KR20140016037A - Method for manufacturing flange structure - Google Patents

Abstract

The present invention efficiently manufactures a double shaft-shaped flange structure having a flange unit protruding toward an outer diameter. A method for forming an anchor block (D1) formed by forming shaft units (3, 7) on both sides of a flange unit (35) extended to an outer diameter includes a step A forming a first molded article (1A) formed by forming the shaft units (3, 7) on both ends of a material (1) via the elongation of the cylindrical-shaped material (1) in an axial direction by cold-forging or warm forging; a step B forming a second forming unit (1B) formed by forming a primary protruding unit (15) thicker than the flange unit (35) via the protrusion of the center of the first molded article (1A) outward by cold-forging or warm forging; a step C which forms a third molded article (1C) formed by forming a second protruding unit (25) which is larger than the flange unit (35) via the pressurization of the first protruding unit (15) by cold-forging or warm forging and which prevents at least a part of the outer circumference of the first protruding unit (15) from being locked by a die and a punch when forming the second protruding unit by pressurizing the first protrusion unit (15); and a step D forming the outline of the flange unit (35) by chamfering a process margin unit (27) protruding outward further than the outline of the flange unit (35). [Reference numerals] (AA) Step A; (BB) Step B; (CC) Step C; (DD) Step D

Description

[0001] The present invention relates to a method for manufacturing flange structure,

The present invention relates to a method of manufacturing a flange structure.

For example, an anchor block for a parking brake of an automobile is a part having a flange portion that protrudes largely on the outer periphery of the shaft portion. In the production of such a part, the forming of the flange portion is often performed by hot forging (hot forging) because the deformation amount of the material is large.

However, in hot forging, it is difficult to obtain a product with a good surface condition because it requires a large apparatus, leading to cost increase, slow production speed, skill required, It is disadvantageous in that it requires a process.

For this reason, it has been studied to perform all the steps by cold forging. However, in the case where the protrusion of the flange portion is large, the working pressure at the time of molding becomes too large to be realistic.

Further, in the case where the projecting shape of the flange portion is a non-circular shape such as an elliptical shape, it is protruded in a circular shape by upsetting, and then cutting or burr removal is performed according to the shape of the desired flange portion. The yield is lowered.

In order to solve such a problem, Patent Document 1 below discloses a method of manufacturing a flange structure by performing a two-step forging process of a first forging process and a second forging process. In the first forging step, a formed body having a head portion thicker than the flange portion in the anchor block is formed. In the subsequent second forging step, at least a part of the outer periphery of the head portion is not constrained by the die and the punch when the head portion of the formed body formed in the first forging step is pressed between the die and the punch, Thereby forming a molded body having a collar portion larger than that of the molded body. Then, a machining allowance portion protruding outward from the collar portion is punched to form the contour of the flange portion.

By performing the forging in two steps as described above, the collar portion can be formed in a shape close to the final shape of the flange portion in the second forging step, so that the machining allowance portion to be removed is small and the material yield is improved. Further, when the head portion is pressed in the second forging process, a part of the side surface is not constrained by the forming die, and the excess material is ejected as a burr between the punch and the die. Thus, the compression load necessary for molding in each step can be made small, so that a flange portion having a large protruding area can be formed even without hot forging.

However, in Patent Document 1, the product shape of the anchor block to be manufactured is a flat shape (a solid line in Fig. 24) with a shaft portion on only one side. However, the anchor block G has a biaxial shape having a shaft portion on both sides (a shaft portion 7 indicated by a solid line in Fig. 24 and a shape including a shaft portion 3 indicated by a dashed line). In the case of manufacturing a double-shaft anchor block G by the method disclosed in Patent Document 1, as shown in Figs. 25 and 26, an axial success 500 is formed on the punch P side used in the second forging process The head portion H of the formed body set on the die hole 510 of the die D in the second forging step is pressed by the punch P to form the collar portion I and the shaft portion 3 ) Can be formed. However, in Patent Document 1, in order to reduce the compression load at the time of molding, when the head portion H is pressed, a part of the side surface is not restrained by the forming die. Even if the shaft portion 3 is formed simultaneously with the pressing, most of the material flows outwardly and it is difficult to form the shaft portion 3. [

Japanese Patent No. 4920756

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for efficiently manufacturing a biaxially-shaped flange structure having a flange portion protruding in the outer diameter direction, which is completed on the basis of the above-described circumstances.

