JPH081243A - Press die device - Google Patents

Abstract

PURPOSE:To obtain a low cost and long life press die device by which a belt shaped metallic sheet is press-formed for a hatshaped cross section with slight generation of frictional heat. CONSTITUTION:A hat-shaped strip work 1' consisting of a main body (a) with a U-shaped cross section and a flange part (b) is formed by press-forming a belt shaped metallic sheet with a lower die 2 and an upper die 6. The lower die 2 is provided with a rod-like projecting part 3 along the inside surface of the main body (a) of the strip work 1' and a flange forming face 4 extending sideways from the root of this projecting part 3. The upper die 6 is provided with a pad 7 having a recessed face 8 on its lower face along the upper face of the main body (a) of the strip work 1' and along the upper edge on the outer face on both side walls of the main body (a), and with a pair of bending blades 12 which is arranged movably back and forth sideways from the pad 7 and which is provided in the front part with a pressurizing face 13, in nearly an L-shaped cross section, along from the outer face of the side wall of the main body (a) to the upper face of the flange part (b). After the upper die 6 is lowered for a rough bend-forming of the belt-shaped metallic sheet with the pad 7, the bending blades 12 are advanced to simultaneously form the side wall of the main body (a) and the flange part (b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press die apparatus for press-forming a hat-shaped sheet metal work such as a side member of an automobile from a band plate-shaped sheet metal material.

[0002]

2. Description of the Related Art For example, a hat-shaped sheet metal work 1'as shown in FIG. 5 is used as side members fixed to the left and right sides of the upper surface of a floor panel of an automobile. Such a hat-shaped sheet metal work 1'has a main body a having a U-shaped cross section and flange portions b extending from both ends of the main body a, and for example, a press die apparatus as shown in FIGS. 6 and 7. Is press molded using.

The press die apparatus shown in FIG. 6 comprises a fixed lower die 25 and an upper die 26 which moves up and down. Lower mold 25
Has a square bar-shaped convex portion 27 that fits on the inner surface of the main body portion a of the hat-shaped sheet metal work 1 ′. The lower die 25 is provided with an elevating rod 28 that vertically penetrates the lower die 25 and moves up and down. A blank holder 29 is fixed to the upper end of the elevating rod 28, and a work holding lower bending blade 30 is fixed to the blank holder 29. The upper die 26 has, on its lower surface, a concave portion 32 having a U-shaped cross section that fits on the outer surface of the main body portion a of the hat-shaped sheet metal work 1 ′.
The upper curved blade 31 faces the lower curved blade 30. A pressing blade 33 is housed in the recess 32 through a spring member 34.

A strip-shaped sheet metal material 1 shown in FIG. 7 is press-formed into a hat shape by the lower die 25 and the upper die 26. That is, the elevating rod 28 of the lower mold 25 is raised to raise the blank holder 29.
Is held at a position slightly higher than the convex portion 27, and the lower curving blade 30 of the blank holder 29 and the upper curving blade 31 of the upper die 26 are held.
The one end of the sheet metal material 1 in the width direction is firmly clamped from above and below, and the other portion of the sheet metal material 1 is placed in a free state.
In the state shown in FIG. 7, the upper mold 26 is lowered to move the convex portion 2 of the lower mold 25.
7, the central portion of the sheet metal material 1 in the width direction is formed into the recess 32 of the upper die 26.
It is pushed in with a squeezing force and pressed against the pressing blade 33 in the recess 32 to obtain the state of FIG. In the state of FIG. 6, the strip-shaped sheet metal material 1
The center portion of the sheet metal material 1 is press-formed as a U-shaped body portion a of the hat-shaped sheet metal work 1 ', and both ends of the sheet metal material 1 are pressed as flange portions b of the hat-shaped sheet metal work 1'.

[0005]

Problems to be Solved by the Invention From the state of FIG.
5, the central portion of the sheet metal material 1 is replaced by the concave portion 3 of the upper die 26.
A strong ironing force is required to push the sheet metal into 2, and the frictional heat generated by the strong ironing at this time causes seizure of the sheet metal material 1 to the press die, which causes a line stop in the press process, There is a problem that the life of the press die is shortened.

