JP2003202010A - Washer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily, certainly and visually confirm fastening force of a bolt. <P>SOLUTION: This washer 1 is interposed on the load seat surface side at the time of fastening two members 4 on each other with the bolt 3. An outer peripheral part 11 of this washer 1 is made at an upward gradient of 5-10 degrees toward a center, and an inner peripheral part is formed in a projected state having height t2 which is 1.5-2.5 times the thickness of the washer. Consequently, no special tool is required at the time of fastening the bolt, and a fastening end point of the bolt is easily and precisely judged only visually, and the stable fastening force is acquired. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washer used for fastening two members with a bolt, and more specifically, when tightening a bolt with a spanner, the deformation is visually confirmed to complete the tightening ( The present invention relates to a washer whose time point of completion) can be easily determined.

[0002]

2. Description of the Related Art Conventionally, welding of two members has been
Various means such as caulking and joining with bolts are adopted,
It is used properly according to its usage environment. Among these, in the fastening with a bolt, for example, the tightening torque is managed to prevent the bolt from extending, deforming, breaking, or loosening.

However, in the method of controlling the tightening torque, there is a case where the tightening torque is not actually tightened with a predetermined axial force because the variation of the torque coefficient is large. Further, a device for separately measuring the tightening torque is required to confirm the tightening torque.

Therefore, there has been proposed a washer having an arcuate cross section capable of obtaining an accurate tightening force (see, for example, Patent Document 1).

[0005]

[Patent Document 1] Japanese Utility Model Laid-Open No. 63-168313 (first
(Page, Fig. 1)

[0006]

However, since the above-mentioned washer is in line contact only with the outer peripheral edge of the arc, the contact area with the tightening member is small, and if the tightening force only decreases over a long period of tightening. However, when tightening, the tightening member may be flawed.

Further, in the above-mentioned washer, the shape of the washer does not change only by reducing the height of the circular arc (increasing the radius of the circular arc) by tightening, so that the bolt is tightened with a predetermined tightening torque only by visual observation. It is difficult to determine whether it has been done.

Therefore, even when this washer is used, it is necessary to measure the tightening torque separately.

The present invention has been made to solve the above problems, and when tightening two members using a bolt, the tightening force of the bolt can be easily and surely confirmed visually. The aim is to provide washers that can be done.

[0010]

In order to achieve the above object, a washer according to the present invention has an outer peripheral portion of the washer which has an upward slope toward the center and an inner peripheral portion with respect to the outer peripheral portion. Are to be formed in a protruding shape.

When a certain tightening force is applied to the bolt, the outer peripheral portion of the washer interposed between the load bearing surfaces becomes horizontal to secure a predetermined contact area with the member. Since the protruding portion is deformed into a certain shape, the completion of tightening can be easily known by visually confirming this deformation.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The washer according to the present invention is a washer which is interposed on the load bearing surface side when two members are fastened by bolts, and the outer peripheral portion of this washer rises toward the center. In addition to the above, the inner peripheral portion is formed in a protruding shape with respect to the outer peripheral portion.

In the washer according to the present invention, since the outer peripheral portion has an upward slope toward the center, a contact area with the member is ensured without warping in the direction away from the member during tightening. By forming the inner peripheral portion so as to project from the outer peripheral portion, the tightening torque can be visually confirmed.

By the way, the diameter of the outer peripheral portion of the washer according to the present invention is larger than the outer peripheral edge of the bolt used at the longest distance from the central axis, and the thickness thereof is the same as that of the ordinary flat washer. Made slightly thicker than flat washers. Since the protrusion is used to know the end of tightening of the bolt by its deformation, it must always cause a constant deformation under a constant load.

Therefore, it goes without saying that the washer material (hardness) and dimensions according to the present invention are determined according to the diameter and type of the bolt used, and the shape of the protruding portion always causes a constant shape deformation. Therefore, for example, it is desirable to have a trapezoidal shape or an arc shape in a side view. The two members to be fastened are not limited to metal, but may be wood, resin, or the like.

