JPH10331832A - Self-locking washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent loosening of a bolt by forming one washer of both washers into a spring washer provide with a slit in a self-locking waster consisting of a pair of upper and lower ring type washers provided with mutually touching spherical contact faces. SOLUTION: A self-locking washer is constructed of a pair of upper and lower ring type washers 1, 10 provided with mutually touching spherical contact face 10S. The washer 1 serving as an upper washer is a ring type spring washer provided with a slit 5. A fixing face 1F in the washer 1 is constructed of a flat face part 2f on an inner circumferential face and a taper face part 2t on the outer circumference side. Both end parts 1A, 1B of the washer 1 are shifted from each other in the vertical direction. The slit 5 is a radius directional space part cutting off the ring type spring washer 1. On a fixing face 10F of the lower washer 10, a serrate type unevenness part 35 is formed so as to be used as a slide preventive means. In this way, generation of a slide between a member to be fixed and the lower washer 10 can be prevented.

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 a bolt, and more particularly to a detent washer used for a bolt which receives a repeated load or the like.

It is difficult to make the crossing angle between the shaft of the bolt and the head and the crossing angle between the bolt member and the fixed member fixed by the bolt at right angles. Therefore, JIS recognizes the perpendicularity between the bolt axis and the head as an allowable range up to 1 °.

However, when a member such as a flange is tightened with a bolt having a crossing angle that is not a right angle, a part of the outer periphery of the head of the bolt comes into contact with the surface of the member, and connects the contact portion to the bolt central axis. Tensile stress concentrates on the head of the bolt on a straight line and part of the circumference of the bolt root.
That is, since the bottom surface of the bolt head does not entirely adhere to the surface of the member, an average tensile stress does not act on the entire circumference of the bolt head and the shaft root. Therefore, the bolt is likely to bend or break, thereby shortening the service life of the bolt.

In order to solve this problem, the following angle-absorbing washers are used when bolts are used. In the washer sandwiched between the bottom surface of the bolt or nut and the washer of the mechanical part to be tightened, one part of the ball is chamfered, the center line is perpendicular to that surface, and there is a bolt hole through which the bolt passes. A spherical journal having a spherical pressing portion fitted with the spherical surface of the spherical journal, and a flat washer-shaped bearing having a bolt hole are combined with each other, so that the spherical journal is fitted along the spherical surface. An angle-absorbing washer configured to move freely (Japanese Utility Model No. 4-97110).

[0005] The conventional angle-absorbing washer has a problem in that if it is used for a bolt to which a repeated load is applied, the bolt rotates and becomes loose when subjected to vibration.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to prevent a bolt from being loosened by rotation of a washer.

[0007]

According to the present invention, there is provided a detent washer comprising a pair of upper and lower annular washers having spherical contact surfaces which come into contact with each other; one of the both washers has a cut line. A detent washer having a spring washer having a detent.

The present invention is a detent washer comprising a pair of upper and lower annular washers having spherical contact surfaces that abut against each other; one of the both washers is a spring washer having a cut, A detent washer characterized in that the other washer has a non-slip means on its fixed surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A return washer is constituted by an annular washer having a spherical contact surface that abuts against each other and a spring washer. This spring washer is formed in an annular shape through a cut. After inserting the detent washer between the fixed member and the head of the bolt, when the bolt is turned and tightened, the spring washer is tightened while slipping in the rotational direction. In this state, when vibration or the like is applied to the washer and the bolt or nut attempts to return, the cut end of the cut is caught on the seat surface of the bolt or nut, and the other is caught on the contact surface of the washer to prevent the return. The conventional spring washer may spread and break when the cut end of the washer is caught, but in the present invention, the spring washer does not spread and break because the outside is narrowed. Therefore, sufficient strength as a spring washer can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. The detent washer is a pair of upper and lower annular washers 1, 10 having spherical contact surfaces 1S, 10S abutting each other.
It is composed of

The washer 1 is an upper washer and is an annular spring washer having a cut 5. The fixing surface 1F of the washer 1 includes a flat portion 2f on the inner peripheral side and a tapered surface portion 2t on the outer peripheral side. Both ends 1A and 1B of the washer 1 are vertically displaced.

