JP2005068945A - Grating and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grating and its production method for extremely surely reducing production costs. <P>SOLUTION: A fitting hole 1a is penetratingly arranged in an end bar 1. Abutting surfaces 2d and 2e abutting on an inner surface of the end bar 1, and a fitting part 2a fitted to the fitting hole 1a by projecting from the abutting surfaces, are formed on both ends of a bearing bar 2. Original projection parts 2b and 2c are formed in the fitting part 2a, and recessed parts 2f and 2g are formed between the abutting surfaces 2d and 2e and the fitting part 2a. Outside inclined faces 2h and 2i reaching up to this side of the top of the original projection parts 2b and 2c by continuing from the recessed parts 2f and 2g, form an angle of 85 degrees to the abutting surfaces 2d and 2e. The original projection parts 2b and 2c are calked from the outside surface side of the end bar 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  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.

  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.

  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.

  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.

  However, the conventional grating has the following problems because both end bars and the bearing bar are fixed by welding.

  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. In addition, this grating has a problem in that distortion is likely to occur due to heat generated during welding and dimensional accuracy deteriorates. 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. In particular, when the grating is made of a material that is difficult to weld, such as stainless steel, these tendencies are large.

For this reason, a grating that fixes both end bars and the bearing bar by caulking instead of welding has been proposed (Patent Document 1) Japanese Patent Laid-Open No. 2000-87441).
JP 2000-87441 A

  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.

  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.

  The inventors have already filed a patent application for a grating in which a convex portion protruding from the fitting portion is formed as a grating capable of solving such a problem (Japanese Patent Application No. 2002-075463). In this grating, the bearing bar can be fixed to the end bar only by caulking the original convex portion protruding from the fitting portion. 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. Even if the 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 is low.

  However, in this grating, when a bearing bar having a convex portion at the tip of the fitting portion is manufactured by press punching, burrs are likely to occur near the boundary between the contact surface formed on the bearing bar and the fitting portion. When the fitting part of the bearing bar is fitted in the fitting hole of the end plate with this burr remaining, the contact surface of the bearing bar does not contact the inner surface of the end bar while the burr interferes with the inner surface of the end bar. As a result, the gap between the bearing bar and the end bar is generated, causing backlash. This problem can be solved by performing the deburring process after the bearing bar is manufactured by press punching, but the cost for the deburring process is excessive.

  In the manufacturing of the grating of the invention according to the above patent application, when the fitting portion of the bearing bar is fitted into the fitting hole of the end bar and the original convex portion protruding from the fitting portion is caulked, the plasticity of the original convex portion No particular consideration was given to the direction of deformation, and plastic deformation was made little by little in all directions. For this reason, in order to ensure the sufficient mechanical strength of the caulking, the fitting tolerance between the fitting hole of the end bar and the fitting part of the bearing bar is made as small as possible, the size of the original convex part and the protruding height It is necessary to enlarge. However, in order to reduce the fitting tolerance between the fitting hole of the end bar and the fitting part of the bearing bar, it is necessary to raise the accuracy of the mold for the hole machining of the fitting hole and the press working of the fitting part to some extent. Is required. In order to maintain the accuracy of the mold at a certain level or more, it is necessary to manage the mold surface frequently by polishing it back to the original shape, which causes an increase in the manufacturing cost of the grating. In addition, when the size and protrusion height of the original convex part are increased, the bulge of the caulking part becomes large, and when the grating is fitted into the side groove or water collecting trough via the receiving frame, the convex part interferes with the receiving frame. There is a risk. In addition, since the force required to caulk the original convex portion is increased, the life of the mold is shortened, which also causes an increase in the manufacturing cost of the grating.

  The present invention has been made in view of the above-described conventional situation, and it is an object of the present invention to provide a grating and a method for manufacturing the same that can extremely reliably reduce the manufacturing cost.

  The grating according to the first aspect of the present invention is a pair of end bars facing each other and extending in parallel in the length direction, extending in a direction perpendicular to both end bars while facing each other between both end bars, and both ends extending from the end bars. In the grating having a plurality of bearing bars fixed at a predetermined pitch, the both end bars have fitting holes penetrating according to the pitch. A contact surface that contacts the inner surface, a fitting portion that protrudes from the corresponding contact surface and fits into the fitting hole, protrudes from the fitting portion, and is caulked from the outer surface side of the end bar to place the bearing bar in the end bar And the fitting hole extends in the width direction of the end bar, the fitting part is a plate shape that aligns with the fitting hole, and the convex part corresponds to the fitting part. Formed on both ends, The contact surface, characterized in that recess is formed adjacent to the fitting portion.

