JP4950911B2 - Fastening member - Google Patents

Description

  The present invention relates to a fastening member that can be suitably used for a structure such as a building structure.

  Regarding the fastening member used together with the bolt, one of the inventors of the present application has proposed a fastening member having a nut and a washer (washer) having a specific shape in order to enable strong fastening (for example, Patent Document 1). 2).

  FIG. 8 shows a fastening structure similar to that described in Patent Document 1. In this fastening structure 100, the nut 102 has a concave portion 122 that is axially symmetric and has a substantially trapezoidal shape in cross section around one opening of the female screw portion 121. The washer 103 has an axially symmetric and substantially trapezoidal shape in a side view so that a part thereof can enter the concave portion 122 and protrudes from the central portion of the base 131, and the male screw portion 171 of the bolt 107 is formed on the protruding portion 132. A bolt insertion hole 132 </ b> C for insertion is provided, and the bolt insertion hole 132 </ b> C is eccentric from the center position of the protrusion 132. 108 and 109 are fastened bodies. In the fastening structure 100, when the bolt 107 is screwed and fastened to the nut 102, a part of the inner side of the protruding portion 132 of the washer 103 enters the concave portion 122 of the nut 102, and the open side edge of the concave portion 122 is The protruding portion 132 is pressed. When the nut 102 is turned, the center position of the bolt insertion hole 132C of the washer 103 is eccentric with respect to the center position of the protruding portion 132 of the washer 103. Part of the inner peripheral edge of the bolt insertion hole 132C of the washer 103 bites into the thread of the bolt 107. In addition, the contact portion is twisted by biting into the screw thread. As a result, a concentrated radial force is applied at the contact portion, and the washer 103 and the bolt 107 are pressed against each other to be strongly coupled, thereby producing a loosening prevention effect.

  Further, in Patent Document 2, an elastic washer is arranged on the back side of the concave portion 122 of the nut 102 of the fastening structure similar to that shown in FIG. The nut 102 is prevented from falling off even when loosening occurs.

JP 2002-206515 A JP 2007-211892 A

  However, this type of fastening member composed of a nut and a washer is desired to have a further drop-off preventing effect in a harsh environment (for example, a construction site or a multi-story parking lot) in which large vibrations frequently occur. . The inventor of the present application noticed that the coupling between the washer 103 and the bolt 107 in the fastening structure 100 shown in FIG. 8 is extremely strong as a result of diligent efforts, and using this, the nut 102 is further prevented from falling off. Devised a fastening member capable of obtaining

  The present invention has been made in view of the above reasons, and its purpose is to provide a nut having an axially symmetric and substantially trapezoidal recess in the vicinity of one opening of the female screw portion, and a portion of the nut recess. It has an axisymmetrical shape so that it can enter, and has a protruding part that protrudes from the center part of the base part in a substantially trapezoidal shape in side view, and has a bolt insertion hole through which the male threaded part of the bolt passes, and the bolt insertion hole protrudes A fastening member that has a washer eccentric from the center position of the part, and that can be further enhanced in the nut dropping prevention effect by using a strong coupling between the washer and the bolt in a fastening member used together with the bolt It is to provide a member for use.

In order to achieve the above object, a fastening member according to claim 1 includes a nut having an axially symmetric and substantially trapezoidal recess in the vicinity of one opening of the female screw portion, and a part of the nut recess. A projecting portion that is axially symmetric so that it can enter and protrudes from the central portion of the base portion in a substantially trapezoidal shape in side view, and has a bolt insertion hole through which the male screw portion of the bolt is inserted, and the bolt insertion hole is In the fastening member used together with the bolt, the nut has a large-diameter portion on a side close to the base of the washer and a washer. A step portion is formed by having a small-diameter portion on the side away from the base portion, and the washer extends from the outer peripheral edge of the base portion in the protruding direction of the protruding portion, and the tip portion is bent acutely in the axial direction. cage nuts And a plurality of nuts pressing piece which the step portion is formed bent so as to contact elastically pressing is provided.

