hub member 31 is prevented from coming off to the drive source side by the snap ring 17, is fixed to the transmission case 11 by using the detent pin 18, and is coupled to the transmission case 11. The second hub member 31 may be fitted and fixed to the inner peripheral surface 11b of the transmission case 11 by press fitting, and may be coupled to the transmission case 11.

As shown in FIG. 4, a valve body 5 for supplying hydraulic oil to the hydraulic chamber 90 of the brake BR2, the friction plate 70, and the like is arranged below the transmission case 11. The valve body 5 is housed in an oil pan (not shown) attached below the transmission case 11 and fixed to the transmission case 11. The second hub member 31 has a valve body connecting portion 34 for connecting to the valve body 5, and the lubricating oil passage L1 is connected to the valve body 5 through the case opening 11c formed in the transmission case 11. It is formed so as to.

As shown in FIG. 5, a fastening supply oil passage L2 for supplying fastening hydraulic oil to the fastening hydraulic chamber 91 is formed in the vertical wall portion 32 of the second hub member 31, and as shown in FIG. A release supply oil passage L3 for supplying the release hydraulic oil to the release hydraulic chamber 92 is formed therein.

As shown in FIG. 11, the lubrication supply oil passage L1, the release supply oil passage L3, and the fastening supply oil passage L2 are arranged side by side in the circumferential direction on the lower side of the transmission case 11, and the second hub member 31 Is formed so that the lubrication supply oil passage L1, the release supply oil passage L3, and the fastening supply oil passage L2 are connected to the valve body 5, respectively.

As shown in FIG. 3, the vertical wall portion 32 of the second hub member 31 is formed with a stepped portion 32a recessed on the drive source side on the anti-drive source side. The stepped portion 32a of the second hub member 31 is the vertical wall portion 22 of the first hub member 21 when the vertical wall portion 22 of the first hub member 21 is in contact with the vertical wall portion 32 of the second hub member 31. It is formed so that the inner peripheral side is engaged.

The vertical wall portion 32 of the second hub member 31 is formed with a plurality of boss portions 35 extending in a substantially columnar shape on the anti-drive source side on the inner peripheral side. As shown in FIGS. 9 and 11, the plurality of boss portions 35 are dispersedly arranged in the circumferential direction, and each of the boss portions 35 is formed with a screw hole 35a on the counter-drive source side. By screwing the fastening bolt B1 into the screw hole 35a of the boss portion 35 from the anti-drive source side of the fourth hub member 51, the third hub member 41 and the fourth hub member 51 are screwed to the anti-drive source side of the second hub member 31. Are combined.

As shown in FIG. 3, the third hub member 41 extends from a vertical wall portion 42 extending in a direction orthogonal to the axial direction of the transmission case 11 and formed in a substantially disk shape, and from the radial outside of the vertical wall portion 42. A first cylindrical portion 43 extending substantially cylindrically on the anti-drive source side and a second cylindrical portion 44 extending substantially cylindrically from the radial inside of the vertical wall portion 42 toward the anti-drive source side are provided, and the first cylindrical portion 43 is provided. And the second cylindrical portion 44 is formed so as to have substantially the same axial length.

The first cylindrical portion 43 of the third hub member 41 is provided inside the cylindrical portion 23 of the first hub member 21 in the radial direction. The first cylindrical portion 43 of the third hub member 41 is provided with a flange portion 43a extending radially outward so as to abut on the inner peripheral surface of the cylindrical portion 23 of the first hub member 21 on the anti-drive source side, and the first hub. It is provided so as to form a lubrication supply oil passage L1 between the member 21 and the cylindrical portion 23.

The second cylindrical portion 44 of the third hub member 41 has an outer peripheral surface 44a on the drive source side and an outer peripheral surface 44b on the anti-drive source side, and the outer peripheral surface 44b on the anti-drive source side has a release hydraulic chamber 92. The radial dimension is smaller than the outer peripheral surface 44a on the drive source side so as to be formed.

As shown in FIGS. 3, 8 and 13, the second cylindrical portion 44 of the third hub member 41 also has a plurality of second hub members 31 recessed in a substantially rectangular shape from the drive source side to the anti-drive source side. A plurality of boss portion accommodating portions 45 for accommodating each of the boss portions 35 and a bolt insertion hole 44c for inserting the fastening bolt B1 are formed.

