WO2012053250A1

WO2012053250A1 - Bolt and extraction tool

Info

Publication number: WO2012053250A1
Application number: PCT/JP2011/063665
Authority: WO
Inventors: 長谷川　賢司
Original assignee: 株式会社ハマ・システム
Priority date: 2010-10-19
Filing date: 2011-06-15
Publication date: 2012-04-26
Also published as: JP5604526B2; JPWO2012053250A1

Abstract

Provided is a bolt capable of being tightened without using a special tool, incapable of being loosened after being tightened, but capable of being loosened in an emergency situation, and also provided is a tool. A bolt is configured, including: a fastening bolt having a through-hole formed at the shaft center, a serration surface formed at the upper surface of the head portion, and a tool engaging recess portion drilled at the center; a sliding shaft slidably inserted into the through-hole; a top rotational driving body fastened to the upper end portion of the sliding shaft and having a second serration surface that is formed on the lower surface and is to be engaged with the serration surface in a coaxial fashion; and a locking body attached to the lower end portion of the sliding shaft and restricting the movement of the shaft of a tightening bolt. The top rotational driving body has a step portion formed by reducing the diameter or a trench portion, which is formed on the side circumferential surface thereof, a tool engaging portion formed on the upper surface or on the side surface, and a recess portion formed on the upper surface and exposing the upper end surface of the sliding shaft.

Description

Bolt and removal tool

The present invention relates to a bolt that is screwed to an object to be fastened, and particularly to a bolt that is difficult to remove from the object to be fastened after being screwed once to the object to be fastened.

Various bolts that are difficult to remove from the fastened object once screwed to the fastened object have been proposed. The present inventor has also proposed the bolts disclosed in Patent Document 1 and Patent Document 2.

The bolt proposed in Patent Document 1 includes a first bolt having a through hole in the center, and a second bolt shaft that is slidably inserted into a through hole formed in the first bolt shaft and is longer than the first bolt. And a second bolt comprising a second serration provided at one end of the second bolt shaft, and a lock portion provided at the second bolt shaft end opposite to the second serration. A first locking portion that is a locking portion when rotating in one direction and a locking portion that is not rotating when rotating in the opposite direction is formed on the head of the second serration on the surface facing the first bolt head of the second serration. Is formed with a second locking portion that is locked to the first locking portion provided on the first bolt and rotates the first bolt in only one direction, and the maximum diameter of the locking portion is the diameter of the through hole. The bolt is larger than the hole diameter and smaller than the diameter of the first bolt shaft.
Once the object to be fastened is screwed with this bolt, even if the second serration is rotated in the loosening direction so as to remove this connection, the first locking portion and the second locking portion are idled and The rotational force of the two serrations is not applied to the fastening bolt, and the fastening bolt does not rotate in the direction in which it is removed. Therefore, the bolt once tightened cannot be removed as it is.

The bolt disclosed in Patent Document 2 has a recess at the center of the first bolt with the first serration at one end, and the lower body of the second bolt is slidably inserted to provide a lock at the tip. Thus, in the case of the bolt provided with the first serration and the second serration equivalent to those of Patent Document 1, the torque of the second serration is not applied to the fastening bolt in the case of this bolt, as in Patent Document 1. The tightened bolt cannot be removed as it is.
However, it is not easy to remove any of the above-mentioned provisional bolts when necessary.

JP 2009-97707 A JP 2009-275714 A

The present invention provides a bolt that can be tightened without using a special tool, but cannot be easily loosened after tightening, especially when it is removed if necessary. It is an object. Another object of the present invention is to provide a tool for removing the top portion (jig) suitable for use in removing the bolt.

The bolt of the present invention includes a fastening bolt having a through-hole in the shaft center, a serration surface formed on the upper surface of the head, and a recess for engaging a tool in the center thereof, and a slide in the through-hole provided in the fastening bolt. A sliding shaft that is inserted movably, and a second serration surface that is fixed to the upper end portion of the sliding shaft and that is coaxially engaged with the serration surface on the lower surface to constitute a directional rotational force transmission mechanism And a locking member that is attached to the lower end of the sliding shaft and restricts the movement of the sliding shaft. Only the rotational force in the direction to fasten the fastening bolt to the screwed member is transmitted, and the top rotary drive body has a stepped portion or groove portion with a reduced diameter formed on the side peripheral surface thereof, and a tool engaging portion on the upper surface or side surface. The upper surface is provided with a recess in which the upper end surface of the sliding shaft is exposed. It is characterized in that is.

