JP2009028780A - Method for manufacturing hollow-formed material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a hollow-formed material with which a large working quantity can easily be obtained and also, a heading-formation can be performed at high precision. <P>SOLUTION: At the center of a bottom parts of respective large diameter hole parts C1, C2 in a primary-formed material C of the same outer diameter having the solid portion at the intermediate part and the bottomed large diameter hole parts C1, C2 at both end parts, the heading is applied so as to continue the small diameter hole parts D3, D4 to form a secondary-formed material D. Only the center solid portion D5 in the intermediate part in the secondary-formed material D is punched out to form a ternary-formed material E. The ternary-formed material E is compressed in this length direction and at the same time, the heading, with which the intermediate part is bulged to the outside by extending the large diameter hole parts E1, E2 to near the center in the length direction in the intermediate part while expanding the diameters of the small diameter hole parts E3, E4 is applied to form a fourth-formed material F. A small diameter bottomed part F4 left at the center in the length direction in the intermediate bulging part F3 of the fourth-formed material F is punched out to form a finish hollow-formed material G formed of the same diameter-state penetrating hole G4 at the center part of the both end shaft parts G1, G2 and the intermediate bulging part G3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing method by forging of a hollow molded body mainly used for automobile component parts.

Conventionally, hollow molded bodies used for automobile components, that is, having both end shaft portions and an outer bulging intermediate bulging portion, and a through hole is formed in the center portion of these both end shaft portions and the intermediate bulging portion. As a method for manufacturing a hollow molded body, for example, first, a solid material is forged cold, and both end portions are thin-walled portions having a large inner diameter, and an intermediate portion positioned between both end portions is less than the thin-walled portion. Form a primary molded body with a small inner diameter, and then cold-draw only the thin wall portions at both ends to form an intermediate bulge portion of the outer bulge in the intermediate portion, and both end portions Is formed so that the inner diameter of the inner portion is equal to the inner diameter of the intermediate portion.
No. 7-53792

  By the way, in the manufacturing method described above, only the thin wall portions at both ends of the hollow molded body are cold-drawn at a stretch and molded into a desired shape, so that the amount of processing at the time of plastic working It depends on the limit value. For this reason, there is a problem that a large facility is required or that it is difficult to manufacture a hollow molded body that requires a large amount of processing and accuracy.

  Therefore, the present invention compresses in the length direction an intermediate molded body having the same outer diameter that has a large-diameter hole at both ends and the subsequent small-diameter hole penetrates, and simultaneously expands the small-diameter hole. The large diameter hole is extended to near the center in the length direction of the intermediate part, and the intermediate part is bulged outwards, so that a large amount of processing can be easily obtained, and high-precision forging is achieved. An object is to provide a method for producing a hollow body that can be molded.

  In order to solve the above problem, the present invention has both end shaft portions and an intermediate bulge portion of the outer bulge, and a through-hole having the same diameter is formed at the center portion of the both end shaft portions and the intermediate bulge portion. As a method of manufacturing a hollow molded body, first, a cylindrical solid material is formed by forging, and a primary molded body having the same outer diameter having a solid middle portion and bottomed large-diameter holes at both ends is obtained. And then forging so that the small-diameter hole continues in the center of the bottom of each large-diameter hole of the primary molded body, only the central portion in the length direction at the middle is solid, and the large-diameter at both ends Form a secondary molded body having the same outer diameter with a hole portion and a small-diameter hole that follows this, and then punching only the central solid portion in the intermediate portion of the secondary molded body, Forming a tertiary molded body having the same outer diameter having a large-diameter hole portion and a subsequent small-diameter hole portion penetrating therethrough, and thereafter forming a tertiary molded body. At the same time as compression processing in the length direction, while extending the small diameter hole portion, the large diameter hole portion is extended to near the center in the length direction in the intermediate portion and subjected to forging forming to bulge the intermediate portion outward, A quaternary molded body having an outer bulging intermediate bulging portion at the intermediate portion and a large-diameter hole portion near the center in the length direction of the intermediate bulging portion at both end shaft portions is formed. A small-diameter surplus portion left in the center in the length direction of the intermediate bulging portion of the next molded body is punched out to form a through hole having the same diameter at the center portion between both end shaft portions and the intermediate bulging portion. The final hollow molded body is formed.

