JP2012251648A - Screw fastener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw fastener that requires only one operation for fastening and prevents loose due to vibration.SOLUTION: The screw fastener includes a bolt with a main screw threaded on a screw tip side, and a sub screw having a pitch smaller than that of the main screw and threaded on a head side, and a washer, or a washer and a sub washer. In the washer, a female screw to be screwed to the sub screw of the bolt is threaded.A whirl stop relative to a member to be fastened is formed by a projection tooth projecting on a seat face in contact with the member to be fastened of the washer, or projection teeth projecting on both sides of the washer to be interposed between the washer and the member to be fastened, and the washer is screwed in from the bolt head side.

Description

  The present invention relates to a screw fastening body including a bolt and a nut having a locking function.

  In a screw fastening body, it is known that when a bolt shaft perpendicular load is applied to a member to be fastened after the bolt and nut are tightened, the screw of the bolt nut is loosened. This loosening of the screw is a phenomenon that occurs very frequently at the site of factory equipment and is exposed to this danger everywhere in any screw fastener. Therefore, as a countermeasure against the loosening of the bolts and nuts, periodic tightening of the bolts is performed as one of the maintenance activities.

  Conventionally, various techniques have been disclosed for screw fastening bodies of bolts and nuts depending on the necessity, and a technique for fastening using a screw pitch difference such as a double nut as a screw fastening body having a locking function. It is disclosed. For example, a screw bolt having a tightening engagement portion in which a screw is engraved in each of the bolt body and the bolt head and the screw pitch between the bolt body and the bolt head is different, and the bolt head of the screw bolt A technology of a locking bolt including a lock nut that is screwed onto a screw of a part is disclosed (for example, see Patent Document 1).

  The bolt has a screw washer that is screwed to the base of the bolt. The base of the bolt has a large diameter, and a male screw to which the screw washer is screwed is formed on the outer periphery of the bolt. A technique of a bolt locking device in which the screw is formed at a pitch larger than that of the male screw formed on the front end side of the bolt is disclosed (for example, see Patent Document 2).

JP 60-196420 A JP 05-332338 A

  The technique of the screw fastening body of patent document 1 and patent document 2 has the operation | work which tightens the subnut with different pitches after the operation | work which tightens a main volt | bolt or a main nut, from the tightening work by the double nut method which consists of a normal nut. Although it is not complicated, it requires two operations that are substantially the same as a screw fastening body made of a double nut, and has a larger number of work than one work for fastening a screw fastening body made of a single bolt nut. There was a problem that it was impeding practical use at production sites.

  Furthermore, since the technology of the screw fastening body of patent document 1 and patent document 2 aims at prevention of loosening with a high surface pressure between a nut and a member to be fastened, a bolt in a fastening state due to a loosening factor such as a large vibration or the like. When the nut is integrated with the sub-nut, a slip phenomenon may occur between the bottom surface of the sub-nut and the surface of the member to be fastened, and the screw may be rotated. There was a problem that there was only the same loosening prevention effect.

  Therefore, the object of the present invention is that the number of tightening operations for the screw fastening body is the same as the number of ordinary bolt and nut tightening operations, but the bolts and nuts that are in a tightened state are integrated due to loosening factors such as vibration. It is providing the screw fastening body which does not loosen in.

  The inventor realizes the elimination of the troublesome work that is the current problem and the prevention of rotation due to the slip phenomenon that occurs between the member to be fastened and the screw fastening body, while preventing loosening using the pitch difference. The present invention has been developed.

  In the present invention, the pitch and outer diameter of the “main screw” are designed according to the standards defined in JIS, but the pitch and outer diameter of the “sub screw” are established in JIS. Designed not limited to standards.

  In order to solve the above-mentioned problems, the invention of the screw fastening body 1 according to claim 1 is characterized in that the main screw 3 is threaded on the screw tip side and the sub screw 4 having a smaller pitch than the main screw 3 is the head. A screw fastening body 1 including a bolt 2 screwed to the side and a washer 7 or a washer 7 and a washer 20, and the washer 7 is screwed by a female screw that is screwed into the auxiliary screw 4 of the bolt 2. The protrusions 8 are engraved and protruded on the both sides of the washer 20 interposed between the washer 7 and the member to be fastened by the protruding teeth 8 protruding from the seating surface in contact with the member to be fastened. The protruding teeth 8 prevent rotation relative to the member to be fastened, and are screwed in from the bolt head side.

