JP2018167322A - Fatigue strength improvement device and fatigue strength improvement method of weld joint - Google Patents

Abstract

To provide a device and a method for improving fatigue strength of a weld joint having a weld zone formed in a hole.SOLUTION: A fatigue strength improvement device 10 includes a body part 12. The body part 12 has a plunger part 18a, a support part 20a and a driving-force transfer part 16. The driving-force transfer part 16 transfers driving force to at least either of the plunger part 18a and the support part 20a. The driving-force transfer part 16 holds the plunger part 18a and the support part 20a so that the plunger part 18a and the support part 20a are separated relatively in a first direction by the driving force.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus and method for improving the fatigue strength of welded joints.

  Various welded joints are used in structures such as ships and bridges. As a welded joint used in a structure, for example, a welded joint obtained by joining two steel plates by fillet welding can be cited.

  In such a welded joint, it is known that when repeated stress is applied, stress concentration occurs at the weld toe or tensile residual stress occurs. It is also known that fatigue cracks may occur from the weld toe due to such stress concentration.

  Therefore, conventionally, techniques for suppressing the occurrence of fatigue cracks in welded joints have been proposed. For example, in the method for manufacturing a welded joint disclosed in Patent Document 1, a hammering process is performed on at least the weld toe of the turn welded portion of the fillet welded portion. By this striking treatment, compressive residual stress can be applied to the weld toe, and the occurrence of a fatigue crack from the weld toe can be suppressed.

International Publication No. 2011/024784

  By the way, in a welded joint, a hole (for example, scallop) is formed in the joint part of a steel plate and a steel plate, and a weld part may be formed in this hole. Even in such a welded joint, when stress repeatedly acts, stress concentration or the like occurs at the weld toe of the welded portion, and a fatigue crack may occur. For this reason, it is preferable to improve the fatigue strength by applying compressive residual stress also at the weld toe of the weld formed in the hole.

  However, Patent Document 1 does not consider improving the fatigue strength of the weld toe portion of the weld formed in the hole. For this reason, in a welded joint in which a weld is formed in the hole, it is difficult to sufficiently improve the fatigue strength even if the technique of Patent Document 1 is used.

  The present invention has been made to solve such problems, and an object thereof is to provide an apparatus and a method for improving the fatigue strength of a welded joint in which a weld is formed in a hole.

  The gist of the present invention is the following fatigue strength improving apparatus and fatigue strength improving method.

(1) It has a plurality of metal members including a plate-like joining member having a notch and made of metal, and a hole having a depth in the thickness direction of the joining member is formed by the notch. In the weld joint in which the plurality of metal members are welded so that at least two of the metal members are joined in the hole, the welded portion formed in the hole A fatigue strength improving device for improving the fatigue strength of the weld toe,
A pusher portion, a support portion, and a driving force transmission portion that transmits a driving force to at least one of the pusher portion and the support portion,
The driving force transmission unit holds the pusher unit and the support unit such that the pusher unit and the support unit move relative to each other in the first direction by the driving force,
In the hole, the pusher part and the support part are relatively moved in the first direction by the driving force, so that the pusher part and the support part are in contact with the inner surface of the hole, respectively. A fatigue strength improvement device that presses the inner surface of a hole.

(2) The fatigue strength improving apparatus according to (1), wherein the driving force transmission unit is disposed between the pusher unit and the support unit in the first direction.

(3) The length of the pusher portion in the second direction orthogonal to the first direction is longer than the length of the pusher portion in the third direction orthogonal to the first direction and the second direction, The fatigue strength improving apparatus according to (1) or (2).

(4) When the pusher part and the support part are projected in the first direction, the pusher part and the support part overlap,
The fatigue strength according to (3) above, wherein the outer surface of the pusher portion has a curved surface that is convex toward the opposite side of the support portion and curved in an arc shape in a cross section orthogonal to the second direction. Improvement device.

(5) In the cross section orthogonal to the third direction, the curved surface of the pusher portion is convex toward the opposite side to the support portion and is curved in an arc shape.
The fatigue radius according to (4), wherein a curvature radius of the curved surface in a cross section orthogonal to the third direction is not less than 5 times and not more than 100 times a curvature radius of the curved surface in a cross section orthogonal to the second direction. Strength improvement device.

(6) When the pusher part and the support part are projected in the first direction, the pusher part and the support part overlap,
The outer surface of the support portion has a curved surface that is convex toward the opposite side of the pusher portion and curved in an arc shape in a cross section orthogonal to the second direction. The fatigue strength improving apparatus according to any one of the above.

(7) The fatigue strength improving apparatus according to (6), wherein the curved surface of the support portion extends linearly in the second direction in a cross section orthogonal to the third direction.

(8) The fatigue strength improvement according to any one of (1) to (7), wherein a length of the support portion is longer than a length of the pusher portion in a second direction orthogonal to the first direction. apparatus.

(9) The driving force transmission portion moves at least one of the pusher portion and the support portion in the first direction by a fluid,
The length of the driving force transmission portion in the second direction orthogonal to the first direction is at least four times the length of the driving force transmission portion in the third direction orthogonal to the first direction and the second direction. The fatigue strength improving apparatus according to any one of (1) to (8) above.

(10) A plurality of metal members having a notch portion and including a plate-like joining member made of metal are provided, and a hole having a depth in the thickness direction of the joining member is formed by the notch portion. In the weld joint in which the plurality of metal members are welded so that at least two of the metal members are joined in the hole, the welded portion formed in the hole A method for improving the fatigue strength of the weld toe of
The pusher portion and the support portion of the fatigue strength improving device according to any one of (1) to (9) are disposed in the hole, and the pusher portion and the support portion are arranged from the driving force transmission portion. The pusher portion and the support portion are moved relatively apart from each other in the first direction by transmitting a driving force to at least one of them, and the pusher portion is formed in the hole. A method for improving fatigue strength, comprising a step of pressing a weld toe of the weld.

