JP2021038771A - Friction fastening device - Google Patents

Abstract

To provide a friction fastening device capable of reducing drag resistance without complicating a structure.SOLUTION: A wet type friction fastening device (10) has: an outside power transmission member (12); an inside power transmission member (14); a plurality of large-diameter friction plates (16); a small-diameter friction plate (18); and a piston (20) moving each friction plate into a fastening state. An insertion opening (12d) is provided on a peripheral surface of the outside power transmission member. A regulating member (32) is projected out into the inside of the outside power transmission member through the insertion opening, thereby engaging an end portion large-diameter friction plate disposed at the farthest position from the piston and the regulating member, and regulating the end portion large-diameter friction plate at a predetermined position.SELECTED DRAWING: Figure 2

Description

The present invention relates to a friction fastening device, and more particularly to a wet friction fastening device that switches between fastening and non-fastening between an outer power transmission member and an inner power transmission member.

Japanese Unexamined Patent Publication No. 2003-13996 (Patent Document 1) describes a friction engagement device. This friction engaging device includes a large-diameter cylinder having an outer engaging groove on the inner peripheral surface and a small-diameter cylinder having an inner engaging groove on the outer peripheral surface. Further, the large-diameter cylinder is equipped with a plurality of large-diameter friction plates having an outer engaging portion that engages with the outer engaging groove, and the small-diameter cylinder is equipped with an inner engaging portion that engages with the inner engaging groove. A plurality of small diameter friction plates with joints are mounted. When engaging (fastening) the friction engaging device, each large-diameter friction plate and each small-diameter friction plate are pressed against each other, and the large-diameter cylinder and the small-diameter cylinder are fastened by the frictional force acting between them. To.

Further, a plurality of spring clips having a U-shaped holding portion for sandwiching the engaging portion and leaf spring portions provided at both ends of the holding portion are attached to the outer engaging portion or the inner engaging portion. There is. By attaching this spring clip, the distance between each large-diameter friction plate and the small-diameter friction plate is positively widened in the released (non-fastened) state of the friction engagement device, and the drag resistance is reduced.

Japanese Unexamined Patent Publication No. 2003-13996

In the friction engaging device described in Patent Document 1, by attaching a spring clip, the distance between each large-diameter friction plate and the small-diameter friction plate is widened by the spring force of the spring clip to reduce the drag resistance. However, in the friction engaging device described in Patent Document 1, since a spring clip is provided in order to widen the distance between the friction plates, the number of parts increases, the structure becomes complicated, and the assembly man-hours increase. There is a problem that the friction engaging device (friction fastening device) becomes expensive. Further, there is also a problem that the weight of the friction fastening device is increased by providing the spring clip specially.

Therefore, an object of the present invention is to provide a friction fastening device capable of reducing drag resistance without complicating the structure.

In order to solve the above-mentioned problems, the present invention is a wet friction fastening device for switching between fastening and non-fastening between the outer power transmission member and the inner power transmission member, and the outer power transmission member formed in a tubular shape. And, inside the outer power transmission member, the inner power transmission member rotatably arranged with respect to the outer power transmission member, and inside the outer power transmission member, slidable in the axial direction of the outer power transmission member. A plurality of large-diameter friction plates that are arranged and whose outer peripheral edge engages with the inner peripheral surface of the outer power transmission member to prevent rotation with respect to the outer power transmission member, and inside the outer circumference of the inner power transmission member. A plurality of large-diameter friction plates are slidably arranged in the axial direction of the power transmission member, and the inner peripheral edge engages with the outer peripheral surface of the inner power transmission member to prevent rotation with respect to the inner power transmission member. The small-diameter friction plate arranged between each of the above and the inside of the outer power transmission member are movably arranged in the axial direction of the outer power transmission member, and the large-diameter friction plate and the small-diameter friction plate are moved in the axial direction. It has a piston that fastens the outer power transmission member and the inner power transmission member, and an insertion opening is provided on the peripheral surface of the outer power transmission member, and the regulation member is passed through the insertion opening to the outer power transmission member. By projecting inward, the large-diameter end friction plate located at the farthest position from the piston is engaged with the regulating member, and the large-diameter end friction plate is restricted to a predetermined position. ..

In the present invention configured in this way, a large-diameter friction plate whose outer peripheral edge is engaged with the outer power transmission member and a small-diameter friction plate whose inner peripheral edge is engaged with the inner power transmission member are alternately arranged. In the fastened state, the piston moves each large-diameter friction plate and small-diameter friction plate in the axial direction. As a result, the frictional force acting between each large-diameter friction plate and the small-diameter friction plate causes the outer power transmission member engaged with the large-diameter friction plate and the inner power transmission member engaged with the small-diameter friction plate. To be concluded. Further, by projecting the restricting member from the insertion opening provided on the peripheral surface of the outer power transmission member, the end large-diameter friction plate and the restricting member are engaged, and the end large-diameter friction plate is restricted to a predetermined position. Will be done.

According to the present invention configured as described above, the position of the large-diameter friction plate at the end is restricted to a predetermined position by the regulating member. Therefore, when the piston is moved and the friction fastening device is not fastened, the pressure of the lubricating oil flowing between the large-diameter friction plates and the small-diameter friction plates widens the distance between the friction plates at approximately equal intervals. The resistance due to dragging between the friction plates can be reduced.

In the present invention, preferably, the outer power transmission member and the large-diameter friction plate are engaged with the spline groove provided on the inner peripheral surface of the outer power transmission member by the spline teeth provided on the outer periphery of the large-diameter friction plate. The regulating member is arranged so as to engage the spline teeth provided on the large diameter friction plate at the end, and the large diameter friction plate arranged adjacent to the large diameter friction plate at the end is regulated. The spline teeth at the positions corresponding to the members are missing.

According to the present invention configured in this way, the outer power transmission member and the large-diameter friction plate are engaged with each other by the spline grooves and the spline teeth provided, so that the large diameter with respect to the outer power transmission member is ensured. The rotation of the friction plate can be prevented. In addition, the position of the large-diameter friction plate at the end is restricted by engaging the regulating member with the spline teeth of the large-diameter friction plate at the end, and the large-diameter friction plate adjacent to the large-diameter friction plate at the end is a regulating member. The spline tooth at the position corresponding to is missing. Therefore, even if the position of the insertion opening for inserting the regulating member is deviated, the regulating member interferes with the large-diameter friction plate adjacent to the large-diameter friction plate at the end, and the movement of the large-diameter friction plate is caused. It can be prevented from interfering.

In the present invention, it is preferable to further have a ring-shaped member attached so as to go around the outer circumference of the outer power transmission member, and the regulating member has a ring shape so as to project inward in the radial direction of the outer power transmission member. It is formed on a member.

According to the present invention configured as described above, since the regulating member is formed in the ring-shaped member so as to project inward in the radial direction of the outer power transmission member, the regulating member can be easily attached to the outer power transmission member. Can be attached.

In the present invention, preferably, the ring-shaped member is formed by connecting a plurality of arc-shaped members, and ribs extending in the axial direction of the outer power transmission member are formed at both ends of each arc-shaped member. , These ribs are fastened to each other with screws directed in the circumferential direction of the outer power transmission member, so that the arc-shaped members are connected to each other.