In the above-mentioned present invention, the upward gradient from the outer peripheral portion to the center is not particularly limited, but according to the experiments by the present inventors, it has been found that 5 ° to 10 ° is preferable. ing.

As shown in FIG. 6A, when the upward gradient from the outer peripheral portion 11 toward the center is less than 5 ° (0 in FIG. 6).
6), when the washer 1 is deformed by tightening the bolt 3, as shown in FIG. 6B, a warp in a direction away from the member 4 to the outer peripheral portion 11 (hereinafter, “upward warp”).
Say. ) Occurs, the gap generated between the washer 1 and the member 4 increases, that is, the contact area decreases,
The fastening force decreases in the long-term fastening.

On the other hand, when the upward gradient from the outer peripheral portion to the center exceeds 10 °, the working becomes difficult, and at the time of tightening the bolt, the initial washer outer peripheral pressure on the member surface becomes large, and The deformation of the outer peripheral portion becomes non-uniform with respect to a slight difference in undulation of the surface.

Further, the height of the protruding portion of the washer is not particularly limited, but it has been found from experiments by the present inventors that the thickness of the washer is preferably 1.5 to 2.5 times. There is.

The height t2 of the protrusion 12 is the thickness t of the washer.
When it is less than 1.5 times 1, the deformation amount is too small to obtain a predetermined tightening torque (axial force), and it is difficult to visually determine the end of tightening.

On the other hand, as shown in FIG. 7A, when the height t2 of the protrusion 12 exceeds 2.5 times the thickness t1 of the washer, the protrusion 12 is formed when the washer 1 is molded. Is too thin, and the bolt 3 is tightened, as shown in Fig. 7 (b).
As shown in FIG. 5, the inner diameter end of the protrusion 12 warps toward the member 14 side (hereinafter, simply referred to as “warp”), and the deformed shape of the protrusion 12 becomes unstable. If the deformed shape of the protruding portion becomes unstable, the tightening stress (torque) at the time of deformation will vary, and it will not be possible to accurately determine the end of tightening.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a washer according to the present invention will be described based on the embodiments shown in FIGS. FIG. 1 is a vertical cross-sectional view of a washer according to the present invention, FIG. 2 is a state diagram before tightening in which a washer having a vertical cross-section is externally fitted to a bolt having a member penetrating and a nut is screwed, and FIG. FIG. 4 is a vertical cross-sectional view showing another example of the washer according to the present invention when the tightening is completed after a predetermined deformation.

1 to 3, 1 is a washer of a predetermined material (hardness) according to the present invention, the thickness of which is t1,
It has a circular shape with an outer diameter of D1. The outer peripheral portion 11 of the washer 1 has an upward slope of an angle θ toward the center, has a trapezoidal side view in the central portion, and has an upper end diameter D
2. A protrusion 12 having a height t2 (a protrusion amount: t2-t1) is formed, and an inner hole 13 having an inner diameter D3 is provided concentrically with the center of the protrusion 12. The inner diameter of the outer peripheral portion 11 is D
Set to 4.

As can be seen from the positional relationship shown in FIG. 2, the outer diameter D1 of the washer 1 is larger than the longest distance of the outer edge 21 of the nut 2, and the inner diameter D3 of the washer 1 is larger than the outer diameter of the threaded portion of the bolt 3. Needless to say.

The degree of deformation of the washer 1 according to the present invention at the time of tightening may be separately determined depending on the place of use, but it is sufficient that the washer 1 is slightly raised from the member 4 to be fastened as shown in FIG. When tightened,
The bolt 3 is deformed and finally destroyed. The contact area with the member 4 in the slightly raised state is substantially equal to the contact area with the member when a flat washer defined in JIS is interposed.

During the process in which the washer 1 is deformed from the state before tightening shown in FIG. 2 to the state after tightening shown in FIG. 3, the bolt 3 and the nut 2 are subject to the following three types of reaction forces of 1 to 3. Overloaded.

