JP2001124040A - Flanged bolts and flanged nuts and fasteners combining these - Google Patents

Abstract

(57) [Problem] To effectively fasten a member to be tightened on which a coating film is formed. A fastener is a combination of a flanged bolt 17 and a flanged nut. In the bolt with flange, a plurality of concave grooves 17e are radially formed on a bearing surface 17c of a first flange 17d, and the bearing surface 1 excluding the concave groove 17e is formed.
When the area of 7c is Sb and the effective sectional area of the male screw 17a is S, Sb / S is 1 or more and 1.6 or less. When a plurality of grooves are radially formed on the bearing surface of the second flange, and the area of the bearing surface excluding the grooves is Sn, and the effective cross-sectional area of the male screw screwed into the female screw is S, the flanged nut is defined as Sn / S
Is 1 or more and 1.6 or less. First and second flanges 17
The diameter of d is 1.7 to 1.7 times the nominal diameter of the male screw 17a.
2.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flanged bolt having a male screw inserted into a hole formed in a member to be tightened, a flanged nut screwed into a male screw inserted into the hole, and a combination thereof. It is about fasteners.

[0002]

2. Description of the Related Art Conventionally, a combination of a bolt and a nut has been known as a fastener for fastening a member to be tightened.
Instead of providing a washer, these bolts and nuts are formed with flanges whose diameter is larger than the diagonal distance between the head and the nut. It has been known. The flanged bolt has a male thread at one end and a hexagonal head with flange or a 12 point head with flange at the other end. As the flanged nut, a hexagonal nut with a flange and a 12-point nut with a flange in which a female screw that can be screwed into the male screw are formed at the center are known. On the other hand, a hole through which the male screw of the bolt can be inserted is formed in the tightened member to be fastened, and the male member of the bolt is inserted into the hole and the female screw of the nut is screwed into the male screw. The fastener, which is sandwiched between the bearing surface of the head or the 12-point head with a flange and the bearing surface of the flanged nut, is configured such that the member to be tightened can be fastened by such a bolt and nut.

[0003]

However, when a member to be tightened on which a coating film is formed is fastened by a bolt with a flange and a nut with a flange, the tightening of the member to be tightened without a coating film requires a predetermined period of time. After the lapse of time, there was a problem that the bolts and nuts were loosened due to settling of the coating film. That is, a fastener combining a bolt and a nut
The bolt is extended by screwing the female screw of the nut into the male screw inserted into the hole of the member to be tightened, and the tensile stress generated by the expansion of the bolt causes the hexagonal head or the 12-point head between the bearing surface and the nut bearing surface. Hold the clamped member. On the other hand, the coating film formed on the surface of the member to be fastened has a property that its film thickness decreases with time when a compressive force is applied. For this reason, when the member to be tightened on which the coating film is formed is fastened with a flanged bolt and a flanged nut having an enlarged seating surface area, the compressive force per unit area is reduced due to an increase in the seating surface area. Is relatively small. On the other hand, the thickness of the coated film after the fastening gradually decreases thereafter due to the fastening force between the bolt and the nut. Therefore, even when the member to be tightened can be properly fastened at the beginning of fastening, if the film thickness decreases after a predetermined period, the tensile stress generated in the bolt decreases, and the bolt and nut holding the member to be tightened are tightened. There is a problem that loosens. An object of the present invention is to provide a bolt with a flange and a nut with a flange, which can effectively fasten a member to be tightened on which a coating film is formed, and a fastener combining these.

[0004]

The invention according to claim 1 is
As shown in FIG. 1, a male screw 17a is formed at one end, and a hexagonal head 17b with a first flange 17d or a 12-point head with a first flange is formed at the other end. The characteristic configuration is the first flange 1
A plurality of concave grooves 17e are formed radially on the bearing surface 17c of 7d, and when the area of the bearing surface 17c excluding the concave groove 17e is Sb and the effective sectional area of the male screw 17a is S, Sb / S is 1 or more. 6 or less. The invention according to claim 3 is an improvement of the hexagonal nut 18 with the second flange 18d having the female screw 18a formed at the center or the 12-point nut with the second flange, as shown in FIG. The characteristic configuration is that a plurality of concave grooves 18e are radially formed on the seat surface 18c of the second flange 18d, and the seat surface 1 excluding the concave groove 18e is formed.
Assuming that the area of 8c is Sn and the effective cross-sectional area of the male screw to be screwed to the female screw 18a is S, Sn / S is in the range of 1 to 1.6.

