JP3517963B2 - Forming method of cylindrical member - Google Patents

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a molding side of the cylindrical member to be molded by spinning has protrusions on an inner peripheral surface thereof
It relates to the law. 2. Description of the Related Art In recent years, there has been a tendency to frequently use a forming method by spinning as one of forming methods of a cylindrical member, particularly a cylindrical member having a spline on an inner peripheral surface of a clutch drum or the like of an automatic transmission. (See, for example, Japanese Patent Application Laid-Open
Reference). When a clutch drum provided with splines on its inner peripheral surface is formed by spinning , as shown in FIG. 6, the entire outer peripheral surface is formed into a spline-shaped molding surface 63 with a cored bar 61. A molding device having a roller 66 and a molding die 65 is used. First, a sheet metal material 50 having a predetermined thickness and a predetermined diameter is attached to the core metal 61.
Of the core metal 61 while rotating the molding roller 66 at a predetermined speed and moving the material 50 in the axial direction while rotating the molding roller 66 at a predetermined speed. Rolling is performed while being pressed against the spline-shaped forming surface 63 by cold plastic working using the cored bar 61 and the forming roller 66, thereby obtaining a formed product 51 as shown by a chain line in FIG. Molded product 51 obtained by such spinning process
Is a bottomed cylindrical body having a bottom wall portion 52 and a peripheral wall portion 53, as shown in FIG. 7, and has splines 54, 54,・ ・ Is formed. However, the axial length dimension of the molded article 51, scan
Due to the rolling action of the material 50 at the time of pinning, it is extremely difficult to accurately secure the axial length (L0) required as a product only by spinning .
Therefore, after the spinning process is completed, a turning process is performed on the end face on the opening side of the molded product 51, and the turning is performed to the turning line La to obtain a clutch drum as a product having a required axial length L0. . [0005] By the way, as described above,
After spinning , the molded product 51 is used to secure the shaft length.
When turning is performed on the end surface of the molded product 51, the spline 5 extends over the entire length of the inner peripheral surface of the molded product 51 in the conventional molding method.
.. Are formed, the spline 54 is naturally turned. However, when turning is performed on the formed part of the spline 54 in this way, burrs due to the turning process cause the above-mentioned spline 5
4, 54,... Will cause problems such as burrs hindering the fitting operation when the friction plate or snap ring is assembled to the clutch drum. For this reason, conventionally, a series of molding operations incorporate a deburring process for removing burrs generated by turning, which increases the number of man-hours required for this deburring process, reduces workability, increases costs, etc. Various inconveniences have occurred. Accordingly, the present invention has been made to provide a cylindrical member, a method of forming the same, and a forming apparatus for the same, which eliminate the need for a deburring step after the turning, thereby realizing high workability and low cost. Things. According to the present invention, as a specific means for solving the above-mentioned problems, a method for forming a cylindrical member according to the first invention of the present application is characterized in that one end in the axial direction is opened. in those ends of the inner forming shape the cylindrical member protrusion extending in the axial direction is provided on the peripheral surface with closing, ridge molding surface and said having a molding protrusions extending in the axial direction on the outer circumferential surface set to a dimension than the outer diameter of the cylindrical member an outer diameter to be larger and molding Ri by the outer diameter of the protrusion molding surface together continuously to the ends of the ridge molding surface for molding a smooth circumferential surface a core metal smooth molding surface and is provided that is, using a shaping roller is moved to the axial direction in the radially outer side of the metal core, a sheet metal material on the outer peripheral surface of the core metal by the forming roller <br/> depending on the spinning process of pressing One end in the axial direction is open and a ridge extending in the axial direction on the inner peripheral surface thereof; and a smooth inner peripheral surface having an inner diameter larger than the outer diameter of the ridge continuous to the end of the ridge on the opening side. The primary molded article having the following shape is formed, and thereafter, a portion corresponding to the smooth inner peripheral surface of the primary molded article is turned to obtain a predetermined axial length , and then, corresponding to the smooth inner peripheral surface. Part to do
Are provided with a plurality of concave portions so as to protrude inward,
The snap ring receiving groove is formed by the part and the end face of the ridge.
