JP2005140272A - Locking nut and fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a locking nut and a fixing structure using the locking nut preventing looseness of screw connection caused by external force such as external vibration, or an aging effect by positively fastening and fixing a fixed object by a bolt and a nut, and allowing recycling of the bolt and nut. <P>SOLUTION: The nut 3 has an internal thread part formed in the axial direction of an inner peripheral surface, and groove parts 34 provided passing through at least part of the internal thread part radially from both side faces; and the internal thread part of the nut 3 is screwed with an external thread part of the bolt 2. Locking members 4 formed of an elastic material exposed to a through part of the internal thread to apply pressing force to the external thread part of the bolt 2, are fitted into the groove parts 34. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a locking nut that does not loosen even when an external force is applied, and a fixing device using the nut.

  A structure in which a nut is screwed onto a bolt to fasten and fix a member is used in a very wide range of fields, and includes, for example, transportation equipment such as automobiles, airplanes, and trains, and various industrial machines and equipment. On the other hand, even if the nut was initially tightly screwed to the bolt, if external force or vibration is applied from the outside due to various reasons, the solid screwing gradually loosens over time, An unexpected failure occurs in the fixing member that is guaranteed to operate in a state where it is firmly fixed. If the nut is further loosened and removed, it could lead to a major accident.

  For example, Patent Documents 1 to 4 propose various nut structures that prevent loosening of the nut screwed to the bolt and improve safety.

  In Patent Documents 1 and 2, a notch groove (slit) is formed from the side surface of the nut, a part of the nut end surface is protruded, the nut is screwed into a bolt, the protruding surface is brought into contact with the fastening surface, and the notch groove is pressed. A nut structure that narrows the width and shifts the forming direction of the internal thread formed on the inner surface of the nut to make the screw pitch non-aligned and forcibly screw the non-aligned screw into the bolt to obtain a strong connection. It is disclosed.

  Further, in Patent Document 3, at least one deformable slot is provided from the side surface of the lock nut, and a threaded portion is deformed by pressing a nut deforming member provided at a bottom end portion of the lock nut so that the lock nut is arranged around the shaft. A nut structure that holds firmly is disclosed.

  In Patent Document 4, a slit portion is cut out at a predetermined depth from the outer peripheral wall side of the nut toward the axial center side of the nut, and is bent in the axial direction of the nut around the bottom side of the slit portion. A loosening prevention nut is disclosed in which the pitch of the threaded portion of the portion where the bolt is formed is misaligned so that a firm fastening can be obtained when the bolt and the nut are screwed together.

JP 2001-32814 A (disclosed in FIG. 1) JP 59-54809 (disclosed in FIGS. 1 to 3) JP 11-148509 A (disclosed in FIGS. 1 and 3) JP 2002-39143 A (disclosed in FIGS. 1, 2, and 3B)

  In any of these conventional nut structures, the notch groove and slit are formed in the axial direction from the side of the nut, and as the nut is screwed into the bolt, the notch groove and slit gaps are non-uniformly narrowed to the inner surface of the nut. By making the pitch alignment of the formed female screw non-aligned and forcibly screwing the male screw part of the bolt into this non-aligned female screw, that is, by screwing both parts of the male screw part and the female screw part. As a result, it is possible to prevent the occurrence of loosening of the nut screwed into the internal thread of the bolt.

  As described above, the conventional locking nut and the fixing device have a pitch non-aligned portion obtained by unevenly narrowing the gap of the slit formed in the nut by pressing the protrusion formed on the bottom portion of the nut or the slanting inclined surface ( This is a structure that realizes strong coupling by forcibly screwing the male thread portion of the bolt into the deformable portion. That is, the normal shape and structure of the female screw portion of the nut and the male screw portion of the bolt that is screwed to the nut are broken (crush the screw portion).

  Therefore, when the fastening of the member (fixed object) is released for some reason and then fastened and fixed again, the female threaded portion of the nut is destroyed so that it cannot be used, and it cannot be reused and is economically disadvantageous. Is big.

