JP-7857272-B2 - Pipe butt welding jig

JP7857272B2JP 7857272 B2JP7857272 B2JP 7857272B2JP-7857272-B2

Inventors

水野匠三

Assignees

株式会社エムテック

Dates

Publication Date: 20260512
Application Date: 20231130

Claims (3)

A pipe butt welding jig used in a pipe fixing device, comprising a plate-shaped body with a recess on the flat, plate-thick upper surface of the lower half of the upright clamp, a pair of holders that clamp a pipe placed on a receiving member attached to the recess with the upper half of the clamp, and a spacer sandwiched at the lower part of the lower half of the clamp to form a single unit, A pipe butt welding jig characterized by having a rectangular plate-like body in plan view, with a base plate portion having a flat bottom surface and a longitudinal length set longer than the top opening length of the recess, and having a vertical plate portion erected in an L-shape in side view relative to the base plate portion, wherein the thickness of the plate portion extending from one side to the other in the short direction of the horizontally arranged base plate portion is half the distance between the pair of holders, and the length from the inner corner point between the vertical plate portion and the base plate portion to the other side of the base plate portion is half the longitudinal length, and further having a mark provided at the center point along the longitudinal side edge of the bottom surface of the base plate portion.
The pipe butt welding jig according to claim 1, wherein a V-shaped groove perpendicular to the inner surface of the vertical plate portion is formed in the upper surface of the base plate portion, creating a recess and extending from the inner corner point to the other side of the base plate portion in a cross-sectional shape consistent with the groove direction.
The pipe butt welding jig according to claim 1 or 2, wherein a ruler-like scale is provided along the short-side edge of the lower surface of the base plate portion.

Description

This invention relates to a jig for butt welding of pipes (including fittings). In semiconductor manufacturing plants and similar facilities, stainless steel piping is used for fluid transfer, and butt welding of the piping is performed there. Butt welding is performed as follows, for example. First, a pipe is placed on a receiving member 52 attached to a recess 511 in the lower half 5 of a clamp related to a known pipe fixing device D as shown in Figure 11, and then clamped and set between the upper half 6 of the clamp. In this setup, with both upper half 6 of the clamps open, the top plate 91 of a known positioning jig 9 is placed on the upper end surface 522 of the semi-cylindrical receiving member 52 related to the lower half 5 of the rear clamp, and the positioning projection 92 is positioned to protrude into the space S between the holders 4A and 4B (see Figure 1). Then, the butt surface of the pipe placed on the cylindrical inner surface of the semi-cylindrical receiving member 52 related to the lower half 5 of the clamp of the front holder 4A abuts against the vertical surface of the projection 92, and then the upper half 6 of the clamp is rotated around the hinge shaft 531 to clamp and set the pipe between the lower half 5 and the upper half 6 of the clamp. Next, the positioning jig 9 is removed, and the other pipe is placed on the inner surface of the semi-cylindrical receiving member 52 attached to the lower half of the rear clamp 5, so that the abutting surface of the other pipe abuts against the abutting surface of the first pipe. Subsequently, the upper half of the rear clamp 6 is rotated around the hinge shaft 531 to clamp and set the pipe between the lower half of the rear clamp 5 and the upper half of the clamp 6 of the rear holder 4B. In this way, the two abutted pipes 3, 3 are clamped and set by the holders 4A, 4B as shown in Figure 8(d), and then a welding head (not shown) of a known circumferential welding machine is introduced into the upper opening S between the pair of holders 4, 4 and rotated to perform butt welding of the pipes 3, 3. An improved version of the positioning jig 9 used for butt welding of such pipes has also been proposed (for example, Patent Document 1). Japanese Patent Publication No. 2005-34894 Patent Document 1 describes an invention for a positioning jig for butt welding of pipes, which employs a configuration in which a shaft portion with a positioning section at its tip is clamped by a pipe fixing cassette (referred to as pipe fixing device D in this application). This configuration allows for easy determination of the abutting position during pipe setting, even in poor working environments such as when the pipe itself is pulled out at an angle. This is a perspective view of one embodiment of the pipe butt welding jig of the present invention, in which a pipe is set by butting it against the welding jig placed on the lower half of the clamp on the front side.(a) is a front view of a pipe butt welding jig, (b) is a top view thereof, and (c) is a left side view thereof.(a) is a front view of a pipe butt welding jig, and (b) is a rear view thereof.Figure 2(b) is a plan view illustrating the process of marking pipes set in a pipe butt welding jig.Figure 4 is a front view.This is a side view of the main part showing how the pipe butt welding jig is placed on the lower half of the clamp on the front side of Figure 1.(a) is a view taken along the line VII-VII in Figure 6, (b) is a cross-sectional view in which one pipe is butted against the pipe butt welding jig in (a) and placed on the lower half of the left clamp, and (c) is a cross-sectional view in which the pipe is clamped by the right holder from the state in (b).(d) is a cross-sectional view after removing the pipe butt welding jig shown in Figure 7(c), where the butt joint surface of one pipe is placed against the butt joint surface of the other pipe and set in place. (e) is a cross-sectional view after welding has been performed on the butt joint surfaces of both pipes following (d).This is an explanatory plan view showing how to examine the butt joint surface of two pipes after welding.This is an explanatory plan view showing how to check the weld bead width of two pipes after welding.This is a descriptive perspective of conventional technology. The following describes in detail the pipe butt welding jig (hereinafter also simply referred to as "welding jig") according to the present invention. Figures 1 to 10 show one embodiment of the welding jig of the present invention. Figure 1 is a perspective view showing a pipe being set against the welding jig placed on the lower half of the front clamp. Figure 2 shows (a) a front view of the welding jig, (b) a plan view thereof, and (c) a left side view thereof. Figure 3 shows (a) a front view of the welding jig and (b) a rear view thereof. Figure 4 is a plan view showing marking on the piping in Figure 2 (b). Figure 5 is a front view of Figure 4. Figure 6 is a side