JPS5824647B2 - spring washer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spring washer used to buffer the impact generated between a bolt and a nut.

Various spring washers of this type have been known in the past, but representative ones include wave-shaped washers in which peaks and valleys are arranged in succession;
Examples include spring washers that are warped in opposite directions before and after the cut groove.

In the former wave washer, each peak and trough are continuous as shown in Figure 1, so the spring elasticity of the wave washer directly depends on the rigidity of the spring material forming the wave washer. If a thick spring material is used, the necessary elasticity will not be obtained; conversely, if a thin spring material is used, although the necessary elasticity will be obtained, it will easily plastically deform due to strong impact and the subsequent spring There is a drawback that the action cannot be expected, and the latter spring washer has the disadvantage that the second
As shown in the figure, the spring elasticity in front and behind the cut groove becomes large, making it impossible to obtain uniform spring elasticity around the entire circumference, and causing excessive distortion due to torsion due to forces acting from above and below in front and behind the cut groove. It generates stress and is extremely resistant to fatigue; it has drawbacks such as poor personnel.

The present invention has been made in order to solve these conventional problems, and provides a spring washer that can maintain spring elasticity with excellent symmetry with good durability, is easy to manufacture, and is inexpensive to manufacture. It is intended to.

To explain the present invention more specifically with reference to the accompanying drawings, the spring washer 1 according to the present invention has a rectangular cross section, an oval shape,
Alternatively, a circular spring wire is wound into a ring shape as shown in FIG. 3, and as shown in FIG. A total of three peaks M having an angular interval of 120° from each other so as to be alternately continuous in the angular interval, and a mountain portion M having an angular interval of 120° from each other,
A total of three troughs ■ having an angular interval of 60° are formed with respect to the peak M, and when the direction of tightening of the spring washer 1 with the bolt or nut is right-handed, when viewed in the right-handed direction, As is clear from FIG. 4, a cut groove S is provided at an intermediate portion extending from one of the troughs V to the peak M, radially traversing the slope at right angles.

As described above, when the three peaks are formed, as shown in FIG. Can be set to .

For example, the center of the cross section of the spring washer forms one axis, and the preferable inclination angle θ with respect to the mounting substrate is 7° to 30°, and the most preferable angle is 12° to 1
It is 7°.

With four peaks or more, the angle of inclination becomes too large and the necessary spring elasticity cannot be obtained.In Mita, the angle of inclination can be set small, but the peaks are spaced 180 degrees apart from each other. As a result, the support structure becomes unstable, and in the case of Mita's spring washers, they easily overlap during the bolt assembly process, making it difficult to separate them.

In the case of Mita, this difficulty disappears because the mountains come into contact with each other.

In addition, as described above, tightening is performed by providing a cut groove S in the middle part from the valley part V to the peak part M when viewed in the direction, so that when tightening the bolt or nut with the spring washer 1 interposed, Since the cut edge a on the side of the valley (2), which is relatively lifted, has only a slight inclination along the tightening surface of the bolt or nut, it is easy to escape and does not interfere with tightening.

On the other hand, if a cut groove is provided on the opposite side of the peak M, the cut end on the V side of the valley will be lifted up so as to bite into the tightening surface of the bolt or nut, which will hinder tightening. Come.

The groove width of the cut groove S is set so that when the spring washer 1 is tightened, both cut ends a and b are elastically deformed so as to approach each other to maintain the necessary spring elasticity. However, from the viewpoint of manufacturing requirements, the thickness should be about 80 to 90% of the thickness t of the spring material, and the spring washer 1 should not enter through the cut groove S of another spring washer 1 and connect in a chain. It is desirable to prevent this.

Of course, the setting of the groove width W with respect to the spring material thickness t is related to the diameter of the spring washer 1, the shape of the spring material, etc., but in practice, the above setting of 80 to 90% is sufficient and prevents the chain. I can do it.