According to the present invention configured in this way, since the ring-shaped member is configured by connecting a plurality of arc-shaped members, the ring-shaped member can be easily constructed. Further, since the plurality of arc-shaped members constituting the ring-shaped member are connected by fastening the ribs extending in the axial direction of the outer power transmission member to each other with screws, they greatly project in the radial direction of the outer power transmission member. Each arc-shaped member can be connected without any need.

In the present invention, preferably, of the plurality of large-diameter friction plates, the large-diameter friction plate arranged closest to the piston is fixed to the piston so as to move in the axial direction with the movement of the piston. ..

According to the present invention configured in this way, since the large-diameter friction plate arranged closest to the piston is fixed to the piston, when the piston is moved in order to bring the friction fastening device into the non-fastened state. , The large diameter friction plate adjacent to the piston is also moved. As a result, the friction plates spread quickly at approximately equal intervals, and the resistance due to dragging between the friction plates can be reduced at an early stage.

In the present invention, preferably, the piston is configured to be assembled in the outer power transmission member after the large diameter friction plate and the small diameter friction plate are arranged.

In the present invention, the large-diameter friction plate at the end is restricted to a predetermined position by projecting the regulating member from the insertion opening provided on the peripheral surface of the outer power transmitting member. It can also be applied to a type of friction fastening device in which a piston is attached after a large-diameter friction plate and a small-diameter friction plate are arranged.

In the present invention, the friction fastening device is preferably used as a clutch device that transmits rotational power between an outer power transmission member and an inner power transmission member.
The friction fastening device of the present invention can be suitably applied to a clutch device capable of easily forming an insertion opening on the peripheral surface of the outer power transmission member.

According to the friction fastening device of the present invention, the drag resistance can be reduced without complicating the structure.

It is a perspective view of the transmission (automatic transmission) which built in the friction fastening device by embodiment of this invention. It is sectional drawing of the friction fastening device by embodiment of this invention. It is an exploded perspective view of the friction fastening device according to the embodiment of this invention. FIG. 5 is a cross-sectional view of a friction fastening device according to an embodiment of the present invention, in which a drum is cut in a direction orthogonal to an axis at a portion where a regulating member is inserted. It is a perspective view which shows the state which the regulation member is inserted in the drum in the friction fastening device by embodiment of this invention. FIG. 5 is a cross-sectional view of the friction fastening device according to the embodiment of the present invention cut along a spline groove into which a connecting member is inserted. It is a perspective view which shows the state which the connecting member is inserted in the notch of the drum in the friction fastening device by embodiment of this invention. It is sectional drawing which shows the fastening state and the non-fastening state of the friction fastening device of this embodiment. This is an example of a graph showing the relationship between the face-to-face distance, the face-to-face pressure, and the drag torque with respect to the rotation speed of the hub in the conventional wet friction fastening device. It is a figure which shows typically the distribution of the large-diameter friction plate and the small-diameter friction plate in the non-fastened state in the conventional wet friction fastening device. It is a figure which shows typically the distribution of the large-diameter friction plate and the small-diameter friction plate in the non-fastened state in the friction fastening device of the embodiment of this invention. This is an example of simulation results showing the relationship between the inter-face distance between the large-diameter friction plate and the small-diameter friction plate and the pressure between these friction plates. This is an example of a graph obtained by simulation of the relationship between the inter-plane distance, the inter-plane pressure, and the drag torque with respect to the rotation speed of the hub in the friction fastening device according to the embodiment of the present invention.

Next, the friction fastening device according to the embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view of a transmission (automatic transmission) incorporating a friction fastening device according to an embodiment of the present invention.

As shown in FIG. 1, the transmission 1 is mounted on an automobile and is interposed between a drive source E such as an engine or a motor and a wheel W to accelerate or decelerate the rotational power output from the drive source E. It is configured to output to the wheels. In the example shown in FIG. 1, the transmission 1 is a multi-stage automatic transmission (so-called AT), but the wet friction fastening device according to the embodiment of the present invention can be incorporated into a device other than the transmission 1 or is a single unit. It can also be used in.

In the present embodiment, the transmission 1 includes a housing 2, an output shaft 4 (rotating shaft), a transmission 6, an intermittent device 8, and the like.
The housing 2 constitutes the outer shell of the transmission 1, accommodates the intermittent device 8 and the transmission device 6, and rotatably supports the output shaft 4.
The intermittent device 8 (so-called torque converter) is connected to the drive source E, and is configured to input the rotational power output by the drive source E to the transmission 1 as needed.

The transmission 6 is arranged around the output shaft 4 and is interposed between the intermittent device 8 and the output shaft 4 to switch the rotation speed of the rotational power input from the intermittent device 8 and transmit it to the output shaft 4. It is configured to do. The rotational power output from the output shaft 4 of the transmission 1 is transmitted to the wheels W. The transmission 6 incorporates a plurality of planetary gear mechanisms and a clutch device and / or a brake device for switching these planetary gear mechanisms in order to switch the output rotation speed. The transmission 1 is configured to perform forward movement, backward movement, and switching of rotational speed by changing the operating state of these clutch devices or brake devices.

The friction fastening device 10 according to the embodiment of the present invention is used as a clutch device in the transmission 6. Although the clutch and the brake are functionally different, they are structurally almost the same, and the case where the friction fastening device 10 is used as the clutch device will be described in the present specification. FIG. 1 shows an enlarged portion of the friction fastening device 10 provided in the transmission 6.

Next, the configuration of the friction fastening device according to the embodiment of the present invention will be described with reference to FIGS. 2 to 5.
FIG. 2 is a cross-sectional view of a friction fastening device according to an embodiment of the present invention. FIG. 3 is an exploded perspective view of the friction fastening device according to the embodiment of the present invention. FIG. 4 is a cross-sectional view of the friction fastening device according to the embodiment of the present invention, in which the drum is cut in the direction orthogonal to the axis at the portion where the regulating member is inserted.

As shown in FIGS. 2 and 3, the friction fastening device 10 is arranged so as to engage the drum 12 which is the outer power transmission member, the hub 14 which is the inner power transmission member, and the inner circumference of the drum 12. It has a plurality of large-diameter friction plates 16a to 16e, and a plurality of small-diameter friction plates 18a to 18d arranged so as to engage with the outer periphery of the hub 14. Further, as shown in FIG. 2, the friction fastening device 10 covers the piston 20 movably arranged inside the drum 12 in the axis A direction (FIG. 3) of the drum 12 and the piston 20. It has a cover member 22 attached to an end surface of the drum 12 on the piston 20 side.

In the present embodiment, the drum 12 which is the outer power transmission member is rotatably supported with respect to the housing 2, and the friction fastening device 10 functions as a clutch device, but the outer power transmission member is the housing. The friction fastening device 10 functions as a braking device by being configured with a case fixed to 2. Further, in the present specification, the large-diameter friction plates 16a to 16e may be collectively referred to as a "large-diameter friction plate", and the small-diameter friction plates 18a to 18d are collectively referred to as a "small-diameter friction plate". May be called. Further, the large-diameter friction plate and the small-diameter friction plate may be collectively referred to as a "friction plate".

