JP2008215466A - Locking bolt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of not yet producing an excellent object of a locking bolt, though fastening by fastening a sub-object by a bolt by cutting a tap in a main object when a nut cannot be used, since a locking nut is invented and effectively utilized, due to being a case of loosening a screw, particularly, easily causing its looseness in a machine and a building receiving vibration, though fastening of an object and an object by screw-fastening is indispensable in the machine and the building. <P>SOLUTION: The bolt having a through-hole in the axial direction is made, and a split is formed on the screw side of this bolt, and a conical hole is made here, and a tap groove is formed on this inner surface. A collarless set bolt is screwed in its hole with a wrench hole as the innermost side. After fastening this bolt by being inseted into a tap hole, a wrench is inserted into a head of the bolt from a certain hole, and a set bolt is rotated so as to be drawn inside, and a tip part of the bolt is expanded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In structures such as machines and buildings, screws are the most effective for fastening objects together with screws. Screws are often used because a large tightening force can be easily obtained, but there are also uncertain factors, so they have an important role that greatly affects the reliability of the entire product.

  This uncertain element is that the screw is fixed by the friction of the screw surface obtained from the tightening force generated by the axial pulling force (hereinafter referred to as axial force) of the bolt given by the rotational torque. For tightening caused by rotational torque when tightening due to the axial shape of the screw surface due to the fine shape, surface strength, surface treatment, oil and fat adhering to the surface, parallelism of the joint surface, paint, etc. The axial force of this is to change greatly.

  Furthermore, there is a problem of whether the axial force to be applied falls within the elastic deformation or the plastic deformation region past the yield point. Especially when the force applied to the screw changes due to vibration, if the axial force is weak, it is instantaneous. When the friction of the threaded portion is reduced, and when it is tightened to the plastic deformation region, it is not restored to the original shape when it is pulled by a strong force and further deformed, and the friction is reduced. Looseness occurs when this is repeated.

  When there are holes that pass through two objects, bolts and nuts are used as screws, and the bolts and nuts fasten the objects together. On the other hand, when a thread groove is formed on one object by a tap or the like, the object is fastened by tightening only with a bolt.

  Tightening with this screw is always accompanied by the danger of loosening by rotating in the opposite direction when it is not desired, when friction is reduced, as well as an excellent tightening function. This is also related to the condition of the friction surface, but this danger is particularly great in machines and buildings with vibration.

  In order to prevent this loosening, it is usually tightened carefully so that the tightening force is optimal, i.e. the axial force is within the elastic deformation of the bolt or at the initial stage where plastic deformation begins. In many cases, a torque wrench is used, but the uncertain element of the screw still cannot be erased.

  In machines and buildings with vibrations, attention to axial force when tightening screws is not sufficient, and various inventions have been made to prevent this loosening. In particular, in the case of a structure that is tightened on the nut side, a product having an appropriate function has been born, but a bolt that has not yet performed a sufficient function has not been born.

  The present invention relates to the prevention of loosening of the bolt, and relates to a technique for providing a method for making contact between screw threads and screw grooves more dense than normal tightening.

  On the inner side of the hole, a nut having a crest formed in a spiral shape as a hook and a bolt having a crest formed in a spiral shape at the same pitch are formed at the same interval and inclination. Therefore, when it rotates, the contact surface between the mountain portions slips and moves, and the distance between the seat surface of the bolt head and the seat surface of the nut is shortened, whereby the two objects are tightened and fixed.

  As shown in FIG. 3, the ridges of the bolt and the groove of the nut and the irregularities of the bolt groove and the ridge of the nut are completely integrated and in contact with each other without gaps (hereinafter referred to as complete engagement state). It is ideal to prevent loosening, but if the diameter is the same, the threads will not slide and tightening rotation will not be possible. It is made so that there is a slight gap between the peak and the groove.

