JPS58128229A - Manufacture of frame having drawn part and press die used for its manufacture - Google Patents

Abstract

PURPOSE:To eliminate cracks and wrinkles which are apt to be generated on the shoulder, etc. by drawing by blank holding the outside of a hole of a blank having a windowlike hole and the inside of outer periphery of the blank, and forming a frame by drawing. CONSTITUTION:A framelike blank P in which a hole S somewhat smaller than a specified windowlike hole is pierced is placed on a die 11, and the inside P1, of outer periphery of a blank P is held by the first blank holder 13 and the die 11 using an outer slide 13a. When a punch 12 is lowered, the face of the second blank holder 14 comes into contact with the outside P2 of the hole S of the blank P before the bottom of a drawn part A comes into contact with the blank P, and tarts holding. When the punch 12 is further lowered and compresses an elastic body 17, blanking force is increased. When the punch 12 is positioned at the bottom dead center, blanking force becomes maximum, and good drawing work is carried out at the area D in the part A to be drawn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a frame body having a drawn portion, such as a reinforcement for an automobile body, and a press mold used for manufacturing the frame body.

Conventionally, as a manufacturing method for a frame body having a drawing part, for example, a reinforcement R for an automobile body as shown in FIG. 1, a drawing press die as shown in FIG. For example, a rectangular blank 6 is formed, the inner outer periphery 6a of this blank 6 is blank-holted and drawn, and after this drawing is completed, the inner outer periphery is trimmed T and a window W is punched in the center. Ta.

More specifically, in FIG. 2, 1 is a punch with a protruding drawn portion A formed into a rod shape as a whole, 3 is a blank holder, and 2 is a die. First, the rectangular blank 6 is placed on the die 2. Place the blank 6 on the inner side 6a between the second part 2a and the blank holder 3, and press the punch 1 from above with a fil (hereinafter referred to as blank holder) that restrains the blank to some extent. blank 6
The overall frame-shaped cavity B (Fig. 1) was drawn.

By the way, in the drawing process using such a press die for drawing process, the blank month 6 is continuously present inside the drawing part Δ that protrudes from the punch, and the plate edge of the blank is As a result of the plate flowing into the drawing area [0 (Figure 2) only from the outer circumference side of the blank, cracks due to tension occur at the inner shoulder E and the continuous inner flow area F. There was a drawback that wrinkles were likely to occur on the outer shoulder portion M.

The present invention has been made in view of the above-mentioned points, and its purpose is to eliminate the above-mentioned drawbacks. When forming a frame shape having a section, a blank having a window-like hole similar to the navigation hole is formed, and the outer part of the window-like hole of this blank and the inner part of the outer periphery of the blank are held together. The second aspect of the present invention is characterized in that the frame-shaped blank has a drawing section for performing the drawing process, and the drawing process is performed on the outside of the hole of the frame-shaped blank that has been subjected to the window-like hole drilling process. In addition to the first blank holder that holds the blank on the inner side of the outer periphery of the press die, the lower surface of the upper die is opened in the shape of a window (larger than the hole to be processed) into this opening. , a drawing part is formed by disposing a second blank holder having a bolt surface facing the outer side of the window-like hole of the blank, and supporting the blank holder so as to be movable upward through an elastic body. There is a press mold used to manufacture the frame.

FIG. 3 is used to manufacture a frame having a drawn portion according to the present invention. 1 is a cross-sectional view showing one embodiment of a press mold. First, when manufacturing a frame body, for example, a reinforcement R, which has a drawn portion along a window-like hole W as shown in FIG. 1, = A rectangular plate material corresponding to the outer shape of the reinforcement R is obtained from a steel material by shearing processing, and a window-shaped hole similar to the hole W and slightly smaller than the hole W is formed on the plate material. Hole S 3
- punching out to form a frame-shaped blank P; The press mold shown in FIG. 3 has a protrusion N(
(Fig. 3), which can house a drawing part A protruding into a rectangular shape and a second blank holder, which will be described later, and has an opening larger than the hole S in the form of a window. a punch 12 having a recess 18 formed therein; a die 11 having a generally rectangular groove 118 as a whole corresponding to the drawn portion A of the punch 12; Two blank holders 14 are provided. The first blank holder 13 has an upper surface fastened to an outer slide 13a of the press machine via a riser 13b, and is disposed on the outer side of the punch 12.
It holds the outer circumferential inner side P1 of the blank P over the entire circumference, and a first bead 15 is formed on the holding surface, and a concave groove 16 corresponding to the first bead 15 is formed on the bolt surface of the die 11.
is formed, and a blank is sandwiched between the two and drawn while being constrained to some extent.

