JP2000257648A - Clutch drum structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a sufficient allowance for a snap ring and a thick part between a base wall of a snap ring groove and outer surface. SOLUTION: A spline tooth 2 is formed on an inside diameter surface of a clutch drum 1 and a snap ring groove 13 is radially formed on the spline tooth surface. A thick part 10 smaller than the snap ring groove width is made to project so that the thick part can oppose to a corner part 16 in the side of a side wall 13a with which a snap ring 4 comes in contact in the snap ring groove 13 and extend from a shelf-shaped part 11 a formed on a back side of the side wall 13a to an outer surface 11c in an opening end 11a side of the clutch drum 1. The thick part 10 opposes to the corner part 16 in the snap ring groove 13 and extends from the outer surface 11c in the opening end 11a in a cross end of a spline groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch drum used for an automatic transmission of an automobile.

[0002]

2. Description of the Related Art A clutch drum of this type is combined with a clutch hub having spline teeth formed on an inner peripheral surface thereof and spline teeth formed on an outer peripheral surface thereof. Are alternately engaged with the two spline teeth so as to be movable in the axial direction, and the plurality of clutch plates connect the snap ring to the clutch drum with the retaining plate interposed at the open end side of the clutch drum. By fitting into the snap ring groove formed on the inner peripheral side, the retaining is performed, and the other side is pressed by a hydraulically controlled piston,
The clutch plate and the friction plate are engaged so that the clutch hub and the clutch drum rotate integrally.

The conventional clutch drum is shown in FIG.
To FIG. 16 are known.

FIG. 13 is a cross-sectional view of a main part of a clutch drum showing an example of the prior art. Snap ring groove 3 by punching
Is provided. The snap ring groove 3 is formed between the side wall 3a and the bottom wall 3 of the open end 1a of the clutch drum 1.
b intersects at a substantially right angle to form a corner portion 6,
The side wall 3a is a contact surface of the snap ring 4.

FIGS. 14 to 16 show another example of a conventional clutch drum. FIG. 14 is a perspective view showing the clutch drum around the snap ring groove from the outside.
FIG. 15 is a perspective view similarly drawn from the inside, and FIG.
It is DD sectional drawing in 5.

In this example, the point that a snap ring groove 3 is provided from the inner side to the outer side in the radial direction on the surface of the spline teeth provided on the inner peripheral surface of the cylindrical portion of the clutch drum 1 is the same as the prior art. However, the entire width of the tip corner of the snap ring contact surface 3a of the snap ring groove 3 is formed in the chamfered portion 3c, and the bottom wall 3 of the snap ring groove is formed.
The fillet 3d covering the entire width of the shelf 3e formed on the back side of the snap ring contact surface 3a is formed by press molding in opposition to the corner 6 in b.

[0007]

In the conventional clutch drum 1 shown in FIG. 13, a corner portion 6 is formed such that a side wall portion 3a and a bottom wall portion 3b of an opening end 1a cross at a substantially right angle. By forming the snap ring groove 3, it is intended that the snap allowance S 1 of the snap ring 4 is widened.

On the other hand, the width S1 of the snap ring 4 is widened, so that the thickness T1 between the corner 6 of the snap ring groove 3 and the outer peripheral wall 1c is large.
Becomes thin, and becomes a starting point at which this part is first broken or cracked in a durability test or the like.

On the other hand, in the conventional clutch drum 1 shown in FIGS. 14 to 16, the entire width of the tip corner of the snap ring contact surface 3a is formed in the chamfered portion 3c, and the snap ring contact surface is formed. As a result of applying the fillet 3d covering the entire width of the shelf 3e formed on the back side of the back 3a, the thickness of the bottom wall 3b and the outer peripheral wall 11c of the snap ring groove 3 is larger than that of the above-described conventional example. T2 became thicker, and it was possible to solve the point where this portion was broken or cracked in a durability test or the like, but on the other hand, the snap ring 4 was caught by the snap ring S2.
Becomes narrower. For this reason, the snap ring is likely to come off, or the snap ring falls down, and the engagement between the clutch plate and the friction becomes uneven, which is related to the performance of the clutch and the durability of the friction plate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a clutch drum structure intended to secure a sufficient margin for a snap ring to be caught and to secure a sufficient thickness between a bottom wall portion and an outer peripheral wall of a snap ring groove. And