  The manufacturing method of the grating according to the first aspect of the present invention has a pair of end bars that have a plurality of fitting holes that extend in the width direction and are provided at a predetermined pitch, and contact surfaces that contact the inner surface of the end bar at both ends. And a plate-like fitting portion that protrudes from the corresponding contact surface and fits into the fitting hole, and has original projections that protrude from both end sides of the fitting portion. A preparation step of preparing a plurality of bearing bars having recesses formed adjacent to the fitting portion, the bearing bars facing each other in parallel according to the pitch, and fitting the fitting portion into the fitting hole And a caulking step for fixing the bearing bar to the end bar by caulking from the outer surface side of the end bar the mating step of bringing the corresponding contact surface into contact with the inner surface and the original convex portion protruding from the fitting hole. And a process.

  In the grating according to the first 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 by the contact surface of the bearing bar contacting 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. For this reason, in this grating, the said malfunction by fixing both end bars and a bearing bar by welding can be avoided.

  Further, in this grating, there is a convex portion at the tip of the fitting portion, so there is no need to use a die having a projection at the tip that comes into contact with the fitting portion, and a die with a flat tip is used. Can be adopted. Further, since only the convex portions protruding from the fitting portions are plastically deformed in the caulking, the force required for caulking is reduced, and even if a die having a flat tip is used, the original can be easily obtained. The convex portion can be caulked. 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.

  Furthermore, in this grating, the fitting hole extends in the width direction of the end bar, the fitting portion is a plate shape that matches the fitting hole, and the convex portions are formed on both ends of the fitting portion, so The strength against the force will be enhanced, and it will have excellent durability.

  Also, in this grating, a recess is formed on the contact surface adjacent to the fitting part where burrs are likely to occur during the manufacturing process of the bearing bar, so the fitting part of the bearing bar is fitted into the fitting hole of the end bar. Even if it is made, the burr | flash which generate | occur | produced in the recessed part does not interfere with the inner surface of an end bar. For this reason, the inner surface of the end bar is caulked in a state where it is securely in contact with the contact surface of the bearing bar, and there is no gap between the bearing bar and the end bar, and no backlash occurs. Moreover, it is not necessary to deburr the bearing bar after it is manufactured by pressing.

  Therefore, according to the grating of the first invention and the manufacturing method of the grating of the first invention, a reduction in manufacturing cost can be realized extremely reliably.

  In the grating of the first invention, the recess preferably has a radius of curvature in the length direction of the bearing bar. If it is like this, when the original convex part is pressed and crimped, stress will not concentrate on one part of a recessed part, but it can take charge of stress in the whole recessed part. For this reason, it is possible to prevent the original convex portion from being damaged when the original convex portion is caulked.

  Moreover, it is preferable that the bearing bar has a rectangular shape with a cross-sectional shape having long sides in the width direction. Such a bearing bar is often used in the grating since the strength against the downward force that the grating receives from the outside is large. In addition, since the cross-sectional shape is simpler and cheaper than a T-shaped or I-shaped bearing bar, the manufacturing cost of the grating can be reduced.

  The grating according to the second aspect of the present invention is a pair of end bars facing each other and extending in parallel in the length direction, extending in a direction perpendicular to both end bars while facing each other between both end bars, and both ends extending to the end bars. In the grating having a plurality of bearing bars fixed at a predetermined pitch, the both end bars have fitting holes penetrating according to the pitch. A contact surface that contacts the inner surface, a fitting portion that protrudes from the corresponding contact surface and fits into the fitting hole, protrudes from the fitting portion, and is caulked from the outer surface side of the end bar to place the bearing bar in the end bar And the fitting hole extends in the width direction of the end bar, the fitting part is a plate shape that aligns with the fitting hole, and the convex part corresponds to the fitting part. Formed on both ends, The outer peripheral surface from the top of the original convex portion that is the convex portion before being bent to the corresponding contact surface on the side close to the original convex portion is inclined outward with an acute angle with the corresponding contact surface on the side close to the original convex portion. A surface is formed.

