JP2007211892A - Fastening set member and fastening structure using this member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fastening structure capable of further improving the looseness preventive effect, by improving the fastening structure having a nut 2 having an axially symmetrical and cross-sectional view substantially trapezoidal recessed part 21 on one opening side of a female screw part 26, and a first washer 3 having a projection part 31 projectingly formed in an axially symmetrical and side view substantially trapezoidal shape to be fitted to its recessed part 21, having an insertion hole 35 for inserting a male screw part 41 of a bolt 4 into an upper part of the projection part 31 and making the insertion hole 35 eccentric from a central position of the projection part 31. <P>SOLUTION: This fastening structure 1B also has an elastic material second washer 5 having the insertion hole having an outer diameter substantially equal to an inner diameter of the recessed part 21 of the nut 2 and an inner diameter substantially equal to an outer diameter of the male screw part 41 of the bolt 4, and fills up a clearance of a noncontact part between the first washer 3 and the male screw part 41 of the bolt 4 by elastically deforming the second washer 5, when fastened by threaded engagement. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fastening assembly member in a structure (for example, a building structure) and a fastening structure using the same.

  Regarding the fastening structure using nuts and bolts, one of the inventors of the present application proposes a nut and washer having a specific shape in order to enable firm fastening in Patent Document 1 included as the inventor. .

  FIG. 8 shows a fastening structure described in Patent Document 1. As shown in FIG. In this fastening structure 101, the nut 102 has a concave portion 121 that is axially symmetric and has a substantially trapezoidal shape in cross section on one opening side of the female screw portion 126. The washer 103 has a protruding portion 131 that is axially symmetric and fits into the concave portion 121 of the nut 102 and is formed in a substantially trapezoidal shape when viewed from the side, and the male screw portion 141 of the bolt 104 is inserted into the upper portion 131a of the protruding portion 131. An insertion hole 135 is provided, and the insertion hole 135 is eccentric from the center position of the protrusion 131. 106 and 107 are fastened bodies. In this fastening structure 101, when screwed and fastened, the concave portion 121 of the nut 102 and the protruding portion 131 of the washer 103 are fitted. At this time, since the center position of the insertion hole 135 of the washer 103 is eccentric with respect to the center position of the protrusion 131 of the washer 103, the tightening torque acts as a lateral force on the thread of the bolt 104, and the washer 103 A part of the periphery of the insertion hole 135 bites into the thread of the bolt 104. Further, the meshing with the screw thread causes a twist at the contact portion. As a result, a concentrated lateral force (perpendicular to the central axis of the bolt 104) is applied at the contact portion, that is, the washer 103 and the bolt 104 are pressed against each other, thereby producing a loosening prevention effect.

JP 2002-206515 A

  By the way, loosening prevention in a fastening structure is an extremely important theme from the past and in the future, and a fastening structure having a higher locking effect is always required. The same applies to the fastening structure described in Patent Document 1.

  The inventor of the present application is that the looseness of the fastening structure is greatly influenced by minute vibrations, and in the fastening structure described in Patent Document 1, the contact between the washer 103 and the male screw part 141 of the bolt 104 is pinpointed. Attention is paid to the fact that all of the force generated between the washer 103 and the male threaded portion 141 of the bolt 104 is applied to this portion. As a result of the research, the fastening assembly described in detail below and the fastening structure using the same I came up with a body.

  This invention is made | formed in view of the reason which concerns, The objective is improving the fastening structure described in patent document 1, and the assembly member for fastening which can improve a loosening prevention effect, and it It is in providing the fastening structure used.

  In order to achieve the above object, the assembly member for fastening according to claim 1 is fitted to a nut having an axially symmetric recess having a trapezoidal shape in cross section on one opening side of the female screw portion, and the recess of the nut. The projection is formed so as to be axially symmetric and substantially trapezoidal in side view, and has an insertion hole through which the male screw portion of the bolt is inserted, and the insertion hole is offset from the center position of the projection. A first washer having a center, and a second washer made of an elastic material having an outer diameter substantially equal to the inner diameter of the concave portion of the nut and having an inner diameter substantially equal to the outer diameter of the male thread portion of the bolt. A fastening member used together with a bolt, wherein a second washer is fitted in the recess of the nut, and the projecting portion of the first washer is opposed to the recess of the nut, and the fastened body by the bolt and the nut When screwing and fastening The first washer and the bolt are engaged with each other, and the insertion hole of the first washer meshes with the male threaded portion of the bolt, whereby the first washer twists at the contact portion. The second washer is elastically deformed to fill the gap in the non-contact portion with the male screw portion.

