JP2014126159A - Device for preventing loosening of nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for preventing loosening of a nut, which securely exhibits a function of preventing loosening of the nut, has high operability, and is reduced in cost.SOLUTION: A device for preventing loosening of a nut, includes a bolt 14 for fixing members to be fixed 11 and 12, a first nut 16, and a second nut 18. The first nut 16 includes a small-diameter portion 34 that protrudes to a side opposite to the member to be fixed 12 and has a taper face 34a whose diameter decreases toward the tip end side thereof. A tapered fitting face 38 to be fitted to the small-diameter portion 34 of the first nut 16 is formed in the second nut 18, and the second nut 18 is screwed to the bolt 14. The members to be fixed 11 and 12 are fastened by the first nut 16, and the second nut 18 is fastened while the fitting face 38 of the second nut 18 is fitted to the small-diameter portion 34 of the first nut 16, so that the small-diameter portion 34 of the first nut 16 is reduced in diameter to be press-contacted to the bolt 14.

Description

  The present invention relates to a nut locking device that prevents a nut from being loosened by screwing onto a bolt to fasten and fix a member to be fastened.

  Conventionally, tightening with a double nut is generally used as a nut locking method. However, as a more reliable locking mechanism, there has been a locking device in which various ideas are formed on the nut.

  For example, a nut locking device disclosed in Patent Document 1 includes a nut formed with a projecting portion having a truncated cone-shaped tapered surface, and a nut having a recess into which the tapered surface of the nut is fitted. A pair of nuts are provided, and one female screw portion is provided eccentrically in a direction orthogonal to the screw axis with respect to the central axes of the protrusions and recesses of the pair of nuts. As a result, when one nut is tightened with respect to the other, the eccentric female screw portion is pressed in the thread direction on one side of the male screw portion of the bolt in which one nut and the other nut are screwed together. The frictional force between the screws that are screwed together becomes strong and exhibits a loosening prevention effect.

  In the locking nut disclosed in Patent Document 2, the nut outer diameter portion between at least a pair of longitudinal grooves of the outer peripheral portion of the nut divided by a plurality of longitudinal grooves is pressed and deformed in the radial direction to reduce the diameter. In the state of being screwed into the bolt, the reduced diameter portion is elastically deformed by the bolt to be expanded in diameter, and the nut is securely held. Furthermore, since it expands and contracts by elastic deformation even when it is attached and detached multiple times, it exhibits a stable locking effect.

  In addition, as disclosed in Patent Documents 3 and 4, a nut fixing structure is also proposed in which a nut that is divided into two in the axial direction of the screw shaft and has a tapered portion on the outer surface is fitted into the tapered portion from the outside and tightened. Has been. The nut of this structure can be directly attached to the middle position of the long bolt to fix the object, and the taper portion ensures the tightening of the nut. .

JP 61-244912 A JP 2001-334343 A Japanese Unexamined Patent Publication No. 7-19225 JP-A-11-93933

  However, in the nut locking device disclosed in Patent Document 1, the screw threads are pressed on one side of the bolt and the nut by the eccentric female screw of the pair of nuts. The contact portion is biased to one side of the peripheral surface of the bolt and nut, and as a result, the coupling strength between the bolt and nut is weakened.

  In the locking nut disclosed in Patent Document 2, the side surface of the nut is plastically deformed by press molding to partially form a reduced diameter portion, and when screwing with a bolt, the reduced diameter portion is elastically deformed to expand the diameter. Therefore, there was a problem in durability and reliability of the plastic deformation portion. Furthermore, it is difficult to set the dimensions of plastic deformation at the time of manufacture and elastic deformation at the time of use, and a high-precision nut is required for a high-quality nut, which is expensive and difficult to manufacture.

  Furthermore, the split nuts disclosed in Patent Documents 3 and 4 are easy to attach in the middle of a long bolt, and are not expected to prevent the nut from loosening. Moreover, handling is troublesome, and this structure cannot be applied to a nut locking device as it is.

  The present invention has been made in view of the above background art, and an object of the present invention is to provide a nut locking device that reliably exhibits a nut locking function, has good operability, and is inexpensive.

  The present invention provides a nut locking device that is held by a pair of nuts when a fixed member is clamped and fixed by a bolt and a nut, and includes a first nut that is screwed into a male screw portion of the bolt. The first nut is formed with a small-diameter portion that protrudes on the opposite side to the fixed member and has a tapered surface that decreases in diameter toward the tip side, and is fitted to the small-diameter portion of the first nut. And a second nut that is screwed into the male thread portion of the bolt, and the fitting surface of the first nut and the fitting surface of the second nut are female of each nut. The second nut is formed coaxially with the threaded portion, tightens the fixed member with the first nut, and engages the fitting surface of the second nut with the small-diameter portion of the first nut. Tighten the second nut A locking device of the nut to be pressed against the male threaded portion of the bolt by diameter of the small diameter portion of the first nut by fit with.

  A through slit that penetrates the female screw portion is formed in the small diameter portion of the first nut. Furthermore, the through slit of the nut may have one slit penetrating in the axial direction of the first nut.

  A washer is provided between the first nut and the fixed member, the first nut side surface of the washer includes a tapered portion that is a tapered concave surface, and faces the washer of the first nut. A convex tapered surface that is in surface contact with the tapered portion is formed on the end surface.

  The first nut has a female screw portion of a right-hand thread, the second nut has a female screw portion of a left-hand screw, and a male screw of a right screw is provided at a portion where the first nut of the bolt is screwed. A portion where the second nut is formed is formed with a left-handed male screw.

  According to the nut locking device of the present invention, the nut locking function can be exhibited by a simple operation, and the manufacturing is easy and the cost is low.

