JP6916051B2 - Joining member for steel pipe pile - Google Patents

Description

The present invention relates to a metal joint member for a steel pipe pile, which is temporarily welded to the open end of a steel pipe for a steel pipe pile and then main-welded.

Conventionally, steel pipe piles have been manufactured by attaching an excavation blade to the tip of the steel pipe or connecting the steel pipes to each other via a joint. The joining members joined to the steel pipe for steel pipe piles, such as drilling blades or fittings, are made of metal and these are joined to the steel pipe by welding. Specifically, by inserting the tip of the joining member into the open end of the steel pipe, the welding material is formed by arc welding at the groove formed along the circumferential direction between the steel pipe and the joining member. It is poured.

For example, as such a joining member, Patent Document 1 proposes a joint (joining member) to be joined to a steel pipe for a steel pipe pile. The joining member shall be at least three spaced in the circumferential direction at the groove portion for forming the annular groove (groove) for welding, the fitting convex portion for the backing, and the boundary portion thereof. It has a built-up part of the place. In the build-up portion, a root interval is formed in a state where the open end of the steel pipe is in contact with the contact portion of the build-up portion.

By using such a joining member (joint), welding is performed along the annular groove (groove) for welding in a state where the fitting convex portion is fitted to the steel pipe in an inwardly fitted state. The steel pipe and the joining member can be joined.

Japanese Patent No. 4298561

Here, it is common to temporarily weld the joining member shown in Patent Document 1 to a steel pipe for a steel pipe pile before main welding. This will be described below with reference to FIGS. 15 (a) and 15 (b). FIG. 15 (a) is an enlarged cross-sectional view along the axial direction of the steel pipe 91 for explaining a state in which the joining member 92 is temporarily welded to the steel pipe 91 for a steel pipe pile, and FIG. 15 (b) is an enlarged cross-sectional view. FIG. 5 is a cross-sectional view taken along the line GG of FIG. 15A for explaining the main welding of the temporarily welded steel pipe 91 and the joining member 92.

When the steel pipe 91 and the joining member 92 are temporarily welded, the tip portion 93 of the joining member 92 is inserted into the steel pipe 91 as shown in FIG. 15 (a). In this state, the molten temporary welding material 95 is poured into a part of the annular groove (groove) 94 in the circumferential direction formed between the steel pipe 91 and the joining member 92, and the temporary welding material 95 is fused to these. Let me. As shown in FIG. 15B, the temporary welding material 95 is formed so as to rise in the annular groove (groove) 94 for main welding along the circumferential direction. When the annular groove 94 including the temporary welding material 95 is main-welded along the circumferential direction, it is difficult for the main welding material 97 to be uniformly melted at the end of the temporary welding material 95 (FIG. 15 (FIG. 15). See b) "Welding defects are likely to occur").

This is because the surface to be welded is preferably substantially orthogonal to the direction in which the arc generated during the main welding is radiated (the direction in which the welding rod 96 is sent). Has a shallow angle θ with respect to the direction in which the arc radiates. Therefore, it is considered that the main welding material 97 at the time of the main welding is not sufficiently melted.

The present invention has been made in view of these points, and at the open end of a steel pipe for a steel pipe pile, after temporary welding to the open end, the welding material at the time of main welding is more uniformly melted. It is an object of the present invention to provide a joining member for a steel pipe pile.

In view of the above problems, the joining member for steel pipe piles according to the present invention is a joint for metal steel pipe piles which is temporarily welded to the open end portion of the steel pipe for steel pipe piles and then main-welded. An annular groove for main welding between a tip portion of a member that enters the open end portion from the inside and an end face of the open end portion with the tip portion inserted into the open end portion. An inclined portion for a groove forming a groove is formed, and the joining member is a temporary welding material fused at the time of temporary welding at a boundary portion between the tip portion and the inclined portion for the groove. The temporary welding material is temporarily welded to the open end portion of the steel pipe, and the boundary portion is spaced in the circumferential direction so that the temporary welding material melted during the temporary welding flows into the bottom portion of the annular groove. It is characterized in that temporary welding recesses are formed at at least three places.

According to the present invention, before performing temporary welding, the end face of the open end of the steel pipe for a steel pipe pile and the groove of the joint material are in a state where the tip of the joint member is inserted into the open end of the steel pipe. A groove that serves as an annular groove for main welding is formed between the sloped portion and the inclined portion. At this time, temporary welding recesses are formed at at least three positions spaced apart from each other in the circumferential direction at the boundary between the tip of the joining member and the grooved inclined portion of the joining member. Then, when performing temporary welding, the molten temporary welding material flows into the temporary welding recess, and at the boundary portion, the temporary welding material is joined via the three temporary welding materials fused during the temporary welding. The member is tentatively welded to the open end of the steel pipe. As a result, the temporary welding material flows into the recess for temporary welding, and the temporary welding material is unlikely to rise. Therefore, during the main welding, the surface including the surface of the temporary welding material (that is, toward the groove which is the annular groove). The welded material can be fused from a direction substantially orthogonal to the circumferential tangent line). As a result, it is possible to suppress poor penetration of the main welded material in the vicinity of the temporary welded material.

