JPH01210624A - Clutch drum structure of automatic transmission - Google Patents

Abstract

PURPOSE:To lessen the outer diameter of an automatic transmission by setting the plate thickness of a connection of a cylindrical body an a bottomed cylindrical body thinner than the plate thickness of a portion formed with a spline. CONSTITUTION:A cylindrical body 20 made of a simple cylindrical member is formed on the inner peripheral surface with a spline 36 and on the outer peripheral surface with a contact surface for a brake band 37. The plate thickness t of a connection 38 is set thinner than the plate thickness T of the portion formed with the spline 36 within a range of giving no damage to the strength. The cylindrical body 20 is secured fixedly to a bottomed cylindrical portion 19 with the inner peripheral surface of the connection 38 being attached closely to the outer peripheral surface of a large diameter cylindrical portion 32. Thus, the outer diameter dimension of the whole drum is lessened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to the structure of a drum of a clutch that is engaged and released in order to change the power transmission path and change the speed in a self-assisted speed change.

Conventional technology Another automatic transmission for general vehicles is between the input shaft connected to the torque converter and the output shaft connected to the propeller shaft. ! By providing several sets of planetary gear i-structures and changing the power transmission path through these planetary gear structures as appropriate using friction engagement means such as clutches and brakes operated by hydraulic pressure or one-way clutches, a predetermined transmission can be achieved. The vehicle is configured to be set to the following gears. This type of automatic transmission n must have a structure that is effective in reducing shift shock.
There are various demands such as small size and light weight and good assembling and manufacturability in order to have good in-vehicle compatibility, and various improvements have been made to meet these demands.

In other words, the general structure of a clutch for each automatic transmission is, as shown in FIG. A piston 5 is freely disposed between the hub 2 and the outer hub 2, and spline-fitted to the inner circumferential surface of the outer hub 2.
A fim plate 6 and a friction plate 8 spline-fitted to the outer peripheral surface of the inner hub 7 are provided in front of the piston 5, and the boss portion 1 is provided in front of the piston 5.
It has a configuration in which a return spring 9 is provided on the outer circumferential side.

However, if the pressure-receiving area of the piston 5 is too large, there is a risk that shift shock will worsen.In order to increase the transmitted torque with a small number of friction plates 6, on the other hand, it is preferable that the outer diameter of the friction plates 6 is large. In the clutch configuration of , piston 5 or I! Since the inner diameter of the outer peripheral hub 2 is determined by the outer diameter dimension of either one of the Jm plates 6, the outer diameter of the friction plate 6 is determined by the outer diameter of the piston 5, or vice versa. The diameter is restricted, and as a result, it is difficult to set the piston 5 and the friction plate 6 to optimal dimensions.

A configuration that can eliminate such inconveniences is described in Japanese Patent Laid-Open No. 61-38227. This is a double-structured cylindrical body by folding a cylindrical iu on the inner circumferential side at the middle part in the axial direction, and placing the folded part on the inner circumferential surface in a dense layer. A slit is formed along the axial direction in the folded part, and the outer circumferential edge of the friction plate is engaged with the protruding part, and the inner circumferential surface of the folded part of the cylindrical body is joined to the outer circumferential surface of the annular plate-shaped member. The drum was constructed by With this configuration, the drum has a so-called two-piece 4 structure, and the piston is housed inside the annular plate-shaped member, whereas the friction plate is attached to the inner circumferential side of the cylindrical body. The outer diameter dimensions of the friction plate and the friction plate are not mutually restricted, and therefore each can be set to the jisJ dimension.

Problems to be Solved by the Invention However, in the configuration described in the above-mentioned Japanese Unexamined Patent Publication No. 61-38227, the part where the friction plate is attached has a double circle HJfi.
Because of the structure, the plate thickness was excessive, which caused the problem that the outer diameter of the automatic transmission became correspondingly large.

This invention was made against the background of the above-mentioned situation.
The object of the present invention is to provide a VA construction of a clutch drum that can reduce the outer diameter of an automatic transmission.

Means for Solving the Problems In order to achieve the above object, this U-mechanism moves a piston forward by fluid pressure and transmits torque by pressing a friction plate with the piston to bring it into contact. A clutch for automatic transmission n includes a bottomed cylindrical body having a side wall extending in the inner circumferential direction at one end of the cylindrical part whose inner circumferential surface is a friction surface on which the piston slides, and a brake band whose outer circumferential surface is a cylindrical body. a cylindrical body having a contact surface and a spline for fitting the friction plate on the inner circumferential surface, and the cylindrical body is joined to the outer circumferential surface of the bottomed cylindrical body, and This is characterized in that the plate thickness of the joint portion that overlaps the bottomed cylindrical body is set to be thinner than the plate thickness of the portion where the spline is formed.

Function: In this drum of light, the friction plate is spline-fitted to the inner circumferential surface of the cylindrical body, the brake band is arranged on the outer circumferential side of the cylindrical body, and the piston for engaging the friction plate is attached to the bottomed cylinder. It is housed inside the body so that it can move forward and backward. At the joints between these cylindrical bodies and the bottomed cylindrical bodies, the plate thickness of the cylindrical body is thinner than the part where the spline is formed, so the outer diameter of the cylindrical body can be made smaller by the reduction in plate thickness. Therefore, the diameter of the drum as a whole is reduced, so that the outer diameter of the automatic transmission is reduced.