  In particular, when a slit is formed in the small diameter portion of the first nut, the effect of reducing the diameter of the first nut is large, and the female screw portion of the first nut is more securely pressed against the male screw portion of the bolt and is surely loosened. Demonstrate the stopping effect.

  Further, when the first nut is a right-hand thread and the second nut is a left-hand thread, the first nut is reliably prevented from loosening against the force in the loosening direction of the first nut, and the effect of preventing loosening is high.

It is a partially broken right side view of the nut locking device of the first embodiment of the present invention. It is an exploded right side view of the nut locking device of the first embodiment. It is the right side view (a) of the first nut of the nut locking device of the first embodiment, the partially broken right side view (b), and the rear view (c). It is a right side view (a), a partially broken right side view (b), and a rear view (c) of the second nut of the nut locking device of the first embodiment. It is the right view (a) which shows the other example of the 1st nut used for the nut locking device of 1st embodiment, the partial fracture | rupture right view (b), and a rear view (c). It is a partially broken right side view of the nut locking device of the second embodiment of the present invention. It is a decomposition | disassembly right view of the locking device of the nut of 2nd embodiment. It is the right view (a) of the 1st nut of the nut locking device of 2nd embodiment, the partially broken right view (b), and the rear view (c). It is a partially broken right side view of the nut locking device of the third embodiment of the present invention. It is a decomposition | disassembly right view of the nut locking device of 3rd embodiment. It is the right side view (a) of the first nut of the nut locking device of the third embodiment, the partially broken right side view (b), and the rear view (c). It is a partially broken right side view of the nut locking device of the fourth embodiment of the present invention. It is a decomposition | disassembly right view of the locking device of the nut of 4th embodiment. It is a decomposition | disassembly right view of the locking device of the nut of 5th embodiment of this invention. It is a decomposition | disassembly right view of the locking device of the nut of 5th embodiment. It is the right view (a) of the 1st nut of the nut locking device of 5th embodiment, the partially broken right view (b), and the rear view (c).

  Embodiments of the nut locking device of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of the present invention. A nut locking device 10 of this embodiment has, for example, through holes 11a and 12a, and fixed members 11 and 12 that are fixed to each other. And comprises a bolt 14, a first nut 16, and a second nut 18.

  As shown in FIGS. 1 and 2, the bolt 14 includes a head 20, a right screw portion 22 located on the lower surface side of the head 20, and an end of the right screw portion 22, and then the right screw portion 22. An outer diameter is formed with a valley diameter, and a left-hand thread portion 24 extending to the tip is provided.

  The first nut 16 is screwed on the opposite side of the head 14 of the bolt 14 with the washer 26 sandwiched between the fixed members 11 and 12. The first nut 16 has a right-handed female screw portion 30, a large-diameter portion 32 whose outer shape is formed in a hexagonal column shape is located on the fixed member 12 side, and a small-diameter portion whose diameter is smaller than that of the large-diameter portion 32. 34 projects from the opposite side and is screwed onto the bolt 14. The small-diameter portion 34 includes a tapered surface 34a having a one-step diameter that is smaller than that of the large-diameter portion 32 and further becoming tapered toward the end surface. The female screw portion 30 of the first nut 16 is a normal screw near the opening of the large-diameter portion 32, and the other portion is a hard screw.

  The outer shape of the second nut 18 is formed in a hexagonal column shape, and a tapered fitting surface 38 that fits and contacts the small diameter portion 34 of the first nut 16 is formed, and the taper of the small diameter portion 34 of the first nut 16 is formed. It is fitted and attached to the surface 34a. The second nut 18 has a left-handed female screw portion 40 having a smaller diameter than the female screw portion 30 of the first nut 16 and an inner diameter of the female screw portion 30 equal to the valley diameter. Further, the tapered surface 34 a of the first nut 16 and the fitting surface 38 of the second nut 18 are formed coaxially with the female thread portions of the first and second nuts 16 and 18.

  As shown in FIG. 1, the nut locking device 10 according to this embodiment is used by inserting bolts 14 into the through holes 11 a and 12 a of the fixed members 11 and 12 and the head 20 to the fixed member 11. The washer 26 is fitted to the bolt 14, the female screw portion 30 of the first nut 16 is screwed into the right screw portion 22, and the fixed members 11 and 12 are fastened and fixed by the first nut 16. . Further, the second nut 18 is screwed into the left screw portion 24 of the bolt 14.

  Here, the length of the right screw portion 22 of the bolt 14 is set according to the thickness of the fixed members 11 and 12 to be fixed, and is fixed to the left from the first nut 16 while being fixed by the first nut 16. It is sufficient that the screw portion 24 is exposed.

  The second nut 18 screwed into the left threaded portion 24 of the bolt 14 is fitted to the tapered surface 34a of the first nut 16, and the fitting surface 38 of the second nut 18 is changed to the first by tightening the second nut 18. The first nut 16 is pressed against the tapered surface 34a of the one nut 16 and pressed in the reduced diameter direction. As a result, the inner diameter of the small diameter portion 34 of the first nut 16 is compressed and contracted by elastic deformation, and the female screw portion 30 of the first nut 16 is firmly pressed against the right screw portion 22 of the bolt 14.

  In this state, even if a force in the loosening direction acts on the first nut 16 of the right screw, even if it is pressed by the second nut 18 of the left screw and the force in the loosening direction is transmitted to the second nut 18, that direction Since this force is in the tightening direction, the second nut 18 does not loosen, and the first nut 16 does not loosen. Furthermore, since the second nut 18 is tightened, the small diameter portion 34 of the first nut 16 is pressed so as to be in pressure contact with the entire circumference of the right screw portion 22 of the bolt 14. , 18 are in strong contact with each other over the entire circumference, a strong frictional force is generated, and there is no loosening, and the strength against the load is high.

