JP2020159499A - Frictional engagement device and power transmission device - Google Patents

Abstract

To suppress the lowering of the durability of the most adjacent plate.SOLUTION: A frictional engagement device comprises: a plurality of first plate members in which a plurality of spline protrusions fit into a plurality of spline grooves formed in an outer circumferential surface of a first cylindrical portion are formed at an inner circumferential surface; a plurality of second plate members in which a plurality of spline protrusions fit into a plurality of spline grooves formed in an inner circumferential surface of a second cylindrical portion are formed at an outer circumferential surface, the second plate members being arranged alternately with the first plate members in an axial direction; and a piston which has an annular body portion, and a plurality of axially projected projections with circumferential intervals between the projections and the body portion, and can pressurize the plurality of first and second plate members by the plurality of projections. The frictional engagement device further comprises a positioning unit positioning the piston in such a way that pressurizing positions of the plurality of projection in the most adjacent plate which is most adjacent to the piston out of the plurality of first and second plate members are located between peripheral directions of the adjacent two spline protrusions.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to friction engaging devices and power transmission devices.

Conventionally, as a friction engagement device of this type, a device including a brake drum, a brake hub, a plurality of clutch plates, a plurality of clutch discs, and a piston has been proposed (see, for example, Patent Document 1). .. Here, a plurality of spline grooves extending in the axial direction are formed on the inner peripheral surface of the brake drum at intervals in the circumferential direction, and a plurality of spline grooves of the brake drum are formed on the outer peripheral surface of the plurality of clutch plates. A plurality of teeth are formed to be fitted to the. A plurality of spline grooves extending in the axial direction are formed on the outer peripheral surface of the brake hub at intervals in the circumferential direction, and a plurality of spline grooves of the brake hub are fitted on the inner peripheral surface of the plurality of clutch discs. A plurality of teeth are formed. The plurality of clutch plates and the plurality of clutch discs are alternately arranged in the order of the clutch plates and the clutch discs along the axial direction from the piston side. The piston has a circular plate-shaped main body portion and a plurality of pressing portions protruding in the axial direction at intervals in the circumferential direction from the main body portion. In this friction engagement device, the clutch plate and the clutch disc are pressed from one side in the axial direction by a plurality of pressing portions of the piston to engage in friction.

Japanese Unexamined Patent Publication No. 2013-164110

In the friction engagement device described above, the piston rotates relative to the closest clutch plate (closest plate), and the multiple pressing parts of the piston are near the teeth of the closest plate (stress tends to concentrate and the strength is low). Part) may be pressed. In this case, the durability of the closest plate may be reduced.

The friction engaging device and the power transmission device of the present disclosure are mainly intended to suppress a decrease in the durability of the closest plate.

The friction engaging device and the power transmission device of the present disclosure have adopted the following means in order to achieve the above-mentioned main object.

The friction engagement device of the present disclosure is
A first tubular portion having a plurality of spline grooves extending in the axial direction at intervals in the circumferential direction on the outer peripheral surface.
A second tubular portion that surrounds the first tubular portion and has a plurality of spline grooves extending in the axial direction at intervals in the circumferential direction on the inner peripheral surface.
A plurality of first plate members in which a plurality of spline protrusions fitted in the plurality of spline grooves of the first tubular portion are formed on an inner peripheral surface, and a plurality of first plate members.
A plurality of spline protrusions fitted in the plurality of spline grooves of the second tubular portion are formed on the outer peripheral surface, and a plurality of second plate members are arranged alternately with the first plate member in the axial direction. ,
It has an annular main body portion and a plurality of projecting portions protruding in the axial direction at intervals in the circumferential direction from the main body portion, and the plurality of first plate members and the plurality of second plate members are formed by the plurality of projecting portions. With a piston that can be pressed from one side in the axial direction,
It is a friction engagement device equipped with
Of the plurality of first plate members and the plurality of second plate members, the pressing positions of the plurality of protrusions on the closest plate closest to the piston are between the two adjacent spline protrusions in the circumferential direction. A positioning unit that positions the piston as described above.
The gist is to prepare.

In the friction engagement device of the present disclosure, the circumferences of two spline protrusions in which the pressing positions of the plurality of protrusions on the closest plate closest to the piston among the plurality of first plate members and the plurality of second plate members are adjacent to each other. A positioning unit for positioning the piston so as to be between the directions (position different from the spline protrusion in the circumferential direction) is provided. As a result, it is possible to prevent the piston from pressing the vicinity of the spline protrusion of the closest plate (the portion where stress is likely to be concentrated and the strength is low). As a result, it is possible to suppress a decrease in the durability of the closest plate.

