JP2007315524A - Lock nut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensively manufacturable lock nut capable of providing very high effect in preventing its loosening. <P>SOLUTION: This lock nut has a dividing slit 2 for dividing a screw hole 6 vertically from a side face 11 on an upper part side of the nut, a lock resistance providing part 3 formed on an upward side by the dividing slit 2, a lock pin fitting hole 4 extending through from a bottom face 13 of the nut to the dividing slit 2, and a lock pin 5 fitted into the lock pin fitting hole 4 and pressing the lock resistance providing part 3 upward when tightening the nut. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lock nut which is fastened to a male screw and exhibits a strong locking function while being easy to manufacture and operate.

  Conventionally, there has been proposed a lock nut that is fastened to a male screw and exerts a locking function. For example, a lock nut described in Japanese Patent Application Laid-Open No. 11-148509 includes a deformable slot disposed in a direction transverse to the axis of a screw hole, and a nut provided at the bottom end and aligned in the axial direction with the slot. And a deformable member. And if a lock nut is attached to the circumference | surroundings of a threaded shaft, a nut deformation member will be engaged with a workpiece | work, a lock nut will be deformed, and it will hold | maintain a lock nut around a shaft (patent document 1).

Japanese Patent Laid-Open No. 11-148509

  However, in the invention described in Patent Document 1, since it is necessary to provide a special and complicated member such as a nut deforming member, a machine for manufacturing the lock nut is necessary, and the manufacturing cost is increased. Becomes higher. Moreover, when trying to prepare various sizes and materials, there is a problem that the production line must be increased in accordance with the type and the cost is further increased.

  In addition, competition for lock nuts is fierce, and nuts with a wide variety of special shapes and complex structures / combinations have been proposed, all of which have a high anti-loosening effect sufficient to meet the needs of the site. The reality is that no product has been developed that is compatible with low cost.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a lock nut that can be manufactured at a low cost while exhibiting an extremely high locking effect.

  The feature of the lock nut according to the present invention is that a split slit that divides the screw hole vertically from the side surface on the upper side of the nut, a lock resistance applying portion formed on the upper side by the split slit, and the bottom surface of the nut A lock pin insertion hole that penetrates to the split slit and a lock pin that is inserted into the lock pin insertion hole and can press the lock resistance applying portion upward when the nut is fastened.

  The lock nut according to the present invention is characterized by a female screw hole having the same pitch as the screw hole of the lock target nut to be loosened and having three or less threads, and a smaller diameter than the outer edge of the lock target nut. It has an outer edge portion and a locking projection that protrudes from the outer edge portion at a predetermined downward inclination angle and comes into contact with the upper end surface of the lock target nut.

  Further, the lock nut according to the present invention is characterized in that a female screw hole having three or less threads is formed at the same pitch as the screw hole of the lock target nut to be locked, and the upper end surface of the lock target nut. A locking step portion that abuts against the upper end surface of the nut to be locked is formed on a part of the bottom surface facing the nut.

  According to the present invention, the return torque is higher than the tightening torque, and a high locking effect that is unthinkable by conventional lock nuts can be obtained, and it is easily manufactured by processing a commercially available nut. Therefore, it is possible to manufacture at an extremely low cost.

  Hereinafter, a lock nut according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a lock nut 1A of the first embodiment, and FIG. 2 is a cross-sectional view taken along line 2A-2A of FIG.

  As shown in FIGS. 1 and 2, the lock nut 1 </ b> A of the first embodiment is obtained by processing a commercially available hexagonal nut, and is mainly divided slits formed on the upper side of the nut. 2, a lock resistance applying portion 3 formed on the upper side by the division slit 2, a lock pin insertion hole 4 penetrating into the division slit 2, and a lock pin 5 inserted into the lock pin insertion hole 4 have.

  Hereinafter, each component will be described in more detail. As shown in FIGS. 1 and 2, the split slit 2 is formed so as to divide the screw hole 6 vertically from the side surface 11 on the upper side of the nut, and the upper portion of the nut is configured as the lock resistance applying portion 3. It has become.