  According to the present invention, the fatigue strength of a welded joint in which a weld is formed in the hole can be improved.

FIG. 1 is a view showing a fatigue strength improving apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a driving force transmission unit. FIG. 3 is a cross-sectional view showing the pressing unit. FIG. 4 is a cross-sectional view showing the support unit. FIG. 5 is a diagram illustrating an example of a welded joint. FIG. 6 is a diagram showing a fatigue strength improving device arranged around and in the through hole. FIG. 7 is a view of the deck plate, the lateral rib, and the welded portion in the direction indicated by the arrow X in FIG. FIG. 8 is a perspective view showing another example of the driving force transmission unit. FIG. 9 is a view showing a fatigue strength improving apparatus according to another embodiment of the present invention. FIG. 10 is a schematic diagram illustrating an example of a fatigue strength improving apparatus that does not use a hydraulic jack. FIG. 11 is a schematic diagram illustrating another example of a fatigue strength improving apparatus that does not use a hydraulic jack. FIG. 12 is a schematic diagram illustrating another example of a fatigue strength improving apparatus that does not use a hydraulic jack. FIG. 13 is a schematic diagram showing still another example of a fatigue strength improving apparatus that does not use a hydraulic jack. FIG. 14 is a diagram illustrating a fatigue strength improving apparatus including support units having different shapes. FIG. 15 is a diagram showing a fatigue strength improving device arranged around and in the through hole.

  Hereinafter, a fatigue strength improving apparatus and a fatigue strength improving method according to an embodiment of the present invention will be described.

  FIG. 1 is a view showing a fatigue strength improving apparatus according to an embodiment of the present invention. In addition, in Fig.1 (a), the side surface of the main-body part of the fatigue strength improvement apparatus which concerns on this embodiment is shown, and in FIG.1 (b), the front surface of the said main-body part is shown. Moreover, in FIG. 1, the 1st direction, 2nd direction, and 3rd direction which are mutually orthogonal are shown. In other drawings, the first direction, the second direction, and the third direction orthogonal to each other are shown as appropriate.

  With reference to FIG. 1, the fatigue strength improvement apparatus 10 (henceforth the improvement apparatus 10) which concerns on this embodiment is provided with the main-body part 12 and the drive source 14 (refer Fig.1 (a)). The main body 12 includes a driving force transmission unit 16, a pressing unit 18, and a support unit 20. In the present embodiment, the driving force transmission unit 16 is disposed between the pressing unit 18 and the support unit 20 in the first direction. In the present embodiment, the pressing unit 18 and the support unit 20 are detachably provided to the driving force transmission unit 16.

  FIG. 2 is a diagram illustrating the driving force transmission unit 16. Although details will be described later, the driving force transmission unit 16 moves the pressing unit 18 in the first direction by the fluid. In the present embodiment, for example, a hydraulic jack (output is, for example, 5 kN or more and 200 kN or less) is used as the driving force transmission unit 16. Referring to FIGS. 1 and 2, driving force transmission portion 16 includes a holding portion 16a, an attachment portion 16b, and a piston 16c.

  With reference to FIG. 2, in this embodiment, the holding | maintenance part 16a has a flat cylinder shape. Referring to FIGS. 1 and 2, holding portion 16 a connects first surface 161 and second surface 162 parallel to each other in the first direction, and the outer edge of first surface 161 and the outer edge of second surface 162. Thus, it has the outer peripheral surface 163 extended in a 1st direction.

  The piston 16c is held by the holding portion 16a so as to be able to advance and retreat in the first direction. The holding part 16a is filled with a fluid (oil in this embodiment) for moving the piston 16c in the first direction. The stroke of the piston 16c is set to 10 mm or less, for example.

  The holding part 16a is connected to the drive source 14 via the attachment part 16b. In the present embodiment, a hydraulic pump is used as the drive source 14. The hydraulic pressure generated by the drive source 14 is transmitted from the oil in the holding portion 16a to the piston 16c, and the piston 16c moves in the first direction so as to protrude from the first surface 161. Thereby, in a 1st direction, the pusher part 18a mentioned later moves so that it may leave | separate relatively from the support part 20a mentioned later. Thus, in this embodiment, the hydraulic pressure generated by the drive source 14 is used as a drive force for moving the piston 16c and the pressing unit 18.

  With reference to FIG. 1, in the present embodiment, the length of the driving force transmission unit 16 in the second direction is longer than the length of the driving transmission unit 16 in the third direction, for example, the driving force transmission unit 16 in the third direction. Is set to 4 times or more (preferably 5 times or more). Thereby, in order to arrange the main body portion 12 in the through holes 40a, 40b, and 40c (see FIG. 6) described later, the piston 16c is fluid (oil) in the holding portion 16a even when the main body portion 12 is elongated. ) Can sufficiently increase the area of the portion that receives pressure. As a result, it is possible to transmit a sufficient driving force to the piston 16c in the driving force transmitting portion 16 while allowing the main body portion 12 to be disposed in through holes 40a, 40b, and 40c (see FIG. 6) described later. Note that the length of the driving force transmission unit 16 in the second direction represents the longer of the length of the holding unit 16a in the second direction and the length of the piston 16c in the second direction. In addition, the length of the driving force transmission portion 16 in the third direction represents the longer one of the length in the third direction of the holding portion 16a and the length in the third direction of the piston 16c.

