JP4751979B2 - Metal core for notch press molding of headrest stay - Google Patents

Description

  The present invention relates to a core metal for notch press molding of a headrest stay used to press-mold a plurality of notches for adjusting the height of a headrest on a side surface of a pipe member formed as a headrest stay with a punch die.

  Conventionally, as a core metal for notch press molding of a headrest stay, relative rotation between a groove that accepts an indented portion in the diameter by molding the notch and an indented portion in the diameter that is continuous in one circumferential direction from this groove An electro-sewing pipe that is provided with a groove that allows axial movement from the circumferential groove and allows relative movement in the axial direction relative to the indented portion within the diameter, and that forms a headrest stay There has been proposed one in which a concave groove that escapes from the weld bead is provided on the opposite peripheral side surface (Patent Document 1).

  In the metal core for notch press molding, a groove for notch molding, a groove for allowing rotation, a groove for extracting the metal core are provided continuously, and a concave groove for escaping the weld bead is provided separately. The structure is complicated and the manufacturing cost is high.

  In addition, since a groove that allows continuous relative rotation with the indented portion in the diameter is provided in a circumferential direction from the groove that receives the indented portion in the diameter, the groove for receiving the indented portion in the diameter is provided. The bottom contact is shifted to one side from the center of gravity of the punch type. For this reason, along with the press forming of the notch by the punch die, a rotational moment acts on the pipe member, and the side surface portion of the pipe member facing the groove for extracting the core metal or the recessed groove for escaping the weld bead is deformed. There is a fear.

  In addition to the above-described cored bar, the support surface of the indented portion formed by forming the notch and the notched surface that does not interfere with the indented portion in the diameter are formed so as to be adjacent to each other in the circumferential direction, and the corner portion is indented in the diameter. Formed on a curved surface that does not interfere with the insertion part (Patent Document 2), and also formed a rotation-permissible groove that is continuous in the circumferential direction from the concave groove that accepts the indented part in the diameter by molding of the notch, and continues from this rotation-permissible groove In addition, there has also been proposed a method in which a flat cutout surface that does not interfere with the indented portion in the diameter is formed in the axial direction (Patent Document 3).

  The core bar of the second example is formed so that it can be extracted from the pipe member when it is rotated 90 ° from the support surface of the indented portion formed by notching to a notch surface that does not interfere with the indented portion in the diameter. The core bar of the third example is formed so that it can be extracted from the pipe member when it is rotated 180 ° from a concave groove that accepts the indented portion in the diameter formed by the notch to a flat notched surface that does not interfere with the indented portion in the diameter. .

In the second and third examples, the portion that escapes from the bead portion of the electric sewing pipe that forms the headrest stay as in the first example is not provided on the axis that rotates 90 ° or 180 °. Although it can be applied when forming a headrest stay, it cannot be applied when forming a headrest stay from an electric-welded pipe in which a weld bead exists in the diameter.
Japanese Patent No. 2974049 JP 2002-2430 A JP 2002-120022 A

  According to the present invention, a notch for adjusting the height of the headrest can be formed on a pipe member made of an electric seam pipe having a weld bead, and the notch can be stably pressed into a desired groove shape by a simple groove structure. The purpose is to provide money.

  An object of the present invention is to provide a core metal for notch press molding of a headrest stay that can be used many times from one and can maintain a long life.

Claim 1 of the present invention is a rod-shaped metal core used for press-molding a plurality of notches for adjusting the height of the headrest with a punch die on the side surface of a pipe member formed as a headrest stay, and a diameter of the notch formed by the molding. a plurality of grooves for receiving the invagination of the inner in the axial portion, has a truncated face for releasing invagination of radially inward from the groove axially entire length by the rotation of the relative 75 ° direction and the pipe member, A cored bar for press-molding a notch groove of a headrest stay having a support surface supporting the inner diameter of the pipe member over the entire length in the axial direction,
A support surface that has an arc shape having the same diameter as the inner diameter of the pipe member is formed on both sides of the pipe member along the longitudinal center line, and the straight line connecting the ends of the arcs of each support surface is used as a reference. an angle of 15 ° outwardly from a vertical line through an arc each end of the support surface each kept inclined from arc each end of each support surface, and, as part flank the notch surfaces of the sides that intersect at the horizontal centerline of the pipe member In addition to the above, at least the top support surface is provided with a concave groove having a circular arc surface having a radius excluding the projecting dimension of the indented portion from the radius of the pipe member and having a bottom surface extending over the cutout surfaces on both sides.

  A second aspect of the present invention is characterized in that a plurality of concave grooves for receiving indentations within a diameter formed by notching are provided on the top and bottom support surfaces.