Example Next, embodiments of the invention will be described with reference to the drawings.

FIG. 1 shows a clutch 1 for connecting an input shaft 11 to a sun gear 13 of a planetary gear mechanism 12 in an automatic transmission t110.
4 is a sectional view showing an example to which the present invention is applied, in which the input shaft 11 is rotatably attached to a torque converter casing extension 16 fitted to the inner circumferential side of a housing 15 of a hydraulic pump (not shown). The clutch 14 is provided on the outer peripheral side of the boss portion of the hydraulic pump housing 15. That is, the clutch drum 17 rotatably attached to the outer periphery of the boss portion of the hydraulic pump housing 15 is
It is constructed by joining three members: a cylindrical member 18, a bottomed cylindrical body 19, and a cylindrical body 20, and the configuration of each member is as follows.

As shown in FIG. 2, the cylindrical member 18 has a boss portion 22 with a fitting hole 21 on the inner circumferential side, and a small diameter cylindrical portion 23 having a length of about half of the boss portion 22, at the rear end of each. (Right end in the figure.Hereinafter, the right side in the figure is referred to as the rear side or back side.
Turn the left side toward the face or front side. ), the side wall portion 2 is integrated with the side wall portion 24 formed in the
A groove 25 extending to the outer peripheral edge is formed in the radial direction on the back surface of the housing 4, and a diagonal hole 26 connecting the groove 25 to the inner peripheral surface of the fitting hole 21 is formed on the side wall portion 24 and the boss portion 22. It is formed through 1A. The outer circumferential surface of the small diameter cylindrical portion 23 is a sliding surface on which a piston 27 (described later) slides while maintaining a liquid-tight state, and an annular groove 29 into which a snap ring 28 is fitted is formed at its tip. A snap ring 28 fitted into the annular groove 29 holds the return spring 30 and fixes the tape 31 to the outer periphery of the small diameter cylindrical portion 23. Inside the circle with the above configuration 4
418 can be manufactured by cutting including machining of the oblique hole 26.

On the other hand, as shown in FIG. 2, the bottomed cylindrical body 19 is a member having a concave cross section by punching out the center, and has a rear end of a large diameter cylindrical part 32 having a larger diameter than the small diameter cylindrical part 23. A side wall portion 33 is integrally provided on the inner peripheral side of the large diameter cylindrical portion 3.
The inner circumferential surface of the piston 2 serves as a sliding surface on which the piston 27 slides while maintaining a liquid-tight state. Since the bottomed cylindrical body 19 having such a shape has a pure 111 shape, it can be manufactured by press working.

The cylindrical member 18 and the bottomed cylindrical body 19 are the cylindrical member 1
The front side of the side wall part 33 of the bottomed cylindrical body 19 is assembled and joined so that the front side of the side wall part 33 of the bottomed cylindrical body 19 faces and fits tightly against the back surface of the side wall part 24 of the cylinder body 8. Therefore, a groove 25 is formed on the back surface of the side wall portion 24 of the cylindrical member 18.
As a result, a gap is formed between each side wall portion 24 , 33 in the radial direction and extending to the outer circumference of the cylindrical member 18 , and this gap extends through the oblique hole 26 into the fitting hole 21 . There are 3/4 oil channels running offshore around the circumference. In addition, when joining each cylindrical part 018, 19, a side wall part 33 that is attached to the bottomed cylindrical body 19 is placed behind the boss part 22 of the cylindrical member 18.
An annular protrusion 35 protruding to a plate thickness of about They can be joined by welding. In addition, in the portions of the side walls 24.33 that face each other, that is, the portions corresponding to the oil passages 34, the oil pressure supplied to the oil passages 34 causes each side wall portion 24.
Since the cart acts in a direction that separates the side walls 24, 2, it is preferable to weld the mutually opposing portions of each side wall 24, 32 at a plurality of locations by spot welding, projection welding, or the like in order to maintain strength.

Further, the cylindrical body 20 is a simple cylindrical member with a spline 36 formed on its inner circumferential surface and whose outer circumferential surface is the contact surface of the brake band 37, and the spline 36 extends from the left end to the middle in FIG. The part formed in between and to the right of it is the so-called joint part 38, and the plate thickness t of this joint part 38 is set to be thinner than the plate thickness T of the part where the spline 36 is formed, as long as the strength is not impaired. has been done. The cylindrical body 20 has an overall shape of ill, and a spline 3.
6 is manufactured by cutting because it is preferable to have the minimum necessary depth and the outer circumferential surface is preferably an arcuate surface with no irregularities in order to wrap the brake band 37 around it. .

As shown in an enlarged view in FIG. 3, this cylindrical body 20 is attached to the bottomed cylindrical body 19 with the inner circumferential surface of the joint portion 38 in close contact with the outer circumferential surface of the large diameter cylindrical portion 32. It is fixed by means such as beam welding. Therefore, the outer diameter of the drum 17 as a whole is the dimensional difference (T
The diameter is reduced by -t).