-4= Also, the second blank holder 14 is engaged with the retainer 20 hanging down from the recess 18. That is, the retainer 20 has a head 23a, and the sleeve 2 is inserted through the spacer 23b.
1 is fitted onto the outside of the slam 20a, and this structure is inserted into the through hole 19 of the second blank holder 14, and its tip end is screwed onto the top surface of the recess 18. When the punch 12 is at the top dead center, the lower peripheral edge of the through hole 19 comes into contact with the spacer 23b to hold the second blank holder 14 at the bottom dead center. The surface 14a is located below the drawing portion A of the punch 12. Although only one retainer 20 is shown in FIG. 3, at least two or more retainers are provided to stably engage the second blank holder 14. In addition, an elastic body 1 made of urethane rubber or the like is inserted into the recess 18 via a slam 25 whose end is screwed onto the top surface.
7 is attached, and the elastic body 17 is formed so that when the punch 12 moves to the bottom dead center, it comes into contact with the second blank holder 14 and restricts the top dead center as will be described later. The second blank holder 14 formed in this way holds the outer area P2 of the window-like hole of the blank P over the entire circumference at the top dead center position of the blank P using the elastic force of the elastic body 170.

The second blank holder 14 is also similar to the first blank holder 1.
3, it has a bead 26, and the die 11 corresponds to this.
It also has a groove 27.

The beads 15, 26 and recesses 16, 27 are formed on the outer and inner circumferential sides of the drawing section, respectively.

Next, the effect will be explained.

For example, when manufacturing a reinforcement R as shown in FIG. A frame-shaped blank P is prepared by punching out a hole S similar to the window-shaped hole W and slightly smaller than the hole W.

After placing this blank P on the die 11, first, the outer slide 13a on the press machine side is processed, and the outer peripheral inner region P1 of the blank P is sandwiched between the first blank holder 13 and the die 11, and the blank is held. .

Next, the inner slide 26 is processed. Since a bonder is fixed to this inner slide 16 via a retainer 28, the punch 12 is also machined when the inner slide 26 is machined.

Initially, the bonder 12 is at the top dead center, so the second blank holder 14 is held at the bottom dead center by the retainer 20 (the -F surface of the spacer 23b of the retainer 20 is located at the through hole of the second blank holder 14). It is located at a position where the lower peripheral edge portion of the hole 17 abuts. At the bottom dead center, the hole 14a facing the lower surface of the second blank holder 14, that is, the outer side of the window-shaped hole of the blank P, is moved by the punch 12.
Since the holder surface 14 is located below the drawing part A of the blank P, the holder surface 14 reaches the window shape of the blank P before the bottom part (the largest part in the figure) of the drawing part A comes into contact with the blank P as the punch 12 works. The hole S contacts the outside area P2, and blank-holding starts from this time. The contact force at this point (hereinafter referred to as blank force).

) becomes lli of the second blank folder 14.

Furthermore, at the time T1 when the bonder 12 descends and the bottom of the drawing part contacts the blank P, the outer area P2 of the hole S
The blank hold at is in the same blank hold state as above. When the punch 12 further processes the elastic body 17, the lower end surface of the elastic body 17 comes into contact with the step 24a of the hole 24 of the second blank holder 14, and at this point T2, the blanking force increases rapidly.
Furthermore, as the drawing process progresses, the elastic body 17 is compressed, so the blanking force increases with the amount of compression of the elastic body 17. When the punch 12 is located at the bottom dead center, that is, when the drawing process is completed, the second blank holder 14 is located at the top dead center relative to the punch 12, and at this time, the blanking force is at its maximum. Become.