  That is, the relationship between the tightened bolt and nut crest and groove is as shown in FIG. 4 in which only one slope of the ridge formed by the crest is in contact with the bolt, and the extension of the bolt due to the axial force applied to the bolt. The screw is tightened and the two objects are fastened in a state of being pulled by the restoring force of the elastic deformation and the elastic deformation due to the deformation of the collar.

  When it is desired to release the fastening of two objects, it can be loosened by applying a particularly strong rotational force to the screw in the reverse direction of the fastening. It is advantageous to be caulked with mountain ridges and mountain ridges in this way, and because machines and buildings usually require the function of loosening without destroying the screws, There is also a side where a combination of bolts and nuts is often used.

  However, when two objects are fastened, a force is applied in a direction away from one of the two objects, and the force disappears so as to return to the original position, that is, vibration in which the axial force repeatedly changes. Is given, a phenomenon occurs in which the contact portion of the slope temporarily leaves or the frictional force decreases momentarily. When it returns to the original position, the bolt and nut crests and crest contact portions do not return to their original positions, but return to the side where the contact pressure, that is, the frictional force becomes weaker.

  When this phenomenon is repeated due to vibration, the axial force decreases, the frictional force between the peak and peak of the bolt and nut gradually decreases, and when the frictional force becomes weaker, this phenomenon is more likely to occur and the object is fastened. The bolts and nuts that are being tightened are loosened.

  A common way to prevent this is a double nut, but there is doubt about its effectiveness, this is the first nut-bolt contact to push the nut once tightened from above with another nut This is because the pressure is weakened and the two nuts are loosened by rotating in the same direction.

  Also, a solidified sticky material called Loctite (trade name) is applied to the contact surface, and after tightening, the threads are bonded together, or the gap 9 is filled to move in the loosening direction when the contact pressure is weakened. However, in this case, when it is necessary to loosen, there is also a problem that it may not be loosened unless a force close to breaking the bolt head is applied.

  Methods for preventing this phenomenon of loosening have been proposed in many inventions, each with excellent features. This issue of loosening prevention is a major theme and there are few complete solutions, so there are many applications. In addition, although the contents of the invention are diverse, we have chosen to include the problem of preventing nuts that are essentially close to problems, and these are summarized and shown below.

JP-A-5-187428 JP-A-5-209612 JP-A-5-321921 JP 7-4417 A JP-A-8-14241 JP-A-8-42544 JP-A-8-42551 JP-A-8-121455 JP-A-9-210039 JP-A-10-19026 JP 10-37936 A JP-A-10-73118 JP-A-10-131937 JP-A-10-141349 JP-A-10-153211 JP-A-10-184634 JP-A-10-286649 JP 10-311324 A JP 11-6516 A JP-A-11-125231 JP-A-11-128560 JP 2000-120644 A JP2001-116032 JP 2001-334343 A JP 2002-130231 A JP 2002-195236 A JP 2002-206515 A JP 2002-372024 A JP 2003-42128 A JP2003-120642A JP 2003-148438 A JP2003-184848 JP2003-278280 JP 2003-287014 A JP 2003-301829 A JP2004-316715A JP2004-324820 JP-A-2005-9545 JP 2005-69347 A JP 2005-163299 A JP-A-2005-337358 JP-A-2005-344772 JP 2006-10054 JP-A-2006-45588 JP 2006-84017 A JP 2006-153146 A JP 2006-242206 A JP 2006-258199 A WO01 / 014753

  The shortest method for preventing loosening is to stop the rotation of the screw by attaching a detent to the washer. Patent Document 10, Patent Document 18, and Patent Document 47 correspond to that, but articles Since the loosening prevention is established by damaging the surface, there is a problem that once the wound is destroyed, the effect is lost.

  As a method of trying to use an adhesive or a buffer material, Patent Document 16 is an idea of letting an unnecessary portion of the inserted adhesive escape from the hole in the center of the bolt to increase the friction of the contact surface. Similarly, the idea is to make a hole and inject the adhesive into the meshing part of the screw part. This is probably inconvenient when it is desired to loosen, since both the thread contact surface and the gap 9 are bonded together. Patent Document 46 also attempts to promote the penetration of the adhesive by a groove that crosses the thread, but has the same problem.

