JP2019124322A - Fastener - Google Patents

Abstract

To provide a fastener capable of making an integral formation of a thread engaged fastening nut and a lock nut without changing a fastening workability at all and further capable of positively preventing a looseness of the fastening nut.SOLUTION: This invention relates to a fastener in which a shank part 3 of a bolt 1 is composed of a main body shank part 3a and a fine diameter shank part 3b present at its extremity end side, the fine diameter shank part is provided with a narrower pitch male thread than that of male thread arranged at the main body shank part and also a female thread engaged in thread with the male thread arranged at the main body shank part is arranged at a fastening nut 5, a female thread engaged in thread with the male thread arranged at the fine diameter shank part is arranged at a lock nut 6, thereby the lock nut is engaged in thread with the main body shank part, the lock nut is engaged in thread with the fine diameter shank part. The surfaces of abutting the fastening nut and the lock nut are raised up at a front surface and a rear surface between the fastener nut and the lock nut, and there is provided a washer having each of one set of two protrusions 11 forming an engaging protrusion 30 between them.SELECTED DRAWING: Figure 14

Description

  The present invention relates to fasteners, and in particular to fasteners comprising bolts, nuts and washers.

2. Description of the Related Art Conventionally, as a fastener, there is a fastener having a locking structure in which two nuts are screwed into one bolt, that is, a so-called double nut type locking structure.
In this case, the locking nut screwed onto the bolt is subsequently screwed on to the locking nut, and the locking nut is prevented from rotating in the direction of loosening due to vibration or the like by the locking nut.

  In this locking structure, female threads of the same pitch are formed on both the tightening nut and the locking nut, and an external thread of the same pitch is screwed into a bolt formed on the shaft and the friction generated between the tightened nuts The force prevents loosening of the tightening nut.

  Although the fastener according to the conventional structure can prevent the tightening nut from loosening to some extent, when a large vibration is applied for a long time, so-called turning of the tightening nut and the locking nut occurs, and both nuts loosen from the bolt. There was a problem that

Therefore, the applicants of the present invention previously filed a utility model registration application by devising a fastener which can effectively prevent loosening of the nut without causing the nut to rotate by vibration etc. (Patent Document 1) .
The fastener for which the utility model registration application has been filed is characterized in that the shaft portion of the bolt is a main shaft portion and a small diameter shaft portion existing on the tip side, and a male screw of coarse thread is formed on the main shaft portion; By forming a thin thread male screw in the radial shaft portion, forming a female thread to be screwed to the coarse thread into a tightening nut, and forming a female thread to screw into the fine thread from a locking nut, It is a fastener consisting of a bolt and a nut in which a tightening nut is screwed on the main body shaft portion and a locking nut is screwed on the small diameter shaft portion.

  According to the above-described fastener consisting of a bolt and a nut, the pitch between the tightening nut and the locking nut is different, so that the two nuts do not rotate together, thereby effectively preventing the tightening nut from loosening. It was possible.

  On the other hand, in Patent Documents 2 and 3, in a fastener consisting of a double-nut type bolt and a nut using two nuts, concavo-convex portions such as a saw blade are formed in advance on the contact surfaces of the nuts. In addition, there is disclosed a technology for integrating both nuts and preventing loosening from a bolt.

Registered Utility Model No. 3179874 Unexamined-Japanese-Patent No. 2004-204867 Registered Utility Model No. 3153130

  However, in the case of the fastener disclosed in Patent Document 1 described above, when the tightening nut and the locking nut can not move independently due to the frictional force between the nuts, they move integrally. Both nuts can not be rotated due to the difference in pitch, and it was possible to effectively prevent loosening of the tightening nut, but for some reason, the locking nut screwed to the fine thread screwed independently first. If this happens, then the friction between the nuts no longer working together will no longer work, and it may happen that the respective nuts can be loosened independently. Dropout from the bolt was a concern.

  Moreover, in the technology of forming concavo-convex parts such as saw blade shapes in advance on the contact surfaces of the nuts disclosed in Patent Documents 2 and 3, a normal nut can not be used, It is necessary to produce a special nut having an uneven portion, which is expensive. Further, as described in [0004] of Patent Document 2, when the sub-nut is tightened to the main nut, the two uneven portions are rubbed against each other in a state in which an excessive load is applied. The uneven portion is damaged, and as a result, the contact surfaces of the main nut and the sub nut are difficult to be engaged with each other, and the loosening of the main nut can not be effectively prevented.