  In the first embodiment, the split slit 2 is formed at a position where it is converted into the pitch of the screw hole 6 from the upper end surface 12 of the nut in consideration of the balance of deformability and strength of the lock resistance applying portion 3. It is set at a lower position by a distance of about half, and is formed in a direction substantially perpendicular to the axial direction of the screw hole 6. This is because if the formation position of the split slit 2 is too low, the lock resistance applying portion 3 becomes thick and difficult to deform, so that a strong tightening torque is required as described later, and the lock resistance may be insufficient. is there. Further, if the formation position of the split slit 2 is too high, the lock resistance application portion 3 becomes thin and easily breaks, so that the lock resistance may also be reduced.

  In addition, the split slit 2 only needs to be formed so that at least a part of the screw hole 6 is split up and down, but in the first embodiment, the balance of deformability and strength of the lock resistance applying portion 3 is balanced. Considering this, as shown in FIG. 2, the entire screw hole 6 is formed so as to be divided vertically. This is because if the split slit 2 is too shallow, the lock resistance applying portion 3 is not easily deformed, and if the split slit 2 is too deep, the support portion of the lock resistance applying portion 3 is weakened and may be broken. .

  The lock pin insertion hole 4 is a hole for inserting the lock pin 5 and is formed so as to penetrate from the bottom surface 13 of the nut to the split slit 2. In the first embodiment, the lock pin insertion hole 4 is drilled along the axial direction of the screw hole 6, and is formed at a position corresponding to the vicinity of the tip of the lock resistance applying portion 3. Thereby, the torque which the lock resistance provision part 3 receives from the lock pin 5 becomes large, and it deform | transforms effectively even with a slight pressing force.

  The lock pin 5 is made of a strong quenching material or the like, has a cross-sectional shape that can be inserted into the lock pin insertion hole 4, and has a length that can press the lock resistance applying portion 3 upward when the nut is fastened. Has been. In the first embodiment, since the lock pin insertion hole 4 is formed along the axial direction of the screw hole 6, the length of the lock pin 5 is from the bottom surface 13 of the nut to the ceiling surface of the split slit 2, that is, the lock The distance is set to a distance to the lower surface 31 of the resistance applying portion 3 plus a length of about half the pitch of the screw holes 6. In addition, the lock pin 5 should just have required hardness according to the material of the lock nut 1A main body.

  With such a configuration, when the lock pin 5 is inserted until it comes into contact with the lower surface 31 of the lock resistance applying portion 3, the lower end portion 51 of the lock pin 5 protrudes from the bottom surface 13 of the lock nut 1A. Yes. When the nut is fastened, a pressing force is applied to the protruding lower end 51 from the fastening object, so that the lock pin 5 moves upward, and the upper end 52 of the lock pin 5 moves on the lower surface 31 of the lock resistance applying portion 3. By pressing, the lock resistance applying portion 3 is deformed to warp upward.

  In addition, in this 1st Embodiment, although the lock pin insertion hole 4 is formed along the axial direction of the screw hole 6, it is not restricted to this, You may incline a little. In this case as well, when the lock pin 5 is fitted until it contacts the lower surface 31 of the lock resistance applying portion 3, the lower end portion 51 of the lock pin 5 may be set to a length protruding from the bottom surface 13 of the lock nut 1A. . However, if the lock pin 5 is too short, the lower surface 31 of the lock resistance applying portion 3 cannot be pressed sufficiently. Conversely, if the lock pin 5 is too long, the lock pin 5 itself may be deformed, Care must be taken because the lower end 51 does not completely fit into the lock pin insertion hole 4 and the lock nut 1A itself may not be seated on the fastener.

  Further, in the first embodiment, the lock pin 5 is formed in a substantially cylindrical shape, but is not completely linear, and a slight angle (about 1 ° to about 1 ° to within a range in which the lock pin 5 can be inserted into the lock pin insertion hole 4. 2 °). Thereby, moderate frictional resistance arises between the lock pin 5 and the lock pin insertion hole 4, and the inserted lock pin 5 does not fall out. An uneven surface may be formed on the outer peripheral surface of the lock pin 5 for the same effect.