Further, the present invention is an extraction tool for extracting the top rotational drive body of the bolt from the sliding shaft, and at least in a through hole into which the sliding shaft of the top rotational drive body is press-fitted. A sliding shaft pressing body provided with a corresponding rod-shaped tip contact portion, and disposed at a circumferentially equal position coaxially with the tip contact portion, and the tip contact portion in the axial direction of the tip contact portion A plurality of leg members extending downward from the portion, an upper abutting surface provided on each of the distal ends of the leg members, and an engagement portion that is movable in the radial direction, and supports each leg member It is characterized by comprising a support member, and drive means for driving the respective engaging claw portions and the tip contact portion so as to approach each other in the axial direction.

Once the bolt of the present invention has been tightened, it cannot be loosened or removed. When necessary, the bolt can be easily removed using a top removal tool (removal jig). Since this can expose the fastening bolt head, it is easy to loosen and remove the fastening bolt.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the volt | bolt 10 of 1st embodiment of this invention, (a) is a top view, (b) is an axial sectional view, (c) is a top view of a fastening bolt alone, (d) is a front view in the same way It is. The clamp bolt in a first embodiment of the present invention is shown, (a) is a top view, (b) is a partially cutaway front view, and (c) is a bottom view. It is a partial notch front view which shows the state which attached the volt | bolt to the to-be-coupled object, (a) shows the state which the fastening bolt and the clamping bolt closed, (b) shows the open state. It is a partial notch front view which shows the state which attached the volt | bolt to the to-be-coupled object. It is a figure explaining the extraction tool of this invention, (a) is a top view, (b) is a front view. It is a figure explaining the use condition of the extraction tool of this invention. The other Example of the clamping bolt which concerns on 1st embodiment of this invention is shown, (a) is a top view, (b) is a partially notched front view. The further another Example of the clamping bolt which concerns on 1st embodiment of this invention is shown, (a) is a top view, (b) is a partially notched front view. The bolt 10A of 2nd embodiment of this invention is shown, (a) is a partially notched front view, (b) is XX sectional drawing, (c) is a top view of a fastening bolt alone, d) is a front view in the same manner. (A), (b) is a partially notched front view which shows the state which attached the volt | bolt 10A to the to-be-coupled object.

First Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a bolt 10 according to a first embodiment of the present invention, where (a) is a top view, (b) is an axial sectional view, and (c) is a top view (d) of a fastening bolt alone. It is also a front view. The bolt 10 includes a fastening bolt (screw body: first bolt) 11, a tightening bolt (second bolt) 21, and a locking body 31 that is a locking means (locking portion).

The fastening bolt 11 has a spiral groove 11c formed on the outer peripheral surface of the fastening bolt shaft 11a, has a through-hole 11b in the shaft center, and the head 12 has a flat cylindrical shape with a large diameter. A hexagonal recess is formed in the upper surface of the head 12 of the fastening bolt 11 as a tool engaging portion 12a that engages with the rotary tool in the center, and the surrounding annular region has a direction. A serration surface 12b having a stop portion is formed, and the serration surface 12b constitutes a serration mechanism (a constant direction rotational force transmission mechanism) in cooperation with a later-described second serration surface 22a.

A fastening bolt (second bolt) 21 shown in FIG. 2 is fixed to a sliding shaft 21a slidably inserted into a through hole 11b drilled in the fastening bolt shaft 11a, and an upper end of the sliding shaft 21a. And a top rotary body (top rotary drive body) 2b. The sliding shaft 21a and the top rotating body 2a are formed separately and fixed by press-fitting. The top rotating body 22 at the upper end of the sliding shaft 21a is engaged with the serration surface 12b of the fastening bolt 11 on the lower surface to form a second serration surface 22a that constitutes a serration mechanism (a constant direction rotational force transmission mechanism). Is formed. The length L2 of the sliding shaft 21a is longer than the length L1 of the through hole 11b of the fastening bolt 11.