As shown in FIG. 3, the drum 12 is a cylindrical member, and the output shaft 4 (not shown in FIG. 3) penetrates along the central axis A thereof. Further, inside the drum 12, a hub 14 is rotatably arranged along the central axis A. That is, the drum 12 and the hub 14 are arranged concentrically, and the hub 14 is rotatably supported with respect to the drum 12 about the central axis A. Further, on the inner peripheral surface of the drum 12, spline grooves 12a extending in the axial direction A direction of the drum 12 are formed so as to be arranged at intervals in the circumferential direction.

The hub 14 is a cylindrical member having a diameter smaller than that of the drum 12 and is arranged inside the drum 12, and an output shaft 4 (not shown in FIG. 3) penetrates inside the hub 14. In the non-fastened state of the friction fastening device 10, rotation of the hub 14 with respect to the drum 12 is allowed, and rotational power is not transmitted between the hub 14 and the drum 12. On the other hand, in the fastened state of the friction fastening device 10, the hub 14 and the drum 12 are fastened, and rotational power is transmitted between the hub 14 and the drum 12. Further, a plurality of spline grooves 14a extending in the axis A direction are formed on the outer peripheral surface of the hub 14 at intervals in the circumferential direction.

As shown in FIG. 2, the inner peripheral surface of the drum 12 and the outer peripheral surface of the hub 14 face each other in the radial direction, and an annular space is formed as a plate accommodating chamber between them. When the transmission 1 is operated, lubricating oil (ATF: Automatic Transmission Fluid) is circulated and supplied to the plate accommodating chamber from the lubricating device 24 at a constant flow rate. That is, the lubrication device 24 composed of an oil storage tank, a hydraulic pump, or the like (not shown) is provided so as to communicate the oil introduction path 24a formed inside the hub 14 and the oil introduction path 24a with the outer periphery of the hub 14. The ATF is allowed to flow into the plate accommodating chamber through the refueling hole 14b provided. The ATF flowing into the plate accommodating chamber flows out from the oil drain hole 12b provided so as to communicate the plate accommodating chamber and the outer periphery of the drum 12, and the ATF flowing out from the drum 12 is returned formed inside the housing 2. It is returned to the lubricator 24 through the oil passage 24b. That is, the friction fastening device 10 is a wet friction fastening device in which lubricating oil is circulated and supplied.

As shown in FIG. 3, the large-diameter friction plates 16a to 16e are generally donut-shaped metal plates, and are arranged inside the drum 12 in the direction of the axis A. Further, a plurality of spline teeth 17 are formed on the outer peripheral edges of the large-diameter friction plates 16a to 16e at intervals in the circumferential direction. The spline teeth 17 formed on the outer peripheral edge of each large-diameter friction plate are received in the spline grooves 12a formed on the inner peripheral surface of the drum 12, respectively, and are received on the outer peripheral edge of each large-diameter friction plate and inside the drum 12. The peripheral surfaces engage. As a result, each of the large-diameter friction plates 16a to 16e is slidably arranged inside the drum 12 in the axis A direction, and the outer peripheral edge engages with the inner peripheral surface of the drum 12 with respect to the drum 12. Rotation is blocked.

Further, as shown in FIG. 2, a ring groove 12c extending in the circumferential direction is formed on the inner peripheral surface of the end portion of the inner circumference of the drum 12 opposite to the cover member 22. An elastic arc-shaped snap ring 13 is fitted in the ring groove 12c. By fitting the snap ring 13 into the ring groove 12c, the large-diameter friction plate 16e, which is the end large-diameter friction plate arranged at the position farthest from the piston 20 and the cover member 22, is in the direction away from the piston 20 (FIG. The movement to the left in 2) is blocked.

On the other hand, the small-diameter friction plates 18a to 18d are generally donut-shaped metal plates, and are arranged side by side in the axis A direction on the outer periphery of the hub 14. Further, the four small-diameter friction plates 18a to 18d are arranged between the five large-diameter friction plates 16a to 16e, respectively. That is, the large-diameter friction plate and the small-diameter friction plate are arranged alternately in the axis A direction in the drum 12, and the large-diameter friction plate 16a and the large-diameter friction plate 16e are arranged at both ends of these friction plates. Each is located. In the present embodiment, the small-diameter friction plates 18a to 18d are smaller in diameter and thinner than the large-diameter friction plates 16a to 16e. Further, in the present embodiment, the large-diameter friction plate 16e, which is the end large-diameter friction plate, is formed to be thicker than other large-diameter friction plates.

Further, a plurality of spline teeth 19 are formed on the inner peripheral edges of the small-diameter friction plates 18a to 18d at intervals in the circumferential direction. The spline teeth 19 formed on the inner peripheral edge of each small-diameter friction plate are each received in the spline grooves 14a formed on the outer peripheral surface of the hub 14, and the inner peripheral edge of each small-diameter friction plate and the outer peripheral surface of the hub 14 are engaged with each other. It fits. As a result, each of the small-diameter friction plates 18a to 18d is slidably arranged on the outer periphery of the hub 14 in the axis A direction, and the inner peripheral edge engages with the outer peripheral surface of the hub 14 to cause rotation with respect to the hub 14. Be blocked.

As shown in FIG. 2 (not shown in FIG. 3), the piston 20 is a member arranged inside the drum 12 so as to be movable in the axis A direction of the drum 12. By sliding the piston 20 in the axis A direction, the large-diameter friction plates 16a to 16e and the small-diameter friction plates 18a to 18d are moved in the axis A direction, and the drum 12 and the hub 14 are switched between the fastened state and the non-fastened state. Can be done.

That is, the piston 20 includes a main body portion 20a formed in a cylindrical shape, an overhanging portion 20b extending radially outward from one end of the main body portion 20a, and a cylindrical portion 20c provided on the outer periphery of the overhanging portion. It is provided at the tip of the cylindrical portion 20c and has a pressing portion 20d for moving each friction plate. A cover member 22 is attached to one end surface of the drum 12 (the end surface on the piston 20 side) so as to cover the piston 20.

The main body 20a of the piston 20 is a cylindrical portion, is arranged inside the hub 14 on a concentric circle with the drum 12 and the hub 14, and is slidably supported along the axis A of the drum 12. ..
Further, the overhanging portion 20b of the piston 20 is a disk-shaped portion formed so as to extend outward in the radial direction from one end of the main body portion 20a, and extends beyond the end surface of the hub 14 into the plate accommodating chamber. ..

Further, the cylindrical portion 20c of the piston 20 is a portion formed of a cylindrical surface provided on the outer periphery of the overhanging portion 20b, and is directed from the overhanging portion 20b toward the large-diameter friction plate 16a (in a direction away from the cover member 22). It is extending.
Further, the pressing portion 20d of the piston 20 is a flange-shaped portion provided at the tip of the cylindrical portion 20c, is provided on the outer periphery of the cylindrical portion 20c, and extends in parallel with the large-diameter friction plate. When fastening the friction fastening device 10, the piston 20 is moved away from the cover member 22 (to the left in FIG. 2), whereby the pressing portion 20d presses the large-diameter friction plate 16a, and each friction The plate is moved away from the cover member 22. Further, as will be described later, the large-diameter friction plate 16a arranged at the position closest to the piston 20 is attached to the tip of the pressing portion 20d, and is attached to the cover member 22 in the axis A direction as the piston 20 moves. Moved in the approaching direction.

