JP7060189B2 - Telescopic bolt - Google Patents

Description

The present invention relates to bolts, particularly telescopic bolts that are excellent in preventing loosening after fastening.

As a method to prevent loosening of the fastening structure in which the bolt (male screw) and female screw are fitted, there is a method of double-processing the screw thread of the bolt to increase the axial force, and a loosening preventive agent in the gap of the fitting play. There is known a method of increasing the rotational resistance by filling the bolts (see Patent Document 1).
However, since the double processing of the screw thread is a fine processing, it takes more time and cost than the normal processing. Further, when the bolt is screwed using the anti-loosening agent, the dried anti-loosening agent adheres to the screw thread of the bolt after being pulled out from the female screw, which makes it very difficult to reuse the bolt.

Japanese Unexamined Patent Publication No. 2014-149403

It is an object of the present invention to provide a bolt capable of reliably preventing loosening.

In order to achieve the above object, one aspect of the telescopic bolt of the present invention is (i) movable in which a screw thread is provided on the cylindrical surface of the first obliquely cut column having the first facing plane as the notched slope. (Ii) A screw that can be continuously connected to the screw thread of the movable part on the cylindrical surface of the second diagonally cut column having the second facing plane facing the first facing plane via a variable gap as the notched slope. A fixed part that is provided with a mountain and forms a substantially columnar shape in combination with a movable part, and (iii) a fixed part that forms a movable part along the direction of the axis of the substantially columnar shape formed by the first and second diagonally cut columns. With a gap displacement mechanism that moves relatively to displace the variable gap, the movable part and the fixed part form a male screw part of the bolt, and by reducing the variable gap, the screw thread of the movable part can be used. The gist is to fix the male screw part to the female screw with the minimum value of the gap between the screw thread of the movable part and the screw thread of the female screw of the member to be fastened.

According to the present invention, it is possible to provide a bolt that can surely prevent loosening.

It is a front view including a partial sectional view schematically explaining the outline of the telescopic bolt which concerns on 1st Embodiment. It is a side view which looked at the head of the telescopic bolt which concerns on 1st Embodiment from the axial direction. It is a front view including the partial sectional view schematically explaining the state which retracted the movable part of the telescopic bolt which concerns on 1st Embodiment. It is a partially enlarged view which shows the part of the nut in the cross section, which schematically explains the fitted state of the thread of a telescopic bolt and the thread of a nut (the 1: extended state). It is a partially enlarged view which shows the part of the nut in the cross section, which schematically explains the fitted state of the thread of a telescopic bolt and the thread of a nut (part 2: reduced state). It is a partially enlarged view which shows the part of the nut with a cross section schematically explaining the fitted state of the thread of a telescopic bolt and the thread of a nut (part 3: at the time of pressure load). It is a side view which looked at the head of the telescopic bolt which concerns on 1st modification of 1st Embodiment from the axial direction. It is sectional drawing seen from the direction of AA line in FIG. It is a partially enlarged view schematically explaining the outline of the expansion bolt which concerns on the 2nd modification of 1st Embodiment. It is a bird's-eye view (perspective view) schematically explaining the outline of the movable part of the telescopic bolt which concerns on the 2nd modification of 1st Embodiment. It is a front view schematically explaining the outline of the telescopic bolt which concerns on 2nd Embodiment. It is sectional drawing seen from the direction of line BB in FIG. It is a front view schematically explaining the state which retracted the movable part of the telescopic bolt which concerns on 2nd Embodiment. It is a front view schematically explaining the outline of the state which the gap displacement mechanism of the telescopic bolt which concerns on the modification of 2nd Embodiment is fixed by the 1st retaining ring. It is a front view schematically explaining the state which retracted the movable part of the telescopic bolt which concerns on the modification of the 2nd Embodiment. It is a front view schematically explaining the outline of the state which the gap displacement mechanism of the telescopic bolt which concerns on the modification of 2nd Embodiment is fixed by the 2nd retaining ring.

Next, the first and second embodiments will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each member, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that parts having different dimensional relationships and ratios are included between the drawings.

Further, the embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is based on the material, shape, structure, and structure of the constituent parts. The arrangement etc. is not specified to the following. The technical idea of the present invention may be modified in various ways within the technical scope specified by the claims described in the claims. Further, the directions of "left and right" and "up and down" in the following description are merely definitions for convenience of explanation, and do not limit the technical idea of the present invention. So, for example, if you rotate the paper 90 degrees, "left and right" and "up and down" are read interchangeably, and if you rotate the paper 180 degrees, "left" becomes "right" and "right" becomes "left". Of course it will be.

--First embodiment--
<Structure of telescopic bolt>
As shown in FIG. 1, the telescopic bolts (1, 2, 3, 4) according to the first embodiment have a movable portion 1 having a first facing plane S1 as a notched slope and a first facing plane. S1 is provided with a fixing portion 2 having a second facing plane S2 facing the S1 via a variable gap as a notched slope.

The fixed portion 2 forms a substantially columnar shape in combination with the movable portion 1, and the movable portion 1 and the fixed portion 2 form a shaft portion (1) of the telescopic bolt (1, 2, 3, 4) according to the first embodiment. , 2). The schematic shape of the movable portion 1 is an obliquely cut cylinder (cut head cylinder), and threads 1a to 1 g are provided on the cylindrical surface of the obliquely cut cylinder (first obliquely cut cylinder) forming the movable portion 1. ..
The schematic shape of the fixed portion 2 is also an obliquely cut cylinder, and the cylindrical surface of the obliquely cut cylinder (second obliquely cut cylinder) forming the fixed portion 2 has a screw thread continuous with the threads 1a to 1 g of the movable portion 1. 2a to 2g are provided. The movable portion 1 and the fixed portion 2 form a continuous rod shape through a variable gap.

Further, the telescopic bolts (1, 2, 3, 4) according to the first embodiment are fixedly provided so as to be continuous with the end face (neck) of the fixing portion 2 which is the bottom surface of the shaft portion (1, 2). It is provided with a substantially hexagonal columnar head 3. The material of the outer bolt (1, 2, 3) including the shaft portion (1, 2, 3) and the head portion 3 is steel, stainless steel, brass, titanium, aluminum, or the like.
The telescopic bolts (1, 2, 3, 4) according to the first embodiment move the movable portion 1 relative to the fixed portion 2 along the direction of the shaft portion (1, 2). Further, a gap displacement mechanism 4 for displacing the variable gap is provided.