As a result of the intervention of the generally rectangular drawing portion formed in the bond 12 in this way, the first blank is formed on the outside and inside of the region D (FIG. 3) where drawing is performed (Fig. 3). Since the holder 13 and the second blank holder 14 cooperate with the die 11 to hold the blank for a period from the start to the completion of the drawing process, a smoother drawing process can be performed. That is, in the case of this example, as compared with the case of FIG. 2, material also flows from the inside under the blank-hold condition, so that the material flows into the inside shoulder E and the area continuous thereto. v
At the same time, the occurrence of cracks due to tension in the AF was eliminated, and at the same time, the amount of material flowing in from the outside was reduced in accordance with the amount of material flowing in from the inside, so wrinkles were generated at the outside corner M and the flange portion following this. It was possible to solve this problem.

The amount of inflow from the outside and inside can be adjusted as appropriate by adjusting the blanking force using a well-known method, changing the shape of the bead, etc. The punched inner member can also be effectively used because it is a punched material before drawing.

As explained in detail above, in the first invention of the present application, when forming a frame shape having a drawn portion along a window-like hole,
A blank having a window-like hole similar to the hole is formed, and the drawing process is performed by blank-holding the outer part of the window-like hole of this blank and the inner part of the outer periphery of the blank. According to a second aspect of the present invention, there is provided a press die for drawing the outside of the hole of a frame blank having a window-like hole, the first blank holder holding the blank at the inner outer periphery of the blank. In addition, the lower surface of the upper mold is opened in a window shape larger than the hole-machined part, and a second blank holder is arranged in this open part, which has a hole surface facing the outer side of the window-like hole in the blank. At the same time, a press mold is provided in which the blank holder is supported so as to be movable upward through an elastic body, so that when manufacturing a frame body having a drawing part along a window-like hole, the blank is in the drawing area. It now flows into the drawing area from both sides under the blank-holding condition, which eliminates problems such as wrinkles that tend to occur in the past, especially at the shoulders of drawing. The present invention has the effect that drawing forming of a frame body of a vehicle body part having a fairly complicated shape such as a metal frame can be performed satisfactorily.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is an overall partial cross-sectional view showing a conventional reinforcement of an automobile body as a frame body having a drawing part, and Fig. 2 shows a conventional frame having a drawing part. FIG. 3 is an explanatory cross-sectional view of an embodiment of a press mold used directly in carrying out the first invention of the present application. P... Window-shaped hole [frame-shaped blank with processing,
Pl...Inside outer periphery of blank P, S...window-like hole in blank P, P2...window-like hole S in blank P
outer area, 11...die, 12...punch, 13.
...First blank holder, 14...Second blank holder, 17...Elastic body, 18...Opening part is thicker than hole S (window-shaped recess, 20... Retainer. Proceedings Neho (1 cup, June 8, 1980, Commissioner of the Patent Office Shima 1) Haruki Tono 1, Indication of the case 1982 Patent 9gi No. 8,806 Bow 2, Name of the invention Drawing processing part The method of manufacturing the frame and the press mold used for its manufacture 3 The person making the amendment and the relationship Patent appearance ceremony (↑ Location 2 Takaracho, Kanagawa-ku, Yokohama, Kana 111 Prefecture Name (399) Representative of Nissan Jidoho Co., Ltd. Ishihara,
Shun 4, Agent Address: 5 Dia Palace Niban-cho, 11-9 Niban-cho, Chiyoda-ku, Tokyo, Date of Amendment Order: May 7, 1980 (Shipping Date: May 25, 1980) 6, Amendment Order Column 7 of “Title of the invention” in the subject specification, contents of amendment 1 to 1 15

Claims (1)

[Claims] 1. When molding a frame having a drawn portion along a window-shaped hole, a blank having a window-shaped hole similar to the hole is formed, and the window-shaped hole of this blank is formed. A method for manufacturing a frame body having a drawing part, characterized in that the drawing process is performed by blank-holding the outer part of the hole and the inner part of the outer periphery of the blank. 2. A press die for drawing the outside of the hole of a frame-shaped blank that has been subjected to window-like hole punching, in addition to a first blank holder that blank-bolts the inside of the outer periphery of the blank. , the lower surface of the upper mold is opened into a window shape larger than the hole-machined part, and a second blank holder having a hole surface formed opposite to the outer side of the window-like hole of the blank is arranged in this opening part. A press mold used for manufacturing a frame body having a drawing section, characterized in that the blank holder is supported so as to be movable upwardly via an elastic body.