Further, a partition wall portion 20e is provided inside the main body portion 20a of the piston 20, and the inside of the main body portion 20a is partitioned by the partition wall portion 20e between the side of the cover member 22 and the opposite side. Further, a spring 26 is arranged inside the main body portion 20a, and the piston 20 is urged toward the cover member 22 by pressing the partition wall portion 20e. When the piston 20 is moved away from the cover member 22 in order to fasten the friction fastening device 10, the piston 20 is moved against the urging force of the spring 26.

Further, the cover member 22 side of the partition wall portion 20e is a recess that opens toward the cover member 22. On the other hand, a convex portion 22a protruding toward the concave portion of the piston 20 is formed in the central portion of the cover member 22, and the convex portion 22a is inserted into the concave portion of the piston 20. Further, a sealing member 28 is arranged between the outer peripheral surface of the convex portion 22a of the cover member 22 and the inner peripheral surface of the concave portion of the piston 20, and the space between the piston 20 and the cover member 22 is sealed. With this configuration, the space inside the recess of the piston 20 can function as the hydraulic chamber 30. When the friction fastening device 10 is fastened, oil is supplied into the hydraulic chamber 30 from a hydraulic pump (not shown), whereby the pressure in the hydraulic chamber 30 increases, and the piston 20 acts as an urging force for the spring 26. On the contrary, it is moved in the direction of the axis A in the direction away from the cover member 22. Further, when the friction fastening device 10 is not fastened, oil is discharged from the hydraulic chamber 30 by a hydraulic pump (not shown), and the piston 20 moves toward the cover member 22 by the urging force of the spring 26. Will be done.

Next, the fixed structure of the large-diameter friction plate 16e, which is the end large-diameter friction plate arranged at the position farthest from the piston 20 of the large-diameter friction plates, is newly referred to FIGS. 4 and 5. explain.
FIG. 4 is a cross-sectional view of the drum 12 cut in the direction orthogonal to the axis at the portion where the regulating member is inserted. FIG. 5 is a perspective view showing a state in which the regulating member is inserted into the drum 12.

First, as shown in FIG. 2, the drum 12 is formed with an insertion opening 12d at a position adjacent to the large-diameter friction plate 16e. As shown in FIG. 4, the insertion openings 12d are formed so as to penetrate the drum 12 and open into the spline groove 12a at three locations on the circumference of the drum 12. Further, the regulating member 32 is inserted into each of the insertion openings 12d from the outside of the drum 12, and these regulating members 32 project to the inside of the drum 12. The regulating member 32 is made of a thin metal plate having a width narrower than that of the spline groove 12a provided on the drum 12. Here, the insertion opening 12d provided in the drum 12 is formed adjacent to the surface of the large-diameter friction plate 16e on the piston side. Therefore, when the regulating member 32 protrudes inside the drum 12, the spline teeth 17a of the large-diameter friction plate 16e and the regulating member 32 engage with each other, and the large-diameter friction plate 16e is sandwiched between the snap ring 13 and the regulating member 32. Therefore, the position in the axis A direction is regulated.

Further, as shown in FIG. 4, each regulation member 32 is formed as a part of a metal ring-shaped member attached so as to go around the outer circumference of the drum 12. This ring-shaped member is formed by connecting two semi-circular members 33, which are arc-shaped members, and each regulating member 32 is integrated so as to project inward in the radial direction from the semi-arc member 33. Is formed in. It is also possible to attach each regulating member to the drum 12 by welding, screwing, or the like without providing the ring-shaped member for attaching the regulating member 32.

Further, as shown in FIG. 5, ribs 33a are provided at both ends of each semicircular arc member 33, and by fastening these ribs 33a to each other with screws 33b at both ends, the two semicircular arc members 33 can be formed. It is connected. Further, each rib 33a is formed so as to bend at a right angle to the semicircular arc member 33, and is directed so as to extend in the axial direction of the drum 12 with the semicircular arc member 33 attached to the outer periphery of the drum 12. There is. In this way, the ribs 33a oriented so as to extend in the axial direction of the drum 12 are connected to each other by the screws 33b oriented in the circumferential direction of the drum 12. As a result, a ring-shaped member composed of the two semicircular arc members 33 is fixed to the outer periphery of the drum 12, and the regulating member 32 provided on each semicircular arc member 33 is also fixed. Further, the rib 33a for connecting the semicircular arc member 33 is formed so as to extend in the axial direction of the drum 12. Therefore, the semicircular arc member 33 can be mounted more compactly around the drum 12 as compared with the case where the rib 33a is formed so as to extend in the radial direction of the drum 12. Further, by connecting three or more arc-shaped members, a ring-shaped member that goes around the drum 12 can be formed.

Further, in FIG. 3, the regulating member 32 is arranged so as to engage with the spline teeth 17a of the spline teeth provided on the large-diameter friction plate 16e. Further, among the spline teeth provided on the large-diameter friction plate 16d arranged adjacent to the large-diameter friction plate 16e, the spline teeth at the positions corresponding to the spline teeth 17a of the large-diameter friction plate 16e are cut short. It has short spline teeth 17b. That is, since the small-diameter friction plate is formed relatively thin, when the friction fastening device 10 is fastened, the large-diameter friction plate 16e and the large-diameter friction plate 16d adjacent to the large-diameter friction plate 16e are separated by the thickness of the small-diameter friction plate. Located close to. Therefore, if the position accuracy of the insertion opening 12d into which the regulation member 32 is inserted or the processing accuracy of the regulation member 32 is low, or if the assembly tolerance of the friction fastening device 10 is large, the regulation member 32 has a large diameter friction at the time of fastening. There is a risk of interfering with the plate 16d. In order to prevent this, the spline teeth of the large diameter friction plate 16d adjacent to the spline teeth 17a of the large diameter friction plate 16e are set as short short spline teeth 17b to avoid interference between the regulating member 32 and the large diameter friction plate 16d. There is. Further, by setting the spline teeth of the large-diameter friction plate 16d as the short spline teeth 17b, the regulating member 32 thicker than the small-diameter friction plate can be used.

Further, in the examples shown in FIGS. 2 and 3, the short spline teeth 17b are provided only on the large-diameter friction plate 16d adjacent to the large-diameter friction plate 16e, but a plurality of large-diameter frictions in the vicinity of the large-diameter friction plate 16e are provided. The plate may be provided with short spline teeth. Alternatively, the spline teeth at the positions corresponding to the spline teeth 17a of all the large-diameter friction plates 16a to 16d can be set as short spline teeth. Alternatively, instead of cutting out the spline teeth short to make them short spline teeth, the spline teeth may be completely cut out and the spline teeth may not be provided at the corresponding positions.

In FIGS. 3 and 4, for simplification of the drawings, each large-diameter friction plate has seven spline teeth, and these spline teeth are received in the seven spline grooves of the drum 12. However, more spline teeth and spline grooves can be provided.

Next, refer to FIGS. 6 and 7 for the fixing structure of the large-diameter friction plate 16a, which is the large-diameter friction plate on the piston side, which is arranged at the position closest to the piston 20 of the large-diameter friction plates. I will explain.
As described above, the large-diameter friction plate 16a arranged at the position closest to the piston 20 is fixed to the piston 20 and is configured to be moved in the axial direction with the movement of the piston 20. Hereinafter, the fixed structure of the large-diameter friction plate 16a with respect to the piston will be described.