  According to the nut locking device 10 of this embodiment, the first and second nuts 16 and 18 can exert a reliable locking effect, and the thread of the first and second nuts 16 and 18 can be demonstrated. As a whole, it can receive force and has high strength and durability against tightening and external loads.

  As shown in FIG. 5, the first nut 16 may be formed with one full through slit 42 penetrating from the outer surface to the female screw portion 30 in the screw axis direction.

  Thereby, by the tightening by the second nut 18, the action in the diameter reducing direction by the tapered surface 34 a extends to the entire first nut 16, and the tightening effect to the right screw portion 22 of the bolt 14 is obtained even in the large diameter portion 32 portion. Has a more secure locking function.

  Next, a nut locking device 50 according to a second embodiment of the present invention will be described with reference to FIGS. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and a part of the description is omitted. The nut locking device 50 of this embodiment also holds the fixed members 11 and 12 to be fixed to each other, and includes a bolt 14, a first nut 16, and a second nut 18.

  As shown in FIGS. 6 and 7, the bolt 14 continues from the right screw portion 22 and the end portion of the right screw portion 22, and has an outer diameter formed by the thickness of the valley diameter of the right screw portion 22 and continues to the tip. A left-hand thread portion 24 is provided.

  The first nut 16 is screwed onto the opposite side of the bolt 14 from the head 20 with the washer 52 sandwiched between the fixed members 11 and 12. The first nut 16 has a right-handed female screw portion 30, a large-diameter portion 32 whose outer shape is formed in a hexagonal column shape is located on the fixed member 12 side, and a small-diameter portion whose diameter is smaller than that of the large-diameter portion 32. 34 projects from the opposite side and is screwed onto the bolt 14. The small-diameter portion 34 includes a tapered surface 34a having a one-step diameter that is smaller than that of the large-diameter portion 32 and further becoming tapered toward the end surface.

  The first nut 16 of this embodiment is a convex taper surface in which the tapered portion 32a of the first nut 16 is fitted and brought into surface contact with the end surface of the large diameter portion 32 on the fixed member 12 side. A tapered surface 32a that is gently inclined toward the opening of the portion 30 is formed. A concave tapered portion 52a corresponding to the tapered surface 32a is provided on the surface of the washer 52 that the first nut 16 faces, and is provided so as to be able to fit in surface contact with each other. Further, as shown in FIG. 8, the first nut 16 is formed with six through slits 54 penetrating from the tapered surface 34 a of the small diameter portion 34 to the female screw portion 40, one of which is large. It is a full penetration slit 56 that penetrates the diameter portion 32.

  The second nut 18 is the same as that of the above-described embodiment. The second nut 18 is formed with a tapered fitting surface 38 that is fitted to the small diameter portion 34 of the first nut 16, and further has a female screw portion 40 of a left screw. Yes. In the female screw portion 40, the vicinity of the opening of the large diameter portion 32 is a normal screw, and the other portion is a hard screw.

  As shown in FIG. 6, the nut locking device 50 of this embodiment is used by inserting bolts 14 into the through holes 11 a and 12 a of the fixed members 11 and 12 as shown in FIG. The washer 52 is fitted to the screw part, the female screw part 30 of the first nut 16 is screwed into the right screw part 22, and the fixed members 11 and 12 are fastened and fixed. Further, the second nut 18 is screwed into the left screw portion 24 of the bolt 14.

  At this time, the second nut 18 screwed into the left screw portion 24 is fitted to the tapered surface 34a of the first nut 16, and the fitting surface 38 of the second nut 18 is tightened by tightening the second nut 18. It contacts the tapered surface 34a of the first nut 16 and presses it in the direction of diameter reduction. Thereby, the inner diameter of the small diameter portion 34 of the first nut 16 divided by the through slit 54 is reliably reduced. Further, the large-diameter portion 32 is reliably reduced in diameter together with the tightening by the all-through slit 56, the tapered portion 52a of the washer 52 and the tapered surface 32a of the first nut 16, and the first nut 16 is connected to the right screw portion 22 of the bolt 14. The entire female screw portion 30 is pressed more firmly.

  In this state, even if a force in the loosening direction acts on the first nut 16 of the right screw, the first nut 16 does not loosen because the second screw 18 of the left screw is in the tightening direction. Furthermore, since the entire female screw portion 30 of the first nut 16 is pressed by the second nut 18 so as to be in pressure contact with the entire circumference of the right screw portion 22 of the bolt 14, the screw portions are strongly tightened over the entire circumference. It abuts and generates a stronger frictional force that does not loosen.

  According to the nut locking device 50 of this embodiment, the same effects as those of the above embodiment can be obtained, and a more reliable locking effect can be exhibited.

  Next, a nut locking device 60 according to a third embodiment of the present invention will be described with reference to FIGS. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and a part of the description is omitted. The nut locking device 60 of this embodiment also holds the fixed members 11 and 12 to be fixed to each other, but the left screw portion 64 of the bolt 14 is formed to have the same outer diameter as the right screw portion 62. It is.

  As shown in FIG. 11, the first nut 66 of this embodiment is a split nut that is divided into two pieces 66 a and 66 b in the screw axis direction, and the right screw portion at the position of the right screw portion 62 of the bolt 14. Wear so that 62 is inserted. In the second nut 18, the tapered fitting surface 38 of the left-handed second nut 18 similar to the above embodiment is fitted and fixed to the tapered surface 32 a of the small diameter portion 32 of the first nut 66. The first nut 66 is good enough to have a slight gap between the split pieces 66a and 66b when the first nut 66 is attached to the right thread portion 22. Thereby, the loosening prevention effect by the fastening mentioned later is exhibited well.