A locking body 31 having a large-diameter (large-diameter) end flange is coaxially attached to the lower end of the tightening bolt 21 (the tip opposite to the top rotating body 22). Specifies the sliding range. In addition, a coil spring that is wound around the shaft portion of the locking body 31 and separates the end flange from the tip of the fastening bolt 11 as a biasing means that constantly biases the top rotating body 22 toward the fastening bolt 11 side. 41 is provided.

Particularly in the present embodiment, the upper end portion of the sliding shaft 21a and the top rotating body 22 are fixed by press-fitting. In the embodiment, the end of the sliding shaft 21a on the press-fitting side is knurled to extend in the axial direction, and can be removed later, but the strength against rotational force is increased. The reason why the sliding shaft 21a and the top rotating body 22 are press-fitted separately is to enable separation when the screw is loosened when necessary, but in addition, a commercially available long bar is used as the sliding shaft 21a. Since the top rotating body 22 can be easily manufactured by press working, there is an advantage that it can be manufactured and provided at a low cost by press-fitting both.

The top rotating body 22 has a concave portion as a tool engaging portion 22c for rotating the tightening bolt 21 by a third tool on the upper surface. The illustrated tool engagement portion 22c is a cross hole corresponding to a cross driver.

Further, the press-fitting hole penetrates the upper surface (here, the bottom surface of the recess) so that the upper end surface of the sliding shaft 21a is exposed. Further, a step 22d having a reduced diameter is formed on a side surface of the top rotating body 22, and an upper portion of the step 22d is formed into a hemispherical surface having a diameter decreasing upward.

In addition, you may make it utilize the side surface for the above-mentioned tool engaging part. Moreover, it is good also as a structure which replaced with the above-mentioned level | step-difference part 22d, and formed the groove part diameter-reduced to the side peripheral surface in the circumferential direction. It is preferable to reduce the diameter of the upper part of the groove part upward.

The fastening bolt shaft 11a and the sliding shaft 21a in the embodiment of the present invention can be made of a metal such as iron or stainless steel, and the top rotating body 22 formed in a separate process from the bolt shaft is the same metal as the bolt shaft or a hard plastic. Can be created.

簡略 Briefly describe the serration mechanism. FIG. 1 shows an embodiment of a first locking portion 12 c provided on the head of the fastening bolt 11. That is, the serration surface 12b on the upper peripheral edge of the head is formed with a first locking portion 12c that becomes a locking portion when rotating in one direction and does not become a locking portion when rotating in the opposite direction. The first locking portion 12c shown in FIG. 1 has six abutting surfaces 12df provided radially at the periphery of the upper surface of the bolt shaft at equal intervals in the radial direction from the center. The abutment surface 12 df includes an upstanding face 141 and an inclined face 142 which is slantedly lowered in a wedge shape with the tip of the standing face 141 as a top side and extends to the base end side of the standing face 141.

On the other hand, as shown in FIG. 2, the top rotating body 22 is similar to the first locking portion 12 c at the lower peripheral edge facing the first locking portion 12 c provided on the upper peripheral edge of the fastening bolt 11. (Point-symmetrical relationship) A second locking portion 12c is formed, and is configured to mesh with each other to rotate the fastening bolt only in one direction and to rotate idly with respect to the rotational force in the reverse direction. That is, the serration mechanism in the present embodiment transmits only the rotational force in the direction in which the fastening bolt 11 is fastened to the screwed member.

In addition, although the cut-off surface (contact part) was formed as the said latching | locking part, it comprised by the combination of the cut surface and protrusion surface which were cut | disconnected perpendicularly in the triangle shape as a latching | locking part. You can also 1 and 2 show an example in which the number of contact surfaces is six, the number of contact surfaces is preferably about 2 to 8 in consideration of the size of the bolt. It is preferable in terms of machining if it is configured with a small diameter bolt.

In the assembly of the bolt 10 of the embodiment, first, the sliding shaft 21 a is press-fitted into the top rotating body 22 to obtain the tightening bolt 21. Next, the sliding shaft 21a is passed through the through hole 11b of the fastening bolt 11, the coil spring 41 is wound around the shaft portion of the locking body 31 as locking means (locking portion), and the tip of the shaft portion is placed on the sliding shaft 21a. Stick to the tip.