According to the notch press-molding cored bar of the headrest stay according to claim 1 of the present invention, the arc shape has the same diameter as the inner diameter of the pipe member over both sides via the longitudinal center line of the pipe member. a support surface and a top and bottom, from the arc each end angles respectively held by the supporting surface of the 15 ° outward from a vertical line through an arc each end of the support surface a straight line connecting the arc each end of each support surface as a reference The notched surfaces on both sides that are inclined and intersect at the horizontal center line of the pipe member are formed as relief portions, and the arc surface of the radius excluding the projecting dimension of the indented portion from the radius of the pipe member spans the notched surfaces on both sides. By providing a concave groove on the bottom surface at least on the top support surface, the pipe member is supported from the inside by the top and bottom support surfaces, and the fulcrum of the indented portion by the concave groove matches the center of gravity of the punch blade. To the desired groove shape Constant can be formed with. In addition, when the pipe member and the metal core are relatively rotated in the 75 ° direction, the notch surface is relatively positioned so as not to interfere with the indented portion, and the side surface of the notch surface is not brought into contact with the weld bead. Therefore, the core bar can be allowed to be extracted from the pipe member along with the rotation of the core bar.

  According to the core metal for notch press molding of the headrest stay according to claim 2 of the present invention, by providing a plurality of concave grooves in the top and bottom support surfaces for receiving indentations in the diameter by molding of the notches, Since the support surface is used to form the notch from any of the two directions, the number of times of use can be increased from one and the life can be kept long.

  The illustrated embodiment includes a first embodiment configured as a one-way use type as illustrated in FIG. 1 and a second embodiment configured as a two-way use type as illustrated in FIG. 6. This embodiment is common in that it can be removed from the pipe member when it is rotated by 75 ° as a basic structure, and is formed so that a notch can be provided in either the seamless pipe or the electric sewing pipe.

The core metal is produced by cutting a predetermined outer shape and a concave groove from a round bar. As shown in FIG. 2, the notches formed on the side surfaces of the headrest stay are notches N _{1 to} N ₃ for adjusting the height of the headrest, which are formed by oblique notches from the vertical rising surface, and are recessed by the opposing rising surfaces. A total of four notches N ₄ for preventing the headrest stay from being detached are formed by punch blades having different edge shapes at a predetermined interval.

  In connection with the removal of the metal core from the pipe member, it is determined by the line configuration whether the metal core is rotated or the pipe member is rotated, the metal core is pulled out or the pipe member is removed. However, for the sake of convenience, description will be made based on rotating the cored bar and pulling out the cored bar. Further, the punch blade that press-forms the notch will be used as a reference, and the side on which the cutting edge of the punch blade acts on the side surface of the pipe member will be described as the top portion of the core metal.

  As the pipe member, either a seamless pipe or an electric seam pipe is used. In order to easily explain the characteristics of the core bar, an electric seam pipe P in which the weld bead B exists in the diameter is illustrated. Note that the weld bead B has a projecting dimension that is at least smaller than the projecting dimension of the indented part formed by forming the notch.

The core bar according to the first embodiment will be mainly described. The outer shape of the entire axial direction is as follows. As shown in FIGS. 1 and 3, the top and bottom support surfaces 1 and 2 that support the pipe member P from the inside. And a notch portion X (hereinafter referred to simply as “indentation portion”, see the broken line in FIG. 3) and a notch surface 3, 4 on both sides serving as a relief portion that does not interfere. The top support surface 1 is provided with recessed grooves 5 _{1 to} 5 ₄ that receive the indented portions X at predetermined intervals. In addition, a holding portion 6 using a chuck is provided as a base portion.

Supporting surface of the top and bottom 1 and 2, over both sides through the longitudinal center line L ₁ of the pipe member P, and are formed so as to exhibit arcuate same diameter as the inner diameter R of the pipe member P. The notch surfaces 3 and 4 pass through the arc ends 1a and 1b of the support surfaces 1 and 2 with reference to a straight line (not shown) connecting the arc ends 1a and 1b (shown only on one side ) of the support surfaces 1 and 2. perpendicular line _l 1, _{l 2} than 15 ° outwardly of the angle theta _1, theta ₂ respectively held by the supporting surface 1, 2 arc each end 1a, inclined from 1b, and, in the transverse center line _{L 2} of the pipe member P It is formed to intersect.

Each of the concave grooves 5 _{1 to} 5 ₄ is formed as a bottom surface 5 a extending from the radius R of the pipe member P to the radius r ₂ excluding the projecting dimension r ₁ of the indented portion X as a bottom surface 5 a extending over the notch surfaces 3 and 4 on both sides. Has been. The rising portions 5b and 5c of the concave grooves 5 _{1 to} 5 _{4 have} a bottom surface 5a formed by notches N _{1 to} N ₃ for adjusting the height of the headrest and a notch N ₄ for preventing the headrest stay from coming off (see FIG. 2). Are formed at different relative intervals.