The power transmission device of the present disclosure is
A continuously variable transmission that continuously shifts and transmits power between the primary shaft and the secondary shaft,
A forward / backward switching mechanism having the friction engaging device of the present disclosure in any one of the above embodiments and connected to a drive source and the primary shaft.
The gist is to prepare.

Since the power transmission device of the present disclosure includes the frictional engagement device of the present disclosure in any of the above-described aspects, the effect exerted by the frictional engagement device of the present disclosure, for example, a decrease in the durability of the closest plate is suppressed. It can produce the same effect as the effect that can be done.

It is a schematic block diagram which shows the power transmission device 20 of this disclosure. It is a schematic block diagram which shows the periphery of the brake B1 of a power transmission device 20. It is a front view of the separator plate 76. It is explanatory drawing which shows the pressing position of a plurality of protrusions 82 in the closest plate. It is explanatory drawing which shows the pressing position of a plurality of protrusions 82 in the closest plate.

Next, a mode for carrying out the invention of the present disclosure will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing the power transmission device 20 of the present disclosure. The power transmission device 20 shown in the figure is an engine mounted on a front-wheel drive vehicle and arranged horizontally so that the crankshaft of the engine and the left and right drive shafts 59 connected to the drive wheels (not shown) are substantially parallel to each other. It is configured as a transaxle connected to. As shown in the figure, the power transmission device 20 includes a transmission case 60 including a housing (first case) 61, a transaxle case (second case) 62, and a rear case (third case) 63 that are integrally coupled to each other. A starting device 23, an oil pump 30, a forward / backward switching mechanism 35, a belt-type continuously variable transmission (hereinafter referred to as "CVT") 40 as a transmission, a gear mechanism 50, and a differential gear (hereinafter referred to as "CVT") housed inside the case 60. (Differential mechanism) 57 and the like are provided. The housing 61, the transaxle case 62, and the rear case 63 are made of aluminum.

The starting device 23 is configured as a fluid-type starting device with a lockup clutch, and is housed inside the housing 61 of the transmission case 60. The starting device 23 includes a pump impeller 23p connected to the crank shaft of the engine via a front cover 23f as an input member, a turbine runner 23t fixed to the input shaft 41 of the CVT 40, a pump impeller 23p, and a turbine runner 23t. The stator 23s, which is arranged inside and rectifies the flow of hydraulic oil (ATF) from the turbine runner 23t to the pump impeller 23p, the one-way clutch 23o that limits the rotation direction of the stator 23s in one direction, the damper mechanism 24, and the lockup clutch 25. Etc.

When the difference in rotation speed between the pump impeller 23p and the turbine runner 23t is large, the pump impeller 23p, the turbine runner 23t, and the stator 23s function as a torque converter having a torque amplification function due to the action of the stator 23s, and the difference in rotation speed between the two is small. Then it functions as a fluid coupling. However, in the starting device 23, the stator 23s and the one-way clutch 23o may be omitted, and the pump impeller 23p and the turbine runner 23t may function as only the fluid coupling.

The damper mechanism 24 is connected to, for example, an input element connected to the lockup clutch 25, an intermediate element connected to the input element via a plurality of first elastic bodies, and an intermediate element via a plurality of second elastic bodies. It also has an output element that is fixed to the turbine hub. The lockup clutch 25 selects to lock up and release the lockup that mechanically (via the damper mechanism 24) connects the pump impeller 23p and the turbine runner 23t, that is, the front cover 23f and the input shaft 41 of the CVT 40. It is intended to be executed. The lockup clutch 25 may be configured as a hydraulic single-plate friction clutch or a hydraulic multi-plate friction clutch.

The oil pump 30 includes a pump assembly including a pump body 31 and a pump cover 32 arranged between a starting device 23 and a forward / backward switching mechanism 35, an inner rotor (external gear) 33, and an outer rotor (internal gear). It is configured as a so-called gear pump having 34 and the like. The pump body 31 and the pump cover 32 are fixed to the housing 61 and the transaxle case 62. Further, the inner rotor 33 is connected to the pump impeller 23p via a hub. Therefore, when the inner rotor 33 is rotated by the power from the engine, the hydraulic oil (ATF) in the oil pan (hydraulic oil storage portion) (not shown) is sucked and boosted by the oil pump 30 via the strainer (not shown). The generated hydraulic oil is supplied (discharged) to a hydraulic control device (not shown).