In this embodiment, a coil spring 41 is inserted between the locking body 31 and the tip of the fastening bolt 11 (see FIG. 1). The coil spring 41 serves to keep the top rotating body 22 of the fastening bolt 21 in contact with the head of the fastening bolt 11 at all times. That is, the fastening bolt 11 and the fastening bolt 21 are integrated. The coil spring 41 can be omitted when it is not necessary.

In order to couple the two fastened objects A and B with the bolt 10 of this embodiment, as shown in FIG. 3A, at least the fastened object B on the lower side is inserted into the spiral groove 11c of the fastening bolt 11. The spiral groove C to be screwed is cut, and the fastening bolt 11 is screwed into the spiral groove C. When screwing, for example, a hexagonal wrench (not shown) is inserted into a hexagonal groove provided at the head of the tightening bolt 21 and rotated to provide a second locking portion 22b provided on the top rotating body 22 on the fastening bolt 11. The fastening bolt 11 is rotated by meshing with the first locking portion 12c, the fastening bolt 11 is screwed into the spiral groove C of the article to be fastened (A,) B, and the lower part of the top rotating body 22 is brought into contact with the surface of the fastened object A. Fasten objects A and B by contacting

As shown in FIG. 3 (b), after the objects A and B are once screwed with the bolt 10, the fastening bolt 21 is rotated in the removing direction (in the direction opposite to the tightening direction) to remove this connection, The first locking portion 12c and the second locking portion 22b are idle so that the rotational force of the top rotating body 22 is not applied to the fastening bolt 11 and does not rotate in the direction in which the fastening bolt 11 is removed. Once tightened, it cannot be removed as it is

In addition, the bolt 10 of this embodiment is screwed to the article to be fastened B through a through hole provided in the bottom of a recessed part or a countersink hole formed by pressing provided in the article to be fastened A 'as shown in FIG. Therefore, it is also suitable for an application in which the head of the fastening bolt 11 is screwed off from the surface of the article A ′ to be fastened. In this case, it becomes more difficult to loosen and the crime prevention property is increased.

In order to release the coupling of the objects A and B to be fastened, for example, the top rotary drive body is removed from the sliding shaft using an extraction tool 50 as shown in FIG. FIG. 5A is a top view partially omitted, and FIG. 5B is a front view. The removal tool 50 is a block body having a U-shaped cross section, and in the drawing, a support frame 51 having a short leg portion 51a extending downward and opening downward, and a pressing body support supported by the support frame 51 so as to be movable in the vertical direction. Supported by the movable support 58 on the inner side of the short leg portion 51a of the support frame 51, the movable support body 52, the rod-shaped sliding shaft pressing body 53 fixed to the pressing body support section 52 and extending downward. The two end portions 54a (engaging claw portion 54b and tip member 54c) are disposed along the short foot portion 51a at a point-symmetrical position with respect to the central axis and project from the tip of the short foot portion 51a. The leg member 54 is configured to include a slide shaft pressing body 53 and a drive means 55 that drives the leg member 54 so that the distal end portions 54a of the leg member 54 approach each other in the long axis direction.

The rod-shaped slide shaft pressing body 53 has a cross-sectional shape (here circular) corresponding to the top of the slide shaft and the inner diameter of the press-fitted through hole, and presses the slide shaft from the press-fit portion. Extrude. As a height adjustment mechanism for adjusting the tip position of the slide shaft pressing body 53, the tip of a long screw 57 having a rotation knob 56 fixed to the top of the beam 51b of the support frame 51 is slid. The shaft pressing body 53 is engaged with a support member 58 to which the shaft pressing body 53 is attached. It should be noted that the rod sliding shaft pressing body 53 only needs to be able to enter and penetrate the press-fit portion at least by a predetermined length of the tip portion, and thus has a structure in which a tip rod-like portion (tip contact portion) having a predetermined length is attached to an appropriate support. May be.

Each leg member 54 is a long metal plate-like member having a spring property in the radial direction, and its tip is bent to the inner peripheral side to form an engagement claw portion 54b. In the lower part, a tip member 54c having a lower surface formed on an inclined surface retreating in the inner circumferential direction is attached to form an engaging claw portion (engaging portion).

