JPH069720B2 - Wheel rim manufacturing method and manufacturing apparatus thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of manufacturing a wheel rim of an automobile and a manufacturing apparatus thereof.

(Prior Art) As a wheel rim of an automobile, for example, a wheel rim having a shape shown in FIG. 1 is known. Generally, like the wheel rim H, it is provided on both sides of a cylindrical well portion W at a substantially central portion thereof. Is provided with flange portions F ₁ and F ₂ , and both flange portions F ₁ and F ₂ are provided.
Reference numeral ₂ indicates the first step portions a ₁ and a ₂ , the first side wall portions b ₁ and b ₂ , and the second step portions c ₁ and c _{2 in} this order from both ends of the well portion W toward the opening end of the wheel rim H. And the second side wall portions d ₁ and d ₂ which are the rim end portions are formed in a two-step staircase shape. A hump curved outwardly for locking a tire (not shown) fitted to the wheel rim H on each of the first side wall portions b ₁ and b ₂ of the flange portions F ₁ and F ₂ . The portions h ₁ and h ₂ are provided, and the second side wall portions d ₁ and d ₂ , which are the rim end portions, are curved so as to project outward.

When manufacturing this kind of wheel rim H, conventionally,
For example, as disclosed in Japanese Unexamined Patent Publication No. 56-131033, both ends of a cylindrical body made of a metal material such as an aluminum alloy and having the diameter of the well portion W are pressed several times to expand the tube. By doing so, the both end portions are gradually formed into the shapes of the flange portions F ₁ and F ₂ . More specifically, in the above-mentioned press working, a side die is externally fitted to the outer peripheral surface of the cylindrical body, and a punch is internally fitted to the cylindrical body in its axial direction, and both end portions of the cylindrical body are individually attached to the side die by the punch. The pipe is expanded to a predetermined shape by pressing it toward the outside, and both ends of the cylindrical body are formed into the shapes of the flange portions F ₁ and F ₂ by repeating these operations.

Further, in the above molding of the hump portion _h 1, _{h 2} and the rim edge _d 1, _{d 2} of the wheel rim H, the hump portion _h 1,
Since h ₂ and the rim end portions d ₁ and d ₂ are curved so as to project to the outside, the pump portions h ₁ and h ₂ and the rim end portions d ₁ and d ₂ are formed by the press working as described above. Since the punch cannot be die-cut even if an attempt is made, the conventional method is Japanese Patent Laid-Open No. 56-
As disclosed in 131033 JP, first step portion _a 1 of the flange portion _F 1, _{F 2} in the press working of the, _{a 2,} a first side wall portion _b 1, _{b 2,} a second step portion _{c 1} , C ₂ and the second side wall parts d ₁ and d ₂ which are the rim end parts are molded into a preliminary flange part, and then the first side wall part b ₁ of the preliminary flange part is formed by roll molding. , B ₂ are curved so that the portions corresponding to the hump portions h ₁ and h ₂ are projected to the outside to form the pump portions h ₁ and h _2, and the second side wall portion d ₁ of the preliminary flange portion, the d ₂ be curved so as to project outwardly so that to form the rim edge d _1, d _2.

However, this type of roll forming requires more time than press working, which has been an obstacle to improving the manufacturing efficiency of the wheel rim H.

Further, as described above, in the press work in which the punch is simply fitted in the cylindrical body and the both ends of the cylindrical body are laterally pressed toward the side die, the both ends are flanged portions F ₁ ,
If an attempt is made to expand the pipe at one time until it has a shape substantially the same as that of F ₂ , a large tensile load may be applied to both ends of the cylindrical body, which may cause adverse effects such as buckling. Since pressing has to be performed, a large number of processing steps are required, which has been an obstacle to improving the manufacturing efficiency of the wheel rim H.

(Problems to be Solved) The present invention solves such inconveniences, the hump portion and the rim end portion of the wheel rim can be formed by press working, and the wheel rim can be efficiently manufactured by a small number of working steps. The purpose is to provide a method that can.

It is another object of the present invention to provide a device capable of efficiently forming the hump portion and the rim end portion by press working to manufacture a wheel rim.

(Means for Solving the Problem) In order to achieve the above object, the method for manufacturing a wheel rim of the present invention is such that both flange portions at both ends of the well portion respectively have a first step portion from both end positions of the well portion to an opening end, First
The first and second side walls are formed by the side wall portion, the second step portion, and the second side wall portion in two steps, and both first side wall portions have a hump portion that is curved outward, and both second side walls that are rim end portions. A method for manufacturing a wheel rim of an automobile curved so that a portion thereof protrudes outward, wherein the flange portion is provided at both ends of a cylindrical body having a diameter of the well portion made of a metal material. The first step of press-molding a preliminary flange portion having substantially the same shape and having smooth first step portion, first side wall portion, second step portion, and second side wall portion, and then both preliminary flange portions were formed. A side die divided from the side of the cylindrical body is externally fitted to the outer peripheral surface of the cylindrical body, and the cylindrical body is pressed in the axial direction between a pair of punches internally fitted to both preliminary flange portions thereof. , Each preliminary flange part by the pressurization A predetermined portion of the first side wall portion is curved toward a concave portion provided in the side die to form the hump portion, and a second side wall portion of each preliminary flange portion is curved toward a concave portion provided in the side die. And a second step of forming the rim end portion.