The forward / backward switching mechanism 35 is housed inside the transaxle case 62, and has a double pinion type planetary gear 36, and a brake B1 and a clutch C1 as hydraulic friction engaging elements. The planetary gear 36 meshes with the sun gear 36s, which is an external gear, and the ring gear 36r, which is an internal gear arranged concentrically with the sun gear 36s, and one meshes with the sun gear 36s and the other meshes with the ring gear 36r. It has a carrier 36c that holds a plurality of sets of two pinion gears 36pa and 36pb so as to be rotatable (rotatable) and revolving. The sun gear 36s is fixed to the input shaft 41 of the CVT 40. The carrier 36c is connected to the primary shaft 42 of the CVT 40.

The brake B1 fixes the ring gear 36r of the planetary gear 36 to the transaxle case 62 so as not to rotate when the engaging hydraulic pressure is supplied from the hydraulic control device, and transformers the ring gear 36r in response to the supply stop of the engaging hydraulic pressure. It is rotatably released with respect to the axle case 62. Further, the clutch C1 connects the carrier 36c of the planetary gear 36 to the input shaft 41 (sun gear) when the engaging hydraulic pressure is supplied from the hydraulic control device, and the carrier 36c and the input shaft respond to the stop supply of the engaging hydraulic pressure. The connection with 41 is released.

As a result, if the brake B1 is released and the clutch C1 is engaged, the power transmitted to the input shaft 41 can be directly transmitted to the primary shaft 42 of the CVT 40 to advance the vehicle. Further, if the brake B1 is engaged and the clutch C1 is released, the rotation of the input shaft 41 is converted in the reverse direction and transmitted to the primary shaft 42 of the CVT 40, so that the vehicle can be moved backward. Further, if the brake B1 and the clutch C1 are released, the connection between the input shaft 41 and the primary shaft 42 can be released.

The CVT 40 is provided on a primary pulley 43 provided on a primary shaft (first shaft) 42 as a drive-side rotation shaft and a secondary shaft (second shaft) 44 as a driven-side rotation shaft arranged in parallel with the primary shaft 42. A secondary pulley 45 provided, a transmission belt 46 wound around a pulley groove of the primary pulley 43 and a pulley groove of the secondary pulley 45, and a primary cylinder 47 which is a hydraulic actuator for changing the groove width of the primary pulley 43. And a secondary cylinder 48, which is a hydraulic actuator for changing the groove width of the secondary pulley 45. The primary pulley 43 has a fixed sheave 43a formed integrally with the primary shaft 42, and a movable sheave 43b slidably supported by the primary shaft 42 in the axial direction via a ball spline. Further, the secondary pulley 45 is pivotally supported by a fixed sheave 45a integrally formed with the secondary shaft 44 and a return spring 49 which is a compression spring while being slidably supported by the secondary shaft 44 via a ball spline. It has a movable sheave 45b that is urged in the direction.

The primary cylinder 47 is formed behind the movable sheave 43b of the primary pulley 43, and the secondary cylinder 48 is formed behind the movable sheave 45b of the secondary pulley 45. Hydraulic pressure is supplied to the primary cylinder 47 and the secondary cylinder 48 from the hydraulic pressure control device so as to change the groove width between the primary pulley 43 and the secondary pulley 45. By controlling the hydraulic pressure supplied to the primary cylinder 47 and the secondary cylinder 48, the power transmitted from the engine to the primary shaft 42 via the starting device 23 and the forward / backward switching mechanism 35 is steplessly changed to the secondary shaft. It becomes possible to transmit to 44. Then, the power transmitted to the secondary shaft 44 is transmitted to the left and right drive wheels via the gear mechanism 50, the differential gear 57, and the drive shaft.

The gear mechanism 50 includes a counter drive gear 51 that rotates integrally with the secondary shaft 44, and a counter shaft that extends parallel to the secondary shaft 44 and the drive shaft 59 and is rotatably supported by the transmission case 60 via a bearing. The third shaft) 52, the counter driven gear 53 fixed to the counter shaft 52 and meshing with the counter drive gear 51, and the drive pinion gear (final) formed integrally with the counter shaft 52 or fixed to the counter shaft 52. A drive gear) 54 and a differential ring gear (final driven gear) 55 that meshes with the drive pinion gear 54 and is connected to the differential gear 57 are provided.

