JP2000202527A - Closing method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a polygonal closed sheet metal product wherein a buckling deformation or the like is not generated even though a core bar is not used, also a projection is made in the inside or outside of its cross section and bending precision is high. SOLUTION: In a closing method wherein a workpiece 2 whose cross section shape is a polygon is bent into a final closed shape with a punch 7 and a die 1, the workpiece 2 is placed on the die 1 and pressurized with force fF of a spring or the like in the direction orthogonal to the transferring direction of a ram of a press machine driving the punch 7 while pressurizing the workpiece 2 with the punch 7 in the D direction of the die 1, and the workpiece 2 is simultaneously rocked to execute closing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closing method and apparatus for bending a sheet metal product having a closed cross section. More particularly, the present invention relates to a closing method and an apparatus for producing a structural member having a polygonal cross section, a reinforcing member, or the like from a sheet metal material without using a mandrel.

[0002]

2. Description of the Related Art Closing is bending of a workpiece made of sheet metal having a closed cross section. That is, the term “closing” refers to a bending process that is divided into a pre-process and a post-process, and is formed by bending the pre-process into a shape that facilitates the closing in the post-process, and finally closing in the post-process. In this closing, the waist is bent, that is, buckling, bending, and other phenomena appear, and the product accuracy often deteriorates.

[0003] For this purpose, a bending die is used both in a pre-process and in a post-process of closing, and in this bending, a core is inserted into a processed product in order to increase bending accuracy. However, especially when bending the processed product by inserting the core metal in the post-process,
The length of the product shape is limited because the mandrel accepts the bending pressure entirely. In addition, in the structure of a processed product in which a complicated projection such as bending is formed on the inside to be closed when the core is inserted, the core cannot be pulled out. .

[0004] If a direct closing process is performed only with a die and a punch without inserting a cored bar, the shape, accuracy and length are limited. That is, it is inevitable that the processed product has a limited cross-sectional shape and dimensions. As described above, in the conventional technique using the closing process, the shape of the product is restricted, so that two parts may be connected and used by means such as welding and bolts. Therefore, a processing step and a processing time are required, resulting in a high cost.

[0005]

SUMMARY OF THE INVENTION The present invention has been made under the above-mentioned technical background, and achieves the following objects. An object of the present invention is to provide a closing method and apparatus for bending a closed sheet metal product having a polygonal cross section without using a metal core. It is another object of the present invention to provide a closing method and an apparatus for bending a closed sheet metal product having a high bending accuracy without a buckle or the like and a polygonal cross section. It is still another object of the present invention to provide a closing method and apparatus for bending a closed sheet metal product having a polygonal cross section and having a deformed portion.

[0006]

The present invention employs the following means to achieve the above object. A closing method according to a first aspect of the present invention is a closing method for bending a processed product made of a sheet metal material and having a polygonal cross section into a final closed shape with a punch and a die. All the supporting surfaces of the dies supporting the side portions of the polygon do not include a surface parallel to the pressing direction of the ram. As a result, a vertical pressing force is generated on each side of the processed product, and precise bending can be performed without buckling, falling, warping, or distortion.

A second closing method according to the present invention is a closing method for bending a workpiece made of sheet metal and having a polygonal cross section into a final closed shape with a punch and a die, The workpiece is placed on the die, and the workpiece is pressed in the direction of the die with the punch, and is pressed in a direction orthogonal to the moving direction of the ram of the press machine that drives the punch, and simultaneously. The closing is performed by swinging the processed product. The difference of the closing method of the second invention from the closing method of the first invention is that the processing is performed by applying pressure in a direction perpendicular to the moving direction of the ram of the press machine for driving the punch.

However, in the closing method according to the second aspect of the present invention, all the supporting surfaces of the dies supporting the polygonal side portions of the processed product do not include a surface parallel to a pressing direction of the ram. Is good. As a result, a vertical pressing force is generated on each side of the processed product, and precise bending can be performed without buckling, falling, warping, or distortion.

Further, in the first or second closing method of the present invention, all the supporting surfaces of the dies for supporting the polygonal side portions of the processed product have a surface perpendicular to the pressing direction of the ram. Those that do not are more effective. These closing methods are preferably applied to a workpiece whose cross section is made of a sheet metal having a rectangular shape. Similarly, this creates a vertical force on each side of the workpiece, causing it to buckle, fall,
Precise bending can be performed without distortion.

