JP2001140832A - Torque control fastening device for bolt and nut, and bolt and nut with torque control fastening device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safe and labor saving torque control fastening device for a bolt and nut and a bolt and nut with a torque control fastening device capable of performing highly reliable and positive torque control. SOLUTION: This device is provided with a cover body 12 having a recessed part 12a attached to a head part 18a of the bolt 18, and a fastening body 14 articulated to the cover body 12 for fastening the bolt 18. It is comprised by integrally articulating the cover body 12 and the fastening body 14 with an articulating part 16 ruptured at a specific fastening torque having an outline shape with a cross sectional area at maximum at a portion contacting a bottom face of the fastening body 14, gradually decreasing toward the cover body 12, and at minimum at a portion contacting a vertex face 12b of the cover body 12. The cover body 12, the fastening body 14, and the articulating part 16 are formed by a resin of the same material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt capable of controlling the tightening torque of a bolt or a nut when the bolt or the nut is tightened outdoors or indoors.
TECHNICAL FIELD The present invention relates to a nut for controlling torque of a nut, a bolt with a torque controlling fastener, and a nut.

[0002]

2. Description of the Related Art In general, when tightening bolts and nuts, it is desirable to tighten them so as not to over-tighten or insufficiently tighten. However, when tightening by rotating a simple tool such as a spanner manually, the desired tightening is required. It is difficult to tighten with a fixed tightening force, and the tightening tends to vary. For this reason, when tightening bolts and nuts especially at places where tightening torque management is necessary, use a torque wrench or an electric bolt tightening tool with a torque limiter that can understand the tightening torque, but such a tool has a complicated structure. Expensive because
In addition, since the shape itself is large and bulky, there is a problem that a tightening operation in a narrow place is difficult and a use range is limited.

To solve such a problem, FIG.
(A) As shown in (b), a cover body 3 having a concave portion 3a to be attached to a head 1a or a nut (not shown) of the bolt 1 and a bolt that is integrally connected to the cover body 3 and tightens the bolt 1 The cover body 3 and the tightening body 4 are formed of the same material and are made of the same synthetic resin. One that is attached or previously attached to bolts and nuts, rotates and breaks the upper tightening body 4, and tightens it with a specified tightening torque to perform torque management is used.

[0004]

However, when such a bolt and nut torque management fastener is attached to the bolt and nut, and the fastener 4 is rotated and broken, the fastener 4 is disengaged. As shown in FIG. 7 (an example used for bolt tightening), it does not break at the boundary surface of the cover body 3, but can break at the portion of the tightening body 4 located slightly above the top surface 3 a of the cover body 3. In many cases, the fractured surface 4a is inclined without being horizontal, and the inclination angle and the uneven shape of the fractured surface 4a are variously changed. And reliable torque management could not be performed.

[0005] In addition, unless a large torque is applied, the tightening body 4 does not break. Therefore, before the tightening body 4 breaks, the unevenness of the inner wall surface of the concave portion 3a of the cover body 3 is crushed and becomes ridiculous. The torque control fastening tool attached to the nut sometimes idles, so that the torque control of the bolt and the nut could not be reliably performed.

Further, in this type of torque management fastener, after the bolts and nuts are tightened, the cover body 3 is held in a state of being attached to the bolts and nuts, and serves as an anticorrosion cover for the bolts and nuts. However, since the uneven portion of the fractured surface 4a protrudes above the top surface 3a of the cover body 3, it is dangerous, and there is a possibility that the wires and the like may be damaged by contact. It is necessary to sharpen it with a file, sandpaper, or the like, and there is also a problem that if the number of bolts and nuts is large, the work is complicated and time-consuming.

[0007] The present invention has been made in view of such a problem, and can perform reliable and reliable torque control. Further, after tightening bolts and nuts, the top surface of the cover body is flattened. It is an object of the present invention to provide a bolt and a nut with a torque management fastener for a bolt and a nut, and a bolt and a nut with a torque management fastener which are safe and troublesome.

[0008]

According to another aspect of the present invention, there is provided a bolt and nut torque management fastener according to the present invention, wherein the cover has a concave portion to be attached to the head or nut of the bolt. Body, a tightening body connected to the cover body and tightening a bolt and a nut, wherein the cover body and the tightening body are formed of a synthetic resin of the same material. , The cross-sectional area of the portion made of synthetic resin of the same material and in contact with the bottom surface of the fastening body is the largest, and the cross-sectional area gradually decreases toward the cover body and the portion of the portion in contact with the top surface of the cover body It has an outer shape of a tapered hip with a minimum cross-sectional area and is integrally connected at a connecting portion that is broken by a specified tightening torque.

Further, the bolt with a torque management fastener according to a second aspect of the present invention is characterized in that the torque management fastener is previously integrally attached to a head of the bolt. .

