JP4343087B2 - Constant axial force bolt device - Google Patents

Description

  The present invention relates to a constant axial force bolt device that has a small number of components, is easy to assemble, does not separate components, has good workability, and provides a constant tightening axial force.

  Conventionally, this type of device includes a device that is tightened with a torque wrench with a predetermined torque, a device that is tightened using a so-called breakaway bolt that breaks the bolt head with a constant torque, or a nut that is tightened with a latitudinal device and an elastic body. Are known (for example, Patent Document 1).

  And a washer having a hole through which the bolt can pass, a seat, a ring screwed to the seat to move up and down in the axial direction, and a portion surrounded by the washer, the seat and the ring. The ring or the seat is provided with at least a scale or an index for knowing the amount of rotation of the ring. A desired gap can be set between the upper surface and the upper surface of the ring, and when the bolt is tightened, the elastic body is deformed by the specified tightening force of the bolt and the washer and the ring come into contact with each other. A detection seat for bolt tightening force is known (for example, Patent Document 2).

  Furthermore, the bolt shaft part is equipped with a tightening force adjustment lid, a disc spring, and a power storage ring, and the nut is tightened to compress the disc spring, the spring force is stored in the tightening device, and then the nut is loosened and stored. There is known a tightening device that applies a spring force applied to a member to be tightened (for example, Patent Document 3).

Japanese Utility Model Publication No. 51-041064 JP 63-096307 A JP 2003-322220 A

  The above-described conventional constant axial force tightening device has the following problems. That is, in Patent Document 1, there are many components, the mechanism is complicated, the weight is heavy, and it is difficult to apply to an accessory attached to a high place such as a power transmission line, such as carrying a large number of cables, and extremely expensive. There was a drawback. Further, in the bolt tightening force detection seat of Patent Document 2, there is a problem in safety that the component parts are loose and the component parts are easily dropped during construction. Furthermore, the tightening device of Patent Document 3 has a troublesome preliminary work such as pre-tightening a disc spring prior to use, and is applicable only to tightening a clamp having a structure in which one end is hinged. was there.

  The present invention has been made in order to solve the above-described problems, and is intended to easily obtain a fixed tightening axial force.In addition, the present invention is easy to assemble and can be used during construction at a high place. An object of the present invention is to provide a safe constant axial force bolt device in which components are not separated.

In order to solve the above-described problems, the constant axial force bolt device of the present invention uses the following means. In addition, the code | symbol attached | subjected corresponds with that of drawing.
(1) According to the first aspect of the present invention, a screw portion M that is screwed onto the application bolt 4 is provided at the bottom of the housing 1 formed of a cylindrical body with a bottom, and a plurality of disc springs 3 and washers 2 are provided on the bolt 4. When the disc spring 3 is assembled in an uncompressed state by screwing the bolt 1 into the housing 1 and assembling the disc spring 3 in an uncompressed state, the disc spring 3 provides a gap G corresponding to a compression amount that expresses a predetermined axial force, In the constant axial force bolt device, the narrow neck portion 12 is provided so that when the gap G is tightened to 0, the screw portion of the bolt is disengaged from the screw portion M provided in the housing 1. is there.

(2) The invention described in claim 2 is the constant axial force bolt device according to the invention described in claim 1, wherein at least one component is magnetized and adsorbed to the bolt 4 to be integrated. .
(3) The invention according to claim 3 is characterized in that an adsorption washer 9 made of a permanent magnet is interposed between the inner bottom side of the housing 1 and the disc spring 3. Device.

(4) The invention according to claim 4 is provided with a screw portion M to be screwed to the application bolt 4 at the bottom of the lower housing 5 of the housing having a pair of bottomed cylinders, and the bolt on the upper housing 6 side. 4 is provided with a fitting hole that fits (penetrates), an O-ring groove 7 is provided on the peripheral edge of the housings 5 and 6, and an O-ring 8 is mounted on one side of the O-ring groove 7. When it becomes 0, the internal space formed by the housings 5 and 6 is sealed to form a watertight structure,
The bolt 4 is provided with a disc spring 3 or an elastic body 4, and when the gap G between the pair of housings becomes 0, the threaded portion M of the bolt is disengaged to obtain a predetermined axial force. It is comprised so that it may be, It is the constant axial force bolt apparatus characterized by the above-mentioned.