  The invention of the screw fastening body 1 according to claim 2 is the invention according to claim 1, wherein the outer diameter of the main screw 3 and the auxiliary screw 4 of the bolt 2 is the same as the outer diameter of the auxiliary screw 4 of the bolt 2. In the case where the outer diameter of the auxiliary screw 4 of the bolt 2 is larger than the outer diameter of the main screw 3 or the outer diameter of the auxiliary screw 4 is larger than the outer diameter of the main screw 3. 4 is any one of the cases in which several small thread grooves are communicated with a small outer diameter portion on the main screw 3 side and screwed.

  The invention of the screw fastening body 1 according to claim 3 is the structure according to claim 1 or 2, wherein the main thread portion of the bolt 2 and the thread groove of the sub screw portion are adjacent to each other, or the main body of the bolt. A feature is that the screw portion and the sub screw portion are separated from each other, and a non-threaded portion of the screw groove is provided between the main screw portion and the sub screw portion.

  According to a fourth aspect of the present invention, there is provided the screw fastening body 1 according to any one of the first to third aspects, wherein the outer peripheral surface of the washer 7 has a cylindrical or conical shape in which a fastening tool hook is not formed, or the washer 7. It is characterized by using a polygonal columnar shape in which a tightening tool hooking portion is formed on the outer peripheral surface shape.

  According to a fifth aspect of the present invention, there is provided the screw fastening body 1 according to any one of the first to fourth aspects, wherein the substantially triangular shape of the protruding teeth 8 is a seating surface of a washer 7 provided with a fastening portion of a fastening tool on the outer peripheral surface. As for the projecting teeth 8 projecting from the projecting surface, the slanting surface of the washer 7 relative to the fastening member by the tightening rotation of the bolt 2 is formed into a gently sloping inclined surface, or projecting teeth on both sides. As for the protruding teeth of the washer 20 provided with the protrusion 8, the inclined surface on the side of the relative traveling direction with the washer 7 or the member to be fastened by the tightening rotation of the bolt 2 on either one or both surfaces has a gently inclined shape. It is formed on a slope.

  According to a sixth aspect of the present invention, there is provided a screw fastening body 1 according to any one of the first to fifth aspects, wherein a groove 17 is formed on an outer peripheral surface of the lower portion of the head neck in order to break the head of the bolt 2 with a set torque. And the shaft diameter of the groove bottom portion can be broken with the set torque.

  The invention of the screw fastening body 1 according to claim 7 has a nut screwed to the bolt 2 with a member to be fastened sandwiched between the bolt 2 and the member to be fastened to the seat surface of the nut. Protruding teeth for rotation prevention to be pushed in or inserted into the member are provided.

  In the invention of the screw fastening body 1 according to the first aspect, since the seat surface of the washer 7 does not rotate with the member to be fastened, it is not affected by friction with the seat surface, the pitch difference is small, and the input rotation The efficiency of converting torque into the axial force of the bolt 2 is high, the variation in the axial force is smaller than that of the conventional bolt even in fastening by the torque method, and the rotational angle of the fastening is large. There is an effect that the deviation does not affect the axial force.

  Since the protrusion teeth 8 for preventing rotation are provided on the seat surface side of the washer 7, the protrusion teeth 8 bite into the fastened member and are fixed, so that even if a loosening factor such as vibration occurs, the washer 7 No slip occurs between the seating surface and the surface of the member to be fastened. As a result, even if a loosening factor such as vibration occurs, the bolt or nut in the fastening state does not rotate in an integrated state with the member to be fastened, so that the effect of not loosening occurs. This suggests that the loosening prevention effect is remarkably improved by the fastening technique that combines the pitch difference and the protruding teeth 8.

  Further, according to the present invention, it is possible to abolish or remarkably reduce the maintenance work of periodic tightening of bolts and nuts, and it is possible to reduce the cost such as the work cost related thereto.

  Furthermore, in the case of the conventional screw fastening body, it was tightened too much beyond the torque required for tightening, and the bolt could extend to near the yield point, but the pitch of the sub screw 4 part was made smaller than the main screw 3 part. As a result, a normal bolt having the pitch difference is used. As a result, the rotation angle of the bolt until the target torque is reached is greatly increased and it is difficult to loosen. Therefore, the operator can reduce the stress of the operator because the operator does not overtighten with peace of mind.

  Since it has the effect of not loosening, it is not necessary to increase the bolt tightening force, and it is the washer 7 provided with the protruding teeth 8 that abuts against the member to be fastened, so that the seating surface of the bolt 2 is covered. Since it does not tighten by making it contact | abut to a fastening member, the head of a bolt nut can be made small and the material saving of a bolt nut can be performed.