The fourth hub member 51 extends in a direction orthogonal to the axial direction of the transmission case 11 and is formed in a substantially disk shape, and is arranged on the opposite drive source side of the third hub member 41. A bolt insertion hole 52 through which the fastening bolt B1 is inserted is formed inside the fourth hub member 51 in the radial direction.

As described above, the fastening bolt B1 is inserted into the screw hole of the second hub member 31 from the anti-drive source side of the fourth hub member 51 through the bolt insertion hole 52 of the fourth hub member 51 and the bolt insertion hole 44c of the third hub member 41. By screwing to 35a, the third hub member 41 is coupled to the anti-drive source side of the second hub member 31, and the fourth hub member 51 is coupled to the anti-drive source side of the third hub member 41. ..

The fourth hub member 51 is formed so as to extend radially outward from the second cylindrical portion 44 of the third hub member 41, and the outer peripheral surface of the fourth hub member 51 is fitted to the piston 80. On the outer peripheral surface of the fourth hub member 51, a peripheral groove 54 for a snap ring is formed, which is recessed inward in the radial direction from the fitting portion with the piston 80 in a substantially rectangular cross section. A snap ring 55 formed in a substantially rectangular cross section is attached to the 54.

When the snap ring 55 is not attached, the diameter is smaller than that when the snap ring 55 is attached, and the snap ring 55 is formed in a substantially annular shape. On the radial center side of the piston 80, a groove portion 80a for a snap ring is formed corresponding to the snap ring 55 and is recessed from the counter-drive source side to the drive source side in a substantially L-shaped cross section. The snap ring 55 causes the piston 80 to come into contact with the side surface of the snap ring groove portion 80a on the drive source side and the anti-drive source side abuts on the side surface of the snap ring peripheral groove 54 on the anti-drive source side. It is designed to regulate to a predetermined release position.

In this way, the hub member 20, specifically the fourth hub member 51, is provided with the snap ring 55 as a regulating member that regulates the piston 80 to the released position. The snap ring 55 is arranged at a position where it overlaps with the piston 80 in the axial direction, and is provided so as to abut on the radial center side of the piston 80.

In the hub member 20, the first hub member 21, the second hub member 31, the third hub member 41, and the fourth hub member 51 are each formed of an aluminum-based material and are made of the same material.

The drum member 60 has a cylindrical portion 61 which is arranged so as to face the outer peripheral side of the cylindrical portion 23 of the first hub member 21 and extends in a substantially cylindrical direction in the axial direction, and a transmission in the radial direction from the anti-drive source side of the cylindrical portion 61. It is provided with a vertical wall portion 62 extending in a direction orthogonal to the axial direction of the case 11 and formed in a substantially disk shape.

The vertical wall portion 62 of the drum member 60 is coupled to the ring gear R3 as a rotating member. The cylindrical portion 61 of the drum member 60 has a spline portion 61a having a spline formed on the inner peripheral surface thereof, and the rotating side friction plate 72 constituting the friction plate 70 is spline-engaged with the spline portion 61a. The fixed-side friction plate 71 and the rotary-side friction plate 72 are alternately arranged in the axial direction.

The piston 80 is arranged between the hub member 20 and the drum member 60, specifically, between the cylindrical portion 23 of the first hub member 21 and the cylindrical portion 61 of the drum member 60, and the third hub member 41. It is slidably fitted to the outer peripheral surface of the second cylindrical portion 44. The piston 80 is prevented from coming off to the anti-drive source side by a snap ring 55 that regulates the piston 80 to the release position.

The piston 80 is formed in an annular shape, and as shown in FIG. 4, a pressing portion 81 provided on the outer peripheral side to press the friction plate 70 and a hydraulic chamber forming portion provided on the inner peripheral side to form the hydraulic chamber 90. The 82 is provided with a connecting portion 83 for connecting the pressing portion 81 and the hydraulic chamber forming portion 82. The hydraulic chamber forming portion 82 of the piston 80 includes a fastening hydraulic chamber forming portion 84 that forms the fastening hydraulic chamber 91, and a releasing hydraulic chamber forming portion 85 that forms the releasing hydraulic chamber 92.

