JPS6366618B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method of forming a steel sheet molded product having a cross section with a dovetail portion in the isthmus between the mountains by cold roll forming, For example, this is a roll forming method applied to forming deck plates used as synthetic floor boards for buildings, bridges, etc.

BACKGROUND OF THE INVENTION FIG. 2 shows a cross section of a certain deck plate used in composite flooring. This deck plate supports the poured fresh concrete during concrete pouring, and after the concrete hardens, it is integrated with the concrete to form a composite floor plate.

Conventionally, like this deck plate, a steel plate molded product having a cross section with a dovetail portion 3 is formed on the isthmus portion 2 between the ridges 1, as shown in Fig. 3 with the bent portion enlarged. As a method, there is a molding method shown in the molding process diagrams shown in FIGS. 5a to 5f. That is, first, the mountain 1 is formed (a in the figure). This mountain 1 is the central mountain, and FIGS. 5 a to 5 f show the right half from the center, and the molding is performed symmetrically.

Next, as shown in FIG. A square protrusion 4 having a curved point is formed in a lifted state so that the bottom part 2a of the isthmus part 2 is inclined upward. A portion of this cross-sectional shape (a portion of the isthmus portion 2) in which the square protrusion 4 is located at the center of the bottom portion 2a in the lifted state is tentatively referred to as a lifting protrusion 5.

Next, the outer peak 1 is formed (c in the same figure).

After completing the forming of the cross section having the lifting protrusion 5 between the two peaks 1, 1 of the predetermined final peak pitch P as described above, the thrust bending force by the vertical thrust rolls and the horizontal bottom part by the upper and lower horizontal rolls are applied. A dovetail is formed by the forces acting within the material during return. In other words, between the upper and lower horizontal roll stands,
As shown in e and f, the upper left and right vertical bending rolls 6, 6 and only one of the lower vertical bending rolls 7 bend the lower bending point N inward to form a square shape. The side part 4b of the protrusion 4 is inclined, and the lifting protrusion 5 is successively pushed down between the upper and lower horizontal rolls. In this case, there is no space to arrange two lower vertical bending rolls 7, so
They are arranged alternately as shown in d, e, and f in the figure.

Note that the forming process diagram in FIG. 5 shows only the main forming rolls, and in reality, the forming process is performed using multiple stages of forming rolls.

[Problems to be Solved by the Invention] The above dovetail portion 3 has a blind corner where the lower bending point N goes inside the upper bending point M and cannot come into contact with the horizontal roll. Because of this, it is impossible to mold it using normal methods.
Various methods are being devised, and the above-mentioned conventional molding method is one of them.

The above-mentioned forming method has no problem if the bent portion of the dovetail portion 3 has a relatively gentle bending shape, but it becomes a problem if a sharp bending shape is required. That is, in FIG. 3, the depth dimension W and height dimension H of the bent portion of the dovetail portion 3 are small, the interval between the upper and lower bending points M and N is extremely narrow, and the bending radius R is small. , and in the case of a bent shape in which the bending angle α is considerably larger than 90°, the following problems occur. That is, (i) It is difficult to provide a sufficiently large rigidity to the support mechanism of the vertical rolls 6, 7 as shown in Figures 5d, e, and f. It is difficult to ensure a predetermined small bending radius R and a large bending angle α in the bent portion of the portion 3.

(ii) The lower vertical bending roll 7 can only be placed on one side of the bent portion of the dovetail portion 3 due to the narrow space. Since the molding is performed alternately, the unbalance of the acting force causes return deformation in which the inclination angle θ increases, making it impossible to mold into the desired shape.

For this reason, it has been extremely difficult to ensure the predetermined dimensions W, H, R, and θ in the bent portion of the dovetail portion 3.

The present invention was made against the above background, and an object of the present invention is to provide a roll forming method that can ensure a predetermined dimension even if the dovetail portion has a sharply bent shape.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides the first
By the following steps (i) to (iv) described with reference to the drawings, a cross-section with a dovetail-like part was formed in the isthmus between the mountains.