According to the present invention, there is provided a method of forming a flange structure formed by forming a shaft portion on both sides of a flange portion extending in an outer diameter direction, wherein a columnar material is axially stretched by cold or warm forging, Molding a primary molded body formed by forming a shaft portion and forming a secondary molded body formed by forming a primary protruding portion thicker than the flange portion by protruding the central portion of the primary molded body outward by cold or warm forging And pressing the primary protrusion by cold or warm forging to form a secondary protrusion having a larger outer shape than the flange, the method comprising the steps of: pressing the primary protrusion to form the secondary protrusion; , At least a part of the outer periphery of the primary protrusion is constrained by a die and a punch The method comprising prevent, than the outer shape of the flange parts of the machining allowance by cutting projecting outwardly from said secondary projections includes a step of forming the contour of the flange.

According to the present invention, it is possible to efficiently manufacture a biaxially-shaped flange structure having a shaft portion on both sides of a flange portion protruding in the outer diameter direction.

1 is a view showing an anchor block forming procedure in the embodiment.
2 is a side sectional view showing the structure of a multi-stage forging mold apparatus.
3 is a side sectional view showing the structure of the mobile device.
Fig. 4 is a diagram showing the inversion operation of the work. Fig.
5 is a side sectional view of the punch and the die in the molding stage S1 (mold opening state).
Fig. 6 is a side sectional view of the punch and the die in the molding stage S1 (mold clamping state).
Fig. 7 is a side sectional view of the punch and the die in the molding stage S2 (mold opening state).
Fig. 8 is a side sectional view of the punch and the die in the molding stage S2 (mold clamping state).
Fig. 9 is a side sectional view of the punch and the die in the molding stage S3 (mold opening state).
10 is a side sectional view of the punch and the die in the molding stage S3 (mold clamping state).
11 is a side sectional view of the punch and the die in the molding stage S4 (mold opening state).
Fig. 12 is a side sectional view of the punch and the die in the molding stage S4 (mold clamping state).
Fig. 13 is a side sectional view of the punch and the die in the molding stage S5 (mold opening state).
Fig. 14 is a side cross-sectional view of the punch and the die in the molding stage S5 (mold clamping state).
15 is a side sectional view of the punch and the die in the molding stage S6 (mold opening state).
16 is a side sectional view of the punch and the die in the molding stage S6 (mold clamping state).
17 is a side sectional view of the punch and the die in the molding stage S7 (mold opening state).
Fig. 18 is a side sectional view of the punch and the die in the molding stage S7 (mold clamping state).
Fig. 19 is a side sectional view of the single-shot forging die apparatus (mold opening state).
FIG. 20 is a side sectional view of the single-shot forging die apparatus (a mold-fastening state). FIG.
21 is a side sectional view of the punching device.
22 is a perspective view showing a machining allowance cut out from the anchor block and the anchor block.
23 is a side sectional view of the die and the punch when the shaft portion is formed on the punch side.
24 is a front view of an anchor bolt having a biaxial shape.
Fig. 25 is a side sectional view of a punch and a die showing the forming operation of the shaft portion (mold opening state). Fig.
Fig. 26 is a side sectional view of a punch and a die showing a forming operation of the shaft portion (a molding frame fastened state).

An embodiment of the present invention will be described with reference to Figs. 1 to 23. Fig.

The flange structure manufactured in this embodiment is an anchor block 1D (hereinafter referred to as an anchor block 1D) for a parking brake of an automobile. It has shaft portions (3, 7) on both sides of a substantially elliptical flange portion (35) extending in the outer diameter direction. In the present embodiment, the columnar material 1 shown in Fig. 1 is formed into an anchor block 1D through four steps A to D described below. On the other hand, the material of the material (1) is, for example, an alloy steel.

(1) Step A for molding the primary molded body 1A in which the shaft portions 3 and 7 are formed on both sides from the work 1 by cold forging or warm forging.

(2) A step B for molding a secondary molded body 1B having a primary protruding portion 15 having a thicker shape than the flange portion 35 from the primary molded body 1A by cold forging or warm forging.

(3) Step C for molding the third molded body 1C having the secondary protruding portion 25 larger than the flange portion 35 from the secondary molded body 1B by cold forging or warm forging.

(4) Step D for forming a contour of the flange portion 35 by cutting the machining allowance portion 37 protruding outwardly from the outer diameter of the flange portion 35 from the secondary projecting portion 25.

On the other hand, cold forging means compression-molding the material 1 at room temperature (room temperature), and warm-forging means compressing the material 1 by heating (for example, 550 to 800 degrees).