The pressing portion 81 of the piston 80 is arranged on the opposite drive source side of the friction plate 70, the hydraulic chamber forming portion 82 is arranged radially inside the friction plate 70, and the connecting portion 83 forms the pressing portion 81 and the hydraulic chamber. It extends inward in the radial direction of the friction plate 70 from the anti-drive source side of the friction plate 70 so as to connect with the portion 82.

In the automatic transmission 10, the piston 80 is coupled to the first piston member 86 including the pressing portion 81, the hydraulic chamber forming portion 82, and the connecting portion 83, and the hydraulic chamber forming portion 82. It is provided and is formed of a second piston member 87 that partitions the fastening hydraulic chamber 91 and the releasing hydraulic chamber 92.

The first piston member 86 is formed with a snap ring groove portion 80a provided in the connecting portion 83 corresponding to the snap ring 55. As shown in FIG. 4, the first piston member 86 is provided with a fitted portion 86a that projects annularly toward the anti-drive source side, and the second piston member 87 is fitted so that the second piston member 87 projects annularly toward the drive source side. A joint portion 87a is provided.

In the piston 80, the fitted portion 86a of the first piston member 86 and the fitting portion 87a of the second piston member 87 are fitted by press fitting, so that the first piston member 86 and the second piston member 87 are coupled. Is formed. The second piston member 87 is coupled to the first piston member 86 to partition the fastening hydraulic chamber 91 on the anti-drive source side and the release hydraulic chamber 92 on the drive source side.

The first piston member 86 extends radially inward from the anti-drive source side of the friction plate 70 and is fitted to the outer peripheral surface of the fourth hub member 51, and the drive source side is fitted from the fourth hub member 51. It extends radially inward from the portion 86a and is fitted to the outer peripheral surface 44a of the second cylindrical portion 44 of the third hub member 41. A seal member 86b that seals between the first piston member 86 and the third hub member 41 is attached to the radially inner end of the first piston member 86.

The second piston member 87 is coupled to the first piston member 86, extends radially inward from the fitting portion 87a, and is fitted to the outer peripheral surface 44b of the second cylindrical portion 44 of the third hub member 41. The second piston member 87 extends radially inward from the first piston member 86, and seals between the second piston member 87 and the third hub member 41 at the radially inner end of the second piston member 87. The seal member 87b is attached.

In this way, the fastening hydraulic chamber 91 is formed by a space portion partitioned by the first piston member 86, the second piston member 87, the third hub member 41, and the fourth hub member 51. The release hydraulic chamber 92 is formed by a space portion partitioned by a first piston member 86, a second piston member 87, and a third hub member 41.

As shown in FIG. 5, the urging unit 100 is arranged in the fastening hydraulic chamber 91. The second piston member 87 forming the fastening hydraulic chamber 91 is configured such that the anti-drive source side receives the urging force by the spring 101 of the urging unit 100. The spring 101, the fastening hydraulic chamber 91, and the releasing hydraulic chamber 92 are arranged at positions where the plurality of friction plates 70 are radially inside and overlap each other in the radial direction.

The urging unit 100 includes a plurality of springs 101 composed of coil springs extending in the axial direction, and a holding plate 102 formed in an annular shape to hold an end portion of the plurality of springs 101 on the drive source side. The holding plate 102 is provided with a plurality of spring guide portions 103 that project cylindrically toward the anti-drive source side and on which a plurality of springs 101 are mounted, respectively, at a position where the plurality of springs 101 overlap in the radial direction and in the circumferential direction. Are placed in different positions.

In the urging unit 100, the holding plate 102 is supported by the anti-drive source side of the second piston member 87, and the anti-drive source side of the spring 101 mounted on the holding plate 102 is supported by the drive source side of the fourth hub member 51. It is attached to the hub member 20. The urging unit 100 is set so that the piston 80 is in the zero clearance position when the spring 101 has a free length.