  According to the present invention, a cylindrical solid material is formed by forging to form a primary molded body having the same outer diameter with a solid middle portion and bottomed large-diameter holes at both ends, and then primary Forging molding so that the small-diameter hole portion is continuous with the center of the bottom of each large-diameter hole portion of the molded body, only the central portion in the length direction at the intermediate portion is solid, and has the large-diameter hole portions at both ends, and Subsequently, a secondary molded body having the same outer diameter with a small-diameter hole portion is formed, and thereafter, only the central solid portion in the intermediate portion of the secondary molded body is punched and large-diameter hole portions are formed at both ends. Since the third molded body having the same outer diameter through which the subsequent small-diameter hole portion passes is formed, the tertiary molded body can be forged with high accuracy. Further, at the same time as compressing the tertiary molded body in its length direction, while expanding the small diameter hole portion, the large diameter hole portion is extended to near the center in the length direction in the intermediate portion to bulge the intermediate portion outward. Forming a quaternary molded body having an outer bulging intermediate bulging portion at the intermediate portion and a large-diameter hole extending near the center in the length direction of the intermediate bulging portion at both end shaft portions by performing forging molding Therefore, it is possible to easily obtain a large amount of processing for forming the quaternary molded body and to perform forging processing with high accuracy. After that, by punching the small diameter part left in the center in the length direction of the intermediate bulging part of the quaternary molded body that has been forged with high precision, both end shafts are maintained while maintaining the accuracy of the quaternary molded body. The final hollow molded body in which the portion and the intermediate bulging portion are penetrated to the same diameter can be finished with high accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a method for producing a hollow molded body according to the present invention. First, as shown in FIG. 1, a solid metal round bar is cut into a predetermined length to form a cylindrical hollow material A.

  Next, the solid material A is continuously forged by a multistage forging machine under cold conditions.

  In the first stage of the forging machine, as shown in FIGS. 2 and 3, the solid material A is upset by the die 10 and the punch 11 to form the formed body B.

  In the second stage of the forging machine, as shown in FIGS. 4 and 5, large diameter holes C1 and C2 are formed on the central axis at both ends of the shaped body B by forging with a die 20 having a forming pin 20a and a punch 21. To form a cylindrical primary molded body C having the same outer diameter and having a large-diameter hole C1 and C2 with bottoms at both ends.

  In the third stage of the forging machine, as shown in FIGS. 6 and 7, a die 30 having a stepped molding pin 30a and a stepped punch 31 are provided at the center of the bottom of each large-diameter hole C1, C2 of the primary molded body C. Are formed so that the small-diameter holes D3 and D4 are continuous with each other, and only the central portion D5 in the longitudinal direction in the middle portion is solid, and the large-diameter holes D1 and D2 are provided at both ends and the small diameter following this. A secondary molded body D having the same outer diameter and having the holes D3 and D4 is formed.

  In the fourth stage of the forging machine, only the central solid part D5 in the intermediate part of the secondary molded body D is formed by the die 40 having the punching pin 40a and the cylindrical punch 41 as shown in FIGS. Punching is performed to form a tertiary molded body E having the same outer diameter having large-diameter holes E1 and E2 at both ends and through which the small-diameter holes E3 and E4 pass. The punching waste E5 punched by the punching pin 40a is discharged to the outside through a discharge passage 41a provided on the punch 51 side.

  In the fifth stage of the forging machine, as shown in FIGS. 10 and 11, a die 50 having a molding part 50a and a molding pin 50b, and a cylindrical punch 51 comprising a cylindrical molding part 51a and a center punch 51b are used. The third compact E is compressed in the length direction, and at the same time, the large diameter holes E1 and E2 are extended to near the center in the length direction in the middle while expanding the small diameter holes E3 and E4. The outer bulge has an intermediate bulging portion F3 at the middle portion, and large-diameter hole portions F1 and F2 that are close to the center in the length direction of the intermediate bulging portion at both end shaft portions. The quaternary molded product F is formed. In this case, the small-diameter surplus portion F4 remains at the center in the length direction of the intermediate bulge portion F3.

  In the sixth stage (final stage) of the forging machine, as shown in FIGS. 12 and 13, the die 60 having the punching pin 60a and the cylindrical punch 61 are used in the intermediate bulging portion F3 of the quaternary molded body F. The small diameter part F4 remaining in the center in the length direction is punched and a through hole G4 having the same diameter or substantially the same diameter is formed at the center part of both end shaft parts G1, G2 and the intermediate bulge part G3. A hollow molded body G is formed. The punching waste G4 punched by the punching pin 60a is discharged to the outside through a discharge passage 61a provided on the punch 61 side.

