JP3263357B2 - Grating and grating forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grating mounted and set on an upper portion of a groove such as a U-shaped groove, and a method of forming the grating.

[0002]

2. Description of the Related Art Grating has a basic form formed of a metal material in a lattice shape, and is required to have a high mechanical strength to cover the upper end of a U-shaped groove or the like to support loads of passing vehicles and pedestrians. The molding process requires a lot of man-hours. Therefore, there is a grating shown in the specification and drawings of Japanese Utility Model Application No. 4-75165 as a structure which improves the moldability and reduces the molding cost.

[0003] That is, the grating of good formability (see FIG. 4) is described as "a bearing bar 2 which is arranged side by side at a predetermined pitch with the band width direction of the band being vertical, and a bearing bar which is arranged orthogonal to the bearing bar 2. The bearing bar 2 comprises a bar-shaped connecting bar 3 fixedly connected to the upper end of the bar 2, and a part of each of both ends of the bearing bar 2 is formed into a bent piece 4 which is bent at approximately 90 ° in the opposite direction. A structure in which left and right frame portions of a rectangular body are formed by continuity. "

[0004]

The grating 1 comprising the bearing bar 2 with the bent piece 4 described above is composed of a bent piece base 4 and a bent piece base 5 of an adjacent bearing bar 2.
It is necessary to secure the mechanical strength as the grating, and to make the bent piece 4 bend both ends of the bearing bar material of the straight band material. Therefore, a slight variation in shape cannot be avoided. In view of the above circumstances, there is a drawback that the grating 1 after molding has a curved shape of “central dent in the front-rear direction and end protrusion in the front-rear direction (dotted line in the front-rear direction)” mainly due to variation in the shape of the bent piece 4. However, such a curved form has a poor fit to a U-shaped groove or the like, and has a backlash, and lacks consistency between a road surface and a grating surface.

The present invention provides a grating which solves the above-mentioned disadvantages of the prior art, and a method of forming the grating.

[0006]

SUMMARY OF THE INVENTION To solve the above technical problems, the present invention is directed to a bearing bar which is arranged side by side with the band width direction being vertical, and is arranged at an upper end of the bearing bar at right angles to the bearing bar. It consists of a fixed bar-like connecting bar,
In the grating in the form of a lattice having a bent piece obtained by bending a part of each of both ends of the bearing bar in the opposite direction by approximately 90 ° and joining the tip of the bent piece to the bent piece base of the adjacent bearing bar, The upper surface and the lower surface of the grating are each formed in a plane form, and the lower end portions of the joining points are welded and connected, and the bearing bars in the juxtaposed posture are fixedly connected to each other at upper and lower points in the width direction. Grating "

[0007] In the forming of the grating according to the present invention, long bearing bars having a vertical band width direction are juxtaposed at a predetermined pitch, and a connecting bar having a predetermined length is cut on the long bearing bar. The long bearing bar material is placed and forwarded in the longitudinal direction, and the long bearing bar material and the connecting bar material are welded and connected, and the welded material is cut in accordance with the grating width. To form a primary molded grating in which both ends of the bearing bar material of the grating element are pressed and molded into a bent piece, and then the upper and lower surfaces of the primary molded grating Is maintained in a flat form by a press pressing means, and a lower end portion of a joining point between each end of the bent piece and the bent piece base of the adjacent bearing bar is welded and fixed to be formed. It has become the molding method "of the grating which is characterized the door.

[0008]

The above-mentioned grating of the present invention has both ends fixed structure in which the upper and lower ends of the bearing bar group are fixed by making the upper and lower surfaces planar, so that the conventional curved deformation does not exist. Then, the molding method of the present invention is to sequentially form the grating element body by sequentially feeding the material, then form a bent piece on the grating element body, and then maintain the upper and lower surfaces in a planar form. Since the lower end point of the bent piece is welded and connected, the high quality grating of the present invention can be sequentially mass-produced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a grating 1 according to an embodiment of the present invention will be described with reference to FIG. That is, it comprises a bearing bar 2 which is arranged side by side at a predetermined pitch P with the band width direction of the band being vertical, and a connecting bar 3 which is arranged orthogonally to the bearing bar 2 and embedded and connected to the upper end of the bearing bar 2,
A bent piece 4 is formed by bending a part of each end of the bearing bar 2 by 90 ° in opposite directions.
Are joined to the bent piece base 5 of the adjacent bearing bar 2, and the upper and lower faces 9 and 9 of the grating 1 of the lattice body forming the left and right frames of the rectangular body by the bent pieces 4 in a continuous form. Each of which has a planar form,
The joint lower end point 6 of the tip of each bent piece 4 and the bent piece base 5 of the adjacent bearing bar 2 is welded and connected, so that the bearing bar 2 is fixed at upper and lower points in the width direction to form a fixed structure at both ends.

Next, a grating forming method according to an embodiment of the present invention will be described with reference to FIGS. That is, FIG.
In forming the grating 1 of the embodiment, a bearing bar material 10 of a long band material for forming the bearing bar 2
Are arranged side by side with the bearing bar pitch P of the grating 1 to be formed with the band width direction vertical, and the juxtaposed width is set as the grating length L of the grating 1,
The connecting bar material 11 cut to a predetermined length is placed on the bearing bar material 10 such that the relative position with respect to the bearing bar material 10 matches the shape of the grating 1, and the processing device 20
Continuously. Then, at the welding station 22 of the processing device 20, the upper end of the bearing bar material 10 and the connecting bar material 11 are resistance-welded and connected and fixed, and then, at the next processing station 23, the long welding material is "grating". 1 grating width B + bent piece 4
The length B2 is equal to "length B2 × 2" and is cut transversely from the cut line 13, and the grating body 30 is sequentially and continuously formed.