In this way, in the urging unit 100, the spring 101 exerts an urging force on the piston 80 from the release position to the zero clearance position in the fastening direction. Then, when the fastening hydraulic pressure is supplied to the fastening hydraulic chamber 91 when the piston 80 is in the zero clearance position, the piston 80 presses the plurality of friction plates 70, and the plurality of friction plates 70 are vertically connected to the first hub member 21. It is sandwiched between the wall portion 22 and the piston 80 and moved to a fastening position where the relative rotation becomes impossible.

On the other hand, when the piston 80 is in the fastening position, when the fastening hydraulic pressure is discharged from the fastening hydraulic pressure chamber 91 and the release hydraulic pressure is supplied to the release hydraulic pressure chamber 92, the piston 80 is urged and moved in the release direction. , The piston 80 is moved to the zero clearance position. The piston 80 is further urged and moved in the release direction against the spring 101 to move to the release position.

In the automatic transmission 10, as shown in FIG. 3, the cylindrical portion of the first hub member 21 is attached to the connecting portion 83 of the piston 80, specifically, the bulging portion 83a that bulges from the pressing portion 81 toward the anti-drive source side. A notched portion 83b for the first hub member is formed corresponding to the spline portion 25 of the 23. The anti-drive source side of the spline portion 25 of the cylindrical portion 23 of the first hub member 21 is fitted to the notch portion 83b for the first hub member of the piston 80, and the first hub member 21 and the piston 80 are axially connected to each other. They are arranged so that they overlap.

FIG. 14 is a front view showing a hub member of a brake and a main part of a piston. As shown in FIG. 14, the notch portion 83b for the first hub member is formed corresponding to the first tooth portion 26 of the spline portion 25. The notch 83b for the first hub member is notched larger than the cross-sectional shape of the first tooth portion 26 of the spline portion 25 of the first hub member 21, and is arranged along the side surfaces 26a on both sides of the first tooth portion 26. It has side surfaces 83c on both sides. As shown in FIG. 7, the piston 80 has a plurality of first hub member 21, specifically, three notches 83b for the first hub member corresponding to the three first tooth portions 26, substantially in the circumferential direction. It is formed at equal intervals.

In the first hub member 21, when the piston 80 rotates in the circumferential direction, the side surface 83c of the notch portion 83b for the first hub member comes into contact with the side surface 26a of the first tooth portion 26 of the first hub member 21, and the piston 80. Is restricted from rotating by a predetermined amount or more, for example, by a predetermined amount or more such that the rotation angle of the piston 80 is 1 degree.

The side surface 83c of the notch portion 83b for the first hub member functions as a regulating portion arranged along the side surface 26a of the tooth portion 26 of the spline portion 25 of the hub member 20, and the hub member 20, specifically the first hub. The member 21 functions as a piston rotation restricting member that restricts the piston 80 from rotating in the circumferential direction by a predetermined amount or more.

As shown in FIG. 11, the second hub member 31 is formed with two bolt insertion holes 32b in the vicinity of the fastening supply oil passage L2 and the release supply oil passage L3. As shown in FIG. 13, the third hub member 41 is formed with a screw hole 41a corresponding to the bolt insertion hole 32b of the second hub member 31.

As shown in FIG. 12, the third hub member 41 screwes the fastening bolt B2 from the drive source side of the second hub member 31 into the screw hole 41a of the third hub member 41 through the bolt insertion hole 32b of the second hub member 31. It is coupled to the second hub member 31 by being combined. As shown in FIG. 13, the third hub member 41 has a peripheral supply oil passage L2 for fastening and a supply oil passage L3 for release between the second hub member 31 and the third hub member 41 on the drive source side. A sealing member 47 for sealing is attached.

Next, a supply oil passage for supplying hydraulic oil to the brake BR2 will be described.
The lubrication supply oil passage L1 for supplying the lubricating hydraulic oil to the friction plate 70 is formed in the first hub member 21, the second hub member 31, and the third hub member 41. The fastening supply oil passage L2 for supplying the fastening hydraulic oil to the fastening hydraulic chamber 91 is formed in the second hub member 31, the third hub member 41, and the fourth hub member 51. The release supply oil passage L3 for supplying the release hydraulic oil to the release hydraulic chamber 92 is formed in the second hub member 31 and the third hub member 41.