  Patent Document 21 uses the fact that the space at the tip becomes smaller when a bolt is inserted into a tapped hole and tightened, and an elastic material is put here to push it out to the meshing part of the screw part. It is. In Patent Document 36, a linear elastic body is wound around the thread of the bolt to prevent it from loosening, and Patent Document 38 attempts to prevent the loosening by placing a buffer on the seat surface of the bolt. Although it is effective, if the loosening starts, the effect is lost.

  There are things that try to stop the rotation of the nut with a cover to cover, Patent Document 30 and Patent Document 44, which are effective according to the purpose and use scene.

  As a special method, there is a method of winding a coil spring of Patent Document 20 around a thread groove, but there is a concern about the tightening strength because the contact area is small. Patent Document 42 is a method of making protrusions and grooves and meshing them, and Patent Document 22 and Patent Document 32 are methods of using screw grooves with different pitches, but there are doubts about the effectiveness. Patent Document 8 and Patent Document 40 attempt to partially reduce the pitch, or crush the pitch to partially increase the frictional force with the bolt, but the effect is also questionable.

  Patent Document 7 discloses an effective use of the washer. This is intended to spread the pressure applied to the seating surface by placing a washer with a thick outer periphery on the seating surface of the nut head. If it is, it is invalid.

  There is an invention in which when a nut is tightened, the screw is tilted by the force, and a dense part is formed in meshing between the peak part and the groove part. Patent Document 15 reduces the thickness on one side. It is going to be done with a tilted washer, and this becomes invalid once loosened. Patent Document 43 is excellent in that the bearing surface of the nut is inclined, and in this case, there is also an effect of a double nut. In patent document 31, the effect of a double nut and the effect of an inclination are anticipated, and the substantially similar effect can be anticipated.

  Patent Document 13 does this for a bolt. The seat surface of the head of the bolt is tilted, so that the tip of the bolt is expected to bend, but the magnitude of the effect is unknown.

  As a foreign material, Patent Document 34 attempts to maintain an axial force with a spring against a large contraction of a fixed article such as wood, but it is unclear whether it is effective against vibration. In Patent Document 41, tightening is performed via a spring washer, which is also mainly intended for contraction of wood. Patent Document 33 is also an object of wood, but it is necessary to insert a wedge further to forcibly spread the spring and sometimes apply a hand. In either case, the position of the bolt and nut is maintained only by the friction generated by the axial force.

  There is a double nut method of reverse screw. Patent Document 12 and Patent Document 35 correspond to this. The former is a screw whose thickness is changed and the inside is thick, the outside is thin and a reverse screw is formed, and the latter is formed with a reverse screw bolt in advance on the bottom surface of the nut. The nut of the reverse screw is screwed into this. In both cases, the two nuts rotate in the reverse direction, making it less likely to loosen than the double nut, but there is no complete engagement.

  Patent Document 1, Patent Document 5, Patent Document 9, Patent Document 25, Patent Document 28, Patent Document 45, and Patent Document 48 are the simplest ones that try to use the wedge effect straight. These are things that are tightened so that the diameter of the screw becomes thin by the wedge effect using the force of screwing, and there is a possibility that it is in a completely meshed state, but both are used for nuts .

  It is an effective material, and the unevenness that engages eccentrically on the mutual contact side of the double nut is made, and after tightening the nut in a state where it is engaged, only the outer nut is further tightened, and by eccentricity, it is transverse to the axial direction. There is Patent Document 29 in which a force in the direction is generated between two nuts to increase the pressing pressure of the nut crests on the bolt crests. This is the difference between the eccentricity and the diameter of the bolt nuts. There is a problem that there is a narrow optimum value.