Further, a bolt with a torque management fastener according to a third aspect of the present invention is characterized in that the torque management fastener is integrally attached to a nut in advance.

In the present invention, since the torque management fastener having the above configuration is used, such a bolt and nut torque management fastener is attached to the bolt and nut, and the tightening body is rotated. When the bolts and nuts are tightened, the part in contact with the top surface of the cover body, which minimizes the cross-sectional area of the connecting part, is surely broken, and the fractured surface is formed almost horizontally along the top surface of the cover body. In addition, since the uneven shape does not greatly change, the variation in the tightening torque is reduced, and the bolts and nuts can be tightened with the specified tightening torque, so that highly reliable torque management can be performed.

Further, since the tightening torque, that is, the torque required for breaking becomes substantially constant, when the connecting portion is broken, excessive torque is not applied to the cover body of the fastening tool, and the inside of the concave portion of the cover body is not damaged. The unevenness of the wall surface will not be ridiculous, and the torque management fasteners attached to the bolts and nuts will not run idle, so that the torque control of the bolts and nuts can be performed reliably.

Also, after the bolts and nuts are tightened, the unevenness of the fractured surface does not protrude above the top surface of the cover, so that the cover is safe. It is not necessary to sharpen the top of the head flat with a knife, a file or the like, and the bolts and nuts can be easily tightened without any trouble.

Further, according to the bolt and the nut with the torque management fastener of the present invention, since the torque management fastener is previously integrally attached to the head and the nut of the bolt, the torque management fastener is used. The bolts and nuts can be efficiently tightened without being lost during the tightening of the bolts and nuts.

[0015]

Next, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 (a), 1 (b) and 1 (c), the torque management fastener 10 for the bolt and nut is used.
Has a hexagonal recess 12a to be attached to the head or nut of the bolt, a cover body 12 having a hexagonal outer shape, a hexagonal outer shape, a circular flange 14a at the bottom, and a A tightening body 14 having a circular hole 14b for tightening bolts and nuts, wherein the cover body 12 and the tightening body 14 are
The cross-sectional area of the bottom surface of the tightening body 14, that is, the portion in contact with the bottom surface of the circular flange 14 a is the largest, and the cross-sectional area gradually decreases toward the cover body 12 and crosses the portion in contact with the top surface 12 b of the cover body 12. It has an outer shape with a tapered bottom that minimizes the area, for example, a truncated inverted cone, and is integrally connected at a connecting portion 16 that is broken by a specified tightening torque. The cover body 12, the fastening body 14, and the connecting portion 16 are formed of the same material of synthetic resin, for example, a fiber reinforced plastic material (FRP), and the fastening tool 10 is manufactured by injection molding or the like.

The circular hole 14b has the same inner diameter from the opening to the bottom, and has a flat bottom surface and a height equal to or slightly lower than the top surface 12b of the cover body 12. Is set. This circular hole 14
With b, not only the torque management fastener 10 can be reduced in weight and material can be saved, but also the specified tightening torque of the fastener can be adjusted by variously changing the inner diameter of the circular hole 14b. Thus, the adjustable range of the tightening torque is widened and effective. However, the adjustment of the specified tightening torque can be performed by changing the outer shape of the connecting portion 16 or the like.

The truncated inverted conical taper angle θ of the connecting portion 16 (see FIG. 1A) is set in the range of 60 to 135 degrees, preferably in the range of 90 to 120 degrees. If the taper angle θ is less than 60 degrees, the torque for breaking the tightening body tends to vary, and the fracture surface does not occur at the same location and tends to become dirty. If the angle exceeds 135 degrees, the outer surface of the connecting portion 16 and the top surface 12b of the cover body 12
The gap of the horizontal V-shaped wedge-shaped groove formed by
There is a tendency that a portion where the connecting portion 16 contacts the top surface of the cover body 12 cannot be manufactured to the designed size. The setting of the tightening torque depends on the cross-sectional area of the portion of the connecting portion 16 in contact with the top surface 12b of the cover body 12, the material (the type of the synthetic resin, the degree of hardening,
The amount can be adjusted by appropriately selecting the amount of a reinforcing member such as glass fiber.

In the above example, the connecting portion 16 is formed in a truncated inverted conical shape. However, the truncated inverted pyramid or the conical shape is not formed in a straight line but in a concave or convex curved shape. You may.

Further, since the connecting portion 16 has the outer shape of the tapered bottom as described above, the lateral V is formed between the outer surface of the connecting portion 16 and the top surface 12b of the cover body 12 over the entire circumference. A wedge-shaped groove is formed, but one of the opposing surfaces of the groove also serves as the top surface 12b of the cover body 12, so that the minimum cross-sectional area of the connecting portion 16 is changed in order to change the specified tightening torque. Similarly, the connecting portion 16 can be formed without changing the taper angle θ, and a stable quality torque management fastener 1 having a desired tightening torque can be obtained.
It is easy to obtain 0.

