JP4680534B2 - Welding method for cross-linked structure - Google Patents

Description

  The present invention relates to a method for welding a crosslinked structure in which a metal piece inserted into a gap portion of a metal structure is welded.

  Various types of bridging structures are known in which metal pieces are welded to gaps in metal structures. For example, a bridge material (reinforcing material) is welded to the upper end of a water jacket of an open deck cylinder block. There is a closed deck type cylinder block.

  As a manufacturing method of this closed deck type cylinder block, for example, after inserting the bridge material into the upper end of the water jacket of the open deck type cylinder block, both side walls of the water jacket and the both sides of the bridge material separated from the top deck by a predetermined dimension. Insert the brazing material in the lower part of the gap with the wall, and then join the lower side wall of the bridge material by brazing by laser welding the both side walls of the water jacket and the both side walls of the bridge material from the top deck side, It is known that the upper side wall is joined by laser welding to produce a closed deck type cylinder block (see, for example, Patent Document 1).

JP-A-7-103064

  By the way, in manufacturing a bridge structure such as the closed deck type cylinder block described in Patent Document 1, for example, FIG. 7 shows a partial plan view, and FIG. 8 shows a cross-sectional view taken along line III-III in FIG. As described above, the metal piece 103 which is a bridge member inserted into the upper end portion of the gap portion 102 which becomes the water jacket of the metal structure 101 forming the open deck type cylinder block is connected to all the boundaries between the gap portion 102 and the metal piece 103. , That is, the boundary portions 104 and 105 that contact the gap portion 102 and the boundary portions 106 that do not contact the gap portion 102 that connects the boundary portions 104 and 105 are welded portions 107, and the end of the boundary portion 104 that contacts the gap portion 102 When welding with the end of the boundary 105 in contact with the gap 102 as the welding end, welding with the gap 102 At the starting point or welding end point, the molten metal of the weld 107 so that flows down into the gap portion 102.

  Therefore, as shown in a partial enlarged side view of the welded portion 107 of the boundary portion 105 from the gap 102 side in FIG. 9, a notch-shaped recess 108 is formed in the welded portion 107 at the welding start point or the welding end point. There is a concern that stress may be concentrated on the portion.

  As a countermeasure, as shown in a partial plan view in FIG. 10, the boundary portions 104 and 105 in contact with the gap portion 102 are not welded portions, and only the boundary portion 106 not in contact with the gap portion 102 is used as the welded portion 107. It is conceivable to perform welding with the end on the side as the welding start point and the end on the boundary 105 side as the welding end point.

  However, in this welding method, particularly when a high-energy beam such as laser welding is used to obtain a deep welding depth or a fine welding process is performed, the flow of metal melted by the beam is reduced. Therefore, there is a concern that a hole-like recess 109 is formed at the end point of welding, which also causes stress concentration.

  7, 8, and 10, with respect to the gap portion 102, the right boundary portion of the metal piece 103 in the drawing shows a welded state, and the left boundary portion shows an unwelded state.

  Accordingly, an object of the present invention made in view of such a point is a cross-linked structure in which a metal piece can be reliably welded to a metal structure and a sufficient weld strength can be obtained without forming a recess that causes stress concentration in the weld. It is to provide a body welding method.

The invention of the method for welding a crosslinked structure according to claim 1, which achieves the above object, includes a welding method for a crosslinked structure in which a metal piece inserted in a gap portion of the metal structure is welded to the metal structure. A boundary between the metal structure and the metal piece that is not in contact with the gap is defined as a welded portion, and other than both ends in the length direction of the welded portion are defined as a welding start point and a welding end point. , Slope-in welding for welding the entire length of the welded portion under welding conditions with lower input energy than the main welding from the welding start point, main welding for welding the entire length of the welded portion with a predetermined input energy, and main welding And slope-out welding in which the entire length of the welded portion is welded to the welding end point under welding conditions with lower input energy.

  According to a second aspect of the present invention, there is provided the method for welding a crosslinked structure according to the first aspect, wherein the welding start point and the welding end point are substantially the same point in the central portion in the length direction of the welded portion. After welding from the welding start point to one end in the longitudinal direction of the welded portion, it is folded and welded to the other end in the lengthwise direction of the welded portion. In the main welding, welding is performed from the other end to the one end, and the slope-out welding is performed. Then, after welding from the said one end to the said other end, it is turned up and welded to the said welding end point.

  According to a third aspect of the present invention, in the method for welding a crosslinked structure according to the first or second aspect, the metal structure is an open deck type cylinder block, and the metal piece is an upper end of a water jacket of the open deck type cylinder block. It is a bridge material press-fitted into the part.

According to a fourth aspect of the present invention, in the method for welding a crosslinked structure according to any one of the first to third aspects, the welding by the high energy beam is welding by an electron beam.

  According to the first aspect of the present invention, since the boundary between the metal structure and the metal piece that is not in contact with the gap is the weld, the molten metal does not flow into the gap and the length of the weld Since the welding start point and welding end point other than both ends of the direction are used, the high-energy beam performs slope-in welding and slope-out welding under welding conditions with lower input energy than the main welding before and after the main welding. Can be made to follow the movement of the beam reliably. Therefore, the metal piece can be reliably welded to the metal structure without forming a concave portion that causes stress concentration in the welded portion, and sufficient welding strength can be obtained.

