JP2007239913A - Clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clutch preventing partial wear of a clutch plate. <P>SOLUTION: The clutch is provided with the clutch plate 5d comprised of a plurality of driven plates 5a and a plurality of drive plates 5b, and a retaining plate 20 supported by a snap ring 21 secured to an inner circumference face of a clutch drum and regulating displacement of the clutch plate axially displaced by pressing of a piston 9. It is characterized by that the retaining plate is formed perpendicular to an axis of the clutch drum, the retaining plate is comprised of an annular support part 20a supported by the snap ring, and a contact part 20b connected to an inner side of the support part, contacting the clutch plate, and provided with a U-shaped cross section shape, and the contact part contacts the clutch plate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a clutch, and more particularly to a clutch used in an automatic transmission.

  As a conventional clutch, there is a structure including a clutch drum, a pair of friction plates, a piston, and the like (see Patent Document 1). The clutch drum includes a spline portion having a spline formed on an inner peripheral surface thereof, an outer peripheral wall portion, and a vertical wall portion extending radially inward from the outer peripheral wall portion.

  A clutch hub having a spline facing the spline portion is arranged inside the clutch drum, and a plurality of pairs of friction plates that respectively engage with the spline portion and the spline are provided alternately in the axial direction. The pair of friction plates includes a metal plate and a friction plate in which a friction material is bonded to a surface facing the metal plate, and the metal plate engages with a spline portion of the clutch drum. A ring-shaped cylinder is formed in the outer peripheral wall portion of the clutch drum, and the inner peripheral surface of the outer peripheral wall portion is a sliding surface of the piston.

  The piston is provided with a seal ring on each of the outer peripheral surface and the inner peripheral surface, and has a pressing portion extending toward the pair of friction plates. A return spring is provided between the rotary shaft and a spring holder positioned by a snap ring, and the pressing portion is biased in a direction away from the friction plate.

  An oil passage is formed in the rotating shaft, and the piston presses the pair of friction plates by supplying pressure oil to the cylinder.

The end surface opposite to the end surface of the pair of friction plates pressed by the piston is applied to a retaining plate that engages with the spline portion of the clutch drum, and the retaining plate is fitted into a recess formed in the spline portion. The snap ring defines the axial position of the rotating shaft.
Japanese Utility Model Publication No. 05-033244

  The outer peripheral side of the retaining plate is supported by a snap ring, and deformation due to the pressing of the piston is suppressed. However, since the inner peripheral side is not supported by the snap ring, the rigidity against the pressing force is lower than that of the outer peripheral side, and displacement occurs in the pressing direction. For this reason, the surface pressure distribution of the retaining plate and the friction plate in contact with the retaining plate is higher on the outer peripheral side than on the inner peripheral side, and the friction material bonded to the friction plate promotes wear on the outer peripheral side. In other words, so-called uneven wear occurs.

  The present invention has been made in view of these facts, and an object of the present invention is to provide a clutch that suppresses deformation of the inner peripheral side of the retaining plate and prevents uneven wear of the friction material.

  The present invention includes a cylindrical clutch drum, a clutch hub arranged coaxially with the clutch drum, and a plurality of juxtaposed on the inner peripheral surface of the clutch drum so as to be movable in the axial direction of the central axis of the clutch drum A clutch plate comprising: a drive plate; and a plurality of driven plates interposed between the drive plates so as to be frictionally engageable and movably engaged with the clutch hub in an axial direction; and the driven plate and the drive Displacement of the clutch plate that is supported by a piston that presses from one direction so as to frictionally engage the plates and a snap ring that is locked to the inner peripheral surface of the clutch drum, and that is displaced in the axial direction by the pressing of the piston A retaining plate that regulates the center of the clutch drum. An annular support portion that is formed at a right angle with respect to the snap ring, and a contact portion that is connected to the inner peripheral side of the support portion and that contacts the clutch plate. A cylindrical first flange portion extending from the inner peripheral end of the support portion to the snap ring side coaxially with the central axis, and from the snap ring side end of the first flange portion to the central axis And a cylindrical second flange portion extending from the inner peripheral side end portion of the wall portion to the clutch plate side coaxially with the central axis. The release end of the second flange portion contacts the clutch plate, and the position where the clutch plate contacts the retaining plate and the position where the piston presses the clutch plate are opposed to each other in the axial direction. A clutch, characterized in Rukoto.