Inside the second diagonally cut cylinder forming the fixing portion 2, the first guide hole 12 and the second guide hole 13 concentric with the axial center of the fixing portion 2 are provided as continuous stupid holes. Inside the first diagonally cut cylinder forming the movable portion 1, a female screw 11 having a valley having a diameter slightly smaller than the diameter of the first guide hole 12 is provided concentrically with the axial center of the movable portion 1.

The telescopic bolt (1, 2, 3, 4) according to the first embodiment further includes a gap displacement mechanism 4 having an inner bolt (41, 42, 43) as a main part. The inner bolts (41, 42, 43) have a cylindrical portion 41 and a male screw portion 43 having a thread that is continuously fitted at the end of the cylindrical portion 41 corresponding to the thread of the female screw 11. A cylindrical portion 41 is provided with a substantially disk-shaped head 42 that is continuous with the cylindrical portion 41.
The material of the inner bolt (41, 42, 43) is steel, stainless steel, or the like, like the outer bolt (1, 2, 3). The cylindrical portion 41 has a smaller diameter than the shaft portions (1, 2) of the outer bolts (1, 2, 3).

The inner bolt (41, 42, 43) rotates while being inserted inside a series of holes (12, 13), and displaces the gap between the movable portion 1 and the fixed portion 2 along the direction of the axis. (Shift) is provided so that it is possible. In this series of holes (12, 13), the male screw portion 43 on the tip side fits into the female screw 11 of the movable portion 1, and the cylindrical portion 41 in the region other than the male screw portion 43 is the head 3 and the fixing portion. It penetrates the inside of 2 respectively.

The first facing plane S1 is a plane extending upward to the right from the screw tip side shown on the left side in FIG. 1 toward the fixed portion 2 side, and the movable portion 1 has a chikuwa (obliquely cut straight cylinder) shape.
Further, the second facing plane S2 that defines the variable gap on the fixed portion 2 side is a plane extending downward to the left from the neck side shown on the right side in FIG. 1 toward the movable portion 1 side, and the fixed portion 2 is movable. It has a chikuwa shape like the part 1. The movable portion 1 and the fixed portion 2 form a continuous rod shape through a variable gap.

The male screw portion 43 of the inner bolt (41, 42, 43) is screwed inside the female screw 11 to make the movable portion 1 movable in the axial direction of the shaft portion (1, 2). When inserting the outer bolts (1, 2, 3) into the inside of the fastened member from which the female screw 11 has been cut, as shown in FIG. 1, the tip surface (screw tip) of the male screw portion 43 is a female screw. The variable gap is set to the optimum value at the time of insertion by making the state separated from the bottom surface of 11.

The telescopic bolts (1, 2, 3, 4) according to the first embodiment are variable when the threads 1a to 1g of the movable portion 1 and the threads 2a to 2k of the fixing portion 2 are smoothly continuous. The value of the gap becomes the optimum value at the time of insertion.
In FIG. 1, the crest of the leftmost screw thread 1a of the movable portion 1 and the flanks on both sides of the crest are variable gaps with the crest of the leftmost screw thread 2a of the fixed portion 2 and the flanks on both sides of the crest. An example is a state in which the screws are smoothly continuous in the vertical direction. Similarly, the threads 1b to 1g of the other movable portion 1 and the threads 2b to 2k of the fixing portion 2 are smoothly continuous in the vertical direction when the variable gap is set to the optimum value at the time of insertion.

The width w of the variable gap is preferably about 0.08 to 0.12 mm according to the rule of thumb for the outer bolts (1, 2, 3) having an outer diameter of about 4 mm to 800 mm.
In FIG. 1, the angle formed by the first facing plane S1 of the movable portion 1 and the plane orthogonal to the axis of the telescopic bolt (1, 2, 3, 4) is defined as the division angle θ for dividing the shaft portion (1, 2). Shows. The division angle θ is preferably about 40 ° or more and about 60 ° or less, for example, 45 °.
When the division angle θ is less than 40 °, that is, when it goes parallel to the end face of the screw tip, the expansion bolt (1, 2, 3, 4) is sent to the female screw cut in the fastened member as described later, and then the gap displacement. The force required to retract the cylindrical portion 41 of the mechanism 4 becomes too large, and the load increases.

On the other hand, when the division angle θ exceeds 60 °, that is, when the division angle θ increases toward parallel to the axis, the region on the screw tip side of the movable portion 1 becomes too thin, and the telescopic bolts (1, 2, 3, 4) ) May not be able to withstand the stress applied by repeating shortening and stretching. In that case, the telescopic bolts (1, 2, 3, 4) may break.

The head 3 of the outer bolt (1, 2, 3) is provided with a recess serving as an embedding hole 14 for embedding the head 42 of the inner bolt (41, 42, 43). Further, on the upper end side of the head portion 3 of the outer bolts (1, 2, 3), a cap hole 15 having a diameter larger than that of the embedded hole 14 is provided as a shallow step portion, and the cap hole 15 has the diameter of the cap hole 15. A flat washer-shaped cap 46 having a diameter corresponding to the above is embedded. Further, the upper surface of the cap 46 is set at a position aligned with the upper end surface of the head portion 3 of the bolt. The lower surface of the cap 46 is set at a position aligned with the upper end surface of the head 42 of the inner bolt (41, 42, 43).

Two screw holes 17a, 17b extending along the axial direction of the telescopic bolts (1, 2, 3, 4) are provided on the lower surface side of the cap hole 15 around the embedding hole 14, and the screw holes 17a, Screws 47a and 47b are inserted into each of 17b. On the inner surface of the screw holes 17a and 17b, female screws that are fitted corresponding to the threads of the male screws of the screws 47a and 47b are provided.

The two screws 47a and 47b are symmetrically arranged with the head 42 of the inner bolt (41, 42, 43) interposed therebetween. The two screws 47a and 47b are attached to the head 3 of the outer bolt (1, 2, 3) so that the cap 46 having a hole in the center is pressed against the bottom surface of the cap hole 15 through a certain clearance to be fixed. It is attached. The head 42 is sandwiched between a part of the lower surface of the fixed cap 46 and the bottom surface and the side surface of the embedding hole 14, so that the axial movement of the inner bolts (41, 42, 43) is restricted and the head 42 can rotate smoothly. Will be.

As shown in FIG. 2, the head 42 of the inner bolt (41, 42, 43) is formed with, for example, a substantially plus (+) -shaped recess. Since the central part of the cap 46 is opened concentrically with the outer circumference and the central part of the head 42 of the inner bolt (41, 42, 43) is partially exposed, an instrument such as a Phillips screwdriver is inserted and the inner bolt is inserted. It is possible to rotate (41, 42, 43).