(i) Form mountains 1 on both sides of the isthmus part 2, and
A rectangular protrusion 4 having bending points M and N at the same positions as the bending point positions M and N of the dovetail part 3 is placed in the center of the isthmus part 2, so that the bottom part 2a of the isthmus part 2 is tilted upward. (Fig. 1a), (ii) forming the upper side 4a of the square protrusion 4 into a downwardly convex arc shape with upper and lower horizontal rolls (Fig. 1b), iii) While maintaining the interval between the peaks 1, 1 on both sides of the isthmus position at a predetermined final peak pitch P, the arcuate upper side 4a of the square protrusion 4 is pushed up by the lower support roll 17, Square protrusion 4
Vertical roll 1 for punching and bending the left and right sides 4b of
8 and 18, and bend it inward to form the square protrusion 4.
The process of placing the lower bending point N inside the upper bending point M (Fig. 1 c); (iv) While also maintaining the mountain pitch P, the raised isthmus part 2 is moved to the upper and lower horizontal flat rolls 19,
20, press down and press down the bottom part 2.
Step of returning a to horizontal (FIG. 1d) In FIG. 1, T indicates the upper horizontal roll and B indicates the lower horizontal roll.

[Operation] If the upper side 4a of the square protrusion 4 is formed into a downwardly convex arc shape, the bending angle α of the upper bending point M will be 90° or more. Moreover, since this bending is performed by upper and lower horizontal rolls that can apply a sufficiently strong rolling force, a sufficiently small bending radius R can be obtained. That is, a small bending radius R and a bending angle of 90° or more are achieved at the upper bending point M position before forming the blind corner, which facilitates forming in the subsequent process.

Since the support rolls 17 act symmetrically on the dovetail portion, there is no unbalance of the acting force as in the conventional case where a vertical roll is applied only to one side of the bent portion, and there is no return deformation that increases the inclination angle θ. Can be molded.

After the side part 4b of the square protrusion 4 is slightly inclined inward by the upper vertical bending roll 18 and the support roll 17, the peak pitch P is fixed and pressed down by the upper and lower flat rolls 19, 20. A buckling deformation occurs due to the acting force within the material, so that the lower bending point N of the dovetail portion 3 goes further inside than the upper bending point M, and a predetermined dovetail shape is obtained.

[Example] The example described below concerns the molding of a deck plate having the cross section shown in FIG.
That is, it has three trapezoidal peaks 1, a hook-shaped step 7 on the oblique side 6 of each trapezoidal peak 1, and a dovetail-shaped part in the center of the isthmus 2 between the trapezoidal peaks 1. It is a cross section with 3. This deck plate is molded by the molding process shown in FIG. To roughly explain this forming process, () First, the central trapezoidal peak 1 having the key-shaped stepped portion 7 is formed in the steps shown in Fig. 4, and the isthmus portion 2 is formed in the steps shown in (). At the desired position, a cross-sectional shape with a rectangular protrusion 4 in the center of the raised bottom part 2a, that is, a lifting protrusion 5, is formed, and in the steps of () to -, the trapezoidal peak 1 on the edge side is roughly formed. , () In the steps of ~, the dovetail portion 3 is molded into a predetermined final shape, and the trapezoidal peak 1 on the edge side is also molded into a predetermined shape in parallel.

Note that the steps shown in the figure are forming stands with upper and lower horizontal rolls, and
The process shown in between is a forming process using vertical rolls arranged between horizontal roll stands. In addition, the illustrated steps ~ are shown with some of the molding stands omitted, and the actual number of molding stands is as follows.
Usually more. Further, T in the figure indicates an upper horizontal roll, and B indicates a lower horizontal roll.

Details will be explained below.

() process (~) This process consists of the central trapezoidal peak 1 with the key-shaped step 7.
This is the process of molding.

