JPH07229509A - Vibration-proof screw - Google Patents

Abstract

PURPOSE:To prevent occurrence of loosening with certainty by providing 6 bolt which has a first stage right male screw and a second stage male screw having pitch smaller than that of the first stage male screw, and a two-stage nut which has female screws corresponding to the male screws. CONSTITUTION:A bolt 1 and nuts 2, 2a are provided. The bolt 1 has a first stage male screw part 3 prepared by cutting a right screw 3a on a screw shaft on a lower side of a screw head 7, and a second stage male screw part 4 prepared by cutting a left screw part 4a having a small diameter and screw pitch on a thin stepped portion on the lower side, of the male screw part 3. A nut to be screwed with the bolt 1 has a two-stage structure in which the nut 2 has a female screw 5 provided with a root diameter corresponding to the male screw part 3a and the nut 2a has a female screw 6 corresponding to the male screw part 4a. It is thus possible, by the use of the antivibration screw, to remarkably reduce release of the screw, and to prevent removal of the nut through reduction of fastening force caused by different thermal expansion rate due to different materials in the bolt and fastening object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration resistant screw having a locking mechanism.

[0002]

2. Description of the Related Art Various attempts have been made to prevent loosening of screws due to vibration or intermittent impact or fatigue.

[0003] As one example thereof, a method in which a groove or the like cut into a screw head is wound around a member to be fastened with a lock wire and locked, a method in which a bolt or a nut is processed to screw a set screw, and a screw thread is used. After tightening the adhesive after applying it, there is a method such as brazing, welding, etc. to completely prevent rotation.

[0004]

However, in such a conventional example, when a lock wire is used, there is a problem that it takes a lot of work to identify the locking direction and to attach and detach the wire. In the latter two cases, the rotation can be more reliably prevented, but there is a problem that disassembly and reuse is impossible.

In view of the above problems, it is an object of the present invention to provide a vibration resistant screw which is easy to rotate and release and disassemble and can be securely fixed.

[0006]

In order to achieve the above-mentioned object, the present invention provides a first-stage male screw portion in which a right-hand screw having an outer diameter substantially equal to that of a screw shaft portion is threaded, and the first-stage male screw portion. A male screw portion has a stepped end portion with a bolt having a second-stage male screw portion in which an outer diameter and a pitch are left-hand threads smaller than the first-stage male screw portion, and each of the male screw portions. It is provided with a two-step nut having a female thread having a root diameter that is screwed correspondingly.

Further, it has a male screw portion in which a right-hand screw having an outer diameter substantially equal to that of the screw shaft portion is screwed, and a male screw portion in which a left-hand screw is screwed on a taper portion at the tip of the male screw portion by a taper. It is provided with a bolt and a two-step nut having a taper-type female thread having a root diameter that is screwed in correspondence with each male thread portion.

Further, pinholes are provided at specific portions of both bolts and nuts having the first and second male threads.
There is provided a locking pin having a magnet formed at a tip end portion which is inserted at a point where the two pinholes coincide with each other when the nut is tightened to lock the nut.

Further, pinholes are provided at specific portions of both the bolt and the nut having the taper portion, and when the nuts are tightened, the pinholes are inserted at a point where the pinholes are aligned with each other, and a tip portion for locking the rotation is provided. It has a locking pin formed of a magnet.

Further, an engaging concave portion accommodating in one side an engaging member biased and held by an elastic member is provided at a specific abutting portion of both the bolt and the nut having the first and second male threads, and the nut is provided. At the time of tightening, the engaging member is provided with an engaging portion that prevents the engaging member from being rotated and engaged with the mating engaging concave portion at a coincident point of the both engaging concave portions.

Further, an engaging recess for accommodating an engaging member biased and held by an elastic member is provided at a specific abutting portion of both the bolt and the nut having the taper portion, and when the nut is tightened, both engaging portions are engaged. The engagement member includes an engagement portion that engages with the other engagement recess at a point where the engagement recesses coincide with each other to prevent rotation.