Although the outer shapes of the cover body 12 and the tightening body 14 are hexagonal, they need not be hexagonal as long as they can be turned with a spanner or the like.

Next, a method of using the torque management fastener 10 will be described with reference to FIG. 2 (a). The bolt 18 is lightly screwed into the member A to be tightened. Next, the head 1 of the bolt 18
8a, the concave portion 12 of the cover body 12 of the torque management fastener 10 is provided.
Then, the fastener 10 is attached to the head of the bolt. Next, the connecting portion 16 of the upper fastening body 14 is broken with a simple tool such as a spanner.

Shortly before the bolt 18 is screwed into the member A to be tightened, the torque control fastener 10 is mounted on the head 18a of the bolt 18 and the tightening body 14 is rotated with a tool such as a spanner. Alternatively, the bolt 18 may be screwed into the member A to be tightened to break the tightening body 14.

The cover 12 remaining on the head 18a of the bolt 18 may be removed or may be left attached. At this time, it is preferable to fix the cover with an adhesive in order to prevent the cover from coming off.

When such a bolt and nut torque management fastener 10 is attached to the bolt 18 and the fastener 14 is rotated, the cross-sectional area of the connecting portion 16 is reduced as shown in FIG. The portion that contacts the top surface 12b of the cover body 12, which is the smallest, is reliably broken, and the fracture surface is formed almost horizontally along the top surface of the cover body, and the uneven shape does not change significantly, so that the tightening torque is reduced. And the bolts and nuts can be tightened with the specified tightening torque, and highly reliable torque management can be performed.

Further, in the above structure, when the connecting portion 16 is broken, excessive torque is not applied to the cover body 12 of the torque management fastener 10, so that the inner wall surface of the concave portion 12a of the cover body 12 is crushed. Without being stupid,
The torque control fastening tool 10 attached to the bolt does not run idle, and the tightening torque of the bolt 18 can be reliably controlled.

Further, after the bolt 18 is tightened, the fractured surface 16a of the connecting portion 16 does not protrude above the top surface 12b of the cover body 12 as shown in FIG. There is no danger of the wires and the like coming into contact with each other, and there is no need for a complicated operation of flattening the top surface 12b of the cover body 12 with a knife, a file or the like as in the related art.

In the above embodiment, after the bolt 18 is screwed into the member A to be tightened, and before the screw is strongly tightened, or shortly before screwing into the member A to be tightened, the torque control tightening is performed on the head 18a of the bolt 18. As shown in FIG. 3, the tool 10 is inserted into the recess 12 a of the cover body 12 into the head 18 a of the bolt 18.
The bolt 20 with the torque management fastener may be fixed to the head 18a in advance by being fixed with an adhesive.

In this way, there is no danger that the fastener 10 will be lost when the bolt 18 is tightened, and the connecting part 16 is broken and the fastener 14 is separated from the cover body 12. It is preferable that the cover body 12 remaining on the cover protects the bolt 18 from external force and corrosion.

Further, in the above-described embodiment, an example in which the torque management fastening tool 10 is attached to the bolt 18 has been described. However, as shown in FIG. May be used to tighten the nut 22 with a specified tightening torque. The method of use is the same as in the case of tightening the bolt 18 described above, and a description thereof will be omitted.

As shown in FIG. 5, the torque management fastener 10 has a recess 12a of the cover body 12 and a nut 2 as shown in FIG.
2, and may be fixed with an adhesive, for example, to form a nut 24 with a torque management fastener that is integrally attached to the nut 22 in advance. In this case, nut 2
2 there is no risk of the fastener 10 being lost, and the connecting part 16 is broken, and the fastener 14 is
The cover body 12 remaining on the nut 22 after separation from the nut 2 is preferable because it protects the nut 22 from external force and corrosion. It is desirable that the recess 12a be provided with, for example, a circular relief groove 12c for accommodating the tip of the bolt.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A hexagonal concave portion 12a (having a hexagonal side width of 13 m)
m, depth 4.8 mm)
A hexagonal fastening body 14 having (a hexagonal side width 16.9 mm, height 7 mm), a circular flange 14 a (outer diameter 18 mm, width 1 mm), and a circular hole 14 b (inner diameter 8.85 mm, depth 9 mm). (Hexagon opposite side width 12.9mm, height 8mm),
The connecting portion 16 has a truncated inverted cone shape (width 1 mm, outer diameter 11.25 mm of a portion in contact with the top surface 12b of the cover body 12), and the cover body 12, the fastening body 14 and the connecting portion 16 are all made of FRP (glass). Ten prototype torque control fasteners 10 for bolts and nuts formed of 50% by weight of fiber + 50% by weight of nylon resin (trade name: Technil, Showa Denko) were manufactured by injection molding. This is attached to the head of a hexagonal bolt M8 × 35, and the tightening body 14 is rotated by a wrench with a torque measuring sensor to break at the connecting portion 16, and the torque required for the break (tightening torque) is tested. Measurements were made on 10 works.
The results are as shown in Table 1.