  Since the pitch of the main screw 3 and the sub screw 4 of the bolt 2 is different, the washer 7 cannot be screwed in from the screw tip side where the main screw 3 is screwed, but the screw groove 16 is screwed into the bolt head. Since the inner diameter of the washer 7 is sized so that it can be screwed in from the bolt head side, corresponding to the case where the screw groove is not threaded, the washer 7 can be easily screwed into the bolt 2. Play.

  If the head of the bolt 2 is made small, it is difficult to understand the proper tightening torque of the bolt 2. Therefore, if the diameter (size) of the bolt 2 is engraved on the flat surface of the upper surface of the head, etc. It can be tightened with an appropriate tightening torque.

  In addition, since the washer 20 is not provided with the protruding teeth 8 and the protruding teeth 8 are provided on the washer 20, the material of the washer 7 may be the same as that of a conventional ordinary nut, and it does not need to have high hardness to bite into the fastened member. There is an effect.

  The invention according to claim 2 has the same effect as the invention according to claim 1. Further, by making the inner diameter of the sub screw 4 part larger than the head part of the bolt 2, there is an effect that the screw groove 16 of the head part of the bolt 2 can be eliminated.

  Further, the bolt 2 has an outer diameter on the head side larger than the outer diameter on the screw tip side, and the auxiliary screw 4 is threaded into two or three threads of the outer diameter portion on the head side and the outer diameter portion on the screw tip side. In which the main screw 3 is screwed into the outer diameter portion on the screw tip side, from the state in which the seat surface of the washer 7 is in contact with the member to be fastened to the completion of bolt tightening. When the screwing length of the bolt 2 is set to the above-mentioned two or three threads, the inner diameter of the bolt through hole of the member to be fastened is smaller than the outer diameter portion of the auxiliary screw portion. There is an effect that the outer diameter portion may be a size that can be inserted.

  Invention of Claim 3 has the same effect as invention of Claim 1 or 2. Further, in the case of the configuration in which the main screw 3 and the sub screw 4 are adjacently connected, when the washer 7 is screwed into the bolt 2, it is screwed into the washer 7, so that the pitch of the screw and the large pitch of the main screw 3 are increased. The pitch difference between the two is a deterrent to the washer 7 from rotating. If the washer 7 is screwed into the bolt 2 before the bolt 2 is screwed by this deterrent, the bolt 2 and the washer 7 are integrated and screwed together when the bolt 2 is screwed into the fastened member. There is an effect that can be done. Further, even if an unthreaded portion such as a cylindrical portion is provided between the main screw 3 portion and the sub screw 4 portion, the unthreaded portion serves as a deterrent to the rotation of the washer 7, When the bolt 2 is screwed into the member to be fastened, the bolt 2 and the washer 7 can be integrated and screwed together.

  The invention according to claim 4 has the same effect as the invention according to any one of claims 1 to 3. Furthermore, when the hooking portion of the tightening tool is formed on the outer peripheral surface of the washer, there is an effect that the washer can be tightened with a tightening tool such as a socket wrench.

  The invention according to claim 5 has the same effect as the invention according to any one of claims 1 to 4. Further, when there is play between the fastened members, such as when an O-ring is interposed between the fastened members or when the fastened member is distorted, the screw 2 is screwed into the bolt 2 before the final fastening with the bolt 2 Then, the bolt is rotated together with the washer 7 and temporarily tightened. However, since the gentle slope 9 is formed, the resistance during rotation can be reduced. Therefore, when the projection teeth 8 and 9 are provided on the washer 7, it is possible to prevent the surface of the fastened member from being curled, or when the projection teeth 8 and 9 are provided on the washer 20. There is an effect that it is possible to prevent the seat surface of the washer 7 from being curled.

  The invention according to claim 6 has the same effects as any of claims 1 to 5. In addition, an annular groove is provided in the lower part of the neck of the bolt head, and the bolt head is broken and separated with a constant tightening force, so that the screw fastening body 1 is extremely difficult to loosen. There exists an effect that it is suitable for use of assembly, such as an electric wire tower or a steel frame structure. Moreover, since the tightening tool is less likely to be hooked by making the outer peripheral surface of the washer conical, there is an effect that it is not accidentally loosened.

  The invention described in claim 7 has the same effect as that of any one of the inventions of claims 1 to 6 even in the case where the fastened member is sandwiched between the bolt and the nut.

