JP2007187273A - Washer, nut, and fastener - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fastener that is easy to manufacture and has a sufficient locking effect. <P>SOLUTION: A nut 2 includes a recess part 21 on the side and outside of a washer 3, the recess part 21 being axisymmetric and having an opening area which becomes larger toward the washer 3. The washer 3 includes a projection part 31 formed on the radially inner side on the side of the nut 2, the projection part 31 being axisymmetric and having an outer diameter which becomes smaller toward the nut 2. The center position of a hole of the washer 3, into which a bolt 4 is inserted, is decentered from the center position of the projection part 31. As a result, the recess part 21 of the nut 2 and the projection part 31 of the washer 3 constitute a contact part for fitting when fastening. Further, projections 39 are formed on the part of the washer 3 that makes a contact with the nut 2, the projections 39 extending aslant in the direction of tightening the nut 2 with respect to the radial direction passing the center position of the projection part 31. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fastener having a locking function, and a washer and a nut used in the fastener.

  In fastening structures (fasteners) using bolts and nuts, loosening after fastening of bolts and nuts has been a major issue.

  In order to solve this problem, Patent Document 1 includes a concave portion having an axially symmetric and substantially trapezoidal cross section on the washer side and inside of the nut, and an axially symmetric and substantially trapezoidal convex portion on the nut side and inside of the washer. A fastening structure in which the concave portion of the nut and the convex portion of the washer are fitted, and the hole provided in the washer is located inside the convex portion of the washer, and the center position of the hole is the center of the convex portion of the washer A locking structure for preventing loosening that is eccentric with respect to the position is disclosed. In this technique, the hole provided in the washer is located inside the convex part of the washer, and the center position of the hole is eccentric with respect to the central position of the convex part of the washer. Since the portion to be bite into the thread portion of the bolt, the portion constituting the hole of the washer is greatly distorted, and a strong locking effect can be obtained by the force of this distortion.

  However, the technique disclosed in Patent Document 1 has a problem that the return (loosening) of the nut occurs after fastening because the force required to rotate the nut when loosening is smaller than the rotation of the nut when fastening. . In addition, since the nut is first loosened and then the washer is loosened, there is a problem that variations in the loosening prevention effect occur.

Therefore, in Patent Document 2, in addition to the structure of Patent Document 1, a rotation resistance portion having a substantially right-angled cross section provided at the contact portions of the nut and the washer so that the directions of the inclined surfaces are opposite to each other. Thus, the force required for the rotation when loosening is larger than the rotation when fastening.
Japanese Patent No. 3522695 (publication date July 26, 2002) Japanese Patent Laying-Open No. 2005-69347 (Publication date: March 17, 2005)

  However, in the technique of the above-mentioned Patent Document 2, since the rotation resistance portions of both the washer and the nut are rubbed at the time of fastening, the rotation resistance portion may be deformed and a sufficient return prevention effect may not be obtained. there were. In addition, at the time of fastening, in order to allow the nut to rotate while the rotational resistance portions of both the washer and the nut rub, it is necessary to reduce the height of the vertical portion in the substantially right triangle of the cross section. In some cases, the rotational resistance for obtaining the return prevention effect cannot be obtained sufficiently.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fastener capable of reliably obtaining a locking effect, and a washer and a nut used in the fastener. .

  In order to solve the above-described problems, the washer of the present invention comprises a nut and a washer having a hole through which a bolt shaft passes. The nut has an opening that is symmetrical with respect to the washer side and inside and toward the washer side. The washer has a concave portion with an increased area, and the washer has a convex portion with an axially symmetric inner side and a narrower outer diameter toward the nut side, and the hole provided in the washer is an inner side of the convex portion. The center position of the hole is eccentric with respect to the center position of the convex part of the washer, and the concave part of the nut and the convex part of the washer constitute a contact part and fit when fastened. A washer used for a fastener that extends in a direction inclined to the tightening direction of the nut relative to the radiation passing through the center position of the convex portion, and protrudes toward the nut side. At least one protrusion is formed. It is characterized in.

  According to said structure, the said nut has a recessed part with which the area of the opening became large toward the washer side and an inner side in axial symmetry, and the washer side, and the said washer is axially symmetrical and nut on the nut side and inner side It has a convex part whose outer diameter becomes narrower toward the side, and at the time of fastening, the concave part of the nut and the convex part of the washer constitute a contact part and fit. Further, the hole provided in the washer is located inside the convex part, and the center position of the hole is eccentric with respect to the central position of the convex part of the washer, so that the concave part in the nut and the convex part in the washer When they are brought into contact with each other, the washer moves and / or deforms in a direction in which the center position of the hole coincides with the center position of the convex portion of the washer, and the washer is pressed against the bolt. As a result, a pressing force acts between the bolt and the nut, and a loosening prevention effect (first loosening prevention effect) for preventing the nut from loosening from the fastening state is generated.

  Furthermore, since the protrusion part is formed in the contact part with the said nut in the said washer, if a nut is tightened at the time of fastening, this protrusion part will press-contact with a nut. Due to this pressure contact, the force F resulting from the tightening torque of the nut extends in a direction tilted in the tightening direction of the nut with respect to the radiation (diameter direction of the convex portion) where the protruding portion passes through the center position of the convex portion. Therefore, it is decomposed into a component F1 in the radiation direction passing through the center position of the convex portion and a component F2 in the circumferential direction of the convex portion. Accordingly, a force F1 in the direction of pressing the washer against the bolt acts on the contact portion between the nut and the protrusion provided on the washer. Thereby, after the completion of fastening, the nut does not begin to loosen unless a force corresponding to the above-described force F applied to the protruding portion during fastening is applied. That is, the locking effect can be further strengthened (second locking effect).

  In addition, an inclination angle γ with respect to the radiation passing through the center position of the protrusion in the extending direction of the protrusion may be 0 ° <γ ≦ 60 °. By setting the angle γ within this range, the force in the direction of tightening the nut can be reliably applied at the time of fastening, and the second loosening prevention effect can be more reliably obtained.

