JP2007107716A - Locking nut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a locking nut capable of effectively locking an upper nut and a lower nut, preventing corotation of the lower nut when the upper nut is fastened, being fastened with a proper torque value by easily visually confirming rotating amount of the upper nut, reducing manufacturing costs and transport costs while improving appearance, and preventing injury and the like by an angular portion of the upper nut. <P>SOLUTION: The lower nut 2B has an inclined recessed portion 23 provided with a circumferential inclined recessed face 24 along an upper edge of a screw hole 21, the upper nut 3B has an inclined projecting portion provided with an inclined projecting face 34 having an inclination angle smaller than that of the inclined recessed face 24, along a lower edge of a screw hole 31, and a tip of the inclined projecting portion 33 is brought into contact with the inclined recessed face 24 and fastened to deform the inclined projecting portion 33 along the inclined recessed face 24. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a locking nut that prevents a nut that tightens an object to be fastened together with a bolt from being loosened.

  Conventionally, a locking nut that prevents the tightened nut from loosening has been proposed. For example, the locking nut described in Japanese Utility Model Publication No. 48-29257 is composed of an upper nut and a lower nut that are screwed into a bolt, and these upper and lower nuts are tapered convex protrusions that fit into each other. The part and the recessed part are formed (patent document 1). And the center of either the said convex part or the said recessed part is formed slightly eccentric with respect to the axial center line of a clamping bolt. As a result, when the upper and lower nuts are tightened, the convex part and the concave part come into contact with each other to generate a shearing force in the radial direction on the screw shaft.

  In addition, the locking nut described in Japanese Patent Application Laid-Open No. 2002-195236 has a contact portion protruding at a position below the side surface of the upper nut, and the tightening tool contacts the contact portion. While preventing co-rotation, the rotation amount of the upper nut can be visually recognized by the position of the contact portion (Patent Document 2).

Japanese Utility Model Publication No. 48-29257 JP 2002-195236 A

  However, in the conventional locking nuts including the inventions described in Patent Document 1 and Patent Document 2, the rotation amount cannot be confirmed without a torque wrench or the contact portion as described above, and an appropriate torque value is obtained. There is a problem that it cannot be tightened with. Further, in the conventional locking nut, the lengths of the opposite sides of the lower nut and the upper nut are formed in the same dimension. For this reason, depending on the tightening angle, the sharp corner portion of the upper nut protrudes from the lower nut, and the appearance is impaired. Therefore, the nut must be separately concealed. Furthermore, since the corner | angular part of an upper nut protrudes from the side part of a lower nut, it becomes easy to hook and there exists a possibility that an operator may be injured.

  The present invention has been made in order to solve such problems. In addition to effectively increasing the locking of the upper nut and the lower nut, the lower nut rotates together when the upper nut is tightened. It is possible to easily check the amount of rotation of the upper nut and tighten it with an appropriate torque value, while reducing the manufacturing cost and transportation cost while improving the aesthetics, and by the corner of the upper nut. An object of the present invention is to provide a locking nut that can prevent injury and the like.

  A feature of the locking nut according to the present invention is a locking nut comprising a lower nut and an upper nut that are screwed into a bolt, and the lower nut has a circumferential shape along the upper edge of the screw hole. The upper nut has an inclined convex portion formed with an inclined convex surface having an inclination angle smaller than the inclined angle of the inclined concave surface along the lower edge of the screw hole. The tip of the inclined convex portion is brought into contact with the inclined concave surface and tightened to deform the inclined convex portion along the inclined concave surface. Here, the chamfered portion of the commercially available nut can be used as it is for the inclined concave portion.

  In addition, a feature of the locking nut according to the present invention is a locking nut composed of a tapered washer and a fastening nut, and the tapered washer is circumferentially inclined along the upper edge of the washer hole. The fastening nut has a sloped convex part formed with a sloped convex surface having an inclination angle smaller than the sloped angle of the sloped concave surface along the lower edge of the screw hole. The tip of the inclined convex portion is brought into contact with the inclined concave surface and tightened to deform the inclined convex portion along the inclined concave surface.