Hereinafter, steps A to D will be described in order. In the present embodiment, steps A and B are performed by using one multi-stage forging die apparatus 50. As shown in Fig. 2, the multi-stage forging die apparatus 50 has seven molding stages S1 to S7 each having a pair of punches P and dice D of seven stages. The dies D and the punches P are fastened together at a time in seven stages by a forming mold clamping device (not shown). The multistage forging die apparatus 50 is provided with a moving device 140 for transferring the material 1 to the respective molding stages S at a pitch and the respective materials 1 simultaneously molded in the respective molding stages S The material 1 is formed in each of the molding stages S while being successively transferred to the next stage of molding. On the other hand, in the following description, the mold clamping means that the punch P approaches the die D, and the mold opening means that the punch P is separated from the die D.

3, the moving device 140 has a movable plate 141 which can reciprocate in the arranging direction of the forming stages S1 to S7 (vertical direction in Fig. 3). Seven sets of support portions 145 made up of a pair of blade portions 142 and 143 corresponding to the respective molding stages S1 to S7 are provided on the movable plate 141 and extruded from each die hole of each of the dies D1 to D7 And supports the raw material 1 and the primary molded body 1A. Therefore, by moving the movable plate 141 in the vertical direction in Fig. 3 after supporting the material 1 and the primary formed body 1A extruded from each die hole by the respective supporting portions 145, The primary molded body 1 and the primary molded body 1A can be carried to the next stage of molding S1 to S7. The movable plate 141 returns to the original position after the conveyance and waits for the next conveyance.

The second supporting portion (the workpiece 1 is transported from the second forming stage S2 to the third forming stage S3) 145R provided on the movable plate 141 is formed so that the entirety of the hinge H Lt; / RTI > The supporting part 145R rotates 180 degrees about the hinge H when the work 1 is transported from the second forming stage S2 to the third forming stage S3 so that the direction of the work 1 is 180 (See Fig. 4). 3 shows only the die D and the moving device 140, and the punch P is omitted. 4 shows only the die D and the support portion 145R, and the punch P and the movable plate 141 are omitted.

1. Step A for molding the primary molded product (1A)

Step A is performed through five steps in five forming stages S1 to S5.

<First and second molding stages>

The first die D1 constituting the first shaping stage S1 is formed into a cylindrical shape by a metal and the die hole 51 is provided on the machined surface (the surface facing the first punch P1) Zd (See FIG. 5). The die holes 51 are sized to accommodate the blank 1 from the front. The depth of the die hole 51 is longer than the entire length of the blank 1 so that the entire blank 1 can be received therein. Further, inside the die hole 51 (right side in Fig. 5), there is provided a conical tapered portion 53 whose tip is narrowed toward the inside.

The first punch P1 as a counterpart of the first die D1 is formed into a cylindrical shape by a metal and a punch pin 55 is provided on the machined surface (the surface facing the first die D1) do. The punch pin (55) faces the die hole (51) and is coupled to the die hole (51) with no gap.

In the molding stage S1 described above, the punch pin 55 is press-fitted into the die hole 51 by the mold clamping so that the tip end of the workpiece 1 inserted into the die hole 51 is pushed inward. Thus, the work 1 is deformed to fill the tapered portion 53, and the tapered portion 2 is formed at one end (the right end in Fig. 6) of the work 1 (see Fig. 6). The molded work 1 is extruded from a die hole 51 by a knock-out pin 57 provided in the first die D1 and supported by a support portion 145 waiting at the entrance of the die hole 51 . Thereafter, the work 1 is conveyed to the next forming stage S2 by the moving device 140. Then,

The second die D2 constituting the second forming stage S2 is formed into a cylindrical shape by a metal and the die hole 61 is provided on the machining surface (the surface facing the punch P2) Zd 7). The die hole 61 is sized to accommodate the blank 1 without gaps. The depth of the die hole 61 is longer than the entire length of the work 1, and the entire work 1 can be accommodated therein. On the inner surface of the die hole 61, there is provided an axis 63. The shaft holder 63 is smaller in pore diameter than the die hole 61 and functions to form the shaft portion 3 at the end of the work 1.

The second punch P2 as a counterpart of the second die D2 is formed into a cylindrical shape by metal and a punch pin 65 is provided on the machined surface (the surface facing the second die D2) do. The punch pin 65 faces the die hole 61 and is coupled to the die hole 61 with no gap (see Fig. 7).