It is a schematic diagram of a screw conclusion object which made a main screw and a subscrew of the present invention continue. It is a schematic diagram of the screw conclusion object which provided the cylindrical part between the main screw and the subscrew of the present invention. It is a front schematic diagram of the washer which protruded the protrusion tooth. It is a front schematic diagram of the washer which provided the vertical groove in the outer peripheral surface. It is a plane schematic diagram of the washer which provided the vertical groove in the outer peripheral surface. It is a front schematic diagram of the washer which provided the projection tooth on the upper and lower surfaces. (A) is a conceptual diagram in the case of the screw fastening body which consists of a normal volt | bolt nut, (b) and (c) are explanatory drawings of the loosening prevention effect. (A) is a conceptual diagram of a screw fastening body according to the present invention when a secondary screw is screwed into a bolt, and (B) is a screw fastening body according to the present invention in which a main screw and a secondary screw are screwed into a bolt. FIG. It is explanatory drawing of the screw fastening body which screwed the auxiliary | assistant screw to the large outer diameter part by the side of the head of a volt | bolt, and the same small outer diameter part as a main screw. It is explanatory drawing of the screw fastening body which screwed the subscrew only in the big outer diameter part by the side of the head of a volt | bolt. It is explanatory drawing of the screw fastening body which provided the groove | channel so that a diameter might be made small in the neck lower part of a bolt head in order to make it fracture | rupture with fixed tightening force.

  The screw fastening body 1 which is this invention is demonstrated in FIG. 1 or FIG. The screw fastening body 1 according to the present invention includes a bolt 2 in which a main screw 3 is threaded on a screw tip side and a sub screw 4 having a smaller pitch than the main screw 3 is threaded on a head side, a washer 7, Or it is the screw fastening body 1 containing the washer 7 and the washer 20, Comprising: The said washer 7 is screwed by the female screw screwed together with the subscrew 4 of the said bolt 2, and the to-be-fastened member of the said washer 7 is fastened. Relative to the member to be fastened by the projecting teeth 8 projecting on the seating surface in contact or by the projecting teeth 8 projecting on both sides of the washer 20 interposed between the washer 7 and the member to be fastened. This is a screw fastening body 1 that is prevented from rotating and is screwed in from the bolt head side.

  A washer is not required when projecting teeth 8 are projected from the washer. However, when projecting teeth 8 are not projected from the washer, a washer that does not project projecting teeth, the washer, and a fastened member And a washer 20 provided on both sides with anti-rotation protrusions interposed between the two.

  Further, the structure of the screw fastening body 1 is a nut-free form when the screw is screwed into the bolt insertion hole of the fastened member 5, and the screw is screwed into the bolt insertion hole of the fastened member 5. If not, as shown in FIG. 11, the member to be fastened is sandwiched between the bolt 2 and the nut 30 provided with the projection teeth for rotation prevention.

  The screw dimensions of the main screw 3 of the bolt 2 are designed based on the standards defined in JIS, and the screw dimensions such as the pitch and outer diameter of the auxiliary screws 4 are not limited to the JIS standards.

  As shown in FIG. 1, the outer diameter of the secondary screw 4 of the bolt 2 is set equal to the outer diameter of the main screw 3 or larger than the outer diameter of the main screw 3 as shown in FIG. 2. As a result, the seating surface of the washer threadedly engaged with the auxiliary screw of the bolt can be brought into contact with the fastened member.

  In addition, when the outer diameter of the secondary screw 4 of the bolt 2 is the same as the outer diameter of the main screw 3, the washer 7 is screwed from the head so that the outer diameter of the head of the bolt 2 is Although the thread groove 16 may exist, there is no practical problem. Since the washer 7 is screwed in from the head, the outer diameter of the bolt head is smaller than the outer diameter of the threaded portion of the bolt 2. However, if the head is shaped like a dodecagon and can be tightened only with a socket wrench, the concern of slipping during tightening can be eliminated.

  Also, the outer diameter of the secondary screw 4 of the bolt 2 is made larger than the outer diameter of the main screw 3, and the internal diameter of the secondary screw 4 of the bolt 2 is designed to exceed the outer diameter of the head of the bolt 2. In this case, the thread groove 16 can be prevented from being formed in the bolt head.

  As shown in FIG. 1, the main screw 3 portion and the sub screw 4 portion of the bolt 2 are adjacent to each other in the positional relationship between the main screw 3 portion and the sub screw 4 portion. Thus, the respective thread grooves of the main screw 3 and the sub screw 4 may be communicated to be continuous, or the thread grooves may be discontinuous without communicating. Alternatively, as shown in FIG. 2, a non-threaded portion such as the cylindrical portion 11 may be provided between the main screw 3 portion and the sub screw 4 portion so as to be separated from each other.