Here, if the joint member can be temporarily fixed to the steel pipe by temporary welding, even if the steel pipe and the joint member are in contact with each other without forming a root interval at the portion where the temporary weld material is fused. good. However, in a more preferable embodiment, a root interval is formed between the wall surface forming the temporary welding recess and the end face of the open end in a state where the tip is inserted into the open end. The temporary welding recess is formed so as to be formed. As a result, the temporary welding material can be poured into the root interval, and the penetration of the temporary welding material between the steel pipe and the joining member can be improved.

Further, as long as the joining member can be joined to the steel pipe without any parallel deviation or angle deviation from the axis of the steel pipe, the shape is not particularly limited, but more preferably, the tip portion is used. Is formed with a tapered inclined portion that regulates a deviation parallel to the axis of the steel pipe, and the boundary portion is a position different from the position where the temporary welding recess is formed, and is spaced in the circumferential direction. A build-up portion is formed at at least three places, and the end face of the steel pipe is brought into contact with the build-up portion with the tip portion inserted into the open end portion. A contact portion that regulates the deviation of the angle between the axis of the steel pipe and the axis of the joining member is formed, and the contact portion of the build-up portion is brought into contact with the end face of the steel pipe. A route interval is formed in the circumferential direction excluding the portion.

According to this aspect, the inner edge of the open end of the steel pipe is brought into contact with the tapered inclined portion to regulate the deviation parallel to the axis of the steel pipe, and the end face including the inner edge of the steel pipe is brought into contact with the abutting portion. By doing so, it is possible to regulate the deviation of the angle between the axis of the steel pipe and the axis of the joining member. In this state, since the root spacing is formed in the circumferential direction excluding the contact portion, the main welding material can be poured into the root spacing during the main welding, and the main welding material between the steel pipe and the joining member can be poured. It is possible to improve the penetration of.

Further, the temporary welding recess may coincide with the open end at a position along the axial direction of the steel pipe, but in a more preferable embodiment, a part of the temporary welding recess is formed together with the tip. It is formed so as to enter the open end. According to this aspect, since a part of the temporary welding recess is formed so as to enter the open end together with the tip, the temporary welding material joins the joining member to the steel pipe from the inside of the open end. be able to.

Further, in the temporary welding recess, an inclined wall surface is formed in the vicinity of the end face of the steel pipe in a state where the tip portion is inserted into the open end portion so as to form an obtuse angle with the end face. There is. According to this aspect, when the steel pipe and the joining member are temporarily welded, the direction in which the arc is radiated during the temporary welding is set with respect to both the inclined wall surface of the joining material and the end face of the steel pipe. Can be brought closer to the direction in which it is easier to blend. Therefore, it is possible to improve the penetration of the temporary weld material into the inclined wall surface of the joint material and the end face of the steel pipe.

Examples of the joining member include a joint joined to a steel pipe, but in a more preferable embodiment, the joining member is an excavation blade. Since the diameter of the drilling blade is larger than the diameter of the steel pipe, when the drilling blade is temporarily welded to the steel pipe and main welded, unlike the joint, these are performed at an angle close to the direction orthogonal to the axis of the steel pipe. Welding will be performed. However, even in such a case, as described above, temporary welding and main welding can be performed more uniformly in the circumferential direction.

According to the joining member according to the present invention, at the open end of a steel pipe for a steel pipe pile, after temporary welding to the open end, the welding material at the time of main welding can be more uniformly melted.