  In addition, among the contours of the cross section perpendicular to the extending direction of the projecting portion, at least one of the portions projecting from the installation surface of the projecting portion is within an angle range of 90 ° ± 10 ° with respect to the installation surface. A certain configuration may be adopted.

  According to said structure, the force of the direction which tightens a nut can be made to act more suitably at the time of fastening, and the said 2nd locking effect can be acquired more suitably.

  Also, provided with a support portion that is provided on the fastened body side of the convex portion and comes into contact with the fastened body at the time of fastening, and the protruding portion extends outward from the convex portion with respect to the center position of the convex portion. As such, it may be configured to be formed on the upper surface of the support portion.

  According to said structure, since the protrusion part is formed in the upper surface of the said support part so that it may extend toward the outer side of the said washer from the said convex part, at the time of fastening, the front-end | tip of the said recessed part in a nut is this Abuts against the protrusion. Thereby, the force of the direction which tightens a nut can be made to act more suitably on the contact surface with the said protrusion part in a nut.

  Further, at the time of fastening, the washer-side end portion of the recess in the nut and the convex portion constitute a contact portion, and the protruding portion is pressed against the washer-side end portion of the recess in the nut at the time of fastening. It is good also as a structure.

  According to the above configuration, at the time of fastening, the washer side end portion of the recess in the nut and the convex portion constitute a contact portion, so that the pressure contact force between the nut and the washer is concentrated on the washer side end portion. Become. And the said 2nd locking effect can be made stronger by providing the said protrusion part in the position where this press-contact force concentrates.

  Further, a support portion that comes into contact with the fastened body at the time of fastening is provided on the fastened body side of the convex portion, and an inclination angle of the support portion with respect to the surface of the fastened body is larger than 0 ° and the convex portion It is good also as a structure smaller than the inclination-angle with respect to the said to-be-fastened body surface.

  According to said structure, when a nut is tightened at the time of a fastening, a spring effect | action will arise in a support part by this fastening torque. Due to this spring action, the portion constituting the hole in the washer is strongly pressed by the bolt, so that the loosening prevention effect can be further increased (third loosening prevention effect).

  Further, the thickness of the portion that contacts the bolt at the time of fastening may be thinner than the pitch of the threads provided on the bolt.

  In this case, when the washer presses against the bolt by fitting the washer and the nut, the washer can be bitten into the screw thread of the bolt. Thereby, a composite loosening prevention effect (fourth loosening prevention effect) is obtained by the wedge effect. That is, when the nut is tightened, the tightening torque acts on the screw thread as a force from the side (in a direction substantially perpendicular to the bolt axis). As a result, the washer bites into the screw thread, and the washer and the bolt Since the positional relationship is fixed, a stronger locking effect can be obtained.

  Further, since the screw thread of the bolt is spiral, when the tip of the washer meshes with the spiral thread of the bolt, the contact portion of the washer with the screw thread is twisted. The effect of this twist and the helical thread formed on the bolt can further strengthen the locking effect (fifth locking effect).

  In order to solve the above problems, the nut of the present invention comprises a nut and a washer provided with a hole through which a bolt shaft passes. The nut is symmetrical with respect to the washer side and the inside thereof, and the opening portion becomes closer to the washer side. The washer has a concave portion with an increased area, and the washer has a convex portion with an axially symmetric inner side and a narrower outer diameter toward the nut side, and the hole provided in the washer is an inner side of the convex portion. The center position of the hole is eccentric with respect to the center position of the convex part of the washer, and the concave part of the nut and the convex part of the washer constitute a contact part and fit when fastened. A nut used in a fastener that extends in a direction inclined to the tightening direction of the nut from the radiation passing through the center position of the hole at a contact portion with the washer and protrudes toward the washer side. At least one protrusion is formed. It is characterized in.

  According to said structure, the said nut has a recessed part with which the area of the opening became large toward the washer side and an inner side in axial symmetry, and the washer side, and the said washer is axially symmetrical and nut on the nut side and inner side It has a convex part whose outer diameter becomes narrower toward the side, and at the time of fastening, the concave part of the nut and the convex part of the washer constitute a contact part and fit. Further, the hole provided in the washer is located inside the convex part, and the center position of the hole is eccentric with respect to the central position of the convex part of the washer, so that the concave part in the nut and the convex part in the washer When they are brought into contact with each other, the washer moves and / or deforms in a direction in which the center position of the hole coincides with the center position of the convex portion of the washer, and the washer is pressed against the bolt. As a result, a pressing force acts between the bolt and the nut, and a loosening prevention effect (first loosening prevention effect) for preventing the nut from loosening from the fastening state is generated.

  Furthermore, since the protrusion part is formed in the contact part with the said washer in the said nut, if the nut is tightened at the time of fastening, this protrusion part will press-contact with a washer. Due to this pressure contact, the force F resulting from the tightening torque of the nut extends in a direction in which the protruding portion is inclined in the tightening direction of the nut with respect to the radiation passing through the center position of the hole (diameter direction of the hole). Therefore, it is decomposed into a component F1 in the radiation direction passing through the center position of the hole and a component F2 in the circumferential direction of the hole. Therefore, a force F1 in the direction of pressing the washer against the bolt acts on the contact portion between the protrusion provided on the nut and the washer. Thereby, after the completion of fastening, the nut does not begin to loosen unless a force corresponding to the above-described force F applied to the protruding portion during fastening is applied. That is, the locking effect can be further strengthened (second locking effect).

  In order to solve the above-described problems, the fastener of the present invention includes a nut and a washer having a hole through which a bolt shaft passes, and the nut is axially symmetric to the washer side and to the inside, opening toward the washer side. The washer has a convex part with an axially symmetric inner side and an outer diameter that becomes narrower toward the nut side, and the hole provided in the washer is a hole of the convex part. Located on the inside, the center position of the hole is eccentric with respect to the center position of the convex part of the washer, and when tightened, the concave part in the nut and the convex part in the washer constitute a contact part and fit. A fastener to be joined is characterized by using any one of the above washers and / or the nut.