(5) The invention according to claim 5 is characterized in that a polishing surface or an adhesive surface 11 is formed on the outer bottom surface of the housing 1 or 5 in contact with the material 13 to be fastened to prevent co-rotation with the bolt 4. The constant axial force bolt device according to any one of claims 1 to 4.
(6) In the invention according to claim 6, when a single elastic member or a plurality of laminated elastic members are mounted in the cavity (S) of the housing and the elastic member is tightened with a predetermined axial force, the housing The constant axial force bolt device according to claim 4, wherein the hollow portion (S) is hermetically sealed.

(7) In the invention according to claim 7, the volume of the rubber-like elastic body in the cavity (S) of the housing is tightened with a predetermined axial force so that the gap (G) between the peripheral edges of the housing is zero. 7. The constant axial force bolt device according to claim 6, wherein the constant axial force bolt device is configured so as to substantially coincide with a volume of the hollow portion (S).
(8) The constant axial force bolt device according to claim 6 or 7, wherein a predetermined axial force is obtained by changing the hardness of the rubber-like elastic body. It is.

According to the present invention, the following constant axial force bolt device can be provided, and an industrially remarkable effect can be obtained.
1. According to the first aspect of the present invention, the number of components is small and the assembly is simple. That is, a screw portion M that is screwed to the applicable bolt 4 is provided at the bottom of the housing 1, a plurality of disc springs 3 and washers 2 are mounted on the bolt 4, and the bolt 4 is screwed and locked to the housing 1. Since the narrow neck portion is provided at a predetermined position of the bolt so that the bolt is released after being tightened by the axial force, the component parts are not released. In addition, since the compression amount of the disc spring is preferentially defined, a constant tightening axial force is always obtained regardless of the torque coefficient of the bolt.
2. According to the second aspect of the present invention, since one or more components are magnetized and adsorbed to the bolts to be integrated, the components are not released, and can be safely and quickly without dropping the components even when working at high places. Can be tightened.
3. According to the third aspect of the invention, since the adsorption washer made of a permanent magnet is interposed, the constant axial force bolt device can be provided at a lower cost than the second aspect of the invention.

4). According to the invention described in claim 4, since the elastic body such as a disc spring or rubber is mounted in the sealed space, the elastic body does not corrode and deteriorate the spring characteristics even in a highly corrosive environment. .
5. According to the fifth aspect of the present invention, since a polished surface or an adhesive surface is formed on the outer bottom surface of the housing to prevent co-rotation with the bolt, the tightening operation can be performed efficiently.
6). According to the sixth aspect of the present invention, since the rubber-like elastic body is used as the constant axial force generating member in the sealed space, the constant axial force bolt device that is light and inexpensive and has no fear of deterioration such as ultraviolet rays is provided. Can be provided.
7). According to the seventh aspect of the present invention, the volume of the hollow portion (S) of the housing and the volume of the rubber-like elastic body when the rubber-like elastic body is tightened with a predetermined axial force are substantially the same. Since it comprised, the sag of the rubber-like elastic body by long-term clamping can be suppressed to the minimum.
8). According to the eighth aspect of the invention, since the predetermined constant axial force is obtained by changing the hardness of the rubber-like elastic body, the set axial force can be adjusted inexpensively and in a wide range.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic sectional view of a constant axial force bolt device 10 showing a first embodiment of the present invention. In the figure, reference numeral 1 denotes a flat pan-bottomed housing made of a cylindrical body with a bottom, and a threaded portion M to be screwed onto the bolt 4 is provided at the center of the bottom surface. The housing 1 can be press-molded from a steel plate or mass-produced from ductile cast iron. 2 is a washer, 3 is a disc spring, made of spring steel, stainless steel for springs, etc. In the first embodiment, four are used in series, and in this case, the spring constant of one disc spring is 4 Double displacement amount can be obtained. If two sets are stacked in parallel and used in series, four sets of spring constants can be doubled. In any case, these combinations can be arbitrarily determined in consideration of the set axial force. 4 is a bolt. The above iron components are used after being subjected to electrogalvanizing, hot dip galvanizing, hot dip zinc aluminum alloy plating or the like.
G is a gap between the lower surface of the washer 2 and the upper peripheral surface of the housing 1, and is an interval corresponding to the compression amount of the disc spring 3 that can express a predetermined axial force when the disc spring 3 is tightened by the bolt 4. .

