JP6459030B2 - Crack growth prevention apparatus and method - Google Patents

Description

  The present invention relates to a crack progress preventing apparatus and method for preventing the progress of a crack in a structure having a crack.

  Cracks may occur in structures such as bridges and cranes. A technique for preventing the progress of cracks that have occurred is described, for example, in Patent Document 1 below. In patent document 1, the circular hole is formed in the front-end | tip of the crack which arose in the steel bridge. This prevents stress from concentrating on one place and prevents the crack from progressing.

JP 2009-102961 A

  However, on the surface of the structure, it may be difficult to recognize where the tip of the crack is located. For example, cracks are mainly generated inside the structure, and the crack may not appear clearly on the surface of the structure. In such a case, a circular hole may be formed at a position deviated from the tip of the crack, and the progress of the crack may not be prevented.

  In addition, when forming a circular hole to prevent the progress of cracks, the effect of preventing crack propagation cannot be obtained with a small circular hole. That is, it is necessary to form an appropriately sized circular hole.

  Therefore, in the method of forming a circular hole, a skilled worker needs to accurately recognize the tip of the crack and form a circular hole of an appropriate size.

  Therefore, it is desirable to prevent the crack from progressing by a simple operation regardless of the skill level of the operator even if the tip position of the crack cannot be accurately recognized.

  Accordingly, an object of the present invention is to provide an apparatus and a method capable of preventing the progress of a crack by a simple operation regardless of the skill level of the operator even when it is difficult to accurately recognize the tip position of the crack. There is.

In order to achieve the above-mentioned object, according to the present invention, there is provided a crack progress preventing device for preventing the progress of a crack generated in a structure,
The structure includes a reinforced portion in which a crack is generated, and the reinforced portion includes a first surface and a second surface located on opposite sides of each other,
First and second fixing members respectively positioned on both sides of the crack with respect to the direction along the first surface and fixed to the first surface;
Third and fourth fixing members respectively positioned on both sides of the crack with respect to the direction along the second surface and fixed to the second surface;
A first connecting screw member for connecting the first and second fixing members to each other;
A second connecting screw member for connecting the third and fourth fixing members to each other;
One end and the other end of the first connecting screw member are respectively the first and second fixing members so that the first connecting screw member can rotate with respect to the first and second fixing members. At least one of the connection between the one end portion and the first fixing member and the connection between the other end portion and the second fixing member is screwed,
One end and the other end of the second connecting screw member are respectively the third and fourth fixing members so that the second connecting screw member can rotate with respect to the third and fourth fixing members. At least one of the connection between the one end portion and the third fixing member and the connection between the other end portion and the fourth fixing member is screwed,
When the first connecting screw member is rotated with respect to the first and second fixing members, the distance between the first and second fixing members is reduced by the screwing,
When the second connecting screw member is rotated with respect to the third and fourth fixing members, the distance between the third and fourth fixing members is reduced by the screwing. An apparatus is provided.

  The crack progress preventing device of the present invention is configured as follows, for example.

The first fixing member overlaps the third fixing member in a direction orthogonal to the first surface, and the second fixing member overlaps the fourth fixing member in a direction orthogonal to the first surface. The second, third and fourth fixing members are arranged on the reinforced portion,
A first fixing mechanism for fixing the first and third fixing members to the reinforced portion;
A second fixing mechanism for fixing the second and fourth fixing members to the reinforced portion,
The first fixing mechanism is
A penetrating portion that penetrates the first fixing member, the reinforced portion, and the third fixing member;
A first fixing force application portion that is screwed to one end portion of the penetration portion;
A second fixing force application unit coupled to the other end of the penetrating unit,
In a state where the first fixing member, the reinforced portion, and the third fixing member are located between the first and second fixing force applying portions, the first fixing force applying portion is placed on the penetrating portion. By rotating the first fixing member, the first fixing member, the second reinforcing member, and the third fixing member are sandwiched between the first fixing member and the second fixing member, and the first fixing member and the third fixing member are sandwiched between the first fixing member and the third fixing member. Fixed,
The second fixing mechanism is
A penetrating portion that penetrates the second fixing member, the reinforced portion, and the fourth fixing member;
A third fixing force application portion screwed into one end portion of the through portion;
A fourth fixing force application portion coupled to the other end portion of the penetrating portion of the second fixing mechanism,
With the second fixing member, the portion to be reinforced, and the fourth fixing member positioned between the third and fourth fixing force applying portions, the second fixing mechanism is positioned with respect to the penetrating portion of the second fixing mechanism. The third and fourth fixing force applying portions sandwich the second fixing member, the reinforced portion, and the fourth fixing member by rotating the fixing force applying portion 3 and the second and fourth fixing members. The member is fixed to the reinforced portion.

  In this configuration, the first and third fixing members can be easily fixed to the reinforced portion by simply rotating the first fixing force applying portion with respect to the penetrating portion. Similarly, the second and fourth fixing members can be easily fixed to the reinforced portion.

The first and second fixing members are each formed with a connecting hole, and internal threads opposite to each other are formed on the inner peripheral surfaces of these connecting holes. The one end part and the other end part of the member are respectively formed with male threads opposite to each other, whereby the one end part and the other end part of the first connecting screw member are respectively the first fixing member. Screwed into the inner peripheral surface of the connecting hole and the inner peripheral surface of the connecting hole of the second fixing member,
Each of the third and fourth fixing members is formed with a connecting hole. On the inner peripheral surfaces of these connecting holes, female screws opposite to each other are formed. The second connecting screw The one end portion and the other end portion of the member are respectively formed with male threads opposite to each other, whereby the one end portion and the other end portion of the second connecting screw member are respectively the third fixing member. And the inner peripheral surface of the connecting hole of the fourth fixing member and the inner peripheral surface of the connecting hole of the fourth fixing member.