  The fastening member according to claim 2 is characterized in that in the fastening member described in claim 1, the concave portion of the nut has a recessed portion into which the second washer is fitted. To do.

  The fastening assembly member according to claim 3 is the fastening assembly member according to claim 1 or 2, wherein the insertion hole of the second washer has an inner peripheral edge that is uneven in the radial direction. It is characterized by.

  According to a fourth aspect of the present invention, there is provided a fastening structure including a bolt having a male screw portion and a head, a nut having an axially symmetric recess having a trapezoidal shape in cross section on one opening side of the female screw portion, and a recess in the nut. A projecting portion that is axially symmetrical and formed in a substantially trapezoidal shape in side view, and has an insertion hole through which the male screw portion of the bolt is inserted, and the insertion hole is offset from the center position of the projecting portion. A first washer having a center, and a second washer made of an elastic material having an outer diameter substantially equal to the inner diameter of the concave portion of the nut and having an inner diameter substantially equal to the outer diameter of the male thread portion of the bolt. A fastening structure having a second washer fitted in the recess of the nut, the projecting portion of the first washer opposed to the recess of the nut, and the bolted body and the nut to be fastened. When the joint is fastened, the protrusion of the recess of the nut and the first washer And the first washer insertion hole meshes with the male threaded portion of the bolt to cause twisting of the first washer at the contact portion, and the non-contact portion between the first washer and the male threaded portion of the bolt The gap is filled with the second washer elastically deformed.

  The fastening structure according to claim 5 is the fastening structure according to claim 4, wherein the concave portion of the nut has a recessed portion into which the second washer is fitted.

  The fastening structure according to claim 6 is the fastening structure according to claim 4 or 5, wherein the insertion hole of the second washer has an inner peripheral edge that is uneven in the radial direction. And

  According to the assembly member for fastening and the fastening structure using the same according to the present invention, when micro vibration occurs between the first washer and the male screw portion of the bolt in the fastened state, the first washer and the male screw of the bolt It is possible to improve the loosening prevention effect by dispersing the force at the contact portion of the portion to the second washer that fills the gap between the first washer and the non-contact portion of the male screw portion of the bolt.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part of a fastening member 1A according to an embodiment of the present invention. The figure also shows bolts 4 used together with the fastening assembly member 1A. The bolt 4 has been widely used conventionally, and includes a male screw portion 41 and a head portion 42. The fastening member 1 </ b> A includes a nut 2, a first washer 3, and a second washer 5. The nut 2, the first washer 3, and the bolt 4 have high hardness and are made of metal (for example, iron or stainless steel). It is desirable that the first washer 3 has a hardness at least equal to or higher than that of the nut 2. The second washer 5 is made of an elastic material.

  2A and 2B show the nut 2, where FIG. 2A is a plan view, FIG. 2B is a cross-sectional view along AA, and FIG. 2C is a bottom view. The nut 2 is a prism (for example, a regular hexagonal prism), and has an internal thread portion 26 that meshes with the external thread portion 41 of the bolt 4. On one opening side (the lower side in FIG. 2B) of the female screw portion 26, a concave portion 21 that is axially symmetric and has a substantially trapezoidal shape in cross section is formed to be recessed from the lower surface 28. Axisymmetric means symmetrical about the central axis T of the nut 2.

  Specifically, the recess 21 includes a recess side surface 22 and a recess upper surface 23. The opening of the female screw portion 26 described above exists in the center portion of the upper surface 23 of the recess. More specifically, the side surface 22 of the recess has an inclined angle that changes in the middle, and the surface side portion (inclined portion) 22A having a relatively gentle inclination and the back side portion (indented portion) where the inclination is steep and vertical or almost vertical. ) 22B. The inclination x of the inclined portion 22A is preferably about 10 degrees to about 15 degrees with respect to the central axis T. The recessed portion 22B is a portion for fitting a second washer 5 (to be described later) to the nut 2 and has an inner diameter and a depth at which the second washer 5 can be fitted stably.