It is a main part side view which shows the joining member (excavation blade) and a part of a steel pipe which concerns on 1st Embodiment. It is sectional drawing which follows the AA line of FIG. It is a bottom view of the excavation blade of FIG. It is a top view of the excavation blade of FIG. It is an enlarged view of the main part which shows the tip part of the excavation blade of FIG. 1 and the open end part of a steel pipe. It is a top view of the state in which a part of the excavation blade of FIG. 5 is broken. (A), (b), and (c) are enlarged cross-sectional views showing the drilling blades and the open ends of the steel pipe along the lines BB, CC, and DD of FIG. 6, respectively. It is a side view for demonstrating the position of the welding rod at the time of temporary welding and the main welding of a cutting blade and a steel pipe. The process of temporary welding between the excavation blade and the steel pipe is shown. (A) is a cross-sectional view for inserting a welding rod before temporary welding, (b) is a cross-sectional view after temporary welding, and (c) is (b). It is a cross-sectional view in the horizontal direction. The process of main welding of the drilling blade and the steel pipe is shown. (A) is a cross-sectional view for inserting a welding rod before main welding, (b) is a horizontal cross-sectional view of (a), and (c) main welding. A cross-sectional view in the middle, (d) is a cross-sectional view in the horizontal direction of (c). (A), (b), and (c) are cross-sectional views of the main parts of the excavation blade and the steel pipe showing other examples of the recesses for temporary welding, respectively. (A) is a side view of a main part showing a joint member (joint) and a part of a steel pipe according to the second embodiment, and (b) is a side view of the main part of the joint. (A) is a side view of the main part showing the excavation blade and a part of the steel pipe according to the reference example, and (b) is a side view of the main part of the excavation blade. (A) is a plan view of a main part of the excavation blade, and (b) and (c) are enlarged cross sections showing the excavation blade and the open end of the steel pipe along the lines EE and FF of (a), respectively. It is a figure. (A) is an enlarged cross-sectional view along the axial direction of the steel pipe for explaining a state in which a joint member is temporarily welded to a conventional steel pipe for a steel pipe pile, and (b) is a temporarily welded steel pipe pile. It is sectional drawing along the GG line of (a) for demonstrating the main welding with a joint member.

Hereinafter, some embodiments of the joining member according to the present invention will be described in detail with reference to FIGS. 1 to 12.

[First Embodiment]
In the first embodiment, the excavation blade will be described as a joining member with reference to FIGS. 1 to 10. As shown in FIG. 1, the steel pipe pile 100 buried in the ground to support the foundation of a building or the like is a joint member 10 joined by welding to the steel pipe 1 for the steel pipe pile and the tip of the steel pipe 1. At least has. In the present embodiment, the joining member 10 is a metal (for example, cast iron) rotary buried steel pipe pile excavation blade (hereinafter referred to as an excavation blade) 10 joined to the lower end of the steel pipe 1. The steel pipe 1 is cut so that the end face 2 is perpendicular to the axis CL. The steel pipe 1 has a wall thickness of about 2.5 to 6.0 mm and is formed in a pipe shape with a length of up to about 6 m. The length and wall thickness of the steel pipe 1 are appropriately set according to the number of floors of the building and the like.

As shown in FIGS. 1 to 4, the excavation blade 10 has a bottomed tubular main body portion 11, the lower end of the main body portion 11 is closed by a conical surface portion 12, and the upper portion is open. A spiral blade plate 13 is formed so as to project from the outer periphery of the excavation blade 10. In the present embodiment, the spiral blade plate 13 is integrally formed with the main body portion 11 as one blade, but may be composed of a plurality of blade plates inclined at an angle that facilitates entry into the ground. A plurality of tip blades are formed so as to protrude from the conical surface portion 12 at the lower end, and in the present embodiment, four outer peripheral blades 14A located on the outer peripheral side and four inner peripheral blades 14B located on the inner peripheral side are provided. As shown in FIG. 1, the excavation blade 10 completes the steel pipe pile 100 by coaxially welding the vicinity of the base end of the tip portion 15 of the main body portion 11 to the open end portion 3 of the steel pipe 1.

The excavation blade 10 of the present embodiment is characterized in a portion facing the open end 3 of the steel pipe 1 when it is joined to the steel pipe 1. Specifically, as shown in FIGS. 5 and 6, the tip portion 15 of the excavation blade 10 is inserted into the opening end portion 3 of the steel pipe 1 from the inside in a portion facing the steel pipe 1. A groove inclined portion 20 for forming a groove to be an annular groove 21 for main welding is formed between the portion 15 and the end surface of the opening end portion 3. Then, the excavation blade 10 is temporarily welded to the open end portion 3 of the steel pipe 1 at the boundary portion between the tip portion 15 and the groove inclined portion 20 via the temporary welding material 26 described later fused at the time of temporary welding. It is a thing.

The tip portion 15 of the excavation blade 10 is a portion for entering the tip side, and a tapered slope portion 16 that regulates a deviation parallel to the axis CL of the steel pipe 1 is formed, and the tapered slope portion 16 has a tapered slope portion 16. A grooved inclined portion 20 continuous with this is formed. The tapered slope portion 16 has a smaller inclination angle of the excavation blade 10 with the axis cl of 10 to 20 ° than the groove inclination portion 20, and the excavation blade 10 can easily enter the opening end portion 3 of the steel pipe 1. At the same time, the parallel deviation between the axis CL of the steel pipe 1 and the axis cl of the excavation blade 10 is regulated within a predetermined range. In the present embodiment, the diameter of the tip of the tapered slope portion 16 is set smaller than the inner diameter of the steel pipe 1, and the diameter of the boundary portion between the groove inclined portion 20 and the tapered slope portion 16 is substantially equal to the inner diameter of the steel pipe 1. It has become. The groove portion 20 is formed so that the inclination angle of the excavation blade 10 with the axis cl is as large as about 45 to 60 ° as compared with the tapered slope portion 16. The groove portion 20 forms a groove to be an annular groove 21 for main welding between the tip portion 15 and the end surface 2 of the opening end portion 3 in a state where the tip portion 15 is inserted into the opening end portion 3. It is a thing.