FIG. 2 is a schematic configuration diagram showing the periphery of the brake B1 of the power transmission device 20, and FIG. 3 is a front view of the separator plate 76. As shown in FIG. 2, the transaxle case 62 has an annular wall portion 62a, a tubular inner cylinder portion 62b extending axially from the inner circumference of the annular wall portion 62a, and an outer circumference of the annular wall portion 62a. An outer cylinder portion 62c extending from the inner cylinder portion 62b in the axial direction to the same side is provided. The annular wall portion 62a is formed with a recess 62d that is recessed from the inner cylinder portion 62b or the outer cylinder portion 62c side (right side in FIG. 2) in the axial direction to the opposite side.

A plate-shaped connecting member 37 is attached to the ring gear 36r (brake hub 70 of the brake B1) of the planetary gear 36. The plate-shaped connecting member 37 has an annular portion 37 whose outer peripheral portion is connected to the ring gear 36r and a tubular shape extending from the inner circumference of the annular portion 37 to the inner tubular portion 62b side of the transaxle case 62 in the axial direction. It has a portion 37b and an annular portion 37c extending radially inward from an end portion of the tubular portion 37b opposite to the annular portion 37. The annular portion 37c is rotatably supported by the carrier 36c of the planetary gear 36.

The brake B1 includes a brake hub (first tubular portion) 70, a brake drum portion (second tubular portion) 72, a plurality of friction plates (first plate member) 74, and a plurality of separator plates (second plate). A member) 76, a backing plate 78, a piston 80, a spring support member 86, and a plurality of return springs (not shown).

The brake hub 70 is integrally formed with the ring gear 36r of the planetary gear 36, and a plurality of spline grooves 70s extending in the axial direction are formed on the outer peripheral surface of the brake hub 70 at intervals in the circumferential direction. ..

The brake drum portion 72 is a part of the outer cylinder portion 62c of the transaxle case 62, and a plurality of spline grooves extending in the axial direction at intervals in the circumferential direction are formed on the inner peripheral surface of the brake drum portion 72 (not shown). Omitted) is formed. The brake drum portion 72 surrounds the brake hub 70.

The friction plate 74 is an annular member to which a friction material is attached to both sides, and a plurality of spline grooves 70s formed on the outer peripheral surface of the brake hub 70 can be fitted on the inner peripheral surface of the friction plate 74. Spline protrusions 74s are formed. The friction plate 74 is spline-fitted to the brake hub 70 to regulate rotation with respect to the brake hub 70.

The separator plate 76 is an annular member having smooth surfaces on both sides, and can be fitted into a plurality of spline grooves (not shown) formed on the inner peripheral surface of the brake drum portion 72 on the outer peripheral surface of the separator plate 76. A plurality of spline protrusions 76s (see FIG. 3) are formed. The separator plate 76 is arranged with the plurality of friction plates 74 fitted to the brake hub 70 alternately (specifically, the separator plate 76, the friction plate 74, and the separator plate are arranged from the piston 80 side (left side in FIG. 2). It is spline-fitted to the brake drum portion 72 (in the order of 76 and the friction plate 74), and the rotation with respect to the brake drum portion 72 is restricted.

The backing plate 78 is an annular member, and a plurality of spline protrusions (not shown) that can be fitted into a plurality of spline grooves (not shown) formed on the inner peripheral surface of the brake drum portion 72 are formed on the outer peripheral surface of the backing plate 78. Omitted) is formed. The backing plate 78 is spline-fitted to the brake drum portion 72 so as to be in contact with the friction plate 74 on the side farthest from the piston 80 among the plurality of friction plates 74, and the brake drum of the outer cylinder portion 62c of the transaxle case 62. Axial movement (specifically, movement toward the side separated from the piston 80) is restricted by the snap ring 79 mounted on the side separated from the annular wall portion 62a from the portion 72.