  In the present invention, since the contact portion of the retaining plate with which the clutch plate contacts is a U-shaped cross section composed of the first flange portion, the wall portion and the second flange portion, while maintaining the rigidity of the retaining plate, The contact position of the retaining plate and the clutch plate can be set to a position opposite to the position where the piston presses the clutch plate, the pressure distribution of the friction material can be made uniform, and uneven wear of the friction material can be prevented. .

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

  FIG. 1 is a partial schematic view of an automatic transmission to which a clutch of the present invention is applied.

  This automatic transmission includes an input shaft 1 to which engine power is transmitted, a fixed pulley 2 of a primary pulley of a V-belt transmission mechanism that shifts the rotational speed of the input shaft 1 and transmits power to an output shaft (not shown), And a forward / reverse switching mechanism 3 that is installed between the input shaft 1 and the fixed pulley 2 and that controls the rotational direction of the power transmitted from the input shaft 1 to the fixed pulley 2. In this embodiment, the V-belt type continuously variable transmission mechanism will be described as the transmission mechanism, but the present invention is not limited to this.

  The forward / reverse switching mechanism 3 includes a set of planetary gear mechanisms 4 and two clutches (forward clutch 5 and reverse clutch 6).

  More specifically, the planetary gear mechanism 4 is a so-called double pinion type planetary gear mechanism, in which a first pinion 4p1 and a second pinion (not shown) are engaged with each other via a first pinion shaft 4ps1 and a second pinion shaft (not shown). The carrier 4c is connected to the inner peripheral surface of the cylindrical outer wall 7a of the forward clutch drum 7 formed coaxially with the input shaft 1 by spline coupling. The inner wall 7 b of the forward clutch drum 7 is also formed in a cylindrical shape coaxially with the input shaft 1, and the inner wall 7 b is splined to the outer peripheral surface of the input shaft 1.

  Further, a drive plate 5b, in which a driven plate 5a of the forward clutch 5 is connected to the inner peripheral surface of the outer wall 7a of the forward clutch drum 7 by spline coupling, and a friction material 5c (see FIG. 2) is bonded to both surfaces is a planetary gear. The forward clutch hub 15 connected to the sun gear 4s of the mechanism 4 is fixed. Here, the driven plate 5a and the drive plate 5b are configured in a stacked manner in a direction parallel to the axial direction of the input shaft 1, that is, the forward clutch 5 is configured as a multi-plate clutch, and the driven plate 5a and the drive plate 5b are stacked. This is referred to as a clutch plate 5d (see FIG. 2). The one end surface of the clutch plate 5d comes into contact with a hollow disk-like retaining plate 20 supported by a snap ring 21 provided on the inner peripheral surface of the outer wall 7a of the forward clutch drum 7, and the position thereof is defined. The The other end surface is pressed toward one end surface by a piston 9 described later.

  The sun gear 4s meshes with the first pinion 4p1 and is fixed to the fixed pulley 2 to rotate the fixed pulley 2. Further, a bearing 16 is installed between the forward clutch hub 15 and the carrier 4c, and the carrier 4c is positioned in the axial direction, and relative rotation between the forward clutch hub 15 and the carrier 4c is allowed.

  A ring gear 4 r that meshes with a second pinion (not shown) of the planetary gear mechanism 4 is fixed to a case 8 of the automatic transmission via a reverse clutch 6. Similar to the forward clutch 5, the reverse clutch 6 is also configured as a multi-plate clutch.