As shown in FIGS. 3 and 4, the lubrication supply oil passage L1 has a radial oil passage 131 provided in the vertical wall portion 32 of the second hub member 31 and extending in the radial direction, and the diameter of the second hub member 31. A circumferential oil passage 132 connected to the directional oil passage 131 and provided in an annular shape in the circumferential direction between the cylindrical portion 23 of the first hub member 21 and the cylindrical portion 43 of the third hub member 41, and the first hub member 21. A supply port 133 provided in the cylindrical portion 23 of the above, connected to the circumferential oil passage 132, and opened on the outer peripheral surface of the cylindrical portion 23 of the first hub member 21 to supply the hydraulic oil for lubrication to the friction plate 70. It is configured in preparation.

As shown in FIG. 10, a plurality of supply ports 133 are provided side by side in the axial direction of the cylindrical portion 23 of the first hub member 21, and a plurality of supply ports 133 are provided apart from each other in the circumferential direction of the cylindrical portion 23 of the first hub member 21. Be done. The supply port 133 is preferably provided so as to open to the tooth tips of the tooth portions 26, 27 of the spline portion 25 of the cylindrical portion 23 of the first hub member 21, but the tooth bottom of the tooth portions 26, 27 of the spline portion 25. It is also possible to provide it so as to open in.

The second hub member 31 is formed so that the lubrication supply oil passage L1 is connected to the valve body 5. The radial oil passage 131 of the second hub member 31 is provided in the vertical wall portion 32 of the second hub member 31 and opens on the lower surface of the valve body connecting portion 34, and is connected to the valve body 5. The valve body 5 is capable of supplying lubricating hydraulic oil to a plurality of friction plates 70 through the lubricating oil passage L1.

As shown in FIG. 5, the fastening supply oil passage L2 includes a radial oil passage 111 provided in the vertical wall portion 32 of the second hub member 31 and extending in the radial direction, and a second cylindrical portion of the third hub member 41. Hydraulic oil for fastening is provided in 44 and is connected to the radial oil passage 111 of the second hub member 31 and extends in the axial direction, and is provided through the radial oil passage 112 provided in the fourth hub member 51 and extends in the radial direction. It is configured to include an axial oil passage 113 that is opened and connected to the chamber 91. The radial inside of the radial oil passage 111 of the second hub member 31 is formed by being covered with the third hub member 41, and the radial oil passage 112 of the fourth hub member 51 is covered with the third hub member 41. Is formed.

The second hub member 31 is formed so that the fastening supply oil passage L2 is connected to the valve body 5. The radial oil passage 111 of the second hub member 31 is provided in the vertical wall portion 32 of the second hub member 31 and opens on the lower surface of the valve body connecting portion 34, and is connected to the valve body 5. The valve body 5 is capable of supplying the fastening hydraulic oil to the fastening hydraulic chamber 91 through the fastening supply oil passage L2 to supply a predetermined fastening hydraulic pressure.

As shown in FIG. 6, the release supply oil passage L3 includes a radial oil passage 121 provided in the vertical wall portion 32 of the second hub member 31 and extending in the radial direction, and a second cylindrical portion of the third hub member 41. It is provided with an axial oil passage 122 provided in 44, connected to the radial oil passage 121 of the second hub member 31, and extended in the axial direction, and opened and connected to the release hydraulic chamber 92. There is. The radial inside of the radial oil passage 121 of the second hub member 31 is formed by being covered with the third hub member 41.

The second hub member 31 is formed so that the release supply oil passage L3 is connected to the valve body 5. The radial oil passage 121 of the second hub member 31 is provided in the vertical wall portion 32 of the second hub member 310 and is opened on the lower surface of the valve body connecting portion 34 to be connected to the valve body 5. The valve body 5 is capable of supplying the release hydraulic oil to the release hydraulic chamber 92 through the release supply oil passage L3 to supply a predetermined release hydraulic pressure.

In the automatic transmission 10, as shown in FIG. 11, the radial oil passages 111, 121, and 131 constituting the fastening supply oil passage L2, the release supply oil passage L3, and the lubrication supply oil passage L1, respectively, are in the circumferential direction. They are arranged side by side. As shown in FIG. 12, the circumferential oil passage 132 constituting the lubricating supply oil passage L1 is connected to the radial oil passage 131 and extends in an annular shape in the circumferential direction.