  Reference numeral 11 denotes a lubricant layer, an adhesive layer, or an adhesive layer provided on the outer bottom surface of the housing 1, and is provided to prevent the housing from rotating together with the bolt 4 and lowering the tightening efficiency. However, it can be substituted by roughening by blasting or the like, and may be omitted when the surface of the material 13 to be fastened is rough. In the case where 11 is an adhesive layer, for example, a material manufactured by ThreeBond Co., Ltd. coated with a precoat mech processing agent in which an adhesive is incorporated in microcapsules is suitable. In this precoat mech processing coating agent, when the housing 1 is rotated between the fastened materials 13 when the bolts are tightened, the microcapsules are broken and the adhesive is leached and the housing is fixed to the fastened material 13. . Since it is the above structure, if it tightens the to-be-fastened material 12 with the volt | bolt 4 and it visually recognizes that the clearance gap G will be 0, it can clamp | tighten a to-be-fastened material with a predetermined | prescribed axial force reliably with a predetermined | prescribed axial force. is there.

Note that the effective length Ls of the threaded portion of the bolt 4 is set to a length that slightly engages with the threaded portion M provided on the bottom surface of the housing 1 when assembled with a gap G as shown. Further, a narrow neck portion 12 is provided at the terminal end of the screw of the bolt 4, and when tightened with a specified axial force, the screwing of the housing 1 and the screw of the bolt 4 is released, and the specified axial force is surely applied. Designed to be transmitted to the fastener. If comprised in this way, a series of component parts with which the volt | bolt 4 was mounted | worn can be integrated, and dropping off etc. can be prevented.
In addition, if any of the components 1 to 4 is magnetized and mutually adsorbed and integrated, it is easy to assemble, and since the components do not separate during construction, the tightening operation can be performed efficiently and dropped. There is no safety.

  FIG. 2 is a schematic cross-sectional view of a constant axial force bolt device 20 showing a second embodiment of the present invention. In the figure, reference numeral 9 denotes a flat washer made of a permanent magnet, which is provided with a dent on the bottom surface of the housing 1 and attracted. If comprised as mentioned above, iron parts will not adsorb | suck to the volt | bolt 4, and it will not drop | omit, but an assembly state is maintained also in conveyance etc., and it is convenient. In addition, the flat washer 9 of the permanent magnet can be installed directly without providing a recess in the housing, or a plurality of permanent magnets can be installed on the top and bottom to further strengthen the attractive force. In the present embodiment, the screw hole M provided in the center of the bottom surface of the housing 1 can be a fool hole.

FIG. 3 is a schematic sectional view of a constant axial force bolt device 30 showing a third embodiment of the present invention. That is, the present embodiment provides a constant axial force bolt device having a watertight structure in which a disc spring or the like is prevented from being deteriorated by corrosion.
In the figure, reference numerals 5 and 6 denote a pair of symmetrically shaped flat pan-bottomed cylindrical bodies which are configured to form a cavity (S) when they are opposed to each other. At the center of the bottom surface of the lower housing 5, a screw portion M that is screwed to the bolt 4 is provided, and a flaw hole that fits the bolt 4 is provided at the same location of the upper housing 6. In the present embodiment, for simplicity of explanation, the shape of the housing is a flat pan-bottomed cylindrical body, but is not restricted to such a shape, and may be a cubic polygonal shape. Is self-explanatory.