[0011]

In order to achieve the above object, a clutch drum structure according to the present invention has spline teeth formed on an inner peripheral surface of a cylindrical portion of a clutch drum, and is formed on a surface of the spline teeth from a radially inner side. A snap ring groove is formed outwardly, and the clutch drum is opposed to a snap ring contact surface side corner portion of the snap ring groove from above a shelf-like portion surface formed on the back side of the snap ring contact surface. A thick part smaller than the groove width of the snap ring groove is formed so as to protrude so as to extend toward the outer peripheral wall on the opening end side.

With the above structure, the thick portion forms a beam structure extending between the side wall of the clutch drum opening end in the snap ring groove and the shelf portion formed on the back side of the snap ring contact surface. The rigidity of the intersection of the clutch drum opening end side wall and the bottom wall in the groove can be increased.

Further, since the thick portion is provided on a part of the side wall of the clutch drum opening end and protrudes toward the outer peripheral wall of the clutch drum, the margin of the snap ring in the spline groove is sacrificed. Without having to do it.

[0014]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a general clutch drum. The clutch drum 1 has a cylindrical shape with a bottom, and is used in combination with a clutch hub (not shown) disposed inside. Spline teeth 2 are formed on the inner peripheral surface of the clutch drum 1 and spline teeth are also formed on the outer peripheral surface of the clutch hub. A plurality of clutch plates and friction plates (not shown) are alternately provided between the two. Each is provided so as to be movable in the axial direction by engaging with the spline teeth 2 of the clutch drum 1 and the spline teeth of the clutch hub.

A plurality of clutch plates engaged with the clutch drum 1 have snap rings (both not shown) fitted in snap ring grooves 3 with a retaining plate interposed at the open end side of the clutch drum 1. When the opposite side is pressed by a hydraulically controlled piston (not shown), the clutch plate and the friction plate are engaged, and the clutch hub and the clutch drum rotate integrally. It has become.

FIGS. 2 to 4 show a first embodiment of the present invention. FIG. 2 is a sectional view taken along the line A--A in FIG. 1, FIG. FIG.

2 to 4, a clutch drum 1 is shown.
On the side of the open end 11a, a snap ring groove 13 is formed on the surface of the spline teeth 2 from the inside in the radial direction to the outside by half punching using a punch and a die described later.

The snap ring groove 13 has a side wall 13a on the opening end 11a side of the clutch drum 1 and a side wall 13a.
a bottom wall 13b, one end of which crosses at a substantially right angle with respect to a;
The clutch drum 1 is continuously connected to the other end of the bottom wall 13b.
And a side wall portion 13c extending while being inclined inward in the radial direction.

The side wall 13a forms a snap ring contact portion, and together with the bottom wall 13b, the corner 1
6 are formed.

Since the snap ring groove 13 is formed by press working or the like, a convex portion 11b is formed on the outer peripheral side of the clutch drum 1 so as to face the snap ring groove 13.

On the outer peripheral wall of the clutch drum 1, a substantially triangular thick portion 10 intermittently protruding from the ledge 11b of the convex portion 1b press-cuts the snap ring groove 13 by a punch and a die which will be described later. The thick portion 10 is formed by material flow when formed, and the thick portion 10 opposes substantially the center of the corner portion 16 of the side wall portion 13a in the spline groove 13 and has a shelf-like portion 11b formed on the back side of the side wall portion 13a.
Outer peripheral wall 1 of the opening end 11a of the clutch drum 1 from above
1c, and is formed to be smaller than the groove width of the snap ring groove 13.

As a result, even if the thick portion 10 located substantially at the center of the side wall portion 13a exists on the outer peripheral side of the clutch drum 1, the snap ring 4 in the snap ring groove 13 is formed.
And the corner portion 16 of the snap ring groove 13 and the clutch drum 1
The thickness T between the outer peripheral wall 11c and the outer peripheral wall 11c is increased to prevent breakage or cracking starting from this portion in a durability test or the like.