  Similarly, using the effect of eccentricity, using the wedge effect together, using a washer that has a tapered convex part, the taper is eccentric, and drilling a concave part in the center of the seat surface of the nut that meshes with this, There is an invention in which the concave portion and the convex portion of the washer are meshed and a force is generated in the lateral direction when the nut is tightened. Although this is patent document 27 and patent document 39, some anxiety remains in the slip between the lower surface of a washer and the object to be fastened. This effect disappears when the tightening force with the object is lost.

  Furthermore, there exists invention shown by patent document 19 and patent document 26 as an outstanding thing. This is because the double nut has tapered recesses and protrusions that mesh with each other, keep one eccentric, tighten the first nut of the double nut, and then tighten the subsequent nut. The two nuts engage with each other through the bolt crests also in the lateral direction, creating a partial but complete engagement. In this case, the engagement between the nuts does not change regardless of the fastening force with the object to be fastened, that is, even if the axial force changes.

  The invention of Patent Document 14 also utilizes lateral stress due to eccentricity, and the invention of Patent Document 49 projects a curved surface to the seat surface of the nut, dents this surface, and tightens the screw. This surface is deformed and the bottom of the screw is to be deformed.

  In the inventions of Patent Document 17 and Patent Document 24, an inclined mountain shape having a vertical groove with a thin meat is formed on the top of the nut, and this is squeezed with a force from above to make the inner diameter of the nut a desired diameter. When tightening the nut and tightening the nut, it uses the elasticity of this mountain-shaped part to tighten it tightly and make an excellent meshing state with the thread surface of that part.

  As described above, some locking nuts are effective, but this cannot be used for the purpose of fastening and fixing a secondary object having a hole in a main object formed with a tap. In this case, the tip of the bolt cannot be used, and no effective invention is found.

  Bolts using the same principle as the inventions of Patent Document 17 and Patent Document 24 are presented. That is the invention of Patent Document 37, but the effect on the tip of the bolt away from the position where the eccentricity is made is reduced.

  In the invention shown in Patent Document 11, a disc receiving member having an eccentric taper hole is inserted at the bottom of a tap hole, a protrusion having a taper is formed at the tip of a bolt, and when the bolt is tightened, the hole and the protrusion are engaged with each other. However, if the depth of the tapped hole is not exactly as desired, it will not be effective.

  The invention of Patent Document 3 also has a wedge placed on the bottom of the tap hole and the tip of the bolt can be widened with this, but it has the same problem of requiring depth accuracy, and when the bolt is once loosened This wedge effect disappears.

  In the invention of Patent Document 4, a through-hole is formed in an outer bolt, a hole that spreads in a trumpet shape is formed at the tip of the outer bolt, and a split is provided at the tip of the outer bolt. On the other hand, an inner bolt that is thinner than the through hole is provided, and the opposite side of the screw side is formed into a wedge shape with an enlarged tip, and this is passed through the through hole of the outer bolt. After tightening the outer bolt, The nut is squeezed and pulled, and the tip of the outer bolt is widened by the wedge hole-shaped portion at the tip of the outer bolt so as to make a complete meshing state with the tap hole.

  The invention of Patent Document 2 is based on the same concept, in which a tapped hole is cut inside the wedge-shaped portion, and a screw formed at the tip of the inner bolt that is thinner than the through hole of the outer bolt is replaced with a screw cut into the tapped hole. By engaging the mountain and tightening the inner bolt, the wedge-shaped portion is pulled, the outer shape of the outer bolt is expanded, and a complete engagement state between the outer bolt and the tap hole is created.

  Although the inventions of Patent Document 2 and Patent Document 4 are both based on an excellent idea and effective, it seems that the magnitude of the effect does not reach a fully engaged state. This means that the wedge must be pulled within the range of the axial force of the thin inner bolt, and that the screw's expansion and contraction influences the spreading force of the wedge, and this screw is used to give a sufficiently strong axial force to the thin inner bolt. This is because there will be a limit on the diameter.