The first-stage male screw portion is threaded with a left-hand thread and the second-stage male screw portion is screwed with a right-hand screw, and a nut is screwed in correspondence with each male screw portion.

Further, a male screw portion having an outer diameter substantially equal to that of the screw shaft portion is threaded with a left screw, and a male screw portion having a small outer diameter of the taper portion is screwed with a right screw, and the corresponding male screw portion is screwed. It has a matching nut.

[0014]

According to the above construction, the first-stage male screw portion of the right screw or the left screw having an outer diameter of approximately the screw shaft diameter is threaded on the upper portion of the bolt, and the lower-diameter portion having the step is provided with the single-stage portion. Since the outer diameter and pitch of the eyes are small and the left and right are the opposite, the left-handed or right-handed second-stage male thread is threaded and screwed into the corresponding nut.
It can suppress screw loosening.

Alternatively, a right-handed screw thread or a left-handed screw thread having an outer diameter of approximately a screw shaft diameter is threaded on the upper portion of the bolt, and the lower taper portion has an outer diameter and a small pitch and an upper male thread portion. Since the left-handed and right-handed left-handed male threads are threaded and screwed into the corresponding nuts, it is possible to suppress screw loosening.

Alternatively, pinholes are provided at specific portions of both nuts corresponding to the bolts having the first and second male threads, or nuts corresponding to the bolts having the taper portion, so that the nuts are screwed and tightened. When the two pinholes match each other, the distal end portion inserts the locking pin of the magnet and locks the bolt and the nut, so that the loosening of the screw can be reliably prevented.

Alternatively, an engaging recess is provided at a specific abutting portion of both a nut corresponding to a bolt having a male thread portion at the first and second stages, or a nut corresponding to a bolt having a taper portion. An engaging member biased by an elastic member is housed in one of the engaging recesses of the nut, and if both engaging recesses match when tightening the nut, the engaging member projects into the mating engaging recess. Since they are engaged, the bolt and the nut are automatically locked to prevent the screw from loosening.

[0018]

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

FIG. 1 is a front view of a vibration resistant screw according to an embodiment of the present invention.

The embodiment shown in FIG. 1 comprises a bolt 1 and nuts 2 and 2a. The bolt 1 has a male screw portion 3 of a first stage in which a right screw 3a is cut on a screw shaft portion below a screw head 7. When,
A small-diameter portion having a step below the male screw portion 3 has a second-stage male screw portion 4 in which a left screw 4a having a small outer diameter and a small pitch is cut. The mating nut 2 has a female screw 5 having a root diameter corresponding to the male screw portion 3a,
The two-stage nut 2a has a female screw 6 corresponding to the male screw portion 4a.

When such a vibration resistant screw is used for tightening the object to be tightened, it is locked by a two-stage screw whose left-right tightening direction and pitch are different from those in the case of only the first-stage male screw 3a. As a result, the amount of screw loosening is significantly reduced, and not only screw loosening due to vibration but also when the material of the bolt and the tightened object is different, the amount of thermal expansion changes due to the temperature rise during machine operation, and the tightening force decreases. It is also possible to prevent accidents where the nut rotates and falls off.

Although the first-stage male screw 3a is shown as a general right screw, the second-stage male screw 4a is used as the left screw.
It is also possible to use the right screw.

FIG. 2 is a front view of a vibration resistant screw according to a second embodiment of the present invention.

In the second embodiment shown in FIG. 2, the first embodiment separates the first-stage male screw portion 3a and the second-stage male screw portion 4a with a step, but not the difference. A taper is attached toward the tip, and a male screw portion 11 obtained by cutting the right screw 11a is provided on the upper portion of the bolt 10 so that the outer diameter and the pitch are reduced toward the tip portion where the diameter is reduced by the taper in the lower portion. Left screw 1
1b is used as a cut male screw portion. Therefore, the nut is also a two-step nut having a female screw 13 having a root diameter corresponding to the right screw 11a and a female screw 12 having a female screw 14 corresponding to the male screw 11b.