In the molding stage S2 described above, the punch pin 65 is press-fitted into the die hole 61 by the forming die fastening, thereby pushing the work 1 inserted into the die hole 61. [ Thereby, one end of the work 1 is extruded in the axial direction (the right direction in Fig. 7), and is deformed to fill the shaft shaft 63 (see Fig. 8). The work 1 is stretched in the axial direction and the shaft portion 3 having a smaller diameter than the outer shape of the work 1 is formed at one end portion (right end portion in Fig. 7) of the work 1 (see Fig. 8 ). On the other hand, the step performed in the second forming stage S2 corresponds to the 'one-side shaft forming step' of the present invention.

The molded work 1 is extruded from the die hole 61 by the knockout pin 67 and supported by the support portion 145R waiting at the entrance of the die hole 61. [ Next, the work 1 is conveyed by the moving device 140 to the next forming stage S3.

During the movement from the second forming stage S2 to the third forming stage S3, the work 1 is rotated 180 degrees by the rotation of the supporting portion 145R to be inverted, and the third forming stage S3, (The end opposite to the shaft portion 3) with respect to the die hole 81 of the non-forming die. On the other hand, when moving between stages, reversing the work 1 by rotation of the supporting portion 145R corresponds to the &quot; reversing step &quot; of the present invention.

<Third and Fourth Molding Stages>

The third and fourth dies D3 and D4 constituting the third and fourth forming stages S3 and S4 are formed in the shape of a cylinder by a metal and dice holes 81 and 91 (See Figs. 9 and 11). The die holes 81 and 91 are sized to accommodate the work 1. The depth of the die holes 81 and 91 is shorter than the entire length of the work 1 and when the work 1 is inserted into the die holes 81 and 91, The front end of the work 1 on which the work 3 is formed is projected. Shafts 83 and 93 are formed at inner ends of the dice holes 81 and 91, respectively. The shaft shafts 83 and 93 are smaller in diameter than the dice holes 81 and 91 and serve to form the shaft portion 7 at the end of the work 1. [

The third punch P3 and the fourth punch P4 which are the counterparts of the third dice D3 and the fourth dice D4 are all formed in the shape of a cylinder by the metal and the machined surface Zd is formed with punch balls (85, 95) are formed. The shapes of the punch holes 85 and 95 correspond to the tip end shape of the work 1, that is, the shape of the shaft portion 3, and the shaft portions 3 projecting from the machining surface Zd on the sides of the dies D3 and D4 So that it can be accommodated. The punch holes 85 and 95 are provided with punch pins 86 and 96, respectively. The punch pins 86 and 96 are positioned so that the tip of the pin abuts the tip of the shaft portion 3 inserted into the punch holes 85 and 95 when the mold is fastened.

In the molding stages S3 and S4, the punches P3 and P4 push the material 1 accommodated in the dies 81 and 91 to the inside of the dies 81 and 91 by the mold clamping. 9 and 11) is pushed out in the axial direction (the rightward direction in Figs. 9 and 11), and the other end of the work 1 is pushed in the axial directions 83, 93) (Figs. 10 and 12).

The pores 83 and 93 formed in each of the dies D3 and D4 pass through the stage and become smaller in pore size. The material 1 passes through two steps and is stepwise extended in the axial direction, The shaft portion 7 is formed. As a result, the shaft portions 3 and 7 are formed at both ends of the work 1 (see Fig. 12), and the primary formed body 1A is formed. The primary molded body 1A is then extruded from the die hole 91 by the knockout pin 97 and supported by the support portion 145 waiting at the entrance of the die hole 91. [ Then, the material 1 is conveyed by the moving device 140 to the next forming stage S5. On the other hand, the steps performed in the third forming stage S3 and the fourth forming stage S4 correspond to the "other shaft forming step" of the present invention.

<Fifth Molding Stage>

The fifth die D5 constituting the fifth shaping stage S5 is formed in a cylindrical shape by a metal and a die hole 101 is formed on the machined surface (the surface facing the fifth punch P5) Zd (See Fig. 13). The die hole 101 becomes a size capable of accommodating the primary formed body 1A. At the center of the die hole 101, a flat forming portion 103 is provided.

The fifth punch P5 which is a partner of the fifth die D5 is formed in the shape of a cylinder by a metal in the same manner as the fifth die D5 and has a machining surface (a surface facing the fifth die D5) Zp), a punch hole 105 is formed. The shape of the punch hole 105 is such that the shaft portion 3 protruding from the machined surface Zd of the fifth die D5 is accommodated in correspondence with the tip end shape of the primary formed body 1A, It is possible to do. The punch hole 105 is provided with a punch pin 106. The punch pin 106 is configured such that the tip of the pin abuts the tip of the shaft portion 3 inserted into the punch hole 105 when the mold is fastened.

