JP4859524B2 - Press forming method of metal part having shaft portion and spring hook - Google Patents

Description

  The present invention relates to a press molding method for accurately press-molding a metal part having a shape having a shaft section and a spring hook having a circular cross section at both ends of an elongated main body.

  Various kinds of small metal parts are incorporated in various electronic devices such as mobile phones and portable game machines. Among these metal parts, those having a simple shape can be manufactured by press-molding a metal plate. However, a metal part having a complicated shape cannot be accurately formed by press-molding. For this reason, such a small metal part having a complicated shape is generally regarded as a die-cast product.

  For example, a metal swivel with a complicated shape in which a shaft section having a circular cross section and a spring hook having a rectangular cross section are formed on both sides of an elongated main body, and a concave spring hook groove is formed on the surface of the spring hook. Parts cannot be manufactured by press molding, but are manufactured by die casting.

  In the case of a die-cast product, a large amount of burrs is generated during production, so a deburring process is necessary. Further, in the case of a metal part provided with a shaft portion, post-processing such as applying hard plating to the shaft portion to improve wear resistance is necessary. Furthermore, in the case of die casting, there is a problem that mass production efficiency is worse than press molding.

  In view of such a point, an object of the present invention is to enable a metal part having a complicated shape including a shaft part to be accurately manufactured by press molding.

In order to solve the above-mentioned problems, the present invention provides a metal plate material having a predetermined thickness by press molding, and has an elongated main body portion having a predetermined cross section and a circular cross section projecting from both end faces of the main body portion. In a method of manufacturing a metal part having a shaft portion and a spring hook provided with a spring hooking groove protruding from a portion away from the shaft portion on both end faces of the main body portion,
A roughing step of roughing a metal part forming portion corresponding to the metal part by pressing the metal plate material in a partially connected state;
A body part molding step for press-molding the body part on the roughened metal part molding part;
A spring-hanging step of press-forming the spring hooks at both ends of the metal part molding portion;
A shaft portion forming step for forming the shaft portion at both ends of the metal part forming portion;
A press molding process for finishing the spring hook and the shaft part;
And a separation step of separating the metal part molding portion from the metal plate material.

Here, the spring-hanging molding process includes:
A first trimming step for trimming the portion of the metal part molded portion so that the contour shape in the planar direction of the spring hook is given to the spring-loaded molded portion;
A pre-crushing step of pressing the spring-loaded portion to a predetermined thickness as a whole;
A first spring crushing step of pressing the portion so that a contour shape in the thickness direction of the spring hook is given to the spring hook molded portion;
A second trimming step for trimming the spring-hanging portion so that a contour shape in the plane direction of the spring hook is given to the spring-hanging portion;
A second spring crushing step of pressing the part so that a contour shape in the thickness direction of the spring hook is imparted to the spring-hanging part;
And a third trimming step of trimming the metal part molded portion so as to give a spring hook and a contour shape in the planar direction of the shaft portion to both ends.

In addition, the shaft part forming step includes
A shaft crushing step of pressing the shaft part forming part at both ends of the metal part forming part so as to have a circular cross section;
A deburring process to remove burrs remaining on the molded shaft part;
A shaft tip cutting step for cutting the tip of each shaft portion so as to have a predetermined length is included.

  In the press molding method of the present invention, a simple-shaped main body is press-molded, then a complex-shaped spring hook is press-molded, and then a metal plate is pressed in the thickness direction to form a shaft section having a circular cross section. Press molding. In spring-pressing press forming, by repeatedly performing trimming and pressing, the contour shape in the planar direction of the spring hook and the contour shape in the thickness direction are alternately applied to the spring-forming portion of the metal plate material. Like to do. By repeatedly performing trimming and pressing, a complicated spring hook can be accurately press-formed. Also, the metal plate material is pressed in the thickness direction to form a shaft section with a circular cross section, and then the meat protruding laterally is cut (burred), so the shaft section is also pressed with high accuracy. Can be molded.