  According to said structure, the locking effect can be acquired reliably.

  As described above, the washer of the present invention extends to the contact portion with the nut in a direction inclined by an angle γ in the tightening direction of the nut with respect to the radiation passing through the center position of the convex portion. The protrusion part which protrudes in is formed. Further, the nut of the present invention extends at the contact portion with the washer in a direction inclined by an angle γ in the tightening direction of the nut with respect to the radiation passing through the center position of the hole and protrudes toward the washer side. The part is formed. The fastener of the present invention includes any one of the above washers and / or the nut.

  Therefore, the washer, the nut, and the fastener of the present invention can appropriately obtain the locking effect.

  An embodiment of the present invention will be described with reference to the drawings.

  Fig.1 (a) is sectional drawing which shows the state before the completion of fastening in the fastener 1 concerning this embodiment, FIG.1 (b) is sectional drawing which shows the state at the time of completion of fastening. As shown in these drawings, the fastener 1 includes a bolt 4, a washer 3, and a nut 2.

  The bolt 4 includes a screw part 41 and a head part 42. The nut 2 is axially symmetric with respect to the shaft 4a of the bolt 4 on the washer 3 side (fastened body 5 side) and inside (bolt 4 side), and the shape of the cross section parallel to the shaft 4a is substantially the same. It has a trapezoidal recess 21. The washer 3 has a convex portion 31 which is axially symmetric with respect to the axis 4a of the bolt 4 and has a substantially trapezoidal cross-sectional shape parallel to this axis on the nut 2 side and inside.

  Then, the threaded portion 41 of the bolt 4 is passed through the holes provided in the fastened bodies 5 and 6, and the nut 2 is tightened so that the washer 3 is sandwiched between the fastened body 5, thereby fastening the fastened body 5. And 6 are concluded.

  The materials of the nut 2 and the washer 3 are not particularly limited, but it is preferable that the washer 3 is harder (higher in hardness) than the nut 2 as described later. In this embodiment, the material of the nut 2 is S35C, and the material of the washer 3 is S45C. The washer 3 is hardened.

  2A is a plan view of the nut 2, FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A, and FIG. 2C is a bottom view of the nut 2.

  As shown in FIG. 2 (b), a screw portion 41 of the bolt 4 is formed on the inner upper portion of the nut 2 (on the side opposite to the washer 3) in the range of the height S from the upper surface of the nut 2. An internal thread portion 26 is formed so as to mesh with the external thread portion. Further, a concave portion 21 having an axial symmetry and a substantially trapezoidal cross section is formed in the lower portion inside the nut 2 so that the height from the bottom surface becomes H ′. The term “axisymmetric” as used herein means that the nut 2 is symmetric with respect to the central axis T of the nut 2 (which coincides with the axis 4a of the bolt 4 when fastened).

  The concave portion 21 includes an inclined portion 22, a lower surface intersection portion 25 located at the intersection of the inclined portion 22 and the bottom surface 28, an upper surface portion 23 that is the upper surface of the concave portion 21, and an intersection of the upper surface portion 23 and the inclined portion 22. And the upper surface intersection 24 located at the top. In the present embodiment, the angle θ with respect to the central axis T of the inclined portion 22 is set to about 14 °. However, the size of the angle θ is not limited to this, and may be appropriately set in consideration of the shape of the washer 3 so that the washer 3 can be pressed against the bolt 4 at the time of fastening.

  As described above, since the concave portion 21 having an axial symmetry and a substantially trapezoidal cross section is formed in the lower portion inside the nut 2, as shown in FIG. 2C, the inner diameter 27 of the female screw portion 26 and the upper surface intersection portion 24 are formed. The lower surface intersection 25 is a concentric circle.

  As shown in FIG. 2C, the outer shape of the nut 2 is a regular hexagon having a two-face width (distance between opposite sides) of V. In the present embodiment, the outer shape of the nut 2 is a regular hexagon, but the present invention is not limited to this.

  The dimensions of the outer diameter D of the female screw portion 26, the diameter D ′ of the upper surface intersection portion 24, the diameter D ″ of the lower surface intersection portion 25, and the two-surface width V are set to increase in this order. That is, D, D ′, D ″, and V are set so as to satisfy the relationship D <D ′ <D ″ <V.

  Further, the height S of the female screw portion 26 and the height H ′ of the recess 21 satisfy the relationship of H = S + H ′, where H is the height of the nut 2. Note that the height S of the female screw portion 26 and the height H ′ of the recess 21 are not particularly limited, and the height S is set so as to obtain a necessary strength for the screw portion and is loosened. What is necessary is just to set height H 'so that the stop effect can fully be acquired.

  3A is a top view of the washer 3, and FIG. 3B is a cross-sectional view taken along the line BB in FIG. 3A.

  As shown in this figure, the washer 3 includes a convex portion 31, a support portion 32, and a protruding portion 39 provided above the support portion 32. In the present embodiment, the convex portion 31, the support portion 32, and the protruding portion 39 are distinguished for convenience of explanation, but these may be formed integrally. Moreover, the protrusion part 39 is manufactured by special processes, such as forging, cutting, casting, or a press, for example.

  The support portion 32 is formed below the convex portion 31, and the support portion 32 comes into contact with the fastened body 5. The angle of the support portion 32 with respect to a plane perpendicular to the axis xx common to the axis 4a of the bolt 4 and the center axis T of the nut 2 is α. In this embodiment, α = 10 °.

  As shown in FIG. 3 (b), the convex portion 31 includes a curved lower point 34, a curved portion 36, a curved upper point 38, and a hole 35, and is arranged on the nut 2 side and on the inner side with respect to the shaft 4 a of the bolt 4. They are symmetrical and provided so that the cross-sectional shape parallel to the axis is substantially trapezoidal. As shown in FIG. 3A, the curved lower point 34 forms a circle centered on the center position i of the convex portion 31. The center position i of the convex portion 31 is on the xx axis.