In the molding stage S5, the punch P5 pushes the primary molded body 1A accommodated in the die hole 101 into the die hole 101 by fastening the die. As a result, the primary molded body 1A is deformed in the die hole 101, and the planar portion 8 is formed on the outer peripheral surface of the primary molded body 1A (see Fig. 14). The primary molded product 1A is then extruded from the die hole 101 by the knockout pin 107 and supported by the support portion 145 waiting at the entrance of the die hole 101. [ Then, the primary formed body 1A is transported by the moving device 140 to the next forming step S6. On the other hand, in Fig. 14, the flat portion 8 is shown as a white portion.

2. Step B for molding the secondary formed body 1B

Step B is carried out through two steps S6 to S7 in two molding stages.

The sixth die D6 constituting the forming stage S6 is formed into a cylindrical shape by metal, and a die hole 111 is provided on the working surface Zd (see Fig. 15). The die hole 111 is sized to accommodate the primary formed body 1A. The depth of the die hole 111 is shorter than the entire length of the primary molded body 1A so that the approximately right half region of the primary molded body 1A can be accommodated therein. At the entrance of the die hole 111, a diameter side diameter enlarging mirror 112 is provided, and the opening becomes wider toward the entrance. At the center, a molding hole 113 having a larger diameter than the outer shape of the primary molded body 1A is provided. The molding hole 113 is for forming the step portion 13 in the central portion (central portion in the axial direction) of the primary molded body 1A.

The sixth punch P6 to be a partner of the sixth die D6 is formed into a cylindrical shape by a metal, and a punch hole 115 is provided on the machined surface Zp (see Fig. 15). At the entrance of the punch hole 115, a punch-side enlargement mirror 116 is provided. Similarly to the die-side diameter increasing mirror 112, the punch-side enlargement mirror 116 has a wider opening toward the entrance. The punch-side enlargement mirror 116 is set in correspondence with the die-side enlargement mirror 112 and has a primary protruding portion 15 protruding outward in the central portion (central portion in the axial direction) of the primary formed body 1A . The punch hole 115 is provided with a punch pin 117. The punch pin 117 is configured so that the tip of the pin abuts the tip of the shaft portion 3 inserted into the punch hole 115 when the mold is fastened.

In the molding stage S6, the punch P6 pushes the primary molded body 1A accommodated in the die hole 111 into the die hole 111 by the mold clamping. The primary molded body 1A is pushed by the punch P6 to be compressed so as to shorten the overall length so that the central portion is deformed to fill the bulging portions 112 and 116 and the molding hole 113 (see Fig. 16).

The seventh die D7 constituting the forming stage S7 is formed into a cylindrical shape by a metal, and the die hole 121 is provided on the working surface Zd (see Fig. 17). The die hole 121 is sized to accommodate the primary formed body 1A. The depth of the die hole 121 is shorter than the entire length of the primary molded body 1A so that the approximately right half region of the primary molded body 1A can be accommodated therein. At the entrance side of the die hole 121, a diameter-side diameter increasing mirror 122 is provided. A molding hole 123 having a larger diameter than the outer shape of the primary molded body 1A is formed at the center. The molding hole 123 is for forming the step portion 13 on the outer periphery of the primary molded body 1A.

The seventh punch P7 to be the partner of the seventh dice D7 is formed into a cylindrical shape by metal, and the punch hole 125 is provided on the machined surface Zp (see Fig. 17). At the entrance of the punch hole 125, a punch-side enlargement mirror 126 is provided. The punch-side enlargement and reduction mirror 126 serves as a set in correspondence with the die-side diameter enlarging mirror 122 and forms a primary protrusion 15 protruding outward at the center of the primary formed body 1A. The punch hole 125 is provided with a punch pin 127. The punch pin 127 is configured so that the tip of the pin abuts the tip of the shaft portion 3 inserted into the punch hole 125 when the mold is fastened.

In the molding stage S7, the punch P7 pushes the primary molded body 1A accommodated in the die hole 121 into the die hole 121 by the mold clamping. The primary molded body 1A is compressed so as to shorten the entire length by being pushed by the punch P7 so that the center portion is deformed to fill the bulging portions 122 and 126 and the molding hole 123 (see FIG. 18).