  Accordingly, an object of the present invention is to securely fix and fix an object to be fixed with a bolt and a nut, to prevent loosening of a screw connection due to an external force such as external vibration or a change with time, and to reuse the bolt and nut. An object of the present invention is to provide a locking nut and a fixing structure using the same.

  In order to solve the above-mentioned problems, the locking nut and the fixing structure using the same according to the present invention employ the following characteristic configuration.

(1) an internal thread formed in the axial direction of the inner peripheral surface;
A groove provided through at least a part of the female screw portion in the radial direction from both side surfaces;
A loosening prevention member made of an elastic material fitted in the groove and exposed to the through-hole of the female screw to give a pressing force in the axial direction;
With a locking nut.

  (2) The locking nut according to (1), wherein the locking member is connected at one end side, has two opposed arc portions, and the other end is open.

  (3) The loosening prevention nut according to (1) or (2), wherein the loosening prevention member has a shape and a size that do not protrude outside the nut when fitted in the groove.

  (4) The locking nut according to any one of (1) to (3), wherein a diameter on one side with respect to the groove is smaller than a diameter on the other side.

  (5) The loosening prevention nut according to any one of the above (1) to (4), wherein the loosening prevention member is formed by folding a round bar-shaped or square-shaped elastic body wire.

  (6) The female screw portion of the nut having the female screw portion formed in the axial direction of the inner peripheral surface and the groove portion provided through the at least part of the female screw portion in the radial direction from both side surfaces is the male screw of the bolt A fixing structure comprising a loosening prevention member that is screwed with a portion and is made of an elastic material that is exposed to a through portion of the female screw and applies a pressing force to the male screw portion of the bolt.

  (7) The female screw portion of the nut having the female screw portion formed in the axial direction of the inner peripheral surface and the groove portion provided through the at least part of the female screw portion in the radial direction from both side surfaces is the male screw of the bolt A locking structure in which a loosening prevention member made of an elastic material that is screwed into the portion and applies a pressing force to the male screw portion of the bolt is exposed to the through portion of the female screw and fitted into the groove portion.

  (8) The fixing structure according to (6) or (7), wherein the locking member is connected at one end side, has two opposed arc portions, and the other end portion is open.

  (9) The fixing structure according to any one of (6) to (8), wherein the locking member has a shape and a size that do not protrude outside the nut when the locking member is fitted in the groove.

  (10) The fixing structure according to any one of (6) to (9), wherein a diameter on one side with respect to the groove is smaller than a diameter on the other side.

  (11) The fixing structure according to any one of (6) to (10), wherein the loosening prevention member is configured by folding a round bar-shaped or square-shaped elastic body wire.

  According to the locking nut of the present invention and the fixing structure using the same, it is possible to prevent loosening without destroying the normal shape of the female threaded portion of the nut and the male threaded portion of the bolt that is screwed to the nut, and reuse after use It is possible to use resources effectively.

  In addition, since there is no need for a protrusion or slanted inclined surface on the bottom of the nut, it is possible to apply a load evenly to the object, and it is possible to fix the screw by omitting the washer, etc. Manufacture is possible simply by grooving the nut, which contributes to cost reduction.

  Hereinafter, preferred embodiments of a locking nut and a fixing structure using the same according to the present invention will be described with reference to the drawings.

  First, a first embodiment will be described with reference to FIGS. FIG. 1 is a partially sectional side view showing a state in which an object is fastened and fixed, and shows an example in which two objects, that is, a first member 1A and a second member 1B are fastened and fixed by bolts 2 and nuts 3. Yes. 2 and 4 show a cross-sectional view of the nut in FIG. 1 and a plan view when the present embodiment is applied. FIG. 3 is a plan view of a preferred locking member 4 (elastic clip member) used in this embodiment.

  In a state where the first member 1A and the second member 1B are in close contact, and the positions of the mounting holes 11A and 11B of the respective members are matched, the bolt 2 is inserted into the mounting holes 11A and 11B, and the base end portion is Holding on the side of the two members 1 </ b> B, the tip end portion projects from the first member 1 </ b> A. In this state, the first member 1A and the second member 1B are fixedly fastened by screwing the nut 3 into the bolt 2.