The cylindrical portion 41 is inserted over all of the first guide hole 12 and the second guide hole 13, and is provided so that the male screw portion 43 reaches the movable portion 1. The inner surfaces of the first guide hole 12 and the second guide hole 13 are formed so as to smoothly rub against the outer surface of the cylindrical portion 41.

As shown in FIG. 3, the movable portion of the outer bolt (1, 2, 3) is rotated by rotating the head 42 of the inner bolt (41, 42, 43) by the screw connection of the male screw portion 43 and the female screw 11. 1 shifts to the head 3 side. The inner bolts (41, 42, 43) rotate while their movement to the head 42 side is suppressed by the cap 46.
If the screw is a right-handed screw, if the head 42 of the inner bolt (41, 42, 43) is rotated clockwise, the movable portion 1 shifts with respect to the inner bolt (41, 42, 43) and the width of the variable gap is changed. w is shortened. If the head 42 is rotated counterclockwise, the width w of the variable gap becomes large. In this way, the movable portion 1 can move back and forth along the axial direction by the rotation of the cylindrical portion 41.

Hereinafter, a state in which a variable gap having an optimum value at the time of insertion is formed between the movable portion 1 and the fixed portion 2 is defined as an “extended state”. The variable gap of the optimum value at the time of insertion is such that the movable portion 1 is fixed in the direction in which the screw tip of the male screw portion 43 of the inner bolt (41, 42, 43) is separated from the bottom surface of the female screw 11 as shown in FIG. It is formed by advancing in a direction relatively separated from the portion 2.
Further, the movable portion 1 moves in the direction in which the variable gap disappears with respect to the fixed portion 2 to the position where the first facing plane S1 and the second facing plane S2 come into contact with each other. The state in which the nominal length of 1, 2, 3, 4) is shortened is defined as the "shortened state".

Nominal length L1 (see FIG. 1) of the telescopic bolt (1, 2, 3, 4) in the extended state and L2 (see FIG. 3) of the nominal length L2 of the telescopic bolt (1, 2, 3, 4) in the shortened state. The difference (L1-L2) is determined by using the axial width w of the variable gap and the division angle θ.
L1-L2 = w / sinθ ... (1)
Can be expressed by equation (1). For example, when the variable gap width w = 0.1 mm and the division angle θ = 60 °, L1-L2 forming the axial shift distance is obtained from the equation (1).
L1-L2 = 0.1mm / sin60 ° ≒ 0.115mm
Will be.

<How to use bolts>
As shown in FIG. 4, between the telescopic bolts (1, 2, 3, 4) and the threads of the member to be fastened 5, a certain gap (play) is formed when they are fitted to each other. It is assumed that the dimensions and shape of are set.
In FIG. 4, when the outer bolts (1, 2, 3) are sent to the inside of the fastened member 5, they are located near the boundary between the movable portion 1 and the fixed portion 2 of the outer bolts (1, 2, 3). The area containing the three threads 1f, 1g, 2h is shown enlarged. Further, as shown by the lower left arrow in FIG. 4, the feeding direction of the outer bolts (1, 2, 3) is from the right side to the left side.

First, in order to make the telescopic bolts (1, 2, 3, 4) in the extended state, the inner bolts (41, 42, 43) are rotated clockwise, and the tip surface (screw tip) of the male screw portion 43 is set to the female screw 11. The width w of the variable gap is set to the optimum value at the time of insertion by moving it toward the bottom surface of. If the width w of the variable gap is the optimum value at the time of insertion, when the outer bolts (1, 2, 3) are sent to the inside of the fastened member 5, the outer bolts (1, 2, 3) are attached to the threads on the fastened member 5 side. The three threads 1f, 1g, 2h on the 1, 2, 3) side come into contact with the leading flanks 1f ₁ , 1g ₁ , 2h ₁ , respectively. The leading flank 1f 1,1g _{1,2h 1} is located _on the front side in the feeding direction.
In FIG. 4, of the three threads 1f, 1g, 2h, the follow-up flanks 1f ₂ , 1g ₂ of the two threads 1f, 1g of the movable portion 1 and the corresponding fastened member 5, respectively. The play distances df ₁ , deg ₁ formed between the threads and measured along the axial direction are shown.

Then, the screw tips of the shaft portions (1, 2) of the outer bolts (1, 2, 3) are brought to the inside of the fastened member 5 to the positions necessary for fastening. Then, as schematically shown by the counterclockwise arrow on the left side in the enlarged view of FIG. 5, the inner bolts (41, 42, 43) forming the gap displacement mechanism 4 are replaced with the outer bolts (1, 2, 3). Rotate it so that it recedes toward the head 3 side. This rotation forms a shortened state of the outer bolts (1, 2, 3) and locks the outer bolts (1, 2, 3) with respect to the member to be fastened 5.

By shortening the outer bolts (1, 2, 3), the pressure side flanks (following side flanks) 1f ₂ , 1g ₂ of the two threads 1f, 1g of the movable part 1 and the female cut into the fastened member 5 The play distance between the threads of the screw is also shortened (df ₁ → df ₂ , deg ₁ → deg ₂ ). FIG. 5 illustrates a state in which the ridgeline of the screw thread 1 g at the right end of the movable portion 1 and the ridgeline of the screw thread 2 g on the fixed portion 2 side are displaced in the axial direction due to the shortened play distance. .. On the other hand, the play distance between the pressure side flank (following side flank) 2h ₂ of the screw thread 2h on the fixing portion 2 side and the thread of the female screw cut in the fastened member 5 does not change.

In this way, by moving the movable portion 1 so as to be relatively close to the fixed portion 2 side by the gap displacement mechanism 4, the threads 1a to 1 g of the movable portion 1 and the threads 1a to 1 g are fitted. The outer bolts (1, 2, 3) are locked to the fastened member 5 by shortening the play distance of the female screw cut into the mating fastened member 5 with the thread.
That is, by setting the variable gap to the minimum value, the minimum value is the gap between the threads 1a to 1g of the movable portion 1 and the threads of the female threads cut in the fastened member 5 that fits the threads 1a to 1g. The shortened state of the telescopic bolts (1, 2, 3, 4) is formed.

In the locked state, the play distance between the threads 1a to 1g of the movable portion 1 and the threads of the fastened member 5 is short. Therefore, when pressure is applied to the shortened telescopic bolts (1, 2, 3, 4) to loosen the fastened state, as shown in FIG. 6, the threads 1a to 1 g of the movable portion 1 are the screws of the fastened member 5. It bites into the mountain with much greater force than in the stretched state. Therefore, the pressure supported by each other between the threads becomes very large.