The excavation blade 10 has four intervals in the circumferential direction so that the temporary welding material melted during temporary welding flows into the bottom of the annular groove 21 at the boundary between the tip portion 15 and the groove inclined portion 20. A recess 22 for temporary welding is formed at the place. In the present embodiment, the temporary welding recesses 22 are formed at four places along the circumferential direction at intervals of 90 °, but at least three places may be formed along the main direction, and the diameter of the steel pipe 1 may be formed. It is preferable to increase according to.

Further, the excavation blade 10 has a position different from that of the temporary welding recess 22 at the boundary portion between the tip portion 15 and the groove inclined portion 20, and is built up at four locations at intervals in the circumferential direction. The portion 23 is formed in a protruding state. In the present embodiment, the build-up portions 23 are also formed at four locations along the circumferential direction at intervals of 90 °, but at least three locations may be formed along the circumferential direction, and the diameter of the steel pipe 1 may be formed. It is preferable to increase according to.

The build-up portion 23 is located at a position different from the position where the temporary welding recess 22 is formed at the boundary portion between the tip portion 15 and the groove inclined portion 20, and is on the same circumference as the temporary welding recess 22. It is formed (in the circumferential direction). In the present embodiment, the protruding built-up portion 23 and the recessed temporary welding recess 22 are alternately formed at intervals of 45 °. As shown in FIG. 7 (c), the protruding outer surface 23a of the built-up portion 23 is formed as a rectangular flat surface parallel to the axis CL of the steel pipe 1, and the flat surface on the tip side has the tip portion 15 as the steel pipe 1 A contact portion 23b is formed that comes into contact with the end surface of the steel pipe 1 in a state of being inserted into the open end portion 3 of the steel pipe 1. The contact portion 23b has a function of regulating an angle deviation between the axis of the steel pipe 1 and the axis of the excavation blade 10 when the tip portion 15 is inserted into the open end portion 3 of the steel pipe 1. Therefore, when the end faces 2 of the steel pipe 1 are evenly contacted with the four contact portions 23b, the parallel deviation and the angular deviation of the axis CL of the steel pipe 1 and the axis cl of the excavation blade 10 are kept within a desired range. Can be done.

Although the excavation blade 10 of the present embodiment shows an example in which the tip portion 15 of the tubular main body portion 11 is provided with a recess 22 for temporary welding and a build-up portion 23, the build-up portion 23 is indispensable. Even in a configuration in which only the temporary welding recess 22 is provided instead of the portion, the penetration of the main welding material at the time of the main welding can be made in a good state. Further, in FIG. 7C, the tapered slope portion 16 formed at the tip portion 15 has a clearance with the inner peripheral surface 4 of the steel pipe 1, but this clearance is reduced to reduce the clearance to the lower end of the tapered slope portion 16. Is in contact with (fits) the inner peripheral surface 4 of the steel pipe 1, so that the axis CL of the steel pipe 1 and the axis cl of the excavation blade 10 can be matched.

Here, the temporary welding recess 22 and the build-up portion 23 formed in the tip portion 15 of the excavation blade 10 will be described in more detail with reference to FIG. 7. FIG. 7A is a cross-sectional view of a portion where the temporary welding recess 22 and the build-up portion 22 are not formed, and FIG. 7B is a cross-sectional view of a main part including the temporary welding recess 22. FIG. 7C is a cross-sectional view of a main part including the built-up portion 23.

In FIG. 7A, a tapered slope portion 16 and a groove inclined portion 20 are continuously formed on the tip portion 15 of the excavation blade 10. In FIG. 7 (b), the groove inclined portion 20 is formed at the boundary portion between the tapered slope portion 16 and the groove inclined portion 20, and in FIG. 7 (c), the tapered slope portion 16 and the groove inclined portion 20 are formed. A build-up portion 23 is formed at a boundary portion with the portion 20. In a state where the abutting portion 23b is in contact with the end surface 2 of the steel pipe 1, the gap between the steel pipe 1 and the end surface 2 and the groove inclined portion 20 of the excavation blade 10 is used as the annular groove 21 serving as the groove for the main welding. It is formed.