The piston 80 is made of, for example, aluminum, and includes an annular main body portion 81, a plurality of (for example, six) protruding portions 82, and a convex portion 83. The inner circumference of the main body 81 is supported by the inner cylinder portion 62b of the transaxle case 62 so as to be movable in the axial direction, and the outer circumference of the main body 81 is larger than the brake drum portion 72 by the outer cylinder portion 62c of the transaxle case 62. It is supported so as to be movable in the axial direction on the annular wall portion 62a side. A seal member 84i is arranged between the inner circumference of the main body 81 and the outer peripheral surface of the inner cylinder 62b, and the seal member 84o is located between the outer circumference of the main body 81 and the inner peripheral surface of the outer cylinder 62c. Is placed. As a result, the brake B1 is engaged with the main body portion 81 and the annular wall portion 62a, the inner cylinder portion 62b, and the outer cylinder portion 62c of the transaxle case 62 on the annular wall portion 62a side of the brake drum portion 72. Therefore, an engaging oil chamber 90 to which hydraulic pressure is supplied is defined. Therefore, the portion of the transaxle case 62 on the annular wall portion 62a, the inner cylinder portion 62b, and the outer cylinder portion 62c on the annular wall portion 62a side of the brake drum portion 72 can be considered as an engaging oil chamber imaging portion. The engaging oil chamber 90 is connected to a hydraulic control device (not shown) via an oil passage (not shown).

The plurality of projecting portions 82 extend from the main body portion 81 toward the friction plate 74 and the separator plate 76 in the axial direction at intervals in the circumferential direction, and are formed in a rectangular shape when viewed in the axial direction. The convex portion 83 extends from the main body portion 81 to the side opposite to the plurality of protruding portions 82 in the axial direction. The convex portion 83 enters the concave portion 62d of the transaxle case 62. The relative rotation amount of the piston 80 with respect to the transaxle case 62 and the separator plate 76 is determined by the shapes of the concave portion 62d of the transaxle case 62 and the convex portion 83 of the piston 80.

The spring support member 86 is an annular member, and is arranged so as to vertically overlap with at least a part of the connecting member 37 (annular portion 37c in FIG. 2) when viewed in the radial direction of the spring support member 86. As a result, the shaft length of the brake B1 can be shortened. The spring support member 86 is formed with a plurality of holes 86h (the same number as the protrusions 82 of the piston 80) extending in the circumferential direction at intervals in the circumferential direction, and each hole 86h is formed with each of the pistons 80. The protrusion 82 is inserted. A plurality of return springs (not shown) are arranged between the spring support member 86 and the main body 81 of the piston 80 at positions different from the holes 86h in the circumferential direction of the spring support member 86. As the return spring, for example, a coil spring is used. The spring support member 86 is moved in the axial direction by a snap ring 87 mounted on the annular wall portion 62a side of the brake drum portion 72 of the outer cylinder portion 62c of the transaxle case 62 (specifically, the friction plate 74 and the separator plate). Movement to the 76 side) is regulated.

In the brake B1 configured in this way, when hydraulic pressure is supplied from the hydraulic control device to the engaging oil chamber 90 via the oil passage, the piston 80 moves toward the friction plate 74 and the separator plate 76, and the plurality of protrusions 82 The brake B1 is frictionally engaged with each other by pressing them. At this time, the piston 80 may rotate slightly relative to the transaxle case 62 and the separator plate 76. As described above, this relative rotation amount is determined by the shape of the concave portion 62d of the transaxle case 62 and the convex portion 83 of the piston 80.

4 and 5 are explanatory views showing the pressing positions of the plurality of protrusions 82 on the closest plate, which is the separator plate 76 closest to the piston 80. In FIGS. 4 and 5, the black-painted rectangles indicate the pressing positions of the plurality of protrusions 82. FIG. 4 shows the state when the relative rotation amount of the piston 80 with respect to the closest plate is maximum counterclockwise, and FIG. 5 shows the state when the relative rotation amount of the piston 80 with respect to the closest plate is maximum clockwise. Is shown. From FIGS. 4 and 5, regardless of the relative rotation amount of the piston 80 with respect to the closest plate, the plurality of protrusions 82 of the piston 80 are between (periphery) in the circumferential direction of two adjacent spline protrusions 76s on the closest plate. It can be seen that the pressure is pressed (a position different from the spline protrusion 76s in the direction). In other words, the transaxle is such that the pressing positions of the plurality of protrusions 82 of the piston 80 on the closest plate are between the two adjacent spline protrusions 76s in the circumferential direction (positions different from the spline protrusions 76s in the circumferential direction). The position and shape of the concave portion 62d of the case 62 and the shape of the convex portion 83 of the piston 80 are determined. That is, the concave portion 62d of the transaxle case 62 and the convex portion 83 of the piston 80 function as positioning portions that define the pressing positions of the plurality of protruding portions 82 of the piston 80 on the closest plate. By this positioning portion, it is possible to prevent the plurality of protrusions 82 of the piston 80 from pressing the vicinity of the spline protrusions 76s of the closest plate (the portion where stress is easily concentrated and the strength is low). As a result, it is possible to suppress a decrease in the durability of the closest plate. Moreover, since the transaxle case 62 is provided with the concave portion 62d and the piston 80 is provided with the convex portion 83 as the positioning portion, the strength of the main body portion 81 of the piston 80 can be ensured.