  Thus, the one end portion and the other end portion of the first connecting screw member are respectively the inner peripheral surface of the connecting hole of the first fixing member and the inner peripheral surface of the connecting hole of the second fixing member. Are screwed into female screws formed in opposite directions. Therefore, the compression stress which the 1st and 2nd fixing member gives to a crack generating location can be adjusted only by rotating the 1st connecting screw member. The same applies to the second connecting screw member.

Each of the first and second fixing members has a connection hole, and the connection hole of the first fixing member passes through the first fixing member.
The first connecting screw member passes through the first fixing member through the connecting hole of the first fixing member, and an engaging portion is coupled to one end of the first connecting screw member. The joint portion is located on the opposite side of the second fixing member with respect to the first fixing member, and the engaging portion has a size larger than the connection hole of the first fixing member,
The male screw formed on the other end of the first connecting screw member is screwed into the female screw formed on the inner peripheral surface of the connecting hole of the second fixing member,
Each of the third and fourth fixing members has a connection hole, and one of the third and fourth fixing members has one connection hole penetrating the one fixing member.
The second connecting screw member passes through the one fixing member through the connecting hole of the one fixing member, and one of the one end portion and the other end portion of the second connecting screw member has an engaging portion. The engaging portion is located on the opposite side of the third and fourth fixing members with respect to the one fixing member, and the engaging portion is for connecting the one fixing member. Have dimensions larger than the hole,
A male screw formed on the other of the one end and the other end of the second connecting screw member is screwed into a female screw formed on the inner peripheral surface of the connecting hole of the other fixing member.

  As described above, the engaging portion at one end of the first connecting screw member can be engaged with the first fixing member, and the other end of the first connecting screw member is the connecting hole of the second fixing member. Screwed into the inner peripheral surface of Therefore, the compression stress which the 1st and 2nd fixing member gives to a crack generating location can be adjusted only by rotating the 1st connecting screw member. The same applies to the second connecting screw member.

Each fixing member is plate-shaped,
Each fixing member is fixed to the reinforced portion so as to contact the reinforced portion in the thickness direction of the fixing member,
Each fixing member has an end surface facing a direction orthogonal to the thickness direction,
The connecting hole of each fixing member is formed on the end face of the fixing member.

  Thus, the connection hole of each fixing member is formed on the end surface of the fixing member. Therefore, the force pulling between the first and second fixing members via the first connecting screw member is generated at the position of the connecting hole within the thickness range of each fixing member that is plate-shaped, and the plate It faces in the direction orthogonal to the thickness direction of each fixing member. Therefore, no bending moment is generated in each fixing member due to the pulling force. Therefore, even if a strong compressive stress is applied to the cracked portion, the fixing member is not easily damaged.

Each fixing member
A contact portion fixed to the reinforced portion so as to contact the reinforced portion in the thickness direction of the fixing member;
A rising portion rising from the contact portion in a direction in which the first surface or the second surface faces;
The connecting hole is formed in the rising portion.

  Thus, since the connection hole is formed in the rising portion that rises from the contact portion, a sufficient space can be secured between the first or second connection screw member and the portion to be reinforced. Therefore, a tool for rotating the connecting screw member can be inserted into this space, and the connecting screw member can be rotated with this tool. Therefore, the operation | work which rotates a connection screw member becomes easy.

Further, according to the present invention, there is provided a crack progress preventing method using the above-described crack progress preventing device,
When the structure includes a to-be-reinforced portion having a crack, and the to-be-reinforced portion includes a first surface and a second surface located on opposite sides of each other,
(A) fixing the first and second fixing members to the first surface on each side of the crack in the direction along the first surface;
(B) fixing the third and fourth fixing members to the second surface on each side of the crack in the direction along the second surface;
(C) rotating the first connecting screw member in a direction to reduce the distance between the first fixing member and the second fixing member;
(D) rotating the second connecting screw member in a direction to reduce the distance between the third fixing member and the fourth fixing member;
By alternately repeating the steps (C) and (D), the first and second fixing members act on the crack occurrence site, and the third and fourth fixing members act on the crack occurrence site. There is provided a crack propagation preventing method characterized by gradually increasing the compressive stress alternately.

  According to the present invention described above, on each of the first surface and the second surface, the two fixing members are fixed to both sides of the crack, and the connecting screw member that connects the two fixing members is rotated. Thereby, the distance between two fixing members can be reduced and the compressive stress which the two fixing members give to a crack can be increased. Therefore, the compressive stress can be applied to the cracked portion by a simple operation of rotating the connecting screw member. Thereby, progress of a crack can be prevented. In this case, if the two fixing members are located on both sides of the crack, the progress of the crack can be prevented even if the two fixing members are not accurately located on both sides of the tip of the crack. This is because even if it is outside the range sandwiched between the two fixing members, the compressive stress also acts on the portion adjacent to the range (tip of the crack). Therefore, the progress of the crack can be easily prevented regardless of the skill level of the operator.

  In addition, by alternately rotating the first connecting screw member on the first surface side and the second connecting screw member on the second surface side, the first surface screw and the second surface act on the occurrence of cracks, respectively. The compressive stress to be generated can be gradually increased alternately. Thereby, without applying a strong compressive stress from only one of the first surface and the second surface, a compressive stress of the same degree (that is, the difference is within an allowable value) from both the first surface and the second surface. Finally, a strong compressive stress can be applied to the crack occurrence location while acting on the crack occurrence location.

(A) shows an example of the structure which the crack generate | occur | produced, (B) shows the crack progress prevention apparatus by 1st Embodiment of this invention. (A) is a 2A-2A arrow view of FIG. 1 (B), (B) is a 2B-2B arrow view of FIG. 1 (B). 3 is a flowchart of a crack growth preventing method according to the first embodiment of the present invention. It is explanatory drawing of the crack progress prevention method. It is another explanatory drawing of the crack progress prevention method. 3 shows a crack growth preventing apparatus according to a second embodiment of the present invention. 9 shows a crack growth preventing apparatus according to a third embodiment of the present invention.