  Also, the manufacturing method of the grating according to the second aspect of the invention has a pair of end bars that are provided at a predetermined pitch and have a plurality of fitting holes extending in the width direction, and a contact surface that contacts the inner surface of the end bar at both ends. And a plate-like fitting portion that protrudes from the corresponding contact surface and fits into the fitting hole, and has a convex portion that protrudes to both ends of the fitting portion, and the top of the original convex portion. A plurality of bearing bars are formed on the outer peripheral surface from the contact surface on the side close to the original convex portion to the corresponding contact surface on the side close to the original convex portion and the outer inclined surface forming an acute angle. A preparatory step, 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, and the fitting By caulking the original convex part protruding from the hole from the outer surface side of the end bar, the original convex part is It is plastically deformed outwardly of and characterized in that it comprises a crimping step of fixing the said end bar.

  In the grating according to the second invention, as in the grating according to the first invention, a pair of end bars facing each other and extending in parallel in the length direction, and facing each other between the both end bars, are perpendicular to the both end bars. In a grating having a plurality of bearing bars that extend and both ends are fixed to each end bar at a predetermined pitch, the both end bars have fitting holes penetrating according to the pitch, and the bearings At both ends of the bar, a contact surface that contacts the inner surface of the end bar, a fitting portion that protrudes from the corresponding contact surface and fits into the fitting hole, protrudes from the fitting portion, and from the outer surface side of the end bar A convex portion that is caulked to fix the bearing bar to the end bar, the fitting hole extends in the width direction of the end bar, and the fitting portion has a plate shape that aligns with the fitting hole; The convex portion is the It is formed on both end sides of the engaging portion. For this reason, like the grating of the 1st invention, it can manufacture by caulking and can avoid the trouble by fixing both end bars and a bearing bar by welding. Moreover, since only the convex part protruded from the fitting part is caulked with a small force, the die for caulking can be simplified, and the manufacturing cost is low. Furthermore, even if caulking is repeated, the degree of wear and deformation of the mold or the like is small, and the management cost of the mold or the like can be low.

  Further, in the grating according to the second aspect of the invention, the outer peripheral surface from the top of the original convex portion, which is the convex portion before being caulked, to the corresponding contact surface on the side close to the original convex portion is on the side closer to the original convex portion. Since the outer inclined surface forming an acute angle with the contact surface is formed, when the original convex portion is caulked, the original convex portion is plastically deformed so as to spread toward the contact surface closer to the original convex portion. It becomes. For this reason, the variation width due to plastic deformation of the original convex portion is larger than the variation width when the original convex portion is uniformly plastically deformed in all directions, and the fitting hole of the end bar is slightly larger than the fitting portion of the bearing bar. Even if it is large, a sufficient caulking width can be secured. For this reason, it is not necessary to increase the accuracy of the mold for drilling the fitting hole of the end bar, and the manufacturing cost of the mold can be reduced. Furthermore, the management cost of the mold and the like for maintaining the accuracy of the mold is also low.

  It is preferable that an inner inclined surface that forms an acute angle with the corresponding contact surface on the side close to the original convex portion is formed on the inner peripheral surface opposite to the outer peripheral surface among the peripheral surfaces of the original convex portion. If it is like this, when the original convex part is caulked, it can be more reliably plastically deformed in the direction of the contact surface near the original convex part. Further, since the pressure for plastic deformation is further reduced, the life of the caulking mold is further increased.

  The angle formed by the outer inclined surface and the contact surface on the side close to the original convex portion is preferably 80 ° or more and less than 89 °. According to the test results of the inventors, when the angle formed by the outer inclined surface and the contact surface on the side close to the original convex portion is 80 ° or more, the original convex portion is fitted in the fitting hole. The gap in the width direction becomes small, and when the original convex portion is caulked, it becomes difficult for rattling to occur. Further, if the angle formed between the outer inclined surface and the contact surface on the side close to the original convex portion is less than 89 degrees, when the original convex portion is caulked, the direction toward the contact surface on the side close to the original convex portion The plastic deformation can be ensured.

  In the gratings of the first and second inventions, 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.

  Moreover, it is preferable that both support parts protrude from the original 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.

