JPS6144576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for simultaneously performing U-shaped bending and curling of the entire periphery of a sheet metal product surrounded by a three-dimensional curve, such as a motorcycle fender or a vehicle bumper, in the same process; It is related to the device.

Products such as motorcycle fenders and vehicle bumpers are made by forming metal thin plate members into a roughly U-shape.In the case of fenders, the entire body is shaped into a roughly arc shape, and in the case of bumpers, both ends are shaped into roughly arc shapes. do. Such products can be obtained by press punching, drawing, etc., but if the cut surfaces of the plate at the end of the obtained molded product are left untouched, it may be dangerous for accidents or maintenance, and it may also be susceptible to vibrations during driving. There is a risk of cracks occurring due to etc. For this reason, curling is performed on the terminal portion to form a curled portion.

Conventionally, a metal plate is formed into a gutter shape with a U-shaped cross section.
When forming a curled part around the entire circumference, the gutter-like product forming method requires the following steps: blanking, forming, pre-bending, curling, and U-bending, resulting in a large number of steps and the work is troublesome and complicated. Even if this process is shortened, at least three steps are required: U-bending, curling of both ends, and curling of the straight parts on both sides.Furthermore, in the drawing method, draw, trim, side bend steps 1 to 3, and curling 1 to 3 are required. 2
This method requires various steps such as process and restriking, requires a large number of processing steps, is complicated and time-consuming, and has problems such as poor productivity and relatively high production costs.

The present inventors have devised the present invention in order to solve the above-mentioned problems in the conventional method of U-shaped bending and curling around the entire circumference.

The purpose of the present invention is to punch out a material into a developed shape,
In addition, the material, which has been pre-bent at the necessary ends as necessary, is set between the male and female dies for U-bending, and the U-bending is first performed, and while the material is being held, both ends of the material are Then, the straight parts on both sides are curled, and U-bending of the material and curling all around are done simultaneously, which greatly reduces the process and man-hours, simplifies work, saves labor, and simplifies equipment. It is an object of the present invention to provide a method and apparatus for simultaneously performing U-shaped molding and full-circumference curling molding, which can reduce costs.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The premise of the present invention is to punch out a thin metal plate into the developed shape of a molded product. For example, it is punched into the developed shape of a motorcycle fender or a vehicle bumper _, and FIG. ₁ shows a basic punched material for forming a motorcycle fender. Both sides W ₂ , W ₂ are linear and form an elongated oval shape. A predetermined number of attachment holes W ₃ . In addition, in the punching process, a curling preformed stepped portion W in the form of a downwardly recessed groove is formed at both ends of _the straight portions on both sides of the material W, as shown in FIG. _Five ,
W ₅ is molded at the same time.

The above-mentioned material W is put between the male and female molds, and is bent into a U-shape and formed into a gutter shape between the molds.The U-shaped bent state is maintained between the molds, and both ends of the material are held. Curling is performed using a curling mold that moves forward and backward by moving the material downward, and then the end portions on both sides of the material are curled using linear curling molds that are placed on both sides of the material.

The obtained molded product has a U-shaped cross section and a curled portion around the entire circumference, and in the case of a fender, the entire molded product is molded into an arc shape.

Next, we will explain the specific molding process in conjunction with the molding equipment.
I will explain in detail after the figure.

The molding apparatus 1 is as shown in FIG. 2, and although the right half of the figure is a cross section, it has a symmetrical mechanism.

The upper mold 2 is a movable mold, which is moved up and down by a press machine ram (not shown), and has an inverted U-shaped groove-shaped U-bending die 3 in the longitudinal direction of the upper mold 2, in the left-right center in the figure, and in the widthwise center. is provided so that the groove is open downward, and the groove is also open in the length direction. If the molded product is a fender, the downward U-shaped molding groove 3a of the die 3 is set to have a shape outside the cross-sectional shape of the fender, as shown in FIG. There are guide recesses 2 on both left and right outer sides near both ends of the upper mold 2.
a.... are arranged vertically, and the lower die main body 4 is guided by a guide plate, which will be described later.

Reference numeral 4 denotes a lower mold body, which is located on the press machine bolster (bed).The body 4 has a planar frame shape, and inside it is a floating mold that is surrounded by this and can be slid relatively freely between the body 4 and the press machine bolster (bed). A base 5 is provided, and the floating base 5 is supported by a plurality of parallel dictation pins 6. A U-bending punch 7 is provided in the center of the upper surface of the base 5 in the length direction, and has a forming protrusion 7a at the upper end that matches the forming groove 3a of the die 3, and the protrusion 7a has an upwardly curved arc shape. Conforms to the cross-sectional shape of the inner surface of the fender.