Further, in the embodiment, the piston 80 of the brake B1 and the engaging oil chamber imaging portion (annular wall portion 62a of the transaxle case 62, inner cylinder portion 62b, and annular wall portion 62a rather than the brake drum portion 72 of the outer cylinder portion 62c). By forming the side portion) from aluminum, the weight of the brake B1 and eventually the power transmission device 20 can be reduced as compared with those formed of iron or the like. In the power transmission device 20, the brake B1 engaged for reverse travel is less frequently subjected to a large torque for forward travel as compared with the clutch C1. Therefore, even if the piston 80 and the engaging oil chamber defining portion are made of aluminum, the durability of the brake B1 can be ensured.

In the embodiment, the positioning portion is composed of a convex portion 83 extending axially from the main body portion 81 of the piston 80 and a concave portion 62d formed in the annular wall portion 62a of the transaxle case 62. , A convex portion extending axially from the annular wall portion 62a of the transaxle case 62, and an axially recessed portion from the end surface of the main body 81 of the piston 80 on the annular wall portion 62a side so as to engage with the convex portion. It may be composed of recesses.

In the embodiment, the spring support member 86 is axially overlapped with at least a part of the connecting member 37 when viewed in the radial direction thereof, but may not be axially overlapped with the connecting member 37.

In the embodiment, the piston 80 of the brake B1 and the engaging oil chamber defining portion are made of aluminum, but the present invention is not limited to this.

In the embodiment, as the first plate member to be spline-fitted to the brake hub 70, a friction plate 74 which is an annular member to which friction materials are attached to both sides is used, and is spline-fitted to the brake drum portion 72. As the second plate member, a separator plate 76, which is an annular member having both sides smoothly formed, is used. However, as the first plate member and the second plate member, an annular member having one surface formed smoothly and a friction material attached to the other surface may be used, respectively.

In the embodiment, the friction engaging device of the present disclosure is provided by a brake hub (first tubular portion) 70, a brake drum portion (second tubular portion) 72, a plurality of friction plates (first plate member) 74, and a plurality of friction engaging devices. It is applied to the brake B1 provided with the separator plate (second plate member) 76 and the piston 80, but the first tubular portion, the second tubular portion, the plurality of first plate members, and the plurality of second plate members are applied. And a piston may be provided. For example, the friction engaging device of the present disclosure includes a clutch hub, a clutch drum, a plurality of first plate members whose inner circumference is spline-fitted to the outer circumference of the clutch hub, and a spline fit to the inner circumference of the clutch drum. It may be applied to a clutch including a plurality of second plate members to be combined and a piston capable of pressing a plurality of first plate members and a plurality of second plate members by a plurality of projecting portions.

In the embodiment, the friction engaging device of the present disclosure is applied to the brake B1 of the power transmission device including the CVT 40 and the forward / backward switching mechanism 35, but to the brake and the clutch of the power transmission device including the stepped transmission. It may be applied.

As described above, the first tubular portion (70) in which a plurality of spline grooves (70s) extending in the axial direction are formed on the outer peripheral surface at intervals in the circumferential direction, and the first tubular portion (70). A second tubular portion (72) in which a plurality of spline grooves extending in the axial direction are formed on the inner peripheral surface at intervals in the circumferential direction, and the plurality of the first tubular portion (70). A plurality of first plate members (74) in which a plurality of spline protrusions (74s) fitted in a spline groove (70s) are formed on an inner peripheral surface, and the plurality of splines of the second tubular portion (72). A plurality of spline protrusions (76s) fitted in the groove are formed on the outer peripheral surface, and a plurality of second plate members (76) alternately arranged with the first plate member (74) in the axial direction and an annular shape. It has a main body portion (81) and a plurality of projecting portions (82) protruding in the axial direction at intervals in the circumferential direction from the main body portion (81), and the plurality of protrusions (82) form the plurality of positions. A friction engaging device (B1) including a piston (80) capable of pressing one plate member (74) and the plurality of second plate members (76) from one side in the axial direction, wherein the plurality of second plate members (76) are provided. The two splines in which the pressing positions of the plurality of protrusions (82) in the closest plate closest to the piston (80) of the one plate member (74) and the plurality of second plate members (76) are adjacent to each other. It is a gist to include positioning portions (62d, 83) for positioning the piston (80) so as to be between the protrusions (76s) in the circumferential direction.