As a result, in the present embodiment, the side wall 13
The protrusion 12 is formed so as not to protrude to the inner peripheral side of the clutch drum 1 at a part of the inner peripheral end corner portion of a.
The snap margin 4 of the snap ring 4 can be made sufficiently wide.

Reference numeral 5 denotes a retaining plate interposed between the snap ring 4 and the clutch plate.

Next, a press die for forming the snap ring groove 3 on the clutch drum 1 on which the spline teeth 2 are formed will be described with reference to FIGS.

FIGS. 5A and 5B are partial cross-sectional views of a mold for forming the snap ring groove 3. FIG.
Fig. 6 (1) is a partial perspective view depicting the molding surface of the upper mold, and Fig. 6 (2) is a partial perspective view depicting the molding surface of the lower mold.

The above-mentioned mold is composed of an upper mold 21 and a lower mold 22.
The upper die 21 has a snap ring groove 3
Is formed, and a slit punch 24 for forming the snap ring groove 3 is integrally provided so as to protrude from the molding surface 23a of the pad 23.

The lower die 22 is provided with a slit die 25 and an insert die 26 integrally formed with each other. A concave portion 25b corresponding to the slit punch 24 is formed on a molding surface 25a of the slit die 25. Is formed.

In this structure, when the snap ring groove 3 is formed on the inner peripheral surface of the clutch drum 1 so as to cross the spline teeth 2, the semi-finished product is opened in the mold open state shown in FIG. The clutch drum 1a is positioned and set on the slit die 25 and the insert die 26 of the lower die 22, and then the upper die 21 is lowered, and FIG.
The mold is clamped as shown in (2). At this time, the slit punch 24 descends while entering the recess 25b of the slit die 25 until the pad 23 and the slit die 25 clamp the clutch drum 1, and the snap ring groove 3 is formed by half-pressing. Will be.

The insert die 26 has a recess 2
A notch 26a opening to 5b is formed. As a result, in the process of forming the snap ring groove 13, the material flows and enters the recess 25 b, and the thick portion 10 is formed.

In the above-mentioned mold, the slit punch 24 is formed integrally with the molding surface 23a of the pad 23 so as to project therefrom. However, the present invention is not limited to this. The slit punch 24 is provided so as not to protrude with respect to the surface 23a and slidably with respect to the pad 23. When the snap ring groove 3 is formed, the slit punch 24 is
The snap ring groove 3 may be formed by sliding in two directions.

FIGS. 7 to 9 show a second embodiment of the present invention. FIG. 7 is a perspective view showing the clutch drum around the snap ring groove from the outside, and FIG. FIG. 9 and FIG. 9 are BB sectional views in FIG.

In the second embodiment, compared to the first embodiment, a pair of thick portions 10 are formed on both sides of the corner 16 between the side wall 13a and the bottom wall 13b. However, since the other configurations are the same, the same reference numerals are given to the drawings and detailed description is omitted.

10 to 12 show a third embodiment of the present invention. FIG. 10 is a perspective view showing a clutch drum around a snap ring groove from the outside.
FIG. 11 is a perspective view similarly drawn from the inside, and FIG.
It is CC sectional drawing in 0.

In the third embodiment, as compared with the first embodiment, the thick portion 10 has one end facing the corner 16 of the spline groove 13 and the other end facing the clutch drum 1. Are different in that they are formed by a bead shape having a U-shaped cross section which is formed to protrude so as to extend to the outer peripheral wall of the open end 11a of FIG. Omit the explanation.