As shown in FIG. 3, a specific spline groove 12e among the spline grooves formed in the drum 12 is notched in a part of the bottom surface, and the large-diameter friction plate 16a is pistoned in the notch. A connecting member 34 (FIG. 6) for fixing to 20 is inserted. Further, among the spline teeth accepted in the spline groove 12e, the short spline teeth 17c formed on the large-diameter friction plates 16b to 16e are formed shorter than the other spline teeth. On the other hand, for the large-diameter friction plate 16a closest to the piston 20, the spline teeth accepted by the spline groove 12e are also formed to have the same length as the other spline teeth.

FIG. 6 is a cross-sectional view of the friction fastening device 10 of the present embodiment cut along the spline groove 12e into which the connecting member 34 is inserted, and FIG. 7 is a perspective view showing a state in which the connecting member 34 is inserted into the notch. It is a figure.
As shown in FIGS. 6 and 7, a part of the bottom surface of the spline groove 12e is cut out, and the cutout portion 12f extends in the axial direction from the end portion of the drum 12 on the piston side. The connecting member 34 is arranged inside the notch 12f, and the large-diameter friction plate 16a is fixed to the piston 20. Further, since the spline teeth formed on the large-diameter friction plates 16b to 16e are short spline teeth 17c, interference between the connecting member 34 and the short spline teeth 17c is avoided.

Specifically, the connecting member 34 is formed of a thin metal plate, and has a belt-shaped annular portion 34a wound around the cylindrical portion 20c of the piston 20 and the annular portion 34a toward the large-diameter friction plate 16a. It has an extending engaging portion 34b and.
The annular portion 34a is composed of an elongated metal thin plate, and is configured to fix the connecting member 34 to the piston 20 by being wound around the cylindrical portion 20c of the piston 20. Further, since the flange-shaped pressing portion 20d is provided at the tip of the cylindrical portion 20c, the annular portion 34a wound around the outer circumference of the cylindrical portion 20c engages with the pressing portion 20d, and the annular portion 34a has a large diameter. It is prevented from shifting toward the friction plate.

As shown in FIG. 6, the engaging portion 34b is composed of an elongated metal thin plate, extends outward in the radial direction of the piston 20 from the annular portion 34a, and then is bent in the axial direction A to form a large-diameter friction plate 16a. It extends beyond the opposite side of the piston 20. That is, the engaging portion 34b of the connecting member 34 passes through the inside of the notch portion 12f and extends beyond the spline teeth 17 of the large-diameter friction plate 16a. Further, the engaging portion 34b is bent inward in the radial direction after passing over the large-diameter friction plate 16a to form a convex portion 34c protruding inward in the radial direction, and extends in the axis A direction. .. By bending inward in the radial direction, the convex portion 34c of the engaging portion 34b engages with the surface of the large-diameter friction plate 16a opposite to the piston 20, and the large-diameter friction plate 16a becomes the piston 20. It is fixed. Further, the large-diameter friction plate 16a is attracted to the side of the piston 20 by engaging with the engaging portion 34b of the connecting member 34, and the large-diameter friction plate 16a comes into contact with the pressing portion 20d of the piston 20. That is, the connecting member 34 urges the large-diameter friction plate 16a toward the piston 20 to bring the large-diameter friction plate 16a into contact with the pressing portion 20d of the piston 20.

Further, the engaging portion 34b of the connecting member 34 extends in the axial direction in the notch portion 12f provided in the spline groove 12e, but the spline teeth of the large-diameter friction plates 16b to 16e are accepted by the spline groove 12e. Is formed short as a short spline tooth 17c. Therefore, even when the piston 20 is moved (to the left in FIG. 6) in order to fasten the friction fastening device 10, the engaging portion 34b extending beyond the large diameter friction plate 16a is the large diameter friction plate. It does not interfere with other large diameter friction plates other than 16a.

In the examples shown in FIGS. 3 and 7, the engaging portion 34b of the connecting member 34 is inserted into the cutout portion 12f formed by one of the seven spline grooves 12e, but the connecting member 34 It is preferable to configure the present invention so that a plurality of engaging portions 34b are provided in the vehicle and the engaging portions 34b are inserted into the notches provided in the plurality of spline grooves. Preferably, three or more engaging portions 34b are provided, and the large-diameter friction plate 16a on the piston side is urged toward the piston 20 at three or more locations. As a result, the large-diameter friction plate 16a can be reliably brought into contact with the pressing portion 20d of the piston 20.

Further, in the examples shown in FIGS. 3 and 6, the short spline tooth 17c accepted by the spline groove 12e is formed shorter than the other spline teeth 17, but the spline tooth is located at a position corresponding to the spline groove 12e. It is not necessary to provide. Further, in the examples shown in FIGS. 3 and 6, the spline teeth for engaging the engaging portion 34b of the large-diameter friction plate 16a are set to have a normal length, and the spline teeth of the large-diameter friction plates 16b to 16e are formed short. However, it is also possible to form long spline teeth for engaging the engaging portion 34b and to form spline teeth of the large-diameter friction plates 16b to 16e with a normal length. Further, in the present embodiment, the engaging portion 34b is engaged with the spline teeth of the large-diameter friction plate 16a, but the present invention is configured so as to engage the engaging portion 34b with a portion other than the spline teeth. You can also do it. In this case, it is necessary to appropriately adjust the shapes of the drum 12 and the large-diameter friction plates 16b to 16e so as not to interfere with the engaging portion 34b.

Next, the procedure for assembling the friction fastening device 10 according to the present embodiment will be described.
First, the hub 14 is rotatably arranged in the drum 12. Next, the snap ring 13 (FIG. 2) is inserted into the drum 12 in a reduced diameter state, and the diameter of the snap ring 13 is expanded at a position where the snap ring 13 is aligned with the ring groove 12c of the drum 12. As a result, the snap ring 13 is fitted into the ring groove 12c. Next, the large-diameter friction plate 16e, which is an end large-diameter friction plate, is inserted from the end on the cover member 22 side of the drum 12. The large-diameter friction plate 16e slides in the axis A direction from the end on the cover member 22 side in a state where the spline grooves 12a on the inner peripheral surface of the drum 12 and the spline teeth 17 are engaged with each other, and comes into contact with the snap ring 13. It is inserted to the position.

Next, the small-diameter friction plate 18a is inserted from the end of the drum 12 on the cover member 22 side. The small-diameter friction plate 18a slides in the axis A direction from the end on the cover member 22 side along the spline groove 14a of the hub 14 in a state where the spline teeth 19 and the spline groove 14a are engaged with the large-diameter friction plate 16e. It is inserted to the position where it abuts. Hereinafter, the large-diameter friction plate and the small-diameter friction plate are alternately inserted into the drum 12. After arranging the large-diameter friction plate 16a on the piston side in the drum 12, the piston 20 is assembled in the drum 12.

In this state, the connecting member 34 (FIG. 6) is attached so that the annular portion 34a is fitted around the cylindrical portion 20c of the piston 20. When the connecting member 34 is attached to the piston 20, the engaging portion 34b of the connecting member 34 is expanded outward in the radial direction by elastic deformation. By expanding the engaging portion 34b outward in the radial direction, the convex portion 34c of the engaging portion 34b gets over the spline teeth 17 of the large-diameter friction plate 16a. In a state where the connecting member 34 is fitted to a predetermined position of the piston 20, the convex portion 34c that has passed over the spline teeth 17 engages with the large-diameter friction plate 16a, and the large-diameter friction plate 16a is formed by the connecting member 34 on the piston 20. It is pressed against the pressing portion 20d. As a result, the large-diameter friction plate 16a is attached to the piston 20, and the large-diameter friction plate 16a slides in the axis A direction together with the piston 20. Next, the cover member 22 is attached to the end face of the drum 12 so as to cover the piston 20.