  The bending portion 36 has an average angle of approximately β with respect to the xx axis. The size of the angle β is not particularly limited, but β = 15 ° in the present embodiment.

  As shown in FIG. 3A, the outer diameter point 37 of the hole 35 positioned at the upper portion of the convex portion 31 forms a circle, and the center position j of this circle, that is, the center position j of the hole 35 is It is on the y-y axis. Thus, the center position j of the hole 35 is on the yy axis, and the center position i of the convex portion 31 is on the xx axis. That is, the center position j of the hole 35 and the center position i of the convex portion 31 are eccentric.

  Note that the diameter of the circle formed by the outer end portion 33 of the support portion 32 (outer diameter of the washer 3) p, the diameter p '' of the circle formed by the curved lower point 34, which is the lowest point of the curved portion 36, and the curved shape. The diameter p ′ of the circle formed by the curved upper point 38 which is the uppermost point of the portion 36, the diameter d of the hole 35, and the diameter D of the female thread portion 26 in the nut 2 described above are set so as to decrease in this order. Yes. That is, the relationship p> p ″> p ′> d> D is established.

  Further, the diameter p ′ of the circle formed by the curved upper point 38 is smaller than the diameter D ′ of the upper surface intersection 24 in the nut 2, and the diameter p ″ of the circle formed by the curved lower point 34 is The nut 2 has a size equal to or larger than the diameter D ″ of the lower surface intersection 25. That is, the relationship of p ′ <D ′ <D ”≦ p” is established. Thus, when the concave portion 21 in the nut 2 and the convex portion 31 in the washer 3 are in a fitted state, the lower surface intersection point 25 of the concave portion 21 in the nut 2 is pressured around the curved portion 36 of the convex portion 31 in the washer 3. It will be in a state to apply.

  As shown in FIGS. 3A and 3B, the protrusion 39 passes through the center position i of the convex portion 31 along the upper surface of the support portion 32 from the lower portion of the convex portion 31 (curved portion 36). It is formed so as to extend in a direction inclined by an angle γ in a direction in which the nut 2 is tightened at the time of fastening than radiation. In the present embodiment, the angle γ is set to 45 °, but the present invention is not limited to this. Although details will be described later, by changing the set value of the angle γ, it is possible to change the degree of the loosening prevention effect at the time of fastening and the degree of force (return torque) required at the time of releasing the opposite of the fastening. it can.

  The length of the projecting portion 39 in the extending direction is not particularly limited, and at least a part of the projecting portion 39 and the nut 2 may be in pressure contact during fastening. Further, the shape of the tip portion in the extending direction is not particularly limited, and may be a rounded shape as shown in FIG.

  Further, as shown in FIG. 3A, eight protrusions 39 are provided at equal intervals along the circumferential direction of the washer 3. Thereby, when the nut 2 is tightened at the time of fastening, at least one or more protrusions 39 are surely pressed into the nut 2 (particularly the lower surface intersection 25 of the nut 2) and bite.

  FIG. 4 is a cross-sectional view of a cross section (the cc cross section shown in FIG. 3A) perpendicular to the extending direction of the protrusion 39. As shown in this figure, the protrusion 39 has a rectangular cross section perpendicular to the extending direction of the protrusion 39. Note that the width w and height t of the protrusion 39 may be appropriately set according to the size of the fastener 1 (diameter of the bolt 4) and the like, and are not particularly limited. In the case of M8, the width w may be set to about 0.5 mm and the height t may be set to about 0.3 mm.

  Next, the operation when the nut 2 is tightened in the fastener 1 will be described.

  As shown in FIG. 1A, the nut 2 is rotated along the male thread of the bolt 4 with the fastened bodies 5 and 6 and the washer 3 placed in this order on the head 42 of the bolt 4. (Tighten). Then, first, the lower surface intersection 25 in the recess 21 of the nut 2 comes into contact with the curved portion 36 of the protrusion 31 in the washer 3.

  The center position i of the convex portion 31 is on the xx axis shown in FIG. 3A, and this xx axis is common to the central axis T of the nut 2 shown in FIG. After the lower surface intersection 25 of the concave portion 21 contacts the curved portion 36 of the convex portion 31 of the washer 3, the curved portion 36 of the convex portion 31 of the washer 3 fits along the concave portion 21 of the nut 2, HYPERLINK "JP-B-3522695.files \\ 000004.gif" As shown in FIG.1 (b), the convex part 31 of the washer 3 and the concave part 21 of the nut 2 will be in the state fitted.

  At this time, as described above, since the center position j of the hole 35 in the washer 3 and the center position i of the convex portion 31 are eccentric, the convex portion 31 of the washer 3 is shown in FIG. The outer diameter point 37 of the hole 35 provided in the pressure contact part of the screw portion 41 of the bolt 4 (the left side in FIG. 1B).

  FIG. 5 is a perspective view showing the result of analyzing the contact stress acting on each part of the fastener 1 during fastening by the finite element method. In addition, the arrow shown in the figure has shown the direction and magnitude | size of the stress which acts on the contact surface of each member. As shown in this figure (on the right side of the bolt 4 in FIG. 5), when the nut 2 is rotated (tightened), the lower surface intersection 25 of the concave portion 21 in the nut 2 and the curved portion of the convex portion 31 in the washer 3 are fastened. 36 is brought into contact and fitted, and the washer 3 is pressed against the bolt 4. As a result, as indicated by arrows a and b shown in FIG. 1 (b), it corresponds to the resultant force of each contact stress shown in FIG. 4) (force perpendicular to the axis 4a). Further, as a result, the contact surface between the bolt 4 and the nut 2 on the opposite side via the shaft 4a of the bolt 4 with respect to the contact portion between the nut 2 and the washer 3, the arrows c, shown in FIG. As shown in d, a force that presses the bolt 4 and the nut 2 against each other acts, and a loosening prevention effect (first loosening prevention effect) that prevents the nut 2 from loosening from the fastening state occurs.

