JP3824263B2 - Grating and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a grating used for a gutter, a water collecting tank, and the like and a method for manufacturing the same.
[0002]
[Prior art]
Grating is laid in a gutter, a water collecting trough, etc., and rain water etc. flow into a gutter etc., a vehicle etc. can pass through it, and it prevents that a big foreign material enters a gutter etc.
[0003]
This grating is a pair of end bars facing each other and extending in parallel in the length direction, and extending between each end bar and a direction perpendicular to both end bars, and both ends are fixed to each end bar at a predetermined pitch. And a plurality of bearing bars. Further, a cross bar for connecting the bearing bars to each other may be provided.
[0004]
In the conventional grating, welding is performed between both end bars and both ends of each bearing bar, whereby each bearing bar is fixed to the end bar with a required mechanical strength.
[0005]
[Problems to be solved by the invention]
However, the conventional grating has the following problems because both end bars and the bearing bar are fixed by welding.
[0006]
That is, in this grating, since there are as many welding locations as the bearing bar, there are many welding locations, which requires a long time for manufacturing, and consequently increases the manufacturing cost.
[0007]
In addition, this grating has a problem in that distortion is likely to occur due to heat generated during welding and dimensional accuracy deteriorates.
[0008]
Furthermore, since this grating may cause a welding residue to be caught inside the welded portion or generate a nest, those defective portions may be damaged during use, resulting in rattling.
[0009]
In particular, when the grating is made of a material that is difficult to weld, such as stainless steel, these tendencies are large.
[0010]
For this reason, a grating has been proposed in which both end bars and the bearing bar are fixed by caulking (Japanese Patent Laid-Open No. 2000-87441). In this grating, both end bars have fitting holes provided at a predetermined pitch. Further, at both ends of each bearing bar, a contact surface that contacts the inner surface of the end bar and a fitting portion that protrudes from the contact surface and fits into the fitting hole are formed. When manufacturing this grating, first, such an end bar and a bearing bar are prepared as a preparation process. And as a fitting process, a bearing bar is faced mutually parallel according to pitch, a fitting part is fitted to a fitting hole, and a contact surface is made to contact this inner surface. Thereafter, as a caulking step, the bearing bar is fixed to the end bar by caulking the fitting portion protruding from the fitting hole from the outer surface side of the end bar with a press die or the like. In the grating obtained in this way, the above-mentioned problems caused by fixing both end bars and the bearing bar by welding can be avoided.
[0011]
However, in the grating manufactured by caulking in this manner, since the tip of the fitting portion before caulking is flat, a mold having a protrusion at the tip that contacts the fitting portion is used, and the protrusion is within the fitting portion. You have to get in and push the material outwards. For this reason, the metal mold | die etc. which are used at the time of manufacture become complicated, and it is difficult to reduce the manufacturing cost. In addition, since the protrusions such as molds are worn and deformed by repeated caulking, the protrusions are periodically polished and returned to their original shapes. Will also grow. For this reason, the reduction in manufacturing cost due to the use of caulking is impaired.
[0012]
The present invention has been made in view of the above-described conventional situation, and an object to be solved is to provide a grating and a method for manufacturing the same that can surely reduce the manufacturing cost.
[0013]
[Means for Solving the Problems]
The grating according to the present invention has a pair of end bars facing each other and extending in parallel in the length direction, extending between the both end bars in a direction perpendicular to the both end bars, and both ends extending to the end bars. In gratings with multiple bearing bars fixed at a predetermined pitch,
The both end bars have fitting holes penetrating in accordance with the pitch, and at both ends of each bearing bar, a contact surface that contacts the inner surface of the end bar, and a protrusion that protrudes from the corresponding contact surface. And a convex portion that protrudes from the fitting portion and is caulked from the outer surface side of the end bar to fix the bearing bar to the end bar.
[0014]
The manufacturing method of the grating according to the present invention includes a pair of end bars having a plurality of fitting holes penetrating at a predetermined pitch, and a contact surface that contacts the inner surface of the end bar at both ends. A preparation step of preparing a plurality of bearing bars that have a fitting portion that protrudes and fits into the fitting hole, and that has original protrusions protruding from the fitting portion,
A fitting step in which the bearing bars face each other in parallel according to the pitch, the fitting portion is fitted into the fitting hole, and the contact surface is brought into contact with the inner surface;
A caulking step of fixing the bearing bar to the end bar by caulking the original convex portion protruding from the fitting hole from the outer surface side of the end bar.
