JPS6027880B2 - Method of manufacturing lattice - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a lattice body, and its purpose is to produce a steel gate that has a beautiful appearance for a long time.
The objective is to provide a method for mass-producing fences, grids, etc. at low cost.

In this type of product, each part is directly welded and the surface is painted, but the welded parts are irregularly built up, which not only spoils the aesthetics, but also causes paint to adhere to the welded parts. The adhesion strength decreases, and in the case of general-purpose galvanized steel pipes, the zinc plated on the surface to prevent rust is washed away due to the rise in temperature at the welded part, resulting in rust formation and long-term use. In particular, if a through hole is provided in the crosspiece and a central shaft is iron-bonded to the crosspiece and the two are welded together, rainwater may enter the inside of the crosspiece through the gap created between the central shaft and the through hole in the crosspiece. Significant rusting.

On the other hand, in the case of a lattice body in which the crosspieces and center shafts are assembled using screws or rivets, it is necessary to use expensive materials such as stainless steel or aluminum for these fasteners, which not only increases the cost of materials but also requires assembly work. Even when these materials are used, it is difficult to avoid the occurrence of rust due to electrolytic corrosion of the steel due to the difference in the metal materials used in the fastening parts.

In view of these circumstances, the inventor of the present invention made extensive studies and found that a through hole was bored in one side of the crosspiece made of a hollow metal tube, and a metal center shaft was inserted into the through hole of the crosspiece. The desired purpose is achieved by making the outer diameter of the inner shaft larger than the tip position, and by welding the tip of the center shaft and the inner surface of the tube of the crosspiece, and fixing the center shaft in the through hole of the crosspiece in an airtight state. This is what I did.

According to the lattice body processed by the method of the present invention and surface-painted, the crosspiece and the center shaft are settled on the inner surface of the tube of the crosspiece, and the outer diameter of the center shaft is made larger at the inner end than the tip position, so that the crosspiece and the center shaft are fixed. It is extremely firmly fixed in an airtight state, does not use dissimilar metals such as fasteners, so it does not cause electrolytic corrosion, and it can be mass-produced at low cost by processing multiple joints at the same time, giving favorable results. .

The present invention will be specifically explained below with reference to the drawings.

In the embodiment shown in FIGS. 2 and 3, Senbishi 1, 1 made of hollow metal tubes are arranged at both ends, and through holes 2, 2... When inserting the metal center shafts 3, 3, .・ is formed, and a gap exists between the outer peripheral surface of the center shafts 3, 3... and the inner peripheral surface of the through holes 2, 2..., and the electrode grip of the Ryuki welding machine is attached to the center shafts 3, 3... 3... and the crosspieces 1, 1 and energized, the center shafts 3, 3,
When the tips of ... melt and shrink, the through holes 2, 2 of the crosspieces 1, 1
... are supported by the brim-like protrusions 4, 4, etc. of the center shaft 3, and the center shaft is fixed in an airtight state in the through hole of the crosspiece. In the embodiment shown in FIGS. 4 and 5, through holes 2, 2, .・When inserting the center shafts 3, 3... into the through holes of the crosspieces, the ends of the center shafts 3, 3... are made into a tapered shape.
A gap exists between the outer circumferential surface of the through holes 2, 2... and the inner circumferential surfaces of the through holes 2, 2..., and when the tips of the center shafts 3, 3... shrink due to spacing due to welding, cause 1 , 1, the center shaft 3 is inserted into the through hole 2, 2...
The tapered part of the rod is fixed in the through hole of the crosspiece with the center shaft in an airtight state.

In the method of the present invention, since the welding portion is limited to the tips of the center shafts 3, 3 that are in contact with the inner surfaces of the pipes of the crosspieces 1, 1, the heating of the members during welding is slight, and the flanges of the center shafts 3, 3... Protrusion 4
, 4... or the tapered part comes into close contact with the through holes 2, 2... of the crosspiece, as this will cause a significant current change in the electric welding machine.
Automatic control can be carried out extremely smoothly.