Next, two semi-arc members 33 (FIG. 4) provided with the regulating member 32 are arranged around the drum 12, and each regulating member 32 is inserted into the insertion opening 12d of the drum 12. With each regulating member 32 inserted into each insertion opening 12d, the semicircular arc members 33 are fastened to each other with screws 33b, and the semicircular arc member 33 is fixed around the drum 12. As a result, each regulating member 32 is fixed in a state of protruding inward of the drum 12 from the insertion opening 12d. When the regulating member 32 protrudes, the large-diameter friction plate 16e is sandwiched and fixed between the snap ring 13 and the regulating member 32 (FIG. 2). As a result, the position of the large-diameter friction plate 16e in the axis A direction is restricted.

As described above, in the friction fastening device 10 of the present embodiment, the large-diameter friction plates 16a to 16e and the small-diameter friction plates 18a to 18d are arranged in the drum 12, and then the piston 20 is arranged in the drum 12. It is assembled by fixing the cover member 22 to the drum 12. Further, two semi-circular members 33 provided with the regulating member 32 are attached around the drum 12, and the regulating member 32 is projected inside the drum 12. As a result, the large-diameter friction plate 16e arranged at the position farthest from the piston 20 can be fixed by the regulating member 32 even after the piston 20 is arranged.

Next, the operation of the friction fastening device 10 according to the embodiment of the present invention will be described with reference to FIGS. 8 to 13.
FIG. 8 is a cross-sectional view showing a fastened state and a non-fastened state of the friction fastening device 10 of the present embodiment. FIG. 9 is an example of a graph obtained by simulation the relationship between the inter-plane distance, the inter-plane pressure, and the drag torque generated by the inter-plane distance with respect to the rotation speed of the hub. FIG. 10 is a diagram schematically showing the distribution of a large-diameter friction plate and a small-diameter friction plate in a non-fastened state in a conventional wet friction fastening device. FIG. 11 is a diagram schematically showing the distribution of the large-diameter friction plate and the small-diameter friction plate in the non-fastened state in the friction fastening device 10 of the present embodiment. FIG. 12 is an example of simulation results showing the relationship between the inter-plane distance between the large-diameter friction plate and the small-diameter friction plate and the pressure between these friction plates. FIG. 13 is an example of a graph obtained by simulation of the relationship between the inter-plane distance, the inter-plane pressure, and the drag torque generated by the inter-plane distance with respect to the rotation speed of the hub 14 in the friction fastening device 10 of the present embodiment.

The friction fastening device 10 of the present embodiment can switch between a fastening state and a non-fastening state between the drum 12 and the hub 14 by hydraulic control. Specifically, as shown in FIG. 8, the large-diameter friction plates 16a to 16e and the small-diameter friction plates 18a to 18d are in close contact with each other (fastened state), and the large-diameter friction plates 16a to 16e and the small-diameter friction plate are in close contact with each other (fastened state). The friction fastening device 10 is switched between a state in which each of 18a to 18d becomes separable (non-fastening state).

That is, when the pressure oil is supplied to the hydraulic chamber 30 (FIG. 2), as shown on the left side of FIG. 8, the pressing portion 20d of the piston 20 moves in a direction away from the cover member 22. As a result, a pressing force is applied to each large-diameter friction plate and each small-diameter friction plate, and the fastening state is established. In the fastened state, each friction plate including the large-diameter friction plate 16e is received by the snap ring 13, and the pressing portion 20d is moved to a position farthest from the cover member 22.

On the other hand, when the pressure oil is discharged from the hydraulic chamber 30, the piston 20 (pressing portion 20d) is moved toward the cover member 22 by the elastic force of the spring 26, as shown on the right side of FIG. As a result, the pressing force acting on each large-diameter friction plate and each small-diameter friction plate is removed, and the non-fastened state is obtained. In the non-fastened state, the pressing portion 20d is moved to the position closest to the cover member 22, so that the distance between the large-diameter friction plate 16a and the large-diameter friction plate 16e is the widest. In this state, each large-diameter friction plate and each small-diameter friction plate arranged between the large-diameter friction plates 16a and 16e are in a free state between the large-diameter friction plates 16a and 16e (sliding in the axis A direction). State).

In this non-fastened state, no pressing force acts on each large-diameter friction plate and each small-diameter friction plate, and the friction plates are slidable in the axial direction. No frictional force acts between them. However, since the friction fastening device 10 of the present embodiment is wet, ATF is interposed between the friction plates, and frictional resistance is generated by the fluid friction, which may cause torque loss (dragging phenomenon).

That is, when the hub 14 is rotating in the non-fastened state, a centrifugal force acts on the ATF between the friction plates, and the flow of the ATF is promoted in the radial direction from the inside to the outside. Normally, the ATF is supplied to the plate accommodating chamber at a constant flow rate, and as the rotation speed of the hub 14 increases, the flow velocity due to centrifugal force increases, and between each friction plate, the ATF is supplied to the plate accommodating chamber at a higher flow rate. The amount of ATF discharged from the plate storage chamber is increased. In such a state, a pressure difference in the radial direction is formed between the plate surfaces of the large-diameter friction plate and the small-diameter friction plate that are adjacent to each other, and a negative pressure is generated between the plate surfaces.

FIG. 9 shows the relationship between the face-to-face distance (distance between the large-diameter and small-diameter friction plates), the face-to-face pressure (pressure between the large-diameter and small-diameter friction plates), and the drag torque generated thereby with respect to the rotation speed of the hub. Is an example of a graph obtained by simulation. The face-to-face distance S0 represents an appropriate face-to-face distance when each of the large-diameter friction plate and the small-diameter friction plate is evenly arranged in the movable range L, that is, at equal intervals in the non-fastened state. ..

As shown in FIG. 9, in the region where the rotation speed is low, the centrifugal force acting on the ATF is small, and the supply amount of ATF is larger than the outflow amount, so that the surface pressure is also high (positive pressure) and the surface distance is large. , The appropriate inter-plane distance S0 is obtained. Therefore, the frictional resistance is small and the drag torque is also small. On the other hand, in the region where the rotation speed is high, the centrifugal force acting on the ATF becomes large. As a result, the outflow amount of ATF exceeds the supply amount, and a negative pressure is generated between the plate surfaces.

Since each of the large-diameter friction plate and the small-diameter friction plate in the non-fastened state is in a free state in the axial direction, they are attracted to each other by the action of the negative pressure, and the face-to-face pressure becomes 0 (zero) due to the pressure balance. On the other hand, the inter-plane distance becomes smaller. Therefore, in the conventional wet friction fastening device, as shown in FIG. 10, the large-diameter friction plate and the small-diameter friction plate in the non-fastened state are unevenly positioned in the movable range L at the time of high rotation. It becomes. That is, each large-diameter friction plate and small-diameter friction plate are positioned unevenly with respect to a range in which they can move in the axial direction, and the distance between the friction plates is a face-to-face distance S smaller than the appropriate face-to-face distance S0, and each friction plate. Will be crowded. As a result, the conventional wet friction fastening device has a problem that the drag torque increases due to the fluid friction of the ATF existing between the plate surfaces.