  In addition, when the recessed portion 22B is present, the second washer 5 can be stably positioned in the vicinity of the upper surface 23 of the recess. However, since the recessed portion 22B has a steep inclination, the mold releasability is generally good. Absent. Therefore, since it may be necessary to shorten the life of the mold or to process the recessed portion 22B separately, the recessed portion 22B may be omitted and only the inclined portion 22A may be provided. In this case, when the first washer 3 is fitted into the recess 21 of the nut 2 as described later, the second washer 5 is also fitted at the same time.

  The nut 2 has a circle 27 of an intersection (concave portion lower point) 25 between the recess side surface 22 and the lower surface 28, an intersection (concave portion upper point) 24 of the recess side surface 22 and the recess upper surface 23, and an inner diameter (minimum diameter) of the female screw portion 26. As shown in the bottom view of FIG. 2C, it is substantially concentric.

  3A and 3B show the first washer 3, wherein FIG. 3A is a plan view and FIG. 3B is a cross-sectional view taken along the line BB. The first washer 3 has a projecting portion 31 that is axially symmetric so as to fit into the recess 21 of the nut 2 and is formed in a substantially trapezoidal shape in a side view so as to project from the base portion 32, and a bolt 4 on an upper portion 31 a of the projecting portion 31. The male threaded portion 41 has an insertion hole 35 through which the insertion hole 35 is eccentric from the center position of the protruding portion 31. The side surface (projecting side surface) 36 of the projecting portion 31 is inclined, and the upper surface (projecting upper surface) 39 of the upper portion 31a of the projecting portion 31 has little or almost no tilt. The base 32 positioned below the protrusion 31 supports the first washer 3 and may be slightly inclined or flat, and at least the outer periphery (supporting lower point) 33 and the body to be fastened. Contact.

  The diameter of the circle drawn by the intersection (projecting upper point) 38 between the projecting side surface 36 and the projecting upper surface 39 is smaller than the diameter of the concave upper point 24 of the nut 2 described above. In addition, the diameter of the circle drawn by the intersection (projecting lower point) 34 between the projecting side surface 36 and the base 32 is equal to or larger than the diameter of the recess lower point 25 of the nut 2. The center positions of these circles are at point i on the XX axis shown in FIG. 3, and the XX axis is common to the central axis T of the nut 2 in FIG.

  On the other hand, the center position of the circle drawn by the peripheral edge 37 of the insertion hole 35 is at point j on the Y-Y axis shown in FIG. Therefore, since the center position i point of the protrusion 31 is on the XX axis shown in the figure, the center position j point of the insertion hole 35 and the center position i point of the protrusion 31 are different. That is, the center position i point of the protrusion 31 is eccentric with respect to the center position j point of the insertion hole 35.

  4A and 4B show the second washer 5, where FIG. 4A is a plan view and FIG. 4B is a cross-sectional view taken along the line C-C. The second washer 5 is provided between the nut 2 and the first washer 3 when fastening. The second washer 5 has an insertion hole 51 having an outer diameter substantially equal to the inner diameter of the concave portion 21 of the nut 2 and substantially equal to the outer diameter (maximum diameter) of the male screw portion 41 of the bolt 4. There is no. The outer peripheral edge 53 of the second washer 5 and the inner peripheral edge 52 forming the insertion hole 51 are substantially concentric circles. More specifically, the diameter of the inner peripheral edge 52 (the inner diameter of the second washer 5) is the same as the outer diameter of the male screw portion 41 of the bolt 4 so that no gap is formed between the inner screw 52 and the male screw portion 41 of the bolt 4. It should be the same or slightly smaller. The diameter of the outer peripheral edge 53 (the outer diameter of the second washer 5) is a size that can be fitted into the recessed portion 22B of the recessed portion 21 of the nut 2 (for example, around 10% of the inner diameter of the recessed portion 22B). The thickness is set to be at least smaller than the depth of the recess 21 of the nut 2 so as not to hinder contact between the recess 21 of the nut 2 and the protrusion 31 of the first washer 3 when fastened. In this embodiment, the depth is slightly larger than the depth of the recessed portion 22B. Further, the lower surface (the surface on the first washer 3 side) 54 of the second washer 5 does not hinder the contact between the male thread portion 41 of the bolt 4 and the protruding portion 31 of the first washer 3 when fastened. It is desirable to be flat (no protrusions).