In FIG. 7B, a temporary welding recess 22 is formed at the boundary between the tapered slope portion 16 of the tip portion 15 and the groove inclined portion 20. That is, in the present embodiment, the temporary welding recess 22 is formed so that the temporary welding material 26 melted at the time of temporary welding flows into the bottom of the tubular groove 21. A root spacing R is formed between the inner peripheral surface 4 of the steel pipe 1 and the tapered slope portion 16 at the upper portion of the temporary welding recess 22. The route interval R is the size of the gap formed by the tip portion 15 of the excavation blade 10 and the open end portion 3 of the steel pipe 1 in the direction in which the arc is radiated during arc welding (the direction in which the welding rod is sent). By providing this route interval R, the temporary welded material 26 or the main welded material 27 from the inside of the open end 3 of the steel pipe 1 can be used with the tip 15 of the excavation blade 10 and the open end of the steel pipe 1. It can be blended into the part 3.

In FIG. 7C, the built-up portion 23 is formed so as to project at the boundary portion between the tapered slope portion 16 of the tip portion 15 and the groove inclined portion 20. In the present embodiment, the build-up portion 23 is integrally formed of cast iron as a part of the excavation blade 10, and has an outer surface 23a formed in a plane parallel to the axis of the excavation blade 10 and a steel pipe 1. It has an abutting portion 23b that comes into contact with the end surface 2. The outer side surface 23a and the contact portion 23b intersect at a right angle.

The joining (welding) between the excavation blade 10 and the steel pipe 1 as the joining member of the present embodiment configured in this way will be described below. As shown in FIG. 8, the tip portion 15 of the excavation blade 10 and the open end portion of the steel pipe 1 are opposed to each other, and the tip portion 15 is inserted into the open end portion of the steel pipe 1 from the inside. Since the diameter of the tip of the tip 15 is set smaller than the inner diameter of the steel pipe 1 and gradually increases at the tapered slope 16, the tip 15 of the excavation blade 10 can be easily inserted into the open end of the steel pipe 1. ..

When the tip portion 15 is inserted into the open end portion of the steel pipe 1, as shown in FIG. 7 (c), a build-up formed at four positions at the boundary portion between the tip portion 15 and the groove portion inclined portion 20 is formed. The contact portion 23b of the portion 23 and the end surface 2 of the steel pipe 1 come into contact with each other to prevent further entry. In addition to this, the axis cl of the excavation blade 10 and the axis CL of the steel pipe 1 are parallel to each other, and these axis cls and CLs substantially coincide with each other (see FIG. 8).

In this state, the temporary welding recesses 22 formed by being recessed at the four boundary portions are located at the bottom of the annular groove 21 for main welding and as shown in FIG. 7B, and the annular groove 21 is formed. A route spacing R is formed between the tapered slope portion 16 and the inner peripheral surface 4 of the steel pipe 1. Then, as shown in FIG. 7A, in the other portion where the build-up portion 23 and the temporary welding recess 22 are not formed, the tapered slope portion 16 and the groove inclined portion 20 form an annular groove as a groove. 21 is formed, and a route interval R is also formed between them.

The joining of the excavation blade 10 and the steel pipe 1 in such an arranged state will be described below with reference to FIGS. 8 and 9. First, temporary welding in the temporary welding recesses 22 formed at four locations on the peripheral surface of the tip portion 15 will be described. The temporary welding performed before the main welding is performed at four sites where the temporary welding recesses 22 are formed. Specifically, as shown in FIG. 8, in a state where the tip portion 15 of the excavation blade 10 is inserted into the open end portion 3 of the steel pipe 1, the welding rod 25 is used for welding while rotating the tip portion 15. Hereinafter, the details will be described with reference to FIGS. 9 (a) to 9 (c). 9 (a) to 9 (c) and FIGS. 10 (a) to 10 (d) described later are cross-sectional views of a main part rotated 90 ° clockwise from the state of FIG. 8 for explanation.

As shown in FIG. 9 (a), when the welding rod 25 was diagonally inserted into the annular groove 21 along the groove inclined portion 20 and the arc was blown, it melted as shown in FIG. 9 (b). The temporary welding material 26 enters the route interval R and flows into the temporary welding recess 22. The temporary welding material 26 melts into the steel pipe 1 and the excavation blade 10, and the excavation blade 10 is partially temporarily fixed at one temporary welding recess 22 of the steel pipe 1. The amount of the temporary welding material 26 is preferably such that the concave portion 22 for temporary welding is filled and the temporary welding material 26 can enter the root interval R and does not protrude too much into the annular groove 21. Temporary fixing is performed at. When the same temporary welding is performed in order in the remaining three temporary welding recesses 22 while rotating the steel pipe pile 100, the excavation blade 10 is securely temporarily fixed at four locations on the outer circumference of the steel pipe 1. .. In this way, the excavation blade 10 is temporarily attached to the open end portion 3 of the steel pipe 1 via the temporary welding material 26 fused at the time of temporary welding at the boundary portion between the tip portion 15 and the groove inclined portion 20. Will be welded.