In the friction engagement device of the present disclosure, the circumferences of two spline protrusions in which the pressing positions of the plurality of protrusions on the closest plate closest to the piston among the plurality of first plate members and the plurality of second plate members are adjacent to each other. A positioning unit for positioning the piston so as to be between the directions (position different from the spline protrusion in the circumferential direction) is provided. As a result, it is possible to prevent the piston from pressing the vicinity of the spline protrusion of the closest plate (the portion where stress is likely to be concentrated and the strength is low). As a result, it is possible to suppress a decrease in the durability of the closest plate.

In the friction engaging device of the present disclosure, the engaging oil chamber defining portions (62a, 62b, 62c) that support the piston (80) and define the engaging oil chamber (90) with the piston (80). The positioning portion (62d, 83) is formed on one of the piston (80) and the engaging oil chamber defining portion (62a, 62b, 62c) and is a convex portion that projects in the axial direction. (83), and is formed on the other of the piston (80) and the engaging oil chamber defining portion (62a, 62b, 62c) and engages with the convex portion (83) from the end face in the axial direction. It may be composed of a recess (62d) that is recessed so as to be formed. In this way, the strength of the main body of the piston can be ensured.

In this case, the plurality of projecting portions (82) project from the main body portion (81) to one side in the axial direction, and the convex portion (83) protrudes from the main body portion (81) to the other side in the axial direction. It may be the one to do.

Further, in this case, the second tubular portion (72) and the engaging oil chamber imaging portion (62a, 62b, 62c) are a part of the case (62), and the closest plate is the first. It may be a two-plate member (76).

In the friction engagement device of the present disclosure, a return spring for urging the piston (80) so as to be separated from the plurality of first plate members (74) and the plurality of second plate members (76), and the return. The plurality of protrusions (82) are provided with an annular stop member (86) having a plurality of holes (86h) extending at intervals in the circumferential direction while restricting the axial movement of the spring. It may be inserted through a plurality of holes (86h).

In this case, a connecting member (37) connected to the first tubular portion (70) is provided, and the stop member (86) is axially connected to at least a part of the connecting member (37) when viewed from the radial direction. It may overlap with. In this way, the shaft of the friction engaging device can be shortened.

The power transmission device of the present disclosure includes a continuously variable transmission (40) for continuously shifting and transmitting power between a primary shaft (42) and a secondary shaft (44), and a book of any of the above-described embodiments. It is a gist to have the disclosed friction engaging device (B1) and to include a forward / backward switching mechanism (35) connected to a drive source and the primary shaft (42).

Since the power transmission device of the present disclosure includes the frictional engagement device of the present disclosure in any of the above-described aspects, the effect exerted by the frictional engagement device of the present disclosure, for example, a decrease in the durability of the closest plate is suppressed. It can produce the same effect as the effect that can be done.

In the power transmission device of the present disclosure, the forward / backward switching mechanism (35) is connected to the first rotating element (36s), the second rotating element (36r), and the primary shaft (42) connected to the drive source. A planetary gear (36) having a third rotating element (36c), and any one of the first rotating element (36s), the second rotating element (36r), and the third rotating element (36c). As the friction engaging device, the clutch (C1) for connecting the two to each other and releasing the connection between the two and the second rotating element (36r) are fixed to the case so as not to rotate and the fixing is released. It may have a brake (B1).

In this case, the piston (80) is provided with engaging oil chamber defining portions (62a, 62b, 62c) that support the piston (80) and define the engaging oil chamber (90) with the piston (80). 80) and the engaging oil chamber defining portion (62a, 62b, 62c) may be formed of aluminum.

The embodiments for carrying out the present disclosure have been described above, but the present disclosure is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present disclosure. Of course.

The present disclosure is available to the manufacturing industry of friction engaging devices and power transmission devices and the like.