According to a first aspect of the present invention, there is provided a closing apparatus for bending a workpiece made of sheet metal having a polygonal cross section into a final closed shape with a punch and a die. Has a die mounting surface substantially partially identical in shape to the final outer shape of the processed product for mounting the processed product, and the punch has the final outer shape for mounting the processed product. A punch pressurizing surface having the same shape portion as the rest of the shape is provided, and the punch comprises swinging means for swinging the workpiece for final bending by the vertical driving of the ram.

According to a second aspect of the present invention, there is provided a closing apparatus for bending a workpiece made of sheet metal and having a polygonal cross section into a final closed shape with a punch and a die. Has a die mounting surface substantially partially identical in shape to the final outer shape of the processed product for mounting the processed product, and the punch has the final outer shape for mounting the processed product. Pressing means for pressing the punch in a direction orthogonal to a moving direction of a ram of a press machine for driving the punch, comprising: Comprises rocking means for rocking the workpiece for final bending.

In the closing apparatus according to the first or second aspect of the present invention, the swinging means is provided on the die, and is provided on the die for supporting the punch in a swingable manner. Guide and fixed to the ram,
A frame supporting the punch, and within the frame,
The punch comprises: a punch support means for swingably supporting the punch so as to be movable in a direction perpendicular to the vertical movement direction of the ram; and a guide roller fixed to the punch and guided by the guide.

In the closing apparatus according to the first or second aspect of the present invention, it is preferable that the die mounting surface does not include a surface parallel to a pressing direction of the ram and a surface perpendicular to the pressing direction.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a principle diagram showing the principle of the closing of the present invention. FIG. 1 shows an example of closing a sheet metal structural member 2 (see FIG. 2) having a rectangular cross section and a predetermined length. In the pre-process, a corner 3
And the corner 4 at a diagonal position to this is bent by 90 degrees.
Angle 5 between angles 3 and 4 is an obtuse angle greater than 90 degrees, ie angle α has been bent in the previous step. These bending methods in the pre-process are techniques known as linear bending and will not be described in detail here.

The die 1 has a die L-shaped groove 6 formed therein. The die L-shaped groove 6 is formed at an angle of 90 degrees so as to match the corner 3 of the structural material 2. The bottom surface of the die L-shaped groove 6 is formed at a predetermined angle with the die 1, that is, at an angle θ with the vertical movement direction D of the ram (not shown) of the press machine. On the other hand, a punch L-shaped groove 8 is formed on the lower surface of the punch 7.

The closing device 13 is composed of the die 1 and the punch 7 having the above-described structures. In order to carry out the closing process with the closing device 13, first, the structural material 2 is placed in the die L-shaped groove 6 so as to conform to the shape of the groove. After that, the structural material 2 is inserted so as to cover the upper part thereof with a punch L-shaped groove 8 formed on the lower surface of the punch 7. At this time, the punch 7 is pulled by means of a spring or the like with a pulling force F in a direction orthogonal to the descending direction of the ram of the press machine.

Due to the pulling force F of the punch 7, the structural member 2 has a die L-shaped groove 6 and a punch L
It is slightly pressed in a direction perpendicular to the surface of the groove 8. However,
The tensile force F is a load that is not necessary from the principle of the bending process of the present invention. Desirably, the tensile force F should be present. This is for the following two reasons. The first point is that, as described later, the left and right (longitudinal direction) rotating shafts (guide rollers 47 to be described later) of the punch 7 are restricted by the coil spring 56 on the mold structure to restrict the movement of the punch 7. That is, there are no members.

The second point is that buckling always occurs on the workpiece,
From the viewpoint of preventing falling, warping, and distortion, it is preferable to always apply the tensile force F during bending. Assuming that the die 1 is fixed in this state, the punch 7 is lowered by the ram in the vertical movement direction D. Simultaneously with the lowering of the punch 7, the punch 7 swings around a fulcrum 10 which is a contact point between the punch 7 and the die 1.

At this time, a pressure accompanying the lowering of the punch 7 and a tensile force F perpendicular thereto act on the structural material 2.
Due to these pressures, a pressing force f, which is a component force, acts on the structural material 2 in a direction orthogonal to the corners of the die L-shaped groove 6 and the punch L-shaped groove 8. Since the structural material 2 is closed by performing an arc motion while receiving the pressing force f, each side of the structural material 2 is bent while being in close contact with the surfaces of the die L-shaped groove 6 and the punch L-shaped groove 8.