  As described above, a cylindrical solid material A is formed by forging to form a primary molded body C having the same outer diameter having a solid middle portion and bottomed large-diameter holes C1 and C2 at both ends. Then, forging is performed so that the small-diameter holes D3 and D4 are continuous with the center of the bottom of each large-diameter hole C1 and C2 of the primary molded body C, and only the central portion D5 in the length direction in the intermediate portion is solid. The secondary molded body D having the same outer diameter having the large diameter holes D1 and D2 at both ends and the subsequent small diameter holes D3 and D4 is formed, and then the intermediate portion of the secondary molded body D Only the central solid portion D5 is punched out to form a tertiary molded body E having the same outer diameter having large-diameter holes E1, E2 at both ends and through which the small-diameter holes E3, E4 pass. Since it did in this way, the tertiary molded object E can be compacted and formed with high precision without difficulty. Further, at the same time as compressing the tertiary molded body E in its length direction, the large diameter holes E1 and E2 are extended to near the center in the length direction at the middle while expanding the small diameter holes E3 and E4. The large-diameter hole portion F1 is formed by forging to make the portion bulge outward, the intermediate portion is provided with an intermediate bulge portion F3 that is outwardly bulged, and the shaft portions at both ends reach the center in the length direction of the intermediate bulge portion F3. , F2 is formed, a large amount of processing can be easily obtained in forming the quaternary molded body F, and forging can be performed with high accuracy. Thereafter, the precision of the quaternary molded body F is maintained as it is by punching the small-diameter surplus portion F4 remaining in the center in the length direction of the intermediate bulging portion F3 of the quaternary molded body F that has been formed with high precision. In this state, the final hollow molded body G in which both end shaft portions G1, G2 and the intermediate bulging portion G3 are penetrated to the same diameter can be finished with high accuracy.

  It is a front view of the solid raw material used with the manufacturing method of this invention.   It is a front view of the molded object shape | molded by the 1st step | paragraph in the manufacturing method.   It is explanatory drawing of the forging state in the 1st step | paragraph.   It is a front view of the molded object shape | molded by the 2nd step | paragraph in the manufacturing method.   It is explanatory drawing of the forging state in the 2nd step | paragraph.   It is a front view of the molded object shape | molded by the 3rd step | paragraph in the manufacturing method.   It is explanatory drawing of the forging state in the 3rd step | paragraph.   It is a front view of the molded object shape | molded by the 4th step | paragraph in the manufacturing method.   It is explanatory drawing of the punching state in the 4th step | paragraph.   It is a front view of the molded object shape | molded by the 5th step | paragraph in the manufacturing method.   It is explanatory drawing of the forging state in the 5th step | paragraph.   It is a front view of the molded object shape | molded by the 6th step | paragraph in the manufacturing method.   It is explanatory drawing of the punching state in the 6th step | paragraph.

Explanation of symbols

A Solid material C Primary compact C1, C2 Large diameter hole D Secondary compact D1, D2 Large diameter hole D3, D4 Small diameter hole D5 Central solid part E Tertiary compact E1, E2 Large diameter hole E3 , E4 Small-diameter hole part F Quartz molded body F1, F2 Large-diameter hole part F3 Intermediate bulge part F4 Small-diameter surplus part G Final hollow molded body G1, G2 Both end shaft part G3 Intermediate bulge part G4 Through-hole

Claims (1)

  As a method for producing a hollow molded body having both end shaft portions and an intermediate bulging portion of an outer bulge, and having through holes of the same diameter formed in the center portion of these both end shaft portions and the intermediate bulging portion, First, a cylindrical solid material is forged and formed to form a primary molded body having the same outer diameter with a solid middle portion and bottomed large-diameter holes at both ends, and then each primary molded body. Forging is performed so that the small-diameter hole is continuous with the center of the bottom of the large-diameter hole, and only the central part in the length direction of the middle part is solid. A secondary molded body having the same outer diameter with a hole is formed, and thereafter, only the central solid portion in the intermediate portion of the secondary molded body is punched to have a large-diameter hole at both ends and After forming a tertiary molded body of the same outer diameter through which the small-diameter hole portion passes, and then compressing the tertiary molded body in the length direction at the same time , While expanding the small-diameter hole part, extend the large-diameter hole part to near the center in the length direction of the intermediate part and apply the forging to bulge the intermediate part to the outside. And forming a quaternary molded body having a large-diameter hole extending near the center in the length direction of the intermediate bulging portion at both end shaft portions, and in the final step, in the intermediate bulging portion of the quaternary molded body The final portion of the small diameter remaining in the center in the length direction is punched to form a final hollow molded body in which a through-hole having the same diameter is formed at the center of both end shaft portions and the intermediate bulge portion. A method for producing a hollow molded body, which is characterized by the above.

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