  In the present invention, it is preferable that the upper nut is formed with a diagonal length smaller than the opposite side length of the lower nut. With this configuration, the corners of the upper nut almost never protrude to the outside of the lower nut, so that the degree of tightening of the upper nut can be clearly seen and the tightening tool incorrectly And tighten together.

  Furthermore, in the present invention, one of the center of the inclined recess of the lower nut and the center of the inclined protrusion of the upper nut is formed so as to coincide with the axis of the screw hole, and the other is formed as the shaft of the screw hole The upper nut has a value obtained by adding an eccentric amount of the inclined convex portion or the inclined concave portion to a half value of the diagonal length of the diagonal length of the lower nut. It is preferably formed so as to be less than half the value. By adopting such a configuration, the upper nut is formed in a size that takes into account the amount of eccentricity, so that the corners of the upper nut do not completely jump out of the lower nut. Can be most effective in terms.

  According to the present invention, it is possible not only to effectively increase the locking of the upper nut and the lower nut, but also to prevent the upper nut from being accidentally turned to the lower nut when tightening the upper nut, and the amount of rotation of the upper nut. Can be easily seen and tightened with an appropriate torque value, and also avoids being injured by being caught on the corners of the upper nut, and the appearance of the upper nut that is smaller than the lower nut is superposed. Not only is it novel, it can also have the practicality of reducing manufacturing and transportation costs.

  Hereinafter, a first embodiment of a locking nut 1 according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a locking nut 1 of the first embodiment, and FIGS. 2 and 3 are perspective views of a lower nut 2 and an upper nut 3, respectively. 4 and 5 are a plan view and a right side view, respectively, showing the locking nut 1 of the first embodiment, and FIG. 6 is a sectional view taken along line 6A-6A in FIG.

  The locking nut 1 according to the first embodiment mainly includes a lower nut 2 for fastening a fastened object to a fastening object, and an upper nut 3 for preventing the loosening by locking the lower nut 2. Composed.

  Hereinafter, each component will be described in more detail. As shown in FIGS. 1 to 6, the lower nut 2 and the upper nut 3 are formed in a substantially hexagonal nut shape. The screw holes 21 and 31 of each nut are formed in the same diameter, and are screwed into the same bolt. In the lower nut 2, a substantially truncated cone-shaped recess 22 is formed on the upper surface facing the upper nut 3. The recess 22 is disposed so as to coincide with the axis of the screw hole 21 and is formed so as to reduce in diameter downward. Further, the upper nut 3 is formed with a substantially frustoconical convex portion 32 fitted to the concave portion 22 on the lower surface side facing the lower nut 2. The convex portion 32 is disposed at a position eccentric from the axial center of the screw hole 31 by a predetermined eccentric amount, and is formed so as to reduce in diameter downward. In the first embodiment, the center of the convex portion 32 of the upper nut 3 is decentered with respect to the axis of the screw hole 31 in order to exert the locking function, but the present invention is not limited to this. As will be described later, the center of the recess 22 of the lower nut 2 may be eccentric with respect to the axis of the screw hole 21.

  The upper nut 3 is formed such that the opposite side length and the diagonal length are smaller than the size of the lower nut 2, and the wall thickness is thinner than that of the lower nut 2. Here, the opposite side length refers to the distance between two parallel surfaces (so-called two-surface width) among the six side surfaces of the nut, and the diagonal length refers to the length of the longest diagonal line. To do. Therefore, as shown in FIG. 7, the value obtained by adding the eccentric amount (eccentric distance) of the convex portion 32 to the half value of the diagonal length of the upper nut 3 is equal to or less than the half value of the opposite side length of the lower nut 2. Is set so that the corners of the upper nut 3 do not protrude from the sides of the lower nut 2 in plan view. Further, the upper nut 3 of the first embodiment is formed to have a smaller height in the axial center line direction than the lower nut 2 and is made more compact.

  Next, the operation of the locking nut 1 according to the first embodiment having such a configuration will be described with reference to FIGS. 8 to 11.

  First, when the fastened object 5 is fastened to the fastened article 4 by the locking nut 1 of the first embodiment, as shown in FIG. 8, bolts are inserted into the pilot holes h that communicate the fastened article 4 and the fastened object 5. 6 is inserted. Subsequently, the lower nut 2 is screwed onto the bolt 6 with the concave portion 22 of the lower nut 2 facing upward. At this time, since the difference in size between the upper nut 3 and the lower nut 2 is visually recognized, the operator does not accidentally screw the upper nut 3 first.