[0015]
In the grating according to the present invention, the fitting portion of the bearing bar is fitted into the fitting hole of the end bar, and the protruding portion protrudes from the fitting portion when the contact surface of the bearing bar contacts the inner surface of the end bar. The convex portion is caulked from the outer surface side of the end bar to fix the bearing bar to the end bar. If the convex part before caulking is the original convex part, the bearing bar before caulking projects the original convex part from the fitting part, and the original convex part becomes the fitting part by caulking the original convex part. The material can be spread outwardly, thereby securing the bearing bar to the end bar.
[0016]
For this reason, in this grating, the said malfunction by fixing both end bars and a bearing bar by welding can be avoided.
[0017]
In addition, in this grating, since there is a convex portion at the tip of the fitting portion, there is no need to use a die having a projection at the tip that contacts the fitting portion, a die having a flat tip, etc. Can be adopted. Further, only the convex portion protruding from the fitting portion is plastically deformed in the caulking. For this reason, the force required for caulking is reduced, and the original convex portion can be easily caulked even when a die having a flat tip is employed. For this reason, the mold can be simplified, and the manufacturing cost thereof is low. Further, even if caulking is repeated, the degree of wear and deformation of the mold and the like is small, and the management cost of the mold and the like can be low.
[0018]
Therefore, according to the grating of the present invention, it is possible to surely reduce the manufacturing cost.
[0019]
It is preferable that the fitting hole extends in the width direction of the end bar, the fitting portion has a plate shape that is aligned with the fitting hole, and the convex portions are formed on both ends of the fitting portion. Grating is susceptible to downward force because a vehicle or the like passes over the grating. If such a fitting hole, a fitting part, and a convex part are employ | adopted, since the intensity | strength with respect to those downward force will be strengthened, it will have the outstanding durability.
[0020]
It is preferable that support portions protruding from the convex portions are formed at both ends in the width direction on the outer surfaces of both end bars. If this is the case, when the grating is fitted into the side groove or the water collecting trough via the receiving frame, the convex portion does not interfere with the receiving frame.
[0021]
It is preferable that both support parts protrude from the original convex part which is a convex part before caulking. If it is like this, the jig for caulking can be made into a simple shape. That is, when caulking the original convex portion, it is necessary to fix the end bar on the side opposite to the caulking side. Here, if both the support portions protrude from the original convex portion, a flat surface is formed on the fixing jig, and the flat surface is brought into contact with the support portion of the end bar to be fixed, thereby obstructing the original convex portion. Without being done, the end bar can be easily fixed. For this reason, the fixing jig for caulking can be simplified, the manufacturing cost of the jig can be reduced, and the manufacturing cost of the grating can be reduced.
[0022]
The bearing bar preferably has a T-shaped or I-shaped cross section. Since such a bearing bar has a high strength against the lateral force that the grating receives from the outside, it is often used in the grating, but has a portion extending in the horizontal direction at least upward. This is because it is difficult to employ fixing by welding, and defects due to welding are likely to occur.
[0023]
The effect of the present invention is great when the end bar and the bearing bar are made of stainless steel. End bars and bearing bars made of stainless steel are preferable for grating because they are excellent in corrosion resistance. On the other hand, discoloration occurs when fixing by conventional welding is employed. For this reason, when these end bars and bearing bars are employed for high durability due to excellent corrosion resistance, it is necessary to perform surface treatment such as electrolytic polishing and painting after welding. In this respect, in the present invention, both end bars and the bearing bar are fixed by caulking, so there is no risk of discoloration due to welding, and there is no need to perform surface treatment such as electrolytic polishing or painting. For this reason, in this case, a grating having excellent corrosion resistance can be produced at low cost.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to FIGS.
[0025]
The grating according to the embodiment is made of SUS304, and includes a pair of end bars 1, a plurality of bearing bars 2, and a single cross bar 3, as shown in FIG. Both end bars 1 face each other and extend in parallel in the length direction, and the bearing bar 2 extends in a direction perpendicular to the end bar 1 while facing each other between both end bars 1. The cross bar 3 passes through each bearing bar 2 at right angles.