[0037]

As described above, in the clutch drum structure according to the present invention, the spline teeth are formed on the inner peripheral surface of the cylindrical portion of the clutch drum, and the snap ring grooves are formed on the surface of the spline teeth from the inner side to the outer side in the radial direction. And facing the snap ring abutment surface side corner portion in the snap ring groove, from the shelf-like surface formed on the back side of the snap ring abutment surface toward the opening end side outer peripheral wall of the clutch drum. In order to extend, a thick part smaller than the groove width of the snap ring groove is formed so as to protrude, so that the thick part allows the clutch drum opening end side wall part in the snap ring groove to be formed. A beam structure is formed extending between the snap ring contact surface and the shelf-shaped portion formed on the back side, and the clutch drum opening end side wall and the bottom in the snap ring groove are formed. Can parts and increases the rigidity of the corner portions intersecting, do not become a starting point or cause cracking or fracture of the sites in the durability test and the like.

Further, since the thick portion is provided on a part of the side wall of the clutch drum opening end, and protrudes toward the outer peripheral wall of the clutch drum, the snap ring is caught by the spline groove at the cost of catching. Without having to do it.

[Brief description of the drawings]

FIG. 1 is a perspective view of a general clutch drum.

FIG. 2 is a sectional view taken along the line AA in FIG. 1 showing the first embodiment of the present invention.

FIG. 3 is a perspective view of FIG.

FIG. 4 is a perspective view of FIG.

FIGS. 5A and 5B are partial longitudinal sectional views of a mold for forming a snap ring groove according to the present invention, wherein FIG. 5A shows a mold opened, and FIG. 5B shows a mold closed.

FIG. 6 (1) is a partial perspective view illustrating a molding surface of an upper mold in FIG. 5, and FIG. 6 (2) is a partial perspective view similarly depicting a molding surface of a lower mold.

FIG. 7 shows a second embodiment of the present invention and is a perspective view in which a clutch drum around a snap ring groove is drawn from the outside.

FIG. 8 is a perspective view similarly drawn from the inside.

FIG. 9 is a sectional view taken along line BB in FIG. 7;

FIG. 10 shows a third embodiment of the present invention, and is a perspective view in which a clutch drum around a snap ring groove is drawn from the outside.

FIG. 11 is a perspective view similarly drawn from the inside.

12 is a sectional view taken along the line CC in FIG.

FIG. 13A shows one example of a conventional clutch drum.
It is -A sectional drawing.

FIG. 14 is a perspective view showing another example of a conventional latch drum, in which a clutch drum around a snap ring groove is drawn from the outside.

FIG. 15 is a perspective view of the clutch drum around the snap ring groove drawn from the inside.

16 is a sectional view taken along line DD of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Clutch drum 2 Spline tooth 10 Thick part 11a Open end 11b Shelf-shaped part 11c Outer peripheral wall 12 Projection 13 Snap ring groove 13a Side wall part 13b Bottom wall part 16 Corner part

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsumasa Yabutani 19-1 Gomijima, Fuji-shi, Shizuoka Prefecture F-term in Unipres Co., Ltd. (reference) 3J056 AA60 BA03 BC01 CB05 GA05 GA12

Claims (4)

[Claims] 1. A spline tooth is formed on an inner peripheral surface of a cylindrical portion of a clutch drum, and a snap ring groove is formed on a surface of the spline tooth from an inner side to an outer side in a radial direction, and a snap ring abuts on the snap ring groove. The snap ring groove is formed so as to extend toward the outer peripheral wall on the opening end side of the clutch drum from the surface of the shelf portion formed on the back side of the snap ring contact surface, facing the surface side corner portion. A clutch drum structure characterized in that a thick portion smaller than the groove width is formed so as to protrude. 2. The clutch according to claim 1, wherein the thick portion is formed so as to face substantially the center in the width direction of the spline groove and to extend to an outer peripheral wall on an opening end side. Drum structure. 3. The spline groove is formed so as to face a corner portion of the spline groove on the snap ring contact surface side and protrude from an outer peripheral wall of an opening end of a width direction end of the spline groove. Item 2. The clutch drum structure according to Item 1. 4. The thick portion opposes a corner portion on the snap ring contact surface side of the spline groove, and from a shelf upper surface formed on the back side of the snap ring contact surface to an opening end of the clutch drum. 2. The clutch drum structure according to claim 1, wherein the clutch drum structure is formed by a bead which is formed so as to rise and protrude from an outer peripheral wall toward the clutch drum.