As a solution to such a problem, in some cases, oil is applied to the press die to reduce the frictional resistance at the time of pressing the sheet metal material to suppress the generation of frictional heat. However, the effect of suppressing frictional heat by applying oil is thin,
There is a problem that it is difficult to extend the life of the press die and the work for applying the oil is troublesome, which deteriorates the workability of the sheet metal material pressing process.

In order to prolong the service life of the press die, in particular, the curved edge of the press die is made of a material having excellent heat resistance and abrasion resistance, and a special heat treatment is also performed. However, even if the curved edge of the press die is made of a heat and abrasion resistant material, there is a problem in durability against a large ironing force during sheet metal material pressing, making it difficult to prolong the life of the press die. There is a problem that a curved blade made of a heat and abrasion resistant material becomes expensive and a running cost becomes high.

When the strip-shaped sheet metal material 1 of FIG. 7 is press-formed into a hat shape, depending on the material of the sheet metal material 1,
At the time of demolding after the press molding, both side walls of the U-shaped main body a of the hat-shaped sheet metal work 1'expanded by spring back, and there was a problem that a predetermined hat shape was not obtained.

It is an object of the present invention to provide a long-life press die apparatus in which almost no frictional heat is generated when a strip-shaped sheet metal material is press-formed into a hat-shaped cross section.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a strip-shaped sheet metal material is pressed by a male lower die and a female upper die to form a main body having a U-shaped cross section in the width direction and the main body. A press die device for forming a hat-shaped sheet metal work consisting of flange portions extending from both ends in the width direction of the portion, and a rectangular rod-shaped convex portion along the inner surface of the main body of the hat-shaped sheet metal work in the lower die, A flange forming surface is provided that extends laterally from the base of this convex portion and follows the lower surface of the flange of the hat-shaped sheet metal work, and the upper mold has the upper surface of the main body of the hat-shaped sheet metal work and the outer edge of the outer wall of both side walls of the main body. A pad having a concave concave surface on the lower surface and a pressing surface having a substantially L-shaped cross section, which is arranged so as to be able to move back and forth on both side walls of the main body of the hat-shaped sheet metal work, and which extends from the outer surface of the main body side wall to the upper surface of the flange at the front. And a pair of curved blades having a After pressing the upper surface of the convex portion and the concave surface of the upper die pad to perform rough bending of the two corners of the upper edges of both side walls of the main body of the hat-shaped sheet metal work, the pair of curved blades are advanced to perform rough bending. It is characterized in that both ends of the sheet metal material excluding the central portion in the width direction are simultaneously pressed by the pressing surfaces of the curved blades against the side surfaces of the convex portion of the lower mold and the flange forming surface to perform L-shaped press forming.

Further, according to the present invention, a slide surface inclined downward to the flange forming surface side is provided on the side of the flange forming surface of the lower mold, and a hanging cam for supporting a curved blade on the front surface is provided on the lower surface of the upper mold. It is movably connected, and is characterized by a structure in which the curved blade is advanced by pressing the hanging cam on the slide surface of the lower die by the lower die to slide the slide surface.

Further, in the present invention, in order to prevent the deformation due to the spring back caused by the material of the hat-shaped sheet metal work, both side surfaces of the convex portion of the lower die are U-shaped of the hat-shaped sheet metal work to be press-molded. It is characterized in that it has tapered side surfaces with an angle that allows for the amount of springback on both side walls of the main body.

[0013]

[Operation] By pressing the central portion of the strip-shaped sheet metal material in the width direction with the upper surface of the lower die convex portion and the concave surface of the upper die pad, the sheet metal material is roughly bent without being squeezed. After forming, the two corners of the upper edges of both side walls of the main body of the hat-shaped sheet metal work are formed, and thereafter, both sides except the center portion in the width direction of the sheet metal material that is roughly bent by the advance of a pair of curved blades. The edges are pressed against the convex side surface of the lower die and the flange forming surface at the same time without being squeezed by the pressing surface of the curved blade, and press-formed into an L-shape. As a result of forming the flange portion, frictional heat is hardly generated in a series of press forming.

Further, the pair of curved blades of the upper die simultaneously presses both end portions of the sheet metal material except the widthwise central portion against the side surfaces of the convex portion and the flange forming surface of the lower die to form an L shape. As a result, both sides of the convex part of the lower die can be made into a negative angle taper surface considering the springback amount of both side walls of the body part of the hat-shaped sheet metal work, and the body part depending on the material of the hat-shaped sheet metal work. Deformation due to springback can be prevented.