It is characterized in that formed. According to the present invention, the following functions and effects are obtained by adopting such a configuration. According to the molding method of the first aspect of the invention to such a cylindrical member of the present application, continuous to and outside diameter thereof at the end portion of the collision strip forming surface and projecting strip forming surface is the outer diameter of the protrusion molding surface A core metal provided with a smooth molding surface that is set to be larger and smaller than the outer diameter of the cylindrical member to be molded, and a molding roller that can be moved in the axial direction on the radially outer side of the core metal. For the primary molded product formed by spinning using, a portion corresponding to the smooth inner peripheral surface thereof is turned to obtain a predetermined axial length, and then the above-mentioned smooth inner peripheral surface is formed.
A plurality of recessed parts are protruded inward to the corresponding part
Provided by the recess and the end face of the ridge.
Since it forms the receiving groove, there is no burr due to turning in the ridge forming portion of the cylindrical member, so that a deburring step after the turning is not necessary, and the molding cost of the cylindrical member is reduced accordingly. Cost reduction is promoted . BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a molding apparatus according to an embodiment of the present invention; FIG. 1 shows a clutch drum for an automatic transmission as a cylindrical member according to an embodiment of the present invention formed by such a forming method. The clutch drum 1 includes a bottom wall 11 and a peripheral wall 1.
2 are integrally formed in a cylindrical shape with a bottom. On the inner peripheral side of the clutch drum 1, a cylinder portion 17 having a smooth inner peripheral surface continuous with the bottom wall portion 11 is formed, and an end portion of the cylinder portion 17 near the bottom wall portion 11 is formed. , A plurality of splines 13, 13,... (Corresponding to ridges in claims) extending in the axial direction of the clutch drum are formed continuously with the splines 13, 13,. A circumferential groove having a predetermined width is formed at an end on the clutch drum opening end side by a plurality of recessed portions 15, 15,... Formed corresponding to the plurality of splines 13, 13,. Are formed. When the clutch drum 1 is assembled to an automatic transmission, a piston (not shown) for engaging a clutch is fitted in the cylinder portion 17 and the splines 13, 13,. A plurality of friction plates (not shown) are mounted on the portion, and a snap ring (not shown) is fitted in the snap ring receiving groove 14 to prevent the friction plate from falling off and to serve as a reaction member of the piston. Be placed. The clutch drum 1 having such a structure is formed by a molding method described later using a molding device described later. In this case, from the viewpoint of simplifying the molding operation,
Various new configurations are employed for forming the splines 13 and the like. Hereinafter, a molding apparatus including such a novel configuration and a molding method thereof will be described with reference to FIGS. FIG. 3 shows a disk-shaped material W1 having a predetermined thickness.
Splines 13 and 13 of the internal by spinning,
Shows a forming apparatus Z for obtaining a bottomed cylindrical primary molded product W2 provided with. Then, in the next step, the end face of the primary molded product W2 formed by the molding apparatus Z is turned to adjust the axial length, and in the next step, the die 41 and the punch 42 (see FIG. 5) are connected. Press molding is performed to obtain a clutch drum 1 having a required shape. The molding apparatus Z includes a core metal 2, a molding die 4, and a molding roller 6, which will be described later. The above core 2
Has a first cylindrical forming surface 24 formed of a smooth circumferential surface on the outer peripheral surface 23 from the front end surface 22 side, a spline-like forming surface 25 having a plurality of forming splines 27, 27,. And a second cylindrical molding surface 26 which is a surface of a cylinder. The core support shaft 3 is fitted into a shaft hole 21 provided at the axial center of the cylindrical body. The gold 2 is driven to rotate at a predetermined speed by a predetermined driving mechanism (not shown) via the core metal support shaft 3. Here, each molding surface 24, 2 of this cored bar 2
The shapes of 5 and 26 are set as follows. That is, first, the axial widths of the molding surfaces 24, 25, and 26 are described. In this embodiment, the first cylindrical molding surface 24 is used.