  In the nut locking device 60 of this embodiment, the bolt 14 is inserted into the through holes 11a and 12a of the fixed members 11 and 12 and the washer 52 is fitted to the screw portion of the bolt 14 as in the above embodiment. The fixed members 11 and 12 are fastened and fixed by the second nut 18 by screwing into the female screw portion 30 of the first nut 66. Tightening is performed by screwing the second nut 18 into the left screw portion 24 of the bolt 14.

  At this time, similarly to the second embodiment, the diameter is reduced by the tapered surface 34a of the first nut 66 and the fitting surface 38 of the second nut 18, and the tapered portion 52a of the washer 52 and the tapered surface 32a of the first nut 66. Thus, as the second nut 18 is tightened, the large-diameter portion 32 is also reliably reduced in diameter, and the female screw portion 30 of the first nut 66 is more firmly pressed against the right screw portion 22 of the bolt 14.

  According to the nut locking device 60 of this embodiment, the same effect as that of the above embodiment can be obtained, and the thickness of the threaded portion of the bolt 14 is constant, so that it is more convenient to use.

  Next, a nut locking device 70 according to a fourth embodiment of the present invention will be described with reference to FIGS. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and a part of the description is omitted. The nut locking device 70 of this embodiment also holds the fixed members 11 and 12 to be fixed to each other, but the bolt 14 uses a normal bolt formed only by the right screw portion 72.

  This embodiment uses a first nut 16 similar to the first nut 16 of the second embodiment shown in FIG. 8, and the second nut 18 has a female screw portion 40 with a right-hand thread. The one with the same shape is used.

  Similarly to the above-described embodiment, the nut locking device 70 of this embodiment is configured such that the bolt 14 is inserted into the through holes 11a and 12a of the fixed members 11 and 12, the washer 52 is fitted to the bolt 14, and the first The female screw portion 30 of the nut 16 is screwed into the right screw portion 72 and the fixed members 11 and 12 are fastened and fixed. Further, the second nut 18 is also screwed into the right thread portion 72 of the bolt 14.

  At this time, similarly to the above-described embodiment, due to the reduced diameter of the tapered surface 32a of the first nut 66 and the fitting surface 38 of the second nut 18, and the tapered portion 52a of the washer 52 and the tapered surface 32a of the first nut 66, As the second nut 18 is tightened, the small-diameter portion 34 and the large-diameter portion 32 are also reliably reduced in diameter, so that the female screw portion 30 of the first nut 66 is more firmly pressed against the right screw portion 72 of the bolt 14.

  According to the nut locking device 70 of this embodiment, the same effect as that of the above embodiment can be obtained, and the bolt 14 can be a normal right-screw only bolt and can be used more generally. Can be used, and it is easier to use.

  Next, a nut locking device 80 according to a fifth embodiment of the present invention will be described with reference to FIGS. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and a part of the description is omitted. The nut locking device 80 of this embodiment also holds the fixed members 11 and 12 to be fixed to each other. As in the fourth embodiment, the bolt 14 is a normal bolt formed by only the right screw portion 72. Is used.

  In the first nut 82 of this embodiment, as shown in FIG. 16, six through slits 84 penetrating from the tapered surface 34 a of the small diameter portion 34 to a part of the large diameter portion 32 to the female screw portion 40 are equally spaced. It is formed.

  Similarly to the above-described embodiment, the nut locking device 80 of this embodiment is configured such that the bolt 14 is inserted into the through holes 11a and 12a of the fixed members 11 and 12 and the washer 26 is fitted to the bolt 14 so that the first The female screw portion 30 of the nut 82 is screwed into the right screw portion 72 and the fixed members 11 and 12 are fastened and fixed. Further, the second nut 18 is also screwed into the right thread portion 72 of the bolt 14. At this time, similarly to the above-described embodiment, when the second nut 18 is tightened, the diameter of the small-diameter portion 34 of the first nut 82 is reduced by the tapered surface 32a of the first nut 82 and the fitting surface 38 of the second nut 18. Further, the diameter of the large-diameter portion 32 is partially reduced, and the female screw portion 30 of the first nut 82 is more firmly pressed against the right screw portion 72 of the bolt 14.

  According to the nut locking device 80 of this embodiment, the same effect as that of the above embodiment can be obtained, and the bolt 14 can be a normal right-screw only bolt and can be used more generally. Can be used, and it is easier to use.

  The nut locking device of the present invention is not limited to the above-described embodiment, and the number of through slits and the formation position of the slits of the first nut can be set as appropriate, and in the case of only a part of the small diameter portion or It can be set as appropriate according to the application and strength, such as a part extending from the small diameter part to a part of the large diameter part, or a combination of only the small diameter part and a slit extending to the large diameter part. Moreover, the washer to be used can be appropriately selected, such as a normal washer or one having a tapered portion.

10, 50, 60, 70, 80 Nut locking device 11.12 Fixed member 14 Bolt 16, 66, 82 First nut 18 Second nut 22 Right screw portion 24 Left screw portion 26, 52 Washer 30, 40 Female Threaded portion 32 Large diameter portion 32a, 34a Tapered surface 34 Small diameter portion 38 Fitting surface 42 56 All through slits 44, 54, 84 Through slit

  The present invention relates to a nut locking device that prevents a nut from being loosened by screwing onto a bolt to fasten and fix a member to be fastened.

  Conventionally, tightening with a double nut is generally used as a nut locking method. However, as a more reliable locking mechanism, there has been a locking device in which various ideas are formed on the nut.