  A preferred embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

[First embodiment]
FIG. 1A shows an example of a structure 1 in which a crack 1a has occurred. The structure 1 includes a reinforced portion 2 in which a crack 1a is generated. The structure 1 is, for example, a component member of a bridge for passing a car road or a train track, or a component member of a crane, but is not limited thereto. In addition, the crack 1a is a fatigue crack which generate | occur | produced when the load is repeatedly given to the to-be-reinforced part 2, for example.

  FIG. 1B shows a crack growth preventing apparatus 10 according to the first embodiment of the present invention. The crack progress preventing device 10 prevents the progress of the crack 1 a generated in the structure 1. FIG. 1 (B) shows a state in which a compressive stress is applied to the occurrence site of the crack 1 a of the reinforced portion 2 by the crack progress preventing device 10. The portion to be reinforced 2 includes a first surface 2a and a second surface 2b that are located on opposite sides. The crack 1a may extend from the first surface 2a to the second surface 2b and penetrate the reinforced portion 2 in the thickness direction of the reinforced portion 2, as in the example of FIG. Or the crack 1a may arise only in one of the 1st surface 2a and the 2nd surface 2b, and may not penetrate the to-be-reinforced part 2. FIG. Or the crack 1a may not have appeared in the 1st surface 2a and the 2nd surface 2b, but may have arisen only in the to-be-reinforced part 2. FIG. In addition, in a preferable example, the to-be-reinforced part 2 is a plate-shaped member (for example, steel member), and the up-down direction of FIG. 1 (B) is the thickness direction of the to-be-reinforced part 2 which is a plate-shaped member.

  In the example of FIG. 1B, the first surface 2a and the second surface 2b face in opposite directions. In the example of FIG. 1B, the first surface 2a and the second surface 2b are planes parallel to each other.

  The crack progress preventing device 10 includes first to fourth fixing members 3a, 3b, 3c, 3d, first and second connecting screw members 5a, 5b, and first and second fixing mechanisms 7a, 7b. Is provided.

  As shown in FIG. 1B, the first and second fixing members 3a and 3b are positioned on both sides of the crack 1a in the direction along the first surface 2a and are fixed to the first surface 2a.

  As shown in FIG. 1B, the third and fourth fixing members 3c and 3d are positioned on both sides of the crack 1a in the direction along the second surface 2b and fixed to the second surface 2b.

  The first connecting screw member 5a connects the first and second fixing members 3a and 3b to each other. One end 9a and the other end 9b of the first connecting screw member 5a are respectively connected to the first and second fixing members 3a and 3b so that the first connecting screw member 5a can rotate with respect to the first and second fixing members 3a and 3b. The first and second fixing members 3a and 3b are connected to each other. At least one of the connection between the one end portion 9a of the first connection screw member 5a and the first fixing member 3a and the connection between the other end portion 9b of the first connection screw member 5a and the second fixing member 3b ( In the first embodiment, both) are made by screwing.

  For this purpose, in the first embodiment, connection holes 4a and 4b are formed in the first and second fixing members 3a and 3b, respectively. These connection holes 4a and 4b are opposed to each other in the direction in which the first and second fixing members 3a and 3b are attached to the first surface 2a as shown in FIG. 1B. It is open. Female threads that are opposite to each other are formed on the inner peripheral surfaces of the connecting holes 4a and 4b. Correspondingly, male screws in opposite directions are formed on the outer peripheral surfaces of the one end portion 9a and the other end portion 9b of the first connecting screw member 5a. Thereby, the one end 9a and the other end 9b of the first connecting screw member 5a are respectively connected to the inner peripheral surface of the connecting hole 4a of the first fixing member 3a and the second end as shown in FIG. The fixing member 3b is screwed into the inner peripheral surface of the connecting hole 4b.

  Therefore, in FIG. 1B, when the first connecting screw member 5a is rotated around the axis of the connecting screw member 5a with respect to the first and second fixing members 3a, 3b, The distance between the second fixing members 3a and 3b changes.

In the first embodiment, the first connecting screw member 5a may be configured as a so-called turnbuckle shaft. In this case, a nut 24 is preferably fixed to the first connecting screw member 5a as shown in FIG. By rotating the nut 24 with a wrench or other tool, the first connecting screw member 5a can be rotated with respect to the first and second fixing members 3a and 3b.
Further, through holes 6a and 6b described later are formed in the first and second fixing members 3a and 3b, respectively.

  The second connecting screw member 5b connects the third and fourth fixing members 3c and 3d to each other. The one end portion 13a and the other end portion 13b of the second connecting screw member 5b are respectively connected to the second connecting screw member 5b so that the second connecting screw member 5b can rotate with respect to the third and fourth fixing members 3c, 3d. 3 and the fourth fixing members 3c and 3d. At least one of the connection between the one end portion 13a of the second connection screw member 5b and the third fixing member 3c and the connection between the other end portion 13b of the second connection screw member 5b and the fourth fixing member 3d ( In the first embodiment, both) are made by screwing.

  Therefore, connection holes 4c and 4d are formed in the third and fourth fixing members 3c and 3d, respectively. These connection holes 4c and 4d oppose each other with the third and fourth fixing members 3c and 3d attached to the second surface 2b as shown in FIG. 1B. Female threads that are opposite to each other are formed on the inner peripheral surfaces of the connecting holes 4c and 4d. Correspondingly, male screws in opposite directions are formed on the outer peripheral surfaces of the one end portion 13a and the other end portion 13b of the second connecting screw member 5b. Thereby, the one end 13a and the other end 13b of the second connecting screw member 5b are respectively connected to the inner peripheral surface of the connecting hole 4c of the third fixing member 3c and the fourth end as shown in FIG. The fixing member 3d is screwed into the inner peripheral surface of the connecting hole 4d.