  The material of the second washer 5 is desirably rubber (for example, neoprene rubber having excellent weather resistance), but may be any material having similar elasticity such as silicon or other synthetic resin.

  Although the nut 2, the first washer 3, and the second washer 5 have been described above, these constitute a set and constitute a set member for fastening 1A, which is provided to the market. Alternatively, on the assumption that the fastening assembly member 1A is configured, each may be provided to the market alone. Since the bolt 4 is a general one that has been widely used as described above, the bolt 4 is provided to the market together with or independently of the fastening assembly member 1A.

  Next, a fastening structure 1B using the fastening member 1A will be described with reference to FIG. This figure is a cross-sectional view of the main part of the fastening structure 1B, where (a) is before completion of fastening and (b) is after completion of fastening.

  As shown in FIG. 5 (a), the male threaded portion 41 is inserted over the head portion 42 of the bolt 4 to place the fastened bodies 6 and 7 and the first washer 3 in this order, and the second portion is placed in the recessed portion 22B. In a state where the second washer 5 is fitted, the female screw part 26 is screwed into the male screw part 41 and the nut 2 is rotated. Then, the recess lower point 25 of the nut 2 comes into contact with the protruding side surface 36 of the first washer 3.

  As the nut 2 is further rotated, the protruding side surface 36 of the first washer 3 gradually fits into the recess 21 while receiving pressure from the recess lower point 25 of the nut 2.

  At this time, as described above, the center position j point of the insertion hole 35 of the first washer 3 and the center position i point of the protrusion 31 are decentered, so that they are shown on the center right side of the drawing of FIG. As shown in the figure, a part of the periphery of the insertion hole 35 of the first washer 3 is in contact with the male threaded portion 41 of the bolt 4, and since they are of high hardness, they have a shape that bites between the screw threads while strongly repelling each other. .

  In addition, since the thread of the male screw portion 41 is spiral, the peripheral portion of the insertion hole 35 of the first washer 3 meshes with the spiral thread of the male screw portion 41 while strongly repelling each other. Thus, a kind of twist occurs in the first washer 3 in the vicinity of the contact portion.

  Moreover, the area where the first washer 3 contacts the male thread portion 41 of the bolt 4 is extremely small and is a pinpoint. Between the other 1st washer 3 and the external thread part 41 of the volt | bolt 4, it is a non-contact part and the clearance gap has arisen. The gap is the largest on the opposite side of the axisymmetric side of the contact portion between the first washer 3 and the male thread portion 41 of the bolt 4 (on the left side in the center of the drawing in FIG. 5B).

  The gap between the male screw portion 41 of the bolt 4 and the non-contact portion between the first washer 3 is filled with the second washer 5 as shown in FIG. That is, the projecting upper surface 39 of the first washer 3 contacts the second washer 5 before and after the recess lower point 25 of the nut 2 contacts the projecting side surface 36 of the first washer 3. The second washer 5 is elastically deformed as the protruding portion 31 of the first washer 3 is fitted into the recess 21 of the nut 2, and is formed in the gap between the male screw portion 41 of the bolt 4 and the non-contact portion of the first washer 3. It will protrude and fill the gap.

  Thus, the following effects are produced.