  According to the invention of claim 2, the welded portion is welded three times in one way in total by slope-in welding and slope-out welding, and the welded portion is welded once in one way by main welding, so the welded portion is uniform over the entire length. To improve the welding quality.

  According to the invention of claim 3, it is possible to easily manufacture a good closed deck type cylinder block having no recess that causes stress concentration in the welded portion.

  The invention of claim 4 shows a specific example of welding with a high energy beam, and can be effectively performed by welding with an electron beam.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6.

(First embodiment)
FIGS. 1 to 3 are diagrams for explaining the first embodiment, FIG. 1 is a partial plan view of a bridging structure, FIG. 2 is a cross-sectional view taken along the line II of FIG. 1, and FIG. It is a figure for doing.

  The bridging structure 1 shown in FIGS. 1 and 2 is obtained by inserting and welding a metal piece 4 to the upper end of the gap 3 of the metal structure 2. In FIGS. 1 and 2, The right side of the metal piece 4 in the drawing shows a welded state, and the left side shows an unwelded state.

  In the metal structure 2, a positioning groove 5 for the metal piece 4 having a width larger than the width of the gap portion 3 is formed at the upper end portion of the gap portion 3, and the metal piece 4 is formed in the positioning groove 5. Inserted. Therefore, in a state where the metal piece 4 is inserted into the positioning groove 5, as the boundary portion between the gap portion 3 and the metal piece 4, the boundary portion 11 in contact with the gap portion 3 on each side of the metal piece 4 with respect to the gap portion 3. And 12 and a boundary portion 13 that is connected to the boundary portions 11 and 12 and does not contact the gap portion 3 is formed.

In the present embodiment, the boundary portions 13 that do not come into contact with the gap portions 3 on both sides of the metal piece 4 are welded by high energy beams such as a CO ₂ laser, a YAG laser, and an electron beam as the weld portions 15, respectively. The boundary portions 11 and 12 in contact with are not welded. For this reason, preferably, the metal piece 4 is press-fitted into the positioning groove 5 so that the width dimension of the boundary portions 11 and 12 is as small as possible, and the molten metal at the time of welding of the welded portion 15 12 so that it does not flow out.

  The welded portion 15 has the same point S at the central portion in the length direction as a welding start point and a welding end point. First, the welding portion 15 has the entire length of the welded portion 15 under welding conditions in which input energy (heat input) is lower than that of the main welding. Slope-in welding to be welded is performed, then main welding is performed to weld the entire length of the welded portion 15 under a predetermined input energy welding condition that provides a sufficient penetration depth. Finally, the input energy is higher than that of the main welding. Slope out welding is performed in which the entire length of the welded portion 15 is welded to the welding end point S under low welding conditions and the beam is gradually extracted.

  Welding conditions in slope-in welding and slope-out welding are controlled by controlling the welding speed (scanning speed) and welding current according to the material of the metal structure 2 and the metal piece 4 and the depth dimension to be joined. The input energy of is lower than that during main welding.

  In the present embodiment, as shown in FIG. 3, in the first slope-in welding, the welding scan (S 1) is performed from the welding start point S to one end Sa in the length direction of the welded portion 15, and then folded to return the length of the welded portion 15. Welding scanning (S2) is performed up to the other end Sb in the vertical direction. In the next main welding, a welding scan (S3) is performed from the other end Sb of the welded portion 15 to the one end Sa. In the subsequent slope-out welding, when welding scanning (S4) is performed from one end Sa to the other end Sb of the welded portion 15, the welding is turned back and welding scanning is performed to the welding end point S (S5).

  As described above, according to the present embodiment, the boundary portion 13 between the metal structure 2 and the metal piece 4 that is not in contact with the gap portion 3 is used as the welded portion 15, and the center portion in the longitudinal direction of the welded portion 15 is the same. Since the point S is the welding start point and the welding end point, the slope-in welding and the slope-out welding are performed before and after the main welding under the welding conditions having lower input energy than the main welding. It is possible to reliably prevent the molten metal from flowing down to the flow, and to reliably follow the flow of the molten metal by the beam to the movement of the beam. Therefore, the metal piece 4 can be reliably welded to the metal structure 2 without forming a recess that causes stress concentration in the welded portion 15, and sufficient welding strength can be obtained.

  In addition, as shown in FIG. 3, in the slope-in welding, the welding scanning of S1 and S2 is performed, and in the slope-out welding, the welding scanning of S4 and S5 is performed, so that the welded portion 15 is totaled from the Sa end to the Sb end. One-way welding is performed three times, and in the main welding, the welded portion 15 is welded once in one way by the welding scan of S3. Therefore, the welded portion 15 can be uniformly welded over the entire length, and the welding quality can be improved.