In carrying out the method of the present invention, the crosspieces 1, 1 and the center shafts 3, 3...
Minimizing the welding area is an extremely important requirement in order to reduce the temperature rise of the parts and to avoid the loss of zinc, which is plated on the surface of galvanized steel pipes to prevent rust. As shown in FIGS. 6 and 7, dot-like protrusions are formed on the ends of the metal center shafts 3, 3, etc., so as to make dot-like contact with the inner surface of the crosspiece, or as shown in FIG. As shown in FIG. 2, it is desirable that the ends of the metal center shafts 3, 3, .

In addition, when fixing a plurality of metal center shafts 3, 3, etc. to the crosspieces 1, 1 at the same time, a center shaft in which a metal hollow tube is provided with an elongated notch in the axial direction is used as shown in Fig. 9. By imparting elasticity to the ends of the center shafts, all the center shafts can be properly abutted on the inner surface of the crosspiece.

According to the method of the present invention, through-holes 2, 2... are bored in one side of the crosspieces 1, 1 made of hollow metal tubes, and the metal center shafts 3, 3
When inserting ... into the through holes 2, 2 ... of the crosspiece, the outer diameter of the central shaft at the inner end layer is made larger than the tip position,
Since the tips of the center shafts 3, 3... and the inner surfaces of the pipes of the crosspieces 1, 1... are welded, the welded parts are not exposed on the outside of the crosspieces or the center shafts, making it possible to produce a beautiful lattice body. Yes, center axis 3
, 3... are welded to the inner surface of the tube of the crosspiece 1, and the through holes 2,
2, the center shaft is very firmly attached to the crosspiece, and the center shaft 3, 3... is attached to the through hole 2, 2... of the crosspiece.
Since the welding between the tip of the center shaft and the inner surface of the crosspiece is completed by closely contacting the flanges 4, 4... or the tapered portions of the center shafts 3, 3... as the welded portion is air-cooled, The metal sign-shaped protrusions 4, 4... or the tapered portions press against the through holes 2, 2... of the crosspieces 1, 1 and generate internal stress, so the airtightness at the through hole positions of the crosspieces is poor. In addition, the outer peripheral surfaces of the crosspiece and center shaft are all smooth and have good paint adhesion, so rust will not occur over a long period of time.The method of the present invention also significantly reduces the work process. Since it can be simplified and automated, gates, fences, etc. can be mass-produced at extremely low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a lattice body made by the method of the present invention, FIGS. 2 and 3 are enlarged sectional views of essential parts showing the state before and after the welding process of the method of the present invention, and FIGS. FIG. 5 is an enlarged sectional view of the main part showing the state before and after the welding process, showing another example, and FIGS. 6 to 9 are perspective views with a part of the metal center shaft cut out in the method of the present invention, respectively. show,
In the figure, l represents a crosspiece, 2 represents a through hole, 3 represents a central shaft, and 4 represents a brim-shaped projection. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1. A through hole is bored in one side of a crosspiece made of a hollow metal tube,
When inserting the metal center shaft into the through hole of the crosspiece, the outer diameter of the inner end of the center shaft is made larger than the tip position, and the tip of the center shaft and the inner surface of the tube of the crosspiece are welded, and the center shaft is inserted into the through hole of the crosspiece. A method for producing a lattice body characterized by establishing an airtight state. 2 A through hole is drilled on one side of the crosspiece made of hollow metal tube,
When inserting the metal center shaft into the through hole of the crosspiece, a gap is created between the outer peripheral surface of the center shaft and the inner peripheral surface of the through hole, and the outer diameter of the center shaft at the inner end position is smaller than the tip position. 2. The method of manufacturing a lattice body according to claim 1, wherein the center shaft is enlarged and fixed in the through hole of the crosspiece in an airtight state by shrinking the center shaft by welding. 3. The method for manufacturing a lattice body according to claim 1, which uses a metal center shaft having a brim-like projection formed at an inner end position. 4. The method of manufacturing a lattice body according to claim 1, which uses a metal center shaft having a tapered end. 5. The method of manufacturing a lattice body according to claim 1, which uses a metal center shaft having dot-shaped protrusions formed at the end thereof. 6. The method of manufacturing a lattice body according to claim 1, which uses a metal center shaft having an acute angle end and linearly contacting the inner surface of the crosspiece. 7. The method of manufacturing a lattice body according to claim 1, which uses a center shaft in which a metal hollow tube is provided with an elongated notch in the axial direction, and elastically abuts the center shaft against the inner surface of the crosspiece.