  Furthermore, when the end bar and the bearing bar are made of stainless steel, the effects of the first invention and the second invention are great. 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 gratings of the first and second inventions, 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 for 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.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the grating according to the embodiment includes a pair of end bars 1 that face each other and extend in parallel in the length direction, and a plurality of end bars 1 that face each other and extend in a direction perpendicular to the end bar 1. Bearing bars 2 and side bars 3 which are fixed to both ends of both end bars 1 and extend in a right angle direction.

  The end bar 1 is made of SUS304, and as shown in FIG. 2, a rectangular fitting hole 1a having a substantially U-shaped cross section and extending in the width direction is provided at predetermined pitch intervals. A fitting hole 1b that is slightly narrower than the fitting hole 1a is provided at both ends of the end bar 1 in the length direction. At both ends in the width direction on the outer surface of the end bar 1, support portions 1c and 1d extend in parallel with the length direction.

  The bearing bar 2 is also made of SUS304, and has a rectangular cross section and a thickness of 4 mm. As shown in FIG. 3, plate-like fitting portions 2a aligned with the fitting holes 1a are provided at both ends of the bearing bar 2, and original projections 2b and 2c are provided at both ends of both fitting portions 2a. Is formed to protrude. Abutting surfaces 2d and 2e that abut against the inner surface of the end bar 1 are formed above and below the fitting portion 2a. The height h4 from the contact surfaces 2d, 2e to the top of the original convex portions 2b, 2c is only the height h3 of the original convex portions 2b, 2c than the depth h1 of the fitting hole 1a (see FIG. 2). The height is set higher than the height h2 (see FIG. 2) from the inner surface of the end bar 1 to the outer surfaces of the support portions 1c and 1d. Concave portions 2f and 2g having a radius of curvature R1 in the length direction of the bearing bar 2 are formed between the fitting portion 2a and the contact surfaces 2d and 2e. The concave portions 2f and 2g are formed so as to be deeper and deeper from the convex portions 2b and 2c, reaching the deepest portion, and then gradually shallower toward the contact surfaces 2d and 2e. The outer inclined surfaces 2h and 2i extending continuously from the concave portions 2f and 2g to the top of the original convex portions 2b and 2c form an angle of 85 degrees with respect to the contact surfaces 2d and 2e. The crests 2j and 2k of 2c have a radius of curvature R1 in the length direction of the bearing bar 2. Further, the inner inclined surfaces 2m and 2n at positions beyond the tops of the original convex portions 2b and 2c are inclined at an angle of 75 ° with the contact surfaces 2d and 2e on the side close to the original convex portions 2b and 2c. . Further, as shown in FIG. 1, a fitting hole 2 o is formed through the center of the bearing bar 2.

  The side bar 3 is also made of SUS304, and has a U-shaped cross section as in the end bar 2 as shown in FIG. As shown in FIG. 4, both ends of the side bar 3 have the same shape as both ends of the bearing bar 2, and the fitting portion 3a, the original convex portions 3b and 3c, the contact surfaces 3d and 3e, the concave portions 3f and 3g. The outer inclined surfaces 3h and 3i, the top portions 3j and 3k, and the inner inclined surfaces 3m and 3n are formed. Further, as shown in FIG. 1, a fitting hole 3 o is provided in the center of the side bar 3.

  As shown in FIG. 1, the fitting portion 2 a of the bearing bar 2 is fitted into the fitting holes 1 a of both end bars 1, and the original protruding portions 2 b and 2 c are caulked so that each bearing bar 2 has both end bars 1. It is fixed to. Similarly to the bearing bar 2, the fitting portion 3 a of the side bar 3 is fitted into the fitting holes 1 b at both ends of both end bars 1 and fixed by caulking. Further, the cross bar 4 is inserted into the fitting hole 2o of the bearing bar 2 and the fitting hole 3o of the side bar 3, and is fixed to each end bar 2 and side bar 3 by caulking the exposed portion of the cross bar 4. Has been.

  The grating of the embodiment configured as described above is manufactured as follows.