  For example, a nut locking device disclosed in Patent Document 1 includes a nut formed with a projecting portion having a truncated cone-shaped tapered surface, and a nut having a recess into which the tapered surface of the nut is fitted. A pair of nuts are provided, and one female screw portion is provided eccentrically in a direction orthogonal to the screw axis with respect to the central axes of the protrusions and recesses of the pair of nuts. As a result, when one nut is tightened with respect to the other, the eccentric female screw portion is pressed in the thread direction on one side of the male screw portion of the bolt in which one nut and the other nut are screwed together. The frictional force between the screws that are screwed together becomes strong and exhibits a loosening prevention effect.

  In the locking nut disclosed in Patent Document 2, the nut outer diameter portion between at least a pair of longitudinal grooves of the outer peripheral portion of the nut divided by a plurality of longitudinal grooves is pressed and deformed in the radial direction to reduce the diameter. In the state of being screwed into the bolt, the reduced diameter portion is elastically deformed by the bolt to be expanded in diameter, and the nut is securely held. Furthermore, since it expands and contracts by elastic deformation even when it is attached and detached multiple times, it exhibits a stable locking effect.

  In addition, as disclosed in Patent Documents 3 and 4, a nut fixing structure is also proposed in which a nut that is divided into two in the axial direction of the screw shaft and has a tapered portion on the outer surface is fitted into the tapered portion from the outside and tightened. Has been. The nut of this structure can be directly attached to the middle position of the long bolt to fix the object, and the taper portion ensures the tightening of the nut. .

JP 61-244912 A JP 2001-334343 A Japanese Unexamined Patent Publication No. 7-19225 JP-A-11-93933

  However, in the nut locking device disclosed in Patent Document 1, the screw threads are pressed on one side of the bolt and the nut by the eccentric female screw of the pair of nuts. The contact portion is biased to one side of the peripheral surface of the bolt and nut, and as a result, the coupling strength between the bolt and nut is weakened.

  In the locking nut disclosed in Patent Document 2, the side surface of the nut is plastically deformed by press molding to partially form a reduced diameter portion, and when screwing with a bolt, the reduced diameter portion is elastically deformed to expand the diameter. Therefore, there was a problem in durability and reliability of the plastic deformation portion. Furthermore, it is difficult to set the dimensions of plastic deformation at the time of manufacture and elastic deformation at the time of use, and a high-precision nut is required for a high-quality nut, which is expensive and difficult to manufacture.

  Furthermore, the split nuts disclosed in Patent Documents 3 and 4 are easy to attach in the middle of a long bolt, and are not expected to prevent the nut from loosening. Moreover, handling is troublesome, and this structure cannot be applied to a nut locking device as it is.

  The present invention has been made in view of the above background art, and an object of the present invention is to provide a nut locking device that reliably exhibits a nut locking function, has good operability, and is inexpensive.

The present invention provides a nut locking device that is held by a pair of nuts when a fixed member is clamped and fixed by a bolt and a nut, and includes a first nut that is screwed into a male screw portion of the bolt. The first nut is formed with a small-diameter portion that protrudes on the opposite side to the fixed member and has a tapered surface that decreases in diameter toward the tip side, and is fitted to the small-diameter portion of the first nut. And a second nut that is screwed into the male thread portion of the bolt, and the fitting surface of the first nut and the fitting surface of the second nut are female of each nut. The first nut and the second nut are formed in the same direction as the screw portion, and the directions of the screws are opposite to each other. The first nut is a split nut divided into two in the axial direction of the female screw portion. The first nut of the bolt is screwed The male screw portion of the portion and the portion where the second nut is screwed are formed so that the direction of the screw of the male screw portion is reverse, and the diameter of each male screw portion in the reverse direction of the bolt is equal. While the fitting surface of the second nut is fitted to the small diameter portion of the first nut, the fixed member is tightened by the first nut, and the second nut is opposite to the first nut. It is a nut locking device that rotates in a direction and tightens, and the second nut is tightened to reduce the diameter of the small-diameter portion of the first nut and press-contact with the male screw portion of the bolt.

  A washer is provided between the first nut and the fixed member, the first nut side surface of the washer includes a tapered portion that is a tapered concave surface, and faces the washer of the first nut. A convex tapered surface that is in surface contact with the tapered portion is formed on the end surface.

  The first nut has a female screw portion of a right-hand thread, the second nut has a female screw portion of a left-hand screw, and a male screw of a right screw is provided at a portion where the first nut of the bolt is screwed. A portion where the second nut is formed is formed with a left-handed male screw.

  According to the nut locking device of the present invention, the nut locking function can be exhibited by a simple operation, and the manufacturing is easy and the cost is low.

  In particular, since the thickness of the threaded portion of the bolt is constant, it is more convenient to use and reliably exhibits a loosening prevention effect.

  Further, when the first nut is a right-hand thread and the second nut is a left-hand thread, the first nut is reliably prevented from loosening against the force in the loosening direction of the first nut, and the effect of preventing loosening is high.

It is a partially broken right side view of the nut locking device. It is a decomposition | disassembly right view of the locking device of a nut. It is the right side view (a) of the first nut of the nut locking device, the partially broken right side view (b), and the rear view (c). It is the right view (a) of the 2nd nut of a nut locking device, a partially broken right view (b), and a rear view (c). It is the right view (a) which shows the other example of the 1st nut used for the locking device of a nut, the partially broken right view (b), and a rear view (c). It is a partially broken right side view of another nut locking device. It is a decomposition | disassembly right view of the other nut locking device. It is the right view (a) of the first nut of the other nut locking device, the partially broken right view (b), and the rear view (c). It is a partially broken right side view of the nut locking device of the embodiment of the present invention. It is a decomposition | disassembly right view of the locking device of the nut of this embodiment. It is the right side view (a) of the first nut of the nut locking device of this embodiment, the partially broken right side view (b), and the rear view (c). It is a partially broken right side view of another nut locking device. It is an exploded right side view of other locking devices. It is a decomposition | disassembly right view of the other nut locking device. It is an exploded right side view of other locking devices. It is the right view (a) of the 1st nut of another locking device, the partial fracture right view (b), and the rear view (c).