The cut 5 is an annular spring washer 1
Is cut in a radial direction, and its width w is appropriately selected as needed.

The spherical radius 1R of the contact surface 1S is, for example, 6
The radius 1R is equal to the lower washer 10 mm.
Is appropriately selected in consideration of the contact surface 10S.

A non-slip preventing means, for example, a saw-toothed uneven portion 35 is formed on the fixing surface 10F of the lower washer 10. The number and shape of the uneven portions 35 are appropriately selected as needed. The member 15 to be fixed is
Slip between the and the lower washer 10 is prevented.

The spherical surface radius 1 of the contact surface 10S of the washer 10
0R is formed, for example, to 60 mm, and the contact surface 10R
A flat portion 10f is formed on the outer periphery of S. The radius 10R of the contact surface 10S is appropriately selected as needed,
For example, a value larger than the radius 1R of the contact surface 1S of the upper washer 1 is selected.

The operation of this embodiment will be described. Bolt holes 1b, 10b of upper and lower washers 1, 10 are provided in bolt holes 15b and tapped holes 16b of fixed members 15, 16 such as flanges.
b, the shaft 21 of the bolt 20 is inserted into the bolt holes 1b, 10b, 15b, and the tapped hole 16b.
Is rotated in the tightening direction.

Then, the screw 21 moves in the direction of arrow A20 while being screwed into the member 16, and the bottom surface 2 of the head 22 is moved.
2b is in contact with the fixing surface 1F of the upper washer 1. Further, when the head 22 is rotated in the same direction, the force applied to the washers 1 and 10 becomes uneven, but the spherical contact surface 1S of the spring washer 1 is replaced with the spherical contact surface 10S of the lower washer 10. It rotates while making surface contact with it and tightens while slipping in the screwing direction.

Then, as shown in FIG.
Is fixed at a state inclined at an angle θ with respect to the horizontal line 22f. At this time, the bottom surface 22 of the bolt head 22
b is pressed against the spring washer 1.

At this time, a substantially uniform bending moment is applied on the root circumference P of the head 22 with the bolt shaft.

The value of the bending moment can be obtained by a load W × span SP. This span SP is 1 × L / 2
Can be represented by Here, l is the distance between the circumference P of the root with the bolt shaft and the inner circumference of the washer 1, L is the contact length in the radial direction between the flat portion 2f of the washer 1 and the bottom surface 22b of the bolt 22, and the span SP is the inside of the root with the bolt. The length from the circumference P to the position where the center load is applied. In this embodiment, since the span SP in the above equation is smaller than that of the conventional example, the value of the bending moment is reduced, and the fatigue fracture of the bolt can be prevented.

In this tightened state, if a load is repeatedly applied to the bolt 20, vibration is generated and the bolt tries to rotate, but the ends 1A and 1B of the spring washer 1
And cannot be rotated by the spherical contact surface 10S. Therefore, the bolt 20 can maintain the tightened state even when vibration occurs.

Since the fixing surface 10F of the lower washer 10 is provided with the uneven portion 35, the washer 10 is prevented from slipping.

A second embodiment of the present invention will be described with reference to FIGS. The difference between this embodiment and the first embodiment (FIGS. 1 to 8) is as follows. (1) The fixing surface 1F of the spring washer 1 includes a top 31T having an arc-shaped cross section and a tapered surface 31t descending from the inner periphery toward the outer periphery. Radius 3 of this top 31T
1R is appropriately selected as needed. In this embodiment, the span SP is the distance from the inner peripheral surface of the bolt 20 to the top 31T of the spring washer 1 and is much shorter than in the first embodiment, so that the bending moment is small. (2) The fixing surface 10F of the lower washer 10 is flat.