According to the first and third aspects of the present invention, the bearing surfaces 17c, 18 of the bolt 17 and the nut 18 are provided.
Since a plurality of concave grooves 17e and 18e are formed in c, respectively, the areas of the respective bearing surfaces 17c and 18c that come into contact with the coating film are reduced as compared with bolts and nuts that do not form the concave grooves 17e and 18e. Since the compressive force per unit area is increased by the reduction of the seat surface area, the male screw 17 inserted through the hole formed in the member to be tightened having the coating film is used.
When the nut 18 is screwed into a, the coating film is compressed relatively much from the beginning of fastening. A coating film that has been compressed a relatively large amount from the beginning of fastening has a relatively small amount of compression after a predetermined period of time, and as a result, a decrease in stress occurring in the bolt is suppressed, and the bolt and nut are loosened. To prevent that. In addition, the 12-point head with a flange refers to a head in which a hexagon with a coaxial and the same size is shifted by 30 degrees and a flange is attached. A 12-point nut with a flange is a hexagon with a coaxial and the same size. It refers to a nut with a flange that is shifted by 30 degrees.

The invention according to claim 2 is the invention according to claim 1, wherein the diameter of the first flange 17d is equal to the external thread 17a.
Are flanged bolts having a nominal diameter of 1.7 to 2.0. The invention according to claim 4 is the invention according to claim 3, wherein the diameter of the second flange 18d is equal to the internal thread 18a.
The flanged nut is in the range of 1.7 to 2.0 of the nominal diameter of the external thread to be screwed into the nut. According to the second and fourth aspects of the present invention, the original function of the flanged bolt and the flanged nut is ensured, and the flanged bolt and the flanged nut which can be replaced with a conventional product using a washer are provided. provide. If the diameter of the first and second flanges 17d and 18d is less than 1.7 times the nominal diameter of the male screw, the original function of the flanged bolt and the flanged nut for equalizing the surface pressure and the frictional force of the seat surface will be reduced. This causes the bolt holes to loosen in the bolt holes due to settling of the seat surfaces of the bolts and nuts. First and second flanges 17d, 18
For flanged bolts and flanged nuts whose diameter d exceeds 2.0 times the nominal diameter of the male thread, the flange 1
Since the diameter of 7d and 18d exceeds the diameter of the conventionally used washer, it cannot be a substitute for the conventional product.

A fifth aspect of the present invention is a fastener comprising a flanged bolt 17 according to the first or second aspect and a flanged nut 18 according to the third or fourth aspect, as shown in FIG. In the invention according to claim 5, the seating surface 17 is provided.
Since a fastener is constituted by a flanged bolt and a flanged nut in which a plurality of concave grooves 17e and 18e are respectively formed in c and 18c, a relatively large number of coating films are compressed from the beginning of fastening with the fastener and the coating film is formed. The formed member to be tightened is effectively fastened.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. As shown in FIG. 7, a cab 12 is mounted in front of a chassis frame 11 of a vehicle 10, and various devices and components including a fuel tank 13 are mounted on a side portion of the chassis frame 11. Hereinafter, the installation of the fuel tank will be described as a representative. As shown in FIG. 6, the chassis frame 11 is a steel material having a U-shaped cross section, and the fuel tank 13 is attached to the chassis frame 11 via a bracket 14. The bracket 14 is attached to the chassis frame 11 by the fastener 16 of the present invention, and the fastener 16 in this embodiment is a combination of a hexagon bolt 17 with a flange and a hexagon nut 18 with a flange. On the other hand, as shown in FIG. 6, the chassis frame 11 and the bracket 14 are each coated,
b and 14b are formed, and holes 11a and 14a having the same diameter and through which male screws 17a can be inserted communicate with the chassis frame 11 and the bracket 14.