The inventors of the present application have found that the dragging phenomenon can be effectively suppressed with an extremely simple configuration based on the mechanism of occurrence of the dragging phenomenon. The friction fastening device 10 according to the embodiment of the present invention has been developed based on this knowledge.

In the conventional friction fastening device, in the non-fastened state, all the large-diameter friction plates and the small-diameter friction plates are in an axially free state, so that they are attracted by the action of negative pressure and come close to each other, and the friction plates are spaced apart from each other. Is smaller than the appropriate inter-plane distance S0, which causes a problem that the drag torque becomes large. On the other hand, in the friction fastening device 10 according to the embodiment of the present invention, the large-diameter friction plate 16e farthest from the piston 20 is fixed to the drum 12, and the large-diameter friction plate 16a adjacent to the piston 20 is the piston 20. It is fixed to. By adopting this configuration, in the friction fastening device 10 of the present embodiment, all the friction plates arranged between the large diameter friction plate 16a and the large diameter friction plate 16e can be moved as shown in FIG. We have succeeded in distributing them at almost equal intervals within the range L.

First, FIG. 12 is an example of simulation results showing the relationship between the inter-plane distance between the large-diameter friction plate and the small-diameter friction plate and the pressure (inter-plane pressure) between these friction plates. The ATF supplied into the plate accommodating chamber flows in between the large-diameter friction plates and the small-diameter friction plates, and the inflowing ATF flows out from between the friction plates due to the centrifugal force acting on the ATF. Here, when the distance between the surfaces of the friction plates is large, the flow path resistance acting on the ATF flowing between the friction plates is small, and the ATF between the friction plates is easily discharged by centrifugal force. On the other hand, when the distance between the surfaces of the friction plates is small, the flow path resistance acting on the ATF flowing between the friction plates is large, and the ATF between the friction plates is less likely to be discharged. As a result, as shown in FIG. 12, the inter-plane pressure between the friction plates is high when the inter-plane distance of the friction plates is small, and low when the inter-plane distance is large.

Here, the piston 20 is moved to the right in FIG. 8 when shifting from the fastened state of the friction fastening device 10 shown on the left side of FIG. 8 to the non-fastened state. In the friction fastening device 10 of the present embodiment, since the large-diameter friction plate 16a located on the piston side is fixed to the piston 20, the large-diameter friction plate 16a is also moved to the right together with the piston 20. As a result, a gap is created between the large-diameter friction plate 16a and the small-diameter friction plate 18a, which are in close contact with each other. When such a gap is generated, the inter-surface pressure between the large-diameter friction plate 16a and the small-diameter friction plate 18a decreases, as shown in the simulation result of FIG. As a result, the face-to-face pressure between the large-diameter friction plate 16a and the small-diameter friction plate 18a becomes lower than the face-to-face pressure between the small-diameter friction plate 18a and the large-diameter friction plate 16b. Based on this pressure difference, the small diameter friction plate 18a is moved to the right in FIG.

When the small-diameter friction plate 18a is moved to the right, a gap is formed between the small-diameter friction plate 18a and the large-diameter friction plate 16b. As a result, the face-to-face pressure between the small-diameter friction plate 18a and the large-diameter friction plate 16b becomes lower than the face-to-face pressure between the large-diameter friction plate 16b and the small-diameter friction plate 18b. As a result, the large-diameter friction plate 16b is moved to the right in FIG. By repeating such an action, the gap formed between the large-diameter friction plate 16a and the small-diameter friction plate 18a propagates between the friction plates, and a gap is generated between the friction plates. As a result, when the large-diameter friction plate 16a adjacent to the piston 20 is moved together with the piston 20, each of the other friction plates is also sequentially moved to the right in FIG.

Also, if the spacing between certain friction plates is narrower than the spacing between adjacent friction plates, the pressure between the narrowly spaced friction plates is higher than the pressure between the widely spaced friction plates. Become. When such a pressure difference occurs, the space between the friction plates with a narrow space is expanded, the space between the friction plates with a wide space is narrowed, and the space between the friction plates is automatically adjusted to be even. To. There is a relatively large space on the back side (the side of the snap ring 13) of the large-diameter friction plate 16e located at the farthest position from the piston 20, and a pressure different from the pressure between the friction plates acts. However, since the large-diameter friction plate 16e is fixed to the drum 12 in the axis A direction, the large-diameter friction plate 16e cannot be moved in the axial direction based on the pressure difference on both sides of the large-diameter friction plate 16e. Absent. As a result, when the piston 20 is moved to the non-fastened position, as shown in FIG. 11, the large-diameter friction plates 16a to 16e and the small-diameter friction plates 18a to 18d are arranged at substantially equal intervals in the movable range L. Then, the distance between the friction plates becomes an appropriate inter-plane distance S0.

FIG. 13 is an example of a graph obtained by simulation of the relationship between the inter-plane distance, the inter-plane pressure, and the drag torque generated by the inter-plane distance with respect to the rotation speed of the hub 14 in the friction fastening device 10 according to the embodiment of the present invention. In FIG. 13, the simulation result by the friction fastening device 10 of the present embodiment is shown by a solid line, and the simulation result by the conventional friction fastening device (FIG. 7) is shown by an imaginary line.

As shown in FIG. 13, in the friction fastening device 10 of the present embodiment, the distance between the friction plates is automatically adjusted to a substantially appropriate inter-plane distance S0. Therefore, unlike the conventional friction fastening device, the inter-plane distance does not become small in the region where the rotation speed is high, and the appropriate inter-plane distance S0 is maintained even in the region where the rotation speed is high. Further, in the region where the rotation speed is high, the ATF between the friction plates is discharged by the centrifugal force, so that the inter-plane pressure between the friction plates becomes a negative pressure. However, in the friction fastening device 10 of the present embodiment, since the negative pressure acts evenly between the friction plates, the distance between the friction plates is maintained evenly. As described above, in the friction fastening device 10 of the present embodiment, the drag torque is significantly increased even in the high rotation speed region because the distance between the friction plates is maintained at the appropriate interfacet distance S0 even in the high rotation speed region. It is possible to reduce the drag torque without doing so.

According to the friction fastening device 10 of the embodiment of the present invention, the position of the end large-diameter friction plate 16e is regulated to a predetermined position by the regulating member 32 (FIG. 2). Therefore, when the piston 20 is moved and the friction fastening device 10 is not fastened, the intervals between the friction plates are substantially equal due to the pressure of the lubricating oil flowing between the large-diameter friction plates and the small-diameter friction plates. Spreading (FIG. 11) and resistance due to dragging between friction plates can be reduced (FIG. 13).