A pair of straight side curling dies 8, 8 are fixedly supported on both sides 4a of the lower die main body 4, on the front and back sides in the front and back directions in the drawing. A molding groove 8a in the form of an inverted U-shaped groove is provided at the upper end of each of the dies 8, 8 so as to be open to the upper surface and both ends thereof.
The dies 8, 8 are located at the lower sides of both sides of the punch 7 during standby, facing both sides in the length direction of the material W to be formed between the punch 7 and the die 3, and are disposed over the length of both sides. has been done.

On the other hand, both ends of the punch 7 on the floating base 5 mentioned above slide toward or away from both ends of the punch so that the tip curl dies 9, 9 face each other on the left and right sides of the punch 7 in the figure. Can be set freely. During standby, the dies 9, 9 are located apart from both ends of the punch 7, as shown in FIG. 9a are provided respectively. and groove 9
a is the material when the material is formed into a U-shaped gutter shape,
Both tips are provided to match the three-dimensional shape of the curling bead. Further, the opposing inner end portions 9b, 9b of the dies 9, 9 are formed into U-shapes that face each other in plan view so as to match the planar projection shape of both tip portions after molding.

Pins 9c are provided across the outer portions of the tip curling dies 9, 9, and guide rollers 10 are pivotally supported at both ends of the pins 9c that protrude on both sides of the dies. On the other hand, guide plates 11 are fixed on both sides of the lower mold body 4 near both ends, and the guide plates 11 are raised upward and extend to both sides of the die 9, and the plates 11... ......
A symmetrical horizontal V-shaped cam groove 12 is formed at both ends so that the peaks face each other and face inward. The cam groove 12 is connected to each guide plate 11...
Each part of the groove is continuous with an oblique side 12a formed on the inner surface of the groove, whose upper part is an inward downward slope, a central part 12b is a horizontal peak, and a downward side from the central part 12b is an outward downward downward downward slope 12c. Rollers 10 protruding from both sides of both dies 9, 9 in this cam groove 12...
engage.

In the above, the material W is cut into the die 3 and punch 7 of the upper and lower molds 2 and 4 as shown in FIGS. 2 and 3.
After that, the upper die is lowered and the center part of the lower surface of the material W is supported by the center part of the protrusion 7a of the punch 7, and the flat lower surfaces 3b, 3b on both sides of the forming groove 3a of the die 3 are
reaches the upper surface of the preformed step portions W ₅ , W ₅ on both sides of the material W. The material W is set so that its axial direction (lengthwise direction) is along the upper and lower punches and dies.

Next, the upper die 2 is moved down, and the die 3 is lowered, the protrusion 7a of the punch 7 enters the forming groove 3a of the die, and the material W is formed into a gutter shape with a U-shaped cross section. As shown in FIGS. 4 and 5, the trough-like forming load is held by a dicing pin 6. As a result, a gutter-shaped material W ₈ is formed, and the stepped portions W ₅ and W ₅ on both sides face downward as the U-bending of the material is completed, and both ends 7b and 7b in the width direction of the forming protrusion 7a of the punch 7 and forming grooves are formed. The edge portions 3c _{, 3c} between both ends of 3a and the lower surface sandwich the intermediate portion formed including the inner portion _W6 of the widthwise base of the step portions _W5 , _W5, and Each terminal portion W ₇ holds the punch 7 and faces inward while being separated from it.

With the U-shaped forming completed, the upper mold body 2 is moved down while the material W ₈ is held between the die 3 and the punch 7. Along with this, the floating base 5 also moves downward, and the rollers 10 that were engaged with the upper ends of the cam grooves 12 are guided by the inwardly facing oblique sides 12a of the grooves and symmetrically move inward. It is slidably guided on each end of the floating base 5. As a result, Figure 2,
As shown in FIG. 4, the curl dies 9, 9, which were spaced apart from both ends of the material W or W ₈ , are placed in the sixth position.
As shown in the figure, they slide in the direction toward each other. The guide plate 11 engages with the recess 2a of the upper die 2 to ensure linear upward movement, and reaches the horizontal V-shaped peak 12b at the lower end of the oblique side 12a, so that the inner end forming groove 9a of the dies 9 has a cross section of U. It is in contact with both tips of the mold material W ₈ , and the tip is bent inward by the guiding action of the groove 9 a and curled, forming a curled portion W ₉ at the tip as shown in Figure 7. It happens.