  Therefore, in FIG. 1B, when the second connecting screw member 5b is rotated around the axis of the connecting screw member 5b with respect to the third and fourth fixing members 3c, 3d, The distance between the fourth fixing members 3c and 3d changes.

In the first embodiment, the second connecting screw member 5b may also be configured as a so-called turnbuckle shaft. In this case, the nut 26 is preferably fixed to the second connecting screw member 5b as shown in FIG. By rotating the nut 26 with a wrench or other tool, the second connecting screw member 5b can be rotated with respect to the third and fourth fixing members 3c, 3d.
The third and fourth fixing members 3c and 3d are formed with through holes 6c and 6d, which will be described later, respectively.

  In FIG. 1B, the first fixing member 3a overlaps the third fixing member 3c in the direction orthogonal to the first surface 2a, and the second fixing member 3b is orthogonal to the first surface 2a. The first, second, third, and fourth fixing members 3a to 3d are arranged in the reinforced portion 2 so as to overlap the fourth fixing member 3d in the direction.

  The first fixing mechanism 7 a fixes the first and third fixing members 3 a and 3 c to the reinforced portion 2. For this purpose, the first fixing mechanism 7 a includes a through portion 17 that penetrates the first fixing member 3 a, the reinforced portion 2, and the third fixing member 3 c, and a first portion that is screwed into one end of the through portion 17. And a second fixing force applying portion 21 coupled to the other end of the through portion 17. In one example, the penetrating portion 17 is a bolt having a male screw formed on the outer peripheral surface of one end portion thereof, the first fixing force applying portion 19 is a nut screwed to one end portion of the penetrating portion 17, and The second fixing force applying portion 21 is a bolt head fixed to the other end portion of the bolt 17. The first fixing member 3a, the reinforced portion 2 and the third fixing member 3c are formed with through holes 6a, 16 and 6c through which the through portion 17 passes, respectively.

  2A is a view taken along the line 2A-2A in FIG. 1B, and FIG. 2B is a view taken along the line 2B-2B in FIG. 1B.

  In the example of FIG. 2, two first fixing mechanisms 7a having the above-described configuration are provided. However, the number of the first fixing mechanisms 7a may be one or three or more. When a plurality of first fixing mechanisms 7a are provided, the same number of through holes 6a, 16, 6c as the number of first fixing mechanisms 7a correspond to the plurality of first fixing mechanisms 7a, respectively. Formed.

  With such a configuration of the first fixing mechanism 7a, the penetrating portion 17 penetrates the first fixing member 3a, the to-be-reinforced portion 2, and the third fixing member 3c, and the first and second fixing members 7a and 7c. With the first fixing member 3 a, the reinforced portion 2, and the third fixing member 3 c positioned between the fixing force applying portions 19 and 21, the first fixing force applying portion 19 is moved to the through portion 17. Rotate against. As a result, the first and second fixing force applying portions 19 and 21 sandwich the first fixing member 3a, the portion to be reinforced 2 and the third fixing member 3c, so that the first and third fixing members 3a, 3 c is fixed to the reinforced portion 2.

  The second fixing mechanism 7 b fixes the second and fourth fixing members 3 b and 3 d to the reinforced portion 2. For this purpose, the second fixing mechanism 7b includes a through portion 23 that passes through the second fixing member 3b, the reinforced portion 2, and the fourth fixing member 3d, and a third portion that is screwed into one end portion of the through portion 23. The fixing force application part 25 and a fourth fixing force application part 27 coupled to the other end of the through part 23 are provided. In one example, the penetrating portion 23 is a bolt having a male screw formed on the outer peripheral surface of one end portion thereof, the third fixing force applying portion 25 is a nut that is screwed to one end portion of the penetrating portion 23, and 4 is a bolt head fixed to the other end of the bolt 23. The second fixing member 3b, the reinforced portion 2 and the fourth fixing member 3d are formed with through holes 6b, 18 and 6d through which the through portion 23 penetrates, respectively.

  In the example of FIG. 2, two second fixing mechanisms 7b having the above-described configuration are provided. However, the number of the second fixing mechanisms 7b may be one or three or more. When a plurality of second fixing mechanisms 7b are provided, the same number of through holes 6b, 18 and 6d as the second fixing mechanisms 7b correspond to the plurality of second fixing mechanisms 7b, respectively. Formed.

  With such a configuration of the second fixing mechanism 7b, the penetrating portion 23 penetrates the second fixing member 3b, the reinforced portion 2 and the fourth fixing member 3d, and the third and fourth In a state where the second fixing member 3b, the reinforced portion 2 and the fourth fixing member 3d are positioned between the fixing force applying portions 25 and 27, the third fixing force applying portion 25 is moved to the through portion 23. Rotate against. As a result, the second and fourth fixing members 3b, 25d sandwich the second fixing member 3b, the reinforced portion 2 and the fourth fixing member 3d with the third and fourth fixing force applying portions 25, 27. 3d is fixed to the reinforced portion 2.

  In FIG. 2A, one first connecting screw member 5a and one second connecting screw member 5b are shown. However, according to the present invention, the plurality of first connection screw members 5a and the corresponding plurality of connection holes 4a, 4b are orthogonal to the arrangement direction of the first and second fixing members 3a, 3b. They may be provided at intervals in the direction (the vertical direction in this figure in FIG. 2A). Similarly, according to the present invention, the plurality of second connection screw members 5b and the plurality of connection holes 4c, 4d corresponding thereto are orthogonal to the arrangement direction of the third and fourth fixing members 3c, 3d. It may be provided with an interval in the direction to be performed (the vertical direction in this figure in FIG. 2B).