[0026]
As shown in FIG. 2, the end bar 1 has a substantially U-shaped cross section, and has fitting holes 1a penetrating at a predetermined pitch. The fitting hole 1 a has a rectangular shape extending in the width direction of the end bar 1. At both ends in the width direction on the outer surface of the end bar 1, support portions 1b and 1c extending in parallel with the length direction are formed so as to protrude.
[0027]
As shown in FIGS. 3 and 4, the bearing bar 2 has a substantially T-shaped cross section, and at both ends of the bearing bar 2 are plate-like fitting portions that are aligned with the fitting holes 1 a of the end bar 1. 2a is provided. Original projections 2b and 2c are formed to protrude from both ends of both fitting portions 2a. Abutting surfaces 2 d and 2 e that can abut against the inner surface of the end bar 1 are formed above and below both fitting portions 2 a at both ends of the bearing bar 2. The height h4 from the contact surfaces 2d, 2e to the original convex portions 2b, 2c is made larger by the height h3 of the original convex portions 2b, 2c than the depth h1 of the fitting hole 1a shown in FIG. . Moreover, h4 is made smaller than the width h2 from the inner surface of the end bar 1 shown in FIG. 2 to the outer surfaces of the support portions 1b and 1c. The bearing bar 2 is provided with a circular fitting hole 2f extending in parallel with the end bar 1 at a central position in the longitudinal direction.
[0028]
As shown in FIG. 5, the fitting portion 2a of the bearing bar 2 is fitted in the fitting holes 1a of both end bars 1, and each bearing bar 2 is moved by caulking the original convex portions 2b and 2c. It is fixed to the end bar 1. The cross bar 3 is inserted into the fitting hole 2 f of the bearing bar 2, and the cross bar 3 is fixed to each bearing 2 by caulking the exposed portion of the cross bar 3.
[0029]
The grating of the embodiment configured as described above is manufactured as follows.
[0030]
<Preparation process>
As shown in FIG. 4, a U-shaped long member made of SUS304 is cut to a predetermined length, and a fitting hole 1 a is penetrated at a predetermined pitch by a press to form an end bar 1. Further, a T-shaped long member made of SUS304 is cut into a predetermined length, and a fitting portion 2a, original convex portions 2b and 2c, contact surfaces 2d and 2e, and a fitting hole 2f are formed by a pressing method. The bearing bar 2 is used. Further, the tubular member made of S304 is cut to the same length as the end bar 1 to form a cross bar 3.
[0031]
<Mating process>
The bearing bars 2 face each other in parallel at a predetermined pitch and are aligned with a jig (not shown). As shown in FIG. 5, each cross bar 3 is inserted into the fitting hole 2f of the bearing bar 2, and the fitting portion 2a of the bearing bar 2 is inserted into the fitting hole 1a of the end bar 1 as shown in FIG. Then, the contact surfaces 2 d and 2 e of the bearing bar 2 are brought into contact with the inner surface of the end bar 1.
[0032]
<Caulking process>
A mold 4 having a flat pressing surface 4a is prepared and fixed to a pressing machine (not shown). And the press surface 4a of the metal mold | die 4 is pressed against the original convex parts 2b and 2c, and is made into plastic deformation, and it is set as the convex parts 2g and 2h shown in FIG. At this time, the support portions 1b and 1c of the end bar 1 opposite to the side to be pressed are fixed in contact with a plane of a fixed block (not shown). Thus, as shown in FIG. 8, the original convex portions 2b and 2c of the bearing bar 2 are caulked to the end bar 1 to become convex portions 2g and 2h. Further, the exposed portion of the cross bar 3 shown in FIG. 5 is caulked with a mold (not shown) to fix the fitting portion between the cross bar 3 and the bearing bar 2. Thus, the grating of the embodiment shown in FIG. 1 is manufactured.
[0033]
In the grating of the embodiment, as shown in FIG. 6, since the original convex portions 2b and 2c are present at the tip of the fitting portion 2a, a mold having a protrusion at the tip that contacts the fitting portion 2a, etc. It is not necessary to use a metal mold, and a die having a flat tip can be employed. Further, only the original convex portions 2b and 2c projecting from the fitting portion 2a are plastically deformed by caulking. For this reason, the force required for caulking is reduced, and the original convex portion can be easily caulked even when a die having a flat tip is employed. For this reason, the mold can be simplified, and the manufacturing cost thereof is low. Further, even if caulking is repeated, the degree of wear and deformation of the mold and the like is small, and the management cost of the mold and the like can be low.