  The length of the driving force transmission unit 16 in the first direction (the length when the piston 16c is fully extended) is set to 15 to 20 mm, for example. The length of the driving force transmission unit 16 in the second direction is set to 100 mm or less, for example. The length of the driving force transmission unit 16 in the third direction is set to 20 mm or less, for example. Note that the size of the driving force transmission portion 16 can be appropriately changed according to the shapes of through holes 40a, 40b, and 40c (see FIG. 6), which will be described later. For example, the length of the driving force transmission portion 16 in the second direction The length is set to 5 mm or more and 50 mm or less, and the length of the driving force transmitting portion 16 in the third direction is set to 1 mm or more and 5 mm or less.

  The pressing unit 18 has a pusher portion 18a and a base portion 18b. The pusher portion 18a and the base portion 18b are fixed. The base portion 18b is attached to the piston 16c. In the present embodiment, the base portion 18b is provided so as to be removable from the piston 16c. Thereby, the pressing unit 18 can be replaced according to the damage of the pusher portion 18a and the shape of through holes 40a, 40b, and 40c (see FIG. 6) described later. In addition, although detailed description is abbreviate | omitted, the press unit 18 can be attached to piston 16c, for example using fastening members, such as a screw | thread.

  The support unit 20 has a support portion 20a and a base portion 20b. The support portion 20a and the base portion 20b are fixed. The base part 20b is fixed to the second surface 162 of the holding part 16a. In the present embodiment, the base portion 20b is provided so as to be removable from the holding portion 16a. Thereby, the support unit 20 can be replaced according to the damage of the support part 20a and the shape of through-holes 40a, 40b, 40c (see FIG. 6) described later. In addition, although detailed description is abbreviate | omitted, the support unit 20 can be attached to the holding | maintenance part 16a using fastening members, such as a screw, for example. In the present embodiment, the pressing unit 18 and the support unit 20 are provided so that when the pusher portion 18a and the support portion 20a are viewed in the first direction, the pusher portion 18a and the support portion 20a are positioned so as to overlap each other. It has been. In other words, the pressing unit 18 and the support unit 20 are provided so that the pusher portion 18a and the support portion 20a overlap when the pusher portion 18a and the support portion 20a are projected in the first direction.

  In the present embodiment, the length of the pusher portion 18a in the second direction is larger than the length of the pusher portion 18a in the third direction.

  3A is a view showing the pressing unit 18 in the section AA in FIG. 1A, and FIG. 3B is a pressing unit 18 in the section BB in FIG. 1B. FIG. In addition, the cross section shown to Fig.3 (a) is a cross section which passes along the center of the pusher part 18a in a 2nd direction. Moreover, the cross section shown in FIG.3 (b) is a cross section which passes along the center of the pusher part 18a in a 3rd direction.

  Referring to FIGS. 1 and 3, the outer surface of the pusher portion 18 a is defined as a support portion 20 a with respect to the driving force transmission portion 16 in a cross section orthogonal to the second direction (the cross section shown in FIG. 3A). It has a curved surface 181 that is convex toward the opposite side and is curved in an arc shape. Further, in the present embodiment, the curved surface 181 of the pusher portion 18a has the support portion 20a with respect to the driving force transmission portion 16 even in a cross section orthogonal to the third direction (the cross section shown in FIG. 3B). It protrudes toward the opposite side and curves in an arc shape. In other words, the curved surface 181 is convex toward the opposite side to the support portion 20a in the first direction.

  In the present embodiment, the radius of curvature of the tip portion of the curved surface 181 in the cross section orthogonal to the third direction (the cross section shown in FIG. 3B) is, for example, the cross section orthogonal to the second direction (FIG. 3A). The radius of curvature of the distal end portion of the curved surface 181 in the cross section shown in FIG. The curvature radius of the tip of the curved surface 181 in the cross section orthogonal to the second direction is appropriately set according to the size and shape of through-holes 40a, 40b, and 40c (see FIG. 6) to be described later, for example, 3 mm or less Set to In the cross section orthogonal to the second direction, the radius of curvature of the portion of the presser portion 18a that pushes the weld toe end (that is, the tip of the curved surface 181) is the weld toe end (described later in FIG. 6). The radius of curvature of the surface of the weld toe portion 44a) is preferably somewhat larger. Specifically, since the radius of curvature of the surface of the weld toe is usually about 1 mm or less, the front end of the curved surface 181 in the cross section orthogonal to the second direction (the cross section shown in FIG. 3A). The curvature radius is set to 1 mm or more, for example.

  4A is a diagram showing the support unit 20 in the section AA in FIG. 1A, and FIG. 4B is the support unit 20 in the section BB in FIG. 1B. FIG. In addition, the cross section shown to Fig.4 (a) is a cross section which passes along the center of the support part 20a in a 2nd direction. Moreover, the cross section shown in FIG.4 (b) is a cross section which passes along the center of the support part 20a in a 3rd direction.

  Referring to FIGS. 1 and 4, the outer surface of the support portion 20 a is a pusher portion 18 a with respect to the driving force transmission portion 16 in a cross section orthogonal to the second direction (the cross section shown in FIG. It has a curved surface 201 that is convex toward the opposite side and is curved in an arc shape. In other words, the curved surface 201 is convex toward the opposite side of the pusher portion 18a in the first direction. In the present embodiment, the curved surface 201 of the support portion 20a extends linearly in the second direction in a cross section perpendicular to the third direction (the cross section shown in FIG. 4B). In this way, by forming the curved surface 201 so as to extend linearly in the second direction, when the main body portion 12 is disposed in the through holes 40a, 40b, and 40c (see FIG. 6) described later, the support portion The contact area between 20a and the welded joint 30 can be increased. Thereby, the main-body part 12 can be stably supported by the support part 20a. Moreover, the deformation of the welded joint 30 at the contact portion with the support portion 20a can be suppressed by increasing the contact area.