  In 1st Embodiment, each fixing member 3a-3d is plate shape. Each of the fixing members 3a to 3d is attached to the reinforced portion 2 (that is, the first surface 2a or the second surface 2b) in the thickness direction of the fixing member. The connecting holes 4a to 4d of the fixing members 3a to 3d fixed to the reinforced portion 2 are formed on the end surfaces 22a to 22d of the fixing member. That is, as shown in FIG. 1B, the connecting hole 4a is formed in the end surface 22a of the first fixing member 3a, and the connecting hole 4b is formed in the end surface 22b of the second fixing member 3b. The hole 4c is formed in the end surface 22c of the third fixing member 3c, and the connection hole 4d is formed in the end surface 22d of the fourth fixing member 3d. Note that the end surfaces 22a to 22d face the direction orthogonal to the thickness direction of the fixing members 3a to 3d, respectively.

  FIG. 3 is a flowchart of a crack progress preventing method using the crack progress preventing apparatus 10 described above. Based on FIG. 3, the crack propagation preventing method will be described. The crack propagation preventing method includes steps S1 to S5. Steps S1 to S5 are performed by an operator.

  FIG. 4A is an explanatory diagram of step S1.

  In step S1, as shown in FIG. 4A, the positions at which the first and second fixing members 3a and 3b are arranged on the first surface 2a of the reinforced portion 2 are determined. At this time, the first and second fixing members 3a and 3b are arranged on both sides of the crack 1a in the direction along the first surface 2a (the left-right direction in FIG. 4A). In step S1, the first and second fixing members 3a and 3b are connected to each other by the first connecting screw member 5a. In the first embodiment, the male threads formed at the one end 9a and the other end 9b of the first connecting screw member 5a are the connecting holes 4a and 4b of the first and second fixing members 3a and 3b, respectively. Is screwed into a female screw formed on the inner peripheral surface.

  Similarly, in step S1, as shown in FIG. 4A, positions where the third and fourth fixing members 3c and 3d are arranged on the second surface 2b of the reinforced portion 2 are determined. At this time, the third and fourth fixing members 3c and 3d are arranged on both sides of the crack 1a in the direction along the second surface 2b (the left-right direction in FIG. 4A). In step S1, the third and fourth fixing members 3c and 3d are connected to each other by the second connecting screw member 5b. In the first embodiment, the male screws formed on the one end 13a and the other end 13b of the second connecting screw member 5b are the connecting holes 4c, 4d of the third and fourth fixing members 3c, 3d, respectively. Is screwed into a female screw formed on the inner peripheral surface.

  Further, the through holes 6a and 6c of the first and third fixing members 3a and 3c arranged at the positions determined in step S1 are aligned with each other so as to be positioned on the same straight line. Similarly, the through holes 6b and 6d of the second and fourth fixing members 3b and 3d arranged at the positions determined in step S1 are aligned with each other so as to be located on the same straight line.

  In addition, it is good to provide the mark for arrangement | positioning in the to-be-reinforced part 2 in the position of 1st-4th fixing member 3a-3d determined by step S1.

  In step S2, the positions where the through holes 16 and 18 are formed in the reinforced portion 2 are determined. The first surface 2a is marked for through holes at the same positions as the through holes 6a and 6b of the first and second fixing members 3a and 3b arranged at the positions determined in step S1.

  FIG. 4B is an explanatory diagram of step S3.

  In step S3, through holes 16 and 18 are formed in the reinforced portion 2 as shown in FIG. 4B at the position of the mark for the through hole attached in step S2, using an appropriate tool. At this time, the first to fourth fixing members 3 a to 3 d are not yet fixed to the reinforced portion 2. Therefore, step S3 may be performed with the first to fourth fixing members 3a to 3d removed from the reinforced portion 2. The through hole 16 and the through holes 6a and 6c of the first and third fixing members 3a and 3c arranged at the position determined in step S1 are located on the same straight line. Similarly, the through hole 18 and the through holes 6b and 6d of the second and fourth fixing members 3b and 3d arranged at the position determined in step S1 are located on the same straight line.

  5A and 5B are explanatory diagrams of step S4.

  In step S4, as shown in FIGS. 5A and 5B, the first fixing mechanism 7a fixes the first and third fixing members 3a and 3c to the reinforced portion 2, and the second fixing mechanism 7b. Thus, the second and fourth fixing members 3 b and 3 d are fixed to the reinforced portion 2. More details are as follows.

  First, as shown in FIG. 5A, the through portion 17 is passed through the through holes 6a, 16, and 6c, and the through portion 23 is passed through the through holes 6b, 18, and 6d. At this time, the second fixing force application portion 21 is coupled to the other end portion of the penetration portion 17, and the fourth fixing force application portion 27 is coupled to the other end portion of the penetration portion 23. .

  Next, as shown in FIG. 5B, the first fixing force application portion 19 is screwed into one end portion of the penetration portion 17, and the third fixing force application portion 25 is attached to one end portion of the penetration portion 23. Screw together. Thereafter, by rotating the first fixing force applying portion 19, the first fixing force applying portion 19 and the second fixing force applying portion 21, the first fixing member 3 a, the reinforced portion 2, and the third The first fixing member 3a and the third fixing member 3c are fixed to the reinforced portion 2 by sandwiching the fixing member 3c. Similarly, by rotating the third fixing force application portion 25, the second fixing member 3 b, the reinforced portion 2, the second fixing force application portion 27, the third fixing force application portion 25, and the fourth fixing force application portion 27. The second fixing member 3b and the fourth fixing member 3d are fixed to the reinforced portion 2 by sandwiching the four fixing members 3d.

  In this way, in step S4, the first and second fixing members 3a and 3b are fixed to the first surface 2a on both sides of the crack 1a in the direction along the first surface 2a, and the second surface 2b. The third and fourth fixing members 3c and 3d are fixed to the second surface 2b on both sides of the crack 1a in the direction along the line.

  Step S5 includes steps S51 to S54.