The shape of the large-diameter work is gradually thinner and larger in shape as it passes the stage, and a primary protrusion 15 is formed in the center of the primary formed body 1A through two processes. On the other hand, 'extending' in the outer diameter direction means 'protruding' in the outer diameter direction. Similarly, the molding ball is similarly formed into a stepwise thin and large shape passing through the stage, and the step 13 is formed at the center of the primary formed body 1A through two steps. Thus, the secondary formed body 1B is molded from the primary molded body 1A (see Fig. 18).

On the other hand, like the shape of the flange portion 35 of the target anchor block 1D, the shape of the primary projecting portion 15 is an almost oval shape extending in the outer diameter direction when viewed in the axial direction, The protruding length of the flange portion 35 is shorter than the protruding length of the flange portion 35 and the thickness t is thicker than the thickness of the flange portion 35 (see Fig. 1).

Then, the molded secondary molded product 1B is extruded from the die hole 121 by the knockout pin 129. The extruded secondary molded product 1B is conveyed to the single-shot forging mold apparatus 200 through processes such as removal of impurities, surface treatment and the like.

3. Step C for molding the third molded article (1C)

Step C is performed by a one-step process in the single-shot forging die apparatus 200 described below.

As shown in FIG. 19, the single-shot forging die apparatus 200 includes a die 210 and a punch 250. The die 210 is formed in a cylindrical shape by a metal, and the die side concave portion 211 is provided on the upper surface (the surface facing the punch 250). The dice-side concave portion 211 is the same as the outer shape seen from above when viewed from the axial direction of the flange portion 35 of the anchor block 1D. At the center position of the bottom surface of the die-side concave portion 211, a shaft 213 for receiving the shaft portion 7 of the secondary formed body 1B is provided in the longitudinal direction. The secondary molded body 1B is set in the die 210 by inserting the shaft portion 7 into the shaft 213.

On the other hand, the punch 250 is formed into a cylindrical shape by metal, and is movable in the vertical direction. Further, a punch-side concave portion 251 is provided on the lower surface of the punch 250 (the surface facing the die 210). The punch side concave portion 251 is the same as the outer shape viewed from the bottom when viewed from the axial direction of the flange portion 35 of the anchor block 1D. Further, at the center position of the upper surface of the punch side concave portion 251, a shaft portion 253 for receiving the shaft portion of the secondary formed body 1B is provided in the longitudinal direction. The punch 250 is fixed to a processing apparatus (not shown). On the other hand, the sum of the depth of the die-side concave portion 211 and the depth of the punch-side concave portion 251 is smaller than the thickness of the desired flange portion 35.

The single-shot forging die apparatus 200 operates the processing apparatus to lower the punch 250 to fasten the forming die. The primary projecting portion 15 of the secondary molded body 1B set on the die 210 is compressed between the die 210 and the punch 250 and expanded in the planar direction by the forming die fastening, 25) are formed (see Fig. 20).

The lowering of the punch 250 is performed until the distance from the bottom surface of the die side concave portion 211 to the ceiling surface of the punch side concave portion 251 is substantially equal to the thickness of the desired flange portion 35 250) is lowered.

On the other hand, the sum of the depth of the die-side concave portion 211 and the depth of the punch-side concave portion 251 is smaller than the thickness of the flange portion 35. [ A part of the upper and lower surfaces and the outer periphery (side surface) of the primary protruding portion 15 that widens in the clearance between the die 210 and the punch 250 at the time of forming by the forming die fastening, Side pinched portion 251, but most of the outer periphery is not constrained.

Therefore, a part of the primary projecting portion 15 is released from the die-side recessed portion 211 and the punch-side recessed portion 251 and freely flows outward (in the planar direction). As described above, a part of the outer periphery of the primary projecting portion 15 is not constrained by the forming die, and an extra material is projected as a margin (hereinafter referred to as a processing margin portion 27) outwardly between the punch 250 and the die 210 It is possible to perform forging without requiring an excessive working pressure. Thus, the third molded article 1C having the secondary projections 25 can be obtained. The thickness of the secondary projecting portion 25 is equal to the thickness of the blend portion 35 of the target anchor block 1D. The shape of the secondary protruding portion 25 is substantially elliptical with respect to the outer shape (outline) of the flange portion 35 of the anchor block 1D as seen from the axial direction, as large as the machining allowance portion 27 protruding outward .