Next, the method for manufacturing the spring washer 1 according to the present invention will be explained. For example, as shown in FIG. After the wavy spring material 2 is press-formed into a wavy spring material 2 having alternating sections, as shown in FIG. With the width direction of the wavy spring material 2 perpendicular to the winding shaft 3, the inside of the width is applied to the winding shaft and the outside is stretched, while the length direction is wound into a ring shape to form a spiral. The wavy spring material 2 is wound in a shape such that the crests and troughs of the adjacent turns of the wavy spring material 2 laminated in the width direction are brought into close contact with each other, and a total of 3 pieces are formed in one turn. The series of wavy spring members 2' is aligned in the axial direction of the winding shaft as shown by the direction of the arrow in FIG. By cutting linearly with one cutting line, each roll is separated and a cut groove as described above is formed in the part cut along the cut line, and the front and back grooves are formed at both ends of this cut groove. A desired spring washer 1 can be obtained by correcting the difference using a press or the like so that the difference continues from the valley to the peak.

Note that the winding shaft 3 is not limited to a cylindrical shape, and if a regular polygonal shape such as a regular hexagon or a regular octagon is used, it is possible to form a spring washer in a regular polygonal shape.

The total compression tightening load characteristics of the spring washer 1 manufactured as described above are determined by JIS standard B1251-2 inner diameter 6, Omrn,
Figure 8 shows the results of a comparative experiment with a spring washer with a plate width of 2.7 mrrt and a plate thickness of 1.5 mm.

As shown in Figure 8, when the horizontal axis is the nominal diameter (mrn) and the vertical axis is the tightening load (ky), the above JIS standard B1
For the full compression tightening load characteristic A of the spring washer No. 251-2, the inner diameter and plate width are the same as the above spring washer, and the thickness is %.
In other words, the full compression tightening load characteristic opening of the spring washer 1 according to the present invention, which is set to 0.75 mm, has a much better rise against the nominal diameter, and is more than comparable to the spring washer of JIS B1251-3 for heavy loads. It shows extremely excellent properties.

As is clear from the detailed description above, the spring washer according to the present invention has a Mita structure in which peaks and valleys are alternately continuous at angular intervals of 60°, so Not only can the tightening surface of the bolt or nut be evenly supported by the Mita section with the , A cut groove with a width of 80% to 90% of the thickness of the spring material is provided in the middle part from the valley to the peak when viewed from the tightening direction, perpendicular to the slope and across the width direction. Even when the thickness of the spring material is increased, the necessary spring elasticity can be obtained without damaging the tightening surface by digging into it.
Moreover, smooth tightening can be performed without any problems during tightening.

Furthermore, as is clear from the foregoing, the spring washer according to the present invention is extremely easy to manufacture and can be manufactured in large quantities.
It is possible to provide a spring washer for assembly into a bolt that has excellent spring elasticity.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing conventional spring washers, respectively;
3 is an explanatory plan view of the spring washer according to the present invention, FIG. 4 is an explanatory front view, and FIG. 5 is an explanatory side view,
6 and 7 are perspective explanatory views for explaining the manufacturing process of the spring washer according to the present invention, and FIG. 8 is a diagram showing the total compressive tightening load characteristics of the spring washer according to the present invention and a conventional product. It is a graph showing the results of a comparative experiment. M... Yamabe, ■... Tanibe, S...
... Cut groove.

Claims (1)

[Claims] 1 Spring materials with approximately the same cross section are wound in a ring shape with a Mita structure in which arc-shaped peaks and valleys are alternately continuous at 60° intervals across the entire width direction, and the above-mentioned peaks and valleys are formed. The angle of inclination between the two parts is 7° to 30°, and a spring material is provided in the width direction at right angles to the inclined surface in the middle part from one of the troughs to the peaks when viewed from the tightening direction. 80% of thickness
A spring washer characterized by having a cut groove with a width of ~90%.