Therefore, in the state where the shortened telescopic bolts (1, 2, 3, 4) are fitted with the female threads cut on the member to be fastened 5, they are strengthened even if various pressures for loosening the screw connections are applied. The locked state is firmly maintained by the biting force between the threads. Therefore, loosening of the screw connection can be reliably prevented. The various pressures include axial force generated by fastening, vibration in the axial direction, displacement in the direction orthogonal to the axial direction, and the like.

On the other hand, when loosening the screw connection, the movable portion 1 is moved so as to be relatively separated from the fixed portion 2 side by the gap displacement mechanism 4, and the variable gap of the telescopic bolt (1, 2, 3, 4) is changed. The width w reshapes the stretched state, which is the optimum value at the time of insertion. Then, the play distance between the threads 1a to 1g of the movable portion 1 and the threads of the female threads cut in the fastened member 5 is restored, and the pressure supported by each other is reduced, so that the screw connection can be easily loosened. Can be done.

<Bolt manufacturing method>
Next, a method for manufacturing telescopic bolts (1, 2, 3, 4) such as SUS304 and SUS316 according to the first embodiment will be described. First, a non-expandable bolt (usually used bolt) having a desired nominal length L1 is prepared as a base material for outer bolts (1, 2, 3).

A recess for the embedding hole 14 is formed in the head 3 of the non-expandable bolt so that the head 42 of the inner bolt (41, 42, 43) forming the main part of the gap displacement mechanism 4 is embedded. Specifically, the head 3 of the outer bolt (1, 2, 3) is cut from the end face side with a lathe, a milling machine, etc. according to the shape of the head 42 of the inner bolt (41, 42, 43). A recess for the embedding hole 14 is formed.

Further, a hole having a diameter larger than that of the embedding hole 14 is cut with a lathe, a milling machine, or the like so as to form a step portion for embedding the cap 46 in the upper part of the cap hole 15, and a recess for the cap hole 15 is formed. Further, female screws forming the two screw holes 17a and 17b are formed on the lower surface of the cap hole 15 located on the outer peripheral side of the embedding hole 14 by a cutting tap or the like.

Next, inside the outer bolts (1, 2, 3), from the bottom of the cap hole 15 of the head 3 toward the screw tip, along the axis center, a lathe, a drilling machine, or the like, the inner diameter of the female screw 11 to be planned. A hole is drilled to the size of the female screw 11 to form a stupid hole that reaches the position of the planned bottom of the female screw 11.

Next, after fixing the shafts of the outer bolts (1, 2, 3), the shafts of the outer bolts (1, 2, 3) are cut so that the two cut surfaces cut the shaft diagonally. The movable portion 1 and the fixed portion 2 are formed by dividing the parts into two so as to face each other in parallel. The two divisions can be performed by a wire saw, a diamond cutter, an ultrasonic cutter, a plasma cutter, a laser cutter, or the like.

The cutting is performed so that the first facing plane S1 and the second facing plane S2 and the plane orthogonal to the axial direction intersect diagonally at a set division angle θ.
The distance of the portion removed by cutting is the width w of the variable gap between the fixed portion 2 and the movable portion 1. For example, considering the cutting width of the wire saw, the outer bolt (1) is polished after cutting. , 2, 3) The desired variable gap width w can be realized by grinding one pitch or more of the threads.

Next, using the stupid hole of the movable portion 1 as a pilot hole, a cutting tap having an outer diameter larger than the inner diameter of the stupid hole is screwed in to perform tapping, and a female screw corresponding to the male screw portion 43 of the gap displacement mechanism 4 is screwed. 11 is formed. Further, boring, reamer finishing, boring, etc. are performed to enlarge the outer diameter of the stupid hole provided in the fixing portion 2 so as to be slightly larger than the outer diameter of the cutting tap.

Then, in a series of holes (12, 13) enlarged by the boring, an inner having a male screw portion 43 having an outer diameter substantially the same as the outer diameter of the cutting tap used for tapping the stupid hole of the movable portion 1. Bolts (41, 42, 43) are manufactured as the main part of the gap displacement mechanism 4. The outer diameter of the cylindrical portion 41 of the inner bolt (41, 42, 43) may be the same as that of the male screw portion 43 or smaller than that of the male screw portion 43.

Next, the manufactured inner bolt (41, 42, 43) is inserted into the female screw 11 of the movable portion 1 via the first guide hole 12 and the second guide hole 13 of the outer bolt (1, 2, 3). The male screw portion 43 is screwed in to connect with the fixing portion 2 and the head 3.
Next, the cap 46 is placed on the head 42 so that the head 42 of the inner bolt (41, 42, 43) is embedded in the embedding hole 14 of the head 3 of the outer bolt (1, 2, 3), and the screw 47a is placed. , 47b fixes the cap 46 to the head 3. By the above steps, the telescopic bolts (1, 2, 3, 4) according to the first embodiment are completed.

According to the method for manufacturing a telescopic bolt according to the first embodiment, it is possible to easily manufacture a stretchable bolt simply by performing simple processing such as drilling, thread cutting, and cutting on an existing bolt that is usually used. can.

(First modification of the first embodiment)
The telescopic bolts (1, 2, 3, 4) shown in FIGS. 1 to 6 are outer bolts (1, 2, 3) having a flat end face on the opposite side to the shaft portion (1, 2, 3) of the head 3. ) Is used as the base material. However, as shown in FIGS. 7 and 8, even if the bolt is provided with _a hexagonal hole 3a1 for inserting a hexagonal wrench deeper than the embedding hole 14 in FIG. Applicable. This bolt is a bolt in the basic form in which a so-called cap bolt is used as a base material for outer bolts (1, 2, 3).

The inner bolt (41a, 42, 43) is the main part of the gap displacement mechanism 4a of the telescopic bolt (1, 2, 3a, 4a) according to the first modification of the first embodiment. As shown in FIG. 8, the gap displacement mechanism 4a is such that the head 42 is embedded in the recess under the bottom surface of the hexagonal hole 3a ₁ of the head 3a of the telescopic bolt (1, 2, 3a, 4a). Have been placed. Then, the cap 46 is attached to the bottom surface of the hexagonal hole 3a ₁ .

In the first modification, the telescopic bolt shown in FIG. 1 is in that the cap hole 15 of the head 3 of the telescopic bolt (1, 2, 3, 4) shown in FIG. 1 is not formed as a dedicated recess. It is different from (1, 2, 3, 4). Therefore, as shown in FIG. 8, the length of the second guide hole 13a of the head 3a of the telescopic bolt (1, 2, 3a, 4a) is the length of the telescopic bolt (1, 2, 3, 4a) shown in FIG. 4) It is shorter than the length of the second guide hole 13 of the head 3. Depending on the length of the second guide hole 13a, the length of the cylindrical portion 41a of the gap displacement mechanism 4a is shorter than that of the cylindrical portion 41 of the gap displacement mechanism 4 shown in FIG.