  The curvature radius of the tip of the curved surface 201 in the cross section orthogonal to the second direction (the cross section shown in FIG. 4A) is, for example, the curve in the cross section orthogonal to the second direction (the cross section shown in FIG. 3A). It is set to be not less than 2 times and not more than 10 times the radius of curvature of the tip of the surface 181. The curvature radius of the tip of the curved surface 201 in the cross section orthogonal to the second direction (the cross section shown in FIG. 4A) is set to, for example, 2 mm or more and 20 mm or less.

  With reference to FIG. 1, in this embodiment, the length of the support part 20a is larger than the length of the pusher part 18a in the second direction. The length of the support part 20a in the second direction is set to, for example, 5 mm or more and 50 mm or less.

  The improvement device 10 according to the present embodiment includes a plurality of metal members including a plate-shaped joining member having a notch and made of metal, and is deepened in the thickness direction of the joining member by the notch. In the welded joint, the plurality of metal members are welded so that a hole having a thickness is formed, and a welded portion for joining at least two of the metal members is formed in the hole. It is suitably used when improving the fatigue strength of the weld toe portion of the weld portion formed in the above. In a welded joint used in a building structure or the like, a scallop having a size corresponding to a circle having a radius of about 35 mm is often formed. The improvement device 10 according to the present embodiment can appropriately improve the fatigue strength of the weld toe of the weld formed in such a scallop.

  Hereinafter, an example of how to use the improvement apparatus 10 will be described. FIG. 5 is a diagram illustrating an example of a welded joint in which the fatigue strength improving method is performed. FIG. 5 shows a steel slab as an example of a welded joint.

  With reference to FIG. 5, the steel deck 30 includes a deck plate 32, a main girder 34, a lateral rib 36, and a longitudinal rib 38. The lateral rib 36 has a plurality of notches 36a, 36b, 36c. By the notch 36a, a through hole 40a is formed between the deck plate 32, the main beam 34, and the lateral rib 36, and penetrates the lateral rib 36 (more specifically, the web of the lateral rib 36) in the plate thickness direction. Has been. In addition, a through hole 40b is formed between the horizontal rib 36 and the vertical rib 38 by the notch 36b, and a through hole 40c is formed between the deck plate 32, the horizontal rib 36 and the vertical rib 38 by the notch 36c. Is formed.

  In the steel deck 30 of FIG. 5, the deck plate 32, the main girder 34, the lateral ribs 36, and the longitudinal ribs 38 are examples of metal members, and the web of the lateral ribs 36 is an example of a plate-shaped joining member. It is.

  Referring to FIG. 5, a part of each of welded portions 42a, 42b, and 42c is formed in through hole 40a. In the present embodiment, welds 42a, 42b, and 42c are formed so as to pass through the through hole 40a. The welded portion 42a joins the deck plate 32 and the main beam 34, the welded portion 42b joins the deck plate 32 and the lateral rib 36, and the welded portion 42c joins the main beam 34 and the lateral rib 36. ing. Although a detailed description is omitted, a part of the welded portion 42d that joins the horizontal rib 36 and the vertical rib 38 is formed in the through hole 40b. The other part of the weld 42d is formed in the through hole 40c. In the present embodiment, the weld portion 42d is formed so as to pass through the through hole 40b and the through hole 40c. Further, a part of the welded part 42e for joining the deck plate 32 and the vertical rib 38 and a part of the welded part 42f for joining the deck plate 32 and the lateral rib 36 are respectively formed in the through holes 40c. . In the present embodiment, the welded portions 42e and 42f are each formed so as to pass through the through hole 40c.

  In the present embodiment, the improvement device 10 described above is disposed in each of the through holes 40a to 40c, and the inner surfaces of the through holes 40a to 40c (more specifically, the weld toes of the welds 42a to 42f). Compressive residual stress can be imparted to the weld toe by pushing with the pusher 18a. Thereby, the fatigue strength of the weld toe part of each welding part 42a-42f can be improved in each through-hole 40a-40c. As a result, the fatigue strength of the steel deck 30 can be improved. In this embodiment, when the pusher portion 18a presses the inner surface of each through hole 40a to 40c, the support portion 20a also presses the inner surface of each through hole 40a to 40c. In other words, when the pusher portion 18a presses the inner surface of each of the through holes 40a to 40c, the support portion 20a comes into contact with the inner surface of each of the through holes 40a to 40c, thereby causing the driving force transmitting portion 16 and the pressing unit 18 ( The pusher part 18a) is supported. In the present embodiment, the time for which the pusher portion 18a presses the inner surface of each of the through holes 40a to 40c is set to 1 second or more, for example. In addition, when the time which the pusher part 18a presses the inner surface of each through-hole 40a-40c is set to less than 1 second, it is preferable to push the same location repeatedly by the pusher part 18a.

  Hereinafter, the fatigue strength improving method will be described more specifically by taking an example of the case where the improving device 10 is disposed in the through hole 40a.

  FIG. 6 is a schematic view showing the improvement device 10 arranged around and in the through hole 40a. FIG. 7 is a view of the deck plate 32, the lateral rib 36, and the welded portion 42b in the direction indicated by the arrow X in FIG. In FIG. 7, the horizontal ribs 36 are hatched in order to clarify the positional relationship among the deck plate 32, the horizontal ribs 36, and the welded portions 42b.

  With reference to FIGS. 6 and 7, welded portion 42 b includes a rotating welded portion 44. The rotation welding part 44 is a part formed so that the edge part by the side of the notch part 36a of the horizontal rib 36 among the welding parts 42b may be rotated.

  In this embodiment, as shown in FIG. 6, by arranging the improvement device 10 in the through hole 40 a, the weld toe portion 44 a of the turning welded portion 44 can be pushed by the pusher portion 18 a. As a result, it is possible to improve the fatigue strength of the turn welded portion 44 formed in the through hole 40a, which is difficult with the conventional apparatus.