  The present invention has been made in view of the various problems of the prior art described above, and its object is to integrate the screwed clamping nut and the locking nut without changing the fastening workability. It is an object of the present invention to provide a fastener comprising a bolt, a nut and a washer which can reliably prevent the loosening of the clamping nut and the loosening of the fastener.

In order to achieve the above object, the present invention is a fastener as described in the following (1) to (5).
(1) The shaft of the bolt is a main shaft and a small diameter shaft present on the tip side, and an external thread is provided on the main shaft, and an external thread is provided on the main shaft in the small shaft. An external thread with a narrower pitch is provided, and a female thread engaged with an external thread provided on the shaft of the main body is provided on the tightening nut, and a female thread engaged with the external thread provided on the small diameter shaft is secured. A fastening tool in which a tightening nut is screwed on the main body shaft portion and a locking nut is screwed on the small diameter shaft portion by being provided on a nut, the tightening nut and the locking nut In the meantime, digging up the surfaces of the clamping nut and the locking nut to be abutted on the front and back surfaces and interposing a washer provided with a pair of projections forming an engaging projection therebetween. Characterized by a fastener.
(2) The fastener according to the above (1), wherein a pair of projections provided on the washer is formed at different positions on the front surface and the back surface.
(3) A pair of projections provided on the washer digs up the surfaces of the clamping nut and the locking nut that are in contact, digs up the protrusions, and blocks the meat portion dug up by the protrusions. The fastener according to the above (1) or (2), characterized in that it comprises a detent projection that forms the engagement projection with the digging projection.
(4) The fastener according to (3), wherein the digging projections and the blocking projections are respectively formed on slightly different circumferences slightly shifted on the front and back surfaces of the washer. .

  According to the above-described fastener according to the present invention, two pieces are formed between the tightening nut and the locking nut by digging the surface of the nut in contact with the front surface and the back surface and forming the engagement convex portion therebetween Since a washer provided with a pair of projections is interposed, by tightening both nuts are integrated through the washer and can not rotate independently. On the other hand, in the fastener targeted by the present invention, a fastening nut screwed to an external thread provided on the main body shaft, and an external thread having a narrower pitch than the external thread of the main body axis provided on the small diameter shaft Since it consists of a locking nut to be engaged, the progress by the rotation of the two nuts differs, and the tightening nut and the locking nut can not rotate together. The dual action of the above-described fastener according to the present invention, that is, the action of integrating the tightening nut and the locking nut by the washer having a projection, and the pitch difference to prevent the turning of the locking nut and the locking nut. Together with the action, it becomes a fastener that can reliably prevent the loosening of the nut.

FIG. 1 is a side view showing an embodiment of a bolt used in the present invention. FIG. 1 is a top perspective view of one embodiment of a clamping nut for use in the present invention. FIG. 1 is a top perspective view of one embodiment of a locking nut used in the present invention. FIG. 1 is a top perspective view showing an embodiment of a washer used in the present invention. FIG. 5 is a bottom perspective view of the washer shown in FIG. 4; It is a top view of a washer shown in FIG. It is a front view of the washer shown in FIG. It is sectional drawing of the part which follows the AA of FIG. It is an expanded sectional view of the part which follows the B-B gland | gland of FIG. FIG. 10 is a view showing an embodiment of a fastening structure using the bolt, the fastening nut and the locking nut, and the washer shown in FIGS. 1 to 9, before the fastening nut and the fastening nut are screwed to the bolt. It is the side view which made the cross section a part which showed the state. FIG. 11 is a side view, partly in cross section, showing a state in which a tightening nut is screwed on a bolt in the fastening structure shown in FIG. 10; FIG. 11 is a side view, partly in cross section, showing a state in which a tightening nut and a locking nut are screwed to a bolt with a washer interposed in the fastening structure shown in FIG. 10. It is the expanded sectional view which showed notionally the state in which the engagement convex part is formed in the nut surface by the protrusion provided in the washer. It is an enlarged sectional view showing the situation of the washer interposed between the tightening nut and the locking nut after tightening.

  Hereinafter, an embodiment of a fastener concerning the above-mentioned present invention is described in detail, showing a drawing.