Regarding the configurations other than the head 3a and the gap displacement mechanism 4a of the telescopic bolts (1, 2, 3a, 4a) according to the first modification, the telescopic bolts (1, 2, 3 shown in FIGS. 1 to 6) are shown. Since it is equivalent to the corresponding configurations in (1) and (4), duplicate explanations will be omitted.

Also in the telescopic bolts (1, 2, 3a, 4a) according to the first modification, the telescopic bolts are provided by the gap displacement mechanism 4a in the same manner as the telescopic bolts (1, 2, 3, 4) shown in FIGS. 1 to 6. (1, 2, 3a, 4a) is shortened. Therefore, the play distance between the pressure-side flanks of the threads 1a to 1g of the movable portion 1 and the threads of the female threads cut in the member to be fastened 5 is shortened, and the threads 1a to 1g of the movable portion 1 and the threads to be fastened 1 are fastened. The pressure supported by each other between the threads of the member 5 becomes significantly large. Then, the telescopic bolts (1,2,3a, 4a) firmly bite into the fastened member 5, thereby reliably preventing the telescopic bolts (1,2,3a, 4a) and the fastened member 5 from loosening. can.

Further, since the telescopic bolts (1, 2, 3a, 4a) according to the first modification can work using the hexagon socket 3a ₁ of the head 3a, the workability at the time of fastening or loosening is improved. be able to. Other effects of the telescopic bolts (1, 2, 3a, 4a) according to the first modification are the same as those of the telescopic bolts (1, 2, 3, 4) shown in FIGS. 1 to 6.

(Second variant of the first embodiment)
Further, FIG. 9 shows a case where the width w of the variable gap is widened just before disassembly. In the telescopic bolts (1, 2, 3, 4) according to the second modification of the first embodiment, the movable portion 1 protrudes toward the fixed portion 2 in a part of the region of the first facing plane S1. A protrusion 6 that serves as a parallel key (fixing pin) is provided. A key groove (recess) 7 into which the protrusion 6 can be fitted is provided in a part of the region of the second facing plane S2 of the fixing portion 2 corresponding to the shape of the protrusion 6.

FIG. 10 is a schematic bird's-eye view of the movable portion 1 as viewed from the side of the first facing plane S1, and schematically shows the case where the protrusion 6 is a one-ended round parallel key. The protrusion 6 may be a straight key or a parallel key having round ends, and is not limited to the parallel key, and may have a shape similar to a rod-shaped or flat hexahedron or a sloped key with a head. Further, other shapes such as a columnar shape such as a round key or a semicircular key or a pyramidal trapezoidal shape may be used.

The shape of the recess 7 shown in FIG. 9 may be any shape as long as the protrusion 6 fits smoothly, and the shape can be appropriately changed together with the protrusion 6 as long as the integralness of the movable portion 1 and the fixed portion 2 is improved. .. Regarding the configurations other than the protrusions 6 and the recesses 7 of the telescopic bolts (1, 2, 3, 4) according to the second modification shown in FIG. 9, the telescopic bolts (1, 1) shown in FIGS. 1 to 6 are shown. Since it is equivalent to the corresponding configurations of 2, 3 and 4), duplicate explanations will be omitted.

According to the telescopic bolts (1, 2, 3, 4) according to the second modification, the protrusions 6 and the recesses 7 corresponding to each other are combined and fitted. Due to this fitting, when the outer bolts (1, 2, 3) are inserted into the fastened member 5, the movable portion 1 with respect to the inner bolts (41, 42, 43) due to the torque applied to the movable portion 1. It is possible to prevent it from rotating very slightly. Further, it is possible to prevent the inner bolts (41, 42, 43) from rotating in conjunction with this slight rotation.

Furthermore, in order to shorten the width w of the variable gap, it is possible to prevent rattling, shaking, etc. when rotating the inner bolt (41, 42, 43), so that the force at the time of tightening is effectively transmitted, and the shortened telescopic bolt (shortened telescopic bolt). The integrity of the movable portion 1 and the fixed portion 2 of 1, 2, 3, 4) is improved. As a result, the fastening operation of the telescopic bolts (1, 2, 3, 4) in the fastened state and the fastened member 5 can be reliably, accurately and quickly executed, and loosening after fastening can be prevented more firmly. The other effects of the telescopic bolts according to the second modification are the same as those of the telescopic bolts (1, 2, 3, 4) shown in FIGS. 1 to 6.

--Second embodiment--
In the telescopic bolt according to the first embodiment, a series of holes (12) are provided by providing stupid holes coaxially and having the same diameter in the head portion 3 and the fixing portion 2 of the outer bolts (1, 2, 3) on the same straight line. , 13) was formed. Then, the inner bolt (41, 42, 43) forming the main part of the gap displacement mechanism 4 in which the male screw portion 43 is inserted into the female screw 11 of the movable portion 1 via the series of holes (12, 13). The movable portion 1 was shifted to retract by using a rotary motion.
However, the telescopic bolt according to the second embodiment provides a gap displacement mechanism that is pulled out and shifted toward the head side so as to displace the gap of the outer bolt by a mechanism other than the rotational movement of the screw.

<Structure of telescopic bolt>
As shown in FIG. 11, the telescopic bolts (1, 2, 3, 8) according to the second embodiment have a movable portion 1 having a first facing plane S1 as a notched slope and a first facing plane. A fixing portion 2 having a second facing plane S2 facing S1 via a variable gap as a notched slope is provided.
The fixed portion 2 forms a substantially columnar shape in combination with the movable portion 1, and the movable portion 1 and the fixed portion 2 form a shaft portion (1) of the telescopic bolt (1, 2, 3, 8) according to the second embodiment. , 2). The movable portion 1 is provided with threads 1a to 1g on the cylindrical surface of the first diagonally cut cylinder (cut head cylinder).
The fixing portion 2 is provided with threads 2a to 2g continuous with the threads 1a to 1g of the movable portion 1 on the cylindrical surface of the second diagonally cut cylinder. The movable portion 1 and the fixed portion 2 form a continuous rod shape through a variable gap.