  The pitch difference between the main screw and the sub screw, or the unthreaded portion serves as a deterrent to the rotation of the washer 7, and when the bolt 2 is screwed into the fastening member, the bolt 2 and the washer 7 are integrated and screwed. Yes.

  Here, when the washer and the bolt are set and screwed into the member to be fastened, and the bolt is tightened after the protruding tooth of the washer contacts the member to be fastened, the washer is fixed by the protruding tooth. The bolt goes in the screwing direction. In this case, as shown in FIG. 10, the diameter of the bolt insertion hole of the fastened member is larger than the outer diameter of the secondary screw portion of the bolt so that there is a gap m between the main threaded portion of the bolt and the fastened member. Keep it.

  On the other hand, as shown in FIG. 9, when the outer diameter on the head side of the bolt is larger than the outer diameter on the screw tip side, the auxiliary screw 4 is connected to the outer diameter portion on the head side and the outer diameter on the screw tip side. When the thread groove is communicated with 2 to 3 threads of the part and screwed, the diameter of the bolt insertion hole of the member to be fastened should be larger than the outer diameter of the main thread of the bolt. The gap n between the portion and the member to be fastened is smaller than the gap m shown in FIG. 10, and the inner diameter of the bolt through hole of the member to be fastened can be reduced.

  The main screw 3 and the sub screw 4 of the bolt 2 have a head shape, a main screw, and a sub screw on the shaft formed by molding the head, the main screw portion, and the sub screw portion, as can be understood by developing the screw portion linearly. Can be manufactured by rolling them separately or integrally, and no special manufacturing method is required. At this time, the external thread 4 part of the external thread can be set to an arbitrary outer diameter and pitch.

  The washer 7 is threaded at the same pitch as the secondary screw 4 of the bolt 2, so that the secondary screw 12 of the screw and the seating surface in contact with the fastened member bite into the fastened member, and the washer 7 and fastened member are connected. It consists of a shape including the protrusion teeth 8 for rotation prevention to be fixed.

  As shown in FIG. 3, when the washer 7 is not rotated with a fastening tool, the washer 7 may have any shape such as a circular shape or a square shape in plan view, but the washer is fastened for temporary fastening or the like. When rotating with a tool, in a plan view, a square shape such as a dodecagon or a plurality of grooves 10 perpendicular to the rotation direction of the washer is provided as shown in FIG. 4 or FIG. The outer peripheral surface is formed in a substantially circular shape. Whatever shape of the outer peripheral surface is preferred, there is no problem when tapping. When the nut 30 is used on the main screw side, the shape of the nut 30 is different from the main screw or the sub screw as shown in FIG. It has the same shape as the washer 7 and the same function.

  The shape of the protruding teeth 8 of the washer 7 is formed in a substantially triangular shape such as a substantially equilateral triangle or a substantially isosceles triangle in a front view, and in the substantially triangular shape, the side of the washer that is in contact with the member to be fastened is formed. As shown in FIG. 4, the shape of the anti-rotation protruding teeth 8 protruding from the seat surface is such that the surface on the tightening rotation direction side from the tip of the protruding teeth is gentle with respect to the seat surface in a front view. The shape formed on the inclined surface 9 is also included. In addition, only the tooth | gear part can raise the hardness of the protrusion tooth | gear 8 by induction hardening.

  When the washer 7 having the protruding teeth 8 having a substantially triangular shape in front view is used, the protruding teeth 8 bite into the fastened member, and the washer 7 provided with the protruding teeth 8 protrudes due to vibration or the like. It is possible to provide a screw fastening body 1 that does not rotate and does not loosen.

  Also, a washer provided with a substantially triangular protruding tooth 8 formed on a slope 9 having a gently sloping shape on the surface in the direction of relative movement from the front end portion of the protruding tooth 8 to the fastened member by tightening rotation in a front view. 7 is used, when there is play between the fastened members, such as when an O-ring is interposed between the fastened members or when the fastened members are distorted, before the final tightening with the bolt 2 heads. The washer is rotated and temporarily tightened, but at that time, the surface of the fastened member can be prevented from being curled.

  In the case where the washer is not provided with the protrusion teeth 8 for preventing rotation, as shown in FIG. 6, a flat plate-shaped annular washer 20 having protrusion teeth 8 for rotation prevention on the upper and lower surfaces is provided. Is interposed between the washer and the member to be fastened.