Both the width dimension (L21) and the width dimension (L22) of the spline-shaped molding surface 25 are set to dimensions corresponding to the cylinder length and spline length required for the clutch drum 1 as a product, respectively. 2 The width dimension (L23) of the cylindrical molding surface 26 is the primary molded product W2
The width dimension of the extended cylindrical portion 32 (L12, see FIG. 4) is set to have a predetermined margin, so that it has a width dimension (L20) as a whole. On the other hand, the diameters of the molding surfaces 24, 25 and 26 are set as follows in this embodiment. That is, first, the diameter (D24) of the first cylindrical molding surface 24
Is set according to conditions such as clutch engagement force.
The spline-shaped molding surface 25 is formed by the spline 2 for molding.
7, the root diameter (D23) is set to be larger by a predetermined amount than the diameter of the first cylindrical forming surface 24, and the cutting edge circle diameter of the forming spline 27 so as to have a predetermined tooth height, that is, The outer diameter (D22) of the spline-shaped forming surface 25 is set. Further, the outer diameter (D21) of the second cylindrical forming surface 26 is determined by changing the outer diameter (D21) of the cutting edge circle diameter (D
It is set larger than 22) by a predetermined amount. Therefore, the outer diameter of each of the molding surfaces 24, 25, 26 is the same as that of the first cylindrical molding surface 2.
It gradually increases from the fourth side toward the second cylindrical forming surface 26 side. The molding die 4 is provided with a front end face 22 of the cored bar 2.
The central portion of the material W1 is sandwiched and held between the material and the core material 2, and the material W1 is rotated integrally with the metal core 2. In particular, in this embodiment, a punch 5 is provided at a deep portion of the shaft. When the material W1 is sandwiched between the molding die 4 and the core 2, the axial center of the material W1 is interposed between the molding die 4 and the die 21 a formed by the tip of the shaft hole 21 of the core 2. The boss 16 is formed by partially drawing. The forming roller 6 is disposed at a position outside the core 2 in the radial direction so as to be movable in the axial direction of the core 2,
While rotating at a predetermined speed, the forming die 4
The material W1 is plastically deformed by moving from the side toward the metal core 2, and is sequentially pressed against the molding surfaces 24, 25, 26 to form a required shape on the inner surface side. The material W1 is formed by the molding apparatus Z having such a configuration.
A primary molded product W2 is formed by spinning. The primary molded product W2 formed by the spinning process is, as shown in FIG. 4, a bottom wall portion 11 having a boss 16 at the center and an inner peripheral portion thereof. A cylinder forming portion 30 having a surface as a cylinder portion 17 and a plurality of splines 1 on an inner peripheral surface thereof.
Are formed as a bottomed cylindrical body having a spline forming portion 31 in which 3, 13,... Are formed, and a peripheral wall portion 12 including an extended cylindrical portion 32 having an inner peripheral surface having a smooth circumferential surface. Then, in the primary molded product W2, the entire width (L1
0), the cylinder forming section 30 and the spline forming section 31 occupy the width dimension (L11), and the extending cylindrical section 32 occupies the width dimension (L12).
The width dimension (L13) of 1 is the spline length originally required for the clutch drum 1. Also, the extension cylinder 3
The width dimension (L12) of 2 is a width dimension necessary for forming the snap ring receiving groove 14 (see FIG. 1) in the extended cylindrical portion 32 (that is, a forming allowance of the snap ring receiving groove 14). The turning line (La), which is the turning completion position, is set at a position of a dimension (L14) from the end surface of the spline 13, particularly in consideration of the machining allowance for the turning of the end face. The diameter of the primary molded product W2 is calculated from the inner diameter (D15) of the cylinder portion 17 to the inner diameter of the spline forming portion 31, that is, the cutting edge diameter (DD) of the spline 13.