  A side wall 7c that connects the outer wall 7a and the end of the inner wall 7b of the forward clutch drum 7 is formed. The forward clutch drum 7 defined by these walls is provided with a piston 9 that presses the forward clutch 5 in a direction parallel to the axial direction. Is done. The piston 9 is moved along the inner peripheral surface of the outer wall 7a in the axial direction by the oil pressure of the oil chamber 10 formed between the side wall 7c of the forward clutch drum 7, and the other end surface of the forward clutch 5 is moved to one end surface side. The friction force is generated between the driven plate 5a and the drive plate 5b, and the engine power transmitted to the input shaft 1 is transmitted to the sun gear 4s. Hydraulic oil is supplied to the oil chamber 10 from an oil passage 1 a formed in the input shaft 1.

  A hub 11 fixed to the forward clutch drum 7 is installed, and a spring 12 that presses the piston 9 in the axial direction is installed between the hub 11 and the piston 9. Since such a spring 12 is provided, when the forward clutch 5 is not engaged, the hydraulic oil is not supplied to the oil chamber 10, the hydraulic pressure in the oil chamber 10 is reduced, and the pressing force of the spring 12 is changed to the hydraulic pressure in the oil chamber 10. , The piston 9 moves in a direction away from the forward clutch 5, and the engagement of the forward clutch 5 is interrupted.

  A piston 13 for pressing the reverse clutch 6 and generating a frictional force between the driven plate 6 a and the drive plate 6 b of the reverse clutch 6 is installed in the case 8, and an oil chamber (not shown) between the case 8 and the piston 13 is installed. When the hydraulic oil is supplied, the piston 13 presses the reverse clutch 6 to bring the reverse clutch 6 into an engaged state. A spring that disengages the reverse clutch 6 is not shown. Further, a bearing 17 is installed between the ring gear 4r and the carrier 4c, and the carrier 4c is positioned in the axial direction, and relative rotation between the ring gear 4r and the carrier 4c is allowed.

  In the forward / reverse switching mechanism 3 configured as described above, when the forward clutch 5 is engaged and the reverse clutch 6 is not engaged, the rotation of the input shaft 1 is transmitted from the forward clutch drum 7 to the forward clutch 5 and forward clutch 5. This is transmitted to the sun gear 4 s through the clutch hub 15, and the sun gear 4 s rotates the fixed pulley 2. That is, the rotation of the input shaft 1 and the rotation of the fixed pulley 2 rotate in the same direction.

  On the other hand, when the reverse clutch 6 is engaged and the forward clutch 5 is not engaged, the rotation of the input shaft 1 is transmitted from the forward clutch drum 7 to the sun gear 4s from the carrier 4r, the first and second pinions, The sun gear 4 s rotates in the direction opposite to the rotation direction of the input shaft 1, and the sun gear 4 s rotates the fixed pulley 2. That is, in this case, the rotation of the input shaft 1 and the rotation of the fixed pulley 2 rotate in opposite directions.

  Next, the detailed configuration of the retaining plate, which is the point of the present invention, will be described with reference to FIG. FIG. 2 is a diagram in which the configuration of the retaining plate of the present invention is applied to the forward clutch 5. The present invention is characterized in that the cross-sectional shape on the inner peripheral side of the retaining plate 20 is a U-shaped cross section. This will be specifically described below.

  The retaining plate 20 is formed in an annular shape, and the cross-sectional shape thereof is formed on a ring-shaped support portion 20a supported by the snap ring 21 and the inner peripheral side thereof, and is in contact with the driven plate 5a in the axial direction so that the piston 9 is roughly divided into a contact portion 20b that regulates the displacement of the driven plate 5a in the axial direction due to the pressure of the pressure 9.