Next, the main welding in the annular groove 21 formed between the grooved inclined portion 20 and the end surface 2 of the steel pipe 1 will be described below with reference to FIG. As shown in FIGS. 10A and 10B, a welding rod 25 is inserted from the annular groove 21 toward the temporary welding material 26 that has melted into the temporary welding recess 22 at the back of the annular groove 21, and the steel pipe pile. While rotating 100, an arc is blown from the tip of the welding rod 25 to the wall surface of the annular groove 21. As a result, as shown in FIGS. 10C and 10D, the main welding material 27 in which the welding rod 25 is melted is fused so as to cover the temporary welding material 26, and is filled in the annular groove 21 to form a groove. It also melts into the wall surface between the inclined portion 20 and the end surface 2 of the steel pipe 1. In this way, the main welding is performed.

The pre-formed temporary welding material 26 flows into the temporary welding recess 22, and as shown in FIG. 10B, the temporary welding material 26 is less likely to rise than before. Therefore, in this main welding, the annular groove 21 The main welded material 27 can be fused from a direction substantially orthogonal to the portion including the surface of the temporary welded material 26 toward the groove. As a result, it is possible to suppress poor penetration of the main welded material 27 in the vicinity of the temporary welded material. As a result, the steel pipe 1 and the excavation blade 10 can be uniformly joined, and the quality of the steel pipe pile can be improved.

Further, as shown in FIG. 8, the diameter of the excavation blade 10 is larger than the diameter of the steel pipe 1. Therefore, when the excavation blade 10 is temporarily welded to the steel pipe 1 and main welded, unlike the joint described later, these weldings are performed by the welding rod 25 at a shallow angle φ with respect to the end face 2 of the steel pipe 1. Will do. As a result, when the excavation blade 10 is used as a joining member, it is difficult to melt the temporary welding material 26 and the main welding material 27 into the end surface 2 of the steel pipe due to its shape. However, even in such a case, in the present embodiment, by providing the above-mentioned temporary welding recess 22, the temporary welding and the main welding can be performed more uniformly in the circumferential direction, so that the steel pipe 1 and the excavation blade can be performed. The bondability with 10 can be improved.

[Modified example of the first embodiment]
Next, a modified example of the temporary welding recess formed in the joining member of the present invention will be described with reference to FIG. In the excavation blade 10A shown in FIG. 11A, a part of the temporary welding recess 22A formed at the boundary between the tapered slope 16 at the tip and the groove 20 is a steel pipe 1 together with the tip 15. It is formed so as to enter the open end portion 3 of the. Specifically, the temporary welding recess 22A is longer in the axial direction than the temporary welding recess 22 of the above-described embodiment, and extends from the end surface 2 of the steel pipe 1 to the inside of the open end 3. In the temporary welding recess 22A formed in this way, the drilling blade 10 can be temporarily fixed to the steel pipe 1 at the time of temporary welding by the temporary welding material 26, which can be temporarily fixed in a wide range from the inside of the open end of the steel pipe 1. Therefore, the joint strength is improved and stable temporary fixing is possible. The diagonal broken line arrow indicates the insertion direction of the welding rod.

In the excavation blade 10B shown in FIG. 11B, the tip of the temporary welding recess 22B formed at the boundary between the tapered slope 16 at the tip and the groove 20 is the open end of the steel pipe 1. An inclined wall surface 22a is formed in the vicinity of the end surface 2 of the steel pipe 1 so as to form an obtuse angle α with the end surface 2 in a state of being inserted into the portion 3. In the temporary welding recess 22B formed in this way, when the steel pipe 1 and the excavation blade 10 are temporarily welded toward the tip end side of the excavation blade 10B, the direction in which the arc during the temporary welding is radiated is determined by the inclined wall surface. It can be made closer to a right angle with respect to 22a, and the penetration of the temporary welding material 26 in the vicinity of the inclined wall surface 22a can be improved.

In the excavation blade 10C shown in FIG. 11C, the temporary welding recess 22C formed at the boundary between the tapered slope 16 at the tip and the groove 20 has the bottom surface 22b of the annular groove 21 as the end face. The sloped surface is deep on the two sides and shallow on the side away from the end surface 2. In the temporary welding recess 22C formed in this way, when the steel pipe 1 and the excavation blade 10 are temporarily welded toward the tip side of the excavation blade 10C, the root spacing R side can be temporarily welded more firmly, which is less. The temporary welding material 26 can be reliably temporarily fixed.