  In step S51, the first connecting screw member 5a is rotated in a direction to reduce the distance between the first fixing member 3a and the second fixing member 3b. Thereby, the 1st and 2nd fixing members 3a and 3b fixed to the to-be-reinforced part 2 apply a compressive stress to the generation | occurrence | production location of the crack 1a.

  In step S52, the second connecting screw member 5b is rotated in a direction to reduce the distance between the third fixing member 3c and the fourth fixing member 3d. Thereby, the 3rd and 4th fixing members 3c and 3d fixed to the to-be-reinforced part 2 apply a compressive stress to the generation | occurrence | production location of the crack 1a.

  In step S53, the first connecting screw member 5a is further rotated in a direction to reduce the distance between the first fixing member 3a and the second fixing member 3b. Thereby, the compressive stress which the 1st and 2nd fixing members 3a and 3b act on the generation | occurrence | production location of the crack 1a increases.

  In step S54, the second connecting screw member 5b is further rotated in a direction to reduce the distance between the third fixing member 3c and the fourth fixing member 3d. Thereby, the compressive stress which the 3rd and 4th fixing members 3c and 3d act on the generation | occurrence | production location of the crack 1a increases.

Such step S53 and step S54 are repeated alternately. Thereby, the compressive stress that the first and second fixing members 3a and 3b act on the occurrence location of the crack 1a, and the compression stress that the third and fourth fixing members 3c and 3d act on the occurrence location of the crack 1a, and Are gradually increased alternately. As a result, finally, the compressive stress that the first and second fixing members 3a and 3b act on the occurrence location of the crack 1a, and the third and fourth fixing members 3c and 3d act on the occurrence location of the crack 1a. The compressive stress to be generated is set to a strong value of the same level (preferably the same). Thus, in a preferred example, the first to fourth fixing member 3a, 3b, 3c, the 3d, the cracking portion of the reinforcement portion ^2, the compressive stress of the values in the 50N / mm ² ~200N / mm 2 Make it work.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the second embodiment, points that are not described below are the same as those in the first embodiment.

  FIG. 6 shows a crack growth preventing apparatus 10 according to the second embodiment. In the second embodiment, each fixing member 3 a to 3 d has a contact portion 29 and a rising portion 31. The contact portion 29 is fixed to the reinforced portion 2 so as to contact the reinforced portion 2 in the thickness direction of the corresponding fixing members 3a, 3b, 3c, and 3d. In a state where the fixing members 3a to 3d are fixed to the reinforced portion 2 as shown in FIG. 6, each rising portion 31 rises from the contact portion 29 in the direction in which the first surface 2a or the second surface 2b faces. . Corresponding connecting holes 4a, 4b, 4c, 4d are formed in the rising portion 31.

  The crack progress preventing method according to the second embodiment using the crack progress preventing apparatus 10 according to the second embodiment is the same as the crack progress preventing method according to the first embodiment.

[Third embodiment]
Next, a third embodiment of the present invention will be described. In the third embodiment, points not described below are the same as those in the first embodiment or the second embodiment described above.

  FIG. 7A and FIG. 7B show a crack growth preventing apparatus 10 according to the third embodiment. FIG. 7A shows the case where the configuration of the third embodiment is applied to the above-described first embodiment, and FIG. 7B shows the case where the configuration of the third embodiment is applied to the above-described second embodiment. Show the case.

  As shown in FIGS. 7A and 7B, the connecting hole 4a passes through the first fixing member 3a. The first connecting screw member 5a passes through the first fixing member 3a through the connecting hole 4a of the first fixing member 3a. An engaging portion 33 is coupled to one end portion 9a of the first connecting screw member 5a. In a state where the first and second fixing members 3a and 3b are fixed to the reinforced portion 2 as described above, the engaging portion 33 is connected to the first portion as shown in FIGS. It is located on the opposite side of the second fixing member 3b with respect to the fixing member 3a. The engaging portion 33 has a size larger than the connecting hole 4a of the first fixing member 3a. Thereby, this engaging part 33 cannot pass through the connection hole 4a. On the other hand, the other end 9b of the first connecting screw member 5a is screwed into a female screw formed on the inner peripheral surface of the connecting hole 4b of the second fixing member 3b.

  Therefore, as described above, when the first connecting screw member 5a is rotated in a direction in which the distance between the first and second fixing members 3a and 3b is reduced, the engaging portion 33 becomes the first fixing member. By engaging with 3a, a force for applying a compressive stress to the occurrence location of the crack 1a is applied to the first fixing member 3a.

  Similarly, as shown in FIGS. 7A and 7B, one of the third and fourth fixing members 3c and 3d (the fixing member 3c in the example of FIG. 7) has a connection hole 4c or 4d. The one fixing member is penetrated. The second connecting screw member 5b passes through the one fixing member through the connecting hole 4c or 4d (the connecting hole 4c in the example of FIG. 7) of the one fixing member. An engaging portion 35 is coupled to one of the one end portion 13a and the other end portion 13b of the second connecting screw member 5b (one end portion 13a in the example of FIG. 7). In the state where the third and fourth fixing members 3c and 3d are fixed to the reinforced portion 2 as described above, the engaging portion 35 has one of the above-described ones as shown in FIGS. With respect to the fixing member (fixing member 3c in FIG. 7), it is located on the opposite side of the third (fourth fixing member 3d in the example of FIG. 7) of the third and fourth fixing members 3c, 3d. The engaging portion 35 has a size larger than the connecting holes 4c and 4d of the one fixing member described above. Thereby, the engaging part 35 cannot pass through the connection holes 4c and 4d of the one fixing member described above. On the other hand, the other of the one end 13a and the other end 13b of the second connecting screw member 5b is the inside of the connecting holes 4c and 4d (the connecting hole 4d in the example of FIG. 7) of the other fixing member described above. It is screwed into a female screw formed on the peripheral surface.

