JPS63157771A - Method for forming crating - Google Patents

Abstract

PURPOSE:To improve the quality of a grating by forming insertion parts of connecting bars on a bearing bar and forming and providing welding projections on the inside edges of the insertion parts at the same time and improving the productivity of the coupling and forming and enabling its automation. CONSTITUTION:The notched insertion parts 8 to fit the connecting bars 3 from the upper part are formed on the prescribed positions of the upper edge of the bearing bar 2 and the welding projections 9 formed at the same time when the insertion parts 8 are formed are formed on the bottoms of the insertion parts 8. The connecting bars 3 are inserted into the insertion parts 8 of the bearing bar 2 and the lower surfaces of the connecting bars are abutted on the upper bottoms of the welding projections 9 and inserted therein. After then, terminals 13 for electrifying are fitted to the bearing bar 2 and terminals 12 for electrifying are pressed and brought into contact with the upper surfaces of the connecting bars 3 and a current is applied to the terminals 12 and 13 for electrifying and the connecting bars 3 and the bearing bar 2 are subjected to the spot welding and joined.

Description

[Detailed Description of the Invention] "Industrial Application Field" Mizuyomae is a grating made by bonding plate-shaped or rod-shaped metal members and forming them into a lattice shape, which is used as a cover for a trench, manhole, sewage basin, etc. This relates to a molding method.

"Prior Art" Generally, in the case of a grating having a rectangular shape, for example, as shown in Fig. 8, two band-shaped end plates 1, which serve as frames on two long sides, are opposed to each other. Between the end plates 1, two groups of bearing bars with the required pitch are arranged in parallel, and the inner surface of the end plate 1 and both end surfaces of the bearing bars 2 are individually welded, and a , connecting bars 8, which are separate members, are connected in parallel to the end plate 1 in rows of pins to form a lattice shape. The connecting structure of the connecting bar 3 is as shown in FIG.
At the same time, a horizontally elongated insertion window 5 is formed in the body of the pairing bar 2, and the connection bar 8 is flattened and inserted into the insertion window 5, rotated 90', and the fitting groove 4A4B and the bearing bar are inserted. 2 are fitted and connected, or when the bearing bar 2 has a T-shaped cross section, as shown in Fig. It has a structure that connects groups.

"Problems to be Solved by the Invention" The grating of the conventional structure shown in the vJa diagram above is connected to the insertion window 5 after forming the fitting groove 4A4B of the connection bar 8 and the insertion window 5 of the bearing bar 2. Since the bars 8 are inserted and rotationally fitted, an increase in process and man-hours is unavoidable, and in the case shown in Figure 4, the work of attaching the spacer tubes 6 to the adjacent bearing bars 2 is extremely complicated. However, both methods have difficulties in processing, and the process of connecting the connecting bars 3 cannot be automated.

When the forming means shown in FIG.
(From the viewpoint of processing cost), it can be performed only every few pieces, so there is a quality problem in that the fixing performance between the connecting bar 8 and the bearing gay <-2 is poor.

An object of the present invention is to provide a new molding method that solves the problems of the prior art described above.

``Means for Solving the Problems'' The present invention achieves the above-mentioned objects by ``a group of bearing bars arranged in parallel at a required pitch, in which a connecting bar is connected to form a lattice-like grating. At the same time as forming the bar insertion part, a welding protrusion is formed on the inner edge of the insertion part, and then a connecting bar is inserted into the insertion part, and the welding protrusion connects the bearing bar and the connecting bar. This method is used to instantaneously spot weld and connect the two parts.

"Operation" According to the above-described molding method of the present invention, when forming an insertion part by press working, for example, a welding protrusion is simultaneously formed on the insertion part, and the connecting bar and the welding protrusion are pressed into contact with each other, instantaneously. Since spot welding can be performed, the construction method is simplified and made more efficient, and the process of connecting the bearing bar 2 and the connecting bar 8 can be automated.Furthermore, the bearing bar 2 and the connecting bar 3 can be individually welded. This has effects such as improving connection quality.

"Example" Hereinafter, a detailed explanation will be given based on an example. First, with reference to FIG. 1 showing a first embodiment, a large number of bearing bars 2 made of flat bars with a rectangular cross section are arranged in parallel, and a rectangular connecting bar 8 is connected to the upper end of the bearing bars 2. This is an example in which the present invention is applied to the formation of a lattice grating. That is,
When connecting the bearing bars 2 arranged in parallel at a required pitch in a lattice shape using the connecting bars 8, a notch-shaped insertion portion 8 is provided at a predetermined position on the upper edge of the bearing bar 2, into which the connecting bars 8 are fitted from above. is formed, and a welding protrusion 9 is formed at the bottom of the insertion portion 8 at the same time as the insertion portion 8 is formed.

This welding protrusion 9 is formed as a welding point when welding and joining the fitted connecting bars 3, and is formed and provided at the same time as the notch processing of the insertion portion 8 by pressing. In order to make the welding point effective, the welding protrusion 9 has a trapezoidal cross section, and the upper bottom surface 10, which is the top, continues in the direction of the pressing process. The width of the upper base 10 of the welding protrusion 8 in this embodiment is approximately 0.5 mm, and the width of the lower base 1 is approximately 0.5 mm.
1 has a width of about 3.0mm and a height of about 1.0mm.