The driving means 55 bends the metal plate into a U-shape to form a pressure part 59a and a leg part plate 59b that hangs down on both sides thereof, and the upper end of the lever 59 is pivotally supported on the support frame 51. The shaft support pin 60a is constituted by a sliding contact pin 60b which is fixed to the movable support 58 and engages with an arc-shaped long hole 59c formed below the leg plate. The lever 59 is normally biased in the direction opposite to the arrow F by a biasing means (not shown), the end of the long hole 59c serves as a stopper, and the tip of the pressurizing portion 59a rotates to the top. Kept in position. The long hole 59c is formed so as to be inclined with respect to the circumference around the pivot pin 60a. That is, the holes are formed by shifting from the circumference so as to gradually move away from the pivot pin 60a counterclockwise in the drawing. Each leg member 54 is supported so as to be movable in the axial direction, and from the edge of the arc-shaped long hole 59c formed in the leg plate of the lever 59 via the sliding contact pin 60b, the arrow F in the figure of the lever 59 is shown. The removal force (pull-up force) is transmitted according to the rotation in the direction. At this time, the lifting effect larger than the pressing force applied to the lever 59 is applied due to the wedge effect due to the hypotenuse, so that it can be easily removed.

Note that the removal tool 50 is not limited to the illustrated example, and various modifications are possible. For example, the bending angle of the leg member 54 may be an acute angle with respect to the inner surface, and the lower surface and the upper contact surface of the engaging claw portion may be formed on an inclined surface that retreats toward the inner circumferential direction. good. In this case, the stepped portion on the bolt side to be engaged is also formed on an inclined surface that recedes in the inner circumferential direction. In this way, the engaging claw portion once engaged with the step portion on the bolt side tends to move toward the inner peripheral side even if a force is applied during pulling, so there is no possibility of coming off. Further, three or more leg members 54 having engaging claws may be arranged at the circumferentially equal position coaxially with a plurality of tip abutting parts, and the stability of the engagement is increased and the leg members 54 are detached during the work. There are advantages that it becomes difficult and the strength at the time of pulling is increased.

Each leg member 54 itself is also a cylindrical plate-like long plate-like member other than that shown in the above-described embodiment, and its distal end is bent toward the inner peripheral side to form an engaging claw portion. Also good. In this case, the inner peripheral end of the partial annular shape is preferably matched with the curvature adapted to the top of the target bolt. There is an advantage that the strength against the pulling force and the engagement strength are increased since the leg member 54 has a large width in addition to having a spring property in the radial direction. It can also be used to remove bolts that are immersed in counterbores and screwed.

Further, in the embodiment, the engaging claw portion 54b stays in an arrangement suitable for the target bolt by utilizing the spring property of the leg member 54. However, the rigid leg member 54 is adopted and the base end portion thereof is used. It is configured to be swingable by pivoting and to define the normal position of each engaging claw by appropriate urging means for moving each engaging claw to the center and an appropriate stopper. Also good.

In addition, the long hole 59c may be a straight shape instead of an arc shape. Also in this case, it is provided so as to be gradually inclined away from the pivot pin 60a counterclockwise in the drawing.

Subsequently, the loosening operation of the bolt 10 will be described. First, the top rotating body 22 is removed using the removal tool 50. For this purpose, as shown in FIG. 6, the tip end (engagement claw portion) of the above-described extraction tool 50 is pressed against the top of the bolt 10 and pushed in. Thereby, each engagement claw part 54b at the tip of the flange is opened by the slope (or hemispherical surface) of the bolt 10, and when passing through the step part, it closes and engages with the step part. Next, the rotary knob 56 at the upper end of the tool is turned to allow the tip of the sliding shaft pressing body 53 to enter until it contacts the upper end of the sliding shaft 21a. Thereafter, the pressing portion 59a of the lever 59 is pushed down, so that the top rotating body 22 is pulled up by the leg member 54 with the end of the sliding shaft 21a as a supporting point, and the top rotating body 22 that has been press-fitted is slid. Detach from the shaft 21a.