Further, in the first step, both ends of the cylindrical body are substantially similar in shape to the flange portion, and the first step portion, the first side wall portion, the second step portion and the second side wall portion are all smooth. At the same time, a primary step of press-molding a primary preliminary flange portion in which the inclination angles of the first and second step portions are smaller than a predetermined angle, and a cylindrical body for molding the primary preliminary flange portion are added in the axial direction. While pressing, the first of each of the spare flange portions of the primary
And a second step of press-forming the second step portion by pressing the second step portion until the inclination angle thereof increases to a predetermined angle, and forming the both preliminary flange pieces in the first step. Each is done in one pressing step,
It is characterized in that the forming of both preliminary flange portions in the secondary step is performed in one pressing step.

In order to achieve the above-mentioned object, a wheel rim manufacturing apparatus of the present invention is an apparatus for manufacturing a wheel rim by the above-mentioned manufacturing method, and includes a first pressing device for performing the first step, and a second pressing device for performing the first step. A second press device for carrying out the steps, wherein the second press device is provided in a lower mold of the cylinder with the axial center of the cylinder body in which both of the preliminary flange portions are formed being oriented in the vertical direction. A lower punch that is internally fitted to a preliminary flange portion on the lower side of the body, and an upper side of a cylindrical body that is integrally provided with the lower punch that is lowered toward the lower die and that is integrally fitted to the lower punch An upper punch that is internally fitted to the auxiliary flange portion when descending, and an upper punch that is internally fitted to the lower punch, together with the upper punch that is internally fitted to the lower punch, and an outer peripheral surface of the cylindrical body. With a divided side die that is fitted from the side, Formed on the outer peripheral surface of both punches is a molding surface having substantially the same shape as the inner peripheral surface of the preliminary flange portion, and jaws that are locked to both ends of the cylindrical body when fitted inside the cylindrical body of both punches. Forming surfaces having substantially the same shape as the outer peripheral surfaces of the upper and lower preliminary flange portions of the cylindrical body are formed on the upper and lower portions of the inner peripheral surface of the side die, and the recesses that form the hump portion and the rim end portion on the forming surface. Are provided in a circumferential shape.

(Operation) According to the method for manufacturing a wheel rim of the present invention, the cylinder body in which both of the preliminary flange portions are press-molded at both ends in the first step has the shaft between the pair of punches in the second step. By pressing in the direction, the predetermined portion of the first side wall portion and the second side wall portion formed smoothly of each preliminary flange portion are curved toward the recess provided in the side die. The hump portion and the rim end portion are formed by pressing with a side die to obtain a wheel rim.

When the first step is composed of the primary and secondary steps, when the primary spare flange portions are formed on both ends of the cylindrical body in the primary step by one pressing step, respectively. Because the inclination angles of the first and second stepped portions of each primary spare flange portion are smaller than a predetermined angle, the tube expansion amount at both ends of the cylindrical body is small, and the tensile load acting on this is relatively small. As a result, each of the primary spare flange portions is molded without any problem in one pressing process. Then, in the secondary step, when molding the primary both preliminary flange portions into the both preliminary flange portions in one pressing step, respectively, the cylindrical body having the primary both preliminary flange portions is formed in the axial direction thereof. Since both the preliminary flange portions are formed by pressing the first and second stepped portions of each primary preliminary flange portion until the inclination angle thereof increases to a predetermined angle while pressurizing with Since the tensile load acting on is relatively small, each preliminary flange portion can be formed without trouble in one pressing step.

Further, according to the wheel rim manufacturing apparatus of the present invention, first, the preliminary flange portions are press-molded at both end portions of the cylindrical body by the first pressing device, and the first pressing device is well known as the first pressing device. A press device or the like is used. Then
When forming the hump portion and the rim end portion on both preliminary flange portions by the second pressing device, first, the lower punch is fitted in the lower preliminary flange portion of the cylindrical body, and then the upper die Is lowered so that the upper punch is fitted into the preliminary flange portion on the upper side of the cylindrical body and the side die is fitted onto the outer peripheral surface of the cylindrical body. At this time, both ends of the cylindrical body are locked to the jaws of the both punches, and the cylindrical body is pressed in the axial direction as the upper punch descends, whereby the first and the second flanges of the preliminary flange portion are pressed. The second side wall portion is pressed in the axial direction and tends to bend. Further, since the forming surfaces of both punches have substantially the same shape as the preliminary flange portion, and the recesses are provided at positions corresponding to the hump portion and the rim end portion of the side die forming surface, At these positions, the first and second side wall portions of each preliminary flange portion curve and project into the recess, thereby forming the hump portion and the rim end portion.