20 Power transmission, 23 Starter, 23f front cover, 23o one-way clutch, 23p pump impeller, 23s stator, 23t turbine runner, 24 damper mechanism, 25 lockup clutch, 30 oil pump, 31 pump body, 32 pump cover, 33 Inner rotor, 35 forward / backward switching mechanism, 36 planetary gear, 36c carrier, 36pa pinion gear, 36r ring gear, 36s sun gear, 37 connecting member, 37a annular part, 37b tubular part, 37c annular part, 40 CVT, 41 input shaft, 42 Primary shaft, 43 Primary pulley, 43a fixed sheave, 43b movable sheave, 44 secondary shaft, 45 secondary pulley, 45a fixed sheave, 45b movable sheave, 46 transmission belt, 47 primary cylinder, 48 secondary cylinder, 49 return spring, 50 gear mechanism , 51 counter drive gear, 52 counter shaft, 53 counter driven gear, 54 drive pinion gear, 57 differential gear, 59 drive shaft, 60 transmission case, 61 housing, 62 transformer axle case, 62a annular wall, 62b inner cylinder, 62c outside Cylinder, 62d recess, 63 rear case, 70 brake drum, 72 brake hub, 70s spline groove, 74 friction plate, 74s, 76s spline protrusion, 76 separator plate, 78 backing plate, 79,87 snap ring, 80 piston, 81 Main body, 82 protruding parts, 83 convex parts, 84i, 84o seal member, 86 spring support member, 86h hole, 90 engagement oil chamber, B1 brake, C1 clutch.

Claims (9)

A first tubular portion having a plurality of spline grooves extending in the axial direction at intervals in the circumferential direction on the outer peripheral surface.
A second tubular portion that surrounds the first tubular portion and has a plurality of spline grooves extending in the axial direction at intervals in the circumferential direction on the inner peripheral surface.
A plurality of first plate members in which a plurality of spline protrusions fitted in the plurality of spline grooves of the first tubular portion are formed on an inner peripheral surface, and a plurality of first plate members.
A plurality of spline protrusions fitted in the plurality of spline grooves of the second tubular portion are formed on the outer peripheral surface, and a plurality of second plate members are arranged alternately with the first plate member in the axial direction. ,
It has an annular main body portion and a plurality of projecting portions protruding in the axial direction at intervals in the circumferential direction from the main body portion, and the plurality of first plate members and the plurality of second plate members are formed by the plurality of projecting portions. With a piston that can be pressed from one side in the axial direction,
It is a friction engagement device equipped with
Of the plurality of first plate members and the plurality of second plate members, the pressing positions of the plurality of protrusions on the closest plate closest to the piston are between the two adjacent spline protrusions in the circumferential direction. A positioning unit that positions the piston as described above.
A friction engagement device comprising. The friction engaging device according to claim 1.
It is provided with an engaging oil chamber defining portion that supports the piston and defines an engaging oil chamber with the piston.
The positioning portion is formed on one of the piston and the engaging oil chamber defining portion and has a convex portion protruding in the axial direction, and the other of the piston and the engaging oil chamber defining portion. It is composed of recesses that are formed in and recessed so as to engage with the convex portion from the end face in the axial direction.
Friction engagement device. The friction engaging device according to claim 2.
The plurality of projecting portions project from the main body portion to one side in the axial direction.
The convex portion projects from the main body portion to the other side in the axial direction.
Friction engagement device. The friction engaging device according to claim 2 or 3.
The second tubular portion and the engaging oil chamber imaging portion are part of the case.
The closest plate is the second plate member.
Friction engagement device. The friction engaging device according to any one of claims 1 to 4.
A return spring that urges the piston away from the plurality of first plate members and the plurality of second plate members.
An annular spring support member that regulates the axial movement of the return spring and has a plurality of holes extending at intervals in the circumferential direction.
With
The plurality of protrusions are inserted into the plurality of holes.
Friction engagement device. The friction engaging device according to claim 5.
A connecting member to be connected to the first tubular portion is provided.
The spring support member axially overlaps with at least a part of the connecting member when viewed in the radial direction.
Friction engagement device. A continuously variable transmission that continuously shifts and transmits power between the primary shaft and the secondary shaft,
A forward / backward switching mechanism having the friction engaging device according to any one of claims 1 to 6 and connected to a drive source and the primary shaft.
Power transmission device equipped with. The power transmission device according to claim 7.
The forward / backward switching mechanism includes a planetary gear having a first rotating element connected to the drive source, a second rotating element, and a third rotating element connected to the primary shaft, the first rotating element, and the first rotating element. A clutch that connects any two of the two rotating elements and the third rotating element to each other and disconnects the two, and fixes the second rotating element to the case so as not to rotate. It has a brake as the friction engagement device to be released.
Power transmission device. The power transmission device according to claim 8.
It is provided with an engaging oil chamber defining portion that supports the piston and defines an engaging oil chamber with the piston.
The piston and the engaging oil chamber defining portion are made of aluminum.
Power transmission device.