Also in this case, the male screw 11a can be a left screw and the male screw 11b can be a right screw.

The second embodiment also has the same screw loosening prevention effect as in the previous embodiment, and in particular, in the case of a tightened body that requires guide locking because of the shape of the male screw portion 11b at the tip of the bolt 10. It is suitable.

FIG. 3 is a front view of a vibration resistant screw according to a third embodiment of the present invention.

The embodiment shown in FIG. 3 is one in which the locking force of the screw of the first embodiment is further strengthened to reduce the looseness, and the bolt 1 and the nut 2 are at specific positions, that is, at the tightening end position. It passes through the pinholes 20 and 21.

When the object to be tightened is tightened with the bolt 1 and the nut 2, if the pin holes 20 and 21 of both are overlapped with each other, the locking pin 22 shown in FIG.
The magnet 23 at the tip of 2 is attracted to the screw body to securely lock the bolt 1 and the nut 2, so that the locking force is further strengthened and the loosening of the screw is eliminated.

FIG. 6 shows this locked state. The tightened bodies 26 and 27 are tightened and coupled with a bolt and a nut, and the locking pin 22 is inserted and locked in the matched pin hole.

When the locking pin 22 is to be removed, a thin metal rod or the like can be applied and tapped to easily remove it.

Although the pinhole is provided on the nut 2 in the drawing, it may be provided on the nut 2a or on both.

FIG. 5 is a front view of a vibration resistant screw according to a fourth embodiment of the present invention.

In the fourth embodiment shown in FIG. 5, both the bolt 10 and the nut 12 of the taper screw of the second embodiment have pinholes 24,
25 through the pinhole 24, as in the third embodiment.
When 25 matches, the locking pin 22 is inserted, and the bolt and nut are locked as shown in FIG. 6 to strengthen the locking force. Also in this case, although the pinhole is provided on the nut 12 in the drawing, it may be provided on the nut 12a or on both.

FIG. 7 is an enlarged view of the essential portions of the vibration resistant screw according to the fifth embodiment of the present invention.

In the fifth embodiment shown in FIG. 7, with the screws of the first and second embodiments, the operation for strengthening the locking described in the third and fourth embodiments is automatically performed. It is a thing.

Engagement recesses 32 on the bolts 1 and 10 side at specific positions (tightening end positions) on the contact surfaces of the bolts and nuts.
An engaging recess 33 is provided on the nut 2 or 12 side, and an engaging member (for example, a metal rod body) locked by the coil spring 31 in one engaging recess 32 (or in the engaging recess 33 on the nut side). ) 30 is stored and placed, and when the engaging recesses 32 and 33 face each other at the end of tightening, the metal rod 30
Since they protrude into the engaging recess 33 and engage with each other, the bolts 1 and 10 and the nuts 2 and 12 are automatically locked to prevent loosening. When removing, the metal rod 30 is pushed with a pin from an outside pore (not shown) and the nut is turned. Also in this case, the engaging recesses are provided on the nuts 2 and 12 in the figure, but they may be provided on the nuts 2a and 12a, or on both.

In each of the above embodiments, the fixing method using the bolt and the nut is described. However, when a part of an object such as a thick iron plate or the like constitutes a female screw instead of the nut, the root portion of the bolt which is a male screw is used. It is possible to prevent the bolt from entering the female screw portion extremely deeply by providing a pinhole in the and inserting the pin or the like into the pinhole.

[0039]

As described above, according to the present invention,
The bolts are divided into the first step, the second step, and the taper, and each has a two-step screw structure with opposite outer diameters and pitches in opposite directions, and the nut has a corresponding two-step female thread structure. It has a suppressing effect.

Further, when the pinholes are opened at the specific portions of both the bolt and the nut and both pinholes match at the end of tightening, the locking pin with magnet is inserted and locked, so that the locking is performed. This has the effect of strengthening the force, reliably preventing screw loosening, and easily disassembling.