  Therefore, as described above, when the second connecting screw member 5b is rotated in a direction in which the distance between the third and fourth fixing members 3c and 3d is reduced, the engaging portion 35 is fixed to the one fixing member described above. By engaging with the member, a force for applying a compressive stress to the location where the crack 1a occurs is applied to the one fixing member.

  In FIG. 7A, the connecting hole 4a and the through hole 6a are shifted from each other in the direction orthogonal to the paper surface of FIG.

  In the third embodiment, the second connecting screw member 5b and the connecting holes 4c and 4d are not shown in FIG. 7A but shown in the first embodiment (FIG. 1B). There may be.

  The crack progress preventing method according to the third embodiment using the crack progress preventing apparatus 10 according to the third embodiment is the same as the crack progress preventing method according to the first embodiment.

  According to the first embodiment, the second embodiment, and the third embodiment of the present invention described above, in each of the first surface 2a and the second surface 2b, two fixing members 3a and 3b are provided on both sides of the crack 1a. Alternatively, by fixing the members 3c and 3d and rotating the connecting screw member 5a or 5b for connecting the two fixing members, the distance between the two fixing members is reduced, and the compressive stress applied to the crack 1a by the two fixing members is reduced. Can be increased. Therefore, compressive stress can be applied to the location where the crack 1a occurs by a simple operation of rotating the connecting screw members 5a and 5b. Thereby, progress of the crack 1a can be prevented. In this case, if two fixing members are located on both sides of the crack 1a, the two cracks 1a can be developed even if the two fixing members are not exactly located on both sides of the tip of the crack 1a. Can be prevented. This is because even if it is outside the range sandwiched between the two fixing members, the compressive stress also acts on the portion adjacent to the range (the tip of the crack 1a). Therefore, the progress of the crack 1a can be easily prevented regardless of the skill level of the operator.

  Moreover, by alternately rotating the first connecting screw member 5a on the first surface 2a side and the second connecting screw member 5b on the second surface 2b side, the first surface 2a and the second surface 2b are respectively rotated. It is possible to gradually increase the compressive stress applied to the crack 1a generation site alternately. Thereby, without applying a strong compressive stress from only one of the first surface 2a and the second surface 2b, both the first surface 2a and the second surface 2b have the same degree (that is, the difference is within an allowable value). It is possible to finally apply a strong compressive stress to the occurrence location of the crack 1a while applying a compressive stress to the occurrence location of the crack 1a.

  The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

  For example, in the first embodiment, the second embodiment, and the third embodiment described above, the first and second fixing mechanisms 7a and 7b are omitted, and in the above-described step S4, the first and second fixing members 3a are omitted. 3b may be fixed to the reinforced portion 2 by welding or other means, and the third and fourth fixing members 3c and 3d may be fixed to the reinforced portion 2 by welding or other means. In this case, the other points are the same as described above.

DESCRIPTION OF SYMBOLS 1 Structure, 1a Crack, 2 Reinforced part, 2a 1st surface, 2b 2nd surface, 3a, 3b, 3c, 3d 1st-4th fixing member, 4a, 4b, 4c, 4d Connection hole, 5a , 5b First and second connecting screw members, 6a, 6b, 6c, 6d Through holes, 7a, 7b First and second fixing mechanisms, 9a One end of the first connecting screw member, 9b First connection The other end of the screw member, 10 Crack growth prevention device, 13a One end of the second connecting screw member, 13b The other end of the second connecting screw member, 16 Through hole, 17 Through part (bolt), 18 Through hole , 19 First fixing force applying portion (nut), 21 Second fixing force applying portion (bolt head), 23 Through portion (bolt), 24 nut, 25 Third fixing force applying portion (nut), 26 nut , 27 Fourth fixing force applying part (bolt head), 29 Contact Part, 31 rising part, 33 engaging part, 35 engaging part

Claims (6)