(Example) An outline of an example of a method for manufacturing a wheel rim of the present invention will be described with reference to FIGS. 1 and 2 (a) to (d). Figure 2 (a) ~ (d)
FIG. 3 is an explanatory cross-sectional view for explaining the outline of the method for manufacturing the wheel rim H shown in FIG.

In this manufacturing method, first, both ends of a cylinder A shown in FIG. 2 (a) made of an iron-based alloy, an aluminum alloy, etc. are expanded, and the wheel rim H of the wheel rim H is expanded as shown in FIG. 2 (b). The primary preliminary bulge portion Fa having a shape substantially similar to the flange portions F ₁ and F _2.
1 and Fa ₂ are molded. At this time, the spare flange portion F
a ₁ , Fa ₂ of the first step portion a ₁ , a ₂ , the first side wall portion b ₁ ,
b ₂ , the second step portions c ₁ and c ₂ and the second side wall portions d ₁ and d ₂ are all formed to be smooth, and the first and second step portions a ₁ , a ₂ and c ₁ , c _{2 are formed.} Are formed with a relatively small inclination angle with respect to the axis of the cylindrical body A.

Next, the primary auxiliary flange portions Fa ₁ and Fa ₂ are formed so that the inclination angles of the first and second step portions a ₁ , a ₂ and c ₁ and c ₂ thereof are increased, and the primary auxiliary flange portions Fa ₁ and Fa ₂ are formed as shown in FIG. As shown, the first step portions a ₁ and a ₂ , the first side wall portions b ₁ and b ₂ and the second step portions c ₁ and c having substantially the same shape as the flange portions F ₁ and F ₂ are formed.
₂ and the second side wall portion _d 1, pre _{d 2} are both smooth fragi portion _Fb 1, Fb ₂ is press-formed, followed by the pre flange _Fb 1, first side wall _b 1 of Fb _{2, b 2} Of the humps h ₁ , h ₂ and the rim end d ₁ , as shown in FIG. 2 (d), are curved so that predetermined portions of the second side walls d ₁ , d ₂ protrude outward. d ₂ is formed, which results in the wheel rim H. Then, each of the above-mentioned moldings is performed by the press working described in detail below.

A method of forming the primary preliminary bulging portions Fa ₁ and Fa ₂ and a press device X for performing the forming will be described with reference to FIGS.
Description will be given with reference to FIGS. 3 is an explanatory sectional view of the press machine X, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, and FIG.
FIG. 6 is a sectional view taken along the line VV of FIG. 4, and FIGS. 6 (a) and 6 (b) are operation explanatory views for explaining the operation of the press apparatus X.

In FIGS. 3 and 4, reference numeral 1 designates an upper die having an upper punch 2 on the lower surface and capable of moving up and down together with the upper punch 2, and 3 denotes a lower die having a lower punch 4 on the upper surface at a position directly below the upper punch 2. A die 5 is a horizontal lift table that is vertically movable between the molds 1 and 3, and 6 is a lift table 5 that is integrally movable with the punches 5 and is concentric with both punches 2 and 4 so as to raise and lower the axis. A support base 7 for detachably supporting the lower surface of the cylindrical body A oriented in the direction is provided at a position around the cylindrical body A supported by the support base 6 on the elevating table 5 so as to be vertically movable integrally therewith. A side die; 8 is a detaching means for detaching the support base 6 supporting the cylindrical body A from the cylindrical body A;
Is a moving means for moving the side die 7 so that the side die 7 is fitted onto the outer peripheral surface of the cylindrical body A supported by the support base 6.

Each of the punches 2 and 4 has molding surfaces 2a and 4a having substantially the same shape as the inner peripheral surfaces of the primary preliminary flange portions Fa ₁ and Fa ₂ on the outer peripheral surface thereof, as shown in the third drawing, and the upper die When the upper punch 2 and the lower punch 4 are lowered toward the lower punch 4, the upper punch 2 and the upper punch 2 are fitted in the upper and lower portions of the cylindrical body A which is concentric with the punches 2 and 4 and which are oriented vertically. At the end of the lowering of 1, the tip end surfaces of the cylindrical body A come into contact with each other at a substantially central position.

As shown in FIG. 3, the elevating table 5 is supported on the upper end portion of a cushion pin 10 which penetrates the lower mold 3 from below the lower mold 3 and is vertically movable to project toward the upper mold 1. The outer surface is slidably contacted with the inner surface of the backup member 11 which is erected on the side of the lower mold 3, and is vertically movable along the inner surface. The cushion pin 10 is erected vertically below the lower mold 3 and is erected on a cushion plate 12 which is urged upward by a spring (not shown) or the like, and urges the elevator table 5 upward. is doing. Further, a circular opening 5a having a diameter through which the lower punch 4 can freely penetrate is provided at a position between the punches 2 and 4 of the lift table 5 when the punch 5 is lowered, as shown in FIGS. 4 and 5. A plurality of grooves 5b extending radially from the opening 5a are formed on the upper surface of the lifting table 5.