[0015]

EXAMPLE A first example of a press die apparatus for press-forming the hat-shaped sheet metal work 1'of FIG. 5 will be described with reference to FIGS. 1 to 3, and a second example will be described with reference to FIG. To do.

The press die apparatus of the first embodiment shown in FIG. 1 comprises a fixed lower die 2 and an upper die 6 which moves up and down. The lower mold 2 has a square bar-shaped convex portion 3 and a convex portion 3 at the center of the upper surface.
Flange forming surface 4 extending in the orthogonal direction from the lower ends of both side surfaces of the
Have. The convex portion 3 has an upper surface and both side surfaces, and forms the inner surface of the main body portion a having a U-shaped cross section of the hat-shaped sheet metal work 1 ′. The flange forming surface 4 forms the lower surface of the flange portion b at both ends in the width direction of the hat-shaped sheet metal work 1 ′. Further, at both ends of the upper surface of the lower mold 2, tapered slide surfaces 5 that descend in the direction of the convex portions 3 are formed.

The upper die 6 has a pad 7 at the center of the lower surface and a pair of curved blades 12 at both ends of the lower surface. The pad 7 is the upper mold 6
The guide key 1 is inserted into the groove 14 formed vertically in the center of the lower surface of the
Guided by 5, it is stored so that it can move up and down. A spring member 16 is mounted between the pad 7 and the top surface of the groove 14, and the pad member 7 is constantly urged downward by the spring member 16. Pad 7
Has a concave surface 8 at the center of the lower surface. The concave surface 8 has a shallow groove shape along the upper surface of the main body a of the hat-shaped sheet metal work 1 ′ and the upper edges of the outer surfaces of both side walls, and a push pin 9 is provided at the center of the top surface of the concave surface 8.
Is inserted so as to project downward. A spring member 17 is mounted between the push pin 9 and the top surface of the groove 14, and the spring member 17 causes the push pin 9 to always receive a downward elastic force.

A suspension cam 11 is connected to each of a pair of blocks 10 projecting from both ends of the lower surface of the upper die 6, and a curved blade 12 is fixed to the front portion of the pair of suspension cams 11. Tapered slide members 18 facing each other in a V shape are attached to the lower surfaces of the pair of blocks 10, and the hanging cams 11 are mounted on the slide members 18 so as to be slidable in the vertical and diagonal directions of the slide members 18. . A spring material 19 is mounted between each suspension cam 11 and the lower surface of the lower mold 2, and the suspension material 11 is constantly elastically downward by the spring material 19. When the upper mold 6 is lowered toward the lower mold 2,
The lower surface of each hanging cam 11 rides on the slide surface 5 of the lower mold 2,
When the upper mold 6 is further lowered, the suspension cam 11 is pressed by the slide surface 5 and moves forward along the slide surface 5 in the lower front of the inclination of the slide surface 5, that is, in the direction in which the pair of suspension cams 11 approach each other. The curved blade 12 is fixed so as to protrude from the front surface of the hanging cam 11.

The curved blade 12 is made of a wear-resistant metal in the shape of a substantially rectangular rod, and has a pressing surface 13 composed of two substantially orthogonal surfaces, a front surface and a lower surface. The pressing surface 13 has a shape along two side surfaces of the convex portion 3 of the lower mold 2 and the flange forming surface 4 at right angles, and simultaneously forms the outer surface of the main body a of the hat-shaped sheet metal work 1 ′ and the upper surface of the flange portion b at the same time. Press appropriately. The pair of curved blades 12 perform a forward movement approaching each other and a backward movement moving away from each other.

The press die apparatus of FIG. 1 operates as shown in FIGS. 2 and 3 to press-form the strip-shaped sheet metal material 1 into a hat shape. FIG. 2 shows a state where the upper die 6 is at the position of the top dead center with respect to the lower die 2, and in this state, the convex portion 3 of the lower die 2 is placed.
When the central portion of the strip-shaped sheet metal material 1 in the width direction is placed thereon, the pad 7 of the upper die 6 is lowered, and the push pin 9 protruding from the concave surface 8 of the pad 7 is a convex portion at the center of the sheet metal material 1. 3 is pressed to position and hold the sheet metal material 1 on the convex portion 3. At this time, the pair of hanging cams 11 and the curved blades 12 of the lower mold 2 are attached to the pad 7
It is in the standby position retracted to both sides from the protruding lower part of.