  The invention of Patent Document 6 is also a different idea. This is done by first screwing a set bolt into the tapped hole with the hexagon wrench hole facing up, and tightening a bolt with a through hole on it. Next, a hexagon wrench is inserted through the through hole of the bolt, the set bolt is rotated in the loosening direction, and the bottom of the bolt is pushed up from the bottom, so that an effect like a double nut is exhibited. In this case, there is an effect of further strengthening the contact between the peak of the bolt and the tap peak of the tap hole, which seems to be effective, but this is the same effect as tightening the bolt strongly, but with the set bolt It is effective because there is friction. However, since the depth of the tapped hole is used with this set bolt, it can be used when the tapped hole is deep, but it cannot be used with a tapped hole with a shallow depth.

  As described above, the locking nut has sufficiently solved the problem, but there are many machines and buildings that cannot use the nut. In other words, the problem of preventing loosening is still unsolved in bolts. The ideal tightening between the bolt and the tapped hole is not due to friction caused by the strong contact caused by the axial force between the peak of the bolt and the peak of the tapped hole due to the axial force. The state is also partial. Although it is made in the locking nut, it is not yet made in the relation between the bolt and the tapped hole.

  As described in Patent Document 2 and Patent Document 4 described above, there is a bolt that penetrates the inside of the bolt and uses this to widen the diameter of the bolt by the wedge effect, but it is necessary to obtain a complete meshing state. It seems impossible to expect thin bolts that pass axial force inside and thin threads that tighten them, and the method of embedding set bolts as in Patent Document 6 requires the depth of the tapped holes. Not practical.

  In particular, in order to increase the degree of freedom in designing machines and buildings, and to make the structure compact and simple, a combination of tapped holes and bolts is necessary, and there is also a desire to reduce the number of bolts used. . Furthermore, bolts having a locking function are often necessary particularly in machines and buildings with vibration.

  In this case, usually, when the bolt is squeezed, an adhesive or an adhesive is applied to the bolt and tightened, or a deforming resin is wound and tightened, and the peak and the peak of the bolt and the tap are bonded or contacted. Although the engagement state is strengthened by filling the gap portion 9 formed on the opposite side of the surface, it is difficult to loosen and separate the objects from each other.

  It is an object of the present invention to provide a safe bolt that is in a fully meshed state in a state where a normal bolt is used, has no danger of loosening, and can be loosened freely when it is desired to loosen. It was possible to solve this problem.

  In the present invention, a bolt has a head that meshes with a tightening tool, and a bolt having a seating surface at a contact portion between the head and an object and having a through hole is used. A split of reference numeral 13 is provided at the tip of the bolt on the screw side, a cone-shaped hole is formed toward the inner side of reference numeral 4, and the diameter becomes thinner toward the inner side of reference numeral 5 or the groove is shallow. A tap groove is formed. A set bolt having a pitch of meshing with the tap groove and a bolt-shaped thread of reference numeral 6 in the screw direction is used to form a hexagonal concave part of reference numeral 7 that meshes correctly with the tip of a hexagon wrench used for this.

  A normal existing product may be used for this set bolt, or a bolt having a narrow tip that meshes with a cone-shaped tap hole of reference numeral 5 whose diameter becomes narrower toward the back is also effective. The direction of the thread may be normal or reverse.

  It is desirable that the hole diameter made in the bolt is the minimum diameter within the range necessary for turning without the maximum diameter of the hexagon wrench. However, since the axial force is the relationship between the cross-sectional area of the bolt and the thread, the diameter is small. The influence of the central part is small and may not be very strict. This hole may be made at the time of manufacture of the bar material used as a raw material, or may be opened at the time of subsequent screw machining.

  This standard screw shape is shown in FIG. 1 in a cross-sectional view taken along the line A-B-C, which is a view of the screw portion viewed from the screw side. This shows the situation when two objects are fastened by tightening bolts. Reference numeral 1 denotes a through hole of the bolt, reference numeral 2 denotes a screw thread part on the bolt side, reference numeral 3 denotes a screw thread part on the tap hole side formed on the object of reference numeral 11, and the reference numerals use common numerals hereinafter.