The support base 6 is a lift base 5 as shown in FIGS. 4 and 5.
Each of the moving bases 13 has a plurality of moving bases 13 which are horizontally movable in the respective grooves 5b and are vertically movable integrally with the lifting base 5, and each moving base 13 is a spring as shown in FIG. It is connected to the lifting table 5 via 14 and is urged toward the center of the opening 5a. And by this bias, each moving table
As shown in FIG. 4, the tip of 13 projects into the opening 5a so that adjacent ones come into contact with each other, and in a corresponding contact state, these are combined together to form a ring-shaped support portion along the lower end surface of the cylindrical body A. 6a is formed, and the cylindrical body A is supported by the supporting portion 6a concentrically with the punches 2 and 4 as shown in FIG. Further, as shown in FIG. 5, a cam hole 13a extending obliquely in the vertical direction is provided at the rear portion of each movable table 13.

As shown in FIG. 3, the detaching means 8 is a movable base of the support base 6.
An arm erected on the lower mold 3 at a position below the cam hole 13a of 13
The arm 15 is provided with a cam 15a which is engaged with the cam hole 13a as shown in phantom lines in FIG. And the cam 15a
Also, the cam holes 13a are detached from the cylindrical body A supported by the supporting portions 6a at the tip end of each moving table 13 as the supporting table 6 is lowered, and the lower punch 4 is opened by the opening 5a of the elevating table 5. Is formed so as to move in the radial direction along the groove 5b to a position where it can penetrate.

As shown in FIGS. 3 and 4, the side die 7 is composed of a plurality of dies 16 arranged in the circumferential direction so as to surround the outer peripheral surface of the cylindrical body A supported by the support base 6. 16
Are mounted on the lift table 5 at a distance from each other, and the cylindrical body A
On the other hand, it is allowed to move horizontally on the lifting table 5 in the radial direction. The outer surface of each die 16 is connected to a backup member 17 standing on the side of the lift 5 as shown in FIG. 3 via a spring 18 as shown in FIG. Is urged to Also, each die
Reference numeral 16 denotes molding surfaces 16a ₁ and 16a ₂ for separately molding the outer peripheral surfaces of the primary spare flange portions Fa ₁ and Fa ₂ at the upper and lower portions of the inner surface thereof, as shown in FIG. When the respective dies 16 are moved toward the cylindrical body A supported by the support base 6, the respective dies 16 come into contact with each other so that the side dies 7 are fitted onto the outer peripheral surface of the cylindrical body A over the entire circumference. At the same time, the molding surfaces 16a ₁ and 16a ₂ are mutually connected to the primary preliminary flange portions Fa ₁ and Fa.
A continuous surface having substantially the same shape as the outer peripheral surface of No. ₂ is formed.

The moving means 9 is located above the gap between the backup member 17 of the lifting table 5 and each die 16 as shown in FIG.
A guide member 19 provided vertically on the lower surface of the
A cam 19a is formed on the 19 and is engaged with a cam surface 16b formed on the outer surface of each die 16 when the upper die 1 is lowered.
The cams 19a and the cam surfaces 16b move the respective dies 16 toward the cylindrical body A as described above as the upper die 1 descends, and the guide members 19 are provided in the gaps between the backup members 17 and the respective dies 16. The side die 7 is formed so as to be fitted into the outer peripheral surface of the cylindrical body A.

In FIG. 3, reference numeral 20 denotes a guide post that is erected on the side portion of the lower die 3, and the upper die 1 has a guide bush 21 that is vertically provided on the side portion of the upper die 1 when the upper die 1 descends. It is guided down to 20 and descends.

Next, the operation of the press device X will be described with reference to FIGS. 3 and 6.
It will be explained according to (a) and (b).

In this press apparatus X, first, the cylindrical body A is supported by the support base 6 as described above in FIG. 3, and in this state, the upper die 1 is lowered toward the lower die 3 so that the upper punch 2 becomes a cylindrical body. It descends toward A.

Then, during this downward movement, first, the cam 19a of the guide member 19 is engaged with the cam surface 16b of each die 16 of the side die 7 to move each die 16 toward the cylindrical body A as described above. The guide member 19 is located at the position of the gap between the backup member 17 of the lifting table 5 and each die 16 as shown in FIG. 6 (a).
Enter as shown, which causes each die 16 to
The side die 7 is pressed onto the outer peripheral surface of the cylindrical body 1 and is fitted onto the outer peripheral surface of the cylindrical body 1 over the entire circumference.