  The bolt 1 used in the present invention has a head 2 and a shaft 3 as shown in FIG. The head 2 is in the shape of a substantially hexagonal column, and is in a shape suitable for tightening with a tool such as a spanner or a hexagonal wrench. The shaft portion 3 is composed of a main body shaft portion 3a and a small diameter shaft portion 3b present on the tip end side, and the main body shaft portion 3a and the small diameter shaft portion 3b have male threads 4a in parallel with each other. , 4b are formed. Here, since the small diameter shaft portion 3b has a smaller shaft diameter than the main body shaft portion 3a, the male screw 4b on the small diameter shaft portion side is located on the main body shaft portion side even when both are formed with parallel male threads. The pitch is narrower than the external thread 4a. In the case where a male thread of a coarse thread is formed on the main body shaft portion 3a and a male thread of a fine thread is formed on the small diameter shaft portion 3b, the difference in pitch becomes larger, which is all right.

  The small diameter shaft portion 3b is preferably formed to have an axial diameter of 60 to 90% of the axial diameter of the main body shaft portion 3a, and more preferably 70 to 85%. This is because, in the case where a thin narrow diameter shaft portion less than 60% is formed, the strength of the small diameter shaft portion is weakened and the locking is engaged with the male screw 4b formed on the small diameter shaft portion. This is not preferable because it becomes difficult to secure a sufficient contact surface between the nut and the tightening nut screwed to the male screw 4a formed on the main body shaft. Conversely, in the case where a small diameter shaft portion exceeding 90% is formed, the pitch formed on the small diameter shaft portion is different when inserting and screwing the tightening nut to the male screw 4a formed on the main body shaft portion. It is not preferable because the male screw 4b may be in the way.

  The pitch of the external thread 4b formed on the small diameter shaft portion 3b is preferably 50 to 80% of the pitch of the external thread 4a formed on the main body shaft portion 3a, 55 to 75% More preferably, it is formed in This is not preferable in fastening work because the progress of the locking nut screwed to the male screw 4b is slow when the narrow-pitch male screw 4b having a narrow pitch less than 50% is formed in the small diameter shaft 3b. On the other hand, in the case where the small diameter shaft portion 3b is formed with an external thread that is more than 80% and does not differ much from the pitch of the external thread 4a formed on the main body shaft portion 3a, the tightening nut and the locking nut It is not preferable because there is a risk of causing it.

  The male screw 4a formed on the main body shaft 3a is not necessarily formed over the entire length of the main body shaft, and may be formed only above the main body shaft 3a as illustrated.

  The tightening nut 5 and the locking nut 6 used in the present invention may be used in the case where the male threads 4a and 4b formed on the main body shaft 3a and the small diameter shaft 3b of the bolt 1 are both parallel threads. Normal nuts can be used as they are. In addition, in the case where the male screws 4a and 4b formed on the bolt 1 are screws of special pitches, the fastening nut 5 and the locking nut formed with the female screws 7 and 8 respectively fitted to the respective male screws 4a and 4b 6 will be used, but in any case, it is not necessary to process it into a special outer shape. The external dimensions of the tightening nut 5 and the locking nut 6 are, as shown in FIGS. 2 and 3, substantially in the shape of a hexagonal column, and suitable for tightening with a tool such as a spanner or a hex wrench. In addition, it is preferable from the viewpoint of workability at the time of tightening that they have the same external dimensions. The hardness of the tightening nut 5 and the locking nut 6 is preferably made of a soft material, for example, a hardness of 20 HRC or less so that it is easily deformed by the projections 11 of the washer 10 described later. What was produced by SS400 used can be used.

  The washer 10 used in the present invention, as shown in FIGS. 4-9, digs up the surfaces of the tightening nut 5 and the locking nut 6 which are in contact with the front surface 10a and the rear surface 10b respectively, A pair of projections 11 are provided to form a portion between them.

  The projection 11 digs up the surface of the clamping nut 5 and the locking nut 6 which are in contact with each other, and holds a portion of the meat excavated by the digging projection 12 between the digging projection 12 and the digging projection 12. And a locking projection 13 which forms an engaging projection. The digging projections 12 and the blocking projections 13 form a set of projections 11 one by one, and in the illustrated embodiment, open 180 degrees on the surface 10 a and the back surface 10 b of the washer 10 respectively. Two sets of projections 11 are formed at positions shifted by 90 degrees on the front and back surfaces. Moreover, in this embodiment, the recessed part 14 is formed in the same position in the surface on the opposite side to the surface in which the protrusion 11 was formed, respectively. In the case of manufacturing the washer 10 provided with the projections 11 used in the present invention by performing press processing using a predetermined mold from a plate-like material, the concave portions 14 secure the thickness portions for forming the projections 11. It is formed from the point of view.