Then, the unnecessary length of the bent piece 4 at one end of the front end bearing bar 2A and the rear end bearing bar 2B of the grating body 30 is "the length B2 hitting the bent piece 4".
Is cut and removed, and then supplied to the bending apparatus 21 to bend the bent piece 4 by a method described in detail below.

That is, the grating element body 30 after the unnecessary portion cut is set in the bending apparatus 21, one side of the left and right side edges is brought into contact with the stopper 26, and in the space adjacent to the bearing bar 2 on the other side. The end of the bearing bar 2 is set in a protruding state by an amount corresponding to the length of the bent piece 4 to be formed by inserting the press receiving die 24. Subsequently, the pin-shaped press die 25 disposed opposite to the press receiving die 24 in the adjacent space is moved forward and relatively moved in the front-rear direction of the grating body 30 shown by the arrow F in the drawing, thereby the end of the bearing bar 2. The part is bent and pressed into the press receiving mold 24,
The bent piece 4 for each side edge of the grating element body 30 is formed in a lump, and the tip of the bent piece 4 is joined to the bent piece base 5 of the adjacent bearing bar 2 sequentially and successively to the primary forming grating 1A. Molding.

Thereafter, the primary molding grating 1
A is placed on the base plate 28, and the upper surface is pressed by the press mold 29 to maintain the upper surface 8 and the lower surface 9 of the primary forming grating 1A in a parallel plane, and in this state, the joining lower end of the bent piece 4 The point 6 is welded and connected, and removed from the base plate 28 to form the grating 1 shown in FIG.

The grating 1 of the embodiment shown in FIG. 1 has an upper surface 8 and a lower surface 9 which are parallel to each other, and each of the bearing bars 2 has a fixed beam structure at both ends, which is fixed at upper and lower points. There is no rattling failure when the cover is set on the groove. In the molding method of the embodiment shown in FIG. 2, high-quality grating of the present invention can be mass-produced sequentially and continuously at low cost.

Incidentally, the molding method of the present invention is not limited to the above embodiment, and the cutting and removing of the unnecessary portions of the bearing bars 2A and 2B may be performed simultaneously with the horizontal cutting of the cut line 13.

[0016]

As described above, the grating according to the present invention has a high formability and a low cost merit in which the left and right frame sides of the rectangular body are formed by continuation of bent pieces obtained by bending both ends of the bearing bar. The grating quality is stably improved without any bending deformation of the grating. And, the grating molding method of the present invention enables continuous mass production molding of the high moldability and high quality grating, and further promotes the cost reduction of the grating. There are various practical effects described above.

[Brief description of the drawings]

FIG. 1 shows grating according to one embodiment of the present invention;
(A) is a front view, (B) is a right side view, (C) is a left side view, and (D) is a plan view.

FIG. 2 is an explanatory view of a procedure and a construction method of a grating forming method according to an embodiment of the present invention.

FIG. 3 is an explanatory view of a method of processing a bent piece in the forming method of the embodiment in FIG. 2;

FIG. 4 shows a conventional grating, (A) is a front view,
(B) is a right side view

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Grating 1A Primary forming grating 2 Bearing bar 3 Connecting bar 4 Curved piece 5 Curved piece base 6 Joint lower end point 10 Bearing bar material 11 Connecting bar material 13 Cut line 20 Processing device 21 Curving device 22 Welding station 23 Processing station Reference Signs List 24 Press receiving die 25 Press pressing die 26 Stopper 28 Base plate 29 Press die 30 Grating body B Grating width L Grating length

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 7-2589 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) E03F 5/06

Claims (2)

(57) [Claims] 1. A bearing bar which is arranged side by side with the band width direction being vertical, and a rod-shaped connecting bar which is arranged orthogonally to the bearing bar and is fixedly connected to an upper end of the bearing bar. A grating in the form of a lattice having a bent part in which both ends of the bent part are bent approximately 90 ° in the opposite direction and the leading end of the bent part is joined to the bent part base of the adjacent bearing bar. Are formed in a planar form, and the lower end portions of the joining points are welded and connected, and the bearing bars in the juxtaposed posture are fixedly connected to each other at upper and lower points in the width direction. 2. The forming of the grating according to claim 1, wherein long bearing bars having a vertical band width direction are juxtaposed at a predetermined pitch, and a connecting bar material cut to a predetermined length is attached to the long bearing bar. Is placed in the longitudinal direction of the long bearing bar material, and then the long bearing bar material and the connecting bar material are welded and connected, and the welded material is cut in accordance with the grating width. To form a primary molded grating in which both ends of the bearing bar material of the grating element are pressed and formed into a bent piece, and then the upper surface of the primary molded grating is formed. The lower surface is maintained in a flat shape by press pressing means, and a lower end portion of a joining point between each end of the bent piece and the bent piece base of the adjacent bearing bar is welded and fixed to form. A molding method for grating.