On the other hand, almost simultaneously with the outer fitting of the side die 7, the upper punch 2 is fitted into the upper portion of the cylindrical body 1 as shown in FIG. 6 (a) and presses the upper portion of the cylindrical body A toward the side die 7, As a result, the upper part of the cylindrical body A is laterally expanded to form the molding surface 2a of the upper punch 2 and the continuous molding surface 16a of the die 7
_The preliminary flange portion Fa ₁ is formed between the two. At this time, the side die 7 and the support base 6 have the cushion pins 10
Is urged upward through the lift table 5 by this, and the urging force is large enough to allow the upper punch 2 to press the upper portion of the cylindrical body A toward the side die 7 as described above, and The size is set so as not to hinder the lowering of the upper mold 1.

As the upper die 1 is further lowered after the above-mentioned forming, the upper punch 1 is integrally lowered with the cylindrical body A, the side die 7, the support base 6 and the elevating base 5, and in the middle thereof, first, the releasing means 8 is removed.
The cams 15a are engaged with the cam holes 13a of the movable bases 13 of the support base 6 as described above, and the movable bases 13, that is, the support bases 6 are moved as shown in FIG. The lower end surface of the cylindrical body A is detached to release the support of the cylindrical body A, and subsequently, the lower punch 4 is fitted in the lower portion of the cylindrical body A as shown in FIG. 6 (b). At this time, the upper punch 2 fitted in the upper portion of the cylindrical body A presses the lower portion of the cylindrical body A toward the lower punch 4 via the side die 7, whereby the lower portion of the cylindrical body A is expanded in the lateral direction. The forming surface 4 of the lower punch 4
The primary preliminary flange portion Fa ₂ is molded between the continuous molding surface 16a _{2 of the} a and the side die 7. At the time of this molding, as shown in FIG. 6 (b), the front end surfaces of both punches 2 and 4 abut each other at substantially the center position of the cylindrical body A so that the cylindrical body A is made into the punches 2 and 4 and the side die 7. No more pressure than necessary.

As described above, in the above press molding, the primary spare flange portions Fa ₁ and Fa ₂ are sequentially molded in one pressing step, and at this time, the primary spare flange portions Fa ₁ and Fa _{2 are formed.}
Since the inclination angles of the first step portions a ₁ and a ₂ and the second step portions c ₁ and c ₂ are small, there is no sudden expansion of the ends of the cylindrical body A, and therefore both ends of the cylindrical body A are The tensile load acting becomes relatively small and the spare flange portion F is not hindered.
a ₁ and Fa ₂ are molded.

Simultaneously with the completion of such molding, the lowering of the upper mold 1 is stopped, and then the upper mold 1 is raised to its original position. Due to this rise, the lower punch 4, the upper punch 2, and the side die 7 are sequentially operated by the reverse operation to the preliminary flanges Fa ₁ , Fa _{2 in} sequence.
While being detached from the molded cylindrical body A, the cylindrical body A is supported by the support base 6, and in this state, the cylindrical body A is carried out from the press device X.

Next, FIGS. 7 and 8 (a), (b) show a method of forming the primary auxiliary flange portions Fa ₁ and Fa ₂ into the auxiliary flange portions Fb ₁ and Fb ₂ and a press device Y for performing the formation. ). FIG. 7 is an explanatory sectional view of the press machine Y, and FIGS. 8 (a) and 8 (b) are operation explanatory views of the main part thereof.

This press device Y has the same basic configuration as the press device X, and as shown in FIG. 7, an upper die 1 having an upper punch 2, a lower die 3 having a lower punch 4, and both die 1, A side die 7 composed of an elevation table 5 which is provided between the two and is urged upward by a cushion pin 10 and a plurality of dies 16 mounted on the elevation table 5 so as to be horizontally movable.
And each die for fitting the side die 7 onto the outer peripheral surface of the cylindrical body A having the primary spare flange portions Fa ₁ and Fa _2.
A moving means 9 for moving 16 is provided, and these have the same structure as the pressing device X. The press Y is not provided with the supporting base 6 and the releasing means 8, and the cylinder A having the preliminary flanges Fa ₁ and Fa ₂ is concentric with the punches 2 and 4 as shown in FIG. The lower punch 4 is directly fitted in the lower part, thereby supporting the cylindrical body A,
In this state, the upper die 1 is lowered to perform the press work.

Incidentally, the molding surface 2 of the two punches 2 and 4 the preliminary flange portion Fb _1, the inner peripheral surface of the Fb ₂ and substantially the same shape to each of the outer peripheral surface
b, 4b, and at the upper end of the molding surface 2b and the lower end of the molding surface 4b, as shown in FIG. 8 (a),
Jaw portions 2x, 4x are provided at both ends when the punches 2, 4 are fitted in the cylindrical body A. Then, the molding surface 16b 1 of the outer peripheral surface and substantially the same shape of each of the upper and lower portions of the inner surface the preliminary flange portion Fb _1, Fb ₂ of each die 16 of Saidodai _7, 16b ₂ are formed.