  Hereinafter, embodiments of a nut locking device will be described with reference to the drawings. 1 to 4 show an embodiment. A nut locking device 10 according to this embodiment has, for example, through-holes 11a and 12a, and sandwiches fixed members 11 and 12 that are fixed to each other. And consisting of a bolt 14, a first nut 16, and a second nut 18.

  As shown in FIGS. 1 and 2, the bolt 14 includes a head 20, a right screw portion 22 located on the lower surface side of the head 20, and an end of the right screw portion 22, and then the right screw portion 22. An outer diameter is formed with a valley diameter, and a left-hand thread portion 24 extending to the tip is provided.

  The first nut 16 is screwed on the opposite side of the head 14 of the bolt 14 with the washer 26 sandwiched between the fixed members 11 and 12. The first nut 16 has a right-handed female screw portion 30, a large-diameter portion 32 whose outer shape is formed in a hexagonal column shape is located on the fixed member 12 side, and a small-diameter portion whose diameter is smaller than that of the large-diameter portion 32. 34 projects from the opposite side and is screwed onto the bolt 14. The small-diameter portion 34 includes a tapered surface 34a having a one-step diameter that is smaller than that of the large-diameter portion 32 and further becoming tapered toward the end surface. The female screw portion 30 of the first nut 16 is a normal screw near the opening of the large-diameter portion 32, and the other portion is a hard screw.

  The outer shape of the second nut 18 is formed in a hexagonal column shape, and a tapered fitting surface 38 that fits and contacts the small diameter portion 34 of the first nut 16 is formed, and the taper of the small diameter portion 34 of the first nut 16 is formed. It is fitted and attached to the surface 34a. The second nut 18 has a left-handed female screw portion 40 having a smaller diameter than the female screw portion 30 of the first nut 16 and an inner diameter of the female screw portion 30 equal to the valley diameter. Further, the tapered surface 34 a of the first nut 16 and the fitting surface 38 of the second nut 18 are formed coaxially with the female thread portions of the first and second nuts 16 and 18.

  As shown in FIG. 1, the nut locking device 10 according to this embodiment is used by inserting bolts 14 into the through holes 11 a and 12 a of the fixed members 11 and 12 and the head 20 to the fixed member 11. The washer 26 is fitted to the bolt 14, the female screw portion 30 of the first nut 16 is screwed into the right screw portion 22, and the fixed members 11 and 12 are fastened and fixed by the first nut 16. . Further, the second nut 18 is screwed into the left screw portion 24 of the bolt 14.

  Here, the length of the right screw portion 22 of the bolt 14 is set according to the thickness of the fixed members 11 and 12 to be fixed, and is fixed to the left from the first nut 16 while being fixed by the first nut 16. It is sufficient that the screw portion 24 is exposed.

  The second nut 18 screwed into the left threaded portion 24 of the bolt 14 is fitted to the tapered surface 34a of the first nut 16, and the fitting surface 38 of the second nut 18 is changed to the first by tightening the second nut 18. The first nut 16 is pressed against the tapered surface 34a of the one nut 16 and pressed in the reduced diameter direction. As a result, the inner diameter of the small diameter portion 34 of the first nut 16 is compressed and contracted by elastic deformation, and the female screw portion 30 of the first nut 16 is firmly pressed against the right screw portion 22 of the bolt 14.

  In this state, even if a force in the loosening direction acts on the first nut 16 of the right screw, even if it is pressed by the second nut 18 of the left screw and the force in the loosening direction is transmitted to the second nut 18, that direction Since this force is in the tightening direction, the second nut 18 does not loosen, and the first nut 16 does not loosen. Furthermore, since the second nut 18 is tightened, the small diameter portion 34 of the first nut 16 is pressed so as to be in pressure contact with the entire circumference of the right screw portion 22 of the bolt 14. , 18 are in strong contact with each other over the entire circumference, a strong frictional force is generated, and there is no loosening, and the strength against the load is high.

  According to the nut locking device 10 of this embodiment, the first and second nuts 16 and 18 can exert a reliable locking effect, and the thread of the first and second nuts 16 and 18 can be demonstrated. As a whole, it can receive force and has high strength and durability against tightening and external loads.

  As shown in FIG. 5, the first nut 16 may be formed with one full through slit 42 penetrating from the outer surface to the female screw portion 30 in the screw axis direction.

  Thereby, by the tightening by the second nut 18, the action in the diameter reducing direction by the tapered surface 34 a extends to the entire first nut 16, and the tightening effect to the right screw portion 22 of the bolt 14 is obtained even in the large diameter portion 32 portion. Has a more secure locking function.

Next, the nut locking device 50 of another embodiment will be described based on FIGS. 6 to 8. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and a part of the description is omitted. The nut locking device 50 of this embodiment also holds the fixed members 11 and 12 to be fixed to each other, and includes a bolt 14, a first nut 16, and a second nut 18.

  As shown in FIGS. 6 and 7, the bolt 14 continues from the right screw portion 22 and the end portion of the right screw portion 22, and has an outer diameter formed by the thickness of the valley diameter of the right screw portion 22 and continues to the tip. A left-hand thread portion 24 is provided.