  The bolt is inserted into the hole of the sub-object 12 and tightened, and then the set bolt is rotated by meshing with the hole 7 of the set bolt through the wrench from the hole 8 on the head of the bolt. Is a rotation direction in which the set bolt moves in the direction of the head of the bolt in accordance with the twist direction of the screw thread. By this rotation, the set bolt expands the thread portion of the reference numeral 2 and the thread of the tap hole of the reference numeral 3 The diameter is increased so that a complete meshing state as shown in FIG. 3 can be obtained from the state shown in FIG.

  The state is shown in FIG. This state is similar to the situation that would be shown in Patent Document 17, Patent Document 24, Patent Document 19, and Patent Document 26 for nuts. However, in the case of the present invention, it is not tightened against strong friction, and it does not make a complete meshing state due to eccentricity, but it tries to uniformly thicken the bolt with an outward force perpendicular to the axial force direction from the inside. This is not only suitable for places where nuts cannot be used, but also has a stable fastening force.

  When the set bolt is rotated, the engagement between the crest and the crest of the screw becomes deep, so that the bolt moves in the direction in which the axial force increases. It is more effective to consider the torque at which the bolt is first tightened so that the axial force is an appropriate value, and to obtain an optimal axial force when the set bolt is tightened. There is also a method of tightening firmly within the elastic limit range that does not reach the yield point, returning it by a predetermined angle, and tightening the set bolt again. Further, tightening without taking these into consideration, even if the axial force increases to the plastic deformation range, even if the fastening force of the two objects decreases, loosening due to vibration does not occur.

With regard to the division of reference numeral 13, if the number of divisions is increased in a state where there is no clear space, the axial force can be maximized. Further, the division of the reference numeral 13 may not be a complete dividing groove, and may be in a state where a thinned portion is left without being completely divided in the thickness direction.
Although it is described as a hexagon wrench, it needs to be engaged, and may be a square or a star.

  In the present invention, a slit 13 is provided at the tip of a bolt having a through-hole, a cone-shaped tap hole is formed, a set bolt is engaged with this, and after tightening the bolt, the set bolt is Rotating with a wrench that passed through the through hole to increase the diameter of the bolt to a large thickness, and this was configured to fully engage the thread formed on the tap with the thread formed on the bolt. It is.

  According to the present invention, a tapped hole having a normal depth formed in a main object having a lot of vibration is used, and the sub-object having the hole is fixed by a normal fixing method. After tightening the bolt, use a hole in the bolt to insert a wrench, and by simply rotating it, the bolt will become thicker and a fully engaged state can be created. Can do.

  Coupling of objects by fastening them is indispensable for machines and buildings. Machines and buildings with no vibration or load changes are rare. Providing bolts with extremely low risk of loosening according to the present invention in such situations is an infinite contribution to the advancement of machines and buildings and the lives of those who benefit from them. It has characteristics that are effective for industrial use.

  Several embodiments of the present invention will be described below with reference to the drawings. For further understanding of the present invention.

  FIG. 1 is an explanatory diagram of the technical contents of the present invention. If dimensions are entered at the same time, it will be a drawing of the embodiment itself, which will be described.

The bolt is M10, the outer diameter of the screw is 9.9 mm, the inner diameter of the tap hole is 8.6 mm, the screw pitch is 1.6 mm, the bolt head thickness is 7 mm, the hexagonal opposite side is 17 mm, The length is 20 mm.
A 3.5 mm hole is formed through the center of the bolt in the axial direction. A slit having a depth of 12 mm is cut in a cross shape in the axial direction on the screw portion on the opposite side of the head of the bolt of the hole, and the slit width is 0.5 mm.

  An M6 tapped hole is cut to a depth of 12 mm on the threaded side, and the groove becomes shallower as the tapped hole goes deeper. This is because when tapping a tap hole using a tap, it can be easily controlled by tapping the depth of the tap, but originally the groove is not formed shallowly and the cross section formed by the peak and groove is not changed. It is desirable to form so that it may become thin.