Next, the operation of the brake BR2 configured in this way will be described.
FIG. 15 is a cross-sectional view showing a brake in the released state, the zero clearance state, and the engaged state. FIG. 15 shows a main part of the brake BR2 shown in FIG.

In FIG. 15A, the fastening hydraulic pressure is discharged from the fastening hydraulic pressure chamber 91, the releasing hydraulic pressure is supplied to the releasing hydraulic pressure chamber 92, the spring 101 is compressed via the piston 80, and the piston 80 is counter-driven. The release state of the brake BR2 is shown in which the piston 80 is moved in the release direction on the source side and the position of the piston 80 is in the release position where the plurality of friction plates 70 are in the release state.

When the brake BR2 is engaged, the release hydraulic pressure is discharged from the release hydraulic pressure chamber 92 in the release state shown in FIG. 15 (a), and the piston 80 receives the urging force of the spring 101 as shown in FIG. 15 (b). It is moved to the free length of the spring 101 in the fastening direction, and the position of the piston 80 reaches the zero clearance position where the piston 80 is in contact with or almost in contact with the friction plates 70 without pressing the plurality of friction plates 70. Then, the brake BR2 is in the zero clearance state.

Then, when the fastening hydraulic pressure was supplied to the fastening hydraulic chamber 91 in the zero clearance state shown in FIG. 15 (b), the piston 80 was supplied to the fastening hydraulic chamber 91 as shown in FIG. 15 (c). It is urged and moved in the fastening direction by the hydraulic pressure for fastening, the piston 80 presses the plurality of friction plates 70, the position of the piston 80 becomes the fastening position where the plurality of friction plates 70 cannot rotate relative to each other, and the brake BR2 is fastened. It becomes a state.

On the other hand, when the brake BR2 is released, the fastening hydraulic pressure is discharged from the fastening hydraulic pressure chamber 91 and the releasing hydraulic pressure is supplied to the releasing hydraulic pressure chamber 92 in the fastening state shown in FIG. It is urged and moved in the release direction on the opposite drive source side by the release hydraulic pressure supplied to the hydraulic chamber 92, passes through the zero clearance state shown in FIG. 15 (b), and reaches the release state shown in FIG. 15 (a). Become.

In the brake BR2, the piston 80 can be accurately moved from the released position to the zero clearance position by the spring 101. When the release hydraulic pressure is discharged from the release hydraulic pressure chamber 92 and the piston 80 is moved in the fastening direction in the release state shown in FIG. 15 (a), the fastening hydraulic pressure is such that the piston 80 is quickly moved. It is also possible to precharge the hydraulic oil in the chamber 91.

As described above, the brake BR2 is slip-controlled when the vehicle starts. When the brake BR2 is fastened, a hydraulic pressure lower than the fastening hydraulic pressure is supplied to the fastening hydraulic pressure chamber 91 to cause the plurality of friction plates 70 to slip, and then the fastening hydraulic pressure is supplied to the fastening hydraulic pressure chamber 91. The friction plate 70 is fastened. On the other hand, when the brake BR2 is released, a hydraulic pressure lower than the release hydraulic pressure is supplied to the release hydraulic pressure chamber 92, and after the plurality of friction plates 70 are in a slip state, the release hydraulic pressure is supplied to the release hydraulic pressure chamber 92. The plurality of friction plates 70 are released from fastening.

When the brake BR2 is engaged and released, lubricating hydraulic oil is supplied to the plurality of friction plates 70 through the lubrication supply oil passage L1, and when the brake BR2 is slip-controlled, the plurality of friction plates are supplied through the lubrication supply oil passage L1. Lubricating hydraulic oil is supplied to 70.

As described above, in the automatic transmission 10 according to the present embodiment, a plurality of friction plates arranged between the hub member 20 coupled to the transmission case 11 and the drum member 60 coupled to the predetermined rotating member R3. A piston rotation regulation that regulates the rotation of the piston 80 by a predetermined amount or more in the circumferential direction by providing a brake BR2 having a 70 and a spring 101 that urges the piston 80 for fastening the plurality of friction plates 70 in the fastening direction. A member 20 is provided.