Accordingly, precise bending can be performed without buckling, falling, warping, or distortion of each side of the structural material 2. The end 11 of the side of the structural material 2 and the end 12 of the other side are crimped by combining grooves and notches alternately for joining. In addition, the tip 11 of the side of this structural material 2
And the other end 12 may be connected by welding or other means. FIG. 2 shows the bent structural material 2
FIG. 3 is a sectional view taken along line III-III in FIG.

[Lower Mold 14] FIG. 4 is an oblique projection view of the lower mold 14. The die holder 15 is a rectangular plate-like base. At both ends in the longitudinal direction of the die holder 15, a fixing plate 1 is provided.
6 are respectively fixed. The lower ends of the guide posts 17 are vertically fixed to the fixing plates 16 respectively.
The guide post 17 is for guiding the upper die 30. The die 1 is fixedly arranged at the center of the die holder 15. The die 1 is provided with a die L-shaped groove 6 for mounting a processed product. The die L-shaped groove 6
A groove for mounting the structural member 2 having a rectangular cross section for closing.

The first mounting surface 18 of the die L-shaped groove 6 is inclined by an angle β with respect to the upper surface 19 of the die 1. First
The second mounting surface 20 formed at right angles to the mounting surface 18 also has the upper surface 1.
9 inclined. At both ends of the die 1, V-shaped fulcrum V blocks 21 made of a plate are arranged. The fulcrum V block 21 has a V-shaped notch 2
2 are formed. The V notch 22 is for making the corner portion 26 (see FIG. 10) of the punch rotating bearing fixing plate 45 abut thereon, and swinging for the closing as described above using this as a fulcrum.

By arranging the fulcrum V blocks 21 at both ends of the die 1, the swing of the punch 7 can be accurately performed. Further outside the fulcrum V-block 21, a first guide member 23 is provided.
And a second guide member 24 are disposed. A guide groove 25 is formed between the first guide member 23 and the second guide member 24. The guide groove 25 is for guiding a guide roller 50 of the upper die 30 described later. With this guidance, the punch 7 performs the above-described swing for closing.

[Upper Die 30] FIG. 7 is a view showing the appearance of the upper die 30. The upper mold 30 has a box shape as a whole. Frames 32, 33 constituting both sides of an upper frame 31 on the ram side of the press machine, and punch supporting plates 34, 35 constituting side surfaces thereof are arranged and fixed with screws.
A punch holder 40, which guides the guide post 17 and is fixed to the ram of the press machine, is fixed to the upper surface of the upper die 30 with bolts (see FIG. 8). The punch holder 40
It is almost the same size as the die holder 15 described above.

Guide bushes 41 for guiding the guide posts 17 are arranged on both sides of the punch holder 40, respectively. The lower end of the shank 42 is fixed to the center of the punch holder 40. Shank 42
It is for fixing to the ram of the press machine. FIG.
FIG. 9 is a sectional view taken along the line IX-IX in FIG. At both ends of the punch 7, punch rotating bearing fixing plates 45 having a plate shape and a substantially rectangular shape and having the same cross section as the punch 7 are fixed with bolts 46 (see FIG. 11).

A guide roller 47 is fixed to the punch rotating bearing fixing plate 45 with bolts 48. The guide roller 47 is for guiding along the guide groove 25 arranged in the die holder 15 to cause the punch 7 to perform the above-described circular motion. On the other hand, the punch support plates 34, 35
Is formed with a guide roller guide hole 49 which is an elliptical through hole. A cylindrical guide roller 47 is inserted and arranged in the guide roller guide hole 49.

Therefore, when the guide rollers 47 disposed at both ends of the punch 7 are driven, the punch 7 is also moved into the guide grooves 25.
It is movable along. On the side surface of the guide roller 47, a cylindrical spring engaging portion 51 is integrally formed coaxially with the guide roller 47. A hook locking groove 52 is formed on the outer periphery of the spring locking portion 51. On the other hand, a rectangular parallelepiped spring fixing portion 53 is arranged and fixed to the side surface of the frame 32. The base end of a cylindrical spring locking portion 54 is fixed to the spring fixing portion 53. A hook locking groove 55 is formed on the outer periphery of the tip of the spring locking portion 54.