By removing the top rotating body 22 as described above, the head of the fastening bolt 11 appears, and in this state, the hexagonal recess (indentation) that allows the fastening bolt provided on the head to rotate is illustrated. A general-purpose tool (driver, wrench, etc.) that is not engaged is engaged and rotated in the direction in which the fastening bolt 11 is removed (the direction opposite to the attaching direction), and the fastening bolt 11 is removed from the article to be fastened.

In the above-described embodiment, the tool engaging portion 12a has a hexagonal recess, but a polygonal hole that fits a polygonal wrench, a minus or a Phillips screwdriver is inserted as the tool engaging portion of the fastening bolt 11. It may be a negative or positive groove, a plurality of depressions, or the like. Further, as the tool engaging portion 22c for rotating the tightening bolt 21, a hexagon socket bolt as shown in FIG. 7, a pentagon socket bolt as shown in FIG. . 7 and 8 are the same as those shown in FIGS. 1 and 2 except for the tool engaging portion 22c, and are not described here.

[Second Embodiment] In the first embodiment, the locking means (lock portion) 3 is provided at the end of the sliding shaft 21a protruding from the fastening bolt 11 of the fastening bolt (second bolt) 5. It can also be set as the structure accommodated in the cylindrical hollow part (recessed part) 11d provided in the fastening bolt 11 from the front end side.

FIG. 9 shows a second embodiment having such a configuration, where (a) is a sectional view of the bolt 10A, (b) is a sectional view taken along line XX of (a), and (c) is a fastening state. A top view (d) of the bolt alone is a front view as well. The bolt 10 </ b> A of the present embodiment includes a fastening bolt 11, a fastening bolt 21, and a locking body 31. In this embodiment, the locking body 31 that is a locking means (locking portion) has an outer diameter that is movable in the cylindrical hollow portion 11 d and is locked by a stepped portion of the through hole of the fastening bolt 11. Designed to be the size to be.

The fastening bolt 11 includes a fastening bolt shaft 11a having a through hole 11b at the center thereof, and a spiral groove 11c is formed on the surface of the fastening bolt shaft 11a. The fastening bolt 11 is provided with a serration surface 12b at the head of the fastening bolt shaft 11a, and a first locking portion 12c is formed on the surface of the serration surface 12b. As shown in FIG. 5, the through-hole 11b is a through-hole, and the through-hole 11b (through-hole) has a diameter larger than the diameter of a sliding shaft 21a described later and smaller than the diameter of a locking body 31 described later. It comprises a hole 11b and a columnar cavity 11d that is continuous with the through-hole 11b and is larger than the diameter of the locking body 31. In other words, as shown in the drawing, the diameter of the through hole 11b has two stages, and the locking body 31 is locked to the stepped portion so as not to come off. In the figure, reference numeral 41 denotes a coil spring (spring).

On the head surface of the serration surface 12b provided on the fastening bolt shaft 11a, a first locking portion 12c is formed which becomes a locking portion when rotating in one direction and does not become a locking portion when rotating in the reverse direction. As shown in FIG. 1, the first locking portion 12 c has a plurality of standing faces 141 and a base end side of the standing faces 141 that are slantedly lowered into a wedge-shaped slope with the tip of the standing face 141 as the top side. And is rotated only in one direction for fastening the fastening bolt 11 to the object to be fastened by engaging with a second locking portion 22b formed on the fastening bolt 21 to be described later, and in the reverse direction (direction for loosening the fastening). ) To the rotational force.

The side peripheral surface of the serration 74 is formed with a polygonal (hexagonal in the figure) tool engaging portion 12a as shown in FIG. The tool engaging portion 12a is configured so that when it is necessary to remove the fastening bolt 11, a tool such as a screwdriver (not shown) is attached and the fastening bolt 11 is turned to be removed. The fastening bolt shaft 11a and the serration surface 12b may be formed separately and bonded together by welding, wearing, or the like, or may be formed integrally.

The head 12 of the tightening bolt 21 has an outer periphery formed in a hexagonal shape on the outside, and can be rotated with a spanner or the like. By forming the hexagonal shape, the tightening bolt 21 can be easily turned, and the fastening bolt 11 is turned to make it easy to fasten the fastening bolt 11 to the object to be fastened. The outside of the head 12 and the head 12 is not formed in a hexagonal shape but is circular or spherical, and a hexagonal recess (tool engaging portion) 12a is formed on the top, and the tightening bolt is rotated through the hexagonal recess. Of course it is good. In any case, the tool engaging portion may have any shape as long as the tightening bolt 21 can be rotated. A second serration member 22e is joined to the head 12 as will be described later.