  When manufacturing the lock nut 1A of the first embodiment as described above, it can be manufactured by various methods. For example, a commercially available normal nut is prepared, and a milling cutter or the like is prepared from the side surface 11 on the upper side. The lock resistance applying portion 3 is formed by forming a slit 2 with a slit. Subsequently, a lock pin insertion hole 4 that is drilled from the bottom surface 13 of the nut with a drilling machine or the like and penetrates to the split slit 2 is formed. Then, a separately processed lock pin 5 is pushed into the lock pin insertion hole 4 and is inserted until it comes into contact with the lower surface 31 of the lock resistance applying portion 3. Thus, the lock nut 1A of the first embodiment is manufactured.

  Next, the operation of the lock nut 1A according to the first embodiment having the above-described configuration will be described with reference to the drawings.

  First, when the fastened object Y is fastened to the fastened object X by the lock nut 1A of the first embodiment, as shown in FIG. 3A, the male screw B that communicates the fastened object X and the fastened object Y. The lock nut 1 </ b> A is screwed together through the washer W, and is screwed until the lower end portion 51 of the lock pin 5 contacts the surface of the washer W. At this time, since the screw hole 6 of the lock nut 1A is only partially cut away by the split slit 2, there is almost no resistance when screwing, and a normal hexagon nut is screwed. There is no change.

  Subsequently, as shown in FIG. 3B, when the lock nut 1A is further tightened by a fastening tool such as a spanner, the lock nut 1A is screwed downward along the male screw B while the lock pin 5 is a washer. The downward movement is restricted by W. For this reason, the lower end portion 51 of the lock pin 5 receives an upward pressing force by the reaction force from the washer W and moves upward, and the upper end portion 52 of the lock pin 5 presses the lower surface 31 of the lock resistance applying portion 3. As a result, the lock resistance applying unit 3 is bent upward from the normal state shown in FIG. 4A with the dividing slit 2 as a boundary, and therefore, as shown in FIG. The screw hole 6 is pressed by the male screw B.

  Then, as shown in FIG. 3C, the lock resistance applying portion 3 is half pitch according to the length of the lock pin 5 by being tightened until the bottom surface 13 of the lock nut 1 </ b> A comes into close contact with the surface of the washer W. The female screw surface of the screw hole 6 is strongly pressed against the screw surface of the male screw B to generate a large frictional resistance, thereby exhibiting a high loosening prevention effect.

“Example: Tightening torque and return torque”
In this example, an experiment was conducted to measure the tightening torque and return torque by the lock nut 1A of the first embodiment. The lock nut 1A used in this experiment was a hot-dip galvanized one having a screw size of M12 and a pitch of 1.75. As a comparative example, commercially available hex nuts of the same size and pitch and made of hot dip galvanizing and UNIQLO plating were used. And after tightening all these three types of nuts with the same tightening torque (43 N · m), the return torque was measured. The result is shown in FIG.

  As shown in FIG. 5, in the hot-dip galvanized and UNIQLO plated commercial products, the tightening torque is 43 N · m, the return torque is 41 N · m, and 31 N · m, respectively. The ratios were 95% and 72%, respectively. On the other hand, in the lock nut 1A according to the first embodiment, the tightening torque is 43 N · m, but the return torque is 50 N · m, and the ratio of the return torque to the tightening torque is 116%. did. In view of the common sense in the industry that the return torque is considered not to exceed the tightening torque, it can be seen how excellent the effect of the lock nut 1A of the first embodiment is.

  For reference, data on tightening torque and return torque for E-nut (made by Showa Seisakusho Co., Ltd.) and idling (IDA ring) widely used as a lock nut as commercially available products other than the above are listed in the catalog. The numerical values are extracted and shown in FIG. As shown in FIG. 6, none of the products has a return torque exceeding the tightening torque. Therefore, it can be seen that the lock nut 1A of the first embodiment has an extremely high locking effect exceeding the common sense of the industry.

According to the first embodiment as described above,
1. Although it has a simple configuration, it is possible to exhibit a high locking effect that requires a return torque higher than the tightening torque.
2. This can be realized by simply processing a commercially available nut, and can produce various sizes and materials easily at low cost.