The central protruding portion 12 is shown in FIGS.
Strain stress generated when pressed downward in the plane of the paper of Fig. 2 (b) and Fig. 3 is pressed down in the plane of FIG. Compressive stress in the circumferential direction that occurs Tensile stress in the circumferential direction that occurs on the outer peripheral portion of the washer 1

Since the above-mentioned reaction force is so strong that it cannot be compared with the reaction force of the spring washer which has been conventionally used, the bolt 3 is tightened only by visually observing the deformation of the washer 1 according to the present invention. Confirmation of the end can be performed accurately and easily.

The embodiment shown in FIGS. 1 to 3 is an example in which the material 4 is fastened by the bolt 3 and the nut 2, and the washer 1 according to the present invention is interposed on the load bearing surface side of the nut 2. However, it goes without saying that the material 4 may be threaded instead of the nut 2 and the washer 1 according to the present invention may be interposed on the load bearing surface side of the bolt 3.

In this embodiment, the protrusion 12 of the washer 1 is formed in a trapezoidal shape in a side view, but as shown in FIG. Needless to say, it has the effect of.

Further, depending on the shape of the protruding portion 12 of the washer 1, an ordinary flat washer may be interposed between the washer 1 and the load bearing surface of the bolt 3 or the nut 2.
The washer 1 may be made of any material (hardness) as long as it is possible to determine the completion of tightening the bolt 3 by its deformation. For example, if the washer has the same material (hardness) as the spring washer, the bolt 3 is tightened. After that, the spring action also exerts a locking effect on the bolt 3.

Next, the results of an experiment conducted to confirm the effect of the washer of the present invention will be described. (No. 1) The washer of the present invention used for the experiment is called M
It is applied to 20 bolts and the material is JIS G31.
31 SPHC, outer diameter D1 is 40.5 mm, thickness t1 is 3.5 mm, outer peripheral gradient θ is 6 degrees, protrusion diameter D2 is 28 mm, protrusion height t2 is 5.5 mm (thickness 1.57 times t1) was used. In the experiment, the Brinell hardness was HB45, HB70, HB by changing the heat treatment conditions.
Fifty pieces each of 90 pieces were manufactured.

The tightening was performed manually, and the completion of the tightening was visually determined as shown in FIG. The call is M20
The proper tightening torque is 1600 to 2420k
It is g · cm. The result is shown in FIG.

As a comparative example, in the washer of the present invention, the thickness t1 is 3.2 mm, the gradient θ of the outer peripheral portion is 0 degree,
The height t2 of the protrusion is 5.0 mm (1.56 mm of the thickness t1).
Bournel hardness of HB45 and HB
Fifty pieces of 70 and HB90 were manufactured and used.
The tightening was performed in the same manner as in the present invention.

As shown in FIG. 5, according to the present invention, although the tightening torques varied from 10 to 40 kg.cm depending on the hardness, the tightening torque was within the proper torque, and the tightening torque was still higher than that of the metal member after tightening. It had a contact area similar to that of a flat washer, and it was possible to determine the tightening force only by visual inspection.

On the other hand, in the comparative example, although the tightening torque substantially the same as that of the present invention shown in FIG. 5 could be obtained, as shown in FIG. 6 (b), the outer periphery of the washer after tightening was obtained. The part is greatly warped in the direction away from the metal member,
The contact area with the metal material was smaller than that of the flat washer, and the tightening force decreased over time.

(Part 2) The washer of the present invention used for the experiment is applied to the bolts of M10, M12, M16 and M20, and the material thereof is SPH of JIS G3131.
Using C etc., Brinell hardness HB, inner diameter D3, outer diameter D
1, the thickness t1, the gradient θ of the outer peripheral portion, and the ratio t2 / t1 of the height t2 of the protruding portion to the thickness t1 are shown in Tables 1, 3, 5, below.
As shown in 7, 9, and 11, various modified products were manufactured and used. The tightening was performed manually, and the completion of the tightening was visually determined in the state shown in FIG. Tables 2, 4, 6, 8, 10, 1 below show the measured torque values, the judgment results and the judgment reasons.
2 shows.