  The shape of the protruding tooth 8 of the washer 20 includes a shape in which the upper surface and the lower surface side are substantially triangular in front view, and the shape of the protruding tooth 8 is substantially triangular in the front view and the upper surface side protruding tooth 8 is tightened with a bolt. A shape in which the inclined surface on the side of the relative direction of movement of the washer is formed as a slanted surface 9 with a gentle slope from the tip of the protruding tooth, and the protruding tooth 8 has a substantially triangular shape on the upper surface when viewed from the front, and a protrusion on the lower surface. A shape in which the slope of the tooth 8 relative to the member to which the washer is fastened by tightening rotation of the bolt is formed on the slope 9 having a gentle slope from the tip of the projection tooth, or the shape of the projection tooth 8 Is formed with a slope 9 on the upper surface side of the projection tooth 8 on the side of the relative advancing direction of the washer by the tightening rotation of the bolt on the slope 9 which is gently inclined from the tip of the projection tooth, and the projection on the lower surface side. How the tooth 8 moves relative to the fastening member of the washer by the bolt tightening rotation The slope of the side, there is a feature that is formed on the slope 9 of the gentle slope from the distal end of the projection teeth.

  When the washer 20 having the substantially triangular shaped projection teeth 8 on the upper surface and the lower surface side in front view is used, the material of the washer 7 is not high hardness but may be the same material as a conventional ordinary nut.

  Further, when using the washer 20 in which the inclined surface of the protruding tooth 8 is formed on the inclined surface 9 having a gently inclined shape, when the O-ring is interposed between the members to be fastened or when the member to be fastened is distorted, When there is play between the members, there is an effect that no crease is generated on the washer 7 or the seating surface side of the fastened member.

  In general, when a bolt is tightened by the torque method, 50% of the torque is consumed for the friction of the bearing surface of the bolt head and 40% of the friction of the screw surface, and the remaining 10% is converted into axial force. It is easy to cause force variation, but when the protruding teeth of the present invention are provided on the washer or washer, the seat surface of the washer does not rotate between the fastened member and is not affected by friction with the seat surface. The pitch difference is small, the efficiency of converting the input rotational torque into the axial force of the bolt is high, the variation in axial force is less than that of conventional bolts in fastening by torque method, and the rotational angle of fastening is large, so the rotational angle method Even in the fastening by, the slight angle deviation does not affect the axial force. Assuming that the normal torque of the bolt is 70 Nm, the input torque to the bolt may be around 58 Nm, which is about 18 to 20% less to obtain the same axial force in the case of the present invention.

  Further, as shown in FIG. 11, a groove 17 for reducing the diameter is provided on the outer peripheral surface of the bolt head neck, and the shaft portion is set to a constant shaft diameter and twisted with a constant tightening force to break the groove portion. By separating the bolt heads, it is possible to make a screw fastening body that is extremely difficult to loosen. In this case, it is suitable for the use of assembling bridges and transmission line towers.

  At this time, if the outer peripheral surface shape of the washer 7 is conical, there is no site where a tool such as a socket wrench can be easily hooked after tightening, so that it is unlikely to loosen accidentally.

  The use of the screw fastening body 1 which is embodiment of this invention is demonstrated.

  In the screw fastening body 1 in which the auxiliary screw 4 is engraved on the bolt 2 according to the embodiment of the present invention, the first shape or the auxiliary screw 4 having the same outer diameter of the main screw 3 and the auxiliary screw 4 is used. In the second configuration in which the outer diameter is larger than the outer diameter of the main screw 3, and further in the first or second configuration, a cylindrical portion 11 or the like is provided between the main screw 3 and the auxiliary screw 4 as shown in FIG. A form in which a non-threaded portion is provided, a form in which the main screw 3 and the sub screw 4 are adjacent to each other as shown in FIG. 1 and the thread groove is continuous or discontinuous, or the outer diameter of the sub screw is larger than that of the main screw. There is a large shape with a secondary screw threaded on the main screw side by two or three threads. In either case, the washer 7 can be set on the bolt 2 before being screwed into the fastened member.

  First, the washer 7 is completely screwed into the auxiliary screw 4 of the bolt 2. At this time, when there is play between the fastened members, such as when an O-ring is interposed between the fastened members or when the fastened member is distorted, the protruding teeth 8 with respect to the seating surface of the washer when viewed from the front. A washer 7 having a protruding tooth having a shape in which the surface on the side of the relative advancing direction of the washer by tightening rotation is formed on the inclined surface 9 having a gently sloping shape from the front end portion of the member, and having a hanging portion of a tightening tool. use.

  Further, when the main screw 3 and the sub screw 4 are separated from each other, for example, a cylindrical portion 11 may be provided at an intermediate portion thereof. In this case, the cylindrical portion 11 makes it difficult to screw the washer easily.