The hexagonal bolt 17 with a flange has a male screw 17a at one end and a hexagonal head 17b at the other end. The hexagon nut with flange 18 has its male screw 1 in the center.
A female screw 18a (FIGS. 3 and 5) that can be screwed into the screw 7a is formed. The male screw 17a of the bolt is inserted into the respective holes 11a and 14a of the chassis frame 11 and the bracket 14, and the nut 18 is screwed into the male screw 17a. Then, the bolt 17 is extended, and the bracket 14 and the chassis frame 11 are separated from each other by the tensile stress generated by the extension of the bolt 17.
8c, and a fastener 16 composed of the bolt 17 and the nut 18 is configured to be able to fasten the bracket 14 to the chassis frame 11.

As shown in FIGS. 1 and 2, the head 17b of the bolt has a conical first diameter larger than the hexagonal diagonal distance.
A flange 17d is formed, and four concave grooves 17e are radially formed on the seat 17c every 90 degrees. Specifically, the hexagonal bolt 17 with a flange used in this embodiment has a male screw 17a with an outer diameter of 12 mm, and the diameter of the first flange 17d is 21.5 mm. The four concave grooves 17e are each formed to have a width of 3 mm and a depth of 0.3 mm. The area of the seating surface 17c excluding these concave grooves 17e is 98.5 mm ² , and the effective sectional area of the male screw 17a having an outer shape of 12 mm is 9 mm.
2.1 mm ² . Therefore, when the area of the bearing surface 17c excluding the four concave grooves 17e is Sb, and the effective cross-sectional area of the male screw 17a having an outer diameter of 12 mm is S, Sb / S is in the range of 1 to 1.6. .1.

As shown in FIGS. 3 to 5, the nut 18 has a conical second flange 1 having a diameter larger than a hexagonal diagonal distance.
8d are formed, and four concave grooves 18e are formed on the seating surface 18c.
Are formed radially every 90 degrees. Specifically, a hexagonal nut 18 with a flange used in this embodiment is a female screw 18 into which a 12 mm male screw 17a of a bolt 17 is screwed.
a is formed, and the diameter of the second flange 18d is 21.5 m.
m. The four concave grooves 18e are each formed to have a width of 3 mm and a depth of 0.3 mm.
The area of the seat surface 18c excluding these concave grooves 18e is 112.
The effective sectional area of the male screw 17a having a diameter of 6 mm ² and a diameter of 12 mm is 92.1 mm ² . Therefore, four grooves 1
The area of the seat surface 18c excluding 8e is Sn, and the outer shape is 12m.
When the effective sectional area of the male screw 17a of m is S, Sn /
S is 1.2, which is in the range of 1 to 1.6.

The male screw 17a of the bolt 17 in such a fastener 16 is connected to the chassis frame 11 and the bracket 14
When the nut 18 is screwed into the male screw 17a, the bolt 17 is extended. The bracket 14 and the chassis frame 11 are clamped between the seating surface 17c of the flanged hexagon bolt 17 and the seating surface 18c of the flanged hexagon nut 18 by the tensile stress generated by the extension of the bolt 17, and the bolt 17 and the nut 1
The fastener 16 formed of the fastener 8 fastens the bracket 14 to the chassis frame 11.

On the other hand, each of the bolts 17 and the nuts 18 has four concave grooves 17 on the seat surfaces 17c and 18c, respectively.
e, 18e, the respective coating films 14b, 11b formed on the bracket 14 and the chassis frame 11 are formed.
The area of each of the seating surfaces 17c and 18c that comes into contact with is reduced in comparison with bolts and nuts that do not form the concave grooves 17e and 18e. For this reason, the nut 1 is screwed into the male screw 17a inserted into the respective holes 11a, 14a of the chassis frame 11 and the bracket 14, so that the bracket 1 held between the respective bearing surfaces 17c, 18c is screwed.
4 and the coating films 14b and 11b of the chassis frame 11 are compressed a relatively large amount from the beginning of the fastening because the compression force per unit area is increased due to the reduction of the seating surface area. The coating films 14b and 11b, which have been relatively compressed from the beginning of the fastening,
After the predetermined time has elapsed, the amount of further compression becomes relatively small. As a result, even after a lapse of a predetermined period after the fastening of the chassis frame 11 and the bracket 14, the decrease in the tensile stress generated in the bolt is suppressed, and the bolt and the nut are prevented from becoming loose.