  According to the fastening member of the present invention, even when the washer and the bolt are strongly coupled and the nut moves in the direction away from the bolt, the nut holding piece of the washer acts so as to suppress the stepped portion of the nut. It is possible to further increase the effect of preventing the nut from falling off by suppressing further movement of the nut.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Fig.1 (a) is a top view of the fastening member 1 which concerns on embodiment of this invention, The same figure (b) is the side view seen from the downward side in the figure of (a). FIG. 2 is a side sectional view of the fastening member 1. 3A and 3B are cross-sectional views of the state immediately after the start of the fastening operation of the fastening structure 10 using the fastening member 1 and the state at the completion of the fastening operation, respectively. The fastening member 1 has a shape in which a nut 2 is incorporated in a washer 3, and the nut 2 and the washer 3 are integrated so as not to fall apart. Note that the bolt 7 used in the fastening structure 10 together with the fastening member 1 is a widely used general-purpose product.

  4A and 4B show the nut 2. FIG. 4A is a side sectional view, and FIG. 4B is a bottom view. The nut 2 has a prismatic shape (for example, a regular hexagonal prism), and has a female threaded portion 21 that engages with a male threaded portion 71 of a bolt 7 that is a general-purpose product. The nut 2 has a concave portion 22 that is axially symmetric and has a substantially trapezoidal shape in cross section around the opening of one of the female screw portions 21 (lower side in FIG. 4A). The recess 22 is located at a position where the open end edge 22a overlaps with the inclined surface 32A of the protrusion 32 of the washer 3, which will be described in detail later. Here, axial symmetry means symmetry with respect to the central axis T of the nut 2. Specifically, the recess 22 includes a bottom surface 22B orthogonal to the side surface 22A and the central axis T, and the side surface 22A is inclined from the open side edge 22a toward the bottom surface 22B. In FIG. 4B, a line drawn by the open side edge 22a, a line drawn by the intersection 22b of the side surface 22A and the bottom surface 22B, and a line drawn by the mountain 21a of the female screw portion 21 (inner diameter of the female screw portion 21) are on the central axis T. Is substantially concentric with the h point as the center. Further, the inclination angle θ of the side surface 22A of the recess 22 is set to about 15 degrees with respect to the central axis T, for example.

  The nut 2 has, on its outer peripheral surface, a large-diameter portion 23A on the side close to the base portion 31 of the washer 3 and a small-diameter portion 23B on the side away from the base portion 31 of the washer 3, thereby forming a step portion 23a. Yes. The length of the small-diameter portion 23B in the axial direction is secured to such an extent that the nut 2 can be rotated with a tool such as a spanner. The step portion 23a is preferably substantially orthogonal to the central axis T, but may be inclined.

  5A and 5B show the washer 3. FIG. 5A is a plan view, and FIG. 5B is a side sectional view. The washer 3 has a base 31 that is sufficiently larger in diameter than the large-diameter portion 23A of the nut 2, and is axially symmetric and has a substantially trapezoidal shape in side view so that a part of the base 31 can enter the recess 22 of the nut 2. A projecting portion 32 projecting into the shape is formed. Specifically, the projecting portion 32 includes an inclined surface 32A and a top surface 32B substantially orthogonal to the central axis X. The inclined surface 32A is formed axially symmetrically, and a bolt insertion hole 32C is formed on the top surface 32B. ing. The inclination angle φ of the inclined surface 32A is equal to or slightly larger than the inclination angle θ of the side surface 22A of the recess 22 so that the open side edge 22a of the recess 22 of the nut 2 can contact the inclined surface 32A of the protrusion 32. For example, it is about 20 degrees with respect to the central axis X.

  The width (the length in the radial direction) of the protrusion 32 is set so that the open-side end edge 22a of the recess 22 of the nut 2 can contact the inclined surface 32A. That is, the diameter of the circle drawn by the intersection 32a between the base 31 and the inclined surface 32A is larger than the diameter of the circle drawn by the open end edge 22a of the recess 22 of the nut 2, and the intersection 32b between the inclined surface 32A and the top surface 32B. The diameter of the circle drawn by is small. The center position of the circle drawn by the intersection point 32a and the circle drawn by the intersection point 32b is at point i on the center axis X, and this center axis X is the same as the center axis T of the nut 2 in FIG. The center position of the circle drawn by the inner peripheral edge 32c of the bolt insertion hole 32C is at the j point on the central axis Y different from the central axis X. Therefore, the center position j of the bolt insertion hole 32C is eccentric from the center position i of the protrusion 32.