  Therefore, according to the present invention, a small metal part having a shaft portion and a spring hook, which has been impossible in the past, can be accurately manufactured by press molding. Compared with the case of manufacturing by die-casting, the deburring process is simplified, and the shaft portion has a higher hardness by press molding, so that post-treatment such as hard plating for preventing wear is substantially unnecessary. Furthermore, it is excellent in mass productivity. As a result, according to the present invention, a small metal part having a complicated shape can be manufactured at a much lower cost than in the prior art, and the productivity is also greatly improved.

  Hereinafter, a metal part press forming method to which the present invention is applied will be described with reference to the drawings.

  1A to 1G are a plan view, a front view, a bottom view, a rear view, a side view, a cross-sectional view of a portion cut along the line F-F, and G It is sectional drawing of the part cut | disconnected by the -G line | wire.

  As shown in these drawings, the metal part 1 of this example has a main body 2 having an elongated and substantially triangular cross section, and the end portions 3 and 4 on both sides of the main body 2 protrude slightly forward from the main body 2. Yes. The outer end surfaces 3a and 4a of the end portions 3 and 4 are formed with shaft portions 5 and 6 having a circular cross section on the front side thereof, and these shaft portions 5 and 6 extend in the material axis direction of the main body portion 2. Yes. Moreover, the spring hooks 7 and 8 of the rectangular cross section which protruded laterally are formed in the site | part of the axial parts 5 and 6 in the outer side end surfaces 3a and 4a. On the back surfaces of these spring hooks 7 and 8, spring hook grooves 7a and 8a are formed. The metal part 1 having this shape is a small part having a maximum thickness of about 1.9 mm and a length of about 20 to 25 mm.

  2 and 3 are explanatory views showing a process of press-molding the metal part 1 from a metal plate material having a constant thickness. With reference to this figure, the press molding method of the metal component 1 of this example is demonstrated.

  First, a long metal plate material having a constant width, for example, an iron plate material (SPCC or the like) is prepared, and this is intermittently sent along a press forming line. For the metal plate material 10, the pilot holes for positioning are punched at regular intervals along the feed direction at the first pilot hole punching position P1. The example shown in the drawing is for taking two pieces, one pilot hole 11, 12 on each side in the width direction of the metal plate material 10, and two pilots at a slight pitch in the feed direction at the center in the width direction. Holes 13 and 14 are formed.

  The metal plate portion 10A between the pilot hole groups 11 to 14 in the feed direction is fed one pitch from the pilot hole punching position P1 to the idle position P2. Thereafter, it is sent out by one pitch and reaches the first slit removal position P3. Here, a U-shaped slit 21 is punched out on one side in the width direction of the metal plate portion 10A. A portion surrounded by the three sides 21 a, 21 b, 21 c inside the U-shaped slit 21 is a metal part forming portion 31 used for forming the metal part 1. The central side 21 b inside the U-shaped slit 21 of this example has a contour shape corresponding to the contour shape of the front side 2 a of the main body 2 of the metal part 1. Thereafter, the metal plate portion 10A is sent out by one pitch to reach the second slit punching position P4, and the U-shaped slit 21 is punched out in a line-symmetric state on the other side in the width direction of the metal plate portion 10A.

  Next, the metal plate portion 10A from which the two U-shaped slits 21 are punched is fed by one pitch to reach the aldol position P5, and then fed by one pitch to reach the slit punching position P6. At the slit punching position P6, a plurality of rectangular slits, for example, three rectangular slits 22a to 22c in this example, are punched out in an independent manner at a portion facing the side 21b of the U-shaped slit 21. That is, the rectangular slits 22 a to 22 c are formed on the rear side of the main body part forming portion 32 for forming the main body part 2 in the metal part 1. Thus, the metal part molding part 31 for press-molding the metal part 1 is partially connected to the metal plate 10 by the U-shaped slit 21 and the rectangular slits 22a to 22c. Roughed in state.