[Second Embodiment]
Next, as a second embodiment of the present invention with reference to FIG. 12, an example in which the joining member is a joint for joining steel pipes will be described below. The joint 30 is a male joint and is connected to a female joint (not shown) connected to a steel pipe.

As shown in FIG. 12, the joint 30 includes a small-diameter tip portion 32, a large-diameter base portion 33 continuous with the tip portion 32, and a connecting portion 34 continuous with the base portion 33. The tip portion 32 has the same configuration as the tip portion 15 of the excavation blade 10 of the above-described embodiment, and has a tapered slope portion 35 on the tip side and a groove inclination portion 36 continuous thereto. Further, the outer diameter of the intermediate base portion 33 is formed to be the same as the outer diameter of the steel pipe 1, and the outer diameter of the lower connecting portion 34 is set to be slightly smaller than the inner diameter of the steel pipe 1.

Although the tip portion 32 is not shown in detail, similarly to the tip portion 15 of the excavation blade 10 described above, a temporary portion 32 used at the time of temporary welding is provided at the boundary portion between the tip portion 32 and the groove portion inclined portion 36. Welding recesses 37 are formed at four locations (at least three locations) spaced apart from each other in the circumferential direction. Similarly, the build-up portions 38 are formed at four locations (at least three locations) that are different from the positions where the temporary welding recesses 37 are formed and are spaced apart in the circumferential direction. .. Then, the tip portion 32 enters the open end portion 3 of the steel pipe 1 located above, and is joined by main welding after temporary welding.

Further, the connecting portion 34 has a smaller diameter than the base portion 33, and a step is formed between the connecting portion 34 and the base portion 33. The connecting portion 34 is fitted onto the above-mentioned female joint (not shown), and the end of the female joint is brought into contact with the base portion 33, and the connecting portion 34 is joined by welding or the like. According to the joint 30 of this embodiment, the steel pipe 1 and the joint 30 can be joined accurately and reliably by temporary welding, and then uniformly joined by main welding. Can be obtained.

[Reference example]
Next, a reference example of the present invention will be described with reference to FIGS. 13 and 14. The joining member according to the reference example is the excavation blade 10D, and in FIGS. 13 and 14, the parts corresponding to the excavation blade 10 of the first embodiment, excluding the outer peripheral blade 14A and the inner peripheral blade 14B, have their symbols. A D is added at the end. The excavation blade of the reference example is different from the excavation blade 10 of the first embodiment in that there is no recess for temporary welding.

As shown in FIGS. 13 (a) and 13 (b), in the excavation blade 10D, a spiral blade plate 13D (not shown) protrudes from the outer periphery of the main body 11D as in the above-described embodiment. The formed portion of the excavation blade 10D facing the steel pipe 1 has a tip portion 15D that enters from the inside. Similarly, the tip portion 15D of the excavation blade 10D is a portion for entering the tip side, and a tapered slope portion 16D that regulates a deviation parallel to the axis CL of the steel pipe 1 is formed.

In this reference example, the tip portion 15D of the excavation blade 10D has no recess for temporary welding, and only the build-up portion 23D is formed. A contact portion 23b is formed in the build-up portion 23D, and the contact portion 23b is formed with the axis CL of the steel pipe 1 when the excavation blade 10D tip portion 15D is inserted into the open end portion 3 of the steel pipe 1. It has a function of regulating the deviation of the angle of the excavation blade 10D from the axis cl. Specifically, the build-up portion 23D is formed at the boundary portion between the tip portion 15D and the groove inclined portion 20 in a state where the build-up portion 23D protrudes at four locations at intervals in the circumferential direction. ing. In this reference example as well, the build-up portions 23D are also formed on the circumference at intervals of 90 °.

In the excavation blade 10D of the reference example, the tip portion 15D of the excavation blade 10D is inserted into the open end portion 3 of the steel pipe 1, and the end surface 2 of the steel pipe 1 is brought into contact with the contact portion 23b of the build-up portion 23D. In this contact state, the route interval R is formed in the circumferential direction excluding the contact portion 23b. The axis CL of the steel pipe 1 of the abutting portion 23b and the axis cl of the excavation blade 10D are parallel to each other, and the deviation of the angle between the axis CL of the steel pipe 1 and the axis cl of the excavation blade 10D can be regulated.

Further, the tapered slope portion 16D facilitates the entry of the excavation blade 10D into the open end portion 3 of the steel pipe 1, and can regulate the parallel deviation between the axis CL of the steel pipe 1 and the excavation blade 10D within a predetermined range. .. In this way, the annular groove 22D for welding between the groove inclined portion 20D and the end surface 2 of the steel pipe 1 can be formed with a uniform width. As a result, uniform welding is possible, and the joint state between the steel pipe 1 and the excavation blade 10D can be improved.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs are designed without departing from the spirit of the present invention described in the claims. You can make changes. For example, in the second embodiment, the male joint is illustrated as the joint member, but a similar structure may be suitable for the female joint.