In the state of FIG. 2, the upper die 6 descends, and first, the central portion of the sheet metal material 1 is pressed by the concave surface 8 of the pad 7 and the upper ends of the convex portions 3 of the lower die 2 to form the sheet metal material 1 as shown in FIG. Rough bending is performed as shown in FIG. That is, the central portion of the sheet metal material 1 is changed to the convex portion 3
By pressing the concave surfaces 8 of the pad 7 on the upper surface of the sheet metal and both corners of the upper surface, only the two corner portions c of the main body portion a of the hat-shaped sheet metal work 1 ′ shown in FIG. Both ends except the part are bent in a V shape (Fig. 3). Friction heat is hardly generated in the rough bending forming of only the central portion of the sheet metal material 1. The upper die 6 further descends in a state where the sheet metal material 1 is roughly bent, and the lower surface of the hanging cam 11 contacts the slide surface 5 of the lower die 2. At this point, the curved blades 12 of the pair of suspension cams 11 are located laterally of the V-shaped side end portions of the sheet metal material 1 that has been subjected to rough bending.

In the state shown in FIG. 3, the upper mold 6 is further lowered, and the pair of suspension cams 11 are pressed against the slide surface 5 of the lower mold 2. As a result, the pair of hanging cams 11 advance due to the cooperative action of the horizontal component force received from the slide surface 5 and the inclined slide member 18 of the block 10, and the pair of curved blades 12 advance. In this way, the hanging cam 11 of the upper die 6 is slid along the slide surface 5 of the lower die 2 to move the curved blade 12 forward, whereby the curved blade 1
The forward movement of 2 is performed smoothly, and the sheet metal material 1 described below
It enables stable press molding.

Pressing surfaces 13 of two orthogonal surfaces of the curved blade 12 that moves forward
Then, the C-shaped side end portion of the sheet metal material 1 is bent and formed into an L shape and simultaneously pressed against the side surface of the convex portion 3 of the lower mold 2 and the flange forming surface 4. The curved blade 12 that has advanced is, as shown in FIG.
The convex portion 3 is fitted between the pad 7 and the flange molding surface 4.
Side surface of and flange forming surface 4 of hat-shaped sheet metal work 1 '
The side wall of the main body a and the flange b are simultaneously press-molded. Since this press forming is performed without squeezing the sheet metal material 1, almost no frictional heat is generated.

By the way, depending on the material of the sheet metal material 1 and the press conditions, both side walls of the main body a of the sheet metal work 1'press-formed into a hat shape are formed into a V shape by spring back at the time of releasing from the die after press forming. May spread. As a measure for preventing work deformation due to such springback, both side surfaces of the convex portion 3 of the lower mold 2 are formed into inverted C-shaped tapered side surfaces 20 as in the press mold apparatus of the second embodiment shown in FIG. The front surface of the curved blade 12 is made into a taper pressing surface 21 corresponding to the taper side surface 20. The negative angle θ formed by the tapered side surface 20 with respect to the vertical line on the lower die 2 is set to an angle that allows for the springback amount of both side walls of the main body a of the sheet metal work 1 ′.

FIG. 4 shows a state in which the central portion of the band plate-shaped sheet metal material 1 is roughly bent and formed by the pad 7 of the upper die 6 and the convex portion 3 of the lower die 2, and in this state, a pair of bends is formed. The blade 12 advances to press-form both end portions of the sheet metal material 1 into a substantially L shape as shown by a chain line in FIG. Tapered side surface 20 of convex portion 3 and curved blade 12
The side end of the sheet metal material 1 that is pressed by the taper pressing surface 21 is pressed at a negative angle θ. After this press forming, when the pair of curved blades 12 is retracted to separate from the both side ends of the sheet metal material 1 formed into the substantially L shape, both side edges of the sheet metal material 1 spring back and the negative angle θ becomes 0. It becomes a predetermined parallel shape.

The present invention may have the following configurations in addition to claim 1.