Cylindrical member 18, bottomed cylinder 19, and cylinder 20
Of the drum 17 formed by welding and rotating as described above, a piston 27 is disposed between the inner peripheral surface of the large diameter cylindrical portion 32 and the outer peripheral surface of the small diameter cylindrical portion 23 so as to be movable back and forth. Te Jj
The oil passage 3/I opens on the back side of the piston 27. Further, the return spring 30 is in contact with a portion of the inner peripheral side of the front surface of the piston 27.

Furthermore, the outer circumferential portion on the tip side of the boss portion 22 is an inner race of a one-sided clutch 39, and a large number of sprags 40 held by a retainer are arranged on the outer circumferential surface of that portion. On the other hand, the outer race of the one-sided clutch 39 is formed by a cylindrical portion 41 integrally formed with the input shaft 11 so as to extend toward the outer circumferential side of the boss portion 22 .

Furthermore, a large number of rsta plates 42 are spline-fitted to the splines 36 of the cylindrical body 20, and other friction plates 43 arranged alternately with respect to these friction plates 42 are connected to the inner periphery of the cylindrical body 20. It is spline-fitted to the outer circumferential surface of the inner circumferential hub 4/4 disposed on the side.

These friction plates 42 and 43 are pressed by the piston 27 and brought into engagement. Further, the other end of a connecting drum 45 whose one end is connected to the sun gear 13 is spline-fitted to one end of the inner circumferential surface of the cylindrical body 20. Therefore, the connecting drum 45 connects the drum 17 and the sun gear. 13 are connected.

The inner peripheral hub 44 is connected to a clutch drum 47 of another clutch 46 disposed adjacent to the clutch 14, and the clutch drum 47 is connected to the cylindrical portion 41 of the input shaft 11. A piston 48 is housed in a narrow part formed by the clutch drum 47 and the cylindrical part 41 so as to be able to move back and forth, and one friction plate 49 pressed by the piston 48 is attached to the inner peripheral surface of the clutch drum 47. Other friction plates 50 are spline-fitted and alternately arranged with respect to this friction plate 49 , and are spline-fitted to the outer circumferential surface of an inner circumferential hub 51 disposed on the inner circumferential side of the clutch drum 47 . The inner peripheral hub 51 is spline-fitted to the outer periphery of the carrier shaft 52.

Note that the reference numeral 53 is a return spring.

In the clutch 14 described above, the piston 2
By supplying hydraulic pressure to the rear side of piston 27
moves forward and engages the friction plates 42 and 40 by pressing them into contact,
As a result, input shaft 11 and sun gear 13 are brought into contact.

The effect of illumination As is clear from the above explanation, the clutch of this excuse
According to II-Zukuri, of a cylindrical body whose outer circumferential surface is used as a brake band contact surface and a spline for fitting a friction plate is formed on the inner circumferential surface, the plate thickness of the part that joins to the outer circumferential surface of the bottomed cylinder is Since the plate thickness is set to be thinner than the part where the spline is formed, the outer diameter of the cylindrical body that defines the outer diameter of the clutch is reduced by the reduction in plate thickness at the joint, and the clutch is accordingly reduced in diameter. The built-in automatic transmission can be made more compact by reducing its outer diameter.

In other words, for a drum whose outer diameter is predefined, the outer diameter of the piston can be increased to ensure a sufficient pressure receiving area, and the outer diameter of the friction plate spline-fitted to the inner circumferential surface can be increased. Therefore, according to Komei's clutch drum, it is possible to increase the transmission torque capacity by increasing the diameter of the IIJ friction plate, and reduce the number of plates required to reduce weight and heat capacity. You can get effects such as:

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of this embodiment of Kitaaki, Fig. 2 is an exploded sectional view of the drum of the clutch, and Fig. 3 is a sectional view of the bottomed cylindrical body and the cylindrical body. FIG. 4 is a partially enlarged cross-sectional view of the joint portion, and is a schematic cross-sectional view of a conventional clutch for automatic transmission 1. 10... Automatic transmission, 14... Clutch, 17
... Drum, 18... Cylindrical member, 19... Bottomed cylindrical body, 20... Cylindrical body, 27... Piston, 32... Large diameter cylindrical part, 36... Spline,
37...Brake band, 38...Joint part,
42...11th board.

Claims (1)

[Scope of Claims] In a clutch for an automatic transmission in which a piston is moved forward by fluid pressure and torque is transmitted by pressing and contacting a friction plate with the piston, the piston slides on an inner circumferential surface. A bottomed cylindrical body is formed with a side wall portion extending in the inner circumferential direction at one end of the cylindrical portion that serves as a moving sliding surface, and the outer circumferential surface serves as a brake band contact surface, and the friction plate is fitted onto the inner circumferential surface. a cylindrical body formed with a spline, the cylindrical body is joined to the outer circumferential surface of the bottomed cylindrical body, and the plate thickness of the joined part of the cylindrical body to the bottomed cylindrical body is the part where the spline is formed. A clutch drum structure for an automatic transmission characterized by being thinner than the plate thickness of the clutch drum.