  Further, at the portion of the washer 3 that contacts the nut 2, the nut 2 is fastened at the time of fastening rather than the radiation passing through the center position i of the convex portion 31 along the upper surface of the support portion 32 from the lower portion of the convex portion 31 (curved portion 36). The protruding portion 39 is formed so as to extend in a direction inclined by an angle γ in the direction of rotation so as to be tightened. When the nut 2 is tightened at the time of fastening, the projecting portion 39 is pressed against the nut 2 and bites in. Thereby, the nut 2 can be further prevented from loosening from the fastened state (second loosening prevention effect).

  This second locking effect will be described in more detail. FIG. 6 is an explanatory view schematically showing the force acting between the nut 2 and the washer 3 at the time of fastening. As shown in this figure, when the concave portion 21 of the nut 2 and the convex portion 31 of the washer 3 are fitted and fastening is completed, the concave portion 21 of the nut 2 and the convex portion of the washer 3 are added in addition to the axial force P. The action / reaction force S · S ′ acts in a composite manner with the force 31, and a force Q in the center direction (force in the direction of pressing the washer 3 against the bolt 4) acts. Thereby, the said 1st loosening prevention effect is acquired.

  FIG. 7A is an explanatory view schematically showing the force acting on the contact portion between the nut 2 and the protruding portion 39. As shown in this figure, when the nut 2 is tightened, the contact portion between the nut 2 and the protrusion 39 has a side surface (side surface on the direction in which the nut 2 is loosened) where the force F is parallel to the extending direction of the protrusion 39. ) Acts mainly vertically on 39a. Here, since the protrusion 39 extends at an angle inclined by an angle γ in the tightening direction of the nut 2 with respect to the radiation passing through the center position i of the washer 3, the force F is as shown in FIG. As shown in FIG. 5, the component F1 in the radiation direction (diameter direction of the convex portion 31) passing through the center position i of the convex portion 31 and the component F2 in the circumferential direction of the convex portion 31 are decomposed. Therefore, a force F <b> 1 in the direction of pressing the washer 3 against the bolt 4 further acts on the contact portion between the nut 2 and the protruding portion 39.

  As a result, the protrusion 39 bears a resistance force against the looseness of the nut 2, and unless the force corresponding to the force F applied to the protrusion 39 during tightening is applied in the direction opposite to the force F, the nut 2 does not begin to loosen (does not start rotating). That is, as shown in FIG. 7B, the force F ′ in the opposite direction and substantially the same magnitude as the force F acting on the protrusion 39 at the time of tightening is narrowed to the protrusion 39 (the nut 2 in the protrusion 39 is tightened). Unless added to the side 39b) on the directional side, the nut 2 does not begin to loosen. Therefore, by providing the protrusion 39, the loosening prevention effect can be further strengthened.

  The washer 3 (the protruding portion 39 of the washer 3) is preferably made of a material harder than the nut 2 (the contact portion of the nut 2 with the washer 3). Thereby, since the protrusion part 39 bites into the nut 2 at the time of fastening, the loosening prevention effect can be strengthened more.

  The washer 3 has a support portion 32 at the lower portion thereof, and the support portion 32 is inclined by an angle α with respect to a plane perpendicular to the xx axis, that is, the surface of the fastened body 5. When the angle α is larger than 0 ° and smaller than the inclination angle of the convex portion 31 with respect to the surface of the fastened body 5 (0 ° <α ≦ 90−β °), the tightening torque of the nut 2 causes the support portion 32 to Spring action occurs. Due to this spring action, the outer diameter point 37 of the hole 35 in the washer 3 is strongly pressed by the screw portion 41 of the bolt 4, so that the loosening prevention effect can be further strengthened (third loosening prevention effect). In addition, the shape of the support portion 32 may be horizontal (angle α = 0) with respect to the fastened body 5, and in that case, a specific effect is obtained that the washer 3 can be horizontally moved accurately. It is done.

  Further, the thickness of the portion constituting the hole 35 of the washer 3 (wall thickness of the washer 3) may be formed so as to be thinner than the pitch of the thread formed on the bolt 4. In this case, since the center position j of the hole 35 in the washer 3 and the center position i of the convex portion 31 are eccentric as described above, the position of the washer 3 or the position of the hole 35 by tightening the nut 2. The position of the outer diameter point 37 moves, and the outer diameter point 37 bites into the thread of the bolt 4.

  For this reason, after fastening the nut 2 through the washer 3, a combined loosening prevention effect (fourth loosening prevention effect) is obtained by a so-called wedge effect. That is, when the nut 2 is tightened to fasten the nut 2, a part of the tightening torque acts as a force from the side (perpendicular to the axis 4a of the bolt 4) on the thread of the bolt 4. Since the outer diameter point 37 of the hole 35 of the washer 3 bites into the thread of the bolt 4 and the positional relationship between the washer 3 and the bolt 4 is fixed, a stronger locking prevention effect can be obtained.

  When the thickness of the portion constituting the hole 35 of the washer 3 (thickness of the washer 3) is smaller than the pitch of the thread formed on the bolt 4, the thread of the bolt 4 is spiral. Therefore, when the outer diameter point 37 of the hole 35 in the washer 3 meshes with the spiral thread of the bolt 4, the contact portion with the thread at the outer diameter of the hole 35 is twisted. The action of the twist and the helical thread formed on the bolt 4 can further strengthen the locking effect (fifth locking effect).

  Next, the result of the vibration test performed on the fastener 1 according to the present embodiment will be described.