In such a press device Y, each die 16 of the side die 7 is moved by the moving means 9 in the same manner as the press device X by the lowering of the upper die 1, and the side die 7 is moved to the above-mentioned side die 7 as shown in FIG. 8 (a). The outer peripheral surface of the cylindrical body A having the primary auxiliary flange portions Fa ₁ and Fa ₂ is externally fitted over the entire circumference, and the upper punch 2 is internally fitted to the upper portion of the cylindrical body A, so that the auxiliary body of the cylindrical body A is spared. The flange Fa ₁ is the forming surface 2b of the upper punch 2.
And the forming surface 16b _{1 of the} sid die 7 is formed on the preliminary flange portion Fb ₁ , and then the upper punch 2 and the side die 7 are caused to interfere and descend by further lowering of the upper die 1, and FIG. 8 (b).
As shown, the preliminary flange portion Fa ₂ of the cylindrical body A is formed on the preliminary flange portion Fb ₂ between the forming surface 4b of the lower punch 4 and the forming surface 16b _{2 of the} side die 7.

More specifically, at the time of forming the preliminary flange portions Fb ₁ and Fb ₂ , both ends of the cylindrical body A provided with the primary preliminary flange portions Fa ₁ and Fb ₂ are as shown in FIG. 8 (a). When the upper punch 2 is fitted, the jaws 2x, 4 of both punches 2, 4 are
with locked to x, between said end wall portions _b 1, _{d 1} and the side wall portions _b 2, _d on ₂ each punch 2 and Saidodai 7 preliminary flange Fa ₂ of the primary spare flange Fa ₁ It is sandwiched between the lower punch 4 and the side die 7. Then, as the upper punch 2 is lowered in this state, first, both side wall portions b ₁ and d _{1 of the} preliminary flange portion Fa ₁ are
Is pressed in its axial direction and the auxiliary flange F
The Saidodai 7 such that the two stepped portions a _1, c ₁ of a ₁ increases its tilt angle between the upper punch 2 and Saidodai 7
Then, as shown in FIG. 8 (b), the primary preliminary flange portion Fa ₁ is molded into the preliminary flange portion Fb ₁ . Then, the upper punch 2 is further lowered to form the primary spare flange portion Fa ₂ into the spare flange portion Fb _{2 in the same} manner as above.

As described above, in forming the preliminary flange portions Fb ₁ and Fb ₂ , the above-described primary preliminary flange portions Fa ₁ and Fa _{2 are formed.}
Similar to the shaping of _{No. 1} , it is sequentially performed in one pressing step, at this time, the cylindrical body A having the primary preliminary flanges Fa ₁ and Fa ₂ is locked between the jaws 2x and 4x of both punches 2 and 4. And axially pressurizing the auxiliary flange portions Fa ₁ , Fa
Scissors first and second side wall portions of the _{2 b} 1, _{b 2} and _d 1, _{d 2} between the two punches 2, 4 and Saidodai 7, the first and second of said preliminary flange _Fa 1, Fa ₂ in this state Since the two step portions a ₁ , a ₂ and c ₁ , c ₂ are pressed in the direction in which the inclination angle increases, the preliminary flange portion F
The tensile load acting on a ₁ and Fa ₂ becomes small and buckling and other adverse effects do not occur. Therefore, the preliminary flange portions Fb ₁ and Fb ₂ are formed without any trouble.

In the above press molding, as in the press machine X, the tip surfaces of both punches 2 and 4 come into contact with each other at the end of the molding as shown in FIG. It is designed not to be pressed.

Next, a method of forming the hump portions h ₁ and h ₂ and the rim end portions d ₁ and d ₂ on the preliminary flange portions Fb ₁ and Fb ₂ and a press device Z for performing the formation are shown in FIG. 9 (a), Explain according to (b). 9 (a) and 9 (b) are operation explanatory views of the main part of the press device Z.

The press device Z has the same configuration as the press device Y,
As FIG. 9 (a) shows, the upper part of Saidodai 7 of the molding surface 16c ₁ with the molding surface 16c ₁ of the outer peripheral surface and substantially the same shape of the flange portion F ₁ of the wheel rim H are formed the hump portion h ₁ and recesses 16x 1 each circumferential direction position corresponding to the rim edge d _1, 16x ₂ is formed, the outer peripheral surface and the molding surface of substantially the same shape of the flange portion F ₂ at the bottom of Saidodai 7 While 16c ₂ is formed, recesses 16y ₁ and 16y ₂ are formed in the circumferential direction at positions corresponding to the hump portion h ₂ and the rim end portion d ₂ of the molding surface 16c ₂ .
In addition, the outer peripheral surfaces of both punches 2 and 4 are flange portions F, respectively.
₁ and F ₂ have substantially the same shape as the inner peripheral surface and the flange portion F
₁ , F ₂ first and second side wall parts b ₁ , b ₂ and d ₁ , d
₂ has molding surfaces 2c and sc in which the surfaces corresponding to ₂ are formed smoothly, and the upper end portion of the molding surface 2c and the lower end portion of the molding surface 4c have jaw portions 2x and 4 respectively as in the pre-casting device Y.
x is formed.