  Further, in the present embodiment, as shown in FIG. 1, the length of the pusher portion 18a in the second direction is larger than the length of the pusher portion 18a in the third direction. With the pusher portion 18a having such a shape, as shown by a broken line in FIG. 7, the region 50 having a predetermined length extending along the weld toe portion 44a can be pushed by a single process. Thereby, the fatigue strength of the steel deck 30 can be improved with a small number of treatments. Further, by reducing the number of times of processing, for example, damage (peeling or the like) of the weld toe portion 44a can be suppressed as compared with a case where a hammering process using ultrasonic vibration is performed on the weld toe portion 44a. . Note that the weld toe portion is not completely linear, and may have a curved portion (a portion extending in a wavy manner). Even when the weld toe portion has such a shape, the length of the pusher portion 18a in each of the second direction and the third direction is set appropriately so that a sufficient amount along the weld toe portion can be obtained. It becomes possible to push the length area appropriately in a single process.

  In the above-described embodiment, the case where the shape of the pusher portion 18a and the support portion 20a is different has been described, but the shape of the pusher portion 18a and the support portion 20a may be the same. In this case, the compressive residual stress can be applied to the weld toe portion by both the pusher portion 18a and the support portion 20a.

  Moreover, although the above-mentioned embodiment demonstrated the case where the press unit 18 was attached to the piston 16c, the structure of the improvement apparatus 10 is not limited to the above-mentioned example. That is, only one of the pressing unit 18 and the support unit 20 may be attached to the piston, or a pair of pistons may be provided in the driving force transmission unit, and both the pressing unit 18 and the support unit 20 may be attached to the piston.

  Moreover, although the above-mentioned embodiment demonstrated the case where the driving force transmission part 16 was provided with the piston 16c whose length in a 2nd direction is longer than the length in a 3rd direction, the structure of a piston is not limited to the above-mentioned example. . For example, as illustrated in FIG. 8, the driving force transmission unit 16 may include a plurality of cylindrical pistons 16 d arranged so as to be aligned in the second direction instead of the above-described piston 16 c. In this case, for each piston 16d, the length in the second direction does not have to be longer than the length in the third direction, so that a ready-made piston can be used. Therefore, from the viewpoint of reducing the manufacturing cost of the improvement device, it is preferable to have a configuration in which cylindrical pistons 16d are arranged as shown in FIG. In FIG. 8, the base portion 18 b of the pressing unit 18 is illustrated in order to facilitate understanding of the positional relationship between the constituent members, but the pusher portion 18 a is not illustrated.

  In the above-described embodiment, the case where the improvement device is used in the welded joint in which the welded portion is formed in the through hole has been described. However, the improvement device according to the present embodiment can be used to improve fatigue strength even in a welded joint in which a weld is formed in a hole that does not penetrate the joining member. For example, although a hole penetrating in the plate thickness direction of the joining member was initially formed in the weld joint, even if one end side of the hole is blocked by another structure, the weld formed in the hole The fatigue strength of the weld toe part of the part can be improved using an improvement device. In addition, when using an improvement device in a welded joint in which a weld is formed in a hole that does not pass through the joining member, a push of a shape that can push the weld toe located at a deep location of the hole It is preferable to use a child part. Even when the hole is deep, if the fatigue crack origin is not at the weld toe located at the deep hole location (that is, compressive residual stress is applied to the weld toe located at the deep hole location). In the case where it is not necessary), pushers of various shapes can be used. In addition, since it is easy to give a compressive residual stress to all the weld toes in a hole, it is preferable that the hole in which the weld part is formed is a through-hole.

  In the above-described embodiment, the case where the improvement device includes the driving force transmission unit having the holding unit that can be arranged in the hole of the weld joint has been described. However, the configuration of the driving force transmission unit is not limited to the above example. FIG. 9 is a view showing a fatigue strength improving apparatus according to another embodiment of the present invention.

  Referring to FIG. 9, fatigue strength improving apparatus 200 (hereinafter abbreviated as improving apparatus 200) according to the present embodiment includes a main body 220 and a drive source 240. The main body 220 includes a driving force transmission unit 260, the above-described pressing unit 18, and the above-described support unit 20. In addition, since the structure of a well-known hydraulic jack can be utilized about structures other than the press unit 18 and the support unit 20 among the improvement apparatuses 200, below, the structure of the improvement apparatus 200 is demonstrated easily.

  In the present embodiment, for example, a manual pump is used as the drive source 240. Although a detailed description is omitted, the drive source may be an electric pump. The driving force transmission part 260 includes a holding part 260a, a base part 260b, a piston (ram) 260c, an arm part 260d, and a claw part 260e. The holding part 260a holds the piston 260c so as to be able to advance and retreat in the first direction. In this embodiment, a ram cylinder is used as the holding portion 260a and the piston 260c.

  The drive source 240 and the holding part 260a are supported by the base part 260b. A flow path that connects the drive source 240 and the holding portion 260a is formed in the base portion 260b. The drive source 240, the flow path of the base portion 260b, and the holding portion 260a are filled with a fluid (oil in this embodiment) for moving the piston 260c in the first direction.

  The arm portion 260d has an L-shape, extends in the second direction and is attached to the piston 260c, and the first arm portion 261 from the one end in the second direction toward the base portion 260b side. And a second arm portion 262 extending in the direction. The claw portion 260e is fixed to the end portion of the second arm portion 262 on the base portion 260b side. The claw portion 260e extends from the end portion of the second arm portion 262 in a direction away from the holding portion 260a in the second direction.