As a result, the piston 80 is restricted from rotating in the circumferential direction by the piston rotation restricting member 20, so that in the automatic transmission 10 provided with the brake BR2 having the spring 101 for urging the piston 80 in the fastening direction. When the brake BR2 is fastened, the piston 80 rotates in the circumferential direction and the spring 101 is suppressed from twisting in the circumferential direction, so that the piston 80 can be accurately moved to a predetermined position.

Further, the spring 101 is a spring 101 that exerts an urging force on the piston 80 in the fastening direction from the release position to the zero clearance position. As a result, the piston 80 can be accurately moved from the released position to the zero clearance position by the spring 101.

Further, the hydraulic chamber 90 is arranged radially inside the plurality of friction plates 70, and the piston 80 includes a pressing portion 81, a hydraulic chamber forming portion 82, and a connecting portion 83. One side of the spline portion 25 of the hub member 20 in the axial direction is arranged in the notch portion 83b for the hub member of the connecting portion 83 of the piston 80, and the piston rotation restricting member 20 is composed of the hub member 20. As a result, in the brake BR2 in which the hydraulic chamber 90 is arranged radially inside the plurality of friction plates 70, the piston 80 extends radially through one axial side of the spline portion 25 of the hub member 20. It can be compactly configured in the axial direction while ensuring the axial length of the portion 25.

Further, the notch portion 83b for the hub member has a regulating portion 83c arranged along the side surface 26a of the tooth portion 26 of the spline portion 25 of the hub member 20. As a result, the rotation of the piston 80 is accurately regulated by the restricting portion 83c of the notch portion 83b for the hub member arranged along the side surface 26a of the tooth portion 26 of the spline portion 25 of the hub member 20 formed with high accuracy. Can be done.

Further, the spring 101, the fastening hydraulic chamber 91, and the releasing hydraulic chamber 92 are arranged at positions where the plurality of friction plates 70 are radially inside and overlap each other in the radial direction. As a result, the spring 101, the fastening hydraulic chamber 91, and the releasing hydraulic chamber 92 can be configured to be more compact in the radial direction than in the case where they do not overlap in the radial direction.

Further, the hub member 20 includes a spline portion 25 and is fitted to the transmission case 11 so as to be connected to the valve body 5 and the first hub member 21 which is spline-engaged with the transmission case 11. A hub member 31 is provided. As a result, the first hub member 21 is spline-engaged with the transmission case 11, so that the first hub member 21 is spline-engaged with the transmission case 11 by the force input from the friction plate 70 via the spline portion 25 when the brake BR2 is fastened. It is possible to suppress the rotation of the hub member 20 in the circumferential direction, and it is possible to prevent the hub member 20 from rotating. Further, since the second hub member 31 is fitted to the transmission case 11, the second hub member 31 can be fixed to the transmission case 11, and at the connection portion between the second hub member 31 and the valve body 5. The hydraulic oil can be efficiently supplied from the valve body 5 to the second hub member 31 by eliminating the backlash in the circumferential direction of the transmission case 11.

FIG. 16 is a cross-sectional view of a modified example of the brake of the automatic transmission according to the embodiment of the present invention. In FIG. 16, a modified example of the brake is shown in a cross-sectional view corresponding to the cross-sectional view of the brake shown in FIG. As shown in FIG. 16, a part of the bulging portion 83a is divided into the connecting portion 83 of the piston 80 corresponding to the first tooth portion 26 of the spline portion 25 of the first hub member 21, and is abbreviated as the pressing portion 81. It is also possible to form the valley portion 83d that is flush with each other and to form the notch portion 83b for the first hub member in the valley portion 83d.

As shown in FIG. 14, the connecting portion 83 of the piston 80 includes a notch portion 83b for a first hub member by dividing a part of the bulging portion 83a corresponding to the first tooth portion 26 of the spline portion 25. It is also possible to form a valley portion 83d surrounded by a two-dot chain line in the circumferential direction, and to form a notch portion 83b for a first hub member in the valley portion 83d.