The core metal of the notch forming such a configuration, since the receiving side of the pipe member P by the punch blade 7 is lowered dynamic as shown in Figure 4 to press the press, the invagination X in the recessed groove 5 ₁ It can be formed as a notch. During the press-forming, together with the pipe member P from the radially inward is supported by the supporting surface 1 and 2 of the top and bottom, the groove 5 ₁ center point fulcrum is to pipe member of the core metal of the dimple X by O Therefore, the notch can be stably formed in a desired groove shape.

After press forming the notch, as shown in FIG. 5, when the core metal is rotated in the 75 ° direction θ ₃ (counterclockwise in the figure), the notch surface 3 is relatively positioned as a relief portion so as not to interfere with the indented portion X. To do. As the core bar rotates, the position of the notch surface 4 can be adjusted with the pipe member P so that the side surface of the cutout surface 4 does not come into contact with the weld bead B. Is acceptable.

As shown in FIGS. 6 and 7, the cored bar according to the second embodiment is provided with concave grooves 5 _{1 to} 5 ₄ and 5 ₁ ′ to 5 ₄ ′ on the top and bottom support surfaces 3 and 4, respectively. It is comprised by. With this metal core, it is used to form a notch from either of the two directions, so that it can be used many times from one and the life can be kept long.

  As the punch type, as shown in FIG. 8, the upper and lower support molds 8 and 9 that hold the pipe member P with a semicircular arc surface, the chuck 10 that sandwiches the core metal to be inserted within the diameter of the pipe member P, and the punch The holder 11 holding the blades 7a to 7d is used, and the punch blades 7a to 7d are moved up and down through insertion holes provided in the upper support die 9 to form notches.

It is a perspective view which shows the metal core for notch press molding of the headrest stay which concerns on one embodiment of this invention. It is a perspective view which shows the pipe member which formed the notch with the metal core for notch press molding of FIG. It is explanatory drawing which shows the relative structure of the core metal for notch press molding of FIG. 1, a pipe member, and a punch blade. It is explanatory drawing which shows the press state by the punch blade of the pipe member which inserted the metal core for notch press molding of FIG. It is explanatory drawing which shows the relative rotation state of the metal core for notch press molding of FIG. 1, and a pipe member. It is a perspective view which shows the metal core for notch press molding of the headrest stay which concerns on another embodiment of this invention. It is explanatory drawing which shows the relative structure of the core metal for notch press molding of FIG. 6, a pipe member, and a punch blade. It is explanatory drawing which shows a punch type | mold provided with the metal core for notch press molding of the headrest stay which concerns on this invention.

Explanation of symbols

P Pipe member L ₁ Vertical center line of ₁ pipe member L ₂ Horizontal center line of ₂ pipe member 1 Top support surface 1a, 1b Both ends of support surface 2 Bottom support surface l ₁ , 1 ₂ perpendicular 3, 4 Notch surface θ ₁ , inclination angle 5 ₁ to 5 of theta ₂ cut-away surface ₄ grooves R radius X invagination r ₁ bottom diameter 7 punch blade plunging dimension r ₂ grooves of invagination of the pipe member

Claims (2)

A bar-shaped metal core used to press-mold a plurality of notches that adjust the height of the headrest with a punch die on the side of the pipe member formed as a headrest stay. Supports the inner diameter of the pipe member by having a notch surface in the axial direction to allow the recess in the diameter to escape from the groove by rotating in the 75 ° direction relative to the pipe member. A core for notch groove press molding of a headrest stay having a surface in the entire length in the axial direction,
A support surface that has an arc shape having the same diameter as the inner diameter of the pipe member is formed on both sides of the pipe member along the longitudinal center line, and the straight line connecting the ends of the arcs of each support surface is used as a reference. an angle of 15 ° outwardly from a vertical line through an arc each end of the support surface each kept inclined from arc each end of each support surface, and, as part flank the notch surfaces of the sides that intersect at the horizontal centerline of the pipe member The headrest stay is characterized in that at least the top support surface is provided with a concave groove having a circular arc surface having a radius excluding the projecting dimension of the indented portion from the radius of the pipe member and extending across the cut-out surfaces on both sides. Metal core for notch press molding. 2. The cored bar for notch press molding according to claim 1, wherein a plurality of concave grooves for receiving indentations within a diameter formed by the notch molding are provided on the top and bottom support surfaces.

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