  The first washer 3 has a small hardness in contact with the male thread 41 of the bolt 4, which is also of a high hardness, and it bites while strongly repelling, so that a so-called wedge effect occurs, and the first washer 3 and the bolt 4 The positional relationship between the male screw portions 41 is fixed. Note that the first washer 3 is likely to bite into the thread when the thickness of the first washer 3 is smaller than the pitch of the thread of the male thread portion 41 of the bolt 4. Further, the first washer 3 is engaged with the male threaded portion 41 of the bolt 4 while being strongly repelled and twisted. Therefore, a concentrated lateral force is applied at the contact portion between the first washer 3 and the male threaded portion 41 of the bolt 4 (the first washer 3 and the bolt 4 are pressed against each other), and a strong loosening prevention effect is obtained. . Furthermore, the force at the contact portion between the first washer 3 and the male threaded portion 41 of the bolt 4 is applied to the contact portion between the male threaded portion 41 of the bolt 4 and the nut 2 opposite to the central axis (the central axis T of the nut 2). It is transmitted, and there is also a concentrated lateral force. Therefore, the bolt 4 and the nut 2 are pressed against each other at that location, and a strong locking prevention effect is obtained.

  On the other hand, when the second washer 5 is deformed to fill the gap between the male screw portion 41 of the bolt 4 and the non-contact portion of the first washer 3, the space between the first washer 3 and the male screw portion 41 of the bolt 4 is fastened. When micro vibrations occur, the first washer 3 and the male threaded portion 41 of the bolt 4 are of high hardness. Therefore, a strong repulsive force acts at the contact portion, but the force is applied to the first washer 3. And the second washer 5 made of an elastic material that fills the gap between the non-contact portions of the male screw portion 41 of the bolt 4. As a result, it is possible to suppress loosening due to minute vibrations. For this purpose, the second washer 5 is elastically deformed, preferably at least half the thickness of the first washer 3, and more preferably more than the thickness of the male thread portion 41 of the bolt 4 and the first washer 3. Fill gaps in contact areas.

  Table 1 shows the results of a durability test of the loosening prevention performed on the fastening structure 1B under excessive conditions. In this test, as shown in FIG. 6, the fastening structure 1 </ b> B is engaged and held in the elongated hole 81 of the holding member 8. The fastening structure 1B can move a maximum distance of 19 mm in the lateral direction (perpendicular to the central axis of the bolt 4) along the hole 81. This test is one of NAS standard vibration tests, in which the holding member 8 is vibrated in the lateral direction to give an impact to the fastening structure 1B, and as a result, whether or not loosening occurs is tested. Bolt 4 uses a JIS standard strength category of 10.8T, tightening torque is 200kg · f / cm, vibration frequency is 29.7Hz (1780rpm), vibration return amplitude is 11mm, vibration time is 17 minutes ( The number of vibrations was approximately 30,000 times). Then, the maximum acceleration in the fastening structure 1B is about 39G. In addition, oil was applied to the threads.

  As a result, in the fastening structure 1 where the second washer 5 was not present, both of the two tests were loosened, but the one having the second washer 5 was both of the two tests. No loosening was observed in

  In the fastening structure 1 </ b> B, a certain amount of force is generated over a wide area between the first washer 3 and the male screw portion 41 of the bolt 4 via the deformed second washer 5. For this reason, since extremely large vibration is applied between the first washer 3 and the male threaded portion 41 of the bolt 4, the position of the contact between the first washer 3 and the male threaded portion 41 of the bolt 4 is somewhat shifted and loosened. Even in this case, the first washer 3 is prevented from coming off from the male thread portion 41 of the bolt 4. As a result, in the fastening structure 1B, it is possible to suppress the first washer 3 and the nut 2 from dropping from the fastened body.

  Next, a modified example of the second washer will be described. FIG. 7 is a plan view of the second washer 9. The second washer 9 is different from the previous example in the shape of the inner peripheral edge forming the insertion hole. That is, the inner peripheral edge 92 of the insertion hole 91 of the second washer 9 is uneven in the radial direction. Other configurations are the same as those of the second washer 5.

  In the second washer 9, since the inner peripheral edge 92 is uneven in the radial direction, the region of the inner peripheral edge 92 is easily deformed, and the male screw portion 41 of the bolt 4 and the non-contact portion of the first washer 3 The gap can be filled more efficiently. Further, when the male screw portion 41 of the bolt 4 is inserted into the insertion hole 91, it is easy to insert even if the minimum diameter of the inner peripheral edge 92 is smaller than the outer diameter of the male screw portion 41 of the bolt 4.