Alternatively, engaging recesses are provided at specific abutting portions of both the bolt and the nut, and an engaging member urged by an elastic member is arranged in one engaging recess so that both engaging recesses coincide with each other. Since it is sometimes engaged by the engaging member, there is an effect that the operation for strengthening the locking force for preventing the loosening of the screw is automatically performed.

[Brief description of drawings]

FIG. 1 is a front view of a vibration resistant screw according to an embodiment of the present invention.

FIG. 2 is a front view of a vibration resistant screw according to a second embodiment of the present invention.

FIG. 3 is a front view of a vibration resistant screw according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a locking pin of the present invention.

FIG. 5 is a front view of a vibration resistant screw according to a fourth embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view showing a tightened state of the bolt shown in FIG.

FIG. 7 is an enlarged front view of an essential part of a vibration resistant screw according to a fifth embodiment of the present invention.

[Explanation of symbols]

 1, 10 Bolt 2, 2a, 12, 12a Nut 3 First-stage male screw part 4 Second-stage male screw part 5, 6, 13, 14 Female screw 7 Screw head 11 Male screw part 20, 21, 24, 25 Pinho -Rule 22 Locking pin 23 Magnet 30 Engagement member 31 Elastic member 32, 33 Engagement recess

Claims (8)

[Claims] 1. A first-stage male screw part in which a right-hand screw having an outer diameter substantially equal to that of a screw shaft portion is threaded, and an outer diameter and a pitch are provided at a tip portion having a step with the first-stage male screw part. A two-stage nut having a bolt having a second-stage male screw portion in which a left-hand thread smaller than the first-stage male screw portion is threaded, and a female screw having a root diameter to be screwed corresponding to each male screw portion. Anti-vibration screw characterized by having. 2. A male screw portion having a right-hand screw having an outer diameter substantially equal to that of the screw shaft portion, and a male screw portion having a left-hand screw screwed on a tapered portion formed by a taper at the tip of the male screw portion. Bolt and
A vibration-resistant screw comprising a two-step nut having a taper-type female screw having a root diameter that is screwed in correspondence with each male screw portion. 3. A pin hole is provided at a specific portion of both the bolt and the nut of the vibration-proof screw according to claim 1, and the pin hole is inserted at a point where the both pin holes coincide with each other when the nut is tightened, and the rotation stopper is locked. An anti-vibration screw having a locking pin whose front end portion is formed of a magnet. 4. A pin hole is provided at a specific portion of both the bolt and the nut of the vibration-proof screw according to claim 2, and when the nut is tightened, the pin hole is inserted at a point where the two pin holes are aligned with each other to lock the rotation. An anti-vibration screw having a locking pin whose front end portion is formed of a magnet. 5. An engaging recess for accommodating an engaging member biased and held by an elastic member in one side is provided at a specific abutting portion of both the bolt and the nut of the vibration-proof screw according to claim 1, and when the nut is tightened. A vibration-resistant screw, comprising: an engaging portion for engaging the engagement member with a mating engagement recess so as to prevent the engagement of the engagement member and the mating engagement recess. 6. An engagement recess for accommodating an engagement member biased and held by an elastic member in one side is provided at a specific abutting portion of both the bolt and the nut of the vibration-proof screw according to claim 2, and when the nut is tightened. A vibration-resistant screw, comprising: an engaging portion for engaging the engagement member with a mating engagement recess so as to prevent the engagement of the engagement member and the mating engagement recess. 7. The left-hand thread is used to connect the first-stage male threaded portion to the second threaded portion.
The vibration-resistant screw according to claim 1, further comprising a nut that is formed by threading a right-hand thread on the male thread portion of the step and is screwed into the male thread portion. 8. A male screw portion having an outer diameter substantially equal to that of the screw shaft portion is threaded with a left screw, and a male screw portion having a smaller outer diameter of the taper portion is screwed with a right screw, and the corresponding male screw portion is screwed. The vibration resistant screw according to claim 2, further comprising a nut to be fitted.