Further, the telescopic bolts (1, 2, 3, 4) according to the second embodiment have a bottom surface of a substantially cylindrical shaft portion (1, 2) composed of the first and second diagonally cut cylinders. It is provided with a substantially hexagonal columnar head portion 3 fixed to the end surface (neck) of the fixing portion 2 so as to be continuous. Further, the telescopic bolts (1, 2, 3, 8) according to the second embodiment move the movable portion 1 relative to the fixed portion 2 along the direction of the shaft portion (1, 2). A gap displacement mechanism 8 that displaces the variable gap is provided.

The gap displacement mechanism 8 is a rod-shaped portion whose tip allows the gap between the movable portion 1 and the fixed portion 2 to be displaced (shifted) along the direction of the axis via a drive hole 11b provided in the movable portion 1. Is the main part. Unlike the female screw 11 of the telescopic bolt (1, 2, 3, 4) shown in FIG. 1, the drive hole 11b is formed so as to penetrate the movable portion 1 from the first facing plane S1 to the screw tip on the opposite side. ing. No screw thread is formed on the inner surface of the drive hole 11b, and the drive hole 11b is flat.

In the rod-shaped portion of the gap displacement mechanism 8, most of the rod-shaped portions other than the tip penetrate the insides of the head portion 3 and the fixed portion 2, respectively, and are provided coaxially with the drive hole 11b on the first guide hole 12 and the first guide hole 12. 2 It is inserted into the inside of a series of holes (12, 13) of the guide hole 13 and operates.
As shown in FIG. 11, the drive hole 11b has substantially the same diameter as the first guide hole 12b and the second guide hole 13b, and is coaxial with the central axis of the movable portion 1 of the telescopic bolt (1, 2, 3, 8). Is set to.

The gap displacement mechanism 8 of the telescopic bolt (1, 2, 3, 8) according to the second embodiment realizes an axial movement mechanism similar to a push turn rivet made of, for example, resin. The gap displacement mechanism 8 is one of a substantially disk-shaped first head (grommet head) 81 shown on the right side of FIG. 11 and a first head 81 which is the center of the disk formed by the first head 81. One end in the longitudinal direction is attached to the surface of the surface, and the constricted portions 82a and 82b for pressurization are provided at the tip portion.

The pressurizing narrowed portions 82a and 82b form a substantially tubular sheath portion (grommet sheath portion) 82 extending perpendicularly to the disk surface of the first head 81. The pressurizing narrowed portions 82a and 82b are bifurcated from the vicinity of the base of the first head 81 toward the opposite end on the left side in FIG.
Further, the gap displacement mechanism 8 includes a transmission pin 84 slidably provided inside the sheath portion 82 and having a glans-shaped tip, and an end portion of the transmission pin 84 on the first head 81 side (FIG. 11). On the right side), it has a substantially disk-shaped second head 83.

The transmission pin 84 forming the gap displacement mechanism 8 can repeatedly perform an operation in which the glans penis at the tip protrudes to the outside of the sheath portion 82 or retracts inward. As shown in FIGS. 11 and 13, the disk of the second head 83 of the gap displacement mechanism 8 has a smaller diameter than the disk of the first head 81. Then, by forming a recess corresponding to the shape of the second head 83 in the first head 81, the second head 83 is stored inside the recess.

In FIG. 11, a telescopic bolt (1, 2) in which the second head 83 is housed inside the recess of the first head 81 and the tip of the second head 83 of the transmission pin 84 protrudes most from the sheath 82. , 3, 8) are shown in the extended state. The tip portions (left side in FIG. 11) of the pressurizing narrowed portions 82a and 82b have a tapered shape such that the inner diameter is smaller than the inner diameters of most of the other parts.

The transmission pin 84 forming the gap displacement mechanism 8 selectively swells in a specific radial direction as shown in a cross-sectional view cut perpendicular to the axial direction in FIG. 12. Therefore, when the transmission pin 84 is rotated about the axis when the second head 83 is pushed or pulled out from the first head 81, the sheath portion 82 is narrowed for pressurization. The outer diameters of the portions 82a and 82b change.

When the transmission pin 84 forming the gap displacement mechanism 8 has a rotation angle at the position shown in FIG. 12, the region surrounded by the movable portion 1 of the telescopic bolt (1, 2, 3, 8) is the sheath portion 82. It projects toward the inner surface side of the drive hole 11b of the movable portion 1 through the gap between the two crotches. In this protruding state, it is fixed to the movable portion 1 with a predetermined frictional force.
Further, inside the fixing portion 2, the outer surface of the sheath portion 82 of the gap displacement mechanism 8 is firmly fixed to the inner surfaces of the first guide hole 12b and the second guide hole 13b by a predetermined frictional force.

If the second head 83 of the gap displacement mechanism 8 is pushed to the locked position with respect to the first head 81 by rotating 90 ° in the direction of the glans penis selectively bulging in the radial direction from the angle shown in FIG. , The outer diameters of the pressurizing constrictions 82a and 82b increase. Therefore, the movable portion 1 is displaced in a direction relatively close to the fixed portion 2 in conjunction with the axial sliding of the transmission pin 84, and the telescopic bolts (1, 2, 3, 8) are shortened. A state is formed.

On the other hand, if the second head 83 is rotated to the angle shown in FIG. 12 and then pushed further to the open position with respect to the first head 81, the outer diameter of the sheath portion 82 at the position of the pressurizing narrowing portions 82a and 82b is reached. Shrinks. Therefore, the movable portion 1 is displaced so as to be relatively separated from the fixed portion 2 in conjunction with the axial slide of the transmission pin 84, and as shown in FIG. 13, the telescopic bolts (1, 2, 3, 8) The stretched state of is formed.
Regarding the configurations other than the drive hole 11b and the gap displacement mechanism 8 of the telescopic bolt (1, 2, 3, 8) according to the second embodiment, the telescopic bolt (1, 2) according to the first embodiment. , 3, 4) are equivalent to the corresponding configurations, so duplicate explanations will be omitted.

Also in the telescopic bolts (1, 2, 3, 8) according to the second embodiment, the gap displacement mechanism 8 is moved from the screw tip side to the head 3 side as in the telescopic bolt according to the first embodiment. The movable portion 1 is shifted and moved relative to the fixed portion 2 side. This movement shortens the distance (play) between the threads 1a to 1g of the movable portion 1 and the threads of the female threads that fit the threads 1a to 1g. By setting the variable gap to the minimum value, the telescopic bolt (which has the minimum value of the gap between the threads 1a to 1g of the movable portion 1 and the threads of the fastened member 5 to be fitted with the threads 1a to 1g). It forms the shortened state of 1, 2, 3, 8).