Regarding the brake BR2 shown in FIG. 16, the notch 83b for the first hub member also has the side surfaces 83c on both sides arranged along the side surfaces 26a on both sides of the first tooth portion 26, and the notch for the first hub member is provided. The side surface 83c of the portion 83b functions as a regulating portion arranged along the side surface 26a of the tooth portion 26 of the spline portion 25 of the hub member 20.

In the first hub member 21, when the piston 80 rotates in the circumferential direction, the side surface 83c of the notch portion 83b for the first hub member comes into contact with the side surface 26a of the first tooth portion 26 of the first hub member 21, and the piston 80. Is restricted from rotating more than a predetermined amount. The hub member 20, specifically, the first hub member 21 functions as a piston rotation restricting member that restricts the piston 80 from rotating in the circumferential direction by a predetermined amount or more.

The brake BR2 shown in FIG. 16 is also provided with a brake BR2 having a spring 101 that urges the piston 80 in the fastening direction because the piston 80 is restricted from rotating in the circumferential direction by the piston rotation restricting member 20. In the automatic transmission 10, the piston 80 can be prevented from rotating in the circumferential direction and the spring 101 from twisting in the circumferential direction when the brake BR2 is engaged, and the piston 80 can be accurately moved to a predetermined position.

The present invention is not limited to the embodiments exemplified, and various improvements and design changes can be made without departing from the gist of the present invention.

As described above, according to the present invention, in an automatic transmission equipped with a brake having a spring that urges the piston in the fastening direction, the spring is suppressed from twisting in the circumferential direction to accurately position the piston in a predetermined position. Since it can be moved, it may be suitably used in the field of manufacturing technology of this type of automatic transmission or a vehicle equipped with the automatic transmission.

10 Automatic transmission 11 Transmission case 20 Hub member 21 First hub member 31 Second hub member 60 Drum member 70 Friction plate 80 Piston 90 Hydraulic chamber 91 Fastening hydraulic chamber 92 Release hydraulic chamber 101 Spring BR2 Second brake R3 Ring gear

Claims (5)

The hub member coupled to the transmission case, the drum member coupled to the predetermined rotating member, the plurality of friction plates arranged between the hub member and the drum member, and the plurality of friction plates are fastened. An automatic transmission equipped with a brake having a piston for squeezing and a spring for urging the piston in the fastening direction.
E Bei piston rotation restricting member for restricting said piston by a predetermined amount or more rotating in the circumferential direction,
The hub member is coupled to the transmission case with a spline portion to which the plurality of friction plates are spline-engaged.
In the drum member, the plurality of friction plates are spline-engaged and coupled to a predetermined rotating member.
A hydraulic chamber to which hydraulic oil for urging the piston is supplied is arranged inside the plurality of friction plates in the radial direction.
The piston includes a pressing portion that presses the friction plate, a hydraulic chamber forming portion that forms the hydraulic chamber, and a connecting portion that connects the pressing portion and the hydraulic chamber forming portion.
One side of the spline portion of the hub member in the axial direction is arranged in a notch portion for the hub member that is cut out corresponding to the spline portion of the hub member at the connecting portion of the piston.
The piston rotation restricting member is composed of the hub member.
An automatic transmission that features that. The spring is a spring that exerts an urging force on the piston from the release position to the zero clearance position in the fastening direction.
The automatic transmission according to claim 1. The hub member notch has a regulating portion arranged along the side surface of the tooth portion of the spline portion of the hub member.
The automatic transmission according to claim 1 or 2 , wherein the automatic transmission is characterized in that. The hydraulic chamber includes a fastening hydraulic chamber to which hydraulic oil for urging the piston in the fastening direction is supplied, and a releasing hydraulic chamber to which hydraulic oil for urging the piston in the releasing direction is supplied.
The spring, the fastening hydraulic chamber, and the releasing hydraulic chamber are arranged at positions where the plurality of friction plates are radially inside and overlap each other in the radial direction.
The automatic transmission according to any one of claims 1 to 3, wherein the automatic transmission is characterized in that. The hub member includes a first hub member having the spline portion and spline-engaged with the transmission case, and is arranged on the other side of the first hub member in the axial direction and below the transmission case. It comprises a second hub member fitted to the transmission case so as to be connected to the valve body.
Automatic transmission according to any one of claims 1 to 4, characterized in that.

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