4. Step D for forming the contour of the flange portion 35

The obtained third molded product 1C is supplied to the next punching step. In the punching step, the machining allowance portion 27 is cut out from the secondary projecting portion 25 to form the contour of the flange portion 35. On the other hand, the punching step is preferably carried out immediately after the formation of the third molded body 1C. If processing is performed after a lapse of time, work hardening is promoted, and cracks tend to occur in the product during punching.

The punching apparatus 300 used in the punching process is provided with a punching die 310 and a punching punch 350 as shown in Fig. The punching die 310 is made of metal, and a punching hole 320 penetrating the punching die 310 in a vertical direction is provided at a center position thereof. The outer shape seen in the up-and-down direction (plate thickness direction) is the same as the outer shape seen from the axial direction of the flange portion 35 in the anchor block 1D. Meanwhile, the punching punch 350 is formed in a shape that allows the punching hole 320 to be inserted almost tightly by the metal. On the lower surface of the punching punch 350, a receiving hole 360 for receiving the shaft portion 3 of the third molded body 1C is provided in the longitudinal direction. The punch 350 is fixed to a processing apparatus (not shown).

In order to perform the punching process using the punching apparatus 300, first, the third molded body 1C is attached to the punching hole 320 with the shaft portion 7 directed downward. Specifically, the machining allowance portion 27 is raised around the hole of the punching hole 320, and the secondary projecting portion (the portion excluding the machining allowance portion 27) 25 is fitted to the inner periphery of the punching hole 320 . Next, the punching punch 350 is lowered by operating the processing apparatus. As a result, the inner portion of the secondary projecting portion 25 is punched out from the periphery of the opening of the punching hole 320. Then, the punched product portion passes through the punching hole 320 and falls downward, and the machining allowance portion 27 remains on the punching die 310. Thus, the machining allowance portion 27 is separated from the secondary projecting portion 25, and the contour of the flange portion 35 is formed. Thus, a biaxially-shaped anchor block 1D having the shaft portions 3 and 7 on both sides of the flange portion 35 is manufactured.

5. Effect description

As described above, in the method of manufacturing the flange structure according to the present embodiment, the primary projecting portion 15 having a thicker shape than the flange portion 35 is formed at the center of the primary molded body 1A in Step B, The protruding portion 15 is further pressed to form the secondary protruding portion 25 which is larger than the flange portion 35 in the outer peripheral direction.

Since the secondary projecting portion 25 is formed through the two steps in this way, it can be formed in a shape close to the final shape of the flange portion 35, so that the machining allowance portion 27 to be removed becomes small, do. In the step B, the primary projecting portion 15 having a thicker shape than the flange portion 35 is formed at the central portion of the primary molded body 1A. When the primary projecting portion 15 is further compressed in Step C, Side surface) of the punch 250 and the dice 210 as a margin without restraining a part of the punch 250 and the dice 210 by the mold. As a result, the compression load required for molding in each step can be made small, so that the flange portion 35 having a large protruding area can be formed without hot forging.

From these, each step can be formed by cold or warm forging, and a large hot forging device is not required. Further, it is possible to make use of the characteristics of cold and warm forging such that it is easy to obtain a product having a good surface condition and precision machining is possible, so that the post-processing such as cutting and polishing can be reduced. Accordingly, cost reduction can be achieved. In addition, since the production speed by cold and warm forging is high, the skill in the temperature management and the like is not required as much as the hot forging, so that the productivity can be improved.

In this embodiment, the shaft portions 3 and 7 are formed at both ends of the work 1 in Step A. If the primary projections 15 or the secondary projections 25 are molded and the shaft 7 is molded at the stage B or C, the material 1 for forming the projections 15 and 25 is upset It is necessary to stretch the blank 1 for forming the shaft portion 7 at the same time, so that the compression load must be increased. Particularly, in the step C, when the secondary projecting portion 25 is formed by compressing the primary projecting portion 15, a part of the outer periphery is not constrained by the forming mold so as to lower the compressive load. Molding of the shaft portion 7 simultaneously with molding of the car protrusion 25 is difficult as long as the non-restraint is abolished to increase the compression load. In this embodiment, since the shaft portions 3 and 7 are formed at both ends of the work 1 in the step A as described above, the primary projections 15 and the secondary projections 25 And the shaft portions 3 and 7 need not be machined.

Therefore, the compression load necessary for the molding in the B step or the C step can be suppressed to the same level as in the case of forming the anchor block (the solid line anchor block shown in Fig. 24) ), The respective steps A to C can be formed by cold or warm forging.