As the upper die main body 2 further descends, the roller 10 moves from the crest 12b of the cam groove 12 to the lower oblique side 1 facing downward and outward.
2c and are guided outward, so that the dies 9, 9 slide outward after the molding is completed, and do not interfere with the molding of the stepped portions _W5 , _W5 on both sides of the material _W8 . Do it like this. As the main body 2 continues to move downward, the floating bases 5, 5 descend while sliding on both sides of the lower mold main body 4, leading to stepped portions _W5 , the tips W of _W5 hanging on both sides of the material _W8 . ₇ is in contact with the molding grooves 8a, 8a, which face inward, and the molding groove 8a is arc-shaped, so that the stepped portions _W5 , _W5 are formed so as to be wound symmetrically inward, and the stepped portions Since the base part W ₆ of W ₅ and W ₅ is held between the edge parts 3c and 7b, the lower step part is curled, and the die 8 is stopped at a position where it maintains a slight clearance from the lower surface 3b of the die 3. and complete the curling process. This is shown in Figures 8 and 9, and the U-shaped material
Curled portions W ₁₀ and W ₁₀ will be processed on both sides of W ₈ .

Thereafter, the molding device was operated in reverse to open the mold and dispense the material, and the obtained material W ₁₁ is shown in FIG.

After that, the next step is to form a fender, bumper, etc.

Although the above description has been made regarding the molding of fenders or bumpers, the products to be molded are not limited thereto.

As is clear from the above, according to the present invention, a U-shaped cross-sectional material that requires curling around the entire circumference can be formed from a material punched into a developed shape, and the U-shape and all-around curling can be simultaneously performed in one process. U-bending and all-around curling, which conventionally required multiple processes and equipment, can now be easily performed with a single molding machine, simplifying and simplifying the work and significantly reducing the number of man-hours. It is possible to achieve efficient and rational molding, which can reduce the number of molds and reduce labor costs, minimize equipment costs, and reduce molding costs and equipment costs, which has great practical effects.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a perspective view of a basic molding material, Fig. 2 is a half-cut side view of a forming device, and Fig. 3 is an enlarged sectional view of a punch and die.
Figure 4 is the same figure as Figure 2 during U-bending forming, and Figure 5
The figure is a view similar to Figure 3 in the same forming state, Figure 6 is a view similar to Figure 2 during curling of the tip of the material, Figure 7 is an enlarged sectional view of the main part of the curling material, FIG. 8 is a view similar to FIG. 2 when both sides are curled, FIG. 9 is a view similar to FIG. 3 in the same molded state, and FIG. 10 is a perspective view of the molded product. In the drawing, W is the material, W ₅ is the preformed part, and W ₈ is U.
Mold material, W ⁹ and W ₁₀ are curl parts, W ₁₁ is molded product, 2
3 is an upper mold, 3 is a die, 4 is a lower mold main body, 5 is a floating base, 7 is a punch, and 8 and 9 are curl dies.

Claims (1)

[Scope of Claims] 1. A material punched into a developed shape and subjected to preliminary bending at the end is set between male and female molds for U-bending, bent into a U-shape, and the state of the U-bending is Both ends of the material held between the molds are curled with curling molds that move forward and backward relative to the material, and then the straight curling molds disposed on both sides of the material are raised or the male and female parts for U-bending are formed. A forming method that simultaneously performs U-shaped forming and full circumference curling, characterized in that both ends of the material are curled by relative movement such as downward movement of the mold. 2. An upper die equipped with a die formed into the completed shape of a U-shaped molded product, a floating base equipped with a punch facing the die and movable up and down relative to the lower die body, and a material provided on the lower die body. a both-side substantially straight part curling die for curling the substantially straight parts on both sides;
Both ends of the material are slidably provided facing both ends of the punch on the floating base, and are provided so as to approach and separate from both ends of the punch in conjunction with the lifting and lowering movement of the floating base. An apparatus for simultaneously performing U-shape forming and full-circumference curling, characterized by comprising a double tip curling die for curling both tip ends of a material provided so as to be close to each other and spaced apart from each other.