  The fastening structure according to the preferred embodiment of the present invention has been described above. However, the present invention is not limited to that described in the embodiment, and various designs within the scope of the matters described in the claims. It can be changed. For example, the first washer 3 may be made of a plastic having high hardness and twist resistance (for example, made of reinforced plastic containing glass fiber). In addition, the size and fine shape of the concave portion 21 of the nut 2, the protruding portion 31 of the first washer 3, and the second washer 5 described in the embodiment are adapted to the environment in which they are used and the object to be fastened. It can be changed arbitrarily.

It is principal part sectional drawing of the assembly member for fastening which concerns on embodiment of this invention. The nut of the assembly member for a fastening same as the above is shown, (a) is a top view, (b) is AA sectional drawing, (c) is a bottom view. The 1st washer of the assembly member for fastening same as the above is shown, (a) is a top view and (b) is a BB sectional view. The 2nd washer of the assembly member for fastening same as the above is shown, (a) is a top view and (b) is a CC sectional view. It is principal part sectional drawing of a fastening structure same as the above, (a) is before completion of fastening, (b) shows the thing after completion of fastening. It is principal part sectional drawing which shows the test of the fastening structure same as the above. It is a top view of another 2nd washer of the assembly member for fastening same as the above. It is principal part sectional drawing of the conventional fastening structure.

Explanation of symbols

1A Assembly member for fastening
1B Fastening structure
2 nuts
3 First washer
4 Bolt 5, 9 Second washer 21 Nut recess 22B Nut recess recess 26 Nut female thread 31 First washer projection 35 First washer insertion hole 41 Bolt male thread 51, 91 1st 2 washer insertion hole

Claims (6)

A nut having an axially symmetric and substantially trapezoidal concave portion on one opening side of the female screw portion;
It has a projecting part that is axially symmetric and fits into the recess of the nut and protrudes in a substantially trapezoidal shape when viewed from the side, and has an insertion hole through which the male threaded part of the bolt is inserted, and the insertion hole projects A first washer eccentric from the center position of the section;
A second washer made of an elastic material having an outer diameter substantially equal to the inner diameter of the concave portion of the nut and having an inner diameter substantially equal to the outer diameter of the male screw portion of the bolt, and used for fastening together with the bolt An assembly member,
When the second washer is fitted into the recess of the nut, the protruding portion of the first washer is opposed to the recess of the nut, and the bolted and nut are screwed and fastened together, the nut recess And the projection of the first washer are fitted, and the insertion hole of the first washer meshes with the male screw portion of the bolt, whereby the first washer twists at the contact portion, and the first washer and the male screw of the bolt A fastening assembly member characterized in that the second washer is elastically deformed to fill a gap in a non-contact portion with the portion. In the assembly member for fastening described in claim 1,
A fastening assembly member, wherein the recess of the nut has a recessed portion into which the second washer is fitted. In the assembly member for fastening described in claim 1 or 2,
An assembly member for fastening, wherein the insertion hole of the second washer has an inner peripheral edge that is uneven in the radial direction. A bolt having a male thread and a head;
A nut having an axially symmetric and substantially trapezoidal concave portion on one opening side of the female screw portion;
It has a projecting part that is axially symmetric and protrudes in a trapezoidal shape in side view so as to fit into the concave part of the nut, and has an insertion hole through which the male screw part of the bolt is inserted, and the insertion hole is a projecting part A first washer eccentric from the center position of
A second washer made of an elastic material having an insertion hole with an outer diameter substantially equal to the inner diameter of the concave portion of the nut and an inner diameter substantially equal to the outer diameter of the male thread portion of the bolt,
When the second washer is fitted into the recess of the nut, the projecting portion of the first washer is opposed to the recess of the nut, and the bolted and nut are screwed and fastened together, the nut recess And the projection of the first washer are fitted, and the insertion hole of the first washer meshes with the male screw portion of the bolt, whereby the first washer twists at the contact portion, and the first washer and the male screw of the bolt The fastening structure is characterized in that the second washer is elastically deformed to fill a gap in a non-contact portion with the portion. The fastening structure according to claim 4,
The recess of the nut has a recessed portion for fitting the second washer. In the fastening structure according to claim 4 or 5,
The insertion structure of the second washer has an inner peripheral edge that is uneven in the radial direction.

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