<Preparation process>
A U-shaped long plate material made of SUS304 is cut into a predetermined length, and press holes are formed through the fitting holes 1a at a predetermined pitch as shown in FIG. 1, and the fitting holes 1b are penetrated at both ends. It is set as end bar 1. Further, a long plate material made of SUS304 and having a thickness of 4 mm is cut into a predetermined length, and the fitting portion 2a, the original convex portions 2b and 2c, the contact surfaces 2d and 2e, and the fitting hole 2o are formed by pressing. The bearing bar 2 is used. Further, the same plate material as the long plate material from which the end bar 1 is manufactured is cut into the same length as the bearing bar 2, and the fitting portion 3a, the original convex portions 3b, 3c, and the contact surface 3d are pressed by the same pressing as the bearing bar 2. 3e and a fitting hole 3o are formed to form the side bar 3. Further, a tubular member made of SUS304 is cut to the same length as the end bar 1 to form a cross bar 4.

<Mating process>
The bearing bar 2 and the side bar 3 are faced and aligned in parallel with each other at a predetermined pitch by a jig (not shown). Then, each cross bar 3 is inserted into the fitting hole 2 o of the bearing bar 2 and the fitting hole 3 o of the side bar 3. Further, as shown in FIG. 5, the fitting portion 2 a of the bearing bar 2 is inserted into the fitting hole 1 a of the end bar 1, and the contact surfaces 2 d and 2 e are brought into contact with the inner surface of the end bar 1. Here, since the concave portions 2f and 2g are formed adjacent to the fitting portion 2a on the contact surfaces 2d and 2e, even if burrs are generated in the concave portions 2f and 2g at the time of pressing, the burrs are not formed. There is no interference with the contact surfaces 2d and 2e. Further, the fitting portions 3 a of the side bar 3 shown in FIG. 1 are fitted into the fitting holes 1 b at both ends of the bearing bar 2, and the contact surfaces 3 d and 3 e are brought into contact with the inner surface of the end bar 1.

<Caulking process>
As shown in FIG. 5, after preparing the metal mold | die 5 by which the press surface 5a was made flat, and fixing to the press machine which is not shown in figure, the press surface 5a of the metal mold | die 5 is pressed against the original convex parts 2b and 2c. As shown in FIG. 3, the outer inclined surfaces 2h and 2i of the original convex portions 2b and 2c are inclined at an angle of 85 ° with the contact surfaces 2d and 2e on the side close to the original convex portions 2b and 2c. Since the inner inclined surfaces 2m, 2n of the original convex portions 2b, 2c are inclined at an angle of 75 ° with the contact surfaces 2d, 2e on the side close to the original convex portions 2b, 2c, the original convex portions 2b, As shown in FIG. 5, 2c plastically deforms in the direction of the arrow in the figure so as to spread outward in the width direction. For this reason, the variation width due to plastic deformation of the original convex portions 2b and 2c is larger than the variation width when the original convex portions 2b and 2c are uniformly plastically deformed in all directions, and the fitting hole 1a of the end bar 1 is a bearing. Even if it is slightly larger than the fitting portion of the bar 2, a sufficient caulking width can be ensured. For this reason, the hole processing of the fitting hole 1a of the end bar 1 does not require so high accuracy, the manufacturing cost of the die can be reduced, and further, a die for maintaining the accuracy of the die, etc. The management cost is also low. Further, 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. 6, the original convex portions 2b and 2c of the bearing bar 2 are caulked to the end bar 1 to become convex portions 2p and 2q.

  Similarly, the fitting portion 3a of the side bar 3 is fixed to the fitting hole 1b of the bearing bar 2. Further, the exposed portion of the cross bar 3 shown in FIG. 1 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.

  In the grating of the embodiment, as shown in FIG. 3, since the original convex portions 2b and 2c are present at the tip of the fitting portion 2a, there is no need to use a mold having a projection at the tip, A flat mold or the like can be used. Further, since only the original convex portions 2b and 2c projecting from the fitting portion 2a are plastically deformed by caulking, the force required for caulking is reduced and a die having a flat tip is employed. However, the original convex portions 2b and 2c can be easily caulked. 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.

  Further, as shown in FIG. 1, 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. Furthermore, since the bearing bar 1 has a rectangular cross-sectional shape, the strength against the downward force is enhanced and the bearing bar 1 has excellent durability. Further, since the shape of the bearing bar 1 is simple and inexpensive, the manufacturing cost of the grating can be reduced. Further, although the thickness of the bearing bar is 4 mm and burrs are likely to occur near the boundary between the contact surfaces 2d, 2e and the fitting portion 2a, the burrs and the inner surface of the end bar 1 are formed by the recesses 2f, 2g. Therefore, the burr does not cause rattling of the grating or decrease in the caulking strength.