The hook of the coil spring 56 is locked between the hook locking groove 52 on the guide roller 47 side and the hook locking groove 52 on the frame 32 side. That is,
The coil spring 56 is in a state where the guide roller 47 is constantly pulled toward the upper frame 31 along the guide roller guide hole 49. A similar mechanism is arranged on the opposite side of the punch 7.

In the above state, when the ram of the press machine is raised and the upper die 30 is raised together with the ram, the state of the center of gravity of the punch 7 is as shown in FIG. Punch 7
Are swingably supported by guide roller guide holes 49. Since the punch 7 is supported swingably,
By the action of the center of gravity, the center of gravity swings so as to be below the guide roller 47. In order to stop the swing, a first stopper 60 is fixed to the inner lower surface of the upper frame 31.

When the ram of the press machine is raised, the swing by the action of the center of gravity of the punch 7 is stopped by the first stopper surface 61 of the first stopper 60. When the ram of the press machine is lowered, the punch 7 moves to the guide roller guide hole 49.
And moving along the guide groove 25, the fulcrum V-block 21
Make a circular motion about the bottom 63 of the V-shaped notch 22 on the upper surface of the. A second stopper 62 is fixed to an inner lower surface of the upper frame 31. The swinging movement of the punch 7 when it is lowered is stopped by the second stopper surface 65 of the second stopper 62, and presses the punch 7 from above.

A punch press rubber 64 is arranged beside the second stopper 62. The punch pressurized rubber 64 is for preventing the punch 7 from escaping from the swing fulcrum, that is, the bottom 63 of the fulcrum V-block 21 when the punch 7 swings. The fulcrum V block 21 is approximately 12 in this example.
Since it is formed at an angle of 8 degrees, the angle may be large and the function as a bearing may not be sufficiently performed. For this purpose, the corner of the punch press rubber 64 is brought into contact with the upper surface of the punch 7 to press the punch 7 with the force of the rubber pressure.

(Operation of First Embodiment) Next, the operation of the first embodiment will be described. First, the structural material 2 that has been bent in the previous step is placed in the die L-shaped groove 6 formed in the die 1. When the ram of the press machine is lowered,
The punch L-shaped groove 8 formed on the lower surface of the punch 7
Is gripped on two sides. When the ram is further lowered, the punch 7 moves along the guide roller guide hole 49 and the guide groove 25, and the V-shaped notch 2 on the upper surface of the fulcrum V block 21 is formed.
A substantially circular motion is made around the bottom 63 of the second.

When the punch 7 is further lowered to a predetermined position, the swinging movement of the punch 7 is stopped by the second stopper surface 65 of the second stopper 62. The tip 11 of the side of the structural material 2 draws an arc with a locus of radius R around the fulcrum 10 and is caulked in combination with the tip 12 of the other side. By this pressing, each side of the structural material 2 does not buckle due to the vertical pressing on each side of the structural material 2, so that it is closely attached to the punch L-shaped groove 8 and the die L-shaped groove 6.

For this reason, precise closing can be performed. Also, since no core metal is used, burring, embossing, overhanging, drawing, coining,
Closing can be performed even if there is a bent part.

[Second Embodiment] In the first embodiment, the closing of a structural material having a rectangular cross section is performed. FIG.
FIG. 4 is a view showing the principle of closing a structural material 70 having a hexagonal cross section. The die 71 has a hexagonal structural material 7.
The holding surface 72 is formed corresponding to the surface of each side of the structural material 70 that closely supports each side of the zero. Each holding surface 72
If the driving direction of the punch 7 is M, there is no holding surface 72 parallel to the moving direction M of the punch 7. The structural material 70 has a corner 7
3 is bent.

Similarly, the holding surface (not shown) of the punch 7
The holding surface 72 parallel to the moving direction of the punch 7 is not formed. At least in the final step of closing, the holding surface 72 parallel to the moving direction of the punch 7 does not appear.

[Example] The size of the structural material 2, 20 mm
(Height) x 80mm (width) x 800mm (length) x 1.6mm
Coil spring 5 when applied to (thickness) SPC material
6 having a tensile force of 400 kgf or more. At this time, the inclination angle β of the die L-shaped groove 6 of the die 1 is 25 degrees. The closing angle α is 115 degrees (see FIG. 1).
reference).

(Other Embodiments) In the above-described embodiment, the cross-sectional shapes are rectangular and hexagonal. However, as described above, even if the cross-sectional shape is triangular, pentagonal, octagonal, etc. The principle of closing is applicable.