  In the present embodiment, the pressing unit 18 is fixed to the claw portion 260e, and the support unit 20 is fixed to the base portion 260b. Specifically, the pressing unit 18 is fixed to the claw portion 260e so that the pusher portion 18a protrudes toward the opposite side of the base portion 260b with respect to the claw portion 260e. Further, the support unit 20 is fixed to the base portion 260b so that the support portion 20a is convex toward the opposite side of the claw portion 260e with respect to the base portion 260b. Also in this embodiment, similarly to the above-described embodiment, when the pusher portion 18a and the support portion 20a are viewed in the first direction, the pusher portion 18a and the support portion 20a are positioned so as to overlap each other. A pressing unit 18 and a support unit 20 are provided. In other words, in the projection obtained by projecting the pusher portion 18a and the support portion 20a in the first direction, the pressing unit 18 and the support unit 20 are provided so that the pusher portion 18a and the support portion 20a overlap. .

  In the present embodiment, the hydraulic pressure generated by the drive source 240 is transmitted to the piston 260c via the oil in the base portion 260b and the holding portion 260a, and the first direction is such that the piston 260c protrudes from the holding portion 260a. Move to. Thereby, the arm part 260d and the claw part 260e move in the first direction so as to be separated from the base part 260b. As a result, the pusher portion 18a moves in the first direction so as to be relatively away from the support portion 20a. Thus, in the present embodiment, the hydraulic pressure generated by the drive source 240 is used as a drive force for moving the piston 260c and the pressing unit 18.

  When using the improvement apparatus 200 which concerns on this embodiment, the press unit 18 and the support unit 20 are inserted in the hole (scallop) of a welded joint. In that state, by moving the pusher portion 18a and the support portion 20a in a direction relatively away from each other in the first direction, the weld toe portion of the weld portion formed in the hole as in the improvement device 10 described above. The fatigue strength of can be improved appropriately. In the present embodiment, the inner surface of the hole can be pushed by the pusher portion 18a in a state where the holding portion 260a is disposed outside the hole of the weld joint. For this reason, it is not necessary to restrict | limit the dimension of the holding | maintenance part 260a to the magnitude | size which can be inserted in a hole. As a result, the piston 260c can be pushed with a large force in the holding portion 260a, and the force by which the pusher portion 18a pushes the inner surface of the hole can be sufficiently increased.

  Moreover, although the above-mentioned embodiment demonstrated the case where a hydraulic jack was used as the main-body part 12 of the fatigue strength improvement apparatus 10, the structure of a fatigue strength improvement apparatus is not limited to the above-mentioned example. For example, the driving force transmission unit may transmit the driving force using an incompressible fluid other than oil. Further, for example, a motor as a drive source may be housed in the drive force transmission unit, and the drive force generated by the motor may be transmitted to the pusher unit 18a by a plurality of gears or the like.

  FIG. 10 is a schematic diagram showing an example of a fatigue strength improving device that does not use a hydraulic jack, FIG. 10 (a) is a side view of the fatigue strength improving device, and FIG. 10 (b) is an internal structure of the fatigue strength improving device. FIG.

  Referring to FIG. 10, a fatigue strength improving apparatus 300 (hereinafter abbreviated as “improving apparatus 300”) according to the present embodiment includes a driving force transmission unit 360, the above-described pressing unit 18, and the above-described support unit 20. It has.

  The driving force transmission unit 360 includes a moving unit 362 and a rotating member 364. A tapered cavity is formed inside the moving unit 362. A thread groove is formed on the inner surface of the moving unit 362. In the first direction, the pressing unit 18 is fixed to one end of the moving unit 362, and the support unit 20 is fixed to the other end of the moving unit 362. In the present embodiment, the moving unit 362 has a configuration that is divided into two in the first direction, and includes a first member 62a and a second member 62b. In the present embodiment, the pressing unit 18 is fixed to the first member 62a, and the support unit 20 is fixed to the second member 62b.

  In the present embodiment, the first member 62a has a recess 621 that is recessed toward one side in the first direction in a side view. The second member 62 b has a convex portion 622 that projects toward one side in the first direction in a side view and fits into the concave portion 621. In the present embodiment, the first member 62a and the second member 62b are combined with each other so as to be relatively movable in the first direction.

  The rotating member 364 includes a head portion 64a and a screw portion 64b extending from the head portion 64a in the second direction. The head portion 64a has a polygonal shape in a cross section orthogonal to the second direction. The screw part 64b has a taper shape so that it becomes so thin that it leaves | separates from the head part 64a in a 2nd direction. In the present embodiment, the rotating member 364 is inserted into the moving unit 362 so that the screw thread of the screw portion 64b is screwed into the thread groove on the inner surface of the moving unit 362.

  In the present embodiment, by rotating the head portion 64a, the screw portion 64b rotates, and the first member 62a and the second member 62b move in a direction that is relatively separated or approached in the first direction. Thereby, the pusher part 18a and the support part 20a move so as to be relatively separated from each other in the first direction. In the present embodiment, the operator can rotate the head 64a using a tool. In addition, a ratchet wrench, an impact wrench, etc. other than a normal wrench can also be used as a tool.

  When using the improvement apparatus 300 which concerns on this embodiment, the press unit 18, the support unit 20, and the driving force transmission part 360 are inserted in the hole (scallop) of a welded joint. In this state, by moving the pusher portion 18a and the support portion 20a in a direction relatively away from each other in the first direction, the welding stop of the welded portion formed in the hole is performed in the same manner as the improvement devices 10 and 200 described above. The fatigue strength at the end can be improved appropriately.

  Further, in the present embodiment, the driving force transmission unit 360 uses the rotational force (driving force) of the head portion 64a as a force in the first direction by a mechanical structure without using hydraulic pressure, and the pusher portion 18a and It can transmit to the support part 20a. Thus, in this embodiment, since the fluid for transmitting a driving force to the pushing part 18a and the support part 20a becomes unnecessary, size reduction of the improvement apparatus 300 becomes easy.