In the pressing apparatus Z, as in the pressing apparatus Y, when the upper punch 2 is fitted into the upper portion of the cylindrical body A provided with the preliminary flange portions Fb ₁ and Fb ₂ , the cylindrical body A has a shape shown in FIG.
As shown in (a), the auxiliary flange portion F is locked between the jaw portion 2x of the upper punch 2 and the jaw portion 4x of the lower punch 4.
The first and second borrowing wall portions b ₁ , b ₂ and d ₁ , d _{2 of} b ₁ , Fb ₂ are sandwiched between the upper punch 2 and the side die 7 and between the lower punch 4 and the side die 7, respectively. And
As the upper punch 2 is lowered in this state, the side wall portions b ₁ and d ₁ of the preliminary flange portion Fb ₁ are pressed in the axial direction thereof and tend to bend. At this time, since the surface corresponding to the both side wall portions b _1, d ₁ of the molding surface 2c of the upper punch 2 is smoothly formed, the both side wall portions b _1, d ₁ is the upper punch 2 side It cannot be bent, so that both side wall parts b ₁ and d ₁
Is 9th at the position of the recesses 16x ₁ and 16x ₂ of the side die 7.
As shown in FIG. 2B, the recesses 16x ₁ and 16x ₂ are curved so as to project into the recesses 16x ₁ and 16x ₂ , so that the hump portion h ₁ and the rim end portion d ₁ are formed and the preliminary flange portion Fb ₁ is formed. The flange portion F ₁ is molded.

Next, the upper punch 2 is further lowered, and similarly to the above, at the positions of the recesses 16y ₁ and 16y ₂ of the side die 7, FIG.
(b) side walls b ₂ of the preliminary flange portion Fb ₂ as shown,
d ₂ is curved so as to project into the recesses 16 y ₁ and 16 y ₂ , so that the hump portion h ₂ and the rim end portion d ₂ are formed, and the preliminary flange portion Fb ₂ is formed into the flange portion F.
₂ and the wheel rim H is obtained.

As described above, in the present embodiment, the pressing device X,
Using Y and Z, flange portions of a predetermined shape are sequentially formed at the upper end and the lower end of the cylinder A in each one pressing step, and the cylinder A is wheel rim in a total of three pressing steps. It is molded into H and has a small number of steps.

In this embodiment, the preliminary bulge portions Fb ₁ and Fb ₂ are formed at both ends of the cylindrical body A by pressing twice. However, the step portions of the preliminary flange portions Fb ₁ and Fb ₂ are relatively inclined, for example. In the case where the angle is small, it is possible to manufacture the wheel rim by forming the preliminary flange portion by one press work and then forming the hump portion and the rim end portion on the preliminary flange portion. Of course.

Further, the primary spare flange portions Fa ₁ and Fa ₂ are individually molded in a single pressing step, and similarly, the preliminary flange portions Fb ₁ and Fb ₂ are individually molded in a single pressing step. Of course, it is also possible to manufacture the wheel rim H with a small number of steps.

(Effect) As is apparent from the above description, according to the wheel rim manufacturing method of the present invention, when the hump portion and the rim end portion are formed, the cylinder in which the preliminary flange portion is formed at both end portions in the first step The hump portion and the rim end portion are pressed by pressing the body in the axial direction in a second step to bend a predetermined portion of the first side wall portion and the second side wall portion of the preliminary flange portion outwardly. Can be molded more efficiently, therefore,
By forming the hump portion and the rim end portion in a short time, the manufacturing efficiency of the wheel rim can be improved.

When the first step comprises primary and secondary steps, the first and second stepped portions of the primary preliminary flange section formed in the primary step are made to have a small inclination angle to form a cylindrical body. Both primary flanges can be formed on both ends of each without any trouble in one pressing step, and then in the secondary step, the cylindrical body with both primary flanges shaped is pressed in the axial direction. By forming the preliminary flange portions by increasing the inclination angles of the first and second step portions of the respective primary preliminary flange portions, both preliminary flange portions are formed on both end portions of the cylindrical body by one pressing process. The wheel rim can be molded without trouble, and therefore, the wheel rim can be manufactured with a small number of processing steps, and the manufacturing efficiency thereof can be further improved.