In the above-described embodiment, the fastener 16 in which the hexagon bolt 17 with a flange and the hexagon nut 18 with a flange are combined has been described. However, the bolt may have a 12-point head with a flange. The nut may be a flanged 12 point nut. Further, in the above-described embodiment, the seat surfaces 17c and 18c
Although the hexagonal bolt 17 with a flange and the hexagonal nut 18 with a flange in which the concave grooves 17e and 18e are formed have been described, as long as the area of the seat surfaces 17c and 18c excluding the concave grooves 17e and 18e meets predetermined requirements, The number of grooves 17e, 18e formed on the surfaces 17c, 18c may be any number as long as it is two or more.

[0015]

Next, examples of the present invention will be described in detail together with comparative examples. <Example 1> After a coating film having a thickness of 300 µm was formed on both surfaces, a steel plate having a length of 50 mm, a width of 50 mm, and a thickness of 6 mm having a round hole with a diameter of 13 mm was prepared. When the area of the bearing surface is Sb and the effective sectional area of the male screw is S, Sb / S
1 having a 12 mm male screw 17a having a diameter of 1 and a hexagonal nut 18 with a flange in FIG. 5 wherein Sn / S is 1 when the area of the seat is Sn. Prepared. Specifically, the diameter of the first flange 17d of the bolt 17 is 21.3 mm, and four concave grooves 17e are formed in the seat surface 17c. The four grooves 17e have a width of 3 mm and a depth of 0.3 mm
Respectively. The area of the bearing surface 17c excluding the concave groove 17e of the bolt 17 is 92 mm ² . On the other hand, the diameter of the second flange of the hexagon nut 18 with a flange is 21.5.
mm, and four concave grooves 18e were formed in the seat surface 18c. The four grooves 17e were formed to have a width of 3 mm and a depth of 0.3 mm. The area of the seat surface 18c excluding the concave groove 18e of the nut 18 is 92 mm ² .

Example 2 The same steel sheet as in Example 1 was prepared. A hexagonal bolt 17 with a flange having a 12 mm male screw 17a having Sb / S of 1.3;
A fastener was prepared by combining a hexagonal nut 18 with a flange with S of 1.3. Specifically, the diameter of the first flange 17d of the bolt 17 is 21.3 mm, and four concave grooves 17e are formed in the seat surface 17c. These four grooves 17e
Was formed with a width of 3 mm and a depth of 0.3 mm. The area of the seat surface 17c excluding the concave groove 17e of the bolt 17 is 120 mm ² . On the other hand, the diameter of the second flange 18d of the flanged hexagon nut 18 was 21.8 mm, and four concave grooves 18e were formed in the seat surface 18c. The four grooves 17e have a width of 3 mm and a depth of 0.3 mm
Respectively. The area of the seat surface 18c excluding the concave groove 18e of the nut 18 is 120 mm ² .

<Comparative Example 1> The same steel plate as in Example 1 was prepared. In addition, a fastener was prepared in which a hexagonal bolt with a flange having a 12 mm male screw 17a with Sb / S of 1.6 and a hexagonal nut with flange with Sn / S of 1.6 were prepared. Specifically, the diameter of the first flange of the bolt was 22.2 mm, and no concave groove was formed on the bearing surface 17c. The area of the bearing surface 17c of the bolt 17 is 150 mm ²
It is. On the other hand, the diameter of the second flange of the hexagon nut with a flange was 21.6 mm, and no concave groove was formed on the seat surface 18c. The area of the seat 18c of the nut 18 is 15
0 mm ² .

<Comparative Example 2> The same steel plate as in Example 1 was prepared. Further, a fastener was prepared in which a hexagonal bolt with a flange having a 12 mm male screw 17a with Sb / S of 2.3 and a hexagonal nut with flange with Sn / S of 2.3 were prepared. Specifically, the diameter of the first flange of the bolt was 24.1 mm, and no concave groove 17e was formed in the seat surface 17c. The area of the seat 17c of the bolt 17 is 210
mm ² . On the other hand, the diameter of the second flange of the hexagon nut with a flange was 23.5 mm, and no concave groove 18e was formed on the seat surface 18c. The seat 18c of the nut 18
Is 210 mm ² .