  Reference numeral 7 denotes an O-ring mounting groove provided at the peripheral edge of the upper and lower housings 5 and 6, and the O-ring 8 is mounted at the location. G is a gap between the peripheral portions of the upper and lower housings 5 and 6, and is an interval corresponding to the compression amount of the disc spring 3 that can express a predetermined axial force when the disc spring 3 is tightened by the bolt 4. Further, when the gap G becomes 0, the upper and lower peripheral edges closely contact each other, and the O-ring is compressed so that the cavity (S) of the housing containing the disc spring has a watertight structure. In addition, a silicone sealing agent etc. can be apply | coated to the peripheral part of the upper and lower housings 5 and 6 without providing an O-ring etc., and it can also be set as a watertight structure. If it does in this way, the O-ring groove | channel 7 can be abbreviate | omitted and it can be set as a cheap thing.

  FIG. 4 is a schematic view showing a state in which the material to be fastened 13 is fastened by the constant axial force bolt device 30 and the peripheral portions of the upper and lower housings 5 and 6 are in close contact with each other. As described above, when the constant axial force bolt device 30 is configured in a watertight structure, the galvanizing process and the like in which the spring characteristics of the disc spring 3 are easily changed can be omitted, and it is economical, and even in a poor corrosive environment, Maintenance costs can be saved because a constant tightening axial force can be maintained without long-term corrosion deterioration.

  According to the present invention, it is possible to provide a constant axial force bolt device that can provide a specified axial force stably with a simple configuration and with no component parts being separated. For example, if used for bolts for assembling power transmission towers, expensive maintenance management costs such as periodic tightening can be reduced. If it is applied to the tightening bolt, it is possible to reduce costs similar to those described above, such as periodic inspection of the state of reduction in gripping force caused by loosening of the bolt. Furthermore, if it is applied to a scaffold clamp bolt for assembling a scaffold at a construction site, it can be fixed with a reliable axial force, so that an extremely safe scaffold can be constructed. Moreover, although the case where the disc spring was applied to the elastic body which is the principal part was demonstrated in embodiment, a coil spring, a square spring, etc. can be used. In the case of a watertight structure, the ultraviolet and ozone atmosphere can be shut off, so elastic bodies such as rubber whose characteristics are likely to deteriorate due to these effects, such as chloroprene rubber, styrene butadiene rubber, butyl rubber, natural rubber and synthetic rubber, Since ethylene propylene rubber, silicon rubber, and the like can be used, and the number of components can be further reduced and the weight can be reduced, the industrial value is great.

  FIG. 5 shows a fourth embodiment in which rubber is used for the above-mentioned elastic body. 14 is a rubber-like elastic body, and the bolt insertion hole 16 is slightly smaller in diameter than the diameter of the bolt 4 in the center. Is provided. A flat washer 15 having a surface larger than the surface of the elastic body 14 is bonded to the upper and lower portions. In addition, the free height including the thickness of the upper and lower washers 15 of the elastic body 14 is designed so that the gap G becomes zero when compressed with a prescribed axial force. In the case of this embodiment, if the plain washer 15 is omitted and the upper and lower housings 5 and 6 are directly bonded with an adhesive or the like, and the inner diameter of the elastic body 14 is made slightly smaller than the diameter of the neck of the bolt 4, By inserting the bolt 4 into the elastic body 14, the whole is integrated, and inconveniences such as dropping off can be eliminated.

  The advantage of using the elastic body 14 is that a desired axial force can be set by changing the surface area of the elastic body 14 without changing the height H of the constant axial force bolt device. Further, the advantage of using the elastic body 14 is that the elastic body 14 itself can be fixed to the bolt with an elastic force without requiring means such as magnetization, so that the materials of the housings 5 and 6 can be made of lightweight aluminum material, titanium material, etc. The non-magnetic material can be used, and a constant axial force bolt device that is greatly reduced in weight can be provided.

  Although not shown, in order to make the constant axial force bolt device of FIG. 5 simpler and cheaper, the flat washer 15 is omitted and the hollow portions (S) of the upper and lower housings 5 and 6 are disposed. It is preferable that the elastic body 14 to be mounted on is not a single piece manufactured using a special mold, but a plurality of elastic bodies made of thin rubber plates that are mass-produced commercially are used. Further, the volume of the elastic body occupying the cavity (S) is substantially equal to the volume of the cavity (S) when the gap (G) between the peripheral edges of the upper and lower housings 5 and 6 becomes zero. If configured, a lightweight and compact constant axial force bolt device can be provided by minimizing the creep (so-called sag) phenomenon due to compressive force, which is a drawback of the rubber-like elastic body which is an organic elastic body. Furthermore, in the constant axial force bolt device by elastic body compression in such a sealed space, the desired axial force can be adjusted over a wide range and inexpensively by changing the hardness of the elastic body. Industrial value is great.