  The metal plate portion 10A after the metal part forming portion 31 is roughed is sent out by one pitch to reach the idle position P7, and through this, it is sent out by one pitch to reach the center crushing position P8. At the center crushing position P8, the main body portion molding portion 32 and the peripheral portion thereof in the metal part molding portion 31 are pressed, and the main body portion molding portion 32 is press-molded so as to be the main body portion 2 having a triangular cross section. Thereafter, the metal plate portion 10A is fed by one pitch to reach the idle position P9, and further fed by one pitch to the first trimming position P10 shown in FIG.

  As shown in FIG. 3, at the first trimming position P <b> 10, trimming is performed on the shaft molding portions 35 and 36 and the spring-loaded molding portions 37 and 38 at both ends of the metal part molding portion 31 using the die 24 having a shape indicated by a bold line. And the contour shape in the planar direction corresponding to the shaft portions 5 and 6 and the spring hooks 7 and 8 is given to the portion. Next, the metal plate portion 10A is sent out by one pitch and reaches the pre-crushing position P11. It is pressed to become.

  Thereafter, the metal plate portion 10A is fed by one pitch and reaches the first spring crushing position P12, and the spring-hanging portions 37 and 38 are press-molded, and the thicknesses of the spring hooks 7 and 8 are formed on these portions. A vertical contour shape is given. Thereafter, the metal plate portion 10A is fed by one pitch to reach the idle position P13, and further fed by one pitch to reach the second trimming position P14. At this second trimming position P14, trimming of both end portions of the metal part molded portion 31 is performed again using the molds 25a and 25b indicated by bold lines in the drawing, and the meat portions protruding laterally in the previous process are cut off, The contour shape in the planar direction corresponding to the shaft portions 5 and 6 and the spring hooks 7 and 8 is given to the portion.

  Further, the metal plate portion 10A is fed by one pitch, and at the next second spring crushing position P15, the spring-hanging portions 37 and 38 are press-molded again, and the thicknesses of the spring hooks 7 and 8 are formed at these portions. A contour shape in the vertical direction is given, and then the meat portion protruding laterally in the process is cut out using the die 26a at the next third trimming position P16. In this example, at the same time, the cutting die 26b is used to trim the front edge portion of the main body molding portion 32 and the front edge portions of the shaft molding portions 35 and 36 that are continuous thereto.

  As described above, the spring hooks 7 and 8 having the complicated shapes including the spring hook grooves 7a and 8a can be press-molded by alternately repeating the spring hooking and the trimming.

  Thereafter, the metal plate portion 10A passes through the idle position P17 and then reaches the burr hitting / R attaching position P18. Here, for deburring and R attaching of the front edge portion of the main body forming portion 32. Is pressed.

  Next, the metal plate portion 10A is sent out by one pitch, reaches the shaft crushing position P19, and is pressed so that the shaft portion forming portions 35 and 36 of the metal part forming portion 31 have a circular cross section. The meat portion protruding laterally by this press molding is cut using the molds 27a and 27b having the shapes indicated by the thick lines at the deburring position P21 next to the idle position P20. Thereafter, at the next shaft tip cut position P22, the tip portions of the shaft portion molding portions 35 and 36 are cut using a die 28 indicated by a thick line, and the lengths thereof correspond to the shaft portions 5 and 6. To be.

  Thereafter, at the forming position P23, the shaft portion forming portions 35 and 36 and the spring hook forming portions 37 and 38 are press-formed. As a result, the shaft portions 5 and 6 and the spring hooks 7 and 8 are obtained in these portions.

  Finally, at the cutting position P24, the metal part forming portion 31 in which the main body portion 2, the shaft portions 5, 6 and the spring hooks 7, 8 are formed is cut out from the metal plate portion 10A using a die 29 indicated by a thick line. Thereby, the metal component 1 is obtained. In addition, after this, surface treatments, such as rust prevention, are given as needed.