  Then, the bolt 2 to which the washer 7 is screwed is screwed into the screw hole of the fastened member.

  As the bolt 2 is screwed into the fastened member, the protruding teeth 8 of the washer 7 come into contact with the surface of the fastened member and stop rotating, and the protruding teeth 8 protruding from the seating surface become the surface of the fastened member. Then, after the seat surface of the washer 7 comes into contact with the fastened member 5, the final fastening is started.

  Here, when there is play between the fastened members, such as when an O-ring is interposed between the fastened members, or when the fastened member is distorted, the protruding teeth against the seating surface of the washer 7 when viewed from the front. After temporarily tightening the bolt together with the washer 7 having the protruding teeth 8 having a shape in which the surface on the side of the relative movement direction of the washer formed by the rotation of tightening is formed on the inclined surface 9 having a gently inclined shape, the bolt is temporarily tightened. Turn the bolt with the head and perform final tightening.

  At the time of temporary tightening, the member to be fastened is fastened by the main screw having a large pitch by tightening the washer, so that play, snag torque, and the like are removed.

  From here, if the tool is applied to the head of the bolt 2 and tightened, the main screw 3 and the sub screw 4 are tightened simultaneously, and the main screw 3 and the sub screw 4 are about to be screwed in due to the pitch difference. A large frictional resistance is generated at the screw contact surfaces of the sub screw 4 and the washer 7, and the screw contact surfaces of the main screw 3 and the member to be fastened, and a large compressive force is generated to fix the bolt 2, the washer 7 and the member to be fastened. It becomes.

  Therefore, when the bolt 2 is screwed into the member to be fastened, the protruding teeth 8 of the washer 7 become a wedge body for preventing rotation to the member to be fastened, and the washer 7 and the member to be fastened are fixed first, and then The secondary screw 4 and the washer 7 are fixed to each other, and the bolt 2 and the member to be fastened are fixed by the main screw 3, so that the member to be fastened, the bolt 2 and the washer 7 are in a very strong fastening state.

  Next, the loosening prevention effect will be described with reference to the conceptual diagram of the bolt and nut combination of the present invention. First, the case of a normal bolt and nut for comparison will be described with reference to FIG. FIG. 7 (a) is a conceptual diagram of tightening with ordinary bolt nuts 22 and 23, and FIGS. 7 (b) and 7 (c) are explanatory views of the loosening prevention effect.

  7 (b) and 7 (c), the horizontal underline b indicates the surface to be fastened of the fastened member 5, and the upper line a indicates the pitch size of the bolts 22 and nuts 23 by lead angles, The sandwiched wedge body 40 indicates the thread of the main screw 29 of the nut 23. FIG. 7B shows the case where the lead angle of the bolt 22 and the nut 23 is small, and FIG. 7C shows the case where the lead angle of the bolt 22 and the nut 23 is large.

  FIGS. 7 (b) and (c) show a form in which the normal nut 23 is pushed into the main threaded portion of the bolt 22 while abutting against the surface of the fastened member 5. FIGS. Therefore, it can be understood that if the pitch of the bolts 22 and nuts 23 is increased, the force to return to the wedge body 40 is easily removed.

  The case of the present invention is shown in FIGS. FIG. 8 (a) represents a conceptual diagram when the sub screw 4 is screwed into the bolt 2. FIG. 8 (b) is a conceptual diagram of the fastening state of FIG. 8 (a).

  In FIG. 8 (b), the upper groove-like body 26 represents the screw groove of the auxiliary screw 12 of the washer 7, and the lower groove-like body 27 represents the screw groove of the main screw 15 of the member 5 to be fastened. Is represented by the inclination of the groove-like body 27, and the pitch of the auxiliary screw is represented by the inclination of the groove-like body 26. The substantially U-shaped wedge body 41 represents the bolt 2, the upper portion of the wedge body 41 represents the thread of the auxiliary screw 4, and the lower portion represents the thread of the main screw 3.

  The shape in which the wedge body 41 as the bolt 2 is pushed into the grooves of different slopes of the main screw 15 of the fastened member 5 and the auxiliary screw 12 of the washer 7 shown in FIG. It can be seen that the bolt 2 is pushed into the groove 26 and the groove-like body 27 so that it is difficult to come out, and the smaller the difference in the inclination (pitch) between the main screw and the sub screw, the harder it is to come off.

  Next, the present invention will be described with examples of use.