  Further, the washer 3 extends in the protruding direction of the protruding portion 32 from the outer peripheral edge of the base portion 31, and has a plurality of nut holding pieces 33 that are bent so that the tip portion overlaps with the stepped portion 23 a of the nut 2. 33, ... are provided. Specifically, the nut holding pieces 33, 33,... Are bent acutely toward the nut 2 side (axial direction) in the vicinity of the outer peripheral edge of the base portion 31, and are intermediate in the axial direction of the large diameter portion 23 </ b> A of the nut 2. It is bent parallel to the central axis T from the vicinity, and further bent perpendicular to the axial direction so as to be close to the stepped portion 23a. When the tips 33a, 33a,... Of the nut holding pieces 33, 33,... Are connected in a circle, the diameter is smaller than the diameter of the large diameter portion 23A of the nut 2 and is smaller than the diameter of the small diameter portion 23B. As a result, the tip portion is superposed on the stepped portion 23 a of the nut 2. The number of the nut holding pieces 33, 33,... Is desirably 3 or more (in this embodiment, 4).

  Various methods can be used for forming the washer 3 and for incorporating the nut 2 into the washer 3. As for the method for forming the washer 3, for example, the nut holding pieces 33, 33,... , 33,... May be bent so as to be bent sequentially as described above. As for the method of assembling the nut 2 into the washer 3, the nut holding pieces 33, 33,..., The tips 33a, 33a,. The recess 22 is placed on the protrusion 32 of the washer 3, and the tips 33 a, 33 a,... Of the nut holding pieces 33, 33,. To be placed.

  In this way, the fastening member 1 is integrated in such a state that the nut 2 cannot be easily removed from the washer 3, so that the nut 2 and the washer 3 are not separately aligned and fastened. Work can be performed efficiently. Furthermore, the fastening member 1 can prevent the nut 2 from falling off as described in the fastening structure 10 below.

  A fastening structure 10 using the fastening member 1 will be described with reference to FIG. The fastening work of the fastening structure 10 is performed by first aligning the fastened body 9, the fastened body 8, and the fastening member 1, the bolt insertion hole 9 </ b> A of the fastened body 9, the bolt insertion hole 8 </ b> A of the fastened body 8, The bolts 7 are inserted in the order of the bolt insertion holes 32 </ b> C of the washer 3, and the male screw portion 71 of the bolt 7 is screwed into the female screw portion 21 of the nut 2. As the bolt 7 is turned, the open side edge 22a of the recess 22 of the nut 2 comes into contact with the inclined surface 32A of the projecting portion 32 (see FIG. 3A), and when the bolt 7 is further turned, the open side The edge 22 a presses the inclined surface 32 </ b> A, and the inner protrusion 32 gradually enters the recess 22 of the nut 2 from where it is pressed by the opening-side edge 22 a.

  Finally, when the bolt 7 is tightened strongly, the center position j point of the bolt insertion hole 32C and the center position i point of the protrusion 32 are eccentric as described above, so the center right side in the drawing of FIG. As shown in FIG. 4, due to the large tightening torque, the inner peripheral edge of the bolt insertion hole 32C is in a form of meshing as a wedge while being partly in contact with the male thread portion 71 of the bolt 7 and repelling strongly. Therefore, a concentrated radial force is applied at the contact portion between the projecting portion 42 and the male threaded portion 71 of the bolt 7, and the projecting portion 42 and the bolt 7 are pressed against each other to be strongly coupled, thereby obtaining a loosening prevention effect. .

  Even if the screwing of the nut 2 and the bolt 7 is loosened due to excessive vibration or other reasons after the fastening operation is completed, the washer 3 is usually strong enough to be coupled with the bolt 7. The connection of 7 does not loosen. Therefore, even if the nut 2 moves in the direction away from the bolt 7, the nut holding pieces 33, 33,... Contact the step portion 23a of the nut 2 and further movement is prevented. Therefore, the nut 2, the washer 3, and the bolt 7 remain substantially in the positional relationship, and the nut 2 is prevented from falling off.

  Next, a fastening member 1 ′ and a fastening member 1 ″ which are modified embodiments of the fastening member 1 will be described.

FIG. 6 is a cross-sectional side view of a fastening structure using a fastening member 1 ′ having a nut 2 and a washer 3 ′ obtained by deforming the washer 3. The state immediately after, (b) is the state when the fastening operation is completed. In the washer 3 ′, the tip end portion of the nut holding piece 33 is bent acutely in the axial direction, and elastically presses the step portion 23a. The other parts of the washer 3 ′ are the same as the washer 3. The fastening member 1 ′ can obtain the same effect as the fastening member 1, and in the fastened state, the tips 33 a of the nut restraining pieces 33, 33,. Since the contact is made while elastically pressing 23a, a slight movement in the direction in which the nut 2 is detached from the bolt 7 is also suppressed.