  The contact portion 20b is connected to the inner peripheral side end portion of the support portion 20a, and is connected to the cylindrical first flange portion 20c extending in the axial direction away from the driven plate 5a and the end portion of the first flange portion 20c. A wall portion 20d extending in a ring shape on the inner peripheral side, and a cylindrical second flange portion 20e connected to the wall portion 20d and extending toward and in contact with the driven plate 5a. The contact portion 20b is formed in a U-shaped cross section that opens to the driven plate 5a side. The first flange portion 20 c extends to the position where the axial position thereof is substantially the same as the end surface 21 a of the snap ring 21, that is, the thickness of the snap ring 21. Further, the tip portion 20 f of the contact portion 20 b that contacts the driven plate 5 a when viewed from the axial direction is set at a position overlapping the piston 9.

  Thus, by making the cross-sectional shape of the contact portion 20b a U-shaped cross-section, the center where the retaining plate 20 contacts the driven plate 5a is opposed to the pressing position of the piston 9 while ensuring the rigidity of the contact portion 20b. It can be set close to each other, the surface pressure distribution of the friction material can be made uniform, and uneven wear can be suppressed.

  Further, the front end portion 20f of the contact portion 20b is formed in an arcuate convex shape, while the driven plate 5a with which the front end portion 20f comes into contact has a planar shape, preferably an arcuate concave groove, 20f contacts. By setting it as such a shape, the area where the front-end | tip part 20f contacts the driven plate 5a can be expanded, and the abrasion loss of the drive plate 5b can be reduced.

  Further, the retaining plate 20 of the present invention can be manufactured by press-molding a flat steel plate, and can be mass-produced at a low cost.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

It is a partial block diagram of the automatic transmission of this invention. It is a figure explaining the detailed structure of a forward clutch. It is a figure explaining the structure of the conventional clutch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Fixed pulley 3 Forward / reverse switching mechanism 4 Planetary gear mechanism 4s Sun gear 4r Ring gear 4c Carrier 4ps Pinion shaft 4p1 First pinion gear 4p2 Second pinion gear 5 Forward clutch 5a Driven plate 5b Drive plate 5c Friction material 5d Clutch plate 6 Reverse clutch 6a Driven plate 6b Drive plate 7 Forward clutch drum 8 Case 15 Forward clutch hub 20 Retaining plate 20a Support portion 20b Contact portion 20c First flange portion 20d Wall portion 20e Second flange portion 20f Tip portion 21 Snap ring

Claims (2)

A cylindrical clutch drum;
A clutch hub disposed coaxially with the clutch drum;
A plurality of drive plates arranged in parallel on the inner peripheral surface of the clutch drum so as to be movable in the axial direction of the central axis of the clutch drum, and inserted between the drive plates so as to be frictionally engageable with each other. A clutch plate composed of a plurality of driven plates that are movably engaged in the axial direction,
A piston that presses from one direction to frictionally engage the driven plate and the drive plate;
A retaining plate that is supported by a snap ring that is locked to an inner peripheral surface of the clutch drum, and that restrains displacement of the clutch plate that is displaced in the axial direction by pressing of the piston;
The retaining plate is formed at a right angle to the central axis of the clutch drum, is connected to the annular support portion supported by the snap ring, and the inner peripheral side of the support portion, and contacts the clutch plate Consisting of contact parts,
The contact portion includes a cylindrical first flange portion extending from the end portion on the inner peripheral side of the support portion to the snap ring side coaxially with the central axis, and the snap ring side end of the first flange portion. A wall portion extending from the portion to the inner peripheral side in a direction perpendicular to the central axis, and a cylindrical second member extending from the inner peripheral end of the wall portion to the clutch plate side coaxially with the central axis A release portion of the second flange portion is in contact with the clutch plate,
The clutch, wherein a position where the clutch plate contacts the retaining plate and a position where the piston presses the clutch plate are opposed to each other in the axial direction.   The release end portion of the second flange portion is formed in an arcuate convex shape, and a portion of the clutch plate that contacts the release end portion is formed with an arcuate groove. The clutch according to 1.