  In the illustrated embodiment, the digging projections 12 are formed in a hemispherical shape with a large diameter, and dig into the surface of the abutting nut and act to build up the meat around them, that is, digging up the meat section . Further, the blocking projection 13 is formed in a hemispherical shape with a small diameter, and blocks the meat portion dug up and raised by the digging projection 12 and engages between the digging projection 12 and the blocking projection 13 The function of forming the convex portion 30 is achieved. It is preferable that the hardness of these digging projections 12 and the holding projections 13 be raised by induction hardening or the like, and the hardness thereof is preferably more than 40 HRC.

  The sizes of the digging projections 12 and the locking projections 13 are appropriately designed according to the size of the washer 10 to be formed, the number of the washers to be formed, and the like. For example, as shown in the illustrated embodiment, when forming the two sets of projections 11 at positions shifted by 90 degrees on the front and back surfaces of the washer with respect to the washer 10 having a diameter of about 30 mm, digging The raised projection 12 is a large hemispherical projection having a height H (see FIG. 9) of 0.3 to 0.7 mm and a bottom diameter D (see FIG. 9) of 1.5 to 2.0 mm. And the protrusion 13 has a height h (see FIG. 9) of 0.2 to 0.6 mm and a bottom diameter d (see FIG. 9) of 1.3 to 1.8 mm. It is appropriate to use hemispherical projections smaller than 12 in diameter. In the illustrated embodiment, hemispherical projections having a height H of 0.5 mm and a bottom diameter D of 1.7 mm are formed as the digging projections 12, and a damming projection 13 having a height h of 0. A hemispherical protrusion having a bottom diameter d of 1.6 mm and 4 mm is formed.

  Moreover, the fact that the digging projections 12 and the locking projections 13 are respectively formed on slightly different circumferences slightly shifted on the front and back surfaces of the washer 10 increases the resistance at the time of tightening to a great extent. It is preferable that the engagement convex portion 30 can be formed between the projections 12 and 13. The shift amount between the digging projection 12 and the blocking projection 13 is appropriately designed according to the size of the washer 10 to be formed and the number to be formed, but the shift amount δ (see FIG. 6) is 0.3 to It is appropriate that they are formed on different circumferences by 2.0 mm. In the illustrated embodiment, the digging projections 12 are formed on the circumference of a diameter of 20 mm, and the damming projections 13 are formed on the circumference of a diameter of 21 mm, whereby the damming projections 13 are formed by digging up. It is formed on the circumference shifted 0.5 mm outward of 12.

The above-mentioned bolt 1, the clamping nut 5 and the locking nut 6, and further the washer 10 may be used to fasten the workpieces in the same manner as in the prior art.
That is, as shown in FIG. 10, first, the shaft portion 3 of the bolt 1 is inserted into the through holes 22 and 23 formed in each of the members 20 and 21 to be fastened. At this time, if necessary, the normal washer 24 is fitted into the shaft portion 3 of the bolt.

  Subsequently, as shown in FIG. 11, the tightening nut 5 is inserted into and screwed into the external thread 4a formed on the main body shaft portion 3a of the bolt 1, and the members 20 and 21 are tightened by tightening. Under the present circumstances, since the narrow external thread 4b of the pitch which exists in the front-end | tip part of the bolt 1 is formed in the small diameter axial part 3b with a thin diameter, screwing the clamping nut 5 to the external thread 4a of the main body axial part 3a In the case, it does not get in any way. Further, the male screw 4a formed on the main body shaft portion 3a is not deformed at all because it has no missing portion, and the tightening nut 5 can be strongly tightened.

  Subsequently, as shown in FIG. 12, with the washer 10 interposed, the locking nut 6 is inserted and screwed into the male screw 4 b formed on the small diameter shaft portion 3 b of the bolt 1. The back surface 10 b of the washer 10 is strongly pressed against the upper surface of the screwing nut 5, and the surface 10 a of the washer 10 is strongly pressed against the lower surface of the locking nut 6. Thereby, the engagement convex portion 30 engaged with the washer 10 on the upper surface of the tightening nut 5 by the projection 11 formed on the lower surface 10b of the washer 10 is locked by the projection 11 formed on the upper surface 10a of the washer 10 The engagement convex part 30 engaged with the washer 10 is formed in the lower surface of the nut 6, respectively (refer FIG.13 (c), FIG. 14).