  As shown in FIG. 2, the nut 3 has a total height H standardized by, for example, the ISO standard. The nut 3 includes a nut base portion 31 from the lower portion to the height H1, a locking portion 32 from the upper portion to the height H2, and a nut upper portion 33 from the locking portion 32 to the height H3 (upper surface). .

  A groove (slit) 34 having the same thickness (width) as the height H2 for forming the locking portion 32 is cut into the position of the nut 3 from the outside by using a milling machine or the like, and is also shown in FIG. Thus, it forms by notching so that the both sides of the full width L of the nut 3 may penetrate the external thread part of the nut 3 of the dimension of width L2. As a result, a locking portion 32 having a width L1 is formed at the center.

  In addition, if the height H1 of the nut base 31 is about 0.75 to 1.1 times that is 0.5 times or more the value that is the nominal diameter of the screw defined by the ISO standard or the like, this height A nut having a sufficient tightening force can be obtained by the H1 portion. The screw pitch may be any of various pitch sizes such as thick, medium, and thin.

  The width L1 of the locking portion 32 is 0.15 to 0.8 times (more preferably 0.3 to 0.7 times) the nominal diameter, and the height H2 of the groove 34 is 0.05 to 0 times the nominal diameter. .2 times (more preferably 0.08 to 0.15 times), and the height H3 of the nut upper portion 33 is 0.1 to 0.3 times the nominal diameter (more preferably 0.15 to 0.25). However, since the degree of contribution to the screw fastening is low and the meaning of preventing the later-described loosening prevention member 4 from falling off is great, there is no problem even in a slightly thin state.

  The loosening prevention member 4 has a shape as shown in FIG. 3. For example, a spring material such as a round bar or a square piano wire is folded around a folded portion 41, and the male screw diameter of the bolt 2 (nut 3 A pressing contact portion 42 that makes pressing contact is formed along about a half circumference of the female screw diameter), and is shaped and manufactured so that an introduction portion 43 that opens outward and protrudes at the tip thereof is formed.

  In FIG. 4, in the free state, the locking member 4 maintains an interval in which the pressing contact portion 42 is narrowed to a free position a by its own spring force, as indicated by a dotted line. By making a spring material (elastic wire) such as a piano wire into a round bar shape or a square shape, the pressing contact mode with the male threaded portion of the bolt is different, and there is a difference in the restriction of the axial movement of the nut.

  As described above, the groove portion 34 is cut out from both directions from the outer peripheral surface of the nut 3 with respect to the female screw shaft center of the nut 3 to form the locking portion 32. A locking member made of an elastic material when the female screw of the nut 3 is screwed into the male screw of the bolt 2 fixed to the fastening object (first member 1A or second member 1B) and is tightened to a predetermined degree. 4 is inserted into the groove portion 34 of the nut 3 from the opening portion of the introduction portion 43, fitted into the locking portion 32, locked, and pressed against the male screw circumferential surface exposed by the bolt 2 and the male thread valley slope in a pressurized state. Make contact.

  That is, when the first member 1A and the second member 1B are fastened and fixed using the bolt 2 and the nut 3, the first member 1A and the second member 1B are brought into close contact with each other, and the positions of the attachment holes 11A and the attachment holes 11B are set. The bolts 2 are inserted into the mounting holes 11A and 11B in the matched state, the base end portion thereof is held on the second member 1B side, and the tip end portion is protruded from the first member 1A to prevent loosening. The first member 1A and the second member 1B are firmly fixed by screwing the female screw of the nut base 31 of the nut 3 with the member 4 removed into the male screw of the bolt 2 at a predetermined pressure using a spanner tool.

  The locking member 4 is inserted by placing the introduction part 43 in the vicinity of the locking part 32 of the groove part 34 and pushing it in, so that the leading end of the introduction part 43 comes into contact with the bolt 2 and further pushing the locking part 4 into the introduction part 43. Is moved along the peripheral surface of the male screw portion of the bolt 2, the inclined peripheral surface of the male screw portion of the bolt 2 is pressed by the pressing contact portion 42, and the axial movement of the nut 3 is restricted and loosened. Preventive effect is obtained.