  Although a detailed description is omitted, a wedge 366 may be used instead of the rotating member 364 as in the fatigue strength improving apparatus 300a (hereinafter, abbreviated as the improving apparatus 300a) shown in FIG. In this case, the pusher portion 18a and the support portion 20a can be moved by hitting the wedge 366 with a tool such as a scissors (not shown).

  FIG. 12 is a schematic diagram showing another example of a fatigue strength improving apparatus that does not use a hydraulic jack, FIG. 12 (a) is a side view of the fatigue strength improving apparatus, and FIG. 12 (b) is a diagram of the fatigue strength improving apparatus. It is a partial sectional view showing an internal structure.

  Referring to FIG. 12, fatigue strength improving apparatus 400 (hereinafter abbreviated as improving apparatus 400) according to the present embodiment includes a driving force transmission unit 410, the above pressing unit 18, and the above supporting unit 20. It has.

  The driving force transmission unit 410 includes a first moving unit 412, a second moving unit 414, and a rotating member 416. Tapered cavities 412a and 412b communicating with each other are formed in the first moving unit 412. The cavities 412a and 412b are formed so as to penetrate the first moving unit 412 in the second direction. In the present embodiment, each of the cavities 412a and 412b has a truncated cone shape so that the diameter becomes smaller as it approaches the center of the first moving unit 412 in the second direction.

  In the first direction, the pressing unit 18 is fixed to one end of the first moving unit 412, and the support unit 20 is fixed to the other end of the first moving unit 412. In the present embodiment, the first moving unit 412 has a configuration that is divided into two in the first direction, and includes a first member 121 and a second member 122. In the present embodiment, the pressing unit 18 is fixed to the first member 121, and the support unit 20 is fixed to the second member 122.

  Also in this embodiment, the 1st member 121 has the recessed part 121a dented toward the one side of a 1st direction in the side view similarly to the 1st member 62a (refer FIG. 10). Moreover, the 2nd member 122 has the convex part 122a which protrudes toward the one side of a 1st direction in side view similarly to the 2nd member 62b (refer FIG. 10), and fits into the recessed part 121a. Also in this embodiment, the first member 121 and the second member 122 are combined with each other so as to be relatively movable in the first direction.

  The second moving unit 414 includes a first insertion member 141 and a second insertion member 142. Each of the first insertion member 141 and the second insertion member 142 has a truncated cone shape. The first insertion member 141 has a screw hole 141a. The screw hole 141 a is formed so as to extend in the axial direction of the first insertion member 141 and penetrate the first insertion member 141. The first insertion member 141 is inserted into the cavity 412 a of the first moving unit 412. The second insertion member 142 has a through hole 142a. The through hole 142 a is formed so as to extend in the axial direction of the second insertion member 142 and penetrate the second insertion member 142. The second insertion member 141 is inserted into the cavity 412 b of the first moving unit 412.

  In the present embodiment, the rotating member 416 is a screw having a head portion 416a, a cylindrical portion 416b, and a screw portion 416c. In the present embodiment, the rotating member 416 is inserted into the first insertion member 141 and the second insertion member 142 such that the screw portion 416c is screwed into the screw hole 141a and the head portion 416a contacts the second insertion member 142. ing.

  In the present embodiment, by rotating the head 416a, the screw portion 416c rotates, and the first insertion member 141 moves toward or away from the head 416a in the second direction. Thereby, the 1st insertion member 141 and the 2nd insertion member 142 move so that it may approach the center of the 1st movement unit 412 in a 2nd direction, or it leaves | separates from a center. In accordance with such operations of the first insertion member 141 and the second insertion member 142, the first member 121 and the second member 122 move in the direction of moving away from each other or approaching each other in the first direction. Thereby, the pusher part 18a and the support part 20a move so as to be relatively separated from each other in the first direction. Also in the present embodiment, as in the case of the improvement device 300 described above, the operator can rotate the head 416a using a tool.

  When using the improvement apparatus 400 which concerns on this embodiment, the press unit 18, the support unit 20, and the driving force transmission part 410 are inserted in the hole (scallop) of a welded joint. In that state, by moving the pusher portion 18a and the support portion 20a in a direction relatively away from each other in the first direction, the welded portion formed in the hole is similar to the improvement devices 10, 200, and 300 described above. The fatigue strength of the weld toe can be improved appropriately. Also in the present embodiment, as in the case of the improvement device 300 described above, the fluid for transmitting the driving force to the pusher portion 18a and the support portion 20a is not necessary, and thus the improvement device 400 can be easily downsized. become.

  FIG. 13 is a schematic diagram showing still another example of a fatigue strength improving apparatus that does not use a hydraulic jack. In the fatigue strength improving device 400a shown in FIG. 13 (hereinafter, abbreviated as the improving device 400a), the through hole 142a of the second insertion member 142 is a screw hole. Specifically, a thread groove is formed in the through hole 142a so as to be a reverse screw to the thread groove formed in the through hole 141a of the first insertion member 141. Further, in the improvement device 400a, a rotation member (screw) 417 is provided instead of the rotation member 416 of the improvement device 400 described above. The rotation member 417 is different from the rotation member 416 in that a screw portion 417b is further provided between the head portion 416a and the screw portion 416c. In the screw portion 417b, a thread is formed so as to be a reverse screw with respect to the screw portion 416c.

  In the present embodiment, by rotating the head 416a, the screw portions 416c and 417b rotate, and the first insertion member 141 and the second insertion member 142 move toward or away from each other in the second direction. . Thereby, the 1st insertion member 141 and the 2nd insertion member 142 move so that it may approach the center of the 1st movement unit 412 in a 2nd direction, or it leaves | separates from a center. In accordance with such operations of the first insertion member 141 and the second insertion member 142, the first member 121 and the second member 122 move in the direction of moving away from each other or approaching each other in the first direction. Thereby, the pusher part 18a and the support part 20a move so as to be relatively separated from each other in the first direction. By the operation of the improvement device 400a, the same effect as that of the above-described improvement device 400 can be obtained. In the present embodiment, the burden on the neck of the rotating member (screw) 417 can be reduced.