Further, according to the wheel rim manufacturing apparatus of the present invention, in the second press device for molding the hump portion and the rim end portion, the second press-fitting apparatus for internally fitting the preliminary flange portion into the second cylindrical body is fitted. The upper punch and the lower punch of the pressing device are provided with jaws to be engaged with both ends of the cylindrical body, and concave portions are provided in the molding surface of the side die fitted onto the cylindrical body, whereby the second pressing device is provided. According to the above-mentioned manufacturing method, the predetermined portion of the first side wall portion and the second side wall portion of the preliminary flange portion are curved into the concave portion by the pressing step according to the above manufacturing method, and the hump portion and the rim end portion are efficiently and surely secured. It can be molded.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view of an example of a wheel rim, FIG.
(a)-(d) is explanatory drawing for demonstrating the outline of an example of the manufacturing method of the wheel rim of this invention, FIG. 3 is an explanatory sectional drawing of an example of a press apparatus, FIG. 4 is of FIG. IV-IV line sectional view, FIG. 5 is the VV line sectional view of FIG. 4, and FIG. 6 (a), (b) is the third
FIG. 7 is an explanatory view of the operation of the press device, FIG. 7 is an explanatory sectional view of an example of the press device, FIGS. 8 (a) and 8 (b) are operation explanatory views of the press device of FIG. 7, and FIG. ), (B) are operation explanatory views of a main part of an example of the press device. DESCRIPTION OF SYMBOLS 1 ... Upper die 2 ... Upper punch 2c ... Upper punch forming surface 2x ... Upper punch jaw 3 ... Lower die 4 ... Lower punch 4c ... Lower punch forming surface 4x ... Lower punch jaw 7 ... Side die 16c ₁ , molding surface of 16c 2 _... Saidodai _{16x 1, 16x 2, 16y 1} , 16y 2 ... recess a ... cylinder H ... wheel rim F _1, F _{1 ...} flange Fa _1, Fa 2 _... primary pre flange portion Fb _1, Fb ₂ ... Preliminary flange portion a ₁ , a ₂ ... First step portion b ₁ , b ₂ ... First side wall portion c ₁ , c ₂ ... Second step portion d ₁ , d ₂ ... 2 Side wall portion (rim end portion) h ₁ , h ₂ ... Hump section X, Y ... First press device Z ... Second press device

Claims (3)

[Claims] 1. Two stairs, in which both flange portions on both sides of the well portion are formed by a first step portion, a first side wall portion, a second step portion and a second side wall portion in this order from both end positions of the well portion to the opening end. A wheel rim of an automobile having a hump portion that is formed in a shape and has first and second side wall portions that are curved outward, and that both second side wall portions that are rim end portions are curved so as to project outward. A method of manufacturing by press molding,
First ends of the cylindrical body, which is made of a metal material and has a diameter of the well portion, have substantially the same shape as the flange portion at both ends.
The first step of press-molding the preliminary flange portion in which the step portion, the first side wall portion, the second step portion and the second side wall portion are all smooth, and then the outer peripheral surface of the cylindrical body in which both preliminary flange portions are formed A side die divided from the side is externally fitted to the cylindrical body, and the cylindrical body is axially pressed between a pair of punches internally fitted to both the preliminary flange portions, and each preliminary is made by the pressing. A predetermined portion of the first side wall portion of the flange portion is curved toward the concave portion provided in the side die to form the hump portion, and the second side wall portion of each preliminary flange portion is formed toward the concave portion provided in the side die. A second step of bending to form the rim end portion, the manufacturing method of a wheel rim. 2. In the first step, the first step portion, the first side wall portion, the second step portion and the second side wall portion are formed on both ends of the cylindrical body in a shape substantially similar to the flange portion, respectively. A primary step of press-molding a primary preliminary flange portion which is smooth and has a tilt angle of the first and second step portions smaller than a predetermined angle; and a cylindrical body formed by molding the primary preliminary flange portion, From the secondary step of press-forming the preliminary flange portions by pressing the first and second step portions of each of the primary preliminary flange portions until the inclination angle increases to a predetermined angle while pressurizing in the direction. It is characterized in that the forming of both the primary preliminary flanges in the primary step is performed in one pressing step, and the forming of the secondary flange portions in the secondary step is performed in one pressing step, respectively. The hoi according to claim 1. Method of manufacturing a Rurimu. 3. An apparatus for manufacturing the wheel rim according to the method of manufacturing a wheel rim according to claim 1, wherein
A cylindrical body comprising a first pressing device for performing a step and a second pressing device for performing the second step, the second pressing device being provided in a lower mold thereof and forming the preliminary flange portions. And a lower punch which is fitted in a preliminary flange portion on the lower side of the cylindrical body in a state where the axis of the cylinder is oriented in the vertical direction, and a vertically movable upper die which is lowered toward the lower die, are integrally provided with the lower punch. And an upper punch fitted inside the cylindrical body in which the lower punch is fitted, and an upper punch fitted inside the cylindrical body in which the lower punch is fitted, and an upper punch fitted inside the cylindrical body in which the lower punch is fitted. And a divided side die which is provided so as to be able to move up and down and is fitted onto the outer peripheral surface of the cylindrical body from its side, and the outer peripheral surfaces of both punches have substantially the same shape as the inner peripheral surface of the preliminary flange portion. Jaw that is locked to both ends of the forming surface and both punches when they are fitted inside the cylindrical body And a forming circle having substantially the same shape as the outer peripheral surfaces of the upper and lower preliminary flange portions of the cylindrical body are formed on the upper and lower portions of the inner peripheral surface of the side die, and the hump portion and the rim are formed on the forming surface. An apparatus for manufacturing a wheel rim, characterized in that a concave portion that forms an end portion is provided circumferentially.