JPH034462Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a backing material for single-sided welding that is used in contact with the back surface of a groove of a material to be welded when building various structures by single-sided welding.

(Prior art and its problems) Conventionally, the backing material used for single-sided welding is used by contacting the back side of the groove of the material to be welded over the entire length of the weld, but depending on the structure of the material to be welded or the situation at the welding site. Due to such constraints, it is often not possible to use a backing material with a length equivalent to the weld length, and in that case, short backing materials are connected and used.

As the backing material, backing materials made of inorganic fibers and solid refractory materials are often used. Inorganic fibers can form a suitable slag to obtain a smooth and beautiful back bead shape, but inorganic fibers alone tend to burn through during high-heat-input welding, so solid particles are usually placed under the inorganic fibers. Fireproof material is installed to prevent weld metal from flowing out.

When connecting and connecting short backing materials and making contact with the back side of the groove of the material to be welded, it is not easy to make the backing materials come into close contact with each other, and if the contact is insufficient, the backing materials may A gap is created at the joint, and an excessive back bead or casting occurs in that area, and if the gap is extreme, the weld metal within the groove will flow out.

The problems of the conventional example will be explained in detail. Figure 1a,
b shows a conventional example, and Fig. 1 a shows a welded material 4.
Fig. 1b shows a case in which the connection part of the backing material in contact with the back surface of the groove is not in sufficient contact, and Fig. 1b shows a case in which the connection part is in sufficient contact. The backing material is composed of a solid refractory material 1 and an inorganic fiber 2, and the contact surface of the solid refractory material 1 to the back surface of the groove and the connecting end surface are covered with the inorganic fiber 2.

In the connection/coupling state shown in Figure 1a, the corners of the connection end surface and the contact surface to the back surface of the groove are rounded, and the contact between the connection parts is insufficient, and the upper surface of the connection parts Since a gap 3 is formed on the lower surface, casting and overlapping occur on the back bead, and in some cases, weld metal flows out.

In addition, in the connection/connection state shown in Fig. 1b, the solid refractory material 1 has sufficient adhesion, so even if a gap 3 occurs, weld metal can be prevented from flowing out, but the occurrence of overcasting and overlapping cannot be avoided. do not have.

From the above, it is possible to easily obtain a smooth and beautiful back bead by filling the gap 3 created by the inorganic fibers 2 and making the lower solid refractory materials more closely adhered to each other. For this reason, various backing materials have been proposed. For example, in Japanese Utility Model Publication No. 1987-4724, it is proposed to insert an insert material made of inorganic fiber into the upper surface of the connection part of the backing material. Select the appropriate insert material each time the material is brought into contact,
The gap 3 mentioned above cannot necessarily be completely eliminated due to the superiority of the contact technology, and if the insertion method is incorrect, the gap 3 will widen and the solid refractory materials will adhere to each other. There is a considerable risk that it may also inhibit the

Furthermore, in Japanese Patent Publication No. 48-29981, it is proposed to incorporate a cushion material made of a plastic or elastic substance into the connecting end surface of the backing material, but even if the cushion material is inserted, the upper surface of the connecting portion usually A gap 3 is created in the connection end surface, and by incorporating the cushion material in the connecting end face, the distance between the solid refractory materials increases and the adhesion is inhibited.
This is not always completely satisfactory as it causes the weld metal to flow out.

(Purpose of the invention) The invention improves the above-mentioned problems in the backing material,
The object of the present invention is to obtain a backing bead that is completely unchanged from other parts at the connection part of a backing material by a simple and easy method.

(Structure and effects of the invention) The invention consists of two layers: an upper layer made of one or more inorganic fibers and a lower layer made of solid refractory material, and the inorganic fibers are formed on the back surface of the groove of the solid refractory material. A backing material for single-sided welding is characterized in that a backing material is configured to cover a contact surface and a connecting end surface, and a gap is provided between a solid refractory material connecting end surface and an inorganic fiber.

That is, as shown in FIGS. 2a and 2b, the backing is composed of two layers: an upper layer of inorganic fibers 2 and a lower layer of solid refractory material 1, and the inorganic fibers 2 cover the connecting end surface of the solid refractory material 1. It is characterized in that a gap 5 is provided in advance between the upper layer inorganic fiber 2 and the lower layer solid refractory material 1 at the connection end surface.

Note that Fig. 2a shows the case of one inorganic fiber, Fig. 2b shows the case of multiple inorganic fibers, and 6 shows the case of two inorganic fibers.
The adhesive tape is shown for fixing the edge of the material to the back side of the backing material.

As shown in Fig. 3, the effect is that when the backing material is connected, connected and brought into contact with the back surface of the groove of the workpiece 4, a gap 5 is provided at the connecting end surface of the backing material. The excess portion of the resulting inorganic fibers 2 is pressed against the connecting end surface of the backing material that is next contacted, thereby filling the gap 3 in the conventional method, as shown in Figures 1a and b. The gap 3 between the connecting parts of the backing materials is completely eliminated as shown in FIG. 3, and the solid refractory materials in the lower layer have sufficient adhesion to each other.

As shown in FIG. 3, the effect is more likely to be obtained if the inorganic fiber layer is more free than the solid refractory material on the back surface near the end of the solid refractory material.

The appropriate length 7 of the void 5 is in the range of 1 to 5 mm; if it is less than 1 mm, it cannot be expected to fill the gap 3, and if it is more than 5 mm, the free portion of the inorganic fiber will be excessive and will inhibit the adhesion of the solid refractory material. I will do it.

Note that the length 7 of the void 5 indicates a value when no external force is applied to the inorganic fiber and the fiber has an arcuate shape in its natural state.

By implementing the present invention as described above, the gap at the backing material connection part is eliminated and the material to be welded is in close contact with the entire back surface of the groove. There is no need to insert an insertion material, and the backing material can be simply and easily connected and connected to the back surface of the groove. Therefore, it is possible to obtain a smooth and beautiful back bead without locally excessive bead or casting.

[Brief explanation of the drawing]

1A and 1B are side views of a conventional example, and FIGS. 2A, 2B, and 3 are side views showing an embodiment of the present invention. 1 is solid refractory material, 2 is inorganic fiber, 3 is gap, 4
is the material to be welded, 5 is the gap, 6 is the adhesive tape, and 7 is the gap length.

Claims (1)

[Scope of utility model registration request] Consisting of two layers: an upper layer made of one or more inorganic fibers 2 and a lower layer made of solid refractory material 1,
In a backing material having a structure in which the inorganic fibers 2 cover the groove back abutment surface and the connection end surface of the solid refractory material 1, there is 1 between the solid refractory material connection end surface and the inner surface of the inorganic fiber 2.
A backing material for single-sided welding, characterized in that a void 5 having a length 7 of ~5 mm is provided.