The proper tightening torques for the calls M10, M12, M16 and M20 are 196 to 2 respectively.
95 kg / cm, 335-503 kg / cm, 815-
It is 1225 kg · cm and 1600 to 2420 kg · cm. Further, Tables 1 to 12 below also show, as a comparative example, the results of the same experiment as the washer of the present invention with respect to the washer of the present invention having the outer peripheral gradient θ of 0 degrees. .

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

[0043]

[Table 5]

[0044]

[Table 6]

[0045]

[Table 7]

[0046]

[Table 8]

[0047]

[Table 9]

[0048]

[Table 10]

As is clear from Tables 1 to 10, in the invention 1 according to claim 2, it was possible to tighten within the proper torque range only by visually confirming the deformation. Also in the invention 2 according to claim 1, in the outer peripheral part, a slight upward warp occurs, or a slight warp occurs,
Deformation of the outer peripheral part was a little uneven, and it was a little difficult to visually confirm the deformation, but it is possible to visually confirm the deformation in any case, within the proper torque range. I was able to tighten it.

On the other hand, in each of the comparative examples, a comparatively large upward warp was generated in the outer peripheral portion and the deformation could not be visually confirmed, or the contact area with the metal material could not be sufficiently secured. .

Tables 11 and 12 below are for determining the tightening torque and determining the condition when tightened. From these Tables 11 and 12, the above Tables 1 to 10 are also shown.
The result of the judgment was confirmed.

[0052]

[Table 11]

[0053]

[Table 12]

In the judgments in Tables 1 to 12, ◯ indicates that the washer was deformed well by tightening and that the end of tightening within the proper torque range could be easily judged by visual observation, and Δ indicates deformation of the washer. Although the condition was a little bad, the completion of tightening within the proper torque range could be determined by visual observation. × indicates that the deformation of the washer is too large and the completion of tightening within the proper torque range can be determined by visual observation. It was not there.

[0055]

As described above, the washer according to the present invention does not require a special tool when tightening the bolt, and even when the empty space at the tightening place is small, the tightening end point of the bolt can be visually checked. It can be easily and accurately determined, and a stable tightening force can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a washer according to the present invention.

FIG. 2 is a view showing a state before tightening a member by bolts using the washer according to the present invention, in which (a) is a plan view and (b) is a front view.

FIG. 3 is a vertical cross-sectional view of the washer according to the present invention when the washer has undergone a predetermined deformation and the tightening is completed.

FIG. 4 is a vertical sectional view showing another example of a washer according to the present invention.

FIG. 5 is a diagram showing an example of the results of implementation when the washer of the present invention is used, showing the relationship between the material hardness of the washer and the tightening torque.

6A is a vertical cross-sectional view showing a comparative example of a washer according to the present invention in which an upslope of an outer peripheral portion is 0 degree, and FIG. 6B is a view when the washer shown in FIG. It is a figure similar to FIG.

FIG. 7 (a) shows that the height t2 of the protrusion is the thickness t of the washer.
1 is a vertical cross-sectional view showing a washer when it exceeds 2.5 times, and (b) is a view similar to FIG. 3 when the washer shown in (a) is used.

[Explanation of symbols]

1 washer 11 outer periphery 12 Projection 13 inner hole 2 nuts 3 bolts 4 members

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masayuki Sotoya             Fukuoka Prefecture Kitakyushu City Kokurakita-ku, Konomi-cho 1-share             Ceremony Company Sumitomo Metal Kokurauchi (72) Inventor Toshihiro Takasugi             Fukuoka Prefecture Kitakyushu City Kokurakita-ku, Konomi-cho 1-share             Ceremony Company Sumitomo Metal Kokurauchi F-term (reference) 3J034 AA03 BA08 CA03

Claims (2)

[Claims] 1. A washer to be interposed on the load bearing surface side when fastening two members with a bolt, wherein the outer peripheral portion of the washer forms an upward slope toward the center, and The washer is characterized in that the inner peripheral portion is formed in a protruding shape. 2. The upward slope toward the center of the outer peripheral portion is 5 to 1
At 0 °, the height t2 of the protrusion on the inner peripheral portion is equal to the thickness t of the washer.
The washer according to claim 1, wherein the washer is formed 1.5 to 2.5 times as large as that of No. 1.