  In the above-described embodiment, as shown in FIG. 1, in the support unit 20, the support portion 20 a is provided so as to protrude from the base portion 20 b in one direction (first direction). The configuration is not limited to the above example. For example, a support unit 250 may be provided instead of the support unit 20 as in the improvement device 10a illustrated in FIG. 14 is different from the above-described support unit 20 in that the support unit 25 is provided instead of the support unit 20a. Hereinafter, the support portion 25 will be briefly described.

  The support part 25 has a first support part 25a and a second support part 25b. The 1st support part 25a is provided so that it may protrude toward one direction (1st direction) from the base part 20b similarly to the above-mentioned support part 20a. On the other hand, the second support portion 25b is provided so as to protrude from the first support portion 25a in a direction intersecting the one direction (first direction) when viewed from the second direction.

  When using the improvement apparatus 10a provided with the support unit 250, for example, as shown in FIG. 15, the driving force transmission unit 16 and the pressing unit 18 are moved by the first support unit 25a and the second support unit 25b in the through hole 40a. Can be supported. That is, in this embodiment, the support part 25 supports the driving force transmission part 16 and the pressing unit 18 by contacting the welded joint 30 (in this embodiment, a steel deck) at two locations in the through hole 40a. can do. Thereby, the driving force transmission part 16 and the pressing unit 18 can be supported more stably. In addition, although detailed description is abbreviate | omitted, the shape of a support unit can be suitably changed according to the shape of a through-hole.

  According to the present invention, the fatigue strength of a welded joint in which a weld is formed in the hole can be improved. Therefore, the present invention can be suitably used for improving the fatigue strength of welded joints constituting structures such as ships and bridges.

10, 10a, 200, 300, 300a, 400, 400a Fatigue strength improving device 12, 220 Main body portion 14, 240 Drive source 16, 260, 360, 410 Drive force transmission portion 18 Press unit 18a Presser portion 20 Support unit 20a Support Part 30 steel deck

Claims (10)

A plurality of metal members including a plate-like joining member having a notch and made of metal are provided, and a hole having a depth in the plate thickness direction of the joining member is formed by the notch. In the welded joint in which the plurality of metal members are welded and a welded portion for joining at least two of the metal members is formed in the hole, the welding stop of the welded portion formed in the hole is provided. A fatigue strength improving device for improving the fatigue strength of the end,
A pusher portion, a support portion, and a driving force transmission portion that transmits a driving force to at least one of the pusher portion and the support portion,
The driving force transmission unit holds the pusher unit and the support unit such that the pusher unit and the support unit move relative to each other in the first direction by the driving force,
In the hole, the pusher part and the support part are relatively moved in the first direction by the driving force, so that the pusher part and the support part are in contact with the inner surface of the hole, respectively. A fatigue strength improvement device that presses the inner surface of a hole.   The fatigue strength improving apparatus according to claim 1, wherein the driving force transmission unit is disposed between the pusher unit and the support unit in the first direction.   The length of the pusher portion in a second direction orthogonal to the first direction is longer than the length of the pusher portion in a third direction orthogonal to the first direction and the second direction. 2. The fatigue strength improving device according to 2. When the pusher part and the support part are projected in the first direction, the pusher part and the support part overlap,
4. The fatigue strength improvement according to claim 3, wherein an outer surface of the pusher portion has a curved surface that is convex toward the opposite side of the support portion and curved in an arc shape in a cross section orthogonal to the second direction. apparatus. In the cross section orthogonal to the third direction, the curved surface of the pusher portion is convex toward the opposite side to the support portion and is curved in an arc shape.
The fatigue strength according to claim 4, wherein a curvature radius of the curved surface in a cross section orthogonal to the third direction is not less than 5 times and not more than 100 times a curvature radius of the curved surface in a cross section orthogonal to the second direction. Improvement device. When the pusher part and the support part are projected in the first direction, the pusher part and the support part overlap,
6. The outer surface of the support portion has a curved surface that is convex toward the opposite side of the pusher portion and curved in an arc shape in a cross section orthogonal to the second direction. The fatigue strength improving apparatus as described.   The fatigue strength improving apparatus according to claim 6, wherein the curved surface of the support portion extends linearly in the second direction in a cross section orthogonal to the third direction.   The fatigue strength improving device according to any one of claims 1 to 7, wherein a length of the support portion is longer than a length of the pusher portion in a second direction orthogonal to the first direction. The driving force transmission unit moves at least one of the pusher unit and the support unit in the first direction by a fluid;
The length of the driving force transmission portion in the second direction orthogonal to the first direction is at least four times the length of the driving force transmission portion in the third direction orthogonal to the first direction and the second direction. The fatigue strength improving apparatus according to any one of claims 1 to 8. A plurality of metal members including a plate-like joining member having a notch and made of metal are provided, and a hole having a depth in the plate thickness direction of the joining member is formed by the notch. In the welded joint in which the plurality of metal members are welded and a welded portion for joining at least two of the metal members is formed in the hole, the welding stop of the welded portion formed in the hole is provided. A method for improving fatigue strength at an end,
In the said hole, the said presser part and the said support part of the fatigue strength improvement apparatus in any one of Claim 1 to 9 are arrange | positioned, Of the said presser part and the said support part, from the said driving force transmission part The welded portion formed in the hole by the pusher portion by moving the pusher portion and the support portion relatively apart in the first direction by transmitting a driving force to at least one of them. A method for improving fatigue strength, including a step of pressing a weld toe.

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