  Next, a second embodiment of the lock nut 1B according to the present invention will be described. In addition, the same code | symbol is attached | subjected about the structure equivalent to the structure of 1st Embodiment mentioned above among the structures of this 2nd Embodiment, and the description is abbreviate | omitted.

  7 and 8 are a plan view and a left side view showing the lock nut 1B of the second embodiment. 9 is a cross-sectional view taken along line 9A-9A in FIG. The lock nut 1B of the second embodiment is of a type that exerts a loosening prevention function by being superimposed and fastened on top of a normal nut.

  As shown in FIGS. 7 to 9, the lock nut 1B of the second embodiment is formed in a substantially hexagonal shape in plan view, and has the same pitch as the screw holes 6 of the lock target nut N to be locked. The female screw hole 7 is provided. The thickness of the lock nut 1B is preferably formed in such a thickness that the thread of the female screw hole 7 is 3 threads or less in consideration of the balance between elastic deformability and strength of the lock nut 1B itself. In the embodiment, it is formed to a thickness of two peaks. This is because if the thickness is four or more, the torque at the time of tightening becomes too large, and the bending stress applied to the male screw becomes large.

  Further, the outer edge portion 8 of the lock nut 1B is formed to have a smaller diameter than the outer edge portion of the lock target nut N, and one locking projection 9 is formed protruding from the outer edge portion 8. The locking protrusion 9 protrudes at a predetermined downward inclination angle, and its tip 91 extends downward from the bottom surface 14 of the lock nut 1B.

  When the lock target nut N is prevented from being loosened using the lock nut 1B of the second embodiment configured as described above, first, the lock target nut N is screwed onto the male screw B as shown in FIG. And rotate until it abuts against the fastener X. Subsequently, when the lock nut 1B is screwed into the male screw B and rotated, as shown in FIG. 10 (b), the lock protrusion protruded from the outer edge portion 8 having a smaller diameter than the outer edge portion of the lock target nut N. 9 stops when the leading end 91 of the 9 abuts against the upper end surface of the nut N to be locked.

  When the lock nut 1B is further tightened by a fastening tool such as a spanner, the lock nut 1B is screwed downward along the male screw B, while the lock protrusion 9 is moved downward by the upper end surface of the lock target nut N. Is regulated. For this reason, as shown in FIG. 10C, the lock nut 1B is inclined so that the side on which the locking projection 9 is formed can be lifted. As a result, the female screw surface of the female screw hole 7 of the lock nut 1B is strongly pressed against the screw surface of the male screw B to generate a large frictional resistance, thereby exhibiting a loosening prevention effect.

  According to the second embodiment as described above, the lock target nut N can be prevented from loosening with a simple configuration and low cost.

  Next, a third embodiment of the lock nut 1C according to the present invention will be described. In addition, the same code | symbol is attached | subjected about the structure equivalent to the structure of each embodiment mentioned above among the structure of this 3rd Embodiment, or it abbreviate | omits description.

  FIG. 11 and FIG. 12 are a front view and a sectional view showing a lock nut 1C of the third embodiment. As in the second embodiment, the lock nut 1C of the third embodiment is of a type that is fastened on top of a normal nut and exerts a locking function.

  As shown in FIGS. 11 and 12, the lock nut 1C according to the third embodiment is formed in a hexagonal shape in plan view, and has the same pitch as the screw holes 6 of the lock target nut N to be locked. A female screw hole 7 is provided. In the third embodiment, the thickness of the lock nut 1 </ b> C is formed such that the screw thread of the female screw hole 7 is 3 threads or less, as in the second embodiment.

  Further, a locking step 10 is formed on a part of the bottom surface 15 of the lock nut 1C so as to abut on the upper end surface of the lock target nut. In the third embodiment, the locking step portion 10 is formed so as to protrude along the axial direction of the female screw hole 7, and its tip portion 101 extends below the bottom surface 15 of the lock nut 1 </ b> C. .