A crack progress preventing device for preventing the progress of cracks generated in a structure,
The structure includes a reinforced portion in which a crack is generated, and the reinforced portion includes a first surface and a second surface located on opposite sides of each other,
First and second fixing members respectively positioned on both sides of the crack with respect to the direction along the first surface and fixed to the first surface;
Third and fourth fixing members respectively positioned on both sides of the crack with respect to the direction along the second surface and fixed to the second surface;
A first connecting screw member for connecting the first and second fixing members to each other;
A second connecting screw member for connecting the third and fourth fixing members to each other;
One end and the other end of the first connecting screw member are respectively the first and second fixing members so that the first connecting screw member can rotate with respect to the first and second fixing members. At least one of the connection between the one end portion and the first fixing member and the connection between the other end portion and the second fixing member is screwed,
One end and the other end of the second connecting screw member are respectively the third and fourth fixing members so that the second connecting screw member can rotate with respect to the third and fourth fixing members. At least one of the connection between the one end portion and the third fixing member and the connection between the other end portion and the fourth fixing member is screwed,
When the first connecting screw member is rotated with respect to the first and second fixing members, the distance between the first and second fixing members is reduced by the screwing,
When the second connecting screw member is rotated with respect to the third and fourth fixing members, the distance between the third and fourth fixing members is reduced by the screwing,
The first and second fixing members are each formed with a connecting hole, and internal threads opposite to each other are formed on the inner peripheral surfaces of these connecting holes. The one end part and the other end part of the member are respectively formed with male threads opposite to each other, whereby the one end part and the other end part of the first connecting screw member are respectively the first fixing member. Screwed into the inner peripheral surface of the connecting hole and the inner peripheral surface of the connecting hole of the second fixing member,
Each of the third and fourth fixing members is formed with a connecting hole. On the inner peripheral surfaces of these connecting holes, female screws opposite to each other are formed. The second connecting screw The one end portion and the other end portion of the member are respectively formed with male threads opposite to each other, whereby the one end portion and the other end portion of the second connecting screw member are respectively the third fixing member. inner threaded peripheral surface and the inner peripheral surface of the connecting hole of the fourth fixing member, turtle crack growth prevention device you wherein a of the connecting hole of the. A crack progress preventing device for preventing the progress of cracks generated in a structure,
The structure includes a reinforced portion in which a crack is generated, and the reinforced portion includes a first surface and a second surface located on opposite sides of each other,
First and second fixing members respectively positioned on both sides of the crack with respect to the direction along the first surface and fixed to the first surface;
Third and fourth fixing members respectively positioned on both sides of the crack with respect to the direction along the second surface and fixed to the second surface;
A first connecting screw member for connecting the first and second fixing members to each other;
A second connecting screw member for connecting the third and fourth fixing members to each other;
One end and the other end of the first connecting screw member are respectively the first and second fixing members so that the first connecting screw member can rotate with respect to the first and second fixing members. At least one of the connection between the one end portion and the first fixing member and the connection between the other end portion and the second fixing member is screwed,
One end and the other end of the second connecting screw member are respectively the third and fourth fixing members so that the second connecting screw member can rotate with respect to the third and fourth fixing members. At least one of the connection between the one end portion and the third fixing member and the connection between the other end portion and the fourth fixing member is screwed,
When the first connecting screw member is rotated with respect to the first and second fixing members, the distance between the first and second fixing members is reduced by the screwing,
When the second connecting screw member is rotated with respect to the third and fourth fixing members, the distance between the third and fourth fixing members is reduced by the screwing,
Each of the first and second fixing members has a connection hole, and the connection hole of the first fixing member passes through the first fixing member.
The first connecting screw member passes through the first fixing member through the connecting hole of the first fixing member, and an engaging portion is coupled to one end of the first connecting screw member. The joint portion is located on the opposite side of the second fixing member with respect to the first fixing member, and the engaging portion has a size larger than the connection hole of the first fixing member,
The male screw formed on the other end of the first connecting screw member is screwed into the female screw formed on the inner peripheral surface of the connecting hole of the second fixing member,
Each of the third and fourth fixing members has a connection hole, and one of the third and fourth fixing members has one connection hole penetrating the one fixing member.
The second connecting screw member passes through the one fixing member through the connecting hole of the one fixing member, and one of the one end portion and the other end portion of the second connecting screw member has an engaging portion. The engaging portion is located on the opposite side of the third and fourth fixing members with respect to the one fixing member, and the engaging portion is for connecting the one fixing member. Have dimensions larger than the hole,
A male screw formed on the other of the one end and the other end of the second connecting screw member is screwed into a female screw formed on the inner peripheral surface of the connecting hole of the other fixing member; turtle crack propagation prevention device shall be the feature. Each fixing member is plate-shaped,
Each fixing member is fixed to the reinforced portion so as to contact the reinforced portion in the thickness direction of the fixing member,
Each fixing member has an end surface facing a direction orthogonal to the thickness direction,
The coupling holes of the fixing member is formed on the end surface of the fixing member, crack propagation preventing apparatus according to claim 1 or 2, characterized in. Each fixing member
A contact portion fixed to the reinforced portion so as to contact the reinforced portion in the thickness direction of the fixing member;
A rising portion rising from the contact portion in a direction in which the first surface or the second surface faces;
The said rising portion, crack propagation preventing apparatus according to claim 1 or 2, characterized in said connecting hole is formed, it. The first fixing member overlaps the third fixing member in a direction orthogonal to the first surface, and the second fixing member overlaps the fourth fixing member in a direction orthogonal to the first surface. The second, third and fourth fixing members are arranged on the reinforced portion,
A first fixing mechanism for fixing the first and third fixing members to the reinforced portion;
A second fixing mechanism for fixing the second and fourth fixing members to the reinforced portion,
The first fixing mechanism is
A penetrating portion that penetrates the first fixing member, the reinforced portion, and the third fixing member;
A first fixing force application portion that is screwed to one end portion of the penetration portion;
A second fixing force application unit coupled to the other end of the penetrating unit,
In a state where the first fixing member, the reinforced portion, and the third fixing member are located between the first and second fixing force applying portions, the first fixing force applying portion is placed on the penetrating portion. By rotating the first fixing member, the first fixing member, the second reinforcing member, and the third fixing member are sandwiched between the first fixing member and the second fixing member, and the first fixing member and the third fixing member are sandwiched between the first fixing member and the third fixing member. Fixed,
The second fixing mechanism is
A penetrating portion that penetrates the second fixing member, the reinforced portion, and the fourth fixing member;
A third fixing force application portion screwed into one end portion of the through portion;
A fourth fixing force application portion coupled to the other end portion of the penetrating portion of the second fixing mechanism,
With the second fixing member, the portion to be reinforced, and the fourth fixing member positioned between the third and fourth fixing force applying portions, the second fixing mechanism is positioned with respect to the penetrating portion of the second fixing mechanism. The third and fourth fixing force applying portions sandwich the second fixing member, the reinforced portion, and the fourth fixing member by rotating the fixing force applying portion 3 and the second and fourth fixing members. The crack progress prevention device according to any one of claims 1 to 4, wherein the member is fixed to the reinforced portion. A crack progress preventing method using the crack progress preventing device according to any one of claims 1 to 5 ,
When the structure includes a to-be-reinforced portion having a crack, and the to-be-reinforced portion includes a first surface and a second surface located on opposite sides of each other,
(A) fixing the first and second fixing members to the first surface on each side of the crack in the direction along the first surface;
(B) fixing the third and fourth fixing members to the second surface on each side of the crack in the direction along the second surface;
(C) rotating the first connecting screw member in a direction to reduce the distance between the first fixing member and the second fixing member;
(D) rotating the second connecting screw member in a direction to reduce the distance between the third fixing member and the fourth fixing member;
By alternately repeating the steps (C) and (D), the first and second fixing members act on the crack occurrence site, and the third and fourth fixing members act on the crack occurrence site. A crack propagation prevention method characterized by gradually increasing the compressive stress alternately.

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