The mechanism of the formation of the engagement convex portion 30 by the projections 11 (the digging projections 12 and the locking projections 13) formed on the washer 10 is as follows.
When the washer 10 interposed between the tightening nut 5 and the locking nut 6 tightens the locking nut 6 strongly, the projections 11 respectively formed on the front surface 10a and the back surface 10b of the washer 10 contact each other. The surfaces of the nuts 5 and 6 are strongly pressed. At this time, the projection 11 digs into the surface of the abutting nuts 5 and 6 and performs an action of raising the meat around it, that is, an action of digging up the meat portion and a digging up 12 The engagement projection 30 is formed between the dug-up projection 12 and the detent projection 13 because the detent projection 13 plays a role of blocking the fat portion (FIGS. 13A to 13C). )reference).

And, after the tightening of the locking nut 6, the engaging convex portion 30 formed on both the nuts 5 and 6 and the projection 11 of the washer 10 are engaged with each other, and the engaging means for preventing relative rotation of the both nuts Thus, the tightening nut 5 and the locking nut 6 are integrated through the washer 10 and can not rotate independently.
On the other hand, a fastening nut 5 screwed on an external thread 4a formed on the main body shaft portion 3a of the bolt 1 and a locking nut 6 engaged on an external thread 4b of the small diameter shaft portion 3b of the bolt 1 The degree of progress due to rotation is different, and the tightening nut 5 and the locking nut 6 can not rotate together.
Both actions described above, that is, an action of integrating the tightening nut 5 and the locking nut 6 through the washer 10 by the engagement means comprising the engagement convex portion 30 formed by the projection 11 provided on the washer 10, And a fastener capable of reliably preventing loosening of both the nuts 5 and 6 from the bolt 1 due to the action of providing a pitch difference to block the turning of the tightening nut 5 and the locking nut 8 together. Become.

  As mentioned above, although embodiment of the fastener which consists of a volt | bolt, a nut, and a washer which concerns on this invention was described, this invention is not limited to the embodiment as stated above at all, This invention described in the claim It is natural that various modifications and changes are possible within the scope of the technical idea of the invention.

  The fastener according to the present invention is widely used to fasten parts used in environments where vibration is applied, for example, fasten parts of home appliances such as automobiles, ships, aircraft, and even washing machines equipped with motors. It is something that can be done.

Reference Signs List 1 bolt 2 head 3 shaft 3a main body shaft 3b thin diameter shaft 4a male screw 4 b male screw 5 tightening nut 6 female locking nut 7 female screw 8 female screw 10 washer 10a front 10b back 11 protrusion 12 digging protrusion 13 Retaining projection 14 Recess 20, 21 Fastening member 22, 23 Through hole 24 Washer 30 Engaging projection

Claims (4)

  The shaft portion of the bolt is a main shaft portion and a narrow diameter shaft portion present on the tip side, and an external thread is provided on the main shaft portion, and the narrow diameter shaft portion has a pitch greater than that of the external thread provided on the main shaft portion A narrow external thread is provided, and a female thread to be engaged with an external thread provided on the body shaft is provided on the tightening nut, and a female thread to be engaged with the external thread provided on the small diameter shaft is provided on the locking nut A fastening nut is screwed on the main body shaft and a locking nut is screwed on the small diameter shaft, between the tightening nut and the locking nut, A surface of the clamping nut and the locking nut to be abutted is excavated on the surface and the back surface, and a washer provided with a pair of projections forming an engagement convex portion therebetween is interposed. , Fasteners.   The fastener according to claim 1, wherein a pair of projections provided on the washer are formed at different positions on the front surface and the rear surface, respectively.   The pair of projections provided on the washer digs up the surfaces of the clamping nut and the locking nut that are in contact, digs up the protrusions, and blocks the digged up and raised portions by the digged protrusions, The fastener according to claim 1 or 2, further comprising a locking projection that forms the engagement projection with the raised projection.   4. The fastener according to claim 3, wherein the digging projections and the locking projections are respectively formed on slightly different circumferences slightly shifted on the front and back surfaces of the washer.

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