  Next, after tightening the lower nut 2 to the fastened object 5 with a tightening tool such as a spanner, the upper nut 3 is turned to the bolt 6 with the convex portion 32 of the upper nut 3 facing downward as shown in FIG. Screw together. When the upper nut 3 is rotated manually, the upper nut 3 stops when the outer peripheral surface of the convex portion 32 comes into contact with the inner peripheral surface of the concave portion 22 of the lower nut 2. At this time, since the convex portion 32 is eccentric with respect to the axial center of the screw hole 31, a part of the outer peripheral surface of the convex portion 32 comes into contact with the inner peripheral surface of the concave portion 22 as shown in FIG. It has become.

  Subsequently, after the upper nut 3 is stopped, the upper nut 3 is further rotated in the tightening direction by a tightening tool such as a spanner. As a result, the convex portion 32 of the upper nut 3 moves downward while being pressed against the concave portion 22 of the lower nut 2 and is inserted. For this reason, the bolt 6 generates shearing forces (arrows in FIG. 11) in directions opposite to each other in the radial direction, and exhibits a loosening prevention effect.

  Moreover, since the recessed part 22 of the lower nut 2 is formed so that it may correspond with the axial center of the screw hole 21, the thickness of a surrounding wall part does not have a bias | inclination and intensity | strength is hold | maintained equally. For this reason, even if the surrounding wall part of the recessed part 22 receives the strong pressing force from the convex part 32, it is hard to be damaged.

  Further, since the upper nut 3 is formed to have a length opposite to the lower nut 2, the tightening tool hardly engages the lower nut 2 by mistake and prevents the lower nut 2 from rotating together. To do. In addition, since the upper nut 3 is formed more compactly than the lower nut 2, the appearance obtained by overlapping and tightening both is excellent in design, and it is not necessary to cover and cover it separately. And if it forms small, it will contribute greatly to material cost reduction.

  Furthermore, as shown in FIG. 4, since the upper nut 3 is smaller than the lower nut 2 in a plan view, the amount of rotation is easily visible, and an appropriate torque value can be easily determined. In the first embodiment, the corners of the upper nut 3 do not protrude from the sides of the lower nut 2 when the upper nut 3 is tightened. For this reason, there is no possibility that the operator may be injured by hooking a finger or the like on the corner.

According to the first embodiment as described above,
1. It is possible to prevent the tightened lower nut 2 and upper nut 3 from being loosened.
2. It is possible to prevent the nuts 2 and 3 from rotating together by making it difficult for the fastening tool to engage the lower nut 2 when the upper nut 3 is tightened.
3. The tightening amount of the upper nut 3 is easy to visually recognize and can be tightened with an appropriate torque value.
4). By making the upper nut 3 compact, material costs, processing costs, transportation costs, and the like can be reduced.
5. The fastening state is excellent in design by overlapping both nuts 2 and 3 of different sizes.
6). There is an effect that it is possible to prevent injuries or the like due to the corners of the upper nut 3.

  Next, a second embodiment of the locking nut 1B according to the present invention will be described. Note that, among the configurations of the second embodiment, the same or corresponding components as those of the above-described first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 12 is a cross-sectional view showing a locking nut 1B of the second embodiment. The feature of the second embodiment is that the loosening prevention effect by tightening the lower nut 2B and the upper nut 3B is enhanced.

  As shown in FIG. 12, the lower nut 2B is formed with an inclined recess 23 on the upper surface side. The inclined concave portion 23 has an inclined concave surface 24 formed in a circumferential shape along the upper edge of the screw hole 21. In the second embodiment, the inclined concave surface 24 is formed with an inclination angle of about 45 °. Since the commercially available nut based on the JIS standard is chamfered at 45 ° to 60 °, a commercially available nut can be used as the lower nut 2B.