The cross-sectional schematic of the constant axial-force bolt apparatus which shows 1st Embodiment of this invention. The cross-sectional schematic of the constant axial-force bolt apparatus which shows 2nd Embodiment of this invention. The cross-sectional schematic of the constant axial-force bolt apparatus which shows 3rd Embodiment of this invention. FIG. 4 is a schematic view showing a state in which the constant axial force bolt device of FIG. The cross-sectional schematic of the constant axial-force bolt apparatus which shows 4th Embodiment of this invention.

Explanation of symbols

1 Housing
2 washer
3 Disc spring
4 bolts
5 Lower housing
6 Upper housing
7 O-ring groove
8 O-ring
DESCRIPTION OF SYMBOLS 9 Plain washer of permanent magnet 10, 20, 30, 40 Constant axial force bolt apparatus 11 Lubricating material layer or adhesive material layer 12 Narrow neck part 13 Fastened material 14 Rubber-like cylindrical elastic body 15 Plain washer 16 Bolt insertion hole
G gap
M Thread part Ls Bolt thread effective length
H Height of constant axial force bolt device
S cavity

Claims (8)

  A threaded portion M that is screwed onto the applicable bolt 4 is provided at the bottom of the housing 1 formed of a cylindrical body with a bottom. A plurality of disc springs 3 and washers 2 are mounted on the bolt 4, and the bolt 1 is attached to the housing 1. When the disc spring 3 is assembled in a non-compressed state by screwing, the disc spring 3 is provided with a gap G corresponding to a compression amount that expresses a predetermined axial force, and is tightened until the gap G becomes zero Further, a thin-neck portion 12 is provided so that the threaded engagement of the bolt is disengaged from the threaded portion M provided in the housing 1.   The constant axial force bolt device according to claim 1, wherein at least one component is magnetized and adsorbed to the bolt 4 to be integrated.   The constant axial force bolt device according to claim 1, wherein an adsorption washer 9 made of a permanent magnet is interposed between the inner bottom side of the housing 1 and the disc spring 3. A screw portion M to be screwed to the application bolt 4 is provided at the bottom of the lower housing 5 of the housing having a pair of bottomed cylinders, and a hole for fitting the bolt 4 is provided on the upper housing 6 side; An O-ring groove 7 is provided on the peripheral edge of the housings 5 and 6 and an O-ring 8 is mounted on one side of the O-ring groove 7. When the gap G becomes 0, the interior formed by the housings 5 and 6. The space is sealed to form a watertight structure,
The bolt 4 is provided with a disc spring 3 or an elastic body 4, and when the gap G between the pair of housings becomes 0, the threaded portion M of the bolt is disengaged to obtain a predetermined axial force. A constant axial force bolt device, characterized by being configured.   5. A polishing surface or an adhesive surface 11 is formed on the outer bottom surface of the housing 1 or 5 in contact with the fastened material 13 to prevent co-rotation with the bolt 4. The constant axial force bolt device described.   When the rubber-like elastic body is mounted in a single or a plurality of layers in the cavity (S) of the housing and the elastic body is tightened with a predetermined axial force, the cavity (S) of the housing is sealed. The constant axial force bolt device according to claim 4, which is configured as follows.   The volume of the rubber-like elastic body occupying the cavity (S) of the housing is such that when the gap (G) between the peripheral edges of the housing becomes 0 by tightening with a predetermined axial force, the volume of the cavity (S) The constant axial force bolt device according to claim 6, wherein the constant axial force bolt device is configured to substantially coincide with the volume. The constant axial force bolt device according to claim 6 or 7, wherein a predetermined axial force is obtained by changing a hardness of the rubber-like elastic body.

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