14), tooth root circle diameter (D13), inner diameter dimension (D
12), and gradually increases in the order of the outer diameter dimension (D11) of the peripheral wall portion 12. Therefore, even if the extension cylindrical portion 32 of the primary molded product W2 obtained by the spinning is turned from the end face to the turning line La, the influence of the processing is exerted on the spline forming portion 31. Therefore, for example, a spline is formed over the entire length of the inner peripheral surface of the primary molded product W2 as in the conventional molding method, and the turning process is performed in the turning process in the spline forming portion. The associated burrs do not occur in the spline 13 portion. For this reason, the deburring step after the turning, which has been conventionally required, is not required at all, and the workability is improved and the cost is reduced by reducing the number of molding steps. After turning the primary molded product W2, as shown in FIG. 5, the die 41 is pressed against the extended cylindrical portion 32 of the primary molded product W2 by using a punch 42. As shown in FIG. 1 and FIG.
, And the plurality of recessed portions 15, 15,.
, And the end faces of the plurality of splines 13, 13, ... form a snap ring receiving groove 14, whereby the clutch drum 1 as a product is obtained. The primary molded product W2 by spinning
At the time of molding, the molding length of the spline 13 is set to the dimension itself required for the clutch drum 1,
Since a spline is not formed up to an unnecessary portion as in the related art, the molding length is shorter than that of the related art. Therefore, there is an advantage that the processing resistance of the spinning processing is small, and the processing becomes easier accordingly .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a cylindrical member according to an embodiment of the present invention. FIG. 2 is an enlarged view taken along the line II-II of FIG. FIG. 3 is a cross-sectional view showing a cylindrical member forming apparatus according to an embodiment of the present invention. FIG. 4 is a sectional view of a primary molded product W molded using the molding apparatus shown in FIG. FIG. 5 is an explanatory diagram of a state in which a snap ring receiving groove is formed in a primary molded product W; FIG. 6 is an explanatory view of a conventional cylindrical member forming method and forming apparatus. FIG. 7 is a sectional view of a molded product formed by the forming apparatus shown in FIG. 6; [Description of Signs] 1 is a clutch drum, 2 is a cored bar, 3 is a cored bar support shaft, 4 is a forming die, 5 is a punch, 6 is a forming roller, 11 is a bottom wall,
12 is a peripheral wall portion, 13 is a spline, 14 is a snap ring receiving groove, 15 is a recessed portion, 16 is a boss, 17 is a cylinder portion, 21 is a shaft hole, 22 is a front end surface, 23 is an outer peripheral surface, and 24 is a first. A cylindrical molding surface, 25 is a spline-shaped molding surface, 26 is a second cylindrical molding surface, 27 is a molding spline, 31 is a spline forming portion, 32 is an extended cylinder portion, 41 is a die, 42
Is a punch, W1 is a material, W2 is a primary molded product, and Z is a molding device.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21D 22/16 B21D 53/28 B21D 53/88 B21H 1/00 B21H 5/02 F16D 13/60

Claims (1)

(57) [Claims 1] When one end in the axial direction is open and the other end is closed
In both cases, a ridge extending in the axial direction is provided on the inner peripheral surface.
A method for forming a cylindrical member, comprising: forming a ridge forming surface having a forming ridge extending in an axial direction on an outer peripheral surface thereof; and forming a smooth circumferential surface continuously at an end of the ridge forming surface. a core metal having an outer diameter and a smooth molding surface set to a smaller size than the outer diameter of the cylindrical member to be large and molding Ri by the outer diameter of the ridge molding surface provided radially outside the core metal And a forming roller that is moved in the axial direction thereof, and one end in the axial direction is opened by a spinning process in which the sheet metal material is pressed against the outer peripheral surface of the core metal by the forming roller, and the inner peripheral surface is formed in the axial direction. , And a primary molded article having a smooth inner peripheral surface having an inner diameter larger than the outer diameter of the ridge connected to the end of the ridge on the opening side, and thereafter, the primary molded article is formed. Turning the part corresponding to the above smooth inner peripheral surface To obtain a predetermined axial length and, thereafter, protruding on the inner circumferential side in a portion corresponding to the smooth inner peripheral surface
A plurality of recesses so that the recesses and the ridges
A method for forming a cylindrical member , wherein a snap ring receiving groove is formed by an end face .