[0034]
Further, as shown in FIG. 5, the grating is a plate shape in which the fitting hole 1a extends in the width direction of the end bar 1, the fitting portion 2a is aligned with the fitting hole 1a, and the original convex portions 2b and 2c are formed. It is formed on both ends of the fitting part 2a. Further, the bearing bar 1 has a T-shaped cross section. For this reason, since the intensity | strength with respect to a downward and horizontal force is strengthened, it will have the outstanding durability.
[0035]
Further, at both ends in the width direction on the outer surface of the end bar 1, support portions 1b and 1c extending in parallel with the length direction are formed to protrude. And both the support parts 1b and 1c protrude from the original convex parts 2b and 2c before caulking. For this reason, when the original convex portions 2b and 2c are caulked to fix the bearing bar 2 to the end bar 1, a fixing jig for caulking can be made into a simple shape. Further, when this grating is fitted into a side groove or a water collecting trough through a receiving frame, the convex portions 2g and 2h do not interfere with the receiving frame.
[0036]
Further, the end bar 1, the bearing bar 2 and the cross bar 3 constituting the grating are all SUS304, and they are fixed by caulking, so that even if surface treatment such as electrolytic polishing or painting is not performed, it is left as it is. It can be a final product. For this reason, the grating excellent in corrosion resistance can be manufactured at low cost.
[0037]
[Brief description of the drawings]
FIG. 1 is a partial perspective view of a grating according to an embodiment.
FIG. 2 is a cross-sectional view of an end bar.
FIG. 3 is a partial front view of a bearing bar.
FIG. 4 is an exploded perspective view of the grating before fitting.
FIG. 5 is an exploded perspective view of the grating before caulking.
FIG. 6 is a partial cross-sectional view of the grating before caulking.
FIG. 7 is a partial sectional view of the grating during caulking.
FIG. 8 is a partial cross-sectional view of the grating after caulking.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... End bar 2 ... Bearing bar 1a ... Fitting hole 2d, 2e ... Contact surface 2a ... Fitting part 2b, 2c ... Original convex part 2g, 2h ... Convex part

Claims (7)

A pair of end bars facing each other and extending in parallel in the length direction, and extending between each end bar and a direction perpendicular to the both end bars, both ends being fixed to each end bar at a predetermined pitch In gratings with multiple bearing bars,
The both end bars have fitting holes penetrating in accordance with the pitch, and at both ends of each bearing bar, a contact surface that contacts the inner surface of the end bar, and a protrusion that protrudes from the corresponding contact surface. A grating that is formed with a fitting portion that is fitted to the end bar and a convex portion that protrudes from the fitting portion and is caulked from the outer surface side of the end bar to fix the bearing bar to the end bar. The fitting hole extends in the width direction of the end bar, the fitting portion has a plate shape aligned with the fitting hole, and the convex portions are formed at both ends of the fitting portion. The grating described. The grating according to claim 1 or 2, wherein support portions projecting from the convex portions are formed at both ends in the width direction on the outer surfaces of both end bars. The grating according to claim 3, wherein both support portions protrude from the original convex portion which is a convex portion before being caulked. The grating according to any one of claims 1 to 4, wherein the bearing bar has a T-shaped or I-shaped cross section. The grating according to any one of claims 1 to 5, wherein the end bar and the bearing bar are made of stainless steel. A pair of end bars having a plurality of fitting holes penetrating at a predetermined pitch, and a fitting surface that has a contact surface that contacts the inner surface of the end bar at both ends, and projects from the corresponding contact surface to fit into the fitting hole. A preparation step of preparing a plurality of bearing bars having a joint portion and having original protrusions protruding from the fitting portion;
A fitting step in which the bearing bars face each other in parallel according to the pitch, the fitting portion is fitted into the fitting hole, and the contact surface is brought into contact with the inner surface;
A grating manufacturing method comprising: a caulking step of fixing the bearing bar to the end bar by caulking the original convex portion protruding from the fitting hole from the outer surface side of the end bar.

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