  About the fastener 1 concerning this embodiment, the vibration test was done and the loosening prevention effect was investigated. In addition, the fastener 1 of size M12P1.75 was used for this test. As for the test method, American Aviation Standard (NAS Standard) No. 3350 was performed. Specifically, the vibration direction was the vertical direction of the bolt axis, the vibration frequency was 29.7 Hz (1780 cps), the total vibration amplitude was 11 mm, the impact length was 19 mm, the test time was 17 minutes, and the number of tests was 30000 times.

  Table 1 shows the torque (return torque) for releasing the fastening state by applying vibration for 10 minutes under the above conditions after making the fastening state with a fastening torque of 400 kgf · cm for 10 fasteners 1 having the same shape. The measurement result is shown.

この表に示すように、上記の条件で１０分間振動を加えても、緩みは発生しなかった。また、戻しトルクは、締め付けトルクの７５％以上１００％以下であり、平均８４％であった。

As shown in this table, even when vibration was applied for 10 minutes under the above conditions, no looseness occurred. Moreover, the return torque was 75% or more and 100% or less of the tightening torque, and averaged 84%.

  Table 2 shows the results of measuring the return torque of 10 fasteners 1 having the same shape, after putting them into a fastening state with a fastening torque of 380 kgf · cm to 400 kgf · cm, applying vibration for 17 minutes under the above conditions. ing.

この表に示すように、上記の条件で１７分間振動を加えても、緩みは発生しなかった。また、戻しトルクは、締め付けトルクの６７．５％以上１０５％以下であり、平均８６％であった。

As shown in this table, even if vibration was applied for 17 minutes under the above conditions, no looseness occurred. The return torque was 67.5% to 105% of the tightening torque, and was 86% on average.

  In addition, as shown in Table 2, the return torque sometimes exceeded the tightening torque. Thus, according to the fastener 1 according to this embodiment, depending on the contact state between the protrusion 39 and the nut 2, a strong loosening prevention effect can be obtained such that the return torque exceeds the tightening torque.

  From these experimental results, it can be seen that the fastener 1 according to the present embodiment has an excellent anti-loosening effect. Further, it can be seen that, while having a sufficient locking prevention effect, the return torque does not become excessive and it is relatively easy to release the fastening state.

  In addition, in the technique of the above-mentioned Patent Document 2, when the rotation resistance portions having a substantially right-angled triangle cross section provided on the nut and the washer mesh with each other, an excessive return torque is required to release the fastening state, and the fastening state is It was difficult to release. Further, when a return torque for releasing the fastening state is applied, the rotation resistance portion is damaged, and it is difficult to reuse the nut and the washer. On the other hand, in the fastener 1 according to the present embodiment, the fastening state can be released without requiring an excessive return torque, and the nut and the washer can be reused.

  As described above, the fastener 1 according to the present embodiment includes the nut 2, the washer 3, and the bolt 4, and is axially symmetrical and substantially trapezoidal in cross section toward the washer 3 side of the nut 2 (as it goes toward the washer 3 side). Convex portion 21 having a shape in which the area of the opening portion is increased), a convex portion having an axial symmetry and a substantially trapezoidal cross section on the nut 2 side and inside of the washer 3 (a shape in which the outer diameter becomes narrower toward the nut side). 31, and the concave portion 21 of the nut 2 and the convex portion 31 of the washer 3 are fitted, and the hole 35 provided in the washer 3 is located inside the convex portion 31, and the center of the hole 35 is provided. The position j is eccentric with respect to the center position i of the convex portion 31 in the washer 3.

  As a result, when the nut 2 is tightened, a part of the concave portion 21 in the nut 2 and a part of the convex portion 31 in the washer 3 come into contact with each other, and the washer 3 presses against the bolt 4. As a result, a force pressing each other acts between the bolt 4 and the nut 2, and a loosening prevention effect that prevents the nut 2 from loosening from the fastened state is generated (first loosening prevention effect).

  Furthermore, in the fastener 1 according to the present embodiment, the central position i of the convex portion 31 extends from the lower portion of the convex portion 31 (curved portion 36) to the contact portion with the nut 2 in the washer 3 along the upper surface of the support portion 32. The projecting portion 39 is formed so as to extend in a direction inclined by an angle γ in a direction in which the nut 2 is rotated so as to be tightened at the time of fastening rather than the radiation passing through.

  Thus, when the nut 2 is tightened at the time of fastening, the projecting portion 39 presses against the nut 2 and bites into the nut 2. Further, by tightening the nut 2 at the time of fastening, a force F in a direction in which the protrusion 39 and the nut 2 are pressed against each other acts. This force F mainly acts in a direction perpendicular to the extending direction on the side surface 39a parallel to the extending direction of the projecting portion 39, and thus the radial force acting on the contact portion between the nut 2 and the projecting portion 39. F1 acts in the direction of pressing the washer 3 against the bolt 4. Thereby, the loosening prevention effect of the nut 2 can be further strengthened (second loosening prevention effect).

  In the present embodiment, the angle γ is set to 45 °. However, the present invention is not limited to this, and the angle γ may be in the range of 0 ° <γ <90 °. However, increasing the angle γ increases the magnitude of the force F1, while conversely decreasing the angle γ decreases the force F1. Therefore, the angle γ may be appropriately set within the range of 0 ° <γ <90 ° in consideration of the degree of the required locking effect and the force required to release the fastening state. In other words, by setting the angle γ within the range of 0 ° <γ <90 °, the force F1 can be increased to such an extent that the loosening prevention effect can be appropriately obtained. In order to more effectively obtain the locking effect, the angle γ is preferably in the range of 0 ° <γ ≦ 60 °, and more preferably 30 ° ≦ γ ≦ 60 °.

  In this embodiment, the shape of the cross section of the protrusion 39 perpendicular to the extending direction of the protrusion 39 is rectangular, but the shape of the cross section is not limited to this, and for example, FIG. ) May be triangular, trapezoidal as shown in FIG. 8 (b), or dome-shaped (arched) as shown in FIG. 8 (c). Moreover, the shape obtained by combining these shapes suitably may be sufficient. For example, the shape may be a combination of a rectangle and a triangle as shown in FIG. 8D, or the shape may be a combination of a rectangle and a dome as shown in FIG.