The lower surface of the second serration member 22e facing the first locking portion 12c provided on the fastening bolt 11 is a serration surface 22a, and the fastening bolt 11 is locked to the first locking portion 12c by one side. A second locking portion 22b that rotates only in the direction (fastening direction) is formed. As shown in the figure, the second locking portion 22b abuts against a standing surface (contact surface) 141 of the first locking portion 12c, and a standing surface 241 (contact surface) that applies a rotational force in one direction thereto, It comprises an inclined surface 142 that is slanted in a wedge-shaped slope shape with the tip of the standing face 241 as the top side and extends to the base end side of the standing face 141, and is engaged with the first locking portion 12c so that the fastening bolt 11 is It is configured to rotate in the direction and idle in the reverse direction. Incidentally, it is also possible to omit the second serration member and to give the lower surface of the head 12 the function of the second serration surface.

In the present embodiment, the lower end portion of the outer periphery of the tightening bolt 21 is extended in a skirt shape (sleeve shape) to constitute a covering member 22f that covers the joint portion between the first locking portion 12c and the second locking portion 22b. . The covering member 22f is provided integrally with the head 12 of the tightening bolt 21. As described above, in this embodiment, the covering member 22f covers the joint portion between the serration surface 12b of the fastening bolt 11 and the second serration 22a. Therefore, it is aesthetically pleasing, and it is possible to effectively prevent theft by the technique of injecting an adhesive or the like to the joining portion and fixing it to loosen the bolt.

Since it is sufficient for the locking body 31 to play the role of preventing the fastening bolt 21 from coming off the fastening bolt 11, the shape thereof can be formed in a circular shape, a polygonal shape, a rod shape, etc., and the mounting to the first locking portion 12c is It can be attached by screwing, welding, adhesive bonding, or the like. By positioning the locking body 31 inside the through hole 11b, it is possible to effectively protect the locking body 31 from accidents that are damaged.

Also in the embodiment of the present invention, as described above, the coil spring 41 as the urging means (spring member) is provided on the locking means (lock portion) 3 of the fastening bolt (second bolt) 2 and the fastening bolt shaft 11a. The cylindrical hollow portion 11g is inserted between the bottom portion where the diameter is reduced by connecting to the through hole 11b, and the gap between the engaging portions of the fastening bolt 11 and the fastening bolt 21 is inserted by inserting the coil spring 41 in this way. Is always closed by the repulsive force of the coil spring 41, and the looseness of the tightening bolt 21 is restrained in a state in which the object to be fastened is coupled, so that it can be used without generating noise when used in a place where vibration occurs. . In addition, the adoption of the coil spring 41 which is an urging means is arbitrary.

Since the assembly process of the bolt 10A of this embodiment is substantially the same as that of the first embodiment, detailed description is omitted. The usage method is the same as that described in the first embodiment. For reference, other usage states will be described.

FIG. 10 shows a use state of the bolt according to the embodiment of the present invention, and it is possible to use a nut without engraving screw grooves in the objects A and B to be fastened. FIG. 10A shows, for example, a taper nut 47 having a taper nut 47 that is tapered by forming all six side surfaces as a nut after connecting the objects A and B to be fastened with the bolt 10A according to the embodiment of the present invention. 11a shows a state of being screwed to the butt portion of 11a, and shows an example of use in which security is improved by eliminating the possibility of loosening the fastening from the nut side. If the nut 47 'cannot be rotated after the objects A and B are connected with the bolt 10A according to the embodiment of the present invention, the hexagon nut 47 is used as shown in FIG. All you need is enough.

During the use of the bolt 10A of this embodiment, the disassembling process of the press-fit portion when it is necessary to loosen it as necessary can be easily performed using the extraction tool 50 as in the case of the first embodiment. Loosen the tightened bolt using a suitable general-purpose tool (driver, wrench, etc.). Details have already been described and will not be repeated here.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without changing the gist of the invention.