  That is, in this state, the arcuate pressing contact portion 42 of the locking member 4 is in press contact with the peripheral surface of the external thread portion of the bolt 2 and the axial movement of the bolt 2 is caused by the upper and lower inner wall surfaces of the groove portion 34. By being regulated, the movement of the locking member 4 in the horizontal direction is regulated, and eventually the movement of the nut is also regulated.

  Accordingly, it is possible to prevent loosening of the coupling between the bolt 2 and the nut 3 due to the application of external force such as external vibration to any of the first member 1A, the second member 1B, the bolt 2 and the nut 3 and the change with time. That is, in the present embodiment, since a load that presses the screw thread of the bolt 2 from above on the inner wall of the pressing contact portion 42 acts, loosening of the coupling can be prevented.

  The nut upper portion 33 of the nut 3 also contributes to the fastening and fixing of the first member 1A and the second member 1B.

  When releasing the fastening of the first member 1A and the second member 1B for some reason such as repair, adjustment, replacement, etc. of the member to be fixed, by pulling out the folded portion 41 protruding outward of the nut 3 The engagement of the pressing contact portion 42 between the bolt 2 and the locking member 4 is released, the locking member 4 is detached from the nut 3, and the nut 3 may be loosened using a spanner tool in this state. In this embodiment, the conventional thread crushing does not occur at all, and can be reused any number of times.

  In the description of the present embodiment, the example in which the locking member 4 is mounted after the nut 3 is fastened to the bolt 2 is described. However, the nut 3 in a state where the locking member 4 is already mounted in the groove portion 34 is described. The bolt 2 may be used for tightening. In this case, immediately after the front end of the bolt 2 is screwed into the female thread portion of the nut base portion 4, the pressing contact portion 42 at the free position “a” is pushed in with the front end portion being expanded and the nut 3 is tightened. When completed, the same fitted state as in the above-described state (state where the locking member 4 is inserted after fastening) is obtained.

  Next, a second embodiment of the present invention will be described. In the first embodiment described above, the folded-back portion 41 and the introduction portion 43 of the locking member 4 protrude outward from the nut 3, so that the locking member 4 is fastened using the nut 3 with the locking member 4 mounted in advance. When working, the box spanner tool cannot be used, and there is a problem that the work efficiency is lowered, and this countermeasure is taken in the second embodiment.

  FIG. 5 is a top view of the nut 3A according to the second embodiment of the present invention, and the difference is clear when compared with FIG.

  The nut 3A of this embodiment is a modification of a part of the nut 3 shown in FIG. 4 as a first embodiment, and is formed in a groove 34 (not shown in FIG. 4) formed below the nut upper portion 33. The width L1 of the corresponding locking portion 32 is left as it is, the thickness h1 of the locking portion 32 at a position perpendicular to the groove 34 forming direction is reduced, and the lengths of the turn-back portion 41 and the introduction portion 43 of the locking member 4 are reduced. By making the length short, the fitted locking member 4 does not protrude outside the nut 3A.

  As shown in FIG. 5, in this embodiment, since the end portions of the folded portion 41A and the introduction portion 43A do not protrude to the outside of the nut 3A, at the time of fastening and fixing, Not only can the nuts be tightened in the same way, but there is no obstacle even if a wide spanner is used, and it is possible to handle the nut tightening using a box spanner, which significantly improves work efficiency. be able to.

Next, a third embodiment will be described with reference to FIGS.
In the first and second embodiments, the outer shapes of the nut base 31 and the nut upper portion 33 are the same, but in this embodiment, at least a part of the nut upper portion 33 formed above the nut base 31 is removed. The diameter is set to a value smaller than the outer diameter of the nut base 31. Further, as in the second embodiment, the fitted locking member 4A does not protrude outside the nut.

  6 and 7 are a sectional view and a top view of a nut 3B according to a third embodiment of the present invention.