(Second Embodiment)
4 to 6 show the structure of the main part of a closed deck type cylinder block for explaining the second embodiment of the present invention. FIG. 4 is a plan view seen from the top deck side, and FIG. II-II sectional view, FIG. 6 is the A section enlarged view of FIG.

  This bridge structure is a closed deck type cylinder block 21 of an engine, and a bridge material which is a metal piece at the upper end of a water jacket 23 which is a gap formed in an open deck type cylinder block 22 which is a metal structure. 24 is press-fitted, and this bridge member 24 is welded to the cylinder block 22 by an electron beam.

  In addition, the closed deck type cylinder block 21 (open deck type cylinder block 22) in this Embodiment is formed with ADC12. The bridge member 24 is made of A5056, which is a solid solution strengthened alloy having substantially the same strength as the ADC 12, and its width W and length L are 12.3 mm and the penetration depth is 9 mm.

  In the present embodiment, the bridge member 24 is welded to the open deck cylinder block 22 in the same manner as in the first embodiment. That is, the boundary portion between the bridge member 24 and the cylinder block 22 that does not contact the water jacket 23 on each side is a welded portion 25, and the same point S at the center in the length direction of each welded portion 25 is a welding start point and a welding end point. S1 and S2 welding scans by slope-in welding shown in FIG. 3, S3 welding scanning by main welding, and S4 and S5 welding scans by slope-out welding are sequentially performed, and the bridge member 24 is an open deck type. Weld to cylinder block 22.

  Here, the welding conditions of the welding scans S1 to S5 by the electron beam are set as shown in the table below, for example.

  Thus, the scanning speed in slope-in welding and slope-out welding is made faster than the scanning speed in main welding, and the amount of heat input per unit time (input energy) is set to 1/5 of that in main welding. A good closed deck cylinder block 21 having no defects such as recesses that cause stress concentration in the portion 25 and no recesses due to the molten metal flowing down to the water jacket 23 can be easily manufactured.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, the welding start point and the welding end point are not limited to the central portion in the longitudinal direction of the welded portion, and can be set at arbitrary positions other than both ends of the welded portion. Can also be set. Moreover, the welding conditions in slope-in welding and slope-out welding can be made different under the conditions equal to or lower than the input energy in the main welding. In the second embodiment, the welding current value can be controlled instead of the scanning speed or together with the scanning speed so that the input energy in the slope-in welding and the slope-out welding can be made lower than that in the main welding. Furthermore, the present invention can be widely applied not only to welding at the time of manufacturing a closed deck cylinder block but also to welding at the time of manufacturing a bridge structure.

It is a fragmentary top view of the bridge | crosslinking structure for demonstrating 1st Embodiment of this invention. It is the II sectional view taken on the line of FIG. It is a figure for demonstrating the welding scan in 1st Embodiment. It is the top view seen from the top deck side which shows the structure of the principal part of the closed deck type | mold cylinder block explaining 2nd Embodiment of this invention. It is the II-II sectional view taken on the line of FIG. It is the A section enlarged view of FIG. It is a fragmentary top view of the bridge | crosslinking structure for demonstrating the conventional welding method. It is the III-III sectional view taken on the line of FIG. It is the partial expanded side view which looked at the welding part by the welding method of FIG. 7 from the clearance gap side. It is a fragmentary top view of the bridge | crosslinking structure for demonstrating the improvement plan of the welding method of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bridge structure 2 Metal structure 3 Crevice part 4 Metal piece 5 Positioning groove 11, 12, 13 Boundary part 15 Welded part 21 Closed deck type cylinder block (bridge structure)
22 Open deck cylinder block (metal structure)
23 Water jacket (gap)
24 Bridge material (metal piece)
25 Welded part S Welding start point / Welding end point Sa One end Sb Other end S1 to S5 Welding scan

Claims (4)

In the welding method of the bridging structure in which the metal piece inserted in the gap portion of the metal structure is welded to the metal structure,
A boundary between the metal structure and the metal piece that is not in contact with the gap is defined as a welded portion, and other than both ends in the length direction of the welded portion are defined as a welding start point and a welding end point. , Slope-in welding that welds the entire length of the welded portion under welding conditions where the input energy is lower than that during main welding from the welding start point;
Main welding for welding the entire length of the weld with predetermined input energy;
A welding method for a bridged structure, comprising: sequentially performing slope-out welding for welding the entire length of the welded portion up to the welding end point under welding conditions having lower input energy than during main welding.   In the slope-in welding, the welding start point and the welding end point are set to substantially the same point in the longitudinal direction of the welded portion, and after welding from the welding start point to one end in the lengthwise direction of the welded portion, the welded portion is folded back. Welding to the other end in the longitudinal direction, welding in the main welding from the other end to the one end, and in the slope out welding, welding from the one end to the other end and then turning back to the welding end point. The method for welding a crosslinked structure according to claim 1.   The bridge according to claim 1 or 2, wherein the metal structure is an open deck cylinder block, and the metal piece is a bridge member press-fitted into an upper end of a water jacket of the open deck cylinder block. Welding method for structures. The high-energy beam by welding, the welding method of the crosslinked structure according to claim 1, characterized in that the welding by electron beam.

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