A third embodiment of the present invention will be described with reference to FIG. The difference between this embodiment and the first embodiment (FIGS. 1 to 8) is that the fixing surface 1F of the spring washer 1 has an arc-shaped cross section 33T, a flat section 33f, and the top section 33T and the flat section 33f. And a tapered surface portion 33t connecting the two. The radius 33R of the top 33T is appropriately selected as needed.

A fourth embodiment of the present invention will be described with reference to FIG. The difference between this embodiment and the first embodiment (FIGS. 1 to 8) is that the fixing surface 1F of the spring washer 1
The tapered surface portion 44t connecting the 4N and the outer peripheral edge 44M constitutes a projection 44P with a sharp cross section. In this washer 1, when the bolt 20 is tightened, the acute angle projection 44P is crushed into an arc or flat surface, and the span SP
Becomes extremely small.

A fifth embodiment of the present invention will be described with reference to FIG. The difference between this embodiment and the second embodiment (FIGS. 9 to 12) is that the contact surface 10S of the lower washer 10 has a tapered surface inclined inward and downward.

A sixth embodiment of the present invention will be described with reference to FIGS. 16 to 19. The difference between this embodiment and the first embodiment is as follows. (1) The spring washer 51 is formed in a circular cross section. (2) The spherical radius D of the spring washer 51 is smaller than the spherical radius 10R of the lower washer 10.

[0028]

The present invention has been configured as described above.
The return can be prevented by the spring washer. Therefore, even if this washer is used in a place where a load is repeatedly applied, it is possible to prevent the bolt from loosening.

[Brief description of the drawings]

FIG. 1 is a plan view of a spring washer showing a first embodiment of the present invention.

FIG. 2 is a front view of the spring washer.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a plan view showing a lower washer.

FIG. 5 is a front view of the lower washer.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 4;

FIG. 7 is a longitudinal sectional view showing a use state.

FIG. 8 is an enlarged view of a main part of FIG.

FIG. 9 is a plan view showing a part of an enlarged sectional view of a spring washer according to a second embodiment of the present invention.

FIG. 10 is a plan view showing a lower washer.

FIG. 11 is a front view of the lower washer.

12 is a sectional view taken along line XII-XII in FIG.

FIG. 13 is a view showing a part of an enlarged cross section of a spring washer according to a third embodiment of the present invention.

FIG. 14 is a view showing a part of an enlarged cross section of a spring washer according to a fourth embodiment of the present invention.

FIG. 15 is an enlarged sectional view showing a lower washer of a fifth embodiment of the present invention.

FIG. 16 is a plan view showing a spring washer according to a sixth embodiment of the present invention.

FIG. 17 is a front view of the spring washer.

18 is a sectional view taken along line XVIII-XVIII in FIG.

FIG. 19 is a longitudinal sectional view showing a use state.

[Explanation of symbols]

 1 spring washer 5 cut 10 lower washer

Claims (6)

[Claims] 1. A detent washer comprising a pair of upper and lower annular washers having spherical contact surfaces which abut against each other; wherein one of the both washers is a spring washer having a cut. And detent washer. 2. A detent washer comprising a pair of upper and lower annular washers having spherical contact surfaces which abut against each other; wherein one of said both washers is a spring washer having a cut, and A detent washer having a non-slip means on its fixed surface. 3. The detent washer according to claim 1, wherein the fixing surface of the spring washer comprises a flat portion on the inner peripheral side and a tapered surface portion on the outer peripheral side. 4. A detent washer according to claim 1, wherein the fixing surface of the spring washer is a tapered surface portion from the inner peripheral side to the outer peripheral side. 5. The detent washer according to claim 1, wherein the spring washer is formed in a circular cross section. 6. The detent washer according to claim 2, wherein the contact surface of the other washer is a spherical surface having a larger radius than the contact surface of the spring washer.