[Usage example 1]
This is the case of the screw fastening body 1 shown in FIG. 1. The external thread of the bolt 2 has a pitch of M12 of 1.75 mm, the secondary screw 4 has an outer diameter of 12 mm, a pitch of 1.5 mm, and a pitch difference of 0.25 mm.

  In FIG. 1, the usage example of the screw fastening body 1 is demonstrated. If the member to be fastened is tightened with the bolt 2, the screw pitch of the sub screw 4 is smaller than the pitch of the main screw 3, so that the washer 7 having the sub screw is less advanced in the axial direction than the main screw 3. Therefore, when the projecting teeth 8 of the washer 7 come into contact with the fastened member with the rotation of the bolt 2 and the rotation of the washer 7 is stopped, the pitch difference between the screws formed on the main screw 3 and the sub screw 4 of the bolt 2 is increased. However, since the projecting teeth 8 of the washer 7 having the auxiliary screw bite in and tighten after the washer 7 comes into contact with the member to be fastened (normal nut 7 is fastened at about 45 °) 200 ° to 250 Tightening is completed at 0 °, and the washer 7 having the secondary screw cannot be rotated until the bolt 2 is completely loosened. Note that there are variations in the measured tightening angle due to the relationship between the snag torque and the like.

  Here, if the pitch difference between the washer 7 having the auxiliary screw and the main screw 3 is adjusted, the number of rotations from the start of tightening to the completion of tightening can be adjusted.

1 Screw Fastener 2 Bolt 3 Main Screw (Bolt)
4 Secondary screw (bolt)
5 Fastened member 7 Washer 8 Projection tooth 9 Inclined slope 10 Groove 11 Cylindrical portion 12 Sub screw (washer)
15 Main screw (fastened member)
16 Thread groove 17 Groove 20 Washer 22 Bolt (Normal bolt)
23 Nut (Normal nut)
26 Groove 27 Groove 29 Main Screw (Nut)
30 Nut 40 Wedge body 41 Wedge body a Upper line b Underline m Gap n Gap

Claims (7)

  A screw fastening body including a bolt in which a main screw is screwed on a screw tip side and a sub screw having a smaller pitch than the main screw is screwed on a head side, and a washer or a washer and a washer, The washer is threaded with a female screw that engages with a sub screw of the bolt, and is formed by a projecting tooth projecting on a seating surface in contact with the member to be fastened of the washer, or between the washer and the member to be fastened. A screw fastening body characterized in that relative rotation with respect to a member to be fastened is made by projecting teeth projecting on both surfaces of a washer interposed between the bolt and screwed from the bolt head side.   When the outer diameter of the secondary screw of the bolt is the same as the outer diameter of the main screw, when the outer diameter of the secondary screw of the bolt is larger than the outer diameter of the main screw, or when the outer diameter of the auxiliary screw is the outer diameter of the main screw 2. The screw fastening according to claim 1, wherein the secondary screw is threaded by connecting a plurality of thread grooves to a small outer diameter portion on the main screw side. body.   A configuration in which the thread groove of the main screw portion and the sub screw portion of the bolt are adjacent to each other to be continuous or discontinuous, or the main screw portion and the sub screw portion of the bolt are spaced apart from each other and between the main screw portion and the sub screw portion. The screw fastening body according to claim 1 or 2, wherein the screw fastening body is provided with a non-threaded portion of the thread groove.   A cylindrical shape or a conical shape in which the tightening tool hook portion is not formed on the outer peripheral surface shape of the washer, or a polygonal column shape in which the tightening tool hook portion is formed on the outer peripheral surface shape of the washer. The screw fastening body according to any one of claims 1 to 3.   As for the protruding teeth projecting on the washer seat surface where the fastening tool hooks are provided on the outer peripheral surface, the substantially triangular shape of the projecting teeth is relatively advanced with the tightened member of the washer by the tightening rotation of the bolt For the washer's protruding teeth, the direction-side inclined surface is formed into a gently inclined surface, or the protruding teeth protruded on both sides, the washer or the cover by bolt tightening rotation on one or both sides The screw fastening body according to any one of claims 1 to 4, wherein the slope in the direction of travel relative to the fastening member is formed as a slope having a gently sloping shape.   In order to break the bolt head with a set torque, a groove is provided in the outer peripheral surface of the head neck lower part, and the shaft diameter of the groove bottom can be broken with the set torque. The screw fastening body according to any one of claims 1 to 5.   2. A nut that is screwed to a bolt with a member to be fastened interposed therebetween, and a rotation-preventing protruding tooth that is pushed in or fitted into the member to be fastened is provided on the seat surface of the nut. The screw fastening body in any one of thru | or 6.

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