  Further, since the support portions 1b and 1c formed so as to protrude from the end bar 1 protrude from the original protrusions 2b and 2c, when the original protrusions 2b and 2c are caulked and the bearing bar 2 is fixed to the end bar 1, it is simply a flat surface. It can be fixed with a simple fixing jig having only Further, when this grating is fitted into a side groove or a water collecting trough via a receiving frame, the convex portions 2p and 2q do not interfere with the receiving frame.

  Furthermore, since the end bar 1, the bearing bar 2 and the cross bar 3 constituting the grating are all made of SUS304, they have excellent corrosion resistance and can be used as the final product without any surface treatment such as electrolytic polishing or painting. can do. For this reason, the grating excellent in corrosion resistance can be manufactured at low cost.

  According to the grating and the manufacturing method thereof of the present invention, it is possible to provide the grating used for the side groove, the water collecting tank and the like at a low manufacturing cost.

It is a partial perspective view of the grating of an Example. It is sectional drawing of an end bar. It is a partial side view of a bearing bar. It is a partial side view of a side bar. It is a partial sectional view of the grating before caulking. It is a partial cross section figure of the grating at the time of caulking. It is a partial sectional view of grating after caulking.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... End bar 2 ... Bearing bar 1a, 1b ... Fitting hole 2d, 2e ... Contact surface 2a ... Fitting part 2b, 2c ... Original convex part 2p, 2q ... Convex part 2f, 2g ... Concave part 2h, 2i ... Outward inclination Surface 2m, 2n ... Inner inclined

Claims (11)

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. And a projection 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 is formed in the end bar. Extending in the width direction, the fitting portion has a plate shape that aligns with the fitting hole, and the convex portions are formed at both ends of the fitting portion, and adjacent contact surfaces are adjacent to the fitting portion. A grating characterized in that a concave portion is formed.   The grating according to claim 1, wherein the recess has a radius of curvature in the length direction of the bearing bar.   The grating according to claim 1 or 2, wherein the bearing bar has a rectangular shape with a cross-sectional shape having long sides in the width direction. 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. And a projection 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 is formed in the end bar. An original convex portion that extends in the width direction and has a plate shape that matches the fitting hole, and the convex portions are formed on both end sides of the fitting portion, and are convex portions before being caulked. An outer inclined surface that forms an acute angle with the corresponding contact surface on the side close to the original convex portion is formed on the outer peripheral surface from the top to the corresponding contact surface on the side close to the original convex portion. Grating.   Of the peripheral surface of the original convex portion, an inner inclined surface that forms an acute angle with the corresponding contact surface on the side close to the original convex portion is formed on the inner peripheral surface opposite to the outer peripheral surface. The grating according to claim 4.   6. The grating according to claim 4, wherein an angle formed by the outer inclined surface and the contact surface closer to the original convex portion is 80 ° or more and less than 89 °.   The grating according to any one of claims 1 to 6, 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 7, 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 8, wherein the end bar and the bearing bar are made of stainless steel. A pair of end bars penetrating at a predetermined pitch and having a plurality of fitting holes extending in the width direction, and having a contact surface contacting the inner surface of the end bar at both ends, projecting from the corresponding contact surface, the fitting holes Has a plate-like fitting portion that fits in, and has an original convex portion that protrudes at both ends of the fitting portion, and a concave portion is formed adjacent to the fitting portion on the corresponding contact surface. Preparing a plurality of bearing bars,
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. A pair of end bars penetrating at a predetermined pitch and having a plurality of fitting holes extending in the width direction, and having a contact surface contacting the inner surface of the end bar at both ends, projecting from the corresponding contact surface, the fitting holes A plate-like fitting portion that fits to the fitting portion, and a convex portion protruding from both ends of the fitting portion, and a corresponding contact surface on the side close to the original convex portion from the top of the original convex portion A preparation step of preparing a plurality of bearing bars formed with an outer inclined surface that forms an acute angle with a corresponding contact surface on the side close to the original convex 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 in which the original convex portion protruding from the fitting hole is caulked from the outer surface side of the end bar, so that the original convex portion is plastically deformed outward in the width direction of the fitting portion and fixed to the end bar. The manufacturing method of the grating characterized by comprising.

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