Further, according to the friction fastening device 10 of the present embodiment, the drum 12 and the large-diameter friction plate are engaged with each other by the spline grooves 12a and the spline teeth 17 provided respectively (FIG. 3), so that the drum is surely engaged. It is possible to prevent the rotation of the large-diameter friction plate with respect to 12. Further, the position of the large-diameter friction plate 16e is restricted by engaging the regulating member 32 with the spline teeth 17a of the large-diameter friction plate 16e at the end (FIG. 2), and is adjacent to the large-diameter friction plate 16e at the end. The large-diameter friction plate 16d lacks spline teeth at positions corresponding to the regulating member 32, and is made into short spline teeth 17b (FIG. 3). Therefore, even if the position of the insertion opening 12d for inserting the regulating member 32 is displaced, the regulating member 32 interferes with the large-diameter friction plate adjacent to the end large-diameter friction plate 16e, and the large-diameter friction thereof. It is possible to prevent the movement of the plate from being hindered.

Further, according to the friction fastening device 10 of the present embodiment, the regulating member 32 is formed on the semicircular arc member 33 so as to project inward in the radial direction of the drum 12 (FIG. 4). It can be easily attached to the drum 12.

Further, according to the friction fastening device 10 of the present embodiment, since the ring-shaped member is formed by connecting the plurality of semicircular arc members 33 (FIG. 4), the ring-shaped member can be easily formed. .. Further, since the plurality of semicircular arc members 33 constituting the ring-shaped member are connected by fastening the ribs 33a extending in the axial direction of the drum 12 to each other with screws 33b, the drum 12 does not protrude significantly in the radial direction. , Each arc-shaped member can be connected.

Further, according to the friction fastening device 10 of the present embodiment, the large-diameter friction plate 16a arranged closest to the piston 20 is fixed to the piston 20 (FIG. 6), so that the friction fastening device 10 is not fastened. When the piston 20 is moved, the large-diameter friction plate 16a adjacent to the piston 20 is also moved. As a result, the friction plates spread quickly at approximately equal intervals, and the resistance due to dragging between the friction plates can be reduced at an early stage.

Further, according to the friction fastening device 10 of the present embodiment, the restricting member 32 is projected from the insertion opening 12d provided on the peripheral surface of the drum 12 to restrict the end large-diameter friction plate 16e to a predetermined position. Therefore, the friction fastening device 10 of the type in which the piston 20 and the cover member 22 are attached after the large-diameter friction plate and the small-diameter friction plate are arranged in the drum 12 can also be applied.

Further, the friction fastening device 10 of the present embodiment can be suitably applied to a clutch device capable of easily forming an insertion opening 12d in the drum 12 which is an outer power transmission member.

Although the preferred embodiment of the present invention has been described above, various modifications can be made to the above-described embodiment. In particular, in the above-described embodiment, the friction fastening device of the present invention has been applied to the clutch device, but the present invention can also be applied to the braking device. Further, in the above-described embodiment, the insertion opening is formed in the portion of the spline groove, but the insertion opening can be provided in the portion other than the spline groove.

Further, in the above-described embodiment, the large-diameter friction plate 16a on the piston side is fixed to the piston 20 by the connecting member 34, but the large-diameter friction plate is fixed to the piston by any other means such as welding. You can also do it. Further, in the above-described embodiment, five large-diameter friction plates and four small-diameter friction plates are provided, but the number of friction plates, the number of spline teeth, and the number of spline grooves can be appropriately changed. Further, the outer power transmission member and the large-diameter friction plate, and the inner power transmission member and the small-diameter friction plate can be engaged with each other by means other than the spline teeth and the spline groove.

1 Transmission 2 Housing 4 Output shaft 6 Transmission 8 Intermittent device 10 Friction fastening device 12 Drum (outer power transmission member)
12a Spline groove 12b Oil drain hole 12c Ring groove 12d Insertion opening 12e Spline groove 12f Notch 13 Snap ring 14 Hub (inner power transmission member)
14a Spline groove 14b Refueling hole 16a Large diameter friction plate (Piston side large diameter friction plate)
16b-16d Large-diameter friction plate 16e Large-diameter friction plate (large-diameter friction plate at the end)
17 Spline tooth 17a Spline tooth 17b Short spline tooth 17c Short spline tooth 18a-18d Small diameter friction plate 19 Spline tooth 20 Piston 20a Main body 20b Overhang 20c Cylindrical part 20d Pressing part 20e Partition part 22 Cover member 22a Convex part 24 Lubrication device 24a Oil introduction path 24b Oil return path 26 Spring 28 Seal member 30 Hydraulic chamber 32 Regulator member 33 Semi-arc member (arc-shaped member)
33a Rib 33b Screw 34 Connecting member 34a Ring part 34b Engaging part 34c Convex part

Claims (7)

A wet friction fastening device that switches between fastening and non-fastening between the outer power transmission member and the inner power transmission member.
The outer power transmission member formed in a tubular shape and
Inside the outer power transmission member, an inner power transmission member rotatably arranged with respect to the outer power transmission member,
Inside the outer power transmission member, the outer power transmission member is slidably arranged in the axial direction, and the outer peripheral edge engages with the inner peripheral surface of the outer power transmission member to engage with the outer peripheral surface of the outer power transmission member. With multiple large diameter friction plates that are blocked from rotating against
It is slidably arranged on the outer periphery of the inner power transmission member in the axial direction of the inner power transmission member, and the inner peripheral edge engages with the outer peripheral surface of the inner power transmission member with respect to the inner power transmission member. A small-diameter friction plate arranged between each of the plurality of large-diameter friction plates, which is prevented from rotating,
Inside the outer power transmission member, the outer power transmission member is movably arranged in the axial direction, and the large-diameter friction plate and the small-diameter friction plate are moved in the axial direction to move the outer power transmission member and the inner side. Has a piston that holds the power transmission member in a fastened state,
An insertion opening is provided on the peripheral surface of the outer power transmission member, and the regulating member is projected inside the outer power transmission member through the insertion opening, so that the end arranged at the position farthest from the piston. A friction fastening device characterized in that the large-diameter friction plate is engaged with the restricting member, and the large-diameter friction plate at the end is regulated at a predetermined position. The outer power transmission member and the large-diameter friction plate are configured to engage with a spline groove provided on the inner peripheral surface of the outer power transmission member by spline teeth provided on the outer periphery of the large-diameter friction plate. The restricting member is arranged so as to engage with the spline teeth provided on the end large-diameter friction plate, and the large-diameter friction plate arranged adjacent to the end large-diameter friction plate is described as described above. The friction fastening device according to claim 1, wherein the spline tooth at a position corresponding to the regulating member is missing. Further, it has a ring-shaped member attached so as to go around the outer circumference of the outer power transmission member, and the regulation member is formed on the ring-shaped member so as to project inward in the radial direction of the outer power transmission member. The friction fastening device according to claim 1 or 2. The ring-shaped member is formed by connecting a plurality of arc-shaped members, and ribs extending in the axial direction of the outer power transmission member are formed at both ends of each arc-shaped member, and these ribs are formed. The friction fastening device according to claim 3, wherein the arc-shaped members are connected to each other by fastening the outer power transmission members with screws directed in the circumferential direction. Among the plurality of large-diameter friction plates, the large-diameter friction plate arranged closest to the piston is fixed to the piston so as to move in the axial direction with the movement of the piston. The friction fastening device according to any one of 4 to 4. The invention according to any one of claims 1 to 5, wherein the piston is configured to be assembled in the outer power transmission member after the large-diameter friction plate and the small-diameter friction plate are arranged. Friction fastening device. The friction fastening device according to any one of claims 1 to 6, wherein the friction fastening device is used as a clutch device for transmitting rotational power between the outer power transmission member and the inner power transmission member.

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