(i) The left and right key-shaped steps have bending points E and F at the same positions as the upper and lower bending points E and F of the key-shaped step 7, and the lower bending point F is bent. A triangular protrusion 8 having a right angle and a bending angle at the upper bending point E larger than the final bending angle is formed by upper and lower horizontal rolls 9 and 10, respectively (FIGS. 4(-)).

(ii) Push up the middle part 11 at the hook-shaped step position with the lower horizontal roll 12, and bend the right angle side of the triangular protrusion 8 so that the upper bending point E extends outward from the lower bending point F. Tilt it (Figure 4).

(iii) With the left and right key-shaped stepped portions supported by the lower horizontal flat rolls 13, move the intermediate portion 11
is rolled down by the upper horizontal flat roll 14 to form a hook-shaped step 7 with a bending angle larger than a predetermined final bending angle (FIG. 4).

(iv) After forming the hook-shaped step 7, bend the trapezoid ridge 1 at the upper and lower bending point positions D and G using upper and lower horizontal rolls so that the trapezoid ridge 1 is bent so that the hook-shaped step 7 is on the oblique side. (Figure 4(,)).

In this case, the bending point D on the center side when forming the triangular protrusion 8 is reversed in the direction of bending and becomes the upper bending point D of the trapezoidal peak 1. There is no problem in terms of appearance.

Step () (Fig. 6~) This step is a step of forming the lifting protrusion 5.

While lifting the adjacent parts of the trapezoidal peak 1 with vertical horizontal rolls, bend the upper bending point M of the dovetail part 3 (Fig. 4), then bend the lower bending point N of the dovetail part 3, A rectangular protrusion 4 having bending points M and N at the same positions as the bending point positions M and N of the dovetail part 3 is placed in the center of the isthmus part 2, so that the bottom part 2a of the isthmus part 2 is tilted upward. Shape it in a lifted state as shown in Figure 4.

Step () (~) Next, the trapezoidal peak 1 on the edge side is roughly formed. This process is the forming process of the central trapezoidal mountain 1 (
~) There are some differences, but they are basically the same. Although it is possible to form the trapezoidal peak 1 into the final shape in this step, it is preferable to form the trapezoidal peak 1 into the final shape in parallel with the subsequent steps in order to avoid increasing the number of stages of forming rolls. In this step, the shape of the lifting protrusion 5 is maintained.

The above steps () to () correspond to the step (i) described in the claims. The process of forming into the shape shown in FIG. 4 is not limited to that of the embodiment. Generally, in roll forming of wide material, the center part is formed first and then the edge sides are formed. In order of Mt. Trapezoid,
For example, in the case of a cross section in which the dovetail portion is in the center of the material, the lifting protrusion 5 is formed first, and then the trapezoidal peaks 1 on both sides thereof are formed. Further, instead of completing the shapes of the trapezoidal peak 1, the lifting protrusion 5, and the trapezoidal peak 1 individually, they may be formed in parallel and completed at the same time.

Step () (~) This step is a step of forming the lifting protrusion 5 into a dovetail shape. In the case of the embodiment, the shape of the trapezoidal peak 1 on the edge side is completed in parallel in this step.

(i) First, the upper side 4a of the square protrusion 4 is formed into a downwardly convex arc shape using upper and lower horizontal rolls 15 and 16 (FIG. 4).

(ii) Next, trapezoid mountains 1, 1 on both sides of the isthmus part 2 position
While keeping the interval at a predetermined final peak pitch P, the arcuate upper side 4a of the square protrusion 4 is pushed up by the lower support roll 17, and the left and right sides 4b of the square protrusion 4 are pushed up on the left and right sides. It is bent inward by vertical rolls 18, 18, the lower bending point N of the rectangular projection 4 is placed inside the upper bending point M, and the side portion 4b is inclined.
This process is performed between the upper and lower horizontal roll stands.