In addition, in the present embodiment, one side shaft portion 3 is formed in the die hole 61 of the second molding stage S2. Next, the work 1 is reversed and transferred to the third forming stage S3, and the other side shaft portion 7 is also moved in the same direction as the one side shaft portion 3 by moving the die 1 of the third and fourth molding stages S3, (81, 91). As described above, in the present embodiment, the shaft portions 3 and 7 on both sides are formed by using the die (D) side die holes 61, 81 and 91. This makes it possible to reduce the number of steps required for forming the shaft portions 3 and 7, as compared with the case where the one side shaft portion 3 and the other side shaft portion 7 are formed by dividing the die D side and the punch side.

The reason for this is that the knockout amount on the punch P side (the stroke length for extruding the processed workpiece) is generally shorter than on the die D side and the punch hole 410 is formed in the die holes 61, ). 23, when the one side shaft portion 3 is formed on the die D side and the other side shaft portion 7 is formed on the punch P side, The peripheral portion 7b of the punch hole 7a comes out of the punch hole 410. [ That is, the end portion 7 has to be formed in a state in which the peripheral portion 7b of the machining end 7a is not constrained. On the other hand, when molding is performed in a state in which the peripheral portion 7b of the machining end 7a is not constrained, the limit value that can be formed without increasing the workpiece diameter is 30% or less of the reduction ratio (external ratio before and after molding).

Therefore, when the reduction ratio exceeds the limit value when the shaft portion 7 is formed, it is necessary to form the shaft portion 7 stepwise by using a plurality of molding stages S so that the reduction ratio does not exceed the limit value . Therefore, when the number of stages of the molding stage S is fixed, the number of steps is lost in forming the shaft portion 7, and as a result, other steps can not be performed, and the process is not established.

In the present embodiment, both shaft portions 3 and 7 on both sides are formed by using the die holes 61, 81 and 91 on the die D side. Since the die ball is deeper than the punch ball, the shaft portion 7 can be formed in a state in which the peripheral portion 7b of the machining end 7a is confined, and the diameter of the workpiece is not increased (see Figs. 9 to 12). Therefore, even when the reduction ratio exceeds 30%, the shaft portion 7 can be formed by one or two steps (twice in this embodiment). Therefore, even if the number of steps of the molding stage S is determined, it is possible to carry out the other steps, so that the process can be performed without difficulty.

<Other Embodiments>

The present invention is not limited to the embodiments described with reference to the above description and drawings, but the following embodiments are also included in the technical scope of the present invention.

(1) In the above embodiment, the flange portion is of an elliptical shape. However, the shape of the flange portion is not necessarily required to be an elliptical shape. For example, the present invention can be preferably applied to a non-circular shape such as a cross shape or a rectangular shape. have. In this case, the shape of the primary projecting portion in the secondary molded body is also matched to the shape of the flange portion.

1: material
1A: Primary molded body
1B: Secondary molding body
1C: Third molding body
1D: Anchor block for parking brake (flange structure)
3, 7: Shaft
15: primary protrusion
25: Second protrusion
35: flange portion
50: Multi-step forging mold device
140: Mobile device
145: Support
200: Single forging mold device
300: Punching device

Claims (2)

A method of forming a flange structure in which a shaft portion is formed on both sides of a flange portion extending in an outer diameter direction,
Forming a primary molded body formed by forming a shaft portion at both ends of the material by stretching the column-shaped material in the axial direction by cold or warm forging;
Forming a secondary molded part formed by forming a primary protrusion having a shape thicker than a flange part by protruding the central part of the primary molded body outward by cold or warm forging,
Molding a third molded body obtained by forming a second protruding portion having a larger outer shape than the flange portion by compressing the first protruding portion by cold or warm forging,
A step of compressing the primary projecting portion to form at least a part of the secondary projecting portion so that at least a portion of the primary projecting portion is not constrained by the die and the punch,
And forming a contour of the flange portion by cutting the processing clearance portion projecting outward from the flange portion from the secondary protrusion. The method of claim 1,
The molding of the primary molded body may include:
A one-side shaft forming step of forming a shaft on one side of the blank by pressing a material attached to a die provided with a die ball having a shaft hole for forming a shaft on one side of the blank,
A step of reversing the direction of the material extruded from the die ball after the one-side shaft forming step,
And a second shaft forming step of forming a shaft on the other side of the work by pressing a workpiece attached to a die provided with a die ball having a shaft hole for forming a shaft on the other side of the workpiece with a punch, &Lt; / RTI &gt;

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