  The first nut 16 is screwed onto the opposite side of the bolt 14 from the head 20 with the washer 52 sandwiched between the fixed members 11 and 12. The first nut 16 has a right-handed female screw portion 30, a large-diameter portion 32 whose outer shape is formed in a hexagonal column shape is located on the fixed member 12 side, and a small-diameter portion whose diameter is smaller than that of the large-diameter portion 32. 34 projects from the opposite side and is screwed onto the bolt 14. The small-diameter portion 34 includes a tapered surface 34a having a one-step diameter that is smaller than that of the large-diameter portion 32 and further becoming tapered toward the end surface.

  The first nut 16 of this embodiment is a convex taper surface in which the tapered portion 32a of the first nut 16 is fitted and brought into surface contact with the end surface of the large diameter portion 32 on the fixed member 12 side. A tapered surface 32a that is gently inclined toward the opening of the portion 30 is formed. A concave tapered portion 52a corresponding to the tapered surface 32a is provided on the surface of the washer 52 that the first nut 16 faces, and is provided so as to be able to fit in surface contact with each other. Further, as shown in FIG. 8, the first nut 16 is formed with six through slits 54 penetrating from the tapered surface 34 a of the small diameter portion 34 to the female screw portion 40, one of which is large. It is a full penetration slit 56 that penetrates the diameter portion 32.

  The second nut 18 is the same as that of the above-described embodiment. The second nut 18 is formed with a tapered fitting surface 38 that is fitted to the small diameter portion 34 of the first nut 16, and further has a female screw portion 40 of a left screw. Yes. In the female screw portion 40, the vicinity of the opening of the large diameter portion 32 is a normal screw, and the other portion is a hard screw.

  As shown in FIG. 6, the nut locking device 50 of this embodiment is used by inserting bolts 14 into the through holes 11 a and 12 a of the fixed members 11 and 12 as shown in FIG. The washer 52 is fitted to the screw part, the female screw part 30 of the first nut 16 is screwed into the right screw part 22, and the fixed members 11 and 12 are fastened and fixed. Further, the second nut 18 is screwed into the left screw portion 24 of the bolt 14.

  At this time, the second nut 18 screwed into the left screw portion 24 is fitted to the tapered surface 34a of the first nut 16, and the fitting surface 38 of the second nut 18 is tightened by tightening the second nut 18. It contacts the tapered surface 34a of the first nut 16 and presses it in the direction of diameter reduction. Thereby, the inner diameter of the small diameter portion 34 of the first nut 16 divided by the through slit 54 is reliably reduced. Further, the large-diameter portion 32 is reliably reduced in diameter together with the tightening by the all-through slit 56, the tapered portion 52a of the washer 52 and the tapered surface 32a of the first nut 16, and the first nut 16 is connected to the right screw portion 22 of the bolt 14. The entire female screw portion 30 is pressed more firmly.

  In this state, even if a force in the loosening direction acts on the first nut 16 of the right screw, the first nut 16 does not loosen because the second screw 18 of the left screw is in the tightening direction. Furthermore, since the entire female screw portion 30 of the first nut 16 is pressed by the second nut 18 so as to be in pressure contact with the entire circumference of the right screw portion 22 of the bolt 14, the screw portions are strongly tightened over the entire circumference. It abuts and generates a stronger frictional force that does not loosen.

  According to the nut locking device 50 of this embodiment, the same effects as those of the above embodiment can be obtained, and a more reliable locking effect can be exhibited.

Next, the locking device 60 of the nut of the embodiment of the present invention will be described based on FIGS. 9 to 11. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and a part of the description is omitted. The nut locking device 60 of this embodiment also holds the fixed members 11 and 12 to be fixed to each other, but the left screw portion 64 of the bolt 14 is formed to have the same outer diameter as the right screw portion 62. It is.

  As shown in FIG. 11, the first nut 66 of this embodiment is a split nut that is divided into two pieces 66 a and 66 b in the screw axis direction, and the right screw portion at the position of the right screw portion 62 of the bolt 14. Wear so that 62 is inserted. In the second nut 18, the tapered fitting surface 38 of the left-handed second nut 18 similar to the above embodiment is fitted and fixed to the tapered surface 32 a of the small diameter portion 32 of the first nut 66. The first nut 66 is good enough to have a slight gap between the split pieces 66a and 66b when the first nut 66 is attached to the right thread portion 22. Thereby, the loosening prevention effect by the fastening mentioned later is exhibited well.

  In the nut locking device 60 of this embodiment, the bolt 14 is inserted into the through holes 11a and 12a of the fixed members 11 and 12 and the washer 52 is fitted to the screw portion of the bolt 14 as in the above embodiment. The fixed members 11 and 12 are fastened and fixed by the second nut 18 by screwing into the female screw portion 30 of the first nut 66. Tightening is performed by screwing the second nut 18 into the left screw portion 24 of the bolt 14.

  At this time, similarly to the above-described embodiment, due to the reduced diameter of the tapered surface 34a of the first nut 66 and the fitting surface 38 of the second nut 18, and the tapered portion 52a of the washer 52 and the tapered surface 32a of the first nut 66, As the second nut 18 is tightened, the large-diameter portion 32 is also reliably reduced in diameter, and the female screw portion 30 of the first nut 66 is more firmly pressed against the right screw portion 22 of the bolt 14.

  According to the nut locking device 60 of this embodiment, the same effect as that of the above embodiment can be obtained, and the thickness of the threaded portion of the bolt 14 is constant, so that it is more convenient to use.