  In addition, the upper nut 3B is formed with an inclined convex portion 33 on the lower surface side facing the lower nut 2B during fastening. The inclined convex portion 33 protrudes circumferentially along the lower edge of the screw hole 31, and the outer peripheral side surface is configured as an inclined convex surface 34. As shown in FIG. 12, the inclined convex surface 34 is formed with an inclination angle smaller than the inclination angle of the inclined concave surface 24 of the lower nut 2B. In the second embodiment, the inclination angle of the inclined convex surface 34 is set to about 16 ° with respect to the axis, but is not limited to this angle, and is smaller than the inclination angle of the inclined concave surface 24, and As will be described later, the angle may be 0 ° (parallel to the axial direction) as long as the angle can be brought into contact with the inclined concave surface 24 and deformed along the inclined concave surface 24.

  In the second embodiment, the configuration is such that there is no gap between the lower nut 2B and the upper nut 3B at the time of fastening, so that the completion of tightening can be visually confirmed. In the second embodiment, the center of both the inclined concave portion 23 of the lower nut 2B and the inclined convex portion 33 of the upper nut 3B is aligned with the axis of the screw hole. However, the present invention is not limited to this. Instead, as in the first embodiment, either the inclined concave portion 23 or the inclined convex portion 33 may be formed to be eccentric from the axis of the screw hole 31.

  Next, the operation of the locking nut 1B according to the second embodiment having the above configuration will be described with reference to FIG.

  When the fastening object 5 is fastened to the fastening object 4 by the locking nut 1B of the second embodiment, as shown in FIG. 13, the inclined recess 23 is directed upward in the bolt 6 inserted through the pilot hole h. In this state, the lower nut 2B is screwed. Subsequently, when the upper nut 3B is screwed into the bolt 6 and rotated with the inclined convex portion 33 facing downward, the upper nut 3B stops when the tip of the inclined convex portion 33 contacts the inclined concave surface 24. To do.

  Then, the upper nut 3B is further rotated in the tightening direction and screwed downward by a tightening tool such as a spanner. Thereby, the inclined convex part 33 is pressed by the inclined concave surface 24 of the lower nut 2 </ b> B, and is deformed in the axial direction along the inclined concave surface 24. Thereby, as shown in FIG. 13, the female screw formed on the inclined convex portion 33 meshes with the male screw of the bolt 6. Further, the inclined convex surface 34 having a smaller inclination angle than the inclined concave surface 24 is deformed so as to be in close contact with the inclined concave surface 24. By simply tightening in this way, the inclined convex portion 33 of the upper nut 3B is easily deformed along the inclined concave surface 24, and the female screw meshes with the male screw, so that it is possible to effectively increase the locking force.

  Next, examples of the second embodiment will be described. In this embodiment, an M16 size nut is used as the lower nut 2B, and an upper nut 3B having a diagonal length smaller than the opposite side length of the lower nut 2B is used. Then, after tightening the lower nut 2B and the upper nut 3B with a tightening torque of 106 N · m, the return torque of the lower nut 2B was measured to examine the degree of the locking effect. The result is shown in FIG.

  As shown in FIG. 14, in all three experimental results, the return torque value exceeds the tightening torque value. The ratio was about 104% at 110 N · m for the first time, about 111% at 118 N · m for the second time, and about 117% at 124 N · m for the third time. In the case of the conventional general locking nut, the return torque is 88 N · m with respect to the tightening torque of 106 N · m, and the ratio is about 83%, and the return torque does not exceed the tightening torque. . From this result, it can be seen that in this embodiment, a remarkable effect can be obtained as compared with the conventional product. Since the return torque is larger than the tightening torque in this way, it has been confirmed that the locking effect is enhanced very efficiently by the locking nut 1B of the second embodiment.

  According to the second embodiment as described above, in addition to the effects of the first embodiment described above, the loosening prevention effect by the lower nut 2B and the upper nut 3B can be improved.

  Next, a third embodiment of the locking nut 1C according to the present invention will be described. Note that, among the configurations of the third embodiment, the same or corresponding components as those of the above-described embodiments are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 15 is a partial cross-sectional view showing a locking nut 1C of the third embodiment. The feature of the third embodiment is that a tapered washer 7 is used instead of the lower nut 2B in the second embodiment, and this is tightened with a fastening nut 8 having the same configuration as the upper nut 3B.