  In addition, the cross-sectional shape of the cross section perpendicular | vertical to the extending direction in the protrusion part 39 is left-right symmetric (surface of the support part 32 (installation surface of the protrusion part 39)), as shown to Fig.8 (a)-FIG.8 (e). It is preferable that the axis is symmetrical with respect to a direction perpendicular to the axis. Thereby, the protrusion part 39 can be formed more easily.

  Further, at least one of the portions (side surfaces 39a and 39b) protruding from the upper surface of the support portion 32 (the installation surface of the protruding portion 39 in the washer 3) out of the contour of the cross section perpendicular to the extending direction of the protruding portion 39 (more More preferably, both) have an angle with respect to this plane in the range of 90 ° ± 10 °. Thereby, said force F can be made to act on the protrusion part 39 appropriately, and the loosening prevention effect can be acquired effectively.

  Further, as shown in FIG. 8 (f), the height of the side surface 39 a on the tightening direction side of the nut 2 in the cross section perpendicular to the extending direction of the protrusion 39 is such that the height of the side surface 39 b on the direction in which the nut 2 is loosened. It is good also as a shape higher than height. Thereby, when the torque of the direction which loosens the nut 2 acts, the force (force which needs to be applied in order to rotate the nut 2) which the protrusion part 39 bears can be enlarged, and the nut 2 can be made harder to loosen. .

  Further, in the present embodiment, eight protrusions 39 are provided along the circumferential direction of the washer 3, but the number of the protrusions 39 is not limited to this, and when the nut 2 is tightened at the time of fastening, What is necessary is just to set suitably so that the at least 1 protrusion part 39 may press-contact the nut 2 reliably. Therefore, it is sufficient that at least one protrusion 39 is provided. Further, the intervals between the protruding portions 39 are not necessarily equal, and may be set as appropriate.

  Note that at least one of the protrusions 39 is preferably formed on a straight line extending from the center position j of the hole 35 through the center position i of the protrusion 31. In this case, the protrusion 39 is provided on the side opposite to the eccentric direction with respect to the center position i of the protrusion 31 at the center position j of the hole 35. Therefore, the concave portion 21 of the nut 2 and the convex portion 31 of the washer 3 come into contact with each other, and the washer 3 moves in a direction in which the central position j of the hole 35 and the central position i of the convex portion 31 of the washer 3 coincide with each other. In this case, the protrusion 39 is formed at a position where the strongest pressing force is generated between the washer 3 and the nut 2. Therefore, the second loosening prevention effect can be further increased.

  In the present embodiment, the shape of the protrusion 39 viewed from above is a substantially rectangular shape with the chamfered tip as shown in FIG. 3A, but is not limited thereto. For example, it is good also as a shape which does not chamfer a front-end | tip part. Further, the side parallel to the extending direction of the protruding portion 39 is not limited to a linear shape, and may be formed in, for example, a jagged shape.

  Further, in the present embodiment, the protruding portion 39 bites into the nut 2 at the time of fastening. However, the present invention is not limited to this, and the protruding portion 39 and the protruding portion 39 are operated so that a force in the direction in which the protruding portion 39 bites into the nut 2 acts. The nut 2 may be in pressure contact.

  In addition, a part of the convex portion 31 (curved portion 36) of the washer 3 according to the present embodiment has a shape with a curved cross section parallel to the axis T. However, the present invention is not limited to this, and this portion has a linear shape. It may be. Further, the angle θ of the nut 2 with respect to the axis T of the concave portion 21 and the angle β of the curved portion 36 of the convex portion 31 of the washer 3 with respect to the xx axis may be equal or different. That is, the shape of the convex portion 31 is not limited as long as the washer 3 can be pressed against the bolt 4 when the nut 2 is tightened, and may be appropriately changed depending on the material of the nut 2 and the washer 3. In any case, it is preferable that the protruding portion 39 is provided at the contact portion between the nut 2 and the washer 3.

  Moreover, in this embodiment, although the volt | bolt 4 shall consist of the thread part 41 and the head 42, it is not restricted to this. For example, the head 42 may not be provided, and the head 42 may be used by being embedded in the fastened body, or may be provided integrally with the fastened body. Moreover, the fastener 1 consists of the nut 2 and the washer 3, and may be used in combination with a bolt as a general-purpose part.

  In the present embodiment, the case of the “right screw” in which the tightening direction of the nut 2 is clockwise has been described. However, the present invention is not limited to this, and the present invention can also be applied to a “left screw”. Even when applied to the “left-handed screw”, the protrusion 39 extends in a direction inclined by an angle γ in a direction in which the nut 2 is rotated so as to tighten the nut 2 at the time of fastening rather than the radiation passing through the center position i of the convex portion 31. What is necessary is just to form.

  In this embodiment, the case where the protrusion 39 is provided on the washer 3 has been described. However, the present invention is not limited to this, and the protrusion 39 may be provided on the nut 2 side. 3 may be provided with protrusions 39.

  When the protruding portion 39 is provided on the nut 2, the protruding portion 39 extending in a direction inclined in the tightening direction of the nut 2 with respect to the radiation passing through the center position of the hole 35 is a contact portion with the washer 3. At least one or more may be formed.

  When the protrusion 39 is provided on the nut 2, the angle γ with respect to the radiation passing through the center position of the hole 35 of the protrusion 39 is in the range of 0 ° <γ ≦ 60 °, as in the case of providing the washer 3. Preferably, 30 ° ≦ γ ≦ 60 ° is more preferable. Further, the cross-sectional shape of the protruding portion 39 is not particularly limited as in the case of providing the washer 3. In addition, among the contours of the cross section perpendicular to the extending direction of the protruding portion 39, at least one (more preferably both) of the nut 2 protruding from the installation surface of the protruding portion 39 has an angle with respect to this surface of 90 °. More preferably within the range of ± 10 °. Also, the number of protrusions 39 to be installed may be at least one as in the case of providing the washer 3. Further, the shape of the protruding portion 39 viewed from above is not particularly limited as in the case of providing the washer 3.