[0039]

As described above in detail, the closing method and the apparatus of the present invention make it possible to produce a closed sheet metal product having a polygonal cross-section with high bending accuracy without using a metal core and without bending. Can be. In addition, since a core metal is not used, a closed sheet metal product having a polygonal cross section partially provided with a deformed portion can be produced, so that the applicable uses of the product are expanded.

[Brief description of the drawings]

FIG. 1 is a principle diagram showing the principle of closing a sheet metal structural material having a predetermined length and a rectangular cross section.

FIG. 2 is an external view of a bent structural material 2. FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is an oblique axis projection view of a lower die.

FIG. 5 is a front view of a lower die.

FIG. 6 is a plan view of FIG. 5;

FIG. 7 is a diagram showing an appearance of an upper die.

FIG. 8 is a front view of the upper die taken along line XX of FIG. 9;

FIG. 9 is a sectional view taken along line IX-IX of FIG. 8;

FIG. 10 is a sectional view taken along line XX of FIG. 9;

FIG. 11 is a cross-sectional view of FIG. 9, showing a state in which the closing processing has been completed.

FIG. 12 is a diagram showing the principle of closing a sheet metal structural material having a predetermined length and a hexagonal cross section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Die 2 ... Structural material 7 ... Punch 6 ... Dice L-shaped groove 8 ... Punch L-shaped groove 14 ... Lower die 15 ... Closing device 21 ... Support point V block 25 ... Guide groove 30 ... Upper die 47 ... Guide roller

Claims (9)

[Claims] 1. A closing method for bending a workpiece made of sheet metal and having a polygonal cross-sectional shape into a final closed shape with a punch and a die, wherein a polygonal side of the workpiece is provided. A closing method, wherein all supporting surfaces of the dies supporting a portion do not include a surface parallel to a pressing direction of the ram. A closing method characterized by the following. 2. A closing method for bending a workpiece made of a sheet metal material and having a polygonal cross section into a final closed shape with a punch and a die, wherein the workpiece is placed on the die. Placed, while pressing the workpiece in the direction of the die with the punch, press in the direction perpendicular to the moving direction of the ram of the press machine that drives the punch, simultaneously swing the workpiece A closing method, wherein the closing is performed. 3. The closing method according to claim 2, wherein all the supporting surfaces of the dies supporting the polygonal side portions of the processed product do not include a surface parallel to the pressing direction of the ram. A closing method characterized by the following. 4. The closing method according to claim 1, wherein all the supporting surfaces of the die supporting the polygonal side portions of the workpiece are the rams. A closing method characterized by not including a plane perpendicular to the pressing direction. 5. The closing method according to claim 1, wherein the processed product is made of a sheet metal material having a rectangular cross section. Closing method. 6. A closing device for bending a workpiece made of a sheet metal material and having a polygonal cross-sectional shape into a final closed shape with a punch and a die, wherein the die mounts the workpiece. A die mounting surface having a shape substantially identical to the final outer shape of the processed product, and the punch is provided with a remaining same-shaped portion of the final outer shape for mounting the processed product. A closing device comprising: a punch pressurizing surface; and a rocking means for rocking the punch for the final bending by the vertical driving of the ram. 7. A closing device for bending a workpiece made of sheet metal and having a polygonal cross section into a final closed shape with a punch and a die, wherein the die mounts the workpiece. A die mounting surface having a shape substantially identical to the final outer shape of the processed product, and the punch is provided with a remaining same-shaped portion of the final outer shape for mounting the processed product. A punch pressurizing surface, a pressurizing means for pressing the punch in a direction orthogonal to a moving direction of a ram of a press machine for driving the punch, and a vertical bending of the ram, whereby the punch performs final bending of the workpiece. Device comprising a swinging means for performing a swinging motion for the closing. 8. The closing device according to claim 6, wherein said swing means is provided on said die, and is provided on said die for supporting said punch in a swingable manner. A frame fixed to the ram and supporting the punch, and a punch for swingably supporting the punch in the frame and movably supporting the ram in a direction perpendicular to the vertical movement direction of the ram. A closing device, comprising: a support unit; and a guide roller fixed to the punch and guided by the guide. 9. The closing device according to claim 6, wherein the die mounting surface is a surface parallel to a pressing direction of the ram,
And a closing device not including a right-angled surface.