  As shown in FIG. 15, the tapered washer 7 has a washer hole 71, and has an inclined recess 73 in which a circumferential inclined concave surface 72 is formed along the upper edge of the washer hole 71. Yes. In the third embodiment, the inclined convex surface 34 of the fastening nut 8 is formed parallel to the axial direction, that is, at an inclination angle of 0 °.

  When the locking nut 1C of the third embodiment is used, after the tapered washer 7 is inserted into the bolt 6 with the inclined recess 73 on the upper side, the fastening nut 8 is connected to the bolt 6 with the inclined convex portion 33 on the lower side. Screw in and tighten. Thereby, like 2nd Embodiment, the inclination convex part 33 contact | abuts to the inclination concave surface 72 of the taper washer 7, and it deform | transforms into the axial direction along the said inclination concave surface 72 according to a clamping force. For this reason, the internal thread formed in the inclined convex portion 33 meshes so as to bite into the external thread of the bolt 6. Further, the inclined convex surface 34 having a smaller inclination angle than the inclined concave surface 72 is deformed so as to be in close contact with the inclined concave surface 72. Therefore, the effect of preventing loosening by the tapered washer 7 and the fastening nut 8 is improved.

  As an example of the third embodiment, a tapered washer 7 having an inclined concave surface 72 having an inclination angle of 45 ° and a fastening nut 8 having an M16 size and a pitch of 2.0 are used. When tightened with a tightening torque of 106 N · m, a return torque of 100 N · m was recorded. Therefore, it has been confirmed that the third embodiment also provides a practically sufficient loosening prevention effect.

  Note that the locking nut according to the present invention is not limited to the above-described embodiments, and can be appropriately changed.

  For example, in each of the above-described embodiments, the lower nuts 2 and 2B, the upper nuts 3 and 3B, or the fastening nut 8 are formed in a substantially hexagonal nut shape, but the present invention is not limited to this. You may make it form in the polygonal shape of a grade.

  In the first embodiment, the concave portion 22 of the lower nut 2 is aligned with the axial center of the screw hole 21, and the convex portion 32 of the upper nut 3 is eccentric with respect to the axial center of the screw hole 31. It is not limited to. For example, as shown in FIG. 16, the recess 22 a of the lower nut 2 a is eccentric with respect to the axis of the screw hole 21, and the protrusion 32 a of the upper nut 3 a is made to coincide with the axis of the screw hole 31. Good. In this case, the thickness of the peripheral wall portion of the concave portion 22a is biased and a thin portion is formed. However, since the convex portion 32a contacts only the thick portion, the convex portion 32a at the time of fastening is separated from the convex portion 32a. The possibility of damage due to the pressing force is low. In this case, the value obtained by adding the eccentric amount (eccentric distance) of the recess 22a to the half value of the diagonal length of the upper nut 3a is set to be equal to or less than the half value of the opposite side length of the lower nut 2a. If it does so, the corner | angular part of the upper nut 3a will not protrude from each side of the lower nut 2a in planar view, and safety will improve.

  Moreover, as a structure which exhibits the locking function, the concave portion 22 or the convex portion 32 is not limited to being eccentric with respect to the screw holes 21 and 31. For example, as shown in FIG. 17, when both the concave portion 22b of the lower nut 2b and the convex portion 32b of the upper nut 3b coincide with the axial centers of the screw holes 21, 31, a slit S is formed in a part of the upper nut 3b. May be formed. According to this configuration, when the upper nut 3b is tightened, the convex portion 32b is pressed by the concave portion 22b, and the slit S is reduced in diameter while being closed. As a result, the convex portion 32b is inserted while strongly pressing against the concave portion 22b while maintaining a radially outward elastic force, thereby exhibiting a loosening prevention effect.

  Further, as another embodiment, the upper nut 3 may be configured by forming a plurality of slits S and bonding the slits S with an elastic metal adhesive such as a synthetic resin. According to this configuration, when the upper nut 3 is tightened, the convex portion 32 is pressed against the concave portion 22 and the metal adhesive between the slits S is reduced in diameter while being compressed. Thereby, since a uniform elastic force is generated outward in the radial direction, the upper nut 3 is not loosened by impact or vibration. Or you may make it form several slit S only in the convex part of the upper nut 3 so that it is not necessary to use a metal adhesive etc. FIG.