(iii) Next, while maintaining the mountain pitch P, the upper and lower horizontal flat rolls 19 and 20 push down the square protrusion 4 to return the bottom part 2a of the isthmus part 2 to the horizontal position (Fig. 4~) . In this process of leveling the bottom part, buckling deformation due to stress generated inside the material during pressing down causes
The lower bending point N of the dovetail portion 3 is sufficiently deeper inside than the upper bending point M, and the dovetail portion 3 having a predetermined shape is obtained.

This bottom horizontal return process is usually carried out using a plurality of horizontal roll stands, as in the embodiment, but between the horizontal roll stands, support rolls 21 and vertical rolls 22 are installed as appropriate, as shown in the intermediate process. The dovetail portion 3 may be arranged so that the shape of the dovetail portion 3 smoothly transitions to the final bent shape.

In addition, in the embodiment, in the step of returning the bottom portion horizontally, the isthmus portion 2 is pushed further down from the horizontal state (FIG. 4), and then returned to the horizontal position in the next stand (FIG. 4). This is to prevent spring back and obtain a correctly horizontal isthmus section 2.

Although the embodiment has a hook-shaped stepped portion 7 on the oblique side of the mountain, it is of course applicable to a simple mountain without the hook-shaped stepped portion 7. Also,
Of course, it can be applied not only when the peak is located at the center in the width direction of the material, but also when the dovetail portion is located at the center.

[Effects of the Invention] As explained above, according to the present invention, the following effects are achieved.

(i) Since the upper side 4a of the square protrusion 4 is formed into a downwardly convex arc shape, at the stage of forming using the upper and lower horizontal rolls, a small bending radius R and a bending angle of 90° or more is made at the upper bending point M position. This facilitates molding in subsequent steps.

(ii) Since the support rolls 17 act symmetrically on the dovetail portion, there is no unbalance in the acting force as in the conventional case where a vertical roll is applied only to one side of the bending portion, and the return angle θ increases. Molding without deformation is possible.

As mentioned above, the conventional problems have been solved, and even if the bent part of the dovetail part has a small depth W and height H, and the dovetail part has a sharp bend, it can be reliably formed into the specified shape. It becomes possible to do so.

[Brief explanation of drawings]

Fig. 1 is a molding process diagram explaining the method of the present invention, Fig. 2 is a sectional view of a deck plate that is the object of molding in an embodiment of the present invention, Fig. 3 is an enlarged view of part A in Fig. 2, and Fig. 4 Figures (Part 1), (Part 2), (Part 3),
(Part 4) is a molding process diagram showing an embodiment of the present invention for molding the deck plate shown in FIG. 2, and FIG. 5 is a molding process diagram showing a conventional molding method. 1...Mountain (trapezoidal mountain), 2...Isthmus, 2a...
Base portion, 3... Dovetail portion, 4... Square protrusion, 4
a... Side part, 5... Lifting protrusion, 17, 21
... Support roll, 18, 22 ... Vertical roll, 19, 20 ... Vertical horizontal flat roll, M ... Upper bending point, N ... Lower bending point, P ...
...Yamapitsuchi.

Claims (1)

[Scope of Claims] 1. A method of forming a steel plate molded product having a cross-section with a dovetail-shaped part in the isthmus between the mountains by cold roll forming, comprising: (i) both sides of the isthmus; A square protrusion is formed in the center of the isthmus part with a bending point at the same position as the bending point of the dovetail part, so that the bottom part of the isthmus part slopes upward. (ii) forming the upper side of the square protrusion into a downwardly convex arc shape with upper and lower horizontal rolls; (iii) adjusting the interval between the peaks on both sides of the isthmus position to a predetermined final peak; While maintaining the pitch P, the arcuate upper side of the square protrusion is pushed up by the lower support roll, and the left and right sides of the square protrusion are pushed up and bent inward by a vertical roll to form the square protrusion. Step of placing the lower bending point inside the upper bending point; (iv) While also maintaining the mountain pitch P, the raised isthmus part is pushed down by the upper and lower horizontal flat rolls, and the bottom part is leveled. A method of roll forming a cross section having a dovetail portion on the isthmus portion.