(2) A slide surface inclined downward to the flange molding surface side is provided on the side of the flange molding surface of the lower mold, and a hanging cam for supporting a curved blade on the front surface can be moved back and forth on the lower surface of the upper mold. 2. The press die device according to claim 1, wherein the bending die is advanced by pressing the hanging cam on the slide surface of the lower die by sliding the slide surface on the lower die.

(3) Both side surfaces of the convex portion of the lower mold are tapered side surfaces with negative angles in consideration of springback amounts of both side walls of the U-shaped main body portion of the hat-shaped sheet metal work to be press-formed. The press die device according to claim 1, which is characterized in that.

[0029]

According to the present invention, the central portion in the width direction of the sheet metal material is pressed by pressing the central portion in the width direction of the strip-shaped sheet metal material with the upper surface of the convex portion of the lower die and the concave surface of the pad of the upper die. Roughly bent without being squeezed, and the edges of both sides of the sheet metal material rough-formed by the forward movement of a pair of curved blades excluding the widthwise central portion are not squeezed by the curved blade pressing surfaces. Since the predetermined hat-shaped sheet metal work is press-formed by being simultaneously pressed by the convex side surface of the lower mold and the flange forming surface and press-formed into an L-shape, frictional heat hardly occurs in a series of press-forming, As a result, seizure of the press die sheet metal material on the press die is eliminated, and the troublesome work of applying oil to the press die is unnecessary, and the efficiency of the production line of the press process can be improved, In addition, the press die must be made of a material with excellent heat resistance and abrasion resistance. Without, the life of the press die, cost reduction can be achieved.

Further, by providing the lower die with the slide surface for advancing the suspension cam for supporting the upper curved blade, the forward movement of the curved blade is stably performed, and the reliability of press forming of the sheet metal material is ensured. Will get better.

Further, since the side surface of the convex portion of the lower die is pressed by the curved blade of the upper die and press-molded, the side surface of the convex portion of the lower die is made into a negative angle taper side surface in consideration of the springback amount of the sheet metal material. This makes it possible to prevent the press-formed sheet metal work from being deformed due to springback, and to provide a press die device capable of forming a hat-shaped sheet metal work with a stable shape.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sheet metal material press-molding showing an embodiment of the present invention.

FIG. 2 is a sectional view of the apparatus shown in FIG. 1 immediately before pressing a sheet metal material.

FIG. 3 is a sectional view of the apparatus shown in FIG.

FIG. 4 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 5 is a perspective view showing an example of a hat-shaped sheet metal work.

6 is a cross-sectional view of a conventional press die device that press-forms the sheet metal work of FIG.

FIG. 7 is a sectional view of the apparatus shown in FIG. 6 immediately before pressing a sheet metal material.

[Explanation of symbols] 1 sheet metal material 1'sheet metal work 2 lower die 3 convex portion 4 flange forming surface 5 slide surface 6 upper die 7 pad 8 concave surface 11 hanging cam 12 curved blade 20 tapered side surface

Claims (1)

[Claims] 1. A strip-shaped sheet metal material is pressed by a male lower die and a female upper die to extend from a main body having a U-shaped cross section in the width direction and both ends in the width direction of the main body. A press die device for forming a hat-shaped sheet metal work consisting of an existing flange portion, wherein the lower die is a rectangular bar-shaped convex portion along the inner surface of the main body of the hat-shaped sheet metal work, and from the root of this convex portion. It has a flange forming surface that extends laterally and extends along the lower surface of the flange portion of the hat-shaped sheet metal work, and the upper mold has a concave surface along the upper surface of the main body of the hat-shaped sheet metal work and the outer surface upper edge of both side walls of the main body. A pair that has a pad on the lower surface and a pressing surface having a substantially L-shaped cross section that is arranged laterally on both side walls of the body part of the hat-shaped sheet metal work so as to be able to move back and forth and that extends from the outer surface of the body part side wall to the upper surface of the flange part. With the curved edge of the strip plate-shaped sheet metal material, After pressing the concave surface of the upper die pad to form the two corners of the upper edges of both side walls of the main body of the hat-shaped sheet metal work by rough bending, a pair of curved blades are advanced to form the rough-formed sheet metal material. A press die apparatus, characterized in that both side ends except for the center portion in the width direction are simultaneously pressed by the pressing surface of a curved blade against the convex side surface of the lower mold and the flange molding surface to perform L-shaped press molding.