  When locking the lock target nut N using the lock nut 1C of the third embodiment configured as described above, the lock target nut N is screwed into the male screw B as in the second embodiment, and the fastener X Then, the lock nut 1C is screwed onto the male screw B and rotated. As a result, the front end 101 of the locking step 10 protruding downward from the bottom surface 15 of the lock nut 1 </ b> C stops when it comes into contact with the upper end surface of the lock target nut N.

  When the lock nut 1C is further tightened with a fastening tool such as a spanner, the lock nut 1C is screwed downward along the male screw B, while the locking step portion 10 is lowered below the upper end surface of the lock target nut N. Movement is restricted. Therefore, as shown in FIG. 13, the lock nut 1C is inclined so that the side on which the locking step 10 is formed can be lifted. As a result, the female screw surface of the female screw hole 7 of the lock nut 1C is strongly pressed against the screw surface of the male screw B to generate a large frictional resistance.

  According to the third embodiment as described above, the same operational effects as those of the second embodiment can be obtained.

  The lock nuts 1A, 1B, and 1C according to the present invention are not limited to the above-described embodiments, and can be changed as appropriate.

  For example, in each of the above-described embodiments, the hexagonal lock nuts 1A, 1B, and 1C have been described. However, the present invention is not limited to this, and any rectangular shape, pentagon, or round shape can be used as long as the shape can be rotated by a fastening tool. Other shapes may be used.

  Moreover, in each embodiment mentioned above, although the normal metal nut is processed and lock nut 1A, 1B, 1C is manufactured, it is not restricted to this, Processing resin, such as a reinforced plastic, It may be manufactured by molding.

It is a perspective view showing a 1st embodiment of a lock nut concerning the present invention. It is the 2A-2A sectional view taken on the line in FIG. It is explanatory drawing which shows the usage method of the lock nut of this 1st Embodiment. In the lock nut of the first embodiment, (a) an enlarged view of a partial cross section before and after (b) fastening. It is a figure which shows the experimental result by a present Example. It is a figure which shows the data regarding a commercially available lock nut. It is a top view which shows the lock nut of this 2nd Embodiment. It is a left view which shows the lock nut of this 2nd Embodiment. It is the 9A-9A sectional view taken on the line in FIG. It is explanatory drawing which shows the usage method of the lock nut of this 2nd Embodiment. It is a front view which shows the lock nut of this 3rd Embodiment. It is sectional drawing of FIG. It is a figure which shows the state which fastened the lock nut of this 3rd Embodiment.

Explanation of symbols

1A, 1B, 1C Lock nut 2 Split slit 3 Lock resistance applying portion 4 Lock pin insertion hole 5 Lock pin 6 Screw hole 7 Female screw hole 8 Outer edge portion 9 Locking protrusion 10 Locking step portion 11 Nut side surface 12 Nut upper end surface 13 Nut bottom 14 Lock nut bottom (second embodiment)
15 Bottom face of lock nut (third embodiment)
31 Lower surface of lock resistance applying portion 51 Lower end portion of lock pin 52 Upper end portion of lock pin 91 Tip end portion of lock projection 101 Tip end portion of lock step B B Male screw N Lock target nut W Washer X Fastener Y Fastened object

Claims (3)

A split slit that splits the screw hole up and down from the side of the upper side of the nut;
A lock resistance applying portion formed on the upper side by the divided slit;
A lock pin insertion hole penetrating from the bottom surface of the nut to the split slit;
A lock nut having a lock pin inserted into the lock pin insertion hole and capable of pressing the lock resistance applying portion upward when the nut is fastened. A female screw hole having the same pitch as the screw hole of the lock target nut to be locked and having three or less threads,
An outer edge part having a smaller diameter than the outer edge part of the nut to be locked;
A lock nut having a locking protrusion protruding from the outer edge portion at a predetermined downward inclination angle and abutting against an upper end surface of the lock target nut.   A female screw hole having three or less threads is formed at the same pitch as the screw hole of the lock target nut to be locked, and the lock target is formed on a part of the bottom surface facing the upper end surface of the lock target nut. A lock nut characterized by forming a step portion for locking that abuts on the upper end surface of the nut.

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