  As can be seen by comparing FIG. 6 and FIG. 2, the outer diameter of the nut upper portion 33 is set to a value L4 that is smaller than the outer diameter L of the nut base 31. Referring to FIG. 7, as in FIG. 5, the width L <b> 5 of the locking portion 32 is left as it is, and the locking portion 4 configured by the slit-like groove portions 34 formed in the radial direction on both sides of the nut 3 </ b> B. By reducing the thickness h at a position perpendicular to the groove forming direction and shortening the lengths of the folded portion 41A and the introduction portion 43A of the locking member 4, the fitted locking member 4 does not protrude outside the nut 3B. It has a structure like this.

  In this embodiment, since the end portions of the folded portion 41A and the introduction portion 43A do not protrude outside the nut 3B, not only can the nut be tightened in the same manner as in the first embodiment when fastening and fixing, Even if a wide spanner is used, there is no obstacle, and it is possible to cope with tightening a nut using a box spanner, and the work efficiency can be remarkably improved.

  The nut used in the locking nut and the fixing device according to the present invention has been described with respect to a hot-water joint in which the present invention is applied to a hexagonal nut. However, other nuts such as a wing nut and a cap nut may be used. The invention can be applied.

  In addition, the dimensions of the width and height in the above-described embodiment are completely arbitrary, and it goes without saying that numerical values may be changed depending on the design.

1 is a partially broken front view showing a fixing device according to a first embodiment of the present invention. It is sectional drawing of the nut shown by FIG. It is a top view of the suitable locking member 4 used in a present Example. It is a top view which shows the fixed structure at the time of application of a present Example. It is a top view of the nut by the 2nd example of the present invention. It is sectional drawing of the nut by the 3rd Example of this invention. It is a top view of the nut by the 3rd example of the present invention.

Explanation of symbols

1A 1st member 11A, 11B Mounting hole 1B 2nd member 2 Bolt 3, 3A, 3B Nut 31 Nut base 32 Locking part 33 Nut upper part 34 Groove part 4 Loosening prevention member (elastic clip pin part)
41, 41A Folding part 42 Pressing contact part 43, 43A Introducing part

Claims (11)

An internal thread formed in the axial direction of the inner peripheral surface;
A groove provided through at least a part of the female screw portion in the radial direction from both side surfaces;
A loosening prevention member made of an elastic material fitted in the groove and exposed to the through-hole of the female screw to give a pressing force in the axial direction;
A loosening nut comprising:   2. The locking nut according to claim 1, wherein the locking member is connected at one end side, has two opposing arc portions, and the other end is open.   3. The locking nut according to claim 1, wherein the locking member has a shape and a size that do not protrude from the nut when fitted in the groove. 4.   4. The locking nut according to claim 1, wherein a diameter on one side with respect to the groove is smaller than a diameter on the other side. 5. The loosening prevention nut according to any one of claims 1 to 4, wherein the loosening prevention member is formed by bending a round bar-shaped or rectangular elastic body wire.   The female threaded portion of the nut having a female threaded portion formed in the axial direction of the inner peripheral surface and a groove portion that penetrates at least a part of the female threaded portion from both side surfaces in the radial direction thereof is screwed with the male threaded portion of the bolt. A fixing structure comprising: a loosening prevention member that is made of an elastic material that is exposed to a penetration portion of the female screw and applies a pressing force to the male screw portion of the bolt, and is fitted into the groove portion.   The female threaded portion of the nut having a female threaded portion formed in the axial direction of the inner peripheral surface and a groove portion that penetrates at least a part of the female threaded portion from both side surfaces in the radial direction thereof is screwed with the male threaded portion of the bolt. A fixing structure comprising: a locking member made of an elastic material that is joined to the male screw portion of the bolt and is exposed to a through portion of the female screw and fitted into the groove portion.   The fixing structure according to claim 6 or 7, wherein the locking member is connected at one end side, has two opposing arc portions, and the other end portion is open.   The fixing structure according to any one of claims 6 to 8, wherein the locking member has a shape and a size that do not protrude outside the nut when fitted in the groove.   The fixing structure according to any one of claims 6 to 9, wherein a diameter on one side with respect to the groove is smaller than a diameter on the other side. The fixing structure according to any one of claims 6 to 10, wherein the loosening prevention member is formed by bending a round bar-shaped or square-shaped elastic body wire.

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