  FIG. 7 is a side sectional view of a fastening structure using a fastening member 1 ″ having a nut 2 ′ obtained by deforming the nut 2 and having the washer 3. FIG. 7A is a fastening work. The state immediately after the start, (b) is the state when the fastening operation is completed. In the nut 2 ′, the small diameter portion 23 B has an axial length slightly larger than the thickness of the nut holding piece 33 of the washer 3, and from the end of the small diameter portion 23 B on the side away from the base 31 of the washer 3. A second large diameter portion 23C is formed, and the tip portions of the nut holding pieces 33, 33,... Are inserted between the large diameter portion 23A and the second large diameter portion 23C. Accordingly, the second step portion 23b is also formed in the second large diameter portion 23C. That is, a groove is formed by the stepped portion 23a, the outer peripheral surface of the small diameter portion 23B, and the second stepped portion 23b, and the tip portions of the nut holding pieces 33, 33,... is there. The length in the axial direction of the second large-diameter portion 23C is secured so that the nut 2 'can be rotated together with a tool such as a spanner. Other portions of the nut 2 ′ are the same as those of the nut 2. The fastening member 1 '' can obtain the same effect as the fastening member 1, and also prevents the nut 2 'from being removed from the washer 3 even when a sudden large external force is applied before the fastening operation or during storage. Is done. Further, during the fastening operation, the nut holding pieces 33, 33,... Are deformed and contact the stepped portion 23 a and the second stepped portion 23 b, so that the nut 2 ′ and washer are compared to the fastening member 1. The frictional force that suppresses the loosening between the three is increased.

  The fastening member according to the embodiment of the present invention has been described above, but the present invention is not limited to that described in the embodiment, and various design changes within the scope of the matters described in the claims. Is possible. For example, the size and fine shape of the concave portion 22 and the protruding portion 32 of the nut 2 described in the embodiment can be arbitrarily changed according to the environment in which they are used and the body to be fastened. Moreover, it is also possible to use together the elastic body washer described in patent document 2 mentioned in the column of background art.

The fastening member which concerns on embodiment of this invention is shown, (a) is a top view, (b) is a side view. It is side view sectional drawing of the member for fastening same as the above. It is side sectional drawing of the fastening structure using the fastening member same as the above, (a) is a state immediately after the start of a fastening operation | work, (b) is a state at the time of completion of a fastening operation | work. The nut same as the above is shown, in which (a) is a side sectional view and (b) is a bottom view. The washer same as the above is shown, (a) is a plan view and (b) is a side view sectional view. It is side sectional drawing of the fastening structure using the modification of the fastening member same as the above, (a) is the state immediately after the fastening operation | work start, (b) is the state at the time of fastening operation completion. It is a side view sectional view of the conclusion structure using another modification of the member for fastening same as the above, (a) is the state immediately after the start of fastening operation, and (b) is the state at the time of completion of fastening operation. It is side surface sectional drawing of the state at the time of completion | finish of the fastening operation | work of the fastening structure using the conventional fastening member.

1, 1 ′, 1 ″ fastening member 2, 2 ′ nut 21 female thread portion of nut 22 concave portion of nut 23a step portion of nut 23A large diameter portion of nut 23B small diameter portion of nut 23C second large diameter portion of nut 3, 3 'washer 31 Washer base 32 Washer protrusion 32C Washer bolt insertion hole 33 Washer nut retainer 33a Washer nut retainer tip 7 Bolt 71 Bolt male thread

Claims (1)

A nut having an axially symmetric and substantially trapezoidal recess in the vicinity of one opening of the female screw portion;
It has an axially symmetric and substantially trapezoidal shape in side view so that a part of it can enter the recess of the nut, and has a bolt insertion hole through which the male threaded portion of the bolt is inserted. In addition, in the fastening member used together with the bolt, the bolt insertion hole has a washer that is eccentric from the center position of the protrusion.
The nut has a stepped portion formed on its outer peripheral surface by having a large diameter portion on the side close to the base portion of the washer and a small diameter portion on the side away from the base portion of the washer.
The washer extends from the outer peripheral edge of the base portion in the protruding direction of the protruding portion, the tip portion is bent acutely in the axial direction, and is bent so as to be elastically pressed and contact the stepped portion of the nut. A fastening member, wherein a plurality of nut holding pieces are provided.

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