  Further, as another embodiment, a cap portion 35 as shown in FIG. 18 may be formed on the upper surfaces of the upper nuts 3 and 3B and the fastening nut 8. The cap portion 35 is formed in a cavity and accommodates the bolts 6 protruding from the upper surfaces of the upper nuts 3 and 3B and the fastening nut 8. According to this configuration, the bolts 6 that are protruded after fastening are concealed to improve the appearance of the locking nuts 1, 1 </ b> B, and 1 </ b> C, and also serve to protect the bolts 6.

It is a perspective view which shows 1st Embodiment of the locking nut which concerns on this invention. It is a perspective view which shows the lower nut of this 1st Embodiment. It is a perspective view which shows the upper nut of this 1st Embodiment. It is a top view which shows the locking nut of this 1st Embodiment. It is a right view which shows the locking nut of this 1st Embodiment. It is the 6A-6A sectional view taken on the line in FIG. It is a top view explaining the size setting of the locking nut which concerns on this invention. It is explanatory drawing which shows the usage method of the locking nut of this 1st Embodiment. It is explanatory drawing which shows the usage method of the locking nut of this 1st Embodiment. It is explanatory drawing which shows the usage method of the locking nut of this 1st Embodiment. It is explanatory drawing which shows the usage method of the locking nut of this 1st Embodiment. It is sectional drawing which shows the locking nut of this 2nd Embodiment. It is explanatory drawing which shows the usage method of the locking nut of this 2nd Embodiment. It is a table | surface which shows the experimental result of the Example in this 2nd Embodiment. It is a partial cross section figure which shows the locking nut of this 3rd Embodiment. It is sectional drawing which shows other embodiment of the locking nut which concerns on this invention. It is a perspective view which shows other embodiment of the locking nut which concerns on this invention. It is a front view which shows other embodiment of the upper nut which concerns on this invention.

Explanation of symbols

1,1B, 1C Loosening prevention nut 2,2B, 2a, 2b Lower nut 3,3B, 3a, 3b Upper nut 4 Fastening material 5 Fastened object 6 Bolt 7 Tapered washer 8 Fastening nut 21 Screw hole 22, 22a, 22b Concave portion 23 Inclined concave portion 24 Inclined concave surface 31 Screw hole 32, 32a, 32b Convex portion 33 Inclined convex portion 34 Inclined convex surface 35 Cap portion 71 Washer hole 72 Inclined concave surface 73 Inclined concave portion S Slit

Claims (4)

A locking nut comprising a lower nut and an upper nut that are screwed onto the bolt,
The lower nut has an inclined recess formed with a circumferential inclined concave surface along the upper edge of the screw hole, and the upper nut has an inclination angle of the inclined concave surface along the lower edge of the screw hole. An inclined convex portion having an inclined convex surface having a smaller inclination angle, and the tip of the inclined convex portion is brought into contact with the inclined concave surface and tightened to tighten the inclined convex portion along the inclined concave surface. A locking nut characterized by being deformed. A locking nut comprising a tapered washer and a fastening nut,
The tapered washer has an inclined recess formed with a circumferential inclined concave surface along the upper edge of the washer hole, and the fastening nut is inclined with respect to the inclined concave surface along the lower edge of the screw hole. An inclined convex portion having an inclined convex surface having a smaller inclination angle than the corner, and the tip of the inclined convex portion is brought into contact with the inclined concave surface and tightened to thereby make the inclined convex portion along the inclined concave surface A locking nut characterized by being deformed.   2. The loosening prevention nut according to claim 1, wherein the upper nut is formed with a diagonal length smaller than the opposite side length of the lower nut. 4. The center of the inclined recess of the lower nut and the center of the inclined convex of the upper nut are formed so that one of them matches the axis of the screw hole, and the other is the axis of the screw hole. Formed eccentrically with respect to
The upper nut is formed such that a value obtained by adding the amount of eccentricity of the inclined convex portion or the inclined concave portion to a half value of the diagonal length is equal to or less than a half value of the opposite side length of the lower nut. A locking nut characterized by that.

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