Further, in the first and second embodiments, the built-up portion is provided to form a root interval between the tip portion of the joining member near the recess for temporary welding and the open end portion of the steel pipe. For example, the build-up portion may be omitted and the shape of the temporary welding recess may be changed to form a root spacing between them.

Further, a part of the temporary welding recess having the shape shown in FIG. 11 (c) may be further formed so as to enter the open end of the steel pipe together with the tip as shown in FIG. 11 (b). ..

1: Steel pipe 2: End face of the open end of the steel pipe 3: Open end 10,10A-10D: Drilling blade (joining member), 11: Main body, 15,15A to 15D: Tip, 16,16D : Tapered slope, 20, 36: Groove slope, 21: Circular groove, 22: Temporary welding recess, 23, 23A: Overlay, 23b: Contact, 24: Route spacing, 25: Welding rod , 26: Temporary welded material, 27: Main welded material, 30: Joint (joining member), 100: Steel pipe pile

Claims (6)

A metal joint member for steel pipe piles that is temporarily welded to the open end of a steel pipe for steel pipe piles and then main-welded.
A groove that serves as an annular groove for main welding is formed between the tip portion that enters the opening end portion from the inside and the end face of the opening end portion with the tip portion inserted into the opening end portion. An inclined portion for the groove is formed.
A tapered inclined portion that regulates a deviation parallel to the axis of the steel pipe is formed at the tip portion.
The joining member is temporarily welded to the open end of the steel pipe at the boundary between the tapered inclined portion and the groove inclined portion via a temporary welding material fused during temporary welding. ,
The tapered inclined portion and the groove inclined portion are provided at at least three places spaced in the circumferential direction so that the temporary welding material melted at the time of temporary welding flows into the bottom of the annular groove at the boundary portion. A recess for temporary welding is formed from the surface ,
A steel pipe characterized in that a part of the temporary welding recess is formed so as to enter from the open end to the internal space of the steel pipe in a state where the tip is inserted into the open end. Joining member for piles. A metal joint member for steel pipe piles that is temporarily welded to the open end of a steel pipe for steel pipe piles and then main-welded.
A groove that serves as an annular groove for main welding is formed between the tip portion that enters the opening end portion from the inside and the end face of the opening end portion with the tip portion inserted into the opening end portion. An inclined portion for the groove is formed.
The joining member is temporarily welded to the open end of the steel pipe at the boundary between the tip and the grooved inclined portion via a temporary welding material fused during temporary welding.
At least three recesses for temporary welding are formed at the boundary portion at least three places spaced in the circumferential direction so that the temporary welding material melted at the time of temporary welding flows into the bottom of the annular groove .
The temporary welding recess is formed with an inclined wall surface that is inclined so as to form an obtuse angle with the end face in the vicinity of the end face of the steel pipe in a state where the tip portion is inserted into the open end portion. A joining member for steel pipe piles. The prior Symbol boundary portion, said a position different from the temporary welding recess formed positions, in at least three locations spaced in the circumferential direction, padding portion is formed,
The end face of the steel pipe is brought into contact with the built-up portion with the tip portion inserted into the open end portion to regulate the deviation of the angle between the axis of the steel pipe and the axis of the joining member. The contact part is formed,
Steel tube according to claim 1, in a state where the abutting portion is abutted against the buildup portion to the end surface of the steel pipe, the circumferentially except for the contact portion, characterized in that the root gap is formed Joining member for piles. A tapered inclined portion that regulates a deviation parallel to the axis of the steel pipe is formed at the tip portion.
The boundary portion is a position different from the position where the temporary welding recess is formed, and a build-up portion is formed at at least three places spaced apart in the circumferential direction.
The end face of the steel pipe is brought into contact with the built-up portion with the tip portion inserted into the open end portion to regulate the deviation of the angle between the axis of the steel pipe and the axis of the joining member. The contact part is formed,
The steel pipe according to claim 2 , wherein a route interval is formed in the circumferential direction excluding the contact portion in a state where the contact portion of the build-up portion is brought into contact with the end surface of the steel pipe. Joining member for piles. The temporary welding is performed so that a root interval is formed between the wall surface forming the temporary welding recess and the end face of the open end in a state where the tip is inserted into the open end. The joining member for a steel pipe pile according to any one of claims 1 to 4, wherein a recess is formed. The joining member for a steel pipe pile according to any one of claims 1 to 5, wherein the joining member is an excavation blade.

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