  When the protrusion 39 is provided only on the nut 2, the nut 2 is made of a material that is harder (higher hardness) than the washer 3 so that the protrusion 39 provided on the nut 2 bites into the washer 3. Is preferred. However, the nut 39 slides on the surface of the washer 3 without biting into the washer 3 until the predetermined tightening torque is reached so that the washer 3 is appropriately moved or deformed to the bolt 4 side when the nut 2 is tightened. It is preferable to determine the hardness of each member so that 2 rotates. The protrusion 39 does not necessarily bite into the washer 3 at the time of fastening, and the protrusion 39 and the nut 2 may be in pressure contact so that a force in a direction in which the protrusion 39 bites into the nut 2 acts.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

  The fastener according to the present invention can obtain a very excellent anti-loosening effect, is easy to manufacture, and is relatively easy to release the fastening state, so that a building structure, piping equipment, transportation equipment, It can be applied to various applications such as mechanical products and electrical products.

It is sectional drawing of the fastener concerning one Embodiment of this invention, (a) has shown the state at the time of completion of fastening (a) before the completion of fastening. (A) is a plan view (top view) of a nut provided in a fastener according to an embodiment of the present invention, (b) is a cross-sectional view of the AA cross section shown in (a), and (c) is this nut. FIG. (A) is a top view (top view) of the washer with which the fastener concerning one embodiment of the present invention is equipped, and (b) is a sectional view of the BB section shown in (a). It is sectional drawing of the protrusion part with which the washer shown in FIG. 3 is equipped. It is a perspective view which shows the result of having analyzed the contact stress which acts on each part in the fastener concerning one Embodiment of this invention by the finite element method. In the fastener concerning one Embodiment of this invention, it is explanatory drawing which showed typically the force which acts between a nut and a washer at the time of fastening. (A) is explanatory drawing which showed typically the force which acts on the contact part of the protrusion part provided in the nut and the washer at the time of fastening in the fastener concerning one Embodiment of this invention. (B) shows typically the force which needs to be made to act on the contact part of the protrusion part provided in the nut and washer in order to cancel | release a fastening state in the fastener concerning one Embodiment of this invention. FIG. (A)-(f) is sectional drawing which shows the modification of the protrusion part with which the washer shown in FIG. 4 is equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fastener 2 Nut 3 Washer 4 Bolt 21 Recessed part 22 Inclined part 23 Upper surface part 24 Upper surface intersection part 25 Lower surface intersection part 26 Female thread part 28 Bottom surface 31 Convex part 32 Support part 34 Curved lower point 36 Curved part 37 Outer diameter point 38 Curved upper part Point 39 Protrusion

Claims (9)

The nut comprises a hole with a hole through which the bolt shaft passes, and the washer has a recess having an opening that is axially symmetrical and has an opening area that increases toward the washer side. A convex portion whose outer diameter is narrower toward the nut side toward the nut side, the hole provided in the washer is located inside the convex portion, and the central position of the hole is the convex portion of the washer Is a washer that is used for a fastener that, when fastened, a concave portion in the nut and a convex portion in the washer constitute a contact portion and are engaged,
At least one or more projecting portions that extend in a direction inclined in the tightening direction of the nut with respect to the radiation passing through the center position of the convex portion and project to the nut side are formed in the contact portion with the nut. A washer characterized by that.   The washer according to claim 1, wherein an inclination angle γ with respect to radiation passing through a center position of the convex portion in the extending direction of the protruding portion is 0 ° <γ ≦ 60 °.   Of the contours of the cross section perpendicular to the extending direction of the projecting portion, at least one of the portions projecting from the installation surface of the projecting portion has an angle with respect to the installation surface within a range of 90 ° ± 10 °. The washer according to claim 1 or 2, characterized in that. Provided on the fastened body side of the convex part, provided with a support part that comes into contact with the fastened body when fastened
The protrusion is formed on the upper surface of the support portion so as to extend outward from the convex portion with respect to the center position of the convex portion. The washer according to claim 1. At the time of fastening, the washer side end portion of the concave portion in the nut and the convex portion constitute a contact portion,
The washer according to any one of claims 1 to 4, wherein the protruding portion is in pressure contact with a washer side end portion of a recess in the nut at the time of fastening.   The washer according to claim 4, wherein an inclination angle of the support portion with respect to the surface of the fastened body is larger than 0 ° and smaller than an inclination angle of the convex portion with respect to the surface of the fastened body.   The washer according to any one of claims 1 to 6, wherein a thickness of a portion that contacts the bolt at the time of fastening is thinner than a pitch of a thread provided on the bolt. The nut comprises a hole with a hole through which the bolt shaft passes, and the washer has a recess having an opening that is axially symmetrical and has an opening area that increases toward the washer side. A convex portion whose outer diameter is narrower toward the nut side toward the nut side, the hole provided in the washer is located inside the convex portion, and the central position of the hole is the convex portion of the washer Is a nut used in a fastener that fits with a concave portion in the nut and a convex portion in the washer constituting a contact portion when fastened,
At least one or more projecting portions that extend in a direction inclined in the tightening direction of the nut with respect to the radiation passing through the center position of the hole and project to the washer side are formed at the contact portion with the washer. A nut characterized by that. The nut comprises a hole with a hole through which the bolt shaft passes, and the washer has a recess having an opening that is axially symmetrical and has an opening area that increases toward the washer side. A convex portion whose outer diameter is narrower toward the nut side toward the nut side, the hole provided in the washer is located inside the convex portion, and the central position of the hole is the convex portion of the washer Is a fastener that is engaged with a concave portion in the nut and a convex portion in the washer at the time of fastening, forming a contact portion;
A fastener using the washer according to any one of claims 1 to 7 and / or the nut according to claim 8.

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