10, 10A ... bolt 11 ... fastening bolt (screw body: first bolt)
11a ... Fastening bolt shaft 11b ... Through hole 11c ... Spiral groove 11d ... Cylindrical cavity (recess)
DESCRIPTION OF SYMBOLS 12 ... Head 12a ... Tool engaging part 12b ... Serration surface 12c ... First latching part 141 ... Standing face 142 ... Inclined surface 21 ... Tightening bolt (second bolt)
21a ... Sliding shaft 2b ... Top rotator (Top rotator)
22a ... 2nd serration surface 22b ... 2nd latching | locking part 241 ... Standing face 242 ... Inclined surface 22c ... Tool engaging part 22d ... Step part 22e ... 2nd serration member 22f ... Cover member 31 ... Locking body 41 ... Coil spring (Biasing means)
47, 47 '... nut 50 ... removal tool 51 ... support frame 51a ... short leg part 51b ... beam part 52 ... pressing body support part 53 ... sliding shaft pressing body 54 ... leg member 54a ... tip part 54c ... tip member 55 ... Driving means 56 ... Rotary knob 57 ... Long screw 58 ... Support member 59 ... Lever 59a ... Pressure part 59b ... Leg plate 59c ... Long hole 60a ... Pivot pin 60b ... Sliding contact pin

Claims

A fastening bolt having a through hole in the shaft center and forming a serration surface on the upper surface of the head and having a tool engaging recess in the center,
A sliding shaft slidably inserted into the through hole provided in the fastening bolt;
A top rotary drive body fixed to the upper end portion of the sliding shaft and having a second serration surface that is coaxially engaged with the serration surface on the lower surface to form a constant direction rotational force transmission mechanism;
A locking body attached to the lower end of the sliding shaft and restricting the movement of the sliding shaft;
Comprising
The constant direction rotational force transmission mechanism transmits only rotational force in a direction in which the fastening bolt is fastened to the screwed member,
The top rotary drive body has a stepped portion or a groove portion with a reduced diameter formed on a side peripheral surface thereof, a tool engaging portion on an upper surface or a side surface, and a concave portion on which the upper end surface of the sliding shaft is exposed on the upper surface. Bolt characterized by being provided.
2. The bolt according to claim 1, wherein at least an upper end portion of an upper side surface of the stepped portion or the groove portion of the top rotary drive body is formed on an inclined surface or a hemispherical surface whose diameter is reduced upward.
The bolt according to claim 1 or 2, wherein the upper end portion of the sliding shaft and the top rotary drive body are fixed by press-fitting.
The bolt according to any one of claims 1 to 3, further comprising biasing means for constantly biasing the top rotary drive body toward the fastening bolt.
An extraction tool for extracting the top rotary drive body of the bolt according to any one of claims 1 to 4 from the sliding shaft,
A sliding shaft pressing body comprising at least a rod-shaped tip abutting portion corresponding to a through-hole into which the sliding shaft of the top rotary driving body is press-fitted at the tip;
A plurality of leg members that are coaxially arranged with the tip contact portion at circumferentially equal positions, and extend downward from the tip contact portion in the axial direction of the tip contact portion;
An upper abutting surface extending on the inner peripheral side provided at each end of the leg member, and an engaging portion movable in the radial direction;
A support member for supporting each leg member;
An extraction tool comprising driving means for driving the engaging claws and the tip contact portion to approach each other in the axial direction.
The said each leg member has spring property in radial direction, The lower surface of the said engaging part is formed in the curved surface or the inclined surface which recedes toward an inner peripheral direction, It is characterized by the above-mentioned. The removal tool described.
The extraction tool according to claim 5 or 6, wherein the upper contact surface of the engaging portion is an inclined surface that forms an acute angle with respect to the inner surface of the leg member.
Each of the leg members is a long flat plate-like member having a spring property in the radial direction, the tip of which is bent toward the inner peripheral side, and the circular engaging claw is formed at the tip. The extraction tool according to claim 7.
Each of the leg members is a cylindrical plate-like long plate-like member having a spring property in the radial direction, and its tip is bent toward the inner peripheral side to form the partially annular engagement claw portion. The extraction tool according to claim 7.