<Comparative Test and Evaluation> The male screw 17a of each bolt 17 in Examples 1 and 2 and Comparative Examples 1 and 2 was inserted into a hole of a steel plate, and a nut 18 in Examples 1 and 2 and Comparative Examples 1 and 2 was used. Was applied with a tensile tester at an axial force of 39.2 kN {4000 kgf}. At this time, the compression amount of the coating film of each steel plate was measured by a shape measuring instrument. FIG. 8 shows the relationship between the result and the bearing surface area ratio represented by Sb / S and Sn / S. As is clear from the curve in FIG. 8 connecting the above results, it can be seen that as the value of the bearing surface area ratio increases, the coating film compression amount decreases. Specifically, in Example 1 in which the value of the bearing surface area ratio is 1, the compression amount of the coating film is 80 μm, but the conventional flanged bolt and flanged nut in which the bearing surface area value is 2.3. In Comparative Example 2, the compression amount is only 8 μm. It is understood that this is because the compression force per unit area is increased as compared with the related art due to the reduction of the seat surface area.

[0020]

As described above, according to the present invention, a plurality of grooves are radially formed on the seat surface of the flanged bolt and the flanged nut, and the area of the seating surface excluding the grooved portion is equal to that of the male screw. Since the cross-sectional area is configured to be not less than 1 and not more than 1.6, the area of each bearing surface in contact with the coating film is reduced as compared with bolts and nuts that do not form a concave groove. Since the compression force per unit area is increased by the reduction of the seat surface area as compared with the related art, a relatively large amount of the coating film is compressed from the beginning of tightening, and the compression amount after a predetermined time has elapsed is relatively small. It is possible to suppress a decrease in stress occurring in the bolt and prevent the bolt and the nut from becoming loose. Therefore, in the fastener in which such a flanged bolt and a flanged nut are combined, the member to be tightened on which the coating film is formed can be effectively fastened. When the diameter of the flange is in the range of 1.7 to 2.0 of the nominal diameter of the male screw, the original function of the bolt with the flange and the nut with the flange is secured, and the conventional product using the washer is used. It is possible to provide a flanged bolt and a flanged nut which can be replaced.

[Brief description of the drawings]

FIG. 1 is a front view showing a bolt with a flange according to the present invention.

FIG. 2 is a bottom view of the bolt.

FIG. 3 is a plan view showing a nut with a flange of the present invention.

FIG. 4 is a front view of the nut.

FIG. 5 is a bottom view of the nut.

FIG. 6 is a sectional view taken along the line AA of FIG. 7, showing a state in which the bracket is attached to the chassis frame by the fastener according to the present invention.

FIG. 7 is a side view of a vehicle using the fastener.

FIG. 8 is a diagram showing a relationship between a seat surface area ratio and a coating film compression amount.

[Explanation of symbols]

 16 Fastener 17 Flange with Flange 17a Male Thread 17b Hex Head 17c Seat 17d First Flange 17e Concave Groove 18 Flanged Nut 18a Female Thread 18c Seat 18d Second Flange 18e Concave Groove

Claims (5)

[Claims] 1. A bolt with flange having a male screw (17a) formed at one end and a hexagonal head (17b) with a first flange (17d) or a 12-point head with a first flange formed at the other end. Multiple concave grooves (17e) on the bearing surface (17c) of the flange (17d)
Are formed radially, and Sb / S is 1 or more and 1.6 or less, where Sb is the area of the bearing surface (17c) excluding the concave groove (17e), and S is the effective sectional area of the male screw (17a). A bolt with a flange, characterized in that: The diameter of the first flange (17d) is equal to that of the external thread (17a).
The flanged bolt according to claim 1, wherein the nominal diameter of the flange is in the range of 1.7 to 2.0. 3. A hexagonal nut (18) with a second flange (18d) having a female screw (18a) formed in the center or a 12-point nut with a second flange, wherein a seating surface (18c) of the second flange (18d) is provided. Multiple grooves (18e)
When the area of the seat surface (18c) excluding the concave groove (18e) is defined as Sn and the effective cross-sectional area of the male screw screwed into the female screw (18a) is defined as Sn, Sn / S is 1 A flanged nut having a diameter of not less than 1.6 and not more than 1.6. 4. The diameter of the second flange (18d) is equal to the internal thread (18a).
4. The flanged nut according to claim 3, wherein the nominal diameter of the male screw screwed into the nut is in the range of 1.7 to 2.0. 5. A bolt (17) with a flange according to claim 1 or 2, and a nut (18) with a flange according to claim 3 or 4.
A combination of fasteners.