[0032]

[Table 1]

As is clear from Table 1, the ten prototypes of the present invention all have a tightening torque close to the calculated value of 126.41 kgf · cm when used at room temperature, and have an average value of 126.41 kgf · cm. 0.1 kgf · cm ± 5%, indicating that the variation in the tightening torque is small and stable.

[0034]

As described above, the torque management fastener for bolts and nuts of the present invention is connected to a cover having a concave portion to be attached to the head or nut of the bolt, and is connected to the cover.
A bolt and a tightening body for tightening a nut, wherein the cover body and the tightening body are formed of the same synthetic resin, and the cover body and the tightening body are formed of a synthetic resin of the same material. A buttocks that is formed and has a maximum cross-sectional area at a portion in contact with the bottom surface of the tightening body, and a gradually decreasing cross-sectional area toward the cover body to minimize a cross-sectional area at a portion in contact with the top surface of the cover body. It has an outer shape of a ball and is integrally connected at the connecting part that is broken by the specified tightening torque, so the variation in tightening torque is small, and bolts and nuts can be tightened with the specified tightening torque. Thus, highly reliable torque management can be performed.

Further, since the tightening torque becomes substantially constant, excessive torque is not applied to the breakage of the tightening body, and
Since the torque management fastening tool attached to the nut does not run idle, the torque of the bolt and nut can be reliably controlled. After tightening bolts and nuts,
Since the uneven portion of the fractured surface does not protrude above the top surface of the cover body, it is safe, there is no risk of damage due to contact with electric wires etc.There is no need to flatten the top surface of the cover body,
No need to troubleshoot bolts and nuts.

Further, the bolt and the nut with the torque management fastener according to the present invention may be configured such that the torque management fastener is attached to the head of the bolt.
Since the torque management fastener is preliminarily attached to the nut in advance, there is no risk of the torque management fastener being lost at the time of tightening the bolt and the nut, and the bolt and the nut can be efficiently tightened.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a torque management fastener for a bolt and a nut according to the present invention, wherein (a) is a longitudinal sectional view, (b) is a plan view,
(C) is a bottom view.

FIGS. 2A and 2B show a use state of the torque management fastener, wherein FIG. 2A is a partial cross-sectional side view showing a state where the fastener is attached to a head of a bolt, and FIG. It is a longitudinal cross-sectional view which shows the state which the attachment fractured | ruptured at the connection part.

FIG. 3 is a partial cross-sectional side view showing a bolt with a torque management fastener, in which the torque management fastener of the present invention is integrally attached to a head of the bolt in advance.

FIG. 4 is a partial cross-sectional side view showing a state in which the torque management fastener of the present invention is used while being attached to a nut.

FIG. 5 is a partial cross-sectional side view showing a nut with a torque management fastener formed by integrally attaching the torque management fastener of the present invention to a nut in advance.

FIGS. 6A and 6B show a state in which a conventional torque management fastener for a bolt and a nut is attached to the head of the bolt, wherein FIG. 6A is a partial cross-sectional side view, and FIG.

FIG. 7 is a longitudinal sectional view showing a state in which the conventional torque management fastener is attached to the head of the bolt, and after the bolt is tightened, the fastener is broken.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Torque management fastening tool of bolt and nut 12 Cover body 12a Recess 12b Top surface 12c Escape groove 14 Fastening body 14a Circular flange 14b Circular hole 16 Connecting part 16a Broken section 18 Bolt 18a Head 20 Bolt with torque management fastening tool 22 Nut 24 Nut with torque control fastener A, B Tightened member θ Taper angle

Claims (3)

[Claims] A cover body having a concave portion to be attached to a head or a nut of a bolt, a bolt connected to the cover body,
A tightening body for tightening the nut, wherein the cover body and the tightening body are formed of a synthetic resin of the same material, a bolt, a torque management tightening tool for the nut, the cover body and the tightening body,
The cross-sectional area of the portion made of synthetic resin of the same material and in contact with the bottom surface of the tightening body is the largest, and the cross-sectional area gradually decreases toward the cover body and crosses the portion in contact with the top surface of the cover body. It has the outer shape of the narrow buttocks that minimizes the area,
A bolt and nut torque management fastener characterized by being integrally connected at a connecting portion that is broken by a specified tightening torque. 2. A bolt with a torque management fastener, wherein the torque management fastener of the bolt is previously integrally attached to a head of the bolt. 3. A nut with a torque management fastener, wherein the torque management fastener of the nut is integrally attached to the nut in advance.