  A set bolt of M6 is screwed into the tapped hole cut into this screw with the engagement hole with the wrench inside. In this case, no special lubricant was used. Although it is desirable to form this set bolt so that the tip end side is thin, a normal set bolt is used here. In this case, the pitch of the screw is 0.5 mm, and the bolt in which the set bolt is embedded is used.

Tapping a 10 mm thick object with a reference number 11, while making a 10.2 mm through hole in a sub object with a reference number 12, and tightening these two objects with a torque wrench to the upper limit of the elastic range using this bolt, Thereafter, the hexagon wrench was rotated in the reverse direction to raise the set bolt toward the head of the bolt. As a result, even if an attempt was made to loosen this bolt, it did not loosen even when a rotational torque of 5 times the tightening force was applied.
Good tightening results were obtained by tightening the set bolt after weakening the tightening force with the torque wrench.

  In the torque wrench for the hexagon head bolt, the hexagon wrench is pushed out from the center of the socket into which the hexagon head of the bolt is pushed by a spring, and supported through the hole in the center of the bolt shaft. The bolt is inserted into a target hole having a tap formed in the back, and the bolt is first tightened, and then the hexagon wrench is rotated to the side where the set bolt is pulled. This was produced as an integrated torque wrench.

  The object to be tightened is a concrete sleeper, in which a washer having a tap is embedded. Place cushioning material on this, put the rails on it, and place the spring retainer. The bolt was tightened to an appropriate spring strength from above, and the built-in set bolt was rotated to the drawing side with a hexagon wrench through the through hole, thereby tightening the tap hole and the bolt. Even when the sub-object was not a hard substance and the pressure on the seating surface of the bolt head was not strong, no loosening occurred.

  When fastening wood such as a building, contraction of an object occurs. Also, in order to avoid exposing the metal to the outside, the nut and spring are hidden inside, and it is often desirable to stop loosening of the bolt. After installation, the wood structure of the structure in which the nut and spring cannot be touched Was effective. Tightening with packing, gasket and spring in the middle was tried, but the result was good. It is also good when you cannot expect the frictional resistance of the bearing surface to rotate in the loose direction.

  This is necessary when the external hexagonal head shape of the bolt that can give a strong tightening force cannot be used, and there is only a flat screwdriver groove in the center with a flat round seating surface. When a through hole was opened in the heart and the screw portion was provided with a method similar to that of the present invention, sufficient fastening could be performed.

  In the present invention, the through hole and the screw tip are processed, and a lubricant is applied to the tap hole, and the set bolt is screwed into the product. The bolt main body which processed the front-end | tip part may be made into a product separately, a bolt may be used as a bolt, or a set bolt may use a commercially available thing. This means that it can be used as a common member even in the case of an object that does not require a complete product.

Cross-sectional view of the locking bolt of the present invention Figure of the screw thread of the locking bolt Cross section of fully engaged state Sectional view with normal screws tightened

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Through-hole 2 Thread part of a bolt side 3 Thread part of a tap side 4 Upper part of cone-shaped hole 5 Tap groove of cone-shaped hole 6 Set bolt 7 Hole of set bolt meshing with wrench 8 Bolt head hole 9 Cavity that can usually be tightened screw 10 Bolt 11 Main object on the side where the tap is formed 12 Sub-object to be attached 13

Claims (2)

  In the bolt having a hole penetrating in the axial direction, an axial split is made on the tip side of the bolt, a tap groove in which the screw diameter in the back is reduced is formed in the opening of the through hole, and the diameter of the through hole is A set bolt with a thickness through which the wrench to be used passes and a set bolt with a hole engaging with the wrench inside is inserted into the tap groove.   There is a hole penetrating in the axial direction, there is a split in the axial direction on the tip side of the bolt, a tap groove is formed in the opening of the through hole, and the through hole is a thickness through which the hexagon wrench to be used passes. A bolt with a set bolt having a hexagonal hole inside which meshes with a wrench, the tap groove and the bolt crest of the set bolt being formed as the diameter becomes smaller toward the inside, and a locking bolt.

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