When this gap becomes the minimum value, the pressure supported by each other between the threads 1a to 1g of the movable portion 1 and the threads of the member to be fastened 5 becomes remarkably large, and the telescopic bolts (1, 2, 3, 8) ) Firmly bites into the fastened member 5. Therefore, it is possible to reliably prevent the telescopic bolts (1, 2, 3, 8) and the member to be fastened 5 from loosening.

Further, in the manufacture of the telescopic bolts (1, 2, 3, 8) according to the second embodiment, unlike the case of the telescopic bolts according to the first embodiment, the female screw 11 is inside the movable portion 1. There is no need to process and form. Therefore, it is only necessary to form a series of holes (11b, 12b, 13b) in the outer bolts (1, 2, 3).
Further, a mechanism similar to the push turn rivet on the market can be used as the gap displacement mechanism 8. Therefore, it becomes easier to manufacture a telescopic bolt. The other effects of the telescopic bolts (1, 2, 3, 8) according to the second embodiment are the same as those of the telescopic bolts according to the first embodiment.

(Modified example of the second embodiment)
In the telescopic bolts (1, 2, 3, 8) shown in FIGS. 11 to 13, the shaft portion of the telescopic bolt (1, 2, 3, 8) uses a mechanism similar to a push turn rivet as the gap displacement mechanism 8. (1, 2) was shortened. However, the gap displacement mechanism according to the second embodiment can be realized even if the mechanism is other than the mechanism similar to the push turn rivet.

As shown in FIG. 14, the telescopic bolts (1, 2, 3, 9) according to the modified example of the second embodiment are coaxial and abbreviated over the movable portion 1, the fixed portion 2, and the head 3. Holes of the same diameter are provided so as to be aligned on the same straight line, and a series of holes (11c, 12c, 13c) are formed. The drive hole 11c of the movable portion 1 of the shaft portion (1, 2) of the bolt shown in FIG. 14 is formed between the first facing plane S1 and the inside, and does not penetrate to the screw tip. No threads are formed on the inner surfaces of the series of holes (11c, 12c, 13c), and they are flat.

The gap displacement mechanism (9,21,22) according to the modification of the second embodiment includes a substantially columnar shaft body 9. Further, the gap displacement mechanism (9,21,22) is attached to the end of the telescopic bolt (1,2,3,9) of the shaft body 9 on the head 3 side, and the telescopic bolt (1,2,9) of the shaft body 9 is attached. A first retaining ring 21 for fixing the first mounting position with respect to 2, 3, 9) is provided.

Further, as shown in FIG. 16, the gap displacement mechanism (9,21,22) has a first stop to fix the second attachment position of the shaft body 9 to the telescopic bolts (1,2,3,9). A second retaining ring 22 having a thickness larger in the axial direction than the first retaining ring 21 which is selectively selected as the ring 21 is provided. The second retaining ring 22 is attached to the end of the telescopic bolt (1, 2, 3, 9) of the shaft body 9 on the head 3 side.

The shaft body 9 has a substantially columnar main body 91 and a substantially columnar neck portion having a diameter smaller than that of the main body 91 provided at the end of the telescopic bolt (1, 2, 3, 9) of the main body 91 on the head 3 side. It has a head portion 92 and a head portion 93 having a substantially disk shape having a diameter larger than that of the neck portion 92 provided at an end portion of the neck portion 92 opposite to the main body 91.

The first retaining ring 21 is, for example, an annular ring such as a C-shaped retaining ring, an E-shaped retaining ring, a grip retaining ring, or a crescent retaining ring in which a hole having a diameter substantially the same as the diameter of the neck portion 92 of the shaft body 9 is formed inside. It can be realized with the members of. The first retaining ring 21 can be attached to and detached from the head 3 of the telescopic bolt (1, 2, 3, 9). Specifically, for example, although not shown, the telescopic bolt (1, 2, 3, 9) is attached to the bottom surface (peripheral surface) of the head 3 of the telescopic bolt (1, 2, 3, 9) on the end face side. The first retaining ring 21 is formed with protrusions, recesses, and the like that are fitted to each other with the end surface of the head 3.
Further, the first retaining ring 21 has a protrusion, a recess, and the like formed on the inner side surface of the hole of the ring so as to be fitted to each other with the outer surface of the neck portion 92 of the shaft body 9. However, it can be attached and detached.

Like the first retaining ring 21, the second retaining ring 22 is an annular member such as a C-shaped retaining ring having a hole having a diameter substantially the same as the diameter of the neck portion 92 of the shaft body 9 formed inside. The second retaining ring 22 is formed by forming protrusions and recesses (not shown) that are fitted to each other on the inner surface of the hole of the ring with the outer surface of the neck portion 92 of the shaft body 9. It can be attached to and detached from the shaft body 9.

The shaft body 9 of the gap displacement mechanism (9,21,22) is inserted over a series of holes (11c, 12c, 13c) of the telescopic bolts (1,2,3,9). Inside the drive hole 11c of the movable portion 1, the outer surface of the main body 91 of the shaft body 9 is bonded by adhesion or the like, and the shaft body 9 operates integrally with the movable portion 1.
Further, the outer surface of the main body 91 of the shaft body 9 is not connected to the fixing portion 2 inside the first guide hole 12c of the fixing portion 2 and the second guide hole 13c of the head portion 3, and the main body of the shaft body 9 is not connected. The outer surface of the 91 and the inner surface of the first guide hole 12c and the second guide hole 13c slide smoothly.

Therefore, when neither the first retaining ring 21 nor the second retaining ring 22 is attached to the main body 91 of the shaft body 9, the movable portion 1 is the shaft of the shaft body 9 of the gap displacement mechanism (9,21,22). It can move in conjunction with the displacement in the direction. Regarding configurations other than the series of holes (11c, 12c, 13c) and the gap displacement mechanism (9,21,22) of the telescopic bolts (1,2,3,9) according to the modified example of the second embodiment. Is equivalent to the corresponding configurations of the telescopic bolts (1, 2, 3, 4) shown in FIGS. 1 to 6, so duplicate description will be omitted.

In the telescopic bolt (1, 2, 3, 9) according to the modified example of the second embodiment, as shown in FIG. 14, the head 3 and the shaft body of the telescopic bolt (1, 2, 3, 9) The first retaining ring 21 is attached to the neck portion 92 of 9. Then, by attaching the first retaining ring 21, the shaft body 9 is fixed to the first attachment position of the telescopic bolt (1, 2, 3, 9), and the movable portion 1 and the fixing portion 2 are fixed with a variable gap having a width w. To face each other through.
On the other hand, as shown in FIG. 15, the first retaining ring 21 is removed from the shaft body 9, the head portion 93 and the neck portion 92 are pinched, and the shaft body 9 is attached to the outside of the head portion 3 of the telescopic bolts (1, 2, 3, 9). If it is displaced so as to be pulled out, the movable portion 1 retracts in conjunction with the displacement of the shaft body 9, and the movable portion 1 and the fixed portion 2 come into contact with each other.