  As described above, in the metal part press molding method of the present example, after roughing the metal part 1 from the metal plate material 10, first, the body portion 2 having a simple shape is press-molded, and then the rectangular cross section is formed. The spring hooks 7 and 8 having a complicated shape are press-molded, and then the shaft portion having a circular cross section is press-molded. Further, in the press molding of the spring hooks 7 and 8, by alternately repeating the step of pressing the metal plate portion in the thickness direction and the trimming step of cutting the meat portion protruding laterally thereby, The spring hook of a complicated shape is obtained with high accuracy. Further, the metal plate portion having a rectangular cross section is pressed to obtain shaft portions 5 and 6 having a circular cross section.

  If the method of this example is used, the small metal part with the complicated shape which was conventionally made into the die-cast product can be accurately manufactured by press molding. In press molding, the deburring process can be simplified compared to die casting. Further, since the shaft portion has a high hardness due to press molding, a processing step for improving wear resistance such as hard plating processing required for the die-cast product is substantially unnecessary. Furthermore, since metal parts can be press-formed by flowing a metal plate material along the press-forming line, it is excellent in mass productivity.

(A)-(g) is a top view which shows the example of the metal component which can be manufactured by this invention, a front view, a bottom view, a rear view, a side view, sectional drawing of the part cut | disconnected by the FF line, and G It is sectional drawing of the part cut | disconnected by the -G line | wire. It is explanatory drawing which shows the process of the roughing part in the press molding method to which this invention is applied, and the part which press-molds a main-body part. It is explanatory drawing which shows the process of the part which press-molds the spring hook following the process of FIG. 2, the process of the part which press-molds a shaft part, and the last process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal part 2 Main-body part 3, 4 End part 5, 6 Shaft part 7, 8 Spring hook 7a, 8a Spring hook groove 10 Metal plate raw material 10A Metal plate part 21 U-shaped slit 22a-22c Slit 24, 25a, 25b , 26a, 26b, 27a, 27b, 28, 29 Mold 31 Metal part molding part 32 Body part molding part 35, 36 Shaft part molding part 37, 38 Spring-loaded molding part

Claims (3)

A metal plate material having a predetermined thickness is subjected to press molding, and an elongated main body portion having a predetermined cross section, a shaft portion having a circular cross section projecting from both end surfaces of the main body portion, and the end portions on both end surfaces of the main body portion, respectively. In a method of manufacturing a metal part having a spring hook provided with a spring hook groove protruding from a portion away from a shaft portion,
A roughing step of roughing a metal part forming portion corresponding to the metal part by pressing the metal plate material in a partially connected state;
A body part molding step for press-molding the body part on the roughened metal part molding part;
A spring-hanging step of press-forming the spring hooks at both ends of the metal part molding portion;
A shaft portion forming step for forming the shaft portion at both ends of the metal part forming portion;
A press molding process for finishing the spring hook and the shaft part;
A metal part press forming method comprising a shaft part and a spring hook, wherein the metal part forming part is separated from the metal plate material. In claim 1,
The spring hanging molding process includes:
A first trimming step for trimming the portion of the metal part molded portion so that the contour shape in the planar direction of the spring hook is given to the spring-loaded molded portion;
A pre-crushing step of pressing the spring-loaded portion to a predetermined thickness as a whole;
A first spring crushing step of pressing the portion so that a contour shape in the thickness direction of the spring hook is given to the spring hook molded portion;
A second trimming step for trimming the spring-hanging portion so that a contour shape in the plane direction of the spring hook is given to the spring-hanging portion;
A second spring crushing step of pressing the part so that a contour shape in the thickness direction of the spring hook is imparted to the spring-hanging part;
And a third trimming step for trimming the metal part molded portion so as to give a spring hook and a planar contour shape of the shaft portion to both ends of the shaft. Press forming method of a metal part provided with a portion and a spring hook. In claim 2,
The shaft part forming step includes:
A shaft crushing step of pressing the shaft part forming part at both ends of the metal part forming part so as to have a circular cross section;
A deburring process to remove burrs remaining on the molded shaft part;
A method for press forming a metal part having a shaft portion and a spring hook, comprising: a shaft tip cutting step for cutting the tip of each shaft portion so as to have a predetermined length.

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