The connecting bar 8 is inserted into the insertion portion 8 of the bearing bar 2 described above, and is inserted with the lower surface of the connecting bar 8 in contact with the upper bottom surface 10 of the welding projection 8.

Thereafter, as shown in the first drawing, the Kufunpu-shaped current-carrying terminal 18 is attached to the bearing bar 2, and the terminal 12 for connection 1 is pressed into contact with the upper surface of the connection bar 8, and the connection inserted into the insertion part 8 is attached. The bar 8 and the bearing bar 2 are pressed and sandwiched between two current-carrying terminals 12.18, and the current-carrying terminals 12.18
Electricity is applied between them to spot-weld and connect the connecting bar 8 and the bearing bar 2.

At this time, a high current is applied for a very short time of 1 to 2 cycles μ of the primary power source for spot welding to achieve instant bonding.

Next, FIG. 2 shows a second embodiment of the present invention in which a connecting bar 8 is passed through and connected to the body of a bearing bar 2 having a T-shaped cross section. In the figure, an insertion part 8 that passes through the connecting bar 8 of the tube body is formed in the body of the bearing bar 2 at a predetermined position (in the middle position of the width), and at the upper part of the inner edge of the insertion part 8. is the same welding protrusion 9 as the embodiment in FIG.
are molded at the same time. That is, the welding protrusion 9 is formed simultaneously with the drilling of the insertion portion 8 using a press, and the connecting bar 8 is brought into contact with the upper bottom surface 10 of the welding protrusion 9 and inserted.

Then, as in the embodiment of FIG. 1, two current-carrying terminals 12.1
8, clamp the connecting bar 8 and the bearing bar 2 while pressing them together, momentarily apply a high current between the current-carrying terminals 12 and 18, weld the connecting bar 8 to the bearing bar 2 via the welding protrusion 9, and then press the connecting bar 8 and the bearing bar 2 together. Connect and form.

According to the above-described molding method of the present invention, the welding protrusion 9 is formed on the insertion portion 8 of the bearing bar 2, and the top of the welding protrusion 9 and the connecting bar 8 come into pressure contact with each other to perform spot welding. Therefore, a concentrated current is generated between the top of the welding protrusion 9 and the connecting bar 3, and the welding protrusion 9 is instantaneously melted to firmly weld the contact surfaces of the two.

Therefore, the joint between the bearing bar 2 and the connecting bar 8 is
As shown in FIG. 1 and FIG. 2, a thin layer 14 made of melted welding protrusions 9 is spread out and interposed to firmly bond the two. Since the welding protrusion 9 is molded at the same time as the insertion part 8, there is no need for special molding means for the welding protrusion 8, and the connecting bar 3 is simply inserted into the insertion part 8 to connect the current-carrying terminal. Installation can be done by simply clamping and energizing to form a bond. Therefore, compared to the conventional means shown in Figure 8.4, the steps and man-hours required for molding are significantly simplified and reduced.

If the above-described method of connecting the bearing bar 2 and the connecting bar 8 is repeated in sequence, there is an advantage that the process of connecting a large number of bearing bar groups and the connecting bar 8 can be automated.

Furthermore, according to the molding method of the present invention, the bearing bar 2 and the connecting bar 8 of each set are individually spot welded, so there is no risk of occurrence of bath bond distortion, and the outer enamel is also smoothed, thereby strengthening the bond. The film becomes more stable and the grating quality can be improved.

"Effects of the Invention" As described above, the grating forming method of the present invention significantly improves the molding productivity of the joint molding of the bearing bar and the connecting bar, and also enables automation of the joint molding. This has many effects such as improving grating quality.

[Brief explanation of the drawing]

1N: Shows the molding method of the first embodiment of the present invention, inside is a perspective view thereof, 0 is an enlarged front view of the insertion part of (5), 0 is a front view showing its combined state Figure 2N: shows the molding method of the second embodiment of the present invention;
0 is a front view of the grating, 0 is a front view showing its combined state, FIG. 3 (A: A perspective view showing the forming method of the conventional means, FIG. 8 0: A plan view of the grating by the conventional means, FIG. 4: Conventional means Front view showing other molding methods Main symbols: 1: End plate, 2: Bearing bar,
8: Connection bar, 8: Insertion part, 9: Welding protrusion, 10: Upper bottom surface of welding protrusion, 11: Lower bottom surface of welding protrusion, 12.18:
energizing terminal

Claims (3)

[Claims] (1) A group of bearing bars arranged in parallel at the required pitch,
In forming a lattice-like grating by connecting connection bars, an insertion part for the connection bar is formed on the bearing bar, and at the same time, a welding protrusion is formed on the inner edge of the insertion part, and then the insertion part is formed on the inner edge of the insertion part. A connecting bar is inserted into the bearing bar, the welding protrusion and the connecting bar are pressed into contact with each other, and a concentrated current is generated in the contact area to spot weld the bearing bar and the connecting bar. How to form grating. (2) A method for forming a grating according to claim (1), wherein welding protrusions are formed on the bottom of the groove-shaped insertion portion. (3) The grating forming method according to claim (1), wherein welding protrusions are formed on the inner edges of the hole-shaped insertion portions.