Since the head 93 of the shaft body 9 projects outward from the head 3 of the telescopic bolt (1, 2, 3, 9), the head 93 of the shaft body 9 and the telescopic bolt (1, 2, 3, 9) The distance between the heads 3 is longer than the distance in the extended state shown in FIG. As shown in FIG. 16, if the second retaining ring 22 is attached between the head 93 of the shaft body 9 having a long distance and the head 3 of the telescopic bolts (1, 2, 3, 9), the shaft body 9 is attached. Can be fixed to the second mounting position of the telescopic bolts (1, 2, 3, 9). By the above series of operations, the shortened state of the telescopic bolts (1, 2, 3, 9) according to the modified example of the second embodiment is completed.

Also in the telescopic bolts (1, 2, 3, 9) according to the modified example of the second embodiment, the gap displacement is the same as the telescopic bolts (1, 2, 3, 4) shown in FIGS. 1 to 6. The telescopic bolt (1,2,3,9) is shortened by the mechanism (9,21,22). Therefore, the play distance between the pressure-side flanks of the threads 1a to 1g of the movable portion 1 and the threads of the fastened member 5 becomes short, and the threads 1a to 1g of the movable portion 1 and the threads of the fastened member 5 are threaded. The pressure between them is much greater. Then, the telescopic bolts (1, 2, 3, 9) firmly bite into the fastened member 5, thereby reliably preventing the telescopic bolts (1, 2, 3, 9) and the fastened member 5 from loosening. Can be done.

Further, also in the telescopic bolts (1, 2, 3, 9) according to the modified example of the second embodiment, the same as in the case of the telescopic bolts (1, 2, 3, 8) shown in FIGS. 11 to 13. It is only necessary to form the drive hole 11c, the first guide hole 12c, and the second guide hole 13c. Further, the gap displacement mechanism (9,21,22) can be realized with a simple member. Therefore, a stretchable bolt can be easily manufactured. The other effects of the telescopic bolts (1, 2, 3, 9) according to the modified example of the second embodiment are the same as those of the telescopic bolts according to the first and second embodiments.

(Other embodiments)
Although the present invention has been described by embodiments disclosed as described above, the statements and drawings that form part of this disclosure should not be understood as limiting the invention. It should be considered from this disclosure to those skilled in the art that various alternative embodiments, examples and operational techniques will be revealed. For example, the fastened member 5 to which the telescopic bolt is fed is not limited to the nut, and can be combined with the telescopic bolt according to the present invention as long as it has a structure having a female screw.
Further, the heads 3 and 3a of the telescopic bolts shown in FIGS. 1 to 16 are all substantially hexagonal columns, but if a gap displacement mechanism can be provided, the heads 3 and 3a may have shapes other than the hexagonal columns. good.

Further, the transmission pin 84 similar to the push turn rivet shown in FIG. 11 and the shaft body 9 shown in FIG. 14 have been described as having a cylindrical shape, but these are examples. For example, it is movable if it is made into another shape such as a polygonal columnar shape, and the shape of the second guide hole 13 of the head 3 of the telescopic bolt into which these are inserted and the shape of the first guide hole 12 of the fixing portion 2 are also formed correspondingly. It can be used as a gap displacement mechanism for retracting the portion 1.

Further, the telescopic bolt according to the present invention may be configured by combining the technical ideas of the respective embodiments and modifications as shown in FIGS. 1 to 16. As described above, the present invention includes various embodiments not described in the present specification and the drawings, and the technical scope of the present invention is the matters specifying the invention relating to the appropriate claims from the above description. It is determined only by.

Since the present invention can provide bolts that can reliably prevent loosening of screw connections, the present invention is particularly suitable when applied to bolts having a screw structure used for fastening various members in, for example, motorcycles and automobiles. In particular, it is suitable as a bolt used for a member to be fastened in which a female screw is embedded in a structure.

1 Movable part 1a to 1g Thread 1f ₁ , 1g ₁ Advance side flank (play side flank)
1f ₂ , 1g ₂ Follower flank (pressure side flank)
2 Fixed part 2a to 2k Thread 2h ₁ , 2l ₁ , 2m ₁ , 2n ₁ Leading flank (play flank)
2h ₂ , 2l ₂ , 2m ₂ , 2n ₂ Follow-up flank (pressure side flank)
3,3a Head 3a ₁ Hexagonal hole 4,4a Gap displacement mechanism 5 Fastened member 6 Protrusion 7 Recess 8 Gap displacement mechanism 9 Gap displacement mechanism 11 Female screw 11b, 11c Drive hole 12, 12b, 12c First guide hole 13 , 13a, 13b, 13c 2nd guide holes 14, 14a Embedded holes 15 Cap holes 17a, 17b Screw holes 21 1st stop ring 22 2nd stop ring 41, 41a Cylindrical part 42 Head 43 Male screw part 46 Cap 47a, 47b Screw 81 1st head 82 Sheath 82a, 82b Pressurizing constriction 83 2nd head 84 Transmission pin 91 Main body 92 Head 93 Head df ₁ , dl ₁ , dl ₁ , dm ₁ Play distance df ₂ , dl ₂ play Distance w Variable gap width L1, L2 Nominal length S1 First facing plane S2 Second facing plane θ Dividing angle

Claims (1)

A movable part having a thread on the cylindrical surface of the first obliquely cut cylinder having the first opposed plane as the notched slope, and
A screw thread that is continuous with the screw thread of the movable portion is provided on the cylindrical surface of the second diagonally cut cylinder having the second facing plane facing the first facing plane via a variable gap as a notched slope. And a fixed part that forms a substantially cylindrical shape in combination with the movable part,
With a gap displacement mechanism that displaces the variable gap by moving the movable portion relative to the fixed portion along the direction of the axis of the substantially cylindrical cylinder formed by the first and second diagonally cut cylinders. ,
It is a telescopic bolt equipped with
The division angle defined by the angle formed by the first facing plane and the plane orthogonal to the axis of the telescopic bolt is 40 ° or more and 60 ° or less.
The movable portion and the fixed portion form a male screw portion of the bolt, and by reducing the variable gap, the screw thread of the movable portion and the female screw of the fastened member that fits with the screw thread of the movable portion. A telescopic bolt characterized in that the male screw portion is fixed to the female screw with the gap between the screw thread and the screw thread as the minimum value.

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