Next, a nut locking device 70 according to still another embodiment will be described with reference to FIGS. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and a part of the description is omitted. The nut locking device 70 of this embodiment also holds the fixed members 11 and 12 to be fixed to each other, but the bolt 14 uses a normal bolt formed only by the right screw portion 72.

  This embodiment uses the same first nut 16 as the first nut 16 of the embodiment shown in FIG. 8, and the second nut 18 has a female screw portion 40 with a right-hand thread and is the same as the above embodiment. The one of the shape is used.

  Similarly to the above-described embodiment, the nut locking device 70 of this embodiment is configured such that the bolt 14 is inserted into the through holes 11a and 12a of the fixed members 11 and 12, the washer 52 is fitted to the bolt 14, and the first The female screw portion 30 of the nut 16 is screwed into the right screw portion 72 and the fixed members 11 and 12 are fastened and fixed. Further, the second nut 18 is also screwed into the right thread portion 72 of the bolt 14.

  At this time, similarly to the above-described embodiment, due to the reduced diameter of the tapered surface 32a of the first nut 66 and the fitting surface 38 of the second nut 18, and the tapered portion 52a of the washer 52 and the tapered surface 32a of the first nut 66, As the second nut 18 is tightened, the small-diameter portion 34 and the large-diameter portion 32 are also reliably reduced in diameter, so that the female screw portion 30 of the first nut 66 is more firmly pressed against the right screw portion 72 of the bolt 14.

  According to the nut locking device 70 of this embodiment, the same effect as that of the above embodiment can be obtained, and the bolt 14 can be a normal right-screw only bolt and can be used more generally. Can be used, and it is easier to use.

  Next, a nut locking device 80 according to still another embodiment will be described with reference to FIGS. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and a part of the description is omitted. The nut locking device 80 of this embodiment also holds the fixed members 11 and 12 to be fixed to each other. As in the fourth embodiment, the bolt 14 is a normal bolt formed by only the right screw portion 72. Is used.

  In the first nut 82 of this embodiment, as shown in FIG. 16, six through slits 84 penetrating from the tapered surface 34 a of the small diameter portion 34 to a part of the large diameter portion 32 to the female screw portion 40 are equally spaced. It is formed.

  Similarly to the above-described embodiment, the nut locking device 80 of this embodiment is configured such that the bolt 14 is inserted into the through holes 11a and 12a of the fixed members 11 and 12 and the washer 26 is fitted to the bolt 14 so that the first The female screw portion 30 of the nut 82 is screwed into the right screw portion 72 and the fixed members 11 and 12 are fastened and fixed. Further, the second nut 18 is also screwed into the right thread portion 72 of the bolt 14. At this time, similarly to the above-described embodiment, when the second nut 18 is tightened, the diameter of the small-diameter portion 34 of the first nut 82 is reduced by the tapered surface 32a of the first nut 82 and the fitting surface 38 of the second nut 18. Further, the diameter of the large-diameter portion 32 is partially reduced, and the female screw portion 30 of the first nut 82 is more firmly pressed against the right screw portion 72 of the bolt 14.

  According to the nut locking device 80 of this embodiment, the same effect as that of the above embodiment can be obtained, and the bolt 14 can be a normal right-screw only bolt and can be used more generally. Can be used, and it is easier to use.

  The nut locking device of the present invention is not limited to the above-described embodiment, and the number of through slits and the formation position of the slits of the first nut can be set as appropriate, and in the case of only a part of the small diameter portion or It can be set as appropriate according to the application and strength, such as a part extending from the small diameter part to a part of the large diameter part, or a combination of only the small diameter part and a slit extending to the large diameter part. Moreover, the washer to be used can be appropriately selected, such as a normal washer or one having a tapered portion.

10, 50, 60, 70, 80 Nut locking device 11.12 Fixed member 14 Bolt 16, 66, 82 First nut 18 Second nut 22 Right screw portion 24 Left screw portion 26, 52 Washer 30, 40 Female Threaded portion 32 Large diameter portion 32a, 34a Tapered surface 34 Small diameter portion 38 Fitting surface 42 56 All through slits 44, 54, 84 Through slit

Claims (5)

In the nut locking device that is held by a pair of nuts when the fixed member is clamped and fixed by a bolt and a nut,
A first nut that is screwed into the male threaded portion of the bolt is provided, and the first nut protrudes on the opposite side to the fixed member, and has a tapered surface with a tapered surface that decreases in diameter toward the tip side. Formed,
A tapered fitting surface that is fitted to the small diameter portion of the first nut is formed, and includes a second nut that is screwed to the male screw portion of the bolt,
The tapered surface of the first nut and the fitting surface of the second nut are formed coaxially with the female thread portion of each nut,
The fixed member is tightened by the first nut, and the second nut is tightened in a state where the fitting surface of the second nut is fitted to the small diameter portion of the first nut. A nut locking device, wherein the small-diameter portion of the first nut is reduced in diameter to be brought into pressure contact with the male screw portion of the bolt.   The nut locking device according to claim 1, wherein a through slit penetrating the female screw portion is formed in the small diameter portion of the first nut.   3. The nut locking device according to claim 2, wherein the through slit of the nut has one slit penetrating in the axial direction of the first nut.   A washer is provided between the first nut and the fixed member, the first nut side surface of the washer includes a tapered portion that is a tapered concave surface, and faces the washer of the first nut. The nut locking device according to claim 1, 2, or 3, wherein a projecting tapered surface that comes into surface contact with the tapered portion is formed on the end surface. The first nut has a right-handed female screw portion, the second nut has a left-handed female screw portion, and a right-handed male screw is formed at a portion where the first nut of the bolt is screwed. The nut locking device